fragments be angular, ragged, and pointed. On the other hand, when this convulsion took place, had the whole not been enveloped in much water- a hypothetical combination which might be supposed to have occurred if heat or fire had caused the catastrophe-then the fragments alluded to would have remained almost as angular and as ragged and pointed as they were when detached. Had the displacement, and its natural consequences, occurred in the midst of water, without any peculiar impetus, such as a rush from the poles towards the equator, to complete the figure or static condition of rotation, it is not at all probable that the stones and fragments, to which I refer, would or could have assumed the perfect appearance of much attrition and of distant travel which those beds of pebbles do. They evidence, by their perfect sphericity, in many instances, when coupled with the solidity of their material, that it was no common flood, no short space travelled over, nor any moderate speed which conferred on them their smoothly rounded form, and which have acquired for them the designation of "travelled fragments."

It is equally as satisfactory to reflect, on taking another view of the case, that without their presence in the precise conditions in which they are found, all the assumptions of this Treatise would have been incomplete, and liable hereafter to have been considered erroneous. And thus, the rolled pebbles afford both positive and negative proof in favour of the cosmogony which is here inculcated.

It is with peculiar satisfaction I am thus enabled to close the geological evidences, in this department, for the truth of the Dynamical System, with a class of phenomena, derived from that science, so universal and so admirably adapted as are the components of the "erratic block group," both by their character and their durability, to point out the form which the earth assumed on being caused to revolve diurnally around its axis. No evidences could possibly have been more appropriate than these "boulders," tangible as they are by the senses, and everywhere to be found. Most heartily ought we to thank the Creator for having permitted that these effects should have proceeded from natural causes, in order, that along with the other designs, which they were

intended to fulfil, they should afford the most undeniable evidence, that when torn asunder from their parent rocks, and strewed over and imbedded in the surface of the surrounding soil, the globe was in the act of receiving from his almighty hand, "who weighed out its hills in his balance," the identical inflections of surface which, to the present moment, it retains.

SECTION V.

GEOLOGICAL PHENOMENA RESULTING FROM THE EARTH'S FIRST DIURNAL ROTATION.

CHAPTER XXVIII.

ON reviewing the leading points of this protracted section

it will be perceived that, first of all, evidences of a mechanical character were adduced to prove, that the earth, which during the period of darkness revolved around the unillumined sun without diurnal motion, was, by the formation of the light, and its division from the darkness, caused to rotate diurnally around its axis. Having dwelt sufficiently on that particular point I proceeded to inquire, in continuation, what were likely, theoretically, to have been the results of this new motion upon the general outlines of the globe. After these were defined, as nearly as possible, a minute and lengthened investigation was entered into, which concluded by determining, satisfactorily, that not only all geological phenomena, but likewise the greater general elevation of land within the equatorial regions, and the formation of continental ridges and oceanic hollows, accorded with these theoretical conclusions.

In conducting the geological inquiries I attended both to the external evidences afforded by the action of one rock upon another, and also to the internal evidences arising from the mineralogical structure of the primary and older secondary rocks, supposing them to have been moved from where they were considered, in the previous chapters, to have been formed. In these investigations, there were included the

mineral veins, dykes, and fissures, and the metallic lodes, and it was made manifest that they, too, could be satisfactorily accounted for by the same System. Going on, afterwards, to the sedimentary rocks, which owe their origin to the deposition of debris, spread abroad by the elevation of mountain chains, it was shown, that with the exception of some of the more recent of the tertiary, whose origin was hinted at in passing, they, likewise, correspond in geological developments with what might, à priori, have been expected from the first diurnal rotation of the earth around its axis, after induration had taken place at the period alluded to. And the whole was closed in by a brief description of the "erratic block group," which was also found to be susceptible of easy elucidation, by the facts and arguments brought to bear upon it.

Under these concurring and favourable circumstances, looking upon the geological and mineralogical evidences as being uninterruptedly linked together from first to last; and feeling assured that the proofs in favour of the Dynamical System have been, throughout, most persistent; it is now considered we may safely conclude, as a final deduction from the whole, that the first diurnal revolution of the earth around its axis took place AFTER the formation of those materials which now constitute the independent coal measures, and immediately BEFORE the deposition of the new red sandstone, the oolitic, and the cretaceous groups: from which conclusion. three important corollaries necessarily follow :

1. That the period during which the earth revolved around the sun without diurnal rotation, extended from the instant of its being translated in space at "the beginning," from the first symptom of stratification until the entire deposition of the material which now constitutes the coal

measures.

2. That as the protuberance of its equatorial regions arises from its diurnal rotation, and this owes its origin to the formation of the light, and its division from the darkness, its excess of equatorial diameter can have existed only since the date recorded in Scripture as being that of the formation of the light.

And 3. As a change of form would produce a corresponding effect on the astronomical relations of our sphere, this would

undoubtedly be perceptible to astronomers, by their accurate investigations responding to the reverberation which took place on that account from the allied but distant bodies of our system; and should leave upon their records, corresponding evidences of a change in the earth's uranographical phenomena, indicative of that alteration of form which geology leads us to consider it underwent; while the exact nature of those deductions should assign the precise period, or nearly so, when this perturbation was first perceptible in the motions of our planet. That, should such be the case, all these views would be corroborated by the testimony of a science dedicated to the investigation of laws which govern regions of space far beyond the sphere we tread upon; and we would thereby enjoy the satisfaction of beholding these sciences mutually shedding their lights on each other, and unitedly conspiring to the advancement and establishment of the TRUTH.

In order to discover whether such, in reality, is the case, let us attend to what is stated in the seventh Theorem, to which please refer.

These results being deduced from principles in astronomy, not very apparent at first sight, and depending on two motions entirely distinct in their nature and origin, they will require to be partially analyzed and laid open to the view, by explanations drawn from the same source which furnished the materials for the theorem. In doing this, I shall commence with the "direct motion of the perigee," more with the design of eliminating it from the argument, than from any immediate tendency it has to aid our convictions; the phenomenon which principally interests the general inquiry being the retrogradation of the node of the earth's equator on the ecliptic.

The following extract proves the effect produced on our satellite in consequence of the redundant matter accumulated in the equatorial regions, and the reciprocal light which this sheds upon the external form and the internal structure of the earth :

"The moon is so near," says Mrs. Somerville, " that the excess of matter at the earth's equator occasions periodic variations in her longitude, and also that remarkable inequality in her latitude, already