Nominal 80 horse | 54.3 | 72.3 | 129 | 21 | 469 | 517
power single | 54.3 | 72.3 | 152 | 29 | 437 | 475
cylinder Farcot | 54.0 | 72.3 | 160 | 35 | 424 | 465
engine. | 40 | 65.0 | 170 | 49 | 438 | 477
_________________|______|______|_________|________|_______|________


These motors, it may be assumed, represent the best practice that has
been obtained up to the present time in the construction of compressed
air motors; with the smallest of them, indicating about one-tenth of a
horse power, the consumption of air, when admitted cold, was 1377
cubic feet and 988 cubic feet when the air was heated before
admission. The half horse power engine consumed 1148 cubic feet of
cold air, and of heated air 791 cubic feet per horse power and per
hour. It should be mentioned that these, the most valuable and
suggestive of all the trials carried out by Professor Riedler, were
conducted with the greatest care, two distinct modes of measuring the
air supplied being followed on two occasions for each test; it may
therefore be considered that the results given are absolutely correct.
The trials were made with an old single cylinder Farcot engine,
nominally of 80 horse power, but indicating over 72.3. With this
engine the consumption of air varied from 465 to 517 cubic feet, the
larger consumption being due to the lower temperature (129 deg. Cent.)
to which the air was raised before admission; in the most economical
result the temperature was 160 deg. Cent. The volumes of air referred
to are, of course, in all cases taken at atmospheric pressure.

Among the important losses that have to be reckoned with in every
system of distributing motive power from a central station--whether by
steam or by electricity, water, or compressed air--losses must occur