William Ainsworth & Sons won a gold medal at the St. Louis World’s Fair of 1904. Notable among their wares was an analytical balance with a short beam made of hard-rolled nickel-aluminum (rather than pure cast aluminum), bearings and knife edges of agate, a double rider apparatus of improved design, and a frame of wood with glass sides and drawer in the base. This example is of that sort. It is a Type T with a 6-inch beam. The ivory index is inscribed “Wm. Ainsworth & Sons / DENVER, COLO. U.S.A. 8095.” New it cost $125.
William Ainsworth (1850-1917) was born in England, came to the United States as a small child, and grew up in the Mid-West. He moved to Central City, Colorado, in the mid-1870s, and earned his living repairing watches and other small instruments. He made his first balance in 1879, and moved to Denver in 1880. The firm became William Ainsworth & Sons in 1899, and soon claimed to be “the largest manufacturers of fine balances in the world.” It later became Denver Instrument, and was acquired by Sartorius in 1999.
Ref: “A Short-Beam Analytical Balance,” The Engineering and Mining Journal 78 (1904): 877.
Denver Fire Clay Company, Illustrated and Priced Catalogue of Assayers’ and Chemists’ Supplies (Denver, 1905), p. 33.
Mine and Smelter Supply Co., Assayers’ and Chemists’ Supplies (1912), p. 30.
William Ainsworth & Sons, Inc., Ainsworth Balances, Bulletin A-11 (Denver, n.d.), p. 3.
Currently not on view
date made
early twentieth century
William Ainsworth and Sons
place made
United States: Colorado, Territory of, Denver
overall: 49 cm x 51 cm x 26 cm; 19 5/16 in x 20 1/16 in x 10 1/4 in
beam: 6 in; 15.24 cm
ID Number
catalog number
accession number
Credit Line
U.S. Department of Interior, Fish & Wildlife Service
Weights & Measures
See more items in
Medicine and Science: Chemistry
Data Source
National Museum of American History


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