By the turn of the century, many of the assaying books published emphasized the need for a good assay balance. They stated a good one could be purchased for $40 to $100. The main sources were the Oertling, Becker, and Troemner balances made in England, Philadelphia and New York, respectively. Having repairs made on these balances meant sending them back to the companies at a considerable cost in time and money.  

After 1875, the western assayer had a much closer source. In 1874, William Ainsworth moved to Central City, Colorado and set up his watch making business. His understanding of the workings of delicate instruments soon earned Ainsworth a reputation throughout Colorado as a reputable source for the repair of balances.

William Ainsworth was born in 1850, in England. At the age of three he immigrated with his parents to Wisconsin. As a youth he apprenticed as a clock maker and worked in the Elgin Watch Company factory in Elgin, Illinois. From his various work experiences he became an excellent toolmaker and mechanical engineer.

By 1877, he had set up shop in Denver, and by 1880 he was building assay balances. By 1894, the Ainsworth Company also was manufacturing the Brunton Compass. In 1906, the company expanded again adding surveyor's transits and levels to its product line. This latter venture was discontinued in 1938, when the transit business was sold to Harry Glantz of the Rocky Mountain Instrument Company.

WMMI is fortunate to have an Ainsworth balance in its collection. The balance (1976.7.1) was donated by WMMI's founder, Frederick Farrar in 1976. It was made before 1898, and was probably made between 1895-1896, as it is stamped with the serial number 856. Its maker's mark reads "Wm Ainsworth, Denver Colo."

Around 1899-1900, the company became the William Ainsworth & Sons Company, since Mr. Ainsworth's two sons had joined him in the business. Mr. Ainsworth died in 1917, and in 1923 his sons operated the company as the William Ainsworth and Sons, Incorporated. In 1965 the company was sold to the Xavier Science Corporation.

Terry Girouard,
Previous Curator of Collections