O 
the lower strata of clouds. 7 Por at least fifteen minutes I 
kept my glass steadily on him. During this time he flew, 
for the most part, in great circles perhaps three hundred 
yards in diameter and over the broadest part of the meadow 
but towards the close of his flight he repeatedly doubled 
back after describing not more than half or even one third 
of a full circle. The full circles were made from left to 
right, that is from east to south to west to north to east 
again and so on, over and over the same course. When he 
turned back he retraced his course and then tunned, again, 
and forth from east to south and west and back 
swinging back^to south and east, etc. The drumming sound 
came to my ears every eight or ten seconds and invariably 
just as the bird dipped downward; it then swept up again 
to his former level. During some of this downward curve 
he descended rather steeply for a distance of 40 or 50 feet, 
during others the drop was not more than 15 or 20 feet 
and at a very gentle incline. Sometimes the undulations 
followed one another so glosely and regularly that the 
bird’s course was not unlike that of a galloping Goldfinch 
or Woodpecker but as a rule he would fly for several rods 
on a level plane between one dip and the next. 
While moving thus he sometimes glided on set wings 
for a few rods. At all other times, whether flying level 
or -swinging first downward and then upward, he moved his 
wings incessantly. I could detect no difference in their 
motion when the winnowing sound was produced from that when 
