)rccccling cx|)1aiiatoi-y obscivniions on ihe pnrliciiliii' local caoscs «-hicli have produced
ibsulciccs. Imvc been especially diwcteil lo tl.,; case of the formation of the great chasm ;
i I'lwir tliiit similar cxi)lanalions «•ill equallv nppiv to the ininor (llslocalions wliich have
the neifflihoniing iinclci-clift-.
ION OF THE ELE\'ATED SUBMARINE REEF,
N THE PROBABLE CAUSES OF ITS ELKVATION.
••cma.kablc c< icled wi is clistiirbanoe, il
•uiergi-HCe. A long .-c
The visitors who iiispectecl tl
scrauihlinffovcrthese upraised (
»ui race coveieci « itli sea «-ecil,;
Tlic nnildle oftliis i-eef Is .mil
level of the highest tides; hut tt
at th! Uiuc of ÜI! iUff, I
.ki wl,™ .CCD from the It
r.t iiDpicai»« of tiosc wf
•ould more correctly tenn its appearance a rcng
nearly tliree quarters of a iiiile, and having
feet in advance of thcoriginal line ofhigh water,
at original condition, more lhan ten feet helo«-
point now i-aised aliout forty feet ahove high
>ut nveiity feet of cherty sandstone, reposing
rith allernnting layers of tlic indurated form of
is of the fox mould at their jnnclion with Ihe
icter of loose sand for a more consolidated texat
angles from
1, and 0
esof
softer :
:e of this easier
•eh il,c appcara
rdcr beds,
re singularly iitruck while
sal this level treading on a
lingle just raised above (ho
he ridge projectcl in arms,
1 n-as that of a respectable
tlie neighbouring Cobb at
sly have floated a boat over
being at
it grows
>ther li ry. The greatest deplb of this basin is said to ho
lo«- water; hut as portions of the i-ocks lining it are drifted
ihallow. The portion of the reef skirting the western gulf «
withiu the fiist six weeks mucb washed in, so as to reduce it into two small pools, which becai
filled with fresh water; this is the slate represented in the plan, I'late I.
The ailjacent sea clifT overhanging this iiewly-i-aiscd reef has been very materially altered
its features by this distui-bance; it originally picsented a uniform inimd face, vai^ying
lo more than one hundred feet in height, cai)ped with chalk, and occftsioiially showing patcl
of gi-een fox mould near the base, the intermediate portions being composed of cherty sandsto
In the centre and towards the eastern extremity stood the pvojecting rocks before described
the great and little pinnaclcs (sec Plates II., VU. and VIII.). This clilT is uow shattered, prese
fifty
broken down, and in some places has considerably subside
feet in advance of its former line, as indeed we should be n:
rous fissures that have opened throughout the imdei-cliff li
great pinnacle was split across its base, but stood for a liir
The lesser pinnacle, before a prominent land maik, now pr
in height, which at first sca.-eely attracts Ihe cycf.
H least fil
The I
•ated b.
accompanied si
milar e
already remnvked, that the ¡)rior subsiilence whit
tt liich took place a few weeks later in the adjoi
examples of submarine elevation. In all these
hypothesis of latei-al and upward pressure, a)
single instance of sncli a pho:nomcnon hav
1 adjoining parts of the same const, We h
I occui-red fifty-oiie years ago at Ueei'. and t
ing cliff of Whitlands, present exactly sim
cases we should be inclined to adopt the SL
ding the most pi-obable solution. 'I'IIÌH press
d, from tlie weight of tl
sand reduced into the :
subsiding masses, under hydroslate
of quicksand : where the point
duce a burst upwards. Now that
however, standin g in the very co urseofthe chasm, was. ¡ntirely destroyed. Tbe tenants of the
farm when firat t listnrbed in the 1 opening, but after
they noticed it tbe
whole was over li 1 a quarter of an hour. The Severn was
: in high Qood at tbe
time, thei-efoi'e the
et. This convulsion is n? ell known from the narrative published
by Flecher of Ma deley. In the p iresentwet winter of IB' 10 many new and coi isiderable landslips
have taken place from time to tin le in the same district c ifCoalbrookDale.
Mr. Murchisoi ble ecroulement at
Chnrn Bank, or 1;h e Palmer's Caii: n, near Ludlow. Like ^íarclay Hill in the upper Ludlow beds.
the area here affc; otcd exceeds fidty acres, but the date of the disruption is un Icnown, Tbe same
author mentions many other trac, !S of similar landslips in
;. ALPI 5 ECROULEMEj
PliEenomena precisely similar tc last described a
occurrence in alpine countries. The earliest mention we find of the tenn "landslip" occurs
with reference to these alpine regions, in a section of Livy, describing the passage of
Hannibal, vol. xxi. c, 36. "They then came to a much more abrupt crag, where the rocks
were so perpendicular, that the soldier could with difCculty force a patb, clinging with his
hands to tbe twigs and projecting stems, that he might thus let himself down ¡ for the spot,
before precipitous in its original form, had been broken down to the depth of about 1000 feet by
a recent LANUSLIP,"—natura loeusjam ante prO!ce¡ií, recenti, TBILRI-LIPSU in pedum viUUadmodum
Considerable convulsions of the same kind are recorded to have happened in modern times.
Thos large dislocations of masses of the green sand forming the tops of the high mountains of
Diablerets and of Mount Chede, near Servoz, have taken place; but the most tremendous and
fatal event of this nature is that which occurred within the present century at ebe Ruffiberg or
Rossberg, a mountain on the sontb-east of tbe Lake of Lug. This is far too well known to
require any detail; it will suffice to state that in this convulsion the whole flank of a mountain,
forming a mass a league in length, 1000 feet in breadth, and 100 in thickness, was precipitated
towaiKls the Lake of Lowerz, in which it produced the most violent and protraeUd agitations j
it buried whole villages in its rains, and occasioned the loss of hundreds of lives; the mountain
consists of beds of the conglomerate called Nagelflue, alternating with sand and clay. It occurred
in the summer of 1806 after a season of excessive wetness, and is universally ascribed to
the undermining agency of tand-springs, altliougb the uninformedinhabitantsof tUedistriot were
at ñi'st very anxious to represent it as an earthquake.
In other parts of the Alps the remarkable t
ecronlemens of considerable magnitude, by 8<
has been rendered impassable.
[. CONCLUSION.—RECAPITULATION OF ARGUMENTS EVINCING THE
CONVULSION OF THE BENDON AND BOWLANU'S CLIFFS NOT TO
HAVE BEEN PRODUCED BY AN EARTHQUAKE.
I that tl strong a sensation, is
means a single case, but cieariy referable to a class of which i
corded : all which have ever by competent observers been ascribed to the aqueous c
have been indicated in our pre&tory remarks; and as we trust wc have shown that i
arc fully adequate to account for all the phicnomena we
fuily sufficient. But we have been rc|ieatedly asked whether wc could undertake
tbe phsenomena could not have been produced by an earthquake; and although the demand IK
somewhat unreasonable, we are yet fully pi-epared lo comply with it, by showing that these pliienomena
ht bave appeared
are absolutely inconsistent with everything known concerning the history and effects of
eartliquakes.
True earthquakes are tremulous concussions of the earth's surface, originating in deeplyseated
causes, and therefore necessarily spreading over tracts of considerable extent. But
here all the pb®noraena were local, and limited to a very confined s|)Ot, and altogether unac-
)mpamed with any appearance ol , The
Bendoa Clilf chasms compared with which the fissures occasioned by recorded earthquakes
dwindle into insignificance, yet neither shook a tile loose, nor cracked a pane of glass in any of
the adjacent farm-houses of Rowsedown, Dowlands, or Bendon, all within three quarters of a
mile of the great focus of disturbance a fact in the most palpable contradict ion with every record
of the operation of true earthquakes. Tbe cottages also, wliich at Dowkmds and at Whitlands
had been brought into a slate of ruin, evidently showd that ruin to have been accomplished by
tlie squeezing forcc impressed by the irregular subsidence uf the ground, and not by anything
like tremulous motion: forwhile portions of the side walls were rent or forced outwards, the
chimneys had in no case been shaken down.
The reader may be referred to the works of Von Buch and the a<lmirable summary in the first
volume of Lyell's Principles of Geology, to show that the regions affected during the historical
period of the globe by earthquakes of any violence, are limited to certain definite zones, and also
marked by the presence of active volcanoes, which may he consiilcred almost as distinctly
ascertained in geographical position as the continents and oceans themselves. Of these volcanic