Percival Lowell was a smart astronomer. He was the first person to build his observatory in a remote location away from city lights, at the top of a high mountain. Lowell picked Flagstaff, Arizona as the location for his observatory. I lived in Flagstaff for four years in college and the observatory is one of Flagstaff’s really big claims to fame because Pluto was discovered there in 1930 (14 years after Lowell’s death).
Anyway, Lowell was a smart guy. He also believed there was life on Mars. He was convinced that lines on the planet’s surface were canals, and when he observed some changes in the appearance of these canals, he concluded that somehow the martians had quickly built these enormous canals 20 miles wide and a thousand miles long.
Mary Proctor wrote this article summarizing Lowell’s findings, and also describing some of the planets people might see in the sky in September.
I love that this stuff appeared in the New York Times Magazine.
MARTIANS BUILD TWO IMMENSE CANALS IN TWO YEARS: Vast Engineering Works Accomplished in an Incredibly Short Time by Our Planetary Neighbors — Wonders of the September Sky. (PDF)
From August 27, 1911