ScientificAmerican1884-01-19.jpg Scientific American 1884-01-12ThumbnailsScientific American 1884-01-26Scientific American 1884-01-12ThumbnailsScientific American 1884-01-26Scientific American 1884-01-12ThumbnailsScientific American 1884-01-26Scientific American 1884-01-12ThumbnailsScientific American 1884-01-26Scientific American 1884-01-12ThumbnailsScientific American 1884-01-26

Application of electricity to tunneling. Electric rock drill used to drill holes for blasting explosives.