Ojibwe wood mortar and pestle, a technology used to thresh wild rice.

Map of Canada, including parts of present-day Minnesota, created in Paris by the French cartographer Guillaume De Lisle in 1783. Mapping was a crucial technology for Europeans traveling across the North American continent looking to establish trade routes and relationships.

Lower section of the electric light mast at Bridge Square, Minneapolis, ca. 1883. The first centralized hydroelectric power in the United States turned on in downtown Minneapolis on September 5, 1882.

Students in a biology laboratory at the University of Minnesota, ca. 1902.

Chemistry laboratory at the University of Minnesota, 1907.

An iron ore shaft in Eveleth. Photograph by William F. Roleff, 1915.

Hot pond and log storage for the new mill of the Northern Lumber Company (Cloquet Lumber Company), 1930. Heated mill ponds, or “hot ponds,” were developed to warm logs so they could be cut even in the winter. Photograph by Buckbee-Mears Company.

Students use a microscope in a science class at Unity Church, St. Paul, 1930.

Researchers at the University of Minnesota working on a project affiliated with the Works Progress Administration (WPA), ca. 1940.

Stand-up sign advertising the Honeywell Chromotherm, ca. 1930s‒1945. Used at Donaldson’s department stores.