A glass ball that records the amount of sunlight is called aCampbell-Stokes recorder. It was invented by John Francis Campbelland Gabriel Stokes improved it. To read more, vi…sit answers.com/topic/campbell-stokes-recorder (MORE)
The heliograph was standard issue for the British and Australianarmies until the 1960s. .
I'm looking for a new mirror for my heliograph. .
There were many heliograph types.… .
The heliograph had many great advantages. (MORE)