354 Geological Survey of the State of Ohio. 
from an investigation of the zoology and botany of Ohio. From 
it we make but a single extract. 
“By knowing the habits of insects, we can often obviate their attacks. 
The farmer may find it advantageous, in those sections of the state where 
the Hessian fly is common, either to postpone sowing his seed until the 
time for depositing the egg of the insect has passed, or to substitute spring 
for winter wheat; and it is also probable that some of the winter varieties 
of this grain may yet be found with stalks so solid that they will resist the 
attacks of this enemy. Many years since, the timber in the navy yards 
of Sweden was rendered unfit for use by the perforations of a small worm. 
The government applied to Linnzus for a preventive of its attacks. He 
recommended to have the timber sunk in water during the few days that 
were occupied by the insect in depositing its eggs. The remedy was 
perfectly effectual; and, simple as it was, saved more than a million of 
dollars annually to his country.” pp. 68, 69, 
The report of Mr. Briggs embraces all the economical facts col- 
lected by him and Mr. Foster, on the detailed survey of the south- 
ern portion of the State. There is an accompanying section to 
illustrate the superposition of the rocks between the great lime- 
stone deposit and the upper part of the coal series. 
With respect to geological sections, says De La Beche, too 
much stress cannot be laid on the importance of rendering 
them as conformable to nature as circumstances will admit: that 
is, the perpendicular elevations and base lines should be, as much 
as possible, in proportion to each other. Without this necessary 
precaution, such sections are little better than caricatures of na- 
ture, and are frequently much more mischievous than useful, 
even leading those who make them to false conclusions, — = 
distortions and false proportions of the various parts. 
It is clearly in the interest of science that they should be er 
they pretend to be, miniature representations of nature.* To 
this section we have three objections. 1. The strata are indi- 
cated without reference to relative thickness. 2. They até 
represented as nearly horizontal with a uniform dip of 30 feet 
per mile, whereas they are more or less undulating. We think 
sit. then physical features of the country could have been 
indicated on the section. Our third objection is of a more serious 
character. The conglomerate is erroneously represented as €X- 
ppepaly to Bainbridge; whereas the outcrop of the con- 
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* Geol. Manual, Phila. ed. 1832, p. 519. 
