59 



They have supposed that, if the axis had been 

 perpendicular to the plane of the orbit, and the 

 seasons had been thus uniform over all the earth, 

 the disagreeable vicissitudes of temperature to 

 which we are now exposed would have been 

 prevented. But this obliquity serves important 

 ends ; it tends to diffuse the influence of the 

 sun's rays over a larger portion of the globe than 

 could have taken place by any other arrange- 

 ment, and in this way extends, in a considerable 

 degree, the habitable surface of the earth. Had 

 the earth's axis been perpendicular, our climate 

 in Britain never could have been warmer than 

 the weather is at the vernal equinox. 



It is true, a much less degree of external heat 

 than this might have answered fully the purpose 

 of sustaining the natural temperature of man ; 

 for, by a beautiful provision of nature, he is ca- 

 pable of maintaining the heat of his body at very 

 nearly the natural standard, under the most in- 

 tense extremes of either cold or heat as at 

 Hudson's Bay, where the thermometer sometimes 

 sinks to 50 degrees below zero, and at Poridi- 

 cherry, where it sometimes rises to 115 degrees 

 above it. But we must remember that, though 

 man is thus a native of every climate, every other 

 form of organized being vegetable as well as 

 animal has its own particular habitat, and re- 

 quires a certain definite temperature to bring it 

 to perfection ; and, as these are essential to the 

 well-being of man, had the particular succession 

 of seasons in which each of them thrives been 



