THE PIPING BULLFINCH.
If one of the mechanical singing-bird toy-boxes is opened so that the machinery is laid bare, the mystery will disappear.
Fig. 154.
The little bird who pops up on his feet when the lid of the box is opened, flutters his wings, and opens his mouth as the trill comes forth, has nothing to do with the sound.
That comes from a short tube, which has a supply of air from a little bellows, regulated by a piston. Its action is controlled by a lever, acted on by the same clockwork which works the bellows, and turns a barrel set with pins for the tune like any barrel-organ.
To make one, get a toy bird, and mount it on a box, concealed in which is such an instrument as is found in musical albums and valentines; the opening of its bill and wings needs a very simple connection with the wheel of the barrel.