File:Evelyn-Photoelectric-Colorimeter.JPG

Evelyn Photoelectric Colorimeter purchased around 1949.

Photo from http://www.isws.illinois.edu/hilites/achieve/psl/pslinst.asp The Illinois State Water Survey (ISWS) was founded as a part of the University of Illinois Chemistry Department in 1895 to survey the waters of Illinois to trace the spread of water-borne diseases. Typhoid epidemics had hit the nation in 1893, and, while it was difficult to conclusively identify the origin of these outbreaks, circumstantial evidence indicated that contaminated water supplies were the primary factor...

Original filename: http://www.isws.illinois.edu/hilites/achieve/psl/images/Evelyn-Photoelectric-Colorimeter.JPG

The honest use is assumed, the source should be attributed.