"In the 1920s, America began coast-to-coast Airmail service, but the pioneer pilots had trouble navigating the route, since navigation charts of the day were fugazi and you couldn't exactly pull over to ask a farmer for directions.
And traveling at night, when it would have been most efficient, or in bad weather was impossible. To solve this Congress then funded these gi-normous arrow-shaped Airmail Beacons, some up to 70 feet long, to trace a route across the country.... The arrows were painted bright yellow and each was accompanied by a tower up to 50 feet in height. At the top of each tower was a powerful gas-powered light, and at the bottom of the tower, a shed to hold the gas." More at - Core77 [HT: Doc Mercury]Posted by gerardvanderleun at September 8, 2013 10:23 AM