BIGELOW: EXPLORATIONS IN THE GULF OF MAINE. 71 
was a steady rise in salinity from the surface downward, at all our 
stations except in the Grand Manan Channel and on German Bank. 
The bottom salinity below the 100-fathom curve varied from 33.5 to 
34.54. There is little if any evidence that the wedge of fresh water 
abreast of Massachusetts Bay, so noticeable from the surface down to 
fifty fathoms, influenced the bottom water, for the salinity curves at 
the bottom show very little easterly swing in this region, and that 
little is probably the result of the bottom contour. The same is true 
also of the influx from the Penobscot, because the southerly swing of 
the curve of 33.8 agrees with the bottom contour, following the slope at 
about the hundred fathom line. It likewise crosses the mouth of 
Massachusetts Bay at one hundred and twenty fathoms, rising to about 
eighty-five fathoms off the northern end of Cape Cod. But it does not 
enter the trough west of Jeffrey’s Ledge, for here the salinity of the 
bottom water in sixty to eighty fathoms is only 33 to 33.2. North- 
eastward from Jeffrey’s Bank the 33 curve rises higher and higher on 
the coastal slope until finally water of this salinity was found at about 
fifty-five fathoms off Petit Manan. The curve must then turn off- 
shore, for the bottom water in the Grand Manan Channel was only 
about 32.5-32.6. No station was made on Grand Manan Bank; 
but judging from conditions on the other banks, it is not likely that 
the bottom water had a salinity as high as 33. The same is also 
true of Lurcher Shoal. On German Bank, also, the bottom water was 
fresher, only 32.9 in thirty-five fathoms; hence it is probable that 
the 32.6 curve came close to the surface along the west coast of Nova 
Scotia. The bottom salinity of Platt’s Bank was above 32.5; and 
it is probable that this was the case on Cashe’s Ledge likewise. On 
the other hand the circumscribed deep basin in the mouth of Massa- 
chusetts Bay (Station 2) had a considerably lower bottom salinity, 
32.92, than the waters at corresponding depths further east. Over the 
eastern arm of the 100-fathom basin the bottom salinity was 34 or 
over, the highest values being at Station 28, 34.5; Station 32, 34.1; 
and Station 36, 34.3, in one hundred and twenty, ninety, and one 
hundred fathoms respectively. But at Station 27, only a few miles 
west of the saltest spot, the bottom salinity at 100 fathoms was only 
33.9. | 
Salinity profiles.— The profiles (fig. 29-33) can not pretend to 
as great accuracy as those for temperature, because the number of 
observations is much smaller; and they are necessarily largely recon- 
structed from the salinity sections. But if regarded only as prelimi- 
nary, they are useful as showing general distribution of salinity. 
