﻿Fig-.l 
  

   Section 
  ^Jij^vdnff 
  probable 
  method 
  of 
  tnirusion 
  ofmecsses 
  

  

  of 
  trctchyte 
  . 
  

  

  Fig-. 
  2. 
  

   Arehinff 
  of 
  strccfxt 
  produced 
  by 
  intrusion 
  of 
  single 
  nuxss 
  uniformly 
  

  

  destributed.. 
  

  

  Fig-. 
  3. 
  

  

  De^ec 
  of 
  ar^ching^ 
  really 
  produced 
  by 
  the 
  irregralar 
  

  

  intrusions. 
  

  

  Intrusion 
  of 
  masses 
  of 
  Trachyte. 
  

   Sierra 
  elljate, 
  

  

  Plate 
  XLVI. 
  

  

  AM. 
  PHOTO-LITHO. 
  CO. 
  N.Y. 
  lOSSORNt'S 
  PROCESSj 
  

  

  