Part 8

A lot of functions to take place in ¹/₁₆₅ of a second, but it worked. The timing of the stop and locking detents, of course, was one of the finest features.

The normal engagement of the carrying detent, it may be understood, would prevent the movement of the wheel by key action or prime actuation, but the patent shows how Felt overcame this.

The carrying stop and locking detent lever N is provided with a cam-arm or pin N, which was arranged to co-act with the cam disc E (see Fig. 1), fast to the prime actuating pinion E. The cam surface was short and performed its function during a short lost motion arranged to take place before the ratchet pawl would pick up and move the numeral wheel under key actuation.

The camming action was outward and away from the center, and thus released the carrying stop from its locking position with the numeral wheel, and continued rotation of the pinion and cam disc would hold the lock out of action until the parts had returned to normal.

With the return action of the keys, segment lever, pinion and cam disc, through the action of a spring attached to the segment lever, the carrying stop detent will again engage and lock the numeral wheel.

Felt really started to manufacture his calculating machine in the fall of 1886, after perfecting his invention. Having only a very limited amount of money with which to produce machines, young Felt, then but 24 years of age, was obliged to make the machines himself, but with the aid of some dies which he had made for some of the principal parts (see reproduction of bill for dies on opposite page), he was able to produce eight finished machines before September, 1887. Two of these machines were immediately put into service, for the training of operators, as soon as they were finished.

Of the first trained operators to operate these machines, which were given the trademark name “Comptometer,” one was Geo. D. Mackay, and another was Geo. W. Martin. After three or four months’ practice Mr. Martin demonstrated one of these machines to such firms as Sprague, Warner & Co., Pitkin & Brooks, The Chicago Daily News, and the Chicago, Burlington & Quincy R. R. Co., and finally took employment with the Equitable Gas Light & Fuel Co. of Chicago (see letter on opposite page) as operator of the “Comptometer.” The Gas Co. has since been merged with several other companies into the Peoples Gas Light & Coke Co. of Chicago.

A very high testimonial of the qualities of the Felt invention was given by Mr. Martin in 1888, a year after he entered the employment of the Gas Co., and is reproduced on page 72.

Another fine testimonial was given by Geo. A. Yulle, Secy. & Treas. of the Chicago Gas Light & Coke Co., in September, 1888 (see page 74). Mr. Mackay, the other operator, secured employment with Albert Dickinson & Co., Seed Merchants, as operator of the “Comptometer.” Mr. Mackay was interviewed a few months ago, and was at that time, after thirty years, still with the same firm, and a strong advocate of the “Comptometer.”

In September, 1887, Felt took one of the first eight machines to Washington and exhibited it to Gen. W. S. Rosecrans, then Registrar of the Treasury, and left the machine in the office of Dr. E. B. Elliott, Actuary of the Treasury, where it was put into constant use. Proof of the date of this use of Felt’s invention in the Treasury is set forth in the reproduction of two letters (see opposite page), one was written by Mr. Elliott and another by Gen. W. S. Rosecrans, in answer to an inquiry of the Hall Typewriter Co. of Salem, Mass. Another of the first eight machines was placed with Dr. Daniel Draper, of the N. Y. State Weather Bureau, New York City.

Felt finally closed a deal with Mr. Robert Tarrant of Chicago, whereby a partnership contract was signed November 28, 1887. The partnership was incorporated January 25, 1889, under the name of the Felt & Tarrant Mfg. Co., who are still manufacturing and selling “Comptometers” under that name.

Laying aside all the evidence set forth in the foregoing history of key-driven machines and their idiosyncrasies, significant proof of Felt’s claim as the first inventor of the modern calculating machine is justified by the fact that no other multiple-order key-driven calculating machine was placed on the market prior to 1902.

Lest we lose sight of a most important feature in dealing with the Art of the Modern Calculator, we should call to mind the fact that as Felt was the originator of this type of machine, he was also the originator of the scheme of operation in its performance of the many and varied short cuts in arithmetical calculation.

The performance of calculation on machines of the older Art differed so entirely from the new that any scheme of operation that may have been devised for their use would lend nothing to the derivation of the new process for operating the key-driven machine of the new Art.

A superficial examination of one of the instruction books of the “Comptometer” will convince most any one that it is not only the mechanism of the machine that made the modern calculator so valuable to the business world, but also the schemes laid down for its use. The instructions for figuring Multiplication, Subtraction, Division, Square Root, Cube Root, Interest, Exchange, Discount, English Currency, etc., involved hard study to devise such simple methods and rules.

The instruction books written by Felt for the “Comptometer, the Modern Calculator,” reflect the genius disclosed in the invention of the machine itself.

Early Efforts in the Recording Machine Art

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.

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.

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.