136 NATURAL HISTORY 



such hardy birds as are known to defy all the severity of Eng- 

 land, and even of Sweden and all north Europe, should want 

 to migrate from the south of Europe, and be dissatisfied with 

 the winters of Andalusia. 



It does not appear to me that much stress may be laid on 

 the difficulty and hazard that birds must run in their migra- 

 tions, by reason of vast oceans, cross winds, &c. ; because, if 

 we reflect, a bird may travel from England to the equator 

 without launching out and exposing itself to boundless seas, 

 and that by crossing the water at Dover, and again at Gibral- 

 tar. And I with the more confidence advance this obvious 

 remark, because my brother has always found that some of 

 his birds, and particularly the swallow kind, are very sparing 

 of their pains in crossing the Mediterranean : for when arrived 

 at Gibraltar, they do not 



" Rang'd in figure wedge their way, 



" And set forth 



tl Their airy caravan high over seas 

 * t( Flying, and OTer lands with mutual wing 



" Easing their flight : " MILTON. 



but scout and hurry along in little detached parties of six or 

 seven in a company ; and sweeping low, just over the surface 

 of the land and water, direct their course to the opposite con- 

 tinent at the narrowest passage they can find. They usually 

 slope across the bay to the south-west, and so pass over oppo- 

 site to Tangier, which, it seems, is the narrowest space. 



In former letters we have considered whether it was pro- 

 bable that woodcocks in moon-shiny nights cross the German 

 ocean from Scandinavia. As a proof that birds of less speed 

 may pass that sea, considerable as it is, I shall relate the fol- 

 lowing incident, which, though mentioned to have happened 

 so many years ago, was strictly matter of fact: As some 

 people were shooting in the parish of Trotton, in the county 

 of Sussex, they killed a duck in that dreadful winter 1708-9, 

 with a silver collar about it's neck, 2 on which were engraven 

 the arms of the king of Denmark. This anecdote the rector 



z I have read a like anecdote of a swan. 



