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BtTLLETIN OF THE BUREAU OF FISHERIES 

 WATER RESISTIVITY OF VARIOUS STREAMS 



The resistivity of the water has such an important influence upon the voltage 

 gradients and voltages that should be used on electric fish screens that it is very- 

 important to know something of the variation in resistivity found in various streams. 



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Fio. 8 



To obtain this information, samples of water were secured from 12 rivers, 1 creek, 

 and the Pacific Ocean. 



Temperature-resistivity data were taken for each of these samples by chilling the 

 water to approximately 40° F., then measuring the resistivity as the sample was 

 warmed in increments to approximately 95° F. All water resistivities used in this 

 investigation were measured by the Kohlrausch U-tube method, using a double com- 



