[Illustration: Diagram of apparatus as described in text]
A jar can be made receiving and discharging a greater quantity of
liquid at one time than at another, and in such a way that, when wine
and water are poured into it, it shall discharge at one time pure
water, at another time unmixed wine, and, again, a mixture of the two.
Its construction is as follows. Let A B (fig. 8) be a pitcher having a
partition in the middle, C D. In the partition, near the circumference
of the vessel, let small holes be pierced in a curve, as at E. In the
opposite side of the partition let there be a circular aperture, F,
through which the tube F G H is to be inserted, being soldered into the
partition, and reaching nearly to the bottom of the vessel at G. Let
the other mouth of the tube H issue at the side of the pitcher, under
the handle, and be soldered into the handle which must be hollow, and
have a hole on its outer surface at K, which may be closed with the
finger when necessary. If, then, closing the vent, as before, we pour
any liquid into the jar, the liquid poured into the upper chamber will
remain there, not being able to continue its way through the narrow
holes into the lower chamber, as there is no other outlet for the air
than through the vent K. When, however, we unclose the vent, the liquid
will descend into the chamber beneath, and then the jar will hold more.
If, then, we first pour in wine so as to fill the chamber B C D, and
then, closing the vent, pour water upon it, the two cannot mix, and if
we invert the jar it will emit pure water. But, when we unclose the
vent, the water continuing to flow, the wine will flow out also, since
air can enter through K to fill up the void left; and afterwards the
wine will flow out unmixed. We may also pour in the water first, and
then, stopping the vent, pour wine upon it, so as to pour out wine for
some, wine and water for others, and mere water for those whom we wish
to jest with.