278 Mr Hardie 07i the Geology oj the 



would necessarily result. The earth's rotation, and its flattened 

 form, which would produce at the two poles a closer contact be- 

 twixt the oxidised crust and the metallic nucleus, are circumstances 

 which would also produce a necessary influence upon the direc- 

 tion of the terrestrial currents. In conclusion, we may add, 

 that the existence of these currents is no longer purely hypothe- 

 tical, since different English naturalists, and first and especially 

 Mr Fox, have succeeded, by means of the galvanometer, in 

 discovering evident traces of them in the metallic veins of the 

 mines of Cornwall. 



GEOLOGY OF THE VALLEY OF OODIPOOR. By J AMES HaRDIE^ 



Esq. Bengal Medical Establishment^ Member of the Asiatic 

 Society, §*c. Communicated by the Author. ( Concluded from 

 p. 59. vol. XV.) 



About two miles to the north of the bund of the Oodisagor, 

 the barrier range is traversed by another barrier or cross valley, 

 the entrance to which is guarded by the Dubaree gate. Pro- 

 ceeding west from this position towards the city of Oodipoor, 

 about nine miles distant, we have first a continuation of the 

 quartz-rocks of the Oodisagor bund. The truncated edges of 

 the nearly vertical quartz strata constantly protrude, as we fol- 

 low the course of a steep and rocky path, which traverses a low 

 ridge connecting the hill ranges on our right and left. On the 

 western slope of this ridge the clay-slates or argillaceous schists 

 first make their appearance ; and the quartz-rocks, as we ap- 

 proach the spot, partake more and more of an argillaceous cha- 

 racter. The strata which now present themselves consist of ar- 

 gillaceous and calcareous schists, which form frequent alternations 

 with each other. The calcareous or rather limestone schists, are 

 of a reddish-brown colour ; they effervesce strongly with acids, 

 are more or less schistose, inclining to fine schistose. Their in- 

 ternal texture is fine angulo-granular ; they include numerous 

 scales of mica, and isomorphous grains of a greyish-coloured 

 limestone are occasionally intermixed with others of a reddish 

 colour. The argillaceous schists are generally soft and sectile ; 

 their colour is different shades of grey; they are generally 



