The Art of recording the addition of columns of figures is old in principle, but not in practice. Many attempts to make a machine that would record legibly under all conditions failed. These attempts have been pointed out from time to time as the first invention of the recording-adding machine, especially by those desirous of claiming the laurels. [Sidenote: _First attempt to record arithmetical computation_] The first attempt at arithmetical recording for which a patent was issued, was made by E. D. Barbour in 1872 (see illustration on opposite page). E. D. Barbour has also the honor of being the first inventor to apply Napier’s principle to mechanism intended to automatically register the result of multiplying a number having several ordinal places by a single digit without mentally adding together the overlapping figures resulting from direct multiplication. He patented this machine in 1872 just prior to the issue of his arithmetical recorder patent. (See page 181.) THE BARBOUR MACHINE The printing device disclosed in connection with the Barbour machine for recording calculations was of the most simple nature, allowing only for the printing of totals and sub-totals. Its manipulation consisted of placing a piece of paper under a hinged platen and depressing the platen by hand in the same manner that a time stamp is used. The ink had to be daubed on the type by a hand operation to make legible the impressions of the type. [Sidenote: _Description of Barbour machine_] The patent drawings of the Barbour machine are so fragmentary that it is almost impossible to draw any conclusion as to its functions without reading the specifications. Fig. 1 represents the base of the machine, while Fig. 4 shows a carriage which, when in place, is superimposed above the base as illustrated in Figs. 3 and 5. The operation of the machine is performed by first pulling out the slides B (shown in Fig. 1), which set the digital degrees of actuation of each order; and, second, by operating the hand-lever K, from its normal position at 0 to 1, if it is desired to add, or to any of the other numbers in accordance to the value of the multiplier if multiplication is desired. The movement of the handle K, from one figure to the other, gives a reciprocation to the carriage, so that for each figure a reciprocation will take place. Each of the slides B, has a series of nine gear racks; each rack has a number of teeth ranging progressively from 1 tooth for the first gear rack to 9 teeth for the last rack, thus the pulling out of the slides B will present one of the gear racks in line to act upon the accumulator mechanism of the carriage as the carriage is moved back and forth over it. The accumulator mechanism consists of the register wheels M¹ and M² and the type wheels M³ and M⁴ mounted on a common arbor and a carry transfer device between the wheels of each order.