﻿10 
  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1927 
  

  

  At 
  the 
  town 
  of 
  Sassnitz 
  on 
  Riigen 
  were 
  located 
  the 
  " 
  Kreideschlem- 
  

   merei 
  " 
  or 
  chalk-washing 
  establishments. 
  An 
  important 
  industry 
  has 
  

   been 
  developed 
  around 
  the 
  use 
  of 
  chalk 
  for 
  various 
  whitening 
  pur- 
  

   poses, 
  but 
  the 
  chalk 
  must 
  be 
  pure 
  and 
  free 
  from 
  fossils 
  and 
  flint 
  

   fragments. 
  To 
  accomplish 
  this, 
  the 
  chalk 
  is 
  passed 
  through 
  the 
  

   washers 
  and 
  all 
  the 
  fine 
  and 
  coarse 
  debris 
  is 
  sieved 
  out 
  and 
  thrown 
  

   aside, 
  leaving 
  the 
  water 
  with 
  its 
  dissolved 
  material 
  to 
  settle. 
  In 
  

   the 
  pile 
  of 
  debris 
  resulting 
  from 
  such 
  washing 
  many 
  fossils 
  have 
  

   been 
  discovered 
  in 
  this 
  area. 
  Not 
  only 
  were 
  many 
  excellent 
  echinoids, 
  

   brachiopods, 
  and 
  other 
  large 
  fossils 
  picked 
  up 
  in 
  the 
  dump 
  heap 
  

   but 
  literally 
  billions 
  of 
  microfossils 
  were 
  obtained 
  simply 
  by 
  shovel- 
  

   ing 
  up 
  several 
  boxes 
  of 
  the 
  fine 
  debris. 
  

  

  MINERAL. 
  COLLECTING 
  IN 
  MEXICO 
  

  

  In 
  collaboration 
  with 
  the 
  Mineralogical 
  Museum 
  of 
  Harvard 
  Uni- 
  

   versity, 
  Dr. 
  F. 
  W. 
  Foshag, 
  of 
  the 
  National 
  Museum, 
  conducted 
  field 
  

   work 
  in 
  that 
  part 
  of 
  the 
  plateau 
  of 
  northern 
  Mexico 
  within 
  the 
  

   States 
  of 
  Chihuahua, 
  Coahuila, 
  and 
  Durango, 
  for 
  the 
  purpose 
  of 
  

   collecting 
  representative 
  minerals 
  from 
  that 
  region. 
  Mexico 
  is 
  very 
  

   rich 
  in 
  minerals, 
  producing, 
  for 
  instance, 
  over 
  40 
  per 
  cent 
  of 
  the 
  

   world's 
  silver, 
  yet 
  but 
  few 
  mineralogical 
  collections 
  have 
  been 
  made 
  

   there. 
  Doctor 
  Foshag 
  was 
  in 
  the 
  field 
  nearly 
  five 
  months, 
  and 
  over 
  

   two 
  tons 
  of 
  material 
  was 
  collected 
  and 
  shipped 
  back 
  to 
  Washington. 
  

   Cordial 
  cooperation 
  was 
  given 
  by 
  Mexican 
  Government 
  officials 
  and 
  

   by 
  American 
  mining 
  engineers 
  in 
  charge 
  of 
  the 
  mines 
  visited. 
  

  

  Some 
  of 
  the 
  interesting 
  features 
  of 
  the 
  trip 
  are 
  described 
  in 
  the 
  

   following 
  extracts 
  from 
  Doctor 
  Foshag's 
  preliminary 
  account: 
  

  

  Sierra 
  Mojada, 
  one 
  of 
  the 
  districts 
  visited, 
  owes 
  its 
  discovery 
  to 
  a 
  band 
  

   of 
  smugglers 
  attempting 
  to 
  elude 
  pursuit. 
  Tlie 
  ore 
  bodies 
  extend 
  for 
  a 
  

   distance 
  of 
  6 
  liilometers 
  along 
  tlie 
  foot 
  of 
  a 
  limestone 
  cliff 
  2,500 
  feet 
  high. 
  

   The 
  district 
  is 
  unusual 
  in 
  that 
  lead, 
  zinc, 
  silver, 
  copper, 
  and 
  sulphur 
  have 
  

   all 
  been 
  mined 
  here. 
  The 
  great 
  length 
  but 
  shallow 
  depth 
  of 
  these 
  mines 
  

   makes 
  it 
  more 
  economical 
  to 
  work 
  tliem 
  by 
  the 
  old 
  Spanish 
  methods 
  than 
  

   by 
  modern 
  ones. 
  Much 
  of 
  the 
  ore 
  is 
  brought 
  to 
  the 
  surface 
  on 
  the 
  backs 
  

   of 
  peons, 
  often 
  up 
  ladders 
  made 
  of 
  notched 
  logs, 
  popularly 
  called 
  "chicken 
  

   ladders." 
  It 
  is 
  said 
  that 
  a 
  strong 
  peon 
  will 
  carry 
  loads 
  in 
  excess 
  of 
  100 
  kilos 
  

   (220 
  pounds.) 
  

  

  In 
  the 
  northeastern 
  part 
  of 
  the 
  State 
  of 
  Durango, 
  near 
  the 
  village 
  of 
  Mapimi, 
  

   is 
  the 
  Ojuela 
  mine 
  — 
  one 
  of 
  tliQ, 
  greatest 
  lead 
  mines 
  of 
  the 
  world. 
  Within 
  

   this 
  one 
  mine 
  are 
  over 
  550 
  miles 
  of 
  tunnels 
  driven 
  to 
  extract 
  the 
  ore. 
  The 
  

   camp 
  itself 
  is 
  perched 
  on 
  a 
  steep 
  limestone 
  mountain. 
  Before 
  the 
  town, 
  rises 
  

   an 
  almost 
  vertical 
  cliff 
  of 
  Cretaceous 
  limestone 
  2,000 
  to 
  3,000 
  feet 
  high. 
  It 
  

   is 
  in 
  the 
  hills 
  lying 
  at 
  the 
  base 
  of 
  this 
  cliff 
  that 
  the 
  ore 
  bodies 
  lie. 
  

  

  EXPLORING 
  FOR 
  FERNS 
  IN 
  JAMAICA 
  

  

  Dr. 
  William 
  R. 
  Maxon, 
  associate 
  curator 
  of 
  plants. 
  United 
  States 
  

   National 
  Museum, 
  spent 
  June 
  and 
  July, 
  1926, 
  in 
  botanical 
  collecting 
  

  

  