392 rHYSICAL GEOGRAPHY OF THE SEA, AND ITS METEOROLOGY. 



line against which the sea is made to dash its waves in the other. 

 Impressed with the perfection of terrestrial adaptations, he who 

 studies the economy of the gi^eat cosmical arrangements is re- 

 minded that not only is there design in giving shore-lines their 

 profile, the land and the water their proportions, and in placing 

 the desert and the pool where they are, but the conviction is 

 forced upon him also that every hill and valley, with the grass 

 upon its sides, is a part of the wonderful mechanism, each having 

 its offices to perform in the grand design. March is, in the 

 southern hemisphere, the first month of autumn, as September is 

 with us ; consequently, we should expect to find in the South 

 Atlantic as large an area of water at 80° and upwards in March, 

 as we should find in the North Atlantic for September. But do- 

 we ? By no means. The area that is covered on this side of the 

 equator with water at 80° and upwards is nearly doiible that ou 

 the other. Thus we have the sea as a witness to the fact which 

 the winds had proclaimed, viz., that summer in the northern 

 hemisphere is hotter than summer in the southern. 



731. Sudden changes in the ivater thermometer. — Pursuing ther 

 study of the climates of the sea, let us now turn to Plate VI, 

 Here we see at a glance how the cold waters, as they come down 

 from the Arctic Ocean through Davis' Straits, press upon the 

 warm waters of the Gulf Stream, and curve their channel into a 

 horse-shoe. Navigators have often been struck with the greais 

 and sudden changes in the temperature of the water hereabouts » 

 In the course of a single day's sail in this part of the ocean,, 

 changes of 15°, or 20°, and even of 30°, have been observed to^ 

 take place in the temperature of the sea. The cause has puzzled 

 navigators long, but how obvious is it now made to appear! 

 This " bend " is the great receptacle of the icebergs which drift 

 down from the north ; covering frequently an area of hundreds of 

 miles in extent, its waters difter as much as 20°, 25°, and in rare 

 cases even as much as 30° of temperature from those about it. 

 Its shape and place are variable. Sometimes it is like a i^eninsula, 

 or tongue of cold water projected far down into the waters of 

 the Gulf Stream. Sometimes the meridian upon wliicli it is in- 

 serted into these is to the east of 40°, sometimes to the west of 

 60°. On my passage to England November, 1800, I passed 

 over this horse-shoe; the water in it was 16° colder than the' 

 water at its side. It looked as though we might have been or* 

 soundings. 



