Book, The Ancient Quipu or Peruvian Knot Record

From ancient times, bureaucrats have kept numerical records of people and property. Those working for the Inca emperor in 16th-century Peru recorded data on arrangements of knotted strings known as quipus. The devices may also have been used as aids to memory in recounting histories of Inca exploits—the Incas had no written language.
Particularly from the 1880s, collections in South America, Europe, and the United States began to include quipus, usually recovered from the graves of makers or users. The devices were of great interest to historian of mathematics Leslie Leland Locke, a charter member of the Mathematical Association of America. Locke (1875–1943), a native of Grove City, Pennsylvania, received his A.B. from Grove City College in 1896 and his M.A. in 1900. He studied further at Pennsylvania State University, Cornell University, and Columbia. He came to Brooklyn to teach at Adelphi College and then worked from 1908 to 1933 at Maxwell Training School for Teachers, later moving to Brooklyn Technical High School. He also taught in the evening session at Brooklyn College.
Around 1909, while studying under historian of mathematics David Eugene Smith at Teacher’s College of Columbia, Locke became interested in the quipu. He examined several examples at the American Museum of Natural History in detail. In a 1912 paper, Locke argued that the knots on the strings of a quipu represented the decimal digits of numbers, arranged vertically by place value. He extended this research in this volume, published by the American Museum of Natural History in 1923. It includes excerpts of numerous early Spanish and other European texts relating to the quipu, and lists forty-five surviving examples. Locke deemed five of these modern or spurious. He obtained and published illustrations of over thirty of the objects, laying the foundation for further studies.
Locke also took great interest in more modern innovations in computing, particularly the calculating machine. He inscribed and presented this copy of his book to Dorr E. Felt, the head of Felt & Tarrant Manufacturing Company. Felt had invented, and Felt & Tarrant manufactured, the Comptometer, a leading adding machine of its day. The book, along with the rest of Felt’s library relating to the history of mathematical instruments, was given to the Smithsonian Institution by Victor Comptometer Corporation, the successor to Felt & Tarrant.
In addition to joining the MAA when it was established, Locke was a charter member of the History of Science Society and active in the National Council of Teachers of Mathematics.
Marcia Ascher and Robert Ascher, Mathematics of the Incas: Code of the Quipu, Mineola, New York: Dover, 1997. This is a corrected republication of the book Code of the Quipu: A Study in Media, Mathematics, and Culture, published in 1981 by the University of Michigan Press.
Stefanie Gaenger. Relics of the Past: The Collecting and Study of pre-Columbian Antiquities in Peru and Chile,1837–1911, Oxford: Oxford University Press, 2014, esp. 101–159.
L. L. Locke, “The Ancient Quipu, A Peruvian Knot Record,” American Anthropologist, n.s. vol. 14, #2 (1912), pp. 325–332.
“Teacher 45 Years: Educator in Mathematics and an Expert on Calculating Machines Dies. . .,” New York Times, August 30, 1943, p. 15 (this is an obituary of Locke).
For a recent database of quipus, see the Khipu Database Project at
date made
Locke, L. Leland
place made
United States: New York, New York
Physical Description
cloth (cover material)
paper (overall material)
overall: 2.1 cm x 19 cm x 27.3 cm; 13/16 in x 7 15/32 in x 10 3/4 in
ID Number
nonaccession number
catalog number
Credit Line
Gift of Victor Comptometer Corporation
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Mathematical Association of America Objects
Data Source
National Museum of American History, Kenneth E. Behring Center


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