PHYSICAL OCEANOGRAPHT OF THE GULF OF MAINE 



713 



In the same way, a March reading of only 32.91 per mille at 175 meters in the 

 trough west of Jeffreys Ledge (station 20061) mirrors the hindrance of free circula- 

 tion at the bottom (p. 691) by the barrier rim to the north. 



Portland 



FIG. 95.— Salinity at a depth of 150 meters, February 22 to March 24, 1920 



Salinities at depths greater than 150 meters did not demonstrate any inflow as 

 actuaUy taking place into the bottom of the gulf in February and March, 1920. 

 Thus we find a general and comparatively uniform gradation at 175 meters from 

 33.5 to 33.8 per mille around the inner slope of the basin generally (but only 33.03 



