Section 49
No. 49. A Trumpet, in the hands of an Automaton, sounded by
compressed Air.
A FIGURE stands upon a pedestal having a trumpet in its mouth: if it be
blown into, the trumpet shall sound. Let A B C D (fig. 49), be an
air-tight pedestal on which a figure stands, and within the pedestal
let there be a hollow
hemisphere, E F G, covered over at the top and having small
holes in the bottom. From the hemisphere a tube, H F, extends upwards
into the figure in the direction of the trumpet, which is provided with
a mouth-piece. Pour liquid into the pedestal through a hole
which must be afterwards stopped again by means of a valve or tap
called a smerisma. Now, if we blow into the bell of the trumpet, the
air passing from us will force out through the holes the water
in the hemisphere, which will mount up into the pedestal: but
when we withdraw the breath, the water will enter the hemisphere again
and force out the air, which, passing out through the mouthpiece, will
produce the sound of a trumpet.
Section 50.
Index.