104 TRANSACTIONS OF THE [MAR. 9, 
Every day brings to light some new application, and its use 
develops with increasing rapidity. A few years ago we depend- 
ed upon the galvanic battery for our electricity. For telegraphy 
and electro-chemistry this answered, at that time, the purpose. 
It was costly and troublesome, and many attempts had been made 
to substitute mechanical generators for the production of elec- 
tricity by the motion of coils of wire in a magnetic field; it was 
not until some time after the discovery of Faraday in 1832 that 
mechanical motion was applied to the production of electric 
currents. 
The electric industry has been born and carried to its present 
state of development within the past ten years. At no time in 
the history of the world have such rapid strides been made in 
any of the applied sciences. This is due largely to the marvel- 
lous skill and competition of inventors, manufacturers, and 
users of so important a commodity; and now, for the first time 
in the history of the world, electricity has become the subject of 
commercial contracts, is bought and sold as a commodity of 
every-day use, recorded and charged for in terms of energy it- 
self, used at the pleasure and convenience of the consumer for 
lighting, heating, mechanical, and chemical purposes. 
Electricians should be congratulated for giving us a commo- 
dity thatis not capable of adulteration—for a given strength and 
electromotive force is perfectly defined, no matter how it may be 
generated or what machine produces it, and with these two mea- 
sures we can calculate the energy consumed. For by multiply- 
ing the volts by the ampéres we get the value expressed in watts, 
746 of which are equivalent to one horse power. ... I need 
hardly tell you that at the present time the most important ap- 
plications of electricity are for light and power. 
As regards the illumination of large spaces by the arc light, 
and the further subdivision for domestic uses of the incandescent 
light, the problem may be considered solved. It has been used 
for lantern projection to a limited extent, but I hope to see a 
general adoption of the are light for this purpose; and having 
devoted some time to the subject, following it up from the days 
in which the current was produced from batteries, until to-day 
when we have on tap a current of electricity as we have gas and 
water supply, it seems most fitting that my experience should be 
given to the members of this Society, and my object in inviting 
you here this evening is to give you some experimental facts, 
and to ask your verdict as to its application for lantern projec- 
tions. 
For lantern projections the usual method is to make use of 
incandescent lime; this was a great advance over the od/ lamp. 
