180 THE ATLANTIC. (CHAP. 111. 
The specitie gravity of the bottom water (2575 fathoms) was 
102459 at 21°°6 C., that of the surface water being 102581 at 
22°°4 CO. 
On Sunday, March 2d, we saw the first patches of gulf-weed 
drifting past the ship, and flying-fish were abundant. Our 
position at noon was lat. 22° 30’ N., long. 42° 6’ W., Sombrero 
Island distant 1224 miles. At night the phosphorescence of 
the sea was particularly brilliant, the surface scintillating with 
bright flashes from the small crustaceans, while large cylinders 
and globes of lambent light, proceeding probably from Pyro- 
soma and some of the Medusze, glowed out, and slowly disap- 
peared in the wake of the vessel at a depth of a few feet. 
The next morning we sounded, at 7 a.m., in 2025 fathoms 
with No. 1 line, the ‘“ Hydra” machine and 3 ewt., a slip water- 
bottle, and one thermometer; a stop-cock water-bottle was bent 
on at 925 fathoms from the bottom. The corrected bottom 
temperature was 1°-9 C., the temperature of the surface being 
22°.8 ©. During the morning, the naturalists were out in a 
boat with the tow-net, and they brought back a number of fine 
examples of Porpita, several of Glaucus Atlanticus, some shells 
of Spirula bearing groups of a small stalked cirriped, and many 
large radiolarians. One of the Spirula shells was covered with 
a beautiful stalked infusorian. 
The dredge was lowered at 9.30 a.m., and hauled in at 4.30 p.m., 
unfortunately again entangled in a coil of the rope, and empty. 
A small quantity of mud attached to the netting of the dredge 
was found to contain a large proportion of the shells of forami- 
nifera, especially Globigerina and Orbulina. The mud was again 
of a pale-gray color, and consisted chiefly of calcic carbonate. 
We proceeded in the evening under all plain sail. The 
soundings on the chart in advance of us seemed to indicate an 
extensive rise, with a depth of water averaging not much more 
than 1700 fathoms, and it was determined to dredge again on 
the following day. 
