Page 498 - 89 history of astronomy_opt
P. 498
appears at sunset. Then there are deep,
narrow, crooked ”rills” which may have been
water-courses; also ”clefts” about half a mile
wide, and often hundreds of miles long, like
deep cracks in the surface going straight
through mountain and valley.
The moon shares with the sun the ad-
vantage of being a good subject for pho-
tography, though the planets are not. This
498
