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BULLETIN OF THE BUREAU OF FISHERIES 
with general report. On the other hand, the westerly counterdrift set in motion 
along the inshore side of the dynamic depression (or cabelling zone) loses in velocity 
and hugs the bank more closely from east to west. 
From the general oceanographic standpoint this demonstration that this sector 
of the “ Gulf Stream ” receives a propulsive impulse from the local hydrostatic 
forces (i. e., is strictly a dynamic drift) is one of the most interesting results of our 
explorations. 
The upper 50 meters or so of the gulf being close to quiescent, dynamically, 
during February and March, the chart for the surface (fig. 188) will as well represent 
the gradient currents down to as deep as 100 meters or so for that season, leading 
to the interesting result that the whole column down to this depth tended to drift 
inward along the eastern side of the Eastern Channel at the time, outward along its 
Fig. 189.— Distribution of density on a profile running from the eastern end of Georges Bank across 
the Eastern Channel, Browns Bank, and the Northern Channel, to the vicinity of Cape Sable, 
March 13 to 23, 1920. Corrected for compression. 
western side, which is also evident in the profile (fig. 189). However, if we descend 
to as great a depth as 150 meters a rather different dynamic distribution appears, 
with the center of anticlockwise revolution located as a low close to the northern 
slope of Georges Bank, with a weak but definite tendency toward a gradient drift 
crossing the basin from northeast to southwest, shown better graphically by the 
dynamic contours (fig. 190) than verbally. This drift was then bounded on the west 
by a considerable dead area covering the whole west-central part of the basin (except 
as interrupted by a subsidiary high marking a clockwise whirl in the offing of 
Penobscot Bay), with a very weak southerly tendency along the western slope in 
the offing of Massachusetts Bay. 
In the eastern side of the area this deep projection points to a slow creep inward 
through the Eastern Channel; but with only one station in the latter it is impossible 
