Table 118 

 DENSITY OF WATER 



403 



Values of the density of pure water under a pressure of one atmosphere, expressed 

 here in g. cm." 8 , have been taken from the compilation or Dorsey * based on the results 

 of various investigators. 



The presence of dissolved air decreases the density of water. Marek 2 reports the fol- 

 lowing differences in density between water which has been freed of air by exhaustion 

 just prior to measurement and water at the same temperature which has been exposed to 

 air for intervals of 1 to 3 days : 



at °C, a difference of 0.0000025 g. cm 



" 5 °C, " " " 0.0000033 " 



" 10 °C, " " " 0.0000032 " 



" 15 °C, " " " 0.0000022 " 



" 20 °C, " " " 0.0000004 " 



1 Dorsey, N. E., Properties of ordinary water substance, pp. 199-201, Reinhold Publ. Corp., New 

 York, 1940. 



2 Marek, W. J., Ann. d. Physik (Wied.), vol. 44, pp. 171-172, 1891. 



Table 119 



THERMAL CONDUCTIVITY OF WATER 



Compiled by Dorsey * from the investigation of Schmidt and Sellschopp. 2 All values 

 are for a pressure of one atmosphere. 



Temperature Thermal conductivity 



Temperature Thermal conductivity 



1 Dorsey, N. E., Properties of ordinary water substance, p. 273, Reinhold Publ. Corp., New York, 

 1940. 

 a Schmidt, E., and Sellschopp, W., Forsch., Gebiete Ingenieurw., vol. 3, p. 277, 1932. 



SMITHSONIAN METEOROLOGICAL TABLES 



