30 



The isosteric lines, Figure 10, page 26, represent in vertical section, 

 the distribution of the specific volume in situ (v). But except in 

 regions where rapid currents prevail, the lines of equal specific volume 

 vary little, especially in the greater depths, from either the lines of 

 equal pressure or the lines of equal depth. This is due to the fact 

 that the effect of the increasing pressures with the depth more than 



o 



offset the variations in the specific volume due purely to temperature 

 or salinity variations. In order to secure a more striking graphic 

 representation of the distribution of specific volume in situ, it is 

 customary to draw the isosteres in accordance with the values of 

 V — Vi (see computations, column 15, p. 28). Although these ciphers 

 are of a smaller numerical value than the actual specific volumes, yet 

 they provide a greater contrast than the latter, and a section thus I 



