One of the most famous English makers of scientific instruments of the 18th C. Mainly remembered for inventing a special type of pocket compound microscope with drum in 1738. Martin illustrated the device in Micrographia nova (1742), in which he also set out the new criteria for microscopic observation and description. Produced many microscopes of this type in London between 1756 and 1782; the models remained very popular even into the 19th C.