So to shape the course on voyages as to make the most of the winds and currents at sea, is the perfection of the navigator's art. How the winds blow, and the currents flow, along this route or that, is no longer matter of opinion or subject of speculation, but it is a matter of certainty determined by actual observation…. The winds and the weather daily encountered by hundreds who have sailed on the same voyage before him, and "the distance made good" by each one from day to day, have been tabulated in a work called Sailing Directions, and they are so arranged that he may daily see how much he is ahead of time, or how far he is behind time; nay, his path has been literally blazed through the winds for him on the sea; mile-posts have been set up on the waves, and finger-boards planted, and time-tables furnished for the trackless waste, by which the ship-master, on his first voyage to any port, may know as well as the most experienced trader whether he be in the right road or no.
… The route that affords the bravest winds, the fairest sweep, and the fastest running to be found among ships, is the route to and from Australia. But the route which most tries a ship's prowess is the outward-bound voyage to California. The voyage to Australia and back, carries the clipper ship along a route which, for more than three hundred degrees of longitude, runs with the "brave west winds" of the southern hemisphere. With these winds alone, and with their bounding seas which follow fast, the modern clipper, without auxiliary power, has accomplished a greater distance in a day than any sea-steamer has ever been known to reach. With these fine winds and heaving seas, those ships have performed their voyages of circumnavigation in sixty days.
[Footnote 62: Formerly an officer of the navy, eminent for his scientific researches and writings on maritime subjects; a native of Virginia.]
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=251.= THE GULF STREAM.
As a rule, the hottest water of the Gulf Stream is at, or near, the surface; and as the deep-sea thermometer is sent down, it shows that these waters, though still far warmer than the waters on either side at corresponding depths, gradually become less and less warm until the bottom of the current is reached. There is reason to believe that the warm waters of the Gulf Stream are nowhere permitted, in the oceanic economy, to touch the bottom of the sea. There is everywhere a cushion of cool water, between them and the solid parts of the earth's crust. This arrangement is suggestive, and strikingly beautiful. One of the benign offices of the Gulf Stream is to convey heat from the Gulf of Mexico, where otherwise it would become excessive, and to dispense it in regions beyond the Atlantic, or the amelioration of the climates of the British Islands and of all Western Europe. Now cold water is one of the best non-conductors of heat, and if the warm water of the Gulf Stream was sent across the Atlantic in contact with the solid crust of the earth,—comparatively a good conductor of heat,—instead of being sent across, as it is, in contact with a cold non-conducting cushion of cool water to fend it from the bottom, much of its heat would be lost in the first part of the way, and the soft climates of both France and England would be, as that of Labrador, severe In the extreme, icebound, and bitterly cold.
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=Ormsby M. Mitchell,[63] 1810-1862.=
=252.= THE GREAT UNFINISHED PROBLEMS OF THE UNIVERSE.
I do not pretend to indorse the theory of Mädler with reference to his central sun. If I did indorse it, it would amount simply to nothing at all, for he needs no indorsement of mine. But it is one of the great unfinished problems of the universe, which remains yet to be solved. Future generations yet are to take it up. Materials for its solution are to accumulate from generation to generation, and possibly from century to century. Nay, I know not but thousands of years will roll away before the slow movements of these far distant orbs shall so accumulate as to give us the data whereby the resolution may be absolutely accomplished. But shall we fail to work because the end is far off? Had the old astronomer that once stood upon the watch-tower in Babylon, and there marked the coming of the dreaded eclipse, said. "I care not for this; this is the business of posterity; let posterity take care of itself; I will make no record"—and had, in succeeding ages, the sentinel in the watch-tower of the skies said, "I will retire from my post; I have no concern with these matters, which can do me no good; it is nothing that I can do for the age in which I live,"—where should we have been to-night? Shall we not do, for those who are to follow us, what has been done for us by our predecessors? Let us not shrink from the responsibility which comes down upon the age in which we live. The great and mighty problem of the universe has been given to the whole human family for its solution. Not by any clime, not by any age, not by any nation, not by any individual man or mind, however great or grand, has this wondrous solution been accomplished; but it is the problem of humanity, and it will last as long as humanity shall inhabit the globe on which we live and move.