210 NOTES ON NEW ENGLAND BIRDS 



June 3, 1858. Lying up there at this season, when 

 the nighthawk is most musical, reminded me of what I 

 had noticed before, that this bird is crepuscular in its 

 habits. It was heard by night only up to nine or ten 

 o'clock and again just before dawn, and marked those 

 periods or seasons like a clock. Its note very conven- 

 iently indicated the time of night. It was sufficient to 

 hear the nighthawk booming when you awoke to know 

 how the night got on, though you had no other evidence 

 of the hour. 



July 17, 1860. The nighthawk's ripping sound, heard 

 overhead these days, reminds us that the sky is, as it 

 were, a roof, and that our world is limited on that side, 

 it being reflected as from a roof back to earth. It does 

 not suggest an infinite depth in the sky, but a nearness 

 to the earth, as of a low roof echoing back its sounds. 



Aug. 9, 1800. But, above all, this* was an excellent 

 place to observe the habits of the nighthawks. They 

 were heard and seen regularly at sunset, — one night it 

 was at 7.10, or exactly at sunset, — coming upward from 

 the lower and more shaded portion of the rocky surface 

 below our camp, with their sparh sparky soon answered 

 by a companion, for they seemed always to hunt in pairs, 

 — yet both would dive and boom and, according to 

 Wilson, only the male utters this sound. They pursued 

 their game thus a short distance apart and some sixty 

 or one hundred feet above the gray rocky surface, in 

 the twilight, and the constant spark sp)ark seemed to be 

 a sort of call-note to advertise each other of their neigh- 

 borhood. Suddenly one would hover and flutter more 



^ [Mt. Monadnock again.] 



