TIM Calculating Machine

This manually operated, non-printing stepped drum calculating machine has a brass and steel mechanism, eight zinc alloy stepped drums, one of them cracked, and iron sides. The drums are only half-cylinders. On top of the drums is a metal plate painted black with slits for sliding levers used to set digits. The digits from 0 to 9 are marked along the edge of each slit. Six of the levers have steel bands next to them with the digits 0 to 9 stamped on them. These bands move so that the number set appears in a row of windows over the levers. The digit indicator is missing for the sixth and eighth windows.
On the carriage are nine windows in the revolution counter and 16 to show the result. The crank at the right is broken and has no handle. Decimal markers include one flimsy painted metal piece for numbers entered, one for the revolution counter, and three for the result. The add & multiply / subtract & divide lever is on the left, but has broken off. The stepped drums are not covered on the underside.
A mark below the entry levers reads: Rechenmaschinenfabrick LUDWIG SPITZ & Co., G.m.b.H., Berlin - Wien - New-York. A mark on the front of the machine reads: TIM. A mark at the left reads: PATENT (/) BREVET. A mark on the front edge of the carriage near the zeroing knobs reads: 828. A mark under the carriage reads: 01153. Another mark reads: Ludwig Spitz & Co. (/) TIM (/) TIME IS MONEY (/) TRADE MARK .
This is a TIM machine removed from a wooden case and placed on an iron stand, but without the central plate and other features of later TIM machines. The TIM was introduced in 1907 and first sold in a cast-iron housing in 1909.
The donor inherited this machine from his father.
Accession file 1994.0092.
E. Martin, The Calculating Machines (die Rechenmaschinen), trans. P. A. Kidwell and M. R. Williams, Cambridge: MIT Press, 1992, pp. 191–194.
Currently not on view
Object Name
calculating machine
date made
ca 1909
Ludwig Spitz & Co.
Physical Description
iron (overall material)
brass (overall material)
aluminum (overall material)
overall: 13.6 cm x 54.5 cm x 18 cm; 5 11/32 in x 21 15/32 in x 7 3/32 in
place made
Deutschland: Berlin, Berlin
ID Number
catalog number
accession number
maker number
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Calculating Machines
Data Source
National Museum of American History, Kenneth E. Behring Center


Add a comment about this object