On the original version of his 1894 map, Percival Lowell (1855 – 1916) had numbered all the canals from 1 through 287, making it difficult to make sense of the features. For clarity here, I manually painted them out. It was laborious, but worth it!
Compare this with the globes of maps from Slipher, Antoniadi, Rudaux and spacecraft.
Drag to rotate, pinch or scroll to zoom. Try the full screen button above.
Original map courtesy of Lowell Observatory.