Tables of temperatures of the sea at different depths beneath the surface : reduced and collated from the various observations made between the years 1749 and 1868, discussed / by Joseph Prestwich.

  • Prestwich, Joseph, 1812-1896.
Date:
1875
Catalogue details

Licence: Public Domain Mark

Credit: Tables of temperatures of the sea at different depths beneath the surface : reduced and collated from the various observations made between the years 1749 and 1868, discussed / by Joseph Prestwich. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    7/98 (page 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 803 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 ot 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 * Voyage towards the South Pole, 1772-1775. By Capt. Cook. 2nd edit. London, 1777, pp. 25, 29, 39. i 1 oyage round the World, 1772-1775, in H.M.S. ‘Resolution.’ By George Poester, F.R.S. London, 1787, yoI. i. pp. 48, 50, 51. + ^ T0yage towards the North Pole, undertaken by His Majesty’s commands in 1773. London, 1774. Appendix, pp. 141-7. § Phil. Trans, vol. 1. p. 308, and vol. liv. p. 261. |i I annex them here, for the purpose of record, with the correction for compression and unequal expansion of spirits afterwards introduced by Cavendish and applied by Phipps. North Latitude. East Longitude. Depth in feet. Temperature in degrees of Eahr. By therm. Corrected. Air. 1773, June 20 O 1 67 5 O 1 0 46 4680 o 15 O 26 48 5 „ „ 30 A.M. . . 70 8 10 55 708 30 31 40 5 „ „ 30 p.H. .. 70 8 10 ? 690 33 33* 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 380,5.