CALCULATING MACHINE, a piece of mechanism for assisting the human intellect in the performance of arithmet ical operations. The system of loga rithms, invented by the celebrated Napier of Merchistoun, in 1614, which is of the greatest assistance to mathematicians and others in the computation of figures, by shortening the ordinary operations, seems to have been instrumental in di recting attention to the construction of an instrument by which arithmetical re sults could be produced by mechanical means, although the abacus had been long used in Europe and Asia for effect ing calculations; an3 Napier himself had produced what may be termed an elementary calculating machine, consist ing of rods with four faces, known as Napier's Bones. The first instrument which can be justly called a calculating machine, was invented by Blaise Pascal, in 1642. It was more especially con trived for the calculation of sums of money, although it would also perform the ordinary operations of arithmetic with numbers on the common, or decimal scale of notation. It consisted of a set
of cylinders, with numbers marked on their external surface, moving on axles to which wheels were attached, with a certain number of notches cut in their circumference. Among the various ma chines of later invention, the two de vised by Mr. Babbage, but never fully executed, are by far the more elaborate. The invention of the brothers Scheutz was based on the description of Mr. Babbage's difference machine, and is similar to it in general principles, though it varies from it in some points in the method adopted in its construc tion. It was purchased by Mr. Rath bone, of Albany, and presented by him to the Dudley Observatory in that city. More modern calculating machines are the slide-rule, adding machines, multi plying and dividing machines, and cash registers, which are described in detail under their several names.