PHYSICAL INVESTIGATIONS OFF THE NEW ENGLAND COAST. 407 
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' In every chart the rather remarkable curvature of the 50° line downward off the 
i continental platform will be instantly noticed, 
i: In the first charts this line extends seaward from the edge of the continent for 
I some distance, then returns toward it again, follows it downward for some distance, 
j and then passes out toward the main body of the ocean. It would be interesting to 
f notice whether it returns toward the surface of the ocean again at some point farther 
I along the line. This body of comparatively warm water lias an average depth of 
about 50 fathoms and has a most lieculiar shape, as will be seen from a comparison 
l| of the several charts. We refer now particularly to the first five, since our data were 
j not sufficiently numerous in the other charts to enable us to verify the existence of 
I this same form of the body of water referred to in the earlier lines. The modifications 
i| in the outline of this mass of water take place in its upper portion, particularly in the 
upper part lying opposite to the continental edge. Where the slope of the jilatform 
!; is slight, as in charts 1 and 2, it is. gradually rounded in this portion, but in charts 3 
I and 4, where the slope is more abrupt, this rounded part is broken into and the water 
■ massed to a greater height beyond it farther seaward. This does not hold good of 
j chart 6, where local influences may produce a different result. Just why this is so 
I we are not able to state, because no perfect lines were made directly to the eastward 
of this line. 
The peculiar shape of this curve would seem to point to a mechanical intrusion oi 
cold water from the surface of the continental platform, which may be reinforced by 
I the specific gravity of the water, as would appear from a study of some of the observa- 
tions made, notably the specific gravities at the 100-fathom line in charts 2 and 3. 
The existence of this body of warm water off the continental edge may offer an 
explanation of the richness of this particular spot in all forms of marine life, as shown 
by the successful dredging of the Albatross upon it. 
The curves of 70° in the first four charts, if studied in succession, remembering 
that they were made at intervals of 10 minutes of longitude to the eastward of one 
another, show very nicely the gradual breaking up of a broad belt of warm water in 
chart 1 into several distinct smaller bands in chart 4. The proximity of the northern- 
most end of this line to the coast on charts 1, 2, 3, and 4 points very strongly to the 
influence of long-continued winds in driving this body of water toward the coast. 
The contrast in the position of the shore end of this line in charts 5 and 6 is very 
striking. These lines are a repetition of the lines of charts 3 and 4, made two weeks 
later, after an interval during which strong northerly winds were constantly blowing. 
The first-mentioned charts (ISTos. 1, 2, 3, and 4) were made after the winds irom the 
south, which had been at work nearly all summer, had about reached the maximum 
of their influence. 
Further than this in the interpretation of our data we dare not go at present. 
Enough has been said to call attention to the interesting nature of the problem we are 
working upon, which has not yet been solved. The facts pointed out warrant further 
investigation, and it is hoped that the work of the coming year may bring us one step 
nearer the accomplishment of our wish. 
