CHAP, viii.] 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 325 fathoms the equa- 

 torial current above and the polar counter- current 

 beneath have room to pass one another, the current 

 from the north being evidently tempered consider- 

 ably 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. 

 Prom 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 temperatures 

 of 8-8, 5*7, 4-5, and 2 '5 C. This space is therefore 

 occupied by cold water, and observation has suffi- 



c c 2 



