Siderography is a mechanical process developed by Jacob Perkins in the early 1800s enabling the unlimited reproduction of engraved steel plates. The process enables the transfer of an impression from a steel plate to a steel cylinder in a . An individual who engraves steel plates was known as a siderographist in the mid 1800s, and a siderographer by the early 1900s. By the 1930s, a was operated by a siderographer, who would manipulate a "system of compound levers" on the press to regulate the amount of pressure exerted on the transfer rolls.