Geology as a means of culture — A. Winchell. loi 
all with which it is historically and genetically connected, and 
all the accessories and means whose employment contributes to 
the attainment of a knowledge of the world in its "vsadest rela- 
tions. It is the organization of all the sciences in a crusade for 
conquest in the realm of the unknown. To illustrate and jus- 
tify a claim so large, I shall venture to recite in brief the proc- 
esses by which geology advances from the most familiar facts 
of observation, step by step through generalizations higher and 
higher, to the grandest doctrines ever enunciated by science; 
and thence by a reverse, or deductive process, to the details of 
events from which actual observation is separated by intervals 
of space and time to finite powers impassable. 
The beginning of all this fabric of geological science is what 
we see by the roadside, in the field, on the mountain slope or 
the ocean's strand. In our daily observations are the facts which 
point the way to the loftiest generalizations of the science. Let 
me confine the reader's attention to a group of phenomena lead- 
ing toward the fundamental doctrine of a cooling globe. About 
our very doors lie the bowlders whose hard and crystalline char- 
acter proclaims the agency of intense heat. In the structure of 
the mountains which we climb, and underneath the lands which 
we inhabit, are square miles of rock similarly crystalline and 
vitrified. These are data of observation. They are data of 
easy and familiar and universal observation. They sustain the 
inductive conclusion that intense heat has been there. Other 
observations on ancient lavas — ^on palisades, dikes and extinct 
volcanoes, indicate that the heat has been sufficient to fuse the 
rocks. Has been — but is now no longer. The heat has sub- 
sided. 
Thermal springs, geysers, artesian borings, deep mines, vol- 
canic eruptions supply other observational data from which we 
induce the doctrine of a heated interior. The earth has cooled, 
but is still hot within. The earth is ifi the midst of a cooling 
process. 
This is a most fruitful principle. If the earth is a cooling 
globe, two inquiries next press upon us. Through what phases 
of existence has it passed in its remote history ; and what vicis- 
situdes is it destined to undergo in the future continuance of the 
cooling processes? From what initium did the cooling process 
