BIGELOW: EXPLOKATIONS IN THE GULF OF MAINE. 



75 



running southeastward from Mt. Desert (Fig. 32) shows the increase 

 in salinity passing off shore in that region. 



In Massachusetts Bay two pairs of Stations, 6 and 45, and 5 and 4(i, 

 (figs. 27, 28) were taken six weeks apart, purposely to show seasonal 

 change, if anv. But the 



Fa. n 51 J^8 







sections show that at both 



46 and 5 the salinity at 



the surface was 31.6, at 30 



fathoms 32.5, and also that 



there was apparently noth- 

 ing to separate Station 6 



from Station 45, at both 



of which the surface sa- 

 linity was 31.9; though as 



the depth at the former 



was twenty-five and at the 



latter forty fathoms, only 



two samples being taken 



at each, it is possible that 



there may be some slight 



divergence in the interme- 

 diate zone. In short, these 



four stations certainly do 



not suggest that there was 



any seasonal change in the 



salinity in Massachusetts 

 Bay during our absence, 

 although there was a very 



pronounced rise in temperature (p. 58) at all depths below five fathoms. 

 Stations 44, 45, 46, all taken on the same day, afford a profile across 

 the Bay, from south to north (fig. 33). The curves show that the 

 core of fresh surface water was thickest in the northern half of the Bay. 

 And as Station 6 is, as we have just seen, interchangeable with 45, and 

 5 with 46, it is clear that this is the characteristic condition in mid- 

 summer. In the southern half of the Bay, the curve of 32.2, found at 

 twenty fathoms at Station 46, rose to within eight fathoms of the sur- 

 face; and the surface salinity was 32 instead of 31.9. But below twenty 

 fathoms the salinities were slightly lower at Station 44 than in the 

 centre of the Bay. Thus we find reproduced, but on a much smaller 

 scale, the spreading of the salinity curves so pronounced on German 

 Bank, and in the mouth of the Grand Manan Channel. And as 

 pointed out (p. 56) the same thing was true of the temperatures. 



Fig. 32. — Salinity profile from near Mt. Desert 

 (Station 37) to Station 28. 



