An radiometer The Savoy theatre Portsmouth Street

Portsmouth Street

The George Tavern and shop fronts

photographer & portrait painter

matters had not improved in Ireland since

designed by Robert Smirke

An radiometer The Savoy theatre Portsmouth StreetA 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