PHYSICAL OCEANOGRAPHY OF THE GULP OE MAINE 
645 
A thermal distribution of the opposite sort, with a shelf of cold water projecting 
seaward, has been recorded repeatedly off this part of the slope at the end of the 
summer. 
NOVEMBER AND DECEMBER 
In 1912 the whole column of water off Gloucester had become vertically homo- 
geneous in temperature (about 9°) by November 20 (fig. 75), suggesting that autum- 
nal cooling had proceeded at about the same rate there as it did in 1915 and 1916 
(p. 638), while the whole column, 70 meters deep, had cooled to about 7.8° to 8.1° by 
December 4 (station 10048). It is interesting that the immediate surface was 0.1° 
to 0.3° warmer there than the deeper levels on both these dates, which may have 
reflected irregularities and setbacks in the progress of cooling from day to day, 
because both these stations were occupied after one or two warm days, though on 
Fig. 74. — Temperature profile crossing the continental shelf off Narragansett Bay, November 10 and 11, 1916 (stations 10405 
to 10508) 
both occasions the air temperature was a degree or so colder than the water at the 
times the readings were taken. 
The Fish Hawk again found the temperature virtually uniform vertically, from 
surface to bottom, all along the southern side of Massachusetts Bay on Decmber 
3, 1925, in depths of 25 to 40 meters; in fact, the surface reading did not differ by more 
than 0.2° from the intermediate or bottom reading at any of the 10 stations. The 
progress of autumnal cooling also was made evident by a mean temperature of about 
6.2° for this side of the bay. Although the preceding autumn had been unusually 
mild (suggesting that in most years the sea temperature is a degree or two lower 
by that date), one station off Plymouth Harbor (No. 10) and two at the head of the 
8951—28 42 
