Around the year 1800 British statesman and scientist Charles Stanhope, 3rd Earl Stanhope (also known as Charles Mahon, 3rd Earl Stanhope), built the first hand press entirely out of iron. The greatly increased rigidity resulting from the iron, rather than wood construction, and an innovative combination of levers turning the screw, caused the platten to descend with decreasing rapidity, and consequently with increasing force, till it reached the type, when a much increased pressure was obtained. These features significantly improved the efficiency of the hand press. However, output increased only modestly, from an average of 200 sheets per hour on a wooden hand press to around 250 sheets per hour with two men working the press. An additional advantage provided by the press was that the platen was made the full size of the bed enabling impression to be done in one pull compared with two pulls on traditional presses.
Stanhope did not patent his press, and the precise year of its origin is unknown. The earliest surviving example is dated 1804. Early models had straight side frames which were prone to breaking due to the immense pressure that could be exerted. These castings were changed in about 1806 to the heavier 'rounded' style. In this form the press continued to be manufactured into the mid-19th century, and remained in use to a limited to a limited extent into the late 19th century, though by around 1880 it had been superceded by the Albion and Columbian hand presses.
Moran, Printing Presses, History and Development from the Fifteenth Century to Modern Times (1973) Chapter 3, "The Stanhope Press," 49-57.
Hart, Charles Earl Stanhope and the Oxford University Press. Reprinted from Collectanea, 111, 1896 of the Oxford Historical Society with notes by James Mosley. London: Printing Historical Society, 1966.