The universal geography : earth and its inhabitants

4 TIIE NOKTH-EAST ATLANTIC.The velocity of this current has not yet been clearly determined, for it flowstoo slowly to be detected in the midst of the various motions produced by thewinds on the surface. Admiral Irminger gives it a mean velocity of 3 miles aday, while Captain Otto thought it amounted to nearly 12 miles, at least on theNorwegian seaboard.* According to Findlay it would take from one to twoyears to reach Europe from Florida, while Petermann considers that a few monthswould suffice.When General Sabine was in Hammerfest in 1823, some barrels ofpalm oil were recovered, belonging to a vessel which had been wrecked theprevious year at Cape Lopez, on the west coast of Africa, near the equator. Thesebarrels must have twice crossed the Atlantic within the twelvemonth. Floatingbottles containing messages from seafarers in distress, and picked up at variouspoints, enable us to fix approximately six months as about the time required forthe displacement of the waters from one to the other side of the Northern Ocean.But if the main current of the Eastern Atlantic be not detected by the velocityof its waters, it is revealed plainly enough by its higher temperature. Hundredsof thousands of observations made by such distinguished hydrographers as Maury,Andrau, "Wallich, Buchan, Irminger, Inglefield, and Mohn have supplied amplematerials for the preparation of a correct chart of this current from month tomonth, and for tracing its shifting limits. In summer, when its outlines arerendered most irregular by its struggle with the polar stream, it is stronglydeflected by the pressure of the cold waters flowing from Baffin's Bay. But afterpassing this arctic stream, which continues to set southwards beneath the surface,the southern current resumes its north-easterly course, so that the isothermal linesrevealing its presence are not deflected from their regular path. It strikes thewestern shores of Iceland, skirting the north coast. But it meets a secondpolar stream about the eastern headlands of the island, causing it to flow back bythe south coast. Here the warm waters, being subjected to an enormous pressure,are again deflected from their north-easterly direction. The polar stream does notat once disappear beneath the surface strata to form a bed for the southern watersmoving in an opposite direction. It struggles long for the ascendancy, and thetwo currents ramify into two parallel belts flowing side by side in contrarydirections. According to Irminger's observations, the whole area betweenIceland and Scotland is intersected by these alternating belts of warm and coldwater belonging to the two opposing currents. During his trip from Stornowayin the Hebrides to Reykjavik in Iceland, in the month of June, 1856, LordDufferin caused the temperature of the surface waters to be tested every two hours,making altogether ninety observations, and detected no less than forty-fourchanges from 2° to 9°, whereas at the two extremes the thermometer markedexactly 48° Fahr.After crossing the polar current, whose normal direction seems to be from JanMayen to the Frisian coast, the Gulf Stream continues to flow north-east, parallelwith the shores of Scandinavia, then rounding its northern limits in the directionof Novaya Zemlya. But while the main volume follows the line of the continent, a* Pctermann's Mittheilungen, 1873, 1878.