ScientificAmerican1917-02-24.jpg Scientific American 1917-02-03ThumbnailsScientific American 1917-03-03Scientific American 1917-02-03ThumbnailsScientific American 1917-03-03Scientific American 1917-02-03ThumbnailsScientific American 1917-03-03Scientific American 1917-02-03ThumbnailsScientific American 1917-03-03Scientific American 1917-02-03ThumbnailsScientific American 1917-03-03

Constructing a huge concrete arch in Switzerland. Bridge architecture and design.