r 291 ] 



the fwallow is commonly pitched upon as the mod 

 notorious inftance of fuch a regular paflage. 



This feems to arife firft from its being feen in 

 fuch numbers during the fummer, from its appear- 

 ing almoft always on the wing, and from its feeding 

 in that pofitionj from which two latter circumftances 

 it is fuppofed to be the bed adapted for fuch diftant 

 migrations. 



And firft, let us confider, from the few facts or 

 reafons we have to argue from, what length of flight 

 either a fwallow or any other bird is probably equal 

 to. 



A fwallow, it is true, feems to be always on the 

 wing j but I have frequently attended, as much as I 

 could, on a particular one ; and it hath appeared to 

 me, that the bird commonly returned to its neft in 

 eight or ten minutes : as for extent of flight, I believe 

 I may venture to fay, that thefe birds are feldom a 

 quarter of mile from their mate or young ones ; they 

 feed whilft on the wing, and are perpetually turning 

 fhort round to catch the infects, who endeavour to 

 elude them as a hare does a greyhound. 



It therefore feems to me, that fwallows are by no 

 means equal to long flights, from their practice during 

 their fummer refidence with us. 



I have long attended to the flight of birds ; and it 

 hath always appeared to me, that they are never on 

 the wing for amufement (as we walk or ride), hut 

 merely in fearch of food. 



The only bird which I have ever obferved to fly 

 without any particular point of direction, is the 

 rook : thefe birds will, when the wind is high, 



Pp 2 ■" Ride 



