834 BULLETIN OF THE BUREAU OF FISHERIES 



The salinities and temperatures of the eastern side of the gulf make it probable 

 that the westerly flow past Cape Sable slackens or ceases by June, at the latest, every 

 year — often a month or more earlier than that. In some years sporadic movements 

 of water undoubtedly take place from east to west past the cape later in the season; 

 but the drift of bottles put out on several lines off Nova Scotia by the Biological 

 Board of Canada during 1922, 1923, and 1924 shows that the circulation over the 

 continental shelf between Browns Bank and the Laurentian Channel becomes exceed- 

 ingly complex during the late summer, variable from summer to summer, and 

 largely controlled by the contour of the bottom.^- 



During some summers a rather definite current from east to west persists along 

 the Nova Scotian coast right through July and August. This statement is based on 

 the drifts for 1924, when a number of bottles set out on three lines normal to the 

 general trend of the coast between Halifax and the Straits of Canso, during July and 

 August, were picked up in autumn in the Gulf of Maine. Many other bottles from 

 the most easterly lines also traveled westward during that summer but stranded 

 before they reached Cape Sable.^' 



The probable tracks of the bottles that went westward, localized some 12 to 25 

 miles out from the land, correspond so closely with the tongue of coldest water 

 charted for May, 1915 (fig. 167), that the dominant drift was evidently essentially 

 the same for both. In May, as temperatures show, this east-west movement involved 

 a stratum of considerable thickness; but in the summer of 1924 it was more strictly 

 a surface phenomenon, probably with the underlying water circling offshore along 

 Eoseway and La Have Banks in the more usual anticlockwise eddy, because what 

 few temperatures were taken in the gulf that summer (p. 996) suggest no greater 

 transference of cold water (such as a bottom current past Cape Sable would entail) 

 than usual. 



The westerly set may again have continued past Cape Sable until September in 

 1926, when many drifts were recorded from the offing of the cape into the gulf, as 

 summarized on page 909. 



The bottle drifts for the other summers of record show, however, that it is 

 unusual for the Nova Scotian current to persist as a definite stream-flow as far west as 

 Cape Sable after June, but that the deep basin between Sable Island Bank on the 

 east and La Have Bank on the west is usually dominated (in summer) by an anti- 

 clockwise eddy named by Doctor Huntsman the "Scotian eddy," similar to, though 

 not as extensive as, the eddy that dominates the basin of the Gulf of Maine. 



In summers of this type whatever drift takes place intermittently around Cape 

 Sable into the eastern side of the Gulf of Maine draws from what Doctor Huntsman 

 describes as a sort of dead-water region off the cape. True, this, in its turn, 

 receives water of low temperature from the Scotian eddy, but also from the warmer 

 slope water that drifts westward along the edge of the continent, as appears from 

 the recoveries of Canadian drift bottles. Consequently, the surface water that 



" Only a preliminary statement of the genera! results has yet appeared (Huntsman, 1924); but Doctor Huntsman has very 

 kindly allowed quotation from his unpublished notes. 



'The account of these experiments contributed in advance of publication by Doctor Huntsman also shows complei drifts 

 Inshore and to the eastward tor many bottles set out off County Harbor and oft Beaver Harbor, which need not be discussed here. 



