624 CYPSELUS MURARIUS. 



Now, the inferences from these facts are : that close, dull, 

 electrical weather, instead of exciting, depresses Swifts and 

 other birds, and renders them dull and silent ; that from the 

 flight of these birds, considered as to its elevation, no indica- 

 tion of the coming weather can be formed ; for on the fine hazy 

 evening, the suffocating, dull, electrical evening, the moder- 

 ately cool dull evening, and the rainy and refreshing evening, 

 they flew much about the same height. 



Until the 12th day of July, the weather continued clear 

 and excessively warm, and the Swifts flew in their usual man- 

 ner, at a low or moderate elevation, occasionally screaming 

 and mingling with each other. On that day, the wind having 

 become easterly, and the upper current moving in an opposite 

 direction, the sky became overcast, and in the evening some 

 showers fell, and a little thunder was heard. Yet the Swifts 

 flew in the same manner, although they were more silent than 

 usual. On the 13th it rained a good deal, yet they flew about, 

 screaming, in the midst of the showers ; but at four o'clock a 

 tremendous flood poured down and seemed to send all the birds 

 to places of shelter ; although immediately after, the Swallows 

 were seen. In the evening the Swifts flew as usual, generally 

 low, and occasionally screaming. On the 14th, the clouds 

 mustered about nine in battle array, and in about half an hour 

 commenced a thunder-storm which lasted until near twelve. 

 The rain fell incessantly, and at times in torrents, yet the 

 Swallows and Swifts kept flying about at the usual height or 

 rather higher, all the time, and so continued all day, without 

 any alteration in their manner. The rain continued at inter- 

 vals until night. All nature seemed refreshed ; the birds were 

 cheerful, and chirped more than usual, and I could perceive a 

 decided alteration in the men and women in the streets, who 

 instead of walking languidly as in hot dry weather, moved 

 with uncommon vivacity. So is it always during or immedi- 

 ately after rain, which is one of our greatest blessings at all 

 seasons, however much it may be blamed by foolish and in- 

 considerate people. 



, By the middle of August the Swifts are all gone, and to 

 him who attends to the habits of birds their absence produces 



