or vallies, should have been formed since that period. Must we then turn from these explanations, and again suppose great relative changes of altitude by vast upheavings of mountain chains in comparatively recent times, giving rise to diluvial waves, or, as supposed by De Beaumont, such upheavings being accompanied by a sudden rise of temperature, to the sudden melting of huge masses of snow and ice, and to powerful torrents resulting from it? Are we in short to appeal with Kapp to the testimony of the Chinese Annals, elucidated by Edward Biot of the French Academy, for evidence of such changes? In them, mention is indeed made at dates of 2400 and 3300 years before our era, of the elevation of two mighty chains of mountains, by which an ancient sea was raised up and became the present Marsh of Gobi, having been drained by an arm of the Yellow River, or through the valley of Tsischi, and at the same time the course of the Yellow and many other rivers were greatly changed. But, truly curious as such documents undoubtedly are, and worthy of the most attentive research in order to ascertain what support can really be given to geological theories by historical evidence, they could not be received as conclusive in respect to the face of Europe, unless something like a chain of deductive reasoning from observed facts could be adduced in support of them. What, then, is the state of the case? Must we reject the ice-transporting theory as insufficient, and stand in despair of ever finding a clue to our difficulties? Far from it: the very difficulty itself points to the true explanation. The northern or Scandinavian boulders are not mixed with the Alpine on the low grounds at the base of the Jura, and this circumstance shows us that there was a limit to the space over which these boulders were transported, and that limit was, probably, the result of the elevation at which the ocean then stood. Whilst, then, this ancient ocean was conveying from the Scandinavian peaks its falling glaciers loaded with fragments of rocks, the glaciers of the Alps were conveying over the ice-covered land the fragments of its broken pinnacles. Such a union of the two modes of transport, combined with sea currents, seems at once consistent with reason and efficient in explanation; for example, it explains the difficulty experienced in understanding the ancient glaciers of the northern face of our Dublin mountains, where we see limestone gravel and fragments of red sandstone accumulated against their base up to a certain point where they end abruptly, and gravel of primitive rocks begins. The limestone gravel and fragments of sandstone may have been conveyed there, and heaped up by the pressure of drifting ice, whilst the descending glacier conveyed primitive fragments, and pushed up before it into a heap the limestone gravel. We have therefore now come to the consideration of the glacier theory, which, propounded and