Page:Heroes of the telegraph (IA cu31924031222494).djvu/60

 Literature of the Arts of Design in the newly founded University of the city of New York. In the month of July he took up his quarters in the new buildings of the University at Washington Square, and was henceforth able to devote more time to his apparatus. The same year Professor Daniell, of King's College, London, brought out his constant-current battery, which befriended Morse in his experiments, as it afterwards did Cooke and Wheatstone, Hitherto the voltaic battery had been a source of trouble, owing to the current becoming weak as the battery was kept in action.

The length of line through which Morse could work his apparatus was an important point to be determined, for it was known that the current grows feebler in proportion to the resistance of the wire it traverses. Morse saw a way out of the difficulty, as Davy, Cooke, and Wheatstone did, by the device known as the relay. Were the current too weak to effect the marking of a message, it might nevertheless be sufficiently strong to open and close the circuit of a local battery which would print the signals. Such relays and local batteries, fixed at intervals along the line, as post-horses on a turnpike, would convey the message to an immense distance. 'If I can succeed in working a magnet ten miles,' said Morse,'I can go round the globe. It matters not how delicate the movement may be.'

According to his own statement, he devised the relay in 1836 or earlier; but it was not until the beginning of 1837 that he explained the device, and showed the working of his apparatus to his friend, Mr. Leonard D. Gale, Professor of Chemistry in the University. This gentleman took a lively interest in the apparatus, and proved a generous ally of the inventor. Until then Morse had only tried his recorder