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Mercedes Euklid

The Mercedes Euklid 16 The Mercedes Euklid 29



The Mercedes Euklid model 16
   Video
The Mercedes Euklid model 29
   Video
Division
History
Models
Promotional material
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Patents
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Mercedes Euklid model 16

The Mercedes Euklid 16 is a manually driven, full keyboard calculator which has automatic division. It was made in Germany from 1927 till 1935.

The keyboard has 13 columns of keys. This is the first model to use an innovative modular design that would remain in use for all models for the next 25 years or so. Each key column is a single replacable module, and has keys with cubical keytops with no space between the keys. In each column only one key can be pressed down at a time, and if you press a second key then the first will pop up again. A small window at the front displays the currently entered digit of the column. The case of the machine is shaped around the keyboard to make it an integral part whereas on previous models the keyboard was more obviously a separate block bolted onto the non-keyboard version of the calculator.

At the front is a carriage with a 16-digit register, and an 8-digit counter. There are two sliding levers on the front of the carriage with which you can reset the counter and the main register to zero. The carriage is attached to an internal spring that pulls it to the left. You can push the carriage to the right manually to the most significant digit of your multiplication or division, and then it can shift to the left digit by digit automatically (during division) or by pressing the tab at the front of the carriage (during multiplication). The carriage shift tab can also be activated by knobs to the right and left of the keyboard. The round metal button at the left of the carriage fully releases the carriage so you can shift it to its home position quickly.

The crank on the right can be attached in two ways - sticking up almost vertically, or forwards toward the user. It can only be turned clockwise, and if you do an anti-clockwise turn nothing happens as the crank then simply does not engage with the rest of the mechanism. A clockwise turn will cause the input to be added or subtracted from the main register, and the counter will be increased or decreased. Which action is performed depends on the settings of the control buttons.

The controls are all buttons, whereas older models also used levers. To the right of the keyboard is an L button which clears any input on the keyboard (Löschen). The button marked A (Addieren) can be latched down to engage the automatic clearing of the keyboard for use in a series of additions or subtractions, whereby the keyboard is cleared at the end of each turn of the crank.

To the left of the keyboard are two pairs of radio buttons. The left pair determines whether to add (+×) or subtract (-) the input from the register. The right pair determines whether the counter is incremented (N) or decremented (C). There is also a button marked D which can be latched down to activate the automatic division. In this mode the other buttons are set automatically for each step in the division. The automatic division is explained in more detail below.

There is an innovative automatic decimal point marker system. There is a small hole to the right of every digit in the input display register. With the lever on the left hand side of the machine you can place a marker after any one of the last 8 digits of the input register, visible through the small hole. Above the counter is an arrow pointer that can be slid to mark the decimal point in the counter. Above the register is a row of holes through which one shows a white marker. This marker is automatically placed at a distance that is the sum of the other two markers. In this way the decimal point will automatically be correctly set during a multiplication.

The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16

The serial number of my machine is 14545, which means it was made in about 1929. Almost every part of the machine has the serial number stamped or scratched on it, sometimes only the last three digits. The easiest way to find the number is to move the carriage to the right so that the number becomes visible on the front edge of the base.

The principle of proportional levers is unique to the Mercedes Euklid series of calculators. The basic version used in the first models used sliders for inputting a number, one for each digit. These would shift a gear along its axle, but instead of engaging with a stepped drum, it engaged with one of ten parallel toothed racks shared by all the input digits. These toothed racks are pivoted to an arm, and when one end of that arm swings out, the racks move different amounts, varying from 0 to 9 units. The register wheels move in one direction only, so when the arm has moved back and the racks have returned to their starting position then the input has been added to the register. For subtraction the other end of the arm is moved so that complementary digits are added.

When a keyboard was used for input instead of sliders, each axle was given five gears that can slide along it, normally resting in a position inbetween two of the racks. When a key is pressed, one of the gears moves slightly up or down to engage with a rack. In this way only one gear is active at any one time, and only a small movement is needed to make it active.

The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16
The Mercedes Euklid 16

Video

Below is a video I made that demonstrates the Mercedes Euklid model 16.




Mercedes Euklid model 29

The Mercedes Euklid 29 is a manually driven, full keyboard calculator which has automatic division. It was made in (East) Germany from 1934 until 1953. It can be considered the successor to the model 12 above, as it has about the same functionality, and was the only manually driven Euklid model remaining (all the others were electric).

The keyboard has 7 columns of keys. There is a carriage with a 12-digit register, and a 6-digit counter. The carriage is at the back, angled towards the user to make the registers earier to read.

The crank on the right is angled towards the front. It can only be turned clockwise. There are two switches to the left of the keyboard. One selects whether a turn of the crank will perform an addition or a subtraction. The other selects whether the counter is incremented or decremented. To the right of the keyboard is a black button which clears the input from the keyboard. Normally this button is marked L for Löschen, but on my machine the button is blank. The other button is marked Add, and when it is pushed down and locked in place, the keyboard will be automatically cleared after every turn of the crank. The button on the left marked Div selects automatic division, and that is explained in more detail below.

The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29

It uses the same proportional lever mechanism as the model 16 above. The main difference is that the carriage is at the rear with the keyboard in front.

The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29
The Mercedes Euklid 29

The serial number of my machine is 48967, which means it was made in about 1941. The serial number can be found on various places on the mechanism, but from the the outside can only be seen on the underside of the carriage when it is shifted to the right.


Video

Below is a video I made that demonstrates the Mercedes Euklid model 29.


In this video I show the proportional lever mechanism in action.



Automatic Division

Automatic division is quite easy to perform. Once it is set up, all you have to do is turn the crank until it finishes the calculation. Here are the steps you would do to set up the division 355/113.

  1. Shift the carriage to the right as far as possible.
  2. Enter the dividend into the main register, in this example 355. You could do this by entering it on the keyboard and adding it, but you can also use the setting knobs of the register to enter it directly.
  3. Reset the counter if necessary. This is important to remember if you used an addition in the previous step as that would have incremented the counter.
  4. Enter the divisor into the keyboard, in this example 113.
  5. Push down the Division button, latching it down. This should set the control buttons correctly - subtraction from the register, the counter set to increment, and the automatic keyboard clearing disabled.
  6. Repeatedly turn the crank until the division is completed. At the end of the calculation the crank should either lock up or disengage the mechanism.
  7. To restore normal functioning, nudge the carriage to the right until it clicks, which restores function of the crank, and also unlatch the Division button to regain manual control of the other buttons.

The division works by repeatedly subtracting until the register underflows (becomes negative). The carriage then shifts to the next digit, and the control buttons switch over so that the machine now adds repeatedly until the register overflows (becomes positive again). The carriage shifts again if possible, and the process repeats. As the counter has an even number of digits, the division ends in addition mode with a positive remainder.

Here is an example division of 123/17:

Register Counter 012300000 000000 -17 Subtract, increment counter 010600000 100000 008900000 200000 007200000 300000 005500000 400000 003800000 500000 002100000 600000 000400000 700000 998700000 800000 +17 Add, decrement counter 998870000 790000 999040000 780000 999210000 770000 999380000 760000 999550000 750000 999720000 740000 999890000 730000 000060000 720000 -17 Subtract, increment counter 000043000 721000 000026000 722000 000009000 723000 999992000 724000 +17 Add, decrement counter 999993700 723900 999995400 723800 999997100 723700 999998800 723600 000000500 723500 -17 Subtract, increment counter 000000330 723510 000000160 723520 999999990 723530 +17 Add, decrement counter 000000007 723529


History

Christel Hamann (1870-1946) was a highly prolific and inventive designer of calculating machines. He founded his own company in 1896, at which his first machines were made. The full range of his lesser known early work is somewhat unclear. It is possible that he started with troncet adders and pinwheel machines, as his name has been linked to the Trick (troncet adder) and the Berolina (pinwheel machine) due to some of his patents. His first proper machine design was called the Gauss, and was a cylindrical machine with number wheels arranged around it. Instead of a single stepped drum in the centre, he used a disc with circular tracks that have varying numbers of teeth. He patented this in 1902. The cylindrical design with a shared stepped drum had been used by Philipp Matthäus Hahn in the 1770s to make a handful of machines, but the Gauss was slightly simpler, and maybe about a thousand were made. The culmination of the cylindrical design was the Curta calculator from 1946 by Curt Herzstark.

In 1904 hamann made a prototype calculator called the Gauss 4. It looked like a standard Arithmometer type of machine with sliders. However, instead of each slider moving a gear that engages with its own stepped drum, in this machine the stepped drums were replaced by a single ridged plate that was like an unrolled stepped drum, or a straightened version of the Gauss's disc, and when the crank was turned this plate was pulled past all the input gears. By 1905 this had developed further into an entirely new principle, proportional levers. Now in place of the ridged plate there were a set of ten parallel toothed racks, again shared by all the input digits. These toothed racks are pivoted to an arm, and when one end of that arm swings out, the racks move different amounts, varying from 0 to 9 units. The register wheels move in one direction only, so when the racks have returned to their starting position the input has been added to the register. For subtraction the other end of the arm is moved so that complementary digits are added. Hamann called this machine the Euklid.

In 1907 Hamann's company became part of Mercedes Büromaschinen-Werke. This small company had been founded only the year before by Gustav Metz and made typewriters, and presumably wanted to expand into making calculators as well. They made a few dozen Mercedes Gauss machines as well as similar amounts of the Mercedes Plus which was an adding machine that Hamann designed, but it was mainly the Mercedes-Euklid machines that became successful and were developed further. The company grew and moved from Berlin to Mehlis (now Zella-Mehlis) in Thüringen, which is where Walther were also based. By the time of the first world war, 8 models had been produced. Development and production were affected by the war, and in about 1922 Hamann left the company and moved back to Berlin to join Deutsche Telephonwerke GmbH where the Hamann calculators were made.

Many more Mercedes-Euklid models were developed in subsequent years, all based on the same principle. When Germany was split up after the second world war the company was in East Germany, where it was allowed to grow, though it soon was producing its machines only for the Eastern Bloc countries. The casing of the machines was changed from green to light grey, and the letter R was added to the model designations. In about 1963 Mercedes became Cellatron, and the machines were rebranded accordingly. Mercedes and then Cellatron produced about 10,000 calculators per year until either 1969 or 1975 (sources disagree on the end date). In 1977 the company became part of the state-owned Robotron Elektronik, and in 1990 this was split up into smaller companies that were bought up by various others after the Iron Curtain had fallen.


Models

The Mercedes-Euklid models are generally split into four series. Below is a table listing most of the models.


Model: Model number.
Years: Years of production. Sources are often contradictory, for example model 8 is sometimes placed as 1918 and model 29 as 1936, while adverts show them in existence in 1915 and 1934 respectively.
Capacity: Number of digits in the input×counter×result registers.
Elec.: N means manually driven, Y means electrically driven.
Keyb.: N means input via sliders, Y means input via keyboard.
Stor.: N means no extra register, T means it has an extra totaliser register, M means it has a memory storage register.
Div.: N means no special division capabilities, S means it has stop division, F means fully automatic division.
Mult.: N means no special multiplication capabilities, S means semi-automatic, K means it has multiplication keys, F means fully automatic multiplication.

Series I
ModelYearsCapacityElec.Keyb.Stor.Div.Mult.Remarks
1 1910-19279/11/13×16NNNSN
2 1911 8/10×13NNNSNOnly a handful were made.
3 1912 13NNNNNDubbed "Copernicus". Only a handful were made.
4 1913-19169/11/13×16NYNSN
5 1914-191516NNTSN
6 1914-1927 13×16NYTSN
7 1915-19329/11/13×16YNNFF
8 1915-1934 9/13×16YYNFF
9 1924-193216NNNFN
10 1924-193216NYNFN
11 1924-193216YNNFN
12 1924-193216YYNFN
13 1925-193216YNTFN
14 1925-1935 9/13×16YYTFN
15 1927-193516NNNFN
16 1927-1935 13×16NYNFN
Series II
ModelYearsCapacityElec.Keyb.Stor.Div.Mult.Remarks
18 V 1929-1936 13×16YYNFF
19 SE1930-1935 13×16YYTFN
19 SV1931-1935 13×16YYTFF
20 1929-1935 13×16YYNFN
Series III
ModelYearsCapacityElec.Keyb.Stor.Div.Mult.Remarks
21 EP1931-195712YYNFS
21 S 1931-195712YYTFS
22 E 1931-1957 13×16YYNFS
23 EP1932-193612YYNFS
23 WP1932-193612YYNFK
23 VP1932-193612YYNFF
24 E 1933-1936 13×16YYMFS
24 W 1933-1936 12×16YYMFK
24 V 1933-1936 13×16YYMFF
25 WP1931-193612YYNFK
26 W 1932-1936 12×16YYNFK
27 VP1931-193512YYNFF
28 V 1932-1935 13×16YYNFF
29 1934-1953 7/9×12NYNFNThe only manual machine after series I.
30 1935-1945 7/9×12YYNN/SN
Series IV
ModelYearsCapacityElec.Keyb.Stor.Div.Mult.Remarks
37 1934-1958 12×12YYNFF
37 SM1935-1958 12×12YYMFF
38 1934-1958 16×16YYNFF
38 SM1935-1958 16×16YYMFF
40 1959-1961 12×12YY?FS
43 1959-1968 16×16YYMFF
44 1956-1969 20×10×20YYMFF
31 1963-196912YYNFS

Mercedes used consecutive serial numbers, shared by all their calculators except for the Trick troncet adder. So not only were these numbers used for the Mercedes Euklid, but also for the few dozen Gauss and Mercedes Plus machines, and for the approximately 4000 Mercedes A adding listing machines made between 1938 and 1945. These numbers can therefore be used to fairly accurately date when the machine was made, but not how many there are of each model. Below is a list of years and the final serial number reached in that year. After 1943 the numbers are based on very rough production estimates, so I have rounded the serial numbers to the nearest 1000 to avoid the appearance of accuracy. There is so much uncertainty that one source even claims that there is a large gap where the serial numbers jumped to 100,000. It is also unclear whether production stopped around 1969 or 1975.

YearSer. NoProd.
1910 1-49 49
1911 102 53
1912 312 210
1913 713 401
1914 1137 424
1915 1147 10
1916 1171 24
1917 1188 17
1918 1196 8
1919 1665 469
1920 2963 1298
1921 3788 825
1922 5563 1775
1923 7569 2006
1924 8996 1427
1925 10052 1056
1926 10926 874
1927 11040 114
1928 12518 1478
1929 14230 1712
YearSer. NoProd.
1930 15306 1076
1931 15917 611
1932 16592 675
1933 17307 715
1934 18735 1428
1935 22572 3837
1936 26369 3797
1937 31086 4717
1938 36716 5630
1939 43121 6405
1940 48240 5119
1941 50865 2625
1942 52689 1824
1943 54291 1602
1944 55700 1409
1945 57000 1300
1946 60000 3000
1947 64000 4000
1948 69000 5000
1949 75000 6000
YearSer. NoProd.
1950 82000 7000
1951 90000 8000
1952 99000 9000
195310900010000
195411900010000
1955123000 4000
1956127000 4000
1957131000 4000
1958137000 6000
1959143000 6000
1960149000 6000
1961155000 6000
196216600011000
196317700011000
196418800011000
196519900011000
196621100012000
196722300012000
196823600013000
196924900013000
YearSer. NoProd.
197026300014000
197127700014000
197229400017000
197330800014000
197432100013000
1975330000 9000


Promotional material

This is a flyer that promotes the models 7 to 12. It is in French, has a stamp from a Belgian retailer, and probably dates from 1925 or 1926.

Mercedes Euclid Flyer
Mercedes Euclid Flyer
Mercedes Euclid Flyer
Mercedes Euclid Flyer
Mercedes Euclid Flyer
Mercedes Euclid Flyer
Mercedes Euclid Flyer

Articles and Advertisements

Here is an extract from Mathematische Instrumente by Andreas Galle from 1912:

1912 Mathematische Instrumente 1
1912 Mathematische Instrumente 2
1912 Mathematische Instrumente 3
1912 Mathematische Instrumente 4

Here is an extract from Modern Instruments and Methods Of Calculation, a Handbook Of the Napier Tercentenary Exhibition, from 1915:

1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation
1915 Modern instruments and methods of calculation

Here is the entry in the Orga-Handbuch erprobter Büromaschinen of 1921 by Ludwig Brauner and Victor Vogt:

1921 Orga-Handbuch - mercedesEuklid1
1921 Orga-Handbuch - mercedesEuklid2
1921 Orga-Handbuch - mercedesEuklid3
1921 Orga-Handbuch - mercedesEuklid4
1921 Orga-Handbuch - mercedesEuklid5
1921 Orga-Handbuch - mercedesEuklid6
1921 Orga-Handbuch - mercedesEuklid7
1921 Orga-Handbuch - mercedesEuklid8
1921 Orga-Handbuch - mercedesEuklid9

Here is the entry in Ernst Martin's 1925 book Die Rechenmaschinen:

1925 Ernst Martin
1925 Ernst Martin
1925 Ernst Martin
1925 Ernst Martin
1925 Ernst Martin
1925 Ernst Martin
1925 Ernst Martin
1925 Ernst Martin

Here is part of an article by F. Zernike which appeared in the Dutch magazine Euclides, in the first issue of the year 1942.

1942 Euclides nummer 1-2a
1942 Euclides nummer 1-2b
1942 Euclides nummer 1-2c
1942 Euclides nummer 1-2d
1942 Euclides nummer 1-2e
1942 Euclides nummer 1-2f
1942 Euclides nummer 1-2g
1942 Euclides nummer 1-2h

Here are a few other small articles from books, newspapers and magazines.

1914-03-17 Newcastle Journal (UK) 1
1923-03-17 Salzburger Volksblatt
1928-04-14 Lavanttaler Bote
1929-05-23 Das interessante Blatt
1929-09-19 Das interessante Blatt
1930-12-30 Die Stunde
1930 Organisations-Lexikon - Mercedes Euklid
1931_Moderne_Buero-Maschinen Mercedes-Euklid
1943-01 Office Appliances
1988-05-08 Informatik - Fuehrer durch die Ausstellung - Deutschen Museum 1
1988-05-08 Informatik - Fuehrer durch die Ausstellung - Deutschen Museum 2

Lastly, here are some advertisements. The first one is for the Gauss, before Mercedes got involved.

1903-01-30 Der Bautechniker
1913-09-08 Berliner Tageblatt
1914-02-15 Berliner Tageblatt
1914-03-17 Newcastle Journal (UK) 2
1915 Modern instruments and methods of calculation
1919-06-08 Berliner Tageblatt
1920-03-18 Koelnische Zeitung
1920-06-14 Arnhemse Courant
1920-10-02 Nieuwe Rotterdamse Courant
1920-10-24 Berliner Tageblatt
1921-03-16 Berliner Tageblatt
1921-03-30 Berliner Tageblatt
1923-07-28 La Stampa
1924-04-04 Nieuwe Rotterdamsche Courant
1924-04-12 Berliner Tageblatt
1925 Ernst Martin p416
1925-12-11 Mercator
1926-01-09 Berliner Boersenzeitung
1926-11-12 Berliner Tageblatt
1927-03-16 Berliner Tageblatt
1927-06-16 Berliner Tageblatt
1928-04-29 Helios
1929-10-24 La Stampa
1930-12-21 Die Stunde
1931-01-04 Die Stunde
1931-05-02 Altonaer Nachrichten
1931-05-23 Altonaer Nachrichten
1934-08-13 De Sumatra post
1934-12-08 Limburger koerier
1935-01-28 Limburger koerier
1935-07-19 De Sumatra post
1936-07-06 De Sumatra post
1938-02-09 De Sumatra post
1939-02-09 Bataviaasch nieuwsblad
1939-02-14 Bataviaasch nieuwsblad
1939-04-04 De Sumatra post
1948-03-01 Die Tat - Zurich
1948-09-09 Die Tat

Patents

PatentFiling datePublished dateNameDescription
DE 88,22311-06-189510-09-1896Christel HamannPlanimeter
US 703,78502-07-190001-07-1902Christel HamannGauss predecessor
US 705,83828-03-190229-07-1902Christel HamannExtra register for pinwheel calculator
US 772,93513-10-190325-10-1904Christel HamannPinwheel calculator improvements
DE 179,24626-11-190430-11-1906Christel HamannSubtraction using complements on pinwheel calculator
DE 194,52723-03-190506-02-1908Christel HamannGauss calculator
See also: US 832,666
DE 209,81731-05-190613-05-1909Mercedes Bureau-Maschinen-Gesellschaft m.b.H.Euklid calculator
See also: US 1,011,617
DE 210,52430-10-190703-06-1909Mercedes Bureau-Maschinen-Gesellschaft m.b.H.Mercedes Plus adding machine
DE 210,66111-02-190807-06-1909Ch. Hamann, Math. Mech. Institut, G.m.b.H.Subtraction mode on Gauss calculator
DE 228,56304-06-190912-11-1910Ch. Hamann, Math. Mech. Institut, G.m.b.H.Calculator for products of more than two factors
DE 234,98415-09-191029-05-1911Ch. Hamann, Math. Mech. Institut, G.m.b.H.Calculation device for trigonometric functions
DE 242,66513-04-191116-01-1912Mercedes Bureau-Maschinen-Gesellschaft m.b.H.Trick, troncet with sliding cover for subtraction
DE 253,52524-06-191113-11-1912Ch. Hamann, Math. Mech. Institut, G.m.b.H.Printing mechanism
US 1,221,31820-04-191203-04-1917Ch. Hamann, Math. Mech. Institut, G.m.b.H.Calculator with fast multiplication
DE 268,72912-04-191327-12-1913Mercedes Bureau-Maschinen-Gesellschaft m.b.H.Trick, version for British currency
DE 278,68012-04-191302-10-1914Ch. Hamann, Math. Mech. Institut, G.m.b.H.Calculator with totaliser
DE 287,77017-02-191405-10-1915Ch. Hamann, Math. Mech. Institut, G.m.b.H.Euklid with automatic multiplication and division
See also: US 1,566,961
US 1,528,01817-01-192103-03-1925Mercedes Bureau-Maschinen- und WaffenwerkeCombined typewriting and counting machine
US 1,566,96201-06-192322-12-1925Mercedes Bureau-Maschinen- und WaffenwerkeCalculator with fast multiplication
DE 434,14605-09-192521-09-1926Mercedes Büro-Maschinen- und Waffen-WerkeAutomatic comma indicator
DE 450,41419-06-192510-10-1927Mercedes Büro-Maschinen- und Waffen-WerkeModular keyboard with display
DE 478,59517-10-192604-07-1929Mercedes Büro-Maschinen- und Waffen-WerkeCarry mechanism

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