rain-water from impurities. One of these, bearing the name of
Roberts, is illustrated in Fig. 4. Its principle of action is to
reject the first portion of the rain which falls (as it is this
which chiefly washes the dirt off the roof), and only to collect the
latter portion of the rain. The water from the roof first runs on
to a strainer, that intercepts rubbish; it then passes through one
of two channels in the upper part of the canter, balanced upon a
pivot. At the commencement of a shower, the canter is raised in the
position shown in Fig. 4, “running to waste,” and the bulk of the
water passes through a channel which directs it into the lower or
wastewater outlet. Meanwhile, a very small proportion of the water is
accumulating in the lower part of the canter, very slowly in light
rain but more rapidly in heavy rain, so that it is filled up by the
time the roof has become clean. Then the weight of water causes it
to fall down as shown in Fig. 4A “running to storage,” so that the
clean water may run through the upper storage outlet pipe. This very
useful little apparatus is made and sold by C. G. Roberts, Collards,
Haslemere, Surrey.
[Illustration: 4A. Rain-water Separator.]
Perhaps this affords as good an opportunity as any of drawing
attention to the highly artistic rain-water heads that have lately
been introduced by Thomas Elsley, of 32 Great Portland Street, W.
These are made to suit every style of architecture and every variety
of roof and guttering, and practically without limit as to size.
Their quality is beyond praise.
It is essential to bear in mind that rain-water is liable to exert
considerable solvent action on lead, consequently pipes and cisterns
of this metal must be avoided. The pipes may be of iron, or of
specially lead-encased block-tin, and the cisterns of “galvanised”
iron or slate.
As Eassie has pointed out, there is much to be considered in the
arrangement of rain-water pipes from a sanitary point of view, where
a separator and storage tank are not in use, because the foul air
delivered from them is sucked into the rooms near the roof, on which
the sun’s heat pours. A fire lighted in a room develops the same
danger when the rain-water pipe terminates near the windows of the
room. Another danger accruing from rain-water pipes which connect
directly with the drain is due to the fact that the joints of the
iron rain-water pipes are seldom air-tight, and foul air is therefore
often driven or sucked into the rooms when the windows are open. It
is easy to imagine how dangerous this must be in houses which have
been fitted up with iron (or even lead) rain-water pipes running down
the interior walls, and having their terminations close to a dormer
window, skylight, or staircase ventilator on the roof, with the foot
of the rain-water pipe taken direct into a drain leading to a town
sewer. But the risk is greatly increased when the rain-water pipes
are connected with a closed cesspool, to which the rain-water pipe is
acting as a ventilator.
When rain-water pipes deliver into the drain directly, they are
often made to act as soil pipes from the closets, in which case the
evil is intensified. The soil from the closets is apt to adhere to
the interior of the pipe, generally on the side opposite to that
traversed by the rain-water, and the poisonous smell escapes at any
bad joints and always at the roof orifice.
When the rain-water pipe is of cast iron, other sources of danger are
present if the pipe is used also for conveying soil from a closet.
Unless the rim of the soil pipe from the closet is joined to the
rain-water pipe by a proper cast-iron socketed joint, the connection
must be made by means of a piece of lead pipe which receives the soil
pipe, and the joint between the lead soil pipe and the upper and
lower parts of the cast-iron pipe cannot be properly soldered. Here
sometimes grievous calamity follows cases where the combined pipe is
ventilating the drain and sewer; the pipe joints are frequently open,
and when the windows are unclosed for ventilation the foul air is
whisked into the house. Eassie insists that it is cheaper to owner
and dweller alike to have a separate soil-pipe erected at first.
[Illustration: 5. Outlet of Rain-water Pipes.]
All rain-water pipes should deliver into the open air, and have no
connection with the drains, except when they are disconnected. They
should discharge their contents over a gully grating as at _a_, Fig.
5, or underneath the grating as at _b_, the ends of the pipes in both
cases being in the open air. Every householder should insist upon
this being carried out. But occasionally the rain-water pipes descend
inside the house and there is no open yard where a disconnecting
gully can be fixed. In such a case a separate drain should be laid
to the nearest area or yard, and separation ensured. In laying down
new drains in a house, where the rain-water pipes must descend in the
interior, it will be better to provide a separate or twin drain to
the nearest open-air space.
Provision must be made at the roof for keeping foreign matters out
of the rain-water pipes. Leaves, soot, and dirt will accumulate
round the pipe orifices, and very often will cause the gutter to be
flooded during a storm. The usual way to avert this is to fix over
the opening of the pipe in the bottom of the gutter a galvanised open
wire half-globe, or a raised cap of thick lead pierced with tolerably
large holes. The cost for this is trifling, but the value is great.
Whenever rain-water pipes _must_ run down the inside wall of a house,
lead should be adopted. Sometimes rain-water pipes are taken down in
the interior, when a very little initial study could have brought
them to the exterior face of a wall--where alone they should be
taken, whenever it is possible to do so.
On attic roofs, and where only one side of the house can be used
for the attachment of rain-water pipes, the water from one side is
brought across the roof by means of a “box” gutter of wood, lined at
the bottom and sides with lead or zinc, and covered with a board.
This often emits a very foul smell, owing to the accumulation of
decaying matter. When such guttering cannot be avoided, it should
occasionally--say once a week--be carefully cleaned out. The same
matters will sometimes silt up and stop the gullies, shown at the
foot of the rain-water pipes (Fig. 5), hence it is equally necessary
to see that these traps are cleaned out, say monthly.
Rain-water pipes are often made the waste pipes of lavatories, baths,
sinks, and slop-pails. When properly disconnected at the foot, in the
open air, and when the top of the rain-water pipe does not terminate
under a window of an inhabited room, this does not much matter;
but when the court-yard is limited in area, and there is a window
belonging to a living or sleeping room just overhead, where the rain
from the roof delivers itself into the upright pipe, an offence will
arise from the decomposing fats of soap, which form a slimy mess
adhering to the interior of the pipe, that no amount of rainfall will
dislodge.
_Cisterns._--Cisterns should be in a cistern-room if possible, but,
at all events, placed where they can be got at, covered over with
suitable fittings, and ventilated to the open air. A drinking-water
cistern should never be placed in a water-closet, for no amount of
disconnection in such a case will suffice to counteract its evil
surroundings. Neither should it be placed in a bath-room, which is
liable to a steam-laden atmosphere. Nothing can be said against a
site out of doors, on the flats, or below (if away from dustbins and
ash-heaps); but in such cases the cistern, with its service pipes,
should be well protected from frost. The position of a cistern
should be equally carefully chosen no matter whether the supply
be constant or intermittent, or whether there be a high or a low
pressure cistern. And not only should it be made certain that the
“standing waste” pipe of the cistern delivers in the open air, but
that any “overflow” pipe of the cistern delivers in like cleanly
fashion. It is too common to take these wastes down to the nearest
sink. It might prove expedient to thus disconnect a cistern waste
when time presses, and when the alternative is costly, but the
practice is not to be commended.
Eassie’s strictures with regard to cisterns apply equally to those
feed cisterns which supply hot-water circulating cisterns or boilers
where water is heated for kitchen, scullery, still-room, or bath-room
uses. It is too common to find the feed cistern, which is the small
iron cistern that automatically keeps the kitchen or other basement
boiler full, placed in the darkest corner of the commonest stowaway
cupboard, with its overflow pipe joined to the drain.
The materials of which cisterns are constructed vary much in town and
country. In old houses will be frequently found cisterns formed of
slabs of stone, just as they have been raised from the quarry, and
sometimes of slabs of rough slate, and than these, provided they are
regularly cleaned out and the waste pipes disconnected, probably no
better basement cistern could be found. The same might perhaps be
said of brickwork cemented inside. Cisterns composed of slate possess
a drawback in their weight, which sometimes prevents them from being
adopted upstairs. It has become a frequent practice now to have them
enamelled white inside, so that the slightest discoloration of the
water, or sediment at the bottom, can be instantly detected.
Cisterns composed of metal throughout embrace old cisterns of cast
lead, dated early in the 18th century; these are quite harmless,
on account of their natural silver alloy, and they may be trusted,
all other conditions being satisfactory. Cast-iron cisterns, made
of plates bolted together, if kept full, and not subject to rust,
are unobjectionable. Wrought iron, which has afterwards been
“galvanised,” is a very common form of cistern, and appears to
be the cheapest. Little can be said in its disfavour, although
experiments made in America have proved that some waters attack the
inner coating. The commonest form of cistern is composed of wooden
framing lined inside with sheet lead. This is not the best for
storing drinking-water, and slate would be preferable; but no one
would say that all water drawn from leaden cisterns would injuriously
affect health. The interior of a lead-lined cistern will be found to
acquire a whitish coating, and it is due to this chemical alteration
of its surface that the contained water can be drunk with more
or less impunity. Nevertheless, there are some waters which very
readily attack lead, and care should be exercised in this respect.
In cleaning out a lead cistern the surface should never be scraped,
but simply washed down with a moderately hard brush. Sometimes houses
are provided with zinc-lined wooden cisterns; this metal for several
reasons is one of the worst materials for water storage, and should
never be used for drinking-water. Neither should wooden butts or
barrels be employed for storing water anywhere in a house, as they
speedily become lined with a low vegetable growth detrimental to
health.
A great mistake consists in storing away a great quantity of water in
abnormally large cisterns, in consequence of which the tap is drawing
off for a very long period the water first delivered to it, and which
is not the cleanest water. This does not so much matter in cisterns
which supply closets or baths, but it is reprehensible when the water
is for the bedroom decanter and the nursery.
_Pipes._--Pipes for conveying water are generally of lead, because it
is more easily bent than any other metal; but frequently iron pipes
are substituted when the water main has to be brought from a great
distance. Eassie remarks that the conveyance of some waters in long
lengths of leaden pipe, in which the water must necessarily stand,
and the use of leaden suction pipes in wells, is not a thing to be
looked upon with great favour. Hence it is that galvanised iron pipes
are used by some, and in the case of water conveyance from a long
distance, the cast-iron pipes coated inside with Dr. Angus Smith’s
solution, or subjected to the Bower-Barff system of protection
against rust, are now very largely adopted. Glass-lined pipes of the
American pattern have also been introduced into this country, but
have not yet made much headway, which is a pity, seeing that glass
forms the best of all conduits for water. Much depends upon whether
the water is of such a character as to rapidly decompose lead.
Leaden pipes, of sufficient weight per lineal foot, may fitly
conduct the flushing water for closets and the cold water to baths
and lavatories; but what is called “lead-encased block-tin pipe”
should be used in conveying water from the separate drinking-water
cistern. The cost is some 50 per cent. more than for leaden pipe,
and there is more difficulty in making the joints, but these points
are overbalanced by the certainty of non-pollution of the water.
Water pipes should be fixed in separate wall chases, easy of access.
Service pipes should also be kept separate from each other, and
provided with proper stop-cocks in case of accident.
_Pumps._--It will not be out of place here to offer a few remarks
on the construction, capacity, and working of the 3 kinds of common
pump in everyday use--i.e. (1) the lift-pump; for wells not over
30 ft. deep, (2) the lift and force, for wells under 30 ft. deep,
but forcing the water to the top of the house, and (3) the lift and
force, for wells 30-300 ft. deep.
The working capacity of a pump is governed by the atmospheric
pressure, which roughly averages 15 lb. per sq. in. It is also
necessary to remember that 1 gal. of water weighs 10 lb. The quantity
of water a pump will deliver per hour depends on the size of the
working barrel, the number of strokes, and the length of the stroke.
Thus, if the barrel is 4 in. diam., with a 10 in. stroke, piston
working 30 times a minute, then the rule is--square the diameter of
the barrel and multiply it by the length of stroke, the number of
strokes per minute, and the number of minutes per hour, and divide by
353, thus:--
42 in. × 10 in. stroke × 30 strokes × 60 minutes
------------------------------------------------
353
= 815 gal. per hour. About 10 per cent. is deducted for loss. The
horse-power required is the number of lb. of water delivered per
minute, multiplied by the height raised in ft., and divided by
33,000. Thus:--
815 gal. × 10 lb. × 30 ft. lift
------------------------------- = 7·4 H.P.
33,000
[Illustration: 6. Lift Pump.]
Fig. 6 shows a vertical section of the simple lift-pump. _a_ is the
working barrel, bored true, to enable the piston or bucket _b_ to
move up and down, air-tight. The usual length of barrel in a common
pump is 10 in. and the diameters are 2, 2½, 3, 3½, 4, 5, and 6 in.;
a 3 in. barrel is called a 3 in. pump. The stroke is the length of
the barrel; but a crank, 5 in. projection from the centre of a shaft,
will give a 10 in. stroke at one revolution; but in the common pump
shown, use is made of a lever pump handle, whose short arm _c d_
is about 6 in. long, and the long arm or handle _d e_ is usually
36 in., making the power as 6 to 1; _f_ is the fulcrum or prop.
Improved pumps have a joint at _f_, which causes the piston to work
in a perpendicular line, instead of grinding against the side of the
barrel. The head _g_ of the pump is made a little larger than the
barrel, to enable the piston to pass freely to the barrel cylinder;
in wrought-iron pumps, the nozzle is riveted to the heads, and unless
the head is larger than the barrel these rivets would prevent the
piston from passing, and injure the leather packing on the bucket.
The nozzle _h_, fixed at the lower part of head, is to run off the
water at each rise of the piston. There is 1 valve _i_ at the bottom
of the barrel, and another in the bucket _b_.
The suction pipe _k_ should be ⅔ the diameter of the pump barrel.
A rose _l_ is fixed at the end of the suction pipe to keep out any
solid matter that might be drawn into the pump and stop the action
of the valves. The suction pipe must be fixed with great care. The
joints must be air-tight: if of cast flange-pipe, which is the most
durable, a packing of hemp, with white and red lead, and screwed up
with 4 nuts and screws, or a washer of vulcanised rubber ⅜ in. thick,
with screw bolts, is best. If the suction pipe is of gas-tube, the
sockets must all be taken off, and a paint of boiled oil and red-lead
be put on the screwed end, then a string of raw hemp bound round and
well screwed up with the gas tongs, making a sure joint for cold
water, steam, or gas.
Many plumbers prefer lead pipe, so that they can make the usual
plumbers’ joint. The tail _m_ of the pump is for fixing the suction
pipe on a plank level with the ground. Stages _n_ are fixed at every
12 ft. in a well; the suction pipe is fixed to these by a strap
staple, or the action of the pump would damage the joints. There are
two plans for fixing the suction pipe; (1) in a well _o_ directly
under the pump; (2) the suction pipe _p_ may be laid in a horizontal
direction, and about 18 in. deep under the ground (to keep the water
from freezing in winter) for almost any distance to a pond, the only
consideration being the extra labour of exhausting so much air. In
the end of such suction pipe _p_ it is usual to fix an extra valve,
called a “tail” valve, to prevent the water from running out of the
pipe when not in use. The action is simply explained. First raise the
handle _e_, which lowers the piston _b_ to _i_; during this movement
the air that was in the barrel _a_ is forced through the valve in
the piston _b_; when the handle is lowered, and the piston begins to
rise, this valve closes and pumps out the air; in the meantime the
air expands in the suction pipe _k_, and rises into the barrel _b_
through the valve _i_; at the second stroke of the piston this valve
closes and prevents the air getting back to the suction pipe, which
is pumped out as before. After a few strokes of the pump handle, the
air in the suction pipe is nearly drawn out, creating what is called
a vacuum, and then as the water is pressed by the outward air equal
to 15 lb. on the sq. in., the water rises into the barrel as fast as
the piston rises: also the water will remain in the suction pipe as
long as the piston and valves are in proper working order.
The following table of dimensions for hand-worked simple lift-pumps
will be found useful:--
+-----------+-------------+---------------+--------+------------+
|Height for | |Water delivered|Diam. of|Thickness of|
|Water to be| Diam. of | per Hour at |Suction | Well Rods |
| raised. |Pump Barrel. |30 Strokes per | Pipe. | for Deep |
| | | Min. | | Wells. |
+-----------+-------------+---------------+--------+------------+
| ft. | in. | gal. | in. | in. |
| 14 | 6 | 1640 | 4 | 1 |
| 20 | 5 | 1110 | 3 | 1 |
| 30 | 4 | 732 | 2½ | ⅞ |
| 40 | 3½ | 555 | 2½ | ¾ |
| 50 | 3 | 412 | 2 | ¾ |
| 75 | 2½ | 260 | 2 | ⅝ |
| 100 | 2 | 183 | 1½ | ⅝ |
+-----------+-------------+---------------+--------+------------+
[Illustration: 7. Lift and Force Pump. 8. Deep-well Pump.]
Fig. 7 shows a lift- and force-pump suitable for raising water from
a well 30 ft. deep, and forcing it to the top of a house. The pump
barrel _a_ is fixed to a strong plank _b_, and fitted with “slings”
at _c_ to enable the piston to work parallel in the barrel, a guide
rod working through a collar guiding the piston in a perpendicular
position, _d_ is the handle. The suction pipe _e_ and rose _f_ are
fixed in the well _g_ as already explained. At the top of the working
barrel is a stuffing-box _h_, filled with hemp and tallow, which
keeps the pump rod water-tight. When the piston is raised to the top
of the barrel, the valve _i_ in the delivery pipe _k_ closes, and
prevents the water descending at the down-stroke of the piston. The
valve in the bucket _l_, also at _m_ in the barrel _a_, is the same
as in the common pump. The pipe _k_ is called the “force” for this
description of pump.
Fig. 8 shows a design for a deep-well pump, consisting of the usual
fittings--viz. a brass barrel _a_, a suction pipe with rose _b_,
rising main pipe _c_, well-rod _d_, wooden or iron stages _e f g_,
and clip and guide pulleys _h_. The well-rod and the rising main must
be well secured to the stages, which are fixed every 12 ft. down the
well. An extra strong stage is fixed at _i_, to carry the pump--if of
wood, beech or ash, 5 ft. × 9 in. × 4 in.; the other stages may be 4
in. sq.
The handle is mounted on a plank _k_ fitted with guide slings, either
at right angles or sideways to the plank. The handle _l_ is weighted
with a solid ball-end at _m_, which will balance the well-rod fixed
to the piston. By fixing the pump barrel down the well about 12 ft.
from the level of the water, the pump will act better than if it were
fixed 30 ft. above the water, because any small wear and tear of the
piston does not so soon affect the action of the pump, and therefore
saves trouble and expense, as the pump will keep in working order
longer. It is usual to fix an air-vessel at _n_. The valves _o_ are
similar to those already described. In the best-constructed pumps,
man-holes are arranged near the valves to enable workmen to clean
or repair the same, without taking up the pump. Every care should
be given to make strong and sound joints for the suction pipe and
delivery pipe, as the pump cannot do its proper duty should the pipes
be leaky or draw air.
To find the total weight or pressure of water to be raised from a
well, reckon from the water level in the well to the delivery in the
house tank or elsewhere. For example, if the well is 27 ft. deep, and
the house tank is 50 ft. above the pump barrel; then you have 77 ft.
pressure, or about 39 lb. pressure per sq. in. That portion of the
pipe which takes a horizontal position may be neglected. The pressure
of water in working a pump is according to the diameter of the pump
barrel. Suppose the barrel to be 3 in. diam., it would contain 7 sq.
in., and say the total height of water raised to be 77 ft., equal
to 39 lb. pressure, multiplied by 7 sq. in., is equal to 539 lb. to
be raised or balanced by a pump handle; then if the leverage of the
pump handle were, the short arm 6 in. and long arm 36 in., or as 6 to
1, you have (539 × 1) ÷ 56 = 90 lb. power on the handle to work the
pump, which would require 2 men to do the work, unless you obtained
extra leverage by wheel work. When the suction or delivery pipe is
too small, it adds enormously to the power required to work a pump,
and the water is then called “wiredrawn.” When pumps are required for
tar or liquid manure, the suction and delivery pipe should be the
same size as the pump barrel, to prevent choking.
The operations of plumbing and making joints in pipes will be found
fully described and illustrated in ‘Spons’ Mechanics’ Own Book’; and
many other methods of raising water for household and agricultural
purposes are explained in ‘Workshop Receipts,’ 4th series.
_Purification._--At a recent meeting of the Institution of Civil
Engineers, Prof. Frankland read a paper dealing with the question of
water purification, in which he remarked that the earliest attempts
to purify water dealt simply with the removal of visible suspended
particles; but later, chemists have turned their attention to the
matters present in solution in water. Since the advance of the
germ theory of disease, and the known fact that living organisms
were the cause of some, and probably of all, zymotic diseases, the
demand for a test which should recognise the absence or presence of
micro-organisms in water had become imperative. It was, however, only
during the last few years that any such test had been set forth, and
this was owing to Dr. Koch, of Berlin. By this means the only great
step which had been made since the last Rivers Pollution Commission
had been achieved. It had been supposed that most filtering materials
offered little or no barrier to micro-organisms; but it was now known
that many substances had this power to a greater or less degree. It
had also been found that, in order to continue their efficiency,
frequent renewal of the filtering material was necessary.