DRIFT DIVISION. 217 
a flow of water from the polar regions, that cannot be explained by any known dynamical law, 
then such a contraction is highly probable.* 
A long train of argument might be brought forward on each of these subjects, both tending 
to the same result. I shall treat them very concisely. 
(A.) Refrigeration and contraction of the earth. 
(a.) The investigations of various philosophers have demonstrated beyond all doubt that the 
earth becomes more and more warm, as we penetrate farther below its surface, (after having 
passed the surface of equable temperature, down to which the temperature is variable from 
the influence of the seasons.) 
(&.) The/om of the earth is precisely that which would be due to a fluid body revolving 
with the present velocity of the earth ; and there is no other cause to which we can properly 
ascribe its former, and probably its present interior fluidity, but caloric. 
(c.) The varied mathematical investigations of Fourier, Cordier, Poisson and Svanberg, 
upon caloric, the refrigeration of heated bodies, and upon the temperature of the earth and 
of space,t notwithstanding the various conclusions, all tend to show that the earth is in a 
cooling state, and radiates into space more caloric than it receives, although it has long ago 
reached what may be called an asymptotic condition. 
These may be considered as affording evidence almost demonstrative that the earth is a 
cooling body, and consequently diminishing in volume ; consequently increasing in its velocity 
of rotation, and in the centrifugal force; and, consequently, in the tendency to a flow of 
water from the polar to the equatorial regions. 
(B.) Currents from the polar regions. 
The train of argument on this subject may also be reduced to a few words : 
(a.) It has been shown that the general directions of boulders and erratics are south¬ 
wardly from their sources and the scratches, in most instances, are also similar in direction, 
in the northern hemisphere. 
(&.) That currents aided in the transportation of most of the erratics, is evident, by most 
of them having been deposited within the areas of the principal valleys of drainage, or through 
which currents would necessarily flow, if the waters of the ocean were at a relative elevation 
* If it can be shown, in addition, that there ARE dynamical laws that necessarily cause such currents as we have under consi¬ 
deration, that have acted through all time when there was a fluid for them to act upon, and that they wotild be heightened in 
effect by the refrigeration of the globe, and that we can trace distinctly the effects of such causes, the evidence may be considered 
demonstrative. The discussion will necessarily be somewhat discursive, instead of being confined to distinct propositions. 
t Memoirs de I’Institute. De la Beche, Geol. Manual, p. 24. Berzelius, Annual Progress of Chemical and Physical 
Science. (Edinburgh Journal of Science, Vol. 3, New Series.) 
t Some local exceptions around elevated mountain ranges are well known, as around the Alps, and the northern primary 
region of New-York; and it is probable that others will be discovered. 
Geol. 1st Dist. 28 
