430 The Origin of the Great Cyclones, [O¢tober, 
the ashes which fell on the ship ‘‘ Conway” while in the 
Pacific, S.W. of Coseguina, were borne thither to her deck, 
in the superior part of the surface trade-wind; and such is 
the generally-accepted interpretation of the incident among 
geographers. 
Lastly, if the ingenious theory of Prof. Dové explains the 
phenomena in the West Indies, it is totally inapplicable in 
the East Indies. The inference forced upon the mind by 
what has been proven of the mechanical and lateral inter- 
ference of the great bodies of trade-winds, from both hemi- 
spheres, fully explains the origin of the rotatory motion, and 
the further development of the cyclone will follow from what 
has been already laid down. If the rotation, at the moment 
of interference, be anticyclonic, 7. e., with the hands of a 
watch, the intro-moving winds will, before they reach the 
depressed centre of the nascent cyclone, feel and obey the 
mechanical or diurnal motion of the earth, and they will 
quickly control the rotation of the atmosphere, and force it 
to become cyclonic. Once formed, however small, and 
though no larger than ‘‘a man’s hand,” the meteor grows, 
and, being embedded in large air-currents, begins its pro- 
gressive movement. It has often seemed unaccountable to 
me that Mr. Redfield did not see and use this solution of 
cyclones. He appears to have at one time entertained it, 
but dismissed it, because, to use his own words, ‘‘ it cannot 
always explain the uniformity of the direction of rotation, 
nor the continued a¢tivity of the storms in their progress to 
other regions and in higher latitudes, where their greatest 
violence is sometimes developed.” But, as we have demon- 
strated, ‘‘the uniform direction of rotation” is fully ex- 
plained by the earth’s rotation, and the ‘continued activity 
of the storms” by the continued or increased supply of 
aqueous vapour to their centrical cylinders and the ensuing 
condensation, acting and rea¢ting upon each other. It is 
not a fact that the storm continues its activity from the mo- 
mentum of the first rotation, as the fly-wheel of a machine 
set revolving by a single impulse, but the rotatory intensity 
rises or falls with the rise and fall of the barometer in the 
centre of the meteor. 
It is all-important, in the praCtical application of this 
whole subject, to bear in mind the movement of the sun in 
declination. 
The solar forces, marshalled around the Equator at the 
time of the Equinox, may be viewed as the extended lines of 
some immense army in position, and girdling the entire 
globe on this great circle. They must be daily conceived of 
