the
gas market. As time passed, and the new illuminant was backward in
appearing, the shares recovered their old value. Edison was severely
blamed for causing the disturbance; but, nevertheless, his announcement
had been verified in all but the question of cost. The introduction of a
practical system of electric lighting employed his resources for several
years. Dynamos, types of lamps and conductors, electric meters, safety
fuses, and other appliances had to be invented. In 1882 he returned to
New York, to superintend the installation of his system in that city.

His researches on the dynamo caused him to devise what he calls an
'harmonic engine.' It consists of a tuning-fork, kept in vibration by
two small electro-magnets, excited with three or four battery cells. It
is capable of working a small pump, but is little more than a scientific
curiosity. With the object of transforming heat direct from the furnace
into electricity, he also devised a 'pyro-electric generator,' but it
never passed beyond the experimental stage.

The same may be said for his pyro-electric motor. His dynamo-electric
motors and system of electric railways are, however, a more promising
invention. His method of telegraphing to and from a railway train in
motion, by induction through the air to a telegraph wire running along
the line, is very ingenious, and has been tried with a fair amount of
success.

At present he is working at the 'Kinetograph,' a combination of
the phonograph and the instantaneous photograph as exhibited in
the zoetrope, by which he expects to produce an animated picture or
simulacrum of a scene in real life or the drama, with its appropriate
words and sounds.

Edison now resides at Llewellyn Park, Orange, a picturesque suburb of
New York. His laboratory there is a glorified edition of Menlo Park, and
realises the inventor's dream. The main building is of brick, in three
stories; but there are several annexes. Each workshop and testing room
is devoted to a particular purpose. The machine shops and dynamo rooms
are equipped with the best engines and tools, the laboratories with
the finest instruments that money can procure. There are drawing,
photographic, and photometric chambers, physical, chemical, and
metallurgical laboratories. There is a fine lecture-hall, and a splendid
library and reading-room. He employs several hundred workmen and
assistants, all chosen for their intelligence and skill. In this retreat
Edison