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ROCHESTER:
PUBLISHED BY AARON PALMER.
Canfield & Warren, Printers.

1845.

PALMER'S

ENDLESS SELF-COMPUTING SCALE.

The proprietors of this invaluable work, beg leave to present the public with the following notice :

This Scale (the result of three years' incessant labor) is designed as an assistant in all arithmetical calculations. The simplicity, rapidity, and accuracy of its results have astonished our best mathematicians. It consists of a logarithmic combination of numbers, arranged in two or more circles, one of which is made to revolve within the other ; which process constantly changes the relation of the figures to each other, and solves an infinite variety of problems. Its advantages are 1st. A complete saving of mental labor; for, by the use of

this Scale, the most intricate calculations are but a

pleasurable exercise of the mind. 2d. A great saving of time. Computations requiring from

three to four days, are wrought out by this Scale in

the incredible short space of one minute.' 3d. Complete accuracy. The results of the computations

on this Scale are infallible. Errors are entirely out

of the question, except through sheer carelessness. 4th. Mental improvement. By this Scale, a knowledge of

the philosophy of numbers, and their relation to each other, is soon obtained. So that, in a little time, many of the common calculations are wrought out by the mere exercise of the mind

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