Memories Of Menlo Park - 10

Memories Of Menlo Park - 10

Returning to the work itself, note of which has al- ready been made in this and preceding

chapters, we find an interesting and unique reminiscence in Mr. Jehl's notes of the

reversion to carbon as a filament in the lamps, following an exhibition of metallicfilament

lamps given in the spring of 1879 to the men in the syndicate advancing the

funds for these experiments: "They came to Menlo Park on a late afternoon train from

New York. It was already dark when they were conducted into the machine- shop, where

we had several platinum lamps installed in series. When Edison had finished explaining

the principles and details of the lamp, he asked Kruesi to let the dynamo machine run. It

was of the Gramme type, as our first dynamo of the Edison design was not yet finished.

Edison then ordered the `juice' to be turned on slowly. To-day I can see those lamps

rising to a cherry red, like glowbugs, and hear Mr. Edison saying `a little more juice,' and

the lamps began to glow. `A little more' is the command again, and then one of the lamps

emits for an instant a light like a star in the distance, after which there is an eruption and a

puff; and the machine-shop is in total darkness. We knew instantly which lamp had

failed, and Batchelor replaced that by a good one, having a few in reserve near by. The

operation was repeated two or three times with about the same results, after which the

party went into the library until it was time to catch the train for New York."

Such an exhibition was decidedly discouraging, and it was not a jubilant party that

returned to New York, but: "That night Edison remained in the laboratory meditating

upon the results that the platinum lamp had given so far. I was engaged reading a book

near a table in the front, while Edison was seated in a chair by a table near the organ.

With his head turned downward, and that conspicuous lock of hair hanging loosely on

one side, he looked like Napoleon in the celebrated picture, On the Eve of a Great Battle.

Those days were heroic ones, for he then battled against mighty odds, and the prospects

were dim and not very encouraging. In cases of emergency Edison always possessed a

keen faculty of deciding immediately and correctly what to do; and the decision he then

arrived at was predestined to be the turning-point that led him on to ultimate success....

After that exhibition we had a house- cleaning at the laboratory, and the metallic-filament

lamps were stored away, while preparations were made for our experiments on carbon

lamps."

Thus the work went on. Menlo Park has hitherto been associated in the public thought

with the telephone, phonograph, and incandescent lamp; but it was there, equally, that the

Edison dynamo and system of distribution were created and applied to their specific

purposes. While all this study of a possible lamp was going on, Mr. Upton was busy

calculating the economy of the "multiple arc" system, and making a great many tables to

determine what resistance a lamp should have for the best results, and at what point the

proposed general system would fall off in economy when the lamps were of the lower

resistance that was then generally assumed to be necessary. The world at that time had

not the shadow of an idea as to what the principles of a multiple arc system should be,

enabling millions of lamps to be lighted off distributing circuits, each lamp independent

of every other; but at Menlo Park at that remote period in the seventies Mr. Edison's

mathematician was formulating the inventor's conception in clear, instructive figures;

"and the work then executed has held its own ever since." From the beginning of his

experiments on electric light, Mr. Edison had a well-defined idea of producing not only a

practicable lamp, but also a SYSTEM of commercial electric lighting. Such a scheme

involved the creation of an entirely new art, for there was nothing on the face of the earth

from which to draw assistance or precedent, unless we except the elementary forms of

dynamos then in existence. It is true, there were several types of machines in use for the

then very limited field of arc lighting, but they were regarded as valueless as a part of a

great comprehensive scheme which could supply everybody with light. Such machines

were confessedly inefficient, although representing the farthest reach of a young art. A

commission appointed at that time by the Franklin Institute, and including Prof. Elihu

Thomson, investigated the merits of existing dynamos and reported as to the best of

them: "The Gramme machine is the most economical as a means of converting motive

force into electricity; it utilizes in the arc from 38 to 41 per cent. of the motive work

produced, after deduction is made for friction and the resistance of the air." They reported

also that the Brush arc lighting machine "produces in the luminous arc useful work

equivalent to 31 per cent. of the motive power employed, or to 38 1/2 per cent. after the

friction has been deducted." Commercial possibilities could not exist in the face of such

low economy as this, and Mr. Edison realized that he would have to improve the dynamo

himself if he wanted a better machine. The scientific world at that time was engaged in a

controversy regarding the external and internal resistance of a circuit in which a generator

was situated. Discussing the subject Mr. Jehl, in his biographical notes, says: "While this

controversy raged in the scientific papers, and criticism and confusion seemed at its

height, Edison and Upton discussed this question very thoroughly, and Edison declared

he did not intend to build up a system of distribution in which the external resistance

would be equal to the internal resistance. He said he was just about going to do the

opposite; he wanted a large external resistance and a low internal one. He said he wanted

to sell the energy outside of the station and not waste it in the dynamo and conductors,

where it brought no profits.... In these later days, when these ideas of Edison are used as

common property, and are applied in every modern system of distribution, it is

astonishing to remember that when they were propounded they met with most vehement

antagonism from the world at large." Edison, familiar with batteries in telegraphy, could

not bring himself to believe that any substitute generator of electrical energy could be

efficient that used up half its own possible output before doing an equal amount of

outside work.