Report of the Commissioner of Patents for the year ..
This is an 1849 annual report of the United States Patent Office, published in Washington by the Office of Printers to the House of Representatives, presenting official patent business to Congress. Its pages are dense engraved plates of mechanical drawings, with numbered figures showing machine parts, gears, linkages, and agricultural implements in plan, section, and perspective views. A designer could draw on their clean line work, labelled diagrams, and the precise technical geometry of mid-nineteenth-century machinery.
