Prof. Bache’s Lecture on the Gulf Stream. 327 
fact that the proximity of the bottom of the sea, makes the 
result less permanent than in the other cases. Without this re- 
sult the mean probable error would be 1:1 mile. 
Taste 3.—Recapitulation, showing the value of the probabl of determination 
of the bands for each section and the average of the whole. 
FRTIEAS j!st_min.| Ist max (2d min.[2d max./3d_min 13d max 4th min. 
Probable errors, 
OGY S100K soo, . ccs ces “75 3°94 | 7-99 
ape May 82 | 1°25 | 254 | 1:5 4°03 | 4°87 
Cape Henry, 3 years........| "84 61] “65 |: 1:70: | 1:06 ‘94 | 3°42 
Cape Hatteras, 2 years,..... 6-77 | 6°36 | 9:31 | 569 | 6-23 
Cape Fear | 1°25 298 | 349 | 1337 
Charleston ‘ 1°25 | 167) 72} 209 | 2:40 82 
i “14 11:27 “41 
St. Augustine 52 5 44 44 55 
Cape Cafiaveral............ 951° 169. | 8 
| Mean probavie error........) 33 | 249 [249 | 4°00 | 401 | 371 | B45 
While these results are so permanent, the mean temperatures 
of the sections change considerably from year to year. e 
average temperature between the surface and 400 fathoms be- 
yond, or outside of the cold wall on the Sandy Hook section in 
1846, was as high as that on the Cape Henry section in 1848, 
and that on the Cape Fear section in 1853, within a degree of 
that of the St. Augustine section in 1853, while the Cape Hatte- 
Yas section in 1848 and in 1853, differed two degrees in mean 
temperatures, Again the temperatures from the surface to 30 
fathoms just below the axis of the stream in the Sandy Hook 
fection in August 1846 was either as high or higher than those 
on the Cafiaveral section in June 1853. In general the Cape 
May section in 1846 and the mean of the Cape Henry section of 
1846, 1847 and 1848 are warmer at the same depths than the 
Sections south of it were in 1848 and 1853. ; 
These results show that there are great changes in copes 
seas 
, 8 
the first range of hills, (see Diagram No. 9, Plate I,) is 1500 feet 
above the onlay to the aed of it, distant 12 miles; and the 
top of the second range 600 feet above the same valley, distant 
15 miles. The first slope is 125 feet, and the second is 40 feet, 
