ME. J. PRESTWICH ON SUBMARINE TEMPERATURES. 
591 
No further attempts of the kind seem to have been made until 1772, when Cook* went, 
with Forster f as naturalist, on his first voyage round the world. They each separately 
record three experiments made, at depths of 600 feet, between the equator and 64° South 
latitude, and they both recognized the decrease, within certain latitudes, of the tempera- 
ture with depth. From some unexplained cause, the experiments were soon discon- 
tinued. No mention is made either in Cook’s or Forster’s narrative of the instruments 
used, except that the latter alludes (p. 45) to the use of thermometers, while Peron 
speaks (p. 318) of Forster’s “ cylindre a double soupape;” so it may be presumed that 
he used Hale’s apparatus with an ordinary thermometer enclosed in it. The apparatus 
was left at the bottom from 15 to 30 minutes. 
In 1773, on the occasion of Captain Phipps’s $ voyage to Spitzbergen, he was furnished 
by the Royal Society with instructions how “ to direct his inquiries.” Sailing past 
Shetland and the Faroe Islands, to the west and north coasts of Spitzbergen, he reached 
80° 48" N. latitude. Dr. Irving, who accompanied the expedition, made nine observa- 
tions at depths varying from 192 to 4098 feet, and extending from the German Ocean 
to the north of Spitzbergen. They first of all used thermometers contrived by Lord 
Charles Cavendish § in 1757. They were on the principle of overflow thermometers, 
which registered the temperature by subtracting from a column of mercury of given 
length the portion which passed over into an attached receiving bulb, and comparing 
the instrument before and after with a standard thermometer ; but, owing to its delicacy, 
difficulties of manipulation, and errors by compression, this instrument was soon 
abandoned. Irving then devised a water-bottle with a coating of wool 3 inches thick, 
and shutting inside with a cone of lead when at the bottom. The temperature was 
taken when brought to the surface. For moderate depths the results, which are 
recorded in the Tables, seem to have been tolerably correct. Those obtained with 
Cavendish’s thermometer are, on the contrary, so discordant || that I have not included 
* Yoyage towards the South Pole, 1772-1775. By Capt. Cook. 2nd edit. London, 1777, pp. 25, 29, 39. 
t Yoyage round the World, 1772-1775, in H.M.S. ‘Resolution.’ By George Forster, F.R.S. London, 
1787, vol. i. pp. 48, 50, 51. 
£ A voyage towards the North Pole, undertaken hy His Majesty’s commands in 1773. London, 1774. 
Appendix, pp. 141-7. 
§ Phil. Trans, vol. 1. p. 308, and vol. liv. p. 261. 
|| I annex them here, for the purpose of record, with the correction for compression and unequal expansion 
of spirits afterwards introduced hy Cavendish and applied hy Phipps. 
North Latitude. 
East Longitude. 
Depth in feet. 
Temperature in degrees of Fahr. 
| By therm. 
Corrected. 
Air. 
1773, June 20 
67 5 
5 46 
4680 
15 
26 
48 5 
„ „ 30 A.M. . . 
70 8 
10 55 
708 
30 
31 
40 5 
„ „ 30 p.h. . . 
70 8 
10 ? 
690 
33 
33 1 
44 75 
„ Aug. 31 
69 0 
0 18 
4038 
22 
32 
59 5 
1 In this experiment the water brought up in Irving’s water-bottle gave a reading of 38 0, 5. 
