398 



OBSERVATIONS ON THE CURKENTS. 



to be extremely errutic. Vessels sometimes have an Easterly current along 

 the Florida Banks, and sometimes a Westerly. Sometimes they set towards 

 the banks, and at other times towards the middle of the strait. These 

 variable currents are to be expected West of the Elbow, but the width of 

 the variable zone is wider West of American Shoal than it is to the East. 

 Vessels passing across the channel between Rebecca Shoal and Tortugas 

 generally experience a Northerly or Southerly set.* 



Section 4. Already described, pages 396 — 397. 



Section 5. Between Jupiter Inlet and Memory Bock, the observations 

 showed a change in velocity accompanying the changes in the moon's 

 declination, as at section 4. At 3^ fathoms the temperature varied between 

 82= and 83-3° ; at 30 fathoms, between 62-2° and 70-3°; and at 85 fathoms, 

 between 60° and 63°. 



Section 6. From Gape Hatteras Shoals towards the S.E. — Here the 

 abnormal state of the weather rendered the observations unreliable, but 

 the same dependence on the moon's declination was observed. The 

 strength of the current, about 25 miles off Cape Hatteras and 5 miles out- 

 side the 100-fathoms line, was found on the surface, on two occasions 

 running to the Northward and Eastward, and on the third to the South- 

 Westward. At a depth of 200 fathoms the direction of the current was 

 found to change regularly, as though tidal, running for about 7 hours 

 S.E. by S. i S., and about 5 hours N.W. by N. ^ N. 



Observations, taken in this position in the years 1887, 1888, and 1890, 

 showed that at high declination the current ran strong to the N.E. ; at 

 mid-declination also to the N.E., but with much less volume; and at zero 

 declination the set was S.W. The five other anchorages extended to a 

 distance of 76 miles South-Eastward of Cape Hatteras. Eor about two- 

 thirds of this distance the currents were found to be mostly to the North- 

 ward and Eastward at all depths, while at the two outer stations only 

 the stratum below 65 fathoms was flowing steadily in that direction. 

 Evidence of the movement of the axis of the Stream to right and left were 

 also found in this section. 



The following Table gives the particulars of the observations : — 



The temperatures show how absolutely unreliable is the commonly 

 • Lieuteoaat Pillsbury, U.S.N. , United States Coast Survey Report, 1887, page 174. 



