456 



Sketches of the Meteorology, §e. 



[Oct. 



laminrc, the other parts of which have been gradually worn down all 

 around them ; and that they now stand as monuments of what the 

 height and nature of these lamina? formerly were,* 



It is by no means uncommon to meet with a vein of quartz, felspar, 

 or trap, passing from one loose block of granite into another, or from 

 a hill into a mass, resting loosely upon its surface ; which clearly prove 

 that these continue to occupy the situations in which they were origi- 

 nally formed. Upon a superficial view, one is naturally led to suppose 

 that the confused heaps of granite blocks are the result of some great 

 convulsion of nature. But by merely tracing the small veins of quartz, 

 felspar, &c. which traverse the granite from one contiguous block into 

 another, and by attending to the accurate adaptation of some of the 

 contiguous parts of th<'se blocks, we can prove that a great proportion 

 of them continue in their original situations ; and that all the appear- 

 ances of confusion which they exhibit, are the result of a partial and 

 irregular disintegration. It is only in the valleys that transported 

 masses are found. We have generally reason to conclude, that all the 

 separate masses, on the sides and summits of the hills, continue to occu- 

 py their original places, however confused these may now appear. 



We have no reason to suppose that all the granite which has been 

 disintegrated and washed away, was of a hardness and durability equal 

 to that of the masses left entire. Had this been the case, their destruc- 

 tion would have required a length of time, which our imagination can- 

 not embrace. But, it is quite evident, that the perishable granite of 

 loose texture, which is so very common, has alone been removed ; 

 and this removal, by depriving the more solid masses of its support, 

 has caused many of them to split, and be precipitated into the neigh- 

 bouring valleys. 



The distribution of the perishable granite is often very irregular; 

 and, in this case, when removed, it must necessarily leave the solid 

 masses with which it was associated in the most fantastic situations ; 

 and thus we can imagine how many of those appearances of confusion 

 met w T ith in the granite of India may have been produced. We can 

 sometimes perceive how the original lamina? might be renewed, by 

 filling up the void spaces between the different masses, and thus con- 

 necting together what were formerly distinct portions of the same 

 lamina. 



In regard to the mineral composition of the granite, it may be said 

 (speaking very generally) to consist of felspar, quartz, mica, and horn* 



* A very clever drawing of a singular column of this kind, from the 

 pencil of Lieut. Lavvford, of Engineers, is before us, sent by Lieut. 

 Newbold, as an illustration of some notes on the geology of the Bellary 

 district. — Editor Madras Journal, 



