ScientificAmerican1903-08-15.jpg Scientific American 1903-01-31ThumbnailsScientific American 1913-07-19Scientific American 1903-01-31ThumbnailsScientific American 1913-07-19Scientific American 1903-01-31ThumbnailsScientific American 1913-07-19Scientific American 1903-01-31ThumbnailsScientific American 1913-07-19Scientific American 1903-01-31ThumbnailsScientific American 1913-07-19
Waterway improvement on the Ohio River. Dam 12, Monongahela River, showing method of bonding monoliths. Navigable pass down movable dams, Ohio and Allegheny Rivers. Bear Trap Dam. Transportation and haulage.



Source: Steve Kirch, collector, and creator of a great website about SCIENTIFIC AMERICAN in the past

Restoration by: magscanner