Calculating Machines

The abacus, an apparatus for devices and machines for multiplication have been proposed, as by Plato, Pascal, and Leibnitz. Napier's bones and Gunter's scale were invented for the purpose of abridging numerical operations. An elaborate machine, planned by Babbage 1822 to perform all kinds of numerical operations, was begun by the English government, but never completed. Calculating machines have not come into general use, on account of the skilled labor required to operate them, as well as on account of their high cost. A machine built by Scheutz in Denmark is owned by the Dudley Observatory at Albany, Observatory at Albany, N. Y., which can calculate tables to fifteen teen places ces of decimals. Webb's adder is a simple apparatus for adding a column of figures none of which exceeds 100. Auchinclo 's averaging machine is a scale on which weights can be moved to perform computations in the equation of payments. Thacher's calculating machine is a series of slide rules arranged in cylindrical form, and is useful when only four places of figures are required in a product or quotient.