John Wolff's Web Museum

The Marchant Calculating Machine Company



Rodney Marchant, c.1916.
Rodney Marchant, c.1916.


Marchant Nameplate, c.1925

Company founder Rodney Marchant studied business and commerce in San Francisco around 1900. While working as an office manager he developed several improvements to traditional bookkeeping systems, and in 1905 he travelled overseas to promote his "Marchant Check Figure System" in England and Europe. He was impressed with the potential of the European pinwheel calculators, which at that time were largely unknown in America. On his return he became the sales agent for the "Dactyle" pinwheel calculator (an Odhner-style machine made in France), which he marketed successfully from premises in Oakland, California.

In 1911 Rodney Marchant obtained a US Patent (No. 994414) for improvements to the carriage shift and handle stop mechanisms of the Odhner-style machines. In conjunction with his brother Alfred he established the Marchant Calculating Machine Company, and began to manufacture a local version of the Dactyle calculator incorporating his new improvements. In 1916 he obtained a further patent (No. 1172817) for a new push-button carriage shift mechanism. A major new factory was constructed, and the Marchant calculators soon became very popular.

It appears that Rodney Marchant may have neglected to license the underlying pin-wheel mechanism to which his improvements were applied, which led to trouble over patent infringements in 1918. The situation was saved by a young Swedish engineer named Carl Friden, who provided Marchant with an original design for an alternative to the pin-wheel mechanism. Instead of individual pins on the rotor, Friden's design used a sliding gear segment which could extend and retract at the appropriate times to advance the register by the required number of positions. Friden had only recently arrived in America, and it is said (by his daughter) that he had developed some of his new designs while stranded in Australia during the 1914-18 war.

Friden continued to develop the extending-segment machines at Marchant during the 1920s, and earned considerable royalties from his inventions. By the end of the decade the product range included manual machines with lever or full-keyboard setting mechanisms, motor-driven machines, and machines with semi-automatic multiplication and division.

Carl Friden sold his interests back to Marchant around 1928 and set out to establish his own calculator company. Harold T Avery became Marchant's Chief Engineer, and led the development of the remarkable "Silent Speed" mechanism that first appeared in 1932. The Silent Speed was based on a continuous-drive mechanism using proportional and differential gears, and was the fastest and quietest machine of its time. The machine formed the basis of Marchant production for the next 30 years. Harold Avery held more than 60 patents for the Silent Speed mechanism, and was still actively involved with its development in the mid-1950s.

In 1958 Marchant merged with the Smith-Corona typewriter company to form Smith-Corona Marchant, which later became the SCM Corporation. SCM expanded the calculator product range by reselling imported machines, including the German Diehl ten-key printing calculators and the Hamann TenKeyMaster. From around 1970 SCM re-sold a variety of mechanical and electronic calculators under the Marchant name, including the Clary Addmaster and the Compucorp range. The calculator business finally closed in 1973.

Marchant calculators did not appear in Australia until overseas trade was re-established after the 1914-18 war. The machines were imported directly by several small businesses, such as the Rebuilt Typewriter Company who placed a brief notice in the Sydney newspapers early in 1921. Marchant established its own presence here when it applied for trademark registration in 1926, and appointed Macdougalls (a major firm of stationers and office suppliers) as their official agents. Macdougalls exhibited the Marchant at trade shows in 1927 and began placing display advertisements in the newspapers in 1928. They remained as Marchant agents until the calculator business closed.

Pinwheel machines

Dactyle (Chateau)  S/N 6487 Dactyle (Chateau), S/N 6487.
Digits: 9 rotor, 8 counter, 13 accumulator.
Dimensions: Body 160W x 140D x 120H, base board 410 x 210mm.
Weight: 7.81 kg.
Manufactured: for Chateau Bros, Paris, c.1897-1929.

The Marchant brothers started their calculator business in the early 1900s by importing and reselling the French "Dactyle" pinwheel machines.

The Dactyle calculators were built in the traditional clock-making district of Jura in the French alps. They were distributed by the Chateau Brothers of Paris, with overseas agents including Muldivo in England and Marchant in the USA. Later versions were also sold under the Chateau name.

The early Dactyle machines bear more than a passing resemblance to the Brunsviga Model B. The Brunsviga machines were manufactured in Germany under licence from Odhner, for sale in Germany and Austria only. It appears that (intially at least) Brunsviga supplied Model B parts for the Chateau Brothers to assemble, so as to provide a "back-door" entry to the French market. Early Dactyles have been found with "Subt" rather than the French "Sous" as the abbreviation for Subtraction, and even with the Brunsviga logo hidden under a Dactyle nameplate. Once local French production became established around 1905 the machines started to diverge as Chateau incorporated many of their own independent developments. Production ended around 1929 with a total of about 13,000 machines sold.

The machine illustrated is a very basic pinwheel calculator from about 1909. It is heavily built of cast iron and brass, with pinwheels 71mm in diameter and 9mm thick. The rotor assembly alone weighs almost 2kg. Although this machine lacks (and has never had) the usual square nameplate on the left-hand side, it is identified by the "Sous" marking for subtraction and the French patent inscription "Bté SGDG" (for "patented without government guarantee") under the serial number and on many of the internal parts.

Internal view.
Serial number and patent notice.


Marchant Standard S/N 5368 Marchant Standard, S/N 5368.
Digits: 9 rotor, 8 counter, 13 accumulator.
Dimensions: Main body 160W x 140D x 120H, base board 410 x 240mm approx.
Weight (machine only): 8.61 kg.
Manufactured: Oakland, California, 1916-1922.

Dactyle and Marchant detent levers

The first Marchant machines from 1911 were essentially direct copies of the contemporary Dactyle/Brunsviga machines, to the extent that many of the parts were directly interchangeable. For example, the illustration at right shows the accumulator detent levers from a Dactyle (top, stamped with the French patent notice), and from a Marchant (below).

The Marchant illustrated (S/N 5368) has the date "3/13/17" scratched into one of the rotor discs. This machine includes the handle latching mechanism from Marchant's 1911 patent, the "push-button" carriage shift mechanism from the 1916 patent, and an internal safety interlock between the carriage and rotor positions. According to the patent description, the handle latch can be engaged and released manually by "ladies or people with weak wrists" to reduce the effort of holding the spring-loaded handle outwards on repeated turns. The carriage shift mechanism at the front of the machine moves the carriage one step in either direction by pressing on the appropriate button or paddle. The carriage can be released and moved manually by pulling forward on the tab between the two paddles. The interlock mechanism prevents mechanical damage by ensuring that the handle can not be turned unless the carriage is locked in one of its set positions, and that the carriage can not be moved unless the pinwheel mechanism is in its home position.

The Marchant machines were usually supplied on a large wooden baseboard with a sheet-metal or fibre-board cover. Later versions were made with different register capacities, with a setting check dial at the upper rear, and eventually with the extending-segment actuating mechanism instead of the original brass pinwheels.

Handle latch mechanism (1911 patent).
Carriage shift mechanism (1916 patent).
Comparison of Brunsviga B, Dactyle, and Marchant machines.


Extending-segment machines

Marchant XL Marchant Model XL, S/N 91709.
Technology: Extending segment, manual.
Digits: 9 keyboard, 9 counter, 18 accumulator.
Dimensions: Body 260mm W x 125D x 160H, extended width 420mm.
Weight: 6.85kg.
Manufactured: Oakland, California, 1920s.

Carl Friden's extending-segment actuator mechanism is described in his US Patent 1476197, which was filed in January of 1921. The new mechanism provided an almost direct replacement for the pin-wheel actuators in the existing Marchant machines. The only external difference was that the setting levers remained in their set positions and did not rotate as the crank was turned.

In 1922 Friden used an improved version of the new actuator in a new calculator design that was available with either pinwheel-style setting levers (the Model XL, illustrated) or with a full keyboard (see below). The counter register of these new models was relocated into the main body of the machine, to the right of the setting levers, with a moving indicator to show the active position. The counter register has full tens-carry via a separate pinwheel-style carry rotor, with a manual reversing lever for division. The "push-button" carriage shift mechanism was replaced with a single rocking lever at the front of the machine, with a carriage release button adjacent to the main crank on the right-hand end. There are separate clearing cranks for the counter and accumulator registers, and a quick-clearing bail for returning the setting levers to zero.

Marchant XL rear view.
Marchant XL internal view (front).
Marchant XL internal view (rear).
Components of Friden's "extending segment" rotor disc.


Marchant XL (later version) Marchant Model XL (later version), S/N 94908.
Technology: Extending segment, manual.
Digits: 9 keyboard, 9 counter, 18 accumulator.
Dimensions: Body 260mm W x 125D x 160H, extended width 420mm.
Weight: 7.0kg.
Manufactured: Oakland, California, 1920s.

This later version of the XL calculator has only a few external differences to the early version above. The setting levers now have coloured plastic caps instead of the previous nickel-plated handles, and a combined release latch and quick-shifting handle has been added at the left-hand end of the carriage, replacing the previous release button on the right-hand end of the body. The patent for the carriage latch was filed in May of 1928, so the machine illustrated would probably have been built after that date.

Internally, however, this later machine has a large number of mechanical changes that were designed to simplify manufacture and reduce costs. The base, feet, end plates, centre plate, sheet-metal cover plates, carriage shelf, carriage base and stops, carry rotor discs and sleeve, and even the main rotor discs have all been significantly altered from the earlier version above. For example, in the earlier version the three die-cast frame plates are keyed and dowelled to the base. In the later version the centre plate is of quite a different design in cast iron, the keys and dowels have been deleted, and alignment of the plates is trusted to close-fitting screws. None of the items listed (apart from the main rotor discs) are directly interchangeable between the two versions.


Marchant XLA Marchant Model XLA, S/N 1408.
Technology: Extending segment, manual.
Digits: 9 keyboard, 9 counter, 13 accumulator.
Dimensions: Body 190mm W x 130D x 140H, overall 360 x 175 x 155mm.
Weight: 7.00kg.
Manufactured: Oakland, California, 1920s.

The Marchant XLA is similar in style to the XL above, but with the counter register in its usual location at the left of the carriage. The counter register has no tens-carry mechanism. There is only a single clearing crank which is turned clockwise to clear the accumulator or anti-clockwise to clear the counter. The machine has the same carriage shift lever as the XL, but has a simplified internal mechanism which removes the need for a separate "quick shift" control. The carriage can simply be pushed by hand in either direction whenever the winding handle is in its home position. The patent for the carriage shift mechanism was filed in 1929. The machine is mounted on a sheet-metal base with a removable cover.

The machine illustrated was acquired in 1959 by Springvale Pigeon Racing Club in Melbourne, Australia, and was used for many years for calculating times, distances, speeds, and handicaps. It has a home-made portable carrying case with a hand-written minutes/seconds/decimal conversion chart pasted inside the lid.

Marchant XLA internal view (rear).


Marchant DRB8 Marchant Model DRB8, S/N 1320.
Technology: Extending segment, full keyboard, manual.
Digits: 9 keyboard, 9 counter, 18 accumulator.
Dimensions: Body 270mm W x 340D x 190H, extended width 380mm.
Weight: 12.9kg.
Manufactured: Oakland, California, 1920s-30s.

During the 1920s Carl Friden developed a broad range of manual, electric, and semi-automatic calculators based on the "extending-segment" mechanism from the XL (above), but using a full-keyboard setting mechanism instead of the rotary setting levers. The levers and the field of numbered columns at the upper left of the machine were replaced with a small window to show the current setting.

The first keyboard Marchant was the basic hand-cranked Model H from 1922. The Model DRB8 (illustrated) from the late 1920s is essentially the same, but with later improvements to the carriage shift and register clearing mechanisms. The long accumulator clearing handle has been removed from the left-hand end of the carriage and combined with the counter clearing handle on the right-hand side. The single handle is rotated clockwise to clear the counter, and anti-clockwise for the accumulator. A pressed-metal cover has been added to the right-hand side of the machine to accommodate the additional clearing mechanism. The carriage has the same release latch and quick-shifting handle as the later (post-1928) Model XL above.

The machine is styled in the same manner as the XL, with a similar cast-aluminium base and the same brass nameplates on the back and sides. The baseplate carries an extensive patent label, with the last issue date in 1928.

The full-keyboard Marchants are initially confusing to operate because the keyboard columns do not align with the registers. The register spacing is carried over from the original Marchant pinwheel machines, while the wider keyboard spacing is similar to other full-keyboard machines of the time. The carriage must always be positioned relative to the setting register above, and not according to the keyboard columns. Marchant's main competitor made much of the fact that their machines had "perfect column alignment".


Marchant DRB10 Marchant Model DRB10, S/N 1152-6.
Technology: Extending segment, full keyboard, electric.
Digits: 10 keyboard, 9 counter, 20 + 16 accumulator.
Dimensions: Body 250mm W x 410D x 200H, overall 420mm W x 460D.
Weight: 22.6 kg.
Manufactured: Oakland, California, 1930s.

Model DRB10 is similar to the DRB8 above, but with the addition of a second "grand total" register in the carriage, an electric motor drive, and a power-assisted clearing mechanism.

The grand total register is mounted in the carriage directly above the main accumulator, and can be engaged and cleared separately. It covers only the leftmost 16 digits, with a round-off mechanism to eliminate the fractional cents accumulated in the first four places. The register mechanism is described in Friden's US Patent 1928125, filed in 1929 and issued in September 1933.

The electric motor and the main gearbox are mounted externally on an extended baseplate at the rear of the machine. The Westinghouse 220V  direct-current motor has an open-frame construction with the commutator and connections fully exposed. (DC distribution was used in many parts of Australia during the 1920s and 30s, before the establishment of a wider AC grid. DC supplies for specific machinery (such as lift motors or theatre arc lamps) were still available in central Sydney into the 1970s, and in Melbourne until quite recently. External electric motors had been available on some Marchant machines since 1915). The motor drive is engaged by the Add and Subtract bars on the keyboard, and by the clearing controls for the three registers in the extended section at the right-hand rear. Carriage positioning is still done by hand.

The complete key-set calculator and its motor drive mechanism are described in Friden's US Patent 1643710, filed in February 1924. The patent also describes a cycle-counting mechanism with an additional row of keys (not present on this DRB10) which will repeat an add or subtract operation for a set number of times to provide semi-automatic multiplication and division. This mechanism formed the basis of the fully-automatic "on-the-fly" multiplier in the later "Silent Speed" range.

The underside of this DRB10 has the same patent label as the DRB8, with three more numbers added on a separate sticker. The last is 1866023, issued in July 1932. However the September 1933 patent for the grand total register is not listed, suggesting that this machine was built between these two dates.

Marchant DRB10 rear view.
Marchant DRB10 motor nameplate.


Marchant H9 Marchant Model H9, S/N 11900.
Technology: Extending segment, full keyboard, manual.
Digits: 9 keyboard, 9 counter, 18 accumulator.
Dimensions: Body 270mm W x 340D x 190H, extended width 380mm.
Weight: 12.8kg.
Manufactured: Oakland, California, 1930s.

The Marchant Model H9 from the mid-1930s is a late revision of the full-keyboard Model H from 1922. It is similar to the DRB8 above, but with a simplified baseplate and a plain black colour scheme. The Marchant name is painted in small letters on the sides and back.

The patent label on this machine ends with US2028540, which was in fact the first patent filed for the complete key-set calculator. The application was filed by Friden in February 1922, but the patent was not issued until January 1936 (despite other patents being issued in the meantime for similar material). The machine illustrated was therefore built after January 1936, concurrently with the new "Silent Speed" machines and well after Friden had parted company with Marchant.


Proportional-gear machines

Marchant Silent Speed logo) The Marchant "Silent Speed" and its descendants use a complex and unusual continuous-drive mechanism based on proportional and differential gearing. Every column of the machine incorporates a ten-speed gearbox with three drive shafts and five selectors. The accumulator tens-carry mechanism is contained entirely within the carriage, using an additive (ie, differential) gearing mechanism with two planetary gearsets per digit. The high-speed division algorithm does not wait for underflow, but uses a predictive trip mechanism based on a two-decade analog magnitude comparator. The machine contains well over four thousand parts, with over one thousand parts in the main register alone. In spite of the complexity, the machines were unsurpassed for speed and reliability.

The Marchant proportional-gear machines were continuously refined and developed over a period of more than thirty years, and were generally regarded as the pinnacle of rotary calculator technology. A detailed description of the mechanism is provided in the Technical Section of this site.

Marchant Silent Speed 10-D Marchant Silent Speed Model 10D, S/N 157664.
Technology: Proportional gears.
Digits: 10 keyboard, 10 counter, 20 accumulator.
Dimensions: Body 290W x 370D x 230H, carriage width 380mm.
Weight: 16.2 kg.
Manufactured: Oakland, California, 1932-

Model 10 D is one of the first "Silent Speed" machines, introduced in 1932. The machine has an internal motor drive, with powered clearing and carriage shift controls. Separate Add and Multiply keys are provided for single or multiple cycles. Division is set up manually, and then proceeds automatically to completion.

Marchant Silent Speed 10-ACT Marchant Silent Speed Model 10ACT, S/N 253767.
Technology: Proportional gears, fully automatic.
Digits: 10 keyboard, 10 counter, 20 accumulator.
Dimensions: Body 290W x 370"D x 230H, carriage width 380mm.
Weight: 16.9 kg.
Manufactured: Oakland, California, 1930s-40s.

Model 10ACT includes an automatic "on-the-fly" multiplier based on Friden's cycle-counting mechanism from 1924. The multiplier keyboard is a single vertical column of keys on the far right of the machine. When a multiplier key is pressed the machine will automatically perform the required number of additions and move the carriage into the next place. The next digit can be entered while the machine is still running, giving a very fast and smooth operation.

Marchant 10DRX Marchant Figurematic Model 10DRX, S/N 412562.
Technology: Proportional gears, fully automatic.
Digits: 10 keyboard, 10 counter, 20 accumulator.
Dimensions: Body 305W x 405D x 230H, carriage width 405mm.
Weight: 17.7 kg.
Manufactured: Oakland, California, 1950s.

In the late 1940s Marchant engaged the noted industrial designer (and expatriate New Zealander) Joseph Sinel to produce a new external casing for the Silent Speed machines. Sinel transformed the rather "busy" appearance of the original machines into a very clean, simple, and elegant design. The new machines had smooth cast-aluminium sides, with sheet-metal front, rear, and bottom covers. The panels are held together by an ingenious system of interlocking flanges, with no screws or fasteners visible anywhere on the external surfaces.

The new models were known as the "Figuremaster" and "Figurematic", but the mechanisms were essentially the same as the "Silent Speed" above.

Marchant10ADX.jpg Marchant Figurematic Model 10ADX, S/N 569259.
Technology: Proportional gears, fully automatic.
Digits: 10 keyboard, 10 counter, 20 accumulator.
Dimensions: Body 305W x 405D x 230H, carriage width 405mm.
Weight: 17.7 kg.
Manufactured: Oakland, California, 1953-

The "Figurematic" Model 10ADX is essentially the same as the 10DRX (above), but with the addition of a push-button carriage tabulator and an automatic division setup key.

Marchant TR10FA Marchant TransFlo Model TR10FA, S/N 638399.
Technology: Proportional gears, fully automatic.
Digits: 10 keyboard, 10 counter, 20 accumulator.
Dimensions: Body 305W x 405D x 230H, carriage width 405mm.
Weight: 18.6 kg.
Manufactured: Oakland, California, 1955-

The "TransFlo" Model TR10FA is essentially the same as the 10DRX (above), but with the addition of a back-transfer mechanism between the accumulator and the setting register. The covers changed from green to blue in the mid-1950s.

Marchant SKA Marchant Deci-Magic Model SKA, S/N 598831.
Technology: Proportional gears, fully automatic.
Digits: 10 keyboard, 11 counter, 20 accumulator.
Dimensions: Body 305W x 405D x 230H, carriage width 405mm.
Weight: 19.8 kg.
Manufactured: Oakland, California, 1958-

The Model SKA (Single Keyboard Automatic) or "Deci-Magic" from 1958 is the most complex and highly developed of the Marchant range. The "on-the-fly" multiplier has been replaced with a new mechanism having internal storage for a full ten-digit value, which is displayed in a separate register at the front of the machine. The storage mechanism is used in multiplication, and also to provide temporary storage for keyboard or back-transferred values. The new mechanism includes automatic division setup, automatic decimal alignment, and a one-touch "Square X" function.

The Deci-Magic mechanism is described in US Patent 3019971, filed in 1956 and issued in 1962. The patent lists five inventors, including Eugene Reynolds and Harold Avery.

SCM Marchant TR SCM Marchant Transflo Model TR, S/N 721280.
Technology: Proportional gears, fully automatic, back transfer.
Digits: 10 keyboard, 11 counter, 20 accumulator.
Dimensions: Body 345W x 405D x 230H, carriage width 420mm.
Weight: 19.9 kg.
Manufactured: Orangeburg, South Carolina, after 1962.

In 1962 SCM moved the production of the Marchant calculators from Oakland to a plant in Orangeburg, South Carolina. The loss of most of the experienced Oakland workforce had an unfortunate effect on the machines' reliability and reputation.

The new models from the Orangeburg plant had a wider and more angular casing, with cast alloy panels held together by a system of concealed toggle clamps. While the new styling lost something of the simplicity and elegance of the 1950s models, the internal mechanism was largely unchanged.

This Model TR is generally similar to the TR10FA (above), with a back-transfer mechanism and on-the-fly multiplier.

Marchant labels and logos

Marchant pinwheel nameplate The Marchant nameplate from the pinwheel machines.

Marchant XL nameplate The Marchant nameplate from the front of the extending-segment machines (XL, XLA, and some full-keyboard models).

Marchant Nameplate, c.1925 This large Marchant nameplate was used on the rear of the XL and on the sides of some of the full-keyboard models.

Marchant Silent Speed logo An early "Silent Speed" logo from the patent label on the underside of an ACT10.

Marchant Silent Speed logo The Marchant logo from the rear of the later Figurematic machines.

Resources for further information


Original text and images Copyright © John Wolff 2002-21.
Last Updated: 6 December 2021 - revised text, added Dactyle, Standard, XL (two versions), and XLA.

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