Figure 38.—Early 19th century: The mass-produced version of the wooden brace and bit took the form illustrated in Book 87 of Cutler's Castle Hill Works. (Courtesy of the Victoria and Albert Museum.)
Figure 39.—18th century: The transitional form of the wooden brace and bit incorporated the overall shape of the mass-produced version but retained the archaic method of fastening the bit to the chuck. The tool is of Dutch origin and suggests the influence of Sheffield design on European tools. (Smithsonian photo 49792-E.)
Figure 40.—1769: Roubo illustrated the metallic brace and, in addition, suggested its use as a screwdriver. (André-Jacob Roubo, L'Art du menuisier,1769.)
Figure 41.—About 1775: Ford, Whitmore and Brunton made and sold clockmaker's braces of metal with a sweep and shank that was imitated by American patentees in the 19th century. (Catalogue of Ford, Whitmore and Brunton, Birmingham, England. Courtesy of the Birmingham Reference Library.)
Figure 42.—1852: Nearly one hundred years after Roubo's plate appeared, Jacob Switzer applied for a patent for an "Improved Self Holding Screw Driver." The similarity of Switzer's drawing and Roubo's plate is striking. (Original patent drawing 9,457, U.S. Patent Office, Record Group 241, the National Archives.)
