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an appointment as professor of the literature of the arts of design in the newly established University of the City of New York. He soon had his crude apparatus set up in a room at the college and in 1835 was able to transmit messages. He now had a little more leisure and a little more money, but his opportunities were still far from what he would have desired. The principal aid which came to him at the university was from Professor Gale, a teacher of chemistry. Gale became greatly interested in Morse's apparatus, and was able to give him much practical assistance, becoming a partner in the enterprise. Morse knew little of the work of other experimenters in the field of electricity and Gale was able to tell Morse what had been learned by others. Particularly he brought to Morse's attention the discoveries of another American, Prof. Joseph Henry. The electro-magnet which actuated the receiving instrument in the crude set in use by Morse in 1835 had but a few turns of thick wire. Professor Henry, by his experiments five years earlier, had demonstrated that many turns of small wire made the electro-magnet far more sensitive. Morse made this improvement in his own apparatus. In 1832 Henry had devised a telegraph very similar to that of Morse by which he signaled through a mile of wire. His receiving apparatus was an electro-magnet, the armature of which struck a bell. Thus the messages were read by sound, instead of being recorded on a moving strip of paper as by Morse's system. While Henry was possibly the ablest of American electricians at that time, he devoted himself entirely to science and made no effort to put his devices to practical use. Neither did he endeavor to profit by his inventions, for he secured no patents upon them. Professor Henry realized, in common with Morse and others, that if the current were to be conducted over long wires for considerable distances it would become so weak that it would not operate a receiver. Henry avoided this difficulty by the invention of what is known as the relay. At a distance where the current has become weak because of the resistance of the wire and losses due to faulty insulation, it will still operate a delicate electro-magnet with a very light armature so arranged as to open and close a local circuit provided with suitable batteries. Thus the recording instrument may be placed on the local circuit and as the local circuit an opened and closed in unison with the main
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