Solar Prism

Reflecting prism for use with a spectroheliograph in making observations of solar spectra.

The astronomer John Evershed FRS (1864-1956) commissioned this glass with the aid of Royal Society grants for the purpose of solar observation at his private observatory in Ewhurst, Surrey. The prism was then transferred for use at the Royal Greenwich Observatory at Herstmonceaux Castle in 1953, before being returned to the Royal Society.