FIRELESS AND STEAM COOKERS
=47. The Fireless Cooker.= The fireless cooker is a box or can having a
diameter somewhat larger than that of the largest vessel to be placed
in it. The space left around the vessel is packed with some insulating
material to keep in the heat (Fig. 22). In home-made cookers, this
material may be hay, feathers, pillows, shredded newspapers, wood
shavings or sawdust. In commercially-made cookers, it is felt, asbestos
wool, cork, or other insulating material. Because most insulating
material will not stay in place and readily absorbs moisture and
odors, some kind of lining is put between it and the vessel holding
the food. This makes a little nest, into which the vessel fits. In the
better made cookers, this lining is made of metal, and the seams are
water-tight.
The steam from the cooking food is absorbed by the insulating material
if this lining is not impervious to water. Enameled or earthen linings,
if well glazed, would also serve this purpose as long as they did not
chip or crack.
The cover, as well as the sides, of the fireless cooker has to be
padded with the insulating material. The cover must also fit well so
that the steam and heat will not escape thru cracks between it and the
body of the cooker.
=48. The Stones of Fireless Cookers.= The stones for fireless cookers
are usually made of soapstone or some composite which will absorb
considerable heat. They should be slightly smaller in diameter than
the nest. They can only be used with safety in cookers which are
metal-lined and insulated with material which will not ignite at a low
temperature. Stones should not be put in home-made cookers which are
not insulated with asbestos or other fireproof material. Hot stones can
be used with safety in any of the commercial cookers which come fitted
with them.
[Illustration: FIG. 22. Section of fireless cooker.]
The temperature in a fireless cooker is below boiling most of the time.
It is, therefore, a device for simmering food, and should be used for
cooking meats, fruits, vegetables and cereal dishes which require or
are improved by long, slow cooking.
Since the food has to be shut in a fireless cooker to keep in the heat,
fireless cookery is a method of steaming of food. For this reason, it
has a slightly different flavor from food baked in the oven, much as
fried food differs from roasted food. Hot stones (Fig. 22) are put in
most fireless cookers. The heat from these brown the food and give
to the otherwise steamed food a flavor similar to that developed in
baking, roasting and frying.
=49. Heating the Stones.= Moisture given off by the cooking food is
absorbed by the stones. They must be dried or heated very slowly to
prevent this moisture from cracking them. When the stones have been
removed from the cooker, wash them, because they absorb odors from the
food. Keep them in some warm, dry place while they are not in use, such
as in the warming oven of the cook stove or on a radiator. When wanted
for use, they will then be dry enough to be placed over the gas-stove
burner if it is not turned too high at first. Drying thus saves time
when the stones are needed.
=50. Care of the Cooker.= The cooker should be left open to air while
not in use. As soon as the food and stones are removed from it, the
moisture should be wiped out and the inside washed with soap and water,
wiped dry and left to air. Such care is needed to prevent the cooker
from taking on the odor of dishes previously cooked and transmitting
some of them to those cooked later.
=51. Other Devices Belonging to Cookers.= In most commercial cookers
there are wire devices to raise the dishes of food from the stone (Fig.
23). This prevents scorching and boiling over when the stones are
heated very hot. These devices are also used to hold a hot stone above
the food to make a brown crust on it. Some cookers are furnished with
valves, permitting the escape of steam when it becomes too abundant.
The pressure of the steam automatically opens the valve. This device
insures the cooking of certain vegetables, cereals or doughs without
their becoming too soggy to be palatable (_A_, Fig. 23).
=52. Directions for Using the Cooker.= Put the stones on to heat.
Prepare the food as for cooking in any other way. Then heat it, either
in the oven or on top of the stove. It is preferable to heat the food
in the same vessel in which it is to be cooked in the fireless cooker.
Transferring food to a cold vessel entails a loss of heat, since the
first vessel is already heated.
[Illustration: FIG. 23. Devices for fireless cooker.]
When the stones and food are hot, place the stone in the bottom of the
cooker. Put in any asbestos mats or other devices which are needed
to protect the food. The stone should be hot enough to respond to the
test for flat irons. It should make the snappy noise of a good hot iron
when the finger is moistened and touched to it. Place the food in the
cooker. Place another stone above the utensil if it is desirable to
have the food brown on top. Close the fireless cooker, and let it stand
until ready for use.
[Illustration: FIG. 24. Gas cookers.]
=53. Time of Cooking Food.= Six hours or over night should be allowed
for the cooking of cereals. Stews should be given two to three hours'
time for cooking.
Large roasts and hams require five to six hours. It is sometimes
necessary, when they are large, to remove them and heat the food and
the stones on the stove once during the process of cooking. Dumplings
and angel cakes cook well in a fireless cooker. So do all dried peas
and beans.
[Illustration: FIG. 25. Steam cooker.]
It is profitable to cook foods requiring more than forty minutes'
heating in a fireless cooker. The heating unit is a part of some
cookers.
Electric cookers, instead of being furnished with stones to be put
inside the nest, have a heating unit and plate for holding heat in the
cooker. Cold food may be put into this cooker, the current turned on,
and the heating and cooking all be done inside the cooker. The electric
oven which is well insulated answers the purpose of a fireless cooker
when the current is disconnected. Either a thermometer, which the
housewife may watch, or thermostat, which controls the current, must be
attached to electric cookers to prevent burning the food or injuring
the cooker with too much heat.
=54. Gas Cookers.= Since heated air rises, special cookers in the form
of insulated caps are made to put over dishes of food heated on gas
burners (Fig. 24).
The inside of the cap must be kept clean. Get the dishes hot with the
cap suspended over the food, but leaving about an inch space for the
escape of gases from the heating unit. As soon as the food and cap have
been sufficiently heated over the fire, turn off the gas and lower the
cap so that it will retain the heat. After the cooker has been used, it
should be wiped out clean; otherwise it will retain some of the odors
of the cooked food.
=55. Steam Cookers.= There are several steam cookers in use in homes.
The simplest of these is a covered pan which has a perforated bottom,
which is set over another pan (_A_, Fig. 25), in which water is placed
for forming steam. One of the difficulties of this cooker is that the
water in the lower pan cannot be watched and may boil dry. On the more
improved cookers a whistling device (_B_, Fig. 25) is attached to the
pan, and when the water becomes low and steam ceases to flow through
it, air begins to come in, and the device makes a whistling noise.
QUESTIONS FOR PART I
1. What is smoke? Under what conditions is the greatest amount of
heat for cooking or other household purposes produced from fuel?
2. How is an oven made to heat evenly?
3. Explain the purpose of each draft and damper on a stove.
4. Observe the amount of fuel used in a coal stove from day to day.
Make the same kind of observation for a gas or electric stove. How
was the stove managed when the least fuel was used?
5. Describe the construction of a gas stove. Find the vent thru which
the gas enters the burner. Is this large or small?
6. Where is the air regulator? For what is it used?
7. What has happened when the gas in a burner "burns back"?
8. How should a kerosene stove be regulated? How should it be cared
for?
9. What precautions should you take against fire from kerosene and
gasoline stoves?
10. Describe the heating unit of an electric stove.
11. How may electric current be saved in the operation of an electric
stove?
12. How does a fireless cooker cook food?
13. How may one determine when it is economical to use a fireless
cooker?
PART II
HEATING DEVICES
CHAPTER VII
WARM-AIR FURNACES
=56. Principle Upon Which a Furnace Works.= The success of warm-air
heating depends on a natural circulation of air thruout all the rooms
which are to be heated. The air is the vehicle of transmission of the
heat from the fire to the rooms to be warmed.
A warm-air furnace is simply a large stove encased in a sheet-metal
jacket (Figs. 26 and 27). The jacket is usually insulated with
asbestos, since the stove is set in the basement where radiation of
heat is not desired. The air entering the casing is warmed by the
stove. As the air is warmed, it expands and becomes lighter, so rises
to the top of the furnace; from here it is conducted to the rooms
above. The warm air which has passed upward must be replaced by cooler
air entering at the bottom of the jacket. In the rooms above, there
must be outlets for the cold air, already in them, so that it may be
replaced by the incoming warm air. Cold-air shafts from the floor
leading downward serve as outlets. Sometimes they return the cooled air
to the base of the furnace jacket.
[Illustration: FIG. 26. Warm-air furnace.]
=57. The Stove Part.= The stove part of the hot-air furnace consists
of a fire pot supported above a place where the ashes may fall and a
chimney to carry off smoke. The draft below the grate in the fire pot
lets in air which is essential to the proper burning of the fuel. In
this respect, it is similar to a cook stove. A draft above the fire
when opened a little lets in air which aids in the complete combustion
of the gases given off by the fuel. Burning these gases adds to the
amount of heat secured from the fuel. Opening the draft wider checks
the burning of the fire. There should be a damper in the smoke pipe.
When this is closed, it checks the draft up the chimney. This is
needed because some chimneys often draw up air too fast to make the
fire burn well. When checking the fire, close the draft below, open the
one above the fire box, and close the one in the pipe. To make the fire
burn fast, open the draft below, close the one above the fire box, and
open the one in the pipe. Remember that a fire will not burn well if
there is too much draft. Adjust the drafts until the fire burns with a
clear, bright flame without giving off smoke. After a fire is built,
the manner of adding fuel makes a difference in the efficiency of the
furnace. When using coal, add it in rather small amounts, spreading
it in a layer over the entire fire. Do not make this layer so thick
that the fire smokes. The fuel will not burn with a clear flame if the
fire is being smothered. Much fuel is wasted by ignorant and careless
management of furnaces.
[Illustration: FIG. 27. Circulation of warm air.]
=58. The Cold-Air Shaft.= It is through a cold-air shaft that the
cooler air comes into the furnace. Some furnaces have this built so
that it draws the cooling air from the rooms above down into the
furnace to be heated again. This is an economical arrangement. Some
others draw fresh air from out of doors into the furnace, letting the
cold air from the rooms above drain into the cellar and out of doors.
This is more expensive, as the air to be heated is usually colder,
but it has the advantage of helping ventilate the rooms by bringing a
constant supply of fresh air.
The cold-air shaft leading from out of doors should have the outer end
covered with wire mesh, and a cloth which should be washed or renewed
often.
Never sweep dirt down a register or cold-air shaft. It comes back into
the room in time. Dust the registers occasionally.
In older heating systems, there was but one large cold-air shaft to
drain the cold air from the rooms above. In more modern houses, a
cold-air shaft is placed in every room that may be shut off from the
others. This does away with the old difficulty of heating a closed
room, for it is as important that the colder air gets out as that the
warm air gets in.
=59. Hot-Air Pipes.= The hot-air pipes lead from the top of the jacket
about the furnace to the floor above. In most houses, one pipe goes to
each room. This is unnecessary if the rooms are not closed off, but if
they are, they need the pipe entering the room. To economize with heat
and regulate the amount of air passing up these pipes, there must be
a shutter in them, near the furnace, as well as in the register. This
shutter is placed near the furnace so that no heat passes into the
pipe when not wanted in the room to which it leads. This saves waste in
radiation from the pipe in the cellar. When a room is not in use, close
this damper.
[Illustration: FIG. 28. Pipeless furnace.]
Since warmed air will continue to travel upward so long as it stays
warmer than the air above, it is important that the pipes have a
continuous rise thruout their entire length, the in some parts the rise
may have to be only very slight. The shorter the pipes, the better,
for there will be less loss of heat from radiation on the way to the
rooms.
[Illustration: FIG. 29. One-room, hot-air heater.]
=60. Location of the Furnace.= A central location for the furnace
is best because the pipes may be shorter, and this makes possible a
greater elevation per foot of each pipe, so that the air can flow thru
it faster. A central location also permits a uniform distribution of
pipes about the furnace, which, in turn, produces a more even flow of
air to all the rooms.
The air from the hot register rises to the top of the room, or, if the
way is open, to the top of the house. Here it spreads over the upper
area. As it cools or is displaced by still hotter air, it falls. When
it reaches the floor, it flows down the cold-air shaft in the floor. If
the cold-air shaft is not in the floor, there may be a layer of colder
air there so the room will not be comfortable.
=61. Air.= There is a constant change of air in all houses, due to
opening of doors and the fact that walls are not air-tight. This may
not be enough for comfort. If a room is not heating well, it has been
found that opening the window to change the air in the room, even when
the outside air is very cold, helps in the circulation of air in the
room, and so with the warming of it. It is difficult to warm a room
filled with stagnant air.
=62. Pipeless Furnaces.= The pipeless furnace works on the same
principle as the one with pipes (Fig. 28). One large opening above
the furnace lets the heat in to some central room, and from here it
circulates into all other rooms not closed off from the central room.
The cold-air shaft may be around the opening for heated air.
Stoves encased in a metal jacket that operate like hot-air furnaces
(Fig. 29) are used in heating one-room schoolhouses and other small
public buildings.
CHAPTER VIII
HOT-WATER SYSTEM OF HEATING
=63. Equipment for Hot-Water Heat.= The hot-water system of heating a
house consists of a boiler in the basement or below the level of the
lowest radiator. This boiler is designed to heat water as it circulates
through coils over the fire (Fig. 30). From the boiler, pipes lead to
radiators and an expansion tank, and return pipes bring the cold water
back to the bottom of the boiler (Fig. 31).
[Illustration: FIG. 30. Garland furnace with hot-water boiler.]
The heat from the furnace fire causes the water to circulate through
this system of boiler, pipes, radiators and tank, due to the fact that
hot water is lighter than cold water.
[Illustration: FIG. 31. Hot-water heating system.]
=64. Heating Unit.= The heating unit of a hot-water system is like any
stove consisting of a fire pot and grate. Some are adjustable so that
different kinds of fuel may be used. A gas burner is sometimes placed
in the fire pot and used for heating a furnace, but this is one of
the most wasteful ways of using gas. A real gas furnace is much more
economical. The fire and heat from the fire circulate around the coils
containing the water. If the coils are not constantly kept full of
water, they will be injured by the heat.
=65. The Management of the Fire.= When burning coal, spread the coal
all over the surface of the fire in a thin layer so as not to smother
it and thus make it burn with a smoky flame. Keep the ashes cleaned out
from underneath the fire and around the fire pot. Clean the flues every
forty-eight hours. Soot on the coils is more effective than asbestos
would be in keeping heat from penetrating to the water. Regulate the
fire with the drafts. Open the one below the fire box to let in air to
aid combustion. Open the one found in most furnace doors a very little.
This aids in the combustion of gases, thus making more economical use
of the fuel, while opening it wider checks the burning of the fire.
Broken and warped doors and drafts let in too much air and destroy the
efficiency of the heater. Open the chimney damper, shown in Fig. 2,
Sec. 3, admitting air to check the draft. Close the chimney or pipe
damper of the type of cook stove shown in Fig. 2, Sec. 3, to check the
draft up the chimney.
=66. The Pipes.= The pipe carrying the hot water from the boiler out
to the heating system leads to the expansion tank, the sometimes
separate pipes lead from the boiler to a radiator. Insulate each pipe,
except the part in the room to be heated, with asbestos or some other
covering, to keep the heat in it. Keep the pipes full of water. When
they are installed, see that they are put in so that they gradually
rise upward. If they dip downward at any point, air will collect at
these places and check the circulation of hot water thru pipes.
[Illustration: FIG. 32. Expansion tank.]
=67. Expansion Tank.= The expansion tank (_A_, Fig. 31, and Fig.
32), placed somewhat higher than the top of the highest radiator, is
fitted with an overflow, for water expands as it is heated. If the
expansion tank is closed so that the overflow pipe will not open except
under pressure after the air in the tank has become compressed by
the expansion of the water, a higher temperature in the pipes may be
reached, but such a furnace must be given more careful attention than
one with an open expansion tank. Learn to know the parts of a heating
system and how they operate before trying to manage it.
=68. Water.= Fill the boiler and radiators full of water, and add
enough more to partly fill the expansion tank. From time to time, note
the height of water in the tank, to know if more must be added. Do not
add water when unnecessary, as fresh water tends to rust pipes faster
than water from which the carbon dioxide and air have been exhausted.
To note the height of water, read the gage.
[Illustration: FIG. 33. Vents for radiators.]
If there is much sediment in the water used, this must be drawn off
from the bottom of the boiler to prevent its accumulating there. When
this is done, fresh water must be added to replace the water drawn off.
Loss of water from evaporation must also be replaced. No water should
be put into the system except to replace such loss. Do not draw the
water out of the system, and refill it from time to time. The practice
of changing the water in the furnace rusts it more than keeping the
same water in it all the time.
=69. Radiators.= Radiators (_B_, Fig. 31) are made of rather
complicated coils of pipe, so often an accumulation of air lodges
in them. This interferes with the circulation of the water and the
radiator does not get hot. There usually is a vent (_A_ and _B_, Fig.
33) attached to each radiator to let out air which collects there. If a
radiator does not heat well, open the air vent until the air ceases to
flow from it and water comes; then close it. Valves should be placed at
places where cold water collects in bad plumbing.
[Illustration: FIG. 34. Radiators under floor.]
In very cold weather, do not entirely shut off the valve of the pipe
leading to any radiator, as the circulation of a little warm water is
needed to keep it from freezing. Radiators may be placed under the
floor (Fig. 34) when so desired.
CHAPTER IX
STEAM-HEATING SYSTEMS
[Illustration: FIG. 35. Steam furnace.]
=70. Equipment for Steam Heat.= A steam-heating system consists of a
boiler, a fire pot, pipes from the boiler leading to the radiators,
and radiators (Fig. 35). On some systems, return pipes are provided to
carry condensed steam or water back to the lower part of the boiler.
A safety valve (Fig. 36) is attached to steam-heating systems instead
of an expansion tank. This keeps the pressure of the steam in the
boiler from becoming too great, and thereby prevents an explosion. The
pressure gage (_B_, Fig. 35) must be set, and, when set, should only be
changed by a person understanding it. Build and manage the fire for a
steam boiler the same as for any stove or furnace. Keep water in the
boiler at 212 degrees Fahrenheit, so steam may form, for without it,
the radiators will not be heated. Small valves are attached to most
steam radiators. Their purpose is to let out air, which accumulates in
the radiator. As soon as the steam begins to come into the radiator, it
forces the air out of the valve. When it reaches the valve, the heat
in the steam causes part of the valve to expand and close the outlet,
which is small. When the radiator is hot, steam should not escape,
provided the valves are in good working order. There is a gage (Fig.
37) furnished with each boiler which shows how much water is in it.
[Illustration: FIG. 36. Safety valve.]
Keep enough water in the boiler to come within certain lines on the
indicator. The top of one of these lines is usually six or eight
inches from the top of the boiler. There is always some variation in
the amount of water in steam furnaces on account of the formation and
condensation of the steam in pipes and radiators. See that the boiler
is never empty, but do not put in fresh water except when necessary.
[Illustration: FIG. 37. Water gage for steam plant.]
The space above the water in the boiler is left for steam. The loss of
water from a boiler in good working order is thru the air valves in the
radiators. If the furnace is properly managed, very little water should
be lost during the course of a year, so there is little need for adding
water.
Some furnaces have two pipes to the radiators. When steam is shut off
from a radiator, the valve leading to the pipe which carries off
the water from condensed steam must be closed, also, to prevent the
pressure of the steam in the boiler from forcing water from the boiler
up this pipe. This may happen because the pipe draining the water from
the radiators enters the furnace near the bottom of the boiler. The
steam being retained in the furnace presses down on the water and so
may force water up the drain pipe, if it is not closed, instead of
raising the safety valve.
Carelessness of this kind may work much damage, for by this means all
the water from the furnace can be forced up into the radiators, leaving
the boiler empty. This makes it important that every woman should
understand the steam-heating system in her home.
Some steam-heating systems have a check valve in the pipe which returns
water to the boiler. This valve permits water to flow thru it in but
one direction; that is, toward the boiler. This prevents a rush of
water from the boiler to the radiators.
Steam furnaces, also, are often equipped with another safety-valve
device, which is a plug of metal which melts at a rather low
temperature and is placed in the boiler directly over the fire. If the
water line in the boiler falls low, this plug melts and steam from the
boiler puts out the fire, thus saving the furnace from damage.
However, melting out the plug makes much work both in replacing the
plug and in cleaning the fire box to rebuild the fire, so that it
should not be depended upon to regulate the heat in the boiler.
Knocking in steam radiators occurs most often in those systems using
the inlet steam pipe for the return of the water which has formed as
a result of condensation. It is caused by water accumulating at some
point and the steam coming up the pipe, violently forcing it back into
the radiator. This only reaches a danger point in systems which do not
have pipes of the proper size, or when the pipes do not slope gradually
downward, so that all the water may flow back to the furnace. On cold
days, there will be some knocking in a steam radiator when it is being
heated in the morning. A two-pipe system, while it is somewhat more
expensive, is less subject to this trouble.
=71. Steam Gages.= Steam gages (_B_, Fig. 35) are devices for
indicating the pressure of steam within an inclosure. They are a kind
of spring balance. When the pressure of the steam increases, it pushes
up on the spring, and this turns the hand of the indicator, which shows
the number of pounds of pressure that the steam is exerting on the
inside of the boiler or container.
=72. Safety Valve.= A safety valve (Fig. 36 and _A_, Fig. 38) consists
of a small opening to a boiler over which is a weight. When steam is
developed until it makes enough pressure on the inside of the valve
to raise this weight, some of the steam escapes, thus lowering the
pressure on the inside until the weight falls back into place. Never
let anything interfere with the action of safety valves.
[Illustration: FIG. 38. Heating plant showing safety valve.]
Most safety valves have the weight attached to a lever which has a
movable weight on it so that the position of the weight on the lever
makes a difference in the number of pounds of pressure required to open
the valve. By means of this device, the temperature of the inside of
the boiler can be kept at one heat or another as desired, since this
temperature increases or decreases with the pressure under which the
steam is held.
Thus, fifteen pounds pressure means a different temperature from ten
pounds pressure. Be sure to adjust the weight for the temperature
desired. Pushing the weight toward the valve lessens the amount of
pressure needed to open the valve. There is usually a steam gage on
boilers to indicate the temperature and pounds of pressure inside. When
the indicator reaches the point desired, the safety valve may be set so
that all steam in excess of the desired amount will escape. When this
is done, the temperature will be held constant in the boiler so long as
a good fire under it is maintained.
CHAPTER X
FIREPLACES AND HEATING STOVES
=73. Construction of Fireplace.= Fireplaces are an enlargement in the
base of a chimney where fire is built. The upper part of the fireplace
is sloped forward, and, in some cases, a damper is placed in the
chimney to regulate the flow of air upward. The damper should not be
so constructed that it will close entirely, for if it did, the smoke
would come into the room. The fire in the fireplace burns best when the
fuel is put in a grate or on andirons so that air can get under it and
be drawn thru it by the draft of the chimney. A steady draft makes the
combustion of the fuel complete and thus prevents smoking.
The hearth is made of fireproof material and should be wide enough to
catch all sparks flying from the fire. A screen is often needed for
safety from fire. Do not pile reserved fuel or put rugs on the hearth.
Fireplaces and chimneys should be built of fireproof brick, stone or
concrete. Have them examined once a year for cracks, as these make them
unsafe. The walls of the chimney and the fireplace should be thick
enough to prevent danger from fire.
=74. Management of Fireplace.= The management of a fireplace is very
simple. The draft up the chimney should be properly regulated so that
the fire does not smoke. Sparks and bits of fuel should not be drawn up
the chimney. The fire should be built so that it is not smothered. Air
should circulate thru the fuel. Keep the ashes cleared away.
There are some fireplaces which are intended to heat rooms after the
manner of hot-air furnaces. The heat and smoke from the fire pass
upward thru a metal heater, encased by an air chamber. Much of the heat
passes thru the metal, warming the air in the chamber. This warmed air
passes thru pipes and registers into the rooms, while the smoke finds
its way to the chimney. To complete the circulation of air, the cold
air from the floor passes into the air chamber near the floor at the
sides of the fireplace. Sometimes fresh air from the outside of the
building is mixed with the air in the chamber.
If there is an opening in the floor of the fireplace, a damper should
be put in this opening to regulate the flow of air. The heater in
a fireplace must be kept free from soot and ashes. If the metal is
covered with soot, heat will not readily pass thru it, and the soot
will collect moisture and cause rusting.
One way to keep the heater clean is to regulate the draft up the
chimney so that ashes and bits of burning fuel are not drawn into it.
Also, the fire should be kept burning with a clear (not smoky) blaze.
Soot is unburnt fuel.
=75. Operating Heating Stoves.= A stove is a device for holding the
fuel and for permitting the heat to pass readily into the room. In the
stove there is space below the fire for collecting ashes. There is an
opening for fresh air to enter below the fuel, to aid combustion, and a
damper above to act as a check draft when open, a chimney to carry off
smoke, and one or two dampers in the chimney to regulate the draft.
When a fire is being built, close the draft over the fire box and open
the one below; open the damper in the chimney--this allows the free
passage of the air up the chimney.
=76. Care of the Stove.= Do not permit a large bed of ashes to
accumulate in the bottom of a stove. A thin layer of ashes must be kept
in the bottom of some wood stoves to keep the fire away from the metal
bottom.
The polish or finish of the stove is a matter of taste. Some stoves
are made of iron, which does not need blacking; some must be blacked.
Blacking keeps them from rusting. All must be kept free from dust and
dirt, as this accumulates moisture and causes the stove to rust.
Letting the stove get red hot warps it. It should not be permitted to
get so hot.
The grate (Fig. 3) in stoves holds the fuel so that air can flow up
thru it. If the grate is clogged with ashes, this cannot happen. The
grate should be shaken to make the ashes drop thru. A clean grate is
important to the complete combustion of the fuel. Shaking after glowing
coals begin to fall is a waste of fuel.
When an attempt to shake the grate is made, it may suddenly refuse to
move. In this case, something may have lodged between its parts, or it
may have been shaken from its proper position. Shaking the stove too
hard may displace the grate. The common remedy for a displaced grate is
to let the fire go out, remove all ashes and cinders, and readjust the
grate.
Some kinds of soft coal form "clinkers," and these catch in the grate.
In burning fuel that makes clinkers, shake the ashes from the fire
several times a day. Remove all accumulations in the fire box daily.
Clinkers are made from substances which melt and recombine, forming
a different material which is quite hard and does not burn. Constant
attention to the fire prevents clinkers from forming in large masses.
CHAPTER XI
GAS, ELECTRIC AND KEROSENE HEATERS
=77. Kinds of Gas Heaters.= There are several types of gas
heaters--those using an illuminating flame and reflector, those fitted
with a Bunsen burner and an asbestos back, and those heating water in
a device like a radiator. The last two burn with a blue flame. All gas
stoves ought to be fitted with a flue for discharging the products of
combustion.
[Illustration: FIG. 39. Gas heater showing air mixer.]
=78. Bunsen Burner and Asbestos-Back Heater.= The burner is a long pipe
punctured with holes extending across the stove. There is an opening
for mixing of air with the gas at the point where this pipe enters the
stove, and a valve to regulate the flow of gas (Fig. 39).
=79. Lighting Gas Stoves.= To light the stove, open the valve, count
three, and apply a lighted match to the burner. Counting three gives
time for the pipe to fill with gas, so that the fire will not flash
back and burn in the air mixer.
=80. Care of Gas Stoves.= The only care that this stove needs is to
keep it polished so that it will not rust. Keep the burner clean of
dust and soot. Be sure that the valve is entirely closed when the gas
is turned off, and that the pipes fit tight at all connections so that
gas cannot leak into the room.
[Illustration: FIG. 40. Reflector gas heater.]
=81. Illuminating Flame and Bright Metal Reflector Heaters.= These
heaters are used with manufactured gas. They burn with an illuminating
flame since there is no device for mixing air with the gas as it enters
the stove. The bright metal reflector not only makes an attractive
stove, but reflects the heat out into the room. Some stoves are made
with tips of aluminum or other non-corrosive metal over the openings
in the burner (Fig. 40). Gas logs are a type of gas heaters used in
fireplaces (Fig. 41).
=82. Gas Radiator Heaters.= Gas radiators (Fig. 42) are another type of
gas heater. The radiator is a coil of pipe. The heating unit is below
the coil and works like any other Bunsen burner. A small amount of
water is kept in the pipes. There is a device attached to the radiator
to automatically adjust the height of the gas fire (_A_, Fig. 42).
[Illustration: FIG. 41. Gas logs.]
=83. Management of Gas Radiator.= Put enough water in the radiator or
coil of pipe to fill it to the depth of one inch. Keep this amount of
water in it at all times.
Light a match, turn on the valve which lets gas flow into the burner,
wait for it to fill with gas, and touch the match to the burner.
Most of these heaters are fitted with thermostats.
[Illustration: FIG. 42. Gas radiators.]
In about thirty minutes after lighting the gas, the water will have
formed enough steam inside the radiator to automatically turn the valve
lowering the gas flame. If the steam pressure falls low, the thermostat
will permit more gas to flow into the radiator by automatically opening
the valve.
There is a safety valve attached to the side of the radiator which
opens if the automatic device fails to close off the gas before the
steam pressure inside becomes too great.
=84. Kerosene Heaters.= Kerosene heating stoves have burners like those
used on kerosene cook stoves. (See Chapter III.) Surrounding, or about,
the burner is a jacketed air space. Here air is heated and rises to the
upper part of the room while fresh air from the lower part of the room
is drawn thru the jacket. Some heat is also given off by radiation.
Fig. 43 shows a picture of an oil heater.
[Illustration: FIG. 43. Oil heater.]
The burners of these stoves should be cared for the same way as the
ones on cooking stoves. The stove should be kept polished and free from
dust. This prevents it from rusting. Wipe off any kerosene which may
accumulate on the outside, for it makes an unpleasant odor.
Take care in moving kerosene stoves not to jar the chimney or other
parts of the burner out of place; otherwise the stove will smoke.
When the stove is lighted, turn the burner quite low. The flame will
become higher as the parts of the stove become heated.
[Illustration: FIG. 44. Electric heater.]
=85. Electric Heaters.= The electric heaters (Fig. 44) are composed of
one or more coils of wire thru which the electric current flows with
difficulty. This heats the coils so hot that they glow. A reflector
throws the heat out into the room. The coil and reflector are attached
to a pedestal. They are desirable for use in rooms which are not quite
warm enough. Care must be taken to avoid getting an electric shock
from electric heaters, as from any other electrical appliances. If the
stove seems to be out of order, have it put in order before using.
Take care not to touch a water pipe or gas pipe at the same time when
touching the heater in the bathroom, as there is a possibility of
getting a shock.
=86. Acetylene Heaters.= Acetylene heaters are similar to the Bunsen
burner and asbestos-back gas heaters. They are provided also with
copper side reflectors. They are used only in localities where gas or
electricity cannot be had.
QUESTIONS FOR PART II
1. What are the essentials in heating a house with a hot-air furnace?
2. How does the "pipeless" furnace differ from the other types?
3. Explain the circulation of water thru a hot-water heating system.
4. What is the purpose of the expansion tank? Where should it be
located?
5. Describe a steam-heating system.
6. What care should be taken in managing a steam-heating system?
7. What precautions should be taken when using an electric heater?
PART III
LIGHTING DEVICES
CHAPTER XII
ELECTRIC LIGHTS
=87. Kinds of Electric Lamps in Use.= The electric lamps on the market
now are either tungsten (also called Mazda) or metallized carbon
(called gem carbon) lamps. Of all lighting appliances, electric lamps
and systems are most easily cared for. If properly selected, they make
an excellent light from the standpoint of hygiene. It is important for
every one to know enough about lighting to be able to select proper
kinds and sizes of lamps.
=88. Electrical Measurements.= A volt is the unit of electric pressure
which compares with the pound as the unit of water pressure.
An ampere is the unit of electricity flowing thru a wire which compares
to the gallon as the unit of water per minute flowing thru a pipe.
A watt is the unit of electrical power. It is determined by multiplying
the volts by the amperes.
A kilowatt equals 1000 watts.
A kilowatt hour equals 1000 watt-hours.
A watt-hour is the amount of energy needed by a device which uses one
watt and is operated for one hour. For example, a 25-watt lamp uses
25 watts, and if it is operated one hour, it uses 25-watt hours of
electricity.
The cost of burning an electric lamp is the number of watts marked
on the lamp multiplied by the hours the lamp is burned, and then
translated into kilowatt hours and multiplied by the price per kilowatt
hour.
[Illustration: FIG. 45. Direct light.]
=89. Carbon Lamps.= Few carbon lamps are being made now, but they may
still be obtained in some stores. The carbon lamp can be distinguished
from Mazda lamps (Fig. 45) by the appearance of the filament. The
carbon lamp gives about 0.40 candles of light per watt of electricity
consumed. Carbon lamps burn, making a yellow or reddish light, and
consume fully twice as much current as Mazda lamps of the same candle
power.
=90. Mazda or Tungsten Lamps.= Tungsten lamps are the ones in common
use. They give 0.80 to 1.00 candle of light to one watt of electricity
used. They have a filament of tungsten and may now be used in any
position. Less electricity is required to bring tungsten to a glowing
white heat than other materials used in lamps.
To compare the brightness of two lamps, do not look at the filament,
but hold pieces of white material like paper at an equal distance from
each lamp and compare the brightness of the surfaces; or put an opaque
object in front of the light and let a shadow be cast on another
object. The brighter light will cast a heavier shadow.
When substituting a new tungsten lamp for a carbon lamp, select one
about one-half the number of watts, unless more light is wanted. In
houses, it is a common practice to substitute a 40-watt Mazda for a
50-watt gem carbon lamp, thus saving ten watts per hour and getting
more light.
=91. Selecting Lamps for a Room.= There are so many possibilities for
the use of electricity in lighting a house, that it becomes a fine
art. When buying lights for a room, consider (1) the size of the room,
(2) the use of the room, and (3) the color of walls, floors, ceilings,
furnishings and decorations. For lighting purposes, lamps may be
obtained ranging from 10 or less to more than 100-candle power.
There are colored, transparent and frosted globes. There are reflectors
and shades of various colors and patterns. To obtain the same degree
of illumination, smaller lamps are needed in small rooms than in large
ones.
=92. Effect of Color Schemes Upon Illumination.= The color of the walls
and furnishings makes a difference in the candle power required to give
a certain amount of light. Those colors which absorb the most light
require the higher candle power, and those reflecting the highest per
cent of light require the lower candle power.
The frosted globes absorb some light, they diffuse the rest of it. They
dispense with the annoyance of glare from lamps, and are useful in
places where the full intensity of the lamps is not required.
The light absorbed by different colors varies considerably, as shown by
the accompanying table:
TABLE SHOWING ABSORPTION OF LIGHT
PERCENTAGE
OF LIGHT
COLOR ABSORBED
White 30
Chrome yellow 38
Orange 50
Clean pine wood 55
Yellow paper 60
Yellow paint (clean) 60
Light pink paper 64
Dirty pine wood 80
Dirty yellow paint 80
Emerald green paper 82
Dark brown paper 87
Vermilion paper 88
Blue green paper 88
Cobalt green paper 88
Deep chocolate paper 96
=93. Distribution of Light.= Light in rooms for general use should
be distributed as evenly as possible thruout the entire room. Avoid
excessive contrasts of brightness and darkness. Have the lamps shaded
to diffuse the light so that no one need look directly at the filament.
When working by a light, do not put the lamp very close to the
material, as this produces too strong contrasts of light and dark, or,
when reading, it produces too much reflection from the white parts of
the paper, which is trying on the eyes.
Direct lighting means that the rays from the lamp go directly into the
room (Fig. 45). Indirect lighting means that the rays are all directed
toward a reflecting surface such as the ceiling (Fig. 46). From here
they are reflected, giving an even amount of light to other parts of
the room. When directed toward the ceiling, they make it the brightest
part of the room.
A semi-indirect light avoids this difficulty (Fig. 47).
In diffused lighting, the lamp is covered, as by frosting, so that the
rays of light are broken up and so scattered that no direct ray shines
into the eyes, and there is no bright spot of light in the room.
[Illustration: FIG. 46. Indirect light.]
When costs must be limited, certain decorative effects must be weighed
for their value, some being more expensive than others.
City lighting plants can provide current for any number of lamps in
a house if it is properly wired. If more lamps are attached than the
wiring will carry, and all are turned on, the fuses will burn out.
Electric plants for private homes (see Sec. 271) usually furnish
current of a different voltage from city electric plants, so special
equipment and lamps must be used with small plants.
Inquire of the company who installed the wiring or electric system, how
many lights and other devices can be attached and for what voltage they
should be made.
[Illustration: FIG. 47. Semi-indirect light.]
CHAPTER XIII
GAS LIGHT
[Illustration: FIG. 48. Mantles.]
=94. Construction of Mantles.= A mantle is a device made of thread
saturated with some fireproof material like a mixture of thorium and
cerium which will glow, giving off a white light when heated hot. The
mantle (_A_ and _B_, Fig. 48) is placed over the burners of lamps using
liquid or gaseous fuel. The gas is mixed with air so that it burns with
a blue flame. The blue flame gives off little light, but it does not
smoke and is much hotter than a yellow flame. When a mantle is placed
over the blue flame, it is heated with less fuel consumption than is
required to make a yellow illuminating flame. The light from the glow
of the mantle is steadier and whiter than the light from an open flame,
so that it is more hygienic.
Mantles are made in different patterns so that they may be used on
upright and inverted burners. The inverted mantle throws more light
downward than an upright mantle. This is advantageous in lighting a
room, for most of the light is wanted in the lower part of the room.
Mantles can be used on lamps burning gas, kerosene, gasoline, alcohol
and acetylene if the burners are made to produce a blue flame. (See
Figs. 48 and 52.)
[Illustration: FIG. 48-_a_. Adjusting gas light.]
=95. Care of Mantles.= Strong jars and drafts will break mantles, for
they are very fragile. The explosion caused by burning back when the
lamp is being lighted is most destructive to mantles. To save mantles,
wait until the lamp has filled with gas before touching the lighted
match to it.
=96. Fixtures for Burning Gas.= Gas will burn just as it escapes from a
pipe. The flame of burning gas is yellow and makes considerable light.
In order to secure more light for the amount of gas burned, put a tip
on the end of the pipe, with a long, narrow slit in the top to spread
the flame. These are usually lava tips. Natural gas gives very little
light when burned in an open flame. Always burn it in mantle lamps.
Its heating value is 1000 B.T.U. per cubic foot. When burned in a
well-adjusted mantle lamp, natural gas will give about 15 candle hours
per cubic foot. The heating value of manufactured gas is rated at 600
B.T.U. per cubic foot. It makes a fair light when used in an open flame
burner. The yellow flame of burning gas makes considerable smoke, even
when carefully adjusted. It gives four times as much light and no smoke
when it is burned in a good mantle lamp.
[Illustration: FIG. 49. Bunsen burner for gas light.]
In the special burner of the mantle lamp, the gas is mixed with air so
that it will burn with a blue flame (Fig. 49). A blue flame is not good
for lighting, but when a mantle is placed over the flame, it becomes
heated, glowing hot. Since the mantle is made of a material which gives
off a white glow, it lights the room with a steady light which is far
better than the flickering light of the open flame (Fig. 48-_a_).
=97. Adjustment.= See that the ports thru which air is drawn into
the lamp are open as wide as needed to give a clear, smokeless flame
without firing back. Some lamps are fitted with a screw beside the
cocks to regulate the amount of gas flowing into the lamp. It should
be adjusted so that no more gas flows into the lamp than is needed to
get as bright a glow as possible from the mantle. Regulate the gas flow
by closing the valve attached to this screw until the mantle decreases
perceptibly in brightness, and then slowly opening it until the mantle
becomes bright. Gas companies often adjust lamps for their customers.
=98. Care of Lamps.= Clean the burners if they become sooted. Replace
mantles if they are broken.
[Illustration: FIG. 50. Open-flame acetylene burner.]
=99. Lighting a Gas Light.= When lighting a lamp, turn on the gas,
count three, and then light the lamp. Counting three gives time for the
burner to fill with gas and prevents burning back with an explosion.
Mantles are very delicate and easily broken by jars or strong drafts.
Burning back may break the mantle.
Burning back means that the gas ignites at the opening where it should
be mixing with the air instead of at the tip of the burner. This
happens when the lamp is lighted before it becomes filled with gas, or
when there is too much air mixed with the gas.
=100. Cold-Process Gasoline Gas.= It is more economical to use
cold-process gasoline gas with a mantle lamp than an open-flame burner
for lighting. Be sure to use the burners made especially for this kind
of gas. The lamps are managed like all others.
=101. Acetylene Lamps.= Open-flame burners are used for acetylene
gas because no mantle burner has been constructed which will operate
reliably with this rich gas.
Acetylene gas gives about ten times as much light per cubic foot as
manufactured gas burned in an open flame. The burners require little
care. Sometimes the holes in burners become stopped, and they should be
cleaned out with a fine pointed instrument like a needle. When they do
not work well, it pays to replace the old tips with new ones.
[Illustration: FIG. 50-_a_. Showing electric lighting device for
acetylene burner.]
Acetylene gas burners are constructed so that a very fine spray of gas
strikes another fine spray, which, when ignited, makes a broad flame.
This flame, which is almost white, gives off light. The burners appear
as illustrated in Fig. 50.
=102. Care of Burners of Acetylene Lamps.= Keep the two holes open.
Clean them with a large needle. See that there are no leaks about the
burners or pipes. If these are found, fill with white lead or some
similar substance, and tighten connections. If this does not suffice,
the trouble should be referred to a plumber. Fig. 50-_a_ shows an
acetylene burner.
Acetylene lamp mantles can be used only with acetylene which is under
high pressure. Therefore, they cannot be used with all plants. The
special burner for mixing air with the acetylene to make it burn with a
blue flame must be used with the mantle.
CHAPTER XIV
KEROSENE LAMPS
=103. Construction of Kerosene Lamps.= A kerosene lamp consists of a
bowl, a burner, a wick and a chimney.
In the ordinary lamp, the bowl for holding the oil is placed below
the burner (Fig. 51). The wick carries the oil from the bowl into the
burner by capillary attraction--one end being in the oil and the other
in the burner.
[Illustration: FIG. 51. Lamps and lamp chimneys.]
The burner, which has holes in it to let in air, holds the wick so
that only the oil reaching the top burns. The area and shape of the
flame depends upon the form of the top surface of the wick. The glass
chimney is used to cause an air current thru the burner and to protect
the flame from outside drafts. A screw moves the wick thru the burner.
If the wick is too small, the fire may burn back thru the burner and
ignite the oil in the bowl. It is important that a wick fit the burner.
If the chimney is too short or broken, the lamp will smoke _(A_, _B_,
Fig. 51).
=104. Management of Kerosene Lamps.= When the lamp smokes, it is
wasting fuel. Smoke is incompletely burnt fuel. The oil in the lamp
should be clean. It should never be mixed with gasoline or other more
explosive oils.
Fill the bowl each day the lamp is used to within one-half inch of the
top. A full bowl helps to make a safe lamp.
Put the chimney on the lamp so that it fits in its holder. Keep it
clean and bright. Keep the wick clean and trimmed evenly. See that it
entirely fills the opening thru the burner. This prevents the fire from
burning back down the burner and igniting the oil in the bowl.
Oil will not pass up a wick which fits too tight. Do not cut a wick to
trim it, but keep the charred part scraped or brushed off even with the
top of the slit in the burner. A burnt match is useful for this purpose.
[Illustration: FIG. 52. Mantle for kerosene lamp.]
=105. Lighting a Kerosene Lamp.= When lighting a lamp, be sure it is in
order and that any openings to the bowl are closed. Lift the chimney,
turn the screw to raise the wick about one-eighth inch above the slit.
Touch a lighted match to the wick, adjust the chimney, and, lastly,
move the wick up or down until it burns clear and bright without
smoking. After the burner becomes warm, the flame may grow higher and
smoke. Do not leave a newly-lighted lamp unwatched. After the lamp is
heated and adjusted, it should burn with a flame of even height.
=106. To Extinguish a Lamp.= Turn the wick down until it is slightly
below the top of the slit. Do not turn too far. It will then go out of
itself, or a slight puff of air will extinguish it. This is safer and
will smoke the chimney less than attempting to blow out the full flame.
=107. Care of Lamps.= Keep the inside and outside of bowl and chimney
clean. Wipe all soot from the burners. Trim the wick each day the lamp
is used. Fill the bowl with oil to within one-half inch of the top. Get
new wicks when the old ones become dirty.
=108. Kerosene Mantle Lamps.= Kerosene mantle lamps (Fig. 52) give
three to four times as much light per unit of oil as the ordinary
kerosene lamp. Many mantle lamps on the market are unreliable. Care,
therefore, should be taken to give the lamp a trial before investing so
as to be sure to get a good one.
The care and lighting of mantle lamps differ so much that the
directions must be furnished by the manufacturer and should be followed
with exactness.
CHAPTER XV
ALCOHOL AND GASOLINE LAMPS
=109. Classification of Lamps.= Since the principle of operation is
the same for most alcohol and gasoline lamps, they will be considered
together.
[Illustration: FIG. 53. Gasoline or alcohol lamp.]
These lamps may be divided into two classes--gravity lamps and
pneumatic, or pressure, lamps.
=110. Gravity Lamps.= Gravity lamps have the tank elevated above the
burner so that the force of gravity brings the fluid to the burner. It
is usually a little to one side of the burner so that it cannot become
heated by it. A pipe from the tank leads downward and either over the
chimney or under the burner, where it will be heated by the flame of
the lamp. When heated, it changes the gasoline or the alcohol to gas.
The pipe carries the gas on to a point where it is mixed with air
before it flows into the burner (Fig. 53).
=111. Lighting the Gravity Lamp.= In order to light these lamps, the
generator must first be heated so as to make the gas. After this has
once been done, the heat of the lamp keeps the generator hot. As soon
as the gas is formed, light the lamp.
These lamps are furnished with mantles. The flame is blue and,
consequently, gives out very little light, but much heat. The mantle
covering the flame is heated to glowing white heat and gives off much
light of a white color.
=112. Pressure Lamps.= Pressure lamps (Figs. 54 and 55) have a strong
tank which holds air and fuel, whether alcohol or gasoline. Air is
pumped into the tank so that it presses on the fuel with force enough
to push the fuel up the pipe leading from the bottom of the tank to the
generator. The air cannot get into the pipe so long as there is fuel
which is heavier than air in the tank, because the pipe which leads to
the burner starts from the bottom of the tank.
[Illustration: FIG. 54. Details of gasoline lamp.]
[Illustration: FIG. 55. Pneumatic gasoline lamp.]
The generator for changing the liquid fuel to gas is placed between
the burners of the lamp, of which there are usually two. After the
generator has been heated, the lighted lamps keep the generator hot.
The gas being very light, continues to rise. It passes thru a place
where it is mixed with air, and goes on into the burner, where it
is ignited. If the lamp burns low, more air must be pumped into the
tank to force up the gasoline or alcohol. When all the fluid has been
burned, the lamp will go out, since, then, only the air which is under
pressure in the tank will be coming into the burner.
Extinguish the lamp by turning off the supply of fuel to the generator.
To light these lamps, first heat the generator, as directed for the
particular lamp in use, and then light the burners. Detailed directions
cannot be given here, as they differ with different lamps.
=113. Gasoline Lamps with Wicks.= There are some gasoline lamps made
with wicks which help conduct the oil into the burner, where it is
changed to gas by the heat from the lamp, mixed with air and burned in
a mantle. The flame, from a mixture of alcohol or gasoline and air,
is blue and gives off little light, but much heat. It is used with a
mantle.
=114. Alcohol Lamps with Wicks.= The wick of one type of alcohol lamp
conducts the alcohol up thru a round tube which it completely fills.
The tube prevents the fire from burning down into the bowl of the lamp.
Alcohol makes a very hot and almost smokeless flame, even when little
air is present. The mantle is put over the flame, and, when heated,
gives a good light. Other ordinary fuels cannot be used on so simple a
lamp because they would smoke the mantle.
=115. Lighting Alcohol or Gasoline Lamps.= Heat the conducting pipe at
the point where the fuel is to be changed to gas. (Directions for this
come with each lamp, and they differ considerably.) After being heated
sufficiently, the valve leading to the burner is opened and the burner
lighted with a match or torch. Use clean gasoline for these lamps,
unmixed with water or other substances.
QUESTIONS FOR PART III
1. Are there any differences in the electric light globes on the
market? If so, in what ways do they differ? How do these differences
affect the lighting power of the globes?
2. What influence has the size and decoration of the room on the
brilliancy of light from a given lamp?
3. How should the light in a living-room be distributed?
4. What are the differences in direct, semi-direct and indirect
lighting?
5. What is the purpose of a mantle for a gas or kerosene lamp?
6. What is the difference in burners to be used with and without
mantles?
7. How is the light from a lamp measured?
8. Which lamp gives the greatest candle power of light for the amount
of fuel used--the one with or the one without a mantle?
PART IV
COOLING DEVICES
CHAPTER XVI
REFRIGERATORS
=116. Principles of Refrigeration.= Refrigerators (Fig. 56) are
designed to prevent the rapid spoiling of food by keeping it too cool
for the rapid growth of bacteria. They vary considerably in their
efficiency, according to their construction and to the way in which
they are managed. To preserve food and to save ice, the housewife must
understand her refrigerator, and she must choose a good one. There is
as much difference in the efficiency with which housewives manage their
refrigerators as there are differences in refrigerators.
[Illustration: FIG. 56. Refrigerator.]
A series of experiments were conducted with a number of different makes
of refrigerators. When the outside temperature was between 80 and 90
degrees Fahrenheit, and when the refrigerators were kept full of ice,
it was found that the temperatures in different refrigerators varied
between 45 and 60 degrees Fahrenheit. When the refrigerators were only
partly full of ice, their temperatures rose several degrees.
The refrigerators which held a temperature of 45 degrees when filled
with ice, or with 100 pounds, used 25 pounds of ice each in three days,
while in the same three days, the ones which could maintain only a
temperature as low as 65 degrees, used 50 pounds each. The warmer the
inside of a refrigerator, the faster the ice melts.
In general, a refrigerator which maintains a low temperature is
cheapest to operate. The refrigerator should be kept full of ice
exposed so that it comes in contact with the air circulating within the
refrigerator. The refrigerator which does not hold a low temperature
will not only use more ice, but be less efficient in keeping food.
=117. The Construction of Refrigerators.= The construction of a
refrigerator should be such that it may be kept clean. There should be
no cracks and corners to catch dirt and make breeding places for molds
and bacteria.
=118. Lining Refrigerators.= The best linings for refrigerators are
porcelain, porcelain enamel, or glass for the more expensive ones,
and galvanized iron or zinc for the less expensive ones. The shelves
are usually made of heavy wire or of bent metal. The latter should be
constructed so that they can be thoroly cleaned.
[Illustration: FIG. 57. Diagram showing circulation in a refrigerator.]
=119. Insulation of Refrigerators.= The more complete the insulation
of a refrigerator, the more efficient it will be. Different kinds of
material, as well as dead-air spaces, are used for this purpose. The
top, as well as the bottom, must be insulated. Materials which are
likely to crack or settle down and leave uninsulated spaces should not
be used. Because sawdust settles, it is not satisfactory. There are
felts, papers and other materials which are good. If the refrigerator
is not water-tight and the insulating material absorbs water, it will
lose its efficiency for insulation.
=120. Circulation in Refrigerators.= The better the circulation
in a refrigerator, the more efficient it will be. The air in the
refrigerator must be free to circulate over the ice. As it cools, it
should drop to the bottom of the ice box. When it warms, it will rise
and be displaced by fresh falling cold air. It should be free to rise
to the top of the refrigerator and from there pass into the ice chamber
and over the ice to be cooled again (Fig. 57). When the ice always
melts unevenly and in the same relative place--that is, more on the
side or bottom--it indicates poor circulation in the refrigerator.
=121. Drip from Melting Ice.= There should be a pan under the ice to
catch the drip from the melting ice, and a drip pipe to carry it out
of the refrigerator (Fig. 57). If the drip pipe passes into a pan set
under the refrigerator, the pan should be emptied so that it will not
overflow. The water in the pan should not be allowed to become stagnant.
If this pipe passes to a drain, it should not be attached to the drain,
but drip into it. The small amount of fresh air passing up the drip
pipe from the room is advantageous. Because some air does flow thru
here, the drip pipe and the drain pipe must be clean and free from
gases and odors.
The drip pipe should be straight and free from places in which dirt may
collect. It must be removable, so that it can be cleaned. The doors of
the refrigerator must shut so tightly that frost or dew will not form
about their edges on a hot day.
=122. Arrangement of Food in the Ice Box.= Ice boxes are usually cooler
at the bottom than at the top. Do not put food in the ice chamber
because this necessitates opening the door and wastes ice. Do not put
papers or flat boxes on the shelves which will interfere with the
circulation of air in the refrigerator.
=123. Filling and Care of the Ice Box.= The housewife must open the
doors of the ice box as seldom as possible, and close them quickly. Do
not cut off the circulation of air from the ice by wrapping it in a
blanket or newspapers. It cannot do its work then. The ice box is kept
cold by the gradual melting of the ice. The ice melts fastest as the
temperature of the ice box rises. Covering the ice may keep it from
melting, but it will also allow the refrigerator to get warm, and so,
whatever is gained in saving ice at first, will be lost at the higher
temperature and in cooling the box again. Steady melting does the most
good.
The shelves and drain pipe should be removable, and these and the
refrigerator should be washed and thoroly scalded once in every two
weeks.
There is a saving in planning to open the refrigerator as little as
possible. The filling of the ice box with a large piece of ice two or
three times a week, rather than with a small piece every day, is more
economical.
CHAPTER XVII
ICELESS REFRIGERATORS; WATER COOLERS
=124. Comparative Efficiency of Iceless Refrigerators.= In some
localities, where it is difficult to get ice often enough to pay for
having a refrigerator, other devices have to be depended upon for
keeping food cool. Except when cold running water can be used in
coolers, they do not take the place of refrigerators, because they
cannot maintain the low temperature of a good refrigerator. As a
rule, the best of the makeshifts are about on a par with the poorer
refrigerators. They are very useful in emergencies.
[Illustration: FIG. 58. Iceless refrigerator.]
=125. Iceless Refrigerator.= One of these devices is called the iceless
refrigerator (Fig. 58). It depends upon the evaporation of water
to make it cool. Water will evaporate sufficiently fast to cool a
refrigerator enough to be of value only in a dry, hot, breezy place.
Under the most ideal condition, an iceless refrigerator may hold as
low a temperature as 65 degrees Fahrenheit, when the thermometer is
registering above 90 degrees.
This refrigerator consists of a cloth-covered frame and a device for
keeping the cloth moistened with fresh water. Since wind or a good
circulation of air helps in the evaporation of water, the iceless
refrigerator must be placed where breezes may reach it, and it should
be anchored so that it will not blow away.
An iceless refrigerator may be made from a rectangular frame of wood,
to which heavy canton flannel is buttoned or tacked. On the top of this
should be placed a pan of water with strips of cloth extending from
the water to the covering of the frame. This will conduct the water
from the pan out onto the cloth. The number of strips of cloth regulate
the rapidity with which the water is carried to the sides of the
refrigerator. The food is set inside (Fig. 58.) The refrigerator should
be placed in a shady spot where the breezes can strike it. Iceless
refrigerators must be kept clean, and the covering of cloth should be
washed occasionally.
[Illustration: FIG. 59. Device for cooling food.]
Some iceless refrigerators are enclosed in a chimney-like closet built
on the house, the cold air coming in at the bottom and being drawn
upward by the natural draft of the chimney-like structures. This draft
hastens the evaporation of the water. Such refrigerators are expensive
and less satisfactory than ice ones.
=126. Small Cooler.= A few things may be kept cool, like a bottle of
milk and a small dish of butter, by setting them in a shallow pan of
water and covering them with a flannel cloth which comes down into the
water and so remains moist (Fig. 59). The evaporation of the water
from the flannel cools the food somewhat below the temperature of the
surrounding air.
=127. Covered Pail.= Another device is a metal pail (Fig. 60) covered
with a heavy layer of cloth and a pan set on top of the cover. Into the
pan is put some water and strips of cloth to conduct out the water.
This may be hung in the kitchen window if it is shaded. The cover and
the strips must be secured so that they will not blow off.
[Illustration: FIG. 60. Covered pail for cooling food.]
=128. Unglazed Earthenware.= Unglazed earthenware pitchers and jugs
make excellent water coolers. The water is put in them, and, as the
container is porous, a small amount filters thru the earthenware, and,
as it reaches the surface and air, it evaporates, cooling the remaining
water.
=129. Cooling with Running Water.= A very little stream of water from a
faucet will cool the baby's milk and keep it from souring. The bottle
should be set in a pan of water which is constantly renewed by the
small stream running from the faucet. (Fig. 61.) This method of cooling
should be used only in homes supplied with water from a spring or in
an emergency. Under most circumstances, it is too extravagant a method
of keeping food to be recommended. In cities it should be prohibited
because it might cause too great a drain on the city water supply.
[Illustration: FIG. 61. Cooling with running water.]
A larger device used for cooling milk is a tank of running water (Figs.
61-_a_-_b_). The water flowing thru this tank commonly flows into
another tank used for the watering of stock. Cans with inverted covers
like those illustrated are waterproof, because the air is caught inside
them so that it cannot get out for the water to replace it. It does
not require a large stream of water to renew that in the tank and keep
it cool. The efficiency of this device depends entirely upon having a
supply of cold water available.
[Illustration: FIG. 61-_a_. Cross-section of cooling tank.]
=130. Refrigerating Plants.= Refrigerating plants are sometimes
installed in private dwellings. These consist of a motor and a machine
for compressing gas, a chamber which is to be cooled, and sometimes
coils of pipe containing brine.
When the gas--for example, ammonia or carbon dioxide--is compressed,
it heats the pump which compresses it. That is, when a liquid or gas
is being compressed, it gives up heat. When a liquid or gas expands,
it takes heat from somewhere. In refrigerating plants, the expanding
gas is made to take the heat either directly from the refrigerator
or storeroom, or from brine which is then used for cooling the
refrigerator or room. Refrigerating plants require the same care as
pumps, motors and refrigerators.
[Illustration: FIG. 61-_b_. Cooling tank.]
=131. Water Coolers.= Since ice is not always pure, it is necessary to
use cooling devices which do not permit it to come into direct contact
with the water. One type of water cooler consists of a can set in an
ice box with a pipe leading to the outside so that the box does not
have to be opened every time that water is wanted (Fig. 62). This can
should be made so that it may be removed, washed and scalded.
Another cooler consists of a tank or water bottle placed on the
outside of a refrigerator or box of ice with a pipe leading thru the
refrigerator or box of ice (Fig. 63). The water flowing thru the pipe
is cooled. The pipe ends at the outside of the ice box with a faucet to
let out the water. This cooler cools only the water flowing into the
pipe instead of the entire tank of water.
[Illustration: FIG. 62. Water cooler containing water tank.]
[Illustration: FIG. 63. Sectional view of water cooler.]
=132. Care of Water Coolers.= Put only clean, pure water into the
coolers, and keep them clean by flushing them out occasionally with
boiling water.
CHAPTER XVIII
FANS AND VENTILATORS
=133. Selecting a Fan.= With the coming of electricity into the home,
fans have become practical home devices. Do not buy a fan or other
electrical device without ascertaining whether the current is direct or
alternating, and what voltage is needed to run it. Most city homes are
now supplied with current ranging between 105 and 115 volts, so most
fans are made for that. Fans will run on a small wire like that used
for lighting.
[Illustration: FIG. 64. Blower.]
[Illustration: FIG. 65. Stationary fan.]
=134. The Construction of the Fan in Common Use.= A motor turns the
fan. There is a regulator on some fans, so that they can be run at
different rates of speed. Oil cups are important parts of fans. When
a new fan is purchased, these cups are full of oil. The oil will last
for many months, but if an old fan heats and sparks while being run,
have an electrician examine it to see if all the parts are in order and
there is a supply of oil. Figs. 64, 65 and 66 show types of fans in
common use.
[Illustration: FIG. 66. Movable electric fan.]
[Illustration: FIG. 67. Stove ventilator.]
=135. Ventilator.= A hood (Fig. 67) with a pipe leading into the
chimney, placed over a cook stove, will conduct hot air and steam up
the chimney. This is due to the fact that warm air rises and cold air
comes in to take its place. An open skylight over a cook stove, also,
makes an excellent ventilator and cooling device for kitchens.
QUESTIONS FOR PART IV
1. How may refrigerators be judged for efficiency?
2. What are the essentials of a good refrigerator?
3. How is an iceless refrigerator cooled? Under what conditions is it
useful?
4. What may be the matter with an electric fan when it heats and
sparks?
PART V
WATER SUPPLY AND SEWAGE DISPOSAL.
CHAPTER XIX
PUMPS AND WATER FILTERS
=136. Suction Pumps.= A pump is a device for lifting water. The pumps
in common use work on the principle that water which is under the
pressure of air will rise to fill a vacuum or a partial vacuum. The
pump is composed of a combination of valves and a piston for forcing
the air out of the pipe to allow the water from below to be forced into
it. A valve catches the water as it starts to flow back. The weight of
the water holds the valve closed.
An outlet above the piston permits the water to flow into a tank or
sink when the piston is again lifted to make a new vacuum and draw more
water (Fig. 68).
=137. Care of Pumps.= The leather or material forming the piston must
be kept moist, or it will shrink and leak. When it becomes worn and
old, it must be renewed. It is not a difficult task to put new packing
on a small suction pump. To do this, remove the pin attaching the
piston to the handle. Lift out the piston, unscrew the bolt which holds
the leather packing in place; put on the new packing, and replace the
bolt, piston and pin.
Always pump with a regular, even stroke--a jerky one tends to wear the
working parts of the pump.
The cylinder and pipe containing water must not be allowed to freeze.
There is usually a plug in the pipe which may be removed to let out
the water when there is danger of freezing. A cracked cylinder or pipe
will leak air and not raise water.
[Illustration: FIG. 68. Suction pump.]
[Illustration: FIG. 69. Force pump.]
Keep the bearings for the handle well oiled. When the pump gets old,
the cylinder becomes worn and leaks. It can sometimes be replaced with
a new cylinder, or more packing must be put on the piston.
=138. Force Pumps.= Force pumps are used on deep wells and in forcing
water into storage tanks. They should be kept oiled; they should
be operated with an even stroke, and the packing in them should be
renewed if they leak air. In force pumps, the valves differ in their
arrangement from suction pumps (Fig. 69).
=139. Compressed-Air Pumps.= Compressed-air pumps consist of a tank
for storing the compressed air--a pump to force air into the tank and
cylinders equipped with valves. These act automatically. Whenever an
outlet pipe is opened, the extra pressure of air from the storage tank
raises the water from the well or cistern (Fig. 70). Air should be kept
in the pressure tank.
[Illustration: FIG. 70. Compressed-air pump system.]
When this arrangement is used, open and close faucets slowly, not with
a jerk. Fig. 70-_a_ shows plumbing where such a system is used.
=140. Water Filters.= Water filters are devices for straining minute
particles out of water. They are made of sand, charcoal or porcelain,
kisselguhr and other materials. They are without value unless they are
kept clean. A dirty filter is worse than none. Almost the only way to
clean them is to sterilize them or put new material in them. Only with
expert care can filters be made effective for removing disease germs.
A dirty filter may prove a menace. Filters are valuable for removing
coarse dirt from the water.
[Illustration: FIG. 70-_a_. System of plumbing with compressed-air
tank.]
Filters on faucets should be cleaned or renewed every day. Large
filters for rain water should be renewed every few months.
CHAPTER XX
PRESSURE TANKS; PLUMBING FIXTURES
=141. Pressure Tanks.= A pressure tank is a device for storing water
under pressure. It is usually placed in the basement of dwelling houses.
=142. Construction of the Pressure Tank.= The tank is tight and strong,
so that it will hold air and water under pressure. The tank originally
has some air in it. When the water is pumped in, the air not being
able to escape, is compressed. When there is a chance for water to
escape from the tank which is connected to water pipes, the pressure
of the compressed air on the water forces it to upstairs rooms and
other points. To this tank is attached a pressure gage which indicates
the amount of pressure; or, in other words, the amount of water in the
tank, for when the water gets low, the pressure is reduced unless the
air has escaped. A glass gage shows the height of water. Provision is
made to let some air into the tank, for otherwise it may in time be
all forced out of the tank or absorbed by the water. The water in a
pressure tank may be used to pump water from a cistern into another
tank.
=143. Care of Pressure Tanks.= A pressure tank must not be pumped up to
the extent that the pressure becomes greater than the strength of the
tank. A safety valve is used in controlling the pressure.
=144. Hot-Water Kitchen Tank.= A force pump is generally used for
pumping water into kitchen tanks, except when water from another tank,
such as a city reservoir, flows into it.
[Illustration: FIG. 71. Instantaneous water heater.]
=145. Instantaneous Water Heaters.= The instantaneous water heater
(Fig. 71) is a device which heats water on its way to the outlet. It is
composed of a heating unit and piping connected to the outlet pipes. In
this type of heater, the pipes must always be kept full of water, and
some device should be attached (Fig. 72) to the heater which will lower
the heat as soon as, or before, the water reaches boiling temperature.
This will prevent steam from forming, which might injure the system.
[Illustration: FIG. 72. Device for heating water automatically.]
=146. Heaters for Tanks.= Hot water is lighter than cold. A pipe from
the bottom of the tank leads into the heater, passes thru the heating
coils and up into the top of the tank (Figs. 73 and 74). Water from
the tank circulates thru this pipe as the hot water rises and the cold
water falls in the tank. As the heater is located on a level with the
bottom of the tank, cold water seeking this level flows into the pipe
and becomes heated (Fig. 76).
[Illustration: FIG. 73. Force pump and boiler.]
A booster is a device which keeps the water hot up to the faucet (Fig.
75). If there is a pilot on a gas water heater, be sure to use it.
The burners should be cared for in the same way as on other heaters
using the same fuel. Keep the tank full of water and the water free
to circulate thru the pipes. Air-tight tanks may become so hot that
steam is formed in large amounts. Tanks which are not connected with
city water pipes may be fitted with safety valves which open when the
pressure of steam inside the tank reaches a certain point, which is
below the danger point.
Should the pipes or tank freeze, do not start the fire in the heater,
but thaw the pipes with applications of hot water or other means until
the water can circulate in them.
Electric heaters are usually incased in a waterproof covering and
put in the center of the tank. Small electric heaters are in use for
heating a glass or other small amount of water. These are called
immersion heaters.
=147. The Elevated Water Tank.= In rural homes, water is sometimes
stored in an elevated tank. This is usually placed in the attic. It is
frequently filled by means of a force pump connected with a windmill
or gasoline engine. If there is no overflow to this tank, which there
should be, it must be watched when being filled to prevent it from
overflowing. It may be fitted with an automatic device similar to those
used on the expansion tanks of hot-water furnaces or tanks to water
closets for regulating the inflow of water.
[Illustration: FIG. 74. Water heater and tank.]
[Illustration: FIG. 75. Booster for hot water.]
=148. Faucets.= Faucets are made in different patterns, but they need
practically the same care (Fig. 77). The leather, or rubber, washer
in a faucet must be renewed when it leaks. To renew the washer,
unscrew the cap from the faucet. Remove the valve. Take off the ring
of packing. Replace with a new ring, and put the faucet together
again. The only tools needed for this repair work are a wrench and a
screwdriver. Shut off the water from the pipe to the faucet before
beginning to repair a leaking faucet.
[Illustration: FIG. 76. Water tank and heater.]
=149. Valves.= Valves are constructed much like faucets.
They, too, sometimes need repacking. Follow the directions for
repacking of faucet (Fig. 78).
[Illustration: FIG. 77. Faucet showing parts.]
[Illustration: FIG. 78. Radiator valve.]
=150. Overflows.= Keep overflows clean. When the plug and overflow are
combined, as they sometimes are, lift out the cylinder forming the
plug and overflow and wash it. When it fails to hold water in the tub
or basin, it may need a new washer on the lower part. This may be
replaced very easily. Fig. 79 shows one type of overflow.
[Illustration: FIG. 79. Cross-section of overflow on bath-tub.]
[Illustration: FIG. 80. Plumber's pump.]
It is more difficult to keep other overflows clean. They may be flushed
or cleaned with a brush attached to a wire.
=151. Traps for Bath Tubs and Basins.= Dirt and slime collects in
traps. Clean them frequently. Always leave clean water in the traps
of bathroom fixtures and sinks. Only matter quickly soluble in water
should pass into drain pipes. Keep matches, hair, sweepings, rags,
fruit skins and stones out of the fixtures.
If the drain from a basin, sink or tub fails to carry away the water,
the stoppage may be removed with a small plumber's pump (Fig. 80). This
is a small rubber cone-like device which is placed over the outlet
to the drain and moved up and down so that it sucks air, water and
whatever may be movable up the pipe.
CHAPTER XXI
CESSPOOLS, SEPTIC TANKS AND CITY SEWER SYSTEMS
=152. Relative Value of Cesspool and Septic Tank.= Sewer pipes for
private water systems usually drain into cesspools or septic tanks
(Figs. 81, and 81-_a_). The waste goes thru a process of decomposition
before passing out into the soil. Sewage should both liquify and
oxidize before entering into the soil. Oxidation purifies liquid sewage
so that it is not contaminating. If oxidation is not brought about in
the cesspool or septic tank, sewage, which is fresh, should be run onto
the surface of the ground where the air and bacteria for oxidation can
be found. Cesspools are not as good as septic tanks because there is
not the surety of sewage being oxidized in them, as there is in the
septic tank. They lack oxidizing chambers.
[Illustration: FIG. 81. Septic tank and tile.]
Unoxidized liquid sewage being in a condition to flow readily thru the
earth, is more dangerous than fresh sewage because it is more likely to
seep into wells.
[Illustration: FIG. 81-_a_. Septic tank.]
=153. Construction of the Septic Tank.= The septic tank is composed of
two chambers--one the liquefying chamber and the other the oxidizing
chamber. Both are water-tight (Fig. 82). The fresh sewage comes into
the liquefying chamber thru a pipe placed near the top of the tank.
Here it stands and liquefies, which is a process of decomposition.
The solids fall to the bottom as they come into this chamber, and the
liquid formed rises to the top and flows into the oxidizing chamber
(_B_, Fig. 82), when it reaches a point a little below the height of
the inlet pipe. It either does this by flowing over a partition or thru
a pipe leading from one compartment to the other.
The second compartment is usually slightly smaller than the first.
Here the sewage is held until the process of oxidation takes place,
which renders it less dangerous. When the sewage in the second chamber
reaches a certain height, it siphons out into a tile which distributes
it over a plot of ground (Fig. 81).
Various kinds of siphons are used, the important feature of them being
that they are constructed so that they drain the tank often enough to
remove the oxidized sewage and not so often as to remove it before it
has become oxidized.
=154. The Size of Tank.= Because the liquid must be drained from the
tank at certain intervals, it is important that the size of the tank be
adapted to the amount of waste it will receive.
[Illustration: FIG. 82. Details of septic tank.]
Septic tanks are kept warm by the heat generated in the oxidizing
process, which is simply slow burning of the waste, so that they rarely
freeze in winter.
Run waste water from the kitchen sink and laundry tubs into a catch
basin to collect the grease from the water, as grease or oil on the
surface of the sewage of a tank will stop the action of the microbes in
the tank by smothering them.
When too much grease does get into it, the tank must be thoroly cleaned.
Do not use lye, chloride of lime, carbolic acid and other chemicals in
drains and septic tanks. Disinfectants of this type put into pipes
leading to a septic tank will kill the useful bacteria which decompose
the sewage.
Use clear boiling water to clean the pipes. This will be cooled by the
time it reaches the tank so that it will not kill the useful bacteria.
Insoluble mineral matter gradually accumulates in septic tanks, so that
they must be cleaned once every few years. Care will postpone the times
for cleaning.
Do not wash vegetables with much earth adhering to them in sinks
leading to cesspools or septic tanks. Shake or rinse off the dirt
before washing them.
=155. Disposal of Waste in Cities.= In some cities, householders are
required by law to have catch basins connected to their sewer systems
to remove leaves and dirt from storm water and grease from kitchen
sinks and laundry tubs. The laws of other cities forbid the use of
catch basins, but urge householders to help care for the city sewer
system by not putting grease into sewer pipes.
Strong chemicals should not be put into the pipes. Use only boiling
water in cleaning pipes. Do not wash vegetables on which there is much
loose dirt in sinks.
CHAPTER XXII
WATER CLOSETS
=156. Construction of Water Closets.= The water closet is a device for
the disposal of excrement. The closet includes a tank of water for
flushing the waste from the bowl to the sewer or waste pipe. Between
the bowl and the waste pipe is a device called a trap which holds water
and seals the end of the waste pipe so that gases from the sewer or the
septic tank cannot come into the house. (Fig. 83-_a_.)
The bowl of the newer models of water closets have the trap as a part
of the bowl, which saves joints and connections likely to catch dirt
and stop up the trap (Fig. 83). The water coming from the flushing
tank is carried around the bowl so that it is flushed clean by the
swift-flowing water. When the water reaches the bottom of the bowl, it
rushes upward a few inches before it can turn downward to the waste
pipe. This it does while flowing rapidly and cleansing the bowl; when
the tank empties, water collects in the bowl to the level, where it can
flow down the waste pipe (Fig. 83). As soon as all the water above this
level has gone down the pipe, the remainder stays in the bowl, forming
the seal until the next time the bowl is flushed. Fig. 83-_a_ shows two
kinds of traps.
If water flows at too rapid a rate thru the trap of the bowl, as in
cases when there is too much pressure on the water or the tank is set
too high so that gravity gives it too much force, or if an excessive
suction is produced in the drain pipe, all the water may run out of the
bowl, leaving the trap unsealed. The remedy for this is a change in
the flushing tank or in its position.
[Illustration: FIG. 83. Section of water closet.]
=157. Siphoning the Trap.= If rags or shreds of material are dropped
into the bowl and lodge in the trap, only a part of them going over
into the waste pipe, they may siphon the water, sealing the trap, over
into the waste pipe. There was more difficulty of this sort with traps
of older models than with the newer types. Always leave clean water in
the trap.
[Illustration: FIG. 83-_a_. Types of traps.]
=158. The Flushing Tank.= The flushing tank (Fig. 84) is a reservoir to
hold sufficient water to cleanse the bowl. In one type of tank, water
is retained in the tank by a plug held in place by the weight of the
water in the tank. By a lever on the outside of the tank, this plug is
lifted when the bowl is to be flushed, and it stays open until all the
water flows out of the tank. When the water has all left the tank, the
plug falls back into the hole and fresh water flowing into the tank
holds it in place, as there is nothing in the pipe below to make it
float upward.
Working at the same time with the plug is a valve in the water supply
pipe, attached to a large hollow float. The valve opens as the water
flows out of the tank, and closes as the tank is filled. This valve
is operated by the float floating on the surface of the water. As the
water flows out of the tank, the float falls, opening the valve and
letting in water. As the tank fills, the float rises to the top of the
tank and shuts off the valve. If the float catches so that it fails
to rise and fall, or becomes disconnected from the valve, it will not
operate the valve. There is an overflow pipe in the tank which carries
off all water rising above a certain level in the tank. This prevents
the tank from overflowing when the valve fails to turn.
[Illustration: FIG. 84. Diagram of flushing tank.]
=159. Repairing the Flushing Tank.= When the water continues to flow
into the tank, take off the cover of the tank and examine the valve
and ball to see why they are not working properly. If disconnected or
caught, remedy the trouble. If the plug fails to stop the flow of water
out of the tank, water will also continue to flow into the tank. To
remedy this temporarily, push the plug down over the outlet and also
note the reason why it has not fallen back automatically. If worn, it
may have to be replaced with a new one.
There should be a valve to close the pipe to the tank. With this valve,
much water can be saved in time of trouble, and greater convenience may
be had in remedying difficulties with the devices inside the tank.
QUESTIONS FOR PART V
1. How does a pump lift water from a well?
2. How do pumps differ in construction?
3. What care should be given a pump?
4. When is a water filter useful? When dangerous?
5. What is a pressure tank? How does it operate?
6. Describe two kinds of water heaters. What precautions should be
taken with each kind of heater?
7. Describe a water faucet. Try to replace an old washer with a new
one.
8. Have you ever cleaned the overflow to a tub or basin? Should they
be cleaned?
9. What are traps? What may cause them to fail to work?
10. How would you select a good trap? How would you clean it?
11. Describe the construction of a septic tank. What is the action
that takes place in a septic tank? What care should be given to it?
12. Examine the tank to a water closet. How does it operate?
PART VI
LAUNDRY EQUIPMENT.
CHAPTER XXIII
WASHING MACHINES
=160. Kinds of Washing Machines.= Washing machines are tools to help
remove dirt from clothes either by friction or by forcing water thru
them. They are known by such names as suction, cylinder, rotary,
oscillating, locomotive and centrifugal machines. These names are used
differently by various authorities.
[Illustration: FIG. 85. Washer to place in boiler.]
[Illustration: FIG. 86. Another type of washer for boiler.]
Washing machines may be attached to any kind of motor, or they may be
manipulated by hand.
=161. Suction Machines.= The suction machines are made to force water
thru the clothes (Figs. 85 and 86). Some are operated by hand, some by
mechanical power, and some are funnel-shaped devices to be placed in
boilers.
Hand or mechanical suction machines have cones or funnels which are
pushed down onto the clothes and then suddenly lifted, causing suction
which draws out the dirt previously loosened by the moisture and
pressure. Mechanical devices attached to the top are sometimes used to
raise and lower the funnels (Figs. 87 and 87-_a_).
[Illustration: FIG. 87. Suction washer.]
The suction washers for use in boilers are placed funnel side down. By
means of these, the steam forming in the bottom of the boiler forces
the water thru the clothes. Distribute the clothes evenly about the
washer. Fill the boiler with water and add shaved soap. When set over
a fire, the steam forming at the bottom raises the water in the funnel
to the top and pushes it out thru the clothes, or raises the funnel and
makes it beat upon the clothes.
[Illustration: FIG. 87-_a_. Washing machine.]
Other machines combine the two methods of washing--forcing water thru
clothes and rubbing them at the same time.
=162. Cylinder Washers.= Cylinder washers contain a perforated
barrel-like device, into which the clothes are placed (Fig. 88). This
cylinder has cleats on the inside to raise the clothes as the cylinder
turns and drop them when they reach the highest point in it, back into
the water, thus pounding water thru them and rubbing them against the
side of the cylinder as they are raised. This is the type used in most
laundries. A cylinder turned by an electric motor is made which can be
placed in the stationary wash tub in small apartments. The tub then
serves as the outer part of the washing machine.
[Illustration: FIG. 88. Cylinder washer.]
=163. Rotary Washers.= In the rotary, or milk-stool, type of washer,
sometimes called "Dolly" (Fig. 89), the stool-like contrivance which
presses against the clothes must be turned half-way around in one
direction, and then back the other way, to prevent twisting, tearing or
otherwise injuring the clothes. The clothes are thus rubbed against the
corrugated sides and bottom of the machine, and thru the water. Never
put too many clothes in this type of machine because too tight packing
causes the machine to tear them.
[Illustration: FIG. 89. Rotary washer.]
=164. Machine with an Oscillating Washing Device.= This washer contains
an oscillating device for rubbing the clothes over the corrugated
bottom. The rubbing device is also corrugated and is put on top of the
clothes and moved backward and forward, thus rubbing them between two
wash-boards (Fig. 90).
[Illustration: FIG. 90. Oscillating washing machine.]
=165. Oscillating Washers.= Oscillating washers have corrugated
bottoms. The clothes are put into the machine with the wash water. The
washer rocks, throwing the clothes backward and forward thru the water,
loosening and squeezing out the dirt. This washer works easiest when
the machine is well filled with water.
=166. Locomotive Washer.= The locomotive washer (Fig. 91) slides
backward and forward, thus churning the water and clothes. It is
operated only by power. A heating unit, usually gas, in the base of the
machine keeps the water hot.
[Illustration: FIG. 91. Locomotive washing machine.]
=167. Centrifugal Washer.= A centrifugal washer (Fig. 91-_a_) contains
a perforated basket which whirls in the water contained in the machine.
The clothes are placed in the basket, rolled into bundles. The rapid
whirling thru the water removes the dirt from the clothes.
[Illustration: FIG. 91-_a_. Centrifugal washing machine.]
=168. Care of Washers.= The bearings and other motor parts of a washing
machine should be kept oiled. Keep belts tight. Run the machine about
ten minutes each while the clothes are in the first wash water and the
two sudsy waters, and five minutes each for the hot and the cold rinse
waters. Blueing had better be done in a tub.
Wooden machines must dry out occasionally, or else they get slimy. Do
not let them get dry enough to crack. Air the machines after use. Cover
them when not in use to keep them clean.
When a gasoline engine is used in operating a washing machine, it
must be set so that the belt will pull straight on the pulley wheel
of the machine. The belt should be tight enough to prevent slipping.
Stationary washers are set to avoid such troubles, but those which are
moved from place to place must be adjusted by the operator.
The pulleys must be adjusted to turn at the number of revolutions per
minute directed for the washer used. This usually does not exceed 150
revolutions of the motor wheel per minute.
Water motors must receive more than 25 pounds of water pressure to
operate a washing machine.
CHAPTER XXIV
WRINGERS
=169. Roller Wringer.= The kind of wringer in most general use is the
one made of two rollers rotating in opposite directions, the clothes
being drawn in between the two by friction, and the water pressed out.
(See Fig. 88.)
The rollers in modern wringers are made of a composition of rubber.
They are adjusted so that they may be brought close together or moved
apart. When wringing thin articles, the rollers should be set close
together, and when wringing heavy articles, they should be set far
apart. This adjustment of the wringer helps to do better work and save
wear and tear on clothing and wringer.
=170. Care of Wringers.= The bearings should be kept oiled, but oil
must be kept off the rollers, as it rots them. Keep the rollers washed
clean. Soap and water will remove the dirt which collects on them.
If this does not clean them, wipe the rollers in a weak solution of
ammonia.
If the rollers get badly stained, wipe them with a cloth dipped in
kerosene. Wash this off immediately, as kerosene dissolves the rubber
as well as the dirt.
Never leave a wringer with the pressure on the rollers when not in use.
The pressure is either adjusted by thumb-screws or by a clamp. Loosen
these when thru with the wringer.
=171. Centrifugal Wringer, or Dryer.= The centrifugal wringer, or
dryer, consists of a tub, inside of which is a smaller tub with
perforated sides. There is a drain at the bottom of the outside tub.
The wringer is attached to a device for making the inside tub turn
rapidly. The power used is either hand or machine (Fig. 92).
[Illustration: FIG. 92. Washer and dryer.]
The rapid turning of the inner tub for three minutes throws the
clothing and water in them to the outside of the revolving center. This
tub being perforated, lets the water thru while retaining the clothing.
Thus, the clothes are wrung as dry as in a wringer of the roller type.
If the machine is turned a longer time, the clothes can be wrung
entirely dry.
=172. Care of the Machine.= When loading centrifugal wringers, put the
heavy pieces at the bottom of the basket. Put articles in basket in
bunches, and pack fairly tight. Do not have loose ends hanging out.
Fold sleeves into garments. Load the basket full if there are clothes
enough. A cover helps to hold the clothes in place. Load so that it
runs even and does not wobble.
Never hold your hand on the extractor after it has started.
=173. Combination Washer and Wringer.= The centrifugal washer and
wringer combined is built so that the basket can be lowered into a
tub of water. The clothes rotating in water are washed. After this is
accomplished, the cylinder is raised, and, when rotated, serves as a
wringer of the centrifugal type.
Load the washer with fewer clothes than for wringing. Roll each garment
into a bunch before putting it into the washer.
Centrifugal wringers are used also as dry-cleaning machines. For this
use, they should be operated out of doors and at a slower speed than
when water is used. Friction heats gasoline, causing it to evaporate
rapidly. The friction between clothing, tub and gasoline when turned at
a high speed may produce a spark which will ignite the gasoline.
CHAPTER XXV
MANGLES AND IRONS
=174. Construction of Mangles.= Mangles are made of rollers rotating
in the same direction, one moving faster than the other, set close
together so that they press the clothes smooth, or they consist of one
roller rotating over a stationary surface called a shoe (Fig. 93).
[Illustration: FIG. 93. Mangle.]
=175. Cold Mangles.= When no heater is attached to the shoe or one
roller, the mangle is a cold mangle. It smoothes clothes, but does
not do as good work as a heated mangle. There is almost nothing about
mangles to get out of order. The only caution necessary is to keep
the bearings oiled, have guards so as not to catch hands in the power
machines, and loosen the roller so that it is not pressed onto any
surface when not in use.
=176. Heated Mangles.= The heated mangles have the heat applied to one
of the rollers or to the shoe. They may be used cold. The heat may come
from gasoline, gas, electricity or kerosene. The management of the
heating unit is the same as for a stove using any of these fuels. The
same care should be taken of the burners as of stove burners.
=177. Care and Use of Mangles.= (1) Have the clothes damp before
putting them thru the mangle. (2) Protect the mangle from dust at all
times. (3) See that belts are properly adjusted on mangles. (4) The
covering put on mangle rollers must be of even thickness, or they
will not do good work. (5) Do not mangle starched garments, or those
on which are many or large buttons. (6) Wax the steel roller while it
is warm, and wipe it clean with a cloth (Fig. 94). (7) Always remove
pressure when not using mangles.
[Illustration: FIG. 94. Waxing roller of mangle.]
=178. Flat, or Sadirons.= Irons are of two kinds--those which must be
heated on a stove, and the self-heating ones. The weight of the iron
governs the amount of heat it will absorb, and this is the amount that
it will give up in ironing. Heat is needed to dry clothes, and as the
cloth can be smoothed best when damp, but will wrinkle again unless
dried while smooth, heat is essential to the ironing process.
The weight of the iron helps in the smoothing process. The heavy irons
do the best grade of work, but are harder to manipulate. The most
satisfactory iron for a woman of average strength to manage weighs six
to eight pounds.
The following points should be remembered in using the iron: (1) Rub
rusty irons with bees'-wax or paraffine and wipe with a cloth. (2) Wash
irons frequently, and rub with sand soap, Dutch cleanser, ashes or salt
to polish them. (3) Rinse in boiling water and wipe dry. Warm on the
stove and rub with bees'-wax, and set away. (4) Before using, wipe with
a cloth. (5) Do not wash electric irons--rub with wax or paraffine.
Wipe off with a clean cloth. (6) It has been found by tests that the
time required in heating the self-heating iron usually equals the time
required for the iron to cool after the heating has been stopped, but
that an iron cools faster on wet, heavy cloth than on thin, dry cloth.
[Illustration: FIG. 95. Parts of electric iron.]
=179. Charcoal Irons.= Charcoal is no longer used for heating irons.
It makes too much dirt. Difficulty is found, also, in keeping charcoal
irons at a constant temperature.
=180. Electric Irons.= An electric iron (Fig. 95) is made up of a heavy
nickel-plated base, a block of iron which holds the heat, and a heating
unit of small wires, or a plate, thru which the current passes, meeting
resistance. Since resistance against the flow of an electric current
produces heat, the iron is heated. It has a handle and shell covering
the heating unit to protect the hand and prevent loss of heat thru the
top.
Getting electric irons too hot injures the heating unit, as electricity
can heat metals so hot that they melt. Excessive heat may disconnect
the circuit by burning the wires in the iron, or it may melt the metal
so as to form a short circuit.
Always follow exactly the directions for connecting and disconnecting
the iron with the current. Some say disconnect at the plug between iron
and cord, or others the plug placed near the socket (Fig. 95-_a_). The
weakest part in irons is likely to be in the attachment plug. When
connecting the plug to the iron, be sure to get it back in place each
time. A plug that does not fit well into place may cause sparking and
develop sufficient heat to burn off the insulation from the cord, if
not the fuses of the system to which the iron is attached.
Never attach an iron to a lighting system without making sure that the
iron is made to be operated on the voltage of the current to which is
is connected. If it is not the same, attaching the iron may either burn
out the fuses of the lighting system, or ruin the iron.
[Illustration: FIG. 95-_a_. Connecting plug for electric attachment.]
Operate the iron at a good temperature for ironing, and take care to
keep it from getting hotter than is required.
=181. Gas Irons.= Gas irons are attached to a tube leading from a gas
pipe. There is a burner inside the iron which is generally a straight
rod with perforations in it for the escape of the mixture of gas and
air. The air mixes with the gas at a point near where the gas pipe
enters the iron. The principle of heating an iron is the same as the
heating of a gas stove (Fig. 96).
The burner in the iron is lighted, and as soon as it has heated the
iron, the ironing can proceed. The only difficulties encountered in
using this kind of an iron are that a quick, jerky stroke may blow out
the flame, and if the work is being done in a drafty place, the iron
may not heat evenly. These difficulties can be overcome, however. The
person using the iron can learn to use a stroke which will be rapid and
still not put out the flame. The ironing board may be protected from
drafts. A gas iron is safe and practical. It is easily controlled by
the valve admitting the gas.
=182. Acetylene Irons.= Acetylene irons are similar to gas irons, the
difference in them being in the construction of the burner.
=183. Alcohol Irons.= Alcohol irons have a tank attached to them
which holds about a half pint of alcohol. This iron is similar to the
gasoline iron shown in Fig. 97. Some alcohol is turned into the iron,
and then the valve is closed. This alcohol is lighted with a match and
used to heat the generator in the iron so that it will be hot enough to
change the alcohol into vapor. As soon as this is done, the alcohol is
again turned on and lighted. The burners in these irons should be kept
free from dirt. Like gas irons, they should be used with a stroke which
will not put out the fire. They cannot be operated in a strong draft.
The heat in them can be regulated by the valve which controls the flow
of alcohol.
[Illustration: FIG. 96. Gas iron.]
[Illustration: FIG. 97. Alcohol iron.]
=184. Gasoline Irons.= There are two kinds of gasoline irons. In one
the tank is a part of the iron (Fig. 97), and in the other the tank is
many feet away, where the gasoline is changed to gas by a cold-process
gasoline gas machine and connected with the iron by a flexible tube.
These latter operate like other gas irons.
Gasoline irons with the tank attached are operated the same as
alcohol irons. The danger in these irons comes in the tanks becoming
overheated. Alcohol is used first to heat the generator because it will
not smoke the iron. The gasoline, when lighted, should burn with a blue
flame.
The tank should be one which has been tested to stand a high gas
pressure, as the gasoline in the tank may become heated and vaporize.
The gas so formed must not escape into the room, where it might be
ignited by a spark. If not allowed to escape, it exerts considerable
pressure inside the tank. If the pressure becomes too great, it will
break the tank, escape and ignite from the flame in the iron. The
opening for filling must always be kept closed when the iron is in use.
QUESTIONS FOR PART VI
1. Explain the construction of various types of washing machines.
What are the advantages of each?
2. What care should a roller wringer receive?
3. How does a centrifugal wringer dry clothes?
4. How does a mangle differ from a wringer?
5. What is the difference in care that should be given to a plain
flat iron and an electric iron?
PART VII
HOUSE-CLEANING EQUIPMENT
CHAPTER XXVI
VACUUM CLEANERS AND CLEANING TOOLS
=185. Principle Upon Which Vacuum Cleaner Works.= The principle of a
vacuum cleaner is that, thru suction, dust and dirt are drawn from
the floor or other surfaces into some container. If the power of the
cleaner is sufficient, it may pick up anything--but cleaners having a
moderate amount of power are somewhat more discriminating. They do,
however, remove the fine, greasy dirt that brooms, brushes and carpet
sweepers fail to get. The coarser dirt and ravelings may be taken up
by a carpet sweeper, with a brush, or picked up by hand. The brush is
combined with the cleaner in many machines (Fig. 98).
[Illustration: FIG. 98. Brush and vacuum cleaner combined.]
=186. Different Kinds of Vacuum Cleaners.= There are cleaners with
bellows, pumps or fans to draw in air and dirt. The ones with bellows
in them work on the principle of a bellows which is reversed so that
when the air is drawn in, it brings the dirt with it. The other kind
works with a fan which draws or sucks air from the floor thru a nozzle
into the machine. In the machine, the dust is filtered out of the air
and collected in a pan.
The machines with fans in them are mostly power machines, as the fan
must revolve very rapidly. The hand machines are mostly of the pump
and bellows types. Some are combined with the carpet sweeper, making
two machines in one. With this device once going over the floor is
sufficient for removing both coarse and fine dirt. The hand machines do
not have as much power of suction as the power machines, but they do
very satisfactory work. They are more effective than a carpet sweeper
in removing dirt, but they do not get as much of it as the stationary
cleaner. Removing the sharp grit from rugs and carpets lengthens the
life of them so that the more grit a cleaner can remove without tearing
the carpet, the more valuable it is.
When the pump type is being used, the piston is drawn up, drawing with
it air and the dirt which is present at the point from which the air
comes. A cloth filters out the dust. The air escapes from the machine
before the piston is lowered to draw in more air and dirt. If this were
not true, the dust would be forced back as the piston was lowered.
=187. Nozzle of Vacuum Cleaner.= The nozzle, or point of entry of air
into the machine, is an important part of a vacuum cleaner. This is
constructed so that it fits the surface from which the dirt is to be
drawn, insuring the drawing up of dust as well as air.
The dirt is drawn from only a few square inches of surface at one time.
The thoroness and rapidity with which the dirt is removed depends upon
the strength of the suction or the power of the machine. Thus, hand
machines may have to be moved over a surface several times if it is
very dirty in order to get all the dirt.
Plain solid nozzles work best on carpets and other surfaces of similar
kind. They are not effective on hard floors, but this is not essential,
as dirt can easily be removed from smooth surfaces with a brush.
=188. Cautions in Using Vacuum Cleaners.= The difficulties to be met
with in vacuum cleaners are leaks. First of all, the machine must be
fitted together perfectly; if not, the dust drawn into the machine
escapes into the air of the room instead of into the collection pan or
chamber.
Machines are made air-tight, but to be cleaned, they must be taken
apart. In putting them together, the housekeeper must take pains to fit
them together perfectly.
Never neglect to empty the dust chamber. Keep the machine properly
oiled. A punctured bellows or a leaky dust strainer will cause dust to
escape after being drawn into the machine. These have to be remedied
with new parts. Some machines leak because of improper manipulation,
such as a too-fast or too-jerky motion in operating them. The
directions for each machine tell how to use it--such directions cannot
be given here because they differ so much.
When the pan has become over-full of dirt, the machine will necessarily
throw out dust as well as air. Letting the machine get over-full of
dust may ruin the machine by making some part leak continuously.
[Illustration: FIG. 99. Electric vacuum cleaner.]
=189. Difference Between Hand and Power Cleaners.= Power machines
differ from hand ones in that they are run by motor power (Figs. 99 and
99-a). They may have larger collecting chambers and may be stationary
in the cellar and connected to the rooms by long pipes (Fig. 100). They
must likewise not be over-full of dust. They must be kept properly
adjusted. As the operation of the mechanism shakes the machine, it may
loosen screws and nuts, so they must be kept tightened. The motor must
also be kept in order. The motors used for vacuum cleaners are the
same as those used on other power devices. They may be small electric
motors, forming a part of the machine, or large motors which operate
several machines.
In any case, they must be given the same care as any other motor of the
same type. (See Chapter XXXVIII.) If they become overheated, they will
not work well. They must be kept lubricated to avoid friction, and they
must be kept properly adjusted. Fig. 100-a shows a number of different
attachments for vacuum cleaners.
[Illustration: FIG. 99-_a_. Electric vacuum cleaner, showing parts.]
=190. Carpet Sweeper.= A carpet sweeper is a combination of brush and
dust pan. The advantage of this device is that the dust is gathered
into the machine as the brush rotates, due to the action of the wheels
on which the machine moves. The dust is collected into pans at each
side of the brush; these are covered so that the dust does not fly into
the air as much as otherwise would be the case (Fig. 101).
[Illustration: FIG. 100. Stationary vacuum cleaner.]
[Illustration: FIG. 100-_a_. Nozzles for vacuum cleaner.]
[Illustration: FIG. 101. Section of carpet sweeper.]
Oil the sweeper regularly about once a month by putting one drop of oil
on the ball bearing on the hub of each wheel. Failure to oil carpet
sweepers causes them to wear out quickly, to squeak, and to run hard.
More oil than is needed only gathers dust and gums the sweeper.
Empty the sweeper (Fig. 102) each time it is used, even during the
sweeping if necessary. Don't fill it to overflowing. Always open the
pans by pressing on the dump levers, not by taking hold of the pans.
Don't let the brush get tangled with hair, ravelings, etc. Take it out
occasionally and clean it (Figs. 103 and 103-_a_). Cut along between
the spiral rows of bristles with a sharp knife or shears, and the
ravelings and hairs can be picked or combed out easily without injuring
the brush (Fig. 104). Never try to pull them off whole. Also remove
any accumulation of dirt or ravelings which catch in the wheels or
bearings. Don't let dirt collect in any part of the machine. Keep it
clean. Good sweepers work best without extreme pressure on the handle.
Never put oil, water or any liquid on the bristles. Don't keep a
sweeper on a warm-air register--it takes the life out of the bristles.
[Illustration: FIG. 102. Emptying sweeper.]
[Illustration: FIG. 103. Releasing brush in sweeper.]
[Illustration: FIG. 103-_a_. Details of construction of carpet sweeper.]
[Illustration: FIG. 104. Cut ravelings from brush.]
[Illustration: FIG. 105. Mop wringer.]
[Illustration: FIG. 106. Another type of mop wringer.]
=191. Mop Wringers.= There are two kinds of mop wringers to attach to
pails. One is made of two flat surfaces which, when pressed together
with the mop between (Fig. 105), squeeze the water out of it, and the
other is made of two wringer rollers which, when brought together by a
lever after the mop is put between them, rotate as the mop is pulled
upward and wring out the water (Fig. 106).
QUESTIONS FOR PART VII
1. How do vacuum cleaners pick up dust?
2. Describe some type of vacuum cleaner.
3. What care should be given a vacuum cleaner?
4. Tell how to clean a carpet sweeper.
PART VIII
DEVICES FOR PREPARATION AND CONSERVATION OF FOOD
CHAPTER XXVII
POTS, PANS, AND OTHER DEVICES
=192. Materials from Which Utensils Are Made.= Since there is
considerable choice in utensils made from different materials, the
housekeeper may like to know something about these materials and about
their care, and the effect of acids and alkalis upon them.
Russia iron is one of the older materials for pots and pans, and it
still holds a place in cookery, for it makes bread, loaf cake and cooky
pans, which give to the food a thin, brown crust, due, undoubtedly, to
the way in which it conducts heat. (See tables on page 158.)
Tinned metal, which is well tempered, also, gives a thin, brown crust
to layer cakes and pies. It makes good bread, loaf cake and cooky pans.
Most of the cheap tin of today is iron-coated with very little tin. It
does good work, but utensils made of it cannot be kept as well polished
and as attractive in appearance as more heavily-tinned ones.
Sheet iron, heavy steel and cast iron make the most popular frying
pans. The heavy iron, holding heat as it does, makes a desirable brown
coating on most foods without the danger of burning experienced with
frying pans of other materials. This is due to specific heat and
conductivity of the metal. Sheet-iron frying pans are useful in cooking
foods which are wanted on short notice. The small-sized ones are most
in use.
=193. Aluminum Alloy.= Satisfactory frying pans are made from aluminum
alloyed with other metal and cast. Real aluminum frying pans warp.
They do not brown the food as well as materials that conduct heat less
rapidly.
=194. Cast-Iron Utensils.= Heavy cast iron finds special favor in the
making of pot roasts, bread sticks and popovers. It browns the roast
and makes a thick crust on bread sticks and popovers.
All iron or tin utensils give better service as they become tempered
with use. They must be kept dry in order to prevent rust. Do not use
them for cooking acid foods.
Granite, cast aluminum and Russia iron are the popular and satisfactory
materials for roasting pans.
=195. Earthenware.= For casseroles and bean pots, earthenware is a
favorite material, the heavy glass gives equally good results. These
materials are fitted for long, slow baking of food. They hold heat and
conduct it to the food in such a way as to produce results which are
difficult to duplicate with utensils of other materials.
=196. Aluminum and Graniteware.= Stew pans are proving satisfactory
when made of aluminum and of high-grade graniteware. An assortment of
pans and double boilers containing utensils of each material gives
the best results, as the granite is most desirable for cooking some
acid and very salty food, while aluminum is light and satisfactory for
preparing other dishes. Never let food stand in aluminum or granite
dishes after being cooked. High-grade graniteware is not as readily
affected by acids as the low, cheap grade. Enameled ware, which is
roughened by a dilute solution of vinegar, is likely to contain
substances injurious to health. Ink will not stain good enameled ware.
Graniteware, like glass and earthenware, makes a heavy crust on the
dishes being baked in them. Graniteware is metal, coated with a sort
of glass. It must be treated like glass. It cracks when dropped. Never
set it on a hot stove when empty or cold, as the heat of the stove will
crack it as it will glass. When hot, do not set it on a cold marble or
a metal table top, as sudden changes in temperature will crack it. With
proper care, granite and enameled ware give good service.
Graniteware is proving desirable for making utensils for use on
electric stoves, the conductivity of the glass coating being so low,
that it conducts the heat to the top of the pan slowly so the food in
it gets to cooking quicker than in utensils made of most of the other
materials.
Aluminum is easily dented and warped by extreme heat. It is attacked by
some strong acids and strong solutions of salt, soda and fruit juices.
Aluminum may be hardened by the addition of six to seven per cent of
copper so that it can be cast into utensils. Great care must be used
not to use cleaning powders which contain strong alkalis for cleaning
aluminum ware. It has light weight, and, when polished, is very
attractive. With proper handling, it gives good service.
=197. Mixing Spoons.= The wooden mixing spoon gives best results, as
it does not mar the utensils, and the handle does not become as hot
as metal. Hard maple or orange wood cut in a plain design makes the
best spoon. Acids do not attack it. Plated silver or solid nickel
spoons come next in usefulness. Softer metals wear off too fast to be
satisfactory.
Nickel is a most desirable material for household utensils, but is very
expensive. It is not in common use in this country.
TABLE SHOWING CONDUCTIVITY AND SPECIFIC HEAT OF METALS
====================+====================+==========================
METAL | CONDUCTIVITY | SPECIFIC HEAT
--------------------+--------------------+--------------------------
Silver | 1.00 | 0.0559
Copper | .74 | .0923
Aluminum | .48 | .2022
Tin | .15 | .0509
Iron | .12 | .1098
Glass | .0017 |
Silicon | | .159 at 10° C.
| | .2029 at 232° C.
Nickel | | .1084
Tungsten | | .035
--------------------+--------------------+--------------------------
CHAPTER XXVIII
PARERS, SEEDERS, GRINDERS, SLICERS, ETC.
=198. Fruit and Vegetable Parers with Knives.= Parers of the type with
a knife have a fork-like device on which the fruit or vegetable is
held while a knife blade, attached to a shaft governed by a spring, is
pressed against the fruit or vegetable so that it cuts off a thin layer
of the surface. Both the fruit and the knife are caused to rotate so
that the whole surface of the sphere-like object will be covered by the
blade of the knife during one or more revolutions of the wheel which
operates them (Fig. 107). The knife is guarded so that it cuts only a
thin layer from the outer surface of the fruit or vegetable. After the
knife has made the complete journey over the surface, a device attached
to the machine pushes the object from the fork so that a new one may be
put in its place. Parers are quite complicated devices, but they have
been perfected so that they are not clumsy, and some can core apples,
stone peaches and slice the fruit.
[Illustration: FIG. 107. Parer.]
Keep this type of machine dry so that it will not rust. Do not put it
into water. Wipe off the blade of the knife and the fork when thru
paring, so that the acid of the fruit will not discolor them and dull
the knife. Keep the other parts dry and oiled. In time the spring
governing the knife becomes weak and the machine will not do good
work. This spring can be replaced on some machines. Parers are usually
made of cheap material so that a new machine costs less than the
repairs.
=199. Parers Which Grate Off Skins.= Another type of parer is a
grater-like device. This is used in larger establishments than the
ordinary home, but is useful where there is much canning of hard fruits
or vegetables to be done at home. It consists of a container, the
inside of which is rough like a grater. The vegetables or apples are
put into the container with water enough to float and separate them,
and the whole is agitated so that the vegetables coming against the
sides have the outer surface removed or grated off. The water acts as
the medium for moving the vegetables and for removing the bits of skin
from the sides of the parer.
[Illustration: FIG. 108. Cherry stoner.]
[Illustration: FIG. 109. Grinder.]
Keep this parer clean by scrubbing the inside with a stiff brush and
rinsing well with water after using. Keep in a dry place.
=200. Seeders and Stoners.= Seeders and stoners are constructed to
punch out the seeds which are contained in cherries, grapes, raisins,
etc.
[Illustration: FIG. 110. Parts of Corona grinder.]
=201. Cherry Stoner.= A simple cherry stoner (Fig. 108) consists of a
small platform with a rod slightly smaller in diameter than a cherry
stone. The cherry is put on an inclined plane so that it rolls over the
hole. The cherry usually stays on the rod until this rod is lifted;
then it passes between two guards which pushes the cherry off on
another incline, where it rolls into a pan (Fig. 108).
There are several makes of stoners, but most of them work on this
principle, whether the rod is lifted by hand or moved by a crank.
[Illustration: FIG. 111. Parts of Universal grinder.]
[Illustration: FIG. 112. Vegetable slicer.]
=202. Grinders.= Grinders are of two principal types--the roller and
the burr. Coffee and other hand mills are of the burr type (Figs. 109
and 110). The food passing between these rough surfaces is ground to a
fine powder as one is turned on the other.
=203. Choppers or Meat Grinders.= Choppers or meat grinders, as they
are sometimes called, consist of a spiral channel, thru which the food
is pushed along. Knives are placed in the sides of some machines to
chop the food as it passes, while in others the knives are only at the
outlet. Keep the fingers out of the hopper when the chopper is being
operated. Keep the machine clean and dry when not in use (Fig. 111).
[Illustration: FIG. 113. Universal vegetable slicer.]
=204. Choppers.= Choppers have been made which really chop the food
without crushing it, but these machines are so clumsy and noisy, that
they have not come into common household use. They consist of chopping
knives which are raised and lowered by levers and a crank.
=205. Slicers.= Slicers vary in design. The following illustrations
(Figs. 112 and 113) show two different types. Care must be taken to
guard the fingers when using slicers. Wash the knives and keep them dry
when not in use. A soiled knife gets dull faster than a clean, dry one.
=206. Lard and Fruit Presses; Sausage Stuffers.= Presses and stuffers
are of two types--the one which depends on the weight exerted on a long
lever, and the other which depends on a screw to press the substances.
The screw forces a flat board or surface down upon the food as it is
turned. More pressure for the size of the device can be secured with
the screw than is practical with a weight on the long arm of a lever
(Fig. 114). The stuffer is like a press, except that the food is forced
out one hole.
[Illustration: FIG. 114. Lard and fruit press.]
CHAPTER XXIX
MIXERS, BEATERS AND CHURNS; COFFEE POTS
=207. Use of Mixers, Beaters and Churns.= Mixers, beaters and churns
are all devices for agitating or stirring food.
[Illustration: FIG. 115. Parts of bread mixer.]
The simpler ones of these devices depend upon the motion of the hand
(Fig. 115), while others have their velocity increased by means of cog
wheels.
The turning of the large wheel turns the small wheel as many times as
number of cogs on the small wheel is contained in the number on the
large wheel (see Fig. 116). To get even more speed or to apply the
power at a different angle, a series of wheels are sometimes used. A
few mixers, like the bread mixer, are simply machines which take the
hands out of the food, thus tending to a higher degree of sanitation,
and a change in the motion which may not be so tiring as kneading. They
do not increase the speed of mixing.
Bread made in a mixer has a somewhat different texture than bread
kneaded by hand, but this does not change its nutritive value.
=208. Care of These Devices.= The principal care needed by these
devices is that they be kept clean and the cog wheels dry. Very little
oil should be used, as it would tend to get it into the food. Sometimes
the rivet holding a wheel needs to be tightened, as, for example, when
one becomes so loose that the wheel slips cogs. If it is too tight, the
wheel may bind and work hard.
[Illustration: FIG. 116. View showing internal arrangement of cake
mixer.]
=209. Freezers.= The freezer is a mixer in a can which is in turn set
in a freezing mixture of ice and salt.
Freezing can be done without stirring the cream. This makes a cream
filled with crystals, while if stirred, it will be smooth and velvety
because it freezes more evenly. The rapidity of freezing and the
proportion of the ice and salt affect the fineness of the grain of the
frozen dish.
A freezer is designed not only to stir the food, but to scrape it from
the sides of the can. That which freezes first must be stirred into
the middle of the can; otherwise, it would form a hard frozen layer of
cream on the sides, leaving the middle unfrozen, and interfere with the
turning of the paddle or beater.
In the bottom of the outside bucket, holding the ice and salt, is a
socket into which the pivot on the bottom of the can fits. The can
turns on this pivot in the direction opposite to which the paddle is
turning. Some freezers are made so that the can stays stationary. The
function of the pivot is then to hold the can in the center of the pail
so that the paddle will be in the proper position to turn easily.
=210. Care of Freezers.= The pail of wood should not be stored in a
very dry place when not in use. The can and paddle must be kept clean
and dry so that they will not rust. The bearings and wheels which turn
the paddle and can must be kept dry and oiled.
There is a hole in the upper part of the tub or pail in which the can
sets, and this should be kept open as it is placed slightly below the
level of the top of the can so as to drain off any water from the
melting ice which otherwise might get into the can and make the food
salty.
Some freezers have another hole at the bottom of the tub. This should
be kept closed while food is being frozen. It is useful to drain off
the water from the tub when the freezer is to be repacked or emptied.
It should not be opened at any other time.
=211. Churns.= Churning can be done with almost any device which
agitates the cream, but the churns which are simplest are most easily
cleaned and least wasteful of butter. They are barrels or other
containers which revolve or swing backward and forward.
Keep churns clean and well aired so they will not give up odors and
flavors to the butter. After a churn has been used, rinse it with cold
water and then wash it in hot water, to which washing soda has been
added. Lastly, rinse with scalding water. Leave open to air when not in
use, but protect from dust and dirt.
=212. Drip Coffee Pots.= Drip coffee is made in a funnel or a
cup-shaped device which is suspended in a coffee pot (Fig. 117). This
is made either of cloth or perforated metal. The coffee is pulverized
and packed into the funnel. Cold water is poured on top of the coffee
and slowly filters thru it, extracting flavoring substances. The water
is heated after it has filtered thru the coffee.
[Illustration: FIG. 117. Drip funnel in percolator.]
=213. Percolator Coffee Pots.= A coffee percolator is a device put in a
coffee pot to hold the ground coffee above the water and pump some of
the water to the top of the pot so that it can seep back down thru the
ground coffee (Fig. 118).
A perforated cup with a perforated cover holds the coffee. Thru the
center of this cup passes a small tube to the top of the pot. At the
bottom of the tube is a flat plate with turned-down edges or other
device which supports the pipe and rests on the bottom of the pot. A
small amount of water gets under this and into the pipe. The heat in
the stove turns the water next the bottom to steam, and this steam,
in escaping, forces the water in the pipe to the top of the pot, and
raises the device slightly so that more water flows under it and into
the pipe, and again steam is formed and more water forced to the top of
the pot. (See Sec. 161, Suction Washers.) After being forced out of the
top of the pipe, the water falls in a spray on the cover of the cup and
seeps down thru the coffee back into the main part of the coffee pot.
The pumping devices in percolators may differ somewhat in design, but
the working principle is the same--that steam is lighter than water and
can be generated in amounts which will force water up thru the central
tube.
[Illustration: FIG. 118. Percolator.]
Coffee grounds must not be allowed to get into the small tube, for they
will hinder the flow of the water. The holes in the cup and cover must
be kept open. There is less waste in using finely-ground coffee than
the coarsely-ground in percolators. A small tube brush is needed for
cleaning percolators. The coffee must not be ground so fine that it
will sift thru the perforations in the cup.
CHAPTER XXX
DISH-WASHERS, CANNERS AND DRYERS
The dish-washers (Fig. 119) have found a place in hotels and large
establishments, they are still in the experimental stage for general
household use.
Small machines on the market, patterned after the hotel type, are
giving good results for home use. When using these machines, place
the dishes in them in the manner directed and use as much water as is
called for.
[Illustration: FIG. 119. Dish-washer.]
Some dish washers work on the plan of revolving the dishes in the
water, some in forcing the water over the dishes, and others by
agitation of both dishes and water.
[Illustration: FIG. 119-_a_. Small dish-washer for household use.]
Keep the pan washed clean. Keep all bearings properly oiled. Have the
machine dry when not in use. There is least breakage in the washers
which hold the dishes stationary (Figs. 119,-_a_,-_b_ and-_c_).
One type of dish-washer has no motor; the force of the running water
washes the dishes. This can only be used where the water supply is
abundant and under considerable pressure. The washers equipped with
paddles for throwing the water over the dishes use about a dishpanful
of water for washing the dishes, and as much more for scalding and
rinsing them. When well scalded in the dish-washer, the dishes will dry
if the cover to the washer is left open.
[Illustration: FIG. 119-_b_. Walker dish-washer.]
=214. Dish Dryer.= There is a number of dish dryers on the market which
hold the dishes separate from each other. Into these dryers, boiling
hot water is poured, over the dishes. There is provision for the water
being drained away immediately, and the heat it imparts to the dishes
dries them. (Fig. 119-_c_.)
=215. Cleaning Silver.= Silver can be cleaned in an aluminum pan
filled with water and soda. There are silver cleaners which are merely
aluminum pans with which come directions for proportioning the soda
and the water. A mixture of salt and baking soda is sometimes used,
combined with a piece of zinc in an aluminum pan. The salt, soda, zinc
and silver are put into the aluminum pan and set on the stove. The
action of the salt and soda on the metals produces an electrolytic
action which brightens the silver.
Do not use this method of cleaning on gray or colored silver.
[Illustration: FIG. 119-_c_. Tray for holding dishes.]
[Illustration: FIG. 120. Water bath canner.]
=216. Canners.= Canners are devices for sterilizing fruit and other
food which is being canned. The wash-boiler type consists of a boiler
or kettle with a rack in the bottom to raise the jars an inch or so
from its bottom to prevent the cracking of the jars. It has a cover
to keep the heat uniform. The water in the canner must entirely cover
the jar. This is usually called a water bath, as the jars must be
completely submerged in the water (Figs. 120 and 120-_a_).
[Illustration: FIG. 120-_a_. Small canning outfit.]
=217. Water Seal.= Water-seal canners are like the water-bath canners,
except that the cover has a flange on it, the depth of the boiler, and
about two inches from the sides of it. This makes a jacket of water
between the flange and sides of the canner. This causes the temperature
inside to rise about two degrees above the ordinary temperature of
boiling water. Food can be sterilized in a little shorter time in this
canner than in the ordinary water bath. It is as important that the
water entirely cover the jar in this canner as in the water bath.
=218. Pressure Canners.= Pressure canners are made very strong and have
covers which fit tight, making it possible to raise the temperature in
them considerably above the boiling temperature of water, so the food
may be sterilized in a very short time.
[Illustration: FIG. 121. Pressure canner showing pet cock.]
The pressure canner has either a rack or a perforated pail on the
inside to raise the jars from the bottom as in other canners. It is
also fitted with a steam gage which registers the pounds of pressure
in the canner. Five to fifteen pounds pressure is used for canning.
The amount of pressure needed and the time of sterilizing depends on
the organism present. A higher pressure is an indication of a higher
temperature in the canner. After the jars are filled and put in the
canner, the cover is fastened down tight by thumb-screws. There is a
pet cock which is kept open when the canner is first heating, to let
the air be forced out by the first steam which forms. As soon as the
steam begins to escape, the pet cock is closed and the temperature
inside of the canner begins to rise above the temperature of boiling
water (Fig. 121).
On the canner is a safety valve which is set so that the instant a
certain number of pounds of pressure is reached, it is lifted up by the
steam. Some of the steam then escapes, thus preventing the pressure in
the canner becoming so great that there is danger of its exploding.
=219. Use of the Canner.= Water is put into the canner to reach to the
bottom of the rack. The jars are filled according to canning directions
and are set in the canner. When the jars are in, the cover is adjusted
to the canner and screwed on tight so that no steam will escape between
the cover and the canner. The pet cock is left open until steam begins
to escape thru it as the canner is heating on the stove. When steam
begins to come, the pet cock should be closed, and the steam-gage hand
then begins to turn, indicating that the pressure in the canner is
rising.
When the steam-gage reaches the point desired, the safety valve is
adjusted so that the steam will escape should the pressure continue to
rise. Until the operator knows where to set the weight to the safety
valve, leave it well out to the end of the rod until the pressure in
the canner has reached the desired point. Then move the weight to the
point on the arm of the valve which will just keep in the steam.
[Illustration: FIG. 122. Device for sealing tin can.]
Be sure the cover is properly adjusted. Be sure to exhaust the air
from the canner before closing the pet cock. Keep the fire so that the
desired pressure will be maintained without the escape of steam from
the safety valve. When steam escapes from the canner thru the pet cock
at a rapid rate, it may cause liquid to flow out of the jars.
Be certain to let the canner cool until the indicator on the steam-gage
has reached zero before opening the canner. When the indicator points
to zero, open the pet cock. If a heavy stream of steam starts to escape
from it, close it again and wait a few minutes longer. Test again by
opening the pet cock; if a very little stream of steam escapes, leave
the pet cock open and wait until steam has stopped escaping from it.
Now loosen the screws holding the cover in place. Partially loosen each
screw. When this is done, fully loosen all and lift off the cover.
These precautions are taken to prevent the operator from being burned
by steam or getting hurt by the cover being lifted by the steam. It
also prevents the breaking of glass jars due to sudden pressure changes.
Never let the canner cool so long before the pet cock is opened that
air will rush into it, due to the vacuum which is sure to form when the
steam is cooled if the pet cock is not opened. Such a condition may
break the jars.
[Illustration: FIG. 123. Dryer.]
Tin cans are sealed with a device (Fig. 122) which folds the edge of
the cover over the top of the can so tightly it will not leak.
=220. Dryers.= Dryers are devices to hold the food being dried in a
thin layer so that the air can be circulated thru it freely. Sometimes
they are devised to direct currents of air thru the drying material. If
the air is heated, the drying is hastened (Fig. 123).
A sieve on which food is spread hung above the stove is a simple drying
device and one of the most practical for home use. The heat currents
rising from the stove pass thru this and dry the food.
Many dryers are constructed on this same principle, having a heating
unit below and trays of food above. These trays have to be shifted from
time to time, as the moisture from the lower ones rises with the heat
to the upper trays, thus retarding their drying. The top trays, if too
numerous, are useless on this account. Two or three seem to be all
that can be used with advantage at one time in home dryers, the some
machines are made with many more.
Another type of dryer has a fan device in it which forces the air thru
at a faster rate than would be accomplished by heat alone. Such air
should pass thru a strainer. Ordinary air, even when drawn from a clean
room, carries much dust with it, and if the dust is not strained out
previously, it is strained out by the food. This injures the quality of
the product. Large commercial dryers provide such a strainer.
=221. Care of Dryers.= Dryers should be kept clean. They should not be
heated enough to cook the food. Set them in a dry, airy place.
CHAPTER XXXI
SEPARATORS AND EMULSIFIERS
=222. Cream Separators.= A cream separator is a device for separating
cream from milk. Separation can be done best while the milk is still
warm (Fig. 124).
Separators should be set in a bright, dry, airy place free from dust
and dirt. Near the separator should be a convenient place for airing
and sunning the tin parts which come in contact with the milk.
The base for the separator should be solid enough so that it will not
shake while the machine is being operated. If set on a wooden floor,
see that the boards are nailed in place, and if the floor is thin,
put heavy strips to cover several boards across it. Fasten the strips
firmly to the floor and set the separator on them. When the machine is
set up, be sure that it is set level.
=223. Different Types of Separators.= There are two types of
separators--one which contains discs of metal (Fig. 125), and the other
which depends upon a cylinder in which the milk rotates (Fig. 124)
for the separation of the cream from the skim milk. Fig. 126 shows a
sectional view of the DeLaval separator.
Cream is lighter than milk, and when milk and cream are whirled
rapidly, the milk, being heavier, flies to the outside of the
container, and the cream stays near the center. Two pails whirled
rapidly made the first separator ever used, but that was clumsy and
impractical.
Modern separators consist of a pan which holds the milk, and which lets
it flow in a stream into the portion of the machine which is being
whirled rapidly by the turning of the wheel at the side. There is a
place in the rotating part which lets the cream flow from the center
into one container, and the milk flow from the outside to another.
[Illustration: FIG. 124. Cream separator.]
The parts of the machine must be fitted together properly; otherwise,
it will fail to do good work.
Always turn the wheel at the speed indicated for the machine with
discs. If there is no speed indicated, turn as fast as needed for good
separation of milk and cream. Take care not to drop and dent any of the
tin parts. Adjust for the density desired for the cream.
[Illustration: FIG. 125. Discs in DeLaval cream separator.]
=224. Washing the Machine.= As soon as milk has been skimmed with the
separator, pour some water into the bowl and run it thru the separator
the same as the milk.
Wash the bowl and other parts in hot water in which washing soda has
been dissolved. Rinse in clear water, and then scald with boiling
water. Once a week give it a more thoro washing, scrubbing all parts
with a brush. Sun the parts when not in use.
=225. Oiling.= The mechanical parts which whirl the separator should
be kept oiled. In oiling, follow the directions which come with the
machine. Use a good grade of oil.
=226. Whey Separator.= A whey separator is a machine very much similar
to a milk and cream separator. It is used in homes where much cheese
is manufactured. It should be given the same care as other separators.
An homogenizer is a device used to give whole milk a consistency which
is much like cream.
[Illustration: FIG. 126. Sectional view of separator.]
=227. Emulsifier.= The emulsifier is a device for combining dried whole
milk with water, or dried skim milk with water and butter fat so that
they make a reconstructed milk of almost the same composition as new
milk. An emulsifier is of interest to the woman who lives in the city.
Emulsifiers are used in large institutions. Some have been installed
in settlement houses and public schools. They might be owned by
communities where people might use a large amount of dried milk. In the
emulsifier, the milk, water and sweet butter are warmed. After this,
they pass thru a device looking much like a separator, but which mixes
the ingredients together instead of separating them. From the mixer the
milk passes over a cooling device, and is ready for use. This machine
should be kept clean, and the parts which come in contact with the milk
scalded out with hot water after being rinsed with cold water.
QUESTIONS FOR PART VIII
1. What metals would you select for a pan to use when a thin crust is
wanted? What materials produce thick crusts?
2. For what purposes would you choose aluminum? Granite? Cast
iron? Glass? Earthenware? On what basis would you make a choice of
utensils? Why wouldn't glass make a good ice-cream freezer?
3. What are the essentials of good parers, slicers and corers?
4. What kind of dish washers are proving the most helpful?
5. Describe a silver-cleaning device. Does the use of such devices
harm the silverware?
6. What is a water-bath canner? How would you make one?
7. What may cause glass jars in pressure cookers to break?
8. How may the breakage be prevented?
9. Explain the ways in which cream may be separated from milk.
10. How do separators help?
PART IX
SUNDRY DEVICES
CHAPTER XXXII
DUMBWAITERS AND OTHER HOUSE FURNISHINGS
=228. Dumbwaiters and Window Adjustments.= Dumbwaiters and elevators
are used in homes where the kitchen is on a different floor from the
dining-room.
[Illustration: FIG. 127. Spring pulley for windows.]
The simplest ones are a set of shelves counterbalanced by weights. When
the elevator is raised, the weights drop down, and when it is lowered,
the weights rise.
Window weights hung over a pulley in the top of the window sash work
on the same principle as dumbwaiters--the weights help in raising the
window. The only care needed is to replace the rope when worn.
Another window pulley is made of metal like that in a clock spring
(Fig. 127). The spring is drawn out when the window is lowered, and the
weight of the window is just enough to hold it, so very little force is
needed to raise the window, as the spring is pulling on it, too.
=229. Check Valves.= Check valves are made to prevent doors from
slamming. They are used in offices and public buildings, and,
occasionally, in homes (Fig. 128). One kind contains glycerine and
castor oil, which move from one compartment to another as the door is
opened and slowly flow back as a spring pulls the door shut.
[Illustration: FIG. 128. Check valve.]
The other kind is operated by compressed air and a spring. The air
causes the steady action of the door stop. Another type of pneumatic
hinge is attached to a door which is hung so that it would naturally
swing shut. When the door is opened, the air is exhausted from part
of the hinge. After it has been opened, the slow equalization of the
air inside the door stop and outside allows the door to close slowly
without slamming.
[Illustration: FIG. 129. Door holder.]