But even before these two indispensable requisites had been supplied by human genius, much had been done to develop the mechanical methods of conveying intelligence. In 1816, Ronalds, of England, constructed a telegraph by means of which he operated a system of pith-ball signals which could be understood. In 1820, Ampère suggested that the deflection of the magnetic needle by an electric current might be turned to account in imparting intelligence at a distance. In 1828, Dyar, of New York, perfected a telegraph by means of which he made tracings and spaces upon a piece of moving litmus paper, which tracings and spaces could be intelligently interpreted through a prearranged code. A little later, 1830, Baron Schilling constructed a telegraph which imparted motion to a set of needles at either end. [Illustration: MORSE TELEGRAPH AND BATTERY.] From this time up to 1837, which last year was a memorable one in the history of telegraphy, the genius of such distinguished men as Morse in America, Wheatstone and Cooke in England, and Steinhill in Munich, was brought to bear on the further evolution of the telegraph. While all these names have been associated with the invention of the first practical telegraph, it is impossible, with justice, to rob that of Morse of the distinguished honor. Morse conceived his invention on board the ship Surry, while on a voyage from Havre to New York, in October, 1832. It consisted, as conceived, of a single circuit of conductors fed by some generator of electricity. He devised a system of signs, which was afterwards improved into the Morse alphabet, consisting of dots or points, and spaces, to represent numerals. These were impressed upon a strip of ribbon or paper by a lever which held at one end a pen or pencil. The paper or ribbon was made to move along under the pencil or pen at a regular rate by means of clockwork. In accordance with these conceptions, Morse completed his instrument and publicly exhibited it in 1835. He gave it further publicity, in much improved form, in 1837. In this form it was entirely original in the important respects that the ribbon or paper was made to move by clockwork, while a pen or pencil gave the impressions, thus preserving a permanent record of the message conveyed. [Illustration: SAMUEL FINLEY BREESE MORSE.]