Rachel Carson - The Sea Around Us

Only a year before the detailed charting of this Pacific current, British and American oceanographers discovered a south-flowing counter current running from the North to the South Atlantic under the Gulf Stream and the Brazil Current. The techniques that make such discoveries possible have only very recently become available to oceanographers. As their use becomes more widespread our almost complete ignorance of the deep circulation of the ocean will be dispelled.

From Bulletin, U.S. Bureau of Fisheries, vol. XXVIII, part 1, 1908, p. 338.

From Natural History, vol. LIII, no. 8, 1944, p. 356. ?

During the 1950’s enormous advances were made in the development of instruments for the recording of water temperatures. A continuous recording of water temperatures to a depth of several hundred feet may be obtained by towing a thermistor chain behind a vessel. The electronic bathythermograph is potentially capable of obtaining temperatures at any depth, depending on the length of cable available. It is a vast improvement over the original bathythermograph because a recorder on deck traces a continuous graph of the temperatures being registered while the vessel is under way. An even more revolutionary development in the study of sea temperatures is the airborne radiation thermometer which, while flown above the sea, registers the surface temperature with an accuracy of a fraction of a degree. Oceanographers regard this instrument as still in the developmental stage, with further refinement of accuracy possible. However, in such work as tracing the edge of the Gulf Stream these airborne thermometers have already proven themselves enormously useful. During a 1960 survey of the Gulf Stream conducted by the Woods Hold Oceanographic Institution, a low-flying plane covered some 30,000 miles, obtaining surface temperatures in various areas of the Stream.

Svenska Hydrog.-Biol. Komm. Skrifter, No. 5, 1912.

From In Northern Mists, 1912 edition, A. H. Clark, vol. 1, pp. 234 and 247.

Many of the old basic works on the sea are now out of print but they are well worth pursuing in libraries for the excellent background they provide.