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.