Evolution of a curious four-speed breast drill

Manufactured in the early decades of the twentieth century, this curious four-speed breast drill was designed by a prolific French inventor named Camille Contal (1868-1960). Between 1900 and 1930, he successfully registered multiple patents in France, the USA, and Germany. His interest in a wide range of mechanical and electrical devices is reflected in these varied patents, which in addition to this breast drill included a ratcheting socket wrench, gearing for a hand-powered vacuum cleaner, an electric horn, a motorcycle chain tensioning device, a refinement of a mechanical piano, an automobile suspension, a variable speed electric drill, and an unoxidizable nickel-copper alloy.
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