66 Feather stonhaugfrs Geological Report, 



These conclusions, to which geological opinions have been for 

 some time tending, and which are now universally adopted, 

 are the result, not only of geological observations, but of ma- 

 thematical and physical reasonings, which lend them every 

 authority when applied to the causes which have determined 

 the spheroidal figure of the earth, and the state of igneous 

 fluidity it must once have been in to assume that figure. If 

 this is to be called a theory, it is only another name for the 

 incontrovertible result arising from the sound generalization 

 of well-ascertained facts. To some, it is true, who have never 

 reflected upon this subject, it may appear startling to hear 

 that continents and chains of mountains have been raised fro-m 

 the interior parts of the earth by the force of subterranean 

 power ; but every effect is proportionate to its cause, and 

 where the first is definite, and the last immeasurable, we must 

 submit to the reasonableness of the proposition, remembering 

 always, that although human power dwindles into insignifi- 

 cance when applied in imagination to disturb a mineral mass 

 like the crust of the earth, yet it is demonstrable that a gas- 

 eous pressure may be generated in such a radius, to which 

 the known mineral mass could make no resistance. In reason- 

 ing, therefore, upon these high matters, we must not measure 

 unknown forces by our own feeble powers, but by the effects 

 they are capable of producing, and, when causes and effects 

 of this high planetary character are under consideration, 

 must reason of them in relation to the proportion in which 

 they stand to each other. 



The evidences of these upheavings of land are common in all 

 extensive countries, especially those where the inclined rocks 

 prevail a character common to all the strata below the carbo- 

 niferous limestone ; and geologists have availed themselves of 

 this very inclined state of the beds, to establish as it were a 

 chronology for the history of all mountain ranges, showing,, 

 relatively, the successive geological periods at which they 

 have been thrust up. It is obvious, if any of the primary 



