SABLE ISLAND—MACDONALD. 267 
i6 miles long; westward again we have the Gréat George’s bank, 
with shoals reaching the surface ; a little further westward we 
reach the shoals of Nantucket; the whole forming an immense 
deposit, following the curvation of the coast. 
We will now turn from geological formation te the course of 
those great currents which divide and control ocean forces. 
By glancing at Maury’s physical chart it will be seen that the 
Gulf Stream, after discharging its heated water through the chan- 
nel formed by the coast of Florida on the one side and Cuba and 
the Bahamas on the other, follows the trend of the American 
coast northward until approaching the shoals of Nantucket where 
it swerves to the N. E., passing south of Sable Island to the tail 
of the great bank of Newfoundland, and then stretching over to 
Europe in a due east direction. 
In opposition to this we have the cold ice-laden current of the 
north, one portion of which after leaving the Arctic ocean, passes 
southward along the eastern coast of Greenland where, being - 
joined by another branch coming from Baffin’s Bay and Davis 
Strait, it passes along the coasts of Labrador and Newfoundland 
to the great banks, where it is met by the northern edge of the 
Gulf Stream. 
At this point a division of the polar current takes place. One 
portion, from its greater density, sinks below the warm current of 
the Gulf Stream, and continues its course southward as a sub- 
marine current. 
The other portion of the polar current, where it impinges on 
the Gulf Stream at the Great bank, becomes deflected to the 
westward partially by contact with the Great bank, and in its 
course its northern edge sweeps around Cape Race into St. 
Mary’s and the other bays north until losing its momentuin it 
falls back and joins the main body of the current. This portion, 
sweeping around and into those bays, is commonly called the 
indraught by mariners, and to it being accelerated by certain 
storms may be attributed the loss of the Cedar Grove at Canso 
and the Cromwell boats and the Hanoverian at Cape Race. 
The southern edge interlaces the Gulf Stream and carries west- 
ern bound vessels at such a rate as frequently leads mariners to 
