518 BULLETIN OF THE BUREAU OF FISHEBIES 



and 1915 she ran oceanographic profiles across the slope abreast of Marthas Vine- 

 yard in August and October, mentioned above (p. 517). In 1916 she again made 

 summer and November cruises from Gloucester to Chesapeake Bay (Bigelow, 

 1922). 



TOPOGRAPHY 



The indentation of the coast between Cape Sable, at the southeast angle of Nova 

 Scotia on the east, and Cape Cod and Nantucket Island, on the west, seems to have 

 gone unnamed until late in the last century, when it was christened "Gulf of Maine." 

 As outlined by the coast, the gulf is roughly rectangular, much wider (about 200 miles) 

 than deep (about 120 miles). It is a far better marked natural province below the 

 surface of the sea than the shallow recession of its shore line would suggest, for its 

 southern boimdary is marked by a shallow rim, or "sill," pierced by three narrow 

 passages only. Passing eastward from Nantucket, with its off-lying shoals, these, 

 successively, and the banks that separate them, are: The South Channel (not very 

 well defined and only 40 to 50 fathoms deep), Georges Bank, the Eastern Channel, 

 Browns Bank, the Northern Channel, and finally the Seal Island or coastal bank off 

 Cape Sable. This rim, as Mitchell (1881) long ago pointed out, 259 mUes in length 

 from Nantucket to Cape Sable, follows, in its main outlines, the arc of a circle whose 

 radius is about 167 mUes. Along this arc the length of Georges Bank, from the 

 deepest trough of the South Channel to the 50-fathom contour on the slope of the 

 Eastern Channel, is about 140 miles, with a greatest breadth of about 80 miles from 

 north to south between the 50-fathom contours. Between these same contours of 

 the Eastern Channel and of the Northern Channel each occupies about 25 miles of 

 the arc. In round figures, the area of Georges Bank is 10,000 square mUes; that 

 portion of Browns Bank west of longitude 65° 30' W. (taken as the arbitrary bound- 

 ary of the region under discussion) is about 550 square miles. 



The area of the gulf north of the rim is given by Mitchell as about 36,000 square 

 mUes. The coast line of the gulf, as it would appear on a small-scale chart, follows 

 a fairly regular curve, but in detail it is extremely complex; for the northern and 

 eastern shores are not only frequently and deeply embayed, but are bordered by a 

 perfect labyrinth of islands, large and small, extending in places 10 to 20 nules sea- 

 ward from the mainland. Its largest bays (Massachusetts on the southwest and the 

 still larger Bay of Fundy on the northeast) are too well known to need more than 

 passing mention. 



The coast of the Gulf of Maine falls into two main types. Cape Elizabeth mark- 

 ing the transition from one to the other. South of this headland the shore line is 

 characterized by a succession of sand beaches alternating with bold headlands, nota- 

 bly Cape Ann, and with rocky stretches, which in Cape Cod Bay give place to the 

 continuous sand strand of the cape. Along this part of the coast there are but few 

 islands, except in Boston Bay, and the fjord type of indentation is notably absent. 

 East of Cape Elizabeth, on the contrary, the shores of the State of Maine are almost 

 continuously rocky, as are the islands of the outlying archipelago already mentioned; 

 and deep bays succeed each other in close succession as far as the mouth of the 

 Bay of Fundy. As a whole, the shores of the gulf are low, seldom rising to more 

 than 100 to 200 feet in the immediate neighborhood of the sea; but the Camden hills 



