Page:Heroes of the telegraph (IA cu31924031222494).djvu/234

 diaphragm to collect the sounds, and a stylus to impress them on a sheet of tinfoil, were its essential parts. Looking on the record of the sound, one could see only the scoring of the stylus on the yielding surface of the metal, like the track of an Alpine traveller across the virgin snow. These puzzling scratches were the foot-prints of the voice.

Speech is the most perfect utterance of man; but its powers are limited both in time and space. The sounds of the voice are fleeting, and do not carry far; hence the invention of letters to record them, and of signals to extend their range. These twin lines of invention, continued through the ages, have in our own day reached their consummation. The smoke of the savage, the semaphore, and the telegraph have ended in the telephone, by which the actual voice can speak to a distance; and now at length the clay tablet of the Assyrian, the wax of the ancient Greek, the papyrus of the Egyptian, and the modern printing-press have culminated in the phonograph, by which the living words can be preserved into the future. In the light of a new discovery, we are apt to wonder why our fathers were so blind as not to see it. When a new invention has been made, we ask ourselves, Why was it not thought of before? The discovery seems obvious, and the invention simple, after we know them. Now that speech itself can be sent a thousand miles away, or heard a thousand years after, we discern in these achievements two goals toward which we have been making, and at which we should arrive some day. We marvel that we had no prescience of these, and that we did not attain to them sooner. Why has it taken so many generations to reach a foregone conclusion? Alas! they neither knew the conclusion nor the means of attaining to it. Man works from ignorance towards greater knowledge with very limited powers.