EDISON, Thomas Alva, inventor, bom in Ohio in 1847. The deficiencies of his education (limited to a school attendance of eight weeks) were in part compensated for by the care of his mother and by his early passion for reading, which took particularly the direction of chemistry. He became when still very young a newsboy on a railway, where he was able to continue his reading, and even to make some experiments in chemistry, and to finally publish an amateur paper. Becoming interested in telegraphy he studied it late at night in a railway station, and in a few months became so expert an operator that he was successively employed at Port Huron, Michigan, Stratford, Canada, and Adrian, Michigan. At this last place he fitted up a small shop for the repair of telegraph instruments, and for the manufacture of novel machinery. From Adrian he went to Indianapolis, Indiana, where he invented his automatic repeater. After brief stays at various places he settled at Cincinnati, Ohio, and at the age of twenty had acquired some little reputation as a successful inventor, but was soon called to Boston on telegraphic business, where he set up a shop for his experiments. Not long afterwards he was made superintendent of the Gold Indicator Co. in New York, and while in that position established his factory for experiments in Newark, New Jersey. In 1876 he resigned his superintendency in order to devote his entire time to research and invention, locating himself for this purpose about twenty-five miles from New York, at a place called Menlo Park. He remained there until 1882, when he was obliged to return to New York to personally supervise the introduction of electric light into the city. Mr. Edison's inventions, which number about three hundred, include the carbon telephone, the phonograph, the micro-tasimeter, the aërophone, the megaphone, the phonometer, the electric pen, and the quadruplex system of telegraphing.