394 
POPULAK SCIENCE EEVIEW. 
however, be accepted without investigation. They are very 
often fallacious, representing angles of inclination incorrectly, 
owing to the exposed section not being at right angles to the 
strike, and not less often deceptive, as inducing the careless 
observer to accept as general that which may be accidental 
or a special exception to a rule. False stratification (already 
alluded to) seen in a small section may be mistaken for real; 
nodular structure may be mistaken for contorted bedding ; 
slight nips and small bends of strata, the result of squeezing, 
may appear to represent great disturbance ; and the confusion 
in bedding produced in the axis of a very unimportant dis- 
location may seem to refer to far more important movements. 
Thus, natural sections must be regarded only as suggestions, 
and each one must be supplemented by others taken both near 
and at a distance to determine the real section. 
Without in any way exhausting the subject, we have already 
gone over a long list of occasions in which geological sections 
are useful and instructive. It is indeed difficult to know in 
what other way so many and such valuable facts could be so well 
represented. The sections are a picture language appealing at 
once to the eye and the intellect, saving long descriptions, and 
capable of being wrought up into almost any degree of accuracy 
when required. But in proportion as they are easily made and 
easily understood they require to be carefully looked after. 
They may be misunderstood either by giving them credit for 
accuracy that does not belong to them, or by the want of a due 
0 -jnsideration of the exaggerations and disproportions that so 
often accompany them. Very few geological books give real 
sections. The great majority of purely geological and tech- 
nical memoirs make no pretensions to accuracy in this respect. 
In them generally sections are used as diagrams to express 
certain facts and save long description. In this light they are 
eminently useful if thoroughly understood. Perhaps the 
account here given may assist some of our readers to regard 
them in the right light, and assist in rendering the ideas of the 
rising geologists definite in matters of stratification. 
