Mick Hartley

Washington, 1927. "Cadillac Motor Co. window."

[Photo: Shorpy/National Photo Company]

The Washington-Cadillac showroom on Connecticut Avenue. At left, a vintage Cadillac from 1905-07; at right, the new LaSalle, in the first year for Cadillac's "companion make." 

The signs in the window – "Prof. Langley's day, 35 miles per hour." That would be the time of the vintage Cadillac. From a comment: "Professor Langley was director of the Smithsonian Institution, 1887-1906, and a pioneer of aviation. Thirty-five miles per hour was the magic number, the speed that would provide enough lift to get a plane off the ground. For some years, the Smithsonian declined to display the Wright Brothers' plane, instead recognizing Langley as inventor of "the first man-carrying aeroplane in the history of the world capable of sustained free flight.""

"Col. Lindbergh's day 105 miles per hour". That would be contemporary with this photo. 105 miles per hour was the average speed for Lindbergh's pioneering trans-atlantic crossing in 1927.