Fishery Research Biologist, U. S. Fish and Wildlife Service, Ann Arbor, 
Michigan; Dr. Ralph Hile, Fishery Research Biologist, U. S. Fish and 
Wildlife Service, Ann Arbor, Michigan; Dr. Alfred M. Beeton, U. S. Fish 
and Wildlife Service, Ann Arbor, Michigan; James H. Johnson, Fishery 
Research Biologist, U. S. Fish and Wildlife Service, Ann Arbor, Michigan; 
Dr. D. V. Anderson, Ontario Department of Lands and Forests, Maple, 
Ontario; Dr. Albert Ballert, Great Lakes Commission, Ann Arbor, Michigan; 
N. H. Beamer, U. S..Geological Survey, Philadelphia, Pennsylvania; Dr. 
Albert E. Berry, General Manager, Ontario Water Resources Commission, 
Toronto, Ontario; Prof. Herbert M. Bosch, School of Public Health, Univer- 
sity of Minnesota, Minneapolis, Minnesota; C. C. Boughner, Chief, Climato- 
logical Section, Department of Transport, Toronto, Ontario; A. V. DeLaporte, 
Director of Laboratories and Research, Ontario Water Resources Commission, 
Toronto, Ontario; Earl Devendorf, Director, Bureau of Environmental Sani- 
tation, New York State Department of Health, Albany, New York; A. H. 
Eichmeier, State Climatologist, U. S. Weather Bureau, East Lansing, Michi- 
gan; N. G. Gray, Dominion Hydrographer, Department of Mines and Technical 
Surveys, Ottawa, Canada; J. R. Harvey, Regional Sanitary Engineer, De- 
partment of Health, Commonwealth of Pennsylvania, Meadville, Pennsylvania; 
J. H. Hubble, U. S. Geological Survey, Columbus, Ohio; Russell L. Johnson, 
Engineer in Charge, Michigan Department of Health, Escanaba, Michigan; 
Ray Joiner, Assistant to the Director, National Weather Records Center, 
U. S. Weather Bureau, Asheville, North Carolina; Lothar A. Joos, State 
Climatologist, U. S. Weather Bureau, Champaign, Illinois; Homer Knox, 
Principal Assistant Sanitary Engineer, State Department of Health, Columbus, 
Ohio; Robert Knutilla, U. S. Geological Survey, Escanaba, Michigan; W. T. 
Laidley, Chief Technical Assistant, U. S. Lake Survey Office, Detroit, 
Michigan; C. R. MacLean, Captain, U. S. Coast Guard, Chief, Operations 
Division, Ninth Coast Guard District, Cleveland, Ohio; Colin MacMillan, 
Marathon Paper Mills, Marathon, Ontario; Dr. O. J. Muegge, State Sanitary 
Engineer, State of Wisconsin Board of Health, Madison, Wisconsin; L. T. 
Pierce, State Climatologist, U. S. Weather Bureau, Columbus, Ohio; Dr. 
B. A. Poole, Director, Bureau of Environmental Sanitation, Indiana State 
Board of Health, Indianapolis, Indiana; H. W. Poston, Assistant Regional 
Engineer, U. S. Public Health Service, Chicago, Illinois; Jack Rademacher, 
Sanitary Engineer, U. S. Public Health Service, Chicago, Illinois; Lawrence 
A. Schaal, State Climatologist, U. S. Weather Bureau, Lafayette, Indiana; 
Cdr. E. O. Standish, Office of Chief of Naval Operations, U. S. Navy, 
Washington, D. C.; The State Climatologist, U. S. Weather Bureau, Albany, 
New York; Joseph H. Strub, Jr., State Climatologist, U. S. Weather Bureau, 
Minneapolis, Minnesota; J. F. J. Thomas, Head, Industrial Waters Section, 
Department of Mines and Technical Surveys, Ottawa, Ontario; Kenneth G. 
Tower, Regional Engineer, Federal Power Commission, Chicago, Illinois; T. 
L. Vander Velde, Chief, Section of Water Supply, Division of Engineering, 
Michigan Department of Health, Lansing, Michigan; Paul J. Waite, State 
Climatologist, U. S. Weather Bureau, Madison, Wisconsin; Fredrick H. Waring, 
Chief Engineer, State Department of Health, Columbus, Ohio; George 
Whetstone, U. S. Geological Survey, Columbus, Ohio; G. H. Wood, District 
Engineer, Department of Northern Affairs and National Resources, Water 
Resources Branch, Ottawa, Ontario; Frank L. Woodward, Director, Division 
of Environmental Sanitation, Minnesota Department of Health, Minneapolis, 
Minnesota. 
The investigators are no less indebted to the various persons who were 
contacted at the individual agencies during the course of the study. The 
limitations of space do not permit listing them here, but the majority have 
been identified in the tabulation of sources in Table 1. To all these per- 
sons who provided essential information, and thereby contributed to the 
successful completion of this survey, we extend our sincere thanks. 
