104 
BULLETIN ON WISCONSIN NATURAL HISTORY SOCIETY. VOL. 2. NO. 2. 
DATA FROM MADISON. 
Madison, Wis., Apr. i8, 1900. 
Period, 12:15 — 12:30. 
In. Out. Speed. Size. Remarks. 
3.5 8.9 swift Flew^ like a shot. 
3.8 8.2 
3- 8.9 3* 
57 7-9 
4.2 7.9 Out of focus. 
Pause of five minutes of no birds. 
3.8 8.3 slow I — , 
4.9 7.2 fast 3+ Out of focus. 
5.8 7.1 Flight of goldfinch. 
5- 2.1 
4.2 8.2 
5- 1-2 
7.9 4.2 Sailed out of the field like a 
meadow lark. 
4. 8.6 swift I 
3.9 8.5 slow I Flitting carelessly. He paused a 
second as if to turn in his 
course. 
Total number of birds, 14. 
cartographic representations. 
The cartographic representations into which the majority, if 
not all, of the data for this work will be placed are of two kinds. 
The first (See Plate I.) represents a graphic view illustrating 
the number of birds seen in periods of fifteen minutes each. Upon 
the assumption that the majority of nocturnal migrants comfnence 
their journey at about the hour of sundown, the eight sets of ob- 
servations upon the accompanying plate were reduced to the same 
time after that hour. The data from which these graphs were 
drawn were collected from six different localities. It w^as hoped 
that they could all be obtained upon the same day, but this was 
nigh impossible. 
It is remarkable to note the similarity in the rise and fall of 
some of these graphs, especially in the cases of Ann Arbor and 
Detroit. From the Madison and Beloit lines it would seem that 
