SS BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
densities in the attempt to reconstruct the movements of its waters 
the most important subject on which the cruise may throw light. 
Perhaps the most striking oceanographic feature of the Gulf of Maine 
in summer, certainly the one which has aroused the most speculation, 
is the existence of a cold band of surface water which bathes the coast 
from Portsmouth as far as the Penobscot, and extends thence across 
the mouth of the Bay of Fundy and along the western coast of Nova 
Scotia, gradually growing broader and broader to the eastward. If we 
were to judge from surface temperatures alone we would naturally 
assume that this cold water was evidence of a cold current following 
the coast; and it has often been referred to as an Arctic current solely 
on this ground. But, as we have seen, the surface currents, at least 
in summer, afford no support to such a view, while serial temperatures 
and salinities show that the phenomenon can be explained on very 
different grounds. 
The coldest surface water was found over German Bank and in the 
Grand Manan Channel; but serial temperatures show that this low 
temperature, at these stations, was solely a surface phenomenon, the 
bottom waters being much warmer there than at corresponding depths 
in the basin or on the west coast of the Gulf. Furthermore the mean 
temperatures for the upper forty fathoms, 7. ¢., for the whole depth 
at Stations 29, 33, and 35, are no lower than they are in the western 
part of the Gulf; (Station 29, 49.8°; Station 33, 49.5°; Stations 
27 and 28, 49°; Station 11, 45.7°; Station 7, 49.1°; Station 2, 46.4°: 
Station 43, 51.1°.) We find, too, that in the northeast part of the Gulf, 
there is much less change in salinity from surface to bottom than in the 
western half. And wher we take into consideration the extraordinary 
violence of the tide, both on German Bank and in Grand Manan 
Channel, and the numerous tide-rips, with which everyone who has 
sailed these waters is familiar, it can hardly be doubted that the low 
surface and high bottom temperatures are merely the evidence of 
thorough mixing of surface and bottom waters, caused by the active 
vertical circulation which necessarily results from the strong currents. 
Verrill (1873, p.438) explained the phenomenon correctly when he wrote 
“the constant mixture of the cold bottom water with the warmer 
surface waters by means of the strong tides and local wind currents, 
causes the remarkably low temperatures observed in the shallow waters 
of these shores.” The temperature conditions on Jeffrey’s Bank re- 
sult from a sunilar phenomenon, though as tidal currents are less strong 
here than they are further to the eastward, the equalization of tem- 
perature from surface to bottom is less complete; and the diminishing 
en eos 
