378 
Frank Carney 
) 
follow upon the findings of the spectroscope and photograph-attach- 
ments of the large telescopes, instruments that were scarcely dreamed 
of in the day of the French savant. 
Among the contributions made to geology since the organization 
of this Academy none is greater than that of T. C. Chamberlin arising 
from his critical examination of the various hypotheses for the origin 
of the solar system, Chamberlin's '‘Planetesimal Hypothesis," in 
the estimation of one who has studied his several papers from the 
related series beginning with, ''A Group of Hypotheses Bearing on 
Climatic Changes" {Journal of Geology, Vol. V (1897), pp, 653; Vol. 
VII, pp. 545-584, 667-685, 751-787) is largely a by-product of his 
studies in reference to the origin of the atmosphere. This fact 
illustrates how interwoven and interdependent are the various phases 
of truth. 
The simplicity of the Laplacian theory, and its accordance with 
all that was then known about the planetary system, the vastness of 
its generalizations, and the meager knowledge of the fundamentals 
in any theory of earth-origin, led to its immediate and almost uni- 
versal acceptance. So long has this theory been taught that the idea 
of a once molten sphere has become a premise, almost an axiom, and 
is made fundamental in explaining mountains, volcanic activity, and 
in petrographical studies. The dissent from its teachings is still very 
local, as is a studious interest in any alternative theory. Conserva- 
tism is the armor, as well as the embalming fluid, of science. 
That the planetesimal theory as now stated, or slightly modified, 
will in time be generally accepted, is the belief of most men who have 
made themselves acquainted with the basis of study from which this 
theory developed. In our generation no greater contribution has 
been made to theoretical geology. 
