ScientificAmerican1875-12-25.jpg Scientific American 1875-12-18ThumbnailsScientific American 1877-07-07Scientific American 1875-12-18ThumbnailsScientific American 1877-07-07Scientific American 1875-12-18ThumbnailsScientific American 1877-07-07Scientific American 1875-12-18ThumbnailsScientific American 1877-07-07Scientific American 1875-12-18ThumbnailsScientific American 1877-07-07

Grand Central Depot [now Terminal]: train despatcher's office. Shown: tracks and switches in the yard, control panel with electrical switches and indicators