PHYSICAL, OCEANOGRAPHY OV THE GULF OF MAINE 



633 



However, surface readings taken by the Halcyon to the eastward of Penobscot 

 Bay early that August proved about 2° lower than the expectation. Bathers, too, 

 reported the water unusually cold along the beaches throughout that summer, after 

 offshore winds. This was corroborated by serial observations off Gloucester, which 

 proved the whole column of water below the 30-meter level 1° to 3° colder in Au- 

 gust, 1923, than it was three weeks earlier in the season even in the cold summer of 

 1916, although the difference in date would suggest just the reverse. Depths greater 

 than 40 meters were also 1° to 3° colder off Cape Elizabeth in 1923 than in any pre- 

 vious August of record (fig. 68), notwithstanding the warm surface just mentioned. 

 This statement would probably hold good for the inner part of the basin in general, 

 also, as well as along the eastern coast of Maine, the relationship being similar near 

 Mount Desert Island and off Mount Desert Kock (table, p. 635). 



It is probable that a summer colder than those of 1916 or 1923 comes very 

 seldom in the Gulf of Maine, because winters so severe, and with so heavy a snow- 

 fall, are exceptional (p. 697). 



The possibility that cycUc changes of temperature may take place in the gulf, 

 with warmer or colder periods enduring over many years, must not be ignored; but 

 nothing of this sort has been recorded there within historic times. 



The following comparative tables for representative localities will show in detail 

 the annual differences in temperature summarized in the preceding pages. ^^ 



Annual differences in temperature 

 MOUTH OF MASSACHUSETTS BAY 



WESTERN BASIN 



" As the readings were not taken at the same levels at all the stations, or at as many levels as it is desirable to show here, it 

 has been necessary in many cases to derive most of the values by interpolation. The temperatures are approximate, therefore, 

 and are given only to the nearest tenth of a degree. Centigrade. 



