[Illustration: Diagram of apparatus as described in text]
If into certain sacrificial vessels a coin of five drachms be thrown,
water shall flow out and surround them. Let A B C D (fig. 21) be a
sacrificial vessel or treasure chest, having an opening in its mouth,
A; and in the chest let there be a vessel, F G H K, containing water,
and a small box, L, from which a pipe, L M, conducts out of the chest.
Near the vessel place a vertical rod, N X, about which turns a lever, O
P, widening at O into the plate R parallel to the bottom of the vessel,
while at the extremity P is suspended a lid, S, which fits into the box
L, so that no water can flow through the tube L M: this lid, however,
must be heavier than the plate R, but lighter than the plate and coin
combined. When the coin is thrown through the mouth A, it will fall
upon the plate R and, preponderating, it will turn the beam O P, and
raise the lid of the box so that the water will flow: but if the coin
falls off, the lid will descend and close the box so that the discharge
ceases.
22. _A Vessel from which a variety of Liquids may be made to flow
through one Pipe._
[Illustration: Diagram of apparatus as described in text]
Several kinds of liquid having been poured into a vessel through one
mouth, it is required that through the same pipe they shall flow out
separately at pleasure. Let A B (fig. 22) be a vessel closed at the
neck by the partition C D; and let there be in it several vertical
partitions, extending to the partition C D and making as many chambers
as we wish to pour in liquids. Suppose, for the present, that these
are two in number, and let the partition be E F. In the partition C D
pierce fine holes, as in a sieve, opening into each chamber, and air
holes, G, H, close to the partition, also opening into the chambers:
again, at the bottom let there be small tubes, K, L, communicating
with the chambers and opening into the common pipe M. If, having first
closed the vents G, H, and the pipe M, we pour one of the liquids
through the mouth of the vessel, it will enter into neither chamber, as
the air has no means of escape: but if one of the vents be opened, the
liquid will pass into that chamber to which the vent belongs; and if,
after closing this vent again, we pour in the other liquid and set free
the other vent, the liquid will pass into the other chamber. Now let
all the vents and the sieve-like holes be closed, and, on opening the
pipe M, no discharge can take place until one of the vents be opened;
when, the air having found an entrance, the liquid contained in that
chamber will flow out. If this vent be closed and the other opened, the
same result will follow.
23. _A Flow of Wine from one Vessel, produced by Water being poured
into another._
[Illustration: Diagram of apparatus as described in text]
If of two vessels standing on a pedestal one be full of wine and the
other empty, whatever quantity of water be poured into the empty
vessel, as much wine shall flow from the other. The following is the
construction. On any pedestal, A B (fig. 23) let there be two vessels,
C D, E F, having their mouths closed by the partitions G H, K L. Let
the tube M N X O pass through the pedestal and bend upwards into the
vessels, reaching very nearly to the partitions at M and O. In E F
place a bent siphon, P R S, the bend being near the vessel’s mouth,
and one leg, shaped like a water-pipe, passing outside. Through the
partition G H let a funnel, T U, descend almost to the bottom of the
vessel, its tube being soldered into the partition. Into the vessel E F
pour wine through a hole, Q, which must afterwards be carefully closed
again. Now, if we pour water into the vessel C D through the funnel,
the contained air will be forced out, and pass through the tube M N X
O into E F, and, in its turn, force out the wine contained in E F: and
this will happen as often as we pour in the water. It is evident that
the air forced out has an equal bulk with the water poured in, and that
it will force out as much wine. If no bent siphon be used, but merely a
pipe at S, the effect will be the same, unless the force of the water
be too great for the pipe.