Page:Heroes of the telegraph (IA cu31924031222494).djvu/238

 lay under the very eyes of Science, and yet she did not see it. The logograph had traced all the curves of speech with ink on paper; and it only remained to impress them on a solid surface in such a manner as to regulate the vibrations of an artificial tympanum or drum. Yet no professor of acoustics thought of this, and it was left to Edison, a telegraphic inventor, to show them what was lying at their feet.

Mere knowledge, uncombined in the imagination, does not bear fruit in new inventions. It is from the union of different facts that a new idea springs. A scholar is apt to be content with the acquisition of knowledge, which remains passive in his mind. An inventor seizes upon fresh facts, and combines them with the old, which thereby become nascent. Through accident or premeditation he is able by uniting scattered thoughts to add a novel instrument to a domain of science with which he has little acquaintance. Nay, the lessons of experience and the scruples of intimate knowledge sometimes deter a master from attempting what the tyro, with the audacity of genius and the hardihood of ignorance, achieves. Theorists have been known to pronounce against a promising invention which has afterwards been carried to success, and it is not improbable that if Edison had been an authority in acoustics he would never have invented the phonograph. It happened in this wise. During the spring of 1877, he was trying a device for making a telegraph message, received on one line, automatically repeat itself along another line. This he did by embossing the Morse signals on the travelling paper instead of merely inking them, and then causing the paper to pass under the point of a stylus, which, by rising and falling in the indentations, opened and closed a sending key included in the circuit of the second line. In this way the received message transmitted