THUEAS: RECORDING SEA-WATER SALINITY 



685 



The densities of the six samples of sea water were measured 

 at 25°C. by the Bureau of Standards. Table 2 gives the 

 densities referred to distilled water at 4°C. and conductivities 

 in reciprocal ohms. The salinities (grams of total salt per 1000 

 grams of sea water) given are calculated from the densities at 

 25°C. by means of Martin Knudsen's Hydrographical Tables. 



TABLE 1 

 Flax Density in Coil 



Samples 2 and 3 are from the same sea water which was col- 

 lected in two bottles. The accuracy of the conductivity meas- 

 urements is limited by the accuracy of determining the densities, 

 which is 2 in the fifth decimal place. 



TABLE 2 

 Specific Conductivities at 25° C. 



The mean temperature coefficient of sea water per degree C. 

 between 18°C. and 25'^C. expressed in terms of conductivity at 

 18°C. is 0.02237 for a salinity of 29, and 0.02212 for a salinity of 

 37. 



