TWO ANTAGONIST DOCTRINES OF GEOLOGY. 59.1 



Before Mr. Lyell entered upon his journey, he had put into the 

 hands of the printer the first volume of his " Principles of Geology, 

 beino- an attempt to explain the former Changes of the Earth's Surface 

 by reference to the Causes now in Operation" And after viewing such 

 phenomena as we have spoken of, he, no doubt, judged that the doc- 

 trine of catastrophes of a kind entirely different from the existing 

 course of events, would never have been generally received, if geolo- 

 gists had at first formed their opinions upon the Sicilian strata. The 

 boundary separating the present from the anterior state of things crum- 

 bled away ; the difference of fossil and recent species had disappeared, 

 and, at the same time, the changes of position which marine strata had 

 undergone, although not inferior to those of earlier geological periods, 

 might be ascribed, it was thought, to the same kind of earthquakes as 

 those which still agitate that region. Both the supposed proofs of 

 catastrophic transition, the organical and the mechanical changes, 

 failed at the same time ; the one by the removal of the fact, the other 

 by the exhibition of the cause. The powers of earthquakes, even such 

 as they now exist, were, it was supposed, if allowed to operate for an 

 illimitable time, adequate to produce all the mechanical effects Avhich 

 the strata of all ages display. And it was declared that all evidence 

 of a- beginning of the present state of the earth, or of any material 

 alteration in the energy of the forces by which it has been modified at 

 various epochs, was entirely wanting. 



Other circumstances in the progress of geology tended the same 

 way. Thus, in cases where there had appeared in one country a sud- 

 den and violent transition from one stratum to the next, it was found, 

 that by tracing the formations into other countries, the chasm between 

 them was filled up by intermediate strata ; so that the passage became 

 as gradual and gentle as any other step in the series. For example, 

 though the conglomerates, which in some parts of England overlie the 

 coal-measures, appear to have been produced by a complete discon- 

 tinuity in the series of changes ; yet in the coal-fields of Yorkshire, 

 Durham, and Cumberland, the transition is smoothed down in such a 

 way that the two formations pass into each other. A similar passage 

 is observed in Central-Germany, and in Thuringia is so complete, that 

 the coal-measures have sometimes been considered as subordinate to 

 Ihe todtlieyendes.* 



Upon such evidence and such arguments, the doctrine of catastro- 



De la Beche, p. 414, Manual. 



