Copper Plates Used to Make Topo Maps on Display

msu-copper-plate

The Michigan State University Map Library now has on display three copper plates used to make the 1912 USGS topographic map of the Lansing, Michigan area. “From the 1880s to the 1950s, the U.S. Geological Survey used engraved copper plates in the process of printing topographic and geographic quadrangle maps. Copper alloy engraving plates were inscribed with a mirror image of the points, contour lines, symbols, and text that constitute a topographic map. Each plate was inscribed with details for a single color of ink.” [via]

Author: Jonathan Crowe

Jonathan Crowe blogs about maps at The Map Room. His essays and reviews have been published by AE, Calafia, The New York Review of Science Fiction, the Ottawa Citizen, Strange Horizons and Tor.com. He lives in Shawville, Quebec.