PHYSICAL OCEANOGRAPHY OF THE GULF OF MAINE 
705 
the several rivers produce a cumulative freshening in the coastwise belt from mid- 
March on, which finally involves the entire periphery of the gulf to greater or less 
extent (p. 723). 
VERTICAL DISTRIBUTION 
Our data on salinity for the years 1913, 1920, and 1925 show that a very close 
approach to vertical uniformity obtains over the gulf down to a depth of 40 to 50 
meters and outside the 100-meter contour during the last week of February and the 
first part of March. Thus, in 1920 the widest range between the surface and the 
