About the dealer

About the object

A Campbell–Stokes sunshine recorder by Casella of London. Circa 1937.

The Campbell–Stokes recorder (sometimes called a Stokes sphere) is a kind of sunshine recorder. It was invented by John Francis Campbell in 1853 and modified in 1879 by Sir George Gabriel Stokes. The original design by Campbell consisted of a glass sphere set into a wooden bowl with the sun burning a trace on the bowl. Stokes's refinement was to make the housing out of metal and to have a card holder set behind the sphere.

The unit is designed to record the hours of bright sunshine which will burn a hole through the card.

Dimensions

Height: 18 cm Width: 21 cm. Depth: 22.5 cm.