422 



Messrs. Carpenter, Jeffreys, and Thomson [Nov. 18, 



of commencing with a "central" and "circumambient" chamber, like 

 ordinary Orbitolites, this type commences with a spire of several turns, 

 precisely like that of a young Cornuspira, thus showing the fundamental 

 conformity of this cyclical type to the spiral plan of growth. — The 

 animals, especially Mollusca, were by no means lively when brought on 

 board and examined ; perhaps this was owing to the great change of 

 temperature (sometimes as much as 20°) between that of the sea-bed and 

 that of the atmosphere. 



37. A very elaborate Series of Temperature-soundings was made in the 

 deepest parts of the sea traversed between the N.W. of Ireland and Rockall 

 Bank, so as to enable us to determine the rate of diminution of temperature 

 with increase of depth (see Table, p. 465). Thus at Station 19, at which 

 the depth was 1360 fathoms, the temperatures were taken at 250, 500, 750, 

 1000, and 1360 fathoms, and showed a progressive though by no means 

 uniform descent to the minimum recorded, which was 37°'4 ; the most rapid 

 change was between 500 and 750 fathoms. A similar Series, taken at Station 

 20, where the depth was 1443 fathoms and the bottom-temperature 37 o, 0, 

 and a third taken at Station 21, where the depth was 1476 fathoms, and the 

 bottom-temperature 36°'9, showed a very close accordance with each other 

 and with the preceding. In another Series taken at Station 22 in 1263 fa- 

 thoms, a careful comparison was made between the temperatures recorded by 

 two "protected" thermometers and six ordinary thermometers ; and the 

 average error of these, which was very nearly 6° at the greatest depth, cor- 

 responded very closely with that indicated by the previous experiments at 

 pressures answering to the several depths at which the observations were 

 made. — The curious observation was made at Station 23, very near the 

 Rockall Bank, that whilst the minimum indicated was 43 0, 4 at a depth of 

 630 fathoms, the maximum index of both thermometers had risen to 74°'8, 

 or more than 1 7° above the surface-temperature. As in no other instance had 

 any temperature been indicated higher than that of the surface, it seemed 

 clear that a warm submarine spring must discharge itself in this locality. 

 Circumstances prevented us, however, from ascertaining any further par- 

 ticulars in regard to it. 



38. While we lay-to within a quarter of a mile from Rockall on the even- 

 ing of Saturday the 3rd of July, fishing-parties were formed, and continued 

 their sport until midnight. The rock was inhabited by a multitude of 

 sea-fowl ; and a large gannet perched on the highest pinnacle, looking 

 like a sentinel or the president of the feathered republic. 



39. At a distance of from 130 to 140 miles from the nearest part of the 

 Irish coast we observed quantities of floating Seaweed (mostly Fucus ser- 

 ratus), and the feathers of sea-fowl covered with Lepas fascicularis and 

 occasionally L. sulcata ; and on the seaweed were also two kinds of sessile- 



Transactions for 1855, p. 193 et seq.; and his " Introduction to the Study of the Fora- 

 minifera" p. 106 et seq. 



