A micro-projector set up used by Professor Peterson of Soils and Agronomy Department for making a count of aggregates in studying soil structure. On the ruled paper on the right appears an image of soil particles magnified 100 times. Iowa State College, Ames, Iowa
Summary
Public domain photograph of college lab, free to use, no copyright restrictions image - Picryl description
Tags
Date
01/01/1942
Contributors
Delano, Jack, photographer
Location
Ames, 42.03471, -93.61994
Source
Library of Congress
Copyright info
No known restrictions. For information, see U.S. Farm Security Administration/Office of War Information Black & White Photographs http://www.loc.gov/rr/print/res/071_fsab.html