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Gulf (Station 10090, Fig. 23), shows that below forty fathoms the 

 trough was filled with water colder than 42° : and this was also true 

 as far off shore as the ridge which is crowned by Cashes Ledge. But, 

 as already pointed out, 42° water did not extend to Station 10090. 

 And the fact that at the latter the lowest temperature (43.5°) was at 

 fifty fathoms, not on the bottom, suggests a slight shelf -like projection 

 of the 42° water. It is safe to say that Jeffrey's Ledge rises above the 

 coldest water locally, for in places it is covered by less than thirty 

 fathoms. And tidal currents may be expected to cause temperature 



Fig. 25. — Tempera tiire profile lengthwise of the trough between Jeffrey's 

 Ledge and the mainland (Stations 10104, 10102). 



disturbances over it. Between the thirty fathom level and the surface 

 the temperature was nearly uniform, depth for depth, from one end of 

 the profile to the other. 



A profile (Fig. 24) parallel to the last, but some twenty-five miles 

 further north, from Cape Elizabeth (Station 10103) to Jeffrey's Bank 

 (Station 10091) is warmer at all depths, except the immediate surface, 

 than the preceding one, with water colder than 43° limited to depths 

 greater than seventy fathoms, and a minimum of 42.6° at eighty fath- 

 oms. Between five and fifteen fathoms the difference between the 



