Origin of modern calculating machines

by J. A. V. Turck

Machine of Early Burroughs Patent

Referring to the [drawings of the Burroughs patent], it will be noted, that in outward form, the machine is similar to the Burroughs machine of today. To give a detailed description of the construction of the machine of this Burroughs patent would make tedious reading and take unnecessary space.

General scheme of Burroughs’ first inventions

The principle involved in the mechanism for recording the items is very similar to that of the Pottin invention; the setting of the type wheels being effected as in the Pottin machine by means of segment gears which the depression of the keys serves to unlatch, and acts to gauge the additive degree of their movement.

Burroughs used the inking form of type proposed as an alternative by Pottin in his patent specification instead of the needles shown in the [Pottin drawings].

In the Burroughs patent, as in the Pottin, it will be noted that there are two sets of wheels bearing figures, one set of which, marked J, situated at the rear, are the type-wheels, and the other set, marked A, at the front of the machine, are for the accumulation of the totals.

For each denominational order of the type and total wheels, there is provided an actuating segmental gear, consisting of a two-armed segmental lever pivoted to the shaft C, and having the gear teeth of its rear arm constantly in mesh with the pinion gear of the type-wheel J, and the gear teeth of the forward arm normally presented to, but out of mesh with the pinion gear of its total wheel A.

Each of these denominational actuators or segment gears is provided with a stop projection X², at the top end of its forward gear rack, which serves as a means for interrupting the downward movement of that end of the segment lever, and thus controls its movement as a denominational actuator.

It will be noted that instead of the key-stems acting directly as a stop for the denominational actuators, as in the Pottin invention, Burroughs used a bell crank type of key lever and the stop-wire C¹ as an intermediate means, and in this manner produced a flat keyboard more practical for key manipulation.

Brief description of machine of early Burroughs patents

The stop-wires C¹, as will be noted, are arranged to slide in slots of the framework, and while normally not presented in the path of the stop-projection X², of the denominational actuators, it may be observed that by the depression of the proper key any one of them may be drawn rearward and into the path of the stop projection X², of its related actuator, and thus serve as a means to intercept the downward action of the actuator.

The denominational actuators in the Burroughs machine were not provided with spring tension that would cause them to act as soon as unlatched by depression of the keys as has been described in relation to the Pottin invention.

While the keys in the Burroughs machine, as in the Pottin invention, served also to unlatch the denominational actuators in their respective orders, no movement of the said actuators or type-wheels took place until a secondary action was performed.

The secondary action, or the operation of the hand lever, marked C⁵, attached to the shaft C, on its initial or forward stroke dragged the denominational actuators down by means of friction and thus set the type-wheels, and by means claimed in the specification, brought about the type impression to print the result of the key-setting or the item so set.

The backward or rear stroke of the hand lever caused the accumulator or total numeral wheels to be engaged and the item to be added to them.

From this single lever action it will be noted that there is an improvement shown over and above the Pottin invention in the fact that but one lever motion is required; Pottin having provided two levers so that in the event of error the operation of one lever would reset the machine without performing any addition or printing.

In the Burroughs invention, the motion of denominational actuators and their type-wheels not being effected through depression of keys, as in the Pottin machine, allowed any error in the setting up of an item to be corrected by the resetting of the keys and relatching of the gears, which it is claimed was provided for by operation of the lever marked B⁷ ([Fig. 1 of the drawings]).

As a means of supplying power to his denominational actuators, Burroughs provided what may be called a universal actuator common to all orders, composed of a rock-frame (arms D², loose on each end of actuating shaft C, and having their outward ends rigidly connected by the bar a⁹) and the arms E, fixed to each end of the shaft C.

Projecting from the inside of each of the arms E, are two lugs, b¹ and b³, which contact with the arms D² of the rock-frame as the shaft C is rocked back and forth by its hand crank C⁵, and thus lower and raise the rock-frame.

The means employed to transmit the reciprocating action of the universal actuator to such denominational actuators as may be unlatched by key depression, consists of a series of spring-pressed arc-shaped levers D¹, pivoted to the rock-frame bar a⁹, which bear against a pin b² fixed in the front arm of the denominational actuators.

Each of the levers D¹, is provided with a notch y, which serves on the downward action of the rock-frame to engage the pins b², of the denominational actuators and draw down with them such actuators as have been unlatched by key depression and to pass over the pins of such actuators as have not been unlatched.

When in the course of such downward movement the denominational actuators are intercepted by the stop-wires C¹, the yielding spring pressure of the levers D¹, allow the notches y, to slip over the pins b², and leave the denominational actuators and their type-wheels set for recording the item thus set up.

The means provided for impression of the type is shown in other drawings of a patent not reproduced here. The means provided consisted of a universal platen, which, the specification states, serves to press the ink-ribbon and paper against the type after all the figures of each item were set.

While Barbour, Baldwin and Pottin all used the universal platen to print the collective setting of type represented in the items or totals, as the case may be, each varied somewhat in detail. Baldwin used a toggle to press the platen toward the type, while Burroughs used a spring to press the platen against the type and a toggle to press it away from the type.

Burroughs claimed to have combined in his invention the printing of the totals, with the printing of the items, each of which it has been shown was claimed by the patentees of previous inventions but had not been combined in one machine prior to the Burroughs attempt.

The process for recording these totals in the Burroughs patent consisted of utilizing the action of the total wheels during their resetting or zeroizing movement to gauge the setting of the type-wheels.

The specification shows that, during the downward motion or setting of the denominational actuators, as they set the type wheels, the numeral wheels are out of gear and receive no motion therefrom; and that after the recording of each item and during the return motion of denominational actuators, the numeral or total wheels are revolved forward in their accumulative action of adding the items and thus registering the total.

Provision is made, however, when it is desired to print the totals, to cause the totalizing wheels to enmesh with the denominational actuators on their downward or setting movement, and for the unlatching of all the racks so that by operating the hand lever C⁵, the downward action of the racks will reverse the action of the totalizing wheels, which will revolve backward until the zeros show at the visible reading point, where they will be arrested by stops provided for that purpose. By this method the forward rotation accumulated on each wheel will, through the reverse action of zeroizing, give a like degree of action to the type-wheels through the denominational actuators. Thus the registration of the total wheels, it is claimed, will be transferred to the type-wheels and the record printed thereof as a footing to the column of numerical items that have been added.

All early arithmetical printing devices impractical

To pass judgment on the recording machines of the patents that have been described, from the invention of Barbour to that of Burroughs, demands consideration, first, as to whether in any of the machines of these patents the primary features of legible recording were present.

The question as to operativeness respecting other features is of no consideration until it is proven that the means disclosed for recording was practical. As non-recording adding or calculating machines they were not of a type that could compete with the more speedy key-driven machines dealt with in the preceding chapters; therefore without the capacity for legible recording, these patents must stand as representing a nonentity or as statutory evidence of the ineffective efforts of those who conceived the scheme of their make-up and attempted to produce a recording-adding machine.

Without the capacity for legible recording, of what avail is it that the machine of one of these patents should disclose advantages over another? It may be conceded that there are features set forth in the Pottin and Burroughs patents that if operatively combined with legible recording would disclose quite an advanced state of the Art at the time they were patented. But credit for such an operative combination cannot be given until it exists.

There is no desire to question the ingenuity displayed by any of these inventors, but in seeking the first practical recording-adding or calculating machine we must first find an operative machine of that type; one which will record in a practical and legible manner regardless of its other qualifications.

Practical method for recording disclosed later

The fact that the fundamental principle used for the impression of the type in the practical recorder of today is not displayed in any of these inventions, raises the question as to the effective operativeness of the printing scheme disclosed in the patents of these early machines.

In each of the four alleged recording-adding machine patents described, it will be noted that the means employed for printing was that of pressing the paper against the group of type by means of a universal platen or plate.

While with such a combination it may be possible to provide a set pressure great enough to legibly print a numerical item or total having eight to ten figures through an ink ribbon, it would not be practical to use the same pressure to print a single-digit figure, as it would cause the type to break through the paper. And yet in the numerical items and totals that have to be recorded in machines of the class under consideration, such wide variation is constantly encountered.

We are all familiar with the typewriter and the legible printing it produces. But suppose instead of printing each letter separately the whole word should be printed at once by a single-key depression, then, of course, single-letter words, such as the article “a” or the pronoun “I” would also have to be printed by a single-key depression. In this supposition we find a parallel of the requirements of a recording-adding machine.

Drawings of Ludlum Patent No. 384,373

Inoperative features of early recording mechanism

If it were possible to so increase the leverage of the typewriter keys enough to cause a word of ten letters to be printed as legibly as a single letter is now printed, ten times the power would have to be delivered at the type-head. Then think what would happen with that same amount of power applied to print the letter “a,” or letter “I.” You would not question that under such conditions the type would break a hole in the paper. And yet the patentees of the said described inventions wanted the public to believe that their inventions were operative. But to be operative as recording-adding machines, they must meet such variable conditions as described.

It is useless to believe that a variation of from one to ten or more type could be printed by a set amount of pressure through an ink-ribbon and be legible under all circumstances.

While the needle-type of Pottin may have printed the items legibly enough for a cash register, it would not serve the purpose of a record for universal use. The use of regular type and the inking ribbon proposed in his specification would bring it within the inoperative features named.