Edison, His Life and Inventions [123]
but also many other qualifications necessary for the manufacture of an improved type of lamp which had become desirable by reason of the rapid adoption of his lighting system.
At the very time Mr. McGowan was making his explorations deep in South America, and Mr. Ricalton his swift trip around the world, Edison, after much investigation and experiment, had produced a compound which promised better results than bamboo fibres. After some changes dictated by experience, this artificial filament was adopted in the manufacture of lamps. No radical change was immediately made, however, but the product of the lamp factory was gradually changed over, during the course of a few years, from the use of bamboo to the "squirted" filament, as the new material was called. An artificial compound of one kind or another has indeed been universally adopted for the purpose by all manufacturers; hence the incandescing conductors in all carbon-filament lamps of the present day are made in that way. The fact remains, however, that for nearly nine years all Edison lamps (many millions in the aggregate) were made with bamboo filaments, and many of them for several years after that, until bamboo was finally abandoned in the early nineties, except for use in a few special types which were so made until about the end of 1908. The last few years have witnessed a remarkable advance in the manufacture of incandescent lamps in the substitution of metallic filaments for those of carbon. It will be remembered that many of the earlier experiments were based on the use of strips of platinum; while other rare metals were the subject of casual trial. No real success was attained in that direction, and for many years the carbon-filament lamp reigned supreme. During the last four or five years lamps with filaments made from tantalum and tungsten have been produced and placed on the market with great success, and are now largely used. Their price is still very high, however, as compared with that of the carbon lamp, which has been vastly improved in methods of construction, and whose average price of fifteen cents is only one-tenth of what it was when Edison first brought it out.
With the close of Mr. McGowan's and Mr. Ricalton's expeditions, there ended the historic world-hunt for natural fibres. From start to finish the investigations and searches made by Edison himself, and carried on by others under his direction, are remarkable not only from the fact that they entailed a total expenditure of about $100,000, (disbursed under his supervision by Mr. Upton), but also because of their unique inception and thoroughness they illustrate one of the strongest traits of his character--an invincible determination to leave no stone unturned to acquire that which he believes to be in existence, and which, when found, will answer the purpose that he has in mind.
CHAPTER XIV
INVENTING A COMPLETE SYSTEM OF LIGHTING
IN Berlin, on December 11, 1908, with notable eclat, the seventieth birthday was celebrated of Emil Rathenau, the founder of the great Allgemein Elektricitaets Gesellschaft. This distinguished German, creator of a splendid industry, then received the congratulations of his fellow-countrymen, headed by Emperor William, who spoke enthusiastically of his services to electro-technics and to Germany. In his interesting acknowledgment, Mr. Rathenau told how he went to Paris in 1881, and at the electrical exhibition there saw the display of Edison's inventions in electric lighting "which have met with as little proper appreciation as his countless innovations in connection with telegraphy, telephony, and the entire electrical industry." He saw the Edison dynamo, and he saw the incandescent lamp, "of which millions have been manufactured since that day without the great master being paid the tribute to his invention." But what impressed the observant, thoroughgoing German was the breadth with which the whole lighting art had been elaborated and perfected, even at that early day. "The Edison system of lighting was as beautifully conceived down to the very
At the very time Mr. McGowan was making his explorations deep in South America, and Mr. Ricalton his swift trip around the world, Edison, after much investigation and experiment, had produced a compound which promised better results than bamboo fibres. After some changes dictated by experience, this artificial filament was adopted in the manufacture of lamps. No radical change was immediately made, however, but the product of the lamp factory was gradually changed over, during the course of a few years, from the use of bamboo to the "squirted" filament, as the new material was called. An artificial compound of one kind or another has indeed been universally adopted for the purpose by all manufacturers; hence the incandescing conductors in all carbon-filament lamps of the present day are made in that way. The fact remains, however, that for nearly nine years all Edison lamps (many millions in the aggregate) were made with bamboo filaments, and many of them for several years after that, until bamboo was finally abandoned in the early nineties, except for use in a few special types which were so made until about the end of 1908. The last few years have witnessed a remarkable advance in the manufacture of incandescent lamps in the substitution of metallic filaments for those of carbon. It will be remembered that many of the earlier experiments were based on the use of strips of platinum; while other rare metals were the subject of casual trial. No real success was attained in that direction, and for many years the carbon-filament lamp reigned supreme. During the last four or five years lamps with filaments made from tantalum and tungsten have been produced and placed on the market with great success, and are now largely used. Their price is still very high, however, as compared with that of the carbon lamp, which has been vastly improved in methods of construction, and whose average price of fifteen cents is only one-tenth of what it was when Edison first brought it out.
With the close of Mr. McGowan's and Mr. Ricalton's expeditions, there ended the historic world-hunt for natural fibres. From start to finish the investigations and searches made by Edison himself, and carried on by others under his direction, are remarkable not only from the fact that they entailed a total expenditure of about $100,000, (disbursed under his supervision by Mr. Upton), but also because of their unique inception and thoroughness they illustrate one of the strongest traits of his character--an invincible determination to leave no stone unturned to acquire that which he believes to be in existence, and which, when found, will answer the purpose that he has in mind.
CHAPTER XIV
INVENTING A COMPLETE SYSTEM OF LIGHTING
IN Berlin, on December 11, 1908, with notable eclat, the seventieth birthday was celebrated of Emil Rathenau, the founder of the great Allgemein Elektricitaets Gesellschaft. This distinguished German, creator of a splendid industry, then received the congratulations of his fellow-countrymen, headed by Emperor William, who spoke enthusiastically of his services to electro-technics and to Germany. In his interesting acknowledgment, Mr. Rathenau told how he went to Paris in 1881, and at the electrical exhibition there saw the display of Edison's inventions in electric lighting "which have met with as little proper appreciation as his countless innovations in connection with telegraphy, telephony, and the entire electrical industry." He saw the Edison dynamo, and he saw the incandescent lamp, "of which millions have been manufactured since that day without the great master being paid the tribute to his invention." But what impressed the observant, thoroughgoing German was the breadth with which the whole lighting art had been elaborated and perfected, even at that early day. "The Edison system of lighting was as beautifully conceived down to the very