48 



bulletin: museum of comparative zoology. 



rise in the surface temperature readings (55°-57°) although the air 

 rose from 58°-63°, and the temperature readings taken on various 

 days show that diurnal warming is very much less in this region than 

 it is in the warmer off-shore waters. So far as our observations go, 

 they suggest that in the cold coast water northeast of Mt. Desert 

 diurnal warming is not usually observal)le; thus the diagram for 

 August 6th (fig. 7) shows a slight fall (56°-57°) from 6 a. m. until 



Rth 

 



5 



10 

 15 

 20 

 25 

 30 



55 

 40 

 45 

 50 

 55 

 60 

 65 

 70 

 75 

 SO 

 85 

 90 

 95 

 100 

 105 



41° 42 45 44 45° 46 4? 48 49 50" 51 52 55 54 55° 56 S7 58 59 60° 61 62 63 64 65° 



Fig. 8. — Temperatui-e sections at Stations 2, 23, 24, 25, 29. 



noon; although between 9 A. M. and 4 p. m. the air temperature rose 

 from 56° to 68°. 



To explain the distribution of the surface temperatures of the Gulf 

 of Maine, just outlined, requires a knowledge of the temperatures in 

 the underlying water layers at the same season, which is afforded 

 for the first time by the Cruise of 1912. 



Temperature sections. — The section made off the mouth of Massa- 



