BIGELOW: EXPLORATIONS OF THE COAST WATERS. 



215 



In early May the temperature of the upper 15 meters or so was 

 already considerably higher than the winter minimum, much more so 

 in the western than in the eastern side of the Gulf, with a west to east 

 range on the surface (Fig. 53) from about 7° off Cape Ann to 3° on 

 German Bank. But in the mid-depths, at from 40 to 100 meters, the 

 coastal zone on the western side of the Gulf (Stations 10266, 10278), 

 was practically as cold (3°-4°) as German Bank and its western slope 

 (Fig. 54, 69), with warmer water in the intervening basin. The profile 

 (Fig. 69) is also interesting both as showing that the minimum temper- 



FiG. 56. — Temperature at 40 meters, June, 1915. 



ature for the central part of the Gulf was at about 100 meters, with 

 warmer water below, the thick layer of surface water warmer than 5° 

 over the Western Basin foreshadowing the high temperature which 

 characterizes that region in summer (p. 166), and as illustrating the 

 mass of cool surface water (4°-) in the eastern side of the Gulf which 

 finds its counterpart in low salinity (p. 223). With the advance of 

 the season the temperature of the surface layers continues to rise 

 faster in the western than in the eastern half of the Gulf, until by the 



