[Illustration: Diagram of apparatus as described in text]
The construction of a flagon which utters a sound when liquid is forced
from it. Take a flagon (fig. 62), such as is about to be described,
the neck of which is closed by the plate A B, and the mouth by C D;
and through both these partitions, fitting into them air-tight, let
a tube, E F, be inserted. G H is the handle of the flagon, and K L a
tube placed in the opposite side of the neck, fitting closely into the
partition A B and far enough distant from C D to allow of the passage
of water: in C D let there be a small pipe M such as will utter sound.
The flagon may be filled through the tube E F, the air passing out
through the tube K L and the pipe M; and if we take the handle of the
flagon and incline it so as to pour out the contents, water will flow
out of the vessel through the tube E F, and into the neck B C through K
L: the air contained in the neck being forced out through M gives forth
a sound. There should be another hole in A B through which air may pass
again when the vessel is righted.
63. _A Water-Clock, made to govern the quantities of Liquid flowing
from a Vessel._
[Illustration: Diagram of apparatus as described in text]
A vessel containing wine, and provided with an open spout, stands upon
a pedestal: it is required by shifting a weight to cause the spout to
pour forth a given quantity,—sometimes, for instance, a half cotyle (¼
pint), sometimes a cotyle (½ pint), and, in short, whatever quantity we
please. A B (fig. 63), is the vessel into which wine is to be poured:
near the bottom is a spout, D: the neck is closed by the partition E
F, and through E F is inserted a tube, G H, reaching nearly to the
bottom of the vessel, but so as to allow of the passage of water. K L
M N is the pedestal on which the vessel stands, and O X another tube
reaching within a little of the partition and extending into the
pedestal, in which water is placed so as to cover the orifice O, of
the tube. Fix a rod, P R, one half within, and the other without, the
pedestal, moving like the beam of a lever about the point S; and from
the extremity P of the rod suspend a water-clock, T, having a hole in
the bottom. The spout D having been first closed, the vessel should be
filled through the tube G H before water is poured into the pedestal,
that the air may escape through the tube X O: then pour water into the
pedestal, through a hole, until the orifice O is closed, and set the
spout D free. It is evident that the wine will not flow, as there is
no opening through which air can be introduced: but if we depress the
extremity R of the rod, a portion of the water-clock will be raised
from the water, and, the vent O being uncovered, the spout D will run
until the water suspended in the water-clock has flowed back and closed
the vent O. If, when the water-clock is filled again, we depress the
extremity R still further, the liquid suspended in the water-clock will
take a longer time to flow out, and there will be a longer discharge
from D: and if the water-clock be entirely raised above the water, the
discharge will last considerably longer. To avoid the necessity of
depressing the extremity R of the rod with the hand, take a weight Q,
sliding along the outer portion of the rod, R W, and able, if placed at
R, to lift the whole water-clock; if at a distance from R, some smaller
portion of it. Then, having obtained by trial the quantities which we
wish to flow from D, we must make notches in the rod R W and register
the quantities; so that, when we wish a given quantity to flow out, we
have only to bring the weight to the corresponding notch and leave the
discharge to take place.
64. _A Drinking-Horn from which a Mixture of Wine and Water, or pure
Water may be made to flow alternately or together, at pleasure._
[Illustration: Diagram of apparatus as described in text]
The construction of a drinking-horn from which at first a mixture shall
flow; when we please, on pouring in water, water alone, and then again
a mixture. Let A B (fig. 64), be a drinking-horn, its neck closed by
the plate C D, through which is inserted a tube, E F, leading to the
orifice F, and having a hole, G, bored in it within the vessel: in the
vessel just under the partition make a vent H. Now, if we close the
orifice F and pour in the mixture, it will pass into the body of the
vessel through the hole G; and if we set F free, the mixture will flow
through it, the air entering by the vent H. Again, if we close H and
pour in pure water, the mixture will no longer flow as the air has no
means of entrance, but pure water; and, when H is set free, both will
flow, the water and the mixture, or rather a mixture which is produced
from the two united.
65. _A Vessel from which Wine or Water may be made to flow separately
or mixed._
[Illustration: Diagram of apparatus as described in text]
If water is poured into a vessel standing upon a pedestal and provided
with a spout somewhat above its bottom, at one time pure water flows
out, at another a mixture of wine and water, and then unmixed wine
alone. Let A B (fig. 65), be the vessel, standing upon a pedestal and
provided with the spout C D, of which the orifice C is above the bottom
of the vessel. Close the neck of the vessel with the partition E F,
and through E F insert the tube G H, projecting slightly above the
partition and extending to the bottom of the vessel except that a space
is left sufficient for the passage of water. In the body of the vessel,
and projecting without it, let there be another tube K L, under which
a vessel of unmixed wine, K M, is to be placed: in the partition E F
pierce a very fine hole N. If, when these arrangements are complete,
we pour water into the vessel through the neck, the liquid lying round
the projection of the tube will remain in the neck; but all above this
will be carried into the body of the vessel, and when it has reached
the orifice C of the spout, there will be a discharge of pure water.
When a stream has begun to issue from the spout, the unmixed wine in
the vessel K M will be drawn up at the same time, on the principle of
the siphon, and a mixture will be discharged; and when the water is
exhausted, the pure wine will flow by itself, except indeed that the
water about the partition E F will be attracted at the same time. When
the small quantity of water on E F has all run through N, the air will
enter and break the continuity and there will be no further discharge.