Chicago eagle. [volume] (Chicago, Ill.) 1889-19??, 1893-02-18
POPULAR SCIENCE NOTES.

marked upon, and the process which is
now claimed to be the most successful in
accomplishing this end is described as
neither complex nor costly. Starting
with the well-known understanding that
air is mixed with coal gas and with by
| drocarbon vapors, and the compound,
when burned, generates much greater
heat than If the air were absent-a
| powerful air blast being also great
economizer in smelling and reducing
ores-the important fact presented IL
! this new method is that the fuel is the
air itself, which, as a powerful blast is
directed upon an incandescent substance,
as coal made white hot, pure carbon, or
any other materials that can be made TO
glow. Coal, hydrocarbons, etc, may be
employed to give the initial incandes-
cence, but once the blast strikes the
luminous body, the utmost intensity of
heat is secured, apparently by the com
bustion of the air, and may be main
tanned for an indefinite period by merely
pressing the incandescence of the surface;
this latter it is stated, may be done b., a
slight manipulation of the surface
brought to incandescence, and with
some slight renewal of carbonaceous
material.
Is OUR GLOBE MoLTEN2-The curl
osity of people regarding the inside
the globe upon which they live, says the
". Y. Times, has close analogy to the
incuriosity of the average individual man
regarding his own internal construction.
Mr. Alfred Russell Wallace in the Fort
nightly Re0ie,O puts forth some interest
ing opinions upon the nature of the
earth's central mass. TO be told that we
re separated from the molten liquid
with which, in his belief, the earth ia
filled, by crust only eighteen miles il.
thickness is at first thought little alarm
ing. That, however, is the view to
which Mr.. Wallace lends the weight of
his authority. Mr.. Wallace is, indeed
rather naturalist than geologist,
but any views of his must have
certain interest. BY the way,
he considers that the suggestion which
has before been referred to in these col
umns, namely, that some use for mankind
might be made of the earth's internal
heat, is not at all impracticable. There
is, of course, no doubt of the existence
of this internal heat Among the indi-
cations of it are volcanoes, geysers, and
hot springs. Another evidence of inter
nal heat is the universal phenomenon of
an increase of heat in descending below
the earth's surface, as is seen in mines
and wells This increase has been com
puted to be about 1 . Fahrenheit for
each sixty feet of descent. There is some
variation, however, according to
the locality In a recent boring at
Wheeling the rate of increase of heat was
found to be greater as the depth in
creased. The average rate of increase,
so says Mr. Wallace, would imply tenn
perature capable of melting rock at the
, depth of about twenty miles. That the
Earth central heated mass is liquid is,
of course, a necessary part of Mr.. Wal
!ace's theory. The favorite belief among
biologists for the past forty years has
been that the earth is solid This was
. the opinion of Sir Charles Lyell and Sir
, William Thomson. But Mr. Wallace as
serts that the tendency of recent geologi-
cal opinion is in the direction of the
, liquid nature of the earths mass. Mr..
Wallace's opinions, we should add, are
based upon those of Mr. Osmond Fisher.
J 1t is claimed that the facts regarding the
strata of rock found in mountain regions
and the deposits ut the mouths of great
, rivers like the Nile and Mississippi con-
2 form to this view. The theory is that, as
| deposits are formed the earth's crust
e sinks from its increased weight and that
= the liquid condition of the earths inner
/ mass allows the crust to so sink. A depos
it is formed in shallow water and sinks
from its own weight. Another deposit
is formed on top of that and the entire
mass sinks still further In mountain
> regions there are piles of strata, hundreds
= and even thousands of feet thick, which
present throughout the indications of hav
:, ing been formed in shallow water. The
: paleozoic rocks of the Allegheny Noun
tains are not less than AZ 900 feet thick
Yet the lowest of these strata, the Pots
i, dam sandstone was not deposited in &
" deep sea, but evidently in shallow water
= near the shore, the beds exhibit
ing distinct river marks The SAME
9 phenomenon appears in the geological
= records of the detas of existing rivers
: At Venice boring of 400 feet has beer
: made entirely in river mud, and neaF thc
bottom were found beds of turf an6
, vegetable matter. In the delta of thu
! Mississippi well at New Orleans, 63C
feet deep, passed through sands ant
> clays containing freshwater shells o
species still in existence The specific
! gravity of the inner molten mass is, o
4 course, according to this theory, some
i what greater than that of the earth
:, crust and has about the same relation t
: it as that water bears to ice. If thi
. were not so, the formation Of
/. crust would be an impossible
- ity, since the crust would Away
2 be sinking into the liquid mass
!. As ice remains and forms a crust above
% water by reason of being slightly lighte
= than water, so does the earth's surface
form a crust above its molten liquiC
+ mass. A corolary Of this view OF Mr.
Il Wallace, or rather, we should say, o
Mr.. Fisher, is that mountains have
> "rootsn; that Is, as iccbtrgs have grea
= masses under water, so do mountain
= have masses sinking into the earth
" liquid matter. The fact that In the 81
! Gothard Tunnel the rate Of increase o