THE ANTARCTIC REGIONS AND THEIR CLIMATOLOGY. 465 



our mast-heads, yard-arms, etc., and above all, the awful sub- 

 limity of the heavens, through which coruscations of auroral 

 light would often shoot in spiral streaks and with meteoric bril- 

 liancy, altogether presented a scene of terrible grandeur and 

 awful sublimity surpassing the wildest dreams of fancy. Words 

 fail to convey any just idea of the magnificence it presented. 

 One must see it and feel it in order to realize it. I have written 

 this because I believe it an unusual occurrence to see the 

 * southern lights ' at all, and also because this was far superior, 

 and, in fact, altogether different from our noiihern lights, as 

 seen from the latitude of Boston." 



872. — An erroneous opinion. — Some objections to these views 

 respecting the comparative mildness of antarctic climates are 

 suggested by common opinion. It is an opinion which is generally 

 received among sailors and physicists that the southern is colder 

 than the northern hemisphere, and that the austral are more 

 severe than the boreal climates, and that the antarctic icebergs, 

 in the silent evidence afforded by their size and numbers, are 

 witnesses of the fact. These objections have an apparent weight ; 

 they deserve consideration. 



873. — Tropical regions of the southern hemisphere cooler, extra- 

 tropical warmer, than those of the northern. — The answer to them is 

 as follows : Between lat. 40^ or lat. 45^ and the equator, and 

 parallel for parallel, the southern hemisphere is cooler than the 

 northern. Eeason teaches, and observations show that it is so. 

 But beyond 45° S. observations are wanting, and we are left to 

 reason and conjecture. That the southern hemisphere should, 

 till within a certain distance of the pole, be warmer in winter 

 and cooler in summer, may be explained by the fact that the 

 southern hemisphere has more water ; that water being more 

 equable than land in its temperature, produces more equable 

 climates ; that the vapour which is taken up from trans-equatorial 

 seas and condensed into rains for cis- equatorial rivers conveys 

 with it a vast amount of heat which the southern hemisphere 

 receives from the sun. It is rendered latent by evaporation on 

 one side of the equator, and made sensible by precipitation on the 

 other. Much of it is set free in the equatorial calm belt, and it 

 is this liberated heat which assists mightily to maintain the 

 thermal equator in its northern position. 



874. Formation of southern icebergs, — So, in like manner, the 

 vapour that is borne to the antarctic regions by the polar-bound 



2 H 



