PHYSICAL OCEANOGRAPHY OP THE GULF OF MAINE 
551 
In 1920 the entire surface of the open gulf ranged between 3° and 4° by.'April 9 
to 20, including the eastern part of Georges Bank, the Eastern Channel, and Browns 
Bank; except for one station on Platts Bank (20094), where active vertical circulation 
caused a fractionally lower surface reading (2.78°), and off the Kennebec River 
(station 20096, 2.78°), where a very low surface salinity (29.94j]per mille, p. 1001) was 
Temperature, Centigrade 
Fig. 23. — Vertical distribution of temperature near the Isles of Shoals and Boone Island at suc- 
cessive dates of the year 1913, to show the progress of vernal warming. A, March 29, 1913; 
B, April 5 (both near Boone Island); C, April 13; D, April 16; E, April 29; F, May 8; G, 
May 14 (C and F are near the Isles of Shoals) 
unmistakable evidence of freshet water. In 1925 the surface of the coastal belt 
(Cape Ann to Mount Desert) was about 1 degree warmer at this season ( Halcyon 
records, p. 1012), grading (south to north) from 5.5° to 2.5°-3.8°, though with the 
water to the eastward of Cape Elizabeth still continuing coldest next the land. 11 
11 Close in to Boothbay 3.3°, but 4.4° near Seguin Island; 1.9° in Southwest Harbor, but 3 to 3.8° near Duck Island, off Mount 
Desert Island. 
