CHAP. VI11.] THE GULF-STREAM. 387 
a little to the north of the strait, the rate is from 
three to five miles an hour. The depth is only 325 
fathoms, and the bottom, which in the Strait of 
Florida was a simple slope and counter-slope, is 
now corrugated. The surface temperature is about 
26°°5 C., while the bottom temperature is 4°5; so 
that in the moderate depth of 3825 fathoms the 
equatorial current above and the polar counter- 
current beneath have room to pass one another, the 
current from the north being evidently tempered - 
considerably by mixture. North of Mosquito inlet 
the stream trends to the eastward of north, and off 
St. Augustine it has a decided set to the eastward. 
Between St. Augustine and Cape Hatteras the set 
of the stream and the trend of the coast differ but 
little, making 5° of easting in 5° of northing. At 
Hatteras it curves to the northward, and then runs 
easterly. In the latitude of Cape Charles it turns 
quite to the eastward, having a velocity of from a 
mile to a mile and a half in the hour. 
A brief account of one of the sections will best 
explain the general phenomena of the stream off the 
coast of America. I will take the section following 
a line at right angles to the coast off Sandy Hook. 
From the shore out, for a distance of about 250 
miles, the surface temperature gradually rises from 
21° to 24° C.; at 10 fathoms it rises from 19° to 22° C.; 
and at 20 fathoms it maintains, with a few irregu- 
larities, a temperature of 19° C. throughout the whole 
space; while at 100, 200, 300, and 400 fathoms it 
maintains in like manner the respective tempera- 
tures of 8°8, 5°7, 4°°5, and 2°5 C. This space is 
therefore occupied by cold water, and observation 
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