He obtained a position as night operator at Port Huron. That kept him busy at night, but he refused to sleep during the daytime as other night operators did, and used that time to work on his own schemes. To catch some sleep he kept a loud alarm-clock at his office, and set it so that he would be waked when trains were due and he was needed. But sometimes trains were off schedule, and again and again he would oversleep. At last the train despatcher ordered Edison to signal him the letter “A” in the Morse alphabet every half hour. The boy willingly agreed. A few nights later he brought an invention of his own to the office, and connected it by wires with the clock and the telegraph. Then he watched it work. Exactly on the half hour a little lever fell, sending an excellent copy of the Morse “A” to the key of the telegraph. Another lever closed the circuit. He kept his eyes on this instrument of his making until he had seen it act faultlessly again at the next half hour. Then he went to sleep. Night after night the signal was sent without a mistake, and the despatcher began to regain some of the confidence he had lost in the young operator. Then one night the despatcher chanced to be at the next station to Edison’s, and it occurred to him to call the latter up and have a chat with him. He signaled for fifteen minutes, and received no answer. Then he jumped on a hand-car and rode to Edison’s station. Looking through the window he saw the youth sound asleep. His eyes took in the strange instrument upon the table. It was near the half hour, and as the man watched he saw one lever of the instrument throw open the key and the other send the signal over the wire. The operator was still sleeping soundly. The despatcher recognized the young man’s ingenuity, but he also realized that he had been fooled, and so he woke Edison none too gently, and told him that his services were no longer in demand on that road. Ingenuity, mechanical short-cuts, new devices for doing old work, were what beset his mind. He was not interested in doing the simple routine service of a telegrapher, he wanted to see what improvements on it he could make. Often this keenness for new ideas led him into trouble with his employers; occasionally it was of real service. At one time an ice-jam had broken the cable-line between Port Huron, in Michigan, and Sarnia, over the Canadian line. The river there was a mile and a half wide. The officers were wondering how they could get their messages across when they saw Edison jump upon a locomotive standing in the train-yard. He seized the valve that controlled the whistle. He opened and closed it so that the locomotive’s whistles resembled the dots and dashes of the telegraph code. He called Sarnia again and again. “Do you hear this? Do you get this?” he sent by the whistle. Four and five times he sent the message, and finally the whistle of a locomotive across the river answered him. In that way communication was again established.