Most of the photos on this site were extracted from reference images (high-resolution tiffs, 20 to 200 megabytes in size) from the Library of Congress research archive. (To query the database click here.) Many were digitized by LOC contractors using a Sinar studio back. They are adjusted by your webmaster for contrast and color in Photoshop before being downsized and turned into the jpegs you see here.
Vintage photos of:
October 1942. State School of Mines in Golden, Colorado. "Speed in metallurgical analysis, to match the rapidity with which the nation arms itself, is possible through use of the spectrograph, a marvelous new machine used for study of materials through measurements of the arc of light they emit when heated. The aluminum and magnesium industries, steel companies and foundries use it for quick study of metals. Mines use it for exploration. The spectrograph will yield an analysis of seven elements in 15 minutes, which would require up to four hours by old chemical methods. Students in defense training courses at a famous mining-engineering school listen as an instructor shows them how the machine operates." Photo by Andreas Feininger, Office of War Information. View full size.
March 1943. Fort Madison, Iowa. "In the train control room at the Shopton shops of the Atchison, Topeka & Santa Fe Railroad. Testing pneumatic train control equipment. This rack is used for testing about eight different parts of the apparatus." Photo by Jack Delano, Office of War Information. View full size.