Page:Physical Geography of the Sea and its Meteorology.djvu/465

Rh the North Atlantic. But as it is, the contrast is very striking. In some aspects, the meteorological agents of the two hemispheres, especially those forces which control the winds and the weather, differ very much. The difference is so wide as to suggest greater regularity and rapidity of circulation on one side of the equator than on the other.

822. Calms in the two hemispheres.—Average Number of Calms to the 1000 Observations between the Parallels of 30° and 55°, in the North and South Atlantic, and between the Parallels 30° and 60° in the North and South Pacific Oceans, as shown by the Pilot Charts. Each one of these observations embraces a period of eight hours; the grand total, if arranged consecutively, with the observations drawn out each to occupy its period separately, would be equal to 373 years. They exhibit several curious and suggestive facts concerning the difference of the atmospherical stability in the two hemispheres.

823. The propelling power of the winds.—If we would discover the seat of those forces which produce this difference in the dynamical status of the two great aerial oceans that envelop our planet, we whould search for them in the unequal distribution of land and water over the two hemispheres. In one the wind is interrupted in its circuits by the continental masses, with their wooded plains, their snowy mantles in winter, their sandy deserts in summer, and their mountain ranges always. In the