Improvements in modern science derived from the East. 17 



been found to exceed in altitude as well as lateral extent the 

 Andes of South-America, hitherto deemed the greatest mountains 

 in the world ; together with the discovery or examination of the 

 <)levated sources of the Indus, the Ganges, and the Brahmapiitraj 

 the three grand rivers of India, constitutes a memorable epoch in 

 the history of Physical Geography. When these discoveries, in- 

 deed, are viewed in conjunction with the innumerable facts of 

 minor, yet considerable importance, that depend on the newly- 

 acquired knowledge of the climate and other peculiarities of the 

 extended table-land of Nepal and Thibet, wo must acknowledge 

 this epoch to be hitherto unequalled in the progress of that science. 



til the kindred science of Geology, however, but one depart* 

 ment has yet received any considerable additions from researches 

 in the East ; viz. that relating to those igneous phaenomena, to the 

 causes of which, operating at a remote period in our planet's 

 physical historyj an extensive and consonant series of facts impels 

 us to refer the formation, to a great extent, of our present 

 continents : — we allude to the phsenomena of volcanos. Prior 

 to Dr. Horsfield's geological investigation of Java, and Sir Stam- 

 ford Raffles's exertions in obtaining accounts of the eruption of 

 Tomboro, in the island of Sumbawa, in 1815, the provinces of 

 Mexico, Guatemala, and Nicaragua, in North-America, and the 

 western side of South-America, appeared to be the only countries 

 in the world, in which the chemical agency productive of intense 

 combustion, exerted to so great an extent in the early stages of 

 the earth's formation, still retained a vigour approaching to what 

 it must have possessed in former ages. But the volcanos of the 

 Indian islands east of Sumatraj are now known to indicate an 

 activity in the causes of volcanic energy, fully equal to that which 

 the Cordilleras of America exhibit ; the most stupendous phajno- 

 mena recorded of the latter, receiving a parallel in the operations 

 of subterraneous fire witnessed in Java and Sumbawa. To these 

 we shall have occasion to return, as we proceed in this memoir. 



Very little information, on the contrary, has yet been obtained, 

 respecting the actual structure, either of the Indian peninsulas or 

 of the islands ; and hence the contributions from the East to that 

 branch of geological science, which is coneerned in investigating 



Vol. III. B 



