. Fresh-water biology. Freshwater biology. 8o FRESH-WATER BIOLOGY of bolting cloth may be attached outside the wire gauze filter, and the whole instrument is then adapted for the various work of the ordinary net. On account of its cheapness and portabiHty a pump of this form is probably best adapted for work not carried on from a station especially equipped for aquatic biology. (b) The clock pump has been used for some years at the Uni- versity of Wisconsin (Juday, 1904). At Wisconsin the pump is fixed to the bottom of the boat and the water, drawn through a half-inch garden hose, is pumped in
. Fresh-water biology. Freshwater biology. 8o FRESH-WATER BIOLOGY of bolting cloth may be attached outside the wire gauze filter, and the whole instrument is then adapted for the various work of the ordinary net. On account of its cheapness and portabiHty a pump of this form is probably best adapted for work not carried on from a station especially equipped for aquatic biology. (b) The clock pump has been used for some years at the Uni- versity of Wisconsin (Juday, 1904). At Wisconsin the pump is fixed to the bottom of the boat and the water, drawn through a half-inch garden hose, is pumped into a submerged plankton net of No. 20 bolting Fig. 23. Thresher tanK-pump m use. The water reaches the pump through the hose at the left and is delivered to the net through the hose at the right. The net cone is seen supported by a rectangular wooden float. (After Kofoid.) (c) The thresher tanh-pump, a double-acting force pump with two cylinders each six by nine inches, has been used by Kofoid (1897). The mode of using the pump is shown (Fig. 23). This pump is fastened to the boat and is too heavy to be carried or to be used apart from a permanent mounting. 3. The Water Bottle. To obtain small samples of water for the study of the nannoplankton a water bottle may be used. Many complicated and expensive forms of these bottles have been devised (see Helland-Hansen) for use at all depths in the sea. The bottle described by Theiler appears to be the simplest and least expensive of them. For use in fresh water a Meyer's bottle (Fig. 24) serves fairly well and is easily made. A stout glass bottle of one or. 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 Ward, Henry Baldwin, 1865-1945; Whipple, George Chandler, 1866-1924. joint author. New York, John Wiley & sons, inc. ; [etc. ,etc. ]
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
