CHAP. Il. ] TENERIFFE TO SOMBRERO. 179 
HOOsathoms: sa seen ses ere SiC: L200 Mathontss. it) setts sae 3 °1C 
800 a BG OG AG OORT OP eS 1300 Srl don (eedccbas ey seeks 2 6 
900 re Ne RA old's Cra: a) 1400 PRE Re Een ae 2 
1000 rf 3 °5 1500 et eR ee NoeT Se CTO rate 26 
1100 ot 3 °3 2720 oy ottomss sees. 1669 
On Saturday, March 1st, we sounded in the morning in 2575 
fathoms, with the “ Hydra” and 3 ewt., the slip water-bottle, 
and one thermometer—the stop-cock water-bottle being again 
attached at 500 fathoms from the “ Hydra.” The bottom was 
ooze still, containing a large proportion of silicate of alumina, 
but with much more calcareous matter and many more minute 
shells than in the previous sounding; showing that we were 
passing from the region of dead red clay which occupies the 
extreme deep water in this place. The small dredge was sent 
down at 9.55 a.m. with 3000 fathoms of rope, 2000 fathoms of 
which were 2-inch rope and new; 1 ewt. was attached 300 fath- 
oms before the dredge, and later in the day an additional hun- 
dred-weight was slipped down the line. At 5.20 p.m. the dredge 
came up bottom upward and quite empty. A little mud on the 
netting showed that it had been at the bottom; and as the 
double chain to which the dredge is immediately attached was 
twisted up into a close spiral, we judged that the bouwleverse- 
ment of the dredge had plainly been caused by the twist in the 
new line. <A series of temperature observations were taken at 
intervals of 20 fathoms from the surface to a depth of 200 
fathoms, in order to determine the depth to which the temper- 
ature of the water is affected by direct radiation. The follow- 
ing is the result: 
SUTIACeT ARAB Aono h micas PQDT OF 120ifathomsn 55%. Seale! 
20 MathOMsinins sas. ace (22 “2 140 ee ce Sele Re yf cna 
40 & aye 160 ee De Eee ee Cte Gwe: 
60 ey 22 °2, 180 S EB Sete Clancy Hs), S15) 
80 & 5 PA ee 200 Maori Resncier ae, Elie: okey | 
100 cs 19 9 
