Campbell-Stokes Sunshine Recorder
Intended to be left outside all year, the recorders 4″ diam. annealed optical glass sphere focuses the suns rays into a fine point onto a paper card inserted into the bowls grooves, marking a line to indicate the hours of sunshine. The sphere attaches to a solid brass arc inscribed with degrees in latitude and the arc rests upon a base cast from non-corrosive gunmetal