154 LIFE ON THE EARTH. 



of North America, to the Arctic circle, the North Cape 

 of Scandinavia, and the icy shores of Spitzbergen. 

 Along the line of this current the isothermal lines 

 are inflected to the northward, beyond the points 

 which they reach in the midst of the continents of 

 Asia and America 10, 15, and even 20 degrees; in 

 other words the northern parts of Europe have their 

 winter climate in particular so mitigated by the aid 

 brought to them over 2000 miles of sea, as to make 

 the yearly average of temperature higher by 10 or 

 15 than places in the corresponding latitudes in the 

 United States. Conceive that by some movement of 

 the solid earth-crust, this current were entirely pre- 

 vented from flowing up the Atlantic, then 10 or 15 

 would be lost to the climate; suppose other un- 

 favourable circumstances arising from the new dis- 

 tribution of land and water, such as a cold current 

 from the north ; perpetual snows would gather on the 

 mountains of Scotland, Cumberland, Wales, and Ire- 

 land; glaciers would be formed in suitable situations; 

 icebergs would be floating on the sea; Arctic shells 

 might be encouraged in growth, and the phenomena 

 of the glacial period be repeated 1 . 



It appears from these considerations, that by a 

 change of the oceanic currents, quite within geolo- 

 gical probability, the warmest meridional band in the 

 1 Hopkins in Geol. Soc. Journal, Vol. vm. 



