Green-Mountain freeman. [volume] (Montpelier, Vt.) 1844-1884, 1855-07-05


place Of the metals are substituted such bad
conductors and non-conductors as rock and lair.
This suggests, too, the probable cause, why the
heat OF slate exceeds by several degrees that Of
granite at the same depth. And this explana-
tion receives confirmation from the fact that
while at 81 fathoms, the difference is 5 40, at
200 fathoms it is but 4.3I. If granite be the
poorer conductor, the temperature should in
crease proportionally faster in this, as we de-
scend, and the difference constantly diminish
as it does.
4th. This sincrease Of temperature can be 9TH
crwise accounted for. confess do not under
stand the reason assigned. do not see how de-
fectiye circulation can be in itself a cause as
higher temper&ure; though doc - -
should be reuaved
quiescent. vsnti
sence spSa 2
may be said
bearing upon ths ~
tcnsest cold are usually Tisil! lud! INC
other cause assigned is the greater pressure of
the atmosphere. How much influence can justly
be attributed to this! 1t is well known fact
that the air pes colder as we ascend, at the
rate Of about = e degree for every 800 feet !;
three degrees for 872 feet; six degrees for 1889
feet. The temperature diminishes, then, as we
ascend, in more rapid ratio than the altitude
increases. conclude from this, that, as we
descend, the temperature Of the air-supposing
condensation to be the sole cause of variation
would increase less rapidly beneath than above
the surface of the earth though I can discover
from the above and other data, no constant law
of increase. We will estimate the increase,
however, to be one degree for every 800 feet !;
and on this supposition, the thermometer ought
to register difference of less than 2.8o between
the depths of 81 and 200 fathoms while in the
article referred to above, the change of temper
ature between these two points in slate rock is
given at 1850. But not to particularize, the
ratio of increase as we descend in the @ria
ocean-one degree for 800 feet, which is too
great for all estimates below the er-level-il
80 much smaller than that established by almos
innumerable observations on thermal springs
and in the solid strata of the globe-one degre'
for every 40 to sixty feet, in the above instanc'
one degree for but 30 feet-that VIC must sup
pose the latter dependent upon On altogethe
d;st:,ot o,uso prt tbn ,o 49,
heat must be due, in part at least, to- othe
causes than condensation. The air is warme'
principally by reflection and radiation from tn
earth, so that the lower strata must be warme
than those more elevated, because nearer thei
source Of heat. Again, suppose body Of ai
to b. condensed, and its latent heat thus mad
apparent it would soon impart this supera
bundant heat to surrounding objects, till it wa
rkuced to their temperature.
Think it fair to conclude, then, ,that, neither th
kinczsased pressysa.saer waHt Of ciscnlation. %
hsuch affect the heat of our globe at grca
ptbs. What, then, does influence it Th
"A pical theory seems to me to be inadc
quate TO It's explanation, as also to the explana
tion Of the phenomena of earthquakes, volcani
eruptipns, gradual changes of elevation takin
place over wide regions, the upheaval of mour
tain chains, the tprobable) former high temper
ature of the colder regions of the globe, 81
Nor can conceive how chemical agents coult
for SO many thousand years, maintain such un
= formity of action, without any perceptible d
minution of their force. All this, as we'll {
tho peculiar form of our plansf-an obla'
spheroid the formation of coal mines, the eli
walton of islands in longitudinal ranges, 81
seem to be most satisfactorily explained by I'll
theory. But there is no room to attempt
justify this theory, or to notice other objection
to it, in this article, which has already grow
too long. C.