But, while these inventions have the charm that invests "the fairy-tales of science," the world-wide fame of Edison rests upon greater gifts to the world; the various improvements he has made in the telegraph, and the perfection to which he has brought the electric light. The invention of the telephone, by which persons are enabled to converse with one another at very long distances, and by which concerts, operas, and orations or sermons in one city can be heard by an audience assembled in another, is one of the most remarkable of Edison's achievements, and one the usefulness of which in various directions it is easy to foresee. The idea of the transmission of messages in opposite directions by the same wire was one that had early occurred to Edison, but he was long in reducing it to practice. The secret once discovered, however, he rapidly progressed until he had brought out the sextuple telegraph, where we believe the ability of the instrument rests at present. The inventor next turned his mind to the study of the electric lamp, in which he saw great possibilities. He believed that he could produce a light that should be cheaper than gas, and also purer, more steady, and more to be depended on. He rejected the principle of the Voltaic arc involved in the Brush patent then in use, by which the electric current was passed through a strip of platinum or other metal that requires a high temperature to melt, because in practice it was found that in fact, owing to the difficulty of regulating the flow of the electric current, the medium did often melt. He therefore sought for a medium that should be practically indestructible, and believed that it would be found in pure carbon enclosed in a vacuum. After many trials with one and another substance, he at length found that by employing slender strips of card-board reduced by intense heat to carbon, connecting them with the wires leading from the machine, and enclosing them in glass bulbs from which the air had been extracted, the desired result could be produced. The next step to accomplish was the division of the light, so that any number of lamps could be supplied by the same pair of wires--a condition absolutely necessary if the invention were to be of practical utility as applied to the lighting of factories, public buildings, or private households, where-ever, in short, many lights are needed. This was finally accomplished, and in December, 1879, an exhibition was given at Menlo Park of a complete system of lighting. This first demonstration of the possibility of light-division created a great interest in scientific circles all over the world, especially as scientific experts had testified before the British House of Commons that the feat was impossible. The Edison incandescent burner is now in use in every city, town, and hamlet in this country, and it would seem as if it must of necessity before long drive the costly, unhealthy, and dangerous