346

CLIMATE OF NOKTU AMERICA.

the lower and colder NW. wind flowing in below and raisingthe south wind into the upper current. The north-westwind enters below the north-east wind, and thus often causesthe wind to change from NE. to NW.

As the southerly winds are propagated from west to eastover the United States, they reach the Atlantic coast of theSouthern State of Georgia sooner than the Northern State ofMaine; but the former is more to the westward than the latter.Hence the north-easters sometimes begin in the south, andare propagated along the Atlantic coast from SW. to NE.;and like the NW. wind is also first felt on the Atlantic coastof Florida and Georgia, because that part of the sea-board isfarthest west.

I have already said that north-east winds are much morecommon in the New England States and Lower Canadaduring the passage of storms from west to east than they arcin the Southern States.* This circumstance I attribute tothe peculiar physical features of the country. The physicalfeatures of any country must be considered in accountingfor the minor and local courses of the winds on the ap-proach of storms. The large map (Plate VI) of the weather 'of 10th November, as already mentioned, shows that thewind was north-east at Montreal, and blowing right towardsthe south-west winds which were prevailing in the Ohiovalley. The direction in which the clouds were moving atMontreal is not given, but in the north-western part of theState of New York the clouds were coming from the south-west, as represented by the naked arrow in the chart (Plate VI).The rise of 23 degrees of temperature in twenty-four hours atMontreal could only be accounted for by the warmth andmoisture brought from the south and west by the currentwhich overlaid the NE. wind. The figure (p. 347) is an ex-aggerated section of the elevation of the country between themouth of the Mississippi and Montreal. The distance is about1400 miles in a straight line. The direction of the windsand the temperatures as at 7 a.m. of the 10th November

* This agrees with Espy’s 18th Generalization. “In the northern parts ofthe United States, the wind generally in great storms sets in from the north ofeast, and terminates from the north of west .”—Report to the Navy.