32 Fish Cultural Association. 
table III. the average means of surface and bottom temper- 
atures. The observations were all made at 3 P. mM, and are 
continuous.from’ March: 1, 1876j;,t0) March 1, 13877. They ane 
reproduced at the end of this paper. There is also a table of 
the daily observations of temperatures at the same stations. 
A study of these tables, which for convenience were mapped 
out in curves on section-paper, afforded some interesting re- 
sults. 
II. MINIMUM LIMITS OF TEMPERATURE, AND THE DATES OF 
APPEARANCE AND DISAPPEARANCE OF SCHOOLS. 
The monthly mean of surface temperatures at Eastport is 
ereatest, in September, when jfjasso des. 6 m., while tiie 
highest daily observation is 51 deg. 5 m. The menhaden do 
not visit Eastport in midsummer. 
Let ‘us divide the monthly averages for May, at Portland, 
into.quarterly periods. The average for May 16th to 23@ is 
47 dee: 1 m:; for May 24th to, z1stiis 51 deg. The quarterly 
month averages for October are 53 deg. 8 m., 50 deg. 8 m., 47 
dex. 9 m., 48 deg..8 m:.. The schools of mendaden arrivesam 
Eastern Maine late in May and early in June, and depart 
usually before the middle of October. 
At Woods Holl, the quarter-month’s averages for May, as 
taken by the signal service observer, are 48 deg. 2 m., 49 deg. 
6 m., 53 deg. 1 m., and 57. deg..6 mi, approximately jonvthe 
monthly average, 52 deg. 3 m. These observations are made 
in the Great Harbor at the railroad wharf. Another series 
of observations, made by Captain Edwards for the Lighthouse 
Board, in the Little Harbor, are believed to indicate more 
nearly the temperature of the Vineyard Sound. These, how- 
ever, are only for bottom. The difference between the monthly 
mean of bottom temperatures for May, at the two stations, 
