BIGELOW: COAST WATER EXPLORATION OF 1913. 231 



been a similar, but more pronounced off shore current opposite Chesa- 

 peake Bay, much as it is represented on the current chart of the North 

 Atlantic (Soley, 1911), and surface density suggests that the fresh 

 water from the Bay spreads out, fan-like, to the north, as well as over 

 the heavier ocean water. The Salter water which alternates with 

 these comparatively fresh tongues is in part a contrast phenomenon; 

 but the salinity curves immediately south of Delaware Bay can only 

 be explained as due to an actual shoreward drift of water of high 

 salinity (p. 187). And the current data at Station 10074 suggest, 

 th'ough they do not prove, that this salt tongue was swinging, eddy-like, 

 toward the southwest. Just north of Delaware Bay, there seems to 

 have been a similar eddy-like movement which, added to the southerly 

 flow of coast Avater, produced the strong southwest current which was 

 found at Station 10072. Surface salinities, like the current measure- 

 ments at Station 10064 suggest traces of a northerly movement, or 

 "banking up" of the ocean water south of Long Island, a process 

 which had progressed so far by the end of August as to raise the surface 

 salinity from about 32.8%o (Station 10062) to about 34%o (Station 

 10112). 



Surface density, being practically the same off Cape Cod as over 

 the outer part of the continental shelf south of Nantucket, does not 

 indicate any general flow across Nantucket Shoals into the Gulf of 

 Maine in July, or vice versa; nor does surface salinity afford any un- 

 mistakable evidence of a dominant current in that region, though the 

 curve of 33% suggests a possible southeasterly drift. Salinities show 

 that there must have been an indraught of ocean water into the 

 eastern side of the Gulf, which is consistent with the fact that the 

 surface density of the northern and eastern parts of the Gulf was very 

 much high^ than that of the ocean water outside George's Bank. 

 To compensate for this tongue of ocean water, there was an outflow of 

 land water off Penobscot Bay; and the salinity curves suggest a 

 general southward drift of surface water along the western coast of 

 the Gulf (Plate 2). 



The salinity curves, and our actual current measurements, agree 

 very well with the earlier data, as summarized in the U. S. Coast Pilot 

 (1912). According to the latter the prevailing drift over Nantucket 

 Shoals is easterly, which agrees so well with our salinity curves as to 

 make it a fair assumption that there is actually a dominant easterly 

 current in this region in summer. The few current measurements 

 which have yet been made on George's Bank (U. S. Coast Pilot, 1912, 

 Mitchell, 1881) indicate a similar easterly drift, veering northward 



