CONTRIVANCE A NECESSITY. l6l 



the wing vanes stretched and exposed at proper 

 angles to the wind. And whenever the onward 

 force previously acquired by flapping, becomes at 

 length exhausted, and the ceaseless inexorabla 

 Force of Gravity is beginning to overcome it, the 

 bird again rises by a few easy and gentle half- 

 strokes of the wing. Very often the same effect 

 is produced by allowing the force of gravity to act, 

 and when the downward momentum has brought 

 the bird close to the ground or to the sea, that 

 force is again converted into an ascending impetus 

 by a change in the angle at which the wing is ex- 

 posed to the wind. This is a constant action with 

 all the oceanic birds. Those who have seen the 

 Albatross have described themselves as never 

 tired of watching its glorious and triumphant 

 motion : — 



" Tranquil its spirit seemed, and floated slow ; 

 Even in its very motion there was rest." * 



Rest — where there is nothing else at rest in the 

 tremendous turmoil of its own stormy seas ! 

 Sometimes for a whole hour together this splendid 

 bird will sail or wheel round a ship in every 



• 



Professor Wilson's Sonnet, " A Cloud," &c. 



