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Original-Odhner

Odhner Arithmometer, type Ag

The Odhner Arithmometer is a mechanical calculator with a simple pinwheel mechanism. This machine was made in Russia, but the lettering on it is in the latin alphabet, not Cyrillic, so this one was made for the international market. The logo on the left says Maschinenfabrik W. T. Odhner, St. Petersburg.

It has 9 input levers for entering a 9-digit input. It has a carriage on which there is a main register with a capacity of 13 digits, and a counter register with 8 digits. The counter does not have a carry mechanism, but shows red digits if turned in the negative direction. There is a bell that rings wheen an overflow or underflow occurs in the register, but it should be noted that carries only occur across 12 places so that the bell can only ring when the carriage is shifted one or more places to the right. This is a type Ag, where the A denotes the capacity and the g means it has an overflow bell.

The serial number is 10,500. In about 1907, from serial number 13000 or so, the company was renamed Original Odhner, so I guess this machine is from about 1906. The top plate has the name of the Dutch reseller engraved, namely J. A. Ruys in Rotterdam, and I have found newspaper ads from that company showing the Odhner.

The mechanism has none of the safety interlocks of later machines. The carriage does not even have a stop to keep it from sliding too far to the right, and it will simply hit the tooth that increments the counter. If the crank is slightly turned, the carriage is free to slide out completely.

There is a strange defect in this machine. It seems that the carry pins on the main cylinder are too long and bump against the top cover, unless that cover is kept a millimeter or so away from the body by not tightening the screws. I doubt that the machine was originally produced like that, but have no idea what could have caused that problem, except that maybe the whole pinwheel cylinder was rebuilt at some point.

Video

Original-Odhner, model 24

The Original-Odhner 24 is a mechanical calculator with a pinwheel mechanism. It has 10 input levers for entering a 10-digit input. It has a carriage on which there is a main register with a large capacity of 20 digits, and a counter register with 11 digits. The counter has a carry mechanism. The input can be cleared by pushing a button on the right which closes the input lever slots, after which you can turn the crank clockwise as far as it will go which causes the input pins to be pushed up, and then returning the crank to its resting position.

The choice of whether to increment or decrement the counter is selected automatically. After the counter is cleared, the first operation of the crank will increment the counter regardless of whether it is a subtraction or an addition, and this counter direction is then locked in for subsequent operations. The machine also has a back transfer mechanism, meaning that you can copy the value in the main register back into the input. If the input is clear, you can press the back transfer button on the right hand side of the carriage, and then clearing the main register performs the transfer.

This model does not have an input display register, but the model 25 does and is otherwise identical to this model 24.

The serial number is 24-244756, which dates the machine to about 1947.

Videos

The first video shows how to use the machine, while the second describes the mechanism.

Original-Odhner LuSiD

The LuSiD is mechanical calculator with a pinwheel mechanism that has some unusual adaptations for handling British currency. One pound sterling is worth 20 shillings, and a shilling is 12 pence, so there are 240 pence in a pound. The usual abbreviations for these coins are L or £, s, and d, which stand for the roman coins Libra, Solidus, and Denarius, and £sd is where the model name came from.

It has 10 input levers for entering a 10-digit input. The carriage has a main register that shows 10 digits, and a counter register with 15 digits. It has the usual clearing levers for the register and counter, and the same input clearing mechanism as the model 24 above.

If you are using the main register for British currency, then its decimal point is at a fixed position, with 7 digits for the number of pounds, and three decimal digits for the fraction of a pound. The sliding switch to the bottom right of the register selects how to display that fraction of a pound. If the switch is moved to the left, a cover moves up to hide the three decimal digits and another cover moves down to reveal that fraction converted to shillings and pence/farthings.

Note that the register actually has three further digits that are not displayed, and the left-most of these carries at 5 so that the visible digits of the register show the result rounded to three decimal digits. This allows calculations to use values accurate to a millionth of a pound, while the register displays the result rounded to the nearest farthing (quarter penny).

The counter's three middle wheels have red digits, and generally these would display the shillings and pence. Note that the third red number wheel actually can count from 0 to 11. While the counter register does have a carry mechanism, there is no carry from the left-most red digit. There is a sliding switch next to the counter for selecting whether it registers ordinary decimals or currency, but note that this switch can only move when the carriage is at its rightmost position. In Single mode, every turn of the crank adds 1 to the current counter digit regardless of the position of the carriage. In currency mode, it adds 1 for each turn at any digit in the pound value, but when shifted to the tenths column it adds 2 to the middle red wheel (because 0.1 pound is 2 shillings) and in the hundredths column it adds 2.4 (because 0.01 pound is 2.4 pence). In this way the counter shows the value in shillings and pence corresponding to the decimal rotations. The carriage location at which the shillings and pence are registered is essentially fixed, but there is a switch that selects between two choices of fixed location, allowing for various sizes of calculation.

The selection of whether to increment or decrement the counter is not made automatically, but must be set manually.

The serial number is 134965, which dates the machine to early 1937.
The main register's conversion to shillings and pence/farthings uses a clever mechanism consisting of a cylindrical shroud with various cut-out windows surrounding two cylindrical drums with numbers. The shroud moves in concert with the hundredths digit, and the two drums with the tenths and thousandths digits.
The counter mechanism is quite complicated. A plate on top of the carriage has a grooved track underneath it, and in Single (decimal) mode it is just a straight horizontal track, while in currency mode the track diverts down lower levels at one end. The cam levers that follow the track each shift a stepped drum gear that determines how much the counter is increased, though the selection switch determines which cam/gear set is active.

Video

Original-Odhner H11C7 adding machine

The Original-Odhner H11C7 is a manual adding listing machine. It has a standard 10-key keyboard, and three sliding buttons for the other functions. Pulling the big lever on the right hand side executes an operation, usually printing the previously entered number and adding it to the main register.

The button with a diamond sign and an asterisk selects totals or subtotals. If shifted downwards (diamond sign ⋄), then pulling the lever will print the subtotal, leaving the register unaffected. If the button is shifted upwards (asterisk ∗), then pulling the lever prints the total, resetting the register to zero. The printed totals or subtotals are followed by an asterisk or diamond sign. The (sub)total button is locked as soon as any input has been given,

If the button with a minus sign is shifted up, then the next operation is a subtraction instead of an addition. Subtracted numbers are printed in red. The machine can handle negative (sub)totals, which are printed in red and with a minus sign underneath the asterisk or diamond sign.

The orange button can be slid upwards (C) to clear the keyboard input. Sliding it downwards (R) sets the Repeat mode, which means that the input is not automatically cleared with every addition or subtraction. This allows additions to be easily repeated, thereby doing simple multiplications.

The serial number is 80203 which means it was made in 1968, though this model was in production from 1964 to about 1971. A section of the top cover lifts off to give access to the ink ribbon. The case is held closed by four screws. The mechanism rests on the rubber feet that stick through the base of the case in order to reduce noise and vibration. Unfortunately most of the rubber feet have degraded and collapsed so that the mechanism now rests directly on the surface of the underlying desk.

Video

History

Willgodt Theophil Odhner created his first working prototype pinwheel calculator in 1875. More machines were hand-built over the next few years, but mass production only started in 1890 from his workshop in Saint Petersburg. As production expanded, he licensed Grimme Natalis & Co in Germany to produce them as well, and they sold them under the brand name Brunsviga from about 1892.

Willgodt died in 1905, and his son Alexander took over the business. The early machines were called Odhner's Arithmometer, but from about 1907 the name Original Odhner began being used in order to differentiate them from competitors. After the Russian revolution the company was nationalised, and the production machinery transported to Moscow. Alexander Odhner moved to Gothenburg in Sweden where the company was rebuilt from scratch as Aktiebogalet Original-Odhner. After a few years Russia produced their own Original-Odhner machines with the machinery they confiscated, though in 1928 the machines were rebranded as Felix machines.

Soon after the Original-Odhner company was set up in Sweden, Alexander Odhner died. The leadership of the company changed several times, and in 1923 even fell into the hands of the Scandinavian Bank, who owned it for a decade. Hans Herlitz, the previous director, managed to gather a consortium of people to buy it back from the bank in 1934. Despite all these tumultous changes, the company managed to develop and expand the range of calculator models. From 1931 they started producing adding-listing machines too.

Herlitz died in 1942, after which the company was taken over by Åtvidabergs Industrier who also owned Facit. When the Facit machines were restyled by Sigvard Bernadotte to have a more modern look, the same was done for the Odhner machines. By 1973 the market for mechanical calculators had collapsed, and the company's assets were bought by Electrolux.

Models

The Odhner pinwheel machines made in Russia came in three main types - A (13 digits), B (15 digits), and C (18 digits) and were called Odhner Arithmometers. They were gradually improved over the years, for example the crank was lengthened so that it was easy to turn even when the carriage was shifted to the right.

When production started in Sweden, it was first called the Arithmos, of which five types were produced. After that, each type was given an official model number, starting with 6. The table below lists these. The information was mostly gathered from Rechner Lexicon. The options column in the table uses the following letters:
   C = Carry mechanism in the counter
   I = Input display register
   B = Back transfer mechanism.

The many adding-listing machine models are not listed here.

The following serial number tables were taken from Rechenmaschinen-Illustrated, where they were compiled by Timo Leipälä. At first all machines were numbered consecutively, regardless of model.

From 1946, various models were given their own numbering scheme.

Manuals

Directions for the use of calculating machines    (PDF, 29.5 MB or archive.org)
Gilbert Wood (A/M) Ltd.
Original-Odhner
1948?
94 page book (+62 blank pages)
225mm × 158mm × 7mm

This book is an English manual for the Original-Odhner calculators. It was published by Gilbert Wood (A/M) Ltd. who were the British distributors for Odhner. There is a brief explanation of the pinwheel machine on the inside covers, while the rest of the pages each contain a worked example from many different kinds of calculations, from simple addition to area calculations and handling British currency. There is no copyright date, but the address on the cover dates this edition to no earlier than 1947.

Original-Odhner arbeitet für Sie!    (PDF, 3.42 MB or archive.org)
Anleitung für das Rechnen auf der neuen, formgestalteten Original-Odhner
AB Original-Odhner
1956
20 page booklet
127mm × 127mm

This small booklet is the German manual for the Original-Odhner 227. It has no copyright date but on the back it says it was printed in Göteborg in 1956.

Odhner - Eine Addiermaschine die begeistert    (PDF, 1.93 MB or archive.org)
AB Original-Odhner
1959?
12 page booklet
127mm × 127mm

This small booklet is the German manual for the Odhner adding listing machines. It has no copyright date but the illustrations feature model X-11-C-8 or X-11-C-9, so it is from 1959 or later.

Paraphernalia

Original-Odhner pocket knife

This pocket knife is nicely decorated with mostly black enamel and gold-coloured designs. On one side it says "Aktiebogalet Original-Odhner" with a border formed by two sea serpents. The other side says "Göteborg" underneath the city's coat of arms depicting a rampant lion holding a sword and a shield, and "Strömstad" underneath another coat of arms depicting a sailing ship at sea. The pocket knife should have two folding blades, but one is missing. It also has a nailfile and a screwdriver.

Articles and Advertisements

Here are various ads about Odhner machines.

Here is the extensive entry for the Odhner machines in Ernst Martin's 1925 book Die Rechenmaschinen.

This is a similar entry in the Dutch book Mechanische hulpmiddelen in de administratie by I.J. Sloos. This is the second edition from 1942, but the 1929 first edition has a slightly shorter entry.

Here are various small articles about Odhner machines.

Patents

Here are some of the patents by Odhner relating to the pinwheel calculators.

Here are a few patents by Odhner relating to their adding machines.

Links

• Rechner Lexicon has a page about Odhner, which has links to many pages for specific models, including Arithmos, the model 24, and the LuSiD.
• Rechenmaschinen-Illustrated has pictures of many Odhner calculators, and a table of Odhner serial numbers.
• Cris Vande Velde has a very early Odhner, a model 24, a page about the prototypes at the Smithsonian, and the Odhner LuSiD.
• Rechnen Ohne Strom has a several Odhner models.
• W.T.Odhner Memorial Site by Kevin Odhner.
• John Wolff has page of various Odhner models, a technical description, and a complete rebuild of the Odhner Model 127.
• Christofer Noering's Swedish Typewriter Page has various Odhner models, and a model family tree overview.
• Thomas Kirchhof has a Odhner model 27, and a Odhner model 239.
• Christian Hamann has a Odhner model 7, a Odhner model 27, and a Odhner model 239
• Detlev Bölters has an Odhner Arithmometer type A, an Odhner Arithmos type 1, an Odhner model 29, and many others.

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