Physical description

Double Prism Optical Spectrograph made of standing L-shaped metallic base in grey enamel which supports a brass collimator/telescope abutting a wooden box containing two prisms and camera. Tradition has it that it was designed by Laby but there is no supporting evidence.

Inscriptions & markings

Engraved on brass cylinder: “Adam Hilger Ltd London England” On end of brass cylinder: “Screw = 5m/m Adam Hilger Ltd London England No. F31.301/25403”