tions
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 tak