Inventing A Complete System Of Lighting - 4

  Inventing A Complete System Of Lighting - 4

 It was during this period of "inventing a system" that so much systematic and continuous

work with good results was done by Edison in the design and perfection of dynamos. The

value of his contributions to the art of lighting comprised in this work has never been

fully understood or appreciated, having been so greatly overshadowed by his invention of

the incandescent lamp, and of a complete system of distribution. It is a fact, however, that

the principal improvements he made in dynamo-electric generators were of a radical

nature and remain in the art. Thirty years bring about great changes, especially in a field

so notably progressive as that of the generation of electricity; but different as are the

dynamos of to-day from those of the earlier period, they embody essential principles and

elements that Edison then marked out and elaborated as the conditions of success. There

was indeed prompt appreciation in some well-informed quarters of what Edison was

doing, evidenced by the sensation caused in the summer of 1881, when he designed,

built, and shipped to Paris for the first Electrical Exposition ever held, the largest dynamo

that had been built up to that time. It was capable of lighting twelve hundred incandescent

lamps, and weighed with its engine twenty-seven tons, the armature alone weighing six

tons. It was then, and for a long time after, the eighth wonder of the scientific world, and

its arrival and installation in Paris were eagerly watched by the most famous physicists

and electricians of Europe.

Edison's amusing description of his experience in shipping the dynamo to Paris when

built may appropriately be given here: "I built a very large dynamo with the engine

directly connected, which I intended for the Paris Exposition of 1881. It was one or two

sizes larger than those I had previously built. I had only a very short period in which to

get it ready and put it on a steamer to reach the Exposition in time. After the machine was

completed we found the voltage was too low. I had to devise a way of raising the voltage

without changing the machine, which I did by adding extra magnets. After this was done,

we tested the machine, and the crank-shaft of the engine broke and flew clear across the

shop. By working night and day a new crank-shaft was put in, and we only had three days

left from that time to get it on board the steamer; and had also to run a test. So we made

arrangements with the Tammany leader, and through him with the police, to clear the

street--one of the New York crosstown streets--and line it with policemen, as we

proposed to make a quick passage, and didn't know how much time it would take. About

four hours before the steamer had to get it, the machine was shut down after the test, and

a schedule was made out in advance of what each man had to do. Sixty men were put on

top of the dynamo to get it ready, and each man had written orders as to what he was to

perform. We got it all taken apart and put on trucks and started off. They drove the horses

with a fire-bell in front of them to the French pier, the policemen lining the streets. Fifty

men were ready to help the stevedores get it on the steamer--and we were one hour ahead

of time."