The fourth and great final addition to the telegraph which crowned it with success was the Morse register and alphabetical code, the invention of Prof. Samuel F. B. Morse, of Massachusetts. Prof. Morse’s invention was made in 1832, while on board ship returning from Europe. He set up an experimental line in 1835, and got his French patent October 30, 1838, and his first United States patent June 20, 1840, No. 1647. In 1844 the United States Congress appropriated $30,000 to build a line from Baltimore to Washington, and on May 24, 1844, the notable message, “What Hath God wrought?” went over the wires. [Illustration: FIG. 6.--THE MORSE CODE.] Morse’s first model, his pendulum instrument of 1837, is illustrated in Fig. 5. A pendulum carrying a pencil was in constant contact with a strip of paper drawn beneath the pencil. As long as inactive the pencil made a straight line. The pendulum carried also an armature, and an electro-magnet was placed near the armature. A current passed through the magnet would draw the pendulum to one side. On being released the pendulum would return, and in this way zigzag markings, as shown at 4 and 5, would be produced on the strip of paper, which formed the alphabet. A different alphabet, known as the Morse Code, was subsequently adopted by Morse, and in 1844 the receiving register shown at Fig. 7 was adopted, which finally assumed the form shown at Fig. 8. The alphabet consisted simply of an arrangement of dots and dashes in varying sequence. The register is an apparatus operated by the combined effects of a clock mechanism and electro-magnet. Under a roll, see Fig. 8, a ribbon of paper is drawn by the clockwork. A lever having an armature on one end arranged over the poles of an electro-magnet, carries on the other end a point or stylus. When an electric impulse is sent over the line the electro-magnet attracts the armature, and the stylus on the other end of the lever is brought into contact with the paper strip, and makes an indented impression. A short impulse gives a dot, and a long impulse holds the stylus against the paper long enough to allow the clock mechanism to pull the paper under the stylus and make a dash. By the manipulation of a key for closing the electric circuit the short or long impulse may be sent, at the pleasure of the operator. [Illustration: FIG. 7.--MORSE RECEIVER.]