be

the earth, and where its mineral treasures may found, can scarcely be deemed devoid of utility by a nation deriving so much of its comfort and wealth, from its mineral resources. But beside supplying our physical wants, the external universe is destined to answer a nobler purpose; its various objects appear intended to excite our curiosity, and stimulate our intellectual powers to the discovery of those laws, by which the successive events we observe in nature are governed. Without this excitement, man would for ever remain the mere creature of animal sensation, scarcely advanced above the beasts of the forest; and the universe would be to him a mute and unmeaning succession of forms, sounds, and colours, without connection, order, or design. In those sciences, which have attained the highest degree of perfection, the skill of the Creator, and the ends and uses of the different parts are most apparent. Geology has not yet made sufficient progress, to carry us far in this path of inquiry; but we see enough to discover, that the very disorder into which the strata on the surface of the globe are thrown, and the inequalities which it presents, are absolutely necessary to its habitable condition. The distribution of its mineral treasures, and particularly of coal, to the cold and temperate regions of the globe, is well deserving attention, and implies a prospective regard for the wants of civilized man: but a cold-hearted philosophy, under the sanction of a quaint expression of Lord Bacon*,

* "Causarum finalium inquisitio sterilis est, et tanquam virgo Deo consecrata nihil parit."

has (to use the words of Dugald Stewart) "made it fashionable to omit the consideration of final causes entirely, as inconsistent with the acknowledged rules of sound philosophizing. The effect of this has been to divest the study of Nature of its most attractive charms, and to sacrifice to a false idea of logical rigour, all the moral impressions and pleasures, which physical knowledge is fitted to yield."

Geology discovers to us proofs of the awful revolutions which have in former ages changed the surface of the globe, and overwhelmed all its inhabitants it reveals to us the forms of strange and unknown animals, and unfolds the might and skill of creative energy, displayed in the ancient world: indeed, there is no science which presents objects that so powerfully excite our admiration and astonishment. We are led almost irresistibly to speculate on the past and future condition of our planet, and on man, its present inhabitant. What various reflections crowd upon the mind, if we carry back our thoughts to the time when the surface of our globe was agitated by conflicting elements, or to the succeeding intervals of repose, when enormous crocodilian animals scoured the surface of the deep, or darted through the air for their prey; or again, to the state of the ancient continents, when the deep silence of nature was broken by the bellowings of the mammoth and the mastodon, who stalked the lords of the former world, and perished in the last grand revolution that preceded the creation of man. Such speculations are somewhat humbling to human pride on the one

hand, but on the other, they prove our superiority over the rest of the animal creation; for it has been regarded by the wisest philosophers in ancient times, as a proof of the high future destiny of man, that he alone, of all terrestrial animals, is endowed with those powers and faculties, which impel him to speculate on the past, to anticipate the future, and to extend his views and exalt his hopes, beyond this visible diurnal sphere.

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CHAPTER XX.

AN OUTLINE OF THE GEOLOGY OF ENGLAND AND WALES.

The outline of the Geology of England, and the map that accompanied it, given in the former edition of this work, presented (the author believes) the first distinct general view of the geology of England, that had ever been published; and though several parts of our island have since been more fully examined, the examinations have confirmed the correctness of the leading facts, stated in the editions of 1813 and 1815.

Since the latter year, the author has visited and revisited almost every part of England and Wales deserving notice, and had collected materials for a more ample description of their Geology. A work has however been published by Messrs. Conybeare and Phillips, entitled "Outlines of the Geology of England and Wales," which contains, as far as it has gone, a very detailed and correct description of English Geology. The Rev. W. D. Conybeare, to whom we are indebted for the greater part of the volume, is unfortunately for the cause of science deceased; but if the work be continued with the same ability, it will leave little further to be desired.

In consequence of this publication, the author had intended to omit the following Chapter; but it has been suggested to him, that many persons who would think a minute description of each rock formation dry and uninviting, might still be desirous of perusing a concise account of the geology of their own country. There are also in the present Chapter some observations on the dubious parts of English Geology, which the author trusts may deserve the attention of experienced geologists.

N.B. The Contents of this Chapter, and the pages, are given in the Index. See 'Geology of England.'

THE shape of islands and continents, is generally determined by the ranges of primary and transition

mountains that traverse them; these have been compared to the skeletons, on which the other parts of a country are constructed.

The length of Britain is determined by different groups of mountains, which viewed on a large scale may be regarded as one mountain range, extending north and south (with its ramifications) along the western side of England and Wales, from Cornwall to Cumberland, and from thence to the northern extremity of Scotland. All the highest mountains in England and Wales are situated in this range, which, in reference to our island, may be called the great Alpine chain. This chain is interrupted by the intervention of the Bristol Channel, and the low grounds of Lancashire and Cheshire, which divide it into three groups or ranges; these, for the sake of distinction, may be denominated the Devonian range, the Cambrian range, and the Northern range. They form the Alpine districts of England (coloured red in the map). The mountains of the great Alpine chain from Cornwall to Cumberland, are composed of primary rocks and of other rocks, which belong chiefly to the class of transition rocks, described Chap. VII. Those parts in which the primary rocks chiefly occur, are shaded by lines. In some few parts east of the Alpine district, the primary and transition rocks also make their appearance, uncovered by the secondary strata. A range of primary and transition mountains appears once to have extended from the Devonian range, in a north-east direction, into Derbyshire: the transition mountains of that county, the Charnwood Forest hills, the sienitic greenstone of Warwick