Томас де Кольмардың 19 ғасырлық механикалық есептегіші

19th century mechanical calculator patented by French inventor Thomas de Colmar

The arithmometer was the first digital mechanical calculator strong enough and reliable enough to be used daily in an office environment. This calculator could add and subtract two numbers directly and could perform long multiplications and divisions effectively by using a movable accumulator for the result. Patented in France by Thomas de Colmar in 1820 and manufactured from 1851 to 1915, it became the first commercially successful mechanical calculator. Its sturdy design gave it a strong reputation for reliability and accuracy and made it a key player in the move from human computers to calculating machines that took place during the second half of the 19th century. Its production debut of 1851 the arithmometer was the only type of mechanical calculator in commercial production, and it was sold all over the world. During the later part of that period two companies started manufacturing clones of the arithmometer: Burkhardt, from Germany, which started in 1878, and Layton of the UK, which started in 1883. Eventually about twenty European companies built clones of the arithmometer until the beginning of World War I.

The arithmometers of this period were four operation machines; a multiplicand inscribed on the input sliders could be multiplied by a single digit multiplier by simply pulling on a ribbon (quickly replaced by a crank handle). It was a complicated design and very few machines were built. Additionally, no machines were built between 1822 and 1844. This hiatus of 22 years coincides almost exactly with the period of time during which the British government financed the design of Charles Babbage's difference engine, which on paper was far more sophisticated than the arithmometer, but wasn’t finished at this time. In 1844 Thomas reintroduced his machine at the Exposition des Produits de l'Industrie Française in the newly created category of Miscellaneous measuring tools, counters and calculating machines but only received an honorable mention. He restarted the development of the machine in 1848. In 1850, as part of a marketing effort, Thomas built a few machines with exquisite Boulle marquetry boxes that he gave to the crown heads of Europe. He filed two patents and two patents of addition in between 1849 and 1851. and true industrial production started in 1851. The constant use of some of the machines exposed some minor design flaws like a weak carry mechanism, which was given an adequate fix in 1856, and an over rotation of the Leibniz cylinders when the crank handle is turned too fast, which was corrected by the addition of a Maltese cross. A patent covering all these innovations was filed in 1865. but was not integrated into the production models.

Under the management of Louis Payen, and later his widow, many improvements were introduced, such as an incline mechanism, a removable top, cursors and result windows that were easier to read, and a faster re zeroing mechanism. Many clone makers appeared during that period, mostly in Germany and the United Kingdom. Eventually twenty independent companies manufactured clones of the arithmometer. All these companies were based in Europe but sold their machines worldwide. The fundamental design stayed the same; and after 50 years at the top, the arithmometer lost its supremacy in the mechanical calculator industry. While in 1890, the arithmometer was still the most produced mechanical calculator in the world, ten years later, by 1900, four machines, the comptometer and Burroughs' adding machine in the USA, Odhner's Arithmometer in Russia, and Brunsviga in Germany had passed it in volume of machines manufactured. Production of the arithmometer stopped in 1915, during World War I.

Alphonse Darras, who had bought the business in 1915, was unable to restart its manufacturing after the war because of the many shortages and a lack of qualified workers.

Because it was the first mass marketed and the first widely copied calculator, its design marks the starting point of the mechanical calculator industry, which evolved into the electronic calculator industry and which, through the accidental design of the first microprocessor to be commercialized, the Intel 4004, for one of Busicom's calculators in 1971, led to the first commercially available personal computer, the Altair, in 1975. Its user interface was used throughout during the 120 years that the mechanical calculator industry lasted. First with its clones and then with the Odhner arithmometer and its clones, which was a redesign of the arithmometer with a pinwheel system but with exactly the same user interface. Over the years, the term arithmometer or parts of it have been used on many different machines like Odhner's arithmometer, the Arithmaurel or the Comptometer, and on some portable pocket calculating machines of the 1940s. Burroughs corporation started as the American Arithmometer Company in 1886. By the 1920s it had become a generic name for any machine based on its design with about twenty independent companies manufacturing Thomas' clones like Burkhardt, Layton, Saxonia, Gräber, Peerless, Mercedes Euklid, XxX, Archimedes, etc.

Thomas started to work on his machine in 1818 while serving in the French Army where he had to do a great deal of calculations. He made use of principles from previous mechanical calculators like the stepped reckoner of Leibniz and Pascal's calculator. He patented it on November 18, 1820. The only known prototype of this time is the 1822 machine on display at the Smithsonian Institution in Washington, D. C.

A 12 digit arithmometer sold for 300 francs in 1853, which was 30 times the price of a table of logarithms book and 1,500 times the cost of a first class stamp (20 French cents), but, unlike a table of logarithms book, it was simple enough to be used for hours by an operator without any special qualifications. An advertisement taken from a magazine published in 1855 shows that a 10 digit machine sold for 250 francs and a 16 digit machine sold for 500 francs.

In 1856, Thomas de Colmar estimated that he had spent 300,000 francs of his own money during the thirty years that he perfected his invention.

The arithmometer is a brass instrument housed in a wooden box often made of oak or mahogany and for the oldest ones ebony (solid or veneer). The instrument itself is divided into two parts.

The bottom part is composed of a set of sliders that are used to input the value of the operands. On the left of it is a control lever which allows to select the current operation, namely Addition/Multiplication or Subtraction/Division. A crank located on the right of the sliders is used to execute the operation selected by the control lever.

The top part is a movable carriage composed of two display registers and two reset buttons. The top display register holds the result of the previous operation and acts as accumulator for the current operation. Each command adds or subtracts the number inscribed on the sliders to the part of the accumulator directly above it. The lower display register counts the number of operations performed at each index therefore it displays the multiplier at the end of a multiplication and the quotient at the end of a division. Each number in the accumulator can be individually set with a knob situated right below it. This feature is optional for the operation counter register. The accumulator and the result counter are in between two buttons used to reset their content at once. The left button resets the accumulator, the right button resets the operation counter. These buttons are also used as handles when lifting and sliding the carriage.

The animation on the side shows a nine toothed Leibniz wheel coupled to a red counting wheel. The counting wheel is positioned to mesh with three teeth at each rotation and therefore would add or subtract 3 from the counter at each rotation. The computing engine of an arithmometer has a set of linked Leibniz wheels coupled to a crank handle. Each turn of the crank handle rotates all the Leibniz wheels by one full turn. The input sliders move counting wheels up and down the Leibniz wheels, which are themselves linked by a carry mechanism. In the arithmometer the Leibniz wheels always turn the same way. The difference in between addition and subtraction is achieved by a reverser operated by the execution lever and located in the movable display carriage.

First lift the carriage using the reset buttons located at its extremities, then slide it. The carriage can only be moved to the right initially. Release it when it is above the index you want (ones, tens, hundreds, ).

First lift the carriage using the reset buttons located at its extremities, then turn them to reset the display registers. The left button resets the accumulator, the right button resets the operation counter.

Set the control lever to Addition/Multiplication and reset the display registers. Each turn of the execution lever adds the number from the sliders to the accumulator. So input the first number and turn the lever once (it adds it to zero) then enter the second number and turn the lever once more.

Set the control lever to Addition/Multiplication and reset the display registers. To multiply 921 by 328, first input 921 on the input sliders and then turn the execution lever 8 times. The accumulator shows and the operation counter shows 8. Now, shift the carriage to the right once and turn the lever 2 times, the accumulator shows and the operation counter shows 28. Shift the carriage one last time to the right and turn the lever 3 times, the product appears on the accumulator and the operation counter displays the multiplier 328.

Set the control lever to Subtraction/Division. Lift the carriage then reset the display registers and input the minuend, right justified, into the accumulator using the corresponding knobs. Lower the carriage to its default position and then set the subtrahend onto the input sliders and turn the execution lever once.

Set the control lever to Subtraction/Division and set the divisor onto the input sliders. While keeping the carriage lifted, reset the display registers, set the dividend, right justified, using the corresponding knobs and shift the carriage so that the highest number in the dividend corresponds to the highest number in the divisor. Lower the carriage then turn the execution lever as many times as required until the number situated above the divisor is less than the divisor, then shift the carriage once to the left and repeat this operation until the carriage is back to its default position and the number in the accumulator is less than the divisor, then the quotient will be in the operations counter and the remainder will be what is left over in the accumulator.

In order to increase the decimal division accuracy add as many zeros as required to the right of the dividend but still input it right justified and then proceed as with an integer division. It is important to know where the decimal point is, when you read the quotient (some markers, first ivory and then metal, were usually sold with the machine and used for this purpose).

In 1885, Joseph Edmondson of Halifax, UK, patented his 'Circular Calculator' – essentially a 20 digit arithmometer with a circular carriage (the slides being arranged radially around it) instead of the straight sliding carriage. One benefit of this was that the carriage always remained within the footprint (to use a modern term) of the machine instead of overhanging the case at one side when the higher decimal places were in use. Another was that one could make a calculation of up to ten places, using half the circumference of the carriage, and then turn the carriage through 180°; the result of the calculation was locked in place by means of brass prongs mounted on the framework, and one could leave it there while making an entirely new calculation using the fresh set of display windows now brought into alignment with the sliders. Thus the machine could be said to have a rudimentary memory. See the Rechenmaschinen Illustrated website (External links below) for pictures and a description.