1851 Great Exhibition: Official Catalogue: Class X.: Caleb Elisha
39. ELISHA, CALEB, 13 New Bond Street — Inventor and Manufacturer.
An eight-day time-piece (regulator), to go by a weight, in a mahogany case, with a compensating pendulum. This pendulum has a brass ball, seven inches diameter, and three-quarters of an inch thick, on the face of which is screwed a brass rim, a quarter of an inch thick and one inch broad; on the inside of this is a steel rim, secured to the brass, one-eighth of an inch thick. The outer diameter of this rim, composed of brass and steel, is also seven inches. This rim is divided or separated at the bottom of the ball, leaving two arms of equal length; at the end of each, is screwed a brass cup, to admit glasses of a conical shape containing mercury, about 4 inches high, the lower diameter being about n inch, and the upper about the half. The adjustments for variations in temperature are made by the compensation rim with mercury in the glasses. The escapement of the clock is of George Graham's construction, dead-beat, but the pallets are jewelled. The vibration is made as short as possible.
A silver lever watch, with compensation radii, composed of brass and steel united. The proportions are about 1 of steel and 2 of brass. The bar is screwed on to the upper plate at one end, and at the other end a hole is drilled, to admit the pendulum or regulating spring, where it is pinned in.
A silver lever watch, with compensation radii, composed of brass and steel, fixed on the index on the cock, the two shifting together, and acting up and down the spring as the regulator is shifted. In the outer end of this radii compensation, are drilled two holes for the pins, between which the pendulum spring plays.
Model of a mahogany door, with machinery. In the posts of the inside of the door are fixed two staples. An iron chain, case-hardened, rather longer than two widths of the door, is drawn through the staples, and when on the outside, the chain is pulled, so as just to admit the hand to secure a padlock into the links of the double chain. The chain is then drawn, with the padlock, out of sight. The lock catch must also be case-hardened.