﻿TRANSACTIONS. 
  

  

  I. 
  — 
  On 
  the 
  Volcanic 
  Geology 
  of 
  the 
  Vivarais 
  (Ardeche). 
  By 
  James 
  D. 
  Forbes, 
  

   Esq., 
  F.R.S., 
  Sec. 
  R. 
  S. 
  Ed., 
  Professor 
  of 
  Natural 
  Philosophy 
  in 
  the 
  University 
  

   of 
  Edinburgh. 
  

  

  (Read 
  3d 
  and 
  17th 
  January 
  1848.) 
  

  

  The 
  limited 
  district 
  of 
  country 
  which 
  I 
  am 
  about 
  to 
  describe, 
  is 
  one 
  of 
  those 
  

   which 
  may 
  rank 
  amongst 
  the 
  least 
  frequented 
  in 
  the 
  civilized 
  part 
  of 
  Europe, 
  yet 
  

   which 
  might 
  justly 
  claim 
  for 
  France 
  the 
  character 
  of 
  romantic 
  beauty 
  which 
  

   travellers 
  on 
  her 
  beaten 
  highways 
  commonly, 
  and 
  not 
  without 
  reason, 
  deny 
  

   to 
  her. 
  

  

  The 
  modern 
  department 
  of 
  the 
  Ardeche, 
  corresponding 
  in 
  part 
  to 
  the 
  ancient 
  

   province 
  of 
  the 
  Vivarais, 
  includes 
  country 
  of 
  very 
  dissimilar 
  features, 
  the 
  southern 
  

   and 
  eastera 
  part, 
  forming 
  the 
  right 
  bank 
  of 
  the 
  Rhone 
  near 
  Viviers, 
  being 
  com- 
  

   paratively 
  flat 
  ; 
  whilst 
  the 
  north-western 
  boundary 
  is 
  the 
  irregular 
  chain 
  of 
  the 
  

   Cevennes, 
  including 
  the 
  localities 
  more 
  immediately 
  to 
  be 
  described. 
  This 
  chain 
  

   is 
  not 
  so 
  remarkable 
  for 
  its 
  absolute 
  height, 
  although 
  that 
  be 
  considerable, 
  rising 
  

   at 
  the 
  Mont 
  Mezenc, 
  in 
  the 
  neighbouring 
  department 
  of 
  the 
  Haute 
  Loire, 
  to 
  an 
  

   elevation 
  of 
  5750 
  English 
  feet 
  above 
  the 
  sea, 
  as 
  from 
  forming 
  the 
  separation 
  of 
  

   a 
  remarkably 
  elevated 
  tract 
  stretching 
  to 
  the 
  north 
  and 
  west, 
  and 
  which 
  suddenly 
  

   subsides, 
  at 
  the 
  point 
  of 
  which 
  we 
  now 
  speak, 
  into 
  the 
  wide 
  champaign 
  country 
  of 
  

   the 
  Lower 
  Rhone, 
  possessing 
  a 
  very 
  different 
  aspect, 
  soil, 
  climate, 
  and 
  population. 
  

  

  The 
  high 
  ground, 
  or 
  plateau, 
  of 
  which 
  we 
  have 
  spoken, 
  being 
  thinly 
  peopled, 
  

   bleak, 
  and 
  steril 
  (in 
  its 
  general 
  character), 
  compared 
  to 
  the 
  fertile 
  and 
  vine-clad 
  

   banks 
  of 
  the 
  Rhone 
  and 
  Saone, 
  immediately 
  to 
  the 
  eastward, 
  is 
  but 
  little 
  tra- 
  

   versed. 
  In 
  fact, 
  only 
  one 
  great 
  road 
  passes 
  through 
  it, 
  the 
  post-road 
  from 
  Paris 
  

   to 
  Perpignan. 
  It 
  will 
  readily 
  be 
  understood, 
  also, 
  why 
  the 
  Cevennes 
  Mountains 
  

   themselves 
  are 
  rarely 
  visited, 
  being 
  left 
  between 
  this 
  great 
  road 
  and 
  the 
  more 
  

  

  VOL. 
  XX. 
  PART 
  I. 
  A 
  

  

  