ScientificAmerican1875-04-10.jpg Scientific American 1875-04-03ThumbnailsScientific American 1875-04-17Scientific American 1875-04-03ThumbnailsScientific American 1875-04-17Scientific American 1875-04-03ThumbnailsScientific American 1875-04-17Scientific American 1875-04-03ThumbnailsScientific American 1875-04-17Scientific American 1875-04-03ThumbnailsScientific American 1875-04-17

The pneumatic despatch system in the Western Union Telegraph building, New York. Root's blower, applied to the pneumatic despatch.