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Arrows to nowhere
Throughout the modern United States can meet these mysterious arrows pointing the way vnikuda.
Well, it is now vnikuda and some hundred years ago, they were like a modern GPS navigatora.
When the first planes began to make their long flights, they are faced with the difficulty of choosing a route, it was very easy to get lost, and the pilots were afraid to climb above the clouds, so as not to stray from the chosen path. Had not yet been used in long-range aircraft radar, it even had izobresti.
That's it and need to install something like beacons pointing the route to pilots, so it was easier to reach your goal. For this was invented and installed on the ground painted in different colors concrete direction. It is now shabby and they took the natural color betona.
The first of these goals-pointers was built in 1924 in Wyoming for postal air services. It was a tremendous success for the times, and in 1929 a network of beacons already stretched from New York to San Francisco.
Project Arrow lasted until 1940, and until that time they were the only benchmark among pilots. The distance between the arrows is about 10 miles and a height it seemed that the earth rascherchivayut dotted lines, on which we must peredvigatsya.
Source: mirfactov.com/