BIRDS IN THE CALENDAR 
from which they had come a few moments 
earlier. 
Swifts fly to an immense height these July 
evenings, mounting to such an altitude as 
eventually to disappear out of sight alto- 
gether. This curious habit, which is but im- 
perfectly understood, has led to the belief that, 
instead of roosting in the nest or among the 
reeds like the swallows, the males, at any rate, 
spend the night flying about under the stars. 
This fantastic notion is not, however, likely 
to commend itself to those who pause to 
reflect on the incessant activity displayed by 
these birds the livelong day. So rarely indeed 
do they alight that country folk gravely deny 
them the possession of feet, and it is in the 
last degree improbable that a bird of such 
feverish alertness could dispense with its 
night's rest. No one who has watched swifts, 
swallows and martins on the wing can fail to 
be struck by the extraordinary judgment 
with which these untiring birds seem to shave 
the arches of bridges, gateposts, and other 
obstacles in the way of their flight by so 
narrow a margin as continually to give the 
impression of catastrophe imminent and 
84 
