OF NATURE. 225 



exterior part inclining towards the head 

 forms an acute angle with the body; the 

 intention being, not to give motion in the 

 line of the legs themselves, but by the 

 combined impulse of both in an interme- 

 diate line, the line of the body. 



Most people know, that have observed at 

 all, that the swimming of birds is nothing 

 more than a walking in the water, where 

 one foot succeeds the other as on the land ; 

 yet no one, as far as I am aware, has re- 

 marked that diving fowls, while under 

 water, impel and row themselves forward 

 by a motion of their wings, as well as by 

 the impulse of their feet : but such is really 

 the case, as any person may easily be con- 

 vinced, who will observe ducks when 

 hunted by dogs in a clear pond. Nor do 1 

 know that any one has given a reason why 

 the wings of diving fowls are placed so for- 

 ward : doubtless, not for the purpose of 

 promoting their speed in flying, since that 

 position certainly impedes it ; but probably 

 for the increase of their motion under water, 

 by the use of four oars instead of two ; yet 



VOL. ir. Q 



