These should be
placed before the metal is lacquered.
** Finding the Horsepower of Small Motors [238]
A small motor often excites curiosity as to its true horsepower,
or fraction of a horsepower. Guesses in this direction vary
remarkably for the same motor or engine. It is comparatively easy
to determine the horsepower put out by almost any machine by the
following method which is intended for small battery motors and
small steam engines.
Before giving the description, it may be well to know what
horsepower means. Horsepower is the rate of work and a unit is
equal to 33,000 ft. lb. per minute, or 550 ft. lb. per second.
That is lifting 33,000 lb. 1 ft. in one minute or 550 lb. 1 ft. in
one second. This may be applied to the problem of finding the
horsepower of a motor by fastening a piece of twine about 25 ft.
long to the shaft of the engine or motor to be tested in such a
way that when the shaft revolves it will wind up the string
similar to a windlass. Place the motor in such a position that the
twine will hang freely without touching anything: out of a high
window will do.
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