By Capt. John Ross,
In the Clerk’s Office of the District Court of the United States
for the Northern District of California.
Printed by SPAULDING & BARTO,
Mining and Scientific Press Job Office,
414 Clay Street, San Francisco.
ON HURRICANES AND THE
LAW OF STORMS.
In the Northern Hemisphere, when the Polar and Equatorial currents of air are alternating with each other, the regular shifting of the wind round the compass will be through S., S.W., W., N.W., N., N.E., E., S.E., S.—and the changes will take place oftener between south and west, and between north and east, than between west and north, and between east and south.
Similarly in the Southern Hemisphere, it may be inferred that when Polar currents of air alternate with Equatorial, the regular shifting of the wind round the compass will be successive through S., S.E., E., N.E., N., N.W., W., S.W., S.
This is Dove’s “Law of Gyration,” (or the law of the rotation of winds). And collecting the main points into a few general propositions, it may be laid down, that all steady winds are modified by the rotation of the earth, in such a manner that Equatorial currents of air receive a westerly deflection, and Polar currents an easterly deflection; but latitudinal currents suffer no change. The N.E. and S.E. Trade Winds are steady Polar currents. The Monsoons are alternations of a Polar and an Equatorial current, twice during the year. Therefore they are N.E. and S.W. in the Northern Hemisphere, and S.E. and N.W. in the Southern Hemisphere.
The S.W. passage winds of the Northern Hemisphere, and the N.W. passage winds of the Southern Hemisphere, are Equatorial currents.