GEOGNOSY OF PENINSULAR INDIA. 241 



tensive overlying trap-formation, which extends in this 

 quarter from the seashore of the Northern Concan to a 

 considerable distance eastward, above and beyond the 

 Ghauts, as far as the river Toombuddra and Nagpore. 

 The rocks of this formation, which are ■ greenstone, basalt, 

 amygdaloid, wacke, and trap-tufa, are columnar, globular, 

 tabular, and amorphous. The amygdaloidal structure is 

 most general in the amygdaloid, in the cavities of which 

 rock amethyst and various beautiful and splendid zeolites 

 occur. The trap hills are tabular, terraced, separated from 

 each other by ravines often of vast magnitude, and the 

 whole frequently covered with fine forests of teak and other 

 trees, forming some of the most romantic scenes in India. 

 The elevation of this part of the range seldom exceeds 

 3000 feet ; but advancing towards the south its height 

 gradually increases, and granite rocks begin to appear above 

 the surface between the seventeenth and eighteenth degrees 

 of north latitude, and from thence forming, along with 

 gneiss and other Xeptunean primitive strata, the chain, with 

 little interruption, all the way to Cape Comorin, and thence 

 to the extremity of the peninsula. The granite tracts of 

 India exhibit the same general forms as granitic countries 

 in other parts of the world. Rugged hills, with bold den- 

 ticulated outlines, lie grouped together in the greatest ir- 

 regularity, or occasionally form ridges, which, when inter- 

 posed between the spectator and the evening or morning 

 sun, present the most varied and fantastic forms. Some 

 of these ridges, when their dark outline is seen at twilight 

 against a ruddy western sky, emulate in their various forms 

 the apparently capricious forms of summer clouds, and we 

 can then trace along their summits the appearances of 

 castles, trees, men, and various strange groups. Many of 

 the hills have the appearance of mere collections of large 

 fragments of rock thrown confusedly together by some con- 

 vulsion of nature ; while frequently larger masses, piled 

 with great regularity on each other, look like remains of 

 gigantic architecture. High insulated masses, forming con- 

 siderable hills, in many instances rise abruptly out of a plain 

 to a height of several hundred feet, and present nearly 

 mural faces on several of their sides ; thus affording situa- 

 tions of immense natural strength, which have almost in- 

 variably been taken advantage of by the natives for the 

 Vol.: III.— X 



