VALLÉE DE CWM-GLAS

Ihe immense moraine Iieap^ lying between the précipice south of tbe road and tbe supposed Cromlech. As already stated, I believe it to hâve been formed by a glacier tbat descended northward from the high recesses of Cwm-glas , and which fairly crossed the Pass , till ils lower end abutted on the south side of YGlyder-fawr *, below Esgair-felen ^ On the side of this glacier tbat faced up the Pass, there being no running water to bear away the débris , moraine malter might well be shed and accumulate to a vast amount, in the manner that appears to bave taken place , on a larger scale , from the upper side of the Glacier des Bois ^hen it formerly crossed the valley of Chamouni ; while from the side of the glacier that faced down the valley, the chief part ofthe moraine would naturally be destroyed almost as fast as formed , by the streams that flowed from beneath the ice ; just as at présent in Switzerland the terminal moraines of the Rhône glacier and of the lower glacier of the Aar never gather to an amount at ail commensurate to the quantity of débris that is constantly floated down to them on the ice. Since the disappearance of the glacier of Cwm-glas , the stream that drains the Pass of Llanberis bas eut away a large part of the great upper moraine, but a large section of the rubbish still remains to attest its former magnitude. Subsequently, when the glacier decreased , and retired behind the spot where the bouse of Blaen-y-nant now stands, an ordinary terminal moraine was shed from its extremity, and clear (races of the débris still run in a long broad north-western Une that crosses both the broocks on either side of the bouse , Not far be* hind the bouse there is a large moraine lying on the slope of the hill on both banks of the western brook. It consits of heaps oftouldersy clayy ad angtdar gravel and blockSy identical in composition and in gênerai aspect with many Swiss moraines. Some ofthe stones are scratched^ the lines crossing each other confusedly; and the great mass of the moraine is formed of three or even four concentric elliptical mounds^ which merge together at their bases, and mark on a small scale the graduai decrease of the Cwm-glas glacier.

* The Great Glyder. I cannot get at the meaning of Glyder, and will be glad of a rational explanation.

' The Yellow Shin or Ridge.

568 BLEÀN-Y-NÀNT. MORAINES.

Thèse circle round Ihe north end of a roche motUonnee , that , in the middle distance of (he drawing, rises like a liltle hill *. Bietn.y.iitDt. R. 4. A liltle fachind Ihe hill , about half a mile south of Blaeny-nant, a beauiiful afid mosi perfect terminal moraine^ grass gro^n. but still strewn mih travelled blocks , ranges across the valIey bel* ween the brooks , almost as regular in form as many an artificial earlhwork. Il is between 1200 and 1300 feet above ihe sea (565 i 396 mètres). Higher up on Ihe west side of the valley , the ^riœ on the rocks run N. N. E. below the space where the glacier in .• cataract of ice once rolled over the clifls that now appear s<i grira. Three white threads of water glance on its black clifTs, the sole représentatives, in another form, of ihe Jagged ice-faU. thaï, on a smaller scale must bave resembled the great cataract ofth-

unl'^TZ.Mt^.S^^^ ^f '^ ^^^' ■" '^^® ^'^P®> though a Utile toilsome, is

easy of ascent, and beyond the rocks, there lies, in ihe inner-

most recess of the mountain , and upland valley, unoiaiched in Wales for wildness, and in which I never met a human being, though I bave been in it more times than I can iell. On ibret sides it is bounded by tall cliffs and mountain peaks , in ihe mi4L^t A670inètreitit.. of which Hc two littlc dccp clear tarns, about 2200 feet (670 mede as pfiiii itw. j^ggj above the sea , each in a perfect basin of rock , in ihîs , on a small scale, resembling the Todten-seey and the lake behind th*' Hôtel of the Grimsel. Between thèse pools and the clîfT below, ai. immense quantity of moraine débris, derived from Crib-go<rL', encumbers the ground. The rocks on which it lies are oflen per-

Rociict fectly smoothedj rounded^ and deeply grooved; and ihe striœXhsA moatonnéei . poli» . lowcr dowu tbc Valley strike straight towards the Pass, herebranch

**"*" to the soulh-west and south-east , foUowing the course of two minor valleys, that bifurcate at the south end of this recess , on eitber side of a peaked ridge that descends from Crib^och io the ground between the pools. Tiny moraine mounds scattered aboui, tell of the last remuants of enduring ice , ère the shrunken glaciers fînalh melted away in the uppermost recesses of Ihe mountain.

* D. A. niastration : moraines et roches moutonnées i Gwm-Glas.

* «The Red Teeth, > a name perfecUy applicable to tiie semled edfe of Uns rîdfe. Uiat, in the glacier days of Wales, rose, scarred by the wealber, «bore tbe ice.

LLYN du'r arddu. 569

Having reached the upper end of Gwm-glas, if the explorer be indiiTerent to the hackneyed route of the posting tourist, he cannot do belter than climb the ridge of Cribgoch , and walk along its edge lowards the summit of Snowdon. There, if the weater be clear, he may see hélovf him three of the glacier valieys that radiate from the summit of the mountain. The rocky amphithéâtre of Glaslyn ^'^ "■»"'' and Llyn Llydaw lies in the east, the deep descent of Cwm-y-Llan ' xroiZ7rsZ^u!i^'^». on the southy and on the westthe broad, précipitons, circular bollow of Cwm-y-clogwyn , in ivhicb , with a favourable lighl, he may see the terminal moraine of an old minor glacier^ faintly cirding the west side of the central pool of Llyn-goch. The last is best seen from the sharp ridge that leads to Beddgelert.

R. 5. Near the route back to Llanberis , a great moraine lies on ^'y» •*"' A'»^*'" the north and west of Llyn du r Arddu. This deep-set hitle tarn (that often rests so still , even when a gale is blowing) lies at the base of a high clifT of felspathic porphyry and greenstone, mostly inaccessible except at its eastern end. Once with a companion I climbed it in a frosty December morning , after a slight fall of snow. It took an hour or more , for we were obliged to help each other with strapSy and occasionally to cut.steps with our hammers in the icc and crumbling rocks. By the outlet of the lake the striae on the rock run north-westerly, and a large roche moutonnée lies a little nearer the cliiT, sprinkled with blocs peixhés. A great stony moraine- ^ Muraines. mound, covereth with angular blocks from the neigh|)ouring heights, "'°''J^"".^*,' "'"'' circles round the lake, and rising high above it on the north, it descends in a long steep slope for more than half a mile down Cwm Brwynog*. From the old mine-shed by theroad, successive conzentric heaps of moraine rubbish are distinctly traceable, the high- ^st of ail being about 2250 feet (685 mètres) above the sea. Huge blocks lie scattered on the surface , one of which , half way down he slope, measures about 18 yards by 14 by 10 (2520 mètres :ubes), and probably weighs nearly 5000 tons. A loose stone, several yards square, — not a severed part, — lies on its summit ,

*The term «JUan» is now commonly appUed to a parish church. It literally means m « enclosure. »

* Riuhy Valley.

monstre.

Cwm-y-clogwyn.

Lac barré par une moraine.

570 CWM-Y-CLOGWYN.

perhaps in Ihe very position it occupied when bolh trcre Itfl iy the ice.

Ât first it is difficult to understand how a moraine so large coulJ bave been deposited by so small a glacier, for the upper side of the moraine lies Uttle more than a mile from the peak of Snowdon, and less than a mile from the slope of Crib-y-ddysgyl , from ibt snow-drainage of which the glacier was formed that flowed over the eastern end the clifTy ground , and passed down the hoUov uf Llyn du'r Ârddu. But the dif&culty is lessened to those who bave seen the prodigious amount of débris that oflen fringes Ihe sid^ and ends of some of the small glaciers that lie on the higber slope> of the Âlps. Thèse, once united to the great glaciers that fill IL^ valleys below, are now, shrunk in size , no longer strong enou.^h to join them , but melt and deposit great heaps of rubbish on tL: adjacent slopes.

Beyond this moraine, with su£Scient search, many ice-roufi'ii surfaces of rock may be seen in Cwm Brwynog, their original ^^jtions being often decayed , but when visible they run north-weî: and north in the direction of the slope of the valley * .

R. 6. On the west, close below the peak of Snowdon, lies Cwmy-clogwyn *, enclosing three little lakes. It is easily reached in les? than two hours from Llanberis , either by the route of Bwlch-y- Maescwm ', or by Bwlch-y-Cwm-brwynog *, at the west end of iLe précipice of Clogwyn-du'r Arddu. Immediately below this watershed , on the south , the lake called Llyn Ffynnon-y-gwas • is possibk dammed up by a moraine , merging into the long slope of drift tLat runs down to Llyn Cwellyn. A cliffy escarpement, over which ih-:

* 1 bave, howewer, often thought that the lower part of this valley is corereo :; Drift , and that if a tributary glacier from it ever joined the main one in the Pasa , k must, of course, hâve done so before the aqueous déposition of this drifted matenal.

* Précipice Valley.

'Literally, «The Gap of the Plain of the Valley, > or «Valley-plain-gap.» This Bu:c%, or gap , in the mountains opens on a broad inclined plain or slope of Drift tbat sk%« down towards Llyn Cwellyn and the road to Beddgelert.

* Rush-valley-gap.

* « Gwas » means a < man-servant , » and « Ffynnon-y-gwas • the sprii^ or « wtH « the raan-servant. »