Evening star. [volume] (Washington, D.C.) 1854-1972, 1883-08-04

From Good Words
The Interesting question of the origin and rise
Of mountain chains has been made the subject
of more especial investigation by French and by
American than by English biologists. Nearly
half century ago the late Ellie de Beaumont
gave to the world the result of his researches, in
his "Systeme des Montagnes rim which he pro-
pounded an hypothesis that still receives very
general acceptance on the continent. but which,
except in q modified view, has found few sup
pOrters in this country.
Assuming for our globe an outer solid crust
with central liquid mass, this distinguished
geOlOgist showed that the earth is necessarily
losing some portion of its heat by radiation from
the surface. and that this process Of cooling,
which has been going on at a slow rate from the
earliest geological times, the central mass
to contract and lessen in volume. This lessen
ing Ofthe heated nucleous has led the crust to
comfort itself in order to fit adapt itself to the
diminished volume of the central nucleous caus-
ing the crust to wrinkle fold in great cOrruga-
tions. or TO fracture. and the fractured edges to
squeeze up in lines of mountain chains.
He showed that mountain chains have been
formed at all geological periods. and that their
relative age could be ascertained by determining
the age of the tilted mountain strata and the
age of those strata which abut horizontally
against their base For 1t is evident that the
mountain range must have been elevated before
| the deposition of the strata which lie horizon
tally at their base. and which are unaffected 10y
the disturbance. that threw up the mountains.
1t follows. therefore, that the mountain cham is
older than the horizontal strata and newer than
the upheaved strata. Thus the age of any
| mountain range is easily determined, relatively
| to the successive groups of strata forming the
| Sedimentary series
Ellie de Beaumont further argued that, as
| the crust of the earth must have become
| thicker by secular refrigeration, it follows that
| the crust was thinner and less strong at the
earlier period of the earth's history than at the
| later periods and, consequently. that the
crumplings and mountain chains, although more
| frequent, were not on so large scale in early
geological times as when the crust had become
| thicker and more rigid.
=. But although there is no doubt that some of
| the oldest mountains are very insignificant in
height, we have no means of knowing what
| their original altitude was or how much of
| their mass has been removed by wear and de-
mutation. Some of the hills i'm the neighbOr-
hood of st. David's. in South Wales. are neither
majestic nor lofty, yet they are among the ear
| Hest of our mountain ranges.
Or look, again, at a range of hills of much
later date; yet still very DID, as, for example. at
the Mendips in our own country and the Arden
mountain Chain, raised before the formation of
our Oolitic hills of Bath and Cheltenham, or of
the Lias cliffs of Lyme Regis 1t is possible
that this range, whlchis now Of comparative in
sgnifcance-in no case attaining height of
| 1900 feet in either England or Belgium-fOrmed
at one time lofty mountain chain. For, judg-
ing from the portions that are wanting and have
been removed from the Mendips, it has been es-
timated that those hills may at one time have
had an elevation Of not less than 6 600 to 5000
feet above the plains of SOmersetshire. while
the Belgian biologists have shown that the Ar
dennes might have scared from Is, 600 to 1S 600
feet above the plains of Belgium. This chain,
now so unimportant. may at one time have
wed with the later-fOrmed Alps and Apennnes
in height and grandeur. How strange and
striking a picture our corner of Western Europe
must have presented in that early age, when
the English channel was not, and when great
chain of mountains, possibly snow-capped,
ranged from the Mendips to Westphalia! The
portions which remain are. as it were, the worm
down stamps of this great mountain chain. the
whole of the vast superintendent mass having
been removed by wear and denudatiOn con-
tinued through long geological times. And
such has been the case in many other mountain
regions OF our globe: on the one hand defOrma-
ton being produced by subterranean forces,
and on the other planning down and leVelling by
| meteorological appncipS