312 LAND-BIRDS. 



tively I spmng from it, but when I looked up to it again, 

 what was my astonishment to see it standing as firm as ever. 

 The Swallows were now pouring out in a black continued 

 stream. I ran back to my post, and listened in amazement to 

 the noise within, which I could compare to nothing else than 

 the sound of a large wheel revolving under a powerful stream. 

 It was yet dusky, so that I could hardly see the hour on my 

 watch, but I estimated the time which they took in getting 

 out at more than thirty minutes. After their departure, no 

 noise was heard within, and they dispersed in every direction 

 with the quickness of thought." Audubon estimated their 

 number at nine thousand. The Chimney Swifts never rest ex- 

 cept in their roosting-places, to the walls of which they cling, 

 partly supported by their stiff tail ; and, so great is their mus- 

 cular vigor, that they never rest by perching. As has already 

 been mentioned, they often rest at noon, or seek refuge during 

 violent storms. On this account, they are very abundant 

 sometimes, and at other times are not to be seen. On enter- 

 ing a chimney, they fall boldly head-foremost in a very uncon- 

 cerned way. Their general flight is so varied that it is 

 difficult to describe. It consists of rapid sailing, combined 

 with quickly repeated strokes of the wings, and sudden turn- 

 ings in every direction. It has so much force that they break 

 off twigs for their nests without any diminution of speed. It 

 is almost unnecessary to say that they feed entirely upon 

 vdnged insects, the indigestible parts of which they are said to 

 disgorge in pellets. 



The Chimney Swifts may easily be distinguished from the 

 true Swallows by their peculiar and more rapid flight, their 

 long wings, and their apparent want of tail (as seen from a 

 distance). They sometimes skim over water, but more often 

 fly at a considerable or even a very great height. 



d. Their only note is a loud ddp, often repeated quickly 

 and vehemently, so as to bear a resemblance to the twittering 

 of the Swallows. Their young, who are bom blind, have a 

 much feebler voice. 



