Fig. 8.
Another pretty conceit of Hero’s is shown in [Fig. 8], in which there is a bird which not only makes a noise but at certain times will drink any liquid which is presented to it. The flow of water being intermittent, the cistern forming the pedestal is alternately filled and emptied. While it is being filled the air escapes through a whistle and causes the bird to sing, and when it is being emptied, by means of a siphon, a partial vacuum is produced and liquid presented to it is drawn up through the beak.
Fig. 9.
The next automaton from Hero is very ingenious and interesting, because it combines hydraulic, pneumatic, and mechanical actions. Here ([Fig. 9]) is a figure of Hercules armed with a bow and arrow; there is also a dragon under an apple tree, from which an apple has fallen to the ground. Upon the apple being lifted, Hercules discharges the arrow at the dragon, which begins to hiss and continues to do so for some minutes. In this apparatus there is a double tank having a connection by a valve (H), which is attached by a cord to the apple (K), another cord, passing over a pulley, connects the apple with a trigger in the right hand of Hercules. Upon lifting the apple the trigger is released, and at the same time the valve is opened, allowing the water in the upper tank to flow into the lower, by which means air is forced through a tube (Z) into the dragon’s mouth, producing a hissing sound, and this will continue until the upper tank is empty. Here ([Fig. 10]) is Bate’s version of the same device, but very inferior to that from which it was taken.
Fig. 10.
The next photograph is taken from another work of Hero’s, “Quatro theoremi aggiunti a gli artifitiosi spiriti,” a copy of which I have here ([Fig. 11]), and which was printed at Ferrara in 1589.