SUEFACE WATERS OF THE NORTH ATLANTIC OCEAN. 
108 
To the west of Iceland the branch of the Irminger current going northward gains 
strength quickly in spring, and ajDparently reaches its greatest surface extension in 
June. During the same period salt water makes its way steadily northward along 
the west coast of Greenland ; this is the westerly branch of the Irminger current 
discovered by the “ Ingolf” expedition. 
In July the drift of water eastward from the American coast attains immense pro¬ 
portions in the lower latitudes. The “ banking-up ” of salt water (35'5 p/u mille 
and over) towards the European coast becomes more marked, and with it the 
tendency to spread northward. But the eastward movement is still apparent farther 
north, a tongue of land water makes its way east from Cape Bace, and again there is 
a drift from the Labrador coast. 
Along with this there is everywhere a large increase in the supplies of Polar water. 
Strong currents appear running southward close to the Labrador coast; the Irminger 
current is overwhelmed by a rush of water southward across the wliole binadth of the 
Denmark Strait, which gradually spreads over a large area to the south-east of 
Greenland ; the current to the east and north-east of Iceland is strengthened, though 
to a less degree ; and to the north of Europe currents of relatively cold and fresli 
water extend southward to the coast, entirely covering the 35 pro miUe water except 
in isolated patches. 
These conditions continue for two months, with the general result that gradients 
of both salinity and temperature become steeper and steeper on the margins of the 
areas described. In September a drift, consisting partly of fresh water from near 
the Newfoundland Banks which has been delivered there by the Labrador current, 
extends across towards the British Isles; the northern area is largely covered by 
Polar water, and between the two is the only part of the western branch ol the 
Irminger current which appears at the surface. 
The autumn conditions following the culmination of the summer type in August 
and September are chiefly the result of a weakening of the easterly currents south of 
lat. 50° N., and a strengthening ot them to the north. The Labrador cui*rent again 
makes its way to the southward round the Newfoundland Banks, the stream being 
not now turned eastward, hence there is an increase of salinity immediately to the 
eastward (due, according to the temperature observations, to mixture from below; 
it is interesting to note the rapidity vdth which the fresh water advances and 
retreats south of the Newfoundland Banks, where it evidently forms a very thin 
though widespread layer), while the weakening of the easterly movement also causes 
lower temperature and salinity in the south-east Atlantic. 
North of lat. 50° N. there is a strong easterly drift from the coast ol Labrador, 
and another from the east coast of Greenland. The current from the east coast of 
Iceland is also deflected more to the north-east, broadening the north-easterly current 
between that island and Scotland. 
This brings us to a distribution of temperature and salinity in Decemljer very 
