EXPLORATIONS, WESTERN ATLANTIC, STEAMER BACHE, 1914. 45 
Straits, and from the southern part of the Gulf along the shore of 
Cuba, into the southern side of the Straits, as into a funnel. Up- 
welling of bottom water against the coast of Florida grows more 
pronounced as this tremendous mass of water forces its way farther 
and farther into the ever narrowing and shoaling channel. 
The unity of temperature between the western end of the Straits 
in 1914, and the Gulf of Mexico as a whole in 1878, is further 
interesting because it shows that the difference of temperature in 
the eastern end of the Straits in the two years can not have been due 
to any intrinsic difference in the reservoir from which the water 
came, but must have been the result of a greater flow of cold bottom 
water in 1878 than in 1914. For all that is yet known, this may be 
a seasonal, not a vicarious or periodic, variation. 
The banking up of cold water against Florida is usually classed as 
the effect of the rotation of the earth, forcing the water out of its 
course toward the right against Cuba and the Bahama Bank, with 
consequent upwelling from the deep layers on the left-hand side of 
the channel, according to Ekman’s (1905) theory (Kriimmel, 1911, 
p- 459). The discovery that the cold comparatively fresh water 
next to Florida is largely true abyssal water from the Gulf of Mexico 
supports this view. The density profile, Cape Florida to Gun Cay 
(fig. 46), shows how much lighter, as well as fresher and colder, the 
water was on the left than on the right side of the current,¢ an 
illustration of how effective the deflective force of the earth’s rotation 
is in establishing the distribution of temperature and salinity in a 
current as rapid as the Florida stream. 
THE COAST WATER OFF CHESAPEAKE BAY. 
Exploration of the coast water was only incidental to the main 
work of the Bache, but stations 10157-10160 off the mouth of Chesa- 
peake Bay, and a series of observations taken on the continental 
shelf in that same general region in January, 1916 (p. 60), by the 
Bureau of Fisheries steamer Roosevelt, may be discussed here because 
of their bearing on the general problem of the origin of the coast 
water and its relationship to the Gulf Stream (Bigelow, 1915, p. 250). 
In January, 1913 (Bache stations), the temperature from the coast 
out to the 35-meter contour was between 6° and 7°, practically 
uniform from surface to bottom. The salinity, however, showed 
considerable vertical range even in the small depth of 18 meters 
(30.01°/,. on the surface, 33.57°/,, on the bottom, station 10157), 
and at the 35-meter contour the freshest water lay at 20 meters 
(station 10159), with salter water both above and below (fig. 48), 
¢ For discussion of the general problem of the effect of the earth’s rotation on ocean currents, see Ekman 
(1905) and McEwen (1912). Foran excellent summary of the results on actual ocean currents, see Murray 
and Hjort (1912), p. 276. 
