Fig. 287.
The head owes its movements to the action of three different sets of levers, each terminating in a disc or pedal immediately over a circular hole in the under side of the base. The apparatus is so placed upon the table that these openings correspond in position with the same number of pistons. [Fig. 287] is a general view of the internal mechanism, the back of the head being removed (as in fact it may be in the original) to give access thereto. [Fig. 288] exhibits (as seen from the rear) the action of the left-hand group of levers, producing the movement of the eyes. When an upward pressure is applied to the foot of the lever a, it causes the upper arm c d of the elbow piece b c d to describe an arc of about a quarter of an inch from left to right, thereby communicating a corresponding movement to the pair of levers e e, working on the pivots f f; and, as a necessary consequence, a reverse movement to the opposite ends of such levers, on which are fixed the eyes g g. As soon as the upward pressure is removed, the spring h, a spiral coil of fine brass wire, draws back the levers e e, and with them the eyes, to their original position. To produce a continuous rolling, the pressure of the piston is applied and relaxed alternately, the effect to the spectator being as if the figure looked first to the left and then to the right, although as already explained, the active movement of the levers is in the one direction only, the normal position of the eyes being in the other direction.
Fig. 288.
Fig. 289.
[Fig. 289] shows the action of the second or middle group of levers, serving to produce the opening of the mouth. The chin of the figure consists of a solid block of wood i, working on a pivot j in each cheek, and so counterweighted that its normal position is as in [Fig. 289], thus keeping the mouth closed. When, however, the shaft k is raised by pressure from below, the lever l rises with it, and proportionately depresses the opposite end of the block i, thereby opening the mouth. As soon as the pressure is removed, the block falls back into its original position, and the mouth closes.
Fig. 290.