Diagram of electrotype apparatus as devised by George Mathiot of the Coast Survey

Diagram of electrotype apparatus as devised by George Mathiot of the Coast Survey. This apparatus allowed the reproduction of copper-plate engravings each of which could only survive 500 to a 1000 or so press impressions before wearing away sufficiently to be useless. This system allowed the production of thousands of charts via plate copies produced from the original engraving.

Photo Category: Coast and Geodetic Survey - Archive Sketch
Photo Date: 1851