J oii VoLcunos. 



there are good reasons for concluding that the quantity of water 

 circulating over the globe's surface in this manner, in given 

 times, has progressively diminished, with its diminution of tem- 

 perature, from the earliest ages of the world ; so that we need 

 not shrink from attributing to its agency, effects far exceeding 

 in magnitude those of which it appears capable at present. 

 u One decided proof of the slowness of the process of excava- 

 tion, wherever it occurs, exists in the sinuosity of water chan- 

 nels, and in such a case, are met with even amongst the lar- 

 gest river vallies, it is idle to talk of transient deluges or de- 

 bacles as the excavating agent." 



" With regard to the periods at which the different continents 

 may have been heaved upwards, our author concludes from the 

 analogy of the volcanic phenomena, that such elevations took 

 place by successive shocks ; the greater number being of minor 

 violence, similar to the earthquakes which occur at present ; 

 but some of prodigious power, (paroxysmal expansions,) and an- 

 alogous to the paroxysms of habitual volcanos. If it is true, that 

 outliers of the plastic clay and chalk have been recognized 

 on-ihe highest summits of the Alps, it would appear that this 

 colossat^bain, and perhaps with it the whole continent of Eu- 

 rope, owes its elevation from beneath the sea to some catastro- 

 phe of this nature, at what we are accustomed to reckon a com- 

 paratively recent geological epoch. The traces of diluvian ac- 

 tion, the boulders of the Alps and Sweden, and the alluvium of 

 the north of Europe, may have been produced by the retreat of 

 the ocean from this elevated surface, and the successive oscilla- 

 tory movements to which it must have been subjected before it 

 regained its level. Other paroxysmal expansions may have oc- 

 curred in earlier ages of the globe's history, and in the old red 

 sandstone formation, it is observed we may perhaps trace the re- 

 sult of such a catastrophe. The occurrence of repeated eleva- 

 tions on a large scale, is, indeed, attested by numerous geological 

 facts. It is also probable, from what we know of the power by 

 which they are occasioned, that they were far more frequent and 

 violent in the early part of the history of the earth than they can 

 be at present ; for, unless we suppose the proportion of caloric 

 transmitted from the interior of the globle towards its surface to 

 have been always on the iucrease, (which is directly the reverse 

 of the opinion professed by the author,) it is clear, that the con- 

 tinual and general increase of the repressive force, by the addi- 

 tions made to the solid strata of the globe, in the products of 

 volcanos, and incrusting springs, and also to the body of water 

 and atmospheric fluids which press upon that surface, must have 

 proportionately diminished the ratio of subterranean expansion, 

 from the commencement of the process up to the present day. 



