As the fall of rain is always measured in inches gauges are made to

indicate the equivalent of a cubic inch of rain on the surface of the

earth. The simplest form of rain-gauge is a square or circular box or

jar with a perfectly flat bottom and perpendicular sides (see Fig. 207).

If the depth of water in such a gauge be measured after a fall of rain,

one can ascertain in inches, or parts of an inch, the amount of rain

that has fallen on the surface of the earth. Care must be taken to have

the edge of the gauge thin and free from dents, the sides perpendicular

and the bottom of the jar perfectly flat, for though in one measurement

these irregularities may not make much difference, they would lead to a

very decided error in a large number of measurements. Evaporation is also

liable in such a gauge to give rise to errors, and extraneous matters

are easily introduced. The better rain-gauges are constructed to avoid

these contingencies, as far as possible and to depend only on the area

of entry for the accuracy of the measurements. This area may be a square,

but is usually circular for convenience. The circle must be accurate, and

its area is then easily calculated, so that one can estimate the amount

of rainfall, however large the receiving vessel may be. The edge of the

circle, which may be made of copper, more durable than iron, must be

sharp, with an overlapping rim to prevent raindrops from being whirled

out of the receiver, and connected by a shoulder to a funnel, which

directs the water into the receiver. This may be a glass bottle fitted

with a cork to hold the funnel firmly, and prevent leakage between the

outside of the funnel and the neck of the bottle (see Fig. 208). A more

convenient receiver, and one less likely to be broken, is a round tin case

of convenient size, with a top fitting accurately under the overlapping

edge of the funnel-shaped cover. In this large receiver may be placed

a small tin mug, with a lip just under the funnel, for conveniently

measuring small quantities of rain, and preventing waste by evaporation.

Any overflow from the mug will be caught in the large receiver (see Fig.

209). The circle of entry may, of course, be of any size; but one whose

diameter is between 4 or 8 inches will be most convenient. Make the circle

determine its area by careful measurement, using the following formula:

D^2 × .7854 = area, each square inch will give cubic inches for area. Take

this amount of water and pour it into a glass, marked at the top of the

water, and then divide the intervening space between this mark and the

bottom into 100 equal parts. This graduated glass will give the rainfall

in inches and 100ths of an inch. As an inch glass is somewhat cumbersome,

a half-inch glass is usually sent out with a rain-gauge. It may, however,

be sometimes convenient to use an ordinary ounce measure, as graduated

glass measures, when broken, are not always easily replaced; so that it

may be necessary to find the corresponding relation between the cubic

inches of receiving area and ounces and drachms. To do this, we will

suppose the diameter of the circular top of gauge to be 4.7 inch; this

squared = 22.09, multiplied by .7854 = 17.349486, divided by 1.733

(an ounce avoir. = 1.733 c. in.) = 10.011 oz. avoir.

Now if the rainfall is collected daily at a certain time in an ounce

measure, the amount may easily be recorded in inches by reference to the

accompanying table:

inch inch

10 oz. = 1.0000 1 oz. = .1000

9 " = .9000 7 dr. = .0875

8 " = .8000 6 " = .0750

7 " = .7000 5 " = .0625

6 " = .6000 4 " = .0500

5 " = .5000 3 " = .0375

4 " = .4000 2 " = .0250

3 " = .3000 1 " = .0125

2 " = .2000

A similar calculation can be made and table prepared for any larger circle

of entry by the same method.

The amount of rainfall in any country is a matter of great importance to

that country, and, like the rise of the Nile in Egypt, it indicates the

coming state of the crops. If we have too small a rainfall, drought and

withered crops follow, and if we get too great a fall of rain, drowned

out crops, and disastrous floods occur, so you see how necessary it is

that those people who are elected to look after the welfare of a nation,

should keep posted on matters of rainfall in all its phases. In India,

China and some other parts of the world the question of rainfall is one

of life and death to the people, and most of the great famines of the past

have been due to the small rainfall. Hundreds of thousands of people used

to perish by famine and disease year after year. Much of this danger from

shortage of rain has happily been avoided in India by the efforts of the

British government, which has inaugurated and carried out great schemes of

irrigation and artificial waterways to prevent the recurrence of famine

from drought. Our own government also is expending large sums of money

on irrigation plans now being executed in Arizona, Texas, Colorado and

other states, which will render immense territories fit for cultivation,

which would otherwise have remained barren and of no use. The matter

of rainfall is of the highest importance to a nation and to the men and

beasts inhabiting it.

"Will it rain to-day?" is a question frequently asked, as regards the

weather, showing how important the subject is, and while I am talking on

it, it may not be amiss to make a few remarks regarding the formation

and distribution of rain, as formulated by learned meteorologists. We

are told that the two great causes of rain are the sun and the ocean--the

latter, of course, includes the great lakes and rivers--and since these

two factors may be taken as constant, it follows that the rainfall over

the earth as a whole will always be constant, while the local variations

will be due to local conditions. The rain which falls on this continent

is drawn up by the sun from the various sources, but the conditions which

cause its precipitation may be said to be local. To your imagination

may be left the tracing of the journey of the rain drops back to the

ocean again. The starting points in considering the causes of rain

are, therefore, heat and moisture. From the surface of land and water

moisture is continually evaporating into the atmosphere, and the higher

the temperature of the air the more watery particles it can hold. If any

reduction in the temperature of this saturated air should take place, the

vapour becomes visible as fog, mist, or cloud, and it is from this vapour

that the rain drops are formed. Recent research says that these watery

particles require minute dust atoms as nuclei before they can form, and it

has been estimated, by experiment, that there are one thousand millions of

them in a cubic foot of saturated air, though their total weight amounts

to only 3 grains. Accepting these figures, the mathematically inclined

may be told that it would require a cloud three miles thick to produce one

inch of rainfall. But before these watery particles can fall to the earth

as rain, they must first form into rain drops, and the question arises,

how are rain drops formed?

These watery particles pass into the air by evaporation, and there are

several ways by which the reduction in temperature necessary to render

them visible can be brought about. It may take place through contact with

a colder body of air, by expansion, or by a reduction of pressure owing

to a rise in altitude. Clouds are said to be formed by this last method,

for a volume of hot air rises higher and higher until it presently reaches

a point when its contained vapour condenses, and becomes visible as a

cloud. Meteorologists repeat one of these processes in the laboratory,

by releasing from pressure damp air placed in a convenient glass globe,

and are able to see something of the methods of cloud formation. It has

been customary to speak of a cloud as being composed of watery particles

floating motionless in the upper air; but although it may appear unchanged

in form, it is all movement. So soon as ever a cloud is formed, its

particles of moisture commence to fall slowly, the rate of fall being in

proportion to the diameter of the particles, and this is due to the slight

resistance the air makes to such very small atoms. In passing, it may be

said that one observer estimates the diameter of these particles as from

.00033 inch to .00025 inch. The component parts of a cloud are always in

motion and recognizing this fact it becomes possible to take the first

step in considering the formation of a raindrop.

An easy way out of the difficulty of explaining the formation of a

raindrop, is to say that, since clouds are so often of two opposite

electric potentials, there is always a continuous bombardment of watery

particles taking place, and some of these must unite and fall as rain.

The meteorologist is always tempted to call in electricity as an agency

whenever he is anxious to discover a cause for some particular phenomenon.

This often explains one mystery by another. The production of rain, snow,

and hail has for many years been explained by vaguely ascribing them to

the action of electricity, without any information being forthcoming as

to the precise way in which this action takes place. Meteorologists are at

present attempting to find a more satisfactory explanation. Another theory

is that the particles of moisture in a cloud, like all other objects,

radiate heat, and, growing cold, condense moisture upon their surfaces,

thereby increasing in weight until they assume the proportions of a drop.

This seemed a reasonable explanation of the formation of a rain drop until

modern research decided that whenever moisture is condensed, latent heat

is set free, so that all moisture deposited on a watery particle only

serves to raise its temperature, and cause evaporation of the moisture

thus acquired. The particles of water could not by this means grow to the

full estate of a rain drop, and the theory is being gradually abandoned.

A rain drop is, according to modern meteorologists, explained in a very

simple way. It has been seen how the hot, damp air is formed into a

cloud, and also how the minute particles of water at once commence to fall

slightly earthwards. Now these little particles as they pass into a warm

layer of air would soon be evaporated, and would never reach the earth at

all. Their downward journey, however, is often through a cloud many miles

thick, and the most modern and simple theory is that in this journey they

overtake some of their fellows, and the joined particles increase their

rate of travel, overtake more and more particles until they presently

become heavy enough to take the final plunge to earth. Were it possible

to be just beneath a cloud, an observer would see rain drops coming from

it of all sizes. The same process goes on in drops, which trickle down a

window pane, or in the effervescing globules in a bottle of seltzer water.

In the latter instance, the process is reversed, for the globules are seen

overtaking one another in an upward direction. There are many points in

favour of this theory of the formation of rain drops, and at least it gets

rid of those elaborate complications, electricity and condensation. With

respect to the formation of rain by the impinging of clouds upon the tops

of cold mountains in the northwest, one authority argues that moisture is

in these circumstances not condensed solely because of the contact with

the cold hills; that rain there is due to a mechanical cause, the watery

particles being squeezed together by the grinding effect of the clouds on

the sides of the mountains in such a way that they coalesce, and fall as

drops.

A rain drop's roundness is due to the action of capillarity. Just as a

circle made by dropping a stone into water owes its shape to the fact

that the force is able to act equally in all directions, so a rain

drop is spherical, owing to similar untrammelled action on the part of

capillarity. These are some of the explanations of the formation of a rain

drop, but meteorologists still have the subject under consideration.

The periods of rainfall are divided broadly into times of drought and

times of flood, and it is in these matters that meteorology is seen in its

practical aspect. Some people ask, "Where does all the rain come from?"

Others are surprised that rainfall totals up to such large quantities.

A fall of rain to a depth of one inch over a very limited area, represents

millions of gallons, but in spite of this vast quantity of falling water,

many times multiplied if the annual rainfall be taken into account, there

still are water famines. The question has often been debated whether man

can modify climate or effectively tamper with the processes which produce

rain. Rain making has not, so far, been a success, though the firing off

of heavy guns has been tried, along with the legitimate avocations of the

meteorologist. The afforesting or deforesting of a district has, however,

a marked effect upon rainfall. Three notable instances are Ascension

Island, Malta, and the neighbourhood of the Suez Canal, where the planting

of trees seems to have had the result of increasing the rainfall. The

effect of trees is felt more in the storage of rain water, while leaves

and roots serve to retain moisture that would otherwise quickly drain

away. A hill may be converted into a sponge by the judicious planting of

trees. The question of the storage of rain water becomes more pressing

each year, and the longer the settlement is put off, the more difficult

will decision become. Engineers called upon to prevent floods and to

conserve rain water reply, "Save our forests, cover the land with trees."

The fact that such problems arise, serve to show how great is the

amount of water formed by the continual falling of the tiny raindrops.

As long as this beneficent downpouring is allowed to drain away unused

or uncontrolled, so long will droughts annoy and water famines bring

distress.

In recording weather conditions, symbols are sometimes used in order to

shorten reports and, while not universal, most nations adopt these: The

symbol for rain is o, a small circle filled in; for lightning [o]; for

thunder T, while the two latter combined make T[o], the symbol for a

thunder-storm. Nearly every weather component has a distinctive symbol,

and since a great part of the meteorologist's work consists in going over

records of observations to search for the number of times the different

phenomena occur during each week or month, the task is much simplified

when observers employ the symbols, as it is easier to pick out a symbol

from a printed or written page than it is to recognize a word. These

symbols, moreover, have been agreed upon as a sort of international

notation, and make it easier for the meteorologists of different countries

to understand the records of foreign meteorological services.

Everybody does not know the Russian word for snow, or the Dutch for

hail, or the Bosnian for rain, but all who run, may read when "snow" is

universally written, and hail represented by a wedge-shaped figure with

lines drawn across. Time and space being limited, nearly all published

records of weather merely set forth the number of days throughout the

year on which the different phenomena occurred, and should snow, hail or

thunder happen two or three times in one day, it would still be counted

only as one day. The yearly totals, therefore, show the number of days on

which these conditions have been observed. It is now an almost universal

custom to count .01 inches or more during the twenty-four hours as a

day of rain. Accordingly, where observers read their rain-gauge to three

places of decimals, that on which less than .005 inch fell would not be

counted as a rainy day. Smaller amounts would, however, be included in

the total. Dew may sometimes fall to the amount of .01 in. or more; and

that is counted as a rainy day, the rule being to consider the amount of

precipitation, irrespective of the manner in which it has fallen. If you

wish to make these observations comparable with published records you

would do well to conform to these rules.

HAIL

Hail, the next weather component to be considered, presents many

difficulties when the attempt is made to explain its origin and formation.

Those who have anything to do with scientific matters are well acquainted

with the hypothesis, which explains a given fact, and in considering

the subject of hail, the meteorologist hears of many hypotheses which

are put forward as complete explanations of this phenomenon. Caution

is, therefore, to be exercised and every reported statement severely

questioned. Remembering the aphorism: "The man or boy who never makes

a mistake will never make anything," meteorologists have attacked the

question of hail formation, and, although many mistakes have probably

been made, the subject has lost a good deal of its mystery. For many

years, it was customary to be content with a recognition of the fact

that hail and lightning very often occur together, and the conclusion was

drawn that the one was in some way responsible for the other. Sufficient

corroboration of this hypothesis was to some meteorologists, found in

the fact that thunder and lightning are said to be almost unknown in the

Arctic regions, and this supposed companion, hail, almost unknown. Roughly

speaking, the assumption was that lightning, as it flashed through a cloud

laden with watery particles, caused hail to form. Such an explanation

only tended to make the subject more mysterious, and the question, How is

hail formed? practically remained unanswered. Many simpler explanations

of hail have been propounded as the result of modern research, and, like

rain and lightning, it has been demonstrated that hail owes its origin

to the movement of the minute watery particles found everywhere in the

atmosphere.

The clouds from which hail fall are ordinarily of great height above

the earth, 40,000 feet or even higher. These are the well-known cirrus.

The first condition necessary to the formation of hail is a powerful

ascending current of hot, moist air, which may condense its moisture in

the shape of the large woolly cloud, known as cumulus. Such a cloud may

be 100 cubic miles in volume, and as long as it retains its shape nothing

is likely to fall from it to the earth beneath. Before the formation of

a thunder-shower, cirriform fibres in some instances break away from the

upper portion of this cloud, the electrical tension is lowered, and rain

falls. The coalescing of the particles of moisture has a great deal to

do with the changes which take place in a cloud. All these changes take

place in the higher clouds in a marked degree, and the varying strata

through which the watery particles pass in ascending to and descending

from this great height bring about the violent change essential to the

formation of hail. The necessary conditions for hail are, therefore, a

powerful, hot, ascending current of air and great variation in the strata

of the atmosphere as regards moisture and temperature. Mountains assist

in forcing currents of air upwards, and one mass of air impinging on

another is also thrown upwards, so that condensation of moisture rapidly

takes place. A hail cloud may be described as a tower of hot air, from

the top of which, vapor is ejected into a frosty region. Hot plains are

accordingly the most favourable spots for the formation of hail, and in

mountainous districts, more hail falls at a distance from the mountains

than among them. Snow is observed in all latitudes and at all heights,

but hail is confined to middle latitudes, and is rare in high latitudes.

The places most affected by hail are those in which, the temperature and

humidity of the air are high, while above, at a great height, there is a

cold area below the temperature of freezing point; but, as in the case of

the rain drop, before anything can be definitely stated, it must be shown

how the particles of moisture coalesce to form hail.

SNOW

Snow is frozen water which falls instead of rain when the temperature

is below the freezing point. The ultimate constituents of snow are

tiny, six-pointed crystals of ice. They assume in combination a thousand

different figures (Fig. 210), all exceedingly beautiful. Professor Tyndall

has shown, further, that the ultimate particles of ice are also these

six-pointed stars. The white colour of snow is caused by the commingling

of rays of all the prismatic colours from the minute snow crystals.

Separately the crystals exhibit different colours.

[Illustration: Fig. 210. Snow crystals]

Snow is usually from ten to twelve times as light as water, bulk for bulk;

so that where the snow falls pretty evenly, the corresponding rainfall is

readily determined by merely measuring the depth of snow and taking one

tenth of the result. The more accurate plan, however, is to thrust the

open end of a cylindrical vessel into the snow, invert the cylinder, and

then melt the snow in it.

Snow plays an important part in the economy of nature. In the first place,

the mere transformation of the water particles into ice is a process

during which a large amount of heat is given out; so that we may regard

the formation of snow renders the air currents warmer than they would

otherwise be. Fallen snow serves to protect the ground, for, owing to its

loose texture, it is a bad conductor of heat; so that, while checking

the radiation of heat from the earth into space, it does not draw off

the earth's heat by conduction. The ground is thus often 23 degrees to

30 degrees warmer than the surface of the snow above, and sometimes the

difference of temperature has been more than 40 degrees.

Red snow and green snow have been met with, more commonly in Arctic

regions, but also in other parts of the world. These colours are caused

by the presence of minute organisms--a species of alga called _Protococcus

nivalis_.

The snow line of mountains is on the slopes below which, all the snow

which falls in the year, melts during the summer. Above the snow line,

therefore, lies the region of perpetual snow. The altitude of the snow

line depends on a variety of conditions. The latitude of a snow range is,

of course, important in determining the position of the snow line, but

many other circumstances have to be considered, as the shape and slope

of the mountain, the aspect of either side of the range, the character of

the surrounding country, the prevalent winds, and so on.

The following table shows the observed height of the snow line in feet

above the sea level in different places:

Place Latitude Height

Spitzbergen 78 N 0.

Sulitelma, Sweden 67 5´ 3.835

Kamtchatka 59 30 5.240

Unalaschta 56 30 3.510

Altai 50 7.934

Alps 46 8.885

Caucasus 43 11.063

Pyrenees 42 45 8.950

Rocky Mountains 43 12.467

North Himalaya 29 19.560

South Himalaya 28 N 15.500

Abyssinian Mts. 13 14.065

Purace 2 2´ 15.381

Nevades of Quito 0 15.820

Arequipa, Bolivia 16 S 17.717

Paachata, Bolivia 18 12.079

Portillo, Chili 33 14.713

Cordilleras, Chili 42 30 6.010

Magellan Strait 53 30 3.707

DESIGNING, MAKING, AND INFLATING PAPER BALLOONS

Draw a rough figure of the balloon, as shown at A, (Fig. 211.)

Divide this into any number of parts (the more the better) by horizontal

lines. Take a radius of balloon on each line, and describe circles, B.

[Illustration: Fig. 211. Paper balloon]

Divide this into twelve parts by radius lines, then make pattern as

follows: Draw a perpendicular, C, with horizontal lines at distance of

horizontal lines on A, but measured on circumference as _c d_. Then set

off on each line from perpendicular one half the distance between the

radius lines, B, on the corresponding circle as _e f_; draw line through

points thus found, and result will be shape of each section. Allow a

little on one side when cutting out for pasting. This will be best made

with strong tissue paper of any colour desired.

[Illustration: Fig. 212. An improved balloon]

Another method, giving a shape somewhat different, is shown in Fig. 212.

First draw an elevation of the balloon it is intended to make, either

full size, on the floor, or to scale. The shape here illustrated differs

slightly from that of balloons usually sold ready made, being wider at the

mouth. This shape, however, is not so liable to catch fire when swayed

about by the wind. Divide the elevation into any number of parts (the

more the better) by horizontal lines as shown (No. 1). Take the radius of

the balloon on each line, as A B, describe circles (No. 2), and divide

these into twelve parts by radial lines. Then to make a pattern, draw

a perpendicular (No. 3), with horizontal lines at the distance of the

horizontal lines (No. 1,) but measured on the circumference as C D. Then

set off on each line from the perpendicular half the distance between

the radius lines (No. 2), on the corresponding circle as E F, and draw a

line through the points thus found, and the result will be the shape of

each section. Allow a little (say 1/4 inch), on one side when cutting out

for pasting. Each section will be made up of one, two, or three pieces,

according to the size of the balloon to be made. If the pieces are cut

as shown (No. 4,) a great saving of paper results. To paste these pieces

together, place them in a pile on the table or bench with the edges flush

and a piece of waste paper under the pile. Now rub the top sheet with the

thumb nail until each piece is moved back from the one immediately under

it about one-fourth inch. Place a piece of waste paper about the same

distance from the edge of the top sheet, and pass the paste brush over the

whole of the exposed edges. No. 5 will explain what is meant. Now place

two of the completed sections together so as to look like No. 3, with a

small part projecting as shown by the dotted line G. Paste the edge of

the under section--that is, the part hatched--and turn it over on to the

dotted line H. When each two of the sections have been joined in this

way, proceed in the same manner to join these together till the whole is

completed. A circular piece of paper is cut out to join the sections at

the top, and a loop of string should be pasted to the top to suspend the

balloon while inflating. A ring of wire with two cross pieces is fitted

to the bottom of the balloon, and the inflammable material,--tow soaked

in methylated spirits--is fastened to the junction of the cross pieces.

MAGNETIZED WATCHES

The owner of a good American watch was a little troubled concerning it,

because it had been running irregularly for some time past. It came out

that he had visited the electric power house and had stayed for some

time examining the works and machinery, so that parts of his watch had

evidently become magnetized by the influence of the dynamos. The watch had

been made some time ago, and had not the power to resist, or neutralize

electric influences, that most watches have now.

To demagnetize the watch would bring it back to its original condition,

but a second visit to the lighting plant would again spoil its

time-keeping qualities. The watchmakers now have a way of making watches

so that they are not affected by magnetism, but comparatively few of the

time pieces in use are non-magnetic, and the average watch is subject to

these seasons of fickleness.

The exceedingly fine and exact construction of the watch is not realized

by the average possessor of the article. An examination of the works

of a watch shows the mechanism as now constructed, although very small

in size, to be accurately planned and executed. Changes of temperature

are provided for, so that the movement is automatically adjusted. The

mainspring and train of gears are usually concealed, while the balance and

hair springs are in full view when the case is open. Upon the regularity

of the movement of the balance depends the time keeping quality of the

watch. On looking closely at the balance, you will observe that it is not

a complete ring, but two halves supported at one end. These rings bear a

number of large-headed screws, placed at irregular distances, which give

it the exact weight and balance required. These half rings will also be

found, on looking closely, to be composed of two metals so closely joined

that a difference in colour alone gives evidence of the quality. This

arrangement of iron and brass, on account of their different coefficients

of expansion and contraction with changes of temperature, has been so

carefully constructed that, with changes of temperature, the balance

assumes such forms as to give it a uniform rate of motion.

The parts affected by magnetism are the balance and springs. The balance

in an ordinary watch moves five times a second, 18,000 times an hour,

and 432,000 times each day; but a slight change in the forces that move

it is necessary to make a difference of several minutes each day. As

the balance moves back and forth, the magnetism of the mainspring is

pulling or pushing it. If this force were constant, and always in the

same direction, the watch would run uniformly. Such, however, is not the

case. When the mainspring is tightly wound, its magnetic poles are in a

certain direction, and in unwinding they are constantly changing, so that

the direction of this force is also constantly changed. The effect on the

balance is to cause the watch to run too fast sometimes, and too slow at

other times.

Non-magnetic watches are made with these parts of a non-magnetic metal, so

that they are not influenced by electric machinery. For testing watches

a small compass is used. When placed over the balance, the needle will

vibrate with the motion of the balance in proportion to its magnetism.

A BOY'S WHEEL-BARROW

[Illustration: Fig. 213. A boy's wheel-barrow. Perspective view]

[Illustration: 213 A. Boy's wheel-barrow. Side elevation]

[Illustration: 213 B. Finished plan]

[Illustration: 213 C. Plan of frame]

The bottom, sides, and ends were about three-quarters of an inch thick.

Good white and red pine were used for the purpose. The stiles and rails of

the bottom framework were mortised and tenoned together as shown at Fig.

213; these may be just stubbed together, or the tenons of the rails can go

right through the stiles. The most satisfactory job is to groove the sides

and ends together, and put all together with oil paint in the joints. If

the joints are painted before the framework of the barrow is put together,

it will last for years; otherwise, being a boy's wheel-barrow, it would

likely often be forgotten and left out in the rain, and the joints getting

wet would hasten decay. Two coats of good oil paint, Indian red, will give

it a very nice appearance. This barrow, while not intended for heavy work,

is capable of carrying quite a load. The wheel was cut out of a piece

of plank about 1-1/2 inches thick, hooped up with an iron tire made from

heavy hoop iron. The axle was made of wood with a 3/4-inch round iron rod

running lengthwise through it and projecting about three inches through

on each end. The arbours or boxing, in which ran the ends of the round

rod, were formed on the ends of the handle stiles, as may be seen in the

illustration. The cost of all the materials for this really useful article

was less than $1.50, all told.

VACUUM CLEANERS

A single hand vacuum cleaner can be made from a powerful suction pump, as

indicated in the sketch Fig. 214. This should be connected with a metallic

box by means of a flexible armoured rubber hose, covered at the end with a

piece of fine wire gauze to prevent large particles of dust, etc., being

drawn into the pump. To another opening of the box should be fastened

another flexible rubber tube, with a bell-shaped metal attachment at the

end. The bell-shaped arrangement should be held closely to the carpet

while the pump is in action. Within the box, the pipe to which the pump is

attached should be bent upward, so that the rush of air shall not bring

the dust with it; the object being to collect the dust in the box. A lid

covers the box so that it can be emptied from time to time. The success

of this arrangement depends on the strength of the pump; if it be a weak

one, the inrush of air through the funnel will be so slight that the dust

will not be raised.

[Illustration: Fig. 214. Home-made vacuum cleaner]

[Illustration: Fig. 215. Metallic vacuum cleaner]

[Illustration: Fig. 216. Simple vacuum cleaner]

Rotary pumps are not satisfactory for vacuum cleaners. The best type for

this work is a plunger, having a large displacement, with a comparatively

short stroke in proportion to the diameter. A suitable pump is shown in

the accompanying illustrations. Fig. 214, shows the section of a single

barrel, but should a greater supply be required, two barrels may be

worked and connected as shown in Fig. 216. The pump is easily made, and

of light construction. In Fig. 215, is a brass cylinder with a flange at

the bottom; this may be made out of a length of 3-inch brass tube with a

flange cut from 1/8-inch sheet brass. The barrel is 8 inches long. G is

the plunger, which may be constructed as a piston; but in the drawing, it

is adapted to the arrangement that is shown in Fig. 216. With a piston

will be required a guide for the rod at the top of the cylinder. E is

a hydraulic cup, its leather kept soft and pliable by oiling. B is the

base, which is hollow, and may be built up in sheet metal. At the centre

at J, the base is divided into two compartments, one side being the inlet

to the pump from the dust box, and the other in communication with the

outlet valve C. C and D are two valves with guards. The valves are discs

of very soft and pliable leather, well saturated with grease, D being the

inlet from the dust box, and C the outlet to the atmosphere. The drawing

clearly shows the construction of the other parts. Fig. 216 shows two

pumps fitted to one base and worked by a rocking lever; both pumps are in

communication with the one inlet N. This arrangement of pumps is easy to

work, portable, and well adapted to domestic purposes in cleaning carpets.

[Illustration: Fig. 217. A motor vacuum cleaner]

Fig. 217, which is reproduced from _The Scientific American_, exhibits

an ingenious form of vacuum cleaner. It has recently been patented, and

consists of a suction-fan operated by a water-motor that may be attached

to the ordinary kitchen faucet. A tube is connected with the chamber of

the suction-fan, and this terminates in a suitable nozzle, or foot plate,

which may be moved over a carpet or rug to draw out the dust and dirt. One

of the advantages of this system is that dirt drawn up by the suction fan

can be carried away with the water down the kitchen drain.

[Illustration: Fig. 218. Home-made power-driven vacuum cleaner]

A good power-driven cleaner may be made at home, says _Popular Mechanics_,

by following these directions: First take a good pine board, 1 inch thick,

1 foot wide, and 3 feet long, and nail to each end a 1-foot length of

2-inch by 2-inch pine, as shown at A, Fig. 218. Next a 3/4-inch board,

1 foot wide and about 1 foot, 3 inches long, should be fastened near the

centre, and at right angles to the first board, as shown at B. Procure a

tin pan measuring about 10 inches in diameter and 3 inches deep. This pan

shown at C, must be fitted with two valves, which are the most important

and difficult part of the work. Cut, from a smooth piece of pine, 1 inch

thick, two discs, 5 inches in diameter, with a 3-inch hole in the centre

of each. Obtain a sheet of packing rubber, 1/8 of an inch thick, and cut

from it two discs, each 5 inches in diameter, and two 3-1/2 inches in

diameter. One of the discs of wood should be fastened to the back of the

pan at the top, as shown at D, Fig. 219, with one of the 5-inch diameter

rubber discs placed between the tin and the wood, and both secured to the

tin by a row of small bolts around the outside edge of the wood. A hole,

3 inches in diameter, can now be cut through the tin and rubber, using

the hole in the wood as a guide. Two discs with a diameter of 3-1/4 inches

should be cut from cigar box wood and fastened centrally on the 3-1/2-inch

rubber disc. One of the latter pieces should be fastened by its top edge

to the top edge of the 5-inch disc of wood, as shown in E. This forms a

flap valve, and great care should be taken to see that the rubber disc

covers the opening all the way around when the valve is closed, so that

it will be air-tight. A spring will be necessary to quicken the action of

this valve. This is best made by fastening a narrow strip of wood across

the valve opening on the inside of the pan, as shown at F, and attaching a

rubber band to the centre of the valve and to this stick. This completes

the outlet or exhaust valve. Another valve must now be made in the same

manner, and fastened to the bottom of the pan on the inside, as shown.

This is the inlet valve, and works in the opposite direction to the outlet

valve just described.

[Illustration: Fig. 219. Home-made, power-driven vacuum cleaner]

Next procure a piece of leatherette about twelve inches in diameter, or

large enough to cover the opening of the pan. This is to be used for the

diaphragm. Cut a round hole about 8 inches in diameter in the upright

piece B (Fig. 218), its centre about 7 inches from the top. From a piece

of 1/2-inch pine, cut two discs 6 inches in diameter. Also secure a piece

of hardwood H 1 inch by 1 foot 2 inches. The discs G should now be placed,

one on each side of the leather diaphragm, exactly in the centre, and

fastened to one end of the 1-foot 2-inch piece by means of a long screw.

This piece H should exactly be in the centre of the diaphragm.

The pan can now be put in place. Set the diaphragm over the hole in the

board B, the stick projecting through the hole. The pan is now placed

over the diaphragm, and held by means of small bolts around the edge.

The diaphragm between the wood and the tin acts as a gasket, and makes an

air-tight joint.

Secure an air-tight tin about 8 inches in diameter and 12 inches high,

and fasten it to the base board, as shown at J, Fig. 218. The cover of

a coffee tin should now be soldered over the inlet valve, as shown at K,

Fig. 219. Solder a hose connection in the centre of this cover, also one

in the side of the tin, as shown at L, Fig. 218. Couple a short piece of

hose M to these connections. The strainer S should be made of very strong

and closely woven unbleached drill. Make it in the form of bag with a

1-inch hem at the top, and place it in the tin, as shown by the dotted

line, the hem fitting closely over the inside edge of the tin. The cover

of the tin is made from a flat pine board about one inch thick, and is

held in place by two 1/4-inch rods fastened in the base board. These rods

have thumb nuts on the top, which allow the cover to be readily removed

or tightened down. It is best to place a rubber or leather gasket between

the cover and the edge of the tin so as to make an air-tight joint.

An air-tight piece of garden hose can be used for the suction hose N,

one end being fastened in the centre of the cover and the other to the

brush or nozzle R, Fig. 218. It is best to buy this nozzle, as it would

be rather expensive and unsatisfactory if home-made.

This machine may be driven by an electric motor of about 1-1/4

horse-power, which should be placed in the position shown in Fig. 218. The

end of the connecting rod H is fastened to a crank on the motor shaft, and

allowed to have about a one and one half inch stroke. The motor is wired

up with a switch, P, and it would be best to connect to a rheostat, to

allow the regulation of speed best suited to the machine. This can readily

be determined after the machine is started. If an electric motor is not

available, a small water motor will do equally well; or it may even be

run by hand, by means of a long lever, fulcrumed at P.

The machine is now ready for using. First, however, test it all over

for leakage, as its success depends on its being perfectly air-tight.

As the motor revolves, the rod H is drawn forward, bringing with it the

diaphragm. This creates a partial vacuum in the pan C, which opens the

inlet valve, sucking the air through the suction hose and strainer, the

air carrying with it the dust and dirt. The refuse is left in the strainer

bag while the air goes on through the connecting hose and pan and outlet

valve into the atmosphere. After the article being cleaned has been gone

over thoroughly, care being taken to hold the nozzle against the material,

the cover may be removed and the bag emptied.

IV

MOTORS AND TYPE-WRITERS

MOTORS, GASOLENE AND STEAM--AUTOMOBILE FRAMES--THE MODERN

TYPE-WRITER--DIRECTIONS FOR SECURING COPYRIGHTS.

There are two classes of heat engines in use; in one class the combustion

takes place on the inside of the cylinder or generator, just as fire is

applied to a tea-kettle, and the heat is transmitted by conduction through

the metal walls to the part of machine doing the work. Motors and machines

of this kind, are generally called "external combustion" engines, of which

the steam engine is a prominent example.

Engines where the combustion takes place inside the machine itself, and

acts directly on it, are engines of the second class, termed "internal

combustion engines." The gasolene engine is of this type, and so are all

gas and oil engines.

The principle of the motor-cycle engine, in its action, is similar to

the regular automobile engine and the gas engine. All these are internal

combustion or explosion engines; that is, their motive power is derived

from the force exerted by the explosion of a gas while under compression,

the compressed gas generally ignited by means of an electric spark.

In the case of gasolene motors, the gas is obtained from the liquid

gasolene, either by allowing air to be drawn through it or by spraying

the spirit through a small hole, the latter being the method most

generally used. A great quantity of air has to be mixed with the vapour

before it will ignite. The amount that is required varies considerably,

atmospheric conditions and the height above sea level causing variations

in the demand. The action of the common gasolene engine is known as the

"four-stroke-cycle," that is, there are four strokes of the piston for

every impulse, one being a "power" stroke and the other three "duty"

strokes, as it were. Each performs a certain operation that is necessary

for the correct working of the engine. Some engines are worked on the

"two-stroke-cycle" principle; in this case, there are only two strokes

for each impulse. This type of engine has many disadvantages, and there

are very few two-stroke engines in use for driving motor cycles.

[Illustration: Fig. 220. Suction stroke begun]

[Illustration: Fig. 221. Compression stroke begun]

[Illustration: Fig. 222. Power stroke begun]

[Illustration: Fig. 223. Exhaust stroke begun]

The principle of the "four-stroke-cycle" is shown in Figs. 220 to 223.

In Fig. 220 the piston A is just beginning the downward stroke, and the

valve B is opened by the pressure of the atmosphere, or by mechanical

means. The piston in descending causes a partial vacuum in the cylinder

head or top C, which allows the atmospheric pressure on the surface of the

gasolene in the carburetor to force some of the liquid through the spray

hole, thence through the inlet-valve opening D, into the compression space

of the engine cylinder. The suction of the piston does not bring in the

explosive mixture of gas and air; it is the pressure of the atmosphere

that causes the mixture of gas and air to rush into the cylinder. Just

before the piston is at the extreme end of the downward or outward stroke,

the inlet valve B is closed by the spring shown, and the piston begins the

first upward or "compression" stroke with both the inlet valve B and the

exhaust valve E closed. The charge is being compressed when the piston is

on its upward stroke, as shown in Fig. 221. Speaking generally, soon after

the piston is over what is known as the "dead centre," and is about the

position shown in Fig. 222, an electric spark is made to jump across two

points of the sparking plug F; this ignites the mixture of gas and air

(which is at a pressure of about 80 lb. per sq. in.), and the explosion

causes the piston to descend on the power stroke. Just before the piston

reaches the bottom of the power stroke, the exhaust valve E, Fig. 223,

opens, and remains open during the upward stroke. The momentum of the

flywheels, etc., carries the piston upward, and thus forces out the

burnt gases through the exhaust opening G, and from there to the silencer.

Immediately the piston begins its next downward stroke, the inlet valve

opens, fresh air is drawn in, and the cycle of operations is repeated as

before. The illustrations show a magneto gear driven by the engine.

These engines when properly arranged are made to do service as marine

motors, and are then installed either horizontally or vertically. A

vertical engine has been shown on previous pages, but perhaps a little

further explanation may not be amiss. Engines for boats are made with

one cylinder or with more, and there are many considerations which

make an engine of two or more cylinders particularly desirable. It is

a self-evident fact that when the limit of size of a single-cylinder

is reached, it is necessary to add other cylinders if greater power is

desired. Even for moderate or small powers, there are many advantages.

Among these may be noted the fact that with the proper arrangement of

cylinders the impulses may be made to occur at shorter intervals than with

a single-cylinder engine. Thus with a two-cylinder engine, the cylinder

may be so arranged that the impulses will occur twice for every revolution

instead of once, as in a single-cylinder. This gives a more even turning

effect to the shaft, and consequently steadier running, and it also

requires a less heavy fly-wheel. The vibration is much less, as one set of

working parts may be made to travel upward while the other is travelling

downward, thus neutralizing the throw of each and lessening the vibration.

In case of the disablement of one cylinder, there is the chance of

getting home on the remaining ones. The weight, power for power, of the

multiple-cylinder engine is less than that of the single-cylinder engine,

as the weight of the fly-wheel and other working parts is less.

While for marine work, single-cylinder engines have been built as large

as eight or ten horse-power, they are so large as to be rather cumbersome

and the practice now is to build engines of more than six horse-power

with two or more cylinders. There are several firms who are making

double-cylinder engines as small as four horse-power, which both as to

weight and reliability are much superior to those of a single-cylinder.

[Illustration: Fig. 224. Two-cylinder engine]

The original method of constructing a multiple engine, and one which is

still used by some builders, is simply to use two or more single-cylinder

engines coupled together. This is a cumbersome method and takes up a

great amount of space. The simplest method which can be recommended is

that shown in Fig. 224. It consists of two single-cylinders mounted on a

common base of special design, bringing the cylinders much nearer together

than when a coupling is fitted to connect two separate engines--as the

shaft can be made in one piece. This particular engine is of the two

port type, two vaporizers V-V being used. The gasolene enters at G and

branches to each vaporizer. The pump is shown at P with the discharge at

W, piped with a branch to each cylinder. The cooling water outlet is at

O. The exhausts are connected to a common pipe with the outlet at E. The

igniting gear for each cylinder is independent and on opposite ends. By

means of the lever L, which is connected to both igniting gears, the time

of ignition is regulated and kept the same on both cylinders. This allows

multiple-cylinder engines to be built with very few extra parts, as the

cylinders, ignition gear, etc., are the same as in the single-cylinder

engine.

[Illustration: Fig. 225. Single-cylinder engine]

A view of a representative single-cylinder engine is shown at Fig. 225.

The cam shaft is located at _a_ and is driven by the gears which are

shown just in the rear of the fly-wheel. At _c_ are the cam and the

roller, which actuates the exhaust valve. The cam consists of a collar

with a flat projection or toe upon its surface; the roller rests just

above the surface of the collar, and is forced upward when struck by

the projection. The roller is inserted to lessen the friction by rolling

instead of rubbing. The valve stem extends upward into the valve chamber,

and is encircled by the coiled spring _e_; the stem is guided by the guide

at _g_. The exhaust is at E; I is the pipe leading from the vaporizer V

to the inlet port in the valve chest. The inlet valve is directly below

the spring S and is inverted, being held in place by the spring. The

dome-shaped cap containing the inlet valve is removable for access to both

valves. The complete cover is also removable. It will be observed that

this engine has an open frame very similar to that of a steam engine,

giving free access to the crank-pin and main bearings; the latter are

shown fitted with oil boxes _b_ instead of the grease cups, as there is no

pressure tending to force the oil out along the shaft as in the two-cycle

type. This open base not only makes the bearings more accessible, but

renders it easier to lubricate them and keep them cool. At H is the

ignition gear. P is the cooling water pump, run by the eccentric _e_. The

suction is piped to _d_ and the pump discharges through the pipe _k_ into

the cylinder. The outlet for the cooling water is at O; N is the cylinder

oil cup for oiling the bore of the cylinder. The compression cock R is for

relieving the compression at starting. The coupling at X is for attaching

the propeller shaft.

In this engine, the cylinder, base and bolting flange are one casting,

the upper half of the main bearing being removable for the insertion of

the shaft. The cover is bolted on separately.

AUTOMOBILE FRAMES

The chassis for the single-cylinder, eight horse-power motor machine shown

herewith is built on the principle of most frames, of any make and is

typical of the majority of light motor car chassis at present in use.

[Illustration: Fig. 226. Eight horse-power single cylinder chassis]

A diagrammatic plan of the eight horse-power, single-cylinder chassis is

shown in the accompanying illustration (Fig. 226) in which, A indicates

parts enclosed, taking the mixture of gasolene and air from the float-feed

spray carburetor B, which has an automatic air regulator. The purpose

of this last device is to dilute the mixture when the engine has a light

load and is inclined to race; generally speaking, this regulator serves to

proportion the ingredients of the explosive mixture to the requirements of

the engine. Current O for the ignition of the explosive mixture (ignition

occurs once for every two revolutions of the fly-wheel), is supplied by

an accumulator and intensified by a high-tension coil. The products of

combustion pass through the exhaust pipe C to the muffler D, from which

they pass to the atmosphere through a series of fine holes. The starting

handle E makes a simple connection with the end of the motor shaft F

when required. G is the fly-wheel. The drive from the engine is through a

universal joint H to the change-speed gear J, the latter consisting of two

trains of toothed wheels, a big wheel on the primary shaft gearing with

a small one on the secondary shaft to give a high speed, and vice versa.

From the change-speed gear, the drive is through a shaft K, having a

universal joint L at each end, to the bevel gearing above the differential

gear of the live rear axle. Bevel gears and the differential gear are

all contained in the casings M. Three brakes are fitted, one operated

by pedal, working on a drum N secured to the propeller shaft, the others

operated by the side lever and working on drums O O, secured to the rear

wheels. The change-speed gear gives three speeds forward and a reverse;

the frame is of pressed steel; the rod and wheels are of the artillery

type and carry 700 mm. by 85 mm. pneumatic tires. The gasolene tank

holds 4-1/2 gallons, sufficient for 200 miles, and the lubricating oil

tank holds 1 gallon, sufficient for 350 miles. Any beginner in motoring

matters, who studies the diagram, will obtain a fair idea of the mechanism

of the customary type of light car chassis.

[Illustration: Fig. 227. Plan of chassis of light racing car--two-cylinder

motor]

A chassis, suitable for a 7-1/2 horse-power quick-speed, two-cylinder

motor, is shown in Fig. 227.

It is not necessary to enter fully into the details of construction after

describing such a typical gear-driven car as that at Fig. 226.

The frame A is of tubular steel, there are four semi-elliptic springs, and

the artillery wheels have 28-inch by 3-inch tires. The two-cylinder engine

B is one casting, with a large waterway covered by an inspection plate

C. The bore is 3.5 inches, stroke 4-inches, cylinder capacity 76.9 cubic

inches, and the piston displacement is 92.300 cubic inches per minute.

A governor automatically throttles the inlet when the motor attempts to

race, but by means of a lever the governor can be cut out and the motor

accelerated from its normal speed of 1,200 revolutions per minute. The

balanced crank has but a single throw; the water circulation is assured by

a motor-driven pump, and there is a belt-driven fan behind the radiator.

The commutator is easily accessible, being mounted on a bevel shaft lying

in a sloping position and passing through the side of the crank chamber.

Ignition is high tension with wide contact, the wiring being enclosed

in a neat wooden casing. The change-speed gear D gives three speeds and

a reverse, and its main bearings are fitted with ring lubricators. A

pressure sight feed lubricator on the dash-board has three outlets, one to

the engine, another to the main clutch, and a third to the driving pinion

on the end of the propeller shaft. The brakes are of the usual kind. In

Fig. 227, E is the carburetor, F the inlet and G the exhaust pipes, H the

exhaust muffler, J the brake pedal, K the clutch pedal, L the band-brake

on the propeller shaft, and M the internal expanding brakes on the wheel

hubs. A shield is arranged under the front of the car to protect the

mechanism from mud and dust. The weight of the car unladen is about 1,414

pounds, the wheel base is 73-1/2 inches, the track 46 inches, and the

over-all dimensions are 111 inches by 60 inches. During a 600-mile trial

this engine consumed 36 gallons, 6 pints of gasolene, this being at the

rate of 1 gallon for every 16.9 car miles; .077 gallon was consumed every

ten miles.

THE MODERN TYPE-WRITER

Every home of importance contains a writing machine of some kind, and

these often require some little adjustment or "fixing." It is within the

capacity of any bright boy to make these adjustments, or to do the little

fixings, if he tries it earnestly.

The first marketable type-writer was introduced in the year 1875. No

sooner had the type-writer acquired a commercial value, than the fire

of inventive talent was awakened in Europe and America, and type-writer

after type-writer appeared on the market--a few came to stay, but the many

disappeared, either during the chrysalis or experimental stage, or shortly

after it had been passed. Inventors and investors have learned that hasty

innovations and untried experiments spell "failure" in the type-writer

field, and only patient and careful study, backed by experience, tireless

effort, and abundant resource, have a chance of success.

By the year 1888, there were six different kinds of machines in the

market, to-day there are at least twenty, but the favourites seem to be,

"The Remington," "Smith Premier," "The Underwood" and "The Oliver."

Modern type-writers may be defined as being tabulating, book recording,

card indexing, and document writing machines. They are speedier and

produce finer and more varied work than their predecessors.

The manner in which the type-writer performs its work is of the simplest.

The type-writer may be considered as composed of three general parts, as

follows:

The keyboard, by which the operation of the machine is directed.

The type mechanism, by which the desired letters are, one after the other,

in any desired sequence, imprinted on the paper.

The carriage, which holds the paper in proper position for writing, and

which, by its regular movements, provides for the spacing of letters and

lines.

The Remington may be considered the pioneer of writing machines. In

appearance the Remington No. 5 (introduced in 1888) is square, and strikes

a novice as being somewhat complicated. It is only the multiplicity

of parts, however, which creates this impression. The machine is not

complex, the same parts being repeated over and over again. The action

is simplicity itself. The machine is quite open on every side, so that

its entire construction can easily be seen. There is a japanned iron

frame enclosing and holding the working parts, consisting of a base, four

upright posts, and a top plate. In front is a series of keys arranged

in four banks, like the keys of an organ, each key representing the two

characters, termed "upper" and "lower" case letters. These are connected

with long light wooden levers, which, being depressed, communicate motion

by means of a rod fastened to the lever of a type bar. At the end of each

type bar is fixed the hard metal type representing the two characters.

The type bars are arranged in a circle, therefore the point of percussion

of the type on the paper is at a common centre. The inking is done by

a ribbon, which travels automatically across the machine, winding and

rewinding on and from spools.

The paper is inserted between two rollers; one of rubber, called the

"paper cylinder," and the other of wood, called the "feed roll." The

rollers are held together by two elastic india-rubber bands. As one

revolves so does the other. The portion which holds these rollers is

designated the "carriage." By a clever, yet simple piece of mechanism,

this carriage is caused to travel, simultaneously with the return of the

type or spacing bar, from right to left, the width of a letter at each

movement across the machine. The carriage works on a sliding frame, and

this sliding mechanism is controlled by two keys, which do not impress

letters on the paper. These change the character of the printing keys,

causing them to print capitals or small letters, numerals or other marks

at will. Depress the key marked "upper case" and all the keys will print

capitals; remove the finger and they all print small letters again.

Moreover, the machine can be arranged to print capitals continuously by

the mere raising of a lever, and quite independently of the "upper case"

shift key.

To obtain an impression, the required key is struck lightly, and the type

bar causes the type to strike against the ribbon, thus leaving an imprint

on the paper held round the cylinder; the carriage moves automatically

the width of the letter, and the operation is repeated until a word is

completed. Then the "spacing bar" at the front of the machine is depressed

at any point, thereby securing the requisite space between the words.

When the end of a line is reached, warning is given by the ringing of a

bell, and then, by pulling out the lever at the right-hand side of the

carriage and gently pressing to the right, the paper carriage is advanced

into position to receive the next line. The distance between the lines

and the width of the writing can be regulated. The paper carriage being

hinged at the back allows of its being raised from the front by the hand,

so that the line that has just been written can be inspected.

The motive power is imparted by an adjustable coiled spring, a thin

leather strap being fastened to it and the carriage, and the uniform space

is governed by two clutches working on a rack. This rack is fixed on a

rocking shaft, and derives a swinging motion from a universal bar fixed

beneath the light wooden key levers.

A small lever attached to the left of the carriage holds its movements

under the control of the operator. Two scales are fixed on the machine,

and these in conjunction with the pointer, permit of head-lines being

centred, corrections made, etc.

In some machines, a special key and its accompanying mechanism is

provided for each character or sign used--such are termed "complete"

keyboard machines. In others, each key is made to represent the letters

or signs--such are designated "single-shift" machines. Others, again, have

two shift-keys, and each key represents not only a lower case (small) and

an upper case (capital) letter, but a figure or other sign as well--such

are known as "double-shift" machines.

The two classes of modern type-writers may be arranged into three groups,

namely:

"Blind" writers, in which the writing remains hidden until exposed by

manipulative effort of the operator. "Semi-visible" writers, which show

only the last lines, or only expose the centre of the paper, hiding

the writing at both ends of the line. "Visible" writers, which expose a

character directly in front of the operator the instant it is imprinted;

the character subsequently does not pass out of sight, by feeding behind

a scale or bar, or other obstruction. This classification and grouping is

for convenience only, and is in no way intended to denote superiority.

[Illustration: Fig. 228. Remington type-writer No. 7]

With regard to the Remington, many changes of the details of construction,

tending toward strength, durability, and a greater ease and convenience

of operations, have been introduced into the machine, which have survived

the severe test of time. This is especially the case with Remington No.7

(see Fig. 228). The most important of these valuable improvements are:

An entirely new form of escapement, giving increased speed and an easy

touch. The carriage is stronger and lighter, and steadier in all respects.

The annoying rubber bands, which guide the paper around the platen have

been discarded for a new form of paper guide, which may be adjusted to

any desired point. The paper feed has been so arranged as to render it

possible to write on wide or narrow paper, and this can be fed into the

machine by a simple movement of the hand without lifting the carriage,

and can be turned forward or backward at will. The ribbon movement is

improved and works entirely automatically, reversing and giving a lateral

movement. The marginal stops also are improved, and simple means provided

for writing outside the margin whenever desired. There is a keyboard lock,

locking the types at the end of the line, and thus preventing one letter

being printed over another. A new variable line spacer is embodied, which

makes it easier to write at any point on the paper, and prolongs the life

of the platen for the reason that the type no longer strikes in unchanging

grooves. An adjustable side guide for arranging the paper to any desired

marginal indentation is a recent addition. A new two colour ribbon lever

bearing a disc, which signals the color which the machine is adjusted to

write is another recent addition.

[Illustration: Fig. 229. Smith Premier No. 4]

The Smith-Premier type (Fig. 229) has six models in the market and

all nearly alike in their mechanism, differing only in the carriage

arrangements, or the number of the characters. The machine is particularly

simple in construction, and claims, by means of a very long and strong

adjustable bearing, to have secured a perfect and permanent alignment.

The type bars work on hardened steel bearings, 1-5/8 inches apart, and

the type bars are the shortest of any on a "complete" keyboard machine.

But the original and exclusive feature of the machine is the rocking

shaft, which replaces the usual wooden or metal key lever. This consists

of a circular rod, passing from the front to the rear of the machine--one

rod for each key. Projecting from each shaft is a small bar, which is

attached at the front end to the lower portion of the key stem. A similar

projection is attached to the rod communicating with the type bar, and

the result is that on the depression of the key the rocking shaft is made

to revolve slightly, and so raise the free end of the type bar to the

printing point. The type bar hangers are solidly riveted to the type ring.

It will be seen that matters are so arranged that the amount of force to

imprint the character is precisely the same in every case--a uniform,

light and elastic touch. A very noticeable feature is its quietness

in operation, due to the rigidity of its parts, and the fact that the

ball-bearing principle is adopted wherever it can be used to advantage.

It is also equipped with a circular brush, built into the machine, into

which a handle can be immediately inserted, when, with a turn or two, the

whole of the type can be cleaned.

The most striking recent development is the adoption of a three-coloured

ribbon device. A simple movement of the lever in front of the machine

brings the required colour into place ready for use. A two-colour or

single colour ribbon may be employed. If desired the ribbon can be

instantly shifted from the printing point for duplicating purposes. The

ribbon reverses automatically, and it is attached to the spools with

clamps--one on each spool, dispensing entirely with pins and tapes.

[Illustration: Fig. 230. The Oliver No. 3]

The Oliver, Fig. 230, differs in mechanical principle from other machines.

It has a wide U-shaped steel type bar, provided with a tool-steel axle as

broad as the bar is long, and braced joints insuring the alignment without

guides. The connection between the type bars and the key levers is direct

and perpendicular. The type bars strike down on the platen in a line

perpendicular to its plane, thus transmitting the maximum power with the

minimum resistance, and further, maintaining the alignment with several

sheets as with one. The type are of steel, and lie face upward--very

convenient for cleaning. The keyboard is the "Universal," having

twenty-eight keys with a "double" shift, giving eighty-four characters

and the special model thirty-two keys, giving ninety-six characters.

The tension and depression of the keys are light and uniform. It may also

be noted that the type blocks decrease in weight with the increase of

length of type bar--necessary to secure a uniform stroke. The escapement

mechanism is exceedingly simple and positive, and although very rapid is

almost frictionless. The writing is semi-visible. The carriage is provided

with three paper-feed rolls, thus ensuring a perfect feed of the paper

down to the bottom edge of the sheet. It runs on anti-friction travellers

on guide rails, ensuring an easy and steady motion. It is equipped with

all the necessary devices. The line space mechanism operates automatically

as the carriage is returned from the left to the right for a new line.

The machine is compact and portable--weight about twenty pounds.

The parts of any of the machines now in the market, may readily be

disconnected, but care must be taken by the novice in laying aside the

parts so that they may be easily and correctly assembled. Repairs on

the various parts may be made while out, and when made may be placed _in

situ_. Any or all of the parts may be cleaned when the carriage is taken

off. A little study of the machine when sitting before a person, will

enable him to understand its mechanism, and when this is accomplished,

cleaning and repairing can be done intelligently.

The tendency of the times is to employ the type-writer whenever possible.

Special devices are from time to time invented to meet extended uses. The

most important of recent applications is to office work for billing and

book-keeping; this work alone has necessitated important modifications. In

this direction, the tabulator calls for review. The lack of a practical

method enabling tabular matter to be typed with a rapidity equal to

that of the ordinary typing has long been felt to be a deficiency in

type-writers. The invention of the tabulator has enormously increased the

scope of the machine in this direction.

The tabulator is a device by means of which, figures or words can be

written in columns, with out employment of the space bar or carriage

release lever, or any adjustment whatever of the carriage by hand. By

its use, the carriage may be set automatically at any point that may

be required. At present this device is an accessory to most machines,

but in the near future, it must form an integral part of all machines,

and further, enable the carriage to be automatically placed in a proper

position to write numbers in correct relation to each other in columns;

that is, units under units, tens under tens, and so on. The built-in

tabulators of to-day, with but two exceptions, are deficient in this

respect. The tabulator in either form does not interfere with the use of

the machine for other work, such as correspondence, etc.

The tabulator was followed by the introduction of a bi-chrome

(two-coloured ribbon), and quite recently the Smith Premier Typewriter

Company has advanced still further in this direction by introducing a

tri-chrome (three-colour) ribbon. By a simple movement it is possible

to vary the colour of the impression instantaneously, so that credits,

marginal notes, footnotes, and underscoring may be indicated in red or

other colour preferred. One-colour ribbons can be used if desired.

The machine embodying the parti-coloured ribbons and tabulator devices are

generally known as "invoicing" machines, and by simple arrangements, every

phase--not only of correspondence, but also of office and statistical

work--can be accomplished, with an enormous saving of time. Items can

be made on sheets, which may be taken from the machine with absolute

certainty that when re-inserted, the subsequent entries will fall into

their proper places.

_Card Indexing._--For greater convenience in card indexing, special

platens are obtainable, or the ordinary platens can be temporarily fitted

with a metal clip. Both can be fitted to or removed from the machine in a

few seconds, and the cards can be adjusted in an instant. The increasing

use of the card file system for a wide variety of purposes lends special

importance to the value of the type-writer for this class of work.

_Interchangeable Carriages._--For years the thousand and one wide forms,

statements, and blanks common in every business office, have been filled

by the pen, the reason being that there was no machine practicable for

both wide and ordinary work. The manufacturers of most of the modern

type-writers now have models embodying interchangeable carriages, which

enable any one possessing a machine with this improvement to have at the

same time a set of carriages from the largest to the smallest, all of

which can be used upon one machine. In one or two makes this is additional

to interchangeable platens.

[Illustration: Fig. 231. Interchangeable carriage]

_Duplicators._--The value of a mechanical contrivance for the rapid and

effective multiplication of copies of documents is fully recognized at

the present time.

Duplicating machines have been on the market for several years. They will

produce from one typescript original up to 3,000 copies, of any size, from

a post card to a sheet of brief, every copy having the exact appearance

of an original. While there are various makes and styles of duplicators,

the main principle is the same throughout. The original is prepared by

the now well-known stencil process; that is, writing the matter required

with a type-writer on a sheet of waxed paper. The pressure of the type

expels the wax out of the paper and leaves openings through which the ink

can penetrate. In the Roneo rotary duplicator, a metal frame supports a

cylinder of thin, perforated steel. On the outer surface of the cylinder

is stretched a linen ink-pad, and over this is placed the stencil. The

pad is inked by a rubber roller resting in an ink receptacle suspended

between the two sides of the framework. By means of a simple lever this

roller can be brought into contact with the cylinder, and ink is thus

supplied as required. The cylinder is rotated by a handle. Paper fed into

the machine is gripped by a rubber impression roller, which presses it

against the stencil as the cylinder revolves, and the sheet perfectly

printed, is then automatically discharged on the other side. The rotary

can be fitted with three devices, namely a feeder, a simple contrivance,

which automatically feeds the sheet into the machine, reducing hand labour

to a minimum; an interlever, which automatically drops an interleaving

sheet as each copy is printed--thus permitting of the use of highly glazed

or very hard paper; a cyclometer for registering the number of copies.

The rotary system is far superior to the hand duplicators in the matter of

speed; such a machine will print ten copies while the hand device prints

one. There is no lost motion, a copy being printed and discharged at every

revolution.

_Press Copying._--At the present time, there are four methods of letter

copying in vogue, namely: (1) The letter-book method, damping sheets and

screw press. (2) Roller process, water bath and drying drum. (3) Carbon

paper. (4) The chemical letter copier.

The roller copies employ a water bath, and give but little if any

improvement in the regulation of the degree of moisture. The copies are

wound on a drying drum to prevent off-setting, and subsequently have to

be cut apart for filing purposes.

The carbon process enables the answers to be filed with the original

letter.

The modern chemical letter copier offers distinct advantages over other

methods. It consists of a simple machine designed to carry a roll of

specially prepared paper. The letter to be copied is laid on the feed

board, the handle is turned, the sheet is fed automatically into the

machine.

It will be noticed that a water bath and brush or damping sheets, are

completely dispensed with; there is no "off-sheeting" and no drying

drum. The copy may be either filed with the letter to which it relates,

or placed, day by day, in a cover having the appearance of an ordinary

letter-book; or two copies can be made of each letter--one for filing and

the other for the book.

(1). A type-writer should be durable. Every part should be simple and

strong and adapted to serve its purpose with the smallest degree of wear.

Every mechanical movement must be definite, and incapable of incomplete

performance. All wearing parts should be adjustable and interchangeable.

(2). It should possess absolutely "visible" writing. The common-sense way

to write easily and speedily is to see what you are writing while you are

writing it.

The writing should be performed in such a part of the machine as to be

most readily seen during progress.

(3). The keyboard--on type bar machines in particular--should be that

known as the "Universal," or "Standard" arrangement.

The keys on any style of keyboard should have a light and uniform

depression, so that the machine may be operated with the minimum of

fatigue.

(4). The types should present an even and regular appearance, termed

"alignment." A type bar made of suitable material in the right way is

the keystone of typewriter construction. In all machinery, there is some

part on which falls the greatest strain and wear; consequently on the

durability of that part rests the life of the machine. The devices used

to secure alignment are numerous and ingenious. One machine depends on a

wide pivoted bearing and a rigid type bar; another has a bearing composed

of a continuous steel rod, with a type bar flexible while in motion,

and made rigid at the printing point by means of guides; a third employs

a wide pivotal bearing, a flexible type bar and an indispensable guide

plate at the printing point; a fourth employs a compound type bar and an

indispensable guide at the printing centre, and so on. Some have wide and

adjustable bearings, to enable the wear to be taken up. These devices,

however, are not the only essentials. The type bar hangers in machines

embodying the pivotal principle need to be rigid and solidly fixed, while

the paper carriage should be perfectly rigid and present a level and even

platen surface for the type to strike against.

(5). The type should be capable of being easily and quickly cleaned, and

in such a way as not to injure the type or soil the hands. A device should

be embodied for rendering it impossible to batter the face of the type

when the type bars are accidentally struck one against the other, and for

preventing the type perforating or puncturing the platen.

(6). The mechanism controlling the movement of the carriage should act

rapidly and uniformly, and its tension should be adjustable. The carriage

should have a sure and regular paper feed and be capable of accommodating

any smaller width of paper; also the margin regulators and bell trip

should be easily and readily altered.

(7). The platen roll should be instantly interchangeable, thereby allowing

of a soft substance platen being used for a single copy work and a hard

one for manifolding. If the hard platen is of reduced diameter, more

perfect alignment is secured on machines employing a complete circle of

rigid type bars and a central top carriage.

(8). The line-spacing mechanism should be variable, and effected by one

movement at all times; that is, the same movement that accomplishes the

line feed should be utilized to return the carriage for a new line.

(9). The ribbon movement should consist of a reliable feeding mechanism,

and allow of the fabric being quickly withdrawn, replaced, or adjusted.

It should bring the whole surface in contact with the type, and also

automatically reverse the endwise travel.

(10). The machine should be as noiseless in operation as possible.

Machines differ very much in this particular. The employment of the

guides to force the alignment introduces metallic contact, and consequent

friction and noise.

COPYRIGHTS

_Directions for Securing Copyrights, under the revised act of Congress,

which took effect August 1, 1874._

(1). A printed copy of the title of the book, map, chart, dramatic or

musical composition, engraving, cut, print, photograph, or a description

of the painting, drawing, chromo, statue, statuary, or model or design

for a work of the fine arts, for which copyright is desired, must be

sent by mail or otherwise, prepaid, addressed: _Librarian of Congress_,

Washington, D. C.

This must be done before publication of the book or other article. No

entry can be made of a written title.

(2). A fee of fifty cents, for recording the title of each book or other

article, must be enclosed with the title as above, and fifty cents in

addition (or one dollar in all), for each certificate of copyright under

seal of the Librarian of Congress, which will be transmitted by early

mail.

(3). Within ten days after publication of each book or other article, two

complete copies of the best edition issued must be sent, to perfect the

copyright, with the address _Librarian of Congress_, Washington, D. C.

The postage must be prepaid, or else the publication enclosed in parcels

covered by printed Penalty Labels, furnished by the Librarian, in which

case they will come free by mail, according to rulings of the Postoffice

Department. Without the deposit of copies above required the copyright

is void, and a penalty of $25 is incurred. No copy is required to be

deposited elsewhere.

(4). No copyright is valid unless notice is given by inserting in every

copy published, on the title page or the page following, if it be a

book; or if a map, chart, musical composition, print, cut, engraving,

photograph, painting, drawing, chromo, statue, statuary, or model or

design intended to be perfected as a work of the fine arts, by inscribing

upon some portion thereof, or on the substance on which the same is

mounted, the following words, viz: "Entered according to act of Congress,

in the year----by----, in the office of the Librarian of Congress, at

Washington," or, at the option of the person entering the copyright, the

words: "Copyright, 19--, by----."

The law imposes a penalty of $100 upon any person, who has not obtained

copyright, who shall insert the notice "Entered according to act of

Congress," or "Copyright," etc., or words of the same import, in or upon

any book or other article.

(5). Any author may reserve the right to translate or to dramatize his

own work. In this case, notice should be given by printing the words

"Right of translation reserved," or "All rights reserved," below the

notice of copyright entry, and notifying the Librarian of Congress of such

reservation, to be entered upon the record.

(6). Each copyright secures the exclusive right of publishing the book

or article entered for the term of twenty-eight years. Within six months

before the end of that time, the author or designer, or his widow or

children, may secure a renewal for the further term of fourteen years,

making forty-two years in all. Application for renewal must be accompanied

by explicit statement of ownership, in the case of the author, or of

relationship, in the case of heirs, and must state definitely the date

and place of entry of the original copyright.

(7). The time within which any work entered for copyright may be issued

from the press is not limited by any law or regulation, but depends

upon the discretion of the proprietor. A copyright may be secured for a

projected work as well as for a completed one.

(8). A copyright is assignable in law by any instrument of writing,

but such assignment must be recorded in the office of the Librarian of

Congress within sixty days from its date. The fee for this record and

certificate is one dollar, and for a certified copy of any record of

assignment one dollar.

(9). A copy of the record (or duplicate certificate) of any copyright

entry will be furnished, under seal, at the rate of fifty cents each.

(10). In the case of books published in more than one volume, or of

periodicals published in numbers, or of engravings, photographs, or other

articles published with variations, a copyright is to be entered for

each volume or part of a book, or number of periodical, or variety, as to

style, title, or inscription, of any other article.

(11). To secure a copyright for a painting, statue, or model or design

intended to be perfected as a work of fine arts, so as to prevent

infringement by copying, engraving, or vending such design, a definite

description must accompany the application for copyright, and a photograph

of the same, at least as large as "cabinet size," should be mailed to the

Librarian of Congress within ten days from the completion of the work or

design.

(12). Copyrights cannot be granted upon Trade-marks, nor upon Labels

intended to be used with any article of manufacture. If protection for

such prints or labels is desired, application must be made to the Patent

Office, where they are registered at a fee of $6 for labels and $25 for

trade-marks.

(13). Every applicant for a copyright must state distinctly the name and

residence of the claimant, and whether the right is claimed as author,

designer, or proprietor. No affidavit or formal application is required.

OFFICE OF THE LIBRARIAN OF CONGRESS.

Transcriber's Notes.

Spelling appears to be evolving between US/UK e.g. both color and

colour, vapor and vapours are seen.

Corrected obvious typos:

guage -> gauge

decending -> descending

radical -> radial

artifical -> artificial

comtemplated -> contemplated

barometor -> barometer

p417. "namely [inserted 'a feeder'], a simple contrivance"

Chapter headings in Contents do not always match chapter headings

in text. II. Building a Boathouse -> II. Building of a Boat House.

Inconsistent hyphenation left as printed:

Both boat house and boat-house are used several times.

Both typewriter and type-writer are used several times.

Both Wheel-barrow and wheelbarrow are used several times.

Both EVERYDAY and every-day are used several times.

Moved equations to single lines to make them clearer.

Some maths errors were found in the text, they have been corrected

as follows:

p126. "find that it has taken five and one-third

times as long, or 10 minutes to do this work."

10 should read 107.

p141. The equation

P2[pi][nu] - Wp = 0 or -- = p2[pi][nu]/p

should read:

P2[pi][nu] - Wp = 0 or -- = P2[pi][nu]/p

p241. The equation

(AB × CD)/2 × AB × 140 lb. = (2 - 3)/2 × 8/1 × 149 lb. = 2,800lb.

should read

(AB + CD)/2 × AC × 140 lb. = (2 + 3)/2 × 8/1 × 140 lb. = 2,800 lb.

p353. 1:733 -> 1.733

p141. and p142. For clarity, the numbering of the equations has been

changed from a mixture of [N] and (N) to (N) only, and the mix

of using [N.] and [N] have been changed so all numbering and

references to the numbering have no "."

The maths in this sequence of equations has gone wrong somewhere

probably due to a mistyped w for W, r' for r'' or a missed divisor.

Corrected incorrect figure references:

p297. D1 -> D´, E1 -> E´

p298. E1 -> E´

p299. G1 -> G´, H1 -> H´, G1 -> G, J1 -> J

p401. Fig. 2 should be Fig. 227

Left as printed:

Inconsistent use of italics between figures and text unless needed to

make description in text unambiguous.

Inconsistent hyphenation in measurements e.g. 7-1/2-in. and 3-1/2 in.