Page:Physical Geography of the Sea and its Meteorology.djvu/297

Rh the surface of the globe. These fogless regions, though certain parts of them are not unfrequently visited by tempests, tornadoes, and hurricanes, are nevertheless much less frequented by gales of wind, as all furious winds are called, than are the regions on the polar side of these two parallels.

503. The most stormy latitudes.—Taking the Atlantic Ocean, north and south, as an index of what takes place on other waters, the abstract logs of the Observatory show, according to the records of 205,304 observing days contained therein, that for every gale of wind that seamen encounter on the equatorial side of these two parallels of 30° N. and S., they encounter 10.4 on the polar side; and that for every fog on the equatorial they encounter 83 on the polar side. As a rule, fogs and gales increase both in numbers and frequency as you recede from the equator. The frequency of these phenomena between the parallels of 5° N. and 5° S., compared with their frequency between the parallels of 45° and 50° N. and S., is as 1 to 103 for gales, and as 1 to 102 for fogs. The observations do not extend beyond the parallels of 60°. It appears from these, however, that both the most stormy and foggy latitudes in the North Atlantic are between the parallels of 45° and 50°; that in the South Atlantic the most stormy latitudes are between the parallels of 55° and 60°, the most foggy between 50° and 55°.

504. Influences of the Gulf Stream and the ice-hearing currents of the south.—How suggestively do these two groups of phenomena remind us, on the one hand, of the Gulf Stream and the ice- bearing currents of the north, and, on the other, of Cape Horn and the Antarctic icebergs which cluster off the Falkland Islands!

505. Sea fogs rare within 20° of the equator—red fogs.—Though sea fogs within 20° on either side of the equator are so rarely seen, yet within this distance, on the north side, red fogs of " sea-dust" (§ 322) are not infrequently encountered by navigators. These can scarcely be considered as coming within the category