206 



bulletin: museum of comparative zoology. 



The water ofT Cape Ann, (Fig. 41 ^), as a whole, is coldest in Febru- 

 ary (191-ib); solar warming is first evident in March, when the tem- 

 perature of the surface rises to that of the deeps; and after that the 

 surface water warms very rapidly, from about 3.5° to its maximum 

 of 17°-1S°, which is reached at the end of July or early in August. 

 The surface then cools almost as rapidly as it warmed, its temperature 



Jan. Feb. Mar Apr. May June July Aug. Sep. Oct.J^ov.Dec. 



Fig. 41. — Annual range of temperature in the sink off Cape Ann at the surface, 50 

 meters, 100 meters, and 150 meters. (1912-1915). This is at the location of 

 Station 10253 in 1914. 



falling to about 10° by the first of October, after which there is a 

 slower, but constant cooling, to the February minimum. Summer 

 warming is less evident and the maximum reached later and later, as 

 the depth increases; at 50 meters the maximum is about 9°-10°, 

 early in October; at 100 meters about 8° in November. 



The salinity is highest at this locality in March (above 33%o for 



' The diagrams for temperature and salinity off Cape Ann (Fig. 41, 42), are combined from 

 the records of 1912-1915, but the annual variations are small. 



