George Applebey collection / HES. Canmore image number SC1531807 (http://canmore.org.uk/collection/1531807) This photo, taken in 1937, shows Cochno Stone cup-and-ring marks painted white by Ludovic Mann as well as a grid of his own devising that he also painted onto the surface of the stone, this being an attempt to find prehistoric standard measurements amidst the symbols.

George Applebey collection / HES. Canmore image number SC1531807 (http://canmore.org.uk/collection/1531807)
This photo, taken in 1937, shows Cochno Stone cup-and-ring marks painted white by Ludovic Mann as well as a grid of his own devising that he also painted onto the surface of the stone, this being an attempt to find prehistoric standard measurements amidst the symbols.