1833.] Voysey’s Report on the Geology of Hyderabad. 299 
Any person who has travelled in India will be aware of the difficul- 
ties attending a deviation from the main road, especially in an unfriend- 
ly country ; this circumstance, with the necessity of attending to those 
professional duties which were incompatible with any protracted ab- 
sence from the camp, will, it is hoped, be a sufficient apology for any 
apparent deficiency in my attempt to take a general survey of the 
mineralogical character of the country in which my partial observations 
have been made. 
It may also be proper to state in this place, that the scarcity of all 
kinds of meteorological and other apparatus prevented me from 
making any other than very general observations; and although provid- 
ed with one of Gay Lussac’s Syphon Barometers, yet the scale had been 
so imperfectly graduated in Calcutta, as to allow me to place but little 
reliance on the observations and calculations of heights obtained from 
it. This latter defect is of minor importance, since the heights of all the 
trigonometrical stations will be determined by Colonel Lamsron him- 
self in the progress of the survey*. 
The geology of the country between the Kistnah and Godavery 
admits of a very simple division, being distinguished from most other 
countries of a similar extent, by the existence of only two formations, 
differing very widely in their characters; viz. granite and WeRNER’s 
fleetz trap, both of which give a striking and separate character to the 
scenery, cultivation, and vegetable productions. It is proposed, there. 
fore, in this sketch, to bring together in a general view the principal 
characteristics of each division; to contrast them; and finally to enu- 
merate the minerals collected, giving their description and analysis as 
far as it could be performed. 
After quitting the limestone on the banks of the Kistnah [to be 
hereafter mentioned], granite alone is the basis of the country, even to 
the Godavery. 
Certain characteristics belong to it throughout, which sufficiently 
mark its identity and contemporaneous formation. They are, 
Ist. The great irregularity of extent and direction of tke ranges. 
2nd. The narrow but lengthened veins or dykes of trap with which 
it is intersected, all running nearly in the same direction, and the 
masses of micaceous and sienitic granite with which it is intermixed. 
3rd. The predominance of the red colour, arising from the red fel- 
spar, which is frequently in large crystals, giving the granite a por- 
phyritic appearance. 
* Colonel LamBron computes the height of Hyderabad, above the level of the 
sea, to be 1800 feet, 
