Ebook Mars

This book is the result of a special study of the planet made during the last opposition, at an observatory put up for the purpose of getting as good air as practicable, at Flagstaff, Arizona. A steady atmosphere is essential to the study of planetary detail: size of instrument being a very secondary matter. A large instrument in poor air will not begin to show what a smaller one in good air will. When this is recognized; as it eventually will be, it will become the fashion to put up observatories where they may see rather than he seen.

Next to atmosphere comes systematic study.