42 EXPLOKATTONS, WESTERN ATLANTIC, STEAMER BACHE, 1914. 



Agassiz (1888). The explorations by the United States Coast and 

 Geodetic Survey (Pillsbury, 1886, 1887, 1889) show that an imper- 

 fect method of observation had much to do with this result, meas- 

 urements with current meters at numerous stations demonstrating 

 that as a whole the current was strongest on the surface, decreasing 

 progressively with depth; and although it was still perceptible and 

 sometimes as strong as the surface current at 130 fathoms (237 

 meters), the lowest level at which readings were regularly taken, 

 the rate of decrease suggested comparative stagnation below about 

 250 fathoms (457 meters) . Although the Bache made no actual current 

 measurements, yet the difficulties encountered in using the oceano- 

 graphic apparatus showed that the current ran very much more 

 rapidly on the surface than in the middepths. 



Fig. 45.— Temi)eratiire sections off Habana, March, 1914. Bache (station 10199), 

 Antonio, May 22, 1878 (.Blake) ( ). 



and off Cape San 



But densities show that the water can not be stagnant in the 

 bottom of the channel, for water of 1 .03 is higher at its exit than 

 at its entrance, a state of instabihty which can only be main- 

 tained in one of two ways — i. e., either by a movement of abyssal 

 water from the Gulf of Mexico up the slope of the channel, or by a 

 cold bottom current from the Atlantic. The last supposition has 

 nothing except the persistent and still popular tendency to credit 

 all cool water along our coasts to the Labrador current ^ to support 

 it. On the contrary, as Agassiz long ago pointed out, the fadt that 

 the general teinperature of the Straits is the same as that of the 

 mass of water west of it, but considerably lower than that of the 

 Atlantic water into which it debouches, in itself seems to forbid the 

 possibility that the cold water in the Straits of Florida comes from 

 the north. A study of the Blake temperature sections on successive 



o Sumner (1913); Soley (1911). 



