158 The American Geologist. September, 1902 
first fundamental of observation. If the previous observations 
are found to be largely erroneous, the man who made them has 
small chance to become a good geologist. The difference be- 
tween had observation and ^ood observation is that the former 
is erroneous; the latter is incomplete. Unfortunately in many 
cases not only are the observations recorded by many men ab- 
solutely false, but the}' are fo intertwined with the theories of 
the author that one is unable to discriminate between what is 
intended to be fact and what is advanced as opinion. It is 
needless to say that the case of such a man is hopeless ; that 
there is no possibility that he shall ever become a geologist. 
I conclude, therefore, that in order to have a standing in the 
future, even as a descriptive geologist, one must interpret 
the phenomena which he observes in the terms of the princi- 
ples of astronomy, physics, chemistry, mineralogy, ajid biology. 
If my statement thus far be true, the outline of the training 
of a man hoping to become a professional geologist is plain. 
Such a man should take thorough and long courses in 
each of the subjects of astronomy, physics, chemistry, mineral- 
ogy, and biology. This means that a large part of the train- 
ing of a geologist is the study of the sciences upon which 
geology is founded. If a man who hopes to be a geologist is 
wholly lacking in a knowledge of any of the basal sciences, 
this defect lie can probably never make good. Even if he so 
desires, the time cannot be found, ^loreover, chemistry, phvs- 
ics, mineralogv, and biology are laboratory sciences and can 
be satisfactorily handled only in the laboratory. If the fun- 
damental work in the basal subjects has been done in the col- 
lege or university, one may keep abreast of their progress dur- 
ing later years . but in order to do this, the basal principles must 
have become living truths to him while a student. If a person- 
al illustration be allowable, during the past five years, in order 
to handle the jiroblems of geology before me, I have spent 
more time in trying to remedy my defective knowledge of 
physics and chemistry and in comprehending advances in 
these sciences since I w^as a college student than I have spent 
upon current papers in geology, and with. I believe, nmch more 
profit to my work. If one has a working knowledge of the 
basal sciences and lacks training in some branch of geology, 
this defect he mav, remedv, for he has the foundation upon 
