184 
THE VOYAGE OF H.M.S. CHALLENGER. 
Station 25. 
Station 26. 
Obcanmha mo* 
HtikTAi b Nm 
1.30 r m. commenced heaving in the dredge. Tlie toggle came up witli only one weight, 
and at 5 p.m. the dredge catne up with a considerable quantity of Red Clay. In the 
course of the afternoon temperatures at intervals of 100 fathoms down to 1500 fathoms 
were obtained. The carbonic acid was determined in the bottom water, and amounted 
to 570 milligrammes per litre. At 7.30 p.m. made all plain sail. 
Distance from Bermuda at noon, 754 miles. Made good 58 miles. Amount of 
current 14 miles, direction N. 37 W. 
Station 26 (Sounding 73), St. Thomas to Bermuda (see Chart 6 and Diagram 2). 
March 27, 1873 ; lat. 21° 26' N., long. 65° 16' W. 
Temperature of air at noon, 73 ‘8 ; mean for the day, 75° *0. 
Temperature of water at surface, 76°”0. 
Density at GO F. at surface, 1‘02704 ; bottom, 1 ’02594. 
Depth, 2800 fathoms; deposit, Red Clay, containing 6 ’00 per cent, of carbonate 
of lime (see Murray and Renard, Deep-Sea Deposits Chall. Exp.). 
At 1.15 p.m. shortened and furled sails, and got up steam to sound. At 2.30 p.m. 
sounded in 2800 fathoms. The thermometer at the bottom registered several degrees 
I clow the freezing point, but it was believed to be faulty. Buchanan sent down some 
small glass hermetically-sealed tubes enclosed in a copper cylinder open at both ends. 
The glass in the case of one of the tubes was shattered into the finest powder, like 
snow. The copper cylinder was compressed and crumpled together opposite the spot 
when' the tube had been. The inference was that, the glass tube giving way very 
suddenly and leaving a comparative vacuum, there was not sufficient time for the 
production of equilibrium by the transmission of water through the ends of the 
cylinder, but this was partly brought about by the more direct action of the pressure, 
the cylinder wall being driven in. The experiment was, indeed, a kind of reversal of 
the explo ion of gases or gunpowder. Obtained sample of bottom water. The carbonic 
•■•rid was determined in the surface water, and amounted to 46’0 milligrammes per 
lit) . Jolly-boat away collecting surface specimens. At 5.10 p.m. completed heaving 
iu sounding line. 
Distance from Bermuda at noon, 654 miles. Made good 100 miles. Amount of 
current 14 miles, direction N. 55 W. 
Surftice Organisms. — Murray was away in jolly-boat picking up Crustacea, Antcn- 
narius, pipe-fish, Ac., from numerous patches of gulf-weed. 
