ScientificAmerican1911-04-15.jpg Scientific American 1911-04-08ThumbnailsScientific American 1911-04-22Scientific American 1911-04-08ThumbnailsScientific American 1911-04-22Scientific American 1911-04-08ThumbnailsScientific American 1911-04-22Scientific American 1911-04-08ThumbnailsScientific American 1911-04-22Scientific American 1911-04-08ThumbnailsScientific American 1911-04-22

Special issue on Light and Heat. Cover showing men working in a metal foundry.