Report of the Commissioner of Patents for the year ..
This is an annual government report issued by the United States Patent Office in Washington in 1849 for Congress and the public, documenting patents granted that year. The four pages show engraved plates of mechanical devices: a crank-driven machine with gears and a wheel, a clamp-like frame, a telescoping cart or gate, and assorted levers and fittings drawn in fine black line with lettered reference marks. A designer could draw on their clean, schematic linework and the way parts are labelled as a vocabulary for technical diagrams.
