The history of the first locomotives in America. From original ...

118
HISTORY OF THE FIRST LOCOMOTIVES IN AMERICA,
including her own weight, was seventeen tons on the level road
at an average speed of twelve and a half miles the hour, thereby
exhibiting (agreeably to Vignoles's late table of the power of loco-
motive-engines) a little less than a six-horse engine.
" Mr. Cooper's engine has to-day moved a gross weight of four
and a half tons from the depot to EUicott's Mills and back in the
space of two hours and ten minutes, which, as you are aware, the
distance being twenty-six miles, gives an average speed of twelve
miles to the hour. As the engine returned with its load to the
same point whence it started, the acclivities and declivities
of the road were, of course, balanced ; and at least as much time
and power (if not more) were required to traverse the whole dis-
tance as would have been on a level road ; therefore (agreeably
to the aforesaid tables of M. Vignoles) Mr. Cooper's engine ex-
hibited an average force during the time it was running of 1.43
horse power, or nearly one and a half, which is more than three
times as much power as the Rocket exhibited during the experiment
above described, in proportion to the cylindrical capacity of
the respective engines. This, no doubt, originated in a consider-
able degree from the steam being used in Mr. Cooper's engine at
a higher pressure than in the Rocket. We are, however, not able
to come to any very correct conclusion as to what extent this
cause prevailed (Mr. Cooper's steam-gauge not being accurately
weighed), which prevents a more minute comparison being made.
It may be said that subsequent practice and experience with the
Rocket have enabled her constructor to produce more favorable
results, which is no doubt the case ; but we have every reason
to expect a similar effect with regard to Mr. Cooper's engine, judging
from what we have witnessed, each exhibition of its power
being, as yet, an improvement upon the one that preceded it. It
is, however, too small and too temporary in its construction to
expect a great deal, from the friction of the parts ; the heat lost in
a small engine being much greater in proportion to the power
than in a large one. But to-day's experiments must, I think, es-
tablish, beyond a doubt, the practicability of using locomotive
steam-power on the Baltimore and Ohio Railroad for the convey-
ance of passengers and goods at such speed and with such safety
(when compared with other modes) as will be perfectly satisfac-
tory to all parties concerned, and with such economy as must be
highly flattering to the interests of the company. It has been
doubted by many whether the unavoidable numerous short curves
Digitized by Microsoft®