Madas Calculating Machine

This manually operated, non-printing stepped drum calculating machine has a brass and steel mechanism painted black, with a black steel cover. Digits are set by pushing down eight German silver levers. The digit set up appears in a row of windows between the levers. A zeroing knob for the levers is left of them. The crank for operating the machine is to the right. To the left of the levers is a window showing a number that relates to automatic division, and two levers, one for automatic division and the other for subtraction / addition-multiplication.
Behind the levers is a carriage with a row of seven revolution counter register windows and 12 result register windows. The revolution register has no carry mechanism. The zeroing knobs for these registers are on the right of the carriage. Above the entry levers, the revolution counting register and the result register are metal bars that carry sliding decimal markers. Thumbscrews are used to set up numbers in the result register. On the left end of the carriage are a bell that rings to indicate over division (e.g. a negative result), and a mechanism for shifting the carriage. The machine has four rubber feet.
A mark on the machine to the left of the levers reads: MADAS (/) U.S.A. Ptd Dec. 16th 1913 (/) etc. A mark on the far left reads: No 5095 (/) MADE IN SWITZERLAND. A mark on the outside of the metal cover reads: MULTIPLICATION AUTOMAT. DIVISION ADDITION SUBTRACTION (/) MADAS.
The steel cover has operating instructions in German and French on a piece of paper pasted inside. The MADAS, designed by Erwin Jahnz, a German living in Switzerland, was produced by the Swiss firm of H. W. Egli. It featured automatic division. The MADAS, introduced in 1913. was made until around 1930.
Compare MA*317288, MA*324278, MA*323586 and 1982.0794.88.
This example is from the collection of Felt & Tarrant Manufacturing Company.
H. W. Egli, Ltd., MADAS 50 Jahre Arbeit, Zurich.
Erwin Jahnz, “Calculating Machine,” U. S. Patent 1,81,310, December 16, 1913.
Currently not on view
Object Name
calculating machine
date made
Egli, Hans W.
Physical Description
metal (overall material)
paper (overall material)
rubber (overall material)
overall: 18.5 cm x 49.5 cm x 20 cm; 7 9/32 in x 19 1/2 in x 7 7/8 in
place made
Schweiz: Zürich, Zurich
ID Number
accession number
catalog number
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Calculating Machines
Data Source
National Museum of American History, Kenneth E. Behring Center


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