132 Kotes, principally Geological, on Soutliern India.^ [Jaw. 



Tippoo. This mausoleum is supportedby finely poHsbcd pilliirsof a dark 

 rock, containing black crystal!*, in a dark paste, rendered still darker 

 by the oil, with which the pillars appear to be constantly rubbed. Buch- 

 anan thought these spots were dark crystals of basaltine, or augite, im- 

 bedded in the hornblende ; and Dr. Benza, who subsequently visited 

 the locality, is also of this opinion, adding moreover, that the hornblende 

 rock of the dykes, in the fosse of the f'>rt just described, is identical with 

 that of the pillars. We are, however, informed by Buchanan, that the 

 rock, from 'vhich the pillars are cut, was brought from Cudhully, near 

 Turivicary, about fifty-two miles N. E. from Seringapatam. 



After a careful examination of the pillars in the mausoleum, and a 

 fragment of them given to my friend Captain Allardyce, by the mullah 

 of the mosque, and of the rouk in situ at the quarry of Cudhully, near 

 Turivicary, from which it was cut, during a subsequent visit to this 

 part of Mysore, I feel assured that the hornblende rock of the dykes at 

 Seringapatam, and that composing these beautiful columns, are by no 

 means identical. Had they been so, the natives would not have gone 

 fifty-two miles to quarry stone, which might have been procured on the 

 spot. The Cudhully rock, and that of the pilhirs, is composed of a dark 

 talcose paste, imbedding black crystals of a mineral, strongly attracted 

 by the magnet. This paste is sectile, and infusible per se before the 

 blow-pipe. The hornblende rock of the dyke on the contrary is hard, 

 and fuses into a greenish black glass : the imbedded crystals of this mi- 

 neral, decomposing, often fall out, imparting a variolated appearance to 

 the surface. The geological situs of the talcose rock will be described 

 in a future paper ; suflfice it to observe that it is associated with the talc 

 slate.* 



The Cauvery river.— ThQ Cauvery at Seringapatam, during the 

 rains, is a deep and rapid river ; but easily fordable during the dry 

 season: the bed is rocky and encumbered by large fragments of 

 granite and gneiss. Its bed cannot vie with those of the Kistnah 

 and Godavery, in precious stones, corne-lians, agt.tes, &c. Gra- 

 nite, greenstone, and gneiss, imbedding corundum, and, though 

 rare, the ruby, with its associated schists, are the rocks gene- 

 rally passed over by its waters. Garnets andiron ore are, however, 

 frequently found in the bed; corundum seldom. This beautiful 

 and sacred stream takes its rise among the Coorg mountains, and tra- 

 verses the peninsula in an easterly by southerly direction. After wa- 

 tering a large part of Mysore, it descends into Coimbatore at the falls 

 of Sivasamudrum, and, passing Trichinopoly, disembogues its waters 

 through various channels into the Bay of Bengal, between Porto Novo 



* See note on tbis subject at the end of this Journal,— ^c^j/or. 



