SPECIFIC VOLUME AND DENSITY OF ATMOSPHERIC AIR AND SEA-WATER. 31 



By measurements under atmospheric pressure on different samples of sea-water 

 of different salinities at a series of different temperatures, Martin Knudsen has 

 determined the quantity <r ST(t . The result is contained in the following formulae: 



For the case of r o the quantity <r m is determined as function of the quantity 

 ol chlorine by the equation 



() 



<r m = 0.069 + I -47o8 CI 0.001570 CP + 0.0000398 CI 3 



Then the quantity <?, T(S is determined as a function of the temperature Tand the quality 

 <r m found from (b) by the equation 



(') 



_ v 



2 T + (o-m + 0.1324) [1 -A T + B T (<r M - 0.1324)] 



the quantities 2 T} A T and B T being the following functions of temperature: 



S =- 



(T-3.98) 2 T + 283 



(C) 



503-570 r + 67.26 

 A T = t(4.7867 0.0981857 + 0.0010843T 2 ) io~ 3 

 B T = t(i8.030 0.8164T + 0.01667T 2 ) io -6 



The quantities o- <00 and o- jt0 determined by these formulae are tabulated in Martin 

 Knudsen's tables. From the tabulated numbers we pass to the corresponding 

 values p lr0 of the density by the formula 



ftrO = I + 



^t0 

 IOOO 



and from these we can pass by an inversion table (table 23 h) to the correspond- 

 ing values of the specific volume. The equations (5) and (a) or the corresponding 

 tables in Knudsen's collection allow us to bring in s as the independent variable. 

 V. Walfrid Ekman has determined the influence of the pressure upon the 

 volume of sea-water of different salinities and at different temperatures. By these 

 measurements the pressures were calculated from the compression of distilled 

 water of o C, the measurements of Amagat* being, after an independent control 

 of their reliability, used as a base for this calculation. Mr. Ekman has kindly fur- 

 nished us with the following formula computed from his own measurements in 

 connection with those of Amasrat: 



(d) 



+/io- 4 [" 



4886 To ,1 



s 7 227 + 28.33T o.55it 2 4- 0.004T 5 



I + O.OOOOI83/ L 



105.5 + 9-5ot-o.i58t 2 - i.s/7'io" 8 



,-28 

 10 



I47.3 2.72T + O.O4T 2 p IO _4 (32.4 O.87T + 0.002T 2 ) 



+ {^^)'h- 5 + - it -*- io_4 < 1 - 8 - - o6t) ] } 



' 







* Amagat: Mdmoires sur l'dlasticitl et le dilatation des fluides jusqu'aux trfes hautes pressions. Annales de 

 Chimie et de Physique, t. 29, 1893, p. 544. 



