INVESTIGATIONS    OF    METALLIFEROUS    ORES.  15 
Unexpected  and  unavoidable  delays  in  the  preparation  of  these 
reports  have  been  caused  by  the  resignation  or  illness  of  the  authors. 
Messrs.  Spurr,  Garrey,  and  Weed  have  resigned  their  positions  on  the 
Survey  to  accept  more  remunerative  positions  with  private  corpora- 
tions, and  Messrs.  Ransome,  Boutwell,  and  Emmons  have  been  inca- 
pacitated for  work  for  several  months  by  illness.  These  causes  have 
also  very  seriously  curtailed  the  field  work  during  the  last  season. 
FIELD    WORK. 
GENERAL    DISCUSSION. 
An  important  part  of  the  economic  investigation  of  metalliferous 
ores  during  the  year  has  been  the  personal  supervision  and  direction 
of  that  part  of  the  work  of  the  division  of  mineral  resources  that  has 
to  do  with  metals  other  than  iron.  As  has  already  Seen  outlined  in 
previous  bulletins,  this  work  has  been  put  under  the  personal  direc- 
tion of  Waldemar  Lindgren,  who,  in  training  various  assistants  to 
carry  out  its  details,  has  found  it  necessary  to  spend  the  greater 
part  of  the  field  season  in  collecting  and  properly  differentiating  the 
statistics  of  gold  and  silver.  Similar  supervision  and  summing  up 
of  the  statistics  of  copper  has  been  placed  in  charge  of  L.  C.  Graton 
and  those  of  lead  and  zinc  in  charge  of  J.  M.  Boutwell.  This  work 
comprises  more  than  a  mere  compilation  of  figures  furnished  by 
others  to  show  production.  It  involves  the  tracing  of  the  metals  back 
to  their  various  sources  and  the  verification,  by  comparison  and  anal- 
ysis, of  the  necessarily  varying  results  obtained  by  different  lines  of 
investigation.  More  than  that,  its  object  is  to  gather  at  the  same 
time  such  geological  data  as  will  enable  the  geologists  in  charge  of  the 
respective  branches  of  the  work  to  prepare  an  annual  review  of  the 
production  and  prospects  of  the  different  metals  in  their  geological  as 
well  as  their  technical  and  commercial  relations,  and  thus  to  provide 
data  for  an  intelligent  forecast  of  the  progress  of  the  industries  in- 
volved and  of  the  direction  it  is  likely  to  take. 
The  regular  work  in  the  field  of  metalliferous  investigations  has 
been  thus  curtailed  by  the  time  necessarily  devoted  to  the  above 
purposes ;  also  by  that  lost  during  the  field  season  through  the  illness 
of  three  important  members  of  the  corps,  and  by  the  loss,  through 
resignation,  of  the  services  of  three  other  members.  The  increasing 
exodus  of  members  of  the  economic  force  of  the  Survey  in  conse- 
quence of  their  employment  by  large  mining  organizations  at  sala- 
ries much  greater  than  those  they  have  been  receiving  from  the 
Government  seriously  impairs  the  efficiency  of  the  work  of  this  branch 
of  the  Survey.  It  is  only  by  years  of  practical  experience  in  the 
field  that  the  geologist,  however  excellent  his  preliminary  training, 
becomes  competent  to  carry  on  independent  work  in  investigating  a 
