Both, and a source of employment as well
Ed,
The temperatures and gravity field of Mars were both known in 1910, and they allowed Huxley to pretty adequately predict what ultimately was found. These facts and their implications did little to stop the formation of the illusion of a habitable planet by most people.
Sadly, for some the return of real data from Mars did little to end their illusions. To this day it is still possible for many to find employment in maintaining those illusions.
Any time you participate in one of these electronic forums you will most likely find yourself among both.
EP