CHAP. V.] THE GULF-STREAM. 345 
125 fathomsi. oso sees secs 13°°8 C. S00Mathomsza..j- esa) Ole 2: 
150 es Sa tfisteveraistor ees Ot ae 350 “ Piss err epte e ugis Ue 
175 DSCREN seer ea 12 6 400 o fh ator ayo art ore 
200 = Bb ccs eue Gea el 500 se BER a Sctercs IBY END 
225 6 eC rr oeeicie rset 0 Jee | 550 eae ee 5° 3 
250 Cee .25.c6 Gc eae Or? 600 Sto Sa catdens wevelsks te ae eoO 
The result shows that the Gulf-stream, in its restricted sense— 
that is to say, the mass of warm water which issues from the 
Strait of Florida and courses in a north-easterly direction at 
a little distance from the coast of North America—was, early 
in May, 1873, at the point where we crossed it and made our 
observations, about 60 miles in width, 100 fathoms deep, and 
its rate three knots an hour. I make the statement thus guard- 
edly, because descriptions of the stream are somewhat discrep- 
ant, and I have no doubt that it varies at a considerable extent 
both in rapidity and volume, influenced by the season and by 
different meteorological conditions. It seems evident, as has 
been already observed by the American Coast Surveyors, that 
the Labrador return current, which is banked up against the 
American coast within the Gulf-stream, passes also under it to 
a certain depth. Comparing Fig. 91,a diagram constructed by 
combining the series of temperatures at Stations X LI. and XLII. 
just before entering the Gulf-stream, with Fig. 92, constructed 
from the soundings near the centre of the stream, we find that 
at a depth of 100 fathoms the temperature is nearly the same 
in both—in the former 18°:1 C., and in the latter 18°°3 C. At 
200 fathoms, the temperatures are respectively 17°:4 C. and 
11°-1 C.,and the difference between them 6°°3 C.; at 300 fath- 
oms, the temperatures are 17° C. and 8°-2 C., and the difference 
8°°8 C.; at 400, they are 13°°7 C. and 6°°6 C., with a difference 
of 7°-1 C. They now begin once more to approach: at 500 
fathoms, the temperatures are 8°-7 C. and 5°75 C., with a dif- 
ference of 3° C.; and at 600 fathoms they are 5°°3 C. and 4°-25 
C., with a difference of about 1° C. The bottom temperature 
at 2495 fathoms at Station XLII. was 1°°8 C.,and at Station 
