An radiometer The Savoy theatre photographer & portrait painter

photographer & portrait painter

Launch of HMS 'Royal Albert'

showing the injured Cavalier discovered by Puritans

music group

An radiometer The Savoy theatre photographer & portrait painterA radiometer with aluminium vanes. An instrument designed for measuring the mechanical effect of radiant energy. Mounted in a partial vacuum, the central rotor spins when the vanes are exposed to light. Chemist William Crookes (1832 1919) initially believed the vanes with black surfaces were pushed around by pressure from light radiation. This was incorrect and other theories were put forward. It was not until 1879 that Osborne Reynolds suggested the