not become constantly deeper as we proceed seaward from the 

 shore, anywhere between Portsmouth, N.H., and Eastport, 

 Maine ; but, on the contrary, the water is usually as deep at 

 twenty to fifty miles from shore as at any greater distance less 

 than two hundred and fifty miles, beyond which the abysses 

 of the ocean begin, and the bottom falls away rapidly to 

 twelve hundred and fourteen hundred fathoms ; and not un- 

 frequently the depth is actually greater at the lesser distance 

 from shore, so that the water shallows seaward. Thus, the 

 greatest depth recorded in the region of the Gulf of Maine, 

 one hundred and sixty fathoms, is only fifty miles from Ports- 

 mouth ; and thirty-five miles from Mt. Desert gives us one 

 hundred and forty-five fathoms : while beyond this the water 

 shallows sensibly, and an equal depth is not found nearer than 

 one hundred and fifty miles from shore. 



Extending easterly from Cape Cod, for nearly two hundred 

 miles, is a broad expanse of shallow water, with depths rang- 

 ing from five to fifty fathoms, and including George's Bank, 

 which reaches the surface one hundred and twenty miles from 

 land. A similar but less distinctly marked area of shallow 

 water stretches southward from Nova Scotia, with a breadth of 

 sixty miles, and a maximum depth of seventy fathoms. Sepa- 

 rating these two areas of moderate depths is a strait of deeper 

 water, eighty to one hundred and fifty-five fathoms. Following 

 the fifty-fathom line, this strait is, perhaps, fifty miles wide ; 

 while for the one-hundred-fathom line it is reduced to thirty- 

 five miles. It is plain that a broad submarine ridge or plateau 

 extends over nearly nine-tenths of the distance between Nova 

 Scotia and South-eastern Massachusetts, forming a nearly com- 

 plete barrier between the comparatively deep water of the Gulf 

 of Maine and the greater depths of the ocean beyond. If the 

 sea bottom were elevated fifty fathoms, the Gulf of Maine, 

 although still three hundred miles long, and having a maximum 

 depth of one hundred and ten fathoms, would be changed from 

 a broad-mouthed bay to an almost completely land-locked gulf. 



The glaciating agent operated powerfully to obliterate that 



