438 Capt. Sabine on the Gulf-stream, &c. 
the Pheasant’s gangway, where the height of the eye was 15 
feet 3 inches above the sea, was 4! 56'*6, being an excess of 
1! 05"-6 above the usual computed and tabular depression. 
On repeating the observations at noon, it was found that a 
change of great magnitude had taken place intermediately; 
the horizon, viewed from the same height, making an angle 
on the second occasion, of only 3! 36!6 with the horizontal 
line passing through the eye. As the ship was in both in- 
stances very steady, and the horizons perfectly clear, the ob- 
servations were decided and certain; and the utmost error of 
which either might be suspected could not be more than 5". 
So great an alteration in the refractive quality of the atmo- 
sphere led to the immediate suspicion, that the temperature 
of the surface-water of the sea must also have greatly altered, 
and that we must have passed from the warm water of the 
stream into the colder surface of the general ocean. This 
suspicion was confirmed on trial, the temperature having fallen 
from 74° at 10 A.M. to 62°*4 at noon, being a difference of 
11°°6. As a measure of precaution.on such a sudden and 
great decrease, Captain Clavering immediately sounded, but 
had no bottom with 120 fathoms: the temperature at 110 fa- 
thoms, indicated by a register-thermometer attached to the 
line above the lead, was 51°°5. ‘The distance from the nearest 
banks noticed in the charts was sixty-five miles. 
The northern boundary of the stream, where we had thus 
quitted it, was between the latitudes of 36° 26! and 36° 38, 
and in the meridian of 72° 30! W. The surface-water on which 
we entered was in motion to the westward, at the average 
rate of sixteen miles, experienced in the following twenty-four 
hours, and generally to the west and south-west between the 
northern side of the stream, and the banks on the coast of 
Maryland. This motion may be more properly characterized 
as a drift-current, occasioned by the prevalence and strength 
of recent northerly gales, than as a counter-current. In ap- 
proaching the banks, the surface-water at 8 A.M. and at noon 
on the 7th of December was 59°5; at 3 P.M. it had fallen 
to 54°-2, on which we immediately sounded and found bottom 
in thirty-three fathoms: on the following morning in thirty 
fathoms, the surface was 53°°5, and at 8 A.M. on the 9th in 
twelve fathoms, but still with no land in sight (being twenty 
miles off the coast) 49°°5. In the afternoon of the same day, 
when about two miles distant from Sandy Hook, the water 
had finally lowered to 45°. Thus in a space of the ocean 
scarcely exceeding 200 miles in direct distance, we found the 
heat of the surface progressively diminished from 74° to 45°. 
On a general review of the influence of the currents which 
have 
