Page:The National geographic magazine, volume 1.djvu/114

 instruments in the hands of experts, will produce far superior results at a much less cost than was possible at the time the Survey was inaugurated.

The charting of the great ocean currents, has long been an interesting investigation to hydrographers the world over. A sketch of the efforts, projects, and devices that have been resorted to by the Coast Survey in the attempt to unravel the mysteries of the Gulf Stream, would exemplify the continuous demand for improvement and new exertions under which those employed upon the work have always labored, although the full measure of knowledge sought has not yet been obtained. But it is not necessary to enter into these details at this time; let it suffice that many experiments and failures pointed out the path to be followed by subsequent observers, and stimulated to new efforts, until at last appliances have been perfected that have already produced wonders, and it is safe to predict, will ere many years show the ocean currents on the charts of the world with the same relative precision that the currents in a river or harbor can now be indicated. Lieutenant Maury gave us current charts that were a marvel in their day, but his information, or data, was defective, and his conclusions, therefore, only approximate; and how to improve on the data he had, has ever since been the subject of research. The depth of the ocean is necessarily an important factor in the study of its features, as erroneous depths lead to false hypotheses. The introduction by the English of a method of sounding with a wire, has therefore proved an important advance. American officers have perfected the apparatus and severely tested the methods, demonstrating the reliability of the results and the total unreliability of the old deep sea soundings taken with a line. These accurate wire soundings have revealed new facts, disproved old theories and formed new ones to guide future researches. So successful is the improved apparatus that specimens of the bottom of the ocean have been brought up from a depth of five miles. The great value of this system, however, is not confined to the mere ascertainment of depths for the hydrographer and cartographer, as may be readily demonstrated by referring to the reports of the Fish Commissioner. A further step towards improving on Maury's results; the crowning glory that is to shed light on much that has been dark, and trace out those ocean currents we have heretofore vainly endeavored to follow, is found in the invention and devices of a naval officer