168  CONTRIBUTIONS    TO   ECONOMIC    GEOLOGY,  1904.        [bull.  260. 
contract.  The  earth,  both  barren  and  rich,  is  carried  out  by  men 
and  washed  by  a  crude  method  of  sluicing.  Modern  methods  are 
being  introduced,  however,  and  hydraulic  plants  for  sluicing,  pudj 
dlers  for  clayey  ground,  and  steam  crushers  for  coarse  ore  are  being 
installed. 
Water  interferes  considerably  in  the  lower  workings,  and  in  many 
of  them  centrifugal  pumps  run  by  steam  are  used,  while  in  others 
Chinese  pumps  run  by  man  pow7er  are  still  in  use. 
Much   of  the  ore  was   formerly   smelted   with   charcoal   in   small;, 
shaft  furnaces,  but  now  nearly  all  of  it  is  smelted  at  Singapore  im 
reverberatory  furnaces. 
The  production  of  tin  in  the  Malay  Peninsula  for  1904  was  05,096  ■ 
tons,  or  nearly  04  per  cent  of  the  total  production  of  the  world  exclu- 
sive of  China. 
Region  north  of  the  Malay  States. — Tin  deposits  are  also  worked 
along  the  Lakawn  Range  in  many  places  in  Tenasserim  and  Burma, 
and  have  been  Avorked  for  centuries  on  the  eastern  side  of  the  range 
by  the  Karen-ni  or  Red  Karen  tribes. 
Yunnan. — China  is  said  to  have  an  output  of  from  10,000  to  20,000 
tons  of  tin  per  year,  from  the  province  of  Yunnan,  but  this  estimate 
is  probably  too  high.  It  is  seldom  that  any  of  this  tin  finds  its  way 
into  the  markets  of  the  world,  being  generally  consumed  in  China. 
The  deposits  occur  at  Tomuko,  Tsementong,  Malaken,  and  KotiB 
those  at  the  last-named  place  being  the  most  important. 
Some  of  the  tin  ore  occurs  in  veins  in  Triassic  limestone  and  in 
residual  deposits  from  the  weathering  of  the  rocks.  At  Malaken  thd 
tin  in  "  red  clay  "  veins  is  giving  way  to  copper. 
French  Indo-China  and  Siam,  on  the  eastern  side  of  the  Lakawn 
Range,  produce  tin  at  a  number  of  places,  but  the  output  is  unim- 
portant at  the  present  time. 
Junk  Ceylon,  the  Mergui  Archipelago,  and  other  islands  off  the 
west  coast  of  the  Malay  Peninsula  have  some  unimportant  deposit!1 
of  tin.  The  geology  and  occurrence  in  these  places  are  similar  to 
those  of  the  Malay  States.     The  output  is  unknown,  but  is  small. 
Singkep,  a  small  island  (about  193  square  miles)  lying  about  ^ 
halfway  between  Banka  and  Singapore,  contains  tin  placers  which  I r, 
have  been  productive  for  more  than  a  century.  The  geology  is 
very  similar  to  that  of  Banka  and  Billiton.  In  1901  it  produced  <( 
793  tons  of  tin.  No  figures  showing  the  production  since  that  time  j; 
are  available. 
Banka. — The  island  of  Banka  lies  about  200  miles  southeast  of 
the  end  of  the  Malay  Peninsula  and  with  Billiton  forms  the  exten- 
sion of  the  tin-bearing  Lakawn  Range.  The  island  contains  several 
large    masses    of    granite,    cut    by    finer-grained    granite,    granitic 
