Various methods have been heretofore described, for raising heavy
bodies, or producing for other purposes, a great force,--usually
miscalled power--by the application of a comparatively small force:
but no method is known, more unlimited in its effect, or more simple
in construction; than the conical windlass. It consists of a simple
horizontal windlass, with a crank at one end, as shown in the
engraving. The windlass is made in a conical form, being a little
larger at one end, than at the other; and if the friction of its
bearings be relieved by the ordinary friction rollers, it will so far
multiply the force applied, as to break a double inch-rope, by the
power of one man at the crank. An endless rope, or one of which the
two ends are spliced together, is passed five or six times round the
small end of the windlass, and down under a single pulley below: then,
as the windlass is turned by the crank, the rope is constantly given
off from one part, while the circumference is greater. Now it is
plain, that if the windlass is one-fifth of an inch larger in
circumference, at the point at which the rope is taken up, than at the
place where it is given off to the pulley, that whatever may be
appended thereto, will be raised one tenth of an inch by each
revolution Then, if we suppose the crank lever to be fifteen inches,
the handle will travel about 100 inches, in each revolution, which
gives a power, or increase of force, of 1000 to one. Therefore, if 100
pounds of power be applied to the crank handle, it will be
sufficient--minus friction--to raise a weight of 100,000 lbs. The only
inconvenience in this apparatus, and which prevents its coming into
more general use, is, that it is too limited in the extent of its
motion, in consequence of the travelling of the rope from one end of
the windlass to the other. Thus, if the windlass be but twenty-five
inches long, and the rope one inch in diameter, it will admit only
twenty revolutions, without renewing. Yet, in many cases, in which an
article in required to be raised, or moved but a few inches, the
conical windlass will be found preferable to any other method.
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