ome timCi and so over to an arable Belli on the oilier side which wiis
strangely torn and disordered- The second posture field, being more soft and springy, was protruded
forwni-d witliout many fissures in tlie turf, which was raised in long ridges resembling
graves, lying at riglit angles to the motion. At tbo bottom of tliia ¡«closure the soil and turf
rose many feet against the bodies of some oaks that obstrueted their further courso, and terminated
this awful couimotion.
"The perpendicular height of tlic precipice, in general, is twenty-thice yaixls ; the length ol'tlic
lapse, or slip, as seen li-om the fielils below, 181; and a partial fail, eonccaled in the coppice,
extends seventy yards more: so that the total length of tliis fragment that fell was 2S1 yards.
About fifty acres of land suffered from this violent convulsion; two bouses were entirely desi
roved; one end of » new barn wa.9 left in ruins, tlie walls being cracked throiigli tlie very
stones tliat composed them •. a hanging coppice was changed to a naked rock i and some grass
grounds and an arable field so broken and rifted by the chasms as to be renderc<l, for a time,
No. II.
EARTH FALLS AT THE UNDERCLIFF, I.SLE OF WIGHT.
NitoQ.J«». 2S. 1840.
Numerous slips of tbe soil bave taken place in tlie Isle of Wight during the last and previous
months; in two instances they have seriously injured the high road, and caused it to be impassable
for the S|Ktcc uf a fortnight.
Tlie fliit case occnn-ed at Ventnor in the middle of November, where ii settlement stiowed
itself for a length of Afiy yards, affecting half the width of the road it continued to subside
until at the end of December it hnil sunk as mueh ns five feet, and thrown down a row of new
cottages which were situated on a steep bank below it: some of the principal houses occiliiying
the wood side above it art: now standing within ten yards of the late fissure. Drains have been
laid down to a depth of thirty feel, and the ioa<l has been in a great measure restored.
The second case, above alluded to, occurred on Christmiis Eve at lilac k Gang, six miles dialant
from Ventnoi- on the same i-oad- Both of the three spots are situuleil in the undtrelilF, a remarkable
tract nine miles in length, and fioui a quarter to half a mile in hrciidth, exieniling
iilong the southern const of tlie island from Dunnosc on ihe east to Black Gang on the west-
The roadway at Blaek Gang stands iinderneaih « pci pcndleuiar cliff of 2.i0 feet upon a natural
terrace, and the seii lies 400 feet below it at a distance of half a mile. The settlement destroyed
this road for ihe space of 100 yards, thrusting it seaward thirty-feet, and deiirussing it twelve feet,
with an inclination outwards, and again in one part undermining iB inner side and giving it a
violent dip to land. The disturbing cause was a spring which crossed the subsoil at right angles
to tlie road, bi'ancliing also in a direction paiallel lo it. The ci ust of tlie load was. entirely
broken into numerous seams from one to two feet wide, and about a font apart ; and so violently
was it distoitcd in iis general aspect that it became piixzling to ti-ace lis course. 'J'lie whole of
the dislocation took place between noon and niidnight on Tuesday the 2.111, of Ueceniher, heini:
nearly the same time as that at which the movenient of the iinderclilf began at Axmouth,
Fifty men were immediately set to work, and several drains were made of al.ont Iwe.itv feci
deep uniler the l oadway with tiles at bottom, and above them a laver of coarw rubble'stone
guarded by furze bushes: ihe road was put into a stale of temporary repair, and reopenc..l ro tinpublic
on thelOth ult.
There are three other inland subsidences of equal and greater iimgnitude wiihin two mile« ct
Blaek Gang, and innumerable lesser ones, besides frequent slips of the sea cliff; the gi-catest ol
these Is trifling when compared with the movement of I "99. Seven acres of land ai-e said to hav,.
settled in the neighbourhood nf Alum Bay nt the west CJtremity of the island.
One of the slips above alluded to has continiwl to increase f.v slow degrees from Christilws t..
tlie present lime. The spot is situatcil a qnnrter of a mile inland at tlie soutliern point of tlie
i5land called St. Catherine's! it lies below the upper cliff, and ccrasequontly the stratification i?
dislocated, and no strict account can he given of the soil. The form of tlic subsided groiind i»
tliat of a horae-shoc, with tlieheel towards the sea, mid it is situated on the slope of a sleep ridge:
its length from north to south is 180 yards, with a fall of 120 feet perpendicular ivhen in its
original position: its average widtli is forly-five yards-
Tlie u|iper portion has sunk so as to present to view, instead of a sloping l«ink of turf, a cliU
of seventy feet high i and its lower portion, «'hich has received the descending mass of earth, hac
been raise<l above the previous level, and ut the bottom fonnsa monnil of eleven feet in heighi.
The original turf still forma the surface, but it is burst into iiinumeialilc fragments, between
wliieh the under-soil appears brimming over in a slate of tlic utmost moisture. iNumerous little
pools of standing water are to he seen upon the surface, although the ground has a.steep dcclivity.
and is moreover scored with so many seams.
The disturbing cause in this instance has been a spring, which makes its ivay tliroiigh the
ridge, and is coii6ned in its course by some large ma.«es of blue marie or guiili.
It happens invariably in the iin<lercliff, that when a mass of soil or rock i^esls upon a subsoil
of gault, and when the upper layer of that gault becomes saturated and lubricated by wet, u slip
takes place. The gault is here fainiliarly called the " Bliii; Slippur."
The formation of the unilerelifl' itself is due to this agency, tlie order of the original strata of
the subsided down being clialk, smdrock and greensand, and gauli which i.s im|)crvious and
detains tlie water that percolates fiom above.
In excavating a drain at St. Catherine's Point, a bed of wood, leaves, mos,, acorns, filberls, tcv.
has been discovered sixteen feet below the surface; some sound, some reduced to peat. It i.
remarkable that the oak and hazel will m t grow in this neighbourhood at present*.