Grant Grasshopper Calculating Machine

This lever-set, non-printing manually operated connection pawl calculating machine has an open iron frame with steel and brass parts and paper labels. Five pins at the front of the machine slide back to set numbers. Next to each pin is a thin strip of paper that has the digits from 0 to 9 printed on it, the digits increasing toward the back of the machine. Each strip also has complementary digits in smaller type, for use in subtraction and division. Moving back a pin drives back a toothed rack.
Behind the racks is a movable carriage with 11 gears on it. A paper strip with digits on it is next to each gear. Turning a crank at the front right of the machine moves the racks back so that they engage the gears, turning each one of them in proportion to the number set.
This machine has a pin which can be set to prevent the crank from turning. When the adding frame reaches the end of its backward movement, a cam set on the crank shaft at the front raises all the register gears a little so that the gears are disengaged from the racks and not moved in the return motion.
The cam on this machine is smaller than on other Grant grasshopper machines. One tooth on each gear extends so that when the gear has made a complete rotation, it engages one of the carry teeth arranged on a spiral shaft above the carriage. As the adding racks return to position, the shaft revolves and the carry tooth pushes the next gear up by one, resulting in a carry. Releasing the carriage and turning it one revolution zeros the result shaft.
The carriage on this machine appears to be frozen in place. An aluminum support at the back causes the top to slope forward.
A paper tag to the right of the pins for setting up numbers reads: Grant Calculating Machine Company (/) LEXINGTON, MASS., U.S.A. (/) MACHINE NUMBER 41 M.
Compare MA*310647, MA*310648, MA*323615 and MA*335633.
This machine is from the collection of L. Leland Locke.
Machinery, October, 1895.
E. Martin, The Calculating Machines (Die Rechenmaschinen), trans. P. A. Kidwell and M. R. Williams, Cambridge: MIT Press, 1992, p. 77.
G. B. Grant, "Calculating-Machine," U. S. Patent 605,288 (June 7, 1898).
Currently not on view
Object Name
calculating machine
date made
Grant Calculating Machine Company
Physical Description
iron (overall material)
steel (overall material)
brass (overall material)
paper (overall material)
aluminum (overall material)
overall: 19.1 cm x 24.5 cm x 24.5 cm; 7 17/32 in x 9 21/32 in x 9 21/32 in
place made
United States: Massachusetts, Lexington
ID Number
catalog number
accession number
maker number
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Mathematical Association of America Objects
Calculating Machines
Data Source
National Museum of American History, Kenneth E. Behring Center


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