﻿Geology 
  and 
  Natural 
  History. 
  153 
  

  

  observed 
  in 
  the 
  chromosphere, 
  and 
  in 
  the 
  nebula 
  of 
  Orion. 
  A 
  

   great 
  number 
  of 
  these 
  lines 
  are 
  identical, 
  and 
  this 
  fact 
  appears 
  to 
  

   throw 
  a 
  new 
  light 
  upon 
  the 
  numerous 
  lines 
  in 
  the 
  sun 
  and 
  the 
  

   fixed 
  stars 
  the 
  origin 
  of 
  which 
  has 
  been 
  obscure. 
  Argon 
  and 
  

   helium 
  apparently 
  establish 
  a 
  close 
  connection 
  between 
  the 
  ele- 
  

   ments 
  of 
  our 
  planet 
  and 
  those 
  of 
  the 
  other 
  celestial 
  bodies. 
  

   When 
  the 
  intensity 
  of 
  the 
  electric 
  discharge 
  through 
  the 
  gas 
  from 
  

   uraninite 
  is 
  augmented, 
  carbon 
  lines 
  are 
  rendered 
  more 
  feeble 
  and 
  

   others 
  stronger. 
  The 
  author 
  believes 
  that 
  this 
  phenomenon 
  indi- 
  

   cates 
  that 
  the 
  gas 
  is 
  a 
  mixture. 
  If 
  one 
  passes 
  the 
  discharge 
  for 
  a 
  

   long 
  time 
  through 
  helium, 
  the 
  yellow 
  luminescence 
  disappears. 
  

   This 
  results 
  from 
  the 
  products 
  of 
  the 
  combination 
  of 
  platinum 
  

   which 
  are 
  decomposed 
  when 
  one 
  afterwards 
  heats 
  the 
  discharge 
  

   tube.— 
  Proc. 
  Roy. 
  Soc, 
  vol. 
  lviii, 
  1895, 
  p. 
  67, 
  113, 
  116, 
  192, 
  193. 
  

  

  ,T. 
  T. 
  

  

  II. 
  Geology 
  and 
  Natukal 
  Histoey. 
  

  

  1. 
  TJ. 
  S. 
  Geological 
  Survey. 
  — 
  The 
  seventeenth 
  annual 
  report 
  

   of 
  the 
  director, 
  C. 
  D. 
  Walcott, 
  gives 
  a 
  full 
  account 
  of 
  the 
  opera- 
  

   tions 
  of 
  the 
  survey 
  for 
  1895 
  and 
  1896 
  (pp. 
  200). 
  There 
  were 
  32 
  

   geological, 
  6 
  paleontological, 
  and 
  a 
  still 
  larger 
  number 
  of 
  topo- 
  

   graphic 
  parties 
  in 
  the 
  field 
  distributed 
  through 
  the 
  United 
  States 
  

   from 
  Alaska 
  to 
  Florida. 
  

  

  Shaler 
  continued 
  work 
  upon 
  the 
  Narragansett 
  coal 
  field. 
  

   Emerson 
  was 
  engaged 
  in 
  mapping 
  central 
  Massachusetts; 
  Dale, 
  

   the 
  adjoining 
  portions 
  of 
  Vermont 
  and 
  New 
  Hampshire 
  ; 
  and 
  

   Hobbs, 
  the 
  Cornwall 
  district 
  of 
  Massachusetts. 
  Wolff 
  and 
  Clark 
  

   in 
  New 
  Jersey 
  ; 
  Keith 
  in 
  Maryland 
  ; 
  Taff, 
  Darton 
  and 
  Campbell 
  

   in- 
  the 
  Virginias 
  ; 
  and 
  Hayes 
  in 
  the 
  southern 
  Appalachians, 
  con- 
  

   tinued 
  geological 
  mapping 
  and 
  completed 
  a 
  number 
  of 
  sheets. 
  

   Eldridge 
  studied 
  the 
  phosphates 
  of 
  Florida, 
  and 
  the 
  gilsonite 
  of 
  

   Utah 
  ; 
  David 
  White 
  continued 
  his 
  work 
  on 
  the 
  coal 
  bed 
  floras 
  

   and 
  his 
  results 
  are 
  proving 
  very 
  valuable 
  in 
  identifying 
  coal 
  hori- 
  

   zons. 
  Van 
  Hise, 
  aided 
  by 
  Bayley, 
  Smyth 
  and 
  others 
  continued 
  

   areal 
  work 
  in 
  the 
  Lake 
  Superior 
  region. 
  Gilbert 
  was 
  in 
  Colorado 
  

   and 
  Kansas; 
  R. 
  T. 
  Hill 
  in 
  Texas 
  ; 
  Weed 
  in 
  Montana. 
  Emmons, 
  

   assisted 
  by 
  Spurr 
  and 
  Tower, 
  surveyed 
  the 
  Aspen 
  mining 
  district 
  

   and 
  made 
  a 
  reconnaissance 
  into 
  Montana 
  and 
  Idaho; 
  Cross 
  

   mapped 
  the 
  Telluride 
  district 
  of 
  Colorado 
  ; 
  R. 
  C. 
  Hills 
  continued 
  

   the 
  survey 
  of 
  the 
  coal 
  and 
  iron 
  areas 
  of 
  south 
  central 
  Colorado. 
  

   Turner 
  and 
  Lindgren 
  were 
  in 
  the 
  gold 
  belt 
  of 
  California 
  ; 
  Branner 
  

   and 
  Lawson 
  in 
  the 
  San 
  Francisco 
  region 
  ; 
  Diller 
  in 
  northwest 
  

   Oregon 
  ; 
  and 
  Willis 
  in 
  northwestern 
  Washington. 
  Becker 
  and 
  

   Dall 
  studied 
  the 
  gold 
  and 
  coal 
  of 
  the 
  coastal 
  regions 
  of 
  Alaska. 
  

   Chamberlin, 
  assisted 
  by 
  Salisbury, 
  Leverett 
  and 
  others, 
  continued 
  

   his 
  glacial 
  investigations. 
  Stanton 
  studied 
  the 
  paleontology 
  of 
  

   the 
  Cretaceous 
  of 
  Texas 
  ; 
  Ward, 
  the 
  paleobotany 
  ot 
  the 
  Cretaceous 
  

   and 
  Jurassic 
  of 
  California; 
  Knowlton 
  of 
  the 
  Denver 
  basin, 
  while 
  

  

  Am. 
  Jour. 
  Sci.— 
  -Fourth 
  Series, 
  Yol. 
  Ill, 
  No. 
  14.— 
  February, 
  1897. 
  

   11 
  

  

  