Nathaniel Green was a British amateur astronomer and professional portrait artist who was among the first to suggest that Schiaparelli's canali on Mars were illusory. Based on his own observations, Green suggested, in 1878, that the linear markings described by the Italian were either a product of drawing technique or that "the atmospheric vibrations have a tendency to cause a series of points in a line to appear connected together."¹ The optical illusion theory was later taken up by Maunder, Newcomb, Antoniadi, and others.

 

Reference

1. Green, N. "On Some Changes in the Markings of Mars, Since the Opposition of 1877," Monthly Notices of the Royal Astronomical Society, 40, 331 (1880).