PHYSICAL OCEAN OGKAPH Y OF THE GULF OF MAINE 
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tends to equalize the regional inequalities in the mid levels of the gulf (fig. 127) as 
the spring draws to a close. Thus, the extreme range of salinity in the gulf was 
little more than half as wide at 100 meters in May, whether of 1915 or of 1920 
(about 0.7 per mille, fig. 127), than in April or in March of 1920 (respectively, 1.1 
Fig. 127.— Salinity at a depth ot 100 meters, May 4 to 14, 1915 (plain figures), combined with May 4 to 17, 1920 (underlined 
figures). The encircled figure in the Bay of Fundy is for May 4, 1917, from Mavor (1923) 
and 1.3 per mille, figs. 94 and 116). At 175 meters (chosen as representative of the 
deep water of the gulf because this particular contour best outlines the trough of its 
basin) the extreme range of salinity was only 0.5 per mille (32.94 to 33.46 per mille) 
