[Illustration: Diagram of apparatus as described in text]
The siphons used in conflagrations are made as follows. Take two
vessels of bronze, A B C D, E F G H, (fig. 27), having the inner
surface bored in a lathe to fit a piston, (like the barrels of
water-organs), K L, M N being the pistons fitted to the boxes. Let
the cylinders communicate with each other by means of the tube X O
D F, and be provided with valves, P, R, such as have been
explained above, within the tube X O D F and opening outwards from the
cylinders. In the bases of the cylinders pierce circular apertures,
S, T, covered with polished hemispherical cups, V Q, W Y, through
which insert spindles soldered to, or in some way connected with, the
bases of the cylinders, and provided with shoulders at the extremities
that the cups may not be forced off the spindles. To the centre of
the pistons fasten the vertical rods S E, S E, and attach to these
the beam A´ A´, working, at its centre, about the stationary
pin D, and about the pins B, C, at the rods S E, S E. Let
the vertical tube S´ E´ communicate with the tube X O D F, branching
into two arms at S´, and provided with small pipes through which to
force up water, such as were explained above in the description of
the machine for producing a water-jet by means of the compressed air.
Now, if the cylinders, provided with these additions, be plunged into
a vessel containing water, I J U Z, and the beam A´ A´ be made to work
at its extremities A´, A´, which move alternately about the pin D, the
pistons, as they descend, will drive out the water through the tube
E´ S´ and the revolving mouth M´. For when the piston M N ascends it
opens the aperture T, as the cup W Y rises, and shuts the valve R; but
when it descends it shuts T and opens R, through which the water is
driven and forced upwards. The action of the other piston, K L, is the
same. Now the small pipe M´, which waves backward and forward, ejects
the water to the required height but not in the required direction,
unless the whole machine be turned round; which on urgent occasions is
a tedious and difficult process. In order, therefore, that the water
may be ejected to the spot required, let the tube E´ S´ consist of
two tubes, fitting closely together lengthwise, of which one must be
attached to the tube X O D F, and the other to the part from which the
arms branch off at S´; and thus, if the upper tube be turned round,
by the inclination of the mouthpiece M´ the stream of water can be
forced to any spot we please. The upper joint of the double tube must
be secured to the lower, to prevent its being forced from the machine
by the violence of the water. This may be effected by holdfasts in the
shape of the letter L, soldered to the upper tube, and sliding on a
ring which encircles the lower.
28. _An Automaton which drinks at certain times only, on a Liquid being
presented to it._
[Illustration: Diagram of apparatus as described in text]
In any place provided with running water make a figure of some animal
in bronze or any other material: when a cup is offered to it, the
animal shall drink with a loud noise so as to present the appearance of
thirst. The following is the construction. A B (fig. 28) is a vessel
into which a stream of running water, C, falls. In A B place a bent
siphon or inclosed diabetes, D E F, one leg of which must project below
the bottom of the vessel. Underneath this let there be an air-tight
pedestal, G H K L, also containing a bent siphon, M N X. Below the
orifice F place a funnel, O P, the tube of which must descend into the
pedestal leaving a passage for the water between its extremity and the
bottom. Let the mouth of the animal be at R, from which a concealed
tube, R S T, must run along one of the feet, or some other part, into
the pedestal. When the vessel A B is filled, the water will overflow
and run into the funnel, filling the pedestal G H K L and emptying
the vessel A B; in like manner, when the pedestal is full, the water
will overflow through the siphon M N X and empty the pedestal; and, as
this becomes empty, the air will enter through the mouth R to fill up
the void that is left. If, then, we apply a drinking vessel at R, the
liquid will be violently attracted and sucked down instead of the air,
until the pedestal within has become empty. Then the vessel A B is
again filled and emptied, and the same will take place as before. In
order that the cup may be applied at the right time, that is, when the
water is being drawn off from the pedestal, let something be contrived
that will move when struck by water from the discharge through the
siphon M N X. When this is seen to move, apply the drinking cup.
29. _An Automaton which may be made to drink at any time, on a Liquid
being presented to it._
[Illustration: Diagram of apparatus as described in text]
There is another way in which, by the aid of running water, the animal
may be made to drink on the revolution of a carved figure of Pan. Let
A B C D (fig. 29) be a pedestal, air-tight on every side, and divided
into two chambers by a partition. On the surface place the animal, and
let the tube E F G pass through its mouth. Within the pedestal, in
the lower chamber, let there be a bent siphon, H K L, the lower leg
projecting from the bottom: and let a funnel, M N, pass through the
middle of the partition, its tube reaching nearly to the bottom. On the
pedestal A B C D place another pedestal, O X, on which the figure of
Pan, P R, is to stand, having attached to it the rod S which projects
below into the pedestal. To S let the tube T U be fastened, at the end
of which is the cup U Q, attached to and communicating with the tube.
Let the tube be of such a length that, when the figure P R turns round,
the cup U Q will be directly above the funnel M N. On the pedestal, and
communicating with it, and directly above the funnel M N, place the
cup W Y. Let the stream Z, (which must be greater than the discharge
through the siphon H K L), flow into W Y: the liquid will pass through
M N into the lower part of the pedestal, the contained air passing out
through E F G: and now the pedestal will continue full as the influx is
greater than the discharge. But, when we turn the figure P R round, the
cup U Q will intercept the stream Z, which will pass elsewhere through
the tube T U, and, as the water no longer flows into the lower chamber
of the pedestal, the siphon H K L will empty it, and the air will enter
through E F G. Thus, when the cup is applied, the animal will drink as
before.
30. _An Automaton which will drink any quantity that may be presented
to it._
[Illustration: Diagram of apparatus as described in text]
The animal may be made to drink without the aid of running water,
or of any thing to move the figure of Pan. Let A B C D (fig. 30) be
a pedestal, and E the mouth of the animal, through the breast and
hinder foot or tail of which a tube, E F G, is inserted, leading from
the mouth E to the interior of the pedestal. The pedestal having
been first firmly fixed, let a hole, E, so fine as to be scarcely
discernible, be bored in the tube E F G which passes through the
animal, in a line with the extremity G. Now if we fill the siphon E F G
with water through some pipe above it, the mouth of which is applied to
E, the siphon will continue full since its two orifices lie in the same
level. If, therefore, a drinking vessel be brought to the mouth E, and
a portion of the mouth immersed in it, it will be found that the leg of
the siphon towards G has become the longer, so that it will attract the
water, and the water attracted is carried into the pedestal A B C D. In
this construction it is not necessary that A B C D should be air-tight.
31. _A Wheel in a Temple, which, on being turned, liberates purifying
Water._
In the porticoes of Egyptian temples revolving wheels of bronze are
placed for those who enter to turn round, from an opinion that bronze
purifies. There are also vessels of lustral water, from which the
worshippers may sprinkle themselves. Let it then be required so to
construct a wheel that, on turning it round, water shall flow from
it to sprinkle the worshippers as we have described. Behind the
entrance-pillar let a vessel of water, A B C D (fig. 31), be concealed,
having a hole, E, perforated in its base. Underneath the base let a
small tube, F G H K, be fastened, having also a hole bored opposite the
orifice in the base, and within this place another tube, L M, soldered
to the tube F G H K at L, and opposite the orifice having in like
manner a hole, S: between these two pipes let another pipe, N X O R,
be closely fitted, with a hole at P opposite to E. Now, if the several
holes are in one line, when water is poured into the vessel A B C D it
will flow out through the pipe L M; but, if the pipe N X O R is made to
revolve so as to change the position of the hole P, the discharge will
cease. Attach the wheel to the pipe N X O R, and, if it is repeatedly
made to revolve, water will flow out.
32. _A Vessel containing different Wines, any one of which may be
liberated by placing a certain Weight in a Cup._
If several kinds of wine be poured into a vessel by its mouth, any one
of them at choice may be drawn out through the same pipe: so that,
if several persons have poured in the several wines, each one may
receive his own according to the proportion poured in by him. Let A
B C D (fig. 32), be an air-tight vessel, the neck of which is closed
by a partition, E F; and let the whole vessel be divided into as many
compartments as we intend there shall be different kinds of wine.
Suppose, for instance, that G H, K L, are the partitions, making three
compartments, M, N, and X, into which the wine will be poured. In the
partition E F pierce small holes, one in each compartment, O, P, R; and
from these holes let small tubes, P S, O T, R U, communicating with the
vessel, extend up into the neck. Perforate the partition E F, near
each tube, with fine sieve-like holes, through which the liquid will
pass into the compartments. When it is desired to pour in each kind of
wine, place the fingers on S, T, and U, and pour in the wine through
the neck Q; it will not pass into either of the compartments as the air
contained in them has no outlet. But, if we set free one of the vents
S, T, or U, the air contained in the corresponding compartment will
pass out through the passage as the wine falls into the compartment.
Then, placing the finger again on this vent, set another free in like
manner, and pour in another kind of wine: and so in order with the
rest, as many as there may be both of compartments and kinds of wine.
We may procure each wine, in its due quantity, through the same pipe in
the following manner. In the base of the vessel A B C D let there be
tubes leading from each compartment, W Y from M, Z A´ from N, and B´ C´
from X: the extremities of these tubes Y, A´ and C´, must communicate
with another tube Y A´ C´, into which another tube, E´ F´, is tightly
fitted, closed at the interior extremity F´, and having holes pierced
in it opposite to Y, A´, and C´ so that, as the tube E´ F´ revolves,
when the holes pierced in it coincide consecutively with the holes Y,
A´, and C´, they may admit the wine contained in each chamber and send
it forth through the outer mouth of the tube E´ F´. To the tube E´ F´
attach an iron rod, G´ H´; to this, at the extremity H´, solder a mass
of lead, K´, and at G´ an iron pin, L´ M´, to the middle of which is
fastened a cup, L, with the concavity upwards: let the interior of this
be a hollow truncated cone of which M´ is the larger circle and N´ the
less, and through this the pin L´ M´ is to pass. Take several balls
of lead, varying in weight, and equal in number to the compartments
M, N, X; and if we place the least of the balls in the cup M´ N´, it
will descend by its weight until it touches the hollow surface of the
truncated cone, causing the tube E´ F´ to revolve until the hole in it
coincides with Y and admits the wine in the compartment M, which will
flow as long as the ball remains in the cup, unless it be entirely
exhausted: when we remove the ball the weight K´ will turn back and
close the orifice Y, and the discharge will cease. Again, insert
another of the balls, and the cup will descend lower and turn the
tube E´ F´ further round until the hole in it reaches the hole A´, and
then the wine in N will flow: as before when the ball is removed the
weight K´ will run down and close the orifice A´, and the wine will
cease to flow. If another ball still heavier be placed in the cup, the
tube E´ F´ will be turned still further round, so that the wine in the
compartment X will flow. It is necessary however that the least of the
balls when placed in the cup should preponderate over the weight K´,
or, in other words, be able to cause E´ F´ to revolve; for then the
other balls will preponderate and move E´ F´.