Armed with this rudimentary knowledge, and with what, in addition, he had learned by practice, Edison passed the next few years of his life in moving about over the country, seeking employment less, it would appear, for the sake of employment than for the opportunity of increasing his practical knowledge of the art that was to swallow up, in his mind, all the other arts. But he seems to have succeeded almost in spite of himself. He was so eager in his chase after knowledge that he was continually tripping himself up. While still at his trade of newsboy on the Grand Trunk Railroad, he had come across, at Detroit probably, a copy of Fresenius' "Qualitative Analysis" and had become so much interested in chemistry, that alongside his printing-press he had fitted up a small laboratory with a chance-medley apparatus for experiments, and one day a bottle of phosphorus was upset, and the car taking fire was only saved by the energy of the conductor, who promptly pitched the whole apparatus, with the printing-press to boot, out at the door, and then gave the young Fresenius-Franklin a thrashing. Later we hear of him, in the course of his wanderings, set to watch a telegraph-machine in the absence of the operator, and to prove that he was on guard he was to send the word six over the line every half-hour. Not to be interrupted in the book he was reading, he contrived a device that did the work automatically. In another office he kept back messages while he was contriving a way to send them more quickly! Disappearing from this office, he appears again in another, this time in Memphis, Tenn. But his interest in solving the problem of duplicate transmission proved so absorbing that he continually neglected his duties, and on the occasion of a change of officers he was dismissed as a useless member of the staff. At Louisville he upsets a carboy of sulphuric acid which ruins the handsome furniture of a broker's office on the floor below, and again finds himself adrift in an unappreciative world. Yet he had proved himself, in spite of all drawbacks, an adept of uncommon skill in telegraphy; and so widespread in scientific circles was his reputation, that he was sent for to Boston to take charge of the main New York wire. The impression made by the records of his life at this time is, that he looked upon all these employments merely as so many opportunities for earning his bread while pursuing his beloved experiments, and that the bread-earning was the least important part of the affair. No doubt, he always meant to do his duty, but the ecstasy of invention and the thirst for discovery carried him out of himself and made him often oblivious of sublunary things. While in Boston he still kept up his experiments and perfected his duplex telegraph, but it was not brought into successful operation until 1872.