Smithsonian Report, 1949.—Hubble PLATE 3 
MARS 
Upper: Photograph with 100-inch reflector, September 2, 1924. 
Lower: Drawing by Pettit with 20-inch reflector, July 12, 1939. These typical 
pictures illustrate the fact that as vet photography does not furnish an objective 
test of the existence of “canals” on Mars. 
