17 



certain minimum number of points, by substituting values in the three 

 given equations. As a first step let us substitute a value of CJ. in 

 the first equation, which will result in the lowest value in the range 

 of salinities which it is desired to span. A few trials indicate that a 

 value of CI. equal to 17.5 gives a desirable value of s equal to 31.618 

 per mille, which in turn is substitute^ in equation (2) furnishing the 

 numeral 25.4025 as the value of iC This again is substituted in 

 equation (3) along with the values for At, Bt, and St for every two 

 degrees ciiange in the range of temperature known to prevail in the 

 particular region which is under investigation. Thus we obtain a 

 series of values for a salinity of 31.618 per mille, and in the same man- 

 ner, another series of temperature points on the graph using other 

 values of salinit}^, as shown in Table I: 



Table I 



The values as tabulated in Table I, upon further substitution, re- 

 sult in the following values as given in Table II: 



Table II 



I 



Having determined arguments 1, 2, and 3, we are now provided 

 with data sufficient to fix the construction of a graph which in turn 

 furnishes a rapid means of obtaining density values from given tem- 

 peratures and salinities. 



