Origin of modern calculating machines

by J. A. V. Turck

First Practical Recorders

The fact that Barbour, Baldwin, Pottin, Ludlum and Burroughs attempted to produce a recording-adding machine shows that as far back as 1872, and at periods down to 1888, there was at least in the minds of these men a conception of the usefulness of such a machine, and the fact that there were five with the same thought is fairly good evidence of the need for a machine of this class.

Burroughs a bank clerk

In some of the human-interest articles issued through the advertising department of the Burroughs Adding Machine Co. it is stated that Wm. Seward Burroughs was a bank clerk prior to his efforts at adding machine construction. It is conceivable, therefore, that his first efforts at adding machine invention should be directed toward the production of a machine that would be of service in the bank for the bringing together of the loose items of account that are to be found in the form of checks, drafts, and the like, by printing a record of the items and their totals during the process of adding them together.

Felt interested in recorder Art

It is not surprising, therefore, that a manufacturer of a successful calculating machine should, through his contact with the trade, come to the conclusion that there was use for a machine of this class in the banks. As proof of this, we find that an application for a recording-adding machine patent was filed January 19, 1888, by D. E. Felt, which was allowed and issued June 11, 1889.

From Drawings of Felt Patent No. 405,024

Felt’s first recording machine

Some of the drawings of this patent will be found [reproduced on the opposite page], from which the reader will note that Felt combined his scheme for recording with the mechanism of the machine he was then manufacturing and selling under the trade name of “Comptometer.”

In this patent is shown the first application of the type sector combined with the individual type impression for printing the figures of the items as they were added, thus giving equal impression, whether there were one or a dozen figures in the item or total to be printed.

While the average mechanical engineer would not at a glance recognize any great advantage in placing the type figures directly on the sector instead of using the type-wheel and segment gear to drive it, as shown in two of the previously described patents, there is plenty of evidence of its advantage in the fact that all the later successful inventors have followed the Felt scheme. It provided more simple construction for the narrow space these parts must occupy for practical linear spacing.

Fell recording mechanism combined with his calculating machine

As the adding mechanism of this machine corresponds to that of the Felt patent 371,496, previously described in the preceding chapter, it is not necessary to duplicate the description here. Suffice it to say, that by the depression of a key in any order, the value of that key is added to the numeral wheel of that order, and if the figure added is great enough when added to that previously registered on the wheel, a ten will be transferred to the higher wheel by a carrying mechanism specially provided to allow the said higher wheel being in turn operated by an ordinal series of keys, thus providing the means whereby a series of denominational orders of key-driven adding mechanism may be interoperative.

Description of Felt’s first recorder

In [Fig. 2 of the drawings] is shown the result of striking the (8) key, which may be considered illustrative of such action in any order, whether units, tens, hundreds, thousands, etc.

The depression of the (8) key is shown to have carried the lever D down eight of its nine additive points of movement, causing the plunger 15, bearing against its upper edge, to drop with it under the action of the plunger spring 17.

To the upper end of this plunger, is pivotally attached an arm of the type sector U, which is in turn pivoted to the rod y, and by the lowering of the plunger 15, is rocked on its pivot, raising the type-head until the number (8) type is presented opposite the printing bar or platen T, which is hung on the pivot arms T¹, so that it may be swung forward and backward.

An ink-ribbon w, and its shifting mechanism is provided, as shown in [Fig. 1]; the paper v, is supplied in ribbon form from a roll and passes between the ink-ribbon and the platen T.

Normally, the platen, the paper and the ink-ribbon are in a retracted position, allowing space for the type sector to raise and lower freely. But, as shown in [Fig. 2], a type impression is taking place through the escapement of the cam wheel R¹ which is located back of the platen, and which, as shown, has forced the cam lever 1 forward, pressing the spring p, against the platen T, thus forcing the paper and ribbon forward against the type, and printing the figure 8.

After the cam-tooth passes, the platen, paper, ink-ribbon and spring return to normal, allowing the type sector freedom to drop when the key is released.

The cam wheel R is propelled by a spring S ([Fig. 1]), wound by the hand-knob S³, and is released for action through the escapement of the pallet wheel R attached to the cam wheel R and the pallet c.

The pallet c is tripped each time a key is depressed and is shown in the tripped position operated by the link P and the plural-armed lever O, N, which through its manifold arms N, may receive action through pins a, of any of the rock bars L, as they are depressed by the keys.

The cycle of action described takes place with every key depressed, except that the movement of the type sector varies according to the key depressed.

First individualized type impression combined with printing sector

As the printing in this Felt invention was by individualized type impression, legibility of recording as well as accurate addition was obtained. Although this patent shows that Felt had produced such an operative combination, there are two features in this patent which would prevent its becoming a marketable machine.

One of these features was that of having to wind the motor spring that furnished power for the type impression. The other feature was that there was no provision for printing the ciphers. Although the ciphers were always omitted from the keyboard of non-recording adders, as they could perform no function in addition or other forms of calculation, they could not without inconvenience, be eliminated from items in recording.