152 GRAY LADY AND THE BIRDS 
can often identify a bird by the sharp outline of its shadow 
in flight. 
“This power of flight has been a subject of wonder for 
many thousand years; we think and we speculate, but no 
one has yet learned the secret in its fulness. 
“<The way of an eagle in the air! This is too wonderful 
for me!’ is an expression of this feeling of mystery, re- 
corded in the book of Proverbs. One thing seems quite 
certain, however — if man ever succeeds in conquering the 
air and sailing through it, it will not be by the power of any 
invention of his own, but because he has at least in 
some degree mastered the knowledge of the flight of the 
bird and adapted it to his own use. 
“The Chimney Swift, that you all know as the Chimney 
Swallow, is one of the most abundant and best-known birds 
of the eastern part of the United States. With troops of 
fledglings, catching their winged prey as they go, and lodg- 
ing by night in some tall chimney, the flocks drift slowly 
south, joining with other bands until, on the northern coast 
of the Gulf of Mexico, they become an innumerable host. 
Then they disappear. Did they drop into the water and 
hibernate in the mud, as was believed of old, their oblitera- 
tion could not be more complete. In the last week in 
March a joyful twittering far overhead announces their 
return to the Gulf coast, but the intervening five months 
is still the Swifts’ secret. 
“The mouse-coloured Bank Swallows, that we saw here 
in flocks a few weeks ago, are almost cosmopolitan, and 
enliven even the shores of the Arctic Ocean with their 
graceful aérial evolutions. Those that nest in Labrador 
allow a scant two months for building a nest and raising 
