. Bulletin. Natural history; Natural history. mmik ^ â ^ %% S'^l Ti Li ^^B nl * fe- -1 ^m li. mt T-'-^l, f =ScU M ra Above, Illinois Natural History Survey laboratory and instrument pier on Ridge Lake, Fox Ridge State Park, near Charleston, 111. This new 18-acre artificial lake is an experimental area for limnology and fish management studies. The laboratory is equipped for many phases of lake work and also furnishes living quarters for Survey technicians. The instrument pier, in lake at left, houses recording instruments for air and water temperatures, a rain gage, a water level recorder, and
. Bulletin. Natural history; Natural history. mmik ^ â ^ %% S'^l Ti Li ^^B nl * fe- -1 ^m li. mt T-'-^l, f =ScU M ra Above, Illinois Natural History Survey laboratory and instrument pier on Ridge Lake, Fox Ridge State Park, near Charleston, 111. This new 18-acre artificial lake is an experimental area for limnology and fish management studies. The laboratory is equipped for many phases of lake work and also furnishes living quarters for Survey technicians. The instrument pier, in lake at left, houses recording instruments for air and water temperatures, a rain gage, a water level recorder, and wind direction and velocity indicators. Ridge Lake, which was stocked in the spring of 1941 with largemouth bass only, was opened to public fishing in 1942. Below, the dam and outlet tower at Ridge Lake, April, 1941, when the lake was beginning to fill. The tower was designed to take care of small rises of water. The water enters the tower at its base, and, when the lake level reaches a point about 3 feet from the top of the tower, the water spills over a partition in the tower and flows through a concrete tunnel to the other side of the dam. A surface spillway (not shown in illustration) carries off flood waters. A valve at the base of the tower allows the lake to be completely drained. The face of the earth dam is shown being rip-rapped with concrete blocks to prevent Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Illinois. Natural History Survey Division. Urbana, State of Illinois, Dept. of Registration and Education, Natural History Survey Division
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Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
