on his style we must plead in, excuse, that, even in so early a stage as the preface, we met with sentences, one of forty-seven and the other of forty-six lines, as difficult to surmount as Derbyshire mountains; that on page first, we saw with astonishment that the county in question "is situated about between the parallels of 52° 38' and 53° 27 of North-Latitude;" that on page second we found that " its greatest breadth is about from E. N. E. to W. S. W.," in consequence "of its greatest length being in a direction from S. S. E. to N. N. W.," that, pushing on, we discovered him at last distinguishing the "range of the Fault," "in every formae," "by a dotted line." p. 120. and that ironstone balls from Brailsford is a farther confirmation of his opinions," &c. &c.

Having stated our disapprobation of the manner in which Mr. F. gives us his observations; and just expressing a wish that he had been rather less caustic in his remarks on his brother geologists; we proceed to the far more pleasant part of our task, and will attempt to give our readers some idea of the matter contained in this highly interesting performance.

Mr. Farey informs us, in the preface, that the observations of which it is the result, were principally made in the years 1807, 1808, and 1809, at the instance of Sir Joseph Banks, and of the Board of Agriculture; and that it is to be looked upon as the first chapter of his report to the Board. He also intimates that the public may expect, at a future period, a more extensive work, with a large geological map, containing a complete detail of the facts which have come under his notice; and a second volume comprising the continuation of his agricultural report. The principal value of the part which we have on our table, is the precise account which it affords of the stratifications of Derbyshire; a considerable portion of the remainder being apparently inserted, merely in compliance with the general directions given by the Board to their reporters.

After mentioning the situation and boundaries, Mr. F. gives a very extensive account of the principal ridges or water-heads, of the hills, and of the valleys, in the county, with their respective strata; which is well, though not very elegantly elucidated by an outline map, indicating the principal eminences, and the direction of the ridges which unite them. It would have been an agreeable and useful addition to this part of the subject, if he had announced the heights of at least some of them..

The second section, enumerates the divisions of the county into hundreds and parishes, and we were glad to notice at the close, a candid acknowledgement of the beneficial effects of

dissenting and methodist preaching, in parts of this county, which would, perhaps, have been otherwise debarred from any religious instruction whatever.

The climate a pears to differ very little from that of the surrounding counties, and Mr. F. will by no means admit, that the mountainous tracts are as inhospitable as travellers and geographers, who are obliged to have recourse to high colouring to give their sketches effect, wish to make us believe. The register of rain kept by order of the Duke of Devonshire, for half a century, at Chatsworth, enables Mr. F. to give us very complete details in this part of the meteorology of Derbyshire. As it may be useful to some of our readers, to compare it with similar observations in other places, we transcribe the table of yearly totals entire.

The following are the yearly totals, viz. in 1761, 26. 525 inches ; 26, 23. 399 inches; and in

This gives an yearly average of 28,411 in. and, from a consideration of the number of rainy and dry days, it appears, that it rains on an average, 120 days in the year in Chatsworth. It also seems that March is the dryest, and October the wettest month, in the proportion of 8: 12; but the most remarkable observation is, that the annual average of rain in the first sixteen years is 30,324, in the second sixteen 28,262, and in the last 27,079; though the number of rainy days has increased. The weather has, consequently, become more humid, and less rainy; a singular and curious instance of a well ascertained change af climate.

The fourth section is intitled soils, but contains the principal part of Mr. F's. geological observations. He introduces

the subject by some general positions relating to stratification, and an enumeration of the British strata which appear to be superior to those of Derbyshire; and then gives us a theory of disclocated and denudated strata. Mr. F. very properly insists upon the difference between what are termed Faults, and the inetalliferous Veins of various strata; which have been strangely misunderstood, confounded, or overlooked by several writers. The imperfect knowledge of these phenomena, which not a few works of science betray, is, we believe, owing to the circumstance, that persons who have only worked the coal and iron-stone measures, know very little of veins, either from their rare occurrence or insignificance in these strata; bnt are on the contrary well acquainted with faults, which are of the utmost importance to them, and very easily discernible. When therefore veins are spoken of, they imagine them to be faults containing ore. On the other hand, miners in the lime-stone strata have all their attention directed towards those dislocations, or veins, which contain the ore they are in search of; they meet with faults sometimes, but having no further business with them, than to avoid or remedy the inconvenience they occasion, and of which they often scarcely understand the reason, give them no particular attention, Authors are usually indebted for their knowledge to practical miners and colliers; but the ideas gathered from either class are partial; and where collected from both, frequenly confused, owing to a belief that both are describing the same phenomenon. We are glad, therefore, that Mr. F. accurately distinguishes them; since, though veins are of great importance, on account of their produce, and as indicating the contractility of the strata, in which they occur; faults are of far greater influence in varying the inclination and situation of these strata, and producing the different appearances which are the immediate study of geology. By the word fault, Mr. Farey with the workmen of the country, understands a fracture or separation of a pile of strata, such as would be produced by forcibly breaking them in two, across the direction of the strata, attended by a degree of dislocation or change of situation in one of the parts, so that strata which formerly joined, are no longer in continuous lines or planes. The fissure is filled with extraneous matter which Mr. F. terms faultstuff. Veins on the other hand are no more than vertical cracks in the strata, attended by no removal, but the separation of the two sides. They sometimes extend through several strata in succession; but the parts thus separated retain their elevation; and frequently strata intevene, which are still entire, or into which the vein penetrates but a small way. They are

generally filled with matter called vein-stuff, which appears to have been introduced by infiltration.

To explain the manner in which the edges of the strata appear at the surface of the ground, on the different sides of a fault, Mr. F. first imagines three different modes in which that part of a pile of strata, separated by a fault, may alter its position with respect to the part from which it is separated, and which is supposed to remain at rest. The angular or parallel fissure being filled with fault-stuff, each of these combinations of quiescent and dislocated piles of strata, becomes again a continuous mass, which is supposed to be cut by six varieties of section, representing the surface of the ground, on which the edges of the strata form the various configurations. Thus forty-eight different appearances are occasioned, besides those of the eight original dislocations, all which are repreented in two coloured plates, which cannot fail to render the subject sufficiently intelligible to every one, who will take the trouble to consider them attentively.

The uppermost regular stratum of Derbyshire, according to Mr. F. is the red marle, which occupies the whole southern part of the county, though occasionally covered and concealed by patches of gravel, considered by our author as an alluvium. The red marle stratum appears to be of a very unequal thickness, but it is remarkable for the very uniform horizontal position of its various beds, though its surface is much diversified by hills and valleys. The spots and patches of very different, and very remarkable mineral substances, which here and there occur in this stratum, render it highly curious. Thus, in Cheshire, it produces the celebrated mines of rock salt and salt springs, with gypsum. The gypsum is also found in several places in Derbyshire, Nottinghamshire, and Staffordshire, either in huge lumps, even forming hills, imbedded in the red marle, or of the fibrous kind (very erroneous y termed the finely striated gypsum, by Mr. F.) in thin horizontal beds, but unaccompanied by the salt. Within this district, sienite also appears; not in strata, but apparently in elevated peaks, enveloped on all sides by the red marle, except where exposure to the weather has laid bare the summits. Mr. F's observations do not furnish us with sufficient data, to ascertain whether the base of the sienite blocks be situated on red marle beds, or whether they perforate it from beneath; and till this is determined, we cannot possibly decide, whether they are to be looked upon as anomalous aggregations belonging to that stratum, (as Mr. F. seems to think) or as the projecting points of a stratum greatly inferior. Slate is another production of the red marle, or rather makes its appear

ance through it, in a manner similar to the sienite, which it sometimes closely accompanies in a vertical position. Mr. F.'s remarks on the confusion which has arisen from mistaking the direction in which the slate splits (the beat of the stone) for an indication of the direction of the stratum, are very just. In the Yorkshire paving stone, the grey slate of the coal districts, and the numerous argillaceous coal shales, the stone naturally separates in a direction parallel to the situation of the strata; but in the true slate this is by no means the case; the grain in the latter being apparently occasioned by a species of crystallization, in the former merely by mechanical aggregation. Besides these extraneous occurrences in this stratum, gritstone, sand, and brick-clay are mentioned; and Mr. F. suspects that the basaltes of Staffordshire and Warwickshire also belong to it.

The red marle stratum appears to be separated from the strata of the northern part of Derbyshire, by an immense fault which transverses the county from E. to W.; to the north of which the strata are so much elevated, that the section formed by the surface of the country, in a nearly horizontal plane, carries away not only the red marle, but the greater part of the subjacent class of yellow limestone strata, and lays bare the coal measures, which lie beneath it. We have no means to estimate, with accuracy, the vertical height to which the northern strata have been elevated, or the southern depressed, but it cannot be less than several hundred feet.

The yellow or magnesian lime emerges from beneath the Nottingham gravel, to the E. of the county, but stripped of the Dudley coal measures, which cover it in Worcestershire, Staffordshire and Cheshire. These Mr. T. supposes to be lost, at a fault concealed beneath the gravel of Sherwood Forest, as they ought to appear between the red marle and the yellow lime. A very small portion of this stratum enters Derbyshire, passing along the eastern boundaries into Yorkshire. Though termed yellow, it varies in colour from red to blue, and from a perfectly dense, to a coarse granular texture, owing, in specimens which we have seen, to an aggregation of primitive rhombs of carbonate of lime. Magnesia prevails in all the beds, and generally to such a degree, as to render the lime from them injurious to vegetation. From under the various beds belonging to the class of yellow lime, there appears in succession the vast variety of coal measures, composing together a stratum distinct in its products, and in its origin; for, notwithstanding the variance of contending systems, and the doubt in which they involve almost every conclusion which