The Invention Of The Incandescent Lamp - 10

The Invention Of The Incandescent Lamp - 10

Between October 21, 1879, and December 21, 1879, some hundreds of these papercarbon

lamps had been made and put into actual use, not only in the laboratory, but in the

streets and several residences at Menlo Park, New Jersey, causing great excitement and

bringing many visitors from far and near. On the latter date a full-page article appeared in

the New York Herald which so intensified the excited feeling that Mr. Edison deemed it

advisable to make a public exhibition. On New Year's Eve, 1879, special trains were run

to Menlo Park by the Pennsylvania Railroad, and over three thousand persons took

advantage of the opportunity to go out there and witness this demonstration for

themselves. In this great crowd were many public officials and men of prominence in all

walks of life, who were enthusiastic in their praises.

In the mean time, the mind that conceived and made practical this invention could not

rest content with anything less than perfection, so far as it could be realized. Edison was

not satisfied with paper carbons. They were not fully up to the ideal that he had in mind.

What he sought was a perfectly uniform and homogeneous carbon, one like the "One-

Hoss Shay," that had no weak spots to break down at inopportune times. He began to

carbonize everything in nature that he could lay hands on. In his laboratory note-books

are innumerable jottings of the things that were carbonized and tried, such as tissuepaper,

soft paper, all kinds of cardboards, drawing- paper of all grades, paper saturated

with tar, all kinds of threads, fish-line, threads rubbed with tarred lampblack, fine threads

plaited together in strands, cotton soaked in boiling tar, lamp-wick, twine, tar and

lampblack mixed with a proportion of lime, vulcanized fibre, celluloid, boxwood,

cocoanut hair and shell, spruce, hickory, baywood, cedar and maple shavings, rosewood,

punk, cork, bagging, flax, and a host of other things. He also extended his searches far

into the realms of nature in the line of grasses, plants, canes, and similar products, and in

these experiments at that time and later he carbonized, made into lamps, and tested no

fewer than six thousand different species of vegetable growths.

The reasons for such prodigious research are not apparent on the face of the subject, nor

is this the occasion to enter into an explanation, as that alone would be sufficient to fill a

fair-sized book. Suffice it to say that Edison's omnivorous reading, keen observation,

power of assimilating facts and natural phenomena, and skill in applying the knowledge

thus attained to whatever was in hand, now came into full play in determining that the

results he desired could only be obtained in certain directions.

At this time he was investigating everything with a microscope, and one day in the early

part of 1880 he noticed upon a table in the laboratory an ordinary palm-leaf fan. He

picked it up and, looking it over, observed that it had a binding rim made of bamboo, cut

from the outer edge of the cane; a very long strip. He examined this, and then gave it to

one of his assistants, telling him to cut it up and get out of it all the filaments he could,

carbonize them, put them into lamps, and try them. The results of this trial were

exceedingly successful, far better than with anything else thus far used; indeed, so much

so, that after further experiments and microscopic examinations Edison was convinced

that he was now on the right track for making a thoroughly stable, commercial lamp; and

shortly afterward he sent a man to Japan to procure further supplies of bamboo. The

fascinating story of the bamboo hunt will be told later; but even this bamboo lamp was

only one item of a complete system to be devised--a system that has since completely

revolutionized the art of interior illumination.