THE SKY-LARK. 7 



-and proclaim the coming of the vernal season. It is, in fact, 

 more joyant in the sun, more inspirable by the life which the 

 solar influence diffuses through the atmosphere, than almost 

 any other creature : not a spring air can sport, not a breeze 

 of morn can play, not an exhalation of freshness from opening 

 bud or softening clod can ascend, without note of it being 

 taken and proclaimed by this all-sentient index to the 

 progress of nature. 



And the form and manner of the indication are as delight- 

 ful as the principle is true. The lark rises, not like most 

 birds, which climb the air upon one slope, by a succession of 

 leaps, as if a heavy body were raised by a succession of 

 efforts, or steps, with pauses between : it twines upward like 

 a vapour, borne lightly on the atmosphere, and yielding to 

 the motions of that as other vapours do. Its course is a 

 spiral, gradually enlarging ; and, seen on the side, it is as if 

 it were keeping the boundary of a pillar of ascending smoke, 

 always on. the surface of that logarithmic column, (or funnel, 

 rather,) which is the only figure that, on a narrow base, and 

 spreading as it ascends, satisfies the eye with its stability arid 

 self-balancing in the thin and invisible fluid. Nor can it 

 seem otherwise, for it is true to nature. In the case of smoke 

 or vapour, it diffuses itself in the exact proportion as the 

 density, or power of support in the air, diminishes ; and the 

 lark widens the volutions of its spiral in the very same pro- 

 portion : of course it does so only when perfectly free from 

 disturbance or alarm, because either of these is a new element 

 in the cause, and as such it must modify the effect. When 

 equally undisturbed, the descent is by a reversal of the same 

 spiral ; and when that is the case, the song is continued 

 during the whole time that the bird is in the air. 



The accordance of the song with the mode of the ascent 

 and descent, is also worthy of notice. When the volutions 

 of the spiral are narrow, and the bird changes its attitude 



