BIGELOW: COAST WATER EXPLORATION OF 1913. 257 
students and laity alike. It is true that the surface temperature falls 
very low in winter near the coast, cooling to about 39° over the zone 
between Marthas Vineyard and New York (Sumner, Osburn, and Cole, 
1913), with even lower winter temperatures in enclosed sounds and 
bays, for instance, 31.2° in February at the Woods Hole Station of the 
Bureau of Fisheries (Sumner, Osburn, and Cole, 1913, p. 48, average 
of three years). But this only happens where surrounding islands give 
the waters more or less the hydrographic character of lakes. And the 
zone over which the surface temperature falls below 40° in the coldest 
month (February) is nowhere more than thirty-five miles broad, south 
and west of Cape Cod, with a steady rise of surface temperature from 
the land.seaward. The cold water is also correspondingly shallow, 
bottom water colder than 40° being probably limited seaward by the 
fifty fathom contour in this region. In short, the water is coldest 
just where it might be expected to be influenced most by the icy north- 
west winds of winter. And so far as the scanty winter data show, 
this is true all along the coast as far as Chesapeake Bay. 
Air temperatures 10°-15° F. below freezing, such as are common 
in winter in southern New England, are surely enough to account for 
considerable cooling of the adjacent water. How closely the winter 
temperature of our coast water depends on the influence of the land 
is illustrated by the fact that Gloucester Harbor, which opens freely 
to the deeps off Massachusetts Bay, is 1°-2° warmer than the more 
enclosed waters of Woods Hole in winter, although a degree of latitude 
further north, and bordering a colder ocean area. (Gloucester Harbor 
in turn, is colder than Massachusetts Bay; for example, its surface 
temperature fell to about 34° during the winter of 1912-1913, the 
lowest reading a few miles outside being 37°. And Boothbay Harbor, 
seventy-five miles north of Gloucester, which bears something the 
same relation to the land as Woods Hole, being shut in by numerous 
islands, is colder than either Gloucester or Woods Hole (about 30° F. 
in February), reflecting the very cold winter climate of northern New 
England; and likewise colder than the water off shore. (The mean 
| temperature for December and March, at Mt. Desert Rock, is about 
38° and 36°; at Boothbay, 37° and 32.2°). These comparisons of 
| surface readings apply just as well to the whole of the upper 30-40 
| fathoms, for our winter work (1914b) has shown that the tempera- 
_ ture of the Gulf of Maine is practically uniform, vertically, to at least 
| that depth from December to March. The fact that in summer the 
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| water is coldest at the bottom of such partially enclosed sinks as the 
trough between Jefirey’s Ledge and the mainland, 7. e¢., just where 
