1846.] on the Western Coast of South India. 231 



take a fine polish. Crystals of glassy felspar occur imbedded when 

 the rock passes into trachyte porphyry ; but I have never seen it with 

 scales of mica, assimilating granite, like the trachytes of Smyrna and 

 Mitylene. In some places it has the appearance of a stratified sand- 

 stone, and in others there can be no doubt of its volcanic origin. In 

 one place it is felspathic; in the other imbedding rock crystal, and 

 globules of quartz. 



As this curious rock is without parallel in India, a detailed descrip- 

 tion of its relations with the contiguous trap, and a series of specimens 

 exhibiting the different mineral alterations the rock undergoes in 

 various parts of its mass from the line of contact to its most dis- 

 tant point from the trap, would be highly interesting and instructive. 

 It is probable that the molten mass of trap and trachyte may have 

 here invaded the sandy bed of a lake or sea, and thus become 

 blended. 



The amygdaloid of Bombay, among other beautiful specimens of 

 the zeolite family, contains that rather rare mineral (in Europe), 

 apophyllite. Chalcedony in most of its varieties, and beautiful agates, 

 are common. 



The temperature of sea water in the harbour of Bombay in April 

 was 87° Fahr. a foot below the surface. The temperature of air in the 

 shade was 85° the time of observation 3 p. m. 



The temperature of water in a well at Bombay, 20 feet deep, was 

 82° ; (which approaches the mean temperature of the place) : the tem- 

 perature of air in the shade was 86°; time, noon; month, April. The 

 temperature of the cave of Elephanta — same month — time, noon — 

 was 85° ; the temperature of the water of a well in Elephanta was 

 75°. 5' — temperature of air in the shade at the moment was 85° ; time 

 of observation, noon. 



