Radiometers and otheoscopes Finish:Single seated on a black ram

seated on a black ram with the face of Bartolomo Pergami

on his way to deliver a resolution of support to Burdett

He is dressed in grey breeches

View of Hanover Lodge

Intended as a subscription ticket for an engraving of Hogarth's ill-fated painting Sigismunda

Radiometers and otheoscopes Finish:Single seated on a black ramRadiometers and otheoscopes, instruments 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 correct