CHAP, III.] TENERIFFE TO SOMBRERO. lw 
the whole time the lead was running out. The depth was 
3150 fathoms; the bottom a perfectly smooth red clay, contain- 
ing scarcely a trace of organic matter—merely one or two mi- 
nute granular masses. The thermometers indicated a bottom 
temperature of 1°-9 C. 
The small dredge was sent down at 2.15 p.m. with two hemp- 
en tangles; and, in order to insure its reaching the bottom, 
we attached to the iron bar, below the dredge, which is used 
for suspending the tangles, a “ Hydra” instrument with de- 
taching weight of 3 ewt. Two additional weights of 1 ewt. 
each were tixed to the rope 200 fathoms before the dredge ; 
3600 fathoms of rope were paid out—1000 fathoms 2 inches 
in circumference, and the remainder (2600 fathoms) 24 inches. 
The dredge came up at 10.15 p.m. with about 1 ewt. of red 
clay. , 
This haul interested us greatly. It was the deepest by sev- 
eral hundred fathoms which had yet been taken, and, at all 
events coincidently with this great increase in depth, the mate- 
rial of the bottom was totally different from what we had been 
in the habit of meeting with in the depths of the Atlantic. 
For a few soundings past, the ooze had been assuming a darker 
tint, and showed on analysis a continually lessening amount of 
calcareous matter, and, under the microscope, a smaller number 
of foraminifera. Now calcareous shells of foraminifera were 
entirely wanting, and the only organisms which could be de- 
tected, after washing over and sifting the whole of the mud 
with the greatest care, were three or four tests of foraminifera 
of the cristellarian series, made up apparently of particles of 
the same red mud. The shells and spines of surface animals 
were almost entirely wanting; and this is the more remarkable, 
as the clay-mud was excessively fine, remaining for days sus- 
pended in the water, looking in color and consistence exactly 
like chocolate, indicating, therefore, an almost total absence of 
movement in the water of the sea where it is being deposited. 
