Jeffersonian Republican. [volume] (Stroudsburg, Pa.) 1840-1853, 1850-08-01

not uncommon. And every where the deeper
4 they are sunk, the warmer is the water they bring
up, and they furnish an additional proof of the u
niversality of the interior heat Of our palnet
/ V. DEEP MINEs.-After descending about 40
feet the temperature of the earth remains the same
both in summer and winter, below that depth il be-
comes warmer as we descend. This increase oi
heat downwardly advances with perfect regularity
"a little faster in some places, and little slower
in others, but in all, without any exception, there
is an unvarying advance On an average around
the globe this increase is one degree of Fahren-
heit for every SO feet in depth. At the bottom OF
the mines in Cornwall, the thermometer stands 50
degrees-ihis is 1900 feet below the surface and
much warmer than summer weather there. We
can conceive Of nothing calculated to stop this ad-
vance of heat in the direction towards the centre
OF the earth, and lift continues to increase accord
ing to the asceltained average rate, then all
known substances must be in a melted condition
90 miles below the surfaced At this rate we must
| volcanoes, for the crust Of the earth must be a
/ she'll resting on molten food Earthly materi-
ais non conductors and therefore this internal
heat cannot escape, affect at the surfaces
In the same manner streams and pools of lava
1 become cooled and hardened on the surface, and
thus their heat is confined, and their interiors after
remain many years in fluid state.
! VI. Fossil Remains of Plants and Animals
These remains show that tropical plants and ami
mails in former geological eras furnished in the
Polar regions. The ivory Of the elephant is dug
up, and furnishes an important branch of industry
on the extreme Northern shores Of Siberia, and
delicate corals of the present warm and mild o.
ceaus. displayed their glories during former peri
DDS in what is now ice bound regions of the Arc
tic zone. Thousands of facts like these from ev-
cry department Of animated nature, proclaim for
mer high temperature in all high Northern latti-
tudes, and this slesated temperature can be ac-
counted for in no other way than from the infu-
ences Of the internal heat of the earth. II has
cooled gradually by radiation TO its present state,
and further sensible cooling is prevented by the
non-conducting crust in which it is enveloped
VII. Ertinct Volcanoes. These by far ont
number the present active ones. In North Amer
ica along the whole line of the Rocky Mountains,
and through the West Indies, they stand thickly
as monuments ofthe past. Their craters are sym
metrcally formed, and they exhibit the same lava
streams, though in hardened state. as those now
burning Ia Germany along the Rhine, travellers
speak of 'the casted crag of Drachenfels," the
Eipel, and many others presenting the same phe-
nomena. The centre of France is studded with
them. especially about Clermont. Tn Italy the
town Of Guinea founded thousand years before
the Christian era, is built in the centre of an ex.
tinct volcano. There is space of go miles in
length and 10 in breadth, there are sixty extinct
craters, one OF which is two miles in diameter All
these with others in every quarter of the world,
should be joined with the 300 that are now burn
ing, if we wish to have the full proof of the fiery
wonders in the interior of our globe.
VIII Lgneous Rocks BY these are meant all
rocks that are not strati6ed, such as the granite
siente and trap They exist abundantly--the
granite as we have before remarked forming the
great foundation rock around the whole globe =
The evidence that they have all had their origin
from liquid fire, are complete. Their position is
beneath, or rising from beneath, the very region of
intense heat. Their shape shows former liquid
condiiion--having been elected in veins, cracks
and crevices of other rocks. Their effects on
these other rocks have been of burning nature
turning chalk into marble. sandstone into quartz,
bituminous coal into anthracite, and slate into mi
ca. Their texture is crystalline such as mol
ten liquid naturally assumes in solidifying Their
composition Is identified with that which now
streams from volcanoes-such as felspar, horn
blend and silica. The transition is gradual and
perfect from modern lasas into all the varieties of
igneous rocks. And artificial experiments have.
shown that these igneous rocks when melted by
great heat in furnaces, assumes on cooling in the
open air the same characteristics as lava, and it is
known that cooling under great pressure as in
volcanic cone, and afterwards rent by earthquake
forces, and exposed TO vieW--presents the exact
form of trap. This latter fact is exhibited on
grand scale at Mount Etna in the Val del Boye.
Here then we have grand, and magnificent evil
dence of the interior heat of the globe-the igne-
Gus rocks, entirely betting around our planet, form
ing the foundation of the earth, rising into lofty
mountain peaks and mountain chains, and yet all.
having their birth from former melted condition.
la this truth all geologsts agreed and confirmed.
The southern shores of that peninsular presents
similar appearances both of rising and of falling
Ancient temples standing on the shore have been
so far let down that the tops OF lofty columns now