VI 



CONTENTS. 



CHAPTER V. 



Order of deposition and its economic bearing 

 Persistence in depth .... 



Decomposition of wolfram 

 Secondary enrichment .... 

 Prospecting for wolfram veins . 



CHAPTER VI. 



Production of wolfram and cassiterite in Burma and its relations to 



World's output .......... 255 



Other deposits of the Indian Empire . . . . . .261 



Descriptions of Tavoy mines ........ 262 



CHAPTER VII. 



Mining Methods — 309 



The tribute system 309 



Concentrating mills ......... 312 



Sampling surface deposits . . . . . . . .316 



Hydraulic mining, sluicing and pumping ..... 318 



Concentrating pans •-....... 320 



High pressure hydraulic plants ....... 320 



Dredging 325 



CHAPTER VIII. 



The origin of the wolfram and cassiterito oros of Tavoy . . . 328 



Pages. 



242 

 245 

 249 

 253 

 253 



Index 



339 



