956 



BULLETIN OF THE BUREAU OF FISHERIES 



overlying Browns Bank, the Eastern Channel, and the water oflp the mouth of the 

 latter; the other situated over the northeastern part of the basin; the two separated 

 by a slight potential elevation of the surface. Contrasting with these "lows," which 



Portland 



7<r 



es- 



68* 



Flo. 203.— Dynamic gradient at the surface, July to August, 1914, referred to a base station in the Eastern Channel. The 

 curves are for every dynamic centimeter. The picture south and east of the heavy dividing line is for July; north 

 and west of it for August 



are obviously the vortices of anticlockwise circulation, is the high in the offing of 

 Massachusetts Bay. A sUght gradient, west to east, is also shown from the north- 

 ern low toward Nova Scotia in August; a steeper gradient of the same order north- 

 ward toward the coast of Maine. There is every reason to suppose that the water 



