Pictures Thomas

“In 1821Charles Xavier Thomas of Colmar (1785-1870) submitted to the Sociėtė d'Encouragement pour L'Industrie Nationale in Paris a calculating machine he had constructed, which he called an arithmometer.

Thomas is usually thought of as the founder of the calculating machine industry because Parson Hahn's efforts probably did not yet amount to an industry since he and his collaborators manufactured only a relatively limited number of their calculating machines. Thomas devoted himself to this branch of industry up to the time of his death, and he raised this industry, over a period of several decades, to a rather high level. In fact, up to the time when the calculating machine industry was introduced into Germany by Arthur Burkhardt ( 1878). the Thomas workshop was the only firm in this line and supplied the whole world with its products. We know, for instance, that the Thomas workshop completed five hundred machines from 1821 to 1865, three hundred machines from 1865 to 1870, four hundred machines from 1871 to 1875, and three hundred machines from 1876 to 1878.

Of course, Thomas never manufactured the machines himself, rather he contracted out this aspect of the business. In the 1870’s , A. M. Hoart was engaged in their manufacture in the house of the Insurance Company Soleil. Later the manufacture was transferred to L. Payen. As of 1920, Aph. Darras, Paris manufactures the arithmometer in France with 12, 16, and 20 places in the result mechanism.”

The Thomas machine was the basis of many other machines: Burkhardt, Bunzel, Saxonia, Austria, Tate-Layton, Peerless, TIM, Archimedes,…

Valéry Monnier maintains a web site dedicated to the Thomas arithmometer. It carries machines inventory with many pictures, patent information and their explanation. In addition it shows examples of arithmometers based on the Thomas machine.

Other links for the Thomas arithmometers:

- A short overview can be found on the "The History of Computing Project".

- Stephen Johnston's article "Making the Arithmometer Count" describes the development in it's historical context

- see also the attached document for some historic aspects

Thomas

- the English patent from 1851 with descriptions, operational procedures and nice drawings is provided by Andries de Man on this web site.

- A working model of an Arithmomèter by Thomas (design end of 19th century) can be found on Stephan Weiss web-page.

Thomas, 1820

The 1820 machine had a ribbon to pull (instead of a crank as later models), a second set of result display for subtraction and division and - most important - a multiplication gear, set by the first slider from left, which allowed the "multiple add" by one "pull". Only clearance of the single result digits.

	principle	stepped drum
	capacity	3 x x 6
	production years	1820 - ???
	machines built	???
	features





		for bigger and more pictures, click on the picture

Thomas, 1848

In the 1848 machine, the ribbon was replaced by a crank at the front side. It still has the multiplication gear. The second set of result displays is gone, the switch from addition / multiplication to subtraction / division was done by a lever. Internally, the stepped drum was reduced from 18 to 9 teeth.

	principle	stepped drum
	capacity	5 x x 10
	production years	1848 - ??
	machines built	???
	features





		for bigger and more pictures, click on the picture

Thomas, 1858

"The main improvement in this version of the Thomas machine is the second counting mechanism without a tens-carry (revolution counting mechanism). The machine was also provided with one zero-setting device that acted on all the windows of the result mechanism and another for all the windows of the revolution-counting mechanism. Previously, all the numeral disks had to be set to zero individually by turning knobs placed below the individual windows. The zero-setting device is in the form of a rotating knob that is turned to the right until all the windows of the respective numeral mechanisms show zero. The zero-setting device of the result mechanism is mounted on the right side of the upper surface of the carriage, whereas the zero-setting mechanism of the revolution-counting register is arranged at the left."

Thomas, 1878

"In this model the setting slides were provided with small springs, which, when the slide has been set to a certain digit, cause the slide to slip into a notch opposite that digit so that an accidental movement of the setting knob during operation of the crank is avoided. The tens-carry mechanism was materially improved. Means were provided to prevent overthrow."

Thomas, s/n 1303

	principle	stepped drum
	capacity	10 x 11 x 20
	production years
	machines built
	features





		for bigger and more pictures, click on the picture

source: V.Monnier

Thomas, s/n 1695

	principle	stepped drum
	capacity
	production years
	machines built
	features





		for bigger and more pictures, click on the picture

source: M.E.Castro Santana

Thomas, Payen

..... need some text here ....

	principle	stepped drum
	capacity
	production years
	machines built
	features





		for bigger and more pictures, click on the picture

source: V.Monnier

Thomas, others

	principle	stepped drum
	capacity
	production years
	machines built
	features





		for bigger and more pictures, click on the picture

source: IBM

last updated: 07-Jan-08