Cambridge, Mass.
1907
April 2
(No 2)
  These facts make it evident that the flight
was not local but more or less general.
Probably it invaded and settled down in the
greater part of eastern Massachusetts. I believe 
that it came not from the South but from
the North and that it was composed of
birds that had passed our latitude during
the fine weather of last week. In other words
the birds were forced by a sudden change from 
clear and mild to snowy and colder weather
to retrace their steps. In some respects the
movement appears to have been similar to
the one which Mr. Wayne observed at
Charleston, South Carolina, several years ago
and repeated in the Auk. His birds, however,
migrated Southward in February and by 
day. All the Sparrows found in our garden
on the morning of April 2 must have arrived
there during the preceding night for there was
not one about the place on the 1st. Of this
I am assured by Mr. Deane. I was at
Concord on the 1st when I found only
a few Fox Sparrows and Juncos in the
region about Ball's Hill - not more, indeed,
than one would expect to see there almost
any day at this time of year.