Golding, William. "Envoy Extraordinary." In Sometime, Never. An anthology of three original stories, one each by WG, John Wyndham, Mervyn Peake. [1956.] New York: Ballantine, 1957.
An alternative history in which a natural philosopher attempts to interest a Roman emperor and his grandson (cleaned up versions of Tiberius and "Caligula" at Capri) in the technological marvels of the steamship, gunpowder, printing, and the pressure cooker. The emperor keeps the pressure cooker and sends the inventor (with an idea for the compass) as Envoy Extraordinary to China.