Origin of modern calculating machines

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.

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.

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.

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.

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.

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.

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.

The Second Felt Recorder

While the last-described Felt patent was still pending, Felt improved his mechanism for recording, installing new features and eliminating the objectionable features referred to. These improvements were of such a satisfactory nature that the Felt & Tarrant Mfg. Co. made twenty-five recording-adders, with the new features, which were sold to various banks. The first of these machines was placed on trial with the Merchants & Manufacturers National Bank of Pittsburgh, Pa., in December of 1889.

Good evidence of the practical features of this machine was set forth in a testimonial given at the time by W. A. Shaw, the cashier of the bank, after it had been given a six months’ test. This testimonial is extant and has been reproduced on opposite page.

Records show that the bank purchased that “Comptograph,” which was the trade name given the Felt recording-adder, and used it until 1899, at which time this machine, along with others of the same make purchased at a later date, were replaced by the bank with “Comptographs” of more modern type.

This Felt recording machine was without question the first practical recording-adding machine ever sold that would produce legible printed records of items and totals under the variable conditions that have to be met in such a class of recording.

After ten years of service this first practical recording-adding machine was still in excellent condition, and in 1907 was secured by the Comptograph Co. from the Bank of Pittsburgh, into which the Merchants & Manufacturers National Bank, along with other banks, had been merged. It was finally procured by Mr. Felt and presented to the National Museum of Washington, D. C., where it may now be found on exhibit along with other inventions produced by Felt. A photo reproduction of this machine as it appeared before it was presented to the Museum, is shown on the opposite page.

Like the machine of the first Felt recorder patent, it was a visible printer, each figure being printed as the key was depressed, the paper being shifted by the hand lever shown at the right.

Unlike the former machine, however, the operator was not called upon to perform the extra operation of winding up a spring to furnish power for the printing.

Power for the printing was stored by the action of the paper shift-lever and an entirely different printing device was used. Provision for printing the ciphers automatically was also a feature of this machine. It was not necessary to operate cipher keys, and there were no such keys to be operated. To print an item having ciphers in it required only the omission of the ciphers as the ciphers would automatically fill in.

The arrangement of the paper shows a good improvement over the first machine, as it was more accessible, being fed from a roll at the top down and around rolls below and looped back so that it is moved upward on the printed surface, where it may be torn off as desired.

The mechanism of this machine is not illustrated in any one patent. The Felt patents Nos. 441,233 and 465,255 cover the new feature, but the later patent, No. 465,255, shows it best. Some of the drawings of the last-named patent are reproduced on the opposite page to help in explanation of the details of the new features.

By referring to the drawings, it will be noted that the form of the front of the casing differs from the machine. Other drawings of the patent, not shown here, disclose features of still later invention than were in the machine of the photo reproduction. But it is with the printing device that we are now interested, and it was in this patent that it was first shown in the form used in the first marketed machine referred to.

The type sector marked 81 is like that of the first patent, except that it is provided with the ciphers as well as the nine digits.

The cipher type are always presented for printing when the sectors are resting at normal. Thus, if an impression can be made without depressing the keys in that order, a cipher will be printed, as will be shown later.

Back of the paper and pivoted to the rod 97, are a series of printing hammers 87, one for each type sector.

The hammers are operated by the spring 88, and are shown retained against the tension of their springs by the trigger latches 89.

These trigger latches are pivoted on the fixed shaft 171ᵃ, and actuated by the springs 92 to cause their engagement with the notch 90 of the printing hammers.

Each of the trigger latches are provided with a laterally extending lug 93, formed on their lower arm, and each lug overlaps the back of the lower arm of the adjacent trigger latch to the right of it, so that if any trigger latch should be operated so as to extricate it from the notch 50 of its printing hammer, its overlapping lug 93, would cause a like action of the trigger latch to the right of that, and so on; thus releasing all the trigger latches to the right of the latch originally released. Such releasing, of course, allowed the printing-hammers 87, to spring forward in all the orders so affected.

The long-stop actuating lever marked 16, corresponds with the lever G of the Felt key-driven calculator shown in a preceding chapter, and performs the same function as the rock bars L of the first Felt recorder patent. These stop levers 16 are pivoted at 17, and are provided with rear arms 86, extending upward with their ends opposite the lateral extending lug 93, of the trigger latch, which corresponds to the order of keys which the lever 16 serves.

In the rear upwardly-extending end of each of these levers 16, an adjusting screw 91, is provided as a tappet for tripping the trigger latch corresponding to its order.

From the above-described combination of mechanism, it may be seen that if a key in any order is depressed, it will, as it comes in contact with the stop lever 16, not only cause the adding mechanism to be stopped through the stop 19, but it will also, through its rear arm 86, cause the trigger latch of its order to trip, and likewise all the trigger latches and printing-hammers to the right, thus printing the figure presented on the printing sector in the order in which the key was operated and the ciphers in the orders to the right in case the keys in the order to the right have not previously been operated.

The individual presentation of the type figures upon key depression, except for the ciphers which were normally presented for printing, required that in striking the keys, to give correct recording of the items, the operation must be from right to left. That is, for example, if the item to be added was $740.85, the operator would depress the (5) key in the units cents column, the (8) key in the tens of cents column; the cipher in the units dollars column would be omitted, the (4) key in the tens of dollars, and the (7) key in the hundreds of dollars column would be struck.

The printing hammers were provided with means for resetting after being tripped in the recording action. This means is connected with the paper shift-lever, so that as the paper was shifted or fed upward, ready for recording the next item, the printing-hammers were all reset and latched on their respective trigger latches, ready for a new item.

Fixed to the shaft 97, on which the printing-hammers are pivoted, is a bail, marked 98, part of which is shown in the drawing, the horizontal bar of which normally lies under and out of the way of the hammers as they plunge forward in printing. And attached to the right-hand end of the shaft 97, is a crank arm connected by a link to the paper-shift hand-lever, which may be seen on the right in the photo reproduction of the machine. This connection is arranged so that depressing the lever causes the shaft 97 to rock the bail 98 rearward, thus picking up any tripped printing-hammers and relatching them.

The totals had to be printed, as in the first-described Felt recorder, by depressing a key corresponding in value to the figure showing on the wheel in each order.

The principle involved in the individual hammer-blow, combined with the ordinal type sector for recording in a recording-adder was new, and was the feature that has made the adding-recording machine of today possible, as is well in evidence by the presence of this combination in all the recorders that have been made by the successful manufacturers of listing or recording-adding and calculating machines. Some manufacturers have substituted a vertical moving type bar for the pivoted sector, but the scheme is the same, as the purpose is to get the arrangement of the type in columnar order, and does not change the fundamental features of the combination which furnished the practical means for the individual type impression.

The Felt Tabulator

The next feature in the Art, that has served in the make-up of the up-to-date recorders, was the wide paper-carriage. This feature will probably be recognized by many as a means supplied for the recording of columns of items in series on sheet-paper.

As will be noted, roll-paper in ribbon form had been used in all the previously illustrated and described recorders. While the Ludlum patent shows a carriage, it had no capacity for handling more than a single column of numerical items. The carriage in the Ludlum machine was a feature necessary to the typewriter construction and offered no solution to the feature of tabulating.

The first disclosure of the wide carriage feature for tabulating was in a machine made by D. E. Felt in 1889, which he exhibited to the U. S. Census Bureau at Washington, D. C., in 1890. The machine was also exhibited at the World’s Fair in Chicago, in 1893, along with other products in this line of the Felt & Tarrant Mfg. Co. A photo reproduction of this machine is shown on opposite page.

The machine was left at the Census Bureau, where it was used for several weeks, and was very much liked. Felt made a contract to furnish ten machines of this type, and the machine was recommended for purchase by G. K. Holmes, Special Agent of the Census Bureau, but like many other government department requisitions, the purchase order was never issued.

Although this feature is now found in all first-class recording-adders, the recording machine Art was too new in 1890 for the new feature to be appreciated, and was not pushed, as there seemed to be no demand for the wide carriage then. On this account Felt delayed applying for a patent on his invention until 1899.

In 1904 a license under the patent was granted the Burroughs Adding Machine Co., but soon after the granting of the license another manufacturer of recording-adders brought out a machine with a wide carriage, which was the start of a series of long-drawn-out infringement suits. The fact that Felt had delayed taking out his patent formed the grounds on which the Court finally decided that Felt, from lack of diligence in applying for a patent, had abandoned his invention, which made it public property.

The tags which may be seen tied to the carriage of the machine are the official tags used to identify it as a court exhibit during the long term of years the suits were pending in litigation.

Outside of the tabulating scheme, the machine was in other respects the same as the recorder just described as the roll-paper “Comptograph.”

The paper, as may be noted, is held in a shiftable carriage and is operated by two levers, one to feed the paper vertically and reset the printing-hammers, while the other moved the carriage laterally for the spacing of the columns of items or the cross-printing when desired. Besides the lever action for shifting and paper-feeding, means were provided on the right-hand end of the carriage for performing these functions; one of these is the thumb knob which served to feed the sheet of paper into the rolls; the other is a small lever which allows the operator to shift the carriage by hand independent of the carriage shift-lever.

The Third Felt Recorder

While the first lot of recording-adders manufactured by Felt were wholly practical, as was well proved by the statements of those who purchased them, it is easy to pick out features in their make-up that today, when compared with the new highly-developed Art, would seem to make them impractical.

The necessity of operating from right to left and the necessity of printing the totals by key depression were features that, in view of there being nothing better in those days, did not seem objectionable to those who used them. They were features, however, that Felt overcame and eliminated in the next lot of machines manufactured and placed on the market in 1890.

This lot of machines, one hundred in number (a goodly number in those days), were equipped with a special hand-knob in front on the left side for automatically printing the totals, and with means by which the ciphers were printed only on operation of the paper shift-lever, which allowed the operator to depress the keys from left to right or any way he pleased.

The best evidence as to what these machines looked like is to be found in the reproduction on the opposite page of an illustration which appeared in “Engineering” of London, in 1891.

It will be noted that the patent drawings of the Felt calculator are also displayed. They were used to describe the adding mechanism of the recorder.

The total printing device is shown and described in patent No. 465,255, while the patent for the printing of the ciphers by the hand shift-lever was not applied for until 1904.

It may be argued, and argued true, that these two later features in their generic application to the recording-adding machine Art were anticipated by Burroughs in his invention herein previously described. But, assuming that these features were operative features in the Burroughs machine, they could not be claimed in combination with a printing mechanism that was operative to give practical results and in themselves did not make the recording-adder possible. Nor was the means shown for recording the totals of use except with means for legible recording.

There is no desire to discredit what Burroughs did, but let the credit for what Burroughs accomplished come into its own, in accordance with the chronological order in which it may be proved that Burroughs really produced a machine that had a practical and legible recording mechanism. Then we will find that to produce such proof we must accept the fact that in all the successful recording machines manufactured and sold by the Burroughs Adding Machine Co., the printing type-sector, the printing type-hammers and the overlapping hammer-triggers with their broad functioning features forming a part of Felt’s invention, have been used to produce legible recording, and that the combination of practical total printing was dependent on Felt’s achievement.

We might say that broadly Burroughs invented means that could be worked in combination with the Felt printing scheme to automatically print the totals, which is in evidence in all the practical machines put out by the Burroughs Co.

But such a combination was first produced by Felt in 1890, and was not produced by Burroughs until 1892.

As has been shown, Felt built his recording scheme into his key-driven calculating machine, and added the paper shifting-lever to furnish the power which was utilized finally for setting the printing-hammers and tripping them for the ciphers.

Such a combination divided the work, but made a two-motion machine, whereas the adding mechanism was designed on the one-motion principle. Now the principle of the two-motion machine was old, very old. The great Gottfried Leibnitz invented the first two-motion calculator in 1694. (See illustration on opposite page.)

The Leibnitz machine was a wonderful invention and there seems to be a question as to its operativeness. As a feature of historic interest, however, it created considerable commotion in scientific circles when exhibited to the Royal Society of London.

The first really practical machine of this type, however, was invented by a Frenchman named Charles Xavier Thomas, in 1820, and has since become known as the “Thomas Arithmometre.”

The Thomas machine is made and sold by a number of different foreign manufacturers, and is used to a considerable extent in Europe and to a limited extent in the United States.

But two-motion calculators, from Leibnitz down to date, have always been constructed so that the primary or first action involved merely the setting of the controlling devices and performed no function in the supplying of power to operate the mechanism which does the adding. With such machines the load was thrown on to the secondary action.

This, of course, made the primary action of setting, a very light action, especially when keys came into use, and as there are several key depressions to each secondary or crank action, it may be understood that while the action of Felt’s printing or paper shift-lever was light, the action of the keys which were called upon to perform most of the work was much harder than it would have been if his adding mechanism had been designed on the key-set crank-operated plan of the regular two-motion machine such as illustrated in the Pottin or Burroughs patents described.

Thus, when Burroughs applied the Felt recording principle to his key-set crank-operated adding mechanism, he produced a type of recording machine which proved to be more acceptable from an operative standpoint than the recorder made by Felt; and yet the writer has read testimonials given by those who had both the Felt key-driven recorder and the Burroughs key-set crank-operated recorders, who claimed they could see no advantage.

Probably the best proof lies in the fact that Felt finally abandoned the key-driven feature in his recorders, as may be noted from the later-day “Comptograph.”

The First Practical
Burroughs Recorder

The first Burroughs patent to show the successful combination referred to was No. 504,963, applied for May 5, 1892, and issued September 12, 1893. The printing scheme, however, while indicated in the said patent, was applied for in a divisional patent, No. 505,078, issued on the same date. Drawings from both these patents are shown on opposite page.

The new printing device, as will be noted, instead of operating at the bottom of the machine, operates at the rear and prints the paper against a roll mounted outside of the casing.

Outside of adopting the Felt method of printing, the general scheme of construction used in the machine of the former-described Burroughs patent was maintained, except that the levers D, used to drag the denominational actuators down, were omitted, and a series of springs, one for each actuator, was supplied to pull such levers down as are released by key-depression when the common actuator drops under crank action.

Thus the description previously given will suffice for a general understanding of the mechanical functions of the adding mechanism and the general scheme for the setting up of the type in these later patents.

The construction of the type sectors, the printing-hammers and the trigger-latches used to retain the hammers against the action of their operating springs is best shown in the drawings of patent No. 505,078 on page 136. Fig. 1 shows the normal relation, while Fig. 2 illustrates the same mechanism in the act of printing.

The type sector as shown in drawings of patent No. 505,078 is marked K, while in the drawings of No. 504,963 it will be found marked 611ᵃ. They are formed from a continuation of the denominational actuators for the total register in the same manner that the type-wheel gear racks h, of the previously described Burroughs patent were formed.

The type u, are arranged on movable blocks marked 618, which are shown held in their retracted or normal position by springs 682, but when pressure is brought to bear against these type blocks in a direction outward from the sector, the spring 682 will give and the type blocks will slide outward in the slots provided to guide their action.

The paper, as will be noted, is fed from a roll, up between the type and the printing-roll 599, in the same manner as the paper of a typewriter, and through the interposition of an ink-ribbon between the type and the paper, the pressing of the type against the ink-ribbon, paper and roll gives imprint.

The pressure brought to bear on the type is through the hammer-blow of the printing-hammers 715, of which there is one for each ordinal printing sector. These hammers are pivoted to the rod 701, and are spring-actuated through the medium of the pin 741, the lever 716, and spring 780, which, combined with the cam-slot w, in the printing-hammers, serve to force the printing-hammers into the position shown in Fig. 2.

The printing-hammers are normally retracted and latched by a series of trigger latches 117, through the latch-tooth b, which engages the lever 716 at v.

Each trigger-latch 117, is pivoted on the rod 700, and provided with an overlapping lug as shown in Fig. 4. These overlapping lugs, like those described on the trigger-latches in the Felt patent, serve as an automatic means of filling in the ciphers in the same manner as described in the Felt machine.

The means for tripping the overlapping trigger latches naturally differed from the means shown in the Felt machine, as the Burroughs machine was not key-driven.

A very ingenious means for the tripping of the trigger-latches is shown, consisting of the dogs 718, and rock-frame 711, and tie-rods 703-704, which co-operate with a cam-shoulder y on the arm of the printing-sectors, to remain neutral or to disengage the trigger-latches through a reciprocating action, shown in dotted lines in Fig. 1, patent No. 505,078.

The tripping action takes place at the end of the forward motion of the actuating hand-crank through connections not shown in the drawings.

It may be understood that on account of the overlapping of the trigger-latches of the printing-hammers that if, as described in relation to the Felt recording-machine, one of the trigger-latches in any order to the left of the units order should be tripped, it would cause all the trigger-latches to the right to be also tripped, and the printing-hammers thus released to spring forward, giving an individual hammer-blow for each type impression.

Thus, if the five-hundred-dollar key should be depressed, only the trigger latch in that order need be tripped. This is brought about through the fact that normally the tripping-dogs 718 are held out of tripping engagement by the cam surface y of the type-sector, as the rock-frame in which the dogs are mounted is moved forward in its tripping action. But as the hundred-dollar order type-sector has been lifted through the setting of the (5) key in that order, it allows the tripping-dog to engage the trigger-latch of that order, and through the overlapping feature of the trigger-latches to trip and print the ciphers to the right.

It will be noted that the application of the printing-hammers varied in detail from that of Felt much the same as placing the latch on the gate post instead of on the gate. In the generic principle, however, the individual hammer-blow for each individual impression was maintained.

There have been many conflicting statements made regarding the date of the first Burroughs listing or recording machine, which is probably due to the fact that the statements were not qualified by such terms as “practically operative” or “legible recording.”

Dates given as that of the first Burroughs recording machine range from 1884 to 1892. In a book published by the Burroughs Co. in 1912, under the title of the “Book of the Burroughs,” there was a statement that the first practical machines were made in 1891.

H. B. Wyeth, at one time sales agent for the Burroughs Co., and whose father was president of the company in 1891 and several years thereafter, testified in court that the first sale of a Burroughs recording machine was made about December, 1892. Corroboration of his testimony is set forth in a Burroughs advertisement which appeared in the February number of Office Appliances Magazine in 1908, a reproduction of which is shown on the opposite page.

That Burroughs was experimenting as early as 1885 is no doubt correct; and that in this respect he antidated Felt’s first attempt to produce a recording-adder, is not questioned. But when it comes to the question of who produced the first practical recording-adder, there is no room for doubt in face of the evidence at hand.