PHYSICAL OCEANOGRAPHY OP THE GULF OF MAINE 
761 
mille, a minimum of 0.1 per mille. This salting was greatest (0.7 to 0.8 per mille for 
the whole column) across the mouth of the bay (stations 30 to 34) and inward over 
its deep central part (stations ISA and 3), consistent with the fact that the source for 
any change of this order must lie in the still higher salinities of the deep water of the 
basin in the offing. In spite of small local variations, however, which are always to 
be expected from station to station near shore, depending partly on the stage of the 
tide when the observations are taken, the average difference in salinity between the 
surface of the bay and the 40-meter level was almost precisely the same on the June 
cruise (0.7 per mille) as it had been three weeks earlier in the season. 
The June stations (fig. 132) on the continental shelf off Shelburne, Nova Scotia 
(10291 to 10295), though outside the geographic limits of the gulf, strictly construed, 
are interesting in this connection as affording a cross section of the westward extrem- 
ity of the Nova Scotian current at the time. Here the vertical range of salinity 
was wider than anywhere in the Gulf of Maine in that month, with values compar- 
atively uniform, depth for depth, over the shelf but considerably higher outside the 
100-meter contour (station 10295). 
Horizontal projections give a more graphic spacial picture of the seasonal alter- 
ations just stated. At the 40-meter level the relationship between May (fig. 125) 
and June (fig. 133) is much the same as at the surface (p. 756) — the eastern side of 
the gulf salter than in May, the western and northern sides of the basin less so, as 
reflected by a translation of the isohaline for 32.5 per mille well out into the basin 
from the position close to the coast of Maine, which it had previously occupied. 
