RECENT RESEARCHES IN THE PHYSICS OF THE SEA.

New Zealand Times, Volume XXX, Issue 4344, 20 February 1875, Page 2 (Supplement)

RECENT RESEARCHES IN THE PHYSICS OF THE SEA.

' (Prom the New York Herald, Dec. 24.) Among the many physical investigations of modern science few equal in importance and world-wide interest that which is occupied with the meteorology of the ocean. Recently, under the auspices of the London Board of Trade, a publication has appeared summarizing the labors of British observers in a part of the tropical sea, which furnishes data for the solution of several great marine problems on which' the world has long waited for light. Many years ago this investigation was originated and extensively pursued by the United States, with a rich harvest of results. Subsequently England took up the same investigation, and, employing her largo commercial marine for gathering information, she has slowly but surely laid andther course in the edifice of .ocean science of which the United States laid the promising foundation. Within the last ten years the philosophy of ocean currents, first clearly brought to light by the United States National Observatory and

Coast Survey researches, has been undergoing severe scientific discussion, aud especially that portion which related to the climatic influence of the great warm currents like the Gulf Stream. Not a few eminent scientists have discarded the deduction which the American researches seemed to .establish, that the warm currents are controlling factors of climate on the continents which th«y wash. Some of our own physical geographers have advanced the. counter hypothesis that the temperature of the air controls that of the sea, and hence they have repudiated the view that the climate of Western Europe is determined by the thermic influence of the Gulf Stream. The recent British publication to which we have referred affords an experimental test, which puts the seal of demonstration upon this whole problem, which Ims agitated thinking minds since the days of Benjamin Franklin. The observations for a single one degree square of the Atlantic, in which this test is applied, number 9600 for air temperatures and 6600 for sea temperatures ; and these are carefully compared and charted in monthly charts. The comparison after eliminating all erroneous or doubtful figures, reveals the remarkable fact that, in every mouth of the year, the temperature changes' of the tropical atmosphere follow those of the tropical ocean, and not the contrary. Nothing could more conclusively prove that the warm ocean is the controlling factor of the warm atmosphere, aud that the latter is uniformly responsive to the changes which the former, under varying solar influence, is certainly undergoing. The deduction, thus verified in. the tropical regions, applies with equal or greater precision in the higher latitudes of the North Atlantic. Ono would suppose that the air resting upon the equatorial seas would be heated by the sun’s rays more intensely than the seas themselves ; and so, during the midday hours, it is. But, while the air is suddenly expanded, it readily parts with its heat by nocturnal radiation into space, the water meantime tenaciously holding on to its caloric. The mean temperature of the latter, for the twenty-four hours in every month of the year is, therefore, higher than that of the air ; and thus the ocean current, which emerges from and is fed by the equatorial water, becomes a mighty distributor of sun-derived heat to the most remote parts of the globe it reaches. This fact, long ago pointed out by physicists, but now fully confirmed by the British charts, explains the wonderful climatic differences observed on the same parallels of latitude, and sets at rest all speculation as to the influence of the Gulf Stream on European meteorology. v The heat and humidity of the British Islea and the neighboring continental countries is thus scientifically traced, were there no conspiring physical agency, to the warmth and vapor breathing current of the Gulf Stream, as is also the remarkable liquefaction of the Arctic ice belt north of Norway, whither the hot current drifts.

These beautiful researches are of profound practical interest to the world of commerce as well as to that of science, and to them will he due the unveiling, if ever unveiled, of the wondrous meteorological machinery of the ocean. The charts which register the normal pressures and temperatures of the oceanic districts determine the proper pulse of the sea. "When the mariner detects a deviation from these figures, by the showing of his glasses, he is enabled at once to read the omens of its feverish tumult and its gathering tempest, and prepare his ship for the worst. The interests of the seaman and the scientist alike urge the earnest aud extensive prosecution of such investigations.