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The Air Mail can be twelve hours behind its schedule from New York to San Francisco and still beat the train mail into the Golden Gate City by twenty hours if the train connection is made at Chicago, and by forty-four hours if that connection is missed.In the service's early days it was even suggested that airplanes deliver to post offices directly, either by dropping packages onto their roofs or taking off and landing on the roofs. In 1918, Superintendent of Mails E. M. Norris told the Times about a merry-go-round rooftop plane launcher in the works:
Some time ago... representatives from two airplane factories measured the roof of the Post Office and said that it was practicable for airplanes to start and alight there. They wanted a fifty-thousand-dollar apparatus built, something like a merry-go-round, by which the airplanes could be spun around until their propellers attained sufficient speed and then be released.
This article available online at:
http://www.theatlantic.com/national/archive/2011/12/what-america-looked-like-1920s-airmail-pilot-suited-up-in-winter-gear/249940/