The Phonogram, Vol. 1:1 (1891-01)

FAMOUS ELECTRICAL IMPROVEMENTS. NOVEL DEVICES THAT ARE FACILITATING MAX'S WORK jVXD PROMOTING THE WORLD’S PROGRESS. $ The Incandescent Lamp. N : no portion of his work is Mr. Edison more exten- sively known to the gen- eral public than through that connected with the incandescent lamp, with the single excep- tion, perhaps, of the phonograph, which has of late brought him world-wide fame. ♦ Experimental or laboratory incandescent lamps have been made before Mr. Edison attacked the problem of producing one which should be commercially efficient. He saw, however, with the insight of genius, that.the subdivision of the electric light was to be attained only bj means of a lamp having a “ high Resistance filament,’* and working on these lines he finally succeeded, after an immense amount of patient research and experimenting, in producing a practical in- •candesccut lamp for commercial use. A few of tttbse experiments may be traced. *j\t first he txiei] making filaments of plati- num, indium, and other rare metals, then threads rubbed with plumbago, coal tar, and similar substances, and latera carbon spiral. The next step .was the famous carbonized paper horseshoe filament, and this carried him a long way on the uphill journey he was making. Finally- he turned his attention to vegetable fibre, and amongst them he found the ideal material that he had been search- ing for. v Lu his experiments, on which up- ward of $100,000 was expended, he tried' every substance he could find in the animal, vegetable, and mineral kingdom^ and the two hemispheres were ransacked by his agewUi .ili search of substances from which fibres could be extracted. It was found that there are no less than 1.200 varieties of bamboo, of which only 300 are useful for any purpose. These gave many experiments. Mr. Edison discovered that a form of bam- boo, which grows only in a certain district of Japan, gave him just what he required. Only a very small portion of each of the canes can be used, and they have to be gath- ered at a certain growth, and seasoned in a certain manner. The fibres are taken from the interior of the bamboo, and carbonized by a special treatment. In this manner all volatile matters are thrown off, and a cellular structure is left behind, giving a filament of very high resistance, which, as intimated al>ove,isthe feature of paramount importance in the successful, economical, commercial incandescent lamp. M r. Edison has extended his investigations and inventive-skill into all fields of electric lighting, and in addition to the large amount of work done by him in dynamos and incan- descent lamps, he has elaborated several complete systems of distribution, in which every detail is worked out in harmony with the whole. There are many ingenious adap- tations of scientific laws in the various por- tions of these systems, in which the best known are the Edison “three-wire system,” “municipal system ” (in which incandescent lamps are used in series on the same circuit or with arc lamps), and the “ system of di- rect conversion.** Few patents taken out by Mr. Edison are of greater scope and value than those covering his methods of distrib- uting electricity for light and power. The Edison electric lighting industries hrrve re- quired, for example, in the United States alone, over 700 miles of underground con- ductors. Although Mr. Edison devoted himself, for a time, almost exclusively to incandescent lighting, he has, nevertheless, done some work in arc lamps, and has taken out several patents in this direction. (19)