STEAM TRAMS AND ELECTRIC TRAMS.

Considerable progress had within recent years been made in the

mechanical appliances intended to replace horses on our public tram

lines. The steam engine now in use in some of our towns had its

drawbacks as as well as its good qualities, as also had the endless

rope haulage, and in the case of the latter system, anxiety must be

felt when the ropes showed signs of wear. The electrically driven

trams appeared to work well. He had not, however, seen any published

data bearing on the relative cost per mile of these several systems,

and this information, when obtained, would be of interest. At the

present time, he understood, exhaustive trials were being made with an

ammonia gas engine, which, it was anticipated, would prove both more

economical and efficient than horses for tram roads. The gas was said

to be produced from the pure ammonia, obtained by distillation from

commercial ammonia, and was given off at a pressure varying from 100

to 150 lb. per square inch. This ammonia was used in specially

constructed engines, and was then exhausted into a tank containing

water, which brought it back into its original form of commercial

ammonia, ready for redistillation, and, it was stated, with a

comparatively small loss.

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Scientific American Supplement No. 822, October 3, 1891 · 第 10 / 59 题