64 Rev. 0. Fisher — Reply to Capt. Hutton. 



Y. — On the Formation of Mountains ; being a Eeply to Captain 



Hutton's Article in the January Number, Page 22. 



By Rev. 0. Fishee,, M.A., F.G.S. 



THE cause of the formation of mountains is so difficult and so 

 vast a question that I cannot undertake to answer all Captain 

 Hutton's objections to what he concisely calls the "contraction" 

 theory. Moreover, I feel that, as far as my endeavours can help to 

 elucidate so great a subject, I shall do better to throw what I have 

 further to say into a form which is not controversial. I desire not to 

 be held a champion of any theory, and shall always honestly abandon 

 any position, which subsequent consideration leads me to think un- 

 tenable. Thus with respect to paragraph (7), p. 26, in Captain Hutton's 

 rejoinder to my critique, I refer to the abstract I have sent to the 

 Magazine of my paper lately read at Cambridge, for it supersedes 

 some of the purely tentative suppositions to which Captain Hutton 

 takes exception, and which I adopted six years ago as " not un- 

 reasonable," in order to test the aiDplication of the theory. 



I have already admitted that some elevatory effect may probably 

 be produced under the conditions that Captain Hutton supposes, as 

 the consequence of " deposition," and I have shown what amount of 

 elevation I should attribute to them on page 255, Geol. Mag. Yol. X. 



I will now take in order Captain Hutton's replies to my criticisms 

 under the headings as he has marked them. 



(<x.) (Par. 1). I refer the reader to my own statement of this 

 argument ; for I think Captain Hutton has not quite understood my 

 meaning. I certainly did not intend to state that, on account of 

 horizontal pressure, "no upward rising would take place," and do 

 not see what words of mine can be thus paraphrased. But with this 

 exception, my views are correctly stated in the first paragraph. 



(Par. 2). The damped paper stretched on a board is an ex- 

 cellent illustration, and, I may remark, does not usually rise up 

 into a dome. But it needs to be observed that exactly the same 

 effect of wrinkling would result from a contraction of the board 

 as from the expansion of the paper. Mr. Maw's example is also 

 in point, so long as the tracts of the earth's surface, which we 

 compare to the brick coping, are not too large in comparison to their 

 thickness, and of sufficient homogeneity and rigidity to be fairly 

 represented by a course of bricks laid edgeways. 



(Par. 3). In the fundamental proposition of my paper " On the 

 Elevation of Mountains," 1869, I am seeking the utmost pressure 

 which could accrue, if the shell were self-supporting and did not 

 give way. For tliis purpose I sujapose it rigid ; but by no means say 

 it is so, but the contrary. If it were rigid, we should get a certain 

 enormous pressure. Since it is not rigid, it gives way ; and the 

 maximum pressure is never attained. I have been entirely mis- 

 understood here. 



I cannot quite make out whether Captain Hutton means to express 

 the same thing that I understand by " an arch " or " dome." If by 

 an arch or dome he means what usually go by those names, then the 

 case is not analogous to that of a portion of the earth's spherical 



