BY GEORGE L. DYER.
In presenting to the National Geographic Society this first annual summary of work accomplished in the domain of the Geography of the Sea, I find it impossible satisfactorily to limit the range of subjects that may be assigned to it. The great ocean is so large a factor in the operations of Nature, that the attempt to describe one of its features speedily involves the consideration of others lying more or less in that shadowy region which may be claimed with equal force by other sections of the Society. It is to be understood, therefore, that the following account merely touches upon several of the characteristics of the oceanic waters, and is not in any sense an attempt to treat them all.
This being the first report to the Society it has been thought advisable to give a brief outline of the progress made in our knowledge of the sea since 1749, when Ellis reported depths of 650 and 891 fathoms off the north-west coast of Africa. Even at that time an apparatus was employed to lift water from different depths in order to ascertain its temperature. It does not appear that this achievement gave impetus to further efforts in this direction, for, except some comparatively small depths and a few temperatures recorded by Cook and Forster in their voyage around the world in 1772–75, and in 1773 by Phipps in the Arctic, at the close of the last century there was but little known of the physical conditions of the sea.
At the beginning of the present century, however, more activity was shown by several governments, and expeditions sent out by France, England and Russia, in various directions, began to lay the foundation of the science of Oceanography.
Exploration of little known regions was the main purpose of most of these expeditions, but attention was paid also to the observation and investigation of oceanic conditions, so that accounts of soundings, temperatures of sea water at various depths, its salinity and specific gravity, the drift of currents, etc., form part of their records.
The first to give us a glimpse of the character of the bottom at great depths was Sir John Ross, the famous Arctic explorer. While sounding in Ponds Inlet, Baffin Bay, in 1819, by means of an ingeniously constructed contrivance called a deep sea clam, he succeeded in detaching and bringing up portions of the bottom from depths as great as 1,000 fathoms. The fact that this mud contained living organisms was the first proof of life at depths where it was thought impossible for it to exist. The truth of this discovery, however, was not generally accepted, many eminent men of science on both sides of the Atlantic contending for and against it, and the question was not finally settled until long afterward, in 1860, when, by the raising of a broken telegraph cable in the Mediterranean, unimpeachable evidence of the existence of life at the greatest depths in that sea was obtained. The science, however, remained in its infancy until about 1850, when Maury originated his system of collecting observations from all parts of the globe, and by his indomitable energy aroused the interest of the whole civilized world in the investigation of the physical phenomena of the sea.
Through Maury's efforts the United States Government issued an invitation for a maritime conference, which was held in Brussels in 1853 and attended by representatives of the governments of Belgium, Denmark, France, Great Britain, Netherlands, Norway, Portugal, Russia, Sweden and the United States. The main object of the conference, to devise a uniform system of meteorological observations and records, was accomplished. According to the agreement, ships' logs were to have columns for recording observations of the following subjects: latitude, longitude, magnetic variation, direction and velocity of currents, direction and force of wind, serenity of the sky, fog, rain, snow and hail, state of the sea, specific gravity and temperature of the water at the surface and at different depths. It was also proposed that deep-sea soundings should be taken on all favorable occasions, and that all other phenomena, such as hurricanes, typhoons, tornadoes, waterspouts, whirlwinds, tide-rips, red fog, showers of dust, shooting stars, halos, rainbows, aurora borealis, meteors, etc., should be carefully described, and tidal observations made when practicable.
The practical results of this conference were great. The systematic and uniform collection of data by men of all nations is going on uninterruptedly to-day, and is furnishing the means for the solution of many of the problems relating to the Geography of the Sea.
An epoch in the progress of this science is marked by the appearance of Maury's Wind and Current Charts, his Physical Geography of the Sea, and his Sailing Directions, which contain the record of the first deep soundings taken by United States vessels; and to the United States, through Maury's efforts, belongs the honor of having inaugurated the first regular cruise for the purpose of sounding in great depths.
Under the instructions of Maury the U. S. brig Dolphin, commanded by Lieutenant Lee, and subsequently by Lieutenant Berryman, was detailed in 1851–3 to search for reported dangers in the Atlantic, and to sound regularly at intervals of 200 miles going and returning. The Dolphin was provided with Midshipman Brooke's sounding apparatus and with it succeeded in obtaining specimens of the bottom from depths of 2,000 fathoms. About the same period the U. S. ships Albany, Plymouth, Congress, John Adams, Susquehanna, St. Louis and Saranac also made soundings in various localities, and to the U. S. S. Portsmouth, in 1853, belongs the honor of having reported the first really deep-sea sounding obtained in the Pacific, 2,850 fathoms, in about 39° 40' N., and 139° 26' W.