572 
BULLETIN OF THE BUREAU OF FISHERIES 
promontory. The Fish Hawk, also, made a general survey of Massachusetts and 
Cape Cod Bays on June 16 and 17 in 1925. A few temperatures were taken by the 
_ Halcyon near Glouces- 
Temperature, Centigrade ^ on the 6th in 1924> 
in the Nantucket 
Shoals region during 
the first half of the 
month in 1925, and 
Dawson (1922) also 
took a considerable 
number of June read- 
ings along Nova Scotia 
in 1904 and 1907. 
RATE OF WARMING 
Progressive warm- 
ing is to be expected, 
of course, over the 
whole area throughout 
the month of June. 
Thus, the surface had 
warmed to 10.56° at 
a station 8 miles off 
Gloucester on the 6 th 
in 1924, and to 12.1°- 
15.2° over Massachu- 
setts Bay generally 
by the 16th or 17th in 
1925, an average 
change of about 5 
degrees since May 20 
to 22. At the 20- 
meter level these mid- 
June temperatures 
averaged about 7.8° 
(18 stations), contrast- 
ing with about 5.5° 
in May (p. 564), with 
the readings for June 
6, 1924 (6.2°) inter- 
mediate, as the date 
would suggest. These 
Massachusetts Bay 
stations for 1925 also 
illustrate interesting regional differences in the rate at which heat penetrates down- 
ward into the water during the late spring and early days of summer, depending 
Fig. 38.— Vertical distribution of temperature on the southwestern slope of Georges Bank to 
show cooling of the bottom water, but warming at the surface, from February to May, 
1920. A and B, February 22 (stations 20046 and 20045); AA and BB, May 17 (stations 
20128 and 20129) 
