Philip Carpenter (1776-1833), was born in Kidderminster, Worcestershire, on November 18, 1776. At 25 he was already a brilliant optician, improving both magic-lantern projection and microscopes. He died in Regent Street on 30 April 1833 and the business was continued by his sister Mary, in partnership with William Westley (died 1887), one of Carpenter's early apprentices in Birmingham, who became a foreman and later a partner and ultimately sole director. Many of his models were retailed by other manufacturers such as Cutts and Crichton.
John Crichton was an instrument maker who worked in London from 1831 to 1865 producing and selling barometers, magnetic compasses, drawing instruments, thermometers, sextants, and telescopes, as well as microscopes, like the one seen here. Crichton mainly worked at 112 Leadenhall St, London.