OF NEW ENGLAND. 299 
like it, except the notes of one or two other birds. It is very 
striking, and, if heard from a near standpoint, rather startling. 
The male Night ‘‘Hawk” produces an equally extraordinary 
sound, which is heard chiefly during the season of courtship. 
Mounting to some height, he falls, head foremost, until near 
the ground, when he checks his downward course, and then 
the “‘ booming” is heard, a sound ‘“‘resembling that produced 
by blowing strongly into the bung hole of an empty hogshead.” 
Iam uncertain as to what causes this noise, having found it 
impossible to make any close observations. Wilson thought it 
produced by the mouth, Audubon, by the concussion caused 
by a change of position in the wings. The Night “ Hawks” 
all leave New England in September. 
§21. Cypselide. Swifts. (See § 20.) 
I. CHATURA 
(A) petacica. Chimney Swift. Chimney “Swallow.” 
(A common summer-resident throughout New England.) 
(a). About five inches long. Sooty-brown, glossed with 
green above; throat, much paler. Lores and wings, black. 
(0). The Chimney ‘Swallows ” soon after their arrival con- 
struct their curious nests, which are composed of. twigs firmly 
glued together by “‘a fluid secreted with the birds.” These 
nests are now placed in chimneys, almost universally through- 
out civilized parts of the country, but they have been found 
attached to boards, and the eggs were originally laid in hollow 
trees or stumps. The eggs of each set are four, average ‘70 X 
‘50 of an inch, and are pure white, unmarked. 
(c). The Chimney Swifts possess powers of flight which are 
probably unsurpassed by those of. any bird not belonging to 
this family. It-is almost certain that they often fly no less 
than a thousand miles in the course of twenty-four hours. 
When providing for their young, they are sometimes busy dur- 
ing a greater part of the day, and even continue their labors 
at night. Usually, they become active at a very early hour, 
sometimes even before dawn, and retire during the warmer 
part of the day, unless it bé cloudy, when they continue their 
