<: ; 
72 On the Rotary Action of Storms. 
formably to the movement of watch hands. ‘Figure A exhibits | 
the rotary action of a storm in the northern hemisphere; figure5 
the same in the southern hemisphere. 
Fig. 4. Fig. 5. 
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The relative motions of the parts of.a small circular space on 
the earth’s surface, by reason of the diurnal revolution, are pre- 
cisely what they would be if the same circular space revolved 
upon an axis passing through its centre parallel to the axis of the 
globe. If such space be regarded as a plane revolving about such 
supposed axis, then the relative motions of its parts are the same 
as if the plane revolved about its centre upon an axis perpendic- 
ular to the plane itself; with this modification, that an entire 
revolution on the axis perpendicular to the plane, would not be 
accomplished in twenty four hours. Such plane daily performs 
such part of a full revolution about such perpendicular axis, as 
the sine of the latitude of its centre is of radius. The plane 
itself—the field over which a storm or a tornado or a water-spout 
is forming—is in the condition of a whirling table. Hence the 
tendency to rotary action in every quarter of the storm is equal, 
and all the forces which propel the air towards the centre coop- 
erate in harmony to cause the revolution. 
Water discharging from a broad basin through a central orifice, 
is subject to the same law. It forms a vortex which in our hem- 
-isphere turns to the left, or against the sun, and in the southerl 
hemisphere must turn to the right or contrary to the sun there. 
These rotations of the atmosphere and of water, being from 
west to east about lines inclined to parallelism with the earth’s 
axis, are singularly coincident in direction with the rotation of 
the globe, and harmonize with the general mechanism of the 
Utica, Feb. 27, 1843. 
