· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · A B C D E F G H I J K L M N O P Q R S T U V W X Y Z · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · & 1 2 3 4 5 6 7 8 9 0 CORRESPONDENT OR KEY. The modes of manipulation for sending intelligence, which at various times have been invented by Prof. Morse, are more various than any other part of the machinery of the telegraph. A few of them will now be described. The first method, invented as early as the year 1832, was that of using a type, resembling saw-teeth, set up in long frames, and made to pass under a lever, by means of machinery, at a uniform rate, for the purpose of closing and breaking the circuit, in a manner hereafter to be described. The following figure, 15, represents the saw-teeth type. The top of the narrow tooth corresponds with the _dots_ of the letters, and the long tooth, with the _lines_ of the letters. For instance, A, has one tooth for a dot, and a long tooth for a line, which is the telegraphic letter A; then follows a space at the end of the type, corresponding with the short space between two letters. [Illustration: FIG. 15.] [Illustration: 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.