The ‘Canali’ and the First Martians
In the 1800s, observatories with larger and larger telescopes were built around the world.
In 1877, Giovanni Virginio Schiaparelli (1835-1910), director of the Brera Observatory in Milan, began mapping and naming areas on Mars.
He named the Martian “seas” and “continents” (dark and light areas) with names from historic and mythological sources.
He saw channels on Mars and called them “canali.”
Canali means channels, but it was mistranslated into “canals” implying intelligent life on Mars.
Because of the then recent completion of the Suez Canal in 1869 (the engineering wonder of the era), the misinterpretation was taken to mean that large-scale artificial structures had been discovered on Mars.
The importance of canals for worldwide commerce at that time without a doubt influenced the popular interest in “canals” on Mars.
In 1894, Percival Lowel, a wealthy astronomer from Boston, made his first observations of Mars from a private observatory that he built in Flagstaff, Arizona (Lowell Observatory).
He decided that the canals were real and ultimately mapped hundreds of them.
Lowell believed that the straight lines were artificial canals created by intelligent Martians and were built to carry water from the polar caps to the equatorial regions.
In 1895, he published his first book on Mars with many illustrations and, over the next two decades, published two more popular books advancing his ideas.
https://www.nasa.gov/audience/forstudents/postsecondary/features/F_Canali_and_First_Martians.html