318 
THE VOYAGE OF H.M.S. CHALLENGER. 
Moselc \ writes : “At night the sea showed wonderful phosphorescence, being lighted 
up for miles around. Wherever the water broke a little on the surface, the white foam 
rilli.mtly lighted up, and the water close to the ship, as viewed from above on the 
bridge, was full of small luminous points. As the water broke at the ship’s side the lower 
studding sails were quite lighted up by the glow. The whole sea had a peculiar weird 
1 >ok. The water was fouud to be full of small Crustacea, larval crabs in the megalopus- 
st age being present in by far the greatest abundance, and the light must evidently be 
< -.insider* as due to them in part, but mostly to Pyrocystis [at first thought to be fish 
.-pawn, afterwards looked upon as an encysted form of Noctiluca], the specimens of which 
were of various sizes and showed phosphorescence when first caught and placed iu a globe of 
water. The spectroscope used on the light under the stern allowed a very small portion 
of red, all the yellow, and a certain amount of green, to be seen, but the light was not 
-trong enough to allow' of exact determination/’ 
O O 
s a 9 s Station 98 (Sounding 169), St. Vincent to St. Paul’s Rocks (see Chart 12 and 
Diagram 7). 
August 14, 1873 ; lat. 9 C 21' 
N., long. 18° 28' W. 
Temperature of air at noon, 79°'8 ; mean for the day, 77°‘7. 
Temperature of w r atcr : — 
Surface, . . ’ . 
78-2 
150 fathoms, 
52-0 
20 fatboms, 
66-5 
200 „ 
49-7 
50 ,, ... 
59-3 
300 „ . . . 
45-2 
< 5 „ 
55-5 
400 „ 
42-0 
100 „ ... 
54-2 
500 
41-2 
125 
53-1 
Bottom, 
367 
Density at 60° F. at surface, 
1-02605 ; 
bottom, 1 '02605. 
Depth, 1750 fathoms; deposit, Globigerina Ooze, containing G2'22 per cent, of 
carbonate of lime (see Murray and Renard, Deep-Sea Deposits Chall. Exp.). 
At 10 a.m. shortened and furled sails, and got up steam to sound. Sounded in 
l 750 f.i thorns, having approached the west coast of Africa, in order to make a haul with 
tin di dgi iii shallower water. Took serial temperatures dow r n to 500 fathoms. At 
12.15 p. \i. put over dredge, and veered 2500 fathoms. At 4 p.m. commenced heaving in 
1 1»< dr> dg* , which came up at 5.15 p.m. containing a few specimens. At 5.40 p.m. made 
-'i!. In th <*vi ning there wa a similar display of phosphorescence as on previous days. 
Distance at noon in direct line from St. Paul’s Rocks, 825 miles. Made good 
loG mil s. Amount of current 13 miles, direction S. 32 E. 
