41(j 



OBSEEVATIONS ON THE CUEEENTS. 



Temperatures {Fahrenheit) observed in crossing and recrossing the GnilJ 

 Stream, by H.M.S. Challenger, April and May, 1873. 



Taking a general view of the temperatures between St. Thomas and 

 Halifax (each of which places lies on about the same meridian as Bermuda), 

 it is to be noticed that the surface temperature gradually increased to the 

 Northward and Southward of Bermuda ; to the Northward by reason of 

 the warm water of the Gulf Stream, till a maximum of 72° is found in 

 36^° N. ; and to the Southward by reason of the lower latitude and the 

 Equatorial Currents, until the surface temperature is found to be 79° at 

 St. Thomas. Below the surface, however, a state of affairs was found to 

 exist as follows : — At 100 fathoms below the surface — at Bermuda, a tem- 

 perature of 66° was found ; at St. Thomas, 70° ; in 36^° N., 66^°. At 200 

 fathoms— at Bermuda, 63^°; at St. Thomas, 63°; in 36^° N. to 40° N., 

 63°. At 500 fathoms — at Bermuda, 46^°, which temperature continued 

 the same to 40° N. ; but at the same depth, in proceeding to the South- 

 ward, the temperature gradually decreased till at St. Thomas it was only 

 43|°, or 3° colder than that found 21 degrees of latitude to the Northwa^-d. 

 This, although a small difference, must be due to the effects of the Gulf 

 Stream. Proceeding to the Eastward from Bermuda, towards the Azores 

 the temperature of the surface water decreased gradually, and that at .^00 

 fathoms remained pretty constant at 46-|-° for 700 miles. 



Commander Bartlett states that the temperatures taken by the Blake, 

 between Montauk Point and Bermuda, did not indicate, in August, 1882, 

 any bifurcation of the Stream into warm and cold bands. The surface 

 temperature increased gradually from 68° F. near the 100-fathoms line to 

 76°, and remained at 74° and 75° until the Stream was entered, when it 

 nj*o as high as 80° and 81°, and continued at nearly the same temperature 

 &U cb« way to Bermuda. The bottom temperature in 260 fathoms was 



