First heavy nocturnal Migration. 



Concord, Llass. 



1893. Stepping out of doors at about 9 P.M. I at once heard 



Aug. 8. V/arblers lisping and chirping in various directions overhead. 

 The sky seemed to be alive with them and the sound of their 

 voices was nearly incessant up to 11 P.M. V7hen I went to bed. 

 This is the first really heavy nocturnal flight that has 

 passed over Concord this suimer. I do not remember to have 

 ever heard more birds within the same length of time. 



Aug. 9. The mysteries of migration are innumerable and some of 



them well-nigh inscrutable. To-night , with precisely the same 

 conditions as last night as regards weather and temperature 

 did not bring one siiigle bird so far as my evee aad ears could 

 detect. 



