The Evolution of Climates. — Mansotu 105 
acute the intellect, the farther will it be tempted to wander into 
these bewildering iields, and the more enticing become the 
witcheries of the "philosophy of assumption," 
The adage, "false in one. false in all," was never more justly 
applied than it might be to many arguments presented to ac- 
count for the series of climates terminating in the Ice age, and 
ushering in the dawn of the solar climates now ranged in zones 
about our planet, and evidently different from the climates pre- 
ceding the Ice age. 
An explanation which will admit of definite proof, and will 
satisfy all the conditions, and not require the distortion of 
known facts, by forcibly fitting them into arbitrary molds, will 
receive universal acceptance. It must start from generally ad- 
mitted premises, and in rigid consonance with known laws, 
interpret the grand eras of climate which have marked the 
geological history of our globe; it must point out and fully 
elucidate wherein and why the present climates of our globe 
differ so radically from those secular variations recorded by 
fossil life; it must explain how present climates were developed 
from the previous state, and correctly set forth the conditions 
towards w'hich this development is now tending. 
Uncertainty and doubt will be removed only when the Ice 
age, the widespread temperate conditions preceding it, and the 
universally tropical climate of the Mesozoic and Paleozoic eras, 
are all explained by logical deductions from universally ac- 
cepted premises and laws. Glacial phenomena, occurring at 
any latitude and during any period of geological time, must be 
shown to be the result of the same laws which have controlled 
climatic development. 
Should there be planets whose conditions apparently indi- 
cate a less advanced period of climatic development than the 
earth is now in, the geological history of the earth if correctly 
interpreted would show that the earth has passed through the 
conditions now prevalent upon the younger planet. If, again, 
there be planets w^hose size and observed conditions seemingly 
mark a greater progress and development than the earth now 
■enjoys, the interpretation of the laws now acting should be 
such as to indicate that the earth's developments are tending 
towards those prevailing upon the older planet. Thus the 
two sciences of geology and astronomy must agree in the solu- 
