CHAPTER IV. ISLANDS AND ROCKS NEAR GUERNSEY. THE east coast of Guernsey is separated by a narrow channel from a formidable group of rocks and islands, ranging north-east and south-west, and nearly parallel to the main island. This channel is called the Little Russel, and in the narrowest part, opposite Vale Castle, there is not more than seven fathoms water. The whole group of islands and rocks is nearly six miles in length, from the Anfroque to the Ferriére rocks, and the width is about two miles. It includes Herm and Jethou-both inhabited-Crevichon, with a few other rocks, partially covered with vegetation, and Brehou, on which a small fort has been. constructed. There are some other large detached rocks always above water; many others that are exhibited only during a part of each tide, and a multitude quite as dangerous as these, that never appear at all. One of the most dangerous rocks in the Little Russel is the Roustel, which lies exactly in mid channel, and only shows within two hours of low water. An area of nearly continuous broken granite, laid bare at low water, extends for about two miles beyond the northern extremity of Herm, the principal island of this group. Except two narrow channels, there is no important break in the rocks, and they connect with a similar group about half a mile wide, projecting beyond the west coast of Herm, looking towards Guern 1 sey. Close to Herm, and forming a tongue at its northern extremity, there is a spit of low, flat land, which extends some distance seawards. That part of the island of Herm permanently above water, is an irregular oval, measuring about a mile and a-half from south to north, and half as much across. As in Guernsey, the southern and eastern part of the island is high and precipitous, while the western and northern parts are lower and more accessible. The low grounds of L'Ancresse are represented in Herm by the long stretch of beach already alluded to; but while in Guernsey the sand is entirely quartz, in Herm it consists exclusively of small shells and fragments of shell, ground into a powder by the sea. On the north-eastern side of the island is a small bay, similarly provided with a shell beach. The summit of Herm is flat. There is a valley at the north end, opening out to the smaller shell beach, and a well-marked through narrow depression on the south side, near Jethou. The central table land is, for the most part, cultivated; but the slopes, especially near the sea, are still wild and covered with coarse, wiry, tufted grass, brambles and gorse. Among them it is difficult to walk. It is possible, however, to make one's way round by the cliffs and scramble down to the rocks at various points, although at the risk of being embayed, should the tide be rising. The scenery of the coast is remarkable. A beautiful white and black granite rock forms the hard back bone; and may be recognised at intervals, around the coast, sometimes projecting from the ground in jagged pinnacles, sometimes seen in boulders and detached rocks. This granite is intersected by many wide veins, extremely variable in their nature, but generally either soft or readily decaying. Deep ravines have consequently been cut by the sea at various places, terminating in small caverns; none of which, however, run in very far. Where the vein is decomposing it turns readily into soil; a great thickness of micaceous sand and fine gravel exists at the surface, and the entrances to the caverns are, in these cases, deeply and richly fringed with ferns, whose brilliant metallic green singularly and beautifully contrasts with the peculiar square, hard lines, produced by the parallel walls and straight top of the sides and roof. But besides these caverns, eaten in by the sea, there is also a noble creux* in this little island. The top is about as large as the Pot in Sark, but the depth is less considerable. At the bottom is a tunnel, communicating with the sea. The origin of this creux is clearly to be traced to the action of water from the surface; and is quite unconnected with the sea; although, no doubt, when the water had once made its way downwards and a channel at the bottom was opened, the carrying away of the fallen rubbish greatly facilitated the enlargement of the hole above. Singularly wild and picturesque are the rocky bits to be seen The word creux (a hollow space), already made use of, is applied in Guernsey to a cavern, but elsewhere in the Channel Islands it means rather a funnel-shaped depression or shaft, communicating at the bottom with the sea by a kind of tunnel. Occasionally, the walls of this tunnel are broken away. at the back of Herm. Some rocks, now quite detached at half tide, are worn into battlements and pinnacles; blackened, and presenting all the features of a ruined mediæval castle. Some large, flat expansions of hard, but much weathered rock, afford a kind of irregular pavement, on which those shod with stout boots can walk pleasantly enough, except when it is interrupted by deep fissures with vertical walls, serving as inlets to the sea. Here and there is a Cyclopean mass of ruined masonry, of nature's own construction. It is in many places almost impossible, or at any rate, very troublesome, to get down to the sea at the back of Herm; but when the coast is reached, and with a falling tide, a large part may be walked over with only the ordinary difficulties of cliffing, and with more than the ordinary satisfaction derived from doing a difficult thing, owing to the nature of the veins, and the variety of minerals met with in a short space. The granite of Herm has been quarried to some extent. It is probably sound; but, on the whole, it seems to decompose more rapidly than that of Guernsey. At any rate, parts of it make an excellent soil, which would repay any amount of cultivation. The land of Herm is in many parts rapidly encroached on by the sea. All round the southern and eastern shores, there is evidence of very recent land slips, and considerable portions of the cliffs are only kept in their places for a time by the roots of brambles and ferns, matted together; or by the grasses which grow on the surface in large tufts. It is quite evident that every season must produce a change, and that the destruction can hardly cease, so long as the island holds together. The numerous rabbits that abound both here and in the adjacent still smaller island of Jethou, are at once a proof of the decomposability of the granite rock, and a cause of the destruction going on with greater vigour than might otherwise be the case. The rabbits take advantage of the sandy sub-soil, where the granite has become rotten, and the long holes they burrow tend to weaken the face of the cliff, by facilitating the passage of water.. Nowhere very high, though generally lofty enough to be quite inaccessible, the hills and cliffs of Herm subside towards the north, terminating there, as has been already said, in a broad expanse, covered very deeply with innumerable fragments of shells. It is a curious sight to watch these sands; sometimes a vast solitary blank, without a pebble, a ripple-mark, or a wormcast upon them-one mass of myriads of shelly particles and shells; at other times, during an excursion from Guernsey, peopled by scores of women and children sweeping into their bags this great wealth of cowries and limpets, and separating from the mass before them all that seems most beautiful or valuable. It is not easy for a stranger to trace the cause of so extensive a shell beach at this particular part of the Channel. There is nothing of the kind elsewhere in the whole group of the Islands, although at Vazon and other bays in Guernsey, and St. Aubin's Bay, St. Ouen's Bay, and elsewhere in Jersey, there are not wanting sands of considerable extent. The shell beach of Herm is quite a different thing from these sands, which are composed of quartz or of pounded granite. A careful consideration of the course of the tidal wave, and the circumstances under which it passes through the two channels of the Great and Little Russel, will, however, explain this anomaly. While a part of the main wave sweeps towards the north-east through all the channels, that portion which has reached the French coast, being turned backwards, produces a north-westerly wave running along the coast of the Cotentin, and expanding when past the rocks north of Jersey. The north of Herm is the point of land where there would be slack water, from the meeting of these currents a short distance to the north; and a submerged island between this and Herm effectually protects the coast from any eddy that might otherwise disturb the shelly F |