notice of the old imaginative Celta, who called them Tomhans, and believed them to be haunts of the fairies,—domiciles whose enchanted places of entrance might be discovered on just one night of the year, but which no man, not desirous of becoming a denizen of fairyland, would do well to enter. The lake above is a fine lonely sheet of water, fringed with birch, and overlooked by many a green uninhabited spot, dimly barred by the plough. A range of stern, solemn-looking hills rises steep and precipitous on either hand; while a single picturesque hill, with abrupt sides and a tabular summit, terminates the upward vista some six or eight miles away. I saw in one reedy bay a whole community of water-lilies opening their broad white petals and golden stamens to the light; and, wishing to possess myself of one that grew nearer the shore than any of the others, and having no such companion as Cowper's dog Beau to bring it me, I cut a long switch of birch, and struck sharply at the stem, that I might decapitate it, and then steer it to land. But the blow, though repeated and re-repeated, fell short; and I had drawn my last, when up there started from the bottom a splendid lily, two-thirds developed, a true Venus, that, rising from the water, looked up to the light, neck-deep, with the rest. The agitation occasioned by the strokes had burst the calyx, and, true to its nature, up the prematurely-liberated flower had sprung. The image which the incident furnished mingled curiously with my attempted restorations of the ancient state of the valley. The delicate lily, rising to the surface in its quiet, sheltered bay, during a bright glimpse of sunshine, formed an interesting point of contrast to what seemed a fast foaming river of ice, that rose on the hillsides more than half their height, and swept downwards, till where it terminated in the plain, in an abrupt moving precipice, that ploughed before it, in its irresistible march, huge hills of gravel and stone. LEVEL STEPPES OF RUSSIA, AND THEORY OF MORAINES. In the level steppes of Russia, where the traveller may journey without seeing a hill for weeks together, the rocks have their grooved and polished surfaces. And even in localities where there are hills, the hills not unfrequently merely add to the difficulty. The lofty top of Schehallion, for instance, is grooved and polished; and, pray, from what neighbouring eminence could the glacier have descended on it? Extreme, however, as the difficulties that environ the phenomena may seem, they have been manfully met by Agassiz, and dealt with in a style in which only a man of genius could have dealt with anything. And if difficulties still attend his theory, there are at least other difficulties which it ingeniously obviates; and it seems but right, at all events, to give it generous entertainment and a fair trial, until such time as it may be found untenable, or until at least something better turns up to set in its place. The flat steppes of Russia have, I have said, their groovings and polishings: they have also their moraine; and so enormous is the extent of the latter, that for week after week the traveller may find it stretching through the central wilds of the empire, on and on without apparent termination, by North Novogorod towards Pinsk, as far as the confines of Silesia. It exists as a broad belt of erratic blocks, mingled with heaps of gravel, and resembles, from its linear continuity, the scattered remains of some such vast wall as that which protected of old the Chinese frontier from the Tartar. And here, says Agassiz, is the moraine of a glacier that had for its centre no group of local eminences, no vanished Alps of the Frozen Ocean, but the North Pole itself. The ice of the Southern Pole advances as far. Could we but reverse the conditions of the two poles, the northern icy barrier would extend to the English Channel, and the whole British islands would lie enveloped in one vast glacial winding-sheet, that, overlying the summits of our hills, would furrow with its parallel striæ even the granitic top of Schehallion. A complete reversal of the conditions of the two poles would account, doubtless, for many of the phenomena existing in connexion with the boulder-clay, which seem otherwise so inexplicable. But is the reversal itself possible? A Laplace or Lagrange could perhaps answer the question. This much, however, men of lower attainments may know that the meteorological condition of the two poles are very different,-the icy barrier advancing, in the case of the one, many degrees nearer the equator than it does in the case of the other; that their astronomical condition is also very different, the sun being many millions of miles nearer the one in winter, and nearer the other in summer. It may be known, further, that these astronomical conditions are in a state of gradual change; that, so far at least as human observation extends, the change has been steadily progressing in one direction; that should it but continue, a time must inevitably arrive when their astronomical circumstances shall be wholly reversed,—a time when the sun shall look down upon our northern hemisphere in aphelion in winter, and in perihelion in summer. True, we do not yet know that the meteorological differences of the poles depend on their astronomical differences, or whether the gradual diminution in the eccentricity of the earth's orbit, which has been lessening these latter differences ever since astronomers registered their observations, may not be like the change in the ecliptic,—the result of a mere oscillation, limited to a few degrees. Let us, however, conclude the case to be otherwise : let us deem the oscillations in the earth's orbit to be so great as to involve an alternate progress in the sun, between his two foci; let us further infer a dependence between his place in each and the meteorological condition of the poles. We stand, let us suppose, on the summit of a hill; but, as if an immense wedge had been thrust between our feet and the soil, we rise to a higher elevation on an inclined plane of ice, and look over a frozen continent, enlivened by no winding arms of the sea, and bounded by no shore. In the words of Coleridge, 'The ice is here; the ice is there; The ice is all around; It cracks and growls, and roars and howls, It is summer; and the sun, in perihelion, looks down with intense glare on the rugged surface. There is a ceaseless dash of streams that come leaping from the more exposed ridges, as they shrink and lessen in the heat, or patter from the sunlit pinnacles, like rain from the eaves of a roof in a thunder-shower. They disappear in cracks and fissures; and we may hear the sound, rising from where they break themselves, far beneath, in chill caverns and gloomy recesses, where, even at this season, at noon the temperature rises but little above the freezing-point, and sinks far beneath it every evening as the sun declines. The night shall scarce have come on when all these water-courses shall be bound up by the frost, and the melted accumulations which they precipitated into the fissures beneath shall be converted into expansive wedges of ice, under the influence of which the whole ice-continent shall be moving slowly onwards over the buried land. Millions of millions of wedges shall ply their work during the night on every square mile of surface, and the coming day shall prepare its millions of millions more. There is thus a slow but steady motion induced towards the open space where the huge glacier terminates ; the rocks far below grind down into a clayey paste, as the ponderous mass goes crushing over them,-deliberate, when at its quickest, as the hour-hand of a timepiece; and vast fragments are borne away from submerged peaks and precipices by the enclasping solid, just as ordinary streams bear along their fragments of rock and stone from the banks and ridges that lie most exposed to the sweep of their currents. All around, according to Milton, 'A frozen continent Lies dark and wild, beat by perpetual storms.' Not a peak of our higher hills appears all are enveloped in their cerements of cold and death. Even along the flanks of the gigantic Alps, the groovings and polishings rise, says Agassiz, to an elevation of nine thousand feet; and then, and not before, do we find the pinnacles that overlooked the scene standing up sharp and unworn. If we ask a varied prospect, we must remove from our present stand, to where Mont Blanc and his compeers raise their white summits over the line of the horizon, to give earnest of a buried continent, or to where the smoke and fire of Hecla ascends amid the level from a dripping crater of ice. CROMARTY. CROMARTY,—my own especial manor, which I have so often beat over, but not yet half exhausted,-presents to the geologist one of the most interesting centres of exploration in Scotland. Does he wish thoroughly to study our Scotch Lias, Upper and Lower, with the Oolitic member which immediately overlies it ?-then let him remove to Cromarty, and study it there. Is he solicitous to acquaint himself with the fossils of the Lower1 Old Red Sandstone in that state of finest preservation in which the microscope finds most of beauty and finish in them?—then let him by all 1 Now ascertained to be Middle. |