ith a hole in the middle,
about a quarter of an inch in diameter. Fix to the tube D E, any sort
of ornament that will keep the machine firm on the basin, observing,
that these supports are sufficiently long to leave about a quarter of
an inch between the end of the tube and the orifice in the basin; and
let there be a vessel under the basin to catch the water that runs
out.

As the small pipes discharge more water into the basin than can run
out of the central orifice, the water will rise in the basin above the
lower end of the pipe, and prevent the air from getting into the
vessel, by which the water will cease to flow from the small pipes.
But as the water continues to flow from the basin, the air will have
liberty again to enter the vessel by the tube, and the water will
again flow from the small pipes, and alternately stop and flow, while
any water remains in the vessel.

As you can guess when the pipes will flow, and when they will stop,
you may so manage it, that they will appear to act by word of command.

_The illuminated Fountain, that plays when the Candles are lighted,
and stops when they are extinguished._

Provide two cylindrical vessels, A B and C D, as in Fig. 6. Connect
them by four tubes open at each end, as H I, &c., so that the air may
descend out of the higher into the lower vessel. To these tubes fix
candlesticks, and to the hollow cover, E F, of the lower vessel, fit a
tube, K, reaching almost to the bottom of the vessel. At G let there
be an aperture with a screw, whereby water may be poured into C D,
which, when filled, must be closed by the screw.

[Illustration: Fig. 6.]

When the candles are lighted, the air in the upper cover and
contiguous pipes will be thereby rarefied, and the jet from the small
tube, K, will begin to play: as the air becomes more rarefied, the
force of the jet will increase, and it will continue to play till the
water in the lower vessel is exhausted. As the motion of the jet is
caused by the heat of the candles, when they are extinguished the
fountain will stop.

_A Fountain which acts by the heat of the Sun._

In the annexed engraving, Fig. 7, G N S is a thin hollow globe of
copper, eighteen inches diameter, supported by a small inverted basin,
placed on a stand with four legs, A B C D, which have between them, at
the bottom, a basin of two feet diameter. Through the leg C passes a
concealed pipe, which comes from G, the bottom of the inside of the
globe.