chapter11.txt

CHAPTER XI







THE INVENTION OF THE INCANDESCENT LAMP







IT is possible to imagine a time to come when the



hours of work and rest will once more be regulated



by the sun. But the course of civilization has been



marked by an artificial lengthening of the day, and by a



constant striving after more perfect means of illumination.



Why mankind should sleep through several hours



of sunlight in the morning, and stay awake through



a needless time in the evening, can probably only



be attributed to total depravity. It is certainly a



most stupid, expensive, and harmful habit. In no



one thing has man shown greater fertility of invention



than in lighting; to nothing does he cling more



tenaciously than to his devices for furnishing light.



Electricity to-day reigns supreme in the field of



illumination, but every other kind of artificial light



that has ever been known is still in use somewhere.



Toward its light-bringers the race has assumed an



attitude of veneration, though it has forgotten, if it



ever heard, the names of those who first brightened



its gloom and dissipated its darkness. If the tallow



candle, hitherto unknown, were now invented, its



creator would be hailed as one of the greatest



benefactors of the present age.







Up to the close of the eighteenth century, the means



of house and street illumination were of two generic



kinds--grease and oil; but then came a swift and



revolutionary change in the adoption of gas. The



ideas and methods of Murdoch and Lebon soon took



definite shape, and "coal smoke" was piped from its



place of origin to distant points of consumption. As



early as 1804, the first company ever organized for



gas lighting was formed in London, one side of Pall



Mall being lit up by the enthusiastic pioneer, Winsor,



in 1807. Equal activity was shown in America, and



Baltimore began the practice of gas lighting in 1816.



It is true that there were explosions, and distinguished



men like Davy and Watt opined that the illuminant



was too dangerous; but the "spirit of coal" had



demonstrated its usefulness convincingly, and a



commercial development began, which, for extent



and rapidity, was not inferior to that marking the



concurrent adoption of steam in industry and transportation.







Meantime the wax candle and the Argand oil lamp



held their own bravely. The whaling fleets, long after



gas came into use, were one of the greatest sources



of our national wealth. To New Bedford, Massachusetts,



alone, some three or four hundred ships



brought their whale and sperm oil, spermaceti, and



whalebone; and at one time that port was accounted



the richest city in the United States in proportion



to its population. The ship-owners and refiners of



that whaling metropolis were slow to believe that



their monopoly could ever be threatened by newer



sources of illumination; but gas had become available



in the cities, and coal-oil and petroleum were now



added to the list of illuminating materials. The



American whaling fleet, which at the time of Edison's



birth mustered over seven hundred sail, had dwindled



probably to a bare tenth when he took up the problem



of illumination; and the competition of oil from



the ground with oil from the sea, and with coal-gas,



had made the artificial production of light cheaper



than ever before, when up to the middle of the century



it had remained one of the heaviest items of



domestic expense. Moreover, just about the time



that Edison took up incandescent lighting, water-gas



was being introduced on a large scale as a commercial



illuminant that could be produced at a much lower



cost than coal-gas.







Throughout the first half of the nineteenth century



the search for a practical electric light was almost



wholly in the direction of employing methods analogous



to those already familiar; in other words, obtaining



the illumination from the actual consumption of



the light-giving material. In the third quarter of



the century these methods were brought to practicality,



but all may be referred back to the brilliant



demonstrations of Sir Humphry Davy at the Royal



Institution, circa 1809-10, when, with the current



from a battery of two thousand cells, he produced an



intense voltaic arc between the points of consuming



sticks of charcoal. For more than thirty years the



arc light remained an expensive laboratory experiment;



but the coming of the dynamo placed that



illuminant on a commercial basis. The mere fact



that electrical energy from the least expensive chemical



battery using up zinc and acids costs twenty



times as much as that from a dynamo--driven by



steam-engine--is in itself enough to explain why so



many of the electric arts lingered in embryo after



their fundamental principles had been discovered.



Here is seen also further proof of the great truth



that one invention often waits for another.







From 1850 onward the improvements in both the



arc lamp and the dynamo were rapid; and under the



superintendence of the great Faraday, in 1858, protecting



beams of intense electric light from the voltaic



arc were shed over the waters of the Straits of Dover



from the beacons of South Foreland and Dungeness.



By 1878 the arc-lighting industry had sprung into



existence in so promising a manner as to engender



an extraordinary fever and furor of speculation. At



the Philadelphia Centennial Exposition of 1876,



Wallace-Farmer dynamos built at Ansonia, Connecticut,



were shown, with the current from which arc



lamps were there put in actual service. A year or



two later the work of Charles F. Brush and Edward



Weston laid the deep foundation of modern arc lighting



in America, securing as well substantial recognition



abroad.







Thus the new era had been ushered in, but it was



based altogether on the consumption of some material



--carbon--in a lamp open to the air. Every



lamp the world had ever known did this, in one way



or another. Edison himself began at that point,



and his note-books show that he made various experiments



with this type of lamp at a very early stage.



Indeed, his experiments had led him so far as to



anticipate in 1875 what are now known as "flaming



arcs," the exceedingly bright and generally orange



or rose-colored lights which have been introduced



within the last few years, and are now so frequently



seen in streets and public places. While the arcs



with plain carbons are bluish-white, those with carbons



containing calcium fluoride have a notable



golden glow.







He was convinced, however, that the greatest field



of lighting lay in the illumination of houses and other



comparatively enclosed areas, to replace the ordinary



gas light, rather than in the illumination of streets



and other outdoor places by lights of great volume



and brilliancy. Dismissing from his mind quickly



the commercial impossibility of using arc lights for



general indoor illumination, he arrived at the conclusion



that an electric lamp giving light by incandescence



was the solution of the problem.







Edison was familiar with the numerous but



impracticable and commercially unsuccessful efforts



that had been previously made by other inventors



and investigators to produce electric light by incandescence,



and at the time that he began his experiments,



in 1877, almost the whole scientific world



had pronounced such an idea as impossible of fulfilment.



The leading electricians, physicists, and experts



of the period had been studying the subject



for more than a quarter of a century, and with but



one known exception had proven mathematically and



by close reasoning that the "Subdivision of the



Electric Light," as it was then termed, was practically



beyond attainment. Opinions of this nature



have ever been but a stimulus to Edison when he



has given deep thought to a subject, and has become



impressed with strong convictions of possibility, and



in this particular case he was satisfied that the subdivision



of the electric light--or, more correctly, the



subdivision of the electric current--was not only



possible but entirely practicable.







It will have been perceived from the foregoing



chapters that from the time of boyhood, when he



first began to rub against the world, his commercial



instincts were alert and predominated in almost all



of the enterprises that he set in motion. This



characteristic trait had grown stronger as he matured,



having received, as it did, fresh impetus and strength



from his one lapse in the case of his first patented



invention, the vote-recorder. The lesson he then



learned was to devote his inventive faculties only to



things for which there was a real, genuine demand,



and that would subserve the actual necessities of



humanity; and it was probably a fortunate circumstance



that this lesson was learned at the outset of



his career as an inventor. He has never assumed to



be a philosopher or "pure scientist."







In order that the reader may grasp an adequate



idea of the magnitude and importance of Edison's



invention of the incandescent lamp, it will be necessary



to review briefly the "state of the art" at the



time he began his experiments on that line. After



the invention of the voltaic battery, early in the ...