By 1885 the
Edison lighting system was commercially developed in all its
essentials, though still subject to many improvements and capable
of great enlargement, and soon Edison. sold out his interests in
it and turned his great mind to other inventions.
The inventive ingenuity of others brought in time better and more
economical incandescent lamps. From the filaments of bamboo fiber
the next step was to filaments of cellulose in the form of
cotton, duly prepared and carbonized. Later (1905) came the
metalized carbon filament and finally the employment of tantalum
or tungsten. The tungsten lamps first made were very delicate,
and it was not until W. D. Coolidge, in the research laboratories
of the General Electric Company at Schenectady, invented a
process for producing ductile tungsten that they became available
for general use.
The dynamo and the central power station brought the electric
motor into action. The dynamo and the motor do precisely opposite
things. The dynamo converts mechanical energy into electric
energy. The motor transforms electric energy into mechanical
energy. But the two work in partnership and without the dynamo to
manufacture the power the motor could not thrive. Moreover, the
central station was needed to distribute the power for
transportation as well as for lighting.
Pages:
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208