82 
MR. H. N. DICKSON ON THE CIRCULATION OF THE 
iiioved Jiorthward. Water of 8° or more uow occupies tlie Faeroe-Shetland Channel, 
but the 8° line does not enter the North Sea. The two parts of the 10° isothermal 
have not altered their positions much, but they are now joined together by an ahnost 
straight line. 
The salinity line shows similar changes of form. The line of 34'0 salinity occupies 
nearly the same position south of the Gulf of St. Lawrence and west of Newfound¬ 
land, blit south-east of the Newfoundland Banks it does not extend so far south, the 
two pai'ts of the line being now joined by a nearly straight portion. Water of 36 
pro mille salinity appears north of 40° N. in patches, as far east as 40° W. ; between 
40° and 50° W. the fresh waters have entirely disappeared from the low latitudes. 
Little change is apparent in the eastern Atlantic ; the 35'5 line is a little more to 
the north, and the 35'3 line stretches from Iceland to the Faeroe Islands, and forms a 
loop extending well into the Noifh Sea. The low temperatures and salinities south¬ 
west of Iceland am to be noticed 
The most important changes are thus, the advance of a warmer and salter area 
into the reuloii north of lat. 40° N. and between Ions;. 40° and 50° W., ajid a verv 
sliglit iiorthwai'd extension of warmer' and salter water along the whole of the 
European coast. 
March, 1896.—The isothermal of 15° now ap])ears north ot 40° N. lat. only in 
mid-Atlantic ; the position of its eastern portion remains ahnost unchanged, but it 
has reti'eated southward off the Gulf of St. Lawrence and the American coast. In 
this region the 5° and 10° lines are somewhat fuller to the south-east, and the gradient 
below 5° has become steeper, apparently on account of an extensive southward move¬ 
ment of ice-cold water from the Gulf of St. Lawrence and east of Newfoundland. In 
mid-Atlantic there is little or no change, and in the eastern part the conditions are 
the same as far north as 60° N., but north of this and east of 30° W. thei'e is a 
marked fall of temperature, averaging al)out 1° between East Iceland and the Faeroe 
Islands. Temperature seems to have risen considerably to the west of Iceland. 
Salinity observations are unfortunately not very well distributed for this month, 
the south-eastern part of the area being unre})resented. The most marked change is 
the advance of the 36 pro mille line to a point in about lat. 50° N. long. 10° W., off the 
south-west of Ireland, apparently due to a continuati(ni north-eastwards of the move¬ 
ment of this line indicated by the comparison of tlie January and February maps; 
the angle formed l)y the 36 line is fairly acute ; in all probability it may be sipjposed 
that it crosses loim. 20° W. in al)out lat. 45° N. In the Western Atlantic the fresher 
CD 
waters a2:)pear further to the eastward ; south-west of long. 50° the 36 line has disap¬ 
peared. In the north-eastern region there is a sliglit but distinct freshening of the 
water; the line of 35'5 now scarcely goes north of lat. 50° N., and between Faeroe 
and Iceland the line of 35‘2 replaces that of 35‘3, and the latter does not now appear 
in the North Sea. 
There is tlius a marked lowering of temperature and salinity in the western region, 
