born in bristol, the son of benjamin holder green (1793–1865), then a haberdasher, and elizabeth ‘betsey’ née everett (1795–1837); his interest in astronomy dated from 1859 when he built a telescope for himself. he produced "soft-pencil" drawings of mars in 1877, which were widely known. shortly after drawing them, he was the first to suggest that canals on mars were an optical illusion.