168 O. H. GISH 
Statistical studies of these questions may seem so laborious as to 
be uneconomical]. However, the variables which are not under man’s 
control are here so numerous that the statistical along with all other 
means of attack must be used. It is feared that the importance of 
considering geophysical problems and data from a statistical view- 
point is not fully appreciated. 
The physicist coming from his problems in the laboratory where 
accessory factors are largely under his control, on his early encounters 
‘with geophysical problems is likely to be either over-optimistic or 
pessimistic, according to temperament. Although his technique and 
thorough knowledge of the underlying principles of method and ap- 
paratus are needed, yet he is likely to be handicapped at the outset 
by a lack of that “‘statistical sense” which is so necessary in the suc- 
cessful geophysicist and which is generally acquired only with time 
and experience. Unfortunately, some persons, otherwise well qualified, 
seem unable to acquire this sense or judgment and as a result continue 
for years to harass editors and to clutter up the literature of geophysi- 
cal science with pet theories and general conclusions based on in- 
adequate data or even trivial manifestations. 
One in whom this statistical sense is lacking is likely either to 
extol or to condemn a method after too brief a trial. In either case he 
may be unaware not only of the many phenomena of the earth which 
act as disturbing influences, but also of the fact that many suitably 
distributed data, or samples, are required under such circumstances 
before a reliable interpretation can be made or a decision either for or 
against a method is justifiable. Both experience and temperament go 
to determine the extent to which a judicious balance may be main- 
tained between optimism and pessimism when evaluating methods or 
interpreting results. 
The element of uncertainty in the final interpretation of a geo- 
physical survey must be not only recognized but also admitted by the 
geologist and the geophysicist who share jointly the responsibility 
for the interpretation. The enthusiast can do real harm by leading 
the patron to expect too much of geophysical methods and thus add 
to the damage already wrought by self-styled “geophysicists”’ of 
either the unscrupulous or the incompetent variety. This probably 
applies with especial force in the case of geoelectric methods. The 
quack and the shyster seem to have a strong predilection for electrical 
vestments. 
Another unfortunate circumstance is that electrical trappings are, 
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