[1] NOTE: The title of this book does not coincide with the above argument, but in view of the common use of the term “calculating” its application is better understood. Considerable contention was raised by parties in a late patent suit as to what constituted the make-up of a calculating machine. One of the attorneys contended that construction was the only thing that would distinguish a calculating machine. But as machines are named by their functioning, the contention does not hold water. That is to say: A machine may be a calculating machine and yet its construction be such that it performs its functions of negative and positive calculation without reversal of its action. Again, a machine may be a calculating machine and operate in one direction for positive calculation and the reverse for negative calculation. As long as the machine has been so arranged that all forms of calculation may be performed by it without mental computation, and the machine has a reasonable capacity of at least eight orders, it should be entitled to be called a calculating machine. [Illustration: Drawings of Spalding Patent No. 293,809] THE SPALDING MACHINE The next machine that has any bearing on the key-driven Art of which there is a record, is illustrated in a patent granted to C. G. Spalding in 1884 (see illustration on opposite page). The Spalding invention, like that of Bouchet, was provided with control for its primary actuation and control for its secondary or carrying actuation. [Sidenote: _Description of Spalding machine_] Referring to the Spalding machine reproduced from the drawings of his patent, the reader will note that in place of the units and tens numeral wheels, a clock hand has been supplied, co-operating with a dial graduated from 0 to 99, showing the figures 5, 10, 15, etc., to 95, for every five graduations. Another similar hand or arrow and dial to register the hundreds is also provided, having a capacity to register nineteen hundred. Attached to the arrows, through a shaft connection at the back of the casing are ratchet wheels, having respectively the same number of teeth as the graduation of the dial to which each hand belongs. Co-operating with the hundred-tooth ratchet of the units and tens register hand is a ratchet and lever motion device (see Fig. 2) to turn the arrow from one to nine points of the graduation of the dial. The ratchet and lever motion device consists of the spring-pressed pawl E, mounted on the lever arm D, engaging the hundred-tooth ratchet, the link or push-rod F, the lever G, and its spring O. It will be noted that a downward action of the lever G, will, through the rod F, cause a like downward action of the lever D, causing the ratchet pawl E to be drawn over the ratchet teeth. Upon the release of the lever G, the spring O, will return it to its normal position and through the named connecting parts, ratchet forward the arrow.