Chaetura nelagica . 
Concord, Mass. Strange actions. 
1893. A little before sunset this evening I saw a flocfc. of fif- 
july 17. teen Chimney Swifts flying in a large circle over the Derby's 
house acting precisely as if they were preparing to descend 
into one of the chimneys to roost. Unfortunately I was unable 
to watch them for more than a minute or less during which time 
they hept flying around and around. When P came out of our 
house a little later they had all disappeared. 
At frequent intervals last night between S and 11 P.M. 
I heard Swifts "rumbling" in our chimney. What can they have 
been doing? The rumbling frequently occurred repeatedly at 
short intervals - certainly not over half a minute, thus lead- 
ing me to conclude that they were not passing out of and into 
the chimney but merely hovering-or something of the hind-wi th- 
in it. Can they have been teaching their young to fly? The 
night was darh and clear. I also heard this rumbling at va- 
rious times through the day. 
