EDISON, Thomas Alva, inventor, b. in Alva, Ohio, 11 Feb., 1847. His mother, who had been a teacher, gave him the little schooling he received, and at the age of twelve he became a newsboy on the Grand Trunk line running into Detroit. While thus engaged he acquired the habit of reading. He also studied qualitative analysis, and conducted chemical experiments on the train till an accident caused the prohibition of further work of the kind. Afterward he obtained the exclusive right of selling newspapers on the road, and, with the aid of four assistants, he set in type and printed the “Grand Trunk Herald,” which he sold with his other papers. The operations of the telegraph, which he constantly witnessed in the stations along the road, awakened his interest, and he improvised rude means of transmitting messages between his father's home in Port Huron and the house of a neighbor. Finally a stationmaster, whose child he had rescued in front of a coming train at the risk of his own life, taught him telegraph operating, and he wandered for several years over the United States and Canada, acquiring great skill in this art, but frequently neglected his practical duties for studies and experiments in electric science. At this time he invented an automatic repeater, by means of which a message could be transferred from one wire to another without the aid of an operator, and in 1864 conceived the idea of sending two messages at once over the same wire, which led to his experiments in duplex telegraphy. Later he was called to Boston and placed in charge of the “crack” New York wire. While in that city he continued his experiments, and perfected his duplex telegraph, but it did not succeed till 1872. He came to New York in 1871, and soon afterward became superintendent of the Gold and Stock Company, inventing the printing telegraph for gold and stock quotations. For the manufacture of this appliance he established a large workshop at Newark, N. J., and continued there till 1876, when he removed to Menlo Park, N. J., and thenceforth devoted his whole attention to inventing. Among his principal inventions are his system of duplex telegraphy, which he subsequently developed into quadruplex and sextuplex transmission; the carbon telephone transmitter, now used by nearly all telephones throughout the world, in which the variation in the current is produced by the variable resistance of a solid conductor subjected to pressure, rendering more faithfully than any other transmitter the inflections and changes in the intensity of the vocal sounds to be transmitted; the microtasimeter, used for the detection, on the same principle, of small variations in temperature, and successfully employed during the total eclipse of 1878 to demonstrate the presence of heat in the sun's corona; the aerophone, which may be used to amplify sound without impairing the distinctness of articulation; and the megaphone, which, when inserted in the ear, so magnifies sounds that faint whispers may be heard at a distance of 1,000 feet. The phonograph, which records sound in such a manner that it may be reproduced at will; and the phonometer, an apparatus for measuring the force of soundwaves produced by the human voice, are inventions of this period. His attention then became absorbed in the problem of electric lighting. He believed that the process of lighting by the voltaic arc, in which great results had already been achieved by Charles F. Brush, would never answer for general illumination, and so devoted himself to the perfection of the incandescent lamp. After entirely perfecting a device for a lamp with a platinum burner, he adopted a filament of carbon inclosed in a glass chamber from which the air was almost completely exhausted. He also solved the problem of the commercial subdivision of the light in a system of general distribution of electricity, like gas, and in December, 1879, gave a public exhibition in Menlo Park of a complete system of electric lighting. This was the first instance of subdivision of the electric light, and created great interest throughout the world, especially as scientific experts had testified before a committee of the English House of Commons in the previous year that such a subdivision was impossible. His system is now in general use, and in 1882 Mr. Edison went to New York for the purpose of supervising its establishment in that city. From 1880 to 1885, while still engaged in developing his electric light system, he found opportunity to plan crushing and separating machinery. On this subject his first patent was issued early in 1880. Mr. Edison says: “I felt certain that there must be large bodies of magnetite in the East which, if crushed and concentrated, would satisfy the wants of the Eastern furnaces for steel-making. Having determined to investigate the mountain region of New Jersey, I constructed a very sensitive magnetic needle which would dip toward the earth if brought over any considerable body of magnetic iron ore. . . . I had a number of men survey a strip reaching from Lower Canada to North Carolina. . . . The amount of ore disclosed by this survey was simply fabulous.” Mr. Edison, conceiving the idea of constructing enormous rolls which would be capable of crushing rocks of greater size than ever before attempted, reasoned that the advantages to be obtained would be fourfold, viz.: a minimum of machinery and parts; a greater compactness; saving of power; and greater economy in mining. Through no fault of the inventor or the invention, the colossal magnetic ore-milling enterprise did not prove successful. Hence he turned his attention toward the production of Portland cement. He began to manufacture the Edison Portland cement by new processes, some of which have been preserved as trade secrets. He then set himself to produce the “poured cement house,” which involved the overcoming of many engineering and other technical difficulties, all of which he attacked with vigor and disposed of patiently, one by one. The result of this invention, which is practically a gift to the workingman, not only of America, but of the world, will be that, sooner or later, all who care to do so will forsake the crowded and insanitary tenements, and be comfortably housed “far from the madding crowd” at a mere nominal monthly rental. The suggestion of the possibility of securing the reproductions of animate motion was made many years before the instantaneous photograph became possible. The kinetoscope was the earliest form of exhibiting machines. This was an apparatus by which a positive print was exhibited to the eyes through a small aperture or peep-hole. In 1895 the films were applied to magic lanterns in modified forms, projecting the images upon a screen. The industry has developed with great rapidity since that date, and all the principal manufacturers of motion pictures are paying a royalty to Edison under his basic patents. The development of the motion picture has resulted in the creation of an art that must always make a special appeal to the mind and emotions of mankind. In 1900 Mr. Edison undertook to solve the problem of the storage-battery. After completing more than ten thousand preliminary experiments, he began to obtain some positive results, and now has so far perfected the storage-battery as to render it entirely suitable for truck and automobile work, and the moving of street and railroad cars. In “Popular Electricity” for June, 1910, Mr, Edison says: “For years past I have been trying to perfect a storage-battery, and have now rendered it entirely suitable to automobile and other work. There is absolutely no reason why horses should be allowed within city limits; for between the gasoline and electric car, no room is left for them. They are not needed. The cow and pig have gone, and the horse is still more undesirable A higher public ideal of health and cleanliness is working toward such banishment very swiftly; and then we shall have decent streets, instead of stables made out of strips of cobble-stones bordered by sidewalks.” Mr. Edison has invented a system of train-telegraphy between stations and trains in motion, by which messages can be sent from the moving train to the central office, the precursor of wireless telegraphy. He has also invented a method of separating placer gold by a dry process. During the Spanish-American War, Edison suggested to the navy department the adoption of a compound of calcium carbide and calcium phosphite, which, when fired in a shell from a gun, would explode and ignite on striking the water, thereby producing a blaze that, during several minutes, would render visible the vessels of a hostile fleet for miles around. A large number of electrical instruments are included in Mr. Edison's inventions, many of them in their original forms being devised for his systems of light and power. Among his numerous devices for which he has filed caveats at the patent office in Washington, the following have been named: Forty-one inventions pertaining to the phonograph; eight forms of electric lamps using infusible earthy oxides and brought to high incandescence in vacuo by high potential current of several thousand volts; a loud-speaking telephone with quartz cylinder and beam of ultra-violet light; four forms of arc light with special carbons; a thermostatic motor; a device for mechanically sealing together the inside part and bulb of an incandescent lamp; regulators for dynamos and motors; three devices for utilizing vibrations beyond the ultra-violet; a great variety of methods for coating incandescent lamp filaments with silicon, titanium, chromium, osmium, boron, etc; several methods of making porous filaments; a number of methods of producing squirted filaments of various materials; seventeen different methods and devices for separating magnetic ores; a continuously operative primary battery; a musical instrument operating one of Helmholtz's artificial larynxes; a siren operated by the explosion of small quantities of oxygen and hydrogen mixed; three other sirens giving vocal sounds or articulate speech; a device for projecting sound-waves to a distance in a straight line and without spreading, on the principle of smoke-rings; a device for continuously indicating on a galvanometer the varying depths of the ocean; a method of largely preventing the friction of water against the hull of a vessel, and incidentally preventing fouling by barnacles; a telephone receiver by which the vibrations of the diaphragm are appreciably amplified; two methods of space telegraphy at sea; an improved and extended string-telephone; devices and methods of talking through water for considerable distances; an audiphone for deaf persons; a sound-bridge for measuring resistance of tubes and other materials for conveying sound; a method of testing a magnet to discover the existence of flaws in the iron or steel of which it is composed; a method of distilling liquids by an incandescent conductor immersed in the liquid; a method of obtaining electricity directly from coal; an engine operated by steam produced by the hydration and dehydration of metallic salts; a device for telegraphing photographically; a carbon crucible kept brilliantly incandescent by current in vacuo, for obtaining reaction with refractory metals; a device for examining combinations of colors and their changes by rotation at different speeds. Mr. Edison's fertility in invention is nothing short of amazing. It has been said that his guess is more than a mere starting-point, and often turns out to be the final solution of a problem. Even “the failure of an experiment simply means to him that he has found something else that will not work, thus bringing the possible goal a little nearer by a process of painstaking elimination.” In 1878 Mr. Edison received the degree of Ph.D. from Union College, and the same year was made Chevalier, and later Officer and Commander of the Legion of Honor by the French government. In 1903 he was appointed honorary chief consulting engineer of the St Louis Exposition of 1904 Mr. Edison has married twice. His first wife was Mary G. Stilwell whom he wedded in 1873; his second wife was Miss Miller, of Ohio.