Robert Hooke (1635-1703), English natural philosopher. Hooke made numerous advances in fields as diverse as astronomy, physics and microbiology, and his name is remembered in Hooke's Law, which relates the load on a spring to its extension. He pioneered the new science of microscopy (microscope held in hand) and published detailed drawings of observations made with his microscopes in 'Micrographia' (1665), such as the flea in the background. Hooke was one of the founding fellows (1663) of the Royal Society, and served as its Curator of Experiments and Secretary. However, no portraits of Hooke remain, only written descriptions of him.