598 
MR. J. PRESTWICH ON SUBMARINE TEMPERATURES. 
there is reason to believe that thermometers of stronger make than usual, and so better 
adapted to resist pressure, were used by Eoss and Parry in their voyages of 1818-19*. 
The usual correction, therefore, cannot be applied to their observations of that date. 
Little or none may be needed. 
In 1822 Sir Edward Sabine made an observation on the temperature of the Carib- 
bean Sea at a depth of 6000 feet (the actual length of rope was 7380 feet, but of this 
1380 feet were allowed for slack and drift), and a reading of 45 0, 5 F. was obtainedf. 
On another occasion on this voyage, Sir Edward used a solid iron case to protect the 
thermometer against pressure, but it did not prove sufficiently close to exclude water. 
In 1823-26 Kotzebue commanded another voyage of circumnavigation J, and on this 
occasion he was accompanied by Emil, von Lenz, who subsequently published several 
important memoirs on the deep-sea temperatures and on the specific gravity of sea- 
water taken on this occasion §. His observations are remarkable from their being 
made at greater depths and their recording lower temperatures than any others made 
up to that time, or, in fact, until long subsequently, in tropical seas. One observation, 
in the Pacific, 21°T4 north latitude, indicated at a depth of 5835 feet, by his corrected 
reading, a temperature of 36°*4 F., and another, 6476 feet deep, in the Atlantic, 32 o, 20 
north latitude, gave 35° - 8 F. 
Although only fifteen observations were made, they were mostly at considerable depths, 
and they were all taken with various precautions and subjected to careful corrections ||. 
On his first voyage Kotzebue experienced so much trouble with the self-registering 
thermometer, owing to the mercury passing over the index and to the shifting of the 
index from jolts or shaking, that on this second voyage Lenz reverted to Hales’s 
mode of taking deep-sea temperatures, using an improved apparatus arranged by Parrot, 
the Kussian Academician^. The apparatus, which he termed a bathometer, was 16 inches 
high by 11 inches in diameter, and held 27‘49 kil. (six gallons) of water. It had valves 
at top and bottom opening upwards, and connected by a rod, to which was attached a 
mercurial thermometer made specially to bear pressure, with a ball 5 lines thick. 
The apparatus was covered over with four alternating layers of sheet iron and canvas, 
saturated with a mixture of boiling tallow and wax, and the whole enveloped in a 
cloth painted over several times. It was calculated to bear a pressure of 3000 toises 
(19,150 feet), and the practice was to leave it at the bottom 15 minutes. It was 
* See also ‘ Depths of the Sea,’ p. 300. 
t Phil. Trans, for 1823, p. 206. See also his ‘ Pendulum and other Experiments.’ London, 1825. 
t Voyage round the World. English translation. London, 1830. 
§ Annalen der Physik und Chemie, Band xx. 1830, pp. 73-131; Edinb. Journ. of Science, vol. vi. 1832, 
pp. 341-45 ; and St. Petersburg Ac. Sc. Bull. v. 1847, col. 65-74. 
|| Physikalische Beobachtungen angestellt auf einer Reise um die Welt unter dem Commando des Capitains 
von Kotzebue in den Jahren 1823-26. St. Petersburgh Acad. Sci. Me'm. i. 1831, pp. 221-334. 
IF There are but few observations given in the English Translation of the Voyage (vol. i. pp. 24 & 29, and 
vol. ii. p. 4), and it is not stated whether or not they are corrected. To these the name of Kotzebue is attached 
in the Tables ; the others made on this voyage are ou the authority and in the name of Lenz. 
