Those interested in sunshine recorders might like to consult the chapter 'Measurement of the duration of sunshine and starshine and of the intensity of solar radiation' in the 'Handbook of Meteorological Instru- ments Part 1' published by the UK Meteorological Office, HMSO 1956.
The standard instruments are illustrated and described. The Cambell-Stokes temperate sunshine recorder Mk II is Stores Ref Met. 90 (frame) and Stores Ref., Met. 192 (sphere) - do they still carry any spares? There are instructions for installation and adjustment, measurement of cards and a discussion of errors. Other sunshine recorders were the Marvin and Jordan types. The Marvin recorder was essentially a differential air thermometer. The later forms of the Jordan recorder consisted of two half cylinders with slits on their flat sides. Sensitized papers inside the cylinders recorded sunlight. Les Cowley
