LAC BARRÉ PAR UNE MORAINE

brooks leap, crosses the entrance to Cwra-y-clogA^Tn , but it is casily accessible y and on the summit of a kind of enclosed tableland lie three tarns ; circled by crags, the loftiest of which, — Pen- WyddfaS — or the peak of Snowdon, shoots high into the air, more than 1500 (457 mètres) feet above the lakes. The whole valley is whal in the Highlands of Scotland would be called a Corrie (or cauldron) , a Geltic name that still lingers in Wales on the north face of Cader Idris ^ though its meaning is now lost to the Welshman.

On the ice-worn surfaces of greenstone and felspalhic porphyry, >vhich form the bottom of the valley, siriœ are easily found y running north-westerly towards its mouth. It is difficult to unravel ail the minuter détails of the glaciation of a valley from which enduring ice bas so long vanished ; but after many a visit , I came to the doubtful inference , that a glacier probably at one time covered the whole bottom of the Cwm , which is still more or less covered with triée moraine matter. This is rendered noth the less probable by the circurastance that due west of Llyn-y-nadroedd*, the rocks are polislied and grooved to the top of a low part of the bounding ridge , as if the glacier had once fiUed the valley up to this point and overflowed towards Llyn Cwellyn '. Afterwards , as the supply of snow decreased , or the climate ameliorated , the glacier seems to bave much diminished and split into three , for a minor moraine encircles Llyn-y-nadroedd on the north and east, and another beautifui small oûe made of angular blocks and stones , now covered with végétation, bounds Llyn-goch*, on the west and south-west, while a third dams up Llyn-glas. A long broad heap of débris runs in the direction of the length of the valley between Llyn-y-nadroedd and Llyn-goch, perhaps shed from two minor glaciers passing down to the lakes. If this were the case, the débris toppled over from the opposite sides of the glaciers y and formed a mound between them , on which thre enormous blocks ofporphyry stiU lie.

' The meaning of < Wyddfa > seems to be quite uncertain. It is said to mean « wild , untilled land,» andalso «the place of présence» (7), or «the eminence» pre-eminently.

* Snake's Pool.

' Unless thèse stHations were formed by drifl ice,

* Propcrly « Uyn^câch • or Red Lake.

Hochet polici et striéet.

572 VALLÉE DE LLYN LLYDAW (sNOWDON).

^'""*« R. 7. Of ail the valleys Ihat lie in the heart of Snowdon , Ihe lar-

(Snowdon). g^st and most magnificent is that of Llyn Llydaw. It is easily reacb». j from Llanberis over the sumrait of Snowdon, or by Cwm-glas over the ridge of Crib-goch ; but both for the lovers of scenery and for those who specially careto observe its glacial phenomena, it is bettr^r to goup the Pass of Llanberis to Gorphwysfa, and so strike into t!;- Valley; or, if Ihere be time, to cross the broken ground to Ib^. right of Nant Gywnant, and from thence ascend Cwm-Dyli', by th ■ calaract to Llyn Llydaw. This route is most instructive , especially if the sides of the Pass bave been explored before ; for then , up L< the watershed of Gorphwysfa, the eye readily comprehends ail ibcorabined signs of an old glacier ofihe largest size in Wales^ especially when habit bas accustomed the explorer to detect in every stage of decay the marks left by the glacier. As already mentionaJ , for hundreds of feet up the sides of the valley, ail the striaiions fud north-westerly along the hills; except in tributary valleys, «/r occasionally at great heighls, where they sometimes conYeq.v a little towards the Pass , as in the higher part of the hollow abuV" Pont-y-gromlech, that leads up to Y Glyder-fawr; or on the hillsiJe about half a mile due west of Gorphwysfa ; and again on the watershed directly west of Llyn-Cwm-flfynnon , where they run both towards the Pass and Nant-y-gwryd.

Close by Gorphwysfa the striœ run across the watershed , as if at its culminating point the pilcd-up siiouf and ice had flowe i in two directions, on one side down the Pass, and on the oib^ towards Nant Gwynanl just as it now does as the upper en.! or snowshed of the Upper-Glacier of the Aar. At the corner «*f the road at Bwlch-y-gwyddel * some of the striations run east and west, as if part of the radiating mass turned down N^mty-gwryd , where the grooves rund about E. N. E. towanl> Capel Curig. On the Snowdon side of the brook that runs frorn Gorphwysfa to Nant Gwynant, they strike E. and S. E. with tbr run of that branch valley; but on a lower level, at the mouth cf

^-CorrecUy, Dylif, meaning «the rush of waten.i The rushing waters tdliof lK»i à may with propriety be translated « Cataract VaUey. ■ ' Irishman's Gap.

, VALLÉES DE LLYN LLYDAW ET DE CWM-DYLI. 573

Cwra-dyli on both sides of Ihe walerfall, they run nearly due east over Ihe lop of the cliffy ground , showing Ihat a glacier once passed through Ihis opening into Nant Gwynant. Further soutb , opposite Gwastad Agnes S and on the northern part of the ridge of Gallt-y-wenalll', the grooves. on Ihe rounded rocks stricke S.E. and S. S. E., and finally curwing round to the S. and S. W. they strike fairly down the valley on the western side of Llyn Gwynant , and right across the mouth of Cwm-y-LIan.

The meaning of the direction of the striœ at the mouth of the . . . \'"^"

, , , Je Llyn Llydaw cl de

Cwm-dyli is this : — \ glacier ^ ahout three miles in lenglh , flowed cwin-dyii. eastward, from below the peak of Snowdon, through the valley of Llyn Llydaw and Gwm-dyli , and united with a stream of ice , thaï , whéii the glaciers of Wales were at their largest, descended from the direction of the Pass of Llanberis and Pen-y-gwryd , where the ice was then of very great thickness , representing the accumulated snow-drainage of a large part of the broad mountain slopes that lie between the eastern peak of Crib-goch and the southern fall of Y Glyder-fawr. I consider that Ihe resuit of this was to produce a mass of ice not less than 500 feet (152 métrés) thick, just above the présent watershed at Gorphwysfa, for without this I cannot account for the longitudinal glacier stria (ions running along the sides of the Pass of Llanberis 1300 feet (398 mètres) above its boltom. If this hypothesis be correct , then it follows that in then opposite direction the mass flowed down towards Nant Gwynant, being so thick at Gorphwysfa , that its surface was higher than the broken ground between Llyn Teyrn* and the upper part of Llyn Gwynant. On this ridge, overlooking the bottom of Cmw-dyli by the waterfall, the siriaiions strike soulh-easterly , as if the greater glacier had quite overridden the mouth of this valley on its northern side , while on the opposite side the striœ indicate that the tributary glacier filled Cwm-Llydaw so high, that it overflowed its southern bauk on Gallty-wenallt, where the ice roUed over the ridge soulh-easterly, and then curved round to the south, to swell the great glacier of Nant

* Agnes 'Plain or Fiat.

•White-hiU; literally, «White Hill-hiU.»

* Ttym, a tyrant or suprême ruler. Llyn reyrn, aKing's Pool.»

Valléei

574 VALLÉES DE CWM-DYLI ET DE LLYN TEYRN.

Gwynant. Whether under thèse circumstanceSy in the deplhs of C\Mndyli by the waterfall, an undercurrent oîice migbt bave flowed casterly beneath the great mass that covered the mountain , I caRnot détermine ; but it is needless to hâve recourse to il, since the dn> by the waterfall mijg^ht subsequently bave been produced by a dumnished glacier ^ that in the latter days of the ice flowed throu^L Cwra-dyli.

Bv the waterfall of Cwm-dyli there are symptoms of a small h-

de Cwm-dyli el do '' •* •* *^

Liyn Teyro. mitiol moraifies y and ail thrDugh the valley above this hoUow, the:.' arenumerous moraine moundsy sometimes running up the Tall.y in rude lines, some of the blocks on which are ten or IweWe Tard> (12 mètres) in diameter. Half a mile further, north-west of liyn Tem, the roks bave heen polished byiccy and the great bosses of greenstuL . that rise in the midst of the valley like the hill behind Ihe Grhny.l Hôtel y are nothing but huge roches moutonnées , dotted vnth Te!spathic blocks resting on their sides and summits. When large>i. the glacier overflowed thèse (just as in old times the Âar gLui:overflowed the hill behind the Hôtel of the Grimsel), but asit d*:clined there are appearances that seeme to indicate that it brancL'i and wound between the islands of greenstone rock y and , decreasi!:; still further, depositedits m^ainesin Unes y where separate too^Ji: of ice protruded from among them.

ijyn Liydaw. R. 8. Approaching Llyn Llydaw, the fuU grandeur of this wonderlid

valley bursts on the beholder. Â lake rather more than a mile m length and of a green colour^ like some of the lakes of Switzr.:land, runs obliquely across the valley. Ârounditrise the cliffsc; Lliwedd^ Crib-goch, andPen Wyddfa, seamed with veins of \\liii^ quartz , looking like streaks of snow on the tall black rocks thu circle the vast amphithéâtre, the scarred sides and ragged outlm ? of which y shaiply defined against the sky, may well seem , t-'' attempted , hopelessly inaccessible to the unpractised climber. b every season and phase of weather, there is a charm in this val } to the lower of the mountains. In quiet sunshine, whea the roci.'. and perhaps a lazy ferry-boat , are reflecled in the still waler: while the wanderer scales the crags amid the seething mists ; . : when the pitiless rain, or bail, or snow, comes driving do^n ti

* Âbout 1800 feet (550 mètres) above tbe sea.

Lac el terrain crraliqae

valley ; but best of ail , in a threatening evening , when the gathered clouds, like the roof of a vast cavern, hang heavily from side to sidc on the edges of hills ; and a streak of light caught from the setting sun , shows redly behind the dim peak of Snowdon, giûmly reilected in the sombre waters of the lake.

The sings of glacier ice are so évident in Cwm Llydaw that it is needless to describe ail the détails. At the outflow of the lake there are moraine-like mounds , formed of earthy matter , stones y and afigular and subangular blocks , which even now partly dam up the lake, and when I ûrst knew it , raised it to a still higher level , ère the channel of the brook was sacrilegiously deepened to lower the wâter, for the sake of saving a few pounds in the construction of an ugly causeway. Close to the outflow, the once beautiful little islets of rock , feathered with healh and grasses , are now united to the mainland, and a broad ugly black rim round the lake, marks alike the extent of the drainage, and the barbarism of the perpetrators of this unhappy outrage on the most beautiful scène inNorth Wales. Between the upper part of Cwmdyli and the north end of Llyn Llydaw, above the brook, there are magniGcent roches mott- "ormne. «i bioc»

•^ •• ^ perchéi k 80 inèlrfi

tonnées y once overflowed by the glacier; their sides and summits , .nitodcs «u-deua* d»

frooi 200 to 300 feet (60 à 90 mètres) above the lake, being stilP«-

strewn with moraine débris and numerous blocs perchés , scattered

on the rocks. On the little peninsula below, the striœ running east-

north-east show the direction of the flow of the glacier , which ,

unchecked by the hill beyond , passed right over the rocky barrier.

From sings higher up the hill, I believe that at one period the ice ^*^ "■* "'*""*

must bave been hère at least 500 feet (160 mètres) thick, and I in- „^ ^o oot è^i-eL

cline to think that it was even much thicker. On the opposite side ^« iso mètres eipiiu.

of the lake, the moraine heaps, of large blocks y clay , and angular

stones somestimes scratched , are remarkably apparent ; and in the

great recess below the cliffs of Uiwedd , the rocks are wonderfuUy

roundedy and dotted with moraine matter and scattered blocks, at least

5O0 feet (160 mètres) above the level of the lake. In the curve of

that recess there are striations somewhat convei^ing towards the

bottom , in the manner that might be expected to be produced by

ice pressing both down the greater slope , and outwards towards

the moutli of the valley ; and well up , on the broken spur of rock

576 VALLÉE DE CWM-Y-LLAM.

thaï runs from LIiwedd lowards the efDux of Ihe lake, Ihe sirîœ Uuz suddenly round more easterly, where once the ice flowed high acivis the ridge and escaped down Cwm-dyli inlo Nant Gwynant. Les roches qui en- Bovond LWn Llydaw, a while torrent leaps down Ihe rocks ih::

vaiuenl le Itc sont n • rv/\/\/\

moutonnées . polie» e» '^^^ ^^ Glaslyn , which hcs about 2000 feet (610 mètres) ab-.vc striées. the sea, in a semicircle of cliffs, close below the peak of Snowd r..

This lake, if report speaks truly, it was actually inlended entireh t drain, in search of some possible copper Iodes, by an adit dri^ec upwards from the broken ground above Llyn Llydaw! AU round iL lake the felspathic porphyries and consoladated asbbeds are m^»*.tonnées; Mdy even when most wealhered, enough of thèse form^ r> main to attest their glacial origin*. They are unusually striking vi both sides of the stream, especially on the south, and on them sc^itered blocks lie perched in many precarious places. SUiœ on iL. ice-vwm surfaces are aiso plentiful ail round the lake. They r Jii more or less easterly, in the direction that it is easy to see must héu been given them by the galhered ice of this elevaled recess seeki:.^ an outlet; and on Ihe higher banks north, south, and west ortL iake , thay oflen slightly converge towards the bottom , in the imnner we might expect from ice pressing dowm the banks, and at t!i: same time outwards towards Llyn Llydaw.

Vallée R. 9. Beyond Glaslyn, ascendingthe ridge by a zig-zag path ll.ai

joins the Llanberis route to the top of Snowdou, or climbing the bih^ on the south side of the lake , it is easy to descend into tho upp^ r part of Cwm-y-Llan, a winding valley that leads to Nant Gwynjiii belween Llyn Gwynant and Llyn-y-Ddinas'. Beddgelert may Ihen k reached by a walk of less than four miles along the tumpike ruaJ. Immediately below the peak of Snowdon in the bottom of C^^ir-' y-Llau, a moraine mound about half a mile in length runs neai!» north an south , formed perhaps in the latter days of the snow aou ice that slipped from the high cliffs of Bwlch-y-maen * and Tt-n Wyddfa, or possibly from the broader opposite slopes betwtxL Bwlch-y-saethau ' and LIiwedd. It consists of the usual hetero

de Cwm-y-Llau.

* D. A. Illustration : roches moutonnées, polies, striées, et blocs perchés s«r les (vjr-. qui encaissent le lac.

^Ûdinas, a fortification or citadel. «Fortification Lake.»

* Mœn , stone. ■ Gap of the Stone.»

' ScUhau , arrows.

et maiériaui erraUquc».

VALLÉE DE CWM-Y-LLAN. 577

neoijs assemblage oï angtilar bbckSy stoneSy and clayy derived from

Ihe hills above. Thèse materials running in a somewhat waving

curve, form a séries of united mounds, which in gênerai character

are undistinguisbable from many a Swiss moraine. Some of thc Monmf»

fragments are scratclied. Standing on the summit of tbe moraine ^

or seen from below, it forms a striking object, especially laken in

connection with the ice-wom surfaces of rock on the sides of the

bounding hills. On thèse the slriœ run more or less southerly,

slightly converging towards the bottom of the valley. Farther down

on both sides the glaciated aspect of the hill sides is still more im-

posing , especially on the slopes below Yr Aran *, where the ice-

worn surfaces contrast almost as strongly with the craggy upper

part of the ridge , as the roches moutonnées above the glaciers of

the Aar do with the sharp serrations that form the crests of thc

mountains. In both cases the same taie is told, of a time when glor

ciers fiUed the valleys almost to the brim, and the upper edges of

tbe mountains rising above the icy surfaces were scarred by ren-

ding frosls.

]ù the angular recess below the peak of Yr Âran, some of the slriœ run north 25® east , and were formed at a period when the ice pressed directly down towards the bottom of the valley. At other places further down they strike east and east-south-east with the Ircnd of the valley, then south-east in the narrow gorge by the mine, where-as with the Aar glacier below the Grimsel " — the pressure of the ice, forcing its way through the strait , ^ound the surface of the rocks so strongly, that to this day it seems as if the glacier had but lately disappeared. Below the gorge the striœ bend to the south, where the ice-flow curved round to join the great glacier , formed by the snow drainage of the valley of Llyn Llydaw and the mountains above Pen-y-gwi7d , which, passing right down to Beddgelert and Pont Aberglaslyn ', formed the south-westerly striations that hère and there mark the barder unweathered rocks ofNantGwynant. No definile moraines occur in Cwm-y-Uan ; besides that at

* The Peaked Mountain.

' Near Pont Aberglaslyn Backland observed the êtriation of the rock , on the west side of the gorge. A framed inscription records it, in his own writing, in the hall ofthe Goat Hôtel, Beddgelert.