THE WILD SWAN. 123 



apt to occasion partial interruptions of that essential 

 operation, which the air contained in the cavity of the 

 bone may enable the bird to bear. 



The quiet regions of the north are the favourite 

 abodes of the "swans ; and they are said to protract 

 their residence there as long as they can ; and, when the 

 lakes begin to freeze, to assemble in flocks and break 

 the ice with their wings, or prevent it from forming by 

 flapping and dashing in the water. Their chosen 

 abodes are to the north of Iceland, for, though far 

 more of them breed there than in the northern parts of 

 Scotland, the Icelanders regard them as birds of pas- 

 sage. Iceland, indeed, seems a place of rendezvous in 

 which numerous flocks, each containing a hundred or 

 more, assemble in their passage northward, in the spring, 

 and again in their passage southward, in the autumn. 

 Their flight is elevated, and the line or wedge in which 

 they are arranged, is so close and serried that the bill of 

 the one is nearly in contact with the tail of that before. 

 Though birds of powerful wing, their progress depends 

 a good deal upon the wind. When they go before a 

 brisk gale, they fly at the rate of one hundred miles an 

 hour ; but, when the wind is against them, their flight 

 is comparatively slow ; and a side wind, which blows 

 them from their course, is understood to hinder them 

 more than one which is right a-head. When on the 

 wing, swans are very difficult to shoot, as, on account 

 of the height at which they fly, and the rapidity of their 

 motion, the aim, even at the time of pulling the trigger, 

 must be taken ten or twelve feet before the bird, 

 otherwise it will have passed before the shot reaches 

 its height. In fact, they are shot with difficulty at any 

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