62 ROCHESTER ACADEMY OF SCIENCE. [May 26, 
In other words the atmosphere having been massed together in any 
particular way under the influence of the forces associated with 
magnetic induction from the sun, equilibrium is maintained as long as 
these forces do not vary. As soon as they undergo variation atmos- 
pheric equilibrium is disturbed and readjustinent begins, in the course 
of which all sorts of eddyings and other phenomena of storm action 
will occur, the peculiarities of which are determined in part by the 
belt-like arrangement to which reference has been made, and in part by 
local conditions. Thus, storms may occur with or without condensa- 
tion of aqueous vapor, this being merely incidental to the re-adjustment 
of pressure carrying air currents across bodies of water or land as the 
case may be. So storms may become violent without steep temperature 
gradients, as in the case of tropical hurricanes, or they may be attended 
by very steep temperature gradients as in many of the severe winter 
storms on the American continent. In either case the temperature 
contrast 1s merely incidental and has little to do with the energy 
displayed, the real force leading to re-adjustment being of a different 
though perhaps allied nature. 
In general the cyclonic circulation of the winds is subsidiary to 
the anti-cyclonic. West Indian hurricanes afford a complete illus- 
tration of this in all its details. For the most part the line of meeting 
of the trade winds is close to the equator, and these air currents coming 
in contact at an acute angle with each other do not produce whirls. In 
August and September, however, the southeast trade is compelled to 
cross the equator, and thus acquires a deflection toward the southwest 
because of the rotation of the earth. The antagonism to the northeast 
trade thus developed, in the upper atmosphere if not at the surface of 
the earth, produces whirls which when once formed drift westward, 
carried along by the relatively stronger northern anti-cyclonic circula- 
tion, until the western margin of such an area of high barometer has 
been reached, when the whirl follows it, recurving northward and 
slowing down in its progress until at the northern margin it again 
moves more rapidly passing eastward along the usual track of eastward 
moving storms. Thus storm tracks and the behaviour of storms in 
many important regards are determined by their relation to the anti- 
cyclonic circulation, which in turn is dependent upon the massing 
together of the atmosphere in the ways described by forces directly 
associated with magnetic induction from the sun and its variations. i 
It is to be noted with regard to the above theory of the mechanism 
of storms that the eastward movement of anti cyclones, which occurs 
at times independently of cyclones, is an anomalous feature that 
