In 1867 the Pacific Coast Business Directory carried a quarter page advertisement for the firm which read: "KNIGHT & CO. Assayers of Gold, Silver and Ores, of Every Description. 32 D Street, Marysville, California. Assays Guaranteed." John J. Ford, Jr. believes that this firm, in business about ten years, was earlier located in Sacramento.

The firm apparently was one of a number of enterprises which served as a convenience for miners, refining and assaying gold and delivering the product in bars.