B A L JE N A. 



285 



Thus it eeemsthat, though the influence of gravita- 

 tion, iirnl some other circumstances an- removed, then 



i-, ,i curve of'-ol;ir action below the level of the sea, 

 in the water, just as there is above in the air. On the 

 averatrc this curve de-ccuds to the greatest depth at 

 the equator, ami it-, depth heeornes less and less as 

 the poles ;ire approached ; though, like the curve of 

 COUL'* -lation in the air, it. shifts northward and south- 

 ward with the Reasons. Whether, therefore, we re- 

 gard the aetion of life in the atmosphere a hove the 

 ni'-;in level of the -ea, or the aetion of the water 

 bclov, -mist understand that its range in 



altitude diminishes as the latitude increases. Whether 

 they at the same point, at any 



period of the year, it would not he ca-y to ascertain ; 

 hut that they that is, the upper limit of the sn: 

 tiori in the air, and the lower one in the water do 

 approach near to each oilier in the high latitu<! 

 certain. 



It must be borne in mind, too, that in proportion as 

 the latitude increases, and the rays of the sun fall 

 more obliquely to the mean level, proportionally more 

 of the action of ti.o-c rays must he direeted to the 

 plan of th.it level, by the aetion of both the atmo- 

 sphere and the water. The oblique rays pass of 



-' through a much greater portion of den-c atmo- 

 sphere than the perpendicular one-, and are in < 

 quence refracted downwards in proportion. By falling 

 more obliquely on the surface of the water, they are 

 reflected upwards by that surface ; and when the 

 angle at which they fall is very small, and in high 

 latitude-, its maximum is only twenty-three and a half 

 <:s more than the di-tanee of the place from the 

 pole, they are reflected wholly into the atmosphere, 

 and barely heat the surface, unless by a second reflec- 

 tion from the atmosphere. Thus it may be considered 

 that, in the polar seas, while the sun is constantly 

 above the horizon, the solar light and heat are conti- 

 nually playing between a limited portion of the mere 

 surface of the sea, and a limited height of the atmo- 

 sphere over it ; and that as the pole is approached, 

 the extent, of action, downward in the sea, and up- 

 ward in the air, is continually diminishing, whi!' 

 diminishes, it be e uniform during the whole 



twenty-four hours. It is not possible to speak with 

 absolute certainty without direct experiments, arid 

 experiments which would riot be easily made in such 

 a mariner as to be perfectly sati-factory ; but, from 

 what has been said, it is highly probable that the 

 maximum of seasonal aetion during the polar summer, 

 though limited both in height and depth, is much 



< r at the surface than the solar action at the 

 equator. 1 rapidity with which the scanty 



'ation of the arctic lands performs its functions 



is a proof of this : one month it is a budless bush, ju-t 



irig from under the snow; next month it is in 



in'_' sun of tho-e distant, clime-, is another proof 

 of how powerfully the continued duration of solar 

 heat, and the action of the atmosphere and the earth 

 or waters, concentrating the heat toward the mean 

 surface in a manner not altogether dissimilar from the 

 operation of a convex or burning lens, work together 



in;.' inere;,< to the powers of life dur- 



MC brief period when these are in operation. 

 Whether ' ( s be produced from eggs com- 



i to the land or to the water, they must be, for 



great part of the winter, at a temperature a low as 



the free/ing point of water ; and the transition from 

 that to almost continual solar action, which come-- ,,n 

 in brief space, lias upon them an effect as ;. 

 though happening in fl different manner, a- that which 

 takes place in tropical climates, where the rain 

 ceed the seasons of parching drought. But the in- 



whcn in their winged state, require at least some 

 height ; and therefore, though they are abundant to 

 a high latitude over the arctic lands, their numbers 

 diminish as the upper and lower limits of solar action 

 approach closely towards each other. 



No where on the land is the mere surface action, in 



high latitudes, so great as it. i-, over t.h<- 

 The melting of the ice, which takes place to a con-.i- 

 dcrable extent during the early part of eve. 

 DO doubt retard* it- operation; while, on the other 

 hand, the free/ing during the autumnal months retards 

 for a little the cooling of that portion of the surface 

 which is still unfro/en. The operation of these re- 

 tardiii. ;mst be considered as kindly to the 



sres, both in coming into their summer activity, 

 arid in subsiding to their winter repo-c ; and the 



must be equally beneficial to the migrant r 

 whether of the land or of the water, which periodi- 

 cally go to share the bounty of the polar summer, and 

 retire to other climates during the winter. 



This great increase of production must be, to pre- 

 serve that balance which is every where the order of 

 nature, accompanied by an equal increase of consump- 

 tion. The number of birds which throng to those 

 it incredible to those who have not witnessed it ; 

 and there is, perhaps no part of the whole -casonal 

 arrangements in these high latitudes more wonderful 

 than the production of whales' food in the green 

 Trie greenness there is not a vegetable, but 

 an animal greenness ; but Still it is not a very over- 

 strained comparison to say that, just as it appears to 

 demand the large-t. of the ruminant mammalia to crop 

 the green vegetable life of the temperate rneadov 



it require the presence of the largest, of all the 

 mammalia to crop, and keep rlown to the proper 



ire of permanent preservation, the green animal 

 life of the polar seas. 



The analogies which we find in nature, though 

 often curious, and to our casual or superficial view, 

 not unfrequently inconsistent, are yet, when we come 



idy them with attention, all in wonderful har- 

 mony with each other ; and the coincidence which 

 we find in point of superior magnitude, especially in 

 the animals that, browse the small vegetation of the 

 meadow, and the baliena, which cull as their food 

 the small surface-productions of the sea, is far from 

 the leasfstriking. It is true that the pasture- of the 

 ox tribe are more perennial, more independent of 

 6 of the whales ; and that the animals 

 are less fleet in their motions. But these are cir- 

 cumstances which we might expect, as no land animal, 

 without wings, could annually migrate to the extremes 

 of latitude. And we find that taking the ox as the 

 commencement of the race upon land, and the com- 

 mon whale as the commencement in the sea, we have 

 gradations of species or genera becoming more 

 discur-ive. The babcnoptera stand in nearly the 

 same relation to the balajna, as the sheep, deer, and 

 antelopes do to the ox, they are lighter in their 

 ' in their motions, rather more varied 

 in their food, and when we come to the most discur- 

 sive species they have much less pronerie's to accu- 



