Fig. 16.
These type were set up in a cavity, made by putting two pieces of long rules of brass plate together, side by side, with a strip of half their width between them; so as to make the cavity sufficiently large to receive the type. This was denominated the port rule, and is represented in [figure 16] by A A. Parts of the type are seen rising above the edge of the rule, and below it are seen the cogs, by which, with the wheel, V, the pinion, L, and the crank, O, the port rule, with its type, were carried along at an uniform rate in a groove of the frame, K, R, under the short lever, C, which has a tooth, or cam, at its extremity. J is a support, one on each side of the frame, for the axis of the lever, B and C, at its axis, I; a and i are two brass or copper mercury cups, fastened to the frame. These cups have the negative and positive wires soldered to them, N and P. D and H are the ends of one copper wire, bent at right angles at that portion of it fastened to the lever, B. The ends of the copper wire are amalgamated, and so adjusted, that when the lever is raised at C, by the action of its cam, passing over the teeth of the type, the lever, B, is depressed, and the wires, D and H, dip into the mercury cups, and thus complete the connection. This plan worked well, but was too inconvenient and unwieldy.
The second method was upon the same principle, with a more compact arrangement. The type being put into a hopper and carried one by one upon the periphery of a wheel, the teeth acting upon a lever in the same manner as in the [figure preceding]. The wheel being horizontal.
Fig. 17.
