474 Reviews — Geological Survey of India. 



The general remarks upon mountain formation in Mr. Middlemiss's 

 concluding chapter are the least satisfactory part of his work. Mr. 

 Mellard Reade's book on " The Origin of Mountain Ranges " is 

 taken as the fulcrum of discussion ; and some effective execution 

 is done in the way of demolishing errors of " fact," but the 

 reductio ad absurdum of the " principle " involved is not complete. 

 Some caution might have been suggested by the knowledge that 

 Babbage and Herschell were the promoters of the said principle in 

 this cause, for such men were not likely to commit absurd blunders 

 in the elements of mechanical physics. The key sentence in Mr. 

 Middlemiss's argument (p. 181) is, to say the least of it, obscure; 

 that "great sedimentation of this kind can only take place by 

 concomitant sinking of the sea-bottom ; so that the rise of the 

 isogeotherms being interpreted means merely the sinking of the 

 floor on which the deposits were laid down." It certainly does 

 mean that much ; but the form of expression is incomplete or even 

 misleading, for the process is not wholly a rising of the isogeotherms, 

 but also a sinking of the strata into zones of higher temperature 

 with the inevitable concomitant expansion, which through tangential 

 resistance must (unless some line of less resistance is already 

 established) result in the plication with elevation of the strata con- 

 cerned, to which action the origin of true mountains is plausibly 

 attributed by the theory in question. Mr. Middlemiss seems to 

 ignore the significant distinction between continental elevation and 

 " true mountains." The total rejection of the Babbage-Herschell 

 principle is the more strange as this starts from the same point — the 

 "condition of approximate hydrostatical equilibrium" of the earth's 

 crust — as does the discussion of the same question by Mr. Fisher, 

 of which so much approval is deservedly expressed. It is not 

 unlikely that the subsidence of the plains' deposits into regions 

 of higher temperature may be a factor in the continued rise and 

 compression of the sub-Himalayan zone, which Mr. Middlemiss 

 emphasizes as if it had been denied. It is clear, too, that the rise 

 extends to the whole of the outer Himalaya, else the transverse 

 river gorges would have become lake-basins, as has occurred in the 

 Alps. But Mr. Middlemiss does not sufficiently keep in mind that 

 the mountains he refers to are but the southern face of the Himalayan 

 massif, the crest of which must, as indicated by the drainage lines, 1 

 have been far to the north of the present range of greatest elevations. 

 The decadence suggested by me was assigned to that central region. 

 The unfortunate expression "life history," as applied to things that 

 have no life, might have helped him here as it seems to have confused 

 him elsewhere : for a man's brain may mature while his limbs 

 go to the bad, or vice versa. Rhetoric is an unsafe and unsavoury 

 ingredient in scientific work. Henky B. Medlicott. 



1 Manual, p. 675. 



