Integraph Unit of Vannevar Bush

Integraph Unit of Vannevar Bush

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This is the integraph-unit used by Vannevar Bush and his colleagues at MIT before they constructed the first differential analyzer. It consists of a Thomson watthour meter (in a box) with a geat train on under the box that has a crank at the rear. A nameplate on the meter reads: Thomson watthour meter / direct current / 3 wire / No 5813227 Type 06 / Amp 10 Volts 231-240 / m27778 General Electric Co. U.S.A.
The object was donated to the museum with a large collection of electrical apparatus, much of it in the Electricity collections.
This instrument is a small part of a device that calculated the integral of the product of two functions. It was variously described as a product integraph and a continuous integraph. Illustrations of the system appear in the 1927 paper cited.
V. Bush, F.D. Gage, and H.R. Stewart, "A Continuous Integraph," Journal of the Franklin Institute, vol. 203 #1, 1927, pp. 63-84.
S. Puchta, "On the Role of Mathematics and Mathematical Knowledge in the Invention of Vannevar Bush's Early Analog Computers," IEEE Annals of the History of Computing, 1996, vol. 18 # 4, pp. 49-59.
Currently not on view
Object Name
date made
ca 1925
Bush, Vannevar
place made
United States: Massachusetts, Cambridge
Physical Description
metal (overall material)
wood (overall material)
rubber (overall material)
glass (overall material)
overall: 63.5 cm x 28 cm x 37 cm; 25 in x 11 1/32 in x 14 9/16 in
box: 12 1/2 in x 7 in x 7 in; 31.75 cm x 17.78 cm x 17.78 cm
ID Number
catalog number
accession number
Credit Line
Gift of Massachusetts Institute of Technology, Department of Electrical Engineering
See more items in
Medicine and Science: Mathematics
Mechanical Integrators and Analyzers
Data Source
National Museum of American History
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