22 THE OCEAN 



sea-water can be found from its density at 

 standard temperature. 



Densimeter, — For the determination of the 

 relative densities of sea-water samples, a 

 differential densimeter was recently intro- 

 duced by J. J. Manley. It is somewhat compli- 

 cated in design, and was at first intended for 

 use in a laboratory on shore. The apparatus 

 has been modified so as to adapt it for use 

 on board ship, and a series of observations has 

 been carried out by N. P. Campbell during a 

 voyage to Ceylon on board one of the Orient 

 mail steamers, apparently with good results. 



For methods of determining salinity see 

 Chapter III. 



