Troncet Arithmographe

Louis-J. Troncet patented this instrument in his native France in 1889, and it was published by Larousse. The American scientist Daniel Draper purchased this example in 1895 for $2.50. It came in a small notebook with a set of multiplication tables.
The Troncet arithmographe, like an instrument issued by the Russian E. Kummer in the 1840s, used flat metal bands with notched edges to represent digits. These bands were moved with the stylus to enter numbers. The instrument has seven crook-shaped columns that reveal the edges of eight notched bands. The crook at the top of each groove is designed to ease carrying or borrowing.
Eight holes below the columns, labeled “ADDITION”, show the results of addition problems. Eight holes above the columns, labeled “SOUSTRACTION,” show the results of subtraction problems. There is no zeroing mechanism. Troncet’s design was widely adopted by later manufacturers.
References: Mareschal, G., “Calculateur mecanique instante,” La Nature, 18 annee, 1890, pp. 307-308.
P. Kidwell, “Scientists and Calculating Machines,” Annals of the History of Computing, 12 (1990): 31-40.
P. Kidwell, "Adders Made and Used in the United States," Rittenhouse, 1994, 8:78-96.
Currently not on view
Object Name
date made
Librairie Larousse
Physical Description
cloth (overall material)
metal (overall material)
overall: 1.6 cm x 11 cm x 14.2 cm; 5/8 in x 4 11/32 in x 5 19/32 in
place made
France: Île-de-France, París
ID Number
catalog number
accession number
Science & Mathematics
See more items in
Medicine and Science: Mathematics
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of John William Christopher Draper and James Christopher Draper

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