sess.

whatever of the process. And Mr Hay seeks to establish for the eye a power analogous to that which the ear certainly does posHe believes the one to be as skilled in geometry as the other is in arithmetic. He argues, and he argues with justice, "We know that the ear is charmed when the notes which are presented to it are due to vibrations, the rapidity of whose recurrence is in some simple ratio, such as 2 to 3, 3 to 4, &c., and is wounded by a slight deviation from such simplicity of proportion; and why should no similar discriminating power lie in the eye?" Mr Hay, as we have already stated, thinks he has discovered the existence of such a power, and should that discovery be confirmed, it is of so much importance that we should not be justified in passing the very mention of it lightly by. We have somehow got to a complete knowledge of the mystery of harmony in sound. Could a like knowledge be obtained of the harmony of form, what a grand step in æsthetic science! Mr Hay asserts that as the ear judges with nicety of relative proportions of aerial pulsations, and is pleased with simple relations, so the eye judges with certainty of relative angular spaces, and is equally pleased with the same simple relations amongst them. We confess we like the idea. It is free from any shade of complexity, and squares well with that noble law of least action which is found to pervade the works of nature. Of the comparison of its consequences with the Parthenon and the human figure we have already spoken, and certainly our expectations have not been disappointed.

We must now conclude by expressing our admiration of the ability, the ingenuity, and the perseverance of Mr Hay, whose constancy in the cause is the best assurance of his conviction of the truth of his theory, and the best guarantee of his success in establishing it on a firm basis.

Geological Map of Europe. By Sir RODERICK' I. MURCHISON and JAMES NICOL. Constructed by A. KEITH JOHNSTON.

When the active and comprehensive mind of Leibnitz, now two centuries ago, seized on the more general and obvious phenomena of geology, which as yet no observations of the details had begun to establish on certain and accurate foundation, he already anticipated, almost a priori, the theoretical links which have subsequently been admitted as the most competent to combine and generalize the numerous facts since ascertained. At that early period, Leibnitz already suggested the execution of maps representing the disposition of the various masses composing the crust of our planet, as the most promising means of advancing a real knowledge of physical geography. This recommendation has been since very fully acted upon, and the advantages he prophesied most amply

realized. In our own island, especially, the most valuable contributions have been made; the Geological Map of England, published in the beginning of this century by the distinguished first president of the Geological Society, G. B. Greenough, Esq., afforded the first specimen of a sufficient geological map of any extensive district; but still these earlier essays may be characterized as topographical, rather than geological maps, as illustrating particular provinces rather than the general features of our globe, or even of its several quarters. We may fairly consider the map specified at the head of this article, as presenting the most promising and valuable specimen of the more advanced stage of geological chartography of which we have spoken. And we say this the more emphatically, because it has not attempted a more extended field than the actual state of information enabled its projectors distinctly and accurately to record; and because it has therefore so satisfactorily accomplished all that it professes to undertake. A bold and accomplished French savant, Boué, has not hesitated to present us with a geological map of the whole surface of our globe; but although we consider this as a useful, as well as bold approximation, it is and must be as yet too vague to convey very exact information, and too destitute of the guarantees of certainty to command general reliance; whereas in the map before us, the district embraced comprises the regions which have been most carefully explored by the hammers and surveyed by the eyes of well-known geologists; and the individuals concerned in its construction are exactly those whom their brethren in the same field of science would at once select as the best qualified to record and combine the results which have been accumulated by so many of the stone-breaking corps in which they themselves hold such high commissions. To justify this assumption, it will be quite sufficient to refer to the name first attached to this production, that of Sir Roderick Murchison, who has more largely perhaps than any other individual contributed to the general stock of our actual geological information. He first brought to a real consummation the investigation of the general series of our geological formations, and of the various successions of animated organizations whose remains are preserved in each. The structure of our own island had long been found to present peculiar facilities for such a task; but Sir Roderick's predecessors, while they had very fully illustrated all the other members of the series, from the sands and clays of the tertiary basins to the rocks composing our great coal fields, and the limestone of the Derbyshire and Pennine mountain-chains on which they repose, still had shrunk from the attempt to classify and arrange in similar groups the formations subjacent to these carbonifera, and left them confusedly huddled together under the vague designation of various transition sands and limestones; but Sir Roderick has now marshalled

all these in as perfect discipline as any of their younger brethren, under a triple order of Silurians, with as full authority as if he were the earl-marshal of the great Arthur, the mythological prince of of that fabled district, or the usher of the black-rod to his ancient court.

Having thus completed the subjugation of Britain, our author undertook a more difficult and hitherto unattempted enterprize, the reduction of the mighty and inaccessible Russia itself. This heroic undertaking he most gallantly and triumphantly achieved, with the cordial assistance of the authorities themselves of the invaded territory, and has brought back with him, in testimony of their admiration, all the stars of all the orders of all the Russias. Since his return, with more exclusively patriotic devotion, his sagacity first indicated the possibility of discovering valuable golddiggings in the valleys of the Australian chains-an example of geological foresight which has since been so richly realized.

On the death of the late De la Beche, he was most suitably and justly placed at the head of the departments which the former before occupied, as Superintendent of the Ordnance Geological Maps, as Principal of the Great Museum of Economical Geology, the only, but the most efficient, school of mineral science which our island (dependent as it is on the resources connected with that science) as yet possesses, and which it principally owes to the comprehensive information of its illustrious statesman, the late Sir Robert Peel.

The former researches of Sir R. I. Murchison in Russia had, years ago, enabled him, from his own independent investigations, to complete a map, embracing all the Russian European territory and the conterminous countries, and therefore including nearly two-thirds of our own quarter of the world. All interested in the advance of geological science, who had enjoyed the advantage of studying this beautiful and complete Russian map, became therefore most desirous that the smaller remaining portion of Europe should be incorporated by the same author, who from his own very general geological researches through the Continent, and from his intimate acquaintance with its first men of science, with whom he is associated as a corresponding member of the French Institute, was known to be so peculiarly competent to the task. This very desirable object is now accomplished by the present publication in the most satisfactory manner.

Such general maps form the most valuable companion and guide to the scientific tourist; they enable him to trace the extended course of the formation with which he is familiar in his own country through the most remote countries, and often under novel affections, induced by local diversities in the general causes which have acted in the deposition and arrangement of strata of uniform age and composition. We remember the astonishment-almost incredulity of a geological friend, when he first observed in an

old Swiss volume on the fossils of the Alps, accurate figures of the turrilated ammonites which he so well knew as denizens of the greensand beneath the chalk ranges of the Kentish and Sussex wolds, and the midland and parliamentary Chiltern Hundreds, but whose forms were here preserved on the summit of Mount Pilatre. With the same surprise we may see the humble English cretaceous downs elevated into the lofty chains of the exterior Alps and the Apennines, and constituting the classical summits of Greece so interesting to our schoolboy memories, Pindus, Parnassus, and Helicon; and the chains of Athens, Laconia, and Arcadia; but we must feel that formations of so high pedigree have a right to swell into a haughtier dignity as they approach the origin of their name, the cliffs of the Isle of Creta, and its proud summit of Ida. We shall also find our own friable material of English chalk converted into the most beautiful crystallized statuary marble in the Tuscan Carrara and Athenian Pentilicus. We are thus also led to form hypothetical yet not altogether unauthorized speculations as to the primitive islands which first heaved their granitic summits close to the general ocean plain, and to endeavour to trace the more limited outlines of the successive seas, and the conditions under which the Silurian deposits were first precipitated, to be succeeded by coral reefs crowned by the free forms of the carboniferous era; and below these again, new waves bore shreds of cephalopodous mollusca, exhibiting the snake-like coil of the ammonite and the acute cone of the belemnite, while monstrous forms of marine saurians, compared with which the crocodile of the Nile and the Ganges appear dwarfed and degenerated, products of a decayed and effete age, floated through the liasic sea, along the borders of Devon and Dorset and the opposite coasts of France. Or we may proceed to the far later period when bears and hyænas herded in the caves of Franconia and Yorkshire; or, as we advance to the close, regard with astonishment troops of elephants and rhinoceroses stalking over the plains of Kew, and look at the hippopotami wallowing in the marshes of what is now the vale of Thames. Or if our researches partake of the idiosyncracies of London aldermen, we may recal with deep sighs of regret the happy ages, now, alas! never to return, when Sheppy was a redundantly productive turtle island; and while its groves could yet have yielded rich desserts of tropical fruits. While in the basin now giving course to the Seine, but then like the Indian Run of Cutch, exposed to alternations which rendered it doubtful whether its correct description should be a marine estuary or a fresh-water lake,* herds of extinct species of tapirs haunted the banks, as their remoter congeners still frequent, in the west, the

*The mouth of the river Heyl, in North-west Cornwall, displays combinations of same nature in a very illustrative manner.

Pampas of South America and the Cordilleras of the Andes, or in the east, the island of Sumatra and peninsula of Malacca ; while the latest European representatives have left scattered skeletons buried in the gypsum quarries of Mont Martre, to be reconstructed by the skill of the illustrious Cuvier, the great resurrection-man of departed worlds; who describes himself as standing among them as in a vast charnel-house, piled with a complete mass of scattered bones of numerous unknown genera, with the hopeless task assigned that he must bid each resume its proper place, and recompose the ancient form to which it once belonged. But at the magic touch of the wand of comparative anatomy, applied as his skill alone could wield it, the injunction so seemingly desperate was at once complied with, and he saw before him groups of genera and species extinct before man had received his first breath, yet now clearly recording to the eye of science the place and rotation in the scale of animated nature which they had once occupied.

For details of these most interesting results of geological investigation, we must indeed refer to the illustrations afforded by palæontology of the subjects associated together in the diversified science of which maps, like that now in our hands, can only place before us the local habitations. But we are gratified to learn that the constructor of this map, Mr Keith Johnston, has inserted, in his most able publication on "Physical Geography," "Illustrations of the Geological Map of Europe," which will be found to contain all the subsidiary information which can be desired.

We may observe in concluding, also, that the map itself presents a striking analogy to the paleontological marvel just recited; for, in like manner, it compounds together in a harmonious and systematized whole, the disjecta membra of isolated frag

ments.

The Englishman, cut off as his abode seems from the rest of the world, here sees, that although now covered by his channel, an original submarine communication has connected every rock of his northern fragment with the precipitous edges of the southern counterparts throughout the cliffs of the French coast. So that whether he travels in his own isle, from Dover to the Land's End, or visits the opposite coast from Calais to Ushant, he will only find, from step to step, an exact recurrence of identical formations and features, and the prolongation of the same masses.

The most important contributions specified in the note to this publication consist in the general geological delineation of the whole of Asia Minor (the first of that extent ever constructed), by M. Pierre de Tchihatchef, for the use of our authors, and the revision of that of the Spanish peninsula by M. de Verneuil, embracing the latest results of his own observations and of those of his colleagues, M. de Collomb and M. de Lorière.