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STANDARD  WORKS  PUBLISHED  BY 


Dr,  WEBSTER'S    DICTIONAR 


UNIVERSITY  OF  CALIFORNIA. 


FROM  THE  LIBRARY  OF 

WILLIAM  M.  PIERSON. 
GIFT  OF  MRS.  PIERSON  AND  L.  H.  PIERSON. 

No. 


books  ever  published,  are  as  follows : — 

1.  Completeness. — It  contains  114,000 
words— more   by  10,000  than  any  other 
Dictionary;  and  these  are,  for  the  most 
part,  unusual  or  technical  terms,  fur  the 
explanation  of  which  a  Dictionary  is  most 
wanted. 

2.  Accuracy  of  Definition. — In  this 
department  the  labours  of  Dr,  Webster 
were  most  valuable,  in  correcting  the  faulty 
and  redundant  definitions  of  Dr.  Johnson, 
which  had  previously  been  almost  univer- 
sally adopted.     In  the  present  edition  all 
the  definitions  have  been  carefully  and 
methodically  analysed  by  W.  &.  Webster, 
Esq.,  the  Rev.  Chauncey  Goodrich,  Prof. 
Lyman,  Prof.  Whitney,  and  Prof.  Gilman, 
with  the  assistance  and  under  the  super- 
intendence of  Prof.  Goodrich. 

3.  Scientific  and  Technical  Terms. — 

In  order  to  secure  the  utmost  completeness 
and  accuracy  of  definition,  this  department 
has  been  subdivided  among  eminent 
Scholars  and  Experts,  including  Prof.Dana, 
Prof.  Lyman,  &c. 

4.  Etymology. — The   eminent   philo- 
logist, Dr.  C,  F.  MAHN,  has  devoted  five 
years  to  perfecting  this  department. 

The  Volume  contains   1576  pages,  more  than  3000  Illustrations 


5.  The  Orthography  is  based  a? 
possible  on  Fixed  Principles.    In  a 
of  doubt  an  alternative  spelling  is 

6.  Pronunciation. — This  has  b< 
trusted  to  Mr.  W.  G.  WEBSTER  a 
WHEELER,  assisted  by  other  schola 
pronunciation  of  each  word  is  indie 
typographical  signs,  which  are  ex 
by  reference  to  a  KEY  printed  at  th< 
of  each  page. 

7.  The  Illustrative    Citation? 

labour  has  been  spared  to  eniboc 
quotations  from  standard  authors 
throw  light   on  the  definitions, 
sess  any  special  interest  of  tho 
language. 

8.  The    Synonyms. — These   ar 
joined  to  the  words  to  which  they 
and  are  very  complete,  x 

9.  The  Illustrations,  which  excee< 
are  inserted,  not  for  the  sake  of  on 
but   to    elucidate  the  meaning  oi 
which  cannot  be  satisfactorily  w 
without  pictorial  aid. 

and 


for  One  Guinea.  It  will  be  found,  on  comparison,  to  be  one  of  the  c 
Volumes  ever  issued.  Cloth,  21s. ;  half-bound  in  calf,  30s. ;  calf  or  half 
31s.  CJ. ;  russia,  £2. 

To  be  obtained  through  all  Booksellers.     Published  by 
GEORGE  BELL  &  SONS,  YOilK  STREET,  COVENT  GARDEN,  L01 


GEORGE  BELL  &  SOS 8. 


WEBSTER'S  COMPLETE  DICTIONARY 

OF  THE  ENGLISH  LANGUAGE,  A'ND  GENERAL  BOOK 
OF  LITERARY  REFERENCE.  With  3000  Illustrations.  Tho- 
roughly revised  and  improved  by  CHAUNCEY  A.  GOODRICH,  D.D., 
LL.D.,  and  NOAH  PORTER,  D.D.,  of  Yale  College. 

n  One  Volume,  Quarto,  strongly  bound  in  cloth,  1840  pages,  price  £1  11s.  6d. ;  half-calf, 
£2 ;  calf  or  half-russia,  £2  25. ;  rusaia,  £2  10*. 

Besides  the  matter  comprised  in  the  WEBSTER'S  GUINEA  DICTIONARY,  this 
rolume  contains  the  following  Appendices,  which  will  show  that  no  pains  have 
)een  spared  to  make  it  a  complete  Literary  Reference-book : — 


i  Brief  History  of  the  English  Lan- 
guage. By  Professor  JAMES  HADLET. 
This  Work  shows  the  Philological  Rela- 
tions of  the  Knglish  Language,  and  traces 
the  progress  and  influence  of  the  causes 

\  which  have  brought  it  to  its  present  con- 

I  dition. 

Principle*  of  Pronunciation.  By 
Professor  GOODRICH  and  W.  A.  WHEELER, 
M.A.  Including  a  Synopsis  of  Words 
differently  pronounced  by  different  au- 
thorities. 

A  Short  Treatise  on  Orthography. 

By  ARTHUR  W.  WRIGHT.  Including  a 
Complete  List  of  Words  that  are  spelt  i& 
two  or  more  ways. 

An  Explanatory  and  Pronouncing 

Vocabulary  ot  the  Names  af  Noted  Fic- 
titious Persons  and  Places,  &c,  tey  W.  A. 
WHEELEB,  M.A.  This  Work  includes  not 
only  persons  ai,d  places  noted  in  Fiction, 
whether  narrative,  poetical,  or  dramatic, 
but  Mythological  and  Mythical  names, 
names  referring  to  the  Ange'.ology  and  De- 
monology  of  various  races,  and  those 
found  in  the  romance  writers ;  Pseu- 
d'.inyms,  Nick- names  of  eminent  persons 
and  parties,  &c.,  &c.  In  fact,  it  is  best 
described  as  explaining  every  name  which 
is  not  strictly  historical.  A,  refer  nee  is 
given  to  the  originator  of  each  name,  and 
where  the  origin  is  unknown  a  quotation 
i?  given  to  some  well-known  writer  in 
which  the  word  occurs. 

This  valuable  Work  may  also  ~be  had 
separately,  post  8vo.,  5s. 

.  .  Pronoun/ing  Vocabulary  of  Greek 

and  Latin  oper  Names.  By  Professor 
THACHEK,  of  Yale  College. 


A  Pronouncing  Vocabulary  of  Scrip- 
ture Proper  Names.  By  W.  A.  WHEELEB, 
M.A  Including  a  List  of  the  Variations 
that  occur  in  the  Douay  version  of  the 
Bible. 

An  Etymological  Vocabulary  of  Mo- 
dem Geographical  N  amee.  By  the  Rev. 
C.  H.  WHEELER.  Containing:— i.  A  List 
of  Prefixes^  Terminations,  and  Formative 
Syllables  in  various  Languages,  with  th<  ir 
meaning  an J  derivation ;  n.  A  brief  List 
of  Geographical  Names  (not  explained  by 
the  foregoing  List),  with  their  derivation 
and  signification,  ail  doubtful  and  obscure 
derivations  being  excluded. 

Pronouncing  Vocabularies  of  Modern 

Geographical   and    Biographical  Names. 
By  J.  THOMAS,  M.D. 

A  Pronouncing  Vocabulary  of  Com- 
mon English  Christian  Names,  with  their 
ieiivations,  signification,  and  diminutives 
(or  nick-names),  and  their  equivalents  in 
several  other  languages. 

A  Dictionary  of  Quotations.  Selected 
and  translated  by  WILLIAM  G.  WERSTEK. 
Containing  all  Words,  Phrases,  Proverbs, 
and  Colloquial  Expressions  from  the 
Greek,  Latin,  and  Mod-rn  Foreign  Lan- 
guages, which  are  Irecjuently  met  with  in 
literature  aud  conversation. 

A  List  of  Abbreviations,  Contrac- 
tions, and  Arbitrary  Sign*  used  ui  Writing 
and  Printing. 

A  Classified  Selection  of  Pictorial 

Illustrations  (70  pages).     With  references 
to  the  text. 


"  The  cheapest  Dictionary  ever  published,  as  it  is  confessedly  one  of  ;he  best.  The  intro- 
iction  of  small  woodcut  illustrations  of  technical  and  scientific  ie.u^  *.k'-  greatly  to  tlw 
ility  of  the  Dictionary."— ChurcJiman. 


)NDON:  GEORGE  BELL  &  SONS,  YORK  STREET,  COTEXT  GARDEN. 

3 


STANDARD  WORKS  PUBLISHED  SY 


WEBSTER'S      DICTIONARY. 


From  tlie  QUARTERLY  REVIEW,  Oct.  1873. 

"  Seventy  years  passed  before  JOHNSON  was  followed  by  Webster,  an 
American  writer,  who  faced  the  task  of  the  English  Dictionary  with  a 
full  appreciation  of  its  requirements,  leading  to  better  practicaljesults." 

"  His  laborious  comparison  of  twenty  languages,  though  never  pub- 
lished, bore  fruit  in  his  own  mind,  and  his  training  placed  him  both  in 
knowledge  and  judgment  far  in  advance  of  Johnson  as  a  philologist. 
Webster's  '  American  Dictionary  of  the  English  Language '  was  pub- 
lished in  1828,  and  of  course  appeared  at  once  in  England,  where 
successive  re-editing  has  as  yet  kept  it  in  the  highest  place  as  a  practical 
Dictionary." 

"  The  acceptance  of  an  American  Dictionary  in  England  has  itself 
had  immense  effect  in  keeping  up  the  community  of  speech,  to  break 
which  would  be  a  grievous  harm,  not  to  English-speaking  nations 
alone,  but  to  mankind.  The  result  of  this  has  been  that  the  common 
Dictionary  must  suit  both  sides  of  the  Atlantic."  .... 

"  The  good  average  business-like  character  of  Webster's  Dictionary, 
both  in  style  and  matter,  made  it  as  distinctly  suited  as  Johnson's  was 
distinctly  unsuited  to  be  expanded  and  re-edited  by  other  hands. 
Professor  Goodrich's  edition  of  1847  is  not  much  more  than  enlarged 
and  amended,  but  other  revisions  since  have  so  much  novelty  of  plan 
as  to  be  described  as  distinct  works."  .... 

"  The  American  revised  Webster's  Dictionary  of  1864,  published  in 
America  and  England,  is  of  an  altogether  higher  order  than  these  last 
£The  London  Imperial  and  Student's].  It  bears  on  its  title-page  the 
names  of  Drs.  Goodrich  and  Porter,  but  inasmuch  as  its  especial  im- 
provement is  in  the  etymological  department,  the  care  of  which  was 
committed  to  Dr.  MAHN,  of  Berlin,  we  prefer  to  describe  it  in  short  as 
the  Webster-Mahn  Dictionary.  Many  other  literary  men,  among  them 
Professors  Whitney  and  Dana,  aided  in  the  task  of  compilation  and 
revision.  On  consideration  it  seems  that  the  editors  and  contributors 
have  gone  far  toward  improving  Webster  to  the  utmost  that  he  will 
bear  improvement.  The  vocabulary  has  become  almost  complete,  as 
regards  usual  words,  while  the  definitions  keep  throughout  to  Webster's 
simple  careful  style,  and  the  derivations  are  assigned  with  the  aid  of 
good  modern  authorities." 

"  On  the  whole,  the  Webster-Mahn  Dictionary  as  it  stands,  is  most 
respectable,  and  CERTAINLY  THE  BEST  PRACTICAL  ENGLISH 
DICTIONARY  EXTANT." 


LONDON:  GEORGE  BELL  &  SONS,  YORK  STREET,  COVENT  GARDEN. 

4 


GEOEGE  BELL  &  SONS. 


SPECIAL    DICTIONARIES    AND   WORKS 
OF    REFERENCE. 


Dr.    Richardson's    Philological    Dictionary    of    the 

ENGLISH  LANGUAGE.  Combining  Explanation  with  Etymology, 
and  copiously  illustrated  by  Quotations  from  the  Best  Authorities. 
New  Edition,  \vith  a  Supplement  containing  additional  Words  and 
further  Illustrations.  In  2  vols.  4to.  £4  1-is.  6d.  Half-bound  in 
Russia,  £5  15s.  6d.  Russia,  £6  12s. 

The   Words,  -with  those  of  the  same  family,  are  traced  to  their 
origin.     The  Explanations  are  deduced  from  the  primitive  meaning 
through  the  various  usages.     The  Quotations  are  arranged  chrono- 
logically, from  the  earliest  period  to  the  present  time. 
The  Supplement  separately.     4to.     12s. 

An  8vo.  edition,  without  the  Quotations,  15s.     Half-russia,   20s. 
Russia,  24?. 

Synonyms  and  Antonyms  of  the  English  Language. 

Collected  and  Contrasted.  By  the  late  Yen.  C.  J.  SMITH,  M.A. 
Post  8vo.  5s. 

Synonyms  Discriminated.  A  Catalogue  of  Synonymous 
Words  in  the  English  Language,  with  their  various  Shades  of  Mean- 
ing, &c.  Illustrated  by  Quotations  from  Standard  Writers.  By  the 
late  Yen.  C.  J.  SMITH,  M.A.  Demy  8vo.  16s. 

A  New  Biographical  Dictionary.  By  THOMPSON  COOPER, 
F.S.A.,  Editor  of  "  Men  of  the  Time,"  and  Joint  Editor  of  "  Athense 
Cantabrigienses."  1  vol.  8vo.  12s. 

This  volume  is  not  a  mere  repetition  of  the  contents  of  previous  works, 
but  embodies  the  results  of  many  years'  laborious  research  in  rare  publica- 
tions and  unpublished  documents.     Any  note  of  omission  which  may  be 
sent  to  the  Publishers  will  be  duly  considered. 
"It  is  an  important  original  contribution  to  the  literature  of  its  class  by  a  painstaking 

scholar it  seems  in  every  way  admirable,  and  fully  to  justify  the  claims  on  its 

behalf  put  forth  by  its  editor."— British  Quarterly  Review. 

"  The  mass  of  information  whicb  it  contains,  especially  as  regards  a  number  of  authors 
more  or  less  obscure,  is  simply  astonishing."  —Spectator. 

"  Comprises  in  1210  pages,  printed  very  closely  in  double  columns,  an  enormous  amount 
of  information."— Examiner. 

"Mr ..Cooper  takes  credit  to  hims'lf,  and  is,  we  think,  justified  in  doing  so,  for  the  great 
care  bestowed  upon  the  work  to  insure  accuracy  as  to  facts  and  dates;  and  he  is  right 
perhaps  in  saying  that  his  dictionary  is  the  most  comprehensive  work  of  its  kind  in  the 
English  language."— .PoZZ  Mall  Gazette. 

A  Biographical  and  Critical  Dictionary  of  Painters 

and  Engravers.  With  a  List  of  Ciphers,  Monograms,  and  Marks. 
By  MICHAEL  BRYAN.  Enlarged  Edition,  with  numerous  additions,  by 
GEORGE  STANLEY.  Imperial  8vo.  £2  2s. 

A  Supplement  of  Recent  and  Living   Painters.    By 

HENRY  OTTLEY.     12s. 

The  Cottage  Gardener's  Dictionary..  With  a  Supple- 
ment, containing  all  the  new  plants  and  varieties  to  the  year  1SG9. 
Edited  by  GEORGE  W.  JOHNSON.  Post  8vo.  Cloth.  6s.  6d. 


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*LON   ON  :  GEORGE  BELL  &  SONS,  Y<  iUK  STREET,  COVENT  GARDEN. 


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THE  ALDINE  EDITION  OF  THE  BRITISH  POETS. 


SUPPLEMENTARY   SERIES. 

TKE  fifty-two  volumes  which  have  hitherto  formed  the  well-known 
Aldine  Series,  embody  the  works  of  nearly  all  the  more  popular  English 
poetical  writers,  whether  lyric,  epic,  or  satiric,  up  to  the  end  of  the 
eighteenth  century.  But  since  that  time  the  wonderful  fertility  of  English 
literature  has  produced  many  writers  equal,  and  in  some  cases  far  superior, 
to  the  majority  of  their  predecessors ;  and  the  widely  augmented  roll  of 
acknowledged  English  poets  now  contains  many  names  not  represented 
in  the  series  of  "  Aldine  Poets." 

With  a  view  of  providing  for  this  want,  and  of  making  a  series  which 
has  long  held  a  high  place  in  public  estimation  a  more  adequate  represen- 
tation of  the  whole  body  of  English  poetry,  the  Publishers  have  deter- 
mined to  issue  a  second  series,  which  will  contain  some  of  the  older  poets, 
and  the  works  of  recent  writers,  so  far  as  may  be  practicable  by  arrange- 
ment with  the  representatives  of  the  poets  whose  works  are  still  copyright. 

One  volume,  or  more,  at  a  time  will  be  issued  at  short  intervals ;  they 
will  be  uniform  in  binding  and  style  with  the  last  fine-paper  edition  of  the 
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one  is  accessible. 

The  following  are  ready,  or  in  preparation. 

THE  POEMS  OF  WILLIAM  BLAKE.  With  Memoir  by  W.  M.  Eossetti, 
and  portrait  by  Jeens. 

TUB  POEMS  OF  SAMUEL  EOGEKS.  With  Memoir  by  Edward  Bell,  and 
portrait  by  .Teens. 

THE  POEMS  OF  THOMAS  CHATTERTON.  2  vols.  Edited  by  the  Rev. 
W.  Skeat,  with  Memoir  by  Edward  Bell. 

THE  POEMS  OF  SIR  WALTER  EALEIGH,  Siu  HUGH  COTTON,  and  Selec- 
tions from  other  Courtly  Poets.  With  Introduction  by  the  Eev.  Dr. 
Hannah,  and  portrait  of  !Sir  W.  Raleigh. 

THE  POEMS  OF  THOMAS  CAMPBELL.  With  Memoir  by  W.  Allingham, 
and  portrait  by  Jeens. 

Ti:::  POEMS  OF  GEORGE  HERBERT.  (Complete  Edition.)  With  Memoir 
by  the  Eev.  A.  B.  Grosart,  and  portrait. 

THE  POEMS  OF  JOHN  KEATS.  With  Memoir  by  Lord  Houghton,  and 
portrait  by  Jeens. 

LONDON:  GEORGE  BELL  &  SONS,  YORK  STREET,  COVENT  GARDEN. 

7 


STAND ABD    WORKS  PUBLISHED  BY 


In  Ten  Volumes, price  2s.  Qd.  each;  in  half-morocco,  £2  10s. 

the  set. 

CHEAP    ALDINE    EDITION    OF 

SHAKESPEARE'S    DRAMATIC    WORKS, 

EDITED  BY  S.  W.  SINGEK. 

Uniform  with  the  Cheap  Edition  of  the  Aldine  Poets. 


THE  formation  of  numerous  Shakespeare  Beading  Societies  has  created 
a  demand  for  a  cheap  portable  edition,  with  LEGIBLE  TYPE,  that  shall  pro- 
vide a  sound  text  with  such  notes  as  may  help  to  elucidate  the  meaning 
and  assist  in  the  better  understanding  of  the  author.  The  Publishers 
therefore  determined  to  reprint  Mr.  Singer's  well-known  Edition,  published 
in  10  vols.,  small  8vo.,  for  some  time  out  of  print,  and  issue  it  in  a  cheap 
form,  uniform  with  the  well-known  Aldine  Edition  of  British  Poets. 


CONTENTS. 

Vol.  I.  The  Life  of  Shakespeare.  The  Tempest.  The  Two  Gentlemen 
of  Verona.  The  Merry  Wives  of  Windsor.  Measure  for 
Measure. 

Vol.  II.  Comedy  of  Errors.  Much  Ado  about  Nothing.  Love's  Labour 
Lost.  Midsummer  Night's  Dream.  Merchant  of  Venice. 

Vol.  III.  Aa  You  Like  It.     Taming  of  the  Shrew.    All's  Well  that 

Ends  Well.     Twelfth  Night,  or  What  You  Will. 
Vol.  IV.  Winter's  Tale.    Pericles.    King  John.    King  Richard  II. 
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HUHBOLDT'S  COSMOS. 


COSMOS: 

A  SKETCH 

OF  A 

PHYSICAL  DESCRIPTION  OF  THE  UNIYEESE. 

BY 

ALEXANDER  VON  HUMBOLDT. 

TRANSLATED    FROM    THE    GERMAN, 
BY 

E,  C.  OTli  AND  W.  S.  DALLAS,  F.L.S. 


Jf»tur«  vero  renim  vis  atque  majestas  in  omnibus  momentis  fide  caret,  si  quis  modo  parte 
ejus  ac  non  totani  complectatur  animo. — Plin.,  Hist.  Nat.  lib.  vii.  c.  1. 


LONDON:  GEOEGE   BELL  AND  SONS,  YOEK  STEEET, 


l/V  /> 

H- 

>7/ 


LONDON : 
PRINTED   BY  WILLIAM   CLOWES  AND  SOUS, 

STAMFORD  STREET  AND  CHARING  CROSS. 


GENERAL  SUMMARY  OF  CONTENTS 


YOLUME  V.  OF  COSMOS. 


INTRODUCTION  to  the  special  results  of  observation  in  the  domain  of 
telluric  phenomena  .         .         .         .     pp.     1—     9 

FIRST  SECTION 9 — 162 

Size,  form,  and  density  of  the  earth     ....     9 —  34 

Internal  heat  of  the  earth 34 —  48 

Magnetic  activity  of  the  eartn 49 — 162 

Historical  portion 49 —  87 

Intensity 87—101 

Inclination 102 — 118 

Declination 118—151 

Polar  light 151—162 

SECOND  SECTION 162—483 

Keaction  of  the  interior  of  the  earth  upon  its  surface  162,  etc. 

Earthquakes  ;   dynamic  action,  waves  of  concussion  165 — 183 

Thermal  springs 184 — 207 

Gas-springs;  salses,  mud-volcanoes,  Naphtha-springs  207 — 223 


Volcanoes  with  and  without  structural  frames  (conical  and  bell-shaped 
mountains) 224—483 

Range  of  volcanoes  from  North  (19|°  N.  L.)  to  South,  as  far  as  46* 
South  latitude  :  Mexican  volcanoes,  pp.  281  and  401  (Jorullo,  pp.  309, 
323,  note  at  p.  310) ;  Cofre  de  Perote,  p.  326,  Cotopaxi,  notes  pp.  337  — 
341.  Subterranean  eruptions  of  vapour,  pp.  342 — 345.  Central  America, 
pp.  268—278.  New  Granada  and  Quito,  pp.  281—285,  and  notes; 
(Antisana,  pp.331 — 336,  Sangay,  p.  446 ;  Tungurahua,  p.  444;  Coto- 
paxi, pp.  338—9 ;  Chimborazo,  p.  461,  note  80;)  Peru  and  Bolivia, 
p.  286,  note;  Chili,  p.  287,  note  75;  (Antilles,  p.  421, note  31). 


VI  SYNOPSIS. 

Enumeration  of  all  the  active  volcanoes  in  the  Cordilleras,  p.  285. 
Relation  of  the  tracts  without  volcanoes  to  those  abounding  in  them, 
p.  296,  note  70  at  283  ;  volcanoes  in  the  North-west  of  America,  to  the 
north  of  the  parallel  of  the  Rio  Gila,  pp.  403—419 ;  review  of  all  the 
volcanoes  not  belonging  to  the  New  Continent,  pp.  285 — 403 ;  Europe, 
pp.  349—350;  islands  of  the  Atlantic  Ocean,  p.  351 ;  Africa,  p.  354; 
Asia;  Continent,  pp.  356— 367  ;  Thian-shan,  pp.  358— 359,  433,  and 
notes  42 — 48;  (peninsula  of  Kamtschatka,  pp.  362—367);  Eastern 
Asiatic  Islands,  p.  367;  (island  of  Saghalin,  Tarakai  or  Kara- 
futo,  notes  97 — 99,  p.  305;  volcanoes  of  Japan,  p.  373;  islands  of 
Southern  Asia,  pp.  377 — 382 ;)  Java,  pp.  298—307.  The  Indian  Ocean, 
pp.  382—388 ;  the  South  sea,  pp.  388 — 401. 


Probable  number  of  volcanoes  on  the  globe,  and  their  distribution  on  the 
continents  and  islands pp.  421 — 431 

Distance  of  volcanic  activity  from  the  sea,  pp.  295-6,  432-3. 
Regions  of  depression,  pp.  431 — 436  ;  Maars,  Mine-funnels,  pp.  231-3. 
Different  modes  in  which  solid  masses  may  reach  the  surface 
from  the  interior  of  the  earth,  through  a  net-work  of  fissures  in  the 
corrugated  soil,  without  the  upheaval  or  construction  of  conical  or 
dome-shaped  piles,  (basalt,  phonolite,  and  some  layers  of  pearl-stone 
and  pumice,  seem  to  owe  their  appearance  above  the  surface,  not  to 
summit-craters,  but  to  the  effects  of  fissures).  Even  the  effusions  from 
volcanic  summits  do  not  in  some  lava-streams  consist  of  a  continuous 
fluidity,  but  of  loose  scoriae,  and  even  of  a  series  of  ejected  blocks  and 
rubbish ;  there  are  ejections  of  stones  which  have  not  all  been 
glowing,  pp.  308,  330,  332—337,  343—347,  note  99  (p.  306)  note  26 
(page  335). 

Mineralogical  composition  of  the  volcanic  rock  :  generalisation  of  the 
term  trachyte,  p.  452 ;  classification  of  the  trachytes,  according  to 
their  essential  ingredients,  into  six  groups  or  divisions  in  conformity 
with  the  definitions  of  Gustav  Rose;  and  geographical  distributioa  of 
these  groups,  pp.  453 — 467 ;  The  designations  andesite  and  andesine, 
pp.  452 — 468,  note,  471.  Along  with  the  characteristic  ingredients  of 
the  trachyte-formations  there  are  also  unessential  ingredients,  the 
abundance  or  constant  absence  of  which  in  volcanoes  frequently  very 
near  each  other,  deserves  great  attention,  p.  473;  Mica,  ibid',  glassy 
felspar,  p.  474 ;  Hornblende  and  augite,  p.  475 ;  Leucite,  p.  476 ; 
olivine,  p.  477 ;  obsidian,  and  the  difference  of  opinion  on  the  forma- 
tion of  pumice,  p.  479 ;  subterranean  pumice  beds,  remote  from  vol- 
canoes, at  Zumbalica  in  the  Cordilleras  of  Quito,  at  Huichapa  in  the 
Mexican  Highland,  and  at  Tschigem  in  the  Caucasus,  pp.  340 — 345. 
Diversity  of  the  conditions  under  which  the  chemical  processes  of  vol- 
canicity  proceed  in  the  formation  of  the  simple  minerals  and  their 
association  into  trachytes,  pp.  472,  473,  483. 


CORRECTIONS  AND  ADDITIONS 

BY  THE  AUTHOR. 


PAGE  32.  LINE  12. 

A  far  more  important  result  in  reference  to  the  density  of  the  earth 
than  that  obtained  by  Baily  (1842)  and  Reich  (1847 — 1850)  has  been 
brought  out  by  Airy's  experiments  with  the  pendulum,  conducted  with 
such  exemplary  care  in  the  Mines  of  Harton,  in  the  year  1854.  Accord- 
ing to  these  experiments,  the  density  is  6'566,  with  a  probable  error  of 
0-182  (Airy  in  the  Philos.  Transact,  for  1856,  p.  342).  A  slight  modi- 
fication of  this  numerical  value,  made  by  Professor  Stokes  on  account 
of  the  effect  of  the  rotation  and  ellipticity  of  the  earth,  gives  the  den- 
eity  for  Harton,  which  lies  at  54°  48'  north  latitude,  at  6'565,  and  for 
the  Equator  at  6' 489. 

PAGE  76.  LINE  10. 

Arago  has  left  behind  him  a  treasury  of  magnetical  observations 
(upwards  of  52,600  in  number)  carried  on  from  1818  to  1835,  which 
have  been  carefully  edited  by  M.  Fedor  Thoman,  and  published  in  the 
(Euvres  Completes  de  Francois  Arago  (t.  iv,  p.  498).  In  these  observa- 
tions, for  the  series  of  years  from  1821  to  1830,  General  Sabine  has 
discovered  the  most  complete  confirmation  of  the  decennial  period  of 
magnetic  declination,  and  its  correspondence  with  the  same  period,  in 
the  alternate  frequency  and  rarity  of  the  solar  spots  (Meteorological 
Essays,  London,  1855,  p.  350).  So  early  as  the  year  1850,  when  Schwabe 
published  at  Dessau  his  notices  of  the  periodical  return  of  the  solar 
spots  (Cosmos,  vol.  iv,  p.  397),  two  years  before  Sabine  first  showed  the 
decennial  period  of  magnetic  declination  to  be  dependent  on  the  solar 
spots  (in  March,  1852,  Phil.  Tr.  for  1852,  p.  i,  pp.  116—121  ;  Cosmo*, 
vol.  v,  p.  76,  note),  the  latter  had  already  discovered  the  important 
result,  that  the  sun  operates  on  the  earth's  magnetism  by  the  magnetic 
power  proper  to  its  mass.  He  had  discovered  (Phil.  Tr.  for  1850,  p.  i, 
p.  216,  Cosmos,  vol.  v,  p.  140),  that  the  magnetic  intensity  is  greatest, 
and  that  the  needle  approaches  nearest  to  the  vertical  direction,  when 
the  earth  is  nearest  to  the  sun.  The  knowledge  of  such  a  magnetical 
operation  of  the  central  body  of  our  planetary  system,  not  by  its  heat- 
producing  quality,  but  by  its  own  magnetic  power,  as  well  as  by  changes 
in  the  Photosphere  (the  size  and  frequency  of  funnel-shaped  openings), 
gives  a  higher  cosmical  interest  to  the  study  of  the  earth's  magnetism 
and  to  the  numerous  magnetic  observatories  (Cosmos,  vol.  1,  p.  184  ; 
vol.  v,  p.  73)  now  planted  over  Russia  and  Northern  Asia,  since  the 
resolutions  of  1829,  and  over  the  colonies  of  Great  Britain  since  1840 — 
1850.  (Sabine,  in  the  Proceedings  of  the  Roy.  Soc.  vol.  viii,  No.  25,  p.  400 
aud  in  the  Phil  Trans,  for  1856.  p.  362). 


CORRECTIONS   AND   ADDITIONS. 


PAGE  85.  LINE  9. 

Though  the  nearness  of  the  moon  in  comparison  with  the  sun  does 
not  seem  to  compensate  the  smallness  of  her  mass,  yet  the  already  well 
ascertained  alteration  of  the  magnetic  declination  in  the  course  of  a 
lunar  day,  the  lunar-diurnal  magnetic  variation  (Sabine,  in  the  Report 
to  the  Brit.  Assoc.  at  Liverpool,  1854,  p.  11,  and  for  Hobart-town  in  the 
Phil.  Tr.  for  1857,  Art.  i,  p.  6),  stimulates  to  a  persevering  observation 
of  the  magnetic  influence  of  the  earth's  satellite.  Kreil  has  the  great 
merit  of  having  pursued  this  occupation  with  great  care,  from  1839 
to  1852,  (see  his  treatise  Ueber  den  Einfluss  des  Mondes  auf  die  hori- 
zontale  Component  der  Magnetischen  Erdlcraft,  in  the  Deukschriften  der 
Wiener  AJcademie  der  Wiss.  Mathem.  Naturwiss.  Classe,  vol.  v,  1853, 
p.  45,  and  Phil.  Trans,  for  1856,  Art.  xxii).  His  observations,  which 
were  conducted  for  the  space  of  many  years,  both  at  Milan  and  Prague, 
having  given  support  to  the  opinion  that  both  the  moon  and  the  solar 
spots  occasioned  a  decennial  period  of  declination,  led  General  Sabine 
to  undertake  a  very  important  work.  He  found  that  the  exclusive  in- 
fluence of  the  sun  on  a  decennial  period,  previously  examined  in  rela- 
tion to  Toronto  in  Canada,  by  the  employment  of  a  peculiar  and  very 
exact  form  of  calculation,  may  be  recognised  in  all  the  three  elements 
of  terrestrial  magnetism  (Phil.  Trans,  for  1856,  p.  861),  as  shown  by 
the  abundant  testimony  of  hourly  observations  onrried  on  for  a  course 
of  eight  years  at  Hobart  Town,  from  January  1841  to  December  1848. 
Thus  both  hemispheres  furnished  the  same  result  as  to  the  operation 
of  the  sun,  as  well  as  the  certainty  "  that  the  lunar-diurnal  variation 
corresponding  to  different  years  shows  no  conformity  to  the  inequality 
manifested  in  those  of  the  solar-diurnal  variation.  The  earth's  induc- 
tive action,  reflected  from  the  moon,  must  be  of  a  very  little  amount." 
(Sabine,  in  the  Phil.  Tr.  for  1857,  Art.  i,  p.  7,  and  in  bl>e  Proceedings 
of  the  Royal  Soc.  vol.  viii,  No.  20,  p.  404).  The  magnetic  portion  of 
this  volume  having  been  printed  almost  three  years  ago,  it  seemed 
especially  necessary,  with  reference  to  a  subject  which  has  so  long 
been  a  favourite  one  with  me,  that  I  should  supply  what  was  wanting 
by  some  additional  remarks. 


INTRODUCTION. 


SPECIAL  RESULTS  OF  OBSERVATION  IN  THE  DOMAIN" 
OF   TELLURIC   PHENOMENA. 

Ix  a  work  embracing  so  wide  a  field  as  the  Cosmos,  which 
aims  at  combining  perspicuous  comjfrehensibility  with  general 
clearness,  the  composition  and  co-ordination  of  the  whole 
are  perhaps  of  greater  importance  than  copiousness  of  detail. 
This  mode  of  treating  the  subject  becomes  the  more  desirable 
because,  in  the  Book  of  Nature,  the  generalization  of  views, 
both  in  reference  to  the  objectivity  of  external  phenomena 
and  the  reflection  of  the  aspects  of  nature  upon  the  imagination 
and  feelings  of  man,  must  be  carefully  separated  from  the 
enumeration  of  individual  results.  The  first  two  volumes  of 
the  Cosmos  were  devoted  to  this  kind  of  generalization,  in 
which  the  contemplation  of  the  Universe  was  considered  as 
one  great  natural  whole,  while  at  the  same  time  care  was 
taken  to  show  how,  in  the  most  widely  remote  zones,  man- 
kind had,  in  the  course  of  ages,  gradually  striven  to  discover 
the  mutual  actions  of  natural  forces.  Although  a  great  accu- 
mulation of  phenomena  may  tend  to  demonstrate  their  causal 
connection,  a  General  Picture  of  Nature  can  only  produce 
fresh  and  vivid  impressions  when,  bounded  by  narrow  limits, 
its  perspicuity  is  not  sacrificed  to  an  excessive  aggregation 
of  crowded  facts. 

As  in  a  collection  of  graphical  illustrations  of  the  surface 
and  of  the  inner  structure  of  the  earth's  crust,  general  maps 
precede  those  of  a  special  character,  it  has  seemed  to  me  that 
in  a  physical  description  of  the  Universe  it  would  be  most 
appropriate,  and  most  in  accordance  with  the  plan  of  the 
present  work,  if,  to  the  consideration  of  the  entire  Universe 
from  general  and  higher  points  of  view,  I  were  to  append  in 
the  latter  volumes  those  special  results  of  observation  upon 

VOL.  v.  B 

\ 


2  COSMOS. 

which  the  present  condition  of  our  knowledge  is  more  parti- 
cularly based.  These  volumes  of  my  work,  must,  therefore, 
in  accordance  with  a  remark  already  made  (Cosmos,  vol.  iii, 
pp.  2 — 6),  be  considered  merely  as  an  expansion  and  more 
careful  exposition  of  the  General  Picture  of  Nature  (Cosmos, 
vol.  i,  pp.  62 — 369),  and  as  the  uranological  or  sidereal  sphere 
of  the  Cosmos  was  exclusively  treated  of  in  the  two  last 
<jolumes,  the  present  volume  will  be  devoted  to  the  con- 
ideration  of  the  telluric  sphere.  In  this  manner  the  ancient, 
simple,  and  natural  separation  of  celestial  and  terrestrial 
objects  has  been  preserved,  which  we  find  by  the  earliest 
evidences  of  human  knowledge  to  have  prevailed  among  all 
nations. 

As  in  the  realms  of  space,  a  transition  to  our  own  plane- 
tary system  from  the  region  of  the  fixed  stars,  illumined  by 
innumerable  suns,  whether  they  be  isolated  or  circling  round 
one  another,  or  whether  they  be  mere  masses  of  remote 
nebulae,  is  indeed  to  descend  from  the  great  and  the  universal 
to  the  relatively  small  and  special ;  so  does  the  field  of  our  con- 
templation become  infinitely  more  contracted  when  we  pass 
from  the  collective  solar  system,  which  is  so  rich  in  varied 
forms,  to  our  own  terrestrial  spheroid,  circling  round  the 
sun.  The  distance  of  even  the  nearest  fixed  star,  a  Centauri, 
is  263  times  greater  than  the  diameter  of  our  solar  system, 
reckoned  to  the  aphelion  distance  of  the  comet  of  1680;  and 
yet  this  aphelion  is  853  times  further  from  the  sun  than  our 
earth  (Cosmos,  vol.  iv,  p.  546).  These  numbers,  reckoning 
the  parallax  of  a  Centauri  at  O."9187,  determine  approximately 
both  the  distance  of  a  near  region  of  the  starry  heavens 
from  the  supposed  extreme  solar  system  and  the  distance 
of  those  limits  from  the  earth's  place. 

Uraiiology,  which  embraces  the  consideration  of  all  that 
fills  the  remote  realms  of  space,  still  maintains  the  character 
it  anciently  bore,  of  impressing  the  imagination  most  deeply 
and  powerfully  by  the  incomprehensibility  of  the  relations 
of  space  and  numbers  which  it  embraces ;  by  the  known 
order  and  regularity  of  the  motions  of  the  heavenly  bodies  ; 
and  by  the  admiration  which  is  naturally  yielded  to  the 
results  of  observation  and  intellectual  investigation.  This 
consciousness  of  regularity  and  periodicity  was  so  early  im- 
pressed upon  the  human  mind  that  it  was  often  reflected  in 


INTRODUCTION.  3 

those  forms  of  speech,  which  refer  to  the  ordained  course  of 
the  celestial  bodies.  The  known  laws  which  rule  the  celestial 
sphere  excite  perhaps  the  greatest  admiration  by  their  sim- 
plicity, based  as  they  solely  are,  upon  the  mass  and  distri- 
bution of  accumulated  ponderable  matter  and  upon  its  forces 
of  attraction.  The  impression  of  the  sublime,  when  it  arises 
from  that  which  is  immeasurable  and  physically  great,  passes 
almost  unconsciously  to  ourselves  beyond  the  mysterious 
boundary  which  connects  the  metaphysical  with  the  physi- 
cal, and  leads  us  into  another  and  higher  sphere  of  ideas.  The 
image  of  the  immeasurable,  the  boundless,  and  the  eternal,  is 
associated  with  a  power  which  excites  within  us  a  more 
earnest  and  solemn  tone  of  feeling,  and  which,  like  the 
impression  of  all  that  is  spiritually  great  and  morally  exalted, 
is  not  devoid  of  emotion. 

The  effect  which  the  aspect  of  extraordinary  celestial 
phenomena  so  generally  and  simultaneously  exerts  upon 
entire  masses  of  people,  bears  witness  to  the  influence  of 
such  an  association  of  feelings.  The  impression  produced 
in  excitable  minds  by  the  mere  aspect  of  the  starry  vault 
of  heaven  is  increased  by  profounder  knowledge,  and  by 
the  use  of  those  means  which  man  has  invented  to  augment 
his  powers  of  vision,  and  at  the  same  time  enlarge  the  horizon 
of  his  observation.  A  certain  impression  of  peace  and  calm- 
ness blends  with  the  impression  of  the  incomprehensible  in 
the  universe,  and  is  awakened  by  the  mental  conception  of 
normal  regularity  and  order.  It  takes  from  the  unfathom- 
able depths  of  space  and  time  those  features  of  terror 
which  an  excited  imagination  is  apt  to  ascribe  to  them. 
In  all  latitudes  man,  in  the  simple  natural  susceptibility 
of  his  mind,  prizes  "  the  calm  stillness  of  a  starlit  summer 
night." 

Although  magnitude  of  space  and  mass  appertains  more 
especially  to  the  sidereal  portion  of  cosmical  delineation,  and 
the  eye  is  the  only  organ  of  cosmical  contemplation,  our 
telluric  sphere  has,  on  the  other  hand,  the  preponderating 
advantage  of  presenting  us  with  a  greater  and  a  scientifically 
distinguishable  diversity  in  the  numerous  elementary  bodies 
of  which  it  is  composed.  All  our  senses  bring  us  in  contact 
with  terrestrial  nature,  and  while  astronomy,  which,  as  the 
knowledge  of  moving  luminous  celestial  bodies  is  most  acces- 

B2 


4  COSMOS. 

sible  to  mathematical  treatment,  has  been  the  means  of  in- 
creasing in  the  most  marvellous  manner  the  splendour  of  the 
higher  forms  of  analysis,  and  has  equally  enlarged  the  limits 
of  the  extensive  domain  of  optics ;  our  earthly  sphere,  on 
the  other  hand,  by  its  heterogeneity  of  elements,  and  by  the 
complicated  play  of  the  expressions  of  force  inherent  in  matter, 
has  formed  a  basis  for  chemistry,  and  for  all  those  branches 
of  physical  science  which  treat  of  phenomena,  that  have  not 
as  yet  been  found  to  be  connected  with  vibrations  generating 
heat  and  light.  Each  sphere  has,  therefore,  in  accordance 
with  the  nature  of  the  problems  which  it  presents  to  our 
investigation,  exerted  a  different  influence  on  the  intellectual 
activity  and  scientific  knowledge  of  mankind. 

All  celestial  bodies,  excepting  our  own  planet  and  the 
aerolites  which  are  attracted  by  it,  are,  to  our  conception  com- 
posed only  of  homogeneous  gravitating  matter,  without  any 
specific  or  so-called  elementary  difference  of  substances. 
Such  a  simple  assumption  is,  however,  not  by  any  means 
based  upon  the  inner  nature  and  constitution  of  these  remote 
celestial  orbs,  but  arises  merely  from  the  simplicity  of  the 
hypotheses,  which  are  capable  of  explaining  and  leading  us 
tc  predict  the  movements  of  the  heavenly  bodies.  This 
idea  arises,  as  I  have  already  had  occasion  frequently  to  re- 
mark (Cosmos,  vol.  i,  pp.  44 — 49  and  pp.  124 — 125  ;  vol.  iii, 
pp.  2,  18,  and  22 — 28),  from,  the  exclusion  of  all  recognition 
of  heterogeneity  of  matter,  and  presents  us  with  the  solu- 
tion of  the  great  problem  of  celestial  mechanics,  in  which 
all  that  is  variable  in  the  uranological  sphere  is  subjected  to 
the  sole  control  of  dynamical  laws. 

Periodical  alternations  of  light  upon  the  surface  of  the 
planet  Mars  do  indeed  point,  in  accordance  with  its  different 
reasons  of  the  year,  to  various  meteorological  processes,  and 
to  the  polar  precipitates  excited  by  cold  in  the  atmosphere  of 
that  planet,  (Cosmos,  vol.  iv,  p.  504).  Guided  by  analogies 
and  reasoning,  we  may  indeed  here  assume  the  presence  of 
ice  or  snow  (oxygen  and  hydrogen),  as  in  the  eruptive 
masses  or  the  annular  plains  of  the  moon  we  assume  the 
existence  of  different  kinds  of  rock  on  our  satellite,  but  direct 
observation  can  teach  us  nothing  in  reference  to  these  points. 
.urea  Newton  ventured  only  on  conjectures  regarding  the 
elementary;  constitution  of  the  planets  which  belong  to  our 


INTRODUCTION.  0 

own  solar  system,  as  we  learn  from,  an  important  conversa- 
tion which  he  had  at  Kensington  with  Conduit  (Cosmos, 
vol.  i,  p.  120).  The  uniform  image  of  homogeneous  gravi- 
tating matter  conglomerated  into  celestial  bodies  has  occu- 
pied the  fancy  of  mankind  in  various  ways,  and  mythology 
has  even  linked  the  charm  of  music  to  the  voiceless  regions 
within  the  realms  of  space  (Cosmos,  vol.  iv,  pp.  431 — 434). 

Amid  the  boundless  wealth  of  chemically  varying  sub- 
stances, with  their  numberless  manifestations  of  force — amid 
the  plastic  and  creative  energy  of  the  whole  of  the  organic 
world,  and  of  many  inorganic  substances — amid  the  meta- 
morphosis of  matter  which  exhibits  an  ever-active  appear- 
ance of  creation  and  annihilation,  the  human  mind,  ever 
striving  to  grasp  at  order,  often  yearns  for  simple  laws  of 
motion  in  the  investigation  of  the  teiTestrial  sphere.  Even 
Aristotle  in  his  Physics  states,  that  "  the  fundamental  prin- 
ciples of  all  nature  are  change  and  motion  ;  he  who  does  not 
recognise  this  truth  recognises  not  nature  herself"  (Phys. 
Auscult.  iii,  1  p.  200  Bekker),  and  referring  to  the  difference 
of  matter  ("  a  diversity  in  essence  "),  he  designates  motion  in 
respect  to  its  qualitative  nature,  as  a  metamorphosis, 
«XXouo<rc9,  very  different  from  mere  mixture,  /*/£*?,  and  a 
penetration  which  does  not  exclude  the  idea  of  subsequent 
separation  (De  Gener.  et  Corrupt,  i,  1  p.  327). 

The  unequal  ascent  of  fluids  in  capillary  tubes — the  endos- 
mosis  which  is  so  active  in  all  organic  cells,  and  is  probably  a 
consequence  of  capillarity  —  the  condensation  of  different 
kinds  of  gases  in  porous  bodies  (of  oxygen  in  spongy  plati- 
num, with  a  pressure  which  is  equal  to  a  force  of  more  than 
700  atmospheres,  and  of  carbonic  acid  in  boxwood  charcoal, 
when  more  than  one-third  is  condensed  in  a  liquid  state 
on  the  walls  of  the  cells) — the  chemical  action  of  contact- 
substances  which,  by  their  presence  occasion  or  destroy  (by 
catalysis)  combinations  without  themselves  taking  any  part 
in  them — all  these  phenomena  teach  us  that  bodies  at  in- 
finitely small  distances  exert  an  attraction  upon  one  another, 
which  depends  upon  their  specific  natures.  We  cannot 
conceive  such  attractions  to  exist  independently  of  motions, 
which  must  be  excited  by  them  although  inappreciable  to 
our  eyes. 

We  are  still  entirely  ignorant  of  the  relations  which  reci- 


6  COSMOS. 

procal  molecular  attraction  as  a  cause  of  unceasing  motion  on 
the  surface,  and  very  probably  also  in  the  interior  of  the 
earth's  body,  exerts  upon  the  attraction  of  gravitation,  by 
which  the  planets  as  well  as  their  central  body  are  main- 
tained in  constant  motion.  Even  the  partial  solution  of  this 
purely  physical  problem  would  yield  the  highest  and  most 
splendid  results  that  can  be  attained  in  these  paths  of  inquiry, 
by  the  aid  of  experimental  and  intellectual  research.  I  pur- 
posely abstain  in  these  sentences  from  associating  (as  is  qom- 
monly  done)  the  name  of  Newton  with  that  law  of  attraction, 
which  rules  the  celestial  bodies  in  space  at  boundless  dis- 
tances, and  which  is  inversely  as  the  square  of  the  distance. 
Such  an  association  implies  almost  an  injustice  towards  the 
memory  of  this  great  man,  who  had  recognised  both  these 
manifestations  of  force,  although  he  did  not  separate  them 
with  sufficient  distinctness,  for  we  find — as  if  in  the  felicitous 
presentiment  of  future  discoveries — that  he  attempted  in  the 
Queries  to  his  Optics  to  refer  capillarity  and  the  little  that 
was  then  known  of  chemical  affinity  to  universal  gravita- 
tion (Laplace,  Expos,  du  Syst.  du  Monde,  p.  384.  Cosmos, 
vol.  iii,  p.  23). 

As  in  the  physical  world,  more  especially  on  the  borders 
of  the  sea,  delusive  images  often  appear  which  seem  for  a 
time  to  promise  to  the  expectant  discoverer  the  possession  of 
some  new  and  unknown  land  ;  so,  on  the  ideal  horizon  of  the 
remotest  regions  of  the  world  of  thought,  the  earnest  inves- 
tigator is  often  cheered  by  many  sanguine  hopes,  which 
vanish  almost  as  quickly  as  they  have  been  formed.  Some 
of  the  splendid  discoveries  of  modern  times  have  undoubtedly 
been  of  a  nature  to  heighten  this  expectation.  Among  these 
we  may  instance  contact-electricity — magnetism  of  rotation, 
which  may  even  be  excited  by  fluids,  either  in  their  aqueous 
form  or  consolidated  into  ice — the  felicitous  attempt  of  con- 
sidering  all  chemical  affinity  as  the  consequence  of  the  elec- 
trical relations  of  atoms  with  a  predominating  poiar  force — 
the  theory  of  isomorphous  substances  in  its  application  to  the 
formation  of  crystals  —  many  phenomena  of  the  electrical 
condition  of  living  muscular  fibre — and  lastly,  the  knowledge 
which  we  have  obtained  of  the  influence  exerted  by  the  sun's 
position,  that  is  to  say,  the  thermic  force  of  the  solar  rays, 
upon  the  greater  or  lesser  magnetic  capacity  and  conducting 


INTRODUCTION.  T 

power  of  one  of  the  constituents  of  our  atmosphere,  namely, 
oxygen.  When  light  is  unexpectedly  thrown  upon  any  pre- 
viously obscure  group  of  phenomena  in  the  physical  world, 
we  may  the  more  readily  believe  that  we  are  on  the 
threshold  of  new  discoveries,  when  we  find  that  these  rela- 
tions appear  to  be  either  obscure,  or  even  in  opposition  to 
already  established  facts. 

I  have  more  particularly  adduced  examples  in  which  the 
dynamic  actions  of  attracting  forces  seem  to  show  the  course  by 
which  we  may  hope  to  approximate  towards  the  solution  of  the 
problem  of  the  original,  unchangeable,  and  hence  named  the 
elementary  heterogeneity  of  substances  (for  instance,  oxygen, 
hydrogen,  sulphur,  potassium,  phosphorus,  tin,  &c.),  and  of  the 
amount  of  their  tendency  to  combine,  in  other  words,  their  che- 
mical affinity.  Differences  of  form  and  mixture  are,  I  would 
again  repeat,  the  only  elements  of  our  knowledge  of  matter  ; 
they  are  the  abstractions  under  which  we  endeavour  to  com- 
prehend the  all-moving  universe,  both  as  to  its  size  and  com- 
position. The  detonation  of  the  fulminates  under  a  slight 
mechanical  pressure,  and  the  still  more  formidable  explosion 
of  terchloride  of  nitrogen,  which  is  accompanied  by  fire, 
contrast  with  the  detonating  combination  of  chlorine  and 
hydrogen,  which  explodes  when  the  sun's  rays  fall  directly 
upon  it  (more  especially  the  violet  rays).  Metamorphosis, 
union,  and  separation  afford  evidence  of  the  eternal  circu- 
lation of  the  elements  in  inorganic  nature  no  less  than  in 
the  living  cells  of  plants  and  animals.  "The  quantity  of 
existing  matter  remains  however  the  same,  the  elements 
alone  change  their  relative  positions  to  one  another." 

We  thus  find  a  verification  of  the  ancient  axiom  of 
Anaxagoras,  that  created  things  neither  increase  nor  de- 
crease in  the  Universe,  and  that  that  which  the  Greeks 
termed  the  destruction  of  matter  was  a  mere  separation  of 
parts.  Our  earthly  sphere,  within  which  is  comprised  all 
that  portion  of  the  organic  physical  world,  which  is  accessible 
to  our  observation,  is  apparently  a  laboratory  of  death  and 
decay  ;  but  that  great  natural  process  of  slow  combustion, 
which  we  call  decay,  does  not  terminate  in  annihilation.  The 
liberated  bodies  combine  to  form  other  structures,  and  through 
the  agency  of  the  active  forces  which  are  incorporated  ill 
them  a  new  life  germinates  from  the  bosom  of  the  earth. 


RESULTS   OF  OBSERVATION  IN  THE  TELLURIC  PORTION 
OF  THE  PHYSICAL  DESCRIPTION   OF  THE   UNIVERSE. 

In  the  attempt  to  grasp  the  inexhaustible  materials 
afforded  by  the  study  of  the  physical  world — or  in  other 
words — to  group  phenomena  in  such  a  manner  as  to  lacili- 
tate  our  insight  into  their  causal  connection,  general  clear- 
ness and  lucidity  can  only  be  secured  where  special 
details  —  more  particularly  in  the  long  and  successfully 
cultivated  fields  of  observation — are  not  separated  from  the 
higher  points  of  view  of  cosmical  unity.  The  telluric 
sphere,  as  opposed  to  the  uranological,  is  separable  into 
two  portions,  namely,  the  inorganic  and  the  organic  depart- 
ments. The  former  comprises  the  size,  form,  and  density 
of  our  terrestrial  planet ;  its  internal  heat ;  its  electro-mag- 
netic activity  ;  the  mineral  constitution  of  the  earth's  crust ; 
the  reaction  of  the  interior  of  the  planet  on  its  outer  surface 
which  acts  dynamically  by  producing  earthquakes,  and  che- 
mically by  rock-forming,  and  rock-metamorphosing  processes  ; 
the  partial  covering  of  the  solid  surface  by  the  liquid  ele- 
ment— the  ocean ;  the  contour  and  articulation  of  the  up- 
heaved earth  into  continents  and  islands  ',  and  lastly  the 
general  external  gaseous  investment  (the  atmosphere).  The 
second  or  organic  domain  comprises  not  the  individual  forms 
of  life  which  we  have  considered  in  the  Delineation  of  Nature, 
but  the  relations  in  space  which  they  bear  to  the  solid  and 
fluid  parts  of  the  earth's  surface,  the  geography  of  plants  and 
animals,  and  the  descent  of  the  races  and  varieties  of  man 
from  one  common,  primary  stock. 

This  division  into  two  domains  belongs  to  a  certain  extent 
to  the  ancients,  who  separated  from  the  vital  phenomena  of 
plants  and  animals  such  material  processes  as  change  of  form 
and  the  transition  of  matter  from  one  body  to  another.  In 
the  almost  total  deficiency  of  all  means  for  increasing  the 
powers  of  vision,  the  difference  between  the  two  organisms1 
was  based  upon  mere  intuition,  and  in  part  upon  the  dogma 
of  self-nutrition  (Aristot.  de  Anima,  ii,  It.  i,  p.  412,  a  14, 

1  See  Cosmos,  vol.  iii,  p.  54. 


THE  EARTH.  9 

Bekker),  and  of  a  spontaneous  incentive  to  motion.  This  kind 
of  mental  comprehension  which  I  have  named  intuition,  to- 
gether with  that  felicitous  acumen  in  the  power  of  combining 
his  ideas,  which  was  so  characteristic  of  the  Stagyrite,  led  him 
to  the  assumption  of  an  apparent  transition  from  the  inani- 
mate to  the  living,  from  the  mere  element  to  the  plant,  and 
induced  him  even  to  adopt  the  view  that  in  the  ever  ascend- 
ing processes  of  plastic  formation  there  were  gradual  and 
intermediate  stages  connecting  plants  with  the  lower  animals 
(Aristot.  de  part.  Animal,  iv,  5,  p.  681,  a  12,  and  hist.  Animal. 
viii,  1,  p.  588,  a  4,  Bekker).  The  history  of  organisms  (taking 
the  word  history  in  its  original  sense,  and  therefore  in  rela- 
tion to  the  faunas  and  floras  of  earlier  periods  of  time)  is  so 
intimately  connected  with  geology,  with  the  order  of  suc- 
cession of  the  superimposed  terrestrial  strata  and  with  the 
chronometrical  annals  of  the  upheaval  of  continents  and 
mountains ;  that  it  has  appeared  most  appropriate  to  me,  on 
account  of  the  connection  of  great  and  widely  diffused  phe- 
nomena, to  avoid  establishing  the  natural  division  of  organic 
and  inorganic  terrestrial  life  as  the  main  element  of  classifi- 
cation in  a  work  treating  of  the  Cosmos.  We  are  not  here 
striving  to  give  a  mere  morphological  representation  of  the 
organic  world,  but  rather  to  arrive  at  bold  and  compre- 
hensive views  of  nature,  and  the  forces  which  she  brings 
into  play. 


I. 

Size,  Configuration,  and  Density  of  the  Earth. — The  Heat  in 
the  interior  of  the  Earth,  and  its  distribution. — Magnetic 
Activity,  manifested  in  changes  of  Inclination,  Declination, 
and  Intensity  of  the  force  under  the  influence  of  the  Sun's 
position  in  reference  to  the  Heat  and  Rarefaction  of  the 
Air. — Magnetic  Storms. — Polar  Light. 

That  which  in  all  languages  is  comprehended  under  ety- 
mologically  differing  symbolical  forms  by  the  expression 
Nature,  and  which  man,  who  originally  refers  everything 


10  COSMOS. 

I 

to  his  own  local  habitation,  has  further  designated  aa 
Terrestrial  Nature  is  the  result  of  the  silent  co-operation 
of  a  system  of  active  forces,  whose  existence  we  can 
only  recognise  by  means  of  that  which  they  move,  blend 
together,  and  again  dissever ;  and  which  they  in  part  deve- 
lope  into  organic  tissues  (living  organisms),  which  have  the 
power  of  re-producing  like  structures.  The  appreciation  of 
nature  is  excited  in'  the  susceptible  mind  of  man  through 
the  profound  impression  awakened  by  the  manifestation  of 
these  forces.  Our  attention  is  at  first  attracted  by  the  re- 
lations of  size  in  space  exhibited  by  our  planet,  which  seems 
only  like  a  handful  of  conglomerated  matter  in  the  immea- 
surable universe.  A  system  of  co-operating  forces,  which 
either  tend  to  combine  or  separate  (through  polar  influences), 
shows  the  dependence  of  every  part  of  nature  upon  other 
parts,  both  in  the  elementary  processes  (as  in  the  formation 
of  inorganic  substances),  and  in  the  production  and  main- 
tenance of  life.  The  size  and  form  of  the  earth,  its  mass, 
that  is  to  say,  the  quantity  of  its  material  parts,  which 
when  compared  with  the  volume  determines  its  density,  and 
by  means  of  the  latter,  under  certain  conditions,  both  the 
constitution  of  the  interior  of  the  earth  and  the  amount  of  its 
attraction,  are  relations  which  stand  in  a  more  manifest,  and 
a  more  mathematically  demonstrable  dependence  upon  one 
another  than  we  observe  in  the  case  of  the  above  named  vital 
processes,  in  the  distribution  of  heat,  in  the  telluric  condi- 
tions of  electro-magnetism,  or  in  the  chemical  metamorphoses 
of  matter.  Conditions,  which  we  are  not  yet  able  to  deter- 
mine quantitatively  on  account  of  a  complication  of  pheno- 
mena, may  nevertheless  be  present,  and  may  be  demon- 
strated through  inductive  reasoning. 

Although  the  two  kinds  of  attraction,  namely,  that  which 
acts  at  perceptible  distances,  as  the  force  of  gravity  (the  gra- 
vitation of  the  celestial  bodies  towards  one  another),  and 
that  which  is  manifested  at  immeasurably  small  distances,  as 
molecular  or  contact-attraction,  cannot  in  the  present  con- 
dition of  science  be  reduced  to  one  and  the  same  law,  yet  it 
is  not  on  that  account  the  less  credible  that  capillary  attrac- 
tion and  endosmosis,  which  is  so  important  in  reference  to 
the  ascent  of  fluids,  and  in  respect  to  animal  and  vegetable 
physiology,  may  be  quite  as  much  affected  by  the  force  of  gra- 


THE  EARTH.  11 

vitation  and  its  local  distribution  as  electro-magnetic  pro* 
cesses  and  the  chemical  metamorphosis  of  matter.  To  refer 
to  extreme  conditions,  we  may  assume  that  if  our  planet  had 
only  the,  mass  of  the  moon,  and  therefore  almost  six  times 
less  intensity  of  gravity,  the  meteorological  processes,  the 
climate,  the  hypsometrical  relations  of  upheaved  mountain 
chains  and  the  physiognomy  of  the  vegetation  would  be  quite 
different  from  what  they  now  are.  The  absolute  size  of  our 
planet  which  we  are  here  considering,  maintains  its  impor- 
tance in  the  collective  economy  of  nature  merely  by  the  re- 
lations which  it  bears  to  mass  and  rotation  ;  for  even  in  the 
universe,  if  ohe  dimensions  of  the  planets,  the  quantitative 
admixture  of  the  bodies  which  compose  them,  their  velo- 
cities and  distances  from  one  another,  were  all  to  increase  or 
diminish  in  one  and  the  same  proportion,  all  the  phenomena 
depending  upon  relations  of  gravitation  would  remain  un- 
changed in  this  ideal  macrocosmos,  or  microcosmos.2 


a.  Size,  Figure,  Ellipticity,  and  Density  of  the  Earth. 

(Expansion  of  the  Picture  of  Nature,   Cosmos,  vol.  i, 

pp.  154—164.) 

The  earth  has  been  measured  and  weighed  in  order  to  de- 
termine its  form,  density,  and  mass.  The  accuracy  which 
has  been  incessantly  aimed  at  in  these  terrestrial  determina- 
tions, has  contributed,  simultaneously  with  the  solution  of 
the  problems  of  astronomy,  to  improve  instruments  of  mea- 
surement, and  methods  of  analysis.  A  very  important  part 

2  "  The  law  of  reciprocal  attraction  which  acts  inversely  as  the  square 
of  the  distance  is  that  of  emanations,  proceeding  from  a  centre.  It  ap- 
pears to  be  the  law  of  all  those  forces,  whose  action  is  perceptible  at 
sensible  distances,  as  in  the  case  of  electrical  and  magnetic  forces.  One 
of  the  remarkable  properties  of  this  law  is  that,  if  the  dimensions  of  all 
the  bodies  in  the  universe,  together  with  their  mutual  distances  and 
their  velocities,  were  proportionally  increased  or  diminished,  they  would 
still  describe  curves  precisely  similar  to  those  which  they  now  describe ; 
so  that  the  universe,  after  being  thus  successively  reduced  to  the  smallest 
conceivable  limits,  would  still  always  present  the  same  appearance  to 
the  observer.  These  appearances  are  consequently  independent  of  the 
dimensions  of  the  universe,  as  in  virtue  of  the  law  of  the  ratio  which 
exists  between  force  and  velocity,  they  are  independent  of  absolute 
movement  in  space." — Laplace,  Exposition  du  Syst.  du  Monde  (Seme  e"d.)( 
p.  385. 


12  COSMOS. 

of  the  process  involved  in  the  measurement  of  a  degree  is 
strictly  astronomical,  since  the  altitudes  of  stars  determine 
the  curvature  of  the  arc,  whose  length  is  found  by  the  solution 
of  a  series  of  triangles.  The  higher  departments  of  mathe- 
matics have  succeeded,  from  given  numerical  data,  in  solving 
the  difficult  problems  of  the  figure  of  the  earth,  and  the  sur- 
face of  equilibrium  of  a  fluid  homogeneous,  or  dense  shell-like 
heterogeneous  mass,  which  rotates  uniformly  round  a  solid 
axis.  Since  the  time  of  Newton  and  Huygens,  the  most  dis- 
tinguished geometricians  of  the  eighteenth  century  have  de- 
voted themselves  to  the  solution  of  these  problems.  It  is  well 
that  we  should  bear  in  mind  that  all  the  great  results  which 
have  been  attained  by  intellectual  labour  and  by  mathe- 
matical combinations  of  ideas,  derive  their  importance  not 
only  from  that  which  they  have  discovered  and  which  has 
been  appropriated  by  science,  but  more  especially  from  the 
influence  which  they  have  exerted  on  the  development  and 
improvement  of  analytical  methods. 

"  The  geometrical  figure  of  the  earth,  in  contradistinction 
to  the  physical,3  determines  the  surface  which  the  super- 
ficies of  water  would  assume  in  passing  through  a  net-work 
of  canals,  connected  with  the  ocean,  and  covering  and  inter- 
secting the  earth  in  every  direction.  The  geometrical  surface 
intersects  the  directions  of  the  forces  vertically,  and  these 
forces  are  composed  of  all  the  attractions  emanating  from  the 
individual  particles  of  the  earth,  combined  with  the  centri- 
fugal force,  which  corresponds  with  its  velocity  of  rota- 
tion.4 This  surface  must  be  generally  considered  as  approxi- 
mating very  closely  to  an  oblate  spheroid,  for  irregularities 
in  the  distribution  of  the  masses  in  the  interior  of  the  earth 
will  also,  where  the  local  density  is  altered,  give  rise  to  irre- 
gularity in  the  geometrical  surface,  which  is  the  product 
of  the  co-operation  of  unequally  distributed  elements.  The 
physical  surface  is  the  direct  product  of  the  surface  of 

3  Gauss,  Bestimmwng  des  JSreitenunterschiedes  zwisclien  den  Sternwarten 
von   Gottingen  und  Altona,    1828,    s.   73.      (These  two   observatories, 
by  a  singular  chance,  are  situated   within   a  few  yards  of  the  same 
meridian.) 

4  Bessel,  Ueber  den  Einflms  der  Unregelmassigkeiten  der  Figur  der  Erdt 
auf  geoddtisclie  Arbeiten  und  Hire    Vergleichung    mit    astronomischen 
Bestimmungen,  in  Schumachers  Astron.  Nachr.    Bd.  xiv,  No.  329,  s.  270, 
and  Bessel  and  Baeyer,  Gradmtysung  in  Ostpreussen,  1838,  s.  427 — 442. 


THE  FIGURE  OF  THE  EARTH.  13 

tho  solid  and  fluid  matter  on  the  outer  crust  of  the 
earth."  Although  while  it  is  not  improbable,  judging  from 
geological  data,  that  the  incidental  alterations  which  are 
readily  brought  about  in  the  fused  portions  of  the  interior 
of  the  earth,  when  they  are  moved  by  a  change  of  position  of 
the  masses,  may  even  modify  the  geometrical  surface  by  pro- 
ducing curvature  of  the  meridians  and  parallels  in  small 
spaces,  and  at  very  widely  separated  periods  of  time  ;  the 
physical  surface  of  the  oceanic  parts  of  our  globe  is  peri- 
odically subjected  to  a  change  of  place  in  the  masses,  occa- 
sioned by  the  ebbing  and  flowing  (or  in  other  words  the 
local  depression  and  elevation)  of  the  fluid  element.  The 
inconsiderable  amount  of  the  effects  of  gravity  in  continental 
regions  may  indeed  render  a  gradual  change  inappreciable  to 
actual  observation ;  and  according  to  Bessel's  calculation,  in 
order  to  increase  the  latitude  of  a  place  by  a  change  of  only 
1",  it  must  be  assumed  that  there  is  a  transposition  in  the 
interior  of  the  earth  of  a  mass,  whose  weight  (its  density 
being  assumed  to  be  that  of  the  mean  density  of  the  earth)  is 
that  of  7296  geographical  cubic  miles.*  However  large  the 
volume  of  this  transposed  mass  may  appear  to  us  when  we 
compare  it  with  the. volume  of  Mont  Blanc,  or  Chimborazo, 
or  Kintschindjinga,  our  surprise  at  the  magnitude  of  the 
phenomenon  soon  diminishes  when  we  remember  that  our 
terrestrial  spheroid  comprises  upwards  of  1696  hundreds  of 
millions  of  such  cubic  miles. 

Three  different  methods  have  been  attempted  although 
with  unequal  success  for  solving  the  problem  of  the  figure  of 
the  earth  whose  connection  with  the  geological  question  of 
the  earlier  liquid  condition  of  the  rotating  planetary  bodies 
was  known  at  the  brilliant  epoch  of  Newton,  Huygens 
and  Hooke.*  These  methods  were  the  geodetico-astro- 

5  Bessel,  Ueber  den  Einfiuss  der  Vcrdnderungen  ties  Erdkorpers  auf  die 
Polhohen,  in  Lindeuau  und  Bohnenberger,  Zeitschi  ift  fur  Astronomic. 
Bd.  v,  1818,  s.  29.      "  The  weight  of  the  earth,  expressed  in  German 
pounds=9933  x  10.21,  and  that  of  the  transposed  mass  =  947  x  10.14." 

6  The  theoretical  labours  of  that  time  were  followed  by  those  of 
Maclaurin,  Clairaut,    and  d'Alembert,    by  Legendre  and  by   Laplace. 
To  this  latter  period  we  may  add  the  theorem  advanced  by  Jacobi,  in 
1834,  that  ellipsoids  of  three  unequal  axes  may,  under  certain  conditions, 
represent  the  figures  of  equilibrium  no  less  than  the  two  previously- 
indicated  ellipsoids  of  rotation. — See  the  treatise  of  this  writer,  whose 


14  COSMOS. 

nomical  measurement  of  a  degree,  pendulum  experiments, 
and  calculations  of  the  inequalities  in  the  latitude  and  longi- 
tude of  the  moon.  In  the  application  of  the  first  method 
two  separate  processes  are  required,  namely,  measurements 
of  a  degree  of  latitude  on  the  arc  of  a  meridian,  and  mea- 
surements of  a  degree  of  longitude  on  different  parallels. 

Although  seven  years  have  now  passed  since  I  brought 
forward  the  results  of  Bessel's  important  labours,  in  refer- 
ence to  the  dimensions  of  our  globe,  in  my  General  Delineation 
of  Nature,  his  work  has  not  yet  been  supplanted  by  any  one 
of  a  more  comprehensive  character,  or  based  upon  more  recent 
measurement's  of  a  degree.  An  important  addition  and  great 
improvements  in  this  department  of  inquiry  may,  however, 
be  expected  on  the  completion  of  the  Russian  geodetic  mea- 
surements, which  are  now  nearly  finished,  and  which,  as  they 
extend  almost  from  the  North  Cape  to  the  Black  Sea,  will 
afford  a  good  basis  of  comparison  for  testing  the  accuracy  of 
the  results  of  the  Indian  survey. 

According  to  the  determinations  published  by  Bessel  in 
the  year  1841,  the  mean  value  of  the  dimensions  of  our 
planet  was,  according  to  a  careful  investigation7  of  ten  mea 

early  death  has  proved  a  severe  loss  to  science,  in  PoggendorfFs  Annalen 
der  Physilc  und  Chemie.  Bd.  xxxiii,  1834,  s.  229—233. 

7  The  first  accurate  comparison  of  a  large  number  of  geodetic  mea- 
surements (including  those  made  in  the  elevated  plateau  of  Quito,  two 
East  Indian  measurements,  together  with  the  French,  English,  and 
recent  Lapland  observations)  was  successfully  effected  by  Walbeck,  at 
Abo,  in  1819.  He  found  the  mean  value  for  the  earth's  ellipticity  to  be 
3oa  176l,  and  that  of  a  meridian  degree  57009.758  toises,  or  324,628  feet. 
Unfortunately  his  work,  entitled  De  Forma  et  Magnitudine  Telluris  has 
not  been  published  in  a  complete  form.  Excited  by  the  encouragement 
of  Gauss,  Eduard  Schmidt  was  led  to  repeat  and  correct  his  results  in  his 
admirable  Handbook  of  Mathematical  Geography,  in  which  he  took  into 
account  both  the  higher  powers  given  for  the  ellipticity,  and  the  lati- 
tudes observed  at  the  intermediate  points,  as  well  as  the  Hanoverian 
measurements  and  those  which  had  been  extended  as  far  as  Formentera 
by  Biot  and  Arago.  The  results  of  this  comparison  have  appeared  in 
three  forms,  after  undergoing  a  gradual  correction,  namely,  in  Gauss's 
JBestimmung  der  Breitenunterschiede  von  Gottingen  undAltona  1828,  s.  82 ; 
in  Eduard  Schmidt's  Lehrluchdcr  Mathem.  und  Phys.  Geographic,  1829, 
Th.  1,  s.  183,  194 — 199;  and  lastly  in  the  preface  to  the  latter  work 
(s.  5).  The  last  result  is,  for  a  meridian  degree  57008.655  toises,  or 
324,261  feet ;  for  the  ellipticity,  zWJ^^ra-  Bessel's  first  work  of  1 830  had 
been  immediately  preceded  by  Airy's  treatise  on  tioa  Figure  of  the  Earth, 


THE  SIZE  OP  THE  EARTH.  15 

Burements  of  degrees,  as  follows  : — The  semi-axis  major  of  a 
rotating  spheroid,  a  form  that  approximates  most  closely  to 

in  the  Encyclopaedia  Metropolitan  a.  Ed.  of  1849,  pp.  220 — 239.  (Here 
the  semi-polar  axis  was  given  at  20.853,810  feet=3949.585  miles,  the 
semi-equatorial  axis  at  20,923,713  feet=3962.824  miles,  the  meridian 
quadrant  at  32,811,980  feet,  and  the  ellipticity  at  ^g^ra)-  The  great 
astronomer  of  Konigsberg  was  uninterruptedly  engaged,  from  1836  to 
1842,  in  calculations  regarding  the  figure  of  the  earth,  and  as  his  earlier 
works  were  emended  by  subsequent  corrections,  the  admixture  of  re- 
sults of  investigations  at  different  periods  of  time  has,  in  many  works, 
proved  a  source  of  great  confusion.  In  numbers,  which  from  their  very 
nature  are  dependent  on  one  another,  this  admixture  is  rendered  still 
more  confusing  from  the  erroneous  reduction  of  measurements ;  as,  for 
instance,  toises,  metres,  English  feet,  and  miles  of  60  and  69  to  the 
equatorial  degree ;  and  this  is  the  more  to  be  regretted  since  many 
works,  which  have  cost  a  very  large  amount  of  time  and  labour,  are 
thus  rendered  of  much  less  value  than  they  otherwise  would  be.  In 
the  summer  of  1837,  Bessel  published  two  treatises,  one  of  which  was 
devoted  to  the  consideration  of  the  influence  of  the  irregulai-ity  of  the 
earth's  figure  upon  geodetic  measurements,  and  their  comparison  with 
astronomical  determinations,  whilst  the  other  gave  the  axes  of  the  ob- 
late spheroid,  which  seemed  to  correspond  most  closely  to  existing 
measurements  of  meridian  arcs  (Schum.  Astr.  Nachr.  bd.  xiv,  No. 
329,  s.  269,  No.  333,  s.  345).  The  results  of  his  calculation  were 
3271953.854  toises  for  the  semi-axis  major;  3261072.900  toises  for 
the  semi-axis  minor ;  and  for  the  length  of  a  mean  meridian  degree, 
that  is  to  say,  for  the  ninetieth  part  of  the  earth's  quadrant  (vertically 
to  the  equator),  57011.453  toises.  An  error  of  68  toises,  or  440.8  feet, 
which  was  detected  by  Puissant,  in  the  mode  of  calculation  that 
had  been  adopted,  in  1808,  by  a  Commission  of  the  National  Institute 
for  determining  the  distance  of  the  parallels  of  Montjouy,  near 
Barcelona,  and  Mola  in  Formentera,  led  Bessel,  in  the  year  1841, 
to  submit  his  previous  calculations  regarding  the  dimensions  of  the 
earth  to  a  new  revision.  (Schum.  Astr.  Nachr.  Bd.  xix,  No.  438, 
s.  97 — 116).  This  correction  yielded  for  the  length  of  the  earth's 
quadrant  5131179.81  toises,  instead  of  5130740  toises,  which  had 
been  obtained  in  accordance  with  the  first  determination  of  the  metre ; 
and  for  the  mean  length  of  a  meridian  degree,  57013.109  toises, 
which  is  about  0.611  of  a  toise  more  than  a  meridian  degree,  at 
45°  lat.  The  numbers  given  in  the  text  are  the  result  of  Bessel's  latest 
calculations.  The  length  of  the  meridian  quadrant,  5131180  toises, 
with  a  mean  error  of  255.63  toises,  is  therefore=10000856  metres,  which 
would  tnerefore  give  40003423  metres,  or  21563.92  geographical  miles, 
for  the  entire  circumference  of  the  earth.  The  difference  between  the 
original  assumption  of  the  Commission  des  Poids  et  Mesures,  according  to 
which  the  metre  was  the  forty-millionth  part  of  the  earth's  circumfer- 
ence, amounts  for  the  entire  circumference  to  3423  metres,  or  1756  27 
which  is  almost  two  geographical  miles,  or  more  accurately 


1 6  COSMOS. 

the  irregular  figure  of  our  earth,  was  3272077.14  toises,  or 
20,924,774  feet  ;  the  semi-axis  minor,  3261139.33  toises, 
or  20,854.821  feet;  the  length  of  the  earth's  quadrant, 
5131179.81  toises,  or  32.811,799  feet ;  the  length  of  a  mean 
meridian  degree,  57013.109  toises,  or  364,596  feet ;  the 
length  of  a  parallel  degree  at  0°  latitude,  and  consequently 
that  of  an  equatorial  degree,  57108.52  toises,  or  365,186 
feet ;  the  length  of  a  parallel  degree  at  45°,  40449.371  toises, 
or  258,657  feet ;  the  ellipticity  of  the  earth,  •?-$-$, TTT  \  an(^ 
the  length  of  a  geographical  mile,  of  which  sixty  go  to  an 
equatorial  degree,  951.8  toises,  or  6086.5  feet. 

The  table  (page  17)  shows  the  increase  of  the  length  of  the 
meridian  degree  from  the  equator  to  the  pole,  as  it  has  been 
found  from  observations,  and  therefore  modified  by  the  local 
disturbances  of  attraction 

The  determination  of  the  figure  of  the  earth  by  the  mea- 
surement of  degrees  of  longitude  on  different  parallels  re- 
quires very  great  accuracy  in  fixing  the  longitudes  of  different 
places.  Cassini  de  Thury  and  Lacaille  employed,  in  1740, 
powder  signals  to  determine  a  perpendicular  line  at  the 
meridian  of  Paris.  In  more  recent  times,  the  great  trigono- 
metrical survey  of  England  has  determined,  by  the  help  of 
far  better  instruments  and  with  greater  accuracy,  the  lengths 
of  the  arcs  of  parallels  and  the  differences  of  the  meridians 
between  Beachy  Head  and  Dunnose,  as  well  as  between 
Dover  and  Falmouth.  These  determinations  were,  however, 
only  made  for  differences  of  longitude  of  1°  26'  and  6C22'  .8 
By  far  the  most  considerable  of  these  surveys  is  the  one  that 
was  carried  on  between  the  meridians  of  Marennes,  on  the 
western  coast  of  France,  and  JFiume.  It  extends  over  the 
western  chain  of  the  Alps,  and  the  plains  of  Milan  and  Padua, 
in  a  direct  distance  of  15°  32'  27",  and  was  executed  under 
the  direction  of  Brousseaud  and  Largeteau,  Plana  and  Car- 

epeaking,  1.84.  According  to  the  earliest  determinations,  the  length  of 
the  metre  was  determined  at  0.5130740  of  a  toise,  while  according  to 
Bessel's  last  determination  it  ought  to  be  0.5131180  of  a  toise.  The 
difference  for  the  length  of  the  metre  is,  therefore,  0.038  of  a  French 
line.  The  metre  has,  therefore,  been  established  by  Bessel  as  equal 
to  443.334  French  lines,  instead  of  443.296,  which  is  its  present  legal 
value  (Compare  also,  on  this  so-called  natural  standard,  Faye,  Lemons  <U 
Cosmographie,  1852,  p.  93). 

8  Airy,  Figure  of  the  Earth  in  the  Encycl.  Metrop.  1849,  pp.  214—216. 


THE  SIZE   OF  THE   EARTH. 


17 


2 

gi 


-*  r-j  o  o  o>  o  <M  T-H  io  i— i  o  p  cq  CM  o 

CO  <M  00  CO  t^  O  i— '  r-H   i— <   O  -^  O   *O   C5  O* 


^GOCCCOO^OCi  O  t-^005  CO  OOr-H 

lOiO^O^OiO^OtC^  -*  CO  CO  <M  CO  ^^ 

i^COCO^OtOOOCO  CO  COCO^O  CO  COCO 

COCQCOCOCOCOCOCO  CO  COCOCO  CO  COCO 


11 


05  o  o    as  co"  r^  co  co" 

I-H  CO  <M  C^  id  *O  r-  1  CM 


c  o  c       co 


COiO         COCO         iO4O 
i—  lOOOi-Hr-H(MCOC<l 


T-HOO 
i—  »   »O  r-l       CO       rHCO 


Geographical  latitude 
of  the  middle  of  the 
measured  arc. 


Ob-^cdco'coidci     CM    O'-'O     o"    oo 

i-H^^H  <M(M  CO<M 


<M«D<M      r-i      OQCO 
rH  COCOf-l"* 


(Mr-H 


COCO 


OiCO5<1      i-t 
CO'—''—'  COCO 


l 


ll 


a 


VOL.  Y, 


18  COSMOS. 

lini,  almost  entirely  under  the  so-called  mean  parallel  of  45*. 
The  numerous  pendulum  experiments  which  have  been  con- 
ducted in  the  neighbourhood  of  mountain  chains,  have  con- 
firmed in  the  most  remarkable  manner  the  previously-recog- 
nised influences  of  those  local  attractions  which  were  in- 
ferred from  the  comparison  of  astronomical  latitudes  with 
the  results  of  geodetic  measurements.9 

In  addition  to  the  two  secondary  methods  for  the  direct 
measurement  of  a  degree  on  meridian  and  parallel  arcs,  we 
have  still  to  refer  to  a  purely  astronomical  determination  of 
the  figure  of  the  earth.  This  is  based  upon  the  action  which 
the  earth  exerts  upon  the  motion  of  the  moon,  or  in  other 
words  upon  the  inequalities  in  lunar  longitudes  and  latitudes. 
Laplace,  who  was  the  first  to  discover  the  cause  of  these 
inequalities,  has  also  taught  us  their  application  by  ingeni- 
ously showing  how  they  afford  the  great  advantage  which 
individual  measurements  of  a  degree  and  pendulum  experi- 
ments are  incapable  of  yielding,  namely,  that  of  showing  in 
one  single  result  the  mean  figure  of  the  earth.10  We  would 

9  Biot,  Astr.  Physique,  t.  ii,  p.  482,  and  t.  iii,  p.  482.     A  very  accu- 
rate geodetical  measurement,  which  is  the  more  important  from  its 
serving  as  a  comparison  of  the  levels  of  the  Mediterranean  and  Atlantic, 
has  been  made  on  the  parallel   of  the  chain  of  the  Pyrenees  by  Cora- 
boeuf,  Delcros,  and  Peytier. 

10  Cosmos,  vol.  i,  p.  160.     "It  is  very  remarkable  that  an  astronomer 
without  leaving  his  observatory,  may  merely  by  comparing  his  obser- 
vations with  analytical  results,  not  only  be  enabled  to  determine  with 
exactness  the  size  and  degree  of  ellipticity  of  the  earth,  but  also  its 
distance  from  the  sun  and  moon — results  that  otherwise  could  only  be 
arrived  at  by  long  and  arduous  expeditions  to  the  most  remote  parts 
of  both  hemispheres.     The  moon  may,  therefore,  by  the  observation  of 
its  movements  render  appreciable  to  the  higher  departments  of  astro- 
nomy, the  ellipticity  of  the  earth,  as  it  taught  the  early  astronomers 
the  rotundity  of  our  earth  by  means  of  its  eclipses"  (Laplace,  Expos,  du 
Syst.  du  M&iide,  p.  230).     We  have  already  in  Cosmos,  vol.  iv,  pp.  481 — 
532,  made  mention  of  an  almost  analogous  optical  method  suggested  by 
Arago,  and  based  upon  the  observation  that  the  intensity  of  the  ash- 
coloured  light,  that  is  to  say  the  terrestrial  light  in  the  moon,  might 
afford  us  some  information  in  reference  to  the  transparency  of  our 
entire  atmosphere.     Compare  also  Airy  in  the  Encycl.  Metrop.  pp.  189, 
236,  on  the  determination  of  the  earth's  ellipticity  by  means  of  the 
motions  of  the  moon,  as  well  as  at  pp.  231 — 235.  on  the  inferences  which 
he  draws  regarding  the  figure  of  the  earth  from  precession  and  nutation. 
According  to  Biot'a  investigations,  the  latter  determination  would  only 


THE  FIGURE  OP  THE  EAKTH.  19 

here  again  refer  to  the  happy  expression  of  the  discoverer  of 
this  method  "  that  an  astronomer  without  leaving  his  obser- 
vatory may  discover  tue  individual  form  of  the  earth  in 
which  he  dwells,  from  the  motion  of  one  of  the  heavenly 
bodies."  After  his  last  revision  of  the  inequalities  in  the 
longitude  and  latitude  of  our  satellite,  and  by  the  aid  of 
several  thousand  observations  of  Burg,  Bouvard,  and  Burck- 
hardt,11  Laplace  found  by  means  of  his  lunar  method  a 
compression  amounting  to  ¥^g-,  which  is  very  nearly  equal  to 
that  yielded  by  the  measurements  of  a  degree  of  latitude 

(2^9)- 

The  vibrations  of  the  pendulum  yield  a  third  means  of  de- 
termining the  figure  of  the  earth  (or  in  other  words  the 
relation  of  the  major  to  the  minor  axis,  on  the  supposition  of 
our  planet  being  of  a  spheroidal  form),  by  the  elucidation  of 
the  law  according  to  which  gravity  increases  from  the  equator 
towards  the  pole.  The  Arabian  astronomers,  and  more  es- 
pecially Ebn-Junis,  at  the  close  of  the  tenth  century,  and 
during  the  brilliant  epoch  of  the  Abbassidian  Califs13,  first 
employed  these  vibrations  for  the  determination  of  time,  and 
after  a  neglect  of  six  hundred  years  the  same  method  was 
again  adopted  by  Galileo,  and  Father  Riccioli  at  Bologna.13 
The  pendulum  in  conjunction  with  a  system  of  wheels  used 
to  regulate  the  clocks  (which  were  first  employed  in  the 
imperfect  experiments  of  Sanctorius  at  Padua  in  1612,  and 
then  in  the  more  perfect  observations  of  Huygens  in  1656), 
gave  the  first  material  proof  of  the  different  intensity  of  gravity 
at  different  latitudes  in  Richer's  comparison  of  the  beats  of 
the  same  astronomical  clock  at  Paris  and  Cayenne,  in  1672. 
Picard  was  indeed  engaged  in  the  equipment  of  this  im- 
portant voyage,  but  he  does  not  on  that  account  assume  to 
himself  the  merit  of  its  first  suggestion.  Richer  left  Paris 

give,  for  the  earth's  ellipticity,  limiting  and  widely  differing  values 
(•5fT  and  -gfa).  Astron.  Physique,  3eme  ed.  t.  ii,  1844,  p.  463. 

11  Laplace,  Mecanique  Celeste,  e"d.  de  1846,  t.  v.  pp.  16,  53. 

l-  Cosmos,  vol.  i,  p.  158.  Edward  Bernard,  an  Englishman,  was  the  first 
who  recognised  the  application  of  the  isochronism  of  pendulum-oscil- 
lations in  the  writings  of  the  Arabian  astronomers.  (See  his  letter,  dated 
Oxford.  April,  1683,  and  addressed  to  Dr.  Robert  Huntington,  in 
Dublin.  Philos.  Transac.  vol.  xii,  p.  567.) 

13  Frgret  de  V Etude  de  la  Philosophic  Ancienne  in  the  Mem.  de  I'Acad, 
des  Inscr.  t.  xviii  Q753),  p.  100. 

C2 


20  COSMOS. 

in  October,  1671,  and  Picard  in  the  description  of  his  mea- 
surement of  a  degree  of  latitude,  which  appeared  in  the  same 
year u  merely  refers  to  "  a  conjecture  which  was  advanced 

14  Picard,  Mtsure  de  la  Terre,  1671,  Art.  4.  It  is  scarcely  probabla 
that  the  conjecture  which  was  advanced  in  the  Paris  Academy  even 
before  the  year  1671,  to  the  effect  that  the  intensity  of  gravity  varies 
with  the  latitude  (Lalande,  Astronomic,  t.  iii,  p.  20  §  2668)  should  have 
been  made  by  the  illustrious  Huygens,  who  had  certainly  presented 
his  Discours  sur  la  Cause  de  la  Gravite  to  the  Academy  in  the  course 
of  the  year  1669.  There  in  no  mention  made  in  this  treatise  of  the 
shortening  of  the  seconds-pendulum,  which  was  being  observed  by 
Richer  at  Cayenne,  although  a  reference  to  it  occurs  in  the  supple- 
ments to  this  work,  (one  of  which  must  have  been  completed  after  the 
publication  of  Newton's  Principia,  and  consequently  later  than  1687). 
Huygens  writes  as  follows: — "Maxima  pars  hujus  libelli  scripta  est, 
cum  Lutetise  degerem  (to  1681)  ad  eum  usque  locum,  ubi  de  altera- 
tione,  quae  pendulis  accidit  e  motu  Terrse."  See  also  the  explanation 
which  I  have  given  in  Cosmos,  vol.  ii,  p.  736.  The  observations  made 
by  Richer  at.  Cayenne  were  not  published  until  1679,  as  I  have  already 
observed  in  the  text,  and  therefore  not  until  fully  six  years  after  his 
return,  and  what  is  more  remarkable,  the  annals  of  the  Academic  des 
Inscriptions  contain  no  notice  during  this  long  period  of  Richer's  im- 
portant double  observations  of  the  pendulum  clock  and  of  the  simple 
seconds-pendulum.  We  do  not  know  the  time  when  Newton  first 
became  acquainted  with  Richer's  results,  although  his  own  earliest 
theoretical  speculations  regarding  the  figure  of  the  earth  date  farther 
back  than  the  year  1665.  It  would  appear  that  Newton  did  not  be- 
come acquainted  until  1682  with  Picard's  geodetic  measurement,  which 
had  been  published  in  1671,  and  even  then  "  he  accidentally  heard  of  it 
at  a  meeting  of  the  Royal  Society,  which  he  was  attending."  His  know- 
ledge of  this  fact  as  Sir  David  Brewster  has  shown  (Memoirs  of  Sir  I. 
Neviton,  vol.  i,  p.  291),  exerted  a  very  important  influence  on  his  deter- 
mination of  the  earth's  diameter,  and  of  the  relation  which  the  fall  of 
a  body  upon  our  planet  bears  to  the  force  which  retains  the  moon  in 
its  orbit.  Newton's  views  may  have  been  similarly  influenced  by  the 
knowledge  of  the  spheroidal  form  of  Jupiter  which  had  been  ascertained 
by  Cassini  prior  to  1666,  but  was  first  described  in  1691  in  the  Memoires 
de  i' Academic  des  Sciences,  t.  ii,  p.  108.  Could  Newton  have  learnt 
anything  of  a  much  earlier  publication,  of  which  some  of  the  sheets 
were  seen  by  Lalaude  in  the  possession  of  Maraldi?  (Compare 
Laiande,  Astr.  t.  iii.  p.  335,  §  3345,  with  Brewster,  Memoirs  of  Sir  /. 
Newton,  vol.  i,  p.  322,  and  Cosmos,  vol.  i,  p.  156.)  Amid  the  simultan- 
eous labours  of  Newton,  Huygens,  Picard,  and  Cassini,  it  is  often  very 
difficult  to  arrive,  with  any  certainty,  at  a  just  appreciation  of  the  diffu- 
sion of  scientific  knowledge,  owing  to  the  tardiness  with  which  men 
at  that  day  made  known  the  result  of  their  observations,  the  pub- 
lication of  which,  was  moreover  frequently  delayed  by  accidental  cir* 
cu  instances. 


THE  FIGURE   OF  THE   EAETH.  21 

by  one  of  the  members,  at  a  meeting  of  the  Academy,  ac- 
cording to  which  the  weight  of  a  body  must  be  less  at  the 
equator  than  at  the  pole,  in  consequence  of  the  rotation  of 
the  earth."  He  adds  doubtfully,  that  although  it  would 
appear  from  certain  experiments  made  in  London,  Lyons, 
and  Bologna,  as  if  the  seconds-pendulum  must  be  shortened 
the  nearer  we  approach  to  the  equator;  yet  on  the  other 
hand  he  was  not  sufficiently  convinced  of  the  accuracy 
of  the  measurements  adduced,  because  at  the  Hague,  not- 
withstanding its  more  northern  latitude,  the  pendulum 
lengths  were  found  to  be  precisely  the  same  as  at  Paris. 
The  periods  at  which  Newton  first  became  acquainted  with 
the  important  pendulum  results  that  had  been  obtained  by 
Richer  as  early  as  1672,  although  they  were  not  printed 
until  1679,  and  at  which  he  first  heard  of  the  discovery  that 
had  been  made  by  C.assini,  before  the  year  1666,  of  the'  com- 
pression of  Jupiter's  disc,  have  unfortunately  not  been  re- 
corded with  the  same  exactness,  as  the  fact  of  his  very  tardy 
acquaintance  with  Picard's  measurement  of  a  degree.  In  an 
age  so  remarkable  for  the  successful  emulation  that  distinguished 
the  cultivators  of  science,  and  when  theoretical  views  led  to 
the  prosecution. of  observations,  which  by  their  results  re- 
acted in  their  turn  upon  theory,  it  is  of  great  interest  to  the 
history  of  the  mathematical  establishment  of  physical  as- 
tronomy, that  individual  epochs  should  be  determined  with 
accuracy. 

Although  direct  measurements  of  meridian  and  parallel 
degrees  (the  former  especially  in  the  cast?  of  the  French 
measurement  of  a  degree15  between  the  latitudes  44°  42' 
and  47°  30',  and  the  latter  by  the  comparison  of  points  lying 
to  the  east  and  west  of  the  Italian  and  Maritime  Alps),1* 
exhibit  great  deviations  from  the  mean  ellipsoidal  figure  of 
the  earth,  the  variations  in  the  amount  of  ellipticity  given 
by  pendulum  lengths  (taken  at  different  geographical  points 
and  in  different  groups)  are  very  much  more  striking.  The 
determination  of  the  figure  of  the  earth  obtained  from  the 

15  Delambre,  East  du  Syst.  Mttriqiw,  t.  iii,  p.  548. 

16  Cosmos,  vol.  i,  p.  159.     Plana,  Operations  G6od6siques  et  Astrono- 
miqucs  pour  la  Mesure    dun  Arc  du  ParalUle  Moyen,  t.  ii,  p.   847; 
Carlini  in  the  £/emeridi  Astronomiche  di  Milano  per  Vanno  1842, 
p.  57. 


22  COSMOS. 

increase  or  decrease  of  gravity  (intensity  of  local  attraction), 
assumes  that  gravity  at  the  surface  of  our  rotating  spheroid 
must  have  remained  the  same  as  it  was  at  the  time  of  our 
earth's  consolidation  from  a  fluid  state,  and  that  no  later 
alterations  can  have  taken  place  in  its  density.17  Not- 
withstanding the  great  improvements  which  have  been  made 
in  the  instruments  and  methods  of  measurement  by  Borda, 
Kater,  and  Bessel,  there  are  at  present  in  both  hemispheres, 
from  Spitzbergen  in  79°  50'  N.L.,  to  the  Falkland  Islands,  in 
51°  35'  S.L.,  where  Freycinet,  Duperrey,  and  Sir  James  Ross 
successively  made  their  observations,  only  from  65  to  70 
irregularly  scattered  points,18  at  which  the  length  of  the 
simple  pendulum  has  been  determined  with  as  much  accu- 
racy as  the  position  of  the  place  in  respect  to  its  latitude, 
longitude,  and  elevation  above  the  level  of  the  sea. 

The  pendulum  experiments  made  by  the  French  astrono- 
mers on  the  measured  part  of  a  meridian  arc,  and  the  obser- 
vations of  Captain  Kater  in  the  trigonometrical  survey  of 
Great  Britain  concurred,  in  showing  that  the  results  do  not 
individually  admit  of  being  referred  to  a  variation  of  gravity 
proportional  to  the  square  of  the  sine  of  the  latitude.  On  this 
account  the  English  Government  determined,  at  the  sugges- 
tion of  the  Vice-President  of  the  Royal  Society,  Davies 
Gilbert,  to  fit  out  a  scientific  expedition,  which  was  en- 
trusted to  my  friend  Edward  Sabine,  who  had  accompanied 
Captain  Parry  on  his  first  polar  voyage  in  the  capacity  of 
astronomer.  In  the  course  of  this  voyage,  which  was  con- 
tinued through  the  years  1822  and  1823,  he  coasted  along 

17  Compare  Biot,  Astronomic  Physique,  t.  ii,  1844,  p.  464,  with  Cosmos, 
vol.  i,  p.  160,  and  vol.  iv,  p.  427,  where  I  have  considered  the  difficulties 
presented  by  a  comparison  of  the  periods  of  rotation  of  planets,   and 
their  observed  compression.      Schubert  (Astron.  Th.  iii,  s.   316)   has 
also  drawn  attention  to  this  difficulty,  and  Bessel  in  his  treatise  On 
Mass  and  Weight  says  expressly,  that  the  supposition  of  the  invariability 
of  gravity  at  any  one  point  of  observation  has  been  rendered  somewhat 
uncertain  by  the  recent  experiments  made  on  the  slow  upheaval  of  large 
portions  of  the  earth's  surface. 

18  Airy  in  his  admirable  treatise  on  the  Figure  of  the  Earth  (Encycl. 
Metropol.  1849,  p.   229)  reckoned  fifty  different  stations  where  trust- 
worthy results  had  been  obtained  up  to  the  year  1830,  and  fourteen 
others,    (those  of   Bouguer,    Legentil,    Lacaille,   Maupertuis   and   La 
Croyere),  which  however  do  not  bear  comparison  with  the  former  iu 
point  of  accuracy. 


THE   FIGURE   OF   THE  EARTH.  23 

the  western  shores  of  Africa,  from  Sierra  Leone  to  the  Is- 
land  of  St.  Thomas,  near  the  Equator,  then  by  Ascension  to 
South  America,  from  Bahia  to  the  mouth  of  the  Orinoco,  on 
his  way  to  the  West  Indies  and  the  New  England  States, 
after  which  he  penetrated  into  the  Arctic  regions  as  far  as 
Spitzbergen,  and  a  hitherto  unexplored  and  ice-bound  portion 
of  East  Greenland  (74°  32').  This  brilliant  and  ably  con- 
ducted expedition  had  the  advantage  of  being  mainly 
directed  to  one  sole  object  of  investigation,  and  of  embracing 
points  which  are  separated  from  one  another  by  93°  of 
latitude. 

The  field  of  observation  in  the  French  expedition  for  the 
measurements  of  degrees  was  more  remote  from  the  equinoc- 
tial and  arctic  zones ;  but  it  had  the  great  advantage  of 
presenting  a  linear  series  of  points  of  observation,  and  of 
affording  direct  means  of  comparison  with  the  partial  curvature 
of  the  arcs  obtained  by  geodetico-astronomical  observations. 
Biot,  in  1824,  carried  the  line  of  pendulum  measurements 
from  Formentera  (38°  39'  56")  where  he  had  already  made 
observations  conjointly  with  Arago  and  Chaix,  as  far  as 
Unst,  the  most  northerly  of  the  Shetland  Islands  (60°  45' 
25"),  and  with  Mathieu  he  extended  it  to  the  parallels 
of  Bordeaux,  Figeac,  and  Padua,  as  far  as  Fiume.19  These 
pendulum  results,  when  compared  with  those  of  Sabine, 
certainly  give  -%^-Q  for  the  compression  of  the  whole  northern 
quadrant,  but  when  separated  into  two  halves,  they  yield 
a  still  more  varying  result,  giving  T^-^  from  the  equator  to 
45°,  and  -^^  from  45°  to  the  pole.20  It  has  been  shown 

19  Biot  and  Arago,  Recueild'Observ.  Geodesiques  et  Astronomiques,  1821, 
pp.  526—540,  and  Biot,  Traite  d'Astr.  Physique,  t.  ii,  1844,  pp.  465— 
473. 

20  Op.  cit.  p.  488.     Sabine  (Super,  for  determining  the  variation  in  the 
length  of  the  Pendulum,  vibrating  Seconds,  1825,  p.  352)  finds  ^irW  from 
all  the  thirteen  stations  of  his  pendulum  expedition,  notwithstanding 
their  great  distances  from  one  another  in  the  northern  hemisphere ; 
and  from  these,  increased  by  all  the  pendulum  stations  of  the  British 
survey  and  of  the  French  geodetic  measurement  from  Formentera  to 
Dunkirk,  comprising  therefore  in  all  a  comparison  of  twenty -five  points  of 
observation  he  again  found  TffW-  ^  *8  st^l  more  striking,  as  was  already 
observed  by  Admiral  Llitke,  that  far  to  the  west  of  the  Atlantic  region 
in  the  meridians  of  Petropawlowski  and  New  Archangel,  the  pendulum 
lengths  yield  a  much  greater  ellipticity,  namely  •^T.    As  the  previously 
applied  theory  of  the  influence  of  the  air  surrounding  the  pendulum 


24  COSMOS. 

in  many  instances,  and  in  both  hemispheres,  that  there  is  an 
appreciable  influence  exerted  by  surrroimding  denser  rocks, 
(basalt,  greenstone,  diorite,  and  melaphyre,  in  opposition  to 
specifically  lighter  secondary  and  tertiary  formations,)  in  the 
same  manner  as  volcanic  islands21  influence  gravity  and 
augment  its  intensity.  Many  of  the  anomalies  which  pre- 
sented themselves  in  these  observations  do  not,  however, 
admit  of  being  explained  by  any  visible  geological  characters 
of  the  soil. 

For  the  southern  hemisphere  we  possess  a  small  number 
of  admirable,  but  very  widely  diffused  observations  made  by 
Freycinet,  Duperrey,  Fallows,  Liifcke,  Brisbane  and  Bumker. 
These  observations  have  confirmed  a  fact  which  had  been 
strikingly  demonstrated  in  the  northern  hemisphere,  namely, 
that  the  intensity  of  gravity  is  not  the  same  for  all  places 
having  the  same  latitude,  and  that  the  increase  of  gravity 
from  the  equator  towards  the  poles  appears  to  be  subjected 
to  different  laws  under  different  meridians.  Although  the 
pendulum  measurements  made  by  Lacaille  at  the  Cape  of 
Good  Hope,  and  those  conducted  in  the  Spanish  circumnavi- 
gating expedition  by  Malaspina,  may  have  led  to  the  belief 
that  the  southern  hemisphere  is  in  general  much  more  com- 
pressed than  the  northern,  comparisons  made  between  the 
Falkland  Islands  and  New  Holland  on  the  one  hand, 

led  to  an  error  in  the  calculation,  and  had  rendered  a  correction  neces- 
sary as  early  as  1786,  (when  a  somewhat  obscure  one  was  given  by  tha 
Chevalier  de  Buat,)  on  account  of  the  difference  in  the  loss  of  weight 
of  solid  bodies,  when  they  are  either  at  rest  in  a  fluid,  or  impelled  in  a 
vibratory  motion,  Bessel  with  his  usual  analytical  clearness  laid  down 
the  following  axiom  in  his  Untersuchungen  iiber  die  Lange  des  einfachen 
Secundertpendels,  s.  32,  63,  126 — 129.  "When  a  body  is  moving  in  a 
fluid  (the  atmosphere),  the  latter  belongs  with  it  to  the  moved  system, 
and  the  moving  force  must  be  distributed  not  only  over  the  particles 
of  the  solid  moved  body,  but  also  over  all  the  moved  particles  of  the 
fluid."  On  the  experiments  of  Sabine  and  Baily,  which  originated  in 
Bessel's  practically  important  pendulum  correction  (reduction  to  a 
vacuum),  see  JohnHerschelin  the  Memoir  of  Francis  Baily,  1845,  pp. 
17—21. 

21  Cosmos,  vol.  i,  p.  159.  Compare,  for  the  phenomena  occurring  in 
islands,  Sabine  Pend.  Exper.  1825,  p.  237,  and  Liitke,  Obs.  du  Pendule 
invariable,  exScuUes  de  1826 — 1829,  p.  241.  This  work  contains  a 
remarkable  table,  p.  239,  on  the  nature  of  the  rocks  occurring  at  16 
pendulum  stations,  from  Spitsbergen  (79°  50'  N.  Lat.)  to  Valparaiso 
(33°  2'  S.  Lat.). 


THE   FIGURE   OF  THE   EARTH.  25 

and  New  York,  Dunkirk,  and  Barcelona  on  the  other, 
have,  however,  by  their  more  exact  results  shown  that 
the  contrary  is  the  case,  as  I  have  already  elsewhere  in- 
dicated.22 

From  the  above  data,  it  follows  that  the  pendulum  (al- 
though it  is  by  no  means  an  unimportant  instrument  in 
geognostic  observations,  being  as  it  were  a  sort  of  plummet 
cast  into  the  deep  and  unseen  strata  of  the  earth)  does  not 
determine  the  form  of  our  planet  with  the  same  exactitude 
is  the  measurement  of  a  degree,  or  the  movements  of  our 
satellite.  The  concentric,  elliptical,  and  individually  homo- 
geneous strata,  which  increase  in  density  according  to  certain 
functions  of  distance  from  the  surface  towards  the  centre  of 
the  earth,  may  give  rise  to  local  fluctuations  in  the  intensity 
of  gravity  at  individual  points  of  the  earth's  surface,  which 
differ  according  to  the  character,  position,  and  density  of  the 
several  points.  If  the  conditions  which  produce  these  devi- 
ations are  much  more  recent  than  the  consolidation  of  the 

22  Cosmos,  vol.  i,  p.  161.  Eduard  Schmidt  (Mathem.  und  Phys.  Geo- 
graphic, Th.  i,  s.  394),  has  separated  from  a  large  number  of  the  pen- 
dulum observations  which  were  made  on  board  the  corvettes  Descubierta 
and  Atrevida,  under  the  command  of  Malaspina,  those  thirteen  stations 
which  belong  to  the  southern  hemisphere,  from  which  he  obtained  a 
mean  compression  of  ^TO-'ST-  Mathieu  obtained  ^g-W  fr°m  a  compa- 
rison of  Lacaille's  observations  at  the  Cape  of  Good  Hope  and  the  Isle 
of  France  with  Paris,  but  the  instruments  of  measurement  used  at  that 
day  did  not  afford  the  same  certainty  as  we  now  obtain  by  the  appli- 
ances of  Borda  and  Kater,  and  the  more  modern  methods  of  observa- 
tion. The  present  would  seem  a  fitting  place  to  notice  the  beautiful 
experiments  of  Foucault,  which  afford  so  high  a  proof  of  the  ingenuity 
of  the  inventor,  and  by  which  we  obtain  ocular  evidence  of  the  rotation 
of  the  earth  on  its  axis  by  means  of  the  pendulum,  whose  plane  of 
vibration  slowly  rotates  from  east  to  west.  (Comptes  rendus  de  I'Acad. 
des  Sc.,  Seance  du  3  Fevrier,  1851,  t.  xxxii,  p.  135).  Experiments  for 
noticing  the  deviation  towards  the  east  in  observations  of  falling 
bodies,  dropped  from  church  towers  or  into  mines,  as  suggested  by 
Benzenberg  and  Reich,  require  a  very  great  height,  whilst  Foucault's 
apparatus  makes  the  effects  of  the  earth's  rotation  perceptible  with  a 
pendulum  only  six  feet  long.  We  must  not  confound  the  phenomena 
.  which  may  be  explained  by  rotation  (as,  for  instance,  Richer's  clock 
experiments  at  Cayenne,  diurnal  aberration,  the  deviation  of  projectiles, 
trade  winds,  etc.),  with  those  that  may  at  any  time  be  produced  by 
Foucault's  apparatus,  .and  of  which  the  members  of  the  Academia  del 
Cimento  appear  to  have  had  some  idea,  although  they  did  not  farther 
develope  it  ^A.utinori,  in  the  Comptes  rendus,  t.  xxxii,  p.  635). 


*O  COSMOS. 

outer  crust,  the  figure  of  the  surface  cannot  be  assumed  to 
be  locally  modified  by  the  internal  motion  of  the  fused 
masses.  The  difference  of  the  results  of  pendulum  measure- 
ments is  however  much  too  great  to  be  ascribed  at  the  pre- 
sent day  to  errors  of  observation.  Even  where  a  coinci- 
dence in  the  results,  or  an  obvious  regularity  has  been  dis- 
covered by  the  various  grouping  and  combination  of  the 
points  of  observation,  the  pendulum  always  gives  a  greater 
ellipticity  (varying  between  the  limits  -^y  and  -3  §~o)  than 
could  have  been  deduced  from  the  measurements  of  a  degree. 
If  we  take  the  ellipticity  which,  in  accordance  with 
Bessel's  last  determination,  is  now  generally  adopted, 
namely,  ^^Jy^,  we  shall  find  that  the  bulging23  at  the 


23  In  Grecian  antiquity  two  regions  of  the  earth  were  designated  as 
being  characterised,  in  accordance  with  the  prevalent  opinions  of  the 
time,  by  remarkable  protuberances  of  the  surface,  namely,  the  high 
north  of  Asia  and  the  land  lying  under  the  equator.  "  The  high  and 
naked  Scythian  plains,"  says  Hippocrates  (de  Acre  et  Aquis  §  xix,  p.  72, 
Littre"),  "without  being  crowned  by  mountains  stretch  far  upward  to 
the  meridian  of  the  Bear."  A  similar  opinion  had  previously  been 
ascribed  to  Empedocles  (Plut.  de  Plac.  Philos.  ii,  8).  Aristotle  (Meteor. 
i,  1  a  1  5,  p.  66,  Ideler)  says  that  the  older  meteorologists,  according  to 
whose  opinions  the  sun  "  did  not  go  under  the  earth,  but  passed  round 
it,"  considered  that  the  protuberances  of  the  earth  towards  the  north 
were  the  cause  of  the  disappearance  of  the  sun,  or  of  the  production  of 
night.  And  in  the  compilation  of  the  Problems  (xxvi,  15,  page  941, 
Bekker),  the  cold  of  the  north  wind  was  ascribed  to  the  elevation  of 
the  soil  in  this  region  of  the  earth,  and  in  all  these  passages  there  is 
no  reference  to  mountains,  but  merely  to  a  bulging  of  the  earth  into 
elevated  plateaux.  I  have  already  elsewhere  shown  (Asie  Centrale,  t.  i, 
p.  58)  that  Strabo,  who  alone  makes  use  of  the  very  characteristic  word 
opoTridia,  says  that  the  difference  of  climate  which  arises  from  geogra- 
phical position  must  everywhere  be  distinguished  from  that  which  we 
ascribe  to  elevation  above  the  sea,  in  Armenia  (xi,  p.  522,  Casaub.),  in 
Lycaonia,  which  is  inhabited  by  wild  assea  (xii,  p.  568),  and  in  Upper 
India,  in  the  auriferous  country  of  the  Derdi  (xv,  p.  706).  "  Even  in 
southern  parts  of  the  world,"  says  the  geographer  of  Amasia,  "  every 
high  district,  if  it  be  also  a  plain,  is  cold  "  (ii,  p.  73).  Eratosthenes 
and  Polybius  ascribe  the  very  moderate  temperature  which  prevails 
under  the  equator  not  only  to  the  more  rapid  transit  of  the  sun 
(Geminus,  JElem.  Astron.  c.  13,  Cleom.  Cycl.  Theor.,  1,  6),  but  more  espe- 
cially to  the  bulging  of  the  earth  (See  my  Examen  Grit,  de  la  Geogr. 
t.  iii,  pp.  150  —  152).  Both  maintain,  according  to  the  testimony  of 
Strabo  (ii,  p.  97),  "  that  the  district  lying  immediately  below  the  equator 
is  the  highest,  on  which  account  much  rain  falls  there,  in  consequence 
of  the  very  large  accumulation  of  northern  clouds  at  the  period  when 


THE  FIGURE  OP  THE  EARTH.  27 

equator  amounts  to  about  645,457  feet ;  about  11-J-,  or  more 
accurately,  11.492  geographical  miles.  As  a  comparison  has 

those  winds  prevail,  which  change  with  the  season  of  the  year."  Of 
these  two  opinions  regarding  the  elevation  of  the  land  in  Northern 
Asia,  (the  Scythian  Europe  of  Herodotus)  and  in  the  equatorial  zone,  the 
former  of  the  two,  with  the  pertinacity  characteristic  of  error,  has  kept 
its  ground  for  nearly  two  thousand  years,  and  has  given  occasion  to  the 
geological  myth  of  an  uninterrupted  plateau  in  the  Tartar  district 
lying  to  the  north  of  the  Himalayas,  whilst  the  other  opinion  could  only 
be  justified  in  reference  to  a  portion  of  Asia,  lying  beyond  the  tropical 
zone,  and  consequently  applies  only  to  the  colossal,  "  elevated  or 
mountain  plateau,  Meru,"  which  is  celebrated  in  the  most  ancient  and 
noblest  memorials  of  Indian  poetry.  (See  "Wilson's  Diet.  Sanscrit  and 
English,  1832,  p.  674,  where  the  word  Meru  is  explained  to  signify  an 
elevated  plateau).  I  have  thought  it  necessary  to  enter  thus  circum- 
stantially into  this  question,  in  order  that  I  might  refute  the  hypothesis 
of  the  intellectual  Freret,  who,  without  indicating  any  passages  from 
Greek  writers,  and  merely  alluding  to  one  which  seemed  to  treat  of 
tropical  rain,  interprets  the  opinion  advanced  regarding  bulgings  of  the 
soil  as  having  reference  to  compression  or  elongation  at  the  poles.  In 
the  Mem.  de  I'Acad.  des Inscriptions,  t.  xviii,  1753,  p.  112,  FreVet  expresses 
himself  as  follows  :—  "  To  explain  the  rains  which  prevailed  in  those 
equinoctial  regions,  which  the  conquests  of  Alexander  first  made  known, 
it  was  supposed  that  there  were  currents  which  drove  the  clouds  from 
the  poles  towards  the  equator,  where,  in  default  of  mountains  to  stop 
their  progress,  they  were  arrested  by  the  general  elevation  of  the  soil, 
whose  surface  at  the  equator  is  farther  removed  from  the  centre  than 
under  the  poles.  Some  physicists  have  ascribed  to  the  globe  the  figure 
of  a  spheroid,  which  bulges  at  the  equator  and  is  flattened  towards  the 
poles,  while  on  the  contrary,  in  the  opinion  of  those  of  the  ancients  who 
believed  that  the  earth  was  elongated  towards  the  poles,  the  polar 
regions  are  farther  removed  than  the  equatorial  zone  from  the  centre 
of  the  earth."  I  can  find  no  evidence  in  the  works  of  the  ancients  to 
justify  these  assertions.  In  the  third  section  of  the  first  book  of  Strabo 
(page  48,  Casaub.),  it  is  expressly  stated  that,  "  after  Eratosthenes  has 
observed  that  the  whole  earth  is  spherical,  although  not  like  a  sphere 
that  has  been  made  by  a  turning-lathe  (an  expression  that  is  borrowed 
from  Herodotus,  iv.  36),  and  exhibits  many  deviations  from  this  form, 
he  adduces  numerous  modifications  of  shape  which  have  been  produced 
by  the  action  of  water  and  fire,  by  earthquakes,  subterranean  currents 
of  wind  (elastic  vapours?),  and  other  causes  of  the  same  kind,  which, 
however,  are  not  given  in  the  order  of  their  occurrence,  for  the  rotun- 
dity of  the  entire  earth  results  from  the  co-ordination  of  the  whole,  such 
modifications  in  no  degree  affecting  the  general  form  of  our  earth,  the 
lesser  vanishing  in  the  greater."  Subsequently  we  read,  also  in  Gros- 
kurd's  admirable  translation,  "  that  the  earth,  together  with  the  sea,  ia 
spherical,  the  two  constituting  one  and  the  same  surface.  The  projec- 
tion of  the  laud,  which  is  inconsiderable  and  may  remain  unnoticed  ia 


28  COSMOS. 

very  frequently  been  made  from  the  earliest  times  of  astro- 
nomical inquiry  between  this  swelling  or  convex  elevation 
of  the  earth's  surface  and  carefully  measured  mountain 
masses,  I  will  select  as  objects  of  comparison  the  highest  of 
the  known  peaks  of  the  Himalayas,  namely,  that  of  Kin- 
tschindjinga,  which  was  fixed  by  Colonel  Waugh  at  28,174 
feet,  and  that  portion  of  the  elevated  plateau  of  Thibet 
which  is  nearest  to  the  sacred  lakes  of  Rakas-Tal  and  Man- 
assarova,  and  which,  according  to  Lieutenant  Henry  Strachey, 
is  situated  at  the  mean  height  of  15,347  feet.  The  bulg- 
ing of  our  planet  at  the  equatorial  zone  is  therefore  not 

lost  in  such  magnitudes,  so  that  in  these  cases  we  are  unable  to  deter- 
mine its  spherical  form  with  the  same  accuracy  as  in  the  case  of  a  sphere 
made  by  a  turning-lathe,  or  as  well  as  the  sculptor,  who  judges  from 
his  conceptions  of  form,  for  here  we  are  obliged  to  determine  by  phy- 
sical and  less  delicate  perception  "  (Strabo,  ii,  p.  112).  "The  world  ia 
at  once  a  work  of  nature  and  of  providence, — a  work  of  nature  inasmuch 
as  all  things  tend  towards  one  point,  the  centre  of  the  whole,  round 
which  they  group  themselves,  the  less  dense  element  (water)  containing 
the  denser  (earth)."  (Strabo,  xvii,  p.  809).  Wherever  we  find  the  figure 
of  the  earth  described  by  the  Greeks,  it  is  compared  (Cleom.  Cycl.  Theor.  i, 
8,  p.  51)  with  a  flat  or  centrally  depressed  disc,  a  cylinder  (Anaximander), 
a  cube  or  pyramid,  and  lastly  we  find  it  generally  held  to  be  a  sphere  not* 
withstanding  the  long  contest  of  the  Epicureans,  who  denied  the  ten- 
dency of  attraction  towards  the  centre.  The  idea  of  compression  does  not 
seem  to  have  presented  itself  to  their  imagination.  The  elongated  earth 
of  Democritus  was  only  the  disc  of  Thales  lengthened  in  one  direction. 
The  drum-like  form,  TO  cfxrjua  rv^Travoaofg,  which  seems  more  especially 
to  have  emanated  from  Leucippus  (Pint,  de  Plac.  Philos.  iii,  10;  Galen. 
Hist.  Phil,  cap.  21;  Aristotle,  de  Ccelo,  ii,  13  page,  293  Bekker),  appears 
to  have  been  founded  upon  the  idea  of  a  hemisphere  with  a  flat  basis, 
which  probably  represented  the  equator,  whilst  the  curvature  was  re- 
garded as  the  oiKovukvr}.  A  passage  in  Pliny,  regarding  Pearls  (xi, 
54),  elucidates  this  form,  whilst  Aristotle  merely  compares  the  segments 
of  the  sphere  with  the  drum  (Meteorol.  ii,  5,  a  10,  Ideler,  t.  i,  p.  563),  as 
we  also  find  from  the  commentary  of  Olympiodorus  (Ideler,  t.  i,  p.  301). 
I  have  here  purposely  avoided  referring  to  two  passages  which  are  well 
known  to  me  in  Agathemerus  (de  Geographia,  lib.  i,  cap.  1,  p.  2,  Hudson) 
and  in  Eusebius  (Evangel.  Prceparat.  t.  iv,  p.  125,  ed.  Gaisford,  1843), 
because  they  prove  with  what  inaccuracy  later  writers  have  often 
ascribed  to  the  ancients  views  which  were  totally  foreign  to  them. 
According  to  these  versions,  "  Eudoxus  gave  for  the  length  and  breadth 
of  the  earth's  disc  values  which  stood  in  relation  to  one  another  as 
1  to  2;  the  same  is  said  in  reference  to  Dictearchus,  the  pupil  of  Aris- 
totle, who,  however,  advanced  his  own  special  proofs  of  the  spherical 
form  of  the  earth  (Marcian,  Capella,  lib.  vi,  p.  192).  Hipparchus  re- 
garded tha  earth  as  rpa7rt£oa<^£,  and  Thales  held  it  to  be  a  sphere!" 


THE  FIGURE  OF  THE  EARTH.  29 

quite  three  times  as  great  as  the  elevation  of  the  highest  of 
our  mountains  above  the  sea's  level,  but  it  is  almost  five 
times  as  great  as  that  of  the  eastern  plateau  of  Thibet. 

We  ought  here  to  observe  that  the  results  of  the  earth's 
compression,  which  have  been  obtained  by  mere  measure- 
ments of  a  degree,  or  by  combinations  of  the  former  with 
pendulum  measurements,  show  far  less  24  considerable  differ- 
ences in  the  amount  of  the  equinoctial  bulging  than  we 
should  have  been  disposed  at  first  sight  to  conclude  from  the 
fractional  numbers.  The  difference  of  the  polar  compres- 
sions (¥{-Q  and  -2^-0)  amounts  to  only  about  7000  feet  in 
the  difference  of  the  major  and  minor  axes,  basing  the  calcu- 
lation on  both  extreme  numerical  limits;  and  this  is  not 
twice  the  elevation  of  the  small  mountains  of  the  Brocken 
and  of  Vesuvius  ;  the  difference  being  only  about  one- tenth 

24  It  has  often  seemed  to  me  as  if  the  amount  of  the  compression  of 
the  earth  was  regarded  as  somewhat  doubtful  merely  from  our  wish 
to  attain  an  unnecessary  degree  of  accwacy.  If  we  take  the  values  of 
the  compression  at  ^,  7-Lj,  ^t  ^,  we  find  that  the  difference  of 
both  radii  is  equal  to  10,554,  10,905,  11,281,  11,684  toises,  or  67,488, 
69,554,  73,137,  74,714  feet.  The  fluctuation  of  30  units  in  the  denomi- 
nator produces  only  a  fluctuation  of  1,130  toises  or  7,126  feet  in  the 
polar  radius,  an  amount  which,  when  compared  with  the  visible  in- 
equalities of  the  earthis  surface  appears  so  very  inconsiderable,  that  I 
am  often  surprised  to  find  that  the  experiments  coincide  within  such 
closely  approximating  limits.  Individual  observations  scattered  over 
wide  surfaces  will  indeed  teach  vis  little  more  than  what  we  already 
know,  but  it  would  be  of  considerable  importance  to  connect  together 
all  the  measurements  that  have  been  made  over  the  entire  surface  of 
Europe,  including  in  this  calculation  all  astronomically  determined 
points."  (Bessel,  in  a  letter  addressed  to  myself,  December,  1828.)  Even 
if  this  plan  were  carried  out,  we  should  then  only  know  the  form  of 
that  portion  of  the  earth,  which  may  be  regarded  as  a  peninsular  pro- 
jection, extending  westward,  about  sixty-six  and  a  half  degrees  from  the 
great  Asiatic  Continent.  The  steppes  of  Northern  Asia,  even  the  mid- 
dle Kirghis  steppe,  a  considerable  portion  of  which  I  have  myself  seen, 
are  often  interspersed  with  hills,  and  in  respect  to  uninterrupted 
levels,  cannot  be  compared  with  the  Pampas  of  Buenos  Ayres,  or  the 
Llanos  of  Venezuela.  The  latter,  which  are  far  removed  from  all 
mountain  chains  and  consist  immediately  below  the  surface  of  secon- 
dary and  tertiary  strata,  having  a  very  uniform  and  low  degree  of  den- 
sity, might  by  differences  in  the  results  of  pendulum  vibrations,  yield 
veiy  decisive  conclusions  in  reference  to  the  local  constitution  cf  the 
deep  internal  strata  of  the  earth.  —  Compare  my  Views  of  Naturt, 
pp.  2—8,  29—32. 


30  COSMOS. 

of  the  bulging  which  would  be  yielded  by  a  polar  compres- 
sion of      - 


As  soon  as  it  had  been  ascertained  by  more  accurate  mea- 
surements of  a  degree,  made  at  very  different  latitudes,  that 
the  earth  could  not  be  uniformly  dense  in  its  interior,  (because 
the  results  showed  that  the  compression  was  very  much 
less  than  had  been  assumed  by  Newton  (-^o"),  an(^  much 
greater  than  was  supposed  by  Huygens  (-5^),  who  con- 
sidered that  all  forces  of  attraction  were  combined  in  the 
centre  of  the  earth,)  the  connection  between  the  amount 
of  compression  and  the  law  of  density  in  the  interior  of  our 
earth  necessarily  became  a  very  important  object  of  ana- 
lytical calculation.  Theoretical  speculations  regarding  gravity 
very  early  led  to  the  consideration  of  the  attraction  of  large 
mountain  masses,  which  rise  freely  and  precipitously  into 
the  atmosphere  from  the  dried  surface  of  our  planet.  New- 
ton, in  his  Treatise  of  the  System  of  the  World  in  a  Popular 
Way,  1728,  endeavoured  to  determine  what  amount  of 
deviation  from  the  perpendicular  direction  the  pendulum 
would  experience  from  a  mountain  2,665  feet  in  height  and 
5,330  feet  in  diameter.  This  consideration  very  probably 
gave  occasion  to  the  unsatisfactory  experiments,  which  were 
made  by  Bouguer  on  Chimborazo,  25  by  Maskelyne  and 

25  Bouguer  who  had  been  induced  by  La  Condamine  to  institute 
experiments  on  the  deviation  of  the  plummet  near  the  mountain  of 
Chimborazo,  does  not  allude  in  his  Figure  de  la  Terre,  pp.  364  —  394 
to  Newton's  proposition.  Unfortunately  the  most  skilful  of  the  two 
travellers  did  not  observe  on  the  east  and  western  sides  of  the 
colossal  mountain,  having  limited  his  experiments  (December,  1738)  to 
two  stations  lying  on  the  same  side  of  Chimborazo,  first  in  a  south- 
erly direction  61°  30'  West,  about  4,572  toises  or  29,326  feet  from 
the  centre  of  the  mountain,  and  then  to  the  South  16°  West  (distance 
1,753  toises  or  11,210  feet).  The  first  of  these  stations  lay  in  a  district 
with  which  I  am  well  acquainted,  and  probably  at  the  same  elevation 
as  the  small  alpine  lake  of  Yana-cocha,  and  the  other  in  the  pumice-stone 
plain  of  the  Arenal  (La  Condamine,  Voyage  d  I'Equateur,  pp.  68  —  70). 
The  deviation  yielded  by  the  altitudes  of  the  stars,  was,  contrary  to  all 
expectation,  only  7.  "5  which  was  ascribed  by  the  observers  themselves 
to  the  difficulty  of  making  observations  so  immediately  in  the  vicinity 
of  the  limit  of  perpetual  snow,  to  the  want  of  accuracy  in  their  instru- 
ments, and  above  all  to  the  great  cavities  which  were  conjectured  to 
exist  within  this  colossal  trachytic  mountain.  I  have  already  expressed 
many  doubts,  based  xipon  geological  grounds,  as  to  this  assumption  of 
very  large  cavities,  and  of  the  very  inconsiderable  mass  of  the  tra- 


THE  FIGURE  OF  THE  EARTH.  31 

Hutton  on  Shehallien,  near  Blair- Athol,  in  Perthshire  ;  to 
the  comparison  of  pendulum  lengths  on  a  plain  lying  at  an 
elevation  of  6000  feet  and  at  the  level  of  the  sea  (as  for 
instance  Carlini's  observations  at  the  Hospice  of  Mont  Cenis, 
and  Biot  and  Mathieu's  at  Bordeaux);  and  lastly  to  the  deli- 
cate and  thoroughly  decisive  experiments  undertaken  in  1837 
by  Reich  and  Bailey  with  the  ingeniously  constructed  torsion- 
balance  which  was  invented  by  John  Mitchell  and  subse- 
quently given  to  Cavendish  by  Wollaston.26  The  three 
modes  of  determining  the  density  of  our  planet  (by  vicinity 
to  a  mountain  mags,  elevation  of  a  mountainous  plateau,  and 
the  balance)  have  already  been  so  circumstantially  detailed 
in  a  former  part  of  the  Cosmos  (vol.  i,  p.  158),  that  it  only 
remains  for  us  to  notice  the  experiments  given  in  Reich's 
new  treatise,  and  prosecuted  by  that  indefatigable  observer 
during  the  interval  between  the  years  1847  and  1850.27 

chytic  dome  of  Chimborazo.  South-south-east  of  this  mountain,  near 
the  Indian  village  of  Calpi,  lies  the  volcanic  cone  of  Yana-urcu,  which 
I  carefully  investigated  in  concert  with  Bonpland,  and  which  is  cer- 
tainly of  more  recent  origin  then  the  elevation  of  the  great  dome- 
shaped  trachytic  mountain,  in  which  neither  I  nor  Boussingault  could 
discover  anything  analogous  to  a  crater.  See  the  Ascent  of  Chimborazo 
in  my  Rhine  Schriften,  Bd.  i,  s.  138. 

26  Baily,  Exper.  with  the  Torsion  Rod  for  determining  the  mean  density 
of  the  earth,  1843,  p.  6;  John  Herschel,  Memoir  of  Francis  Baily, 
1845,  p.  24. 

07  Reich, Neue  Versuchemit  der Drehwage,  in  iheAlkandl.  dermathem. 
physischen  Classe  der  Ron.  Sdchsischen  Gesellschaft  der  Wissenschaften  zu 
Leipzig,  1852,  Bd.  i,  s.  405,  418.  The  most  recent  experiments  of  my 
respected  friend  Professor  Reich,  approximate  somewhat  more  closely 
to  the  results  given  in  Baily's  admirable  work.  I  have  obtained  the 
mean  5.5772  from  the  whole  series  of  experiments:  (a)  with  the  tin 
ball  and  the  longer  thicker  copper  wire,  the  result  was  5.5712,  with  a 
probable  error  of  0.0113;  (b)  with  the  tin  ball,  and  with  the  shorter 
thinner  copper  wire,  as  well  as  with  the  tin  ball  and  the  bi-filar  iron 
wire,  5.5832,  with  a  probable  error  of  0.0149.  Taking  this  error  into 
account,  the  mean  in  (a)  and  (b)  is  5.5756.  The  result  obtained  by  Baily, 
and  which  was  certainly  deduced  from  a  larger  number  of  experiments 
(5.660),  might  indeed  give  us  a  somewhat  higher  density,  as  it  obviously 
rose  in  proportion  to  the  greater  lightness  of  the  balls  that  were  used 
in  the  experiments,  which  were  either  of  glass  or  ivory.  (Reich  in 
Poggend.  Annalen,  Bd.  Ixxxv,  s.  190.  Compare  also  Whitehead  Hearn 
in  the  Philos.  Transact,  for  1847,  pp.  217—229.)  The  motion  of  the 
torsion  balance  was  observed  by  Baily  by  means  of  the  reflection  of  a 
acale  obtained  from  a  mirror,  which  was  attached  to  the  middle  of  th« 


32  COSMOS. 

The  whole  may  in  accordance  with  the  present  state  of  our 
knowledge  be  arranged  in  the  following  manner  : — 

Sliehallien,  according  to  the  mean  of  the  maximum 
4.867  and  the  minimum  4.559,  as  found  by  Play- 
fair 4.713 

Mont  Cenis,  observations  of  Carlini,  with  the  cor- 
rection of  Giulio, 4.950 

The  torsion-balance,  Cavendish  (according  to  Baily's 

calculation)   .    5.448 

Reich,  1838 5.440 

Badly,  1842   5.660 

Reich,  1847—1850  5.577 

The  mean  of  the  two  last  results  gives  5. 62  for  the  density 
of  the  earth  (taking  that  of  water  as  1),  and  consequently 
much  more  than  the  densest  finely  granular  basalt,  which 
according  to  the  numerous  experiments  of  Leonhard  varies 
from  2.95  to  3.67,  and  more  than  that  of  magnetic  iron  (4,9 
-to  5.2),  and  not  much  less  than  that  of  the  native  arsenic  of 
Marienberg  or  Joachimsthal.  We  have  already  elsewhere 
observed  (Cosmos,  vol,  i,  p.  159)  that  from  the  great  distribu- 
tion of  secondary  and  tertiary  formations,  and  of  those  up- 
heaved strata  which  constitute  the  visible  continental  part  of 
our  earth's  surface  (the  plutonic  and  volcanic  upheavals 
being  scattered  in  the  form  of  islands  over  a  small  area  of 
space),  the  solid  portion  of  the  upper  part  of  the  earth's  crust 
possesses  a  density  scarcely  reaching  from  2.4  to  2.6.  If  we 
assume  with  Rigaud  that  the  relation  of  the  solid  to  the 
fluid  oceanic  surface  of  our  globe  is  as  10  :  27,  and  if  further 
we  consider  that  the  latter  has  been  found  by  experiments 
with  the  sounding  lead  to  extend  to  a  depth  of  27,700  feet, 
the  whole  density  of  the  upper  strata,  which  underlie  the  dry 
and  oceanic  surfaces,  scarcely  equals  1.5.  The  distinguished 
geometrician  Plana  has  correctly  observed  that  the  author  of 
the  jftlecanique  Celeste  was  in  error,  when  he  ascribed  to  the 
upper  stratum  of  the  earth  a  density  equal  to  that  of  granite, 

balance,  a  method  that  had  been  first  suggested  by  Reich,  and  was 
employed  by  Gauss  in  his  magnetic  observations.  The  use  of  such  a 
mirror,  which  is  of  great  importance  from  the  exactness  with  which 
the  scale  may  be  read  off,  was  proposed  by  Poggendorfi'  as  early  as  the 
year  1826  (Annakn  der  Physik.  Bd.  vii,  s.  121) 


THE   DENSITY   OF  THE   EARTH.  33 

which,  moreover,  he  estimated  somewhat  highly  at  3,  which 
would  give  him  10.047  for  the  density  of  the  centre  of  the 
earth.2*  This  density  would,  according  to  Plana,  be  16.27  if 
we  assume  that  of  the  upper  strata  =  1.83,  which  differs 
but  slightly  from  the  total  density  of  1 .5  or  1 .6  of  the  earth's 
crust.  The  vertical  pendulum,  no  less  than  the  horizon  ;al 
torsion  balance,  may  certainly  be  designated  as  a  geognostic 
instrument;  but  the  geology  of  the  inaccessible  parts  of  the 
interior  of  our  globe  is,  like  the  astrognosy  of  the  unillumi- 
nated  celestial  bodies,  to  be  received  with  considerable  cau- 

28  Laplace,  Mccanigue  Celeste,  <k1.  de  1846,  t.  v,  p.  57.  The  mean 
specific  weight  of  granite  cannot  be  set  down  at  more  than  2.7,  since 
the  bi-axial  white  potash-mica,  and  green  uni-axial  magnesia-mica  range 
from  2.85  to  3.1,  whilst  the  other  constituents  of  this  rock,  namely 
quartz  and  felspar  are  2.56  and  2.65.  Even  oligoclase  is  only  2.68.  If 
hornblende  rises  as  high  as  3.17,  syenite,  in  which  felspar  always  pre- 
dominates, never  rises  above  2.8.  As  argillaceous  schist  varies  from 
2.69  to  2.78,  while  pure  dolomite,  lying  below  limestone,  equals  only 
2.88,  chalk  2.72,  and  gypsum  and  rocksalt  only  2.3,  I  consider  that 
the  density  of  those  continental  parts  of  the  crust  of  our  earth,  which 
are  appreciable  to  us  should  be  placed  at  2.6  rather  than  at  2.4.  La- 
place, on  the  supposition  that  the  earth's  density  increases  in  arith- 
metical progression  from  the  surface  towards  the  centre,  and  on  the 
assumption  (which  is  assuredly  erroneous)  that  the  density  of  the 
upper  stratum  is  equal  to  3,  has  found  4.7647  for  the  mean  density  of 
the- whole  earth,  which  deviates  very  considerably  from  the  results  ob- 
tained by  Reich  (5.577)  and  by  Baily  (5.660);  this  deviation  being  much 
greater  than  could  be  accounted  for  by  the  probable  error  of  observa- 
tion. In  a  recent  discussion  on  the  hypothesis  of  Laplace,  which  will 
soon  form  a  very  interesting  paper  in  Schumacher's  A str.  Nachrichten, 
Plana  has  arrived  at  the  result  that,  by  a  different  method  of  treating 
this  hypothesis,  Reich's  mean  density  of  the  earth,  and  the  density  of 
the  dry  and  oceanic  superficial  strata,  which  I  estimated  at  1.6,  aa 
well  as  the  ellipticity,  within  the  limits  that  seem  probable  for  the  latter 
value,  may  be  very  closely  approximated  to.  "  If  the  compressibility 
of  the  substances  of  which  the  earth  is  formed,"  writes  the  Turin  geo- 
metrician, "  has  given  rise  to  regular  strata,  nearly  elliptical  in  form, 
and  having  a  density  which  increases  from  the  surface  towards  the 
centre,  we  may  be  allowed  to  suppose  that  these  strata,  in  the  act  of 
becoming  consolidated,  have  experienced  modifications,  which,  although 
they  are  actually  very  small,  are  nevertheless  large  enough  to  preclude 
the  possibility  of  our  deducing,  with  all  the  precision  that  we  could 
desire,  the  condition  of  the  solid  earth  from  its  prior  state  of  fluidity. 
This  reflection  has  made  me  attach  the  greater  weight  to  the  first 
hypothesis  advanced  by  the  author  of  the  Mecanique  Celeste,  and  I 
have  consequently  determined  upon  submitting  it  to  a  new  investi- 
gation." 

VOL.  V.  D 


34  COSMOS. 

tion.  In  a  portion  of  my  work,  which  treats  of  volcanic  pheno- 
mena, I  cannot  wholly  pass  in  silence  those  problems,  which 
have  been  suggested  by  other  inquirers  in  reference  to  the 
currents  pervading  the  general  fluid  in  the  interior  of  our 
planet,  or  the  probable  or  improbable  periodically  ebbing 
and  flowing  movement  in  individual  and  imperfectly  filled 
basins,  or  the  existence  of  portions  of  space,  having  a  very 
low  specific  gravity  and  underlying  the  upheaved  mountain 
chains29  In  a  work  devoted  to  cosmical  phenomena 
no  question  should  be  overlooked  on  which  actual  observa- 
tions have  been  instituted,  or  which  may  seem  to  be  eluci- 
dated by  close  analogies. 

b.  The  Existence  and  Distribution  of  Heat  in  tlie  interior  of 
our  Globe. 

(Expansion  of  the  Delineation  of  Nature, 
Cosmos,  vol.  i,  pp.  160 — 168.) 

Considerations  regarding  the  internal  heat  of  our  earth, 
the  importance  of  which  has  been  greatly  augmented  by  the 
connection  which  is  now  generally  recognised  to  exist  be- 
tween it  and  phenomena  of  upheavals  and  of  volcanic  action, 
are  based  partly  upon  direct,  and  therefore  incontrovertible 
measurements  of  temperature  in  springs,  borings,  and  sub- 
terranean mines,  and  partly  upon  analytical  combinations 
regarding  the  gradual  cooling  of  our  planet,  and  the  influence 
which  the  decrease  of  heat  may  have  exercised  in  primeval 
ages  upon  the  velocity  of  rotation  and  upon  the  direction 
of  the  currents  of  internal  heat.30  The  figure  of  the  com- 
pressed terrestrial  spheroid  is  further  dependent  upon  the 
law,  according  to  which  density  increases  in  concentric 
superimposed  non-homogeneous  strata.  The  first  or  experi- 
mental, and  therefore  the  more  certain  portion  of  the  in- 
vestigation to  which  we  shall  limit  ourselves  in  the  present 
place,  throws  light  only  upon  the  accessible  crust  of  the 
earth,  which  is  of  very  inconsiderable  thickness,  whilst  the 

-9  See  Petit  sur  la  latitude  de  I' Observatoire  de  Toulouse,^  la  density 
moyenne  de  la  cliaine  des  Pyrenees,  et  la  probabilite  quil  existe  un  vide 
sous  cette  cliaine,  in  the  Comptes  rendus  de  I'Acad.  des  Sc.,  t.  xxix,  1849, 
p.  730. 

80  Cosmos,  vol.  i,  p.  1 69. 


THE   HEAT   OF  THE   EARTH.  35 

second  or  mathematical  part,  in  accordance  with  the  nature 
of  its  applications,  yields  rather  negative  than  positive  results. 
This  method  of  enquiry,  which  possesses  all  the  charm  of 
ingenious  and  intellectual  combinations  of  thought,31  leads 
to  problems,  which  cannot  be  wholly  overlooked  when  we 
touch  upon  conjectures  regarding  the  origin  of  volcanic 
forces,  and  the  reaction  of  the  fused  interior  upon  the  solid 
external  crust  of  our  earth.  Plato's  geognostic  myth  of 
the  Pyriphlegethon,32  as  the  origin  of  all  thermic  springs  as 
well  as  of  volcanic  igneous  currents,  emanated  from  the  early 
and  generally  felt  requirement  of  discovering  some  common* 
?ause  for  a  great  and  complicated  series  of  phenomena. 

Amid  the  multiplicity  of  relations  presented  by  the 
earth's  surface,  in  respect  to  insolation  (solar  action)  and 
its  capacity  of  radiating  heat,  and  amid  the  great  differences 
in  the  capacity  for  conducting  heat,  which  varies  in  ac- 
cordance with  the  composition  and  density  of  hetero- 
geneous rocks,  it  is  worthy  of  notice,  that  wherever  the 
observations  have  been  conducted  with  care,  and  under 
favourable  circumstances,  the  increase  of  the  temperature 
with  the  depth  has  been  found  to  present  for  the  most  part 
very  closely  coinciding  results,  even  at  very  different  lo- 
calities. For  very  great  depths  we  obtain  the  most  certain 
results  from  Artesian  wells,  especially  when  they  are  filled 
with  fluids  that  have  been  rendered  turbid  by  the  admixture 
of  clay,  and  are  therefore  less  favourable  to  the  passage  of 
internal  currents,  and  when  they  do  not  receive  many  lateral 
affluents  flowing  into  them  at  different  elevations  through 
transverse  fissures.  On  account  of  their  depth,  we  will 
begin  with  two  of  the  most  remarkable  Artesian  wells, 
namely  that  of  Grenelle,  near  Paris,  and  that  of  the  New 
Salt  Works  at  Oeynhausen,  near  Minden.  We  will  proceed 
in  the  following  paragraph  to  give  some  of  the  most  accurate 
results  which  they  have  yielded. 

According  to  the  ingenious  measurements  of  Walferdin,38 

31  Hopkins,  Physical  Geology,  in  the  Report  of  the  British  Association 
for  1838,  p.  92;  Philos.  Transact.,  1839,  pt.  ii,  p.  381,  and  1840,  pt.  i, 
p.  193;  Hennessey  (Terrestrial  Physics)  in  the  Philos.  Transact.,  1851, 
pt.  ii,  pp.  504—525. 

3-3  Cosmos,  vol.  i,  p.  235. 

33  The  observations  of  Walferdin  were  made  in  the  autumn  of  1847, 
and  deviate  very  slightly  from  the  results  obtained  with  the  same  appa« 

D  2 


36  COSMOS. 

to  whom  we  are  indebted  for  a  complete  series  of  very  deli 
cate  apparatus  for  determinations  of  temperature  at  great 
dfpths  in  the  sea  and  in  springs,  the  surface  of  the  basin 
of  the  well  at  Grenelle  lies  at  an  elevation  of  36.24  metres 
or  119  feet  above  the  level  of  the  sea.  The  upper  outlet 
of  the  ascending  spring  is  33.33  metres  or  109.3  feet  higher. 
This  total  elevation  of  the  ascending  water  (69.57  metres  or 
228.2  feet)  is,  when  compared  with  the  level  of  the  sea  about 
196'8  feet  lower  than  the  outbreak  of  the  green  sandstone 
strata  in  the  hills  near  Lusigny,  south-east  of  Paris,  to 
whose  infiltrations  the  rise  of  the  waters  in  the  Artesian 
wells  at  C  i:enelle  have  been  ascribed.  The  borings  extend 
to  a  depth  of  547  metres  or  1794.6  feet  below  the  base  of 
the  Grenelle  basin,  or  about  510.76  metres  or  1675  feet 
below  the  level  of  the  sea ;  the  waters  consequently  rise  to  a 
total  height  of  580.33  metres  or  1904  feet.  The  tempe- 
rature of  the  spring  is  8l°.95  F. ;  consequently  the  increase 
of  heat  marks  1°  F.  for  about  every  59  feet. 

The  boring  at  the  New  Salt  Works  at  Eehme  is  situated 
231  feet  above  the  level  of  the  sea  (above  the  watermark  at 
Amsterdam).  It  has  penetrated  to  an  absolute  depth  of  2281 
feet  below  the  surface  of  the  earth,  measuring  from  the  point 
M  here  the  operations  were  begun.  The  salt  spring  which, 
when  it  bursts  forth,  is  impregnated  with  a  large  quantity 
of  carbonic  acid,  lies  therefore  2052  feet  below  the  level  of 
the  sea,  a  relative  depth  which  is  perhaps  the  greatest  that 
has  ever  been  reached  by  man  in  the  interior  of  the  earth. 
The  temperature  of  the  salt  spring  at  the  New  Salt  Works 
of  Oeynhausen  is  91°  04  F.,  and  as  the  mean  annual  tem- 
perature of  the  air  at  these  works  is  about  49°. 3  F.,  we 
may  assume  that  there  is  an  increase  of  temperature  of 
1°  F.  for  every  54.68  feet.  The  boring  at  these  Salt  Works34 
is  therefore  491  feet  absolutelv  deeper  than  the  boring  at 

ratus,  by  Arago,  in  1840,  at  a  depth  of  1657  feet,  when  the  borer  had 
left  the  chalk  and  was  beginning  to  penetrate  through  the  gault.  See 
Cosmos,  vol.  i,  p.  167,  and  Comptes  rendus,  t.  xi,  1840,  p.  707. 

34  According  to  the  manuscript  results  given  by  the  superintendent 
of  the  mines  of  Oeynhausen.  See  Cosmos,  vol.  i,  pp.  148,  166  ;  and 
Bischof,  Lehrbuch  der  Chem.  und  Phys  Geologic,  Bd.  i,  Abth.  1,  s.  154 
— 163.  In  regard  to  absolute  depth,  the  borings  at  Mondorf,  in  the 
Grand  Duchy  of  Luxemburg  (2202  feet),  approach  most  nearly  to  those 
at  the  new  salt  works  at  Oeynhauseu. 


INTERNAL  HEAT  OP  THE  EARTH.  37 

Grenelle  ;  it  sinks  377  feet  deeper  below  the  surface  of  the 
sea,  and  the  temperature  of  its  waters  is  9°.  18  F.  higher. 
The  increase  of  the  heat  at  Paris,  is  about  1°  F.  for  59 
feet,  and  therefore  scarcely  T]7th  greater.  I  have  already  else- 
where drawn  attention  to  the  fact  that  a  similar  result  was 
obtained  by  Auguste  de  la  Rive  and  Marcet,  at  Bregny,  near 
Geneva,  in  investigating  a  boring  which  was  only  725  feet 
in  depth,  although  it  was  situated  at  an  elevation  of  more 
than  1600  feet  above  the  Mediterranean  Sea.35 

If  to  these  three  springs,  which  possess  an  absolute  depth 
varying  between  725  feet  and  2285  feet,  we  add  another,  that 
of  Monkwearmouth,  near  Newcastle,  (the  water  rising 
through  a  coal  mine  which,  according  to  Phillips  is  worked 
at  a  depth  of  1496  feet  below  the  level  of  the  sea,)  we 
shall  find  this  remarkable  result,  that  at  four  places  widely 
separated  from  one  another  an  increase  of  heat  of  1°  F. 
varies  only  between  54  and  58.6  feet;36  such  a  coincidence 
in  the  results  cannot,  however,  be  always  expected  to  occur 
when  we  consider  the  nature  of  the  means  which  are  em- 
ployed for  determining  the  internal  heat  of  the  earth  at 
definite  depths.  Although  we  may  assume  that  the  water 
which  is  infiltrated  in  elevated  positions  through  hydrostatic 
pressure  as  in  connected  tubes,  may  influence  the  rising  of 
springs  at  points  of  great  depth,  and  that  the  subterranean 

35  Cosmos,  vol.  i,  p.  166,  and  Memoires  de  la  Societe  d'ffist.  Naturelle  de 
Geneve,  t.  vi,  1833,  p.  243.      The  comparison  of  a  number  of  Artesian 
wells  in  the  neighbourhood  of  Lille,  with  those  of   Saint  Ouen  and 
Geneva  would,  indeed,  lead  us  to  assume,  if  we  were  quite  certain  as  to 
the  accuracy  of  the  numerical  data,  that  the  different  conductive  powers 
of   terrestrial  and  rocky  strata  exert  a  more  considerable   influence 
than  has  generally  been  supposed  (Poisson,  Theorie  Matliematlgue  de 
la  Chaleur,  p.  421). 

36  In  a  table  of  foxirteen  borings,  which  were  more  than  one  hundred 
yards  in  depth,  and  which  were  situated  in  various  parts  of  France, 
Bravais,  in  his  very  instructive  encyclopaedic  memoir  in  the  Patria, 
1847,  p.  145,  indicates  nine  in  which  an  increase  of  temperature  of 
1°  F.  is  found  to  occur  for  every  50 — 70  feet  of  depth,  which  would 
give  a  deviation  of  about  10  feet  in  either  direction  from  the  mean 
value  given  in  the  text.    See  also  Magnus  in  Poggen.  Ann.  Bd.  xxii,  1831, 
B.  146.     It  would  appear,  on  the  whole,  that  the  increase  of  tempera- 
ture is  most  rapid  in  Artesian  wells  of  very  inconsiderable    depth, 
although  the  very  deep  wells  of  Monte  Massi  in  Tuscany,  and  Neuffen 
on  the  north-west  part  of  the  Swabian  Alps,  present  a  remarkable  ex- 
ception to  this  rule. 


38  COSMOS. 

waters  acquire  the  temperature  of  the  terrestrial  strata  with 
which  they  are  brought  in  contact,  the  water  that  is  ob- 
tained through  borings  may,  in  certain  cases,  when  communi- 
cating with  vertically  descending  fissures,  obtain  some  aug- 
mentation of  heat  from  an  inaccessible  depth.  An  influence 
of  this  kind,  which  is  very  different  from  that  of  the  varying 
conductive  power  of  different  rocks,  may  occur  at  individual 
points  widely  distant  from  the  original  boring.  It  is  pro- 
bable that  the  waters  in  the  interior  of  our  earth  move  in 
some  cases  within  limited  spaces,  flowing  either  in  streams 
through  fissures  (on  which  account  it  is  not  unusual  to  find 
that  a  few  only  of  a  large  number  of  contiguous  borings  prove 
successful),  or  else  follow  a  horizontal  direction,  and  thus  form 
extensive  basins — a  relation  which  greatly  favours  the  labour 
of  boring,  and  in  some  rare  cases  betrays,  by  the  presence  of 
eels,  mussels,  or  vegetable  remains,  a  connection  with  the 
earth's  surface.  Although  from  the  causes  which  we  have 
already  indicated,  the  ascending  springs  are  sometimes 
warmer  than  the  slight  depth  of  the  boring  would  lead 
us  to  anticipate,  the  afflux  of  colder  water  which  flows 
laterally  through  transverse  fissures  leads  to  an  opposite 
result. 

It  has  already  been  observed  that  points  situated  on  the 
same  vertical  line  at  an  inconsiderable  depth  within  the 
interior  of  our  earth,  experience  at  very  different  times 
the  maximum  and  minimum  of  atmospheric  temperature, 
which  is  modified  by  the  sun's  place,  and  by  the  seasons  of 
the  year.  According  to  the  very  accurate  observations  of 
Quetelet,  daily  variations  of  temperature  are  not  percep- 
tible at  depths  of  3fths  feet  below  the  surface  ;37  and  at 
"Brussels,  the  highest  temperature  was  not  indicated  until 
Jie  10th  of  December  in  a  thermometer  which  had  been 
Hunk  to  a  depth  of  more  than  25  feet,  whilst  the  lowest  tem- 
perature was  observed  on  the  15th  of  June.  In  like  manner, 
in  the  admirable  experiments  made  by  Professor  Forbes,  in 
the  neighbourhood  of  Edinburgh,  on  the  conductive  power  of 
different  rocks,  the  maximum  of  heat  was  not  observed  until 
the  8th  of  January  in  the  basaltic  trap  of  Calton  Hill  at 
a  depth  of  24  feet  below  the  surface.38  It  would  appear 

#  Quetelet,  in  the  Bulletin  de  I'Acad.  de  Bruxelles,  1836,  p.  75. 

38  Forbes,  Exper.  on  the  temperature  of  the  earth  at  different  depth* 


INVARIABLE  TEMPERATURE.  39 

from  the  observations  which  were  carried  on  for  many 
years  by  Arago  in  the  garden  of  the  Paris  Observatory,  that 
very  small  differences  of  temperature  were  perceptible  30 
feet  below  the  surface.  Bravais  calculated  one  degree  for 
about  every  50  feet  on  the  high  northern  latitude  of  Bosse- 
kop,  in  Finmark  (69°  58'  JS.  L.).  The  difference  between 
the  highest  and  lowest  annual  temperature  diminishes  in 
proportion  with  the  depth,  and  according  to  Fourrier  this 
difference  diminishes  in  a  geometrical  proportion  as  the 
depth  increases  in  an  arithmetical  ratio. 

The  stratum  of  invariable  temperature  depends,  in  respect 
to  its  depth,  conjointly  upon  the  latitude  of  the  place, 
the  conductive  power  of  the  surrounding  strata  and  the 
amount  of  difference  of  temperature  between  the  hottest 
and  the  coldest  seasons  of  the  year.  In  the  latitude 
of  Paris  (48°  50')  the  depth  and  temperature  of  the  Caves 
de  rObservatoire  (86  feet  and  53°.30  F.)  are  usually  re- 
garded as  affording  the  amount  of  depth  and  temperature 
of  the  invariable  stratum.  Since  Cassini  and  Legentil  in 
1783  placed  a  very  correct  mercurial  thermometer  in 
these  subterranean  caves,  which  are  portions  of  old  stone 
quarries,  the  mercury  in  the  tube  has  risen  about  0°.4.39 
Whether  the  cause  of  this  rising  is  to  be  ascribed  to  an 
accidental  alteration  in  the  thermometrical  scale  which, 
however,  was  adjusted  by  Arago  in  1817  with  his  usual 
care,  or  whether  it  indicates  an  actual  increase  of  heat  is 
still  undecided.  The  mean  temperature  of  the  air  at  Paris 
is  51°. 478  F.  Bravais  is  of  opinion  that  the  thermometer 
in  the  Caves  de  V  Observatoire  stands  below  the  limit  cf 
invariable  temperature,  although  Cassini  believes  that  he 
has  found  a  difference  of  TVotfts  °f  a  degree  (Fahr.)  between 
the  winter  and  summer  temperature,  the  higher  tempe- 

in  the  Trans,  of  the  Royal  Soc.  of  Edinburgh,  vol.  xvi,  1849,  pt.  ii, 
p.  189. 

39  All  numbers  refeiTing  to  the  temperature  of  the  Caves  de  V  Obser- 
vatoire have  been  taken  from  the  work  of  Poisson,  Theorie  Mathema- 
tique  de  la  Chaleur,  pp.  415  and  462.  The  Annuaire  Meteoroloyique  de  la 
France,  edited  by  Martins  and  Haeghens,  1849,  p.  88,  contains  correc- 
tions by  Gay-Cussac  for  Lavoisier's  subterranean  thermometer.  The 
mean  of  three  readings,  from  June  till  August,  was  5 3°. 9 5  F.  for 
this  thermometer,  at  a  time  when  Gay-Lussac  found  the  temperature 
to  be  53°.32,  which  was  therefore  a  difference  of  0°.63. 


40  COSMOS. 

rature  being  found  to  prevail  in  the  winter.40  If  we  now 
take  the  mean  of  many  observations  of  the  temperature 
of  the  soil  between  the  parallels  of  Zurich  (47°  22')  and 
Upsala  (59°  51'),  we  obtain  an  increase  of  1°  F.  for  every 
40  feet.  Differences  of  latitude  cannot  produce  a  difference 
of  more  than  12  or  15  feet,  which  is  not  marked  by  any 
regular  alteration  from  south  to  north,  because  the  influence 
which  the  latitude  undoubtedly  exerts,  is  masked  within 
these  narrow  limits  by  the  influence  of  the  conductive 
power  of  the  soil,  and  by  errors  of  observation. 

As  the  terrestrial  stratum  in  which  we  first  cease  to  ob- 
serve any  alteration  of  temperature  through  the  whole  year 
lies,  according  to  the  theory  of  the  distribution  of  heat,  so 
much  the  nearer  the  surface,  as  the  maxima  and  minima  of 
the  mean  annual  temperature  approximate  to  one  another,  a 
consideration  of  this  subject  has  led  my  friend  Boussingault 
to  the  ingenious  and  convenient  method  of  determining  the 
mean  temperature  of  a  place  within  the  tropical  regions 
(especially  between  10  degrees  north  and  south  of  the 
equator)  by  observing  a  thermometer  which  has  been  baried 
8  or  12  inches  below  the  surface  of  the  soil  in  some  well 
protected  spot.  At  different  hours  and  different  months  of 
the  year,  as  in  the  experiments  of  Captain  Hall  near  the 
coast  of  the  Choco  in  Tumaco,  those  at  Salaza  in  Quito,  and 
those  of  Boussingault  in  la  Vega  de  Zupia,  Marmato,  and 
Anserina  Nuevo  in  the  Cauca  valley,  the  temperature 
scarcely  varied  one-tenth  of  a  degree ;  and  almost  within 
the  same  limits  it  was  identical  with  the  mean  temperature 
of  the  air  at  those  places  in  which  it  had  been  determined 
by  horary  observations.  It  was,  moreover,  very  remarkable 
that  this  identity  remained  perfectly  uniform,  whether  the 
thermcmetric  soundings  (of  less  than  one  foot  in  depth) 
were  made  on  the  torrid  shores  of  Guayaquil  and  Payta,  on 
the  Pacific,  or  in  an  Indian  village  on  the  side  of  the  volcano 
of  Pm-ace,  which  I  found  from  my  barometrical  measure- 
ments to  be  situated  at  an  elevation  of  1356  toises,  or  8671 
feet  above  the  sea.  The  mean  temperatures  differed  by 
fully  25°  F.  at  these  different  stations.41 

40  Cassini,  in  the  Mem.  de  TAcad.  des  Sciences,  1786,  p.  511. 

41  Boussingault,  sur  la  profondeur  a  laquelle  on  trouve  dans  la  zone 
torrlde  la  couciie  de  temperature  invariable,  iu  tb.e  Annales  de  Chimie  et 


INVARIABLE  STRATUM.  41 

I  believe  that  special  attentioD  is  due  to  two  observations 
which  I  made  on  the  mountains  of  Peru  and  Mexico,  in 
mines  which  lie  at  a  greater  elevation  than  the  summit  of 
the  Peak  of  Teneriffe,  and  are  therefore  the  highest  in  which 
a  thermometer  has  ever  been  placed.  At  a  height  of 
between  1 2,000  and  18,000  feet  above  the  level  of  the  sea 
I  found  the  subterranean  air  25°  F.  warmer  than  the 
external  atmosphere.  Thus,  for  instance,  the  little  Peruvian 
town  of  Micuipampa42  lies,  according  to  my  astronomical 
and  hypsometrical  observations,  in  the  latitude  6°  43'  S., 
and  at  an  elevation  of  1857  toises  or  11,990  feet,  at  the 
base  of  Cerro  de  Gualgayoc,  celebrated  for  the  richness  of 
its  silver  mines.  The  summit  of  this  almost  isolated 
fortress-like  and  picturesquely  situated  mountain  rises  240 
toises  or  1504  feet  higher  than  the  streets  of  Micuipampa  ; 
the  external  air  at  a  distance  from  the  mouth  of  the  pit  of 

de  Physique,  t.  liii,  1833,  pp.  225—247.  Objections  have  been  advanced 
by  John  Caldecott,  the  astronomer  to  the  Rajah  of  Travaucore,  and  by 
Captain  Newbold,  in  India,  against  the  method  recommended  in  this 
memoir,  although  it  has  been  employed  in  South  America  in  many 
very  accurate  experiments.  Caldecott  found  at  Trevandrum  (Edin. 
Transact,  vol.  xvi,  part  in,  pp.  379 — 393),  that  the  temperature  of  the 
soil  at  a  depth  of  three  feet  and  more  below  the  surface,  (and  therefore 
deeper  than  Boussingault's  calculation,)  was  85°  and  86°  F.,  while  the 
mean  temperature  of  the  air  was  80°.02.  Newbold's  experiments  (Philos. 
Transact,  for  the  year  1845,  pt.  i,  p.  133),  which  were  made  at  Bellary, 
lat.  15°  5',  showed  an  increase  of  temperature  of  4°  F.  between  sunrise 
and  2  p.m.  for  one  foot  of  depth,  but  at  Cassargode,  lat.  12°  29',  there 
was  only  an  increase  of  1°.30  F.,  under  a  cloudy  sky.  Is  it  quite  cer- 
tain that  the  thermometer  in  this  case  was  sufficiently  covered  to  pro- 
tect it  from  the  influence  of  the  sun's  rays?  Compare  also  Forbes, 
E.cper.  on  the  Temp,  of  the  Earth  at  different  depths,  in  the  Edin.  Tran- 
sact, vol.  xvi,  part  ii,  p.  189.  Colonel  A.  Costa,  the  admirable  historian 
of  New  Granada,  has  made  a  prolonged  series  of  observations,  which 
fully  confirm  Boussingault's  statement,  and  which  were  completed, 
about  a  year  ago,  at  Guadua,  on  the  south-western  side  of  the  elevated 
plateau  of  Bogota,  where  the  mean  annual  temperature  is  43°.94  F.  at 
the  depth  of  one  foot,  and  at  a  carefully  protected  spot.  Boussingault 
thus  refers  to  these  experiments: — "The  observations  of  Colonel  A. 
Costa,  whose  extreme  precision  in  everything  which  is  connected  with 
meteorology  is  well  known  to  you,  prove  that  when  fully  sheltered  from 
all  disturbing  influences,  the  temperature  within  the  tropics  remains 
constant  at  a  very  small  depth  below  the  surface." 

4-  In  reference  to  Gualgayoc  (or  Minas  de  Chota)  and  Micuipampa, 
see  Humboldt,  Recueil  d'Observ.  Astron.  vol.  i,  p.  324. 


42  COSMOS. 

the  Mina  del  Purgatorio  was  42°.26  F.,  but  in  the  interior 
of  the  mine,  which  lies  more  than  2057  toises,  or  13,154  feet 
above  the  sea,  I  saw  that  the  thermometer  everywhere  indi- 
cated a  temperature  of  67°.64  F.,  there  being  thus  a  differ- 
ence of  25°. 38  F.  The  limestone  rock  was  here  perfectly 
dry,  and  very  few  men  were  working  in  the  mine.  In  the 
Mina  de  Guadalupe,  which  lies  at  the  same  elevation,  I 
found  that  the  temperature  of  the  internal  .air  was  57°.9  F., 
showing  therefore  a  difference  of  15°. 6 4  F.  when  compared 
with  the  external  air.  The  water  which  flowed  out  from 
the  very  damp  mine  stood  at  52°.34  F.  The  mean  annual 
temperature  of  Micuipampa  is  probably  not  more  than 
45°.  8  F.  Iii  Mexico,  in  the  rich  silver  mines  of  Guanaxuato,*3 
I  found  in  the  Mina  de  Valenciana  the  external  temperature 
in  the  neighbourhood  of  the  Tiro  Nuevo  (which  is  7590  feet 
above  the  sea)  70°.  16  F.,  and  the  air  in  the  deepest  mines,  for 
instance  in  the  Planes  de  San  Bernardo,  1630  feet  below  the 
opening  of  the  shaft  of  Tiro  Nuevo,  fully  80°. 6  F.,  which  is 
about  the  mean  temperature  of  the  littoral  region  of  the 
Gulf  of  Mexico.  At  a  point  147  feet  higher  than  the 
mouth  of  the  Planes  de  San  Bernardo,  a  spring  of  water 
issues  from  the  transverse  rock,  in  which  the  temperature  is 
84°.74  F.  I  determined  the  latitude  of  the  mountain  town 
of  Guanaxuato  to  be  21°  0'  1ST.,  with  a  mean  annual  tem- 
perature varying  between  60°.44  and  61°. 26  F.  The  present 
is  not  a  fitting  place  in  which  to  advance  conjectures,  which 
it  might  be  difficult  to  establish  in  relation  to  the  causes  of 
probably  an  entirely  local  rise  of  the  subterranean  tempera- 
ture at  mountain  elevations,  varying  from  6000  to  more 
than  12,000  feet. 

A  remarkable  contrast  is  exhibited  in  the  steppes  of  Nor- 
thern Asia,  by  the  conditions  of  the  frozen  soil,  whose  very 
existence  was  doubted,  notwithstanding  the  early  testimony 
of  Gmelin  and  Pallas.  It  is  only  in  recent  times  that  cor- 
rect views  in  relation  to  the  distribution  and  thickness  of 
the  stratum  of  subterranean  ice  have  been  established  by 
means  of  the  admirable  investigations  of  Erman,  Baer,  and 
Middendorff.  In  accordance  with  the  descriptions  given  of 
Greenland  by  Cranz,  of  Spitzbergen  by  Martens  and  Phipps, 

43  Essai  Polit.  sur  k  Roy.  de  la  Nouv.  Espagne  (2&me  ed.,  t.  iii, 
P.  201). 


THE   FROZEN   SOIL.  43 

and  of  the  coasts  of  the  sea  of  Kara  by  Sujew,  the  whole  of  the 
most  northern  part  of  Siberia  was  described  by  too  hasty  a 
generalization  as  entirely  devoid  of  vegetation,  always  frozen 
on  the  surface,  and  covered  with  perpetual  snow,  even  in  the 
plains.  The  extreme  limit  of  vegetation  in  Northern  Asia 
is  not,  as  was  long  assumed,  in  the  parallel  of  67°,  although 
sea  -winds  and  the  neighbourhood  of  the  Bay  of  Obi  make 
this  estimate  true  for  Obdorsk ;  for  in  the  valley  of  the 
great  River  Lena,  high  trees  grow  as  far  north  as  the  lati- 
tude of  71°.  Even  in  the  desolate  islands  of  New  Siberia, 
large  herds  of  reindeer  and  countless  lemmings  find  an 
adequate  nourishment.**  MiddendorfFs  two  Siberian  expe- 
ditions, which  are  distinguished  by  a  spirit  of  keen  observa- 
tion, adventurous  daring,  and  the  greatest  perseverance  in  a 
laborious  undertaking,  were  extended  from  the  year  1843  to 
1846  as  far  north  as  the  Taymir  land  in  75°  45'  lat.,  and 
south-east  as  far  as  the  Upper  Amoor  and  the  Sea  of  Ocbotsk. 
The  former  of  these  perilous  undertakings  led  the  learned 
investigator  into  a  hitherto  unvisited  region,  whose  explora- 
tion was  the  more  important  in  consequence  of  its  being 
situated  at  equal  distances  from  the  eastern  and  western 
coasts  of  the  old  Continent.  In  addition  to  the  distribution 
of  organisms  in  high  northern  latitudes,  as  depending  mainly 
upon  climatic  relations,  it  was  directed  by  the  St.  Peters- 
burgh  Academy  of  Sciences  that  the  accurate  determination 
of  the  temperature  of  the  ground  and  of  the  thickness  of  the 
subterranean  frozen  soil  should  be  made  the  principal  objects 
of  the  expedition.  Observations  were  made  in  borings  and 
mines  at  a  depth  of  from  20  to  60  feet  at  more  than  twelve 
points  (near  Turuchansk,  on  the  Jenisei,  and  on  the  Lena)  at 
relative  distances  of  from  1600  to  2000  geographical  miles. 

The  most  important  seat  of  these  geothermic  observations 
was    however   Schergin's  shaft  at  Jakutsk  62°  2'  N.  lat.45 

44  E.  von  Baer,  in  MiddendorfFs  Reise  in  Sib.,  Bd.  i,  s.  vii. 

45  The  merchant  Fedor  Schergin,  cashier  to  the  Russian- American 
Trading  Company,  began,  in  the  year  1828,  to  dig  a  well  in  the  court- 
yard of  a  house  belonging  to  the  company.     As  he  had  only  found 
frozen  earth  and  no  water  at  the  depth  of  90  feet,  which  he  reached  in 
1830,  he  determined  to  give  up  the  attempt,  until  Admiral  Wrangel, 
who  passed  through  Jakutsk  on  his  way  to  Sitcha,  in  Russian  America, 
and  who  saw  how  interesting  it  would  be,  in  a  scientific  point  of  view, 
to  penetrate  through  this  subterranean  stratum  of  ice,  induced  Schergin 


44  COSMOS. 

Here  a  subterranean  stratum  of  ice  was  pierced  to  a  depth 
of  more  than  382  feet.  The  thermometer  was  sunk  at 
eleven  points  along  the  lateral  walls  of  the  shaft  between 
the  surface  and  the  greatest  depth,  which  was  reached  in 
1837.  The  observer  was  obliged  to  be  let  down  standing  in 
a  bucket,  with  one  arm  fastened  to  a  rope,  while  he  read  off 
the  thermometric  scale.  The  series  of  observations,  whose 
mean  error  does  not  amount  to  more  than  0°.  45  F.  embrace 
the  interval  between  April  1844  and  June  1846.  The 
decrease  of  cold  was  not  proportional  to  the  depth  at  indi- 
vidual points,  but  nevertheless  the  following  results  were 
obtained  for  the  total  increase  of  the  mean  temperatures  for 
the  different  superimposed  frozen  strata  : — 

50  feet  -        -                  17°.13F. 

100    „  -        -                 20°.26  „ 

150    „  21°.43  „ 

200    „  23°.27  „ 

250    „  24°.49  „ 

382    „  26°.60  „ 

After  a  very  careful  consideration  of  all  these  observations, 
Middendorff  determined  the  general  increase  of  tempera- 
ture to  be  1°  F.  for  eveiy  space  varying  from  44°.5  to  52 
feet.46  This  result  shows  a  more  rapid  increase  of  heat  in 

to  continue  the  boring  ;  and,  up  to  1837,  although  an  opening  had 
been  made  to  a  depth  of  382  feet  below  the  surface,  it  had  not  pene- 
trated beyond  the  ice. 

46  Middendorff,  Reise  in  Sib.  Bd.  i,  s.  125 — 133.  "If  we  exclude," 
says  Middendorff,  "those  depths  which  did  not  quite  reach  100  feet, 
on  the  ground  that  they  were  influenced  by  annual  deviations  of  tem- 
perature, as  was  determined  by  experiments  previously  made  in  Siberia, 
we  shall  still  find  certain  anomalies  in  the  partial  increase  of  heat. 
Thus,  for  instance,  between  the  depths  of  150 — 200  feet  the  tempera- 
ture rises  at  a  ratio  of  1°  F.  for  only  29.3  feet,  while  between  250 — 
300  feet  the  corresponding  increase  is  96.4  feet.  We  may,  therefore, 
venture  to  assert  that  the  results  of  observations  that  have  hitherto 
been  obtained  in  Shergin's  shaft  are  by  no  means  sufficient  to  deter- 
mine with  certainty  the  amount  of  the  increase  of  temperature,  and 
that,  notwithstanding  the  great  variations  which  may  depend  upon  the 
different  conductive  powers  of  the  terrestrial  strata,  and  the  disturbing 
influence  of  the  air  or  water  which  enters  from  above,  an  increase  of 
1°  F.  occurs  for  every  44 — 52  feet.  The  result  of  52  feet  is  the  mean  of 
BI'X  partial  increases  of  temperature,  measured  at  intervals  of  50  feet 
between  the  depths  of  100  and  882  feet.  On  comparing  the  mean 


THE   TEMPE^iJLt'eARTH.  45 


Schergin's  shaft  than  has  been  obtained  from  different  bor- 
ings in  Central  Europe,  whose  results  approximate  closely  to 
one  another  (see  p.  37).  The  difference  fluctuates  between 
i-th  and  -|th.  The  mean  annual  temperature  of  Jakutsk  was 
determined  at  13°.7  F.  The  oscillation  between  the  summer 
and  winter  temperature  is  so  great,  according  to  Newerow's 
observations,  which  were  continued  for  fifteen  years  (from 
1829  to  1844),  that  sometimes  for  fourteen  days  consecutively 
in  July  and  August,  the  atmospheric  temperature  rises  as 
high  as  77,°  or  even  84°.6  F.,  while  during  120  consecutive 
winter  days  from  November  to  February,  the  cold  falls  to 
between  —  42°.  3  F.  and  —  69°  F.  In  estimating  the  increase 
of  temperature  which  was  found  on  boring  through  the 
frozen  soil,  we  must  take  into  account  the  depth  below  the 

annual  temperature  of  Jakutsk  13°.71  F.  with  that  which  was  found 
from  observation  to  be  the  mean  temperature  of  the  ice  (26°.6)  at  the 
greatest  depth  of  the  mine  (382  feet),  I  find  29.6  feet  for  every  increase 
of  1°  F.  A  comparison  of  the  temperature  at  the  deepest  part  with 
that  at  a  depth  of  100  feet  would  give  44.4  feet  for  this  increase.  From 
the  acute  investigations  of  Middendorff  and  Peters  in  reference  to  the 
velocity  of  transmission  of  changes  of  atmospheric  temperature,  in- 
cluding the  maxima  of  cold  and  heat  (Middend.  s.  133—157,  163—175), 
it  follows  that  in  the  different  borings  which  do  not  exceed  the  in- 
considerable depth  of  from  8  to  20  feet,  "  the  temperature  rises  from 
March  to  October,  and  falls  from  November  to  April,  because  the 
spring  and  autumn  are  the  seasons  of  the  year  in  which  the  changes  of 
atmospheric  temperature  are  most  considerable"  (s.  142  —  145).  Even 
carefully  covered  mines  in  Northern  Siberia  become  gradually  cooled, 
in  consequence  of  the  walls  of  the  shafts  having  been  for  years  in  con- 
tact with  the  air;  this  cause,  however,  has  only  made  the  temperature 
fall  about  1°  F.  in  Schergin's  shaft,  in  the  course  of  eighteen  years. 
A  remarkable  and  hitherto  unexplained  phenomenon,  which  has  also 
presented  itself  in  the  Schergin  shaft,  is  the  warmth  occasionally  ob- 
served in  the  winter,  although  only  at  the  lowest  strata,  without  any 
appreciable  influence  from  without  (s.  156  —  178).  It  seems  still  more 
striking  to  me,  that  in  the  borings  at  Wedeusk,  on  the  Pasina,  when 
the  atmospheric  temperature  is  —  31°  F.  it  should  be  26°.  -4  at  the 
inconsiderable  depth  of  5  or  10  feet  !  The  isogeothermal  lines,  whose 
direction  was  first  pointed  out  by  Kupffer,  in  his  admirable  in- 
vestigations (Cosmos,  vol.  i,  p.  216)  will  long  continue  to  present  prob- 
lems that  we  are  unable  to  solve.  The  solution  of  these  problems  is 
more  e-pecially  difficult  in  those  cases  in  which  the  complete  perfora- 
tion of  the  frozen  soil  is  a  work  of  considerable  time;  we  can,  however, 
no  longer  regard  the  frozen  soil  at  Jakutsk  as  a  merely  local  pheno- 
menon, which,  in  accordance  with  Slobin's  view,  is  produced  by  the 
terrestrial  strata  deposited  from  water  (Middend.  s.  167). 


46  COSMOS. 

surface  at  which  the  ice  exhibits  the  temperature  of  32°  F., 
and  which  is  consequently  the  nearest  to  the  lower  limit  of 
the  frozen  soil ;  according  to  MiddendorfTs  results  which 
entirely  agree  with  those  that  had  been  obtained  much  earlier 
by  Erman,  this  point  was  found  in  Schergin's  shaft  to  be  652, 
or  684  feet  below  the  surface.  It  would  appear,  however, 
from  the  increase  of  temperature  which  was  observed  in  the 
mines  of  Mangan,  Shilow  and  Dawydow,  which  are  situated 
at  about  three  or  four  miles  from  Irkutsk,  in  the  chain  of 
hills  on  the  left  bank  of  the  Lena,  and  which  are  scarcely 
more  than  60  feet  in  depth,  that  the  normal  stratum  of  perpe- 
tual frost  seems  to  be  situated  at  320  feet  below  the  surface.47 
Is  this  inequality  only  apparent  in  consequence  of  the  un- 
certainty which  attaches  to  a  numerical  determination,  based 
on  so  inconsiderable  a  depth,  and  does  the  increase  of  tem- 
perature obey  different  laws  at  different  times  ?  Is  it 
certain  that  if  we  were  to  make  a  horizontal  section  of 
several  hundred  fathoms  from  the  deepest  part  of  Schergin's 
shaft  into  the  adjoining  country,  we  should  find  in  every 
direction  and  at  every  distance  from  the  mine  frozen  soil,  in 
which  the  thermometer  would  indicate  a  temperature  of  4°. 5 
below  the  freezing  point  ? 

Schrenk  has  examined  the  frozen  soil  in  67°  30'  N.  L.  in 
the  country  of  the  Samojedes.  In  the  neighbourhood  of 
Pustojenskoy  Gorodok,  fire  is  employed  to  facilitate  the 
sinking  of  wells,  and  in  the  middle  of  summer  ice  was  found 
at  only  5  feet  below  the  surface.  This  stratum  could  be 
traced  for  nearly  70  feet,  when  the  works  were  suddenly 
stopped.  The  inhabitants  were  able  to  sledge  over  the 
neighbouring  lake  of  Usteje  throughout  the  whole  of  the 
summer  of  1813.48  During  my  Siberian  expedition  with 
Ehrenberg  and  Gustav  Rose,  we  caused  a  boring  to  be  made 

47  Middendorff,  Bd.  i,  s.  160,  164,  179.    In  these  numerical  data  and 
conjectures  regarding  the  thickness  of  the  frozen  soil,  it  is  assumed 
that  the  temperature  increases  in  arithmetical  progression  with   the 
depth.    Whether  a  retardation  of  this  increase  occurs  in  greater  depths 
is  theoretically  uncertain,  and  hence  there  is  no  use  in  entering  upon 
deceptive  calculations  regarding  the  temperature  of  the  centre  of  the 
earth  in   the  fused   heterogeneous  rocky  masses  which  give  rise  to 
currents. 

48  Schrenk's  Reise  durck  die  Tundern  der  Samoje.den,  1848,  Th.  i, 
B.  597. 


THE   FROZEN   SOIL.  47 

in  a  piece  of  turfy  ground  near  Bogoslowsk  (59°  44'  N.  L.) 
among  the  Ural  Mountains  on  the  road  to  the  Turjin  mines.** 
We  found  pieces  of  ice  at  the  depth  of  5  feet,  which  were 
embedded,  breccia-like,  in  the  frozen  ground,  below  which 
began  a  stratum  of  thick  ice  which  we  had  not  penetrated 
at  the  depth  of  10  feet. 

The  geographical  extension  of  the  frozen  ground,  that  is  to 
say,  the  limits  within  which  ice  and  frozen  earth  are  found 
at  a  certain  depth,  even  in  the  month  of  August,  and  con- 
sequently throughout  the  whole  year,  in  the  most  northern 
parts  of  the  Scandinavian  peninsula,  as  far  east  as  the  coasts 
of  Asia,  depends,  according  to  Middendorff' s  acute  obser- 
vations (like  all  geothermal  relations)  more  upon  local 
influences  than  upon  the  temperature  of  the  atmosphere. 
The  influence  of  the  latter  is  on  the  whole,  no  doubt,  stronger 
than  any  other,  but  the  isogeothermal  lines  are  not,  as 
Kupffer  has  remarked,  parallel  in  their  convex  and  concave 
cuives  to  climatic  isothermal  lines,  which  are  determined  by 
the  means  of  the  atmospheric  temperature.  The  infiltration 
of  Hquid  vapours  deposited  by  the  air,  the  rising  of  thermal 
springs  from  a  depth,  and  the  varying  conductive  powers  of 
the  soil,  appear  to  be  especially  active.80  "  On  the  most  nor- 
thern point  of  the  European  continent,  in  Finmark,  between 
the  high  latitudes  of  70°  and  71°,  there  is  as  yet  no  con- 
tinuous tract  of  frozen  soil.  To  the  eastward,  impinging 
upon  the  valley  of  the  Obi,  5°  south  of  the  North  Cape,  we 
find  frozen  ground  at  Obdorsk  and  Beresow.  To  the  east 
and  south-east  of  this  point,  the  cold  of  the  soil  increases, 
excepting  at  Tobolsk  on  the  Irtisch,  where  the  temperature 
of  the  soil  is  colder  than  at  Witimsk,  in  the  valley  of  the 
Lena,  which  lies  1°  farther  north.  Turuchansk  (65°  54' 
JN .  L.)  on  the  Jenisei,  is  situated  upon  an  unfrozen  soil, 
although  it  is  close  to  the  limits  of  the  ice.  The  soil  at 
Ainginsk,  south-east  of  Jakutsk,  presents  as  low  a  tempera- 
ture as  that  of  Obdorsk,  which  lies  5"  farther  north  ;  the  same 
being  the  case  with  Oleminsk  on  the  Jenisei.  From  the  Obi 
to  the  latter  river  the  curve  formed  by  the  limits  of  the 

49  Gustav  Rose,  Reise  nach.  dem  Ural,  Bd.  i,  s.  428. 

50  Compare  my  friend,  G.  von  Helmersen's  experiments  on  the  rela- 
tive conductive  powers  of  ditferent  kinds  of  rocks  (Mem.  de  I' Academic 
de  St.  Petcrsbourg :  Melanges  Physiques  et  Chimifjues,  1851,  p.  32). 


48  t          COSMOS. 

frozen  soil  seems  to  rise  a  couple  of  degrees  farther  north, 
after  which  it  intersects,  as  it  turns  southward,  the  Lena 
valley,  almost  8°  south  of  the  Jenessei.  Farther  eastward, 
this  line  again  rises  in  a  northerly  direction."61  Kupffer,  who 
has  visited  the  mines  of  I^ertshinsk,  draws  attention  to  the 
fact  that  independently  of  the  continuous  northern  mass  of 
frozen  soil,  the  phenomenon  occurs  in  an  island-like  form 
in  the  more  southern  districts,  but  in  general  it  is  entirely 
independent  of  the  limits  of  vegetation,  or  of  the  growth  of 
timber. 

It  is  a  very  considerable  advance  in  our  knowledge,  when 
we  are  able  gradually  to  arrive  at  general  and  sound  cosmical 
viows  of  the  relations  of  temperature  of  our  earth  in  the 
northern  portions  of  the  old  continent ;  and  to  recognise  the 
fact  that  under  different  meridians  the  limits  of  the  frozen 
soil  as  well  as  those  of  the  mean  annual  temperature, 
and  of  the  growth  of  trees,  are  situated  at  very  different 
latitudes ;  whence  it  is  obvious  that  continuous  currents  of 
heat  must  be  generated  in  the  interior  of  our  planet. 
Franklin  found  in  the  north-west  part  of  America  that  the 
ground  was  frozen  even  in  the  middle  of  August  at  a  depth 
of  16  inches,  while  Richardson  observed  upon  a  more  eastern 
point  of  the  coast  in  71°  12'  lat.  that  the  ice-stratum  was 
thawed  in  July  as  low  as  3  feet  beneath  the  herb-covered 
surface.  Would  that  scientific  travellers  would  afford  us 
more  general  information  regarding  the  geothermal  relations 
in  this  part  of  the  earth  and  in  the  southern  hemisphere ! 
An  insight  into  the  connection  of  phenomena  is  the  most 
certain  means  of  leading  us  to  the  causes  of  apparently  in- 
volved anomalies,  and  to  the  comprehension  of  that  which 
we  are  apt  too  hastily  to  regard  as  at  variance  with  normal 
laws. 

31  Middendorff,  Bd.  i,  s.  166.  Compare  also  s.  179.  "The  curve  re- 
presenting the  commencement  of  the  freezing  of  the  soil  in  Northern 
Asia  exhibits  two  convexities,  inclining  southwards,  one  on  the  Obi, 
which  is  very  inconsiderable,  and  the  other  on  the  Lena,  which  is  much 
more  strongly  marked.  The  limit  of  the  frozen  soil  passes  from  Ber- 
resow  on  the  Obi,  towards  Turuchansk  on  the  Jenisei,  it  then  runs 
between  Witirnsk  and  Oleminsk,  on  the  right  bank  of  the  Leua,  and, 
ascending  northwards,  turns  to  the  east." 


49 


c.  Magnetic  Activity  of  the  Earth  in  its  tliree  Manifestations 
of  Force — Intensity,  Inclination,  and  Variation. — Points 
(called  the  Magnetic  Poles),  in  which  the  Inclination  is  90°. 
—  Curves  on  which  no  Inclination  is  observed  (Magnetic 
Equator).  —  The  Four  different  Maxima  of  Intensity. — 
Curve  of  weakest  Intensity. — Extraordinary  Disturbances  of 
the  Declination  (Magnetic  Storms). — Polar  Light. 

(Extension  of  the  Picture  of  Nature,  Cosmos,  vol.  i.  pp.  169 
—197,  vol.  ii.  pp.  717—720,  and  vol.  iv.  pp.  394—398.) 

The  magnetic  constitution  of  our  planet  can  only  be 
deduced  from  the  many  and  various  manifestations  of  ter- 
restrial force  in  as  far  as  it  presents  measureable  relations  in 
space  acd  time.  These  manifestations  have  the  peculiar  pro- 
perty of  exhibiting  perpetual  variability  of  phenomena  to  a 
much  higher  degree  even  than  the  temperature,  gaseous 
admixture,  and  electrical  tension  of  the  lower  strata  of  the 
atmosphere.  Such  a  constant  change  in  the  nearly  allied 
magnetic  and  electrical  conditions  of  matter  moreover  essen- 
tially distinguishes  the  phenomena  of  electro-magnetism 
from  those  which  are  influenced  by  the  primitive  funda- 
mental force  of  matter — its  molecular  attraction  and  the 
attraction  of  masses  at  definite  distances.  To  establish 
laws  in  that  which  is  ever  varying,  is  however  the  highest 
object  of  every  investigation  of  a  physical  force.  Although 
it  has  been  shown  by  the  labours  of  Coulomb  and  Arago 
that  the  electro-magnetic  process  may  be  excited  in  the 
most  various  substances,  it  has  nevertheless  been  proved 
by  Faraday's  brilliant  discovery  of  diamagnetism,  (by  the 
differences  of  the  direction  of  the  axes,  whether  they  incline 
north  and  south,  or  east  and  west,)  '•hat  the  heterogeneity  of 
matter  exerts  an  influence  distinct  from  the  attraction  of 
masses.  Oxygen  gas,  when  inclosed  in  a  thin  glass  tube,  will 
show  itself  under  the  action  of  a  magnet  to  be  paramagnetic, 
inclining  north  and  south  like  iron  ;  and  while  nitrogen, 
hydrogen,  and  carbonic  acid  gases  remain  unaffected,  phos- 
phorus, leather,  and  wood  show  themselves  to  be  diamag- 
netic,  and  arrange  themselves  equatorially  from  east  to  west, 

voi*  v.  K 


50  COSMOS. 

The  ancient  Greeks  and  Romans  were  acquainted  with  the 
adhesion  of  iron  to  the  magnet,  attraction  and  repulsion,  and 
the  transmission  of  the  attracting  action  through  brass  ves- 
sels as  well  as  through  rings,  which  were  strung  together  in  a 
chain-like  form,  as  long  as  one  of  the  rings  was  kept  in  con- 
tact with  the  magnet  ;M  and  they  were  likewise  acquainted 
with  the  non-attraction  of  wood  and  of  all  metals  excepting 
iron.  The  force  of  polarity,  which  the  magnet  is  able  to 
impart  to  a  moveable  body  susceptible,  of  its  influence,  was 
entirely  unknown  to  the  Western  nations  (Phoenicians,  Tus- 
cans, Greeks,  and  Romans).  The  first  notice  which  we  meet 
with  among  the  nations  of  Western  Europe  of  the  knowledge 
of  this  force  of  polarity,  which  has  exerted  so  important  an 
influence  on  the  improvement  and  extension  of  navigation, 
and  which,  from  its  utilitarian  value  has  led  so  continuously 
to  the  inquiry  after  one  universally  diffused,  although  pre- 
viously unobserved  force  of  nature,  does  not  date  farther  back 
tliMitho  llth  and  12th  centuries.  In  the  history  and  enu- 
meration of  the  principal  epochs  of  a  physical  contempla- 
tion of  the  universe,  it  has  been  found  necessary  to  divide 
into  several  sections,  and  to  notice,  the  sources  from  which 
vre  derive  our  knowledge  of  that  which  we  have  here  sum- 
marily arranged  under  one  common  point  of  view.53 

We  find  that  the  application  amongst  the  Chinese  of  the 
directive  power  of  the  magnet,  or  the  use  of  the  north  and 
south  direction  of  magnetic  needles  floating  on  the  surface  of 
water,  dates  to  an  epoch  which  is  probably  more  ancient 
than  the  Doric  migration  and  the  return  of  the  Heraclidse 
into  the  Peloponnesus.  It  seems,  moreover,  very  striking 
that  the  use  of  the  south  direction  of  the  needle  should  have 
been  first  applied  in  Eastern  Asia  not  to  navigation  but  to 
land  travelling.  In  the  anterior  part  of  the  magnetic  waggon 
a  freely  floating  needle  moved  the  arm  and  band  of  a  small 
figure,  which  pointed  towards  the  south.  An  apparatus  of 
this  kind  (called  fse-nan,  indicator  of  the  south,)  was  pre- 

52  The  principal  passage  referring  to  the  magnetic  chain  of  rings 
occurs  in  Plato's  Ion.  p.  533,  D.E  ed.  Steph.     Mention  has  been  made 
of  this  transmission  of  the  attracting  action  not  only  by  Pliny  (xxxiv, 
14)  and  Lucretius   (vi,  910),  but  also  by  Augustine  (de  civitate  Dei, 
xx,  4)  and  Philo  (de  Mwndi  opificio,  p.  32  D  ed.  1691). 

53  Cosmos,  vol.  i,  p.  182  ;  vol.  ii,  p.  628. 


THE   MAGNETIC  NEEDLE.  51 

.sented  during  the  dynasty  of  the  Tscheu,  1100  years  before 
our  era,  to  the  ambassadors  of  Tonquin  and  Cochin-China, 
to  guide  them  over  the  vast  plains,  which  they  would  have 
to  cross  in  their  homeward  journey.  The  magnetic  waggon 
was  used  as  late  as  the  loth  century  of  our  era.64  Several 
of  these  waggons  were  carefully  preserved  in  the  imperial 
palace  and  were  employed  in  the  building  of  Buddhist  mon- 
asteries in  fixing  the  points  towards  which  the  main  sides 
of  the  edifice  should  be  directed.  The  frequent  application 
of  magnetic  apparatus  gradually  led  the  more  intelligent 
of  the  people  to  physical  considerations  regarding  the  nature 
of  magnetic  phenomena.  The  Chinese  eulogist  of  the  mag- 
netic needle,  .Kuopho  (a  writer  of  the  age  of  Constantine  the 
Great),  compares,  as  I  have  already  elsewhere  remarked,  th^ 
attractive  force  of  the  magnet  with  that  of  rubbed  amber. 
This  force,  according  to  him,  is  "  like  a  breath  of  wind 
which  mysteriously  breathes  through  these  two  bodies,  and 
has  the  property  of  thoroughly  permeating  them  with  the 
rapidity  of  an  arrow."  The  symbolical  expression  of  "  breath 
of  wind  "  reminds  us  of  the  equally  symbolical  designation  of 
soul,  which  in  Grecian  antiquity  was  applied  by  Thales,  the 
founder  of  the  Ionian  School,  to  both  these  attracting  sub- 
stances ;  soid  signifying  here  the  inner  principle  of  the  mov- 
ing agent.65 

54  Humboldt,  Asie  Centrale,  t.  i,  p.  xl — xlii,    and  Examen  Crit.  de 
VHist.  de  la  Geographic,  t.  iii,  p.  35.      Eduard  Biot,  who  has  extended 
and  confirmed  by  his  own  careful  and  bibliographical  studies,  and  with 
the  assistance  of  ray  learned  friend  Stanislas  Julien,  the  investigations 
made  by  Klaproth  in  reference  to  the  epoch  at  which  the  magnetic 
needle  was  first  used  in  China,  adduces  an  old  tradition,  according  to 
which  the  magnetic  waggon  was  already  in  use  in  the  reign  of  the  Em- 
peror Hoang-ti.     No  allusion  to  this  tradition  can,  however,  be  found  in 
any  writers  prior  to  the  early  Christian  ages.     This  celebrated  monarch 
is  presumed  to  have  lived  2600  years  before  our  era  (that  is  to  say, 
1000  years  before  the  expulsion  of  the  Hyksos  from  Egypt).     Ed.  Biot 
fur  la  direction  de  I' aiguille  aimantee  en  Chine  in.  the  Comptes  rendus  de 
TAcad.  des  Sciences,  t.  xix,  1844,  p.  822. 

55  Cosmos,  vol.  i,  p.  182.    Aristotle  (de  Anima,  i,  2)  speaks  only  of 
the  animation  of  the  magnet  as  of  an  opinion  that  originated  with 
Thales.     Diogenes  Laertius  interprets  this  statement  as  applying  also 
distinctly  to  amber,  for  he  says,  "  Aristotle  and  Hippias  maintain  as  to 
the  doctrine  enounced  by  Thales."    .    .    .  The  sophist  Hippias  of  Elis, 
who  flattered  himself  that  he  possessed  universal  knowledge,  occupied 
himself  with  physical  science  and  with  the  most  ancient  traditions  of 

E2 


82  COSMOS. 

As  the  excessive  mobility  of  the  floating  Chinese  needles 
rendered  it  difficult  to  observe,  and  note  down  the  ir*dica- 
tions  which  they  afforded,  another  arrangement  was  adopted 
in  their  place  as  early  as  the  12th  century  of  our  era,  in 
which  the  needle  that  was  freely  suspended  in  the  air  was 
attached  to  a  fine  cotton  or  silken  thread  exactly  in  the 
same  manner  as  Couiomb's  suspension  which  was  first  used 
by  William  Gilbert  in  Western  Europe.  By  means  of  this 
more  perfect  apparatus,66  the  Chinese  as  early  as  the  begin- 
ning of  the  12th  century  determined  the  amount  of  the 
western  variation,  which  in  that  portion  of  Asia  seems  only 
to  undergo  very  inconsiderable  and  slow  changes.  From  its 
use  on  land,  the  compass  was  finally  adapted  to  maritime 
purposes,  and  under  the  dynasty  of  Tsin,  in  the  4th  century 
of  our  era,  Chinese  vessels  under  the  guidance  of  the  conp.pass 
visited  Indian  ports  and  the  eastern  coast  of  Africa. 

Fully  200  years  earlier,  under  the  reign  of  Marcus  Aurelius 
Antoninus,  who  is  called  An-tun  by  the  writers  of  the 
dynasty  of  Han,  Roman  legates  came  by  sea  by  way  of  Ton- 
quin  to  China.  The  application  of  the  magnetic  needle  to 
European  navigation  was  however  not  owing  to  so  transient 
a  source  of  intercourse,  for  it  was  not  until  its  use  had 
become  general  thoughout  the  whole  of  the  Indian  Ocean, 
along  the  shores  of  Persia  and  Arabia,  that  it  was  introduced 
into  the  West  in  the  12th  century,  either  directly  through 
the  influence  of  the  Arabs  or  through  the  agency  of  the 
Crusaders,  who  since  1096  had  been  brought  in  contact  with 
Egypt  and  the  true  Oriental  regions.  In.  historical  investi- 
gations of  this  nature,  we  can  only  determine  with  certainty 

the  physiological  school.  "  The  attracting  breath,"  which,  according 
to  the  Chinese  physicist,  Kuopho,  "permeates  both  the  magnet  and 
amber,"  reminds  us,  according  to  Buschmann's  investigations  into  the 
Mexican  language,  of  the  aztec  name  of  the  magnet  tlaihioanani  tetl, 
signifying  "  the  stone  which  attracts  by  its  breath"  (from  ihiotl,  breath, 
and  nna,  to  draw  or  attract). 

56  The  remarks  which  Klaproth  has  extracted  from  the  Penthsaoyan 
regarding  this  singular  apparatus  are  given  more  fully  in  the  Mung- 
kld-vi-than,  Comptes  rendus,  t.  xix,  p.  365.  We  may  here  ask  why,  in 
this  latter  treatise,  as  well  as  in  a  Chinese  book  on  plants,  it  is  stated 
that  the  cypress  turns  towards  the  west,  and,  more  generally,  that  the 
magnetic  needle  points  towards  the  south?  Does  this  imply  a  more 
luxuriant  development  of  the  branches  on  the  side  nearest  the  sun,  or 
in  consequence  of  the  direction  of  the  prevalent  winds? 


THE   MARINER'S   COMPASS.  53 

those  epochs,  which  must  be  considered  as  the  latest  limits 
beyond  which  it  would  be  impossible  for  us  to  nrge  oiit 
inquiries.  In  the  politico-satirical  poem  of  Guyot  of  Pro- 
vins,  the  mariner's  compass  is  spoken  of  (1199)  as  an  instru- 
ment that  had  been  long  known  to  the  Christian  world  ;  and 
this  is  also  the  case  in  the  description  of  Palestine  which  we 
owe  to  the  Bishop  of  Ptolemais,  Jaques  de  Vitry,  and  which 
was  completed  between  the  years  1204  and  1215.  Guided 
by  the  magnetic  needle  the  Catalans  sailed  along  the  north- 
ern islands  of  Scotland  as  well  as  along  the  western  shores  of 
tropical  Africa,  the  Basques  ventured  forth  in  search  of  the 
whale,  and  the  Northmen  made  their  way  to  the  Azores 
(the  Bracir  islands  of  Picigano).  The  Spanish  Leyes  de  las 
Partidas  (del  sabio  Rey  Don  Alonso  el  nono),  belonging  to 
the  first  half  of  the  13th  century,  extolled  the  magnetic 
needle  as  "  the  true  mediatrix  (medianera)  between  the  mag- 
netic stone  (la  piedra)  and  the  north  star."  Gilbert  also,  in 
his  celebrated  work  De  Magnete  Physiologia  Nova,  speaks  of 
the  mariner's  compass  as  a  Chinese  invention,  although  he 
inconsiderately  adds,  that  Marco  Polo  "  qui  apud  Chinas 
artem  pyxidis  didicit,"  first  brought  it  to  Italy.  As,  how- 
ever, Marco  Polo  began  his  travels  in  1271  and  returned  in 
1295,  it  is  evident  from  the  testimony  of  Guyot  of  Provins 
and  Jaques  de  Vitry,  that  the  compass  was  at  all  events  used 
in  European  seas  from  60  to  70  years  before  Marco  Polo  set 
forth  on  his  journeyings.  The  designations  zohron  and 
aphron,  which  Vincent  of  Beauvais  applied  in  his  Mirror  of 
Nature  to  the  southern  and  northern  ends  of  the  magnetic 
needle  (1254),  seem  to  indicate  that  it  was  through  Arabian 
pilots  that  Europeans  became  possessed  of  the  Chinese  com- 
pass. These  designations  point  to  the  same  learned  and 
industrious  nation  of  the  Asiatic  peninsula  whose  language 
too  often  vainly  appeals  to  us  in  our  celestial  maps  and 
globes. 

From  the  remarks  which  I  have  already  made,  there  can 
scarcely  be  a  doubt  that  the  general  application  of  the 
magnetic  needle  by  Europeans  to  oceanic  navigation  as  early 
as  the  12th  century,  and  perhaps  even  earlier  in  individual 
cases,  originally  proceeded  from  the  basin  of  the  Mediter- 
ranean. The  most  essential  share  in  its  use  seems  to  have 
belonged  to  the  Moorish  pilots,  the  Genoese,  Venetians, 


64  COSMOS. 

Majorcans,  and  Catalans.  The  latter  people,  under  the 
guidance  of  their  celebrated  countryman,  the  navigator,  Don 
Jaime  Ferrer,  penetrated,  in  1346,  to  the  mouth  of  the  Rio 
de  Ouro  (23°  40'  KL.),  on  the  Western  Coast  of  Africa,  and, 
according  to  the  testimony  of  Raymundus  Lullus  (in  his 
nautical  work  Fenix  de  las  Maravillas  del  Orbe,  1286)  the 
Barcelonians  employed  atlases,  astrolabes,  and  compasses, 
long  before  Jaime  Ferrer. 

The  knowledge  of  the  amount  of  magnetic  variation  is  of 
a  very  early  date,  and  was  simultaneously  imparted  by  the 
Chinese  to  Indian,  Malay,  and  Arabian  seamen,  through  whose 
agency  it  must  necessarily  have  spread  along  the  shores  of 
the  Mediterranean.  This  element  of  navigation,  which  is  so 
indispensable  to  the  correction  of  a  ship's  reckoning,  was  then 
determined  less  by  the  rising  and  setting  of  the  sun  than  by 
the  polar  star,  and  in  both  cases  the  determination  was  very 
uncertain  ;  notwithstanding  which,  we  find  it  marked  down 
upon  charts,  as  for  instance  upon  the  very  scarce  atlas  of 
Andrea  Bianco,  which  was  drawn  out  in  the  year  1436. 
Columbus,  who  had  no  more  claim  than  Sebastian  Cabot, 
to  be  regarded  as  the  first  discoverer  of  the  variation  of 
the  magnetic  needle,  had  the  great  merit  of  determining 
astronomically  the  position  of  a  line  of  no  variation  2^° 
east  of  the  Island  of  Corvo,  in  the  Azores,  on  the  13th 
of  September,  1492.  He  found,  as  he  penetrated  into  the 
western  part  of  the  Atlantic  Ocean,  that  the  variation 
passed  gradually  from  north-east  to  north-west.  This  obser- 
vation led  him  to  the  idea,  which  has  so  much  occupied  navi- 
gators in  later  times,  of  finding  the  longitude  by  the  position 
of  the  curves  of  variation  which  he  still  imagined  to  be 
parallel  to  the  meridian.  We  learn  from  his  ship's  log,  that 
when  he  was  uncertain  of  his  position  during  his  second 
voyage  (1496),  he  actually  endeavoured  to  steer  his  way  by 
observing  the  declination.  The  insight  into  the  possibility 
of  such  a  method  was  undoubtedly  that  uncommunicable 
secret  of  longitude,  which  Sebastian  Cabot  boasted  on  his 
deathbed  of  having  acquired  through  special  divine  mani- 
festation. 

The  idea  of  a  curve  of  no  declination  in  the  Atlantic  was 
associated  in  the  easily  excited  fancy  of  Columbus  with 
other  somewhat  vague  views  of  alterations  of  climate,  of  an 


VARIATION-CHAETS.  55 

anomalous  configuration  of  the  earth,  and  of  extraordinary 
motions  of  the  heavenly  bodies,  in  which  he  found  a  motive 
for  converting  a  physical  into  a  political  boundary  line. 
Thus  the  raya,  on  which  the  agujas  de  marear  point  directly 
to  the  polar  star,  became  the  line  of  demarcation  between  the 
kingdoms  of  Portugal  and  Castille ;  and  from  the  importance 
of  determining  with  astronomical  exactness  the  geographical 
length  of  such  a  boundary  in  both  hemispheres,  and  over 
every  part  of  the  earth's  surface,  an  arrogant  Papal  decree, 
although  it  failed  in  effecting  this  aim,  nevertheless  exerted  a 
beneficial  effect  on  the  extension  of  astroiiomico-nautical 
science  and  on  the  improvement  of  magnetic  instruments. 
(Humboldt,  Examen  Grit,  de  la  Geog.,  t.  iii,  p.  54.)  Felipe 
Guillen,  of  Seville,  in  1525,  and  probably  still  earlier,  the 
cosmographer  Alonso  de  Santa  Cvuz,  teacher  of  mathematics 
to  the  young  Emperor  Charles  V.,  constructed  new  variation 
compasses  by  which  solar  altitudes  could  be  taken.  The  latter 
in  1530,  and  therefore  fully  150  years  before  Halley,  drew 
up  the  first  general  variation  chart,  although  it  was  certainly 
based  upon  very  imperfect  materials.  We  may  form  some 
idea  of  the  interest  that  had  been  excited  in  reference  to  ter- 
restrial magnetism  in  the  1 6th  century,  after  the  death  of 
Columbus,  and  during  the  contest  regarding  the  line  of 
demarcation,  when  we  find  that  Juan  Jay  me  made  a  voyage 
in  1585,  with  Francisco  Gali,  from  the  Philippines  to  Aca- 
pulco,  for  the  sole  purpose  of  testing  by  a  long  trial  in  the 
South  Sea  a  Declinatorium  of  his  own  invention. 

Amid  this  generally  diffused  taste  for  practical  observation, 
we  trace  the  same  tendency  to  theoretical  speculations  which 
always  accompanies  or  even  more  frequently  precedes  the 
former.  Many  old  traditions  current  amongst  Indian  and 
Arabian  sailors,  speak  of  rocky  islands  which  bring  death  and 
destruction  to  the  hapless  mariner,  by  attracting  through 
their  magnetic  force  all  the  iron  which  connects  together  the 
planks  of  the  ship,  or  even  by  immoveably  fixing  the  entire 
vessel.  The  effect  of  such  delusions  as  these  was  to  give  rise 
to  a  conception  of  the  concurrence,  at  the  poles,  o±  lines  01 
magnetic  variation,  represented  materially  under  the  image 
of  a  high  magnetic  rock  lying  near  one  of  the  poles.  On  the 
remarkable  chart  of  the  New  Continent,  which  was  added  to 
the  Latin  edition  of  1508  of  the  Geography  of  Ptolemy,  we 


56  COSMOS. 

find  that  north  of  Greenland  (Gruenllant),  which  is  repre- 
sented as  belonging  to  the  eastern  portion  of  Asia,  the  north 
magnetic  pole  is  depicted  as  an  insular  mountain.  Its 
position  was  gradually  marked  as  being  farther  south  in  the 
£reve  Compendia  de  la  Sphera,  by  Martin  Cortez,  1545,  as 
well  as  in  the  Geographia  di  Tolomeo  of  Liveo  Sanuto,  1588. 
The  attainment  of  this  point,  called  el  calamitico,  was  asso- 
ciated with  great  expectations,  since  it  was  supposed  in 
accordance  with  a  delusion,  which  was  not  dissipated  till 
long  afterwards,  that  some  miraculoso  stupendo  effetto  would 
be  experienced  by  those  who  reached  it. 

Until  towards  the  end  of  the  16th  century,  men  occupied 
themselves  only  with  those  phenomena  of  variation  which 
exerted  a  direct  influence  on  the  ship's  reckoning  and  the 
determination  of  its  place  at  sea.  Instead  of  the  one  line  of 
no  variation,  which  had  been  found  by  Columbus  in  1492, 
the  learned  Jesuit  Acosta,  who  had  been  instructed  by  Por- 
tuguese pilots  (1589)  expressed  the  belief  in  his  admirable 
Historia  Natural  de  las  Indias  that  he  was  able  to  indicate 
four  such  lines.  As  the  ship's  reckoning,  together  with  the 
accurate  determination  of  the  direction  (or  of  the  angle 
measured  by  the  corrected  compass)  also  requires  the  distance 
the  ship  had  made,  the  introduction  of  the  log,  although  this 
mode  of  measuring  is  even  at  the  present  day  very  imperfect, 
nevertheless  marked  an  important  epoch  in  the  history  of 
navigation.  I  believe  that  I  have  proved,  although  contrary 
to  previously  adopted  opinions,  that  the  first  certain  evidence 
of  the  use  of  the  log  67  (la  cadena  de  la  popa,  la  corredera) 
occurs  in  the  journal  which  was  kept  by  Antonio  Pigafetta 
during  the  voyage  of  Magellan,  and  which  refers  to  the 
month  of  January,  1521.  Columbus,  Juan  de  la  Cosa,  Se- 

57  Cosmos,  vol.  ii,  pp.  631 — 634.  In  the  time  of  King  Edward  III.  of 
England,  when,  as  Sir  Harris  Nicolas  (History  of  the  Royal  Navy, 
1847,  vol.  ii,  p.  180),  has  shown,  ships  were  guided  by  the  compass, 
which  was  then  called  the  sailstone  dial,  sailing  needle,  or  adamant,  we 
find  it  expressly  stated  in  the  accounts  of  the  expemes  for  equipping  the 
king's  ship,  "The  George,"  in  the  year  1345,  that  sixteen  hour-glasses 
had  been  bought  in  Flanders ;  this  statement,  however,  is  by  no  means 
a  proof  of  the  use  of  the  log.  The  ampolletas  (or  hour-glasses)  of  the 
Spaniards  were,  as  we  most  plainly  find  from  the  statements  of  Enciso 
in  Cespides,  in  use  long  before  the  introduction  of  the  log,  "echamlo 
\juuto  por  fantasia  in  la  corredera  de  los  perezosos." 


MAGNETISATION.  57 

bastian  Cabot,  and  Vasco  de  Gama,  were  not  acquainted 
with  the  log  and  its  mode  of  application,  and  they  estimated 
the  ship's  speed  merely  by  the  eye,  while  they  found  the 
distance  they  had  made  by  the  running  down  of  the  sand  in 
the  glasses  known  as  ampolletas.  For  a  considerable  period 
the  horizontal  declination  from  the  north  pole  was  the  only 
element  of  magnetic  force  that  was  made  use  of,  but,  at 
length  (in  1576),  the  second  element,  inclination,  began  to  be 
first  measured.  Robert  Norman  was  the  first  who  deter- 
mined the  inclination  of  the  magnetic  needle  in  London, 
which  he  noted  with  no  slight  degree  of  accuracy  by  means 
of  an  inclinatorium,  which  he  had  himself  invented.  It  was 
not  until  200  years  afterwards,  that  attempts  were  made  to 
measure  the  third  element,  the  intensity  of  the  magnetic 
terrestrial  force. 

About  the  close  of  the  16th  century,  William  Gilbert,  a 
man  who  excited  the  admiration  of  Galileo,  although  his 
merits  were  wholly  unappreciated  by  Bacon,  first  laid  down 
comprehensive  views  of  the  magnetic  force  of  the  earth.58 
He  clearly  distinguished  magnetism  from  electricity  by  their 
several  effects,  although  he  looked  upon  both  as  emanations 
of  one  and  the  same  fundamental  force,  pervading  all  matter. 
Like  other  men  of  genius,  he  had  obtained  many  happy 
results  from  feeble  analogies,  and  the  clear  views  which  he 
had  taken  of  terrestrial  magnetism  (de  magno  magnete 
tellure)  led  him  to  ascribe  the  magnetisation  of  the  vertical 
iron  rods  on  the  steeples  of  old  church  towers  to  the  effect 
of  this  force.  He,  too,  was  the  first  in  Europe  who  showed 
that  iron  might  be  rendered  magnetic  by  being  touched  with 
the  magnet,  although  the  Chinese  had  been  aware  of  the  fact 
nearly  500  years  before  him.59  Even  then,  Gilbert  gave 

58  Cosmos,  vol.  i,  p.  170.     Calamitico  was  the  name  given  to  these 
instruments   in    consequence  of   the    first  needles  for  the   compass 
having  been  made  in  the  shape  of  a  frog. 

59  See  Gilbert,  Physiologia  Nova  de  Magnete,  lib.  iii,  cap.  viii,  p.  124. 
Even  Pliny  (Cosmos,  vol.  i,  p.  170),  remarks  generally,  without,  how- 
ever, referring  to  the  act  of  touching,   that  magnetism  may  be  im- 
parted for  a  long  period  of  time  to  iron.     Gilbert  expresses  himself  as 
follows  in  reference  to  the  vulgar  opinion  of  a  magnetic  mountain  : — 
"  vulgiris  opinio  de  montibus  magneticis  aut  rupe  aliqua  magnetica,  de 
polo  phantastico  a  polo  mundi  distante"  (1.  c.  p.  42 — 98).    The  variation 
and  advance  of  the  magnetic   lines  were   entirely  unknown  to  him. 
•'  Varietas  uniuscujusque  bci  constana  est"  (1.  c.  42,  98,  152,  153. 


58  COSMOS. 

steel  the  preference  over  soft  iron,  because  the  former  has  the 
power  of  more  permanently  retaining  the  force  imparted  to 
it,  and  of  thus  becoming  for  a  longer  time  a  conductor  of 
magnetism. 

In  the  course  of  the  17th  century,  the  navigation  of  the 
Netherlander^  British,  Spaniards  and  French,  which  had 
been  so  widely  extended  by  more  perfect  methods  of  deter- 
mining the  direction  and  length  of  the  ship's  course,  increased 
the  knowledge  of  those  lines  of  no  variation  which,  as  I  have 
already  remarked,  Father  Acosta  had  endeavoured  to  reduce 
into  a  system.60  Cornelius  van  Schouten  indicated,  in  1616, 
points  lying  in  the  midst  of  the  Pacific  and  south-east  of 
the  Marquesas  Islands  in  which  the  variation  was  null. 
Even  now  there  lies  in  this  region  a  singular,  closed  system 
of  isogonic  lines,  in  which  every  group  of  the  internal  con- 
centric curves  indicates  a  smaller  amount  of  variation.61 
The  emulation  which  was  exhibited  in  trying  to  find  methods 
for  determining  longitudes,  not  only  by  means  of  the  varia- 
tion, but  also  by  the  inclination  (which  when  it  was  observed 
under  a  cloudy  starless  sky,  aere  caliginoso?2  was  said  by 
Wright  to  be  "worth  much  gold")  led  to  the  multiplication 
of  instruments  for  magnetic  observations,  while  it  tended  at 
the  same  time  to  increase  the  activity  of  the  observers.  The 
Jesuit  Cabeus  of  Ferrara,  Ridley,  Lieutaud  (1668),  and 
Henry  Bond  (1676),  distinguished  themselves  in  this  manner. 
Indeed,  the  contest  between  the  latter  and  Beckborrow, 
together  with  Acosta's  view  that  there  were  four  lines  of  no 
variation  which  divided  the  entire  surface  of  the  earth,  may 
very  probably  have  had  some  influence  on  the  theory,  ad- 
vanced in  1683  by  Halley,  of  four  magnetic  poles  or  points 
of  convergence. 

66  Historia  Natural  de  las  Indias,  lib.  i,  cap.  17. 

61  Cosmos,  vol.  i,  p.  175. 

62  In  the  very  careful  observations  of  inclination  which  I  made  on  the 
Pacific,  I  demonstrated  the  conditions  under  which  an  acquaintance 
with  the  amount  of  the   inclination  may  be  of  important  practical 
utility  in  the  determination  of  the  latitude  during  the  prevalence,  on 
the  coasts  of  Peru,  of  the  Garua,  when  both  the  sun  and  stars  are  ob- 
scured (Cosmos,  vol.  i,  p.  173).     The  Jesuit,  Cabeus,  author  of  the  Phi' 
losophia  Maynetica  (in  qua  nova  qusedam  pyxis  explicatur,  quse  poli 

7  elevationem,  ubique  demonstrat),  drew  attention  to  this  fact  during  the 
first  half  of  the  17th  century. 


THE   MAGNETIC   POLES.  59 

Halley  is  identified  with  an  important  epoch  in  the  history 
of  terrestrial  magnetism.  He  assumed  that  there  was  in 
each  hemisphere  a  magnetic  pole  of  greater  and  lesssr 
intensity,  consequently  four  points  with  90°  inclination  of 
the  needle,  precisely  as  we  now  find  among  liie  four  points  of 
greatest  intensity  an  analogous  inequality  in  the  maximum 
of  intensity  for  each  hemisphere,  that  is  to  say,  in  the 
rapidity  of  the  oscillations  of  the  needle  in  the  direction  of 
the  magnetic  meridian.  The  pole  of  greatest  intensity  was 
situated,  according  to  Halley,  in  70°  S.L.  120°  east  of 
Greenwich,  and  therefore  almost  in  the  meridian  of  King 
George's  Sound  in  New  Holland  (Nuyts  Land).63  Halley's 
three  voyages,  which  were  made  in  the  years  1698,  1699, 
and  1702,  were  undertaken  with  the  view  of  elaborating  a 
theory  which  must  have  owed  its  origin  solely  to  the  earlier 
voyage  which  he  had  made  seven  years  before  to  St.  Helena, 
and  to  the  imperfect  observations  of  variation  made  by 
Baffin,  Hudson,  and  Cornelius  van  Schouten.  These  were 
the  first  expeditions  which  were  equipped  by  any  government 
for  the  establishment  of  a  great  scientific  object — that  of 
observing  one  of  the  elements  of  terrestrial  force  on  which 
the  safety  of  navigation  is  especially  dependent.  As  Halley 
penetrated  to  52°  south  of  the  equator,  he  was  able  to 
construct  the  first  circumstantial  variation  chart,  which 
affords  to  the  theoretical  labours  of  the  19th  century  a  point 
of  comparison,  although  certainly  not  a  very  remote  one,  of 
the  advancing  movement  of  the  curves  of  variation. 

Halley's  attempt  to  combine  graphically  together  by  lines 
different  points  of  equal  variation  was  a  very  happy  one,64 
since  it  has  given  us  a  comprehensive  and  clear  insight  into 
the  connection  of  the  results  already  accumulated.  My  iso- 
thermal lines  (that  is  to  say  lines  of  equal  heat  or  mean 
annual  summer  and  winter  temperature),  which  were  early 

63  Edmund  Halley,  in  the  Philos.  Transact,  for  1683,  vol.  xii,  No.  148. 
p.  216. 

64  Lines  of  this  kind,  which  he  called  tractus  chalyboeliticos,  were 
marked  down  upon  a  chart  by  Father  Christopher  Burrus,  in  Lisbon, 
and  offered  by  him  to  the  King  of  Spain  for  a  large  sum  of  money ; 
these  lines  being  drawn  for  the  purpose  of  showing  and  determining 
longitudes  at  sea.    See  Kircher:s  Magnes,  ed.  2,  p.  443.     The  first  varia- 
tion chart,  which  was  made  in  1530,  has  already  been  referred  to  IL.  tko 
text  (p.  56). 


60  COSMOS. 

received  with  much  favour  by  physicists,  have  been  formed 
on  a  similar  plan  to  Halley's  isogonic  curves.  These  lines, 
especially  since  they  have  been  extended  and  greatly  im- 
proved by  Dove,  are  intended  to  afford  a  clear  view  of  the 
distribution  of  heat  on  the  earth's  surface,  and  of  the  princi- 
pal dependence  of  this  distribution  on  the  form  of  the  solid 
and  fluid  parts  of  the  earth,  and  the  reciprocal  position  of 
continental  and  oceanic  masses.  Halley's  purely  scientific 
expeditions  stand  so  much  the  more  apart  from  others,  since 
they  were  not,  like  many  later  expeditions,  fitted  out  at  the 
expense  of  the  Government  with  the  object  of  making  geo- 
graphical discoveries.  In  addition  to  the  results  which  they 
have  yielded  in  respect  to  terrestrial  magnetism,  they  were 
also  the  means  of  affording  us  an  important  catalogue  of 
southern  stars  as  the  fruits  of  Halley's  earlier  sojourn  in  the 
Island  of  St.  Helena  in  the  years  1677  and  1678.  This 
catalogue  was  moreover  the  first  that  was  drawn  up  after 
telescopes  had  been  combined,  according  to  Morin's  and 
Gascoigne's  methods,  with  instruments  of  measurement.65 

As  the  17th  century  had  been  distinguished  by  an 
advance  in  a  more  thorough  knowledge  of  the  position 
of  the  lines  of  variation,  and  by  the  first  theoretical 
attempt  to  determine  their  points  of  convergence,  viz.  the 
magnetic  poles,  the  18th  century  was  characterised  by 
the  discovery  of  horary  periodical  alterations  of  variation. 
Graham  has  the  incontestable  merit  of  being  the  first  to 
observe  (London,  1722)  these  hourly  variations  with  accuracy 
and  persistency.  Celsius  and  Hiorter  in  Upsala,66  who  main- 
tained a  correspondence  with  him,  contributed  to  the  exten- 
sion of  our  knowledge  of  this  phenomenon.  Brugmans,  and 
after  him  Coulomb,  who  was  endowed  with  higher  mathe- 
matical powers,  entered  profoundly  into  the  nature  of  ter- 

65  Twenty  years  after  Halley  had  drawn  up  his  catalogue  of  southern 
stars  at  St.  Helena  (which,  unfortunately,  included  none   under  the 
sixth  magnitude)  Hevelius  boasted,  in  his  Firmamentum  Sobescianum, 
that  he  did  not  employ  any  telescope,  but  observed  the  heavens  through 
fissures.     Halley,  who,  during  his  visit  to  Dantzic  in  1679,  was  present 
at  these  observations,  praises  their  exactness  somewhat  too   highly. 
Cosmos,  vol.  iii,  p.  52. 

66  Traces  of  the  diurnal  and  horary  variations  of  the  magnetic  force 
had  been  observed  in  London  as  early  as  1634,  by  Hellibrand,  and  in 
Slam,  by  Father  Tachard,  in  1682. 


MAGNETIC  INTENSITY.  61 

restrial  magnetism  (1784 — 1788).  Their  ingenious  physical 
experiments  embraced  the  magnetic  attraction  of  all  matter, 
the  local  distribution  of  the  force  in  a  magnetic  rod  of  a 
given  form,  and  the  law  of  its  action  ar  a  distance.  In  order 
to  obtain  accurate  results,  the  vibrations  of  a  horizontal 
needle  suspended  by  a  thread,  as  well  as  deflections  by  a 
torsion  balance,  were  in  turn  employed. 

The  knowledge  of  the  difference  of  intensity  of  ter- 
restrial magnetism  at  different  points  of  the  earth's  surface 
by  the  measurement  of  the  vibrations  of  a  vertical  needle 
ID.  the  magnetic  meridian,  is  due  solely  to  the  ingenuity 
of  the  Chevalier  Borda ;  ~Dt  from  any  series  of  speciallv 
successful  experiments,  but  by  a  process  of  reasoning,  and 
by  the  decided  influence  which  he  exerted  on  those  who 
were  equipping  themselves  for  remote  expeditions.  Borda's 
long  cherished  conjectures  were  first  confirmed  by  means 
of  observations  made  from  the  year  1785  to  1787,  by 
i^amanon,  the  companion  of  La  Perouse.  These  results 
remained  unknown,  unheeded,  and  unpublished,  although 
they  had  been  communicated  as  early  as  the  summer 
of  the  last-named  year  to  Condorcet,  the  Secretary  of  the 
Academic  des  Sciences.  The  first,  and  therefore  cer- 
tainly an  imperfect  knowledge  of  the  important  law  of  the 
variability  of  intensity  in  accordance  with  the  magnetic 
latitude,  belongs  undoubtedly67  to  the  unfortunate  but  scien- 
tifically equipped  expedition  of  La  Perouse ;  but  the  law 
itself,  as  1  rejoice  to  think,  was  first  incorporated  in  science 
by  the  publication  of  my  observations,  made  from  1798  to 
1804,  in  the  south  of  France,  in  Spain,  the  Canary  Islands, 
the  interior  of  tropical  America  both  north  and  south  of  the 
equator,  and  in  the  Atlantic  and  Pacific  Oceans.  The  suc- 
cessful expeditions  of  Le  Gentil,  Feuille"e,  and  Lacaille ;  the 
first  attempt  made  by  Wilke,  in  1768,  to  construct  an  incli- 
nation chart }  the  memorable  circumnavigations  of  Bougain- 
ville, Cook,  and  Vancouver,  have  all  tended,  although  by  the 

G"  Cosmos,  vol.  i,  pp.  179 — 181.  The  admirable  construction  of  the 
inclination  compass  made  by  Lenoir,  according  to  Borda's  plan,  the  pos- 
sibility of  having  long  and  free  oscillations  of  the  needle,  the  much 
diminished  friction  of  the  pivots  and  the  correct  adjustment  of  instru- 
ments provided  with  scales,  have  been  the  means  of  enabling  us  accu- 
rately to  measure  the  amount  of  the  terrestrial  force  in  different  zones, 


62  COSMOS. 

help  of  instruments  possessing  very  unequal  degrees  of  exact- 
ness, to  establish  the  previously  neglected,  but  very  important 
element  of  inclination  at  various  intervals  of  time,  and  at 
many  different  points ;  the  observations  being  made  more  at 
sea  and  in  the  immediate  vicinity  of  the  ocean  than  in  the 
interior  of  continents.  Towards  the  close  of  the  18th 
century,  the  stationary  observations  of  declination  which 
were  made  by  Cassini,  Gilpin,  and  Beaufoy  (from  1784  to 
1790),  with  more  perfect  instruments,  showed  definitely  that 
there  is  a  periodical  influence  at  different  hours  of  the  day, 
no  less  than  at  different  seasons  of  the  year, — a  discovery 
which  imparted  a  new  stimulus  to  magnetic  investigations. 

In  the  19th  century,  half  of  which  has  now  expired,  this 
increased  activity  has  assumed  a  special  character  differing 
from  any  that  has  preceded  it.  We  refer  to  the  almost 
simultaneous  advance  that  has  been  made  in  all  branches  of 
the  theory  of  terrestrial  magnetism,  comprising  the  numerical 
determination  of  the  intensity,  inclination  and  variation  of 
the  force  ;  in  physical  discoveries  in  respect  to  the  excitation 
and  the  amount  of  the  distribution  of  magnetism  ;  and  in 
the  first  and  brilliant  suggestions  of  a  theory  of  terrestrial 
magnetism,  which  has  been  based  by  its  founder,  Friedrich 
Gauss,  upon  strictly  mathematical  combinations.  The  means 
which  have  led  to  these  results  are  improvements  in  the 
instruments  and  methods  employed  ;  scientific  maritime 
expeditions,  which  in  number  and  magnitude  have  exceeded 
those  of  any  other  century,  and  which  have  been  carefully 
equipped  at  the  expense  of  their  respective  Governments, 
and  favoured  by  the  happy  choice  both  of  the  commanders 
and  of  the  observers  who  have  accompanied  them ;  and 
various  expeditions  by  land,  which  having  penetrated  far 
into  the  interior  of  continents,  have  been  able  to  elucidate 
the  phenomena  of  terrestrial  magnetism,  and  to  establish  a 
large  number  of  fixed  stations,  situated  in  both  hemispheres 
in  corresponding  north  and  south  latitudes,  and  often  in 
almost  opposite  longitudes.  These  observatories,  which  are 
both  magnetic  and  meteorological,  form  as  it  were  a  net- 
work over  the  earth's  surface.  By  means  of  the  ingenious 
combination  of  the  observations  which  have  been  published 
at  the  national  expense  in  Russia  and  England,  important 
and  unexpected  results  have  been  obtained.  Tlie  establish- 


PROGRESS   IN   MAGNETISM.  63 

men!  of  a  law  regulating  the  manifestation  of  force  which  is 
a  proximate,  although  not  the  ultimate,  end  of  all  investiga- 
tions, has  been  satisfactorily  effected  in  many  individual 
phases  of  the  phenomenon.  All  that  has  been  discovered  by 
means  of  physical  experiments  concerning  the  relations 
which  terrestrial  magnetism  bears  to  excited  electricity,  to 
radiating  heat  and  to  light,  and  ail  that  we  may  assume  in 
reference  to  the  only  lately  generalised  phenomena  of  dia- 
magnetism,  and  to  that  specific  property  of  atmospheric 
oxygen  —  polarity  —  opens  at  all  events  the  cheering  prospect, 
that  we  are  drawing  nearer  to  the  actual  nature  of  the 
magnetic  force. 

In  order  to  justify  the  praise  which  we  have  generally  ex- 
pressed in  reference  to  the  magnetic  labours  of  the  first  half 
of  our  century,  I  will  here,  in  accordance  with  the  nature 
and  form  of  the  present  work,  briefly  enumerate  the  principal 
sources  of  our  information,  arranging  them  in  some  cases 
chronologically,  and  in  others  in  groups.  w 

1803  —  1806.  Krusenstern's  voyage  round  the  world  (1812); 
the  magnetic  and  astronomical  portion  was  by  Horner  (Bd.  iii, 
s.  317). 

1804.  Investigation  of  the  law  of  the  increase  in  the  in- 
tensity of  terrestrial  magnetic  force  from  the  magnetic 
equator  northward  and  southward,  based  upon  observations 
made  from  1799  to  1804.  (Humboldt,  Voyage  aux  Regions 
Equinoxiales  du  Nouveau  Continent,  t.  iii,  pp.  615  —  623  ; 
Lametherie,  Journal  de  Pliysique,  t.  Ixix,  1804,  p.  433  ;  the 
first  sketch  of  a  chart  showing  the  intensities  of  the  force, 
Cosmos,  vol.  i,  p.  179).  Later  observations  have  shown  that 
the  minimum  of  the  intensity  does  not  correspond  to  the 
magnetic  equator,  and  that  the  increase  of  the  intensity 
in  both  hemispheres  does  not  extend  to  the  magnetic  pole. 

1805  —  1806.  Gay-Lussac  and  Humboldt,  Observations  of 
Intensity  in  the  south  of  France,  Italy,  Switzerland,  and 
Germany.  Memoir  "es  de  la  Societe  d'Arcueil,  t.  i.  pp.  1  —  22. 


pp. 

839, 


Compare  the  observations  of  Quetelet,  1830  and  1839,  with  a 

68  The  dates  with  which  the  following  table  begins  (as,  for  instance, 
from  1803  —  1806)  indicate  the  epoch  of  the  observation,  while  the 
figures  which  are  marked  in  brackets,  and  appended  to  the  titles  of  the 
works,  indicate  the  date  of  their  publication,  which  was  frequently 
much  later. 


t  COSMOS. 

"  Carte  de  Tintensite  magnetique  horizontale  entre  Paris  et 
Naples,"  in  the  Mem.  de  VAcad.  de  Bruxelles,  t.  xiv ;  the 
observations  of  Forbes  in  Germany,  Flanders,  and  Italy  in 
1832  and  1837  (Transact,  of  the  Royal  Soc.  of  Edinburgh, 
vol.  xv,  p.  27) ;  the  extremely  accurate  observations  of  Biid- 
berg  in  France,  Germany,  and  Sweden,  1832  ;  the  observa- 
tions of  Dr.  Bache  (Director  of  the  Coasts'  Survey  of  the 
United  States),  1837  and  1840,  at  21  stations  both  in  refer- 
ence to  inclination  and  intensity. 

1806 — 1807.  A  long  series  of  observations  at  Berlin  ro 
the  horary  variations  of  declination  and  the  recurrence  c 
magnetic  storms  (perturbations)  by  Humboldt  and  Oltmannj 
mainly  at  the  periods  of  the  solstices  and  equinoxes  for  [ 
and  6,  or  even  sometimes  9  days,  and  as  many  nights  conse 
cutively,  by  means  of  Prony's  magnetic  telescope  which 
allowed  arcs  of  7  or  8  seconds  to  be  distinguished. 

1812.  Morichini,  of  Borne,  maintained  that  non-magnetic 
steel-needles  become  magnetic  by  contact  with  the  violet 
rays  of  light.  Regarding  the  long  contention  excited  by  this 
assertion  and  the  ingenious  experiments  of  Mrs.  Somer- 
ville,  together  with  the  wholly  negative  results  of  Biess  and 
Moser,  see  Sir  David  Brewster,  Treatise  on  Magnetism,  1837, 
p.  48. 

-1  o-i  f>          i  Q1  Q     ~\ 

18<>3— 1896'  i  ^e  *wo  circumnavioati°n  voyages  of  Otto 
von  Kotzebue,  the  first  in  the  Buric,  the  second,  five  years 
later,  in  the  Predprijatie. 

1817 — 1848.  The  series  of  great  scientific  maritime  expe- 
ditions equipped  by  the  French  Government,  and  which 
yielded  such  rich  results  to  our  knowledge  of  terrestrial 
magnetism ;  beginning  with  Freycinet's  voyage  in  the  cor- 
vette Uranie  1817 — 1820,  and  followed  by  Duperrey  in  the 
frigate  La  Coquille  1822 — 1825,  Bougainville  in  the  frigate 
Thetis  1824—1826,  Dumont  d'Urville  in  the  Astrolabe 
1826  —  1829,  and  to  the  south  pole  in  the  Zelee  1837—1840, 
Jules  De  Blosseville  to  India  1828  (Herbert  Asiat.  Re- 
searches, vol.  xviii,  p.  4,  Humboldt,  Asie  Cent.  t.  iii,  p.  468), 
and  to  Iceland  1833,  (Lottin,  Voy.  de  la  Recherche  1836, 
pp.  376 — 409),  du  Petit  Thouars  with  Tessan  in  the  Venus 
1837—1839,  le  Vaillant  in  the  Bonite  1836—1837,  the 
voyage  of  the  "  Commission  scientifique  du  Nord  "  (Lottin, 


ARCTIC   EXPEDITIONS.  G£ 

Bravais,  Martins,  Siljestrom)  to  Scandinavia,  Lapland,  the 
Faroe  Islands,  and  Spitzbergen  in  the  corvette  la  Recherche 
1835—1840,  Berard  to  the  Gulf  of  Mexico  and  North 
America  1838,  to  the  Cape  of  Good  Hope  and  St.  Helena 
1842  and  1846  (Sabine  in  the  Phil  Transact,  for  1849, 
pt.  ii,  p.  175),  and  Francis  de  Castlenau,  Voy.  dans  les  parties 
centralvs  de  V  Amerique  du  Sud  1847 — 1850. 

1818  — 1851.  The  series  of  important  and  adventurous  ex- 
peditions in  the  ArcticPolar  Seas  through  the  instrumentality 
of  the  British  Government  first  suggested  by  the  praise- 
worthy zeal  of  John  Barrow ;  Edward  Sabine's  magnetic  and 
astronomical  observations  in  Sir  John  Ross's  voyage  to  Davis 
Straits,  Baffin's  Bay,  and  Lancaster  Sound  in  1818,  as  well  as 
in  Parry's  voyage  in  the  Hecla  and  Griper  through  Barrow 
Straits  to  Melville  Island  1819—1820  ;  Franklin,  Richard- 
son, and  Back  1819—1822,  and  ^gain  from  1825—1827, 
Back  alone  from  1833 — 1835,  when  almost  the  only  food 
that  the  expedition  could  obtain  for  weeks  together  was  a 
lichen,  G-yrophora  pustulata,  the  "  Tripe  de  Roche  "  of  the 
Canadian  hunters,  which  has  been  chemically  analyzed  by 
John  Stenhouse  in  the  Phil  Transact,  for  1849,  pt.  ii,  p.  393'; 
Parry's  second  expedition  with  Lyon  in  the  Fury  and  Hecla 
1821 — 1823  ;  Parry's  third  voyage  with  James  Ross  1824 — 
1825  ;  Parry's  fourth  voyage  when  he  attempted  with  Lieu- 
tenants Foster  and  Crozier  to  penetrate  northward  from 
Spitsbergen  on  the  ice  in  1827,  when  they  reached  the  lati- 
tude 82 J  45'  ;  John  Ross,  together  with  his  accomplished 
nephew  Jame.-5  Ross,  in  a  second  voyage  undertaken  at  the 
expense  of  Felix  Booth,  and  which  was  rendered  the  more 
perilous  on  account  of  protracted  detention  in  the  ice,  namely 
from  1829  to  1833  ;  Dease  and  Simpson  of  the  Hudson's 
Bay  Company  1838 — 1839  ;  and  more  recently,  in  search  of 
Sir  John  Franklin,  the  expeditions  of  ( 'aptains  Ommanney, 
Austin,  Penny,  Sir  John  Ross,  and  Phillips  1850  and  1851. 
The  expedition  of  Captain  Penny  reached  the  northern  lati- 
tude of  77°  &  Victoria  Channel  into  which  Wellington 
Channel  opens. 

1819 — 1821.  Bellinghausen's  voyage  into  the  Antarctic 
Ocean. 

1819.  The  appearance  of  the  great  work  of  Hansteen  On 
the  Magnetism  of  the  Earth,  which,  however,  was  completed 

VOL.  V.  F 


66  COSMOS. 

as  early  as  1813.  This  work  has  exercised  an  undoubted 
influence  on  the  encouragement  and  better  direction  of  geo- 
magnetic studies,  and  it  was  followed  by  the  author's  general 
charts  of  the  curves  of  equal  inclination  and  intensity  for  a 
considerable  part  of  the  earth's  surface. 

1819.  The  observations  of  Admirals  Roussin  and  G-ivry 
on  the  Brazilian  coasts  between  the  mouths  of  the  rivers 
Maranon  and  La  Plata. 

1819—1820.  Oersted  made  the  great  discovery  of  the  fact 
that  a  conductor  that  is  being  traversed  by  a  closed  elec- 
tric current,  exerts  a  definite  action  upon  the  direction  of 
the  magnetic  needle  according  to  their  relative  positions, 
and  as  long  as  the  current  continues  uninterrupted.  The 
earliest  extension  of  this  discovery  (together  with  that  of 
the  exhibition  of  metals  from  the  alkalies  and  that  of  the 
two  kinds  of  polarization  of  light — probably  the  most  bril- 
liant discovery  of  the  centuiy — )69  was  due  to  Arago's  observ- 
ation, that  a  wire,  through  which  an  electrical  current  is 
passing,  even  when  made  of  copper  or  platinum,  attracts 
and  holds  fast  iron  filings  like  a  magnet,  and  that  needles 
introduced  into  the  interior  of  a  galvanic  helix  become 
alternately  charged  by  the  opposite  magnetic  poles  in  ac- 
cordance with  the  reversed  direction  of  the  coils  (Ann.  de 
Chim.  et  de  Phys.,  t.  xv,  p.  93).  The  discovery  of  these 
phenomena,  which  were  exhibited  under  the  most  varied 
modifications,  was  followed  by  Ampere's  ingenious  theore- 
tical combinations  regarding  the  alternating  electro-magnetic 
actions  of  the  molecules  of  ponderable  bodies.  These  com- 
binations were  confirmed  by  a  series  of  new  and  highly 
ingenious  instruments,  and  led  to  a  knowledge  of  the  laws 
of  many  hitherto  apparently  contradictory  phenomena  of 
magnetism. 

1820 — 1824.  Ferdinand  von  Wrangel's  and  Anjou's  ex- 
pedition to  the  north  coasts  of  Siberia  and  to  the  Frozen 
Ocean.  (Important  phenomena  of  polar  light,  see  th.  ii, 
s.  259.) 

1820.  Scoresby's  Account  of  the  Arctic  Regions  ;  experi- 
ments of  magnetic  intensity,  vol.  ii,  p.  537 — 554. 

1821.  Seebeck's     discovery   of    thermo-magnetism    and 

69  Malus's  (1808)  and  Arago's  (1811)  ordinary  and  chromatic  polari- 
Kution  of  Light.  See  Cosmos,  vol.  ii,  p.  715. 


MAGNETIC   OBSERVATIONS.  67 

thermo-electricity.  The  contact  of  two  unequally  warmed 
metals  (especially  bismuth  and  copper)  or  differences  of  tem- 
perature in  the  individual  parts  of  a  homogeneous  metallic 
ring,  were  recognised  as  sources  of  the  production  of  mag- 
neto-electric currents. 

1821 — 1823.  Weddell's  voyage  into  the  Antarctic  Ocean 
as  far  as  lat.  74°  15'. 

1822 — 1823.  Sabine's  two  important  expeditions  for  the 
accurate  determination  of  the  magnetic  intensity  and  the 
length  of  the  pendulum  in  different  latitudes  (from  the  east 
coasts  of  Africa  to  the  equator,  Brazil,  Havannah,  Green- 
land as  far  as  lat.  74°  32',  Norway  and  Spitzbergen  in  lat, 
79°  50').  The  results  of  these  very  comprehensive  operations 
were  first  published  in  1824  under  the  title  of  Account  of 
Experiments  to  determine  the  Figure  of  the  Earth,  pp.  460 
—509. 

1824.  Erikson's  Magnetic  Observations  along  the  shores 
of  the  Baltic. 

1825.  Arago  discovers  Magnetism  of  Rotation.     The  first 
suggestion    that    led    to    this    unexpected   discovery  was 
afforded  by  his  observation  on  the  side  of  the  hill  in  Green- 
wich Park  of  the  decrease  in  the  duration  of  the  oscillations 
of  an  inclination  needle  by  the  action  of  neighbouring  non- 
magnetic substances.     In  Arago's  rotation  experiments,  the 
oscillations  of  the  needle  were  affected  by  water,  ice,  glass, 
charcoal,  and  mercury.70 

1825 — 1827.  Magnetic  Observations  by  Boussingault  in 
different  parts  of  South  America  (Marmato,  Quito). 

1826—1827.  Observations  of  Intensity  by  Keilhau  at  20 
stations  (in  Finmark,  Spitzbergen,  and  Bear  Island),  by 
Keilhau  and  Boeck  in  Southern  Germany  and  Italy  (Schum. 
Astr.  Nachr.  No.  146). 

1826 — 1829.  Admiral  Lutke's  voyage  round  the  world; 
the  magnetic  part  was  most  carefully  prepared  in  1834  by 
Lenz  (see  Partie  N  antique  du  Voyage,  1836). 

1826 — 1830.  Captain  Philip  Parker  King's  Observations 
in  the  southern  portions  of  the  eastern  and  western  coasts 
of  South  America  (Brazil,  Monte  Video,  the  Straits  of 
Magellan,  Chili,  and  Valparaiso). 

1827—1839.  Quetelet,   Etat    du   Magnetisme    Terrestre 

7°  Cosmos,  voL  i,  p.  172. 

F  2 


68  COSMOS. 

(Bruxell.es)  pendant  douze  annees.     Very  accurate  observa- 
tions. 

1827.  Sabine,  On  the  determination  of  the  relative  inten- 
sity of  the  magnetic  terrestrial  force  in  Paris  and  London. 
An  analogous  comparison  between  Paris  and  Christiana  was 
made  by  Hansteen  in  1825—1828  (Meeting  of  the  British 
Association  at  Liverpool  1837,  pp.  19 — 23).  The  many 
results  of  intensity,  which  had  been  obtained  by  French, 
English,  and  Scandinavian  travellers,  now  first  admitted  of 
being  brought  into  numerical  connection  with  oscillating 
needles,  which  had  been  compared  together  at  the  three 
above-named  cities.  These  numbers  which  could  therefore 
now  be  established  as  relative  values  were'  found  to  be  for 
Paris  1.348,  as  determined  by  myself,  for  London  1.372 
by  Sabine,  and  for  Christiana  1.423  by  Hansteen.  They 
all  refer  to  the  intensity  of  the  magnetic  force  at  one 
point  of  the  magnetic  equator  (the  curve  of  no  inclination) 
which  intersects  the  Peruvian  Cordilleras  between  Micui- 
pampa  and  Caxamarca,  in  south  latitude  7°  2'  and  western 
longitude  78°  48',  where  the  intensity  was  assumed  by 
myself  as  =  1.000.  This  assumed  standard  (Humboldt, 
Mecueil  d'Observ.  Astr.  vol.  ii,  p.  382 — 385,  and  Voyage  aux 
Regions  Equin.,  t.  iii,  p.  622)  formed  the  basis,  for  forty 
years,  of  the  reductions  given  in  all  tables  of  intensity  (Gay- 
Lussac  in  the  Mem.  de  la  Societe  d'Arcueil,  t.  i.  1807,  p.  21; 
Hansteen,  On  the  Magnetism  of  the  Earth,  1819,  p.  71  ; 
Sabine,  in  the  Hep.  of  the  British  Association  at  Liverpool, 
pp.  43 — 58).  It  has,  however,  in  recent  times  been  justly 
objected  to  on  account  of  its  want  of  general  applicability, 
because  the  line  of  no  inclination71  does  not  connect  together 

71  "  Before  the  practice  was  adopted  of  determining  absolute  values, 
the  most  generally  used  scale  (find  which  still  continues  to  be  very  fre- 
quently referred  to),  was  founded  on  the  time  of  vibration,  observed  by 
Mr.  de  Humboldt,  about  the  commencement  of  the  present  century,  at  a 
station  in  the  Andes  of  South  America,  where  the  direction  of  the  dipping 
needle  was  horizontal,  a  condition  which  was  for  some  time  erroneously 
supposed  to  be  an  indication  of  the  minimum  of  magnetic  force  at  the 
earth's  surface.  From  a  comparison  of  the  times  of  vibration  of  Mr.  de 
Humboldt' s  needle  in  South  America  and  in  Paris,  the  ratio  of  the 
magnetic  force  at  Paris  to  what  was  supposed  to  be  its  minimum  was 
inferred  (1.348),  and  from  the  results  so  obtained,  combined  with  a 
similar  comparison  made  by  myself  between  Paris  and  London,  in  1827, 
with  several  magnets,  the  ratio  of  the  force  iu  London  to  that  of  Mr. 


MAGNETIC   OBSERVATIONS.  69 

the  points  of  feeblest  intensity  (Sabine,  in  the  PJiil.  Transact, 
for  1846,  pt.  iii,  p.  254,  and  in  the  Manual  of  Sclent.  Inquiry 
for  the  use  of  the  British  Navy,  1849,  p.  17). 

1828 — 1829.  The  voyage  of  Hansteen  and  Due  :  Magne- 
tic observations  in  European  Russia  and  in  Eastern  Siberia 
as  far  as  Irkutsk. 

1828 — 1830.  Adolf  Erman's  voyage  of  circumnavigation, 
with  his  journey  through  Northern  Asia,  and  his  passage 
across  both  oceans,  in  the  Russian  frigate  Krotkoi.  The 
identity  of  the  instruments  employed,  the  uniformity  of  the 
methods  and  the  exactness  of  the  astronomical  determina- 
tions of  position  will  impart  a  permanent  scientific  repiita- 
tion  to  this  expedition,  which  was  equipped  at  the  expense 
of  a  private  individual,  and  conducted  by  a  thoroughly  well- 
informed  and  skilful  observer.  See  the  general  declination 
Chart,  based  upon  Erman's  observations  in  the  Report  of  the 
Committee  relat.  to  the  Arctic  Expedition,  1840,  pi.  3. 

1828 — 1829.  Humboldt's  continuation  of  the  observations 
begun  in  1800  and  1807,  at  the  time  of  the  solstices  and 
equinoxes  regarding  horary  declination  and  the  epochs  of 
extraordinary  perturbations,  carried  on  in  a  magnetic  pavi- 
lion specially  erected  for  the  purpose  at  Berlin,  and  provided 
with  one  of  Gambey's  compasses.  Corresponding  measure- 
ments were  made  at  St.  Petersburgh,  Nikolajew,  and  in  the 
mines  of  Freiberg,  by  Professor  Reich,  227  feet  below  the 
surface  of  the  soil.  Dove  and  Riess  continued  these  observa- 
tions in  reference  to  the  variation  and  intensity  of  the 
horizontal  magnetic  force  till  November  1830  (Poggend. 
Annalen.  Bd.  xv,  s.  318— 336;  Bd.  xix,  s.  375—391,  with 
16  tab.  ;  Bd.  xx,  s.  545—555). 

1829—1834.  The  botanist  David  Douglas,  who  met  his 
death  in  Owhyhee,  by  falling  into  a  trap  in  which  a  wild 
bull  had  previously  been  caught,  made  an  admirable  series  of 

de  Humboldt's  original  station  in  South  America  has  been  inferred  to 
be  1.372  to  1.000.  This  is  the  origin  of  the  number  1.372,  which  has 
been  generally  employed  by  British  observers.  By  absolute  measure- 
ments we  are  not  only  enabled  to  compare  numerically  with  one 
another  the  results  of  experiments  made  in  the  most  distant  parts  of 
the  globe,  with  apparatus  not  previously  compared,  but  we  also  furnish 
the  means  of  comparing  hereafter  the  intensity  which  exists  at  the  pre- 
sent epoch,  with  that  which  may  be  found  at  f uture  periods."  S&bine, 
in  the  Manual  for  the  use  of  the  British  Navy,  1849,  p.  17. 


70  COSMOS. 

observations  on  declination  and  intensity  along  the  north- 
west coast  of  America,  and  upon  the  Sandwich  Islands  as 
far  as  the  margin  of  the  crater  of  Kiraueah  (Sabine,  Rep.  of 
the  Meeting  of  the  British  Association  at  Liverpool,  pp.  27 
—32). 

1829.  Kupffer,  Voyage  au  Mont  JSlbrouz  dans  le  Caucase, 
pp.  68—115. 

1829.  Humboldt's  magnetic  observations  on  terrestrial 
magnetism  with  the  simultaneous  astronomical  determina- 
tions of  position  in  an  expedition  in  Northern  Asia  under- 
taken by  command  of  the  Emperor  Nicholas,  between  the 
longitudes  11°  3'  and  80°  12'  east  of  Paris,  near  the  Lake 
Dzaisan  as  well  as  between  the  latitudes  of  45°  43'  (the 
island  of  Birutschicassa  in  the  Caspian  Sea)  to  58°  52'  in 
the  northern  parts  of  the  Ural  district  near  Werchoturie 
(Asie.  Centrale,  t.  iii,  pp.  440 — 478). 

1829.  The  Imperial  Academy  of  Sciences  at  St.  Peters- 
burgh,  acceded  to  Humboldt's  suggestion  for  the  establish- 
ment of  magnetic  and  meteorological  stations  in  the  different 
climatic  zones  of  European  and  Asiatic  Russia,  as  well  as  for 
die  erection  of  a  physical  central  observatory  in  the  capital 
of  the  empire  under  the  efficient  scientific  direction  of  Pro- 
fessor Kupffer.  (See  Cosmos,  vol.  i,  p.  184.  Kupffer  Rap- 
port adresse  a  VAcad.  de  St.  Petersbourg  relatif  a  VObser- 
vatoire  physique  central,  fonde  aiipres  du  Corps  des  Mines, 
in  Schuni.  Astr.  Nadir.  No.  726 ;  and  in  his  Annales  Maq- 
netiques,  p.  xi )  Through  the  continued  patronage,  which  the 
Finance  Minister,  Count  Cancrin,  has  awarded  to  every 
great  scientific  undertaking,  a  portion  of  the  simultaneously 
corresponding  observations72  between  the  White  Sea  and 

~':  The  first  idea  of  the  utility  of  a  systematic  and  simultaneously  con- 
ducted series  of  magnetic  observations  is  due  to  Celsius,  and,  without 
referring  to  the  discovery  and  measurement  of  the  influence  of  polar 
light  on  magnetic  variation,  which  was,  in  fact,  due  to  his  assistant, 
Olav  Hiorter  (March,  1741),  we  may  mention  that  he  was  the  means  of 
inducing  Graham,  in  the  summer  of  1741,  to  join  him  in  his  inves- 
tigations for  discovering  whether  certain  extraordinary  perturbations, 
which  had  from  time  to  time  exerted  a  horary  influence  on  the 
course  of  the  magnetic  needle  at  Upsala  had  also  been  observed  at  the 
same  time  by  him  in  London.  A  simultaneity  in  the  perturbations 
afforded  a  proof,  he  said,  that  the  cause  of  these  disturbances  is  ex- 
tended over  considerable  portions  of  the  earth's  surface,  and  is  not 
dependent  upon  accidental  local  actions  (Celsius,  in  Svenska  Veten- 


MAGNETIC   OBSERVATIONS.  71 

the  Crimea,  and  between  the  Gulf  of  Finland  and  the  shores 
of  the  Pacific  in  Russian  America,  were  begun  as  early  as 
1832.  A  permanent  magnetic  station  was  established  in  the 
old  monastery  at  Pekin,  which,  from  time  to  time  since  the 
reign  of  Peter  the  Great,  has  been  inhabited  by  monks  of' 
the  Greek  Church.  The  learned  astronomer,  Fuss,  who  took 
the  principal  part  in  the  measurements  for  the  determination 
of  the  difference  of  level  between  the  Caspian  and  the  Black 
Sea  was  chosen  to  arrange  the  first  magnetic  establishments 
in  China.  At  a  subsequent  period  Kupffer  in  his  voyage  of 
circumnavigation  compared  together  all  the  instruments 
that  had  been  employed  in  the  magnetic  and  meteorological 
stations  as  far  east  as  Nertschinsk  in  119°  36'  longitude,  and 
with  the  fundamental  standards.  The  magnetic  observations 
of  Fedorow,  in  Siberia,  which  are  no  doubt  highly  valuable, 
are  still  unpublished. 

1830 — 1845.  Colonel  Graham  of  the  topographical  en- 
gineers of  the  United  States,  made  observations  on  the  mag- 
netic intensity  at  the  southern  boundary  of  Canada  (Phil. 
Transact,  for  1846,  pt.  iii,  p.  242). 

1830.  Fuss,  Magnetic,  Astronomical,  and  Hypsometrical 
Observations  on  the  journey  from  the  Lake  of  Baikal, 
through  Ergi-Oude,  Durma,  and  the  Gobi,  which  lies  at  an 
elevation  of  only  2525  feet,  to  Pekin,  in.  order  to  establish 
the  magnetic  and  meteorological  observatory  in  that  city, 
where  Kovanko  continued  for  10  years  to  prosecute  his 
observations  (Rep.  of  the  Seventh  Meeting  of  the  Brit. 
Assoc.  1837,  pp.  497—499  ;  and  Humboldt,  Asie  Centrale, 
t.  i,  p.  8  ;  t.  ii,  p.  141  ;  t.  iii,  pp.  468,  477). 

1831 — 1836.  Captain  Fitzroy  in  his  voyage  round  the 
world  in  the  Beagle,  as  well  as  in  the  survey  of  the  coasts 
of  the  most  southern  portions  of  America,  with  a  Gam- 

skaps  Academiens  Uandlingar  for  1740,  p.  44  ;  Hiorter,  op.  cit.  1747, 
p.  27).  As  Aragc  had  recognised  that  the  magnetic  perturbations 
owing  to  polar  light  are  diffused  over  districts,  in  which  the  pheno- 
mena of  light  which  accompany  magnetic  storms  have  not  been  seen, 
he  devised  a  plan,  by  which  he  was  enabled  to  carry  on  simultaneous 
horary  observations  (in  1823)  with  our  common  friend  Kupffer,  at 
Kasan,  which  lies  almost  47°  east  of  Paris.  Similar  simultaneous  ob- 
servations of  declination  were  begun  in  1828  by  myself,  in  conjunction 
with  Arago  and  Reich,  at  Berlin,  Paris,  and  Freiberg  (see  Poggeud 
Annalen,  Bd.  xix,  s.  337). 


72  COSMOS. 

Ley's  inclinatorium  and  oscillation  needles  supplied  by  Han- 
steen. 

1831.  Dunlop,  Director  of  the  Observatory  of  Paramatta, 
Observations  on  a  voyage  to  Australia  (Phil.  Transact,  for 
1840,  pt.  i,  pp.  133—140). 

1831.  Faraday's  induction-currents,  whose  theory  has 
been  extended  by  Nobili  and  Antinori.  The  great  discovery 
of  the  development  of  light  by  magnets. 

1833  and  1839  are  the  two  important  epochs  of  the  first 
enunciation  of  the  theoretical  views  of  Gauss  :  (1)  Intensitas 
vis  magneticse  terrestris  ad  mensuram  absolutam  revocata, 
1833  ;  (p.  3  :  "  elementum  tertium,  intensitas,  usque  ad 
tempora  recentiora  penitus  neglectum  mansit ") ;  (2)  the 
immortal  work  on  "  the  general  theory  of  terrestrial  mag- 
netism "  (see  Results  of  the  observations  of  the  Magnetic 
Association  in  the  year  1838,  edited  by  Gauss  and  Weber, 
1839,  pp.  1—57). 

1833.  Observations  of  Barlow  on  the  attraction  of  the 
ship's  iron,  and  the  means  of  determining  its  deflecting 
action  on  the  compass.  Investigation  of  electro- magnetic 
currents  in  Terrellas.  Isogonic  atlases.  Compare  Barlow's 
Essay  on  Magnetic  Attraction,  1833,  p.  89,  with  Poisson, 
sur  les  deviations  de  la  boussole  produite  par  lefer  des  vais- 
seaux  in  the  Mem  de  Plnstitut,  t.  xvi,  pp.  481 — 555  ;  Airy, 
in  the  Phil.  Transact,  for  1839,  pt.  i,  p.  167  ;  and  for  1843, 
pt.  ii,  p.  146  ;  Sir  James  Boss,  in  the  Phil.  Transact,  for 
1849,  pt.  ii,pp.  177—195). 

1833.  Moser's  methods  of  ascertaining  the  position  and 
force  of  the  variable  magnetic  pole  (Poggend.,  Annalen,  Bd. 
xxviii,  s.  49—296). 

1833.  Christie  on  the  Arctic  observations  of  Captain  Back. 
Phil.  Transact,  for  1836,  pt.  ii.  p.  377     (Compare  also  his 
earlier   and  important   treatise  in   the  Phil.   Transact,  for 
1825,  pt.  i.  p.  23.) 

1834.  Parrot's  expedition  to  Ararat  (Magnetismus,  bd.  ii, 
s.  53—64). 

1836.  Major  Estcourt,  in  the  expedition  of  Colonel  Ches- 
ney  on  the  Euphrates.  A  portion  of  the  observations  on 
intensity  were  lost  with  the  steamer  Tigris,  which  is  the 
more  to  be  regretted  since  we  are  entirely  deficient  in 
accurate  observations  of  this  portion  of  the  interior  of 


MAGNETIC   OBSERVATIONS.  73 

Western  Asia,  and  of  the  regions  lying  south  of  the  Caspian 
Sea. 

1836.  Letter  from  M.  A.  de  Humboldt  to  H.R.H.  Duke 
of  Sussex,  President  of  the  Royal  Society  of  London,  on  the 
proper  means  of  improving  our  knowledge  of  terrestrial  mag- 
netism by  the  establishment  of  magnetic  stations  and  cor- 
responding observations  (April  1836).     On  the  happy  results 
of  this  appeal,  and  its  influence  on  the  great  Antarctic  expedi- 
tion of  Sir  James  Ross,  see  Cosmos,  vol.  i,  p.  136,  and  Sir 
James  Ross's  Voyage  to  the  Southern  and  Antarctic  Regions 
1817,  vol.  i,  pt,  xii. 

1837.  Sabine,  On  the  Variations  of  the  Magnetic  Intensity  of 
the  Earth  in  the  Report  of  the  Seventh  Meeting  of  the  British 
Association  at  Liverpool,   pp.   1 — 85.     The  most   complete 
work  of  the  kind. 

1837 — 1838.  Erection  of  a  magnetic  observatory  at  Dub- 
lin, by  Professor  Humphrey  Lloyd.  On  the  observations 
made  there  from  1840  to  1846  (see  Transact,  of  the  Royal 
Irish  Academy,  vol.  xxii.  pt.  i,  pp.  74 — 96). 

1837.  Sir  David   Brewster,    A  Treatise  on  Magnetism, 
pp.  185-263. 

1837 — 1842.  Sir  Edward  Belcher's  voyage  to  Singapore, 
the  Chinese  Seas,  and  the  western  coasts  of  America  (Phil. 
Transact,  for  1843,  pt.  ii,  pp.  113,  140—142).  These  observa- 
tions of  inclination,  when  compared  with  my  own,  which 
were  made  at  an  earlier  date,  show  a  very  unequal  advance 
of  the  curves.  Thus,  for  instance,  in  1803,  I  found  the  in- 
clinations at  Acapulco,  Guayaquil,  and  Callao  de  Lima  to  be 
+  38°  48',  +  10°42/and— 9°  54';  while  Sir  Edward  Belcher 
found  +  37°  57',  +  9°  1',  and —  9°  54'.  Can  the  frequent 
earthquakes  upon  the  Peruvian  coasts  exert  a  local  influence 
upon  the  phenomena,  which  depend  upon  magnetic  force 
of  the  earth  ? 

1838—1842.  Charles  Wilkes's  Narrative  of  the  United 
States'  Exploring  Expedition,  vol.  i,  p.  xxi. 

1838.  Lieutenant  James  Sullivan's  Voyage  from  Falmouth 
to  the  Falkland  Islands  (Phil.  Transact,  for  1840,  pt.  i,  pp. 
129,  140—143). 

1838  and  1839.  The  establishment  of  magnetic  stations 
under  the  admirable  superintendence  of  General  Sabine  in 
both  hemispheres  at  the  expense  of  the  British  Government. 


74  COSMOS. 

The  instruments  were  dispatched  in  1839,  and  the  observa- 
tions were  begun  at  Toronto  and  in  Van  Diemen's  Land  in 
1840,  and  at  the  Cape  in  1841  (See  Sir  John  Herschel  in  the 
Quarterly  Review,  vol.  Ixvi,  1840,  p.  297,  and  Becquerel, 
Traite  d*  Electricite  et  de  Magnetisme,  t.  vi,  p.  173).  By  the 
careful  and  thorough  elaboration  of  these  valuable  observa- 
tions, which  embrace  all  the  elements  or  variations  of  the 
magnetic  activity  of  the  earth,  General  Sabiiie  as  superin- 
tendent of  the  Colonial  observatories,  discovered  hitherto 
unrecognized  laws,  and  disclosed  new  views  in  relation  to  the 
science  of  magnetism.  The  results  of  his  investigations  were 
collected  by  himself  in  a  long  series  of  separate  memoirs  (Con- 
tributions to  terrestrial  magnetism)  in  the  Philosophical 
Transactions  of  the  Royal  Society  of  London,  and  in  separate 
works,  which  constitute  the  basis  of  this  portion  of  the 
Cosmos.  We  will  here  indicate  only  a  few  of  the  most  im- 
portant (1)  Observations  on  days  of  unusual  magnetic  disturb- 
ances (storms)  in  the  years  1840  o*kf  1841,  pp.  1 — 107,  and  as 
a  continuation  of  this  treatise,  magnetic  storms  from  1843 — 
1845  in  the  Phil.  Transact,  for  1851,  pt.  i,  pp.  123-139, 
(2)  Observations  made  at  the  Magnetical  Observatory  at  Toronto 
1840,1841,  andl842(43039'KLat, and  81°41'W.  Long.)vol.i, 
pp.  xiv — xxviii;  (3)  The  very  variable  direction  of  magnetic  de- 
clination in  one-half  of  the  year  at  Long  wood  House,  St.  Selena 
(15°  55'  S.  Lat.,  8°  3'  W.  Long.),  Philosophical  Transactions 
for  1847,  pt.  i,  p.  54;  (4)  Observ.  made  at  the  Magn.  and  Meteor. 
Observatory  at  the  Cape  of  Good  Hope  1841—1846;  (5)  Observ. 
made  at  the  Magn.  and  Meteor.  Observatory  at  Hobarton 
(42°  52'  S.  Lat.,  145°  7'  E.  Long.)  in  Van  Diemen's  Land  and 
the  Antarctic  expedition,  vol.  i  and  ii,  (1841 — 1848) ;  on  the  se- 
paration of  the  eastern  and  western  disturbances,  see  vol.  ii,  pp. 
ix — xxxvi;  (6)  Magnetic  phenomena  within  the  Antarctic  polar 
circle  inKergueleris  and  Van  Diemen's  Land  (Phil.  Transact. 
for  1843,  pt.'ii,  pp.  145 — 231)  ;(7)  On  the  isoclinal  and  isody- 
namic  lines  in  the  Atlantic  Ocean,  their  condition  in  1837 
(Phil.  Transact,  for  1840,  pt.  i,  pp.  129—155);  (8)  Basis  of  a 
chart  of  the  Atlantic  Ocean  which  exhibits  the  lines  of 
magnetic  variation  between  60°  N.  Lat.  and  60°  S.  Lat.  for 
the  year  1840  (Phil.  Transact,  for  1849,  pt.  ii,pp.  173—233) ; 
(9)  Methods  of  determining  the  absolute  values,  secular  change, 
ind  annual  variation  of  the  magnetic  force  (Phil.  Transact,  f&t 


MAGNETIC   OBSERVATIONS.  75 

1850,  pt  i,  pp.  201  —  219)  ;  Coincidence  of  the  epochs  of  the 
greatest  vicinity  of  the  sun  with  the  greatest  intensity  of 
the  force  in  both  hemispheres,  and  of  the  increase  of  inclina- 
tion, p.  216  ;  (10)  On  the  amount  of  magnetic  intensity  in 
the  most  northern  parts  of  the  New  Continent  and  upon  the 
point  of  greatest  magnetic  force  found  by  Captain  Lefroy  in 
52°  19'  Lat.  (Phil.  Transactor  1846,  pt,  iii,  pp.  237—336)  ; 
(11)  The  periodic  alterations  of  the  three  elements  of  terrestrial 
magnetism,  variation,  inclination,  and  intensity  at  Toronto 
and  -Ffobarton,  and  on  the  connection  of  the  decennial  period 
of  magnetic  alterations  with  the  decennial  period  of  the 
frequency  of  solar  spots,  discovered  by  ScJiwabe  at  Dessau 
(Phil.  Transact,  for  1852,  pt.  i,  pp.  121—124).  The  observa- 
tions of  variation  for  1846  and  1851  are  to  be  considered  as 
a  continuation  of  those  indicated  in  Ko.  1.  as  belonging  to 
the  years  1840—1845. 

1839.  Representation  of  magnetic  isoclinal  and  isodynamic 
lines  from  observations  of  Humphrey  Lloyd,  John  Phillips, 
Robert  Were  Fox,  James  Ross,  and  Edward  Sabine.  As 
early  as  1833  it  was  determined  at  the  meeting  of  the 
British  Association  in  Cambridge,  that  the  magnetic  inclina- 
tion and  intensity  should  be  determined  at  several  parts  of 
the  empire,  and  in  the  summer  of  1834  this  suggestion  was 
fully  carried  out  by  Professor  Lloyd  and  General  Sabine,  and 
the  operations  of  1835  and  1836  were  then  extended  to 
Wales  and  Scotland  (Report  of  the  Meeting  of  the  Brit. 
Assoc.  held  at  Newcastle,  1838,  pp.  49  — 196),  with  an 
isoclinal  and  isodynamic  chart  of  the  British  islands,  the 
intensity  at  London  being  taken  as  =  1. 

1838 — 1843.  The  great  exploring  voyage  of  Sir  James 
Ross  to  the  South  Pole,  which  is  alike  remarkable  for  the 
additions  which  it  afforded  to  our  knowledge  by  proving  the 
existence  of  hitherto  doubtful  polar  regions,  as  well  as  for 
the  new  light  which  it  has  diffused  over  the  magnetic  con- 
dition of  large  portions  of  the  earth's  surface.  It  embraces 
all  the  three  elements  of  terrestrial  magnetism  numerically 
determined  for  almost  two-thirds  of  the  area  of  all  the 
high  latitudes  of  the  southern  hemisphere. 

1839 — 1851.  Kreil's  observations,  which  were  continued 
for  12  years,  at  the  Imperial  Observatory  at  Prague,  in 
reference  to  the  variation  of  all  the  elements  of  tur- 


76  COSMOS. 

restrial  magnetism,  and  of  the  conjectured  soli-lunar  in- 
fluence. 

1840.  Horary  magnetic  observations  with  one  of  Gambey's 
declination  compasses  during  a  ten  years'  residence  in  Chili, 
by  Claudio  Gay  (see  his  Historia  fisica  y  politica  de  Chile, 
1847). 

1840 — 1851.  Lamont,  Director  of  the  Observatory  at 
Munich.  The  results  of  his  magnetic  observations,  compared 
with  those  of  Gottingen,  which  date  back  as  far  as  1835. 
Investigation  of  the  important  law  of  a  decennial  period  in 
the  alterations  of  declination  (see  Lamont  in  Poggend.  Ann. 
der  Phys.,  1851,  Bd.  84,  s.  572—582,  and  Relshuber,  1852, 
Bd.  85,  s.  179 — 184).  The  already  indicated  conjectural  con- 
nection between  the  periodical  increase  and  decrease  in  the 
annual  mean  for  the  daily  variation  of  declination  in  the 
magnetic  needle,  and  the  periodical  frequency  of  the  solar 
spots  was  first  made  known  by  General  Sabine  in  the  Phil. 
Transact,  for  1852,  and  four  or  five  months  later,  without 
any  knowledge  of  the  previous  observations,  the  same  result 
was  enunciated  by  Rudolf  Wolf,  the  learned  Director  of  the 
Observatory  at  Berne.73  Lament's  manual  of  terrestrial  mag- 
netism, 1848,  contains  a  notice  of  the  newest  methods  of 
observation  as  well  as  of  the  development  of  these  methods. 

1840—1845.  Bache,  Director  of  the  Coasts'  Survey  of  the 
United  States,  Observ.  made  at  the  Magn.  and  Meteorol.  Ob- 
servatory at  Girard's  College,  Philadelphia  (published  in 
1847). 

1840—1842.  Lieutenant  Gilliss  U.  S.  Magnetical  and  Me- 
teorological Observations  made  at  Washington,  published  1847, 
pp.  2—319  ;  Magnetic  Storms,  p.  336. 

1841 — 1843.    Sir  Robert   Schomburgk's   observations   of 

73  The  treatise  of  Eudolf  Wolf,  referred  to  in  the  text,  contains 
special  daily  observation  of  the  sun's  spots  (from  January  1st  to  June 
30th,  1852)  and  a  table  of  Lament's  periodical  variations  of  declination 
with  Schwabe's  results  on  the  frequency  of  solar  spots  (3835 — 1850). 
These  results  were  laid  before  the  meeting  of  the  Physical  Society  of 
Berne,  on  the  31st  of  July,  1852,  whilst  the  more  comprehensive 
treatise  of  Sabine  (Phil.  Transact.  1852,  pp.  116 — 121)  had  been  pre- 
sented to  the  Royal  Society  of  London  in  the  beginning  of  March, 
and  read  in  the  beginning  of  May,  1852.  From  the  most  recent 
investigations  of  the  observations  of  solar  spots,  Wolf  finds  that  be- 
tween the  years  1600  and  1852  the  mean  period  was  11.11  years. 


MAGNETIC   OBSERA'ATIONS.  77 

declination  in  the  woody  district  of  Guiana,  between  the 
mountain  Roraima  and  the  village  Pirara  between  the  paral- 
lels of  4°  57',  and  3°  39'  (Phil.  Transact,  for  1849,  pt.  ii, 
p.  217). 

1841 — 1845.  Magn.  and  Meteor ol.  Observations  made  at 
Madras. 

1843 — 1844.  Magnetic  observations  in  Sir  Thomas  Bris- 
bane's observatory  at  Makerstoun,  Roxburghshire,  55°  84* 
North  lat.  (see  Transact,  of  the  Royal  Society  of  Edin- 
vol.  xvii,  pt.  ii,  p.  188,  and  vol.  xviii,  p.  46). 

1843 — 1849.  Kreil,  On  the  influence  of  the  Alps  upon  the 
manifestations  of  the  Magnetic  Force  (see  Schum.  Astr. 
Nachr.  No.  602). 

1844—1845.  Expedition  of  the  Pagoda  into  high  ant- 
arctic latitudes  as  far  as  64°  and  67°,  and  from  4°  to  117°  E. 
lon^.,  embracing  all  the  three  elements  of  terrestrial  mag- 
netism, under  the  command  of  Lieutenant  Moore,  who  had 
already  served  in  the  Terror  in  the  polar  expedition,  and  of 
Lieutenant  Clerk,  of  the  Royal  Artillery,  and  formerly 
Director  of  the  Magnetic  Observatory  at  the  Cape. — A 
worthy  completion  of  the  labours  of  Sir  James  Ross  at  tho 
South  Pole. 

1845.  Proceedings  of  the  Magn.  and  Meteorol.  Conference 
held  at  Cambridge. 

1845.  Observations  made  at  the  Magn.  and  Meteorol.  Ob- 
servatory at  Bombay  under  the  superintendence  of  Arthur 
Bedford  Orlebar.  This  observatory  was  erected  in  1841, 
on  the  little  island  of  Colaba. 

1845 — 1850.  Six  volumes  of  the  results  of  the  Magn.  and 
Meteorol.  Observations  made  at  the  Royal  Observatory  at 
Greenwich.  The  magnetic  house  was  erected  in  1838. 

1845.  Simonoff.  Professor  at  Kazan,  Recherches  sur  V action 
magnetique  de  la  Terre. 

1846 — 1849.  Captain  Elliot,  Madras  Engineers,  Magnetic 
Survey  of  the  Eastern  Archipelago.  Sixteen  stations,  at  each 
of  which  observations  were  continued  for  several  months  in 
Borneo,  Celebes,  Sumatra,  the  Nicobars,  and  Keeling  Islands, 
compared  with  Madras,  between  16°  N.  lat.  and  12°  S.  lat. 
and  78°  and  123°  E.  long.  (Phil.  Transact,  for  1851,  pt.  i, 
pp.  287 — 331,  and  also  pp.  i — clvii.)  Charts  of  equal  incli- 
nation and  declination,  which  also  expressed  the  horizontal 


1*8  COSMOS. 

and  total  force,  were  appended  to  these  observations,  which 
also  give  the  position  of  the  magnetic  equator  and  of  the  line 
of  no  variation,  and  belong  to  the  most  distinguished  and 
comprehensive  that  had  been  drawn  up  in  modern  times. 

1845 — 1850.  Faraday's  brilliant  physical  discoveries  :  (1) 
In  relation  to  the  axial,  or  equatorial  (diamagnetic74)  direction 
assumed  by  freely  oscillating  bodies  under  external  magnetic 
influences  (Phil.  Transact.,  for  1846,  §  2420,  and  Phil. 
Transact,  for  1851,  pfc.  i,  §§  2718—2796)  ;  (2)  Begarding  the 
relation  of  electro-magnetism  to  a  ray  of  polarized  light, 
and  the  rotation  of  the  latter  by  means  of  the  altered  mo- 
lecular condition  of  the  bodies  through  which  the  ray  of 
polarized  light  and  the  magnetic  current  have  both  been 
transmitted  (Phil.  Transact,  for  1846,  pt.  i,  §  2195  and 
§§2215  —  2221;  (3)  Regarding  the  remarkable  property 
which  oxygen  (the  only  gas  which  is  paramagnetic)  exerts 
on  the  elements  of  terrestrial  magnetism,  namely  that  like 
soft  iron,  although  in  a  much  weaker  degree,  it  assumes  con- 
ditions of  polarity  through  the  diffused  action  of  the  body  of 
the  earth,  which  represents  a  permanently  present  magnet7* 
(Phil.  Transact,  for  1851,  pt.  i,  §§  2297—2967). 

74  See  Cosmos,  vol.  iv,  p.  396.  Diamagnetic  repulsion  and  an 
equatorial,  that  is  to  say,  an  east  and  west  position  in  respect  to  a 
powerful  magnet,  are  exhibited  by  bismuth,  antimony,  silver,  phos- 
phorus, rock  salt,  ivory,  wood,  apple-shavings,  and  leather.  Oxygen  gas, 
either  pure  or  when  mixed  with  other  gases,  or  when  condensed  in  the 
interstices  of  charcoal,  is  paramagnetic.  See  in  reference  to  crystallised 
bodies  the  ingenious  observations  made  by  Plucker  concerning  the 
position  of  certain  axes  (Poggend.  Annal.  Bd.  Ixxiii,  s.  178,  and  Phil. 
Transact,  for  1851,  §§  2836 — 2842).  The  repulsion  by  bismuth  was 
first  recognised  by  Brngmans,  in  1778,  next  by  Le  Bailiff,  in  1827,  and 
finally,  more  thoroughly  tested  by  Seebeck,  in  1828.  Faraday  himself 
(§§  2429—2431),  Reich,  and  Wilhelm  Weber,  who,  from  the  year  1836, 
has  shown  himself  so  incessantly  active  in  his  endeavours  to  promote 
the  progress  of  terrestrial  magnetism,  have  all  endeavoured  to  exhibit 
the  connection  of  diamagnetic  phenomena  with  those  of  induction 
(Poggend.  Annalen,  Bd.  Ixxiii,  s.  241 — 253).  Weber  has,  moreover, 
tried  to  prove  that  diamagnetism  derives  its  source  from  Ampere's 
molecular  currents.  (Wilh.  Weber,  A  bhandlungen  uber  electro- dynaniischv 
Maassbestimmungen,  1852,  s.  545 — 570.) 

'5  In  order  to  excite  this  polarity,  the  magnetic  fluids  in  every  par- 
ticle of  oxygen  must  be  separated,  to  a  certain  extent,  by  the  actio  in 
distans  of  the  earth  in  a  definite  direction,  and  with  a  definite  force. 
Every  particle  of  oxygen  thus  represents  a  small  magnet,  and  all  these 
small  magnets  react  upon  one  another  as  well  as  upon  the  earth,  and 


MAGNETIC   OBSERVATIONS.  79 

1849.  Emory,  Magn.  observations  made  at  the  Isthmus  of 
Panama. 

1849.  Professor  William  Thomson,  of  Glasgow,  A  Mathe- 
matical Theory  of  Magnetism  in  the  Phil.  Transact  for  1851, 
pt.  i.  pp.  243 — 285     (On  the  problem  of  the  distribution  of 
magnetic  force,  compare  §§42  and  56  with  Poisson  in  the 
Mem  de  V  Institut.,  1811,  pt.  i,  p.  1  ;  pt.  ii,  p.  163). 

1850.  Airy,   On   the  present  state  and  prospects  of  the 
science  of  Terrestrial  Magnetism — the  fragment  of  what  pro- 
mises to  be  a  most  admirable  treatise. 

1852.  Kreil,  Influence  of  the  Moon  on  Magnetic  Declination 
at  Prague  in  the  years  1839 — 1849.  On  the  earlier  labours 
of  this  accurate  observer,  between  1836  and  1838,  see  Osser- 
vazioni  sulV  intensita  e  sulla  direzione  della  forza  magnetica 
institute  negli  anni  1836 — 1838  alV  I.  E.  Osservatorio  di 
Milano,  p.  171  ;  and  also  his  Maqnetical  and  Meteorological 
Observations  at  Prague,  vol.  i,  p.  59. 

1852.  Faraday,  On  Lines  of  Magnetic  Force,  and  their 
definite  character. 

1852.  Sabine's  new  proof  deduced  from  observations  at 
Toronto,  Hobarton,  St.  Helena,  and  the  Cape  of  Good  Hope 
(from  1841  to  1851),  that  everywhere  between  the  hours  of 
seven  and  eight  in  the  morning  the  magnetic  declination 
exhibits  an  annual  period ;  in  which  the  northern  solstice 
presents  the  greatest  eastern  elongation,  and  the  southern 

finally,  in  connection  with  the  latter,  they  further  act  upon  a  magnetic 
needle,  which  may  be  assumed  to  be  in  or  beyond  the  atmosphere. 
The  envelope  of  oxygen  that  encircles  our  terrestrial  sphere  may  be  com- 
pared to  an  armature  of  soft  iron  upon  a  natural  magnet  or  a  piece  of 
magnetised  steel;  the  magnet  may  further  be  assumed  to  be  spherical, 
like  the  earth,  while  the  armature  is  assumed  to  be  a  hollow  shell, 
similar  to  the  investment  of  atmospheric  oxygen.  The  magnetic  power 
which  each  particle  of  oxygen  may  acquire  by  the  constant  force  of 
the  earth,  diminishes  with  the  temperature  and  the  rarefaction  of  the 
oxygen  gas.  When  a  constant  alteration  of  temperature  and  an  expan- 
sion follows  the  sun  around  the  earth  from  east  to  west,  it  must  pro- 
portionally alter  the  results  of  the  magnetic  force  of  the  earth,  and  of 
the  oxygen  investment,  and  this,  according  to  Faraday's  opinion,  is  the 
origin  of  one  part  of  the  variations  in  the  elements  of  terrestrial  mag- 
netism. Plucker  finds  that  as  the  force  with  which  the  m  signet  acts 
upon  the  oxygen  is  proportional  to  the  density  of  this  gas,  the  magnet 
presents  a  simple  eudiometric  means  of  recognising  the  presence  of 
free  oxygen  gas  iu  a  gaseous  mixture  even  to  the  100th  or  200th 
part. 


80  COSMOS. 

solstice  the  greatest  western  elongation,  without  the  tempe- 
rature of  the  atmosphere  or  of  the  earth's  crust  evincing  a 
maximum  or  minimum  at  these  turning  periods.  Compare 
the  second  volume  of  the  Observations  made  at  Toronto,  p. 
xvii,  with  the  two  treatises  of  Sabine,  already  referred  to  on 
the  Influence  of  the  sun's  vicinity  (Phil.  Transact,  for  1850, 
pt.  i,  p.  216),  and  of  the  solar  spots  (Phil.  Transact,  for  1852, 
p.  i,  p.  121). 


The  chronological  enumeration  of  the  progress  of  our 
knowledge  of  terrestrial  magnetism  during  half  a  century, 
which  I  have  uninterruptedly  watched  with  the  keenest 
interest,  exhibits  a  successful  striving  towards  the  attainment 
of  a  twofold  object.  The  greater  number  of  these  labours 
have  been  devoted  to  the  observation  of  the  magnetic  activity 
of  our  planet  in  its  numerical  relations  to  time  and  space, 
while  the  smaller  part  belongs  to  experiments,  and  to  the 
manifestation  of  phenomena,  which  promise  to  lead  us  to  the 
knowledge  of  the  character  of  this  activity,  and  of  the 
internal  nature  of  the  magnetic  force.  Both  these  methods 
—  the  numerical  observation  of  the  manifestation  of  terres- 
trial magnetism,  both  in  respect  to  its  direction  and  intensity, 
— and  physical  experiments  on  the  magnetic  force  generally, 
have  tended  reciprocally  to  the  advancement  of  our  physical 
knowledge.  Observations  alone,  independently  of  every 
hypothesis  regarding  the  causal  connection  of  phenomena, 
or  regarding  the  hitherto  immeasurable  and  unattainable 
reciprocal  action  of  molecules  in  the  interior  of  substances, 
have  led  to  important  numerical  laws.  Experimental  phy- 
sicists have  succeeded  by  the  display  of  the  most  wondrous 
ingenuity  in  discovering  in  solid  and  gaseous  bodies  polar- 
ising properties,  whose  presence  had  never  before  been  sus- 
pected, and  which  stand  in  special  relation  to  the  tempera- 
ture and  pressure  of  the  atmosphere.  However  important 
and  undoubted  these  discoveries  may  be,  they  cannot  in  the 
present  condition  of  our  knowledge  be  regarded  as  satisfactory 
grounds  of  explanation  for  the  laws  which  have  already  been 
recognized  in  the  movements  of  the  magnetic  needle.  The 
most  certain  means  of  enabling  us  thoroughly  to  comprehend 


HORARY   VARIATION.  81 

the  variable  numerical  relations  of  space,  as  well  as  to  extend 
and  complete  that  mathematical  theory  of  terrestrial  mag- 
netism, which  was  so  nobly  sketched  by  Gauss,  is  to  pro- 
secute simultaneous  and  continuous  observations  of  all  the 
three  elements  of  the  magnetic  force  at  numerous  well  se- 
lected points  of  the  earth's  surface.  I  have,  however,  else- 
where illustrated  by  example  the  sanguine  hopes  which  I 
entertained  of  the  great  advantages  that  may  be  derived  from 
the  combination  of  experimental  and  mathematical  investi- 
gation.7* 

Nothing  that  occurs  upon  our  planet  can  be  supposed  to 
be  independent  of  cosmical  influences.  The  word  planet 
instinctively  -leads  us  to  the  idea  of  dependence  upon  a 
central  body,  and  of  a  connection  with  a  group  of  celestial, 
bodies  of  very  different  masses  which  probably  have  a.  similar 
origin.  The  influence  of  the  sun's  position  upon  the  mani- 
festation of  the  magnetic  force  of  the  earth,  was  recognised 
at  a  very  early  period.  The  most  distinct  intimation  of  this 
relation  was  afforded  by  the  discovery  of  horary  variation, 
although  it  had  been  obscurely  perceived  by  Kepler,  who,  a 
century  before,  had  conjectured  that  all  the  axes  of  the  planets 
were  magnetically  directed  towards  one  portion  of  the  uni- 
Terse.  He  says  expressly,  "  that  the  sun  may  be  a  magnetic 
body,  and  that  on  that  account,  the  force  which  impels  the 
planets  may  be  centred  in  the  sun."77  The  attraction  of  masses 
and  gravitation  appeared  at  that  time  under  the  semblance 
of  magnetic  attraction.  Horrebow.78  who  did  not  confound 
gravitation  with  magnetism,  was  the  first  who  called  the 
process  of  light  a  perpetual  northern  light,  produced  in  the 
solar  atmosphere  by  means  of  magnetic  forces.  Nearer  our 

76  See  p.  6. 

77  Kepler,  in  Stella  Martis,    pp.  32 — 34  (and  compare  with  it  his 
treatise,  Mysterium  Cosmogr.  cap.  xx,  p.  71). 

78  Cosmos,  vol.  iv,   p.  386,  where,    however,  in  consequence  of  an 
error  of  the  press,  in  the  place  of  Basis  Astronomies  we  should  read 
Clavis  Astronomic^.     The  passage  (§  226)  in  which  the  luminous  process 
of  the  sun  is  characterised  as  a  perpetual  northern  light  does  not  occur 
in  the  first  edition  of  the  Clavis  Astr.  by  Horrebow  (Havn.  1730),  but 
is  only  found  in  the  second  and  enlarged  new  edition  of  the  work  in 
Horrebow's  Operum  Malhematico-Physicorum,  t.  i,  Havn.  1740,  p.  317, 
as  it  belongs  to  this  appended  portion  of  the  Clavis.     Compare  with 
Horrebow's  view  the  precisely  similar  views  of  Sir  William  and  Sir 
John  Herschel  (Cosmos,  voL  iii,  pp.  39,  40). 

VOL.  V.  Q 


82  COSMOS. 

own  times  (and  this  difference  of  opinion  is  very  remarkable) 
two  distinct  views  were  promulgated  in  reference  to  the 
nature  of  the  influence  exerted  by  the  sun. 

Some  physicists,  as  Canton,  Ampere,  Christie,  Lloyd,  and 
Airey,  have  assumed  that  the  sun,  without  being  itself 
magnetic,  acts  upon  terrestrial  magnetism  merely  by  pro- 
ducing changes  of  temperature,  whilst  others,  as  Coulomb, 
believed  the  sun  to  be  enveloped  by  a  magnetic  atmosphere7* 
which  exerts  an  action  on  terrestrial  magnetism  by  distribu- 
tion. Although  Faraday's  splendid  discovery  of  the  para- 
magnetic property  of  oxygen  gas  has  removed  the  great  diffi- 
culty of  having  to  assume  with  Canton  that  the  temperature 
of  the  solid  crust  of  the  earth  and  of  the  sea  must  be  rapidly 
and  considerably  elevated  from  the  immediate  effect  of  the 
sun's  transit  through  the  meridian  of  the  place,  the  perfect 
co-ordination  and  an  ingenious  analysis  of  all  the  measure- 
ments and  observations  of  General  Sabine  have  yielded  this 
result  :  that  the  hitherto  observed  periodic  variations  of  the 
magnetic  activity  of  the  earth  cannot  be  based  upon  periodic 
changes  of  temperature  in  those  parts  of  the  atmosphere 
which  are  accessible  to  us.  Neither  the  principal  epochs  of 
diurnal  and  annual  alterations  of  declination  at  the  different- 
hours  of  the  day  and  night,  nor  the  periods  of  the  mean 
intensity  of  the  terrestrial  force80  coincide  with  the  periods  of 

79  Memoires  de  Mathem.  et  de  Phys.  presentes  a  VAcad.  Roy.  des  Sc. 
t.  ix,  1780,  p.  262. 

30  "So  far  as  these  four  stations  (Toronto,  Hobarton,  St.  Helena, 
and  the  Cape),  so  widely  separated  from  each  other  and  so  diversely 
situated,  justify  a  generalisation,  we  may  arrive  at  the  conclusion  that 
at  the  hour  of  7  to  8  A.M.  the  magnetic  declination  is  everywhere  sub- 
ject to  a  variation  of  which  the  period  is  a  year,  and  which  is  every- 
where similar  in  character  and  amount,  consisting  of  a  movement  of 
the  north  end  of  the  magnet  from  east  to  west,  between  the  northern 
and  the  southern  solstice,  and  a  return  from  west  to  east  between  the 
southern  and  the  northern  solstice,  the  amplitude  being  about  5  minute-s 
of  arc.  The  turning  periods  of  the  year  are  not,  as  many  might  be  disposed 
to  anticipate,  those  months  in  which  the  temperature  at  the  surface  of  our 
planet,  or  of  the  subsoil,  or  of  the  atmosphere  (as  far  as  we  possess  the 
jneans  of  judging  of  the  temperature  of  the  atmosphere)  attains  its 
maximum  and  minimum.  Stations  so  diversely  situated  would,  indeed, 
present  in  these  respects  thermic  conditions  of  great  variety ;  whereas 
uniformity  in  the  epoch  of  the  turning  periods  is  a  not  less  conspicuous 
feature  in  the  annual  variation  than  similarity  of  character  and  nume- 
rical value.  At  all  the  stations  the  solstices  are  the  turning  periods  of 


MAGNETIC  INTENSITY.  83 

the  maxima  and  minima  of  the  temperature  of  the  atmo- 
sphere, or  of  the  upper  crust  of  the  earth.  We  may  remark 
that  the  annual  alterations  were  first  accurately  represented 
by  Sabine  from  a  very  large  number  of  observations.  The 
turning  points  in  the  most  important  magnetic  phenomena 
are  the  solstices  and  the  equinoxes.  The  epoch  at  which 
the  intensity  of  the  terrestrial  force  is  the  greatest,  and  that 
at  which  the  dipping  needle  most  nearly  assumes  the  vertical 
position  in  both  hemispheres,  is  identical  with  the  period  at 
which  the  earth  is  nearest  to  the  sun,81  and  consequently 
when  its  velocity  of  translation  is  the  greatest.  At  this 
period,  however,  when  the  earth  is  nearest  to  the  sun,  namely 
in  December,  January,  and  February ;  as  well  as  in  May, 
June,, and  July,  when  it  is  farthest  from  the  sun,  the  relations 
of  temperature  of  the  zones  on  either  side  of  the  equator  are 
completely  reversed,  the  turning  points  of  the  decreasing  and 

the  annual  variation  at  the  hour  of  which  we  are  treating.  The  only 
periods  of  the  year  in  which  the  diurnal  or  horary  variation  at  that 
hour  does  actually  disappear  are  at  the  equinoxes,  when  the  sun  is 
passing  from  the  one  hemisphere  to  the  other,  and  when  the  magnetic 
direction,  in  the  course  of  its  annual  variation  from  east  to  west,  or 
vice  vers;\,  coincides  with  the  direction  which  is  the  mean  declination 
of  all  the  months  and  of  all  the  hours.  The  annual  variation  is  obvi- 
ously connected  with,  and  dependent  on,  the  earth's  position  in  its  orbit 
relatively  to  the  sun  around  which  it  revolves;  as  the  diurnal  variation 
is  connected  with,  and  dependent  on,  the  rotation  of  the  earth  on  its  axis, 
by  which  each  meridian  successively  passes  through  every  angle  of  in- 
clination to  the  sun  in  the  round  of  24  hours."  Sabine,  on  the  Annual 
and  Diurnal  Variations,  in  the  second  volume  of  Observations  made  at 
the  Magn.  and  Meteor ol.  Observatory  at  Toronto,  p.  xvii — xx.  See  also 
his  memoir,  On  the  Annual  Variation  of  the  Magnetic  Declination  at 
different  periods  of  the  day,  in  the  Philos.  Transact,  for  1851,  pt.  f 
p.  635,  and  the  Introduction  of  his  Observ.  made  at  the  Observatory  a£ 
Hobarton,  vol.  i,  p.  xxxiv — xxxvi. 

81  Sabine,  On  the  means  adopted  for  determining  the  Absolute  Values, 
Secular  Change,  and  Annual  Variation  of  the  Terrestrial  Magnetic  Force, 
in  the  Phil.  Transact,  for  1850,  pt.  i,  p.  216.  In  his  address  to  the  Asso- 
ciation at  Belfast  (Meeting  of  the  Brit.  Assoc.  in  1852),  he  likewise 
observes,  "  that  it  is  a  remarkable  fact  which  has  been  established  that 
the  magnetic  force  is  greater  in  both  the  northern  and  southern  hemi- 
spheres in  the  months  of  December,  January,  and  February,  when  the 
sun  is  nearest  to  the  earth,  than  in  those  of  May,  June,  and  July,  when 
he  is  most  distant  from  it :  whereas,  if  the  effects  were  due  to  tempera- 
ture, the  two  hemispheres  should  be  oppositely,  instead  of  similarly, 
affected  in  eacli  of  the  two  periods  referred  to." 

G    2 


34  COSMOS. 

increasing  intensity,  declination  and  inclination  cannot  there- 
fore be  ascribed  to  the  sun  in  connection  with  its  thermic 
influence. 

The  annual  means  deduced  from  observations  at  Munich 
and  Gottingen,  have  enabled  the  active  director  of  the  Royal 
Bavarian  Observatory,  Professor  Lament,  to  deduce  the 
remarkable  law  of  a  period  of  10^  years  in  the  alterations  of 
declination.83  In  the  period  between  1841  and  1850,  the 
mean  of  the  monthly  alterations  of  declination  attained  very 
uniformly  their  minimum  in  1843|,  and  their  maximum  in 
184S|-,  Without  being  acquainted  with  these  European 
results,  General  Sabine  was  led  to  the  discovery  of  a  periodi- 
cally active  cause  of  disturbance  from  a  comparison  of  the 
monthly  means  of  the  same  years,  namely  from  1843  to  1848, 
which  were  deduced  from  observations  made  at  places  which 
lie  almost  as  far  distant  from  one  another  as  possible  (Toronto 
in  Canada,  and  Hobarton  in  Van  Diemen's  Land).  This 
cause  of  disturbance  was  found  by  him  to  be  of  a  purely 
cosmical  nature,  being  also  manifested  in  the  decennial 
periodic  alterations  in  the  sun's  atmosphere.83  Schwabe, 
who  has  observed  the  spots  upon  the  sun  with  more  constant 
attention  than  any  other  living  astronomer,  discovered  (as  I 
have  already  elsewhere  observed),84  in  a  long  series  of  years 
(from  1826  to  1850),  a  periodically  varying  frequency  in  the 
occurrence  of  the  solar  spots,  showing  that  their  maxima  fell 
in  the  years  1828,  1837,  and  1848,  and  their  minima  in  the 
years  1833  and  1843.  "I  have  not  had  the  opportunity," 
he  writes,  "  of  investigating  a  continuous  series  of  older 
observations,  but  I  willingly  subscribe  to  the  opinion  that 
this  period  may  itself  be  variable."  A  somewhat  analogous 
kind  of  variability — periods  within  periods — is  undoubtedly 
observable  in  the  processes  of  light  of  ©ther  self-luminous- 
suns.  I  need  here  only  refer  to  those  complicated  changes 
of  intensity,  which  have  been  shown  by  Goodricke  and 
Argelander  to  exist  in  the  light  of  /3  Lyras  and  Mira  Ceti. M 

82  Lament,  in  Poggend.  Annalen,  Bd.  Ixxxiv,  s.  579. 

83  Sabine,   On  periodical  laws  discoverable  in  the  mean  effects  of  the 
larger  magnetic  disturbances,  in  the  Phil.  Transact,  for  1852,  pt.  i,  p.  121. 
Vide  supra,  p.  75. 

84  Cosmos,  voL  iv,  p.  398. 

85  Op.  cit.  voL  iii,  p.  228. 


MAGNETIC   VARIATION.  &5 

If,  as  Sabine  has  shown,  the  magnetism  of  the  sun  is 
manifested  by  an  increase  in  the  terrestrial  force  when  the 
earth  is  nearest  to  that  luminary,  it  is  the  more  striking 
that,  according  to  Kreil's  very  thorough  investigations  of  the 
magnetic  influence  of  the  moon,  the  latter  should  hitherto  not 
have  been  perceptible,  either  during  the  different  lunar 
phases,  or  at  the  different  distances  assumed  by  the  satellite 
in  relation  to  the  earth.  The  vicinity  of  the  moon  does  not 
appear,  when  compared  with  the  sun,  to  compensate  in  this 
respect  for  the  smallness  of  its  mass.  The  main  result  of 
the  investigation,  in  relation  to  the  magnetic  influence  of  the 
earth's  satellite,  which,  according  to  Melloni,  exhibits  only  a 
trace  of  calorification8*,  is  that  the  magnetic  declination 
in  our  planet  undergoes  a  regular  alteration  in  the  course  of 
a  lunar  day,  during  which  it  exhibits  a  twofold  maximum 
and  a  twofold  minimum.  Kreil  very  correctly  observes, 
"that  if  the  moon  exerts  no  influence  on  the  temperature  on 
the  surface  of  our  earth  (which  is  appreciable  by  the  ordi- 
nary means  of  measuring  heat),  it  obviously  cannot  in  this 
way  effect  any  alteration  in  the  magnetic  force  of  the  earth ; 
but  if,  notwithstanding,  an  alteration  of  this  kind  is  actually 
experienced,  we  must  necessarily  conclude  that  it  is  pro- 
duced by  some  other  means  than  through  the  moon's  heat." 
Everything  that  cannot  be  considered  as  the  product  of  a 
single  force  must  require,  as  in  the  case  of  the  moon,  that  all 
foreign  elements  of  disturbance  should  be  eliminated,  in  order 
that  its  true  nature  may  be  recognized. 

Although  hitherto  the  most  decisive  and  considerable 
variations  in  the  manifestations  of  terrestrial  magnetism  do 
not  admit  of  being  satisfactorily  explained  by  the  maxima 
and  minima  in  the  variations  of  temperature,  there  can  be 
no  doubt  that  the  great  discovery  of  the  polar  property  of 
oxygen  in  the  gaseous  envelope  of  our  earth  will,  by  a  more 
profound  and  comprehensive  view  of  the  process  of  the 
magnetic  activity,  speedily  afford  us  a  most  valuable  assist- 
ance in  elucidating  the  mode  of  origin  of  this  process.  It 
would  be  inconceivable  if,  amid  the  harmonious  co-operation 
of  all  the  forces  of  nature,  this  property  of  oxygen  and  its 
modification  by  an  increase  of  temperature,  should  not  par- 

86  Kreil,  Einfiuss  des  Mondes  auf  die  Magnetisdie  Declination,  1852, 
s.  27,  29,  46. 


83  COSMOS. 

ticipate  in  the  production  and  manifestation  of  magnetic 
phenomena. 

If,  according  to  Newton's  view,  it  is  very  probable  that 
the  substances  which  belong  to  a  group  of  celestial  bodies  (to 
one  and  the  same  planetary  system)  are  for  the  most  part 
identical,  8T  we  may  from  inductive  reasoning  conclude  that 
the  electro-magnetic  activity  is  not  limited  to  the  gravi- 
tating matter  on  our  own  planet.  To  adopt  a  different 
hypothesis  would  be  to  limit  cosmical  views  with  arbitrary 
'dogmatism.  Coulomb's  hypothesis  regarding  the  influence  of 
the  magnetic  sun  on  the  magnetic  earth  is  not  at  variance 
with  analogies,  based  upon  the  observation  of  facts. 

If  we  now  proceed  to  the  purely  objective  representation 
of  the  magnetic  phenomena,  which  are  exhibited  by  our 
planet  on  different  parts  of  its  surface,  and  in  its  different 
positions  in  relation  to  the  central  body,  we  must  accurately 
distinguish,  in  the  numerical  results  of  our  measurements, 
the  alterations  which  are  comprised  within  short  or  very 
long  periods.  All  are  dependent  on  one  another,  and  in  this 
dependence  they  reciprocally  intensify,  or  partially  neutralize 
and  disturb  each  other,  as  the  wave-circles  in  moving  fluids 
intersect  one  another.  Twelve  objects  here  present  them- 
selves most  prominently  to  our  consideration. 

Two  magnetic  poles,  which  are  unequally  distant  from  the 
poles  of  rotation  of  the  earth,  and  are  situated  one  in  each 
hemisphere  ;  these  are  points  of  our  terrestrial  spheroid  at 
which  the  magnetic  inclination  is  equal  to  90°,  and  at  which 
therefore  the  horizontal  force  vanishes. 

The  magnetic  equator,  the  curve  on  which  the  inclination 
of  the  needle  =  0°. 

The  lines  of  equal  declination,  and  those  on  which  the 
declination  =.  0  (isogonic  lines  and  lines  of  no  variation). 

Tlie  lines  of  equal  inclination  (isoclinal  lines). 

The  four  points  of  greatest  intensity  of  the  magnetic  force, 
two  of  unequal  intensity  in  each  hemisphere. 

The  lines  of  equal  terrestrial  force  (isodynamic  lines). 

The  undulating  line  which  connects  together  on  each 
meridian  the  points  of  the  weakest  intensity  of  the  terrestrial 
force,  and  which  has  sometimes  been  designated  as  a  dynamic 

97  Cosmos,  vol.  i,  pp.  122,  123 ;  also  vol.  iv,  p.  568. 


MAGNETIC   INTENSITY.  87 

equator.  w  This  undulating  line  does  not  coincide  either 
with  the  geographical  or  the  magnetic  equator. 

The  limitation  of  the  zone  where  the  intensity  is  generally 
very  weak,  and  in  which  the  horary  alterations  of  the  mag- 
netic needle  participate,  in  accordance  with  the  different 
seasons  of  the  year,  in  producing  the  alternating  phenomena 
observed  in  both  hemispheres  89. 

In  this  enumeration  1  have  restricted  the  use  of  the  word 
pole  to  the  two  points  of  the  earth's  surface,  at  which  the  hori- 
zontal force  disappears,  because,  as  I  have  already  remarked, 
these  points,  which  are  the  true  magnetic  poles,  but  which 
by  no  means  coincide  with  the  maxima  of  intensity,  have 
frequently  been  confounded  in  recent  times  with  the  four 
terrestrial  points  of  greatest  intensity.  w  Gauss  has  also 
shown  that  it  would  be  inappropriate  to  attempt  to  distinguish 
the  chord  which  connects  the  two  points,  at  which  the  dip  of 
the  needle  =  90°,  by  the  designation  of  magnetic  axis  of 
the  earth91.  The  intimate  connection  which  prevails  between 
the  objects  here  enumerated  fortunately  renders  it  possible 
to  concentrate,  under  three  points  of  view,  the  complicated 
phenomena  of  terrestrial  magnetism  in  accordance  with  the 
u  je  manifestations  of  one  active  force — Intensity,  Incli- 
nation, and  Declination. 

Intensity. 

The  knowledge  of  the  most  important  element  of  terres- 
trial magnetism,  the  direct  measurement  of  the  intensity  of 

88  See  Mrs.  Somerville's  short   but    lucid  description  of   terrestrial 
magnetism,  based  upon  Sabine's  works  (Physical  Geography,   vol.  ii, 
p.  102).  Sir  James  Ross,  who  intersected  the  curve  of  lowest  intensity 
in  his  great  Antarctic  expedition,  December,  1839,  in  19°  S.  lat.  and 
29  '  13'  W.  long.,  and  who  has  the  great  merit  of   having  first  deter- 
mined its  position  in  the  southern  hemisphere,  calls  it  "  the  equator  of 
less  intensity."     See  his  Voyage  to  the  Southern  and  Antarctic  Regions, 
vol.  i,  p.  22. 

89  "  Stations   of   an    intermediate  character,   situated   between  the 
northern  and  southern  magnetic  hemispheres,  partaking,  although  iu 
opposite  seasons,  of  those  contrary  features  which  separately  prevail  (in 
the  two   hemispheres)   throughout  the  year."     Sabine,  in  the   Phil. 
Transact,  for  1847,  pt.  i,  pp.  53—57. 

90  The  pole  of  intensity  is  not  the  pole  of  verticity.     Phil.  Transact* 
for  1846,  pt.  iii,  p.  255. 

91  Gauss,  Allyem...  Theorie  des  Erdmagnetism**,  §  31. 


88  COSMOS. 

i 

the  terrestrial  force,  followed  somewhat  tardily  the  know- 
ledge of  the  relations  of  the  direction  of  this  force  in 
horizontal  and  vertical  planes  (declination  and  inclination). 
Oscillations,  from  the  duration  of  which  the  intensity  is 
deduced,  were  first  made  an  object  of  experiment  towards  the 
close  of  the  18th  century,  and  yielded  matter  for  an  earnest 
and  continuous  investigation  during  the  first  half  of  the  19th 
century.  Graham,  in  1723,  measured  the  oscillations  of  his 
dipping-needle  with  the  view  of  ascertaining  whether  they 
were  constant,92  and  in  order  to  find  the  ratio  which  the 
force  directing  them  bore  to  gravity.  The  first  attempt  to 
determine  the  intensity  of  magnetism  at  widely  different 
points  of  the  earth's  surface,  by  counting  the  number  of 
oscillations  in  equal  times,  was  made  by  Mallet  in  1769.  He 
found,  with  a  very  imperfect  apparatus,  that  the  number  of 
the  oscillations  at  St.  Petersburg  (59°  56'  N".  lat.),  and  at 
Ponoi  (67°  4'),  were  precisely  equal93,  and  hence  arose  the 
erroneous  opinion  which  was  even  transmitted  to  Cavendish, 
that  the  intensity  of  the  terrestrial  force  was  the  same  und-er 
all  latitudes.  Borda,  as  he  has  himself  often  told  me,  was 
prevented,  on  theoretical  grounds,  from  falling  into  this  error, 
and  the  same  had  previously  been  the  case  with  Le  Monnier; 
but  the  imperfection  of  the  dipping-needle,  the  friction  which 
existed  between  it  and  the  pivot,  prevented  Borda  (in  his 
expedition  to  the  Canary  Islands  in  1776),  from  discovering 
any  difference  in  the  magnetic  force  between  Paris,  Toulon, 
Santa  Cruz  de  Tenerifte,  and  Goree  in  Senegambia,  over  a 
space  of  35°  of  latitude.  (Voyage  de  La  Perouse,  t.  i, 
p.  162.)  This  difference  was,  for  the  first  time,  detected  with 
improved  instruments  in  the  disastrous  expedition  of  La 
Perouse  in  the  years  1785  and  1787  by  Lamanon,  who  com- 
municated it  from  Macao  to  the  Secretary  of  the  French 
Academy.  This  communication,  as  I  have  already  stated, 
(see  p.  61),  remained  unheeded,  and  like  many  others  lay 
buried  in  the  archives  of  the  Academy. 

The  first  published  observations  of  intensity,  which  more- 

02  Phil.  Transact,  vol.  xxxiii,  for  1724—1725,  p.  332  ("to  try  if  the 
dip  and  vibrations  were  constant  and  regular"). 

93  Novi  Comment.  Acad.  Scient.  Petropol,  t.  xiv,  pro  anno  1769,  pars  2, 
p.  33.  See  also  Le  Monnier  Lois  du  Magnetism*  comparees  aux  observa* 
tiontf  1776,  p.  50. 


MAGNETIC   INTENSITY.  69 

over  were  instituted  at  the  suggestion  of  Borda,  are  those 
which  I  made  during  my  voyage  to  the  tropical  regions  of 
the  New  Continent  between  the  years  1798  and  1804.  The 
results  obtained  at  an  earlier  date  (from  1791  to  1794), 
regarding  the  magnetic  force,  by  my  friend  de  Rossel,  in  the 
Indian  Ocean,  were  not  printed  till  four  years  after  my 
return  from  Mexico.  In  the  year  1829  I  enjoyed  the  advan- 
tage of  being  able  to  prosecute  my  observations  of  the  mag- 
netic intensity  and  inclination  over  a  space  of  fully  188° 
of  longitude  from  the  Pacific  eastwards  as  far  as  the  Chinese 
Dzungarei,  two-thirds  of  this  portion  of  the"  earth's  surface 
being  in  the  interior  of  continents.  The  differences  in  the 
latitudes  amounted  to  72°  (namely,  from  60°  N.  to  12° 
S.  Lat.). 

When  we  carefully  follow  the  direction  of  the  closed 
isodynamic  lines  (curves  of  equal  intensity),  and  pass  from 
the  external  and  weaker  to  the  interior  and  gradually  stronger 
curves,  we  shall  find  in  considering  the  distribution  of  the 
magnetic  force  in  each  hemisphere,  that  there  are  two  points, 
or  foci,  of  the  maxima  of  intensity,  a  stronger  and  a  weaker 
one,  lying  at  very  unequal  distances  both  from  the  poles  of 
rotation  and  the  magnetic  poles  of  the  earth.  Of  these  four 
terrestrial  points  the  stronger,  or  American,  is  situated  in 
the  northern'  hemisphere94  in  52°  19'  N.  lat.  and  in  92°  W. 
long.,  whilst  the  weaker,  which  is  often  called  the  Siberian,  is 
situated  in  70°  N.  lat.  and  in  120°  E.  long,  or  perhaps  a  few 
degrees  less  to  the  eastward.  In  the  journey  from  Par- 
schinsk  to  Jakutsk,  Erman  found,  in  1829,  that  the  curve  of 
greatest  intensity  (1.742)  was  situated  at  Beresowski  Ostrow 
in  117°  51 '  E.  long,  and  59°  44'  K  lat.  (Erman  Magnet.  Beob. 
s.  172—540;  Sabine,  in  the  Phil  Transact,  jor  1850,  pt.  i, 
p.  218).  Of  these  determinations,  that  of  the  American 
focus  is  the  more  certain,  especially  in  respect  to  latitude, 
while  in  respect  "  to  longitude  it  is  probably  somewhat  too 
far  west."  The  oval  which  incloses  the  stronger  northern 
focus  lies,  consequently,  in  the  meridian  of  the  western  end 
of  Lake  Superior,  between  the  southern  extremity  of  Hud- 

94  In  those  cases  in  which  individual  treatises  of  General  Sabine  have 
not  been  specially  referred  to  in  these  notes,  the  passages  have  been 
taken  from  manuscript  communications,  which  have  been  kindly 
placed  at  my  disposal  by  this  learned  physicist. 


90  COSMOS. 

son's  Bay  and  that  of  the  Canadian  lake  of  Winipeg.  We 
owe  this  determination  to  the  important  land  expedition, 
undertaken  in  the  year  1843,  by  Captain  Lefroy,  of  the 
Royal  Artillery,  and  formerly  director  of  the  Magnetic 
Observatory  at  St.  Helena.  "  The  mean  of  the  lem- 
niscates  which  connect  the  stronger  and  the  weaker  focus 
appears  to  be  situated  north-east  of  Behring's  Straits,  and 
somewhat  nearer  to  the  Asiatic  than  to  the  American 
focus." 

When  I  crossed  the  magnetic  equator,  the  line  on  which 
the  inclination  =  0,  between  Micuipampa  and  Caxamarca,  in 
the  Peruvian  chain  of  the  Andes,  in  the  southern  hemisphere, 
in  7°  2'  lat.  and  78°  48'  W.  long,  and  when  I  observed 
that  the  intensity  increased  to  the  north  and  south  of  this 
remarkable  point,  I  was  led  from  an  erroneous  generalization 
of  my  own  observations,  and  in  the  absence  of  all  points  of 
comparison  (which  were  not  made  till  long  afterwards),  to 
the  opinion  that  the  magnetic  force  of  the  earth  increases 
uninterruptedly  from  the  magnetic  equator  towards  both 
magnetic  poles,  and  that  it  was  probable  that  the  maximum 
of  the  terrestrial  force  was  situated  at  these  points,  that  is 
to  say,  where  the  inclination  =  90°.  When  we  first  strike 
upon  the  trace  of  a  great  physical  law,  we  generally  find  that 
the  earliest  opinions  adopted  require  subsequent  revision. 
Sabine,*5  by  his  own  observations,  which  were  made  from 
1818  to  1822  in  very  different  zones  of  latitude,  and  by  the 
able  arrangement  and  comparison  of  the  numerous  oscillation- 
experiments  with  the  vertical  and  horizontal  needles,  which 
of  late  years  have  gradually  become  more  general,  has  shown 
that  the  intensity  and  inclination  are  very  variously  modi- 
fied ;  that  the  minimum  of  the  terrestrial  force  at  many 
points  lies  far  from  the  magnetic  equator  ;  and  that  in  the 
most  northern  parts  of  Canada  and  in  the  Arctic  regions 
around  Hudson's  Bay  from  52°  20'  lat.  to  the  magnetic  pole 
in  70°  lat.  and  from  about  92°  to  93°  W.  long,  the  intensity, 
instead  of  increasing,  diminishes.  In  the  Canadian  focus  of 
greatest  intensity,  in  the  northern  hemisphere,  found  by 
Lefroy,  the  dip  of  the  needle  in  1845  was  only  73°  77  and 

95  Fifth  Report  of  the  British  Association,  p.  72  ;  Seventh  Report, 
pp.  64 — 68.  Contributions  to  Terrestrial  Magnetism  No  .vii  iu  the 
Phil.  Transact,  for  1846,  pt.  iii,  p.  254. 


MAGNETIC  INTENSITY.  91 

in  both  hemispheres  we  find  the  maxima  of  the  terrestrial 
force  coinciding  with  a  comparatively  small  dip.98 

However  admirable  and  abundant  are  the  observations  of 
intensity  which  we  owe  to  the  expeditions  of  Sir  James  Ross, 
Moore,  and  Clerk,  in  the  Antarctic  polar  seas,  there  is  still 
much  doubt  in  reference  to  the  position  of  the  stronger  and 
weaker  focus  in  the  southern  hemisphere.  The  first  of  these 
navigators  has  frequently  crossed  the  isodynamic  curves 
of  greatest  intensity,  and  from  a  careful  consideration  of 
his  observations,  Sabine  has  been  led  to  refer  one  of  the 
foci  to  64°  S.  lat.  and  137°  30'  E.  long.  Ross  himself,  in  the 
account  of  his  great  voyage,97  conjectures  that  the  focus  lies 
in  the  neighbourhood  of  the  Terre  d'Adelie,  discovered  by 
D'Urville,  and  therefore  in  about  67°  S.  lat.  and  140°  B.  long. 
He  thought  that  he  had  approached  the  other  focus  in  60°  S. 
lat.  and  125  W.  long.;  but  he  was  disposed  to  place  it  some- 
what further  south,  not  far  from  the  magnetic  pole,  and 
therefore  in  a  more  easterly  meridian.98 

Having  thus  established  the  position  of  the  four  maxima 
of  intensity,  we  have  next  to  consider  the  relation  of  the 
forces.  These  data  can  be  obtained  from  a  much  earlier 

96  Sabine,  in  the  Seventh  Report  of  the  Brit.  Assoc.  p.  77. 

9'  Sir  James  Ross,  Voyage  in  the  Southern  and  Antarctic  Regions,  vol.  i, 
p.  322.  This  great  navigator,  in  sailing  between  Kerguelen's  Land  and 
Van  Diemen's  Land,  twice  crossed  the  curve  of  greatest  intensity,  first 
in  46°  44'  S.  lat.  128°  28'  E.  long,  where  the  intensity  increased  to 
2.034,  and  again  diminished,  further  east,  near  Hobarton,  to  1.824 
(Voy.  vol.  i,  pp.  103 — 104) ;  then  again,  a  year  later,  from  January  the 
1st  to  April  the  3rd,  1841,  during  which  time,  it  would  appear  from 
the  k>g  of  the  Erebus  that  they  had  gone  from  77°  47'  S.  lat.  175°  41'  E. 
long,  to  51°  16'  S.  lat.  136°  50'  E.  long.,  where  the  intensities  were 
found  to  be  uninterruptedly  more  than  2.00,  and  even  as  much  as 
2.07  (Phil.  Transact,  for  1843,  pt.  ii,  pp.  211—215).  Sabine's  result  for 
the  one  focus  of  the  southern  hemisphere  (64°  S.lat.  137°  30'  E.  long.) 
which  I  have  already  given  in  the  text,  was  deduced  from  observations 
made  by  Sir  James  Ross  between  the  19th  and  27th  of  March,  1841 
(while  crossing  the  southern  isodynamic  ellipse  of  2.00,  about  midway 
between  the  extremities  of  its  principal  axis),  between  the  southern 
latitudes  58°  and  64°  26',  and  the  eastern  longitudes  of  128°  40'  and 
148°  20'  (Contrib.  to  Terr.  Magn.  in  the  Phil.  Transact,  for  1846,  pt.  iii, 
p.  252). 

98  Ross,  Voyage,  vol.  ii,  p.  224.  In  accordance  with  the  instructions 
drawn  up  for  the  expedition,  the  two  sonthern  foci  of  the  maximum  of 
intensity  were  conjectured  to  be  in  47°  S.  lat.  140°  E.  long,  and  in  CO0 
S.  lat.  235  E  long.  (vol.  i,  p.  xxxvi). 


92  COSMOS. 

source,  to  which  I  have  already  frequently  referred,  that  is  to 
say,  by  a  comparison  with  the  intensity  which  I  found  at  a 
point  of  the  magnetic  equator  in  the  Peruvian  chain  of  the 
Andes,  which  it  intersects  in  7°  2'  lat.  and  78°  48'  W.  long, 
or,  according  to  the  earliest  suggestions  of  Poisson  and  Gau&s, 
by  absolute  measurement."  If  we  assume  the  intensity  at 
the  above  indicated  point  of  the  magnetic  equat or  rr  1.000, 
in  the  relative  scale,  we  find  from  the  comparison  made  be- 
tween the  intensity  of  Paris  and  that  of  London  in  the  year 
1827  (s-ee  page  67),  that  the  intensities  of  these  two  cities 
are  1.348  and  1.372.  If  we  express  these  numbers  in  ac- 
cordance with  the  absolute  scale  they  will  stand  as  about 
=  10.20  and  10.38,  and  the  intensity,  which  was  assumed  to 
be  1.000  for  Peru,  would,  according  to  Sabine,  be  7.57  in  the 
absolute  scale,  and  therefore  even  greater  than  the  intensity 
at  St.  Helena,  which,  in  the  same  absolute  scale  =  6.4.  All 
these  numbers  must  be  subjected  to  a  revision  on  account  of 
the  different  years  in  which  the  comparisons  were  made. 
They  can  only  be  regarded  as  provisional,  whether  they  are 
reckoned  in  the  relative  (or  arbitrary)  scale  or  in  the  absolute 
scale,  which  is  to  be  preferred  to  the  former,  but  even  in 
their  pres-snt  imperfect  degree  of  accuracy  they  throw  con- 
siderable light  on  the  distribution  of  the  magnetic  force — a 
subject  which,  till  within  the  last  half  century,  was  shrouded 
in  the  greatest  obs-curity.  They  afford  what  is  cosmically 
of  very  great  importance,  historical  points  of  departure  for 
those  alterations  in  the  force,  which  will  be  manifested  in 
future  years,  probably  through  the  dependence  of  the  earth 
upon  the  magnetic  force  of  the  sun,  by  which  it  is  influenced. 
In  the  northern  hemisphere  the  stronger  or  Canadian 
focus  in  52°  19'  N.  lat.  and  92°  W.  long,  has  been  most  satis- 
factorily determined  by  Lefroy.  This  intensity  is  expressed 
in  the  relative  scale  by  1.878,  the  intensity  of  London  being 
1.372,  while  in  the  absolute  scale  it  would  be  expressed  by 
14.21,100  Even  in  New  York,  lat.  40°  42',  Sabine  found  the 

99  Phil.  Transact,  for  1850,  pt.  i,  p.  201;  Admiralty  Manual,  1849, 
p.  16;  Erman,  Magnet.  Beob.  s.  437 — 454. 

100  On  the  map  of  isodynamie  lines  for  North  America  which  occurs 
in  Sabine's  Contributions  to  Terrestrial  Magnetism,  No.  vii,  we  find,  by 
mistake,  the  value  14.88  instead  of  14.21,  although  the  latter,  which  ia 
the  true  number,  is  given  at  page  252  of  the  text  of  this  memoir. 


MAGNETIC   INTENSITY.  93 

magnetic  force  not  much  less  (1.803).  For  the  weaker 
northern  or  Siberian  focus,  70°  lat.,  120°  E.  long.,  it  was 
found  by  Erman  to  be  1.74  in  the  relative  scale,  and  by 
Hansteen,  1.76,  that  is  to  say,  about  13.3  in  the  absolute 
scale.  The  Antarctic  expedition  of  Sir  James  Ross  has 
shown  us  that  the  difference  of  the  two  foci  in  the  southern 
hemisphere  is  probably  less  than  in  the  northern,  but  that- 
each  of  the  two  southern  foci  exceeds  both  the  northern  in 
intensity.  The  intensity  in  the  stronger  southern  focus, 
64°  lat.,  137°  30'  E.  long.,  is  at  least  2.06  in  the  relative  or 
arbitrary  scale,1  while  in  the  absolute  scale  it  is  15.60;  in 
the  weaker  southern  focus,  60°  lat.,  129°  40'  W.  long.,  we  find 
also,  according  to  Sir  James  Ross,  that  it  is  1.96  in  the  arbi- 
trary scale  and  14.90  in  the  absolute  scale.  The  greater  or 
lesser  distance  of  the  two  foci  from  one  another  in  the  same 
hemisphere  has  been  recognised  as  an  important  element  of 
their  individual  intensity,  and  of  the  entire  distribution  of 
the  magnetic  force.  "  Even  although  the  foci  of  the  southern 
hemisphere  exhibit  a  strikingly  greater  intensity  (namely 
15.60  and  14.90  in  the  absolute  scale),  than  the  foci  of  the 
northern  hemisphere  (which  are  respectively  14.21  and 
13.30),  the  total  magnetic  force  of  the  one  hemisphere  cannot 
be  esteemed  as  greater  than  that  of  the  other." 

"  The  result  is,  however,  totally  different  when  we  sepa- 
rate the  terrestrial  sphere  into  an  eastern  and  western  part, 
in  accordance  with  the  meridians  of  100°  and  280°  E.  long, 
reckoning  from  west  to  east  in  such  a  manner  that  the 
eastern  or  more  continental  sphere  shall  enclose  South 
America,  the  Atlantic  Ocean,  Europe,  Africa,  and  Asia, 
almost  as  far  as  Baikal,  whilst  the  western,  which  is  the 
more  oceanic  and  insular,  includes  almost  the  whole  of  North 

1  I  follow  the  value  given  in  Sabine's  Contributions,  No.  vii,  p.  252a 
namely  15.60.  We  find  from  the  Magnetic  Journal  of  the  Erebua 
(Phil.  Transact,  for  1843,  pt.  ii,  pp.  169—172),  that  several  individual 
observations,  taken  on  the  ice  on  the  8th  of  February,  1841,  in  77°  47' 
S.  lat.  and  172°  42'  W.  long,  yielded  2.124.  The  varlue  of  the  intensity 
15.60  in  the  absolute  scale  would  lead  us  to  assume  provisionally  that 
the  intensity  at  Hobarton  was  13.51  (Magn.  and  Meteorol.  Obscrv.  made 
at  Hobarton,  vol.  i,  p.  75).  This  value  has,  however,  lately  been  slightly 
augmented  (to  13.56)  (vol.  ii,  xlvi).  In  the  Admiralty  Manual,  p.  17, 
I  find  the  southern  focus  of  greatest  intensity  changed' to  15.8. 


94  COSMOS. 

America,  the  broad  expanse  of  the  Pacific,  New  Holland,  and 
a  portion  of  Eastern  Asia."  These  meridians  lie  the  one 
about  4°  west  of  Singapore,  the  other  13°  west  of  Cape  Horn, 
in  the  meridian  of  Guayaquil.  All  four  foci  of  the  maxi- 
mum of  the  magnetic  force,  and  even  the  two  magnetic  poles 
fall  within  the  western  hemisphere.3 

Adolph  Erman's  important  observation  of  least  intensity 
in  the  Atlantic  Ocean,  east  of  the  Brazilian  province  of 
Espiritu  Santo  (20  S.  lat.,  35  02'  W.  long.),  has  been 
already  mentioned  in  our  Delineation  of  Nature.4  He  found 
in  the  relative  scale  0.7062  (in  the  absolute  scale  5.35). 
This  region  of  weakest  intensity  was  also  twice  crossed  by 
Sir  James  Ross  in  his  Antarctic  expedition6  between  1 9°  and 
21°  S.  lat.,  as  well  as  by  Lieutenant  Sulivan  and  Dunlop 
in  their  voyage  to  the  Falkland  Islands.6  In  his  isodynamic 
chart  of  the  entire  Atlantic  Ocean,  Sabine  has  drawn  the 
curve  of  least  intensity,  which  Ross  calls  the  equator  of  less 
intensity,  from  coast  to  coast.  It  intersects  the  West  African 
shore  of  Benguela,  near  the  Portuguese  colony  of  Mossamedes, 
(15°  S.  lat.);  its  summits  are  situated  in  the  middle  of 
the  ocean  in  18°  W.  long.,  and  it  rises  again  on  the  Brazilian 
coast  as  high  as  20C  S.  lat.  Whether  there  may  not  be 
another  zone  of  tolerably  low  intensity  (0'97),  lying  north  of 
the  equator  (10°  to  12°  lat.),  and  about  20°  east  of  the  Phi- 
lippines is  a  question  that  must  be  left  for  future  investiga- 
tions to  elucidate. 

I  do  not  think  that  the  ratio  which  I  formerly  gave  of 
the  weakest  to  the  strongest  terrestrial  force  requires 
much  modification  in  consequence  of  later  investigations. 
This  ratio  falls  between  1 :  2^  and  1 :  3,  being  sorne- 

3  See  the  interesting  Map  of  the  World,  divided  into  hemispheres  by  a 
plane  coinciding  with  the  meridians  of  100  and  280  E.   of  Greenwich, 
exhibiting  the  unequal  distribution  of  the  magnetic  intensity  in  the  two 
hemispheres,  plate  v,  in  the  Proceedings  of  the  Brit.  Assoc.  at  Liverpool, 
1837,  pp.  72 — 74.      Erman  found  that  the  intensity  of  the  terrestrial 
force  was  almost  constantly  below  0.76,  and  consequently  very  small  in 
the  southern  zone  between  latitudes  24°  25'  and  13°  18',  and  between 
the  western  longitudes  of  34°  50'  and  32°  44'. 

4  Cosmos,  vol.  i,  p.  181. 

5  Voyage  in  the  Southern  Seasn  vol.  i,  pp.  22,  27 ;  vide  supra,  p.  96. 

6  See  the  Journal  of  Sulivan  and  Dunlop,  in  the  Phil.  Transact,  fof 
1840,  pt.  i,  p.  143.     They  found  as  the  minimum  only  0.800. 


MAGNETIC  INTENSITY.  95 

what  nearer  to  the  latter  number,  and  the  difference  of 
the  data7  arises  from  the  circumstance  that  in  some  cases 
the  minima  alone,  and  in  others  the  minima  and  maxima 
together,  have  been  altered  somewhat  arbitrarily.  Sabine8 
has  the  great  merit  of  having  first  drawn  attention  to  the 
importance  of  the  dynamic  equator,  or  curve  of  least  intensity. 
"  This  curve  connects  the  points  of  each  geographical  meri- 
dian at  which  the  terrestrial  intensity  is  the  smallest. 
It  describes  numerous  undulations  in  passing  round  the 
earth,  on  both  sides  of  which  the  force  increases  with  the 
higher  latitudes  of  each  hemisphere.  It  in  this  manner 
indicates  the  limits  between  the  two  magnetic  hemispheres 
more  definitely  than  the  magnetic  equator,  on  which  the 
direction  of  the  magnetic  force  is  vertical  to  the  direction  of 
gravity.  In  respect  to  the  theory  of  magnetism,  that  which 
refers  directly  to  the  force  itself  is  of  even  greater  importance 
than  that  which  merely  refers  to  the  direction  of  the  needle, 
its  horizontal  or  vertical  position.  The  curves  of  the 
dynamic  equator  are  numerous,  in  consequence  of  their 
depending  upon  forces,  which  produce  four  points  (foci)  of 
the  greatest  terrestrial  force,  which  are  unsymmetrical  and 
of  unequal  intensity.  We  are  more  especially  struck  in  these 
inflections  with  the  great  convexity  in  the  Atlantic  Ocean 
towards  the  South  Pole,  between  the  coasts  of  Brazil  and  the 
Cape  of  Good  Hope." 

Does  the  intensity  of  the  magnetic  force  perceptibly 
decrease  at  such  heights  as  are  accessible  to  us,  or  does  it 
perceptibly  increase  in  the  interior  of  the  earth  ?  The  pro- 
blem which  is  suggested  by  these  questions  is  extremely 

7  We  obtain  1:2.44  on  comparing  in  the  absolute  scale  St.  Helena, 
which  is  6.4,  with  the  focus  of  greatest  intensity  at  the  south  pole, 
which  is  15.60,  and  1:2.47  by  a  comparison  of  St.  Helena  with  the 
higher  southern  maximum  of  15.8,  as  given  in  the  Admiralty  Manual, 
p.  17,  and  1 : 2.91  by  a  comparison  in  the  relative  scale  of  Erman's  ob- 
servation in  the  Atlantic  Ocean  (0.706),  with  the  southern  focus  (2.06) ; 
indeed,  even  1:2.95,  when  we  compare  together  in  the  absolute  scale 
the  lowest  value  given  by  this  distinguished  traveller  (5.35),  with  the 
highest  value  for  the  southern  focus  (15.8).     The  mean  resulting  ratio 
would  be  1 :2.69.     Compare  for  the  intensity  of  St.  Helena  (6.4  in  the 
absolute,  or  0.845  in  the  arbitrary  scale),  the  earliest  observations  of 
Fitzroy  (0.836),  Phil.  Transact,  for  1847,  pt.  i,  p.  52,  and  Proceeding  of 
tfie  Meeting  at  Liverpool,  p.  56. 

8  See  Contrib.  to  Terrestr.  Magnetism,  No.  vii,  p.  256. 


90  COSMOS. 

complicated  in  the  case  of  observations  which  are  made 
either  in  or  upon  the  earth,  since  a  comparison  of  the  effect 
of  considerable  heights  on  mountain  journeys  is  rendered 
difficult,  because  the  upper  and  lower  stations  are  seldom 
sufficiently  near  one  another,  owing  to  the  great  mass  of  the 
mountain,  and  since  further,  the  nature  of  the  rock  and  the 
penetration  of  veins  of  minerals,  which  are  not  accessible  to 
our  observation,  together  with  imperfectly  understood  horary 
and  accidental  alterations  in  the  intensity,  modify  the  results, 
where  the  observations  are  not  perfectly  simultaneous.  In 
this  manner  we  often  ascribe  to  the  height  or  depth  alone, 
conditions  which  by  no  means  belong  to  either.  The  nume- 
rous mines  of  considerable  depth  which  I  have  visited  in 
Europe,  Peru,  Mexico,  and  Siberia,  have  never  afforded 
localities  which  inspired  me  with  any  confidence.9  Then, 
moreover,  care  should  be  taken  in  giving  the  depths,  not  to 
neglect  the  perpendicular  differences  above  or  below  the  level 
of  the  sea,  which  constitutes  the  mean  surface  of  the  earth. 
The  borings  %at  the  mines  of  Joachimsthal  in  Bohemia  are  up 
wards  of  2000  feet  in  absolute  depth,  and  yet  they  only  reach 
to  a  stratum  of  rock  which  lies  between  200  and  300  feet 
above  the  level  of  the  sea.10  Very  different  and  more  favour- 
able conditions  are  afforded  by  balloon  ascents.  Gay-Lussac 
rose  to  an  elevation  of  23,020  feet  above  Paris ;  consequently, 
therefore,  the  greatest  relative  depth  that  has  been  reached 
by  borings  in  Europe,  scarcely  amounts  to  T\th  of  this  height. 
My  own  mountain  observations  between  the  years  1709  and 
1806,  led  me  to  believe  that  the  terrestrial  force  gradually 
decreases  with  the  elevation,  although,  in  consequence  of  the 
causes  of  disturbance  already  indicated,  several  results  are  at 
variance  with  this  conjectural  decrease.  I  have  collected  in 
a  note  individual  data,  taken  from  125  measurements  of 
intensity  made  in  the  Andes,  in  the  Swiss  Alps,  Italy,  and 
Germany.11  These  observations  extended  from  the  level  of 

9  We  may  ask  what  kind  of  error  can  have  led  in  the  coal  mines  of 
Flemi  to  the  result  that  in  the  interior  of  the  earth,  at  the  depth  of  87 
feet,  the  horizontal  intensity  had  increased  0.001  ?  Journal  de  I'Institut, 
1845,  Avril,  p.  146.     In  an  English  mine,  which  is  950  feet  below  the 
level  of  the  sea,   Kenwood  did  not -find  any  increase  in  the  intensity 
(Brewster,  Treatise  on  Magn.  p.  275). 

10  Cosmos,  vol.  i,  p.  150. 

11  A  diminution  of  the  intensity  with  the  height  is  shown  in  my 


MAGNETIC   OBSERVATIONS.  97 

the  sea  to  an  elevation  of  15,944  feet,  and  therefore  to  the  very 
limits  of  perpetual  snow,  but  the  greatest  heights  did  not 
afford  me  the  most  reliable  results.  The  most  satisfactory 
were  obtained  on  the  steep  declivity  of  the  Silla  de  Caracas 
(8638  feet),  which  inclines  towards  the  neighbouring  coasts  of 
La  Guayra  ;  the  Santuario  de  Nbstra  Safiora  de  Guadalupe, 

observations  from  the  comparisons  of  the  Silla  de  Caracas  (8638  feet 
above  the  sea,  intensity  1.188),  with  the  harbour  of  Guayra  (height 
0  feet,  intensity  1.262),  and  the  town  of  Caracas  (height  2648  feet, 
intensity  1.209) ;  from  a  comparison  of  the  town  of  Santa  Fe*  de  Bogota 
(elevation  8735  feet,  intensity  1.147),  with  the  chapel  of  Neustra 
Senora  da  Guadalupe  (elevation  10,794  feet,  intensity  1.127),  which 
seems  to  hang  over  the  town  like  a  swallow's  nest,  perched  upon  a  steep 
ledge  of  rock ;  from  a  comparison  of  the  volcano  of  Purace  (elevation 
14,548  feet,  intensity  1.077),  with  the  mountain  village  of  Purace 
(elevation  8671  feet,  intensity  1.087),  and  with  the  neighbouring 
town  of  Popayan  (elevation  5825  feet,  intensity  1.117) ;  from  a  com- 
parison of  the  town  of  Quito  (elevation  9541  feet,  intensity  1.067), 
with  the  village  of  San  Antonio  de  Lulumbamba  (elevation  8131 
feet,  intensity  1.087)  lying  in  a  neighbouring  rocky  fissure  directly 
under  the  geographical  equator.  The  oscillation  experiments,  which  I 
made  at  the  highest  point  at  which  I  ever  instituted  observations  of  the 
kind,  namely,  at  an  elevation  of  15,944  feet  on  the  declivity  of  the  long 
since  extinct  volcano  of  Antisana,  opposite  the  Chussulongo,  were  quite 
at  variance  with  this  result.  It  was  necessary  to  make  this  observation 
in  a  large  cavern,  and  the  great  increase  in  the  intensity  was  no  doubt 
the  consequence  of  a  magnetic  local  attraction  of  the  trachytic  rock,  as 
has  been  shown  by  the  experiments  which  I  made  with  Gay-Lussac 
within,  and  on  the  margin  of,  the  crater  of  Vesuvius.  I  found  the 
intensity  in  the  Cave  of  Antisana  increased  to  1.188,  while  in  the  neigh- 
bouring lower  plateau  it  was  scarcely  1.068.  The  intensity  at  the 
Hospice  of  St.  Gotthard  (1.313)  was  greater  than  that  at  Airolo  (1.309), 
but  less  than  that  at  Altorf  (1.322).  Airolo,  on  the  other  hand,  exceeded 
the  intensity  of  the  Ursern  Lake  (1.307).  In  the  same  manner  Gay- 
Lussac  and  myself  found  that  the  intensity  was  1.344  at  the  Hospice  of 
Mont  Cenis,  whilst  at  the  foot  of  the  same  mountain,  at  Lans  le  Bourg, 
it  was  1.323,  and  at  Turin  1.336.  The  greatest  contradictions  were 
necessarily  presented  by  the  burning  volcano  of  Vesuvius,  as  we  have 
already  remarked.  Whilst  in  1805  the  terrestrial  force  at  Naples  was 
1,274,  and  at  Portici  1.288,  it  rose  in  the  Monastery  of  St.  Salvador  to 
1.302,  whilst  it  fell  in  the  crater  of  Vesuvius  lower  than  anywhere  else 
throughout  the  whole  district,  namely,  to  1.193.  The  iron  contained  in 
the  lava,  the  vicinity  of  magnetic  poles,  and  the  heat  of  the  soil,  which 
probably  has  the  effect  of  diminishing  this  force,  combined  to  produce 
the  most  opposite  local  disturbances.  See  my  Voyage  aux  Regions 
Equinoxiales,  t.  iii,  pp  619 — 626,  and  Mvm.  de  la  Societe  d'Arcueil,  t.  i, 
1807,  pp.  17—19. 

VOL.  V.  H 


98  COSMOS. 

which  rises  immediately  over  the  town  of  Bogota,  upon  the 
declivity  of  a  steep  wall  of  limestone  rock,  with  a  difference 
of  elevation  amounting  to  upwards  of  2000  feet ;  and  the 
volcano  of  Purace,  which  rises  8740  feet  above  the  Plaza 
Mayor  of  the  town  of  Popayan.  Kupffer  in  the  Caucasus,13 
Forbes  in  many  parts  of  Europe,  Laugier  and  Mauvais  on 
the  Canigou,  Bravais  and  Martins  on  the  Faulhorn,  and 
during  their  very  adventurous  sojourn  in  the  immediate 
vicinity  of  the  summit  of  Mont  Blanc,  have  certainly  observed 
that  the  intensity  of  the  magnetic  force  diminished  with  the 
height,  and  this  decrease  appeared  from  Bravais's  general 
consideration  of  the  subject  to  be  more  rapid  in  the  Pyrenees 
than  in  the  chain  of  the  Alps.13 

Quetelet's  entirely  opposite  results,  obtained  in  an  excur- 
sion from  Geneva  to  the  Col  de  Balme  and  the  Great  St. 
Bernard,  make  it  doubly  desirable  for  the  final  and  decisive 
settlement  of  so  important  a  question,  that  observations 
should  be  made  at  some  distance  from  the  surface  of  the 
earth ;  and  these  observations  can  only  be  carried  on  by 
means  of  balloon  ascents,  such  as  were  employed  in  1804,  by 
Gay-Lussac,  first  in  association  with  Biot,  on  the  24th  of 
August,  and  subsequently  alone  on  the  16th  of  September. 
Oscillations  measured  at  elevations  of  19,000  feet,  can  how- 
ever only  afford  us  certain  information  regarding  the  trans- 
mission of  the  terrestrial  force  in  the  free  atmosphere,  when 

12  Kupffer' s  observations  do  not  refer  to  the  summit  of  the  Elbruz, 
but  to  the  difference  of  height  (4796  feet)  between  two  stations,  viz.  the 
bridge  of  Malya,  and  the  mountain  declivity  of  Kharbis,  which  unfor 
tunately  differ  considerably  in  longitude  and  latitude.     Regarding  the 
doubts  which  Necker  and  Forbes  have  advanced  in  relation  to  this  result 
see  Transact,  of  the  Royal  Soc.  of  Edin.  vol.  xiv,  1840,  pp.  23—25. 

13  Compare  Laugier  and  Mauvais,  in  the  Comptes  rcndi*$,  t.  xvi,  1843, 
p.  1175;  and  Bravais,  Observ.  deVIntensite  du  Magnet  isme  Terrestre  en 
France,  en  Suisse,  et  en  Saroie,  in  the  Annales  de  Chemie  et  de  Phys 
Seme  Sfirie,  t.  xviii.  1846,  p.  214;  Kreil,  Einfluss  der  Alpen  auf  die. 
Intensitat,  in  the  Denkschriften  der   Wiener  Akad.  der  Wiss.  Mathem. 
Naturwiss.  Cl.  Bd.  i,  1850,  s.  265,  279,  290.     It  is  very  remarkable  that 
BO  accurate  an  observer  as  Quetelet  should  have  found,  in  a  tour  which 
he  made  in  the  year  1830,  that  the  horizontal  intensity  increased  with 
the   height,  in  ascending  from  Geneva  (where  it  was  1.080),   to  the 
Col  de  Balne  (where  it  was  1.091),  and  to  the  Hospice  of  St.  Bernard 

where  it  was  as  high  as  1.096).  See  Sir  David  Brewster,  Treatise  on 
Uagn.  p.  275. 


MAGNETIC  OBSERVATIONS.  99 

care  is  taken  to  obtain  corrections  for  temperature  in  the 
needles  that  are  employed  both  before  and  after  the  ascent. 
The  neglect  of  such  a  correction  has  led  to  the  erroneous 
result  deducible  from  Gay-Lussac's  experiments,  that  the 
magnetic  force  remains  the  same  to  an  elevation  of  more 
than  22,000  feet,14  whilst  conversely  the  experiment  showed 
a  decrease  in  the  force  on  account  of  the  shortening  of  the 
oscillating  needle  in  the  upper  cold  region.15  Faraday's 
brilliant  discovery  of  the  paramagnetic  force  of  oxygen  must 
not  be  disregarded  in  the  discussion  of  this  subject.  This 
great  physicist  shows  that  in  the  upper  strata  of  the  atmo- 
sphere, the  decrease  in  the  intensity  cannot  be  sought  merely 
in  the  original  source  of  the  force,  namely  the  solid  earth, 
but  that  it  may  equally  arise  from  the  excessively  rarefied 
condition  of  the  air,  since  the  quantity  of  oxygen  in  a  cubic 
foot  of  atmospheric  air  must  differ  in  the  upper  and  lower 
strata.  It  seems  to  me,  however,  that  we  are  not  justified 
in  asbuming  more  than  this — that  the  decrease  of  the  para- 
magnetic property  of  the  oxygenous  parts  of  the  atmosphere 
which  diminish  with  the  elevation  and  with  the  rarefac- 
tion of  the  air,  must  be  regarded  as  a  co-operating  modifying 
cause.  Alterations  of  temperature  and  density  through  the 
ascending  currents  of  air  may  further  alter  the  amount  of 
this  influence.10  Such  disturbances  assume  a  variable  and 
specially  local  character,  and  they  operate  in  the  atmosphere 
in  the  same  manner  as  different  kinds  of  rocks  upon  the 
surface  of  the  earth.  With  every  advance  which  we  may 
rejoice  in  having  made  in  our  knowledge  of  the  gaseous 
envelope  of  our  planet  and  of  its  physical  properties,  we  at  the 
same  time  learn  to  know  new  causes  of  disturbance  in  the 
alternating  mutual  action  of  forces,  which  should  teach  us 
how  cautiously  we  ought  to  draw  our  conclusions. 

The  intensity  of  the  terrestrial  force,  when  measured  at 
definite  points  of  the  surface  of  our  planet,  has,  like  all  the 
phenomena  of  terrestrial  magnetism,  its  horary  as  well  as  its 
secular  variations.  The  horary  variations  were  distinctly 

14  Annales  de  Chimie,  t.  Hi,  1805,  pp.  86—87. 

15  Arago,   in  the  Annuaire  du  Bureau  des  Longitudes  pour  1836, 
p.  287 ;  Forbes,  in  the  Edin.  Transact,  vol.  xiv,  1840,  p.  22. 

16  Faraday,  Exper.  Researches  in  Electricity,  1851,  pp.  53,  77,  §§  2881, 
2S61. 

H   2 


100  COSMOS. 

recognized  by  Parry  during  his  third  voyage,  and  also,  con« 
jointly  with  him,  by  Lieutenant  Foster  (1825)  at  Port 
Bowen.  The  increase  of  intensity  from  morning  till  evening 
in  the  mean  latitudes  has  been  made  an  object  of  the  most 
careful  investigation  by  Christie,  17  Arago,  Hansteen,  Gauss, 
and  Kupffer.  As  horizontal  oscillations,  notwithstanding 
the  great  improvements  which  have  been  made  in  the  present 
day  in  the  dipping-needle,  are  preferable  to  oscillations  of  the 
latter  kind,  it  is  not  possible  to  ascertain  the  horary  varia- 
tion of  the  total  intensity  without  a  very  accurate  knowledge 
of  the  horary  variation  of  the  dip.  The  establishment  of 
magnetic  stations,  in  the  northern  and  the  southern  hemi- 
sphere, has  afforded  the  great  advantage  of  yielding  the 
most  abundant,  and,  incomparatively,  the  most  accurate 
results.  It  will  be  sufficient  here  to  instance  two  points  of 
the  earth's  surface,  which  are  both  situated  without  the 
tropics,  and  almost  in  equal  latitudes  on  either  side  of  the 
equator — namely,  Toronto,  in  Canada,  43°  39'  N.  lat.,  and 
Hobarton,  in  Van  Diemen's  Land,  in  42°  53'  S.  lat.,  with  a 
difference  of  longitude  of  about  15  hours.  The  simultaneous 
horary  magnetic  observations  belong  at  the  one  station  to 
the  winter  months,  while  at  the  other  they  fall  within  the 
period  of  the  summer  months.  While  measurements  are 
made  at  the  one  place  during  the  day,  they  are  being  simul- 
taneously carried  on  at  the  other  station  for  the  most  part 
during  the  night.  The  variation  at  Toronto  is  1°  33'  West ; 
at  Hobarton  it  is  9°  57'  East ;  the  inclination  and  the  inten- 
sity are  similar  to  one  another  ;  the  former  is,  at  Toronto, 
about  75°  15'  to  the  north,  and  at  Hobarton  about  70°  34'  to 
the  south,  whilst  the  total  intensity  is  13'90  in  the  absolute 
scale  at  Toronto,  and  13 '5 6  at  Hobarton.  It  would  appear 
from  Sabine's  investigation,  that  these  well-chosen  stations 
exhibit 19  four  turning  points  for  the  intensity  in  Canada,  and 
only  two  such  points  for  Van  Diemen's  Land.  At  Toronto, 
the  variation  in  intensity  reaches  its  principal  maximum 
at  6  P.M.,  and  its  principal  minimum  at  2  A.M.  ;  a  weaker 
r;  Christie,  in  the  Phil  Transact,  for  1825,  p.  49. 

18  Sabine,  On  Periodical  Laws  of  the  Larger  Magnetic  Disturbances, 
in  the  Phil.  Transact,  for  1851,  pt.  i,  p.  126,  and  on  the  Annnal  Varia- 
tion of  the  Magn.  Declin.  in  the  PhU.  Transact,  for  1851.  pt.  ii,  p.  636. 

19  Observ.  made  at  the  Magn.  and  Meteorol.  Observatory  at  Toronto, 
vol.  i  (1840-  1842),  p.  Ixii 


MAGNETIC   OBSERVATIONS.  101 

secondary  maximum  at  8  A.M.,  and  a  weaker  secondary 
minimum  at  10  A.M.  The  intensity  at  Hobarton,  on 
the  contrary,  exhibits  a  simple  progression  from  a  maxi- 
mum between  5  and  6  P.M.  to  a  minimum  between  8 
and  9  A.M.  ;  although  the  inclination  there,  no  less  than 
at  Toronto,  exhibits  four  turning  points ao.  By  a  com- 
parison of  the  variations  of  inclination,  with  those  of  the 
horizontal  force,  it  has  been  established  that,  in  Canada, 
during  the  winter  months,  when  the  sun  is  in  the  southern 
signs  of  the  zodiac,  the  total  terrestrial  force  has  a  greater 
intensity  than  in  the  summer  months,  whilst  in  Van 
Diemen's  Land  the  intensity  is  greater  than  the  mean  annual 
value — that  is  to  say,  the  total  terrestrial  force — from 
October  to  February,  which  constitutes  the  summer  of  the 
southern  hemisphere,  while  it  is  less  from  April  to  August. 
According  to  Sabine,21  this  intensity  of  the  terrestrial  mag- 
netic force  is  not  dependent  on  differences  of  temperature, 
but  on  the  lesser  distance  of  the  magnetic  solar  body  from 
the  earth.  At  Hobarton,  the  intensity  during  the  summer 
is  13.574  in  the  absolute  scale,  whilst  during  the  winter  it  fe 
13.543.  The  secular  variation  of  intensity  has  hitherto  been 
deduced  from  only  a  small  number  of  observations.  At 
Toronto,  it  appears  to  have  suffered  some  decrease  between 
1845  and  1849,  and  the  comparison  of  my  own  observations 
with  those  of  Rudberg,  in  the  years  1806  and  1832,  give  a 
similar  result  for  Berlin. 22 

20  Sabine,   in  Magn.  and  Meteor.    Observations  at  Hobarton,  vol.  i, 
p.  Ixviii.     "  There  is  also  a  correspondence  in  the  range  and  turning 
hours  of  the  diurnal  variation  of  the  total  force  at  Hobarton  and  at 
Toronto,  although  the  progression  is  a  double  one  at  Toronto  and  a 
single  one  at  Hobarton."     The  time  of  the  maximum  of  intensity  falls 
at  Hobarton  between  8  and  9  A.M.;  whilst  the  secondary   or  lesser  mini- 
mum falls  at  Toronto  about  10  A.M.,  and  consequently  the  increase  and 
diminution  of  the  intensity  fall  within  the  same  hours  in  accordance 
with  the  time  of  the  place,  and  not  at  opposite  hours,  as  is  the  case 
with  respect  to  the  inclination  and  the  declination.     See,  regarding  the 
causes  of  this  phenomenon,  p.  Ixix  (compare  also  Faraday,  Atmospheric 
Magnetism,  §§  3027—3034). 

21  Phil.  Transact,  for  1850,    pt.  i,  pp.  215—217;    Magnet.   Observ. 
at  Hobarton,   vol.  ii,    1852,   p.    xlvi.     See  also   p.    22   of  the  present 
volume.     At  the  Cape  of  Good  Hope  the  intensity  presents  less  differ- 
ence at  opposite   periods  of   the   year  than  the  inclination  (Magnet. 
Observ.  made  at  the  Cape  of  Good  Hope,  vol.  i,  1851,  p.  lv). 

22  See  the  magnetic  part  of  my  work  on  Asie  Centrale,  t.  iii,  p.  442. 


102  COSMOB. 

Inclination. 

The  knowledge  of  the  isoclinal  curves,  or  lines  of  equal 
inclination,  as  well  as  the  more  rapid  or  slower  increase  of 
the  inclination  by  which  they  are  determined,  (reckoning 
from  the  magnetic  equator  where  the  inclination  =  0  to 
the  northern  and  southern  magnetic  pole  where  the  horizontal 
force  vanishes,)  has  acquired  additional  importance  in  modern 
times,  since  the  element  of  the  total  magnetic  force  cannot 
be  deduced  from  the  horizontal  intensity,  which  requires  to 
be  measured  with  excessive  accuracy,  unless  we  are  previously 
well  acquainted  with  the  inclination.  The  knowledge  of  the 
geographical  position  of  both  magnetic  poles  is  due  to  the 
observations  and  scientific  energy  of  the  adventurous  navi- 
gator, Sir  James  Ross.  His  observations  of  the  northern 
magnetic  pole  were  made  during  the  second  expedition  of 
his  uncle,  Sir  John  Boss  (1829— 1833),23  and  of  the  southern 
during  the  Antarctic  expedition  under  his  own  command 
(1839 — 1843).  The  northern  magnetic  pole  in  70°  5'  lat., 
96°  43'  W.  long.,  is  5°  of  latitude  farther  from  the  ordinary 
pole  of  the  earth  than  the  southern  magnetic  pole,  75°  35'  lat., 
154°10'E.  long.,  which  is  also  situated  farther  west  from 
Greenwich  than  the  northern  magnetic  pole.  The  latter  be- 
longs to  the  great  island  of  Boothia  Felix,  which  is  situated  very 
near  the  American  continent,  and  is  a  portion  of  the  district 
which  Captain  Parry  had  previously  named  North  Somerset. 
It  is  not  far  distant  from  the  western  coast  of  Boothia  Felix, 
near  the  promontory  of  Adelaide,  which  extends  into  King 
William's  Sound  and  Victoria  Strait. 24  The  southern  mag- 
netic pole  has  not  been  directly  reached  in  the  same  manner 
as  the  northern  pole.  On  the  17th  of  February,  1841,  the 
Erebus  penetrated  as  far  as  76°  12'  S.  lat.,  and  164°  E.  long, 
As  the  inclination  was  here  only  88°  40',  it  was  assumed  that 
the  southern  magnetic  pole  was  about  ]  60  nautical  miles 
distant.  **  Many  accurate  observations  of  declination,  deter- 

23  Sir  John  Barrow,  Arctic  Voyages  of  Discovery,  1846,  pp.  521 — 
529. 

24  The    strongest   inclination    which  has   as  yet  been   observed  in 
the  Siberian  continent,  is  82°  16',  which  was  found  by  Middendorf,  on 
the  river  Taimyr,  in  74°  17'  N.  lat,  and  95°  40'  E.  long.  (Middend. 
Siber.  Reise,  th.  i,  s.  194). 

25  Qir  James  Eoss,  Voyage  to  the  Antarctic  Regions,  vol.  i,  p.  246.     "I 


MAGNETIC  INCLINATION.  i03 

mining  the  intersection  of  the  magnetic  meridian,  render  it 
very  probable  that  the  south  magnetic  pole  is  situated  in 
the  interior  of  the  great  antarctic  region  of  South  Victoria 
Land,  west  of  the  Prince  Albert  mountains,  which  approach 
the  south  pole,  and  are  connected  with  the  active  volcano  of 
Erebus,  which  is  12,400  feet  in  height. 

The  position  and  change  of  form  of  the  magnetic  equator, 
that  is  to  say,  the  line  on  which  the  dip  is  null,  were  very 
fully  considered  in  the  Picture  of  Nature,  Cosmos,  vol  i., 
p.  176.  The  earliest  determination  of  the  African  node 
(the  intersection  of  the  geographical  and  magnetic  equators) 
was  made  by  Sabine36  at  the  beginning  of  his  pendulum 
expedition  in  1822.  Subsequently,  in  1840,  the  same  learned 
observer  noted  down  the  results  obtained  by  Duperrey, 
Allen,  Dunlop,  and  Sulivan,  and  constructed  a  chart  of  the 
magnetic  equator27  from  the  west  coast  of  Africa  at  Biafra, 
(4°  N.  lat.  9°  30'  E.  long.)  through  the  Atlantic  Ocean  and 
Brazil  (16°  S.  lat.,  between  Porto  Seguro  and  Rio  Grande,)  to 
the  point  where,  upon  the  Cordilleras,  in  the  neighbourhood 
of  the  Pacific,  I  saw  the  northern  inclination  assume  a 
southern  direction.  The  African  node,  as  the  point  of  inter- 
section of  both  equators,  was  situated,  in  1837,  in  3°  E.  long., 
while,  in  1825,  it  had  been  in  6°57/E.  long.  The  secular  motion 
of  the  node,  turning  from  the  basaltic  island  of  St.  Thomas, 
which  rises  to  an  elevation  of  more  than  7000  feet,  was  there- 
fore somewhat  less  than  half  a  degree  westward  in  the  course 
of  a  year ;  after  which  the  line  of  no  inclination  turned 
towards  the  north  on  the  African  coast,  whilst  on  the  Bra- 
zilian coast  it  is  inclined  southward.  The  convexity  of  the 
magnetic  equatorial  curve  is  persistently  turned  towards 
the  south  pole,  while  in  the  Atlantic  Ocean  it  passes  at  a 
distance  of  about  16°  from  the  geographical  equator.  For 
the  interior  of  South  America,  the  terra  incognita  of  Mat  to 

had  so  long  cherished  the  ambitious  hope,"  says  this  navigator,  '"'to 
plant  the  flag  of  my  country  on  both  the  magnetic  poles  of  our  globe; 
but  the  obstacles  which  presented  themselves  being  of  so  insurniount 
able  a  character  was  some  degree  of  consolation  as  it  left  us  no  grounds 
for  self-reproach"  (p.  247). 

26  Sabine,  Pendul.  Exper.  1825.  p.  476. 

27  Sabine,  in  the  Phil.  Transact,  for  1840,  pt.  i,  pp.  136,  139,  146.     I 
follow  for  the  progression  of    the  African   node  the  map   which  is 
appended  to  this  treatise. 


104  COSMOS. 

0 rosso  between  the  large  rivers  of  Xingu,  Madera,  andUcayle, 
we  have  no  observations  of  the  dip  until  we  reach  the  chain 
of  the  Andes,  where,  68  geographical  miles  east  of  the  shores 
of  the  Pacific,  between  Montan,  Micuipampa,  and  Caxamarca, 
I  determined  astronomically  the  position  of  the  magnetic 
equator,  which  rises  towards  the  north-west  (7°  2'  S.  lat.,  and 
78°  46'  W.  long.)  ». 

The  most  complete  series  of  observations  which  we  pos- 
sess in  reference  to  the  position  of  the  magnetic  equator  was 
made  by  my  old  friend,  Duperrey,  during  the  years  1823 — 
1825.  He  crossed  the  equator  six  times  during  his  voyages 
of  circumnavigation,  and  he  was  enabled  to  determine  this 
line  by  his  own  observations  over  a  space  of  2200.29  Accord- 
ing to  Duperrey 's  chart  of  the  magnetic  equator,  the  two 
nodes  are  situated  in  long.  5°  50'  E.  in  the  Atlantic  Ocean, 
and  in  long.  177°  20'  E.  in  the  Pacific,  between  the  meri- 

-3  I  here  give,  in  accordance  with  my  usual  practice,  the  elements  of 
this  not  wholly  unimportant  determination  :  Micuipampa,  a  Peruvian 
mountain  town  at  the  foot  of  Cerro  de  Guelgayoc.  celebrated  for  its 
rich  silver  mines,  6°  44'  25"  S.  lat.,  78°  33'  3"  W.  long.,  elevation  above 
the  Pacific  11,872  feet,  magnetic  inclination  0°.42  north  (according  to  the 
centesimal  division  of  the  circle) ;  Caxamarca,  a  town  situated  on  a 
plateau  at  an  elevation  of  9362  feet,  7°  8'  38"  S.  lat.,  5h  23'  42"  long., 
inclination  0.15  south;  Montan,  a  farm-house  (or  hacienda),  surrounded 
by  Llama  flocks,  situated  in  the  midst  of  mountains,  6°  33'  9"  S. 
lat.,  5h  26'  51"  W.  long.,  elevation  8571  feet,  inclination  0.70  north; 
Tomependa,  on  the  mouth  of  the  Chinchipe,  on  the  river  Amazon,  in 
the  province  of  Jaen  de  Bracamoros,  5°  31'  28"  S.  lat.,  78°  37'  30"  W. 
long.,  elevation  1324  feet,  inclination  3°.55  north;  Truxillo,  a  Peru- 
vian town  on  the  Pacific,  8°  5'  40"  S.  lat.,  79°  3'  37"  W.  long.,  inclina- 
tion 2°.15  south.  Humboldt,  Recueil  d'Observ.  Astron.  (Mvellement 
Barometrique  et  Geode"sique)  vol.  i,  p.  316,  No.  242,  244 — 254.  For 
the  basis  of  astronomical  determinations,  obtained  by  altitudes  of  the 
stars  and  by  the  chronometer,  see  the  same  work,  vol.  ii,  pp.  379 — 391. 
The  result  of  my  observations  of  inclination  in  1802,  in  7°  2'  S.  lat.,  and 
78°  48'  W.  long.,  accords  pretty  closely  by  a  singular  coincidence,  and 
notwithstanding  the  secular  alteration,  with  the  conjecture  of  Le 
Monnier,  which  was  based  upon  theoretical  calculation.  He  says,  "  th» 
magnetic  equator  must  be  in  7°  40'  north  of  Lima,  or  at  most  in  6°  30 
S.  lat.,  in  1776"(Zoi's  du  Magnetisme  comparees  aux  Observations,  pt.  ii, 
p.  59).  _ 

•9  Saigey,  Mem  sur  VEquateur  Magnetique  d'apres  les  Observ.  du 
Capitaine  Duperrey,  in  the  Annales  Maritimes  et  Coloniales,  Dec.  1833, 
t.  iv,  p.  5.  Here  it  is  observed  that  the  magnetic  equator  is  not  a  curve 
of  equal  intensity,  but  that  the  intensity  varies  in  different  parts  of  thia 
equator  from  1  to  0.867. 


THE   MAGNETIC   EQUATOR.  105 

clians  of  the  Fejee  and  Gilbert  Islands.  While  the  magnetic 
equator  leaves  the  western  coasts  of  the  South  American 
continent,  probably  between  Punta  de  la  Aguja  and  Payta, 
it  is  constantly  drawing  nearer  in  the  west  to  the  geogra- 
phical equator,  so  that  it  is  only  at  a  distance  of  2°  from  it 
in  the  meridian  of  the  group  of  the  Mendana  Islands.30 
About  10°  farther  west,  in  the  meridian  which  passes 
through  the  western  part  of  the  Paumotu  Islands  (Low 
Archipelago)  lying  in  153°  50'  E.  long.,  Captain  Wilkes 
found  that  the  distance  from  the  geographical  equator  in 
1840  was  still  fully  2°.31  The  intersection  of  the  nodes  in 
the  Pacific  is  not  as  much  as  180°  from  that  of  the  Atlantic 
nodes,  that  is  to  say,  it  does  not  occur  in  174°  10'  W.  long., 
but  in  the  meridian  of  the  Fejee  Islands,  situated  in  about 
177°  20'  E.  long.  If,  therefore,  we  pass  from  the  west  coast 
of  Africa,  through  South  America  westward,  we  shall  find 
in  this  direction  that  the  distance  of  the  nodes  from  one 
another  is  about  8^°  too  great,  which  is  a  proof  that  the 
curve  of  which  we  are  here  speaking  is  not  one  of  the 
great  circles. 

According  to  the  admirable  and  comprehensive  determi- 
nations which  were  made  by  Captain  Elliot  from  1846  to 
1849,  between  the  meridians  of  Batavia  and  Ceylon,  and 
which  coincide  in  a  remarkable  manner  with  those  of  Jules 
de  Blosseville  (see  page  64),  it  would  appear  that  the 
magnetic  equator  passes  through  the  northern  point  of 
Borneo,  and  almost  due  west  into  the  northern  point  of 
Ceylon,  in  9°  45'  N.  lat.  The  curve  of  minimum  total  in- 
tensity runs  almost  parallel  to  this  part  of  the  magnetic 
equator,32  which  enters  the  western  part  of  the  continent  of 
Africa,  south  of  the  Cape  of  Gardafui.  This  important  re- 
entering  point  of  the  curve  has  been  determined  with  great 
accuracy  by  Rochet  d'Hericourt  on  his  second  Abyssinian 
expedition,  from  1842  to  1845,  and  by  the  interesting  dis- 

30  This  position  of  the  magnetic  equator  was  confirmed  by  Erman  for 
the  year  1830.     On  his  return  from  Kamtscatka  to  Europe,  he  found 
the  inclination  almost  null  at  1°  30'  S.  lat.,  132°  37'  W.  long.;  in  1°  52'  S. 
lat.,  135°  10' W.  long.;  in  1°  54' lat.,  in  133°  45' W.  long.;  in  2°  1'  S.  lat,, 
139°  8'  W.  long.  (Erman,  Magnet  Beob.  1841,  s.  536). 

31  Wilkes,  United  States  Exploring  Expedition,  vol.  iv,  p.  263. 
K  Elliot,  in  the  Phil.  Transact,  for  1851,  pt.  i,  pp.  287—331. 


106  COSMOS. 

cussion  to  which  his  magnetic  observations  gave  rise.33  This 
point  lies  south  of  Gaubade,  between  Angolola  and  Angobar, 
the  capital  of  the  kingdom  of  Schoa,  in  10°  7'  N".  lat.,  and  in 
41°  13'  E.  long.  The  course  of  the  magnetic  equator  in  the 
interior  of  Africa,  from  Angobar  to  the  Gulf  of  Biafra,  is  as 
thoroughly  unexplored  as  that  in  the  interior  of  South 
America,  east  of  the  chain  of  the  Andes,  and  south  of  the 
geographical  equator.  Both  these  continental  districts  are 
nearly  of  equal  extent,  measured  from  east  to  west,  each 
extending  over  a  space  of  about  80°  of  longitude,  so  that  we 
are  still  entirely  ignorant  of  the  magnetic  condition  of  nearly 
one  quarter  of  the  earth's  circumference.  My  own  observa- 
tions of  inclination  and  intensity  for  the  whole  of  the  in- 
terior of  South  America,  from  Cumana  to  the  Rio  Negro,  as 
well  as  from  Cartagena  de  Indias  to  Quito,  refer  only  to  the 
tropical  zone  north  of  the  geographical  equator,  while  those 
which  I  made  in  the  southern  hemisphere,  from  Quito  as  far 
as  Lima,  were  limited  to  the  district  lying  near  the  western 
coast. 

The  translation  of  the  African  node  towards  the  west  from 
1825  to  1837,  which  we  have  already  indicated,  has  been  con- 
firmed on  the  eastern  coasts  of  Africa  by  a  comparison  of  the 
inclination-observations  made  by  Pant  on,  in  the  year  1776, 
with  those  of  Rochet  d'Hericourt.  The  latter  observer 
found  the  magnetic  equator  much  nearer  the  Straits  of  Bab-el- 
Mandeb,  namely,  1°  south  of  the  island  of  Socotora,  in  8°  40' 
"N".  lat.  There  was,  therefore,  an  alteration  of  1°  27'  lat.  for 
49  years,  whilst  the  corresponding  alteration  in  the  longitude 
was  determined  by  Arago  and  Duperrey  to  have  been  10° 
from  east  to  west.  The  direction  of  the  secular  variation  of 
the  nodes  of  the  magnetic  equator  on  the  eastern  coasts  of 
Africa,  towards  the  Indian  Ocean,  was  precisely  similar  to 
that  on  the  western  coast.  The  quantity  of  the  motion 
must,  however,  be  ascertained  from  much  more  accurate 
results  than  we  at  present  possess. 

The  periodicity  of  the  alterations  of  the  magnetic  inclina- 
tion, whose  existence  had  been  noticed  at  a  much  earlier 
period,  has  only  been  established  with  certainty  and 
thorough  completeness  within  the  last  twelve  years,  since 
the  erection  of  British  magnetic  stations  in  both  hemispheres. 
33  Duperrey,  in  the  Comptes  rendus,  t.  xxii,  1846,  pp.  804 — 806. 


MAGNETIC   INCLINATION.  107 

Arago,  to  whom  the  theory  of  magnetism  is  so  largely  in- 
debted, had  indeed  recognised,  in  the  autumn  of  1827,  "  that 
the  dip  was  greater  at  9  A.M.  than  at  6  P.M.,  whilst  the  inten- 
sity of  the  magnetic  force,  when  measured  by  the  oscilla- 
tions of  a  horizontal  needle,  attained  its  minimum  in  the 
first,  and  its  maximum  in  the  second  period."34  In  the 

w  In  a  letter  from  Arago  to  myself,  dated  Mayence,  13th  of  Decem- 
ber, 1827,  he  writes  as  follows: — "I  have  definitely  proved  during  the 
late  Aurorpe  boreales,  which  have  been  seen  at  Paris,  that  this  pheno- 
menon is  always  "accompanied  by  a  variation  in  the  position  of  the  hori- 
zontal and  dipping  needles,  as  well  as  in  intensity.  The  changes  of 
inclination  have  amounted  to  1'  or  8'.  To  effect  this  change,  after 
allowing  for  every  change  of  intensity,  the  horizontal  needle  must 
oscillate  more  or  less  rapidly,  according  to  the  time  at  which  the  obser- 
vation is  made,  but  in  correcting  the  results  by  calculating  the  imme- 
diate effects  of  the  inclination,  there  still  remained  a  sensible  variation 
of  intensity.  On  repeating  by  a  new  method  the  diurnal  observation  of 
inclination,  on  which  I  was  engaged  during  your  late  visit  to  Paris,  1 
found  a  regular  variation,  not  for  the  means  but  for  each  day,  which 
was  greater  in  the  morning  at  nine  than  in  the  evening  at  six.  You 
are  aware  that  the  intensity,  measured  ivith  the  horizontal  needle,  is  on 
the  contrary  at  its  minimum  at  the  first  period,  while  it  attains  its 
maximum  between  six  and  seven  in  the  evening.  The  total  variation 
being  very  small,  one  might  suppose  that  it  was  merely  due  to  a 
change  of  iuclination  ;  and,  indeed,  the  greatest  portion  of  the  apparent 
variation  of  intensity  depends  upon  the  diurnal  alteration  of  the  hori- 
zontal component,  but,  when  every  correction  has  been  made,  there 
still  remains  a  small  quantity  as  an  indication  of  a  real  variation  of  in- 
tensity." In  another  letter,  which  Arago  wrote  to  me  from  Paris  on  the 
20th  of  March,  1829,  shortly  before  my  Siberian  expedition,  he  expressed 
himself  as  follows  : — "  I  am  not  surprised  that  you  should  have  found 
it  difficult  to  recognise  the  diurnal  change  of  inclination,  of  which  I 
have  already  spoken  to  you,  in  the  winter  months,  for  it  is  only  during 
the  warmer  portions  of  the  year  that  this  variation  is  sufficiently  sen- 
sible to  be  observed  with  a  lens.  I  would  still  insist  upon  the  fact, 
that  changes  of  inclination  are  not  sufficient  to  explain  the  change  of 
intensity,  deduced  from  the  observation  of  a  horizontal  needle.  An 
augmentation  of  temperature,  all  other  circumstances  remaining  the 
same,  retards  the  oscillations  of  the  needles.  In  the  evening,  the  tem- 
perature of  my  horizontal  needle  is  always  higher  than  in  the  morning ; 
hence  the  needle  must  on  that  account  make  fewer  oscillations  in  a  given 
time  in  the  evening  than  in  the  morning;  in  fact  it  oscillates  more  fre- 
quently than  we  can  account  for  by  the  change  of  inclination,  and  hence 
there  must  be  a  real  augmentation  of  intensity  from  morning  till  evening 
in  the  terrestrial  magnetic  force."  Later  and  more  numerous  observa- 
tions at  Greenwich,  Berlin,  St.  Petersburg,  Toronto,  and  Hobarton, 
have  confirmed  Arago's  assertion  (in  1827)  that  the  horizontal  intensity 


108  COSMOS. 

British  magnetic  stations  this  opposition  and  the  periodicity 
of  the  horary  variation  in  the  dip  have  been  firmly  estab- 
lished by  several  thousand  regularly  prosecuted  observations, 
which  have  all  been  submitted  to  a  careful  discussion  since 
1840.  The  present  would  seem  the  most  fitting  place  to 
notice  the  facts  that  have  been  obtained  as  materials  on 
which  to  base  a  general  theory  of  terrestrial  magnetism. 
It  must,  however,  first  be  observed,  that  if  we  consider  the 
periodical  variations  which  are  recognised  in  the  three  ele- 
ments of  terrestrial  magnetism,  we  must,  with  Sabine,  dis- 
tinguish in  the  turning  hours  at  which  the  maxima  or 
minima  occur,  two  greater,  and  therefore  more  important,  ex- 
tremes, and  other  slight  variations,  which  seem  to  be  inter- 
calated amongst  the  others,  as  it  were,  and  which  are  for  the 
most  part  of  an  irregular  character.  The  recurring  move- 
ments of  the  horizontal  and  dipping  needles,  as  well  as  the 
variation  in  the  intensity  of  the  total  force,  consequently 
present  principal  and  secondary  maxima  or  minima,  and 
generally  some  of  either  type,  which  therefore  constitutes  a 
double  progression  with  four  turning  hours  (the  ordinary 
case),  and  a  simple  progression  with  two  turning  hours,  that 
is  to  say,  with  a  single  maximum  and  a  single  minimum. 
Thus,  for  instance,  in  Van  Diemen's  Land,  the  intensity  or 
total  force  exhibits  a  simple  progression,  combined  with  a 

was  greater  in  the  evening  than  towards  morning.  At  Greenwich  the 
principal  maximum  of  the  horizontal  force  was  about  6  P.M.,  the  prin- 
cipal minimum  about  10  A.M.  or  at  noon;  at  Schulzendorf,  near  Berlin, 
tile  maximum  falls  at  8  P.M.,  the  minimum  at  9  A.M.;  at  St.  Petersburg 
the  max.  falls  at  8  P.M.,  the  min.  at  llh.  20m.  A.M.  ;  at  Toronto  the 
max.  falls  at  4  P.M.,  the  min.  at  11  A.M.  The  time  is  always  rec- 
koned according  to  the  true  time  of  the  respective  places  (Airy,  Magn. 
Observ.  at  Greenwich  for  1845,  p.  13 ;  for  1846,  p.  102  ;  for  1847,  p.  241; 
Riess  and  Moser,  in  Poggend.  Annalen.  Ed.  xix,  1830,  s.  175  ;  Kupffer, 
Compterendu  Annuel  de  V  Observatoire  Centrale  Magn.  de  St.  Petersb. 
1852,  p.  28 ;  and  Sabine,  Magn.  Observ.  at  Toronto,  vol.  i,  1840 — 1842, 
p.  xlii).  The  turning  hours  at  the  Cape  of  Good  Hope  and  at  St.  Helena, 
where  the  horizontal  force  is  the  weakest  in  the  evening,  seem  to  be 
singularly  at  variance,  and  almost  the  very  opposite  of  one  another 
(Sabine,  Magn.  Obs.  at  the  Cape  of  Good  Hope,  p.  xl,  at  St.  Helena, 
p.  40).  Such,  however,  is  not  the  case  further  eastward,  in  other  parts 
of  the  great,  southern  hemisphere.  "  The  principal  feature  in  the 
diurnal  change  of  the  horizontal  force  at  Hobarton  is  the  decrease  of 
force  in  the  forenoon  and  its  subsequent  increase  in  the  afternoon" 
(Sabine,  Magn.  Obs.  at  Hobarton,  vol.  i,  p.  liv.  vol.  ii,  p.  xliii). 


MAGNETIC   INCLINATION.  109 

double  progression  of  the  inclination,  while  at  one  part  of 
the  northern  hemisphere,  which  corresponds  exactly  with 
the  position  of  Hobarton,  namely,  Toronto,  in  Canada,  both 
the  elements  of  intensity  and  inclination  exhibit  a  double 
progression.3*  At  the  Cape  of  Good  Hope  there  is  only  one 
maximum  and  one  minimum  of  inclination.  The  horary 
periodical  variations  of  the  magnetic  dip  are  as  follows  : — 

I.  Northern  Hemisphere. 

Greenwich:  Maxim.  9  A.M.;  minim.  3  P.M.  (Airy,  Obsero. 
in  1845,  p.  21 ;  in  1846,  p.  113  ;  in  1847,  p.  247).  Inclin. 
in  the  last  named  year  about  9  A.M.  on  an  average  68°  59'  3", 
but  at  3  P.M.  it  was  68°  58'  6".  In  the  monthly  variation, 
the  maximum  falls  between  April  and  June  and  the  mini- 
mum between  October  and  December. 

Paris  :  Maxim.  9  A.M.  ;  minim.  6  P.M.  This  simple  pro- 
gression from  Paris  and  Greenwich  is  repeated  at  the  Cape 
of  Good  Hope. 

St.  Petersburg  :  Maxim.  8  A.M.;  minim.  10  P.M.  Varia- 
tion of  the  inclination  the  same  as  at  Paris,  Greenwich,  and 
Pekin ;  less  in  the  cold  months,  and  the  maxima  more  closely 
dependent  on  time  than  the  minima. 

Toronto  :  Principal  maxim.  10  A.M.  ;  principal  minim. 
4  P.M.  ;  secondary  maxim.  10  P.M.;  secondary  minim.  6  A.M. 
(Sabine,  Tor.  1840—1842,  vol.  i,  p.  Ixi.) 

II.  Southern  Hemisphere. 

Hobarton,  Van  Diemen's  Land  :  principal  minim.  6  A.M.; 
principal  maxim.  11 .  30.  A.M.  ;  secondary  minim.  5  P.M.  ;  second- 
ary maxim.  10  P.M.  (Sabine,  Hob.,  vol.  i,  p.  Ixvii.)  The  incli- 
nation is  greater  in  the  summer  when  the  sun  is  in  the  southern 
zodiacal  signs,  70°  36'.  74  ;  it  is  smaller  in  winter  when  the 
sun  is  in  the  northern  signs,  70°34/.66.  The  annual  mean 
taken  from  the  observations  of  six  years  gives  70°  36'.01. 
(Sabine,  Hob.,  vol.  ii,  p.  xliv.)  Moreover  the  intensity  at 
Hobarton  is  greater  from  October  to  February  than  from 
April  to  August,  p.  xlvi. 

Cape  of  Good  Hope  :  Simple  progression,  the  minim,  being 
0  h.  34  m.  P.M.  ;  maxim.  8  h.  34  m.  P.M.,  with  an  exceedingly 

85  Sabine,  Hobarton,  vol.  i,  pp.  Ixvii,  Ixix. 


110  COSMOS. 

small  intermediate  variation  between  7  and  9  A.M.   (Sabine, 
Carte  Obs.  1841—1850,  p.  liii.) 

The  phenomena  of  the  turning  hours  of  the  maximum  of 
the  inclinations  expressed  in  the  time  of  the  place,  fall  with 
remarkable  regularity  between  8  and  10  A.M.  for  places  in 
the  northern  hemisphere,  such  as  Toronto,  Paris,  Greenwich, 
and  St.  Petersburg,  whilst  in  like  manner  the  minima  of  the 
turning  hours  all  fall  in  the  afternoon  or  evening,  although 
not  within  equally  narrow  limits  (at  4,  6,  and  10  P.M.).    It  is 
so  much  the  more  remarkable,  that  in  the  course  of  very 
accurate  observations  made  at  Greenwich  during  five  years 
there  was  one  year,  1845,  in  which  the  epochs  of  the  maxima 
and  minima  were  reversed.     The  annual  mean  of  the  in- 
clinations was  for  9  A.M.  :  68°  5 6'. 8,  and  for  3  P.M.:  68°  58M. 
"When  we  compare  together  the  stations  of  Toronto  and 
Hobarton,  which  exhibit  a  corresponding  geographical  posi- 
tion on  either  side  of  the  equator,  we  find  that  there  is  at 
Hobarton  a  great  difference  in  the  turning  hours  of  the  prin- 
cipal minimum  of  inclination  (at  4  o'clock  in  the  afternoon 
and  6  o'clock  in  the  morning),  although  such  is  not  the  case 
in  the  turning  hours  of  the  principal  maximum  (10  and 
1 1.  30  A  M.).    The  period  of  the  principal  minimum  (6  A.M.)  at 
Hobarton  coincides  with  that  of  the  secondary  minimum  at 
Toronto.      The  principal  and  secondary  maxima  occur  at 
both  places  at  the  same  hours,  between  10  and  11.  30  A.M. 
and  10  P.M.     The  four  turning  hours  of  the  inclination  occur 
almost  precisely  the  same  at  Toronto  as  at  Hobarton,  only 
in  a  reversed  order  (4  or  5  P.M.,  10  P.M.,  6  A.M.,  and  10  or 
11.  30  A.M.)     This  complicated  effect  of  the  internal  terres- 
trial fo.'rce  is  very  remarkable.     If,  on  the  other  hand,  we 
compare  Hobarton  and  Toronto  in  respect  to  the  order  in 
whicli  the  turning  hours  of  the  alterations  of  intensity  and 
inclination  occur,  we  shall  find  that  at  the  former  place  in 
the   southern   hemisphere  the   minimum   of  the   intensity 
follows  only  2  hours  after  the  principal  minimum  of  the 
inclination,  whilst  the  delay  in  the  maximum  amounts  to 
6  hours,  while  in  the  northern  hemisphere,  at  Toronto,  the 
minimum  of  intensity  precedes  the  principal  maximum  of 
inclination  by  8  hours,  whilst  the  maximum  of  intensity 
differs  only  by  2  hours  from  the  minimum  of  inclination.36 
36  Total  intensity  at  Hobartou,  max.  5h.  30m.  P.M.,  miu.  8h.  30m,  A.M.J 


MAGNETIC   INCLINATION.  Ill 

The  periodicity  of  inclination  at  the  Cape  of  Good  Hope 
does  not  coincide  with  that  at  Hobarton,  which  lies  in  the 
same  hemisphere,  nor  with  any  one  point  of  the  northern 
hemisphere.  The  minimum  of  inclination  is  indeed  reached 
at  an  hour  at  which  the  needle  at  Hobarton  has  very  nearly 
reached  the  maximum. 

For  the  determination  of  the  secular  variation  of  the 
inclination,  it  is  necessary  to  have  a  series  of  observations 
that  have  not  only  been  conducted  with  extreme  accuracy, 
but  which  have  likewise  extended  over  long  intervals  of  time. 
Thus  for  instance,  we  cannot  go  with  certainty  as  far  back 
as  the  time  of  Cook's  voyages,  for  although  in  his  third 
expedition  the  poles  were  always  reversed,  we  frequently 
observe  differences  of  40'  to  55'  in  the  observations  of  this 
great  navigator  and  of  Bayley  on  the  Pacific  Ocean,  a  dis- 
crepancy which  may  very  probably  be  referred  to  the  imper- 
fect construction  of  the  magnetic  needle  at  that  time,  and  to 
the  obstacles  which  then  prevented  its  free  motion.  For 
•London  we  scarcely  like  to  go  further  back  than  Sabine's 
observation  of  August  1821,  which  compared  with  the 
admirable  determination  made  by  himself,  Sir  James  Ross 
and  Fox  in  May  1838,  yielded  an  annual  decrease  of  2'.73, 
whilst  Lloyd  with  equally  accurate  instruments,  but  in  a 
shorter  interval  of  time,  obtained  at  Dublin,  the  very  accord- 
ant result  of  2'.38.37  At  Paris,  where  the  annual  diminution 
of  inclination  is  likewise  on  the  decrease,  this  diminution  is 
greater  than  in  London.  The  very  ingenious  methods  sug- 
gested by  Coulomb  for  determining  the  dip,  had  indeed  led 
their  inventor  to  incorrect  results.  The  first  observation 
which  was  made  with  one  of  Le  Noir's  perfect  instruments 
at  the  Paris  Observatory,  belongs  to  the  year  1798.  At  that 
time  I  found,  after  often  repeating  the  experiments  conjointly 
with  the  Chevalier  Borda  69°  51' ;  in  the  year  1810,  in  con- 
junction with  Arago,  I  found  68°  50'.2,  and  in  the  year 
1826,  with  Mathieu,  67°  56'.7.  In  the  year  1841,  Arago 
found  67°  9',  and  in  the  year  1851,  Laugier  and  Mauvais 

at  Toronto,  principal  max.  6  P.M.,  principal  min.  2  A.M.,  secondary  mar. 
•S  A.M.,  secondary  min.  10  A.M.  See  Sabine,  Toronto,  vol.  i,  pp.  Ixi,  Ixii, 
and  Hobarton,  vol  i,  p.  Ixviii. 

37  Saluue,  Report  on  the  Isoclinal  and  Isodynamic  Lines  in  the  Bril'uh 
Island*,  1839,  pp.  61—63. 


112  COSMOS. 

found  66°  35' :  all  these  observers  adopting  similar  methods 
and  using  similar  instruments.  This  entire  period  which 
extends  over  more  than  half  a  century  (from  1798  to  1851) 
giyes  a  mean  annual  diminution  of  the  inclination  at  Paris 
of  3'.  69.  The  intermediate  periods  stood  as  follows  : — 

From  1798—1810  at  . .  .  .  5',08 

1810—1826  ..  ..  3.37 

1826—1811  ..  ..  3.13 

1841—1851  ..  ..  3.40 

The  decrease  between  1810  and  1826  has  been  strikingly, 
though  gradually  retarded ;  for  an  observation  which  Gay- 
Lussac  made  with  extreme  care  (69°  12')  after  his  return  in 
1806  from  Berlin,  whither  he  had  accompanied  me  after  our 
Italian  expedition,  gave  an  annual  diminution  of  4 '.87  since 
1798.  The  nearer  the  node  of  the  magnetic  equator  approaches 
to  the  meridian  of  Paris  in  its  secular  progression  from  east 
to  west,  the  slower  seems  to  be  the  decrease,  ranging  in  half 
a  century  from  about  5'.08  to  3'.40.  Shortly  before  my 
Siberian  expedition  in  April  1829,  I  laid  before  the  Academy 
of  Berlin,  a  memoir,  in  which  I  had  compared  together  the 
different  points  observed  by  myself,  and  which  I  believe  I 
may  venture  to  say,  had  all  been  obtained  with  equal  care.38 
Sabine  more  than  25  years  after  me  measured  the  inclination 
and  intensity  of  the  magnetic  force  at  the  Havanah,  which  in 
respect  to  these  equinoctial  regions,  affords  a  very  considerable 
interval  of  time,  while  he  also  determined  the  variation  of 
two  important  elements.  Hansteen,  in  1831,  gave  the 
result  of  his  investigations  of  the  annual  variation  of  the 
dip  in  both  hemispheres,39  in  a  very  admirable  work  which 
is  of  a  more  comprehensive  nature  than  my  own. 

38  Humboldt,  in  Poggend.  Annalen,  Bd.  xv,  s.  319—336,  Bd.  xix, 
s.  357 — 391,  and  in  the  Voyage  aux  Regions  Equinox,  t.  iii,  pp.  616 — 
625. 

39  Hansteen,  Ueber  jdlirliche  Verdnderung  der  Inclination,  in  Poggend. 
Ann.  Bd.  xxi,  s.  403 — 429.     Compare  also,  on  the  iofluence  of  the  pro- 
gression of  the  nodes  of  the  magnetic  equator,  Sir  David  Brewster, 
Treatise  on  Magnetism,  p.  247.     As  the  great  number  of  observations 
made  at  different  stations  have  opened  an  almost  inexhaustible  field  of 
inquiry  in  this  department  of  special  investigation,  we  are  constantly 
meeting  with  new  complications  in  our  search  for  the  laws  by  which 
these  forces  are  controlled.    Thus,  for  instance,  in  the  course  of  a  series 


MAGNETIC   OBSERVATIONS.  113 

Although  Sir  Edward  Belcher's  observations  for  the  year 
1838,  when  compared  with  those  I  made  in  1803  (see  p.  73), 
along  the  Western  Coast  of  America,  between  Lima,  Guaya- 
quil, and  A  capulco,  indicate  considerable  alterations  in  the 
inclination  (and  the  longer  the  intermediate  period  the 
greater  is  the  value  of  the  results),  the  secular  variation  of 
the  dip  at  other  points  of  the  Pacific  has  been  found  to  be 
strikingly  slow.  At  Otaheite,  Bayley  found  in  1773,  29°  43' 
and  Fitzroy  in  1835,  30°  14',  whilst  Captain  Belcher  in  1840, 
again  found  30°  17',  and  hence  the  mean  annual  variation 
scarcely  amounted,  in  the  course  of  67  years,  to  O'.Sl.40  A 
very  careful  observer,  Sawelieff,  found  in  Northern  Asia, 
22  years  after  my  visit  to  those  regions,  in  a  journey  which 
he  made  from  Casan  to  the  shores  of  the  Caspian  Sea,  that 
the  inclination  to  the  north  and  south  01  the  parallel  of  50° 
had  varied  very  irregularly.41 

Humboldt.  Sawelieff. 

1829.  1851. 

Casan     ..     68°  26'.7  ..  ..     68°  30'. 8 

Saratow..     64   40.9  ..  ..64   48.7 

Sarepta  . .     62    15 .9  . .  . .     62    39  .6 

Astrachan     59    58 .3  ..  ..60   27.9 

For  the  Cape  of  Good  Hope  we  now  possess  an  extended 
series  of  observations,  which  if  we  do  not  go  further  back 
than  from  Sir  James  Ross  and  du  Petit  Thouars  (1840)  to 
Vancouver  (1791),  may  be  regarded  as  of  a  very  satisfactory 
nature  in  respect  to  the  variation  of  the  inclination  for  nearly 
half  a  century.42 

of  successive  years  we  see  that  the  dip  passes  in  one  of  the  turning  hours 
— that  of  the  maximum  from  a  decrease  to  an  absolute  increase,  whilst 
in  the  turning  hour  of  the  minimum,  the  progressive  annual  decrease 
continued  the  same.  Thus,  at  Greenwich,  the  magnetic  inclination  in 
the  maximum  hour  (9  A.M.)  decreased  in  the  years  1844  and  1845, 
while  it  increased  at  the  same  hour  from  1845  to  184P,  and  continued 
in  the  turning  hour  of  the  minimum  (3  P.M.)  to  decrease  from  1844  to 
1846  (Airy,  Magn.  Observ.  at  Greenwich,  1846,  p.  113). 

40  Phil.  Transact,  for  1841,  pt.  i,  p.  35. 

41  Compare  Sawelieff,  in  the  Bulletin  Physico-Mathematique  de  T Acad. 
Imp.  de  St.  Petersb.  t.  x,  No.  219,  with  Humboldt,  Asie  Centr.  t.  iii, 
p.  440. 

42  Sabine,  Magn.  Observ.  at  the  Cape  of  Good  Hope,  vol.  i,  p.  Ixv.     If 
we  may  trust  to  the  observations  made  by  Lacaille  for  the  year  1751, 

VOL.  V.  I 


114:  COSMOS. 

The  solution  of  the  question  whether  the  elevation  of  the 
soil  does  in  itself  exert  a  perceptible  influence  on  magnetic 
dip  and  intensity,43  was  made  the  subject  of  very  careful 
investigation  during  my  mountain  journeys  in  the  chain  of 
the  Andes,  in  the  Ural,  and  Altai.  I  have  already  observed, 
in  the  section  on  Magnetic  Intensity,  how  very  few  localities 
were  able  to  afford  any  certainty  as  to  this  question,  because 
the  distance  between  the  points  to  be  compared  together 
must  be  so  small  as  to  leave  no  ground  for  suspecting  that 
the  difference  found  in  the  inclination  may  be  a  consequence 
of  the  elevation  of  the  soil,  instead  of  the  result  of  the  cur- 
vature of  the  isodynamic  and  isoclinal  lines,  or  of  some  great 
peculiarity  in  the  composition  of  the  rocks.  I  will  limit 
myself  to  the  four  results  which  I  thought  at  the  time  they 
were  obtained,  showed  more  decisively  than  could  be  done 
by  observations  of  intensity,  the  influence  exerted  by  eleva- 
tion in  diminishing  the  dip  of  the  needle. 

The  Silla  de  Caracas,  which  rises  almost  vertically  above 
La  Guayra,  and  8638  feet  above  the  level  of  the  sea,  south 
of  the  coast  but  in  its  immediate  vicinity  and  north  of  the 
town  of  Caracas,  yielded  the  inclination  of  41°. 90 ;  La 
Guayra,  elevation  10  feet,  inclination  4 2°. 20  ;  the  town  of 
Caracas,  height  above  the  shores  of  the  Bio  Guayre,  2648 
feet,  inclination  42°.  95.  (Humboldt,  Voy.  aux  Reg.  Equi- 
nox., t.  i,  p.  612.) 

Santa  .¥6  de  Bogota :  elevation  8735  feet,  inclination 
27°.  15  \  the  chapel  of  Nuestra  Senora  de  Guadalupe,  built 
upon  the  projecting  edge  of  a  rock,  elevation  10,794  feet,  in- 
clination 26°.80. 

Popayan  :  elevation  5825  feet,  inclination  23°. 25  ;  moun- 
tainous village  of  Purace  on  the  declivity  of  the  volcano, 
elevation  8671  feet,  inclination  21°. 80  ;  summit  of  the  vol- 
cano of  Purace,  elevation  14,548  feet,  inclination  20°. 30. 

Quito  :  elevation  9541,  inclination  14°. 85  ;  San  Antonio 
de  Lulumbamba,  where  the  geographical  equator  intersects 

who,  indeed,  always  reversed  the  poles,  but  who  made  his  observations 
with  a  needle  which  did  not  move  freely,  it  follows  that  there  has  been 
an  increase  in  the  inclination  at  the  Cape  of  Good  Hope  of  3°.08  in 
89  years ! 

43  Arago,  in  the  Annuaire  du  Bureau  des  Long,  pour  1825,  pp.  285 
—288. 


MAGNETIC   OBSERVATIONS.  115 

the  torrid  valley,  elevation  of  the  bottom  of  the  valley  8153 
feet,  inclination  16°. 02.  (All  the  above-named  inclinations 
have  been  expressed  in  decimal  parts  of  a  degree.) 

It  might  perhaps  be  deemed  unnecessary,  considering  the 
extent  of  the  relative  distances  and  the  influence  of  the 
neighbouring  kinds  of  rock,44  for  me  to  enter  fully  into  the 
details  of  the  following  observations  :  the  Hospice  of  St. 
Gotthard,  7087  feet,  inclination  66°  12' ;  compared  with 
Airolo,  elevation  3727  feet,  inclination  66°  54',  and  Altorf, 
inclination  66°  55' ;  or  to  notice  the  apparently  contradictory 
data  yielded  by  Lans  le  Bourg,  inclination  66°  9',  the  Hospice 
of  Mont  Cenis,  6676  feet,  inclination  66°  22',  and  Turin  754 
feet,  inclination  6 6°  3';  or  by  Maples,  Portici  and  the  margin  of 
the  crater  of  Vesuvius;  or  by  the  summit  of  the  Great  Mili- 
schauer  (Phonolith)  inclination  67°  53'.5,  Teplitz  inclination 
67°  19'. 5,  and  Prague  inclination  GG^iT'.e.44  Simultaneously 
with  the  series  of  admirable  comparative  observations  pub- 
lished with  the  fullest  details  of  the  horizontal  intensity, 
which  were  made  in  1844  by  Bravais,  in  conjunction  with 
Martins  and  Lepileur,  and  compared  at  35  stations,  includ- 
ing the  summits  of  Mont  Blanc  (15,783  feet),  of  the  Great  St. 
Bernard  (8364  feet),  and  of  the  Faulhorn  (8712  feet),  the 
above-named  physicists  made  a  series  of  inclination  experi- 
ments on  the  grand  plateau  of  Mont  Blanc  (12,893  feet),  and 
at  Chamouni  (3421  feet).  Although  the  comparison  of  these 
results  showed  that  the  elevation  of  the  soil  exerted  an  in- 
fluence in  diminishing  the  magnetic  inclination,  observations 
made  at  the  Faulhorn  and  at  Brienz  (1870  feet  in  eleva- 
tion) showed  the  opposite  result  of  the  inclination  increasing 
with  the  height.  The  different  investigations  on  horizontal 
intensity  and  inclination  failed  to  yield  any  satisfactory 
solution  of  the  problem.  (Bravais,  Sur  VIntensite  du  Mag- 
net isme  Terrestre  en  France,  en  Suisse,  et  en  Savoie,  in  the 
Annales  de  Chimie  et  de  Physique,  3eme  serie,  t.  xviii,  1846, 
p.  225.)  In  a  manuscript  report  by  Borda  of  his  expedition 

44  I  would  again  repeat  that  all  the  European  observations  of  incli- 
nation \vhichhave  been  given  in  this  page  have  been  reckoned  according 
to  the  diyi§ion  of  the  circle  into  360  parts,  and  it  is  only  in  those  obser- 
vations of  inclination  which  I  made  myself  before  the  month  of  June, 
1804,  in  the  New  Continent,  that  the  centesimal  division  of  the  arc  has 
been,  adhered  to  (Voy.  aux  Regions  Equinox.,  t.  iii,  pp.  615 — 623). 

12 


116  COSMOS. 

to  the  Canary  Islands,  in  the  year  1776,  which  is  preserved 
at  Paris  in  the  Depot  de  la  Marine,  and  which  I  have  been 
enabled  to  consult  through  the  obliging  courtesy  of  Admiral 
Rosily,  I  have  discovered  that  Borda  was  the  first  who  made 
an  attempt  to  investigate  the  influence  of  a  great  elevation 
on  the  inclination.  He  found  that  the  inclination  was  1°  15' 
greater  at  the  summit  of  the  Peak  of  Tenerifie  than  in  the 
harbour  of  Santa  Cruz,  owing  undoubtedly  to  the  local 
attractions  of  the  lava,  as  I  have  often  observed  on  Vesuvius 
and  different  American  volcanoes.  (Humboldt,  Voy.  aux 
Regions  Eqiiinox.,  t.  i,  pp.  116,  277,  288.) 

In  order  to  try  whether  the  deep  interior  portions  of  the 
body  of  the  earth  influence  magnetic  inclination  in  the  same 
manner  as  elevations  above  the  surface,  I  instituted  an  ex- 
periment during  my  stay  at  Freiberg,  in  July  1828,  with  all 
the  care  that  I  could  bestow  upon  it,  and  with  a  constant 
inversion  of  the  poles  ;  when  I  found  after  very  careful  in- 
vestigation that  the  neighbouring  rock,  which  was  composed 
of  gneiss,  exerted  no  action  on  the  magnetic  needle.  The 
depth  below  the  surface  was  854  feet,  and  the  difference 
between  the  inclination  of  the  subterranean  parts  of  the 
mine  and  those  points  which  lay  immediately  above  it,  and 
even  with  the  surface,  was  only  2'.  06  ;  but  considering  the 
care  with  which  my  experiments  were  made,  I  am  inclined 
to  think  from  the  results  given  for  each  needle,  as  recorded  in 
the  accompanying  note,*5  that  the  inclination  is  greater  in 

45  In  the  Churprinz  mine  at  Freiberg,  in  the  mountains  of  Saxony, 
the  subterranean  point  was  133£  fathoms  deep,  and  was  observed  with 
Freiesleben  and  Reich  at  2£  P.M.  (temperature  of  the  mine  being 
60°.08  F.).  The  dipping  needle  A  showed  67°  37'.4,  the  needle  B 
67°  32/.7,  the  mean  of  both  needles  in  the  mine  was  67°  35'.05.  In  the 
open  air,  at  a  point  of  the  surface  which  lies  immediately  above  the 
point  of  subterranean  observation,  the  needle  A  stood  at  11  A.M.  at 
67°  33'.87  and  the  needle  B  at  67°  32'.12.  The  mean  of  both  needles 
in  the  upper  station  was  67°  32'.99,  the  temperature  of  the  air  being 
60°.44  F.,  and  the  difference  between  the  upper  and  lower  result 
2'.06.  The  needle  A,  which,  as  the  stronger  of  the  two,  inspired  me 
with  most  confidence,  gave  even  3'. 53,  whilst  the  influence  of  the  depth 
remained  almost  inappreciable  when  the  needle  B  only  was  used  (Hum- 
boldt,  in  Poggend.  Annal.  Bd.  xv,  s.  326).  I  have  already  described  in 
detail,  and  elucidated  by  examples,  in  Asie  Centr.  t.  iii,  pp.  465 — 467, 
the  uniform  method  which  I  have  always  employed  in  reading  the 
azimuth  circle  in  order  to  find  the  magnetic  meridian  by  corresponding 


MAGNETIC   OBSERVATIONS.  117 

the  Churprinz  mine  than  on  the  surface  of  the  mountain. 
It  would  be  very  desirable  if  opportunities  were  to  present 
themselves  in  cases,  where  there  is  evidence  that  the  rock 
has  not  exerted  any  local  influence  on  the  magnet,  for  care- 
fully repeating  my  experiments  in  mines,  in  which,  like  those 
of  Valenciana  near  Guanaxuato  in  Mexico,  the  vertical 
depth  is  1686  feet ;  or  in  English  coal  mines  nearly  1900 
feet  deep,  or  in  the  now  closed  shaft  at  Kuttenberg  in 
Bohemia,  3778  feet  in  depth.4* 

After  a  violent  earthquake  at  Cumana  on  the  4th  of 
November,  1799, 1  found  that  the  inclination  was  diminished 
0°.90,  or  nearly  a  whole  degree.  The  circumstances  under 
which  I  obtained  this  result,  and  which  I  have  elsewhere 
fully  described, 47  afford  no  sufficient  ground  for  the  suspi- 
cion of  an  error  in  the  observation.  Shortly  after  my  arrival 
at  Cumana  I  found  that  the  inclination  was  43°.53.  A  few 
days  before  the  earthquake,  I  was  induced  to  begin  a  long 
series  of  carefully  conducted  observations  in  the  harbour  of 
Cumana,  in  consequence  of  having  accidentally  noticed  a 
statement  in  an  otherwise  valuable  Spanish  work,  Mendoza's 
Tratado  de  Navegacion,  t.  ii,  p.  72,  according  to  which  it 
was  erroneously  asserted  that  the  hourly  and  monthly 
alterations  of  inclination  were  greater  than  those  of  varia- 
tion. I  found  between  the  1st  and  2nd  of  November  that 
the  inclination  exhibited  very  steadily  the  mean  value  of 
43°.  65.  The  instrument  remained  untouched  and  properly 
levelled  on  the  same  spot,  and  on  the  7th  of  November,  and 
therefore  three  days  after  the  great  earthquake  and  when 
the  instrument  had  again  been  adjusted,  it  yielded  42°. 75. 
The  intensity  of  the  force,  measured  by  vertical  oscillations 
was  not  changed.  I  expected  that  the  inclination  would 
perhaps  gradually  return  to  its  former  position,  but  it  re- 
mained stationary.  In  September,  1800,  in  an  expedition  of 

inclinations,  or  by  the  perpendicular  position  of  the  needle  ;  as  also  to 
find  the  inclination  itself  on  the  vertical  circle  by  reversing  the  bearings 
of  the  needle  and  by  taking  the  readings  at  both  points,  before  and  after 
the  poles  had  been  reversed.  The  position  of  the  two  needles  has,  in 
each  case,  been  read  off  16  times,  in  order  to  obtain  a  mean  result. 
Where  so  small  an  amount  has  to  be  determined,  it  is  necessary  to  enter 
fully  into  the  individual  details  of  the  observation. 

46  Cosmos,  vol.  i,  p.  148. 

47  Humboldt,  Voy.  aux  Regions  Equinox,  t.  i,  pp.  515 — 517. 


118  COSMOS. 

more  than  2000  geographical  miles  on  the  waters  and  along 
the  shores  of  the  Orinoco  and  the  Rio  Negro,  the  same  in- 
strument, which  was  one  of  Borda's,  which  I  had  constantly- 
carried  with  me,  yielded  42°. 80,  showing,  therefore,  the 
same  dip  as  before  my  journey.  As  mechanical  disturb- 
ances and  electrical  shocks  excite  polarity  in  soft  iron  by 
altering  its  molecular  condition,  we  might  suspect  a  connec- 
tion between  the  influences  of  the  direction  of  magnetic 
currents  and  the  direction  of  earthquakes ;  but  carefully  as 
I  observed  this  phenomenon,  of  whose  objective  reality  I 
did  not  entertain  a  doubt  in  1799,  I  have  never  on  any 
other  occasion,  in  the  many  earthquakes  which  I  experienced 
in  the  course  of  three  years  at  a  subsequent  period  in  South 
America,  noticed  any  sudden  change  of  the  inclination, 
which  I  could  ascribe  to  these  terrestrial  convulsions,  how- 
ever different  were  the  directions,  in  which  the  undulations 
of  the  strata  were  propagated.  A  very  accurate  and  ex- 
perienced observer,  Erman,  likewise  found  that  after  an 
earthquake  at  Lake  Baikal,  on  the  8th  of  March,  1828,  there 
was  no  disturbance  in  the  declination48  and  its  periodic 
changes. 

Declination. 

We  have  already  referred  to  the  historical  facts  of  the 
earliest  recognition  of  those  phenomena,  which  depend  upon 
the  third  element  of  terrestrial  magnetism,  namely,  declina- 
tion. The  Chinese,  as  early  as  the  12th  century  of  our  era, 
were  not  only  well  acquainted  with  the  fact  of  the  variation 
of  a  horizontal  magnetic  needle  (suspended  by  a  cotton 
thread)  from  the  geographical  meridian,  but  they  also 
knew  how  to  determine  the  amount  of  this  variation. 
The  intercourse  which  the  Chinese  carried  on  with  the 
Malays  and  Indians,  and  the  latter  with  Arab  and 
Moorish  pilots,  led  to  the  extensive  use  of  the  mariner's 
compass  amongst  the  Genoese,  Majorcans  and  Catalans,  in 
the  basin  of  the  Mediterranean,  on  the  west  coast  of  Africa, 
and  in  high  northern  latitudes ;  while  the  maps,  which  were 
published  as  early  as  1436,  even  give  the  variation  for  dif- 
ferent parts  of  the  sea.49  The  geographical  position  of  a 

48  Erman,  Reise  um  die  Erde,  Bd.  ii,  s.  180. 

49  See  page  52 ;  Petrus  Peregrine  informs  a  friend  that  he  found  the 
variation  in  Italy  was  5°  east  in  1269. 


MAGNETIC  VARIATION.  119 

line  of  no  variation,  on  which  the  needle  turns  to  the  true 
north, — the  pole  of  the  axis  of  the  earth— was  determined 
by  Columbus  on  the  13th  of  September,  1492,  and  it  did 
not  escape  his  notice  that  the  knowledge  of  the  magnetic 
declination  might  serve  in  the  determination  of  geographical 
longitudes.  I  have  elsewhere  shewn,  from  the  Admiral's  log, 
that  when  he  was  uncertain  of  the  ship's  reckoning,  he 
endeavoured,  on  his  second  voyage,  April,  1496,  to  ascertain 
his  position  by  observations  of  declination.  M  The  horary 
changes  of  variation  which  were  simply  recognized  as  certain 
facts  by  Hellibrand  and  Father  Tachard,  at  Louvo,  in  Siam, 
were  circumstantially  and  almost  conclusively  observed  by 
Graham  in  1722.  Celsius  was  the  first  who  made  use  of 
these  observations  to  institute  simultaneous  measurements 
at  two  widely  remote  points.  51 

Passing  to  the  consideration  of  the  phenomena  observed 
in  the  variation  of  the  magnetic  needle,  we  must  first  notice 
its  alterations  in  respect  to  the  different  hours  of  the 
night  and  day,  the  different  seasons  of  the  year  and  the 
mean  annual  values  ;  next,  in  respect  to  the  influence  which 
the  extraordinary,  although  periodically  recurring  disturb- 
ances, and  the  magnetic  position,  north  or  south  of  the 
equator,  exert  on  these  alterations,  and  finally  in  respect  to 
the  different  lines  passing  through  the  terrestrial  points  at 
which  the  variation  is  equal,  or  even  null.  These  linear 
relations  are  certainly  most  important  in  respect  to  the  direci 

50  Humboldt,  Examen.  Grit,  de  VHut.  de  la  Geogr.  t.  iii,  pp.  29,  36. 
38,  44 — 51.     Although  Herrera  (Dec.  i,  p.  23)  says  that  Columbus  had 
remarked  that  the  magnetic  variation  was  not  the  same  by  day  and 
by  night,  it  does  not  justify  us  in  ascribing  to  this  great  discoverer  a 
knowledge  of  the  horary  variation.     The  actual  Journal  of  the  admira1 
which  has  been  published  by  Navarrete,  informs  us  that  from  the  17tk 
to  the  30th  of  September,  1492,  Columbus  had  reduced  everything  to  a 
so-called    "unequal  movement"    of  the  polar  star  and  the  pointers 
(Guardas),  Examen  Grit.  t.  iii,  pp.  56 — 59. 

51  See  pages  60,  70.     The  first  printed  observations  for  London  are 
those  by  Graham,  in  the  Phil.  Transact,  for  1724  and  1725,  vol.  xxxijn, 
pp.  96 — 107  (An  Account  of  Observations  made  of  the  Horizontal  Needle 
at  London,  1722—1723,  by  Mr.  George  Graham).     The  change  of  the 
variation  depends    "  neither   upon   heat  nor  cold,   diy  or   moist  air. 
The  variation  is  greatest  between  12  and  4  in  the  afternoon,  and  the 
least  at  6  01  7  in  the  evening."    These  however,  are  not  the  true  turning 
hours. 


120  COSMOS. 

practical  application  of  their  results  to  the  ship's  reckoning, 
and  to  navigation  generally ;  but  all  the  cosmical  phenomena 
of  magnetism,  amongst  which  we  must  place  those  extraor- 
dinary and  most  mysterious  disturbances  which  often  act 
simultaneously  at  very  remote  distances  (magnetic  storms), 
are  so  intimately  connected  with  one  another,  that  no  single 
one  of  them  can  be  neglected  in  our  attempt  gradually  to 
complete  the  mathematical  theory  of  terrestrial  magnetism. 
In  the  middle  latitudes,  throughout  the  whole  northern 
magnetic  hemisphere,  (the  terrestrial  spheroid  being  as- 
sumed to  be  divided  through  the  magnetic  equator)  the 
north  end  of  the  magnetic  needle, — that  is  to  say,  the  end 
which  points  towards  the  north  pole, — is  most  closely  in  the 
direction  of  that  pole  about  8h.  15m.  A.M.  The  needle  moves 
from  east  to  west,  from  this  hour  till  about  Ih.  45m.  P.M.,  at 
which  time  it  attains  its  most  westerly  position.  This  motion 
westward  is  general,  and  occurs  at  all  places  in  the  northern 
hemisphere,  whether  they  have  a  western  variation,  as  the 
whole  of  Europe,  Pekin,  .Nertschmsk  and  Toronto,  or  an 
eastern  variation,  like  Kasan,  Sitka  in  Russian  America, 
Washington,  Marmato  (New  Grenada),  and  Payta  on  the 
Peruvian  coast.  *2  From  this  most  westerly  point,  at 
Ih.  45m.  P.M.,  the  magnetic  needle  continues  to  retrograde 

52  Proofs  of  this  are  afforded  by  numerous  observations  of  George 
Fuss  and  Kowanko,  at  the  observatory  in  the  Greek  convent  at  Pekin, 
by  Anikin  at  Nertschinsk,  by  Buchanan  Biddell  at  Toronto  in  Canada ; 
(all  these  being  places  of  western  variation);  by  Kupffer  and  Simonoff 
at  Kasan ;  by  Wrangel,  notwithstanding  the  many  disturbances  from 
the  Aurora  borealis  at  Sitka,  on  the  north-west  coast  of  America; 
by  Gilliss  at  Washington;  by  Boussingault  at  Marmato,  in  South  Ame- 
rica ;  and  by  Duperrey  at  Payta,  on  the  Peruvian  shores  of  the  Pacific  ; 
(all  these  being  places  with  an  eastern  variation).  I  would  here  observe 
that  the  mean  declination  was  2°  15' 42"  west  at  Pekin  (Dec.,  1831) 
(Poggend.  Annalen,  Bd.  xxxiv,  s.  54);  4°  1'  44  "west  at  Nertschinsk 
(Sept.,  1832)  (Poggend.  Op.  Git.  s.  61);  1°  33'  west  at  Toronto  (Novem- 
ber, 1847)  (see  Observ.  at  the  Magnet  teal  and  Meteorological  Observatory 
at  Toronto,  vol.  i,  p.  xi,  and  Sabine,  in  the  Phil.  Transact,  for  1851, 
pt.ii,  p.  636),  2°  21'  east  at  Kasan  (August,  1828),  (Kupffer,  Simonoff, 
and  Erman,  Reise  um  die  Erde,  Bd.  ii,  s.  532);  28°  16'  east  at  Sitka 
(November,  1829)  (Erman,  Op.  Git.  s.  546);  6°  33'  east  at  Marmato 
(August,  1828),  (Humboldt,  in  Poggend.  Annalen,  Bd.  xv,  s.  331);  8°  56' 
east  at  Payta  (August,  1823),  (Duperrey,  in  the  Connaissance  des  Temps 
pour  1828,, p.  252).  At  Tiflis  the  declination  was  westerly  from  7  A.M. 
till  2  P.M.  (Parrot,  Reise  zum  Ararat,  1834,  Th.  ii,  s.  58). 


MAGNETIC  VARIATION.  121 

towards  the  east  throughout  the  whole  of  the  afternoon  and 
a  portion  of  the  night  till  midnight,  or  1  A.M.,  while  it  often 
makes  a  short  pause  about  6  P.M.  In  the  night  there  is  again 
a  slight  movement  towards  the  west,  until  the  minimum  or 
eastern  position  is  reached  at  8h.  15m.  A.M.  This  nocturnal 
period  which  was  formerly  entirely  overlooked,  since  a  gradual 
and  uninterrupted  retrogression  towards  the  east  between 
Ih.  45m.  P.M.  and  8h.  15m.  A.M.  was  assumed,  had  already 
been  carefully  studied  by  me  at  Rome,  when  I  was  engaged 
with  Gay-Lussac  in  observing  the  horary  changes  of  variation 
with  one  of  Prony's  magnetic  telescopes.  As  the  needle  is 
generally  unsteady  as  long  as  the  sun  is  below  the  horizon, 
the  small  nocturnal  motion  westward  is  more  seldom  and 
less  distinctly  manifested.  At  those  occasions  when  this 
motion  was  clearly  discernible,  I  never  saw  it  accompanied 
by  any  restlessness  of  the  needle.  The  needle,  during  this 
small  western  period,  passes  quietly  from  point  to  point  of 
the  dial,  exactly  in  the  same  manner  as  in  the  reliable  diurnal 
period,  between  8h.  15m.  A.M.  and  Ih.  45m.  P.M.,  and  very  dif- 
ferently from  the  manner  in  which  it  moves  during  the 
occurrence  of  the  phenomenon  which  I  have  named  a  mag- 
netic storm.  It  is  very  remarkable  that  when  the  needle 
changes  its  continuous  western  motion  into  an  eastern  move- 
ment, or  conversely,  it  does  not  continue  unchanged  for  any 
length  of  time,  but  it  turns  round  almost  suddenly,  more 
especially  by  day,  at  the  above-named  periods,  8h.  15m.  A.M. 
and  Ih.  45m.  P.M.  The  slight  motion  westward  does  not 
commonly  occur  until  after  midnight  and  towards  the  early 
morning.  On  the  other  hand,  it  has  been  observed  at  Berlin, 
and  during  the  subterranean  observations  at  Freiberg,  as  well 
as  at  Greenwich,  Makerstoun  in  Scotland,  Washington  and 
Toronto,  soon  after  10  or  11  P.M. 

The  four  movements  of  the  needle,  which  I  recognised  in 
1805,53  have  been  represented  in  the  admirable  collection  of 
observations  made  at  Greenwich  in  the  years  1845, 1846,  and 

53  See  extracts  from  a  letter,  which  I  addressed  to  Karsten,  from 
Eome,  June  the  22ud,  1805,  "  On  four  motions  of  the  magnetic  needle, 
constituting,  as  it  were,  four  periods  of  magnetic  ebbing  and  flowing, 
analogous  to  the  barometrical  periods."  This  communication  was 
printed  in  Hansteen's  Magnetismus  der  Erde,  1819,  s.  459.  On  the  long 
disregarded  nocturnal  alterations  of  variation,  see  Faraday,  OntheNiyht 
Episode,  §.  3012—3024. 


IZZ  COSMOS. 

1847,  as  the  results  of  many  thousand  horary  observations  in 
the  following  four  turning  points,64  namely,  the  first  mini- 
mum at  8  A.M.;  the  first  maximum  at  2  P.M.  ;  the  second 

54  Airy,  Magnetic  and  Meteorological  Observations  made  at  Greenwich 
(Results,  1845,  p.  6,  1846,  p.  94,  1847,  p.  236).  The  close  correspondence 
between  the  earliest  results  of  the  nocturnal  and  diurnal  turning  hours, 
and  those  which  were  obtained  four  years  later,  in  the  admirable  obser- 
vatories at  Greenwich  and  at  Toronto  in  Canada,  is  clearly  shown  by 
the  investigation  made  by  my  old  friend,  Enke,  the  distinguished  direc- 
tor of  the  observatory  at  Berlin,  between  the  corresponding  observa- 
tions of  Berlin  and  Breslau.  He  wrote  as  follows  on  the  llth  of 
October,  1836  : — "In  reference  to  the  nocturnal  maximum,  or  the 
inflection  of  the  curve  of  horary  variation,  I  do  not  think  that  there 
can  be  a  doubt,  as,  indeed,  Dove  has  also  shown  from  the  Freiberg 
observations  for  1830  (Poggend.  Ann.  Bd.  xix,  s.  373).  Graphical  repre- 
sentations are  preferable  to  numerical  tables  for  affording  a  correct 
insight  into  this  phenomenon.  In  the  former,  great  irregularities  at 
once  attract  the  attention,  and  enable  the  observer  to  draw  a  line  of 
average  ;  while  in  the  latter  the  eye  is  frequently  deceived,  and  indivi- 
dual and  striking  irregularities  are  mistaken  for  a  true  maximum  or 
minimum.  The  periods  seem  to  fall  regularly  at  the  following  turning 
hours : — 

The  greatest  eastern  declination  falls  at    8  A.M.    1  max.  E. 

„        „       western         „  „  1  P.M.    1  min.   E. 

The  secondary  or  lesser  eastern  max.       10  P.M.  11  max.  E. 

„  „  „     western  min.        4  A.M.  11  min,   E. 

The  secondary  or  lesser  minimum  (the  nocturnal  elongation  westward) 
falls,  more  correctly  speaking,  between  3  and  5  A.M.,  sometimes  nearer 
the  one  hour,  and  sometimes  nearer  the  other."  I  need  scarcely  ob- 
serve that  the  periods  which  Enke  and  I  designate  as  the  eastern 
minima  (the  principal  and  the  secondary  minimum  at  4  A.M.)  are  named 
western  maxima  in  the  registers  of  the  English  and  American  stations, 
which  were  established  in  1840,  and  consequently  our  eastern  maxima 
(8  A.M.  and  10  P.M.)  would,  in  accordance  with  the  same  form  of  expres- 
sion, be  converted  into  western  minima.  In  order,  therefore,  to  give  a 
representation  of  the  horary  motion  of  the  needle  in  its  general  charac- 
ter and  analogy  in  the  northern  hemisphere,  I  will  employ  the  terms 
adopted  by  Sabine,  beginning  with  the  period  of  the  greatest  western 
elongation,  reckoned  according  to  the  mean  time  of  the  place  : — 

Freiberg.  Breslau.  Greenwich 

1829.                 1836.  1846-47. 

Maximum  ,~~ ,-....   1  P.M.                1  P.M.  2  P.M. 

Minimum  1  A.M.  10  P.M.  12  P.M. 

Maximum 4  A.M.  4  A.M.  4  A.M. 

Minimum  ,...   SA.M.               8  A.M.  8  A.M. 


MAGNETIC  VAKIATION.  123 

minimum  at  12  P.M.  or  2  A.M.;  and  the  second  maximum  at 
2  A.M.  or  4  A.M.  I  must  here  content  myself  with  merely 
giving  the  mean  conditions,  drawing  attention  to  the  fact, 

Makerstoun.  Toronto.  Washington. 

1842-43.  1845-47.  1840-42. 

Maximum Oh.  40m.  1  P.M.  2  P.M. 

Minimum  10  P.M.  10  P.M.  10  P.M. 

Maximum 2h.  15m.  A.M.  2  A.M.  2  A.M. 

Minimum  7h.l5m.A.M.  8  A.M.  8  A.M. 

The  different  seasons  exhibited  some  striking  differences  at  Greenwich. 
In  the  year  1847  there  was  only  one  maximum  (2  P.M.)  and  one  mini- 
mum (12  night)  during  the  winter;  in  the  summer  there  was  a  double 
progression,  but  the  secondary  minimum  occurred  at  2  A.M.  instead  of 
4  A.M.  (p.  236).  The  greatest  western  elongation  (principal  maximum) 
remained  stationary  at  2  P.M.  in  winter  as  well  as  in  summer,  but  the 
smaller  or  secondary  minimum  fell,  in  1846,  as  usual  (p.  94),  at  about 
8  A.M.  in  the  summer,  and  in  winter  about  1 2  at  night.  The  mean  whiter 
western  elongation  continued  without  intermission  throughout  the  whole 
year  between  midnight  and  2  P.M.  (see  also  for  1845,  p.  5).  We  owe  the 
erection  of  the  observatory  at  Makerstoun,  Roxburghshire,  in  Scotland, 
to  the  generous  scientific  zeal  of  Sir  Thomas  Brisbane  (see  John  Allan 
Broun,  Obs.  in  Magnetism  and  Meteorology  made  at  Makerstoun  in  1843, 
pp.  221 — 227).  On  the  horary  diurnal  and  nocturnal  observations  of 
St.  Petersburg,  see  Kupffer,  Compte-rendu  Meteor,  et  Mag.  a  Mr.  de 
Brock  en  1851,  p.  17.  Sabine,  in  his  admirable  and  ingeniously  com- 
bined graphic  representation  of  the  curve  of  horary  declination  at 
Toronto  (Phil.  Transact,  for  1851,  pt.  ii,  plate  27),  shows  that  there  is 
a  singular  period  of  rest  (from  9  to  11  P.M.)  occurring  before  the  small 
nocturnal  western  motion,  which  begins  about  11  P.M.,  and  continues 
till  about  3  A.M.  "  We  find,"  he  observes,  "  alternate  progression  and 
retrogression  at  Toronto  twice  in  the  24  hours.  In  2  of  the  8  quarters 
(1841  and  1842)  the  inferior  degree  of  regularity  during  the  night  occa- 
sions the  occurrence  of  a  triple  max.  and  min.;  in  the  remaining  quar- 
ters the  turning  hours  are  the  same  as  those  of  the  mean  of  the  2  years." 
(Obs.  made  at  the  Magn.  and  Meteor.  Observatory  at  Toronto,  in  Canada, 
vol.  i,  pp.  xiv,  xxiv,  183 — 191,  and  228;  and  Unusual  Magn.  Distur- 
bances, pt.  i,  p.  vi.)  For  the  very  complete  observations  made  at  Wasb- 
ington,  see  Gilliss,  Magn.  and  Meteor.  Observations  made  at  Washington, 
p.  325  (General  .Law).  Compare  with  these  Bache,  Observ.  at  the  Magn. 
and  Meteor.  Observatory  at  the  Girard  College,  Philadelphia,  made  in  the 
years  1840  to  1845  (3  volumes,  containing  3212  quarto  pages)  vol.  i, 
p.  709,  vol.  ii,  p.  1285,  vol.  iii,  pp.  2167,  2702.  Notwithstanding  the 
vicinity  of  these  two  places  (Philadelphia  lying  only  1°  4'  north,  and 
0*  7'  33"  east  of  Washington),  I  find  a  difference  in  the  lesser  periods 
of  the  western  secondary  maximum  and  secondary  minimum.  The 
former  falls  about  Ih.  30m.  and  the  latter  about  2h.  15m.  earlier  at 
Philadelphia. 


124  COSMOS. 

that  the  morning  principal  minimum  of  8h.  is  not  changed  in 
our  northern  zone  by  the  earlier  or  later  time  of  sunrise. 
At  the  two  solstitial  periods,  and  the  three  equinoxes,  at 
which,  conjointly  with  Oltmanns,  I  watched  the  horary 
variations  for  5  to  6  consecutive  days  and  nights,  T  found 
that  the  eastern  turning  point  remained  fixed  between 
7h.  45m.  A.M.  and  8h.  15m.  A.M.  both  in  summer  and  ir 
winter,  and  was  only  very  slightly  anticipated  by  the  earliei 
period  at  which  the  sun  rose.*6 

In  the  high  northern  latitudes  near  the  Arctic  circle,  and 
between  the  latter  and  the  pole  of  the  earth's  rotation,  the 
regularity  of  the  horary  declination  has  not  yet  been  very 
clearly  recognised,  although  there  has  been  no  deficiency  in 
the  number  of  very  carefully  conducted  observations  regard- 
ing this  point.  The  local  action  of  the  rocks  and  the  fre- 
quency of  the  disturbing  action  of  the  polar  light,  either  in 
the  immediate  vicinity  or  at  a  distance,  made  Lottin  hesi- 
tate in  drawing  definite  conclusions  in  reference  to  these 
turning  hours,  from  his  own  great  and  careful  labours,  which 
were  carried  on  during  the  French  scientific  expedition  of 
Lilloise  in  1836,  or  from  the  earlier  results,  that  had  been 
obtained  with  much  care  and  accuracy  by  Lowenorn,  in 
1786.  It  would  appear  that  at  Reikjavik,  in  Iceland,  64°  8' 
lat,,  as  well  as  at  Godthaab,  on  the  coast  of  Greenland, 
according  to  observations  made  by  the  missionary,  Genge, 
the  minimum  of  the  western  variation  fell  almost  as  in  the 

55  Examples  of  the  slightly  earlier  occurrence  of  the  turning  hours 
are  given  by  Lieutenant  Gilliss,  in  his  Magn.  Observ.  of  Washington, 
p.  328.  At  Makerstoun,  in  Scotland  (55°  35'  N".  lat.),  variations  are 
observed  in  the  secondary  minimum,  which  occurs  about  9  A.M.  in  the 
first  three  and  the  last  four  months  of  the  year,  and  about  7  A.M.  in  the 
remaining  five  months  (from  April  till  August);  the  reverse  being  the 
case  at  Berlin  and  Greenwich  (Allan  Broun,  Observ.  made  at  Makers- 
toun, p.  225).  The  idea  of  heat  exerting  an  influence  on  the  regular 
changes  of  the  horary  variation,  whose  minimum  falls  in  the  morning 
near  the  time  of  the  minimum  of  the  temperature,  as  the  maximum 
very  nearly  coincides  with  maximum  heat,  is  most  distinctly  contra- 
dicted by  the  nocturnal  motions  of  the  needle,  constituting  the  second- 
ary min.  and  secondary  max.  "  There  are  2  maxima  and  2  minima  of 
variation  in  the  24  hours,  but  only  one  minimum  and  one  maximum  of 
temperature"  (Relshuber,  in  Poggend.  Annalen  der  Physik  und  Chemie, 
Bd.  85,  1852,  s.  416).  On  the  normal  motion  of  the  magnetic  needle 
in  Northern  Germany,  see  Dove,  Poggend.  Annalen,  Bd.  xix,  s.  364  — 
374. 


MAGNETIC  VARIATION.  125 

middle  latitudes  at  about  9  or  10  A.M.,  whilst  the  maximum 
did  not  appear  to  occur  before  9  or  10  P.M.66  Farther  to  the 
north,  at  Hammerfest,  in  Finmark,  70°  40'  lat.,  Sabine  found 
that  the  motion  of  the  needle  was  tolerably  regular,  as  in  the 
south  of  Norway  and  Germany,67  the  western  minimum  being 
at  9  A.M.  and  the  western  maximum  at  Ih.  30m.  P.M.;  he 
found  it,  however,  different  at  Spitzbergen,  in  79°  50'  lat., 
where  the  above-named  turning  hours  fell  at  6  and  at 
7h.  30m.  A.M.  In  reference  to  the  Arctic  polar  archipelago, 
we  possess  an  admirable  series  of  observations,  made  during 
Captain  Parry's  third  voyage,  in  1825,  by  Lieutenants  Foster 
and  James  Ross,  at  Port  Bowen,  on  the  eastern  coast  of 
Prince  Regent's  Inlet,  73°  14'  N.  lat.,  which  were  extended 
over  a  period  of  5  months.  Although  the  needle  passed 
twice  in  the  course  of  24  hours  through  that  meridian, 
which  was  regarded  as  the  mean  magnetic  meridian  of  the 
place,  and  although  no  Aurora  borealis  was  visible  for  fully 
2  months  (during  the  whole  of  April  and  May),  the  periods 
of  the  principal  elongations  varied  from  4  to  6  hours,  and 
from  January  to  May,  the  means  of  the  maxima  and  minima 
of  the  western  variation  differed  by  only  Ih.!  The  quantity 
of  the  decimation  rose  in  individual  days  from  1°  30'  to 
6°  or  7°,  whilst  at  the  turning  periods  it  hardly  reaches  as 
many  minutes.88  Not  only  within  the  Arctic  circle,  but 
also  in  the  equatorial  regions,  as,  for  instance,  at  Bombay, 
18°  56'  lat.,  a  great  complication  is  observable  in  the  horary 
periods  of  magnetic  variation.  These  periods  may  be 
grouped  into  two  principal  classes,  which  present  great  dif- 
ferences between  April  and  October  on  the  one  hand,  and 
between  October  and  December  on  the  other,  and  these  are 
again  divided  into  two  sub- periods,  which  are  very  far  from 
being  accurately  determined.69 

56  Voy.  en  Islande  et  en  Greenland,  execute  en  1835  et  1836,  sur  la 
Corv.  la  Recherche;  Physique  (1838),  pp.  214—225,  358—367. 

5?  Sabine,  Account  of  the  Pendulum  Experiments,  1825,  p.  500. 

53  See  Barlow's  "Report  of  the  Observations  at  Port  Bowen,"  in  the 
Edlnb.  New  Philos.  Journal,  vol.  ii,  1827,  p.  347. 

59  Professor  Orlebar,  of  Oxford,  former  superintendent  of  the  Mag- 
netic Observatory  of  the  Island  of  Colaba,  erected  at  the  expense 
of  the  East  India  Company,  has  endeavoured  to  elucidate  the  com- 
plicated laws  of  the  changes  of  declination  in  the  sub-periods  (Ob- 
servations made  at  the  Mayn.  and  Meteor.  Observatory  at  Bombay  in 


126  COSMOS. 

Europeans  could  not  have  learnt,  from  their  own  expe- 
rience, the  direction  of  the  magnetic  needle  in  the  southern 
hemisphere  before  the  second  half  of  the  15th  century,  when 
they  may  have  obtained  an  imperfect  knowledge  of  it  from 
the  adventurous  expeditions  of  Diego  Cam  with  Martin 
Behaim,  and  Bartholomew  Diaz,  and  Vasco  de  Gama.  The 
Chinese,  who,  as  early  as  the  3rd  century  of  our  era,  as  well 
as  the  inhabitants  of  Corea  and  the  Japanese  Islands,  had 
guided  their  course  by  the  compass  at  sea,  no  less  than  by 
land,  are  said,  according  to  the  testimony  of  their  earliest 
writers,  to  have  ascribed  great  importance  to  the  south  direc- 
tion of  the  magnetic  needle,  and  this  was  probably  mainly 
dependent  on  the  circumstance,  that  their  navigation  was 
entirely  directed  to  the  south  and  south-west.  During  these 
southern  voyages,  it  had  not  escaped  their  notice  that  the 
magnetic  needle,  according  to  whose  direction  they  steered 
their  course,  did  not  point  accurately  to  the  south  pole.  We 
even  know,  from  one  of  their  determinations,  the  amount  ^  of 
the  variation  towards  the  south-east,  which  prevailed  during 
the  12th  century.  The  application  and  farther  diffusion  of 
such  nautical  aids  favoured  the  very  ancient  intercourse  of 
the  Chinese  and  Indians  with  Java,  and  to  a  still  greater 
extent  the  voyages  of  the  Malay  races  and  their  colonisation 
of  the  island  of  Madagascar.81 

1845,  Results,  pp.  2 — 7.  It  is  singular  to  find  that  the  position  of  the 
needle  during  the  first  period  from  April  to  October  (western  min. 
7h.  30m.  A.M.,  max.  Oh.  30m.  P.M.  ;  min.  5h.  30m.,  max.  7  P.M.)  coin- 
cides so  closely  with  that  of  Central  Europe.  The  month  of  October  is 
a  transition  period,  as  the  amount  of  diurnal  variation  scarcely  amounts 
to  2  minutes  in  November  and  December.  Notwithstanding  that  this 
station  is  situated  8°  from  the  magnetic  equator,  there  is  no  obvious 
regularity  in  the  turning  hours.  Everywhere  in  nature,  where  various 
causes  of  disturbances  act  upon  a  phenomenon  of  motion  at  recurring 
periods  (whose  duration,  however,  is  still  unknown  to  us),  the  law  by 
which  these  disturbances  are  brought  about  often  remains  for  a  long 
time  unexplained  in  consequence  of  the  perturbing  causes  either  reel- 
procally  neutralising  or  intensifying  one  another. 

60  See  my  Examen  Grit,  de  I'ffist.  de  la  Geogr.  t.  iii,  pp.  34—37. 
The  most  ancient  notice  of  the  variation  given  by  Keutsungchy,  a  writer 
belonging  to  the  beginning  of  the  twelfth  century,  was  east  J-  south. 
Klaproth's  Lettre  sur  I' invention  de  la  Boussole,  p.  68. 

61  On  the  ancient  intercourse  of  the  Chinese  with  Java,  according  to 
Btatements  of  Fahian  in  the  Fo-kue-si,  see  Wilhelin  von  Huraboldt, 
Ueber  die  Kawi  Spracke,  Bd.  i,  s.  16. 


MAGNETIC   VAKIATION.  127 

Although,  judging  from  the  present  very  northern  position 
of  the  magnetic  equator,  it  is  probable  that  the  town  of  Louvo 
in  Siam  was  very  near  the  extremity  of  the  northern  mag- 
netic hemisphere,  when  the  missionary  father,  Guy  Tachard, 
first  observed  the  horary  alterations  of  the  magnetic  varia- 
tion at  that  place  in  the  year  1682,  it  must  be  remem- 
bered, that  accurate  observations  of  the  horary  declina- 
tion in  the  southern  magnetic  hemisphere  were  not  made 
for  fully  a  century  later.  John  Macdonald  watched  the 
course  of  the  needle  during  the  years  1794  and  1795  in  Fort 
Marlborough,  on  the  south-western  coast  of  Sumatra,  as  well 
as  at  St.  Helena.62  The  results  which  were  then  obtained 
drew  the  attention  of  physicists  to  the  great  decrease  in  the 
quantity  of  the  daily  alterations  of  variation  in  the  lower 
latitudes.  The  elongation  scarcely  amounted  to  3  or  4 
minutes.  A  more  comprehensive  and  a  deeper  insight  into 
this  phenomenon  was  obtained  through  the  scientific  expedi- 
tions of  Freycinet  and  Duperrey,  but  the  erection  of  mag- 
netic stations  at  three  important  points  of  the  southern 
magnetic  hemisphere,  at  Hobarton  in  Van  Diemen's  Land, 
at  St.  Helena,  and  at  the  Cape  of  Good  Hope  (where  for  the 
last  10  years  horary  observations  have  been  carried  on  for  the 
registration  of  the  alterations  of  the  three  elements  of  ter- 
restrial magnetism  in  accordance  with  one  uniform  method), 
afforded  us  the  first  general  and  systematic  results.  In 
the  middle  latitudes  of  the  southern  magnetic  hemisphere 

62  Phil  Transact,  for  1795,  pp.  340—349,  for  1798,  p.  397.  The  result 
which  Macdonald  himself  draws  from  his  observations  at  Fort  Marl- 
borough  (situated  above  the  town  of  Bencoolen,  in  Sumatra,  3°  47'  S. 
lat.),  and  according  to  which  the  eastern  elongation  was  on  the  increase 
from  7  A.M.  to  5  P.M.,  does  not  appear  to  me  to  be  entirely  justified. 
No  regular  observation  was  made  between  noon  and  3,  4,  or  5  P.M.,  and 
it  seems  probable,  from  some  scattered  observations  made  at  different 
times  from  the  normal  hours,  that  the  turning  hours  between  the 
eastern  and  western  elongation  fall  as  early  as  2  P.M.,  precisely  the 
same  as  at  Hobarton.  We  are  in  possession  of  declination-observations 
made  by  Macdonald  during  23  months  (from  June,  1794,  to  June, 
1796),  and  from  these  I  perceive  that  the  eastern  variation  increases  at 
all  times  of  the  year  between  7h.  30m.  A.M.  till  noon,  the  needle  moving 
steadily  from  west  to  east  during  that  period.  There  is  here  no  trace 
of  the  type  of  the  northern  hemisphere  (Toronto),  which  was  observ- 
able at  Singapore,  from  May  till  September;  and  yet  Fort  Marlborough 
lies  in  almost  the  same  meridian,  although  to  the  south  of  the  geogra- 
phical equator,  and  only  5°  4'  distant  from  Singapore. 


128  COSMOS. 

the  needle  moves  in  a  totally  opposite  direction  from  that 
which  it  follows  in  the  northern,  for  while  in  the  south  the 
needle  that  is  pointed  southward  turns  from  east  to  west  be- 
tween morning  and  noon,  the  northern  point  of  the  needle 
exhibits  a  direction  from  west  to  east. 

Sabine,  to  whom  we  are  indebted  for  an  elaborate  revi- 
sion of  all  these  variations,  has  arranged  the  horary  observa- 
tions that  were  carried  on  for  five  years  at  Hobarton  (42°  53' 
S.  lat.,  variation  9°  57'  east,)  and  Toronto  (43°  39'  N.  lat., 
variation  1°  33'  west),  so  that  we  can  draw  a  distinction 
between  the  periods  from  October  to  February,  and  from 
April  to  August,  since  the  intermediate  months  of  March 
and  September  present,  as  it  were,  phenomena  of  transition. 
At  Hobarton  the  extremity  of  the  needle  which  points 
northwards  exhibits  two  eastern  and  two  western  maxima 
of  elongation,63  so  that  in  the  period  of  the  year  from  Octo- 
ber to  February  it  moves  eastward  from  8  or  9  o'clock  A.M. 
till  2  P.M.,  and  then  from  2  till  11  P.M.,  somewhat  to  the 
west,  from  11  P.M.  to  3  A.M.  it  again  turns  eastward,  and 
from  3  *o  8  A.M.  it  goes  back  to  the  west.  In  the  period 
between  April  and  August,  the  eastern  turning  hours  are 
later,  occurring  at  3  P.M.  and  4  A.M.,  whilst  the  western  turn- 
ing hours  fall  earlier,  namely  at  10  A.M.  and  at  11  P.M.  In 
the  northern  magnetic  hemisphere  the  motion  of  the  needle 
westward  from  8  A.M.  till  1  P.M.  is  greater  in  the  summer 
than  in  the  winter,  whilst  in  the  southern  magnetic  hemi- 
sphere, where  the  motion  has  an  opposite  direction  between 
the  above-named  turning  hours,  the  quantity  of  the  elon- 
gation is  greater  when  the  sun  is  in  the  southern  than  when 
it  is  in  the  northern  signs. 

The  question  which  I  discussed  seven  years  ago  in  the 
Picture  of  Nature,64  whether  there  may  not  be  a  region  of 
the  earth,  probably  between  the  geographical  and  magnetic 
equators,  in  which  there  is  no  horary  variation  (before  the 
return  of  the  northern  extremity  of  the  needle  to  an  oppo- 
site direction  of  variation  in  the  same  hours),  is  one  which 

63  Sabine,  Magn.  Observ.  made  at  Hobarton,  vol.  i  (1841  and  1842), 
pp.  xxxv ;  2,  148  ;  vol.  ii  (1843—1845),  pp.  iii— xxxv,   172—344.     See 
also  Sabine,  Obs.  made  at  St.  Helena,  and  in  Phil.  Transact,  for  1847, 
pt.  i,  p.  55,  pi.  iv,  and  Phil.  Transact,  for  1851,  pt.  ii,  p.  36,  pi.  xxvii. 

64  Cosmos,  vol.  i,  p.  176. 


MAGNETIC   INTENSITY.  129 

it  would  seem  from  recent  experiments,  and  more  especially 
since  Sabine's  ingenious  discussions  of  the  observations  made 
at  Singapore  (1°  11'  K  lat.),  at  St.  Helena  (15°  56'  S.  lat.), 
and  at  the  Cape  of  Good  Hope  (33°  56'  S.  lat.),  must  be  an- 
swered in  the  negative.  No  point  has  hitherto  been  dis- 
covered, at  which  the  needle  does  not  exhibit  a  horary 
D'otion,  and  since  the  erection  of  magnetic  stations,  the  im- 
portant and  very  unexpected  fact  has  been  evolved,  that 
there  are  places  in  the  southern  magnetic  hemisphere,  at 
which  the  horary  variations  of  the  dipping  needle  alter- 
nately participate  in  the  phenomena  (types)  of  both 
hemispheres.  The  island  of  St.  Helena  lies  very  near  the 
line  of  weakest  magnetic  intensity,  in  a  region  where  this 
line  divaricates  very  widely  from  the  geographical  equator 
and  from  the  line  of  no  inclination.  At  St.  Helena,  the 
movement  of  the  end  of  the  needle  which  points  to  the 
north  is  entirely  opposite  in  the  months  from  May  to  Sep- 
tember from  the  direction  which  it  follows  in  the  analogous 
hours  from  October  to  February.  It  has  been  found  after  five 
years'  horary  observations,  that  during  the  winter  of  the 
southern  hemisphere,  in  the  above-named  periods  of  the 
year,  while  the  sun  is  in  the  northern  signs,  the  northern 
point  of  the  needle  has  the  greatest  eastern  variation  at 
7  A.M.,  from  which  hour,  as  in  the  middle  latitudes  of  Europe 
and  North  America,  it  moves  westward  till  10  A.M.  and  re- 
mains very  nearly  stationary  until  2  P.M.  At  other  parts  of 
the  year,  on  the  other  hand,  namely  from  October  till 
February,  (which  constitutes  the  summer  of  the  southern 
hemisphere  and  when  the  sun  is  in  the  southern  signs  and 
therefore  nearest  to  the  earth)  the  greatest  western  elonga- 
tion of  the  needle  falls  about  8  A.M.,  showing  a  movement 
from  west  to  east  until  noon,  precisely  in  accordance  with 
the  type  of  Hobarton  (42°  53  S.  lat.),"  and  of  other  districts 
of  the  middle  parts  of  the  southern  hemisphere.  At  the 
time  of  the  equinoxes,  or  soon  afterwards,  as  for  instance  in 
March  and  April,  as  well  as  in  September  and  October,  the 
course  of  the  needle  fluctuates  on  individual  days,  showing 
periods  of  transition  from  one  type  to  another,  from  that  of 
the  northern  to  that  of  the  southern  hemisphere.66 

*•'  Sabine,  Observations  made  at  the  Magn.  and  Meteor.  Observatory  at 
St.  Helena  in  1840- -1845,  vol.  i,  p.  30,  and  in  the  Phil.  Transact,  for 

VOL.  V.  K 


130  COSMOS. 

Singapore  lies  a  little  to  the  north  of  the  geographical 
equator,  between  the  latter  and  the  magnetic  equator,  which, 
according  to  Elliot,  coincides  almost  exactly  with  the  curve 
of  lowest  intensity.  According  to  the  observations  which 
were  made  at  Singapore  every  two  hours  during  the  years 
1841  and  1842,  Sabine  again  finds  the  St.  Helena  types  in 
the  motion  of  the  needle  from  May  to  August  and  from 
November  to  February ;  the  same  occurs  at  the  Cape  of 
Good  Hope,  which  is  34°  distant  from  the  geographical  and 
still  more  remote  from  the  magnetic  equator,  and  where 
the  inclination  is  53°  south  and  the  sun  never  reaches  the 
zenith.66  We  possess  the  published  borary  observations  made 

1847,  pt.  i,  pp.  51 — 56,  pi.  iii.  The  regularity  of  this  opposition  in  the 
two  divisions  of  the  year,  the  first  occurring  between  May  and  Sep- 
tember (type  of  the  middle  latitudes  in  the  northern  hemisphere), 
and  the  next  between  October  and  February  (type  of  the  middle  lati- 
tudes in  the  southern  hemisphere),  is  graphically  and  strikingly  mani- 
fested when  we  separately  compare  the  form  and  inflections  of  the 
curve  of  horary  variation  in  the  portions  of  the  day  intervening  be- 
tween 2  P.M.  and  10  A.M.,  between  10  A.M.  and  4  P.M.,  and  between 
d  P.M.  and  2  A.M.  Every  curve  above  the  line  which  indicates  the  mean 
declination  has  an  almost  similar  one  corresponding  to  it  below  it 
(vol.  i,  pi.  iv,  the  curves  A  A  and  BB).  This  opposition  is  perceptible 
even  in  the  nocturnal  periods,  and  it  is  still  more  remarkable,  that 
while  the  type  of  St.  Helena  and  of  the  Cape  of  Good  Hope  is  found  to 
be  that  belonging  to  the  northern  hemisphere,  the  same  earlier  occur- 
rence of  the  turning  hours  which  is  observed  in  Canada  (Toronto)  is 
noticed  in  the  same  months  at  these  two  southern  points.  Sabine, 
Olserv.  at  Hobarton,  vol.  i,  p.  xxxvi. 

66  Phil.  Transact,  for  1847,  pt.  i,  pp.  52,  57,  and  Sabine,  Observations 
made  at  the  Magn.  and  Meteor.  Observatory  at  the  Cape  of  Good  Hope, 
1841 — 1846,  vol.  i,  p.  xii — xxiii,  pi.  iii.  See  also  Faraday's  ingenious 
views  regarding  the  causes  of  those  phenomena,  which  depend  upon 
the  alternations  of  the  seasons,  in  his  Experiments  on  Atmospheric 
Magnetism,  §  3027 — 3068,  and  on  the  analogies  with  St.  Petersburg, 
§  3017.  It  would  appear  that  the  singular  type  of  magnetic  declina- 
tion, varying  with  the  seasons,  which  prevails  at  the  Cape  of  Good 
Hope,  St.  Helena,  and  Singapore,  has  been  noticed  on  the  southern 
shores  of  the  Red  Sea  by  the  careful  observer,  d'Abbadie  (Airy,  On  the 
Present  State  of  the  Science  o/  Terrestrial  Magnetism,  1850,  p.  2).  "  It 
results  from  the  present  position  of  the  four  points  of  maximum  of 
intensity  at  the  surface  of  the  earth,"  observes  Sabine,  "that  the  im- 
portant curve  of  the  relatively,  but  not  absolutely,  weakest  intensity  in 
the  Southern  Atlantic  Ocean  should  incline  away  from  the  vicinity  of 
St.  Helena,  in  the  direction  of  thj  southern  extremity  of  Africa.  The 
astronomico-geographical  position  of  this  southern  extremity,  where  the 
eun  remains  throughout  the  whole  year  north  of  the  zenith,  affords  a 


MAGNETIC   DISTURBANCES.  131 

at  the  Cape  for  six  years,  from  May  to  September,  according 
to  which,  almost  precisely  as  at  St.  Helena,  the  needle  moves 
westward  till  1 1  h.  30  m.  A.M.  from  its  extreme  eastern  posi- 
tion (7h.  30m.  A.M.),  while  from  October  to  March  it  moves 
eastward  from  8h.  30m.  A.M.  to  Ih.  30m.  and  2  P.M.  The 
discovery  of  this  well-attested,  but  still  unexplained  and 
obscure  phenomenon,  has  more  especially  proved  the  import- 
ance of  observations  continued  uninterruptedly  from  hour  to 
hour  for  many  years.  Disturbances  which,  as  we  shall  soon 
have  occasion  to  show,  have  the  power  of  diverting  the 
needle  either  to  the  eastward  or  westward  for  a  length  of 
time,  would  render  the  isolated  observations  of  travellers 
uncertain. 

By  means  of  extended  navigation  and  the  application  of 
the  compass  to  geodetic  surveys,  it  was  very  early  noticed 
that  at  certain  times  the  magnetic  needle  exhibited  an  ex- 
traordinary disturbance  in  its  direction,  which  was  frequently 
connected  with  a  vibratory,  trembling  and  fluctuating  mo- 
tion. It  became  customary  to  ascribe  this  phenomenon  to 
some  special  condition  of  the  needle  itself,  and  this  was 
characteristically  designated  by  French  sailors  Taffolemeni  de 
V aiguille,  and  it  was  recommended  that  une  aiguille  affolee 
should  be  again  more  strongly  magnetised.  Halley  was  cer- 
tainly the  first  who  inferred  that  polar  light  was  a  magnetic 
phenomenon — a  statement  CT  which  he  made  on  the  occasion 

principal  ground  of  objection  against  de  la  Rive's  thermal  explanation 
(Annales  de  Chimie  et  de  Physique,  t.  xxv,  1849,  p.  310)  of  the  pheno- 
menon of  St.  Helena  here  referred  to,  which,  although  it  seems  at  first 
sight  apparently  abnormal,  is  nevertheless  entirely  in  accordance  with 
established  law,  and  is  found  to  occur  at  other  points."  See  Sabine,  in 
the  Proceedings  of  the  Royal  Society,  1849,  p.  821. 

6'  Halley,  Account  of  the  late  surprising  appearance  of  Lights  in  the 
Air,  in  the  Phil.  Transact,  vol.  xxix,  1714 — 1716,  No.  347,  pp.  422 — 
428.  Halley's  explanation  of  the  Aurora  boi-ealis  is  unfortunately  con- 
nected with  the  fantastic  hypothesis  which  had  been  enounced  by  him 
twenty-five  years  earlier,  in  the  Phil.  Transact,  for  1693,  vol.  xvii, 
No.  195,  p.  563,  according  to  which  there  was  a  luminous  fluid  in  th^ 
hollow  terrestrial  sphere  lying  between  the  outer  shell  which  we  inhabit 
and  the  inner  denser  micleus,  which  is  also  inhabited  by  human  beings. 
These  are  his  words  : — "In  order  to  make  that  inner  globe  capable  of 
being  inhabited,  there  might  not  improbably  be  contained  some  lumi- 
nous medium  between  the  balls,  so  as  to  make  a  perpetual  day  below." 
Since  the  outer  shell  of  the  earth's  crust  is  far  less  thick  in  the  region 
of  the  poles  of  rotation  (owing  to  the  compression  produced  at  tho.-j 

K  2 


132  COSMOS. 

of  his  being  invited  by  the  Royal  Society  of  London  to  ex- 
plain the  great  meteor  of  the  6th  of  March,  1716,  which  was 
seen  in  every  part  of  England.  He  says,  "  that  the  meteor 
is  analogous  with  the  phenomenon,  which  Gassendi  first 
designated  in  1621  by  the  name  of  Aurora  borealis" 
Although  in  his  voyages  for  the  determination  of  the  line 
of  variation,  he  advanced  as  far  south  as  52°,  yet  we  learn 
from  his  own  confession,  that  he  had  never  seen  a  northern, 
or  southern  polar  light  before  the  year  1716,  although  the 
latter,  as  I  can  testify,  is  visible  in  the  middle  of  the  tropical 
zone  of  Peru.  Halley,  therefore,  does  not  appear  from  his 
own  observation  to  have  been  aware  of  the  restlessness  of  the 
needle,  or  of  the  extraordinary  disturbances  and  fluctuations 
which  it  exhibits  at  the  periods  of  visible,  or  invisible  north- 
ern or  southern  polar  lights.  Olav  Hiorter  and  Celsius  at 
Upsala  were  the  first  who,  in  the  year  1741,  and  therefore 
before  Halley's  death,  confirmed  by  a  long  series  of  measure- 
ments and  determinations  the  connection,  which  he  had 
merely  conjectured  to  exist  between  the  appearance  of  the 
Aurora  borealis  and  a  disturbance  in  the  normal  course  of  the 
needle.  This  meritorious  investigation  led  them  to  enter 
into  an  arrangement  for  carrying  on  systematic  observations 
simultaneously  with  Graham  in  London,  while  the  extra- 
ordinary disturbances  of  variation,  observed  on  the  appear- 
ance of  the  Aurora,  were  made  subjects  of  special  investiga- 
tion by  Wargentin,  Canton,  and  Wilke. 

The  observations  which  I  had  the  opportunity  of  making, 
conjointly  with  Gay-Lussac,  in  1805,  on  the  Monte  Pincio 
at  Rome,  and  more  especially  the  investigations  suggested  by 
these  observations,  and  which  I  prosecuted  conjointly  with 
Oltmanns  during  the  equinoctial  and  solstitial  periods  of 

parts)  than  at  the  equator,  the  inner  luminous  fluid  (that  is,  the  mag- 
netic fluid),  seeks  at  certain  periods,  more  especially  at  the  times  of  the 
equinoxes,  to  find  itself  a  passage  in  the  less  thick  polar  regions  through 
the  fissures  of  rocks.  The  emanation  of  this  fluid  is,  according  to 
Halley,  the  phenomenon  of  the  northern  light.  When  iron  filings  are 
etrewn  over  a  spheroidal  magnet  (a  terella),  they  serve  to  show  the 
direction  of  the  luminous  coloured  rays  of  the  Aurora.  ' '  As  each  one 
sees  his  own  rainbow,  so  also  the  Corona  appears  to  every  observer  to  be 
at  a  different  point"  (p.  424).  Eegarding  the  geognostic  dreams  of  an 
intellectual  investigator,  who  displayed  such  profound  knowledge  in  all 
his  magnetic  and  astronomical  labours,  see  Cosmos,  vol.  i,  p.  163. 


MAGNETIC   DISTURBANCES.  133 

the  years  1806  and  1807,  in  a  large  isolated  garden  at  Berlin, 
by  means  of  one  of  Prony's  magnetic  telescopes,  and  of  a 
distant  tablet-signal,  which  admitted  of  being  well  illumi- 
nated by  lamp-light,  showed  me  that  this  element  of  terres- 
trial activity  (which  acts  powerfully  at  certain  epochs,  and 
not  merely  locally,  and  which  has  been  comprehended  under 
the  general  name  of  extraordinary  disturbances),  is  worthy, 
on  account  of  its  complicated  nature,  of  being  made  the  sub- 
ject of  continuous  observation.  The  arrangement  of  the 
signal  and  the  cross  wires  in  the  telescope,  which  was  sus- 
pended in  one  instance  to  a  silken  thread  and  in  another  to 
a  metallic  wire,  and  attached  to  a  bar  magnet,  enclosed  in  a 
large  glass  case,  enabled  the  observer  to  read  off  to  8"  in  the 
arc.  As  this  method  of  observation  allowed  of  the  room  in 
which  the  telescope  and  the  attached  bar-magnet  stood.  beinsj 
left  unilluminated  by  night,  all  suspicion  of  the  action  of 
currents  of  air  was  removed,  and  those  disturbances  avoided, 
which  otherwise  are  apt  to  arise  from  the  illumination  of  the 
scale  in  variation  compasses,  provided  with  microscopes, 
however  perfect  they  may  otherwise  be.  In  accordance  with 
the  opinion  then  expressed  by  me  that  "  a  continuous  unin- 
terrupted hourly  and  half-hourly  observation  (Observatio 
Perpetua)  of  several  days  and  nights  was  greatly  to  be  pre- 
ferred to  isolated  observations  extending  over  many  months," 
we  continued  our  investigations  for  5,  7,  and  even  1 1  days 
and  nights  consecutively,68  during  the  equinoctial  and  solsti- 
tial periods — the  importance  of  such  observations  at  these 
times  being  admitted  by  all  recent  observers.  We  soon  per- 
ceived that,  in  order  to  study  the  peculiar  physical  character 
of  these  anomalous  disturbances,  it  was  not  sufficient  to  de- 
termine the  amount  of  the  alteration  of  the  variation,  but 
that  the  numerical  degree  of  disturbance  of  the  needle  must 
be  appended  to  each  observation  by  obtaining  the  measured 
elongation  of  the  oscillations.  In  the  ordinary  horary  course 
of  the  needle,  it  was  found  to  be  so  quiet  that  in  1500  re- 
's When  greatly  fatigued  by  observing  for  many  consecutive  nights, 
Professor  Oltmanns  and  myself  were  occasionally  relieved  by  very 
trustworthy  observers,  as,  for  instance,  by  Mampel,  the  geographer 
Friesen,  the  skilful  mechanician  Nathan  Mendelssohn,  and  our  great 
geognosist,  Leopold  von  Buch.  It  has  always  afforded  me  pleasure 
to  record  the  names  of  those  who  have  kindly  assisted  me  in  my 
labours. 


134 


COSMOS. 


suits,  deduced  from  6000  observations,  made  from  the  middle 
of  May,  1806,  to  the  end  of  June,  1807,  the  oscillation  gene- 
rally fluctuated  only  from  one-half  of  a  graduated  interval  to 
the  other  half,  amounting  therefore  only  to  1'  12";  in  indivi- 
dual cases,  and  often  when  the  weather  was  very  stormy  and 
much  rain  was  falling,  the  needle  appeared  to  be  either  per- 
fectly stationary,  or  to  vary  only  0.2  or  0.3  of  a  graduated 
interval,  that  is  to  say,  about  24"  or  28".  But  on  the  occur- 
rence of  a  magnetic  storm,  whose  final  and  strongest  mani- 
festation is  the  Aurora  borealis,  the  oscillations  were  either  in 
some  cases  only  14'  and  in  others  38'  in  the  arc,  each  one 
being  completed  in  from  1^-  to  3  seconds  of  time.  Fre- 
quently, on  account  of  the  magnitude  and  inequality  of  the 
oscillations,  which  far  exceeded  the  scale  parts  of  the  tablet 
in  the  direction  of  one  or  both  of  its  sides,  it  was  not  pos- 
sible to  make  any  observation.69  This,  for  instance,  was  the 

fi9  The  month  of  September,  1806,  was  singularly  rich  in  great  mag- 
netic disturbances.  By  way  of  illustration,  I  will  give  the  following 
extracts  from  my  journal  :  — 


Sept.  1806,  from  4h.  36m.  A.M.  till  5h.  43m.  A.M. 


If- 


f- 


4h.  40m.  „  7h.    2m. 

3h.  33m.  „  6h.  27m. 

3h.     4m.  „  6h.    2m. 

2h.  22m.  „  4h.  30m. 

2h.  12m.  „  4h.    3m. 

Ih.  55m.  „  5h.  27m. 

Oh.     3m.  „  Ih.  22m. 

The  disturbance  last  referred  to  was  very  small,  and  was  succeeded  by 
the  greatest  quiet,  which  continued  throughout  the  whole  night,  aud 
until  the  following  noon. 

f£  Sept.  1806,  from  lOh.  20m.  P.M.  till  llh.  32m.  P.M. 

This  was  a  small  disturbance,  which  was  succeeded  by  great  calm 
until  5h.  6m.  A.M.  3T°  Sct.S  1806,  about  2h.  46m.  A.M.  a  great  but 
short  magnetic  storm,  followed  by  perfect  calm.  Another  equally  great 
magnetic  disturbance  about  4h.  30m.  A.M. 

The  great  storm  of  ff  September  had  been  preceded  by  a  still 
greater  disturbance  from  7h.  8m.  till  9h.  llm.  P.M.  In  the  following 
winter  months  there  was  only  a  very  small  number  of  storms,  and  these 
could  not  be  compared  with  the  disturbances  during  the  autumnal 
equinox.  I  apply  the  term  great  storm  to  a  condition  in  which  the 
needle  makes  oscillations  of  from  20  to  38  minutes,  or  passes  beyond  all 
the  scale  parts  of  the  segment,  or  when  it  is  impossible  to  make  any 
observation.  In  small  storms,  the  needle  makes  irregular  oscillations  of 
from  5  to  8  minutes. 


MAGNETIC   DISTUKBANCES.  135 

case  for  long  and  uninterrupted  periods  during  the  night 
of  the  24th  September,  1806,  lasting  on  the  first  occasion 
from  2h.  Om.  to  3h.  32m.  A.M.,  and  next  from  3h.  57m. 
to  5h.  4m.  A.M. 

In  general,  during  unusual  or  larger  magnetic  disturbances 
(magnetic  storms),  the  mean  of  the  arc  of  the  oscillations 
exhibited  an  increase  either  westward  or  eastward,  although 
with  irregular  rapidity,  but  in  a  few  cases,  extraordinary 
fluctuations  were  also  observed,  even  when  the  variation 
was  not  irregularly  increased  or  decreased,  and  when  the 
mean  of  the  oscilli 'ions  did  not  exceed  the  limits  apper- 
taining to  the  normal  position  of  the  needle  at  the  given 
time.  We  saw,  after  a  relatively  long  rest,  sudden  motions 
of  very  unequal  intensity,  describing  arcs  of  from  6'  to  15', 
either  alternating  with  one  another  or  abnormally  inter- 
mixed, after  which  the  needle  would  become  suddenly  sta- 
tionary. At  night,  this  mixture  of  total  quiescence  and 
violent  perturbation  without  any  progression  to  either  side 
was  very  striking.70  One  special  modification  of  the  motion, 

"°  Arago,  during  the  ten  years  in  which  he  continued  to  make  care- 
ful observations  at  Paris  (till  1829),  never  noticed  any  oscillations  with- 
out a  change  in  the  variation.  He  wrote  to  me  as  follows,  in  the  course 
of  that  year  : — "  I  have  communicated  to  the  Academy  the  results  of 
our  simultaneons  observations.  I  am  surprised  to  notice  the  oscilla- 
tions which  the  dipping  needle  occasionally  exhibited  at  Berlin  during 
the  observations  of  1806, 1807,  and  of  1828—1829,  even  when  the  mean 
declination  was  not  changed.  Here  (at  Paris)  we  never  experience  any- 
thing of  the  kind.  The  only  time  at  which  the  needle  exhibits  violent 
oscillations  is  on  the  occurrence  of  an  Aurora  borealis,  and  when  its 
absolute  direction  has  been  considerably  disturbed ;  and  even  then,  the 
disturbances  of  direction  are  most  frequently  unaccompanied  by  any 
oscillatory  movement."  The  condition  here  described  is,  however,  en- 
tirely opposite  to  the  phenomena  which  were  observed  at  Toronto 
(43°  91'  N.lat.)  during  the  years  1840  and  1841;  and  which  correspond 
accurately  with  those  manifested  at  Berlin.  The  observers  at  Toronto 
have  paid  so  much  attention  to  the  nature  of  the  motion  that  they 
indicate  whether  the  vibrations  and  shocks  are  "  strong"  or  "slight," 
and  characterise  the  disturbances  in  accordance  with  definite  and 
uniform  subdivisions  of  the  scale,  following  a  fixed  and  uniform  nomen- 
clature. Sabine,  Days  of  Unusual  Magn.  Disturbances,  vol.  i,  pt.  i, 
p.  46.  Six  groups  of  successive  days  (146  in  all)  are  given  from  the 
two  above-named  years  in  Canada,  which  were  marked  by  very  strong 
shocks,  without  any  perceptible  change  in  the  horary  declination. 
Such  groups  (see  op.  cit.  pp.  47,  54,  74,  88,  95,  101),  are  designated  as 
"  Times  qf  Observations  at  Toronto,  at  which  the  magnetometers  were  dii' 


136  COSMOS. 

which  I  must  not  pass  without  notice,  consisted  in  the  very 
rare  occurrence  of  a  vertical  motion,  a  kind  of  tilting  motion, 
an  alteration  of  the  inclination  of  the  northern  point  of  the 
needle,  which  was  continued  for  a  period  of  from  15  to  20 
minutes,  accompanied  by  either  a  very  moderate  degree  of 
horizontal  vibration  or  by  the  entire  absence  of  this  move- 
ment .  In  the  careful  enumeration  of  all  the  secondary  condi- 
tions which  are  recorded  in  the  registers  of  the  English  obser- 
vatories, I  have  only  met  with  three  references  to  "  constant 
vertical  motion,  the  needle  oscillating  vertically,"71  and  these 
three  instances  occurred  in  Van  Diemen's  Land. 

The  periods  of  the  occurrence  of  the  greater  magnetic 
storms  fell,  according  to  the  mean  of  my  observations  in 
Berlin,  about  3  hours  after  midnight,  and  generally  ceased 
about  5  A.M.  We  observed  lesser  disturbances  during  the 
daytime,  as,  for  instance,  between  5  and  7  P.M.,  and  fre- 
quently on  the  same  days  of  September,  during  which  violent 
storms  occurred  after  midnight,  when,  owing  to  the  magni- 
tude and  rapidity  of  the  oscillations,  it  was  impossible  to  read 
them  off  or  to  estimate  the  means  of  their  elongation.  I 
soon  became  so  convinced  of  the  occurrence  of  magnetic 
storms  in  groups  during  several  nights  consecutively,  that  I 
acquainted  the  Academy  at  Berlin  with  the  peculiar  nature 
of  these  extraordinary  disturbances,  and  even  invited  my 
friends  to  visit  me  at  predetermined  hours,  at  which  I  hoped 
they  might  have  an  opportunity  of  witnessing  this  pheno- 
menon, and  in  general  I  was  not  deceived  in  my  anticipa- 

turbed,  but  the  mean  readings  were  not  materially  changed."  The  changes 
of  variation  were  also  nearly  always  accompanied  by  strong  vibrations 
at  Toronto  during  the  frequent  Aurora  boreales  ;  in  some  cases  these 
vibrations  were  so  strong  as  entirely  to  prevent  the  observations  from 
being  read  off.  We  learn,  therefore,  from  these  phenomena,  whose 
further  investigation  we  cannot  too  strongly  recommend,  that  although 
momentary  changes  of  declination  which  disturb  the  needle  may  often 
be  followed  by  great  and  definite  changes  of  variation  (Younghusband, 
Unusual  Disturbances,  pt.  ii,  p.  x),  the  size  of  the  arc  of  vibration  in  no 
respect  agrees  with  the  amount  of  the  alteration  in  the  declination ;  that 
in  very  inconsiderable  changes  of  variation  the  vibrations  may  be  very 
strong,  while  the  progressive  motion  of  the  needle  towards  a  western  or 
eastern  declination  may  be  rapid  and  considerable,  independently  of  any 
vibration ;  and  further,  that  these  processes  of  magnetic  activity  assume 
a  special  and  different  character  at  different  places. 
N  Unusual  Disturb,  vol.  i,  pt.  i,  pp.  69,  101. 


MAGNETIC   DISTURBANCES.  137 

tions.78  Kupffer,  during  his  travels  in  the  Caucasus  in  1829, 
and  at  a  later  period,  Kreil,  in  the  course  of  the  valuable 
observations  which  he  made  at  Prague,  were  both  enabled 
to  confirm  the  recurrence  of  magnetic  storms  at  the  same 
hours.73 

The  observations  which  I  was  enabled  to  make  during  the 
year  1806,  at  the  equinoctial  and  solstitial  periods,  in  refer- 
ence to  the  extraordinary  disturbances  in  the  variation,  have 
become  one  of  the  most  important  acquisitions  to  the  theory  of 
terrestrial  magnetism,  since  the  erection  of  magnetic  stations 
in  the  different  British  colonies  (from  1838  to  1840),  through 
the  accumulation  of  a  rich  harvest  of  materials,  which  have 
been  most  skilfully  elaborated  by  General  Sabine.  In  the 
results  of  both  hemispheres  this  talented  observer  has  sepa- 
rated magnetic  disturbances,  according  to  diurnal  and  noc- 
turnal hours,  according  to  different  seasons  of  the  year,  and 
according  to  their  deviations  eastward  or  westward.  At 
Toronto  and  Hobarton  the  disturbances  were  twice  as  fre- 
quent and  strong  by  night  as  by  day,74  and  the  same  was  the 
case  in  the  oldest  observations  at  Berlin  ;  exactly  the  reverse 
of  what  was  found  in  from  2600  to  3000  disturbances  at 
the  Cape  of  Good  Hope,  and  more  especially  at  the  island  of 
St.  Helena,  according  to  the  elaborate  investigation  of  Cap- 

72  This  was  at  the  end  of  September,  1806.     This  fact,  which  was 
published  in  Poggendorflfs  Annalen  der  Physilc,  Bd.  xv  (April,  1829), 
s.  330,  was  noticed  in  the  following  terms  : — "  The  older  horary  obser- 
vations which  I  made  conjointly  with  Oltmanns,  had  the  advantage 
that  at  that  period  (1806  and  1807),  none  of  a  similar  kind  had  beeii 
prosecuted  either  in  France  or  in  England.     They  gave  the  nocturnal 
maxima   and   minima ;    they  also   showed  how   remarkable  magnetic 
storms  could  be  recognised,  which  it  is  often  impossible  to  record,  owing 
to  the  intensity  of  the  vibrations,  and  which  occur  for  many  nights 
consecutively  at  the  same  time,  although  no  influence  of  meteorological 
relations  has  hitherto  been  recognised  as  the  inducing   cause  of  the 
phenomena."     The  earliest  record  of  a  certain  periodicity  of  extraordi- 
nary disturbances  was  not,  therefore,  noticed  for  the  first  time  in  the 
year  1839.     Report  of  the  Fifteenth  Meeting  of  the  British  Association  at 
Cambridge,  1845,  pt.  ii,  p.  12. 

73  Kupffer,    Voyage  au  Mont  Elbruz  dans  le  Caucase,  1829,  p.  108. 
"  Irregular  deviations  often  recur  at  the  same  hour  and  for  several  days 
consecutively." 

74  Sabine,  Unusual  Disturb,  vol.  i,  pt.  i,  p.  xxi,  and  Younghusband, 
On  Periodical  Laws  in  the  Larger  Magnetic  Disturbances,  in  the 
Transact,  for  1853,  pt.  i,  p.  173. 


138  COSMOS. 

tain  Younghusband.  At  Toronto  the  principal  disturbances 
generally  occurred  in  the  period  from  midnight  to  5  A.M.  ;  it 
was  only  occasionally  that  they  were  observed  as  early  as  from 
10  P.M.  to  midnight,  and  consequently  they  predominated  by 
night  at  Toronto,  as  well  as  at  Hobarton.  After  having 
made  a  very  careful  and  ingenious  investigation  of  the  3940 
disturbances  at  Toronto,  and  the  3470  disturbances  at 
Hobarton,  which  were  included  in  the  cycle  of  6  years  (from 
1843  to  1848),  of  which  the  disturbed  variations  constituted 
the  ninth  and  tenth  parts,  Sabine  was  enabled  to  draw  the 
conclusion75  that  "  the  disturbances  belong  to  a  special  kind 
of  periodically  recurring  variations,  which  follow  recognisable 
laws,  depend  upon  the  position  of  the  sun  in  the  ecliptic  and 
upon  the  daily  rotation  of  the  earth  round  its  axis,  and, 
further,  ought  no  longer  to  be  designated  as  irregular 
motions,  since  we  may  distinguish  in  them,  in  addition  to  a 
special  local  type,  processes  which  affect  the  whole  earth." 
In  those  years  in  which  the  disturbances  were  more  frequent 
at  Toronto,  they  occurred  in  almost  equal  numbers  in  the 
southern  hemisphere  at  Hobarton.  At  the  first-named  of 
these  places  these  disturbances  were,  on  the  whole,  doubly  as 
frequent  in  the  summer,  namely  from  April  to  September,  as  in 
the  winter  months,  from  October  to  March.  The  greatest 
number  fell  in  the  month  of  September,  in  the  same  manner  as 
at  the  autumn  equinox  in  my  Berlin  observations  of  1806.T6 
They  are  more  rare  in  the  winter  months  in  all  places ;  at 

75  Sabine,  in  the  Phil.  Transact,  for  1851,  pt.  i,  pp.  125—127.  "  The 
diurnal  variation  observed  is  in  fact  constituted  by  two  variations 
superposed  upon  each  other,  having  different  laws,  and  bearing  different 
proportions  to  each  other  in  different  parts  of  the  globe.  At  tropical 
stations  the  influence  of  what  have  been  hitherto  called  the  irregular 
disturbances  (magnetic  storms),  is  comparatively  feeble  ;  but  it  is  other- 
wise at  stations  situated  as  are  Toronto  (Canada)  and  Hobarton  (Van 
Diemen's  Island),  where  their  influence  is  both  really  and  proportion- 
ally greater,  and  amounts  to  a  clearly  recognisable  part  of  the  whole 
diurnal  variation."  We  find  here,  in  the  complicated  effect  of  simul- 
taneous but  different  causes  of  motion,  the  same  condition  which  has 
been  so  admirably  demonstrated  by  Poisson  in  his  theory  of  waves 
(Annales  de  Chimie  et  de  Physique,  t.  vii,  1817,  p.  293).  "  Waves  of 
different  kinds  may  cross  each  other  in  the  water  as  in  the  air,  where 
the  smaller  movements  are  superposed  upon  each  other."  See  Lamont's 
conjectures  regarding  the  compound  effect  of  a  polar  and  an  equatorial 
wave,  in  Poggend.  Annalen,  Bd.  Ixxxiv.  s.  583. 

<6  See  p.  134. 


MAGNETIC   DISTURBANCES  139 

Toronto  they  occur  less  frequently  from  November  till 
February,  and  at  Hobarton  from  May  till  August.  At  St. 
Helena  and  at  the  Cape  of  Good  Hope  the  periods,  at  which 
the  sun  crosses  the  equator,  are  characterised,  according  to 
Younghusband,  by  a  very  decided  frequency  in  the  disturb- 
ances. 

The  most  important  point,  and  one  which  was  also  first 
noticed  by  Sabine  in  reference  to  this  phenomenon,  is  the 
regularity  with  which,  in  both  hemispheres,  the  disturbances 
occasion  an  augmentation  in  the  eastern  or  western  variation. 
At  Toronto,  where  the  declination  is  slightly  westward 
(1°  33'),  the  progression  eastward  in  the  summer,  that  is, 
from  June  till  September,  preponderated  over  the  progression 
westward  during  the  winter  (from  December  till  April),  the 
ratio  being  411  :  290.  In  like  manner,  in  Van  Diemen's 
Land,  taking  into  account  the  local  seasons  of  the  year,  the 
winter  months  (from  May  till  A.ugust)  are  characterised  by 
a  strikingly  diminished  frequency  of  magnetic  storms.77 
The  co-ordination  of  the  observations  obtained  in  the  course 
of  6  years  at  the  two  opposite  stations,  Toronto  and  Hobar- 
ton, led  Sabine  to  the  remarkable  result  that,  from  1843  to 
1848,  there  was  in  both  hemispheres  not  only  an  increase  in 
the  number  of  the  disturbances,  but  also  (even  when,  in  order 
to  determine  the  normal  annual  mean  of  the  daily  variation, 
3469  storms  were  excluded  from  the  calculation,)  that  the 
amount  of  total  variation  from  this  mean  gradually  progressed 
during  the  above-named  five  years  from  7 '.65  to  10'.5S. 
This  increase  was  simultaneously  perceptible,  not  only  in 
the  amplitude  of  the  declination,  but  also  in  the  inclination 
and  in  the  total  terrestrial  force.  This  result  acquired  addi- 
tional importance  from  the  confirmation  and  generalisation 
afforded  to  it  by  Lament's  complete  treatise  (September, 
1851)  "regarding  a  decennial  period,  which  is  perceptible  in 
the  daily  motion  of  the  magnetic  needle."  According  to  the 
observations  made  at  Gottingen,  Munich,  and  Kremsmun- 
ster,78  the  mean  amplitude  of  the  daily  declination  attained  its 

77  Sabine,  in  the  Phil.  Transact,  for  1852,  pt.  ii,  p.  110  (Younghusband, 
op.  cit.  p.  169). 

<s  According  to  Lamont  and  Relshuber,  the  magnetic  period  is 
10  years  4  months,  so  that  the  amount  of  the  mean  of  the  diurnal 
motion  of  the  needle  increases  regularly  for  5  years,  and  decreases  for 


140  COSMOS. 

minimum  between  1843  and  1844,  and  its  maximum  from 
1848  to  1849.  After  the  decimation  has  thus  increased  for  5 
years  it  again  diminishes  for  a  period  of  equal  length,  as  is 
proved  by  a  series  of  exact  horary  observations,  which  go  back 
as  far  as  to  a  maximum  in  1786^-.7*  In  order  to  discover  a 
general  cause  for  such  a  periodicity  in  all  three  elements  of 
telluric  magnetism,  we  are  disposed  to  refer  it  to  cosmical 
influences.  Such  a  connection  is  indeed  appreciable,  accord- 
ing to  Sabine's  conjecture,  in  the  alterations  which  take  place 
in  the  photosphere,  that  is  to  say,  in  the  luminous  gaseous 
envelopes  of  the  dark  body  of  the  sun.80  According  to  the 
investigations  which  were  made  throughout  a  long  series  of 
years  by  Schwabe,  the  period  of  the  greatest  and  smallest 
frequency  of  the  solar  spots  entirely  coincides  with  that 
which  has  been  discovered  in  magnetic  variations.  Sabine 
first  drew  attention  to  this  coincidence  in  a  memoir  which 
he  laid  before  the  Royal  Society  of  London,  in  March,  1852. 
"  There  can  be  no  doubt,"  says  Schwabe,  in  the  remarks 
with  which  he  has  enriched  the  astronomical  portion  of  the 
present  work,  "that,  at  least  from  the  year  1826  to  1850, 
there  has  been  a  recurring  period  of  about  10  years  in  the 
appearance  of  the  sun's  spots,  whose  maxima  fell  in  the 
years  1828,  1837,  and  1848,  and  the  minima  in  the  years 
1833  and  1843."81  The  important  influence  exerted  by  the 
sun's  body,  as  a  mass,  upon  terrestrial  magnetism  is  confirmed 
by  Sabine  in  the  ingenious  observation,  that  the  period  at 
which  the  intensity  of  the  magnetic  force  is  greatest,  and  the 
direction  of  the  needle  most  near  to  the  vertical  line,  falls, 
in  both  hemispheres,  between  the  months  of  October  and 

the  same  length  of  time;  on  which  account  the  winter  motion  (the 
amplitude  of  declination)  is  always  twice  as  small  as  the  summer  motion 
(see  Lament,  Jahresbericht  der  Sternwarte  zu  Milnchenfur  1852,  s.  54 — 
60).  The  Director  of  the  Observatory  at  Berne,  Rudolph  Wolf,  finds 
"by  a  much  more  comprehensive  series  of  operations,  that  the  period  of 
magnetic  declination  which  coincides  with  the  frequency  of  the  solar 
spots,  must  be  estimated  at  11.1  years. 

79  See  page  75. 

80  Sabine,  in  the  Phil.  Transact,  for  1852,  pt.  i,  pp.  103,  121.     See 
the  observations  made  in  July,  1852,  by  Rudolph  Wolf,  above  reierred 
to  in  page  76  of  the  present  volume ;  also  the  very  similar  conjectures 
of  Qautier,  which  were  published  very  nearly  at  the  same  time  in  the 
BibliotMque  l/niverselle  de  GenZve,  t.  xx,  p.  189. 

81  Cosmos,  vol.  iv,  p.  397-  400. 


MAGNETIC  DISTURBANCES.  141 

February ;  that  is  to  say,  precisely  at  the  time  when  the 
earth  is  nearest  to  the  sun,  and  moves  in  its  orbit  with  the 
greatest  velocity.82 

I  have  already  treated  in  the  Picture  of  Nature83  of  the 
simultaneity  of  many  magnetic  storms,  which  are  transmitted 
for  thousands  of  miles  and  indeed  almost  round  the  entire 
circumference  of  the  earth,  as  on  the  25th  of  September, 
1841,  when  they  were  simultaneously  manifested  in  Canada, 
Bohemia,  the  Cape  of  Good  Hope,  Van  Diemen's  Land,  and 
Macao  ;  and  I  have  also  given  examples  of  those  cases,  in 
which  the  perturbations  were  of  a  more  local  kind,  passing 
from  Sicily  to  Upsala,  but  not  from  Upsala  farther  north  in 
the  direction  of  Alten  and  Lapland.  In  the  simultaneous 
observations  of  declination  which  were  instituted  by  Arago 
and  myself  in  1829  at  Berlin,  Paris,  Freiberg,  St.  Peters- 
burg, Casan,  and  Nikolajew,  with  the  same  Gambey's  instru- 
ments, individual  perturbations  of  a  marked  character  were 
not  transmitted  from  Berlin  as  far  as  Paris,  and  not  on  any 
one  occasion  to  the  mine  at  Freiberg,  where  Eeich  was  mak- 
ing a  series  of  subterranean  observations  on  the  magnet. 
Great  variations  and  disturbances  of  the  needle  simultan- 
eously with  the  occurrence  of  the  Aurora  borealis  at  Toronto 
certainly  occasioned  magnetic  storms  in  Kerguelen's  Land, 
but  not  at  Hobarton.  When  we  consider  the  capacity  for 
penetrating  through  all  intervening  bodies,  which  distin- 
guishes the  magnetic  force,  as  well  as  the  force  of  gravity 
inherent  in  all  matter,  it  is  certainly  very  difficult  to  form  a 
clear  conception  of  the  obstacles  which  may  prevent  its  trans- 
mission through  the  interior  of  the  earth.  These  obstacles 
are  analogous  to  those  which  we  observe  in  sound-waves,  or 
in  the  waves  of  commotion  in  earthquakes,  in  which  certain 

82  Sabine,  in  the  Phil.  Transact,  for  1850,  pt.  i,  p.  216.     Faraday, 
Exper.  Researches  on  Electricity,  1851,  pp.  56,   73,  76,  §  2891,  2949, 
2958. 

83  Cosmos,  vol.  i,   p.  185 ;   Poggend.  Annalen,  Bd.  xv,  s.  334,  335  ; 
Sabine,  Unusual  Disturb,  vol.  i,  pt.  i,  pp.  xiv — xviii;  where  tables  are 
given  of  the  simultaneous  storms  at  Toronto,  Prague,  and  Van  Diemen's 
Land.     On  those  days  in  which  the  magnetic  storms  were  the  most 
marked  in  Canada  (as,  for  instance,  on  the  22nd  of  March,  the  10th  of 
May,  the  6th  of  August,  and  the  25th  of  September,  1841),  the  same 
phenomena  were  observed  hi  the  southern  hemisphere  in  Australia. 
See  also  Edward  Belcher,  in  the  Phil.  Transact,  for  1843,  p.  133. 


112  COSMOS. 

spots  which  are  situated  near  one  another  never  experience 
the  shocks  simultaneously.84  Is  it  possible  that  certain  mag- 
netic intersecting  lines  may  by  their  intervention  oppose  all 
further  transmission  ? 

We  have  here  described  the  regular  and  the  apparently 
irregular  motions  presented  by  horizontally  suspended 
needles.  If  by  an  examination  of  the  normal  recurring- 
motion  of  the  needle  we  have  been  enabled  from  the  mean 
numbers  of  the  extremes  of  the  horary  variations  to  ascer 
tain  the  direction  of  the  magnetic  meridian,  in  which  the 
needle  has  vibrated  equally  to  either  side,  from  one  solstice 
to  another,  the  comparison  of  the  angles  which  the  magnetic 
meridian  describes  at  different  parallels  with  the  geographi- 
cal meridian  has  led  in  the  first  place  to  the  knowledge  of 
lines  of  variation  of  strikingly  heterogeneous  value  (Andrea 
Bianco,  in  1436,  and  Alonzo  de  Santa  Cruz,  cosmographer 
to  the  Emperor  Charles  V.,  even  attempted  to  lay  down 
these  lines  upon  charts)  ;  and  more  recently  to  the  success- 
ful generalization  of  isogonic  curves,  lines  of  equal  variation, 
which  British  seamen  have  long  been  in  the  habit  of  grate- 
fully designating  by  the  historical  name  of  Halleys  lines. 
Among  the  variously  curved  and  differently  arranged  closed 
systems  of  isogonic  lines,  which  are  sometimes  almost  parallel, 
and  more  rarely  re-enter  themselves  so  as  to  form  oval 
closed  systems,  the  greatest  attention  in  a  physical  point 
of  view  is  due  to  those  lines,  on  which  the  variation  is  null, 
and  on  both  sides  of  which  variations  of  opposite  denomina- 
tions prevail,  which  increase  unequally  with  the  distance.85 
I  have  already  elsewhere  shown  how  the  first  discovery 
made  by  Columbus  on  the  13th  of  September,  1492,  of  a 
line  of  no  variation  in  the  Atlantic  Ocean,  gave  an  impetus 
to  the  study  of  terrestrial  magnetism,  which,  however,  con- 
tinued for  two  centuries  and  a  half  to  be  directed  solely  to 
the  discovery  of  better  methods  for  obtaining  the  ship's 
reckoning. 

However  much  the  higher  scientific  education  of  mariners 
in  recent  times  and  the  improvement  of  instruments  and 
methods  of  observation  have  extended  our  knowledge  of 

84  Cosmos,  voL  i,  p.  208. 

85  Op.  cit.  vol.  i,  pp.  187—189;  vol.  ii,  pp.  657 — 659  and  pp.  52  —CO 
of  the  present  volume. 


LINES   OF  NO   VARIATION.  143 

individual  portions  of  lines  of  no  variation  in  Northern 
Asia,  in  the  Indian  Archipelago  and  the  Atlantic  O^ean, 
we  have  still  to  regret,  that  in  this  department  of  o?ir 
knowledge,  where  the  necessity  of  cosmical  elucidation  is 
strongly  felt,  the  progress  has  been  tardy  and  the  results 
deficient  in  generalization.  I  am  not  ignorant  that  a  large 
number  of  observations  of  accidental  crossings  of  lines  of  no 
variation  have  been  noted  down  in  the  logs  of  various  ships, 
but  sve  are  deficient  in  a  comparison  and  co-ordination  of 
the  materials,  which  cannot  acquire  any  importance  in  re- 
ference to  this  object  or  in  respect  to  the  position  of  the 
magnetic  equator,  until  individual  ships  shall  be  despatched 
to  different  seas  for  the  sole  purpose  of  uninterruptedly  fol- 
lowing these  lines  throughout  their  course.  Without  a 
simultaneity  in  the  observations,  we  can  have  no  history  of 
terrestrial  magnetism.  I  here  merely  reiterate  a  regret 
which  I  have  often  previously  expressed.86 

86  At  very  different  periods,  once  in  1809,  in  my  Recueil  d'Observ. 
Astron.  vol.  i,  p.  368,  and  again,  in  1839,  when,  in  a  letter  addressed  to 
the  Earl  of  Minto,  then  First  Lord  of  the  Admiralty,  a  few  days  before 
the  departure  of  Sir  James  Ross  on  his  Antarctic  expedition,  I  endea- 
voured more  fully  to  develope  the  importance  of  the  proposition  ad- 
vanced in  the  text  (see  Report  of  the  Committee  of  Physics  and  Meteor,  of 
the  Royal  Soc.  relative  to  the  Antarctic  Exped.  1840,  pp.  88 — 91).  "  In 
order  to  follow  the  indications  of  the  magnetic  equator  or  those  of  the 
lines  of  no  variation,  the  ship's  course  must  be  made  to  cross  the  lines  0 
at  very  small  distances,  the  bearings  being  changed  each  time  that  obser- 
vations of  inclination  or  of  declination  show  that  the  ship  has  deviated 
from  these  points.  I  am  well  aware  that,  in  accordance  with  the  com- 
prehensive views  of  the  true  basis  for  a  general  theory  of  terrestrial  mag- 
netism, which  we  owe  to  Gauss,  a  thorough  knowledge  of  the  horizon- 
tal intensity,  and  the  choice  of  the  points  at  which  the  three  elements  of 
declination,  inclination,  and  total  intensity  have  all  been  simultaneously 
measured,  suffice  for  finding  the  value  of  ^-  (Gauss,  §  4  and  27),  and 
that  these  are  the  essential  points  for  future  investigations;  but  the 
sum  total  of  the  small  local  attractions,  the  requirements  of  steering 
ships,  the  ordinary  corrections  of  the  compass,  and  the  safety  of  navi- 
gation continue  to  impart  special  importance  to  the  knowledge  of  the 
position,  and  to  the  movements  of  the  periodic  translation  of  lines  of  no 
variation.  I  here  plead  the  cause  of  these  various  requirements,  which 
are  intimately  connected  with  the  interests  of  physical  geography." 
Many  years  must  still  pass  before  seamen  can  be  enabled,  to  guide  the 
ship's  course  by  charts  of  variation,  constructed  in  accordance  with  the 
theory  of  terrestrial  magnetism  (Sabine,  in  the  Phil.  Transact,  for  1849, 
pt.  ii,  p.  204),  and  the  wholly  objective  view  directed  to  actual  observa- 


1 44  COSMOS. 

According  to  the  facts  which  we  already  generally  know 
concerning  the  position  of  lines  of  no  variation,  it  would 
appear  that  instead  of  the  four  meridian  systems  which  were 
believed  at  the  end  of  the  16th  century  to  extend  from  pole 
to  pole,87  there  are  probably  three  very  differently  formed 
systems  of  this  kind,  if  by  this  name  we  designate  those 
groups  in  which  the  line  of  variation  does  not  stand  in  any 
direct  connection  with  any  other  line  of  the  same  kind,  or 
cannot,  in  accordance  with  the  present  state  of  our  know- 
ledge, be  regarded  as  the  continuation  of  any  other  line.  Of 
these  three  systems  which  we  will  separately  describe,  the 
middle,  or  Atlantic,  is  limited  to  a  single  line  of  no  varia- 
tion, inclining  from  SS.E.  to  NN.W.  between  the  parallels 
of  65°  south  and  67°  north  latitude.  The  second  system, 
which  lies  fully  150°  farther  east,  occupying  the  whole  of 
Asia  and  Australia,  is  the  most  extended,  and  most  compli- 
cated of  all,  if  we  merely  take  into  account  the  points  at 
which  the  line  of  no  variation  intersects  the  geographical 
equator.  This  system  rises  and  falls  in  a  remarkable  manner, 
exhibiting  one  curvature  directed  southward  and  another 

tion,  which  I  would  here  advocate,  would,  if  it  led  to  periodically- 
repeated  determinations,  and  consequently  to  expeditions  prosecuted 
simultaneously  by  land  and  sea,  in  accordance  with  some  preconcerted 
plan,  give  the  double  advantage  of,  in  the  first  place,  yielding  a  direct 
practical  application  and  affording  us  a  correct  knowledge  of  the  annual 
progressive  movement  of  these  lines ;  and  secondly,  of  supplying  many 
new  data  for  the  further  development  of  the  theory  enounced  by  Gauss 
(Gauss,  §  25).  It  would,  moreover,  greatly  facilitate  the  accurate  deter- 
mination of  the  progression  of  the  two  lines  of  no  inclination  and  no  vari- 
tion,  if  landmarks  could  be  established  at  those  points,  where  the  lines 
enter  or  leave  continents  at  stated  intervals,  as,  for  instance,  in  the 

years  1850,  1875,  1900 In  expeditions  of  this  kind,  which 

would  be  similar  to  those  undertaken  by  Halley,  many  isoclinal  and 
isogonic  systems  would  necessarily  be  intersected  before  the  lines  of  no 
declination  and  no  inclination  could  be  reached,  and  by  this  means  the 
horizontal  and  total  intensities  might  be  measured  along  the  coasts,  so 
that  several  objects  would  thus  be  simultaneously  attained.  The  views 
which  I  have  here  expressed  are,  I  am  happy  to  find,  supported  by  a 
very  great  authority  in  nautical  questions,  viz.  Sir  James  Ross.  (See  his 
Voyage  in  the  Southern  and  Antarctic  Regions,  vol.  i,  p.  105.) 

87  Acosta,  Historia  de  las  Jndias,  1590,  lib.  i,  cap.  17.  I  have  already 
considered  the  question  whether  the  opinion  of  Dutch  navigators  re- 
garding the  existence  of  four  lines  of  no  variation  may  not,  through  the 
differences  between  Bond  and  Beckborrow,  have  had  some  influence  on 
Halley 'a  theory  of  four  magnetic  poles  (Cosmos,  vol.  ii,  p  658) 


MAGNETIC   VARIATION.  14/5 

northward  ;  indeed  it  is  so  strongly  curved  at  its  north- 
eastern extremity  that  the  line  of  no  variation  forms  an 
ellipse,  surrounding  those  lines  which  rapidly  increase  in 
variation  from  without  inwards.  The  most  westerly  and 
the  most  easterly  portions  of  this  Asiatic  curve  of  no  varia- 
tion, incline  like  the  Atlantic  line  from  south  to  north,  and 
in  the  space  between  the  Caspian  Sea  and  Lapland  even  from 
SS.E.  to  NN.W.  The  third  system,  that  of  the  Pacific, 
which  has  been  least  investigated,  is  the  smallest  of  all,  and 
lying  entirely  to  the  south  of  the  geographical  equator  forms 
almost  a  closed  oval  of  concentric  lines,  whose  variation  is 
opposite  to  that  which  we  observe  in  the  north-eastern  part 
of  the  Asiatic  system,  and  decreases  from  without  inwards. 
If  we  base  our  opinion  upon  the  magnetic  declination  ob- 
served on  the  coast,  we  find  that  the  African  continent88  only 
presents  lines  which  exhibit  a  western  variation  of  from  6° 
to  29°  ;  for  according  to  Purchas,  the  Atlantic  line  of  no 
variation  left  the  southern  point  of  Africa  (the  Cape  of  Good 
Hope)  in  the  year  1605,  inclining  further  from  east  to  west. 
The  possibility,  that  we  may  discover  in  some  part  of  Central 
Africa  an  oval  group  of  concentric  lines  of  variation,  decreas- 
ing to  0°,  and  which  is  similar  to  that  of  the  Pacific,  can 
neither  be  asserted  or  denied  on  any  sure  grounds. 

The  Atlantic  portion  of  the  American  curve  of  no  varia- 
tion was  accurately  determined  in  both  hemispheres  for  the 
year  1840,  by  the  admirable  investigations  of  General  Sabine 
who  employed  1480  observations,  and  duly  took  into  account 
the  secular  changes.  It  passes  in  the  meridian  of  70°  S.  lat., 
and  about  19°  W.  long./9  in  a  NN.W.  direction,  to  about 

w  In  the  interior  of  Africa,  the  isogonic  line  of  22°  15'  W.  is  espe- 
cially deserving  of  careful  cosmical  investigation, as  being  the  interme- 
diate line  between  very  different  systems,  and  as  proceeding  (accord- 
ing to  the  theoretical  views  of  Gauss),  from  the  Eastern  Indian  Ocean, 
straight  across  Africa  on  to  Newfoundland.  The  very  comprehensive 
plan  of  the  African  expedition,  conducted  by  Eichardson,  Earth,  and 
Ovenveg,  under  the  orders  of  the  British  Government,  may  probably 
lead  to  the  solution  of  such  magnetic  problems. 

sa  Sir  James  Ross  intersected  the  curve  of  no  variation  in  61*  30'  S. 
lat.  and  27°  10'  W,  long.  ( Voyage  to  the  Southern  Seas,  vol.  ii,  p.  357). 
Captain  Crozier  found  the  variation  in  March,  1843,  1°  38'  in  70°  43'  S. 
lat.  and  21°  28'  \V.  long.,  and  he  was  therefore  very  near  the  line  of  no 
variation.  See  Sabine,  On  the  Magn.  Declination  in  the  Atlantic  Ocecv* 
for  1840,  in  the  Phil.  Transact,  for  1849,  pt.  ii,  p.  233, 

VOL,  V.  t 


146  COSMOS. 

3°  east  of  Cook's  Sandwich  Land,  and  to  about  9°  30'  east 
of  South  Georgia  ;  it  then  approaches  the  Brazilian  coast, 
which  it  enters  at  Cape  Frio  2°  east  of  Rio  Janeiro  and  tra- 
verses the  southern  part  of  the  New  Continent  no  farther 
than  0°  36'  S.  lat.,  where  it  again  leaves  it  somewhat  to  the 
east  of  Gran  Para,  near  Cape  Tigloca  on  the  Rio  do  Para, 
one  of  the  secondary  outlets  of  the  Amazon,  crossing  the 
geographical  equator  in  47°  44'  W.  long.,  then  skirting  along 
the  coast  of  Guiana  at  a  distance  of  eighty-eight  geogra- 
phical miles  as  far  as  5°  N.  lat.,  and  afterwards  following  the 
arc  of  the  small  Antilles  as  far  as  the  parallel  of  18°,  and 
finally  touching  the  shore  of  North  Carolina  near  Cape 
Lookout,  south-east  of  Cape  Hattaras  in  34°  50'  N.  lat., 
74°  8'  W.  long.  In  the  interior  of  North  America,  the 
curve  follows  a  north-western  direction  as  far  as  41°  30' N. 
lat.,  77°  38'  W.  long.,  towards  Pittsburgh,  Meadville,  and 
Lake  Erie.  We  may  conjecture  that  it  has  advanced  very 
nearly  half  a  degree  farther  west  since  1840. 

The  Australo-Asiatic  curve  of  no  variation  (if  according 
to  Erman  we  consider  the  part  which  rises  suddenly  from 
Kasan  to  Archangel  and  Russian  Lapland  as  identical  with 
the  part  in  the  sea  of  Molucca  and  Japan)  can  scarcely  be 
followed  as  far  as  62°  in  the  southern  hemisphere.  This 
starting  point  lies  farther  west  from  Van  Diemen's  Land  than 
had  hitherto  been  conjectured,  and  the  three  points,  at  which 
Sir  James  Ross  crossed  the  curve  of  no  variation  on  his  Ant- 
arctic voyage  of  discovery  in  1840  and  1841,90  are  all  situated 
in  the  parallels  of  62°,  54°.  30,  and  46°,  between  133°  and 
135°  40'  E.  long.  ;  and  therefore  mostly  in  a  meridian-like 
direction  running  from  south  to  north.  In  its  further  course, 
the  curve  crosses  Western  Australia  from  the  southern  coast 
of  Nuyts'  Land  about  103  W.  of  Adelaide  to  the  northern 
coast  near  Vansittart  river  and  Mount  Cockburn,  from 
whence  it  enters  the  sea  of  the  Indian  Archipelago  in  a  region 
of  the  world,  in  which  the  inclination,  declination,  total  in- 
tensity, and  the  maximum  and  minimum  of  the  horizontal 
force  were  investigated  by  Captain  Elliot  from  1846  to  1848, 
with  more  care  than  has  been  done  in  any  other  portion  of 
the  globe.  Here  the  line  passes  south  of  Flores  and  through 

*  Sir  James  Ross,  Op.  dt.  vol.  i,  pp.  104,  310,  317. 


MAGNETIC   VARIATION.  147 

the  interior  of  the  small  Sandal-wood  Island,91  in  a  direct 
east  and  west  direction  from  about  120°  30'  to  93°  30'  E 
long.,  as  had  been  accurately  demonstrated  sixteen  years 
before  by  Barlow.  From  the  last  named  meridian  it  ascends 
towards  the  north-west  in  9°  30'  S.  lat.,  judging  by  the  posi- 
tion in  which  Elliot  followed  the  curve  of  1°  east  variation 
to  Madras.  We  are  not  able  here  to  decide  definitely  whether, 
crossing  the  equator  in  about  the  meridian  of  Ceylon,  it- 
enters  the  continent  of  Asia  between  the  Gulf  of  Cambay  and 
Guzurat,  or  further  west  in  the  Bay  of  Muscat,92  and  whether, 
therefore,  it  is  identical93  with  the  curve  of  no  variation, 
which  appears  to  advance  southward  from  the  basin  of 
the  Caspian  Sea  ;  or  whether,  as  Erman  maintains,  it  may 
not  curve  to  the  eastward,  and  rising  between  Borneo  and 
Malacca,  reach  the  Sea  of  Japan,94  and  penetrate  into  Eastern 

91  Elliot,  in  the  Phil.  Transact,  for  1851,  pt.  i,  p.  331,  pi.  xiii.     The 
long  and  narrow  small  island  from  which  we  obtain  the  sandalwood 
(tschendana,  Malay  and  Java,  tschandana,  Sanscrit,  fsandel,  Arab). 

92  According  to  Barlow,  and  the  chart  of  Lines  of  Magnetic  Declina- 
tions computed  according  to  the  theory  of  Mr.  Gauss,  in  the  Report  of  the 
Committee  for  the  Antarctic  Expedition,  1840.     According  to  Barlow  the 
line  of  no  variation  proceeding  from  Australia  enters  the  Asiatic  Con- 

'tinent  at  the  Bay  of  Cambay,  but  turns  immediately  to  the  north-east, 
across  Thibet  and  China,  near  Thaiwan  (Formosa),  from  whence  it 
enters  the  Sea  of  Japan.  According  to  Gatiss,  the  Australian  line 
ascends  merely  through  Persia,  past  Nishnei-Nowgorod  to  Lapland. 
This  great  geometrician  regards  the  Japan  and  Philippine  line  of  no 
variation,  as  well  as  the  closed  oval  group  in  Eastern  Asia,  as  entirely 
independent  of  the  line  belonging  to  Australia,  the  Indian  Ocean, 
Western  Asia,  and  Lapland. 

93  I  have  already  elsewhere  spoken  of  this  identity,  which  is  based  upon 
my  own  declination-observations  in  the  Caspian  Sea,  at  Uralsk  on  the 
Jaik,  and  in  the  Steppe  of  Elton  Lake  (Asie  Centrale,  t.  iii,  pp.  458 — 461). 

94  Adolf  Erman's   Map  of  the  Magnetic  Declination,  1827  — 1830. 
Elliot's  chart  shows,  however,  most  distinctly  that  the  Australian  curve 
of  no  variation  does  not  intersect  Java,  but  runs  parallel  with,  and  at  a 
distance  of  1°  30'  latitude  from  the  southern  coast.     Since,  according 
to  Erman,  although  not  according  to  Gauss,  the  Australian  line  of  no 
variation  between  Malacca  and  Borneo  enters  the  Continent  through 
the  Japanese  Sea,  proceeding  to  the  closed  oval  group  of  Eastern  Asia, 
on  the  northern  coast  of  the  Sea  of  Ochotsk  (59°  30'  N.  lat.),  and  again 
descends  through  Malacca,  the  ascending  line  can  only  be  11°  distant 
from  the  descending  curve  ;  and  according  to  this  graphical  representa- 
tion, the  Western  Asiatic  line  of  no  variation  (from  the  Caspian  Sea  to 
llussian  Lapland)  would  be  the  shortest  and  most  direct  prolongation 
of  the  part  descending  from  north  to  south. 

L  2 


14fc  COSMOS. 

Asia  through  the  Gulf  of  Ochotsk.  It  is  much  to  be  lamented, 
that  notwithstanding  the  frequent  voyages  made  to  and  from 
India,  Australia,  the  Philippines,  and  the  north-east  coasts 
of  Asia,  a  vast  accumulation  of  materials  should  remain 
buried  and  unheeded  in  various  ships'  logs,  which  might 
otherwise  lead  to  general  views,  by  which  we  might  be  en- 
abled to  connect  Southern  Asia  with  the  more  thoroughly 
explored  parts  of  Northern  Asia  and  thus  to  solve  questions 
which  were  started  as  early  as  1840.  In  order,  there- 
fore, not  to  blend  together  known  facts  with  uncertain  hypo- 
theses, I  will  limit  myself  to  the  consideration  of  the  Siberian 
portion  of  the  Asiatic  continent,  as  far  as  it  has  been  ex- 
plored in  a  southerly  direction  to  the  parallel  of  45°  by  Erman, 
Hansteen,  Due,  Kupfler,  Fuss,  and  myself.  In  no  other  part 
of  the  earth  has  so  extended  a  range  of  magnetic  lines  been 
accessible  to  us  in  continental  regions  ;  and  the  importance 
which  European  and  Asiatic  Russia  presents  in  this  respect 
was  ingeniously  conjectured  even  before  the  time  of  Leib- 
nitz.95 

95  I  drew  attention  as  early  as  1843  to  the  fact,  which  I  had  ascer- 
tained from  documents  presenved  in  the  Archives  of  Moscow  and, 
Hanover  (Asie  Centrale,  t.  iii,  pp.  469 — 476),  that  Leibnitz,  who  con- 
structed the  first  plan  of  a  French  expedition  to  Egypt,  was  also  the  first 
who  endeavoured  to  profit  by  the  relations  which  the  Czar,  Peter  tho 
Great,  had  established  with  Germany  in  1712,  by  using  his  influence  to 
secure  the  prosecution  of  observations  for  "  determining  the  position  of 
the  lines  of  variation  and  inclination,  and  for  insuring  that  these  observa- 
tions should  be  repeated  at  certain  definite  epochs"  in  different  parts  of 
the  Russian  empire,  whose  superficies  exceed  those  of  the  portions  of 
the  moon  visible  to  us.  In  a  letter  addressed  to  the  Czar,  discovered 
by  Pertz,  Leibnitz  describes  a  small  hand-globe,  or  terrella,  which  is 
still  preserved  at  Hanover,  and  on  which  he  had  represented  the  curve 
at  which  the  variation  is  null  (his  linea  magnetica  primaria).  Leibnitz 
maintains  that  there  is  only  one  line  of  no  variation,  which  divides  the 
terrestrial  sphere  into  two  almost  equal  parts,  and  hag  four  pwncta, 
flexus  contrarii,  or  sinuosities,  where  the  curves  are  changed  from  con- 
vex to  concave.  From  the  Cape  dft  Verd  it  passes  in  lat.  36°  towards 
the  eastern  shores  of  North  America,  after  which  it  directs  its  course 
through  the  South  Pacific  to  Eastern  Asia  and  New  Holland.  This  line 
is  a  closed  one,  and  passing  near  both  poles,  it  approaches  closer  to  the 
southern  than  the  northern  pole  ;  at  the  latter,  the  declination  must 
be  25°  west,  and  at  the  former  only  5°.  The  motion  of  this  important 
curve  must  have  been  directed  towards  the  north  pole  at  the  beginning 
of  the  18th  century.  The  variation  must  have  ranged  between  0°  and 
15°  east  over  a  great  portion  of  the  Atlantic  Ocean,  the  whole  of  the 


MAGNETIC    VARIATION.  149 

In  order  to  follow  the  usual  direction  of  Siberian  expedi- 
tions from  west  to  east,  and  starting  from  Europe,  we  will 
begin  with  the  northern  part  of  the  Caspian  Sea.  Here,  in 
the  small  island  of  Birutschikassa,  in  Astracan,  on  Lake  Elton, 
in  the  Kirghis  steppe,  and  at  Uralsk,  on  the  Jaik,  between 
45°43'and51°12'NMat.,  and  46° 37' and  51°24'E.  long., the 
variation  fluctuates  from  0°  10'  east  to  0°  37'  west.96  Farther 
northward,  this  line  of  no  variation  inclines  somewhat  more 
towards  the  north-west,  passing  nftui*  Nishnei-Nowgorod.97 
In  the  year  1828  it  passed  between  Osablikowo  and  Doskino 
in  the  parallel  of  56°  K  lat.  an.d  43°  E.  long.  It  becomes 
elongated  in  the  direction  of  Russian  Lapland  between 
Archangel  and  Kola,  or  more  accurately  according  to  Han- 
steen  (1830)  between  Umba  and  Ponoi.98  It  is  not  until  we 
have  passed  over  nearly  two-tiirds  of  the  greatest  breadth 
of  Northern  Asia,  advancing  eastward  to  the  latitudes  of 
from  50°  and  60°  (a  district  in  wLich  at  present  the  variation 
is  entirely  easterly),  that  we  reach  the  line  of  no  variation, 
which  in  the  north-eastern  part  of  the  Lake  of  Baikal,  rises 
to  a  point  west  of  Wiluisk,  which  riches  the  latitude  of  68°, 
in  the  meridian  of  Jakutsk  129°  50'  E.  long.,  forming  at 
this  point  the  outer  shell  of  the  eastern  group  of  oval  con- 
centric lines  of  variation,  to  which  we  have  frequently  re- 
ferred, again  sinking  in  the  direction  of  Ochotsk  in  143°  10' 
E.  long.,  intersecting  the  arc  of  the  Kurile  Islands,  and 
penetrating  into  the  southern  part  of  the  Japanese  Sea. 
A 11  the  curves  of  from  5°  to  15°  eastern  variation  which  oc- 
cupy the  space  between  the  lines  of  no  variation  in  Western 
and  Eastern  Asia,  have  their  concavities  turned  northward. 
The  maximum  of  their  curvature  falls,  according  to  Erman, 
in  80°  E.  long.,  and  almost  in  one  meridian  between  Omsk 

Pacific,  Japan,  a  part'  of  China,  and  New  Holland.  "  As  the  Czar's 
private  physician,  Donelli,  is  dead,  it  would  be  advisable  to  supply  hia 
place  by  some  one  else,  who  will  be  disposed  to  administer  very  little 
medicine,  but  who  may  be  able  to  give  sound  scientific  advice  regarding 
determinations  of  magnetic  declination  and  inclination."  .... 
These  hitherto  unnoticed  letters  of  Leibnitz  certainly  do  not  express 
any  special  theoretical  views. 

96  See  my  Magnetic  Observations,  in  Asie  Centrale,  t.  iii,  p.  460. 

97  Erman,  Astron.  und  Magnet.  Beobachtuwgen  (Reise  urn,  die  Erde, 
Abth.  ii,  Bd.  2,  s.  532. 

93  Hansteen,  in  Poggend.  Ann.  Bd.  xxi,  a.  371. 


1 50  COSMOS. 

and  Tomsk,  and  are  therefore  not  very  different  from  the 
meridian  of  the  southern  extremity  of  the  peninsula  of  Hin- 
dostan.  The  axis  major  of  the  closed  oval  group  extends 
28°  of  latitude  as  far  as  Corea. 

A  similar  configuration,  although  on  a  still  larger  scale, 
is  exhibited  in  the  Pacific.  The  closed  curves  here  form  an 
oval  between  20°  N.  lat.  and  42°  S.  lat.  The  axis  major 
lies  in  130°  W.  long.  That  which  most  especially  distin- 
guishes this  singular  group  (the  greater  portion  of  which 
belongs  to  the  southern  hemisphere  and  exclusively  to  the 
sea)  from  the  continent  of  Eastern  Asia  is.  as  has  been 
already  observed,  the  relative  succession  in  the  value  of  the 
curves  of  variation.  In  the  former,  the  eastern  variation 
diminishes,  whilst  in  the  latter  the  western  variation  in- 
creases the  farther  we  penetrate  into  the  interior  of  the  oval. 
The  variation  in  the  interior  of  this  closed  group  in  the 
southern  hemisphere  amounts,  however,  as  far  as  we  know, 
only  to  from  8°  to  5°.  Is  it  likely  that  there  is  a  ring  of 
southern  variation  within  the  oval,  or  that  we  should  again 
meet  with  western  variation  farther  to  the  interior  of  this 
closed  line  of  no  variation  ? 

Curves  of  no  variation,  like  all  magnetic  lines,  have  their 
own  history,  which,  however,  does  not  as  yet  unfortunately 
date  further  back  than  two  centuries.  Scattered  notices 
may  indeed  be  met  with,  as  early  even  as  in  the  14th  and 
15th  centuries,  and  here  again  Hansteen  has  the  great  merit 
of  having  collected  and  carefully  compared  together  all  the 
various  data.  It  would  appear,  that  the  northern  magnetic 
pole  is  moving  from  west  to  east,  and  the  southern  magnetic 
pole  from  east  to  west ;  accurate  observations  show  us,  how- 
ever, that  the  different  parts  of  the  isogonic  curves  are  pro- 
gressing very  irregularly,  and  that  where  they  were  parallel 
they  are  losing  their  parallelism  ;  and  lastly  that  the  domain 
of  the  declination  of  one  denomination,  that  is  to  say,  east 
or  west  declination,  is  enlarging  and  contracting  in  very 
different  directions  in  contiguous  parts  of  the  earth.  The 
lines  of  no  variation  in  Western  Asia  and  in  the  Atlantic 
are  advancing  from  east  to  west ;  the  former  line  having 
crossed  Tobolsk  in  1716,  while  in  1761,  in  Chappe's  time,  it 
crossed  J  ekatherinenburg  and  subsequently  Kasan,  and  in 
1829  it  was  found  to  have  passed  between  Osablikowo  and 


POLAR   LIGHT.  151 

Doskino,  not  far  from  Nishneinowgorod,  and  consequently 
had  advanced  24°  45'  westward  in  the  course  of  113  years. 
Is  the  line  of  the  Azores,  which  Christopher  Columbus  deter- 
mined on  the  13th  of  September,  1492,  the  same,  which, 
according  to  the  observations  of  Davis  and  Keeling,  in  1607, 
passed  through  the  Cape  of  Good  Hope  r"  and  is  it  identical 
with  the  one  which  we  designate  as  the  Western  Atlantic. 
and  which  passes  from  the  mouth  of  the  river  Amazon  to 
the  sea- coast  of  North  Carolina  ?  if  it  be,  we  are  led  to  ask 
what  has  become  of  the  line  of  no  variation  which  passed  in 
1600  through  Konigsberg,  in  1620  (?)  through  Copenhagen, 
from  1657  to  1662  through  London,  and  which  did  not,  ac- 
cording to  Picard,  reach  Paris,  notwithstanding  its  more 
eastern  longitude,  until  1666,  passing  through  Lisbon  some- 
what before  1668  ?  10C  Those  points  of  the  earth  at  which 
no  secular  progression  has  been  observed  for  long  periods  of 
time  are  especially  worthy  of  our  notice.  Sir  John  Herschel 
has  already  drawn  attention  to  a  corresponding  long  period 
of  cessation  in  Jamaica,1  while  Euler*  and  Barlow3  refer  to  a 
similar  condition  in  Southern  Australia. 

Polar  Light. 

We  have  now  treated  fully  of  the  three  elements  of  ter- 
restrial magnetism  in  the  three  principal  types  of  its  mani- 
festation, namely,  Intensity,  Inclination  and  Declination,  in 
reference  to  the  movements  which  depend  upon  geographical 
relations  of  place,  and  diurnal  and  annual  periods.  The  ex- 
traordinary disturbances  which  were  first  observed  in  the  dip, 
are  as  Halley  conjectured,  and  as  Dufay  and  Hibrter  recog- 
nised, in  part  forerunners,  and  in  part  accompaniments  of  the 

99  Sabine,  Magn.  and  Meteor.  Observ.  at  the  Cape  of  Good  Hope,  vol.  i, 
p.  Ix. 

00  In  judging  of  the  approximate  epochs  of  the  crossing  of  the  line  of 
no  variation,  and  in  endeavouring  to  decide  upon  the  claim  of  priority 
in  this  respect,  we  must  bear  in  mind  how  readily  an  error  of  1°  may 
have  been  made  with  the  instruments  and  methods  then  in  use. 

1  Cosmos,  vol.  i,  p.  174. 

2  Euler,  in  the  Mem.  de  I'Acad.  de  Berlin,  1757,  p.  176. 

3  Barlow,  in  the  Phil.  Transact,  for  1833,  pt.  ii,  p.  671.     Great  un- 
certainty prevails  regarding  the  older  magnetic  observations   of  St. 
Petersburg  during  the  first  half  of  the  18th  century.     The  variation 
seems  to  have  been  always  3°  15'  or  3°  30'  from  1726  to  1772  !     Hart- 
eteen,  Magnetismus  der  Erdc,  s.  7,  p.  143. 


Io2  COSMOS. 

magnetic  polar  light.  I  have  already  fully  treated,  in  the 
Picture  of  Nature,  of  the  peculiarities  of  this  luminous  pro- 
cess, which  is  often  so  remarkable  for  the  brilliant  display  of 
colours  with  which  it  is  accompanied ;  and  more  recent  ob- 
servations have  in  general  accorded  with  the  views  which 
I  formerly  expressed.  "  The  Aurora  borealis  has  not  been 
described  merely  as  an  external  cause  of  a  disturbance  in  the 
equilibrium  of  the  distribution  of  terrestrial  magnetism,  but 
rather  as  an  increased  manifestation  of  telluric  activity, 
amounting  even  to  a  luminous  phenomenon,  exhibited  on  the 
one  hand,  by  the  restless  oscillation  of  the  needle,  and  on  the 
other,  by  the  polar  luminosity  of  the  heavens."  The  polar 
light  appears  in  accordance  with  this  view  to  be  a  kind  of 
silent  discharge  or  shock  as  the  termination  of  a  magnetic 
storm,  very  much  in  the  same  manner  as  in  the  electric  shock, 
the  disturbed  equilibrium  of  the  electricity  is  renewed 
by  a  development  of  light  by  lightning,  accompanied  by 
pealing  thunder.  The  reiteration  of  a  definite  hypothesis  in 
the  case  of  a  complicated  and  mysterious  phenomenon  has  at 
all  events  the  advantage  of  giving  rise  with  a  view  to  its 
refutation  to  more  persistent  and  careful  observations  of  the 
individual  processes.4 

Dwelling  only  on  the  purely  objective  description  of  these 
processes,  which  are  mainly  based  upon  the  materials  yielded 
by  the  beautiful  and  unique  series  of  observations,  which  were 
continued  without  intermission  for  eight  months  (1838, 1839), 
— during  the  sojourn  of  the  distinguished  physicists,  Lottin, 
Bravais  and  Siljestrom — in  the  most  northern  parts  of  Scandi- 
navia,8 we  will  first  direct  our  attention  to  the  sty- called  black 
segment  of  the  Aurora,  which  rises  gradually  on  the  horizon 
like  a  dark  wall  of  clouds.6  The  blackness  is  not,  as  Argel- 

4  Cosmos,  vol.  i,  pp.  187 — 199,  and  Dove,,  in  Poggend.  Annalen,  Bd. 
xix,  s.  388. 

5  The  able  narrative  of  Lottin,  Bravais,  Lilliehob'k,  and  Siljestrom, 
who  observed  the  phenomena  of  the  northern  light  from  the  19th  of 
September,  1838,till  the  8th  of  April,  1839,  at  Bossekop  (69°  58' N.  lat.) 
in  Finmark  and  at  Jupvig  (70°  6'  N.  lat.)  was  published  in  the  fourth 
section  of  Voyages  en  Scandinavie,  en  Laponie,  au  Spitzberg  et  aux  Feroes, 
sur  la  Corvette,  la  Recherche  (Aurores  boreales).     To  these  observations 
are  appended  important  results  obtained  by  the  English  superinten- 
dent of  the  copper  mines  at  Kalfiord  (69°  56'  N.  lat.),  pp.  401—435. 

6  See  the  work  above  referred  to  (pp.  437—444)  for  a  description  of 
the  Segment  obscure  de  V  Aware  boreale. 


i'OLAR   LIGHT. 

ander  observes,  a  mere  result  of  contrast,  since  it  is  occasionally 
visible  before  it  is  bounded  by  the  brightly  illuminated  arch. 
It  must  be  a  process  effected  within  some  part  of  the  atmo- 
sphere, for  nothing  has  hitherto  shown  that  the  obscuration 
is  owing  to  any  material  blending.  The  smallest  stars  are 
visible  through  the  telescope  in  this  black  segment,  as  well 
as  in  the  coloured  illuminated  portions  of  the  fully  developed 
Aurora,  In  northern  latitudes,  the  black  segment  is  seen  far 
less  frequently  than  in  more  southern  regions.  It  has  even 
been  found  entirely  absent  in  these  last  named  latitudes  in 
the  months  of  February  and  March,  when  the  Aurora  was 
frequent  in  bright  clear  weather  ;  and  Keilhau  did  not  once 
observe  it  during  the  whole  of  a  winter,  which  he  spent  at 
Talwig  in  Lapland.  Argelander  has  shown  by  accurate  deter- 
mination of  the  altitudes  of  stars,  that  no  part  of  the  polar 
light  exerts  any  influence  on  these  altitudes.  Beyond  the 
segment,  there  appear,  although  rarely,  Hack  rays,  which  Haii- 
steen  and  I  have  often  watched7  during  their  ascent ;  blended 
with  these,  appear  round  Hack  patches,  or  spots,  enclosed  by 
luminous  spaces.  The  latter  phenomena  have  been  made  a 
special  subject  of  investigation  by  Siljestrom.8  The  central 
portion  of  the  corona  of  the  Aurora  (which  owing  to  the 
effect  of  linear  perspective  corresponds  at  its  highest  point 
with  the  magnetic  inclination  of  the  place),  is  also  usually 
of  a  very  deep  black  colour.  Bravais  regards  this  blackness 
and  the  black  rays  as  the  effect  of  optical  illusions  of  con- 
trast. Several  luminous  arches  are  frequently  simultaneously 
present ;  in  some  rare  cases  as  many  as  seven  or  nine  are  seen 

7  Schweigger's   Jahrbuch   der   Chemie   und   Physik,   1826,    Bd.   xvi, 
s.  198,  and  Bd.  xviii,  s.  364.     The  dark  segment  and  the  incontestible 
rising  of  black  rays  or  bands,  in  which  the  luminous  process  is  annihi- 
lated (by  interference?)  reminds  us  of  Quet's  Recherches  sur  V  Electrochimie 
dans  Ic  vide,  and  of  Ruhmkorffs  delicate  experiments,  in  which  in  a 
vacuum  the  positive  metallic  balls  glowed  with  red  light,  while  the  nega- 
tire  balls  showed  a  violet  light,  and  the  strongly  luminous  parallel  strata 
of  rays  were  regularly  separated  from  one  another  by  perfectly  dark 
strata.     "  The  light  which  is  diffused  between  the  terminal  knobs  of  th« 
two  electric  conductors  divides  into  numerous  parallel  bands,  which 
are   separated   by  alternate   obscure    and   perfectly   distinct    strata." 
C'omptes  rendus  de  T  Acad.  des  Sc.  t.  xxxv,  1852,  p.  949. 

8  Voyages  en  Scandinavie  (Aurores  bor.),  p.  558.     On  the  Corona  and 
bands  of  the  northern  light,  see  the  admirable  investigations  of  Bravaie, 
pp.  502—514. 


1 54  COSMOS. 

advancing  towards  the  zenith,  parallel  to  one  another ;  while 
in  other  cases  they  are  altogether  absent.  The  bundles  of 
rays  and  columns  of  light  assume  the  most  varied  forms,  ap- 
pearing either  in  the  shape  of  curves,  wreathed  festoons  and 
hooks,  or  resembling  waving  pennants  or  sails.9 

In  the  higher  latitudes,  "  the  prevailing  colour  of  the  polar 
light  is  usually  white,  while  it  presents  a  milky  hue  when  the 
Aurora  is  of  faint  intensity.  When  the  colours  brighten, 
they  assume  a  yellow  tinge ;  the  middle  of  the  broad  ray  be- 
comes golden  yellow,  while  both  the  edges  are  marked  by 
separate  bands  of  red  and  green.  When  the  radiation  ex- 
tends in  narrow  bands,  the  red  is  seen  above  the  green. 
When  the  Aurora  moves  sideways  from  left  to  right,  or  from 
right  to  left,  the  red  appears  invariably  in  the  direction  to- 
wards which  the  ray  is  advancing,  and  the  green  remains 
behind  it."  It  is  only  in  very  rare  cases  that  either  one  of 
the  complementary  colours,  green  or  red,  has  been  seen  alone. 
Blue  is  never  seen,  while  dark  red,  such  as  is  presented  by 
the  reflection  of  a  great  fire,  is  so  rarely  observed  in  the 
north  that  Siljestrom  noticed  it  only  on  one  occasion.10  The 
luminous,  intensity  of  the  Aurora  never  even  in  Finmark 
quite  equals  that  of  the  full  moon. 

The  probable  connection  which,  according  to  my  views, 
exists  between  the  polar  light  and  the  formation  of  very 
small  and  delicate  fleecy  clouds  (whose  parallel  and  equivalent 
rows  follow  the  direction  of  the  magnetic  meridian),  has  met 
with  many  advocates  in  recent  times.  It  still  remains  a  doubt- 
ful question,  however,11  whether,  as  the  northern  travellers, 
Thienemann  and  Admiral  Wrangel  believe,  these  parallel 
fleecy  clouds  are  the  substratum  of  the  polar  light,  or  whether 

9  Op.  cit.  pp.  35,  37,  45,  67,  481  ("Draperie  ondulante,  flamme  d"un 
navire  de  guerre  deployce  horizontalement  et  agttee  par  le  vent,  crochets, 
fragments  d'arcs  et  de  guirlandes)."  M.  Bevalet,  the  distinguished  artist 
to  the  expedition, has  given  an  interesting  collection  of  the  many  varied 
forms  assumed  by  this  phenomenon. 

10  See  Voy.  en  Scandinavie  (Aur.  boreal.),  pp.  523—528,  557. 

11  Cosmos,  vol  i,  p.  194  ;  see  also,  Franklin,  Narrative  of  a  Journey  to 
the  Shores  of  the  Polar  Sea  in  1819—1822,  p.  597;  and  Kiimtz,  Lehr- 
buch  der  Meteorologie,  Bd.  iii  (1836),  s.  488—490.     The  earliest  conjec- 
tures  advanced  in  relation  to  the  connection  between  the  northern 
light  and  the  formation  of  clouds  are  probably  those  of  Frobesius.  (Sea 
Auroras  borealis  spectacula,  Helrnst,  1739,  p.  139). 


POLAT?    LIGHT.  . 

they  are  not  rather,  as  has  been  conjectured  by  Franklin, 
Richardson,  and  myself,  the  effect  of  a  meteorological  process 
generated  by  and  accompanying  the  magnetic  storm.  The 
regular  coincidence  in  respect  to  direction  between  the  very 
fine  cirrous  clouds  (polar  bands)  and  the  magnetic  declination, 
together  with  the  turning  of  the  points  of  convergence,  were 
made  the  subjects  of  my  most  careful  observation  on  the 
Mexican  plateau  in  1803,  and  in  Northern  Asia  in  1829. 
When  the  last  named  phenomenon  is  complete,  the  two  ap- 
parent points  of  convergence  do  not  remain  stationary,  the 
one  in  the  north-east  and  the  other  in  the  south-west  (in 
the  direction  of  the  line  which  connects  together  the  highest 
points  of  the  arch  of  the  polar  light  which  is  luminous  at 
night),  but  move  by  degrees  towards  the  east  and  west.12 
A  precisely  similar  turning,  or  translation  of  the  line,  which 
in  the  true  Aurora  connects  the  highest  points  of  the  lumi- 
nous arch,  whilst  its  bases  (the  points  of  support  by  which  it 
rests  on  the  horizon)  change  in  the  azimuth  and  move  from 
east-west  towards  north-south,  has  been  several  times  ob- 
served with  much  accuracy  in  Finmark.13  These  clouds  ar- 

12  I  will  give  a  single  example  from  my  M.S.  journal  of  my  Siberian 
journey: — "I  spent  the  whole  of  the  night  of  the  5 — 6th  of  August 
(1829),  separated  from  my  travelling  companions,  in  the  open  air,  at 
the  Cossack  outpost  of  Krasnajazarki,  the  most  eastern  station  on  the 
Irtisch,   on  the  boundary  of  the  Chinese  Dzungarei,  and  hence  a  place 
whose   astronomical   determination    was   of  considerable   importance. 
The  night  was  extremely  clear.     In  the  eastern  sky  polar  bands  of 
cirrous  clouds  were  suddenly  formed  before  midnight  (which  I  have  re- 
corded as   '  de  petits  moutons  eyalement   espaces,   distribute  en  bandes 
parall&les  et polaires)' .    Greatest  altitude  35°.    The  northern  point  of  con- 
vergence is  moving  slowly  toward  the  east.  They  disappear  without  reach- 
ing the  zenith ;  and  a  few  minutes  afterwards,  precisely  similar  cirrous 
bands  are  formed  in  the  north-east ;  which  move  during  a  part  of  the 
night,  and  almost  till  sunrise,  regularly  northward  70°  E.    An  unusually 
large   number   of  falling  stars  and   coloured  rings  round  the   moon 
throughout  the  night.     No  trace  of  a  true  Aurora.     Some  rain  falling 
from   speckled   feathery   masses   of   clouds.     At  noon  on  the  6th  of 
August  the  sky  was  clear,  polar  bands  were  again  formed,  passing  from 
N.N.E.  to  S.S.W.,  where  they  remained  immoveabie,  without  altering 
the  azimuth,  as  I  had  so  often  seen  in  Quito  and  Mexico."     (The  mag- 
netic variation  in  the  Altai  is  easterly.) 

13  Bravais,  who,  contrary  to  my  own  experience,  almost  invariably 
observed  that  the  masses  of  cirroup  clouds  at  Bossekop  were  directed, 
like   the  Aurora   borealis,  at  right  angles  to  the  magnetic  meridian 
(Voyage*  en  Scandinavie,  Phenomene  de  translation  dans  les  pied*  de 


158  COSMOS. 

ranged  in  the  form  of  polar  bands  correspond,  according  to 
the  above  developed  views,  in  respect  to  position,  with  the 
luminous  columns  or  bundles  of  rays  which  ascend  in  the 
true  Aurora  towards  the  zenith  from  the  arch,  which  is 
generally  inclined  in  an  east  and  west  direction ;  and  they 
cannot,  therefore,  be  confounded  with  those  arches  of  which 
one  was  distinctly  seen  by  Parry  in  bright  day-light  after 
the  occurrence  of  a  northern  light.  This  phenomenon  oc- 
curred in  England  on  the  3rd  of  September,  1827,  when 
columns  of  light  were  seen  shooting  up  from  the  luminous 
arch  even  by  day.14 

It  has  frequently  been  asserted  that  a  continuous  evolu- 
tion of  light  prevails  in  the  sky  immediately  around  the 
northern  magnetic  pole.  Bravais,  who  continued  to  prose- 
cute his  observations  uninterruptedly  for  200  nights,  during 
which  he  accurately  described  152  Aurorse,  certainly  asserts 
that  nights,  in  which  no  northern  lights  are  seen,  are  alto- 
gether exceptional,  but  he  has  sometimes  found  even  when  the 
atmosphere  was  perfectly  clear,  and  the  view  of  the  horizon 
was  wholly  uninterrupted,  that  not  a  trace  of  polar  light 
could  be  observed  throughout  the  whole  night,  or  else  that 
the  magnetic  storm  did  not  begin  to  be  apparent  until  a  very 
late  hour.  The  greatest  absolute  number  of  northern  lights 
appears  to  occur  towards  the  close  of  the  month  of  September ; 
and  as  March,  when  compared  with  February  and  April, 
seems  to  exhibit  a  relatively  frequent  occurrence  of  the  phe- 
nomenon, we  are  here  led,  as  in  the  case  of  other  magnetic 
phenomena,  to  conjecture  some  connection  with  the  period 

I'arc  des  Aurores  bore"ales,  pp.  534 — 537),  describes  with  his  accustomed 
exactitude  the  turnings  or  rotations  of  the  true  arch  of  the  Aurora 
borealis,  pp.  27,  92,  122,  487.  Sir  James  Ross  has  likewise  observed  in 
the  southern  hemisphere  similar  progressive  alterations  of  the  arch  of 
the  Aurora  (a  progression  in  the  southern  lights  from  W.N.W. — E.S.E. 
to  N.N.E. — S.S.W.)  Voyage  in  the  Southern  and  Antarctic  Regions,  vol.  i, 
p.  311.  An  absence  of  all  colour  seems  to  be  a  frequent  characteristic 
of  southern  lights,  vol.  i,  p.  266,  vol.  ii,  p.  209.  Regarding  the  absence 
of  the  northern  light  in  some  nights  in  Lapland,  see  Bravais,  Op.  cit. 
p.  545. 

14  Cosmos,  vol.  i,  p.  191.  The  arch  of  the  Aurora  seen  in  bright  day- 
light reminds  us  by  the  intensity  of  its  light  of  the  miclei  and  tails  of 
the  comets  of  1843  and  1847,  which  were  recognised  in  the  immediate 
vicinity  of  the  sun  in  North  America,  Parma,  and  London.  Op.  cit. 
vol.  i,  p.  85,  vol.  iii.  p.  543. 


POLAR   LIGHT.  L57 

of  the  equinoxes.  To  the  northern  lights  which  have  been 
seen  in  Peru,  and  to  the  southern  lights  which  have  been 
visible  in  Scotland,  we  may  add  a  coloured  Aurora,  which 
was  observed  for  more  than  two  hours  continuously  by 
Lafond  in  the  Candide,  on  the  14th  of  January,  1831,  south 
of  New  Holland,  in  latitude  45°.16 

The  accompaniment  of  sound  in  the  Aurora  has  been  as 
definitely  denied  by  the  French  physicists  and  Siljestrom  at 
Bossekop16  as  by  Thienemann,  Parry,  Franklin,  Richardson, 
Wrangel,  and  A.njou.  Bravais  estimated  the  altitude  of  the 
phenomenon  to  be  fully  51307  toises  (or  52  geographical 
miles),  whilst  an  otherwise  very  careful  observer,  Farquhar- 
son,  considers  that  it  scarcely  amounts  to  4000  feet.  The 
data  on  which  all  these  determinations  are  based  are  very 
uncertain,  and  are  rendered  less  trustworthy  by  optical  illu- 
sions, as  well  as  by  erroneous  conjectures  regarding  the  posi- 
tive identity  of  the  luminous  arch  seen  simultaneously  at  two 
remote  points.  There  is,  however,  no  doubt  whatever  of  tli€ 
influence  of  the  northern  light  on  declination,  inclination, 
horizontal  and  total  intensity,  and  consequently  on  all  the 
elements  of  terrestrial  magnetism,  although  this  influence 
is  exerted  very  unequally  in  the  different  phases  of  this  great 
phenomenon,  and  on  the  different  elements  of  the  force. 
The  most  complete  investigations  of  the  subject  were  those 
made  in  Lapland  by  the  able  physicists  Siljestrom  and 
Bravais17  (in  1838 — 1839),  and  the  Canadian  observations  at 
Toronto  (1840 — 1841),  which  have  been  most  ably  dis- 
cussed by  Sabine.18  In  the  preconcerted  simultaneous  ob- 
servations which  were  made  by  us  at  Berlin  (in  the  Men- 
delssohn-Bartholdy  Garden),  at  Freiberg  below  the  surface 
of  the  earth,  at  St.  Petersburgh,  Kasan  and  Nikolajew,  we 
found  that  the  magnetic  variation  was  affected  at  all  these 
places  by  the  Aurora  boreal  is,  which  was  visible  at  Alford  in 
Aberdeenshire  (57°  15'  N.  lat.)  on  the  night  of  the  19-20th 
of  December,  1829.  At  some  of  these  stations,  at  which 

15  Comptes  rendus  de  PAcad.  des  Sciences,  t.  iv,  1837,  p.  589. 
6   Voyages  en  Scandinavie,  en  Laponie,  etc.,  (Awores  boreales,)  p.  559  ; 
and  Martin's  Trad,  de  la  Meteorologie  de  Kaemtz,  p.  460.     In  reference 
to  the  conjectured  elevation  of  the  northern  light,  see  Bravais,  Op.  cit. 
pp.  549,  559. 

V  Op.  cit.  p.  462. 

18  Sabine,  Unusual  Mcynet.  Disturbances,  pt.  i,  pp.  xviii,  xxii,  3,  54. 


16'S  COSMOS. 

the  other  elements  of  terrestrial  magnetism  could  be  noted, 
the  magnetic  intensity  and  inclination  were  affected  no  less 
than  the  variation.19 

D-uring  the  beautiful  Aurora,  which  Professor  Forbes  ob- 
served at  Edinburgh  on  the  21st  of  March,  1833,  the  inclina- 
tion was  strikingly  small  in  the  mines  at  Freiberg,  while  the 
variation  was  so  much  disturbed  that  the  angles  could  scarcely 
be  read  off.  The  decrease  in  the  total  intensity  of  the  mag- 
netic force  which  has  been  observed  to  coincide  with  the  in- 
creasing energy  of  the  luminosity  of  the  northern  light  is  a 
phenomenon  which  is  worthy  of  special  attention.  The  mea- 
surements which  I  made  in  conjunction  with  Oltmanns  at 
Berlin  during  a  brilliant  Aurora  on  the  20th  of  December, 
1806, M  and  which  are  printed  in  Hansteen's  "  Unter- 
suchungen  iiber  den  Magnetismus  der  Erde,"  were  con- 

19  Dove,  in  Poggend.  Ann.  Bd.  xx,  s.  333 — 341.     The  unequal  influ- 
ence which  an  Aurora  exerts  on  the  dipping  needle  at  points  of  the 
earth's  surface,  which  lie  in  very  different  meridians,  may  in  many 
cases  lead  to  the  local  determination  of  the  active  cause,  since  the  mani- 
festation of  the  luminous  magnetic  storm  does  not  by  any  means  always 
originate  in  the  magnetic  pole  itself ;  while,  moreover,  as  A  rgelander 
maintained  and  as  Bravais  has  confirmed,  the  summit  of  the  luminous 
arch  is  in  some  cases  as  much  as  11°  from  the  magnetic  meridian. 

20  "On  the  20th  of  December,  1806,  the  heavens  were  of  an  azure 
blue,  with  not  a  trace  of  clouds.     Towards  10  P.M.  a  reddish-yellow 
luminous  arch  appeared  in  the  N.N.W.,  through  which  I  could  distin- 
guish stars  of  the  7th  magnitude  in  the  night  telescope.     I  found  the 
azimuth  of  this  point  by  means  of  a  Lyrse,  which  was  almost  directly 
under  the  highest  point  of  the  arch.     It  was  somewhat  further  west 
than  the  vertical  plane  of  the  magnetic  variation.     The  Aurora,  which 
was  directed  N.N.W.,  caused  the  north  pole  of  the  needle  to  be  deflected, 
for,  instead  of  progressing  westward  like  the  azimuth  of  the  arch,  the 
needle  moved  back  towards  the  east.     The  changes  in  the  magnetic 
declination,    which    generally   amount   to    from    2'  27"  to  3'  in    the 
nights  of  this  month,  increased  progressively  and  without  any  great 
oscillation  to  26'  28"  during  the  northern  light.     The  variation  was  the 
smallest  about  9h.  12m.  when  the  Aurora  was  the  most  intense.     We 
found  that  the  horizontal  force  amounted  to  1'  37".73  for  21  vibrations 
during  the  continuance  of  the  Aurora,  while  at  9h.  50m:  A.M.,  and  con- 
sequently long  after  the  disappearance  of  the  Aurora,  which  had  en- 
tirely vanished  by  2h.  10m.  A.M.  it  was  1'  37".17  for  the  same  number 
of  vibrations.     The  temperature  of  the  room,  in  which  the  vibrations  of 
the  small  needle  were  measured,  was  in  the  first  case  37°.76  F.  and 
in  the  second  37°.04  F.    The  intensity  was  therefore  slightly  diminished 
during  the  continuance  of  the  northern  light.     The  moon  presented  no 
coloured  rings."     From  my  magnetic  journal,  see  Hansteen,  s.  4d&. 


TERRESTRIAL   MAGNETISM.  159 

firmed  by  Sabine  and  the  French  physicists  in  Lapland  m 
1838.21 

While  in  this  careful  development  of  the  present  condition 
of  our  positive  knowledge  of  the  phenomena  of  terrestrial 
magnetism,  I  have  necessarily  limited  myself  to  a  mere  ob- 
jective representation  of  that  which  did  not  even  admit  of 
being  elucidated  by  merely  theoretical  views,  based  only 
upon  induction  and  analogy  ;  I  have  likewise  purposely  ab- 
stained in  the  present  work  from  entering  into  any  of  those 
^eognostic  hypotheses,  in  which  the  direction  of  extensive 
mountain  chains  and  of  stratified  mountain  masses  is  con- 
sidered in  relation  to  its  dependence  upon  the  direction  of 
magnetic  lines,  more  especially  the  isoclinal  and  isodynamic 
systems.  I  am  far  from  denying  the  influence  of  all  cosmical 
primary  forces — dynamic  and  chemical  forces — as  well  as  of 
magnetic  and  electrical  currents  on  the  formation  of  crystal- 
line rocks  and  the  filling  up  of  veins  ;22  but  owing  to  the 
progressive  movement  of  all  magnetic  lines  and  their  conse- 
quent change  of  form,  their  present  position  can  teach  us 
nothing  in  reference  to  the  direction  in  primeval  ages  of 
mountain  chains,  which  have  been  upheaved  at  very  different 
epochs,  or  to  the  consolidation  of  the  earth's  crust,  from 
which  heat  was  being  radiated  during  the  process  of  its 
hardening. 

Of  a  different  order,  not  referring  generally  to  terrestrial 
magnetism,  but  merely  to  very  partial  local  relations,  are 
those  geognostic  phenomena,  which  have  been  designated  by 
the  name  of  the  magnetism23  of  mountain  masses.  These 
phenomena  engaged  much  of  my  attention  before  my  Ame- 
rican expedition,  at  a  time  when  I  was  occupied  in  examin- 
ing the  magnetic  serpentine  rock  of  the  Haidberg  moun- 
tain in  Franconia  in  1796,  and  then  gave  occasion  in 

21  Sabine,  On  Days  of  Unusual  Magn.  Disturbances,  pt.  i,  p.  xviii. 
"  M.  Bravais  concludes  from  the  observations  made  in  Lapland  that  the 
horizontal  intensity  diminishes  when  the  phenomenon  of  the  Aurora 
borealis  is  at  its  maximum"  (Martins,  p.  461 ). 

**  Delesse,  Stir  1'association  des  mineraux  dans  les  roches  qui  ont 
un  pouvoir  magnetique  eleve,  in  the  Comptes  rendus  de  I'Acad.  dcs  Sc. 
t.  xxxi,  1850,  p.  806;  and  Annales  des  Mines,  4eme  Sfirie,  t.  xv  (1349), 
p.  130. 

-"'  Reich,  Ueber  Gebirys-und  Gcsteins-Magnetismus,  in  Poggend.  A  itn. 
Bd.  Ixvii,  s.  iJj. 


160  COSMOS. 

Germany  to  a  considerable  amount  of  literary  dissension, 
which,  however,  was  of  a  very  harmless  nature.  They  pre- 
sent a  number  of  problems,  which  are  by  no  means  incapable 
of  solution,  but  which  have  been  much  neglected  in  recent 
times,  and  only  very  imperfectly  investigated  both  as  regards 
observation  and  experiment.  The  force  of  this  magnetism 
of  rocks  may  be  tested  for  the  determination  of  the  increase 
of  magnetic  intensity  by  means  of  pendulum  experiments 
and  by  the  deflection  of  the  needle  in  broken  off  fragments  of 
hornblende  and  chloritic  schists,  serpentine,  syenite,  dolerite, 
basalt,  melaphyre  and  trachyte.  We  may  in  this  manner 
decide  by  a  comparison  of  the  specific  gravity,  by  the  rinsing 
of  finely  pulverised  masses,  and  by  the  application  of  the 
microscope,  whether  the  intensity  of  the  polarity  may  not 
depend  in  various  ways  upon  the  relative  position,  rather 
than  upon  the  quantity,  of  the  granules  of  magnetic  iron 
and  protoxide  of  iron,  intermixed  in  the  mass.  More  im- 
portant, however,  in  a  cosmical  point  of  view  is  the  question 
which  I  long  since  suggested  in  reference  to  the  Haidberg 
mountain  ;  whether  there  exist  entire  mountain  ranges,  in 
which  opposite  polarities  are  found  to  occur  on  opposite  de- 
clivities of  the  mass.24  An  accurate  astronomical  determi- 

24  This  question  was  made  the  subject  of  lively  discussion  when,  in 
the  year  1796,  at  the  time  that  I  fulfilled  the  duties  of  superintendent 
of  the  mining  operations  in  the  Fichtelgebirge,  in  Franconia,  I  dis- 
covered the  remarkable  magnetic  serpentine  mountain  (the  Haidberg) 
near  Gefress,  which  had  the  property  at  some  points  of  causing  the 
needle  to  be  deflected  at  a  distance  of  even  23  feet  (Intelligenz-Blatt  der 
Allgem.  Jenaer  Litteratur-Zeitung,  Dec.  1796,  No.  169,  s.  1447,  and 
Mdrz,  1797,  No.  38,  s.  323  —  326;  Gren's  Neues  Journal  der  Physik, 
Ed.  iv,  1797,  s.  136  ;  Annales  de  Chimie,  t.  xxii,  p.  47).  I  had  thought 
that  the  magnetic  axes  of  the  mountain  were  diametrically  opposed  to 
the  terrestrial  poles  ;  but  according  to  the  investigations  of  Bischoff 
and  Goldfuss,  in  1816  (Beschreibung  des  Fichtelgelirges,  Bd.  i,  s.  176),  it 
would  appear  that  they  discovered  magnetic  poles,  which  penetrated 
through  the  Haidberg  and  presented  opposite  poles  on  the  opposite 
declivities  of  the  mountain,  while  the  directions  of  the  axes  were  not 
the  same  as  I  had  given  them.  The  Haidberg  consists  of  dull  green 
serpentine,  which  partially  merges  into  chloritic  and  hornblende  schists. 
At  the  village  of  Voysaco,  in  the  chain  of  the  Andes  of  Pasto,  we  Baw 
the  needle  deflected  by  fragments  of  porphyritic  clay,  while  on  the 
ascent  to  (Jhimboi-azo,  groups  of  columnar  masses  of  trachyte  disturbed 
thp  motion  of  the  needle  at  a  distance  of  three  feet.  It  struck  me  a-i  n 
very  remarkable  fact  that  I  should  have  found  in  the  black  and  red 


MAGNETISM.  161 

nation  of  the  position  of  such  magnetic  axes  of  a  mountain 
would  be  of  the  greatest  interest,  if  it  could  be  ascertained 

obsidians  of  Quinche,  north  of  Quito,  as  well  as  in  the  gray  obsidian  of 
the  Cerro  de  la  Navajas  of  Mexico,  large  fragments  with  distinct  poles. 
The  large  collective  magnetic  mountains  in  the  Ural  chain,  as  Blagodat, 
near  Kuschwa,  Wyssokaja  Gora,  at  Nishne  Tagilsk,  and  Katschkanar, 
near  Nishne  Turinsk,  have  all  broken  forth  from  augitic  or  rather 
uralitic  porphyry.  In  the  great  magnetic  mountain  of  Blagodat,  which 
I  investigated  with  Gustav  Rose,  in  our  Siberian  expedition,  in  1829, 
the  combined  effect  of  the  polarity  of  the  individual  parts  did  not  indeed 
appear  to  have  produced  any  determined  and  recognisable  magnetic  axes. 
In  close' vicinity  to  one  another  lie  irregularly  mixed  opposite  poles.  A 
similar  observation  had  previously  been  made  by  Ennan  (Reise  urn  die 
Erde,  Bd.  i,  a.  362).  On  the  degree  of  intensity  of  the  polar  force  in 
serpentine,  basaltic,  and  trachytic  rock,  compared  with  the  quantity  of 
magnetic  iron  and  protoxide  of  iron,  intermixed  with  these  rocks,  as  well 
as  on  the  influence  of  the  contact  of  the  air  in  developing  polarity,  which 
had  already  been  maintained  by  Gmelin  and  Gibbs,  see  the  numerous  and 
very  admirable  experiments  of  Zaddach,  in  his  Beobachtungen  uber  die 
Magnetische  Polaritdt  des  Basaltes  und  der  Trachytischen  Gestdne,  1851, 
s.  56,  65 — 78,  95.  A  comparison  of  many  basaltic  quarries,  made  with  a 
view  of  ascertaining  the  polarity  of  individual  columns  which  have  stood 
isolated  for  a  long  period,  and  an  examination  of  the  sides  of  these 
columns  which  have  been  recently  brdught  in  contact  with  the  outer  air 
in  consequence  of  the  removal  from  individual  masses  of  a  certain 
depth  of  earth,  have  led  Dr.  Zaddach  to  hazard  the  conjecture  (see  s. 
74,  80)  that  the  polar  property,  which  always  appears  to  be  manifested 
with  the  greatest  intensity  in  rocks  to  which  the  air  has  been  freely  ad- 
mitted, and  which  are  intersected  by  open  fissures,  "  diffuses  itself  from 
without  inwards,  and  generally  from  above  downwards."  Gmelin  ex- 
presses himself  as  follows  in  respect  to  the  great  magnetic  mountain, 
Ulu-utasse-Tau,  in  the  country  of  the  Baschkiri,  near  the  Jaik  : — "  The 
sides  which  are  exposed  to  the  open  air  exhibit  the  most  intense  mag- 
netic force,  while  those  which  lie  under  ground  are  much  weaker" 
(Reise  durch  Siberien,  1740—1743,  Bd.  iv,  s.  345).  My  distinguished 
teacher,  Werner,  in  describing  the  magnetic  iron  of  Sweden,  in  hia 
lectures,  also  spoke  of  "  the  influence  which  contact  with  the  atmo- 
sphere might  have,  although  not  by  means  of  an  increased  oxidation,  in 
rendering  the  polar  and  attracting  force  more  intense."  It  is  asserted 
by  Colonel  Gibbs,  in  reference  to  the  magnetic  iron  mines  at  Succas- 
suny,  in  New  Jersey,  that  "the  ore  raised  from  the  bottom  of  the  mine 
has  no  magnetism  at  first,  but  acquires  it  after  it  has  been  some  time 
exposed  to  the  influence  of  the  atmosphere"  (On  the  connexion  of  Mag- 
netism and  Light,  in  Silliman's  American  Journal  of  Science,  vol.  i,  1819, 
p.  89).  Such  an  assertion  as  this  ought  assuredly  to  stimulate  obser- 
vers to  make  careful  and  exact  investigations !  When  I  drew  attention 
in  the  text  (see  page  160),  to  the  fact  that  it  was  not  only  the  quantity 
of  the  small  particles  of  iron  which  we're  intermixed  in  the  stone,  but 
Mso  their  relative  distribution  (their  position)  which  ac^ed  as  the  19- 
VOL.  V.  M 


162  COSMOS. 

after  considerable  periods  of  time,  that  the  three  variable 
elements  of  the  total  force  of  terrestrial  magnetism  caused 
either  an  alteration  in  the  direction  of  the  axes,  or  that  such 
small  systems  of  magnetic  forces  were  at  least  apparently 
independent  of  these  influences. 


II. 

Reaction  of  the  interior  of  the  Earth  upon  its  surface  ;  mani- 
festing itself : — a.  Merely  dynamically,  by  tremulous  un- 
dulations (earthquakes] ; — b.  By  the  high  temperature  of 
mineral  springs,  and  by  the  difference  of  the  intermixed 
salts  and  gases  (Thermal  springs);  c.  By  the  outbreak  of 
elastic  fluids,  sometimes  accompanied  by  phenomena  of 
spontaneous  ignition  (ffas  and  mud  volcanoes,  burning 
naphtha  springs,  Salses)  ;  d.  By  the  grand  and  mighty 
actions  of  true  volcanoes,  which  (when  they  have  a  perma- 
nent connexion  with  the  atmosphere  by  fissures  and  craters) 
throw  up  fused  earth  from  the  depths  of  the  interior,  partly 
only  in  the  form  of  red-hot  cinders,  but  partly  submitted  to 
varying  processes  of  crystalline  rock  formation,  poured  out 
in  long,  narrow  streams. 

In  order  to  maintain,  in  accordance  with  the  fundamental 
plan  of  this  work,  the  co-ordination  of  telluric  phenomena 

sultant  upon  the  intensity  of  the  polar  force,  I  considered  the  small 
particles  to  be  so  many  small  magnets.  Seethe  new  vieAvs regarding  this 
subject  in  a  treatise  by  Melloui,  read  by  that  distinguished  physicist 
before  the  Royal  Academy  at  Naples,  in  the  month  of  January,  1853 
(Esperienze  intorno  al  Magnetisms  delle  Rocche,  Mem.  i,  Sulla  Polarita). 
The  popular  notion  which  has  been  so  long  current,  more  especially  on 
the  shores  of  the  Mediterranean,  that  if  a  magnetic  rod  be  rubbed  with 
an  onion,  or  brought  in  contact  with  the  emanations  of  the  plant,  the 
directive  force  will  be  diminished,  while  a  compass  thus  treated  would 
mislead  the  steersman,  is  mentioned  in  Prodi  Diadoclii  Paraphrases 
Ptolem.  libriiv.  deSideruma/ectionibus,  1635,  p.  20  (Delambre,  Hist.de 
I' Astronomic  Ancitnne,  t.  ii,  p.  545).  It  is  difficult  to  conceive  what 
could  have  given  occasion  to  so  singular  a  popular  error. 


VULCANIC  ITY.  163 

— the  co-operation  of  a  single  system  of  impelling  forces — 
in  the  descriptive  representation,  we  must  here  remind  the 
reader,  how,  starting  from  the  general  pr  -perties  of  matter, 
and  the  three  principal  directions  of  its  activity  (attraction, 
vibrations  producing  light  and  heat,  and  electro-magnetic  pro- 
cesses], we  have  in  the  first  section  taken  into  consideration 
the  size,  form,  and  density  of  our  planet,  its  internal  dif- 
fusion of  heat  and  of  magnetism,  in  their  effects  of  intensity, 
dip,  and  variation,  changing  in  accordance  with  definite 
laws.  The  directions  of  the  activity  of  matter  just  mentioned 
are  nearly  allied  *  manifestations  of  one  and  the  same  primi- 
tive force.  They  occur  in  a  condition  of  the  greatest  inde- 
pendence of  all  differences  of  matter,  in  gravitation  and 
molecular  attraction.  We  have  at  the  same  time  represented 
our  planet  in  its  cosmical  relation  to  the  central  body  oi  its 
system ;  because  the  internal  primitive  heat,  which  is  pro- 
bably produced  by  the  condensation  of  a  rotating  nebular 
ring,  is  modified  by  the  action  of  the  sun  (Insolation).  With 
the  same  view,  the  periodical  action  of  the  solar  spots  (that 
is  to  say,  the  frequency  or  rarity  of  the  apertures  in  the 
solar  envelopes)  upon  terrestrial  magnetism,  has  been  referred 
to,  in  accordance  with  the  most  recent  hypotheses. 

The  second  section  of  this  volume  is  devoted  to  the 
entirety  of  those  telluric  phenomena  which  are  to  be 
ascribed  to  the  constantly  active  reaction  of  the  interior  oj 
the  earth  upon  its  surface?  To  this  entirety  I  give  the 
general  name  of  Vulcanism  or  Vulcanicity ;  and  I  regard  it 
as  advantageous  to  avoid  the  separation  of  that  which  is 
causally  connected  and  differs  only  in  the  strength  of  the 
manifestation  of  force  and  the  complication  of  physical  pro- 
cesses. By  taking  this  general  view,  small  and  apparently 
unimportant  phenomena  acquire  a  greater  significance. 
The  unscientific  observer  who  comes  for  the  first  time 
upon  the  basin  of  a  thermal  spring  and  sees  gases  cap- 
able of  extinguishing  light  rising  in  it,  or  who  wanders 
amongst  rows  of  changeable  cones  of  mud  volcanoes,  scarcely 
exceeding  himself  in  height,  never  dreams  that  in  the  calm 
space  occupied  by  the  latter,  eruptions  of  fire  to  the  he'ght 
of  many  thousand  feet  have  often  taken  place ;  and  that  one 

1  Cosmos,  vol.  iii,  p.  39. 

2  Cotmos,  vol.  i,  p.  197 — 199, 


164  COSMOS. 

and  the  same  internal  force  produces  colossal  craters  of  eleva- 
tion, nay  even  the  mighty,  desolating,  lava-pouring  volcanoes 
of  Etna  and  the  Peak  of  Teyde,  and  the  cinder-erupting 
Cotopaxi  and  Tunguragua. 

Amongst  the  multifarious, mutually  intensifying,  phenomena 
of  the  reaction  of  the  interior  of  the  earth  upon  its  external 
crust,  I  first  of  all  separate  those,  the  essential  character  of 
which  is  purely  dynamical,  namely,  that  of  movement  or  tre- 
mulous undulations  in  the  solid  strata  of  the  earth  ;  a  volcanic 
activity  which  is  not  necessarily  accompanied  by  any  chemical 
changes  of  matter,  or  by  the  expulsion  or  production  of  any- 
thing of  a  material  nature.  In  the  other  phenomena  of  the 
reaction  of  the  interior  upon  the  exterior  of  the  earth  : — in 
gas  and  mud  volcanoes,  burning  springs  and  salses,  and  in 
the  large  burning  mountains  to  which  the  name  of  volcano 
was  first,  and  for  a  long  time  exclusively,  applied,  the 
production  of  something  of  a  material  nature  (gaseous  or 
solid),  and  processes  of  decomposition  and  gas-evolution, 
such  as  the  formation  of  rocks  from  particles  arranged  in  a 
crystalline  form,  are  never  wanting.  When  most  fully  gene- 
ralized, these  are  the  distinctive  characters  of  the  volcanic 
vital  activity  of  our  planet.  In  so  far  as  this  activity  is  to 
be  ascribed  in  great  measure  to  the  high  temperature  of  the 
innermost  strata  of  the  earth,  it  becomes  probable  that  all 
cosmical  bodies  which  have  become  conglomerated  with  an 
enormous  evolution  of  heat,  and  passed  from  a  state  of  vapour 
to  a  solid  condition,  must  present  analogous  phenomena.  The 
little  that  we  know  of  the  form  of  the  moon's  surface,  ap- 
pears to  indicate  this.3 — Upheaval  and  plastic  activity  in 
the  production  of  crystalline  rock  from  a  fused  mass,  are 
conceivable  even  in  a  sphere  which  is  regarded  as  destitute 
of  both  air  and  water. 

The  genetic  connexion  of  the  classes  of  volcanic  pheno- 
mena here  referred  to  is  indicated  by  the  numerous  traces 
of  the  simultaneousness  of  the  simpler  and  weaker  with 
stronger  and  more  complex  effects,  and  the  accompanying 
transitions  of  the  one  into  the  other.  The  arrangement  of 
the  materials  in  the  representation  selected  by  me  is  justified 
by  such  a  consideration.  The  increased  magnetic  activity 
of  our  planet,  the  seat  of  which,  however,  is  not  to  be  sought 
3  Cosmos,  vol.  iii,  p.  44;  iv,  pp.  426,  491,  495—498. 


EARTHQUAKES.  165 

in  the  fused  mass  of  the  interior  (even  though,  according  to 
Lenz  and  Kiess,  iron,  in  the  fused  state,  may  be  capable  of 
conducting  an  electrical  or  galvanic  current),  produces  evolu- 
tion of  light  in  the  magnetic  poles  of  the  earth,  or  at  least 
usually  in  their  vicinity.  We  concluded  the  first  section  of 
the  volume  on  telluric  phenomena  with  the  luminosity  of  the 
earth.  This  phenomenon  of  a  luminous  vibration  of  the  ether 
by  magnetic  forces  is  immediately  followed  by  that  class  of 
volcanic  agencies,  which,  in  their  essential  nature,  act  purely 
dynamically,  exactly  like  the  magnetic  force : — causing  move- 
ment and  vibrations  in  the  solid  ground,  but  neither  produc- 
ing nor  changing  anything  of  a  material  nature.  Secondary 
and  unessential  phenomena  (the  ascent  of  flames  during  the 
earthquake,  and  eruptions  of  water  and  evolutions  of  gas* 
following  it)  remind  one  of  the  action  of  thermal  springs  and 
salses.  Eruptions  of  flame,  visible  at  a  distance  of  many 
miles,  and  masses  of  rock,  torn  from  their  deep  seats  and 
hurled  about,6  are  presented  by  the  salses,  which  thus,  as  it 
were,  prepare  us  for  the  magnificent  phenomena  of  the  true 
volcanoes;  which  again,  between  their  distant  epochs  of  erup- 
tion, like  the  salses,  only  exhale  aqueous  vapour  and  gases 
from  their  fissures.  So  remarkable  and  instructive  are  the 
analogies  which  are  presented  in  various  stages  by  the  grada- 
tions of  vulcanism. 

a.  Earthquakes. 

(Amplification  of  the  Picture  of  .Nature. 
Cosmos,  vol.  i.  pp.  199—213). 

Since  the  appearance  in  the  first  volume  of  this  work 
(1845)  of  the  general  representation  of  the  phenomena  of 
earthquakes,  the  obscurity,  in  which  the  seat  and  causes  of 
these  phenomena  are  involved,  has  but  little  diminished  ; 
but  the  excellent  works6  of  Mallet  (1846)  and  Hopkins 
(1847)  have  thrown  some  light  upon  the  nature  of  concussions, 
the  connection  of  apparently  distinct  effects  and  the  separa- 

4  Cosmos,  vol.  i,  p.  214. 

6  Cosmos,  vol.  i,  p.  222.  Compare  Bertrand-Geslin,  "  Sur  les  roches 
lancges  par  le  Volcan  de  bouedu  Monte  Zibio  pres  du  bourg  de  Sassuolo," 
in  Humboldt,  Voyage  aux  Regions  Equinoxiales  du  Nouveau  Continent 
(Relation  ffistorique),  t.  iii,  p.  566. 

'Robert  Mallet,  in  the  Transactions  of  the  Royal  Irish  Academy , 
vol.  xxi  (1848),  pp.  51—113,  and  First  Report  on  the  Facts  of  Earth- 
quake Phenomena,  in  the  Report  of  the  Meeting  of  the  British  A  ssociatior^ 


166  COSMOS. 

tion  of  chemical  and  physical  processes,  which  may  accom- 
pany it  or  occur  simultaneously  with  it.  Here,  as  elsewhere, 
a  mathematical  mode  of  treatment,  such  as  that  adopted  by 
Poisson,  may  have  a  beneficial  effect.  The  analogies  between 
the  oscillations  of  solid  bodies  and  the  sound-waves  in  the 
ordinary  atmosphere  to  which  Thomas  Young7  had  already 
called  attention,  are  peculiarly  adapted  to  lead  to  simpler 
and  more  satisfactory  views,  in  theoretical  considerations 
upon  the  dynamics  of  earthquakes. 

Displacement,  commotion,  elevation,  and  formation  of  fissures 
indicate  the  essential  character  of  the  phenomenon.  We 
have  to  distinguish  the  efficient  force,  which,  as  the  impulse, 
gives  rise  to  the  vibration  ;  and  the  nature,  propagation,  in- 
crease or  diminution  of  the  commotion.  In  tiie  Picture  of 
Nature  I  have  described  what  is  especially  manifested  to  the 
senses ;  what  I  had  myself  the  opportunity  of  observing  for 
so  many  years  on  the  sea,  on  the  sea-bottom  of  the  plains 
(Llanos),  and  at  elevations  of  eight  to  fifteen  thousand  feet ; 
on  the  margin  of  the  craters  of  active  volcanos,  and  in  re- 
gions of  granite  and  mica  schist,  twelve  hundred  geographical 
miles  from  any  eruptions  of  fire  \  in  districts  where  at  cer- 
tain periods  the  inhabitants  take  no  more  notice  of  the  num- 
ber of  earthquakes,  than  we  in  Europe  of  that  of  the  showers 
of  rain,  and  where  Bonpland  and  I  were  compelled  to  dis- 
mount, from  the  restiveness  of  our  mules,  because  the  earth 
shook  in  a  forest  for  15  to  18  minutes  without  intermission. 
By  such  long  custom,  as  Boussingault  subsequently  expe- 
rienced even  in  a  still  higher  degree,  one  becomes  fitted  for 
quiet  and  careful  observation,  and  also  for  collecting  varying 
evidence  with  critical  care  on  the  spot,  nay,  even  for  ex- 
amining under  what  conditions  the  mighty  changes  of  the 
surface  of  the  earth,  the  fresh  traces  of  which  one  recognises, 
have  taken  place.  Although  five  years  had  already  elapsed 

]  850,  pp.  1 — 89  ;   also  Manual  of  Scientific  Inquiry  for  the  Use  of  the 
British  Navy,  1849,  pp.  196 — 223.     William  Hopkins,  On  the  Geological 
Theories  of  Elevation  and  Earthquakes,  in  the  Report  of  the  British  Asso~ 
ciation  for  1847,  pp.  33 — 92.     The  rigorous  criticism  to  which  Mr. 
Mallet  has  subjected  my  previous  work  in  his  very  valuable  memoirs 
(Irish  Transactions,  pp.  99 — 101,  and  Meeting  of  the  British  Association 
at  Edinburgh,  p.  209),  has  been  repeatedly  made  use  of  by  me. 
7  Thomas  Young,   Lectures  on  Natural  Philosophy,    1807,  vol.  f, 
717. 


EARTHQUAKES.  167 

since  the  terrible  earthquake  of  Riobamba,  which,  on  the 
4th  ot  February,  1797,  destroyed  upwards  of  30,000  people  in 
a  few  minutes,8  we  nevertheless  saw  the  formerly  advancing 
cone  of  the  Moya9  which  rose  out  of  the  earth,  and  witnessed 
the  employment  of  this  combustible  substance  for  cooking  in 
che  huts  of  the  Indians.  I  might  describe  the  results  of  alte- 
rations of  the  ground  from  this  catastrophe,  which,  although 
on  a  larger  scale,  were  exactly  analogous  to  those  presented 
by  the  famous  earthquake  of  Calabria  (February  1783), 
and  were  long  considered  to  have  been  represented  ia  an 
incorrect  and  exaggerated  manner,  because  they  could  not 
be  explained  in  accordance  with  hastily  formed  theories. 

By  carefully  separating,  as  we  have  already  indicated,  the 
investigation  of  that  which  gives  the  impulse  to  the  vibra- 
tion, from  that  of  the  nature  and  propagation  of  the  waves 
of  commotion,  we  distinguish  two  classes  of  problems  of  very 
unequal  accessibility.  The  former,  in  the  present  state  of 
our  knowledge,  can  lead  to  no  generally  satisfactory  results, 
as  is  the  case  with  so  many  problems  in  which  we  wish  to 
ascend  to  primary  causes.  Nevertheless,  whilst  we  are  en- 
deavouring to  discover  laws  in  that  which  is  submitted  to 
actual  observation,  it  is  of  great  cosmical  interest  that  we 
should  bear  constantly  in  mind  the  various  genetic  explana- 
tions which  have  hitherto  been  put  forward  as  probable. 
As  with  all  vulcanicity,  the  greater  part  of  these  refer, 
under  various  modifications,  to  the  high  temperature  and 
chemical  nature  of  the  fused  interior  of  the  earth  ;  one  of  the 
most  recent  explanations  of  earthquakes  in  trachytic  regions, 
is  the  result  of  geognostic  suppositions  regarding  the  want  of 
cohesion  in  rocky  masses  raised  by  volcanic  action.  The  fol- 
lowing summary  furnishes  a  more  exact  but  very  brief  indi- 
cation of  the  variety  of  views  as  to  the  nature  of  the  first 
je  to  the  commotion  : — 


The  nucleus  of  the  earth  is  supposed  to  be  in  a  state  of 
igneous  fluidity,  as  the  consequence  of  every  planetary 
process  of  formation  from  a  gaseous  material,  by  evolution 

8  I  follow  the  statistical  account  communicated  to  me  by  the  Corre- 
gidoi-  of  Tacunga  in  1802.      It  rose  to  a  loss  of  30,000—34,000  people, 
but  some  twenty  years  later  the  number  of  those  killed  immediately 
was  reduced  by  about  one-third. 

9  CVwnuw,  voL  i,  p.  209,  Bohn's  edition. 


168  COSMOS. 

of  heat  during  the  transition  from  fluidity  to  solidity. 
The  external  strata  were  first  cooled  by  radiation,  and 
were  the  first  to  become  consolidated.  The  commotion  is 
occasioned  by  an  unequal  ascent  of  elastic  vapours  formed 
(at  the  limit  between  the  fluid  and  solid  parts)  either  from 
the  fused  terrestrial  mass  alone,  or  from  the  penetration 
of  sea-water  into  higher  strata  of  rock,  nearer  to  the  sur- 
face of  the  earth,  the  sudden  opening  of  fissures,  and  by 
the  sudden  ascent  of  vapours  produced  in  the  hotter  and 
consequently  more  elastic  depths.  The  attraction  of  the 
moon  and  sun10  on  the  fluid,  fused  surface  of  the  nucleus 

10  Hopkins  has  expressed  doubts  as  to  the  action  upon  the  fused 
"  subjacent  fluid  confined  into  internal  lakes,"  at  the  Meeting  of  the 
British  Association  for  1847  (p.  57),  as  Mallet  has  also  done  with  regard 
to  "the  subterraneous  lava  tidal  wave,  moving  the  solid  crust  above  it," 
at  the  British  Association  Meeting  for  1850  (p.  20).  Poisson  also,  with 
whom  I  have  often  spoken  regarding  the  hypothesis  of  the  subterranean 
ebb  and  flow,  caused  by  the  sun  and  moon,  considers  the  impulse, 
which  he  does  not  deny,  to  be  inconsiderable,  "  as  in  the  open  sea  the 
effect  scarcely  amounts  to  14  inches."  Ampere,  on  the  other  hand, 
says  : — "  Those  who  admit  the  fluidity  of  the  internal  nucleus  of  the 
earth,  do  not  appear  to  have  sufficiently  considered  the  action  which 
would  be  exercised  by  the  moon  upon  this  enormous  liquid  mass ;  an 
action  from  which  would  result  tides  analogous  to  those  of  our  seas, 
but  far  more  terrible,  both  from  their  extent  and  from  the  density  of 
the  liquid.  It  is  difficult  to  .conceive  how  the  envelope  of  the  earth 
should  be  able  to  resist  the  incessant  action  of  a  sort  of  hydraulic 
ram(?)  of  1400  leagues  in  length"  (Ampere,  Theorie  de  la  Terre,  in  Revue 
des  deux  Mondes,  July,  1833,  p.  148).  If  the  interior  of  the  earth  be 
fluid,  which  in  general  cannot  be  doubted,  as,  notwithstanding  the 
enormous  pressure,  the  particles  are  still  displaceable,  then  the  same 
conditions  are  fulfilled  in  the  interior  of  the  earth  that  give  rise  on  the 
surface  to  the  ocean  tides;  and  the  tide-producing  force  will  con- 
stantly become  weaker  in  approaching  the  centre,  as  the  difference  of 
the  distances  of  every  two  opposite  points,  considered  in  their  relation 
to  the  attracting  bodies,  constantly  becomes  less  in  receding  from  the 
surface,  and  the  force  depends  exclusively  upon  the  difference  of  the 
distances.  If  the  solid  crust  of  the  earth  opposes  a  resistance  to  this 
effort,  the  interior  of  the  earth  will  only  exert  a  pressure  against  its 
crust  at  these  points ;  as  my  astronomical  friend,  Dr.  Brunnow,  ex- 
presses himself,  no  more  tide  will  be  produced  than  if  the  ocean  had  an 
indestructible  covering  of  ice.  The  thickness  of  the  solid  unf  used  crust 
of  the  earth  Is  calculated  from  the  fusing  points  of  the  different  kinds 
of  rock,  and  the  law  of  the  increase  of  heat  from  the  surface  into  the 
depths  of  the  earth.  I  have  already  (Cosmos,  vol.  i,  p.  26),  justified 
the  assumption  that,  at  somewhat  more  than  twenty  geographical 


EARTHQUAKES.  1 69 

of  the  earth,  may  also  be  regarded  as  the  subsidiary  action 
of  a  non -telluric  cause,  by  which  an  increased  pressure  must 
be  produced,  either  immediately  against  a  solid,  superim- 
posed rocky  arch ;  or  indirectly,  when  the  solid  mass  is 
separator!,  in  subterranean  basins,  from  the  fused,  fluid 
mass  by  elastic  vapours. 

The  nucleus  of  our  planet  is  supposed  to  consist  of  un- 
oxidised  masses,  the  metalloids  of  the  alkalies  and  earths. 
Volcanic  activity  is  excited  in  the  nucleus  by  the  access 
of  water  and  air.  Volcanoes  certainly  pour  forth  a  great 
quantity  of  aqueous  vapour  into  the  atmosphere  ;  but  the 
assumption  of  the  penetration  of  water  into  the  volcanic 
focus  is  attended  with  much  difficulty,  considering  the 
opposing  pressure11  of  the  external  column  of  water  and 

miles  (21T6Q,  25  English)  below  the  surface,  a  heat  capable  of  melting 
granite  prevails.  Nearly  the  same  number  (45,000  metres=24  geo- 
graphical miles)  was  named  by  Elie  de  Beaumont  (Geologic,  edited  by 
Vogt,  1846,  vol.  i,  p.  32),  as  the  thickness  of  the  solid  crust  of  the 
earth.  Moreover,  according  to  the  ingenious  experiments  of  Bischot 
on  the  fusion  of  various  minerals,  of  which  the  importance  to  the  pro- 
gress of  geology  is  so  great,  the  thickness  of  the  unfused  strata  of  the 
earth  is  between  122,590  and  136,448  feet,  or  on  the  average  21-i  geo- 
graphical (24 g  English)  miles;  see  Bischof,  Warmelehre  des  Innern unsers 
Erdkorpers,  pp.  286  and  271.  This  renders  it  the  more  remarkable  to 
me  to  find  that,  with  the  assumption  of  a  definite  limit  between  the 
solid  and  fused  parts,  and  not  of  a  gradual  transition,  Hopkins,  from 
the  fundamental  principles  of  his  speculative  geology,  establishes  the 
result  that  "  the  thickness  of  the  solid  shell  cannot  be  less  than  about 
one-fourth  or  one-fifth(?)  of  the  radius  of  its  external  surface"  (Meeting 
of  British  Association,  1847 ',  p.  51).  Cordier's  earliest  supposition  was 
only  56  geographical  (72  English)  miles,  without  correction,  which  is 
dependent  upon  the  increased  pressure  of  the  strata  at  great  depths, 
and  the  hypsqmetrical  form  of  the  surface.  The  thickness  of  the  solid 
part  of  the  crust  of  the  earth  is  probably  very  unequal. 

11  Gay  Lussac,  Reflexions  sur  les  Volcans,  in  the  Annales  de  Chimie  et 
de  Physique,  tome  xxii,  1823,  pp.  418  and  426.  The  author,  who,  in 
company  with  Leopold  von  Buch  and  myself,  observed  the  great  erup- 
tion of  lava  from  Vesuvius  in  September,  1805,  has  the  merit  of  having 
submitted  the  chemical  hypotheses  to  a  strict  criticism.  He  seeks  for 
the  cause  of  volcanic  phenomena  in  a  "very  energetic  and  still  unsatis- 
fied affinity  between  the  substances,  which  a  fortuitous  contact  permits 
them  to  obey  ;"  in  general  he  favours  the  hypothesis  of  Davy  and 
Ampere,  which  is  now  given  up,  "  supposing  that  the  radicals  of  silica, 
alumina,  lime,  and  iron  are  combined  with  chlorine  in  the  interior  of 
the  earth ,"  and  the  penetration  of  sea  water  does  not  appear  to  him  to 
be  improbable  unde^  certain  conditions  (pp.  419,  420,  423,  and  42t>), 


170  COSMOS. 

of  the  internal  lava  ;  and  the  deficiency,  or,  at  all  events, 
very  rare  occurrence  of  burning  hydrogen  gas  during  the 
eruption,  (which  the  formation  of  hydrochloric  acid,la 
ammonia,  and  sulphuretted  hydrogen,  certainly  does  not 
sufficiently  replace)  has  led  the  celebrated  originator  of 
this  hypothesis  to  abandon  it  of  his  own  accord.13 

According  to  a  third  view,  that  of  the  highly  endowed 
South  American  traveller,  Boussingault,  a  deficiency  of 
coherence  in  the  trachytic  and  dolentic  masses  which  form 
the  elevated  volcanoes  of  the  chain  of  the  Andes,  is  re- 
garded as  a  primary  cause  of  many  earthquakes  of  very 
great  extent.  The  colossal  cones  and  dome-like  summits 
of  the  Cordilleras,  according  to  this  view,  have  by  no 
means  been  elevated  in  a  soft  and  semifluid  state,  but 
have  been  thrown  up  and  piled  on  one  another  when 
fectly  hardened,  in  the  form  of  enormous,  shai 
fragments.  In  an  elevation  and  piling  of  this  description, 
large  interstices  and  cavities  have  necessarily  been  pro- 
duced ;  so  that  by  sudden  sinking,  and  by  the  fall  of  solid 
masses  which  are  too  weakly  supported,  shocks  are  pro- 
duced.14 

Upon  the  difficulty  of  a  theory  founded  upon  the  penetration  of  water, 
Bee  Hopkins,  Brit.  Assoc.  Rep.  1847,  p.  38. 

12  According  to  the  beautiful  analyses  made  by  Boussingault,  on  the 
margins  of  five  craters  (Tolima,  Purace,  Pasto,  Tuqueras,  and  Cumbal), 
hydrochloric  acid  is  entirely  wanting  in  the  vapours  poured  forth  by 
the  South  American  volcanoes,  but  not  in  those  of  Italy  (Annales  de 
Chimie,  tome  lii,  1833,  pp.  7  and  23). 

13  Cosmos,  vol.  i,  p.  234,  Boon's  edition.     Whilst  Davy,  in  the  most 
distinct  manner,  gave  up  the  opinion  that  volcanic  eruptions  are  a  con- 
sequence of  the  contact  of  the  metalloid  bases  with  water  and  air,  he 
still  asserted  that  the  presence  of  oxidizable  metalloids  in  the  interior 
of  the  earth  might  be  a  co-operating  cause  in  volcanic  processes  already 
commenced. 

14  Boussingault  says  : — "  I  attribute  most  of  the  earthquakes  in  the 
Cordillera  of  the  Andes  to  falls  produced  in  the  intei-ior  of  these  moun- 
tains by  the  subsidence  which  takes  place,  arid  which  is  a  consequence  of 
their  elevation.      The  mass  which  constitutes  these  gigantic  ridges  has 
not  been  raised  in  a  soft  state  ;  the  elevation  did  not  take  place  until 
after  the  solidification  of  the  rocks.     I  assume,  therefore,  that  the  ele- 
vated masses  ot  the  Andes  are  composed  of  fragments  heaped  upon  each 
other.     The  consolidation  of  the  fragments  could  not  be  so  stable  from 
the  beginning  as  that  there  should  be  no  settlements  after  the  elevation, 
or  that  there  should  be  no  interior  movements  in  the   fragmentary 
masses"  (Boussingault,  /Siw  les  TremUcmcm  de  Terre  des  Andes,  in 


EARTHQUAKES.  171 

The  effects  oftJie  impulse,  the  waves  of  commotion,  may  be 
reduced  to  simple  mechanical  theories  with  more  distinctness 
than  is  furnished  by  the  consideration  of  the  nature  of  the 
first  impulse,  which  indeed  may  be  regarded  as  heterogeneous. 
As  already  observed,  this  part  of  our  knowledge  has  advanced 
essentially  in  very  recent  times.  The  earth-waves  have  been 
represented  in  their  progress  and  their  propagation  through 
rocks  of  different  density  and  elasticity  ;15  the  causes  of  the 
rapidity  of  propagation,  and  its  diminution  by  the  refrac- 
tion, reflection,  and  interference™  of  the  oscillations  have  been 

Annales  de  Chimie  et  de  Physique,  tome  Iviii,  1835,  pp.  84—86).  In 
the  description  of  his  memorable  ascent  of  Chimborazo  (Ascension  au 
Ckimborazo  le  16  Dec.  1831,  loc.  cit.  p.  176),  he  says  again:— "Like 
Cotopaxi,  Antisana,  Tunguragua,  and  the  volcanoes  in  general  which  pro- 
ject from  the  plateaux  of  the  Andes,  the  mass  of  Chimborazo  is  formed 
by  the  accumulation  of  trachytic  debris,  heaped  together  without  any 
order.  These  fragments,  often  of  enormous  volume,  have  been  elevated 
in  the  solid  state  by  elastic  fluids  which  have  broken  out  through  the 
points  of  least  resistance  ;  their  angles  are  always  sharp."  The  cause 
of  earthquakes  here  indicated  is  the  same  as  that  which  Hopkins  calls 
"  a  shock  produced  by  the  falling  of  the  roof  of  a  subterranean  cavity," 
in  his  "Analytical  Theory  of  Volcanic  Phenomena"  (Brit.  Assoc.  Report, 
1847,  p.  82). 

15  Mallet,  Dynamics  of  Earthquakes,  pp.  74,  80,  and  82  ;  Hopkins, 
Brit.  Assoc.  Report,  1847,  pp.  74—82.     All  that  we  know  of  the  waves 
of  commotion  and  oscillations  in  solid  bodies  shows  the  untenability  of 
the  older  theories  as  to  the  facilitation  of  the  propagation  of  the  move- 
ment by  a  series  of  cavities.     Cavities  can  only  act  a  secondary  part  in 
the  earthquake,  as  spaces  for  the  accumulation  of  vapours  and  con- 
densed gases.     "  The  earth,  so  many  centuries  old,"  says  Gay  Lussac 
very  beautifully  (Ann.  de  Chimie  et  de  Phys.  tome  xxii,  1823,  p.  428), 
"  still  preserves  an  internal  force,  which  raises  mountains  (in  the  oxi- 
dized crust),  overturns  cities  and  agitates  the  entire  mass.    Most  moun- 
tains, in  issuing  from  the  bosom  of  the  earth,  must  have  left  vast  cavi- 
ties, which  have  remained  empty,  at  least  unless  they  have  been  filled 
with  water  (and  gaseous  fluids).     It  is  certainly  incorrect  for  Deluc  an<? 
many  geologists  to  make  use  of  these  empty  spaces,  which  they  imaghu 
produced  into  long  galleries,  for  the  propagation  of  earthquakes  to  a 
distance.     These  phenomena,  so  grand  and  terrible,  are  very  powerful 
sonoro\is  waves,  excited  in  the  solid  mass  of  the  earth  by  some  commo- 
tion, which  propagates  itself  therein  with  the  same  velocity  as  sound. 
The  movement  of  a  carriage  over  the  pavement  shakes  the  vastest  edi- 
fices, and  communicates  itself  through  considerable  masses,  as  in  the 
deep  quarries  below  the  city  of  Paris." 

16  Upon  phenomena  of  interference  in  the  earth-waves,  analogous  to 
those  of  the  waves  of  sound,  see  Cosmos,  vol.  i,  p.  211,  Bohn'a  edition, 
and  Humboldt,  Kleinere  Schriften,  Bd.  i.  p.  379. 


172  COSMOS 

mathematically  investigated.  Attempts  have  been  made  to 
reduce  to  a  rectilineal*17  standard  the  apparently  circling 
(rotatory)  shocks  of  which  the  obelisks  before  the  monastery 
of  San  Bruno,  in  the  small  town  of  Stephano  del  Bosco 
(Calabria,  1783),  furnished  such  a  well-known  example.  Air, 
water,  and  earth-waves  follow  the  same  laws  which  are  re- 
cognized by  the  theory  of  motion,  at  all  events  in  space  ;  but 
the  earth-waves  are  accompanied,  in  their  destructive  action, 
by  phenomena  which  remain  more  obscure  in  their  nature 
and  belong  to  the  class  of  physical  processes,  As  such  we  have 
to  mention, — discharges  of  elastic  vapours,  and  of  gases; 
or,  as  in  the  small,  moving  Moya-cones  of  Pelileo,  grit-like 
mixtures  of  pyroxene  crystals,  carbon,  and  infusorial  animal- 
cules with  silicious  shields.  These  wandering  cones  have 
overthrown  a  great  number  of  Indian  huts.18 

In  the  general  Delineation  of  Nature  many  facts  are 
narrated  concerning  the  great  catastrophe  of  Riobamba  (4th 
of  February,  1797),  which  were  collected  on  the  spot  from 
the  lips  of  the  survivors,  with  the  most  earnest  endeavours 
after  historic  truth.  Some  of  them  are  analogous  to  the 
occurrences  in  the  great  earthquake  of  Calabria  in  the  year 
1783  ;  others  are  new,  and  especially  characterized  l>y  the 
mine-like  manifestation  of  force  from  below  upwards.  The 
earthquake  itself  was  neither  accompanied  nor  announced  by 
any  subterranean  noise.  A  prodigious  explosion,  still  indi- 
cated by  the  simple  name  of  el  gran  ruido,  was  not  per- 
ceived until  18  or  20  minutes  afterwards,  and  only  under 
the  two  cities  of  Quito  and  Ibarra,  far  removed  from  Ta- 
cunga,  Hambato,  and  the  principal  scene  of  the  destruc- 
tion. There  is  no  other  event  in  the  troubled  destinies 
of  the  human  race,  by  which  in  a  few  minutes,  and  in 
sparingly  peopled  mountain  lands,  so  many  thousands  at 
once  may  be  overtaken  by  death,  as  by  the  production 
and  passage  of  a  few  earth-waves,  accompanied  by  pheno- 
mena of  cleavage  ! 

17  Mallet  on  vorticose  shocks  and  cases  of  twisting,  in  Brit.  Assoc. 
Report,  1850,  pp.  33  and  49,  and  in  thf  Admiralty  Manual,  1849,  p.  213 
(see  Cosmos,  voL  i,  p.  199,  Bonn's  edition). 

18  The  Moya-cones  were  seen  by  Boussingault  nineteen  years  after  I 
saw  them.     "  Muddy  eruptions,  consequences  of  the  earthquake,  like 
the  eruptions  of  the  Moya  of  P^lileo,  which  have  buried  entire  villages** 
(Ann.  de  Chim.  et  de  Phys.  t.  lyiii,  p.  81). 


EARTHQUAKES.  173 

In  the  earthquake  of  Biobamba,  of  which  the  celebrated 
Valencian  botanist,  Don  Jose  Cavanilles,  gave  the  earliest 
account,  the  following  phenomena  are  deserving  of  special 
attention  :— fissures  which  alternately  opened  and  closed 
again,  so  that  men  saved  themselves  by  extending  both 
arms  in  order  to  prevent  their  sinking ;  the  disappearance 
of  entire  caravans  of  riders  or  loaded  mules  (recuas),  some  of 
which  disappeared  through  transverse  fissures  suddenly  open- 
ing in  their  path,  whilst  others,  flying  back,  escaped  the 
danger ;  such  violent  oscillations  (non-simultaneous  elevation 
iind  depression)  of  neighbouring  portions  of  the  ground,  that 
people  standing  upon  the  choir  of  a  church  at  a  height  of 
more  than  12  feet,  got  upon  the  pavement  of  the  street 
without  falling  ;  the  sinking  of  massive  houses,19  in  which  the 
inhabitants  could  open  inner  doors,  and  for  two  whole  days, 
before  they  were  released  by  excavations,  passed  uninjured 
from  room  to  room,  procured  lights,  fed  upon  supplies  acci- 
dentally discovered,  and  disputed  with  each  other  regarding 
the  probability  of  their  rescue  ;  and  the  disappearance  of 
such  great  masses  of  stones  and  building  materials.  Old 
Riobamba  contained  churches  and  monasteries  amongst 
houses  of  several  stories ;  and  yet,  when  I  took  the  plan  of 
the  destroyed  city,  I  only  found  in  the  ruins  heaps  of  stone 
of  8  to  10  feet  in  height.  In  the  south-western  part  of  Old 
Hiobamba  (the  former  Barrio  de  Sigchuguaicu)  a  mine- 
like  explosion,  the  effect  of  a  force  from  below  upwards,  was 
distinctly  perceptible.  On  the  Cerro  de  la  Culca,  a  hill  of 
some  hundred  feet  in  height,  which  rises  above  the  Cerro  de 
Cambicarca  situated  to  the  north  of  it,  there  lies  stony  rub- 
bish mixed  with  human  bones.  Translator^  movements,  in  a 
horizontal  direction,  by  which  avenues  of  trees  become 
displaced,  without  being  uprooted,  or  fragments  of  culti- 
vated ground  of  very  different  kinds  mutually  displace 
each  other,  have  occurred  repeatedly  in  Quito,  as  well  as 

19  Upon  the  displacement  of  buildings  and  plantations  during  the 
earthquake  of  Calabria,  see  Ly ell's  Principles  of  Geology,  vol.  i,  pp.  484 
— 491.  Upon  escapes  in  fissures  during  the  great  earthquake  of  Rio- 
bamba, see  my  Relation  Historique,  tome  ii,  p.  642.  As  a  remarkable 
example  of  the  closing  of  a  fissure  it  must  be  mentioned  that,  according 
to  Scacchi's  report,  during  the  celebrated  earthquake  (in  the  summer 
of  1851),  in  the  Neapolitan  province  of  Basilicata,  a  hen  was  found 
Caught  by  both  feet  in  the  street  pavement  in  Barile,  near  Melfi, 


174-  COSMOS. 

in  Calabria.  A  still  more  remarkable  and  complicated  phe- 
nomenon is  the  discovery  of  utensils  belonging  to  one 
house  in  the  ruins  of  another  at  a  great  distance ;  a  cir- 
cumstance which  has  given  rise  to  law-suits.  Is  it,  as  the 
natives  believe,  a  sinking  followed  by  an  eruption  ?  or, 
notwithstanding  the  distance,  a  mere  projection  ?  As, 
in  nature,  everything  is  repeated  when  similar  conditions 
again  occur,  we  must,  by  not  concealing  even  what  is  still 
imperfectly  observed,  call  the  attention  of  future  observers 
to  special  phenomena. 

According  to  my  observations  it  must  not  be  forgotten  that 
besides  the  commotion  of  solid  parts  as  earth-waves,  very  dif- 
ferent forces,  as  for  instance  physical  forces,  emanations  of 
gas  and  vapour,  also  assist  in  most  cases  in  the  production  of 
fissures.  When  in  the  undulatory  movement  the  extreme 
limit  of  the  elasticity  of  matter  set  in  motion  (according  to 
the  difference  of  the  rocks  or  the  looser  strata)  is  exceeded 
and  separation  takes  place,  tense  elastic  fluid  may  break  out 
through  the  fissures,  bringing  substances  of  various  kinds 
from  the  interior  to  the  surface  and  giving  rise  again  by  their 
eruption  to  translatory  movements.  Amongst  these  pheno- 
mena, which  only  accompany  the  primitive  commotion  (the 
earthquake)  are  the  elevation  of  the  undoubtedly  wandering 
cone  of  the  Moya,  and  probably  also  the  transportation  of 
objects  upon  the  surface  of  the  earth.20  When  large  clefts 
are  formed,  and  these  only  close  again  at  their  upper  parts, 
the  production  of  permanent  subterranean  cavities  may  not 
only  become  the  cause  of  new  earthquakes,  as,  according  to 
Boussingault's  supposition,  imperfectly  supported  masses  be- 
come detached  in  course  of  time  and  fall,  producing  commo- 
tions, but  we  may  also  imagine  it  possible  that  the  circles  of 
commotion  are  enlarged  thereby,  and  that  in  the  new  earth- 
quake, the  clefts  opened  in  the  previous  one  enable  elastic 
fluids  to  act  in  places  to  which  they  could  not  otherwise  have 
obtained  access.  It  is  therefore  an  accompanying  pheno- 

20  Cosmos,  vol.  i,  p.  201,  Bohn's  edition.  Hopkins  has  very  correctly 
shown  theoretically  that  the  fissures  produced  by  earthquakes  are  very 
instructive  as  regards  the  formation  of  veins  and  the  phenomenon  of 
dislocation,  the  more  recent  vein  displacing  the  older  formations.  But 
long  before  Phillips  (in  his  "  Theorie  der  Gange,"  1791),  Werner 
snowed  the  comparative  ages  of  the  displacing  penetrating  vein  and  oi 
the  disrupted  penetrated  rock  (see  Brit.  Assoc.  Report,  1847,  p.  62). 


EARTHQUAKES.  175 

menon,  and  not  the  strength  of  the  wave  commotion  which 
has  once  passed  through  the  solid  parts  of  the  earth,  that 
gives  rise  to  the  gradual  and  very  important,  but  too  little 
considered  enlargement  of  the  circle  of  commotion?* 

Volcanic  activities,  of  which  the  earthquake  is  one  of  the 
lower  grades,  almost  always  include  at  the  same  time,  move- 
ment and  the  physical  production  of  matter.  In  the  Deli- 
neation of  Nature  we  have  already  repeatedly  indicated  that 
water  and  hot  vapours,  carbonic  acid  gas  and  other  mofettes, 
black  smoke  (as  was  the  case  for  several  days  in  the  rock  of 
Alvidras  during  the  earthquake  of  Lisbon  on  the  1st  Novem- 
ber, 1755),  flames  of  fire,  sand,  mud  and  moyas  mixed  with 
charcoal,  rise  from  fissures  at  a  distance  from  all  volcanoes. 
The  acute  geognosist,  Abich,  has  proved  the  connexion  which 
exists  in  the  Persian  Ghilan  between  the  thermal  springs  of 
Sarcin  (5051  feet),  on  the  road  from  Ardebil  to  Tabriz,  and 
the  earthquakes  which  frequently  visit  the  elevated  districts 
in  every  second  year.  In  October,  1 848,  an  uiidulatory  move- 
ment of  the  earth,  which  lasted  for  a  whole  hour,  compelled 
the  inhabitants  of  Ardebil  to  abandon  the  town ;  and  the 
temperature  of  the  springs,  which  is  between  44°  and  46°  C. 
(=  111°  —  115°  F.)  rose  immediately  to  a  most  painful 
scalding  heat,  and  continued  so  for  a  whole  month.22  As 
Abich  says,  nowhere  perhaps  upon  the  face  of  the  earth  is 
"  the  intimate  connexion  of  fissure-producing  earthquakes, 
with  the  phenomena  of  mud- volcanoes,  of  salses,  of  combus- 
tible gases  penetrating  through  the  perforated  soil,  and  of 

21  Upon  the  simultaneous  commotion  of  the  tertiary  limestone  of 
Cumana  and  Maniquarez  since  the  great  earthquake  of  Cumana  on  the 
14th  December,  1796,  see  Humboldt's  Relation  Historique,  tome  i, 
p.  314  ;  Cosmos,  vol.  i,  p.  208,  Bonn's  edition ;  and  Mallet,  Brit.  Assoc. 
Report,  1850,  p.  28. 

^  Abich,  on  Daghestan,  Schagdagh,  and  Ghilan,  in  Poggend.  A  nnalen, 
Bd.  Ixxvi,  1849,  p.  157.  The  salt  spring  in  a  well  near  Sassendorf,  in 
Westphalia  (in  the  district  of  Amsberg),  also  increased  about  l£  per 
cent,  in  amount  of  saline  matter,  in  consequence  of  the  widely  extended 
earthquake  of  the  29th  July,  1846,  the  centre  of  commotion  of  which 
is  placed  at  St.  Goar,  on  the  Rhine ;  this  was  probably  because  other 
fissures  of  supply  had  opened  (Noggerath,  Das  Erdbeben  im  Rheinge- 
biete  vom  29  Juli,  1846,  p.  14).  According  to  Charpentier's  observation, 
the  temperature  of  the  sulphureous  spring  of  Lavey  (above  St.  Maurice, 
on  the  bank  of  the  Rhone),  rose  from  87°.8  to  97°.3  F.  during  the 
Swiss  earthquake  of  the  25th  August,  1851. 


175  cos;.;os. 

petroleum  springs,  more  distinctly  expressed  or  more  clearly 
recognizable,  than  in  the  south-eastern  extremity  of  the 
Caucasus,  between  Schemacha,  Baku,  and  Sallian.  It  is 
the  part  of  the  great  Aralo-Caspian  basin,  in  which  the  earth 
is  most  frequently  shaken."23  I  was  myself  struck  with  the 
remarkable  fact  that  in  Northern  Asia  the  circle  of  commo- 
tion, the  centre  of  which  appears  to  be  in  the  vicinity  of  Lake 
Baikal,  extends  westwards  only  to  the  eastern  borders  of 
the  Russian  Altai,  as  far  as  the  silver  mines  of  Riddersk, 
the  trachytic  rock  of  Kruglaia  Sopka  and  the  hot  springs  of 
Rachmanowka  and  Arachan,  but  not  to  the  Ural  chain. 
Further,  towards  the  south,  on  the  other  side  of  the  parallel 
of  45°  1ST.,  in  the  chain  of  the  Thianschan  (Mountains  of 
Heaven)  there  appears  a  zone  of  volcanic  activity  directed 
from  east  to  west,  with  every  kind  of  manifestation.  It 
extends  not  only  from  the  fire  district  (Ho-tscheu)  in  Tur- 
fan,  through  the  small  chain  of  Asferah  to  Baku,  and  thence 
over  Ararat  into  Asia  Minor ;  but  it  is  believed  that  it  may 
be  traced,  oscillating  between  the  parallels  of  38°  and  40J  JS  ., 
through  the  volcanic  basin  of  the  Mediterranean  as  far  as 
Lisbon  and  the  Azores.  I  have  elsewhere24  treated  in  detail 

23  At  Schemacha  (elevation  2393  feet),  one  of  the  numerous  meteoro- 
logical stations  founded  by  Prince  Worouzow,  in  the  Caucasus,  under 
Abich's  directions,   18  earthquakes  were  recorded  by  the  observer  in 
the  journal  in  1848  alone. 

24  See  Asie  Centrale,  tome  i,  pp.  324—329,  and  tome  ii,  pp.  108 — 
120;  and  especially  my  Carte  des  Montagues  et  Volcans  de  I'Asie,  com- 
pared with  the  geognostic  maps  of  the  Caucasus,  and  of  the  plateau  of 
Armenia  by  Abich,  and  the  map  of  Asia  Minor  (Argaeus)  by  Peter 
Tschichatschef,  1853  (Rose,  Reise  nac/i  dem  Ural,  Altai,  und  Kaspischem 
Meere,  Bd.  ii,  pp.  576  and  597).     In  Asie  Centrale  we  find: — "From 
Tourfan,  situated  upon  the  southern  slope  of  the  Thianchan,  to  the 
Archipelago  of  the  Azores,  there  are  120  degrees  of  longitude.     This  is 
probably  the  longest  and  most  regular  band  of  volcanic  reactions,  oscil- 
lating  slightly  between  38°  and  40°  of  latitude,  which  exists  upon  the 
face  of  the  earth ;  it  greatly  surpasses  in  extent  the  volcanic  band  of 
the  Cordillera  of  the  Andes  in  South  America.     I  insist  the  more  upon 
this  singular  line  of  ridges,  of  elevations,  of  fissures,  and  of  propaga- 
tions of  commotions,  which  comprises  a  third  of  the  circumference  of  a' 
parallel  of  latitude,  because  some  small  accidents  of  surface,  the  un- 
equal elevation  and  the  breadth  of  the  ridges,  or  linear  elevations,  a.s 
well  as  the  interruption  caused  by  the  sea-basins  (Aralo-Caspian,  Medi- 
terranean,  and  Atlantic  basins),   tend   to  mark   the   great   features 
of  the  geological  constitution  of  the  globe.     (This  bold  sketch  of  a 
i-egnlarly  prolonged  line  of  commotion  by  no  means  excludes  other 


EARTHQUAKES -"  177 


of  this  important  subject  of  volcanic  geography.  In  Greece, 
also,  which  has  suffered  from  earthquakes  more  than  any 
other  part  of  Europe  (Curtius,  Peloponnesos,  i,  s.  42 — 46), 
it  appears  that  an  immense  number  of  thermal  springs,  some 
still  flowing,  others  already  lost,  have  broken  out  with  earth- 
shocks.  A  similar  thermic  connexion  is  indicated  in  the  re- 
markable book  of  Johannes  Lydus  upon  earthquakes  (De 
Ostentis,  cap.  liv,  p.  189,  Hase).  The  great  natural  pheno- 
menon of  the  destruction  of  Helice  and  Bura  in  Achaia 
(373  B.C.  ;  Cosmos,  vol.  iv,  p.  543)  gave  rise  in  an  especial 
manner  to  hypotheses  regarding  the  causal  connexion  of 
volcanic  activity.  "With  Aristotle  originated  the  curious 
theory  of  the  force  of  the  winds  collecting  in  the  cavities 
of  the  depths  of  the  earth  (Meteor,  ii,  p.  368).  By  the  part 
which  they  have  taken  in  the  early  destruction  of  the  monu- 
ments of  the  most  flourishing  period  of  the  arts,  the  unhappy 
frequency  of  earthquakes  in  Greece  and  Southern  Italy  has 
exercised  the  most  pernicious  influence  upon  all  the  studies 
which  have  been  directed  to  the  evolution  of  the  Greek  and 
Roman  civilisation  at  various  epochs.  Egyptian  monuments 
also,  for  example  that  of  a  colossal  Memnon  (27  years  B.C.), 
have  suffered  from  earthquakes,  which,  as  Letronne  has 
proved,  have  been  by  no  means  so  rare  as  was  supposed  in 
the  valley  of  the  Nile  (Les  Statues  Vocales  de  M.emnony 
1&33,  pp.  23—27,  255). 

The  physical  changes  here  referred  to,  as  induced  by  earth- 
quakes by  the  production  of  fissures,  render  it  the  more  re- 
lines  in  the  direction  of  which  the  movements  may  also  be  propa- 
gated.)" As  the  city  of  Khotan  and  the  district  south  of  the  Thian- 
echan  has  been  the  most  ancient  and  celebrated  seat  of  Buddhism,  the 
Buddhistic  literature  was  occupied  very  early  and  earnestly  with  the 
causes  of  earthquakes  (see  Foe-koue-ki,  ou  Relation  des  Royaumes  Boud- 
diques,  translated  by  M.  Abel  Re"musat,  p.  217).  By  the  followers  of  Sak- 
hyamuni  eight  of  these  causes  are  adduced,  amongst  which  a  revolving 
wheel  of  steel,  hung  with  reliques  ('sarira,  signifying  body  in  Sanscrit), 
plays  a  principal  part, — a  mechanical  explanation  of  a  dynamic  phe- 
nomenon, scarcely  more  absurd  than  many  of  our  geological  and  mag- 
netic myths,  which  have  but  recently  become  antiquated  !  According 
to  a  statement  of  Klaproth's,  pnestd,  and  especially  begging  monks  (Bhik- 
*hous)  have  the  power  of  causing  the  earth  to  tremble  and  of  setting 
the  subterranean  wheel  in  motion.  The  travels  of  Fahian,  the  author 
of  the  t'oe-koue-ki,  date  about  the  commencement  of  the  fifth  cen- 
tury. 

VOL.  V.  M 


178  COSMOS. 

markable  that  so  many  warm  mineral  springs  retain  their 
composition  and  temperature  unchanged  for  centuries,  and 
therefore  must  flow  from  fissures  which  appear  to  have  un- 
dergone no  alteration  either  vertically  or  laterally.  The 
establishment  of  communications  with  higher  strata  would 
have  produced  a  diminution,  and  that  with  lower  ones  an 
increase  of  heat. 

When  the  great  eruption  of  the  volcano  of  Conseguina  (in 
Nicaragua)  took  place  on  the  23rd  of  January,  1835,  the 
subterranean  noise25  (los  ruidos  subterraneos)  was  heard  at 
the  same  time  on  the  island  of  Jamaica  and  on  the  plateau 
of  Bogot£,  8740  feet  above  the  sea,  at  a  greater  distance  than 
from  Algiers  to  London.  T  have  also  elsewhere  observed, 
that  in  the  eruptions  of  the  volcano  on  the  island  of  Saint 
Vincent,  on  the  30th  of  April,  1812,  at  2  o'clock  in  the 
morning,  a  noise  like  the  report  of  cannons  was  heard  with- 
out any  sensible  concussion  of  the  earth  over  a  space  of 
160,000  geographical  square  miles.8*  It  is  very  remarkable 
that  when  earthquakes  are  combined  with  noises,  which  is 
by  no  means  constantly  the  case,  the  strength  of  the  latter 
does  not  at  all  increase  in  proportion  to  that  of  the  former. 
The  most  singular  and  mysterious  phenomenon  of  subter- 
ranean sound  is  undoubtedly  that  of  the  bramidos  de  Gua- 
naxuato  which  lasted  from  the  9th  of  January  to  the  middle 
of  February.  1784.  regarding  which  I  was  the  first  to  collect 
trustworthy  details  from  the  lips  of  living  witnesses,  and 
from  official  records  (Cosmos,  vol.  i,  p.  205). 

The  rapidity  of  the  propagation  of  the  earthquake  upon 
the  surface  of  the  earth  must  from  its  nature  be  modified  in 
many  ways  by  the  variable  densities  of  the  solid  rocky  strata 
(granite  and  gneiss,  basalt  and  trachytic  porphyry,  Jurassic 
limestone  and  gypsum),  as  well  as  by  that  of  the  alluvial 
soil,  through  which  the  wave  of  commotion  passes.  It 

85  Acosta,  Viajes  cientificos  d  los  Andes  ecuatoriales,  1849,  p.  56. 

26  Cosmos,  vol.  i,  pp.  204  —  206  ;  Humboldt,  Relation  ffistorique, 
t.  iv,  chap.  14,  pp.  31 — 38.  Some  sagacious  theoretical  observations  by 
Mallet  upon  sonorous  waves  in  the  earth  and  sonorous  waves  in  the  air 
occur  in  the  Brit.  Assoc.  Report,  1850,  pp.  41 — 46,  and  in  the  Admiralty 
Manual,  1849,  pp.  201  and  217.  The  animals  which  in  tropical  coun- 
tries are  disquieted  by  the  slightest  commotions  of  the  earth  sooner 
than  man  are,  according  to  my  experience,  fowls,  pigs,  dogs,  asses,  and 
crocodiles  (CajtnnuH);  the  latter  suddenly  quit  the  bottom  D£  the  riveru, 


EARTHQUAKES.  179 

would,  however,  be  desirable  to  ascertain  once  for  all  with 
certainty  what  are  the  extreme  limits  between  which  the 
velocities  vary.  It  is  probable  that  the  more  violent  com- 
motions by  no  means  always  possess  the  greatest  velocity. 
The  measurements,  moreover,  do  not  always  relate  to  the 
same  direction  which  the  waves  of  commotion  have  followed. 
Exact  mathematical  determinations  are  much  wanted,  and 
it  is  only  at  a  very  recent  period  that  a  result  has  been  ob- 
tained with  great  exactitude  and  care  from  the  Rhenish 
earthquake  of  the  29th  of  July,  1846,  by  Julius  Schmidt, 
assistant  at  the  Observatory  of  Bonn.  In  the  earthquake 
just  mentioned  the  velocity  of  propagation  was  14,956 
geographical  miles  in  a  minute,  that  is  1466  feet  in  the 
second.  This  velocity  certainly  exceeds  that  of  the  waves  of 
sound  in  the  air ;  but  if  the  propagation  of  sound  in  water 
is  at  the  rate  of  5016  feet,  as  stated  by  Colladon  and  Sturm, 
and  in  cast  iron  tubes  11393  feet,  according  to  Biot,  the 
result  found  for  the  earthquake  appears  very  weak.  For 
the  earthquake  of  Lisbon  on  the  1st  of  November,  1755, 
Schmidt  (working  from  less  accurate  data)  found  the  velocity 
between  the  coasts  of  Portugal  and  Holstein  to  be  more 
than  five  times  as  great  as  that  observed  on  the  Rhine,  on 
the  29th  of  July,  1846.  Thus,  for  Lisbon  and  Gluckstadt  (a 
distance  of  1348  English  miles)  the  velocity  obtained  was 
89.26  miles  in  a  minute  or  7953  feet  in  a  second ;  which, 
however,  is  still  3438  feet  less  than  in  cast  iron.27 

27  Julius  Schmidt,  in  Nb'ggerath,  Ueber  das  Erdbebcn  vom  29  Juli, 
1846,  s.  28—37.  With  the  velocity  stated  in  the  text,  the  earthquake 
of  Lisbon  would  have  passed  round  the  equatorial  circumference  of 
the  earth  in  about  45  hours.  Michell  (Phil.  Transact,  vol.  i,  pt.  ii, 
p.  572)  found  for  the  same  earthquake  of  the  1st  November,  1755,  a 
velocity  of  only  50  English  miles  in  a  minute,  that  is,  instead  of  7956, 
only  4444  feet  in  a  second.  The  inexactitude  of  the  older  obser- 
vations and  difference  in  the  direction  of  propagation  may  conduce  to 
this  result.  Upon  the  connexion  of  Neptune  with  earthquakes,  at 
which  I  have  glanced  in  the  text  (p.  181),  a  passage  of  Proclus  in  the 
commentary  to  Plato's  Cratylus,  throws  a  remarkable  light.  "  The 
middle  one  of  the  three  deities.  Poseidon,  is  the  cause  of  movement  in 
all  things,  even  in  the  immovable.  As  the  originator  of  movement  he  ia 
called  'Eworriyaiog-  to  him,  of  those  who  shared  the  empire  of  Saturn, 
fell  the  middle  lot,  the  easily  moved  sea"  (Creuzer,  Symbolik  und 
Mythologie,  Th.  iii,  18.42,  s.  260).  As  the  Atlantis  of  Solon  and  the 
Lyctonia,  which,  according  to  my  idea,  was  nearly  allied  to  it,  are 
geological  myths,  both  the  lands  destroyed  by  earthquakes  are  re* 

K   2 


180  COSMOS. 

Concussions  of  the  earth  and  sudden  eruptions  of  fire 
from  volcanoes  which  have  been  long  in  repose,  whether 
these  merely  emit  cinders,  or,  like  intermittent  springs, 
pour  forth  fused,  fluid  earths  in  streams  of  lava,  have  cer- 
tainly a  single,  common  causal  connexion  in  the  high 
temperature  of  the  interior  of  our  planet ;  but  one  of  these 
phenomena  is  usually  manifested  quite  independently  of  the 
other.  Thus,  in  the  chain  of  the  Andes  in  its  linear  exten- 
sion, violent  earthquakes  shake  districts  in  which  unextin  • 
guished,  often  indeed  active,  volcanoes  exist,  without  the  lat- 
ter being  perceptibly  excited.  During  the  great  catastrophe 
of  Riobamba,  the  volcanoes  of  Tungurahua  and  Cotopaxi,  the 
former  in  the  immediate  \icinity,  and  the  latter  rather  fur- 
ther off,  remained  perfectly  quiet.  On  the  other  hand,  vol- 
canoes have  presented  violent  and  long-continued  eruptions, 
without  any  earthquake  being  perceived  in  their  vicinity, 
either  previously  or  simultaneously.  In  fact,  the  most  de- 
structive earthquakes  recorded  in  history,  and  which  have 
passed  through  many  thousand  square  miles,  if  we  may  judge 
from  what  is  observable  at  the  surface,  stand  in  no  connexion 
with  the  activity  of  volcanoes.  These  have  lately  been  called 
Plutonic,  in  opposition  to  the  true  Volcanic  earthquakes, 
which  are  usually  limited  to  smaller  districts.  In  respect  of 
the  more  general  views  of  vulcanicity,  this  nomenclature  is, 
however,  inadmissible.  By  far  the  greater  part  of  the  earth- 
quakes upon  our  planet  must  be  called  Plutonic. 

That  which  is  capable  of  exciting  earth-shocks,  is  every- 
where under  our  feet ;  and  the  consideration  that  nearly 
|ths  of  the  earth's  surface  are  covered  by  the  sea  (with 
the  exception  of  some  scattered  islands)  and  without  any 
permanent  communication  between  the  interior  and  the 
atmosphere,  that  is  to  say,  without  active  volcanoes,  contra- 
dicts the  erroneous,  but  widely  disseminated  belief  that  all 
earthquakes  are  to  be  ascribed  to  the  eruption  of  some  dis- 
tant volcano.  Earthquakes  on  continents  are  certainly  propa- 

garded  as  standing  under  the  dominion  of  Neptune,  and  Bet  in  opposi- 
tion to  the  Saturnian  continents.  According  to  Herodotus  (lib.  ii, 
c.  43  et  50),  Neptune  was  a  Libyan  deity,  and  unknown  in  Egypt. 
Upon  these  circumstances — the  disappearance  of  the  Libyan  lake 
Tritonis  by  earthquake — and  the  idea  of  the  great  rarity  of  earthquakes 
in  the  valley  of  the  Nile,  see  my  Examen  Critique  de  la  Geograjjlue,  t.  i, 
pp.  171  and  172. 


EARTHQUAKES.  181 

gated  along  the  sea-bottom  from  the  shores,  and  give  rise  to 
the  terrible  sea-waves,  of  which  such  memorable  examples 
were  furnished  by  the  earthquakes  of  Lisbon,  Callao  de  Lima, 
and  Chili.  When,  on  the  contrary,  the  earthquakes  start 
from  the  sea  bottom  itself,  from  the  realm  of  Poseidon,  the 
earth-shaker  (^ffeiai^Owv,  Kivrjot^Owv),  and  are  not  accom- 
panied by  upheaval  of  islands  (as  in  the  ephemeral  exist- 
ence of  the  island  of  Sabrina  or  Julia),  an  unusual  rolling 
and  swelling  of  the  waves  may  still  be  observed  at  points 
where  the  navigator  would  feel  no  shock.  The  inhabitants  of 
the  desert  Peruvian  coasts  have  often  called  my  attention  to 
a  phenomenon  of  this  kind.  Even  in  the  harbour  of  Callao, 
and  near  the  opposite  island  of  San  Lorenzo,  I  have  seen, 
wave  upon  wave  suddenly  rising  up  in  the  course  of  a  few 
hours  to  more  than  10  or  15  feet,  in  perfectly  still  nights, 
and  in  this  otherwise  so  thoroughly  peaceful  part  of  the  South 
Sea.  That  such  a  phenomenon  might  have  been  the  conse- 
quence of  a  storm  which  had  raged  far  off  upon  the  open  sea, 
was  by  no  means  to  be  supposed  in  these  latitudes. 

To  commence  from  those  commotions  which  are  limited 
to  the  smallest  space,  and  evidently  owe  their  origin  to  the 
activity  of  a  volcano,  I  may  mention  in  the  first  place  how 
when  sitting  at  night  in  the  crater  of  Vesuvius  at  the  foot 
of  a  small  cone  of  eruption  with  my  chronometer  in  my  hand, 
(this  was  after  the  great  earthquake  of  Naples  on  the  26th  of 
July,  1805,  and  the  eruption  of  lava  which  took  place  seven- 
teen days  subsequently),  I  felt  a  concussion  of  the  soil  of 
the  crater  very  regularly  every  20  or  25  seconds,  imme- 
diately before  each  eruption  of  red  hot  cinders.  The  cinders, 
thrown  up  to  a  height  of  50 — 60  feet  fell  back  partly  into 
the  orifice  of  eruption,  whilst  a  part  of  them  covered  the 
walls  of  the  cone.  The  regularity  of  such  a  phenomenon 
renders  its  observation  free  from  danger.  The  constantly 
repeated  small  earthquake  was  quite  imperceptible  beyond 
the  crater, — even  in  the  Atrio  del  Cavallo  and  in  the  Her- 
mitage del  Salvatore.  The  periodicity  of  the  concussion 
shows  that  it  was  dependent  upon  a  determinate  degree  of 
tension  which  the  vapours  must  attain,  to  enable  them  to 
break  through  the  fused  mass  in  the  interior  of  the  cone 
of  cinders.  In  the  case  just  described  no  concussions  were 
telt  on  the  declivity  of  the  ashy  cone  of  Vesuvius,  and  in  an 


182  COSMOS. 

exactly  analogous  but  far  grander  phenomenon,  on  the  ash- 
cone  of  the  volcano  of  Sangai,  which  rises  to  a  height  of 
17,006  feet  to  the  south-east  of  the  city  of  Quito,  no  trem- 
bling of  the  earth28  was  felt  by  a  very  distinguished  observer, 
M.  Wisse,  when  (in  December,  1849,)  he  approached  within 
a  thousand  feet  of  the  summit  and  crater,  although  no  less 
than  267  explosions  (eruptions  of  cinders)  were  counted  in 
an  hour. 

A  second,  and  infinitely  more  important  kind  of  earth- 
quake, is  the  very  frequent  one  which  usually  accompanies 
or  precedes  great  eruptions  of  volcanoes,—  whether  the  vol- 
canoes, like  ours  in  Europe,  pour  forth  streams  of  lava  ;  or 
like  Cotopaxi,  Pichincha,  and  Tunguragua  of  the  Andes 
only  throw  out  calcined  masses,  ashes  and  vapours.  For 
earthquakes  of  this  kind  the  volcanoes  are  especially  to  be 
regarded  as  safety  valves,  as  indicated  even  by  Strabo's  ex- 
pression concerning  the  fissure  pouring  out  lava  near  Lelante 
in  Eubcea.  The  earthquakes  cease,  when  the  great  eruption 
has  taken  place. 

Most  widely29  distributed,  however,  are  the  ravages  of  the 
waves  of  commotion  which  pass  sometimes  through  completely 
non-trachytic,  non-volcanic  countries  and  sometimes  through 

28  The  explosions  of  the  Sangai,  or  Volcan  de  Macas,  took  place  on 
an  average  every  13". 4,    see  Wisse,    Comptes  rendus  de  I'Acad.  des 
Sciences,  tome  xxxvi,  1853,  p.  720.     As  an  example  of  commotions  con- 
fined within  the  narrowest  limits,  I  might  also  have  cited  the  report  of 
Count  "Larderel  upon  the  lagoons  in  Tuscany.    The  vapours  containing 
boron  or  boracic  acid  give  notice  of  their  existence  and  of  their  ap- 
proaching eruption  at  fissures  by  shaking  the  surrounding  rocks  (Lar- 
derel, Sur  les  etablissements  industries  de  la  production  d'acide  boracique 
en  Toscane,  1852,  p.  15). 

29  I  am  glad  that  I  am  able  to  cite  an  important  authority  in  confir- 
mation of  the  views  that  I  have  endeavoured  to  develope  in  the  text. 
"  In  the  Andes  the  oscillation  of  the  soil,  due  to  a  volcanic  eruption, 
is,  so  to  speak,  local,  whilst  an  earthquake,  which,  at  all  events  in  ap- 
pearance, is  not  connected  with  any  volcanic  eruption,  is  propagated  to 
incredible  distances.      In  this  case  it  has  been   remarked   that  the 
shocks  followed  in  preference  the  direction  of  the  chains  of  mountains, 
and  were  principally  felt  in  Alpine  districts.     The  frequency  of  the 
movements  in  the  soil  of  the  Andes,  and  the  little  coincidence  observed 
between  these  movements  and  volcanic  eruptions,  must  necessarily  lead 
us  to  suppose  that  in  most  cases  they  are  occasioned  by  a  cause  inde- 
pendent of  volcanoes"  (Boussingault,  Annales  de  Chimie  et  de  Physique, 
t.  Iviii,  1835,  p.  83). 


EARTHQUAKES.  183 

krachytic,  volcanic  regions,  without  exerting  any  influence 
upon  the  neighbouring  volcanoes.  This  is  a  third  group  of 
phenomena,  and  is  that  which  most  convincingly  indicates 
the  existence  of  a  general  cause,  lying  in  the  thermic  nature 
of  the  interior  of  our  planet.  To  this  third  group  also  be- 
longs the  phenomenon,  sometimes,  though  rarely,  met  with 
in  non-volcanic  lands,  but  little  disturbed  by  earthquakes, 
of  a  trembling  of  the  soil,  within  the  most  narrow  limits, 
continued  uninterruptedly  for  months  together,  so  as  to  give 
rise  to  apprehensions  of  an  elevation  and  formation  of  an 
active  volcano.  This  was  the  case  in  the  Piedmontese  val- 
leys of  Pelis  and  Clusson,  as  well  as  in  the  vicinity  of  Pig- 
nerol  in  April  and  May,  1805,  and  also  in  the  spring  of  1829 
in  Murcia,  between  Orihuela  and  the  sea-shore,  upon  a  space 
of  scarcely  sixteen  square  miles.  When  the  cultivated  sur- 
face of  Jorullo  upon  the  western  declivity  of  the  plateau  of 
Mechoacan  in  the  interior  of  Mexico  was  shaken  uninter- 
ruptedly for  90  days,  the  volcano  rose  with  many  thousand 
cones  of  5—7  feet  in  height  (los  Jwrnitos)  surrounding  it. 
and  poured  forth  a  short  but  vast  stream  of  lava.  In  Pied- 
mont and  Spain,  on  the  contrary,  the  concussions  of  the 
oarth  gradually  ceased,  without  the  production  of  any  other 
phenomenon. 

I  have  considered  it  expedient  to  enumerate  the  perfectly 
distinct  kinds  of  manifestation  of  the  same  volcanic  activity 
(the  reaction  of  the  interior  of  the  earth  upon  its  surface) 
in  order  to  guide  the  observer,  and  bring  together  materials 
which  may  lead  to  fruitful  results  with  regard  to  the  causal 
connexion  of  the  phenomena.  Sometimes  the  volcanic 
activity  embraces  at  one  time  or  within  short  periods  sc 
large  a  portion  of  the  earth,  that  the  commotions  of  the  soil 
excited  may  be  ascribed  simultaneously  to  many  causes  re 
lated  to  each  other.  The  years  1796  and  1811  present  par- 
ticularly memorable  examples 30  of  such  a  grouping  of  the 
phenomena, 

30  The  great  phenomena  of  1796  and  1797,  and  1811  and  1812, 
occurred  in  the  following  order  : — 

27th  of  September,  1796.     Eruption  of  the  volcano  of  the  island  of 

Quadaloupe,  in  the  Leeward  Islands,  after  a  repose  of  many  years 
November,  1796.     The  volcano  on  the  plateau  of  Pasto,  between 

the  small  rivers  Guaytara  and  Juanambu,  became  ignited  and 

began  to  smoke  permanently ; 


184  COSMOS. 

b,   Thermal  Springs. 

(Amplification  of  the  Representation  of  Nature. 
Cosmos,  vol.  i,  pp.  216—221). 

Asa  consequence  of  the  vital  activity  of  the  interior  of 
our  planet,  evidenced  in  irregularly  repeated  and  often 
tearfully  destructive  phenomena,  we  have  described  the 

14th  of  December,  1796.  Earthquake  and  destruction  of  the  city  of 
Cumana ; 

4th  of  February,  1797.  Earthquake  and  destruction  of  Rjobamba.  On 
the  same  morning  the  columns  of  smoke  of  the  volcano  of  Pasto, 
at  a  distance  of  at  least  200  geographical  miles  from  Riobamba, 
disappeared  suddenly,  and  never  reappeared ;  no  commotion  was 
felt  in  its  vicinity. 


30th  of  January,  1811.  First  appearance  of  the  island  of  Sabrina,  in 
the  group  of  the  Azores,  near  the  island  of  St.  Michael.  The  ele- 
vation preceded  the  eruption  of  fire,  as  in  the  case  of  the  little 
Kameni  (Santorin)  and  that  of  the  volcano  of  Jorullo.  After  an 
eruption  of  cinders,  lasting  for  six  days,  the  island  rose  to  a 
height  of  320  feet  above  the  surface  of  the  sea.  It  was  the 
third  appearance  and  disappearance  of  the  island  nearly  at  the 
same  point,  at  intervals  of  91  and  92  years. 

Iffay,  1811.  More  than  200  shocks  of  earthquake  on  the  island  of 
St.  Vincent  up  to  April,  1812. 

December,  1811.  Innumerable  shocks  in  the  river-valleys  of  the 
Ohio,^  Mississippi,  and  Arkansas  up  to  1813.  Between  New 
Madrid,  Little  Prairie,  and  La  Saline,  to  the  north  of  Cincin- 
nati, the  earthquakes  occurred  almost  every  hour  for  months 
together. 

December,  1811.     A  single  shock  in  Caraccas. 

26th  of  March,  1812.  Earthquake  and  destruction  of  the  town  of 
Caraccas.  The  circle  of  commotion  extended  over  Santa  Mart  a, 
the  town  of  Honda,  and  the  elevated  plateau  of  Bogota",  to  a  dis- 
tance of  540  miles  from  Caraccas.  The  motion  continued  until  the 
middle  of  the  year  1813. 

80th  of  April,  1812.  Eruption  of  the  volcano  of  St.  Vincent ;  and  on 
the  same  day,  about  2  o'clock  in  the  morning,  a  fearful  subter- 
ranean noise,  like  the  roar  of  artillery,  was  heard  at  the  same  time 
and  with  equal  distinctness  on  the  shores  of  Caraccas,  in  the 
Llanos  of  Calabazo  and  of  the  Rio  Apure,  without  being  accom- 
panied by  any  concussion  of  the  earth  (see  ante,  p.  178).  The 
subterranean  noise  was  also  heard  upon  the  Island  of  St.  Vin- 
cent, but,  and  this  is  very  remarkable,  it  was  stronger  at  some 
distance  upon  the  sea. 


THERMAL   SPRINGS.  185 

earthquake.  In  this,  there  prevails  a  volcanic  power,  which 
in  its  essential  nature  only  acts  dynamically,  producing 
movement  and  commotion,  but  when  it  is  favoured  at  parti- 
cular points  by  the  fulfilment  of  subsidiary  conditions,  it  is 
capable  of  bringing  to  the  surface  material  products,  although 
not  of  generating  them  like  true  volcanoes.  Just  as  water, 
vapours,  petroleum,  mixtures  of  gases,  or  pasty  masses  (mud 
and  moya}  are  thrown  out,  through  fissures  suddenly  opened 
in  earthquakes  sometimes  of  short  duration,  so  do  liquid  and 
aerial  fluids  flow  permanently  from  the  bosom  of  the  earth 
through  the  universally  diffused  network  of  communicating 
fissures.  The  brief  and  impetuous  eruptive  phenomena  are 
here  placed  beside  the  great  peaceful  spring-system  of  the 
crust  of  the  earth,  which  beneficently  refreshes  and  supports 
organic  life.  For  thousands  of  years  it  returns  to  organized 
nature  the  moisture  which  has  been  drawn  from  the  atmo- 
sphere by  falling  rain.  Analogous  phenomena  are  mutually 
illustrative  in  the  eternal  economy  of  nature  ;  and  wherever 
an  attempt  is  made  at  the  generalisation  of  ideas,  the  inti- 
mate concatenation  of  that  which  is  recognized  as  allied  must 
not  remain  unnoticed. 

The  widely  disseminated  classification  of  springs,  into 
cold  and  hot,  which  appears  so  natural  in  ordinary  conversa- 
tion, has  but  a  very  indefinite  foundation  when  reduced 
to  numerical  data  of  temperature.  If  the  temperature  of 
springs  be  compared  with  the  internal  heat  of  man  (found, 
with  thermo-electrical  apparatus,  to  be  98° — 98°. 6  F.  according 
to  Brechet  and  Becquerel),  the  degree  of  the  thermometer  at 
which  a  fluid  is  called  cold,  warm,  or  hot,  when  in  contact 
with  parts  of  the  human  body,  is  very  different  according  to 
individual  sensations.  No  absolute  degree  of  temperature 
can  be  established,  above  which  #,  spring  should  be  desig- 
nated warm.  The  proposition  to  call  a  spring  cold  in  any 
climatic  zone,  when  its  average  annual  temperature  does  not 
exceed  the  average  annual  temperature  of  the  air  in  the  sama 
zone,  at  least  presents  a  scientific  exactitude,  by  affording  a 
comparison  of  definite  numbers.  It  has  the  advantage  of  lead- 
ing to  considerations  upon  the  different  origin  <?f  springs,  as 
the  ascertained  agreement  of  their  temperature  with  the 
annual  temperature  of  the  air  is  recognized  directly  in  un- 
changeable springs;  and  in  changeable  ones,  as  has  beeu 


186  COSMOS.  • 

shown  by  TVahlenberg  and  Erman  the  elder,  in  the  averages 
of  the  summer  and  winter  months.  But  in  accordance  with 
the  criterion  here  indicated,  a  spring  in  one  zone  must  be 
denominated  warm,  which  hardly  attains  the  seventh  cr 
eighth  part  of  temperature  of  one  which  in  another  zone, 
near  the  equator,  will  be  called  cold.  I  may  mention  the 
differences  between  the  average  temperature  of  St.  Peters- 
burg (38°.12  F.)  and  of  the  shores  of  the  Orinoco.  The 
purest  spring  water  which  I  drank  in  the  vicinity  of  the 
cataracts  of  Atures31  and  Maypures  (81°.  14  F.)  or  in  the 
forest  of  Atabapo,  had  a  temperature  of  more  than  79°  F.  ; 
even  the  temperature  of  the  great  rivers  in  tropical  South 
America,  corresponds  with  the  high  degrees  of  heat  of  such 
cold32  springs. 

31  Humboldt,  Voyage  aux  Regions  Equinoxiales,  t.  ii,  p.  376. 

32  Foi  the  sake  of  comparing  the  temperature  of  springs  where  they 
break  fort»i  directly  from  the  earth,  with  that  of  large  rivers  flowing 
through  open  channels,  I  here  bring  together  the  following  average 
numbers  from  my  journals : — 

Rio  Apure,  lat.  7f°  ;  temperature,  81°. 

Orinoco,  between  4°  and  8°  of  latitude ;  81°.5— 85°.3. 

Springs  in  the  forest,  near  the  cataract  of  Maypures,  breaking  forth 
from  the  granite,  82°. 

Cassiquiare,  the  branch  of  the  Upper  Orinoco,  which  forms  the  union 
with  the  Amazon;  only  75°.7. 

Rio  Negro,  above  San  Carlos  (scarcely  1°  53'  to  the  north  of  the 
equator);  only  74°. 8. 

Rio  Atabapo,  79°.2  (lat.  3°  500- 

Orinoco,  near  the  entrance  of  the  Atabapo,  82°. 

Rio  Grande  de  la  Magdalena  (lat.  5°  12'  to  9°  56'),  79°  9'. 

Amazon,  5°  31'  south  latitude,  opposite  to  the  Pongo  of  Rentema 
(Provincia  Jaen  de  Bracamoros),  scarcely  1300  f  'et  above  ths 
South  Sea,  only  72°. 5. 

The  great  mass  of  water  of  the  Orinoco  consequently  pproaches  the 
average  temperature  of  the  air  of  the  vicinity.  During  great  inunda- 
tions of  the  Savannahs,  the  yellowish  brown  waters,  which  smell  of 
sulphuretted  hydrogen,  acquire  a  temperature  of  92°. 8  ;  this  I  found  to 
be  the  temperature  in  the  Lagartero,to  the  east  of  Guayaqtiil,  which 
swarmed  with  crocodiles.  The  soil  there  becomes  heated,  as  in  shallow 
rivers,  by  the  warmth  produced  in  it  by  the  sun's  rays  falling  upon  it. 
With  regard  to  the  multifarious  causes  of  the  low  temperature  of  the 
water  of  the  Rio  Negro,  which  is  of  a  coffee-brown  colour  by  reflected 
light,  and  of  the  white  waters  of  the  Cassiquiare  (a  constantly  clouded 
eky,  the  quantity  of  rain,  the  evaporation  from  the  dense  forests,  and 


THERMAL   SPRINGS.  187 

The  breaking  out  of  springs,  effected  by  multifarious 
causes  of  pressure  and  by  the  communication  of  fissures 
containing  water,  is  such  a  universal  phenomenon  of  the 
surface  of  the  earth,  that  waters  flow  forth  at  some  points 
from  the  most  elevated  mountain  strata,  and  at  others  from 
the  bottom  of  the  sea.  In  the  first  quarter  of  this  century 
numerous  results  were  collected  by  Leopold  von  Buch, 
Wahlenberg  and  myself,  with  regard  to  the  temperature 
of  springs  and  the  diffusion  of  heat  in  the  interior  of  the 
earth  in  both  hemispheres,  from  12°  S.  lat.  to  71°  N.33  The 
springs  which  have  an  unchangeable  temperature  were  care- 
fully separated  from  those  which  vary  with  the  seasons  ; 
and  Leopold  von  Buch  ascertained  the  powerful  influence 
of  the  distribution  of  rain  in  the  course  of  the  year,  that  is 
to  say,  the  influence  of  the  proportion  between  the  relative 
abundance  of  winter  and  summer  rain  upon  the  temperature 
of  the  variable  springs,  which,  as  regards  number,  are  the 
most  widely  distributed.  More  recently34  some  very  ingenious 

the  want  of  hot  sandy  tracts  upon  the  banks),  see  my  river  voyage,  in 
the  Relation  Historique,  t.  ii,  pp.  463  and  509.  In  the  Rio  Guanca- 
bamba  or  Chamaya,  which  falls  into  the  Amazon,  near  the  Pongo  de 
Rentema,  I  found  the  temperature  of  the  water  to  be  only  67°.6,  as  its 
waters  come  with  prodigious  swiftness  from  the  elevated  lake  Sirni- 
cocha  on  the  Cordillera.  On  my  voyage  of  52  days  up  the  river  Mag- 
dalena,  from  Mahates  to  Honda,  I  perceived  most  distinctly,  from 
numerous  observations,  that  a  rise  in  the  level  of  the  water  was  indi- 
cated for  hours  previously  by  a  diminution  of  the  temperature  of  the 
river.  The  refrigeration  of  the  stream  occurred  before  the  cold  moun- 
tain waters  from  the  Paramos  near  the  source  came  down.  Heat  and 
water  move,  so  to  speak,  in  opposite  directions  and  with  very  unequal 
velocities.  When  the  water  near  Badillas  rose  suddenly,  the  tempera- 
ture fell  long  before  from  80°.6  to  74°.3.  As,  during  the  night,  when 
one  is  established  upon  a  low  sandy  islet,  or  upon  the  bank,  with  bag 
and  baggage,  a  rapid  rise  of  the  river  may  be  dangerous,  the  dis- 
co veiy  of  a  prognostic  of  the  approaching  rise  (the  avenida)  is  of  some 
importance. 

33  Leopold  von  Buch,  Physicalisclie    BescJireibung  der  canarischen 
Inseln,  s.  8 :    Poggend.  Annalen,  Bd.  xii,  s.  403 ;  Bibliotheque  Britan- 
nique,  Sciences  et  Arts,  t.  xix,  1802,  p.  263 ;  Wahlenberg,  De  Veget.  et 
Glim,     in  Helvetia   Septentrionali    Observatis,   pp.   Ixxviii  and  Ixxxiv  ; 
Wahlenberg,   Flora   Carpathica,   p.   xciv,   and   in   Gilbert's   Annalen, 
Bd.  xli,  s.  115 ;  Humboldt,  in  the  Mem.  de  la  Soc.  d'Arcucil,  t.  iii  (1817) 
p.  599. 

34  De  Gasparin,  in  the  Bibliotheque  Univ.  Sciences  et  Arts,  t.  xxxviii, 
1828,  pp.   54,  113  and  264 ;  Mem.  de  la  Soc.  Centrale  d 'Agriculture, 


188  COSMOS. 

comparative  observations  by  De  Gasparin,  Schouw  and  Thur- 
mann  have  thrown  considerable  light,  in  a  geographical  and 
hypsometrical  point  of  view,  in  accordance  with  latitude  and 
elevation  upon  this  influence.  Wahlenberg  asserted  that  in 
very  high  latitudes  the  average  temperature  of  variable  springs 
is  rather  higher  than  that  of  the  atmosphere  ;  he  sought  the 
cause  of  this,  not  in  the  dryness  of  a  very  cold  atmosphere  and 
in  the  less  abundant  winter  rain  caused  thereby,  but  in  the 
snowy  covering  diminishing  the  radiation  of  heat  from  the  soil. 
In  those  parts  of  the  plain  of  Northern  Asia,  in  which  a 
perpetual  icy  stratum,  or  at  least  a  frozen  alluvial  soil  mixed 
with  fragments  of  ice  is  found  at  a  depth  of  a  few  feet,85  the 
temperature  of  springs  can  only  be  employed  with  great  cau- 
tion for  the  investigation  of  Kupffer's  important  theory  of 
the  isogeothermal  lines.  A  two-fold  radiation  of  heat  is 
then  produced  in  the  upper  stratum  of  the  earth  :  one  up- 
wards towards  the  atmosphere,  and  another  downwards 
towards  the  icy  stratum.  A  long  series  of  valuable  observa- 
tions made  by  my  friend  and  companion,  Gustav  Rose,  during 
our  Siberian  expedition  in  the  heat  of  summer  (often  in 
springs  still  surrounded  by  ice)  between  the  Irtysch,  the 
Obi,  and  the  Caspian  Sea,  revealed  a  great  complication  of 
local  disturbances.  Those  which  present  themselves  from 
perfectly  different  causes  in  the  tropical  zone,  in  places  where 

1826,  p.  178;  Schouw,  Tableau  du  Ciimat  et  de  la  Vegetation  de  TItalie 
vol.  i,  1839,  pp.  133 — 195  ;  Thurmann,  Sur  la  temperature  des  sources  de 
l(t  chatne  du  Jura,  comparee  a  ceUe  des  sources  de  la  plaine  Suisse,  des 
Alpes  et  des  Vosges,  in  the  Annuaire  Meteor ologique  de  la  France,  1850, 
Plj.  258 — 268.  As  regards  the  frequency  of  the  summer  and  autumn 
rains,  De  Gasparin  divides  Europe  into  two  strongly  contrasted  regions. 
Valuable  materials  are  contained  in  Kamtz,  Lehrbuch  der  Meteorologie, 
Bd.  i,  s.  448  —  506.  According  to  Dove  (Poggend.  Annalen,  Bd. 
xxxv,  s.  376)  in  Italy.  "  at  places  to  the  north  of  which  a  chain  of 
mountains  is  situated,  the  maxima  of  the  curves  of  monthly  quantities 
of  rain  fall  in  March  and  September ;  and  where  the  mountains  lie  to 
the  south,  in  April  and  October."  The  totality  of  the  proportions  of 
rain  in  the  temperate  zones  may  be  comprehended  under  the  following 
general  point  of  view  : — "  The  period  of  winter  rain  in  the  borders  of 
the  tropics  constantly  divides,  the  further  we  depart  fi'om  these,  into 
two  maxima  united  by  slighter  falls,  and  these  again  unite  into  a 
summer-maximum  in  Germany;  where,  therefore,  a  temporary  want  of 
rain  ceases  altogether."  See  the  section  "Geothermik"  in  the  excellent 
Lehrbuch  der  Geoynosie,  by  Naumaun,  Bd.  i,  (1850),  s.  41—73. 
35  See  above,  p.  45. 


THERMAL  SPRINGS.  189 

•mountain  springs  burst  forth  upon  vast  elevated  plateaux, 
eight  or  ten  thousand  feet  above  the  sea  (Micuipampa, 
Quito,  Bogota),  or  in  narrow,  isolated  mountain-peaks  many 
thousand  feet  higher,  not  only  include  a  far  greater  part  of 
the  surface  of  the  earth,  but  also  lead  to  the  consideration 
of  analogous  thermic  conditions  in  the  mountainous  countries 
of  the  temperate  zones. 

In  this  important  subject  it  is  above  all  things  necessary 
to  separate  the  cycle  of  actual  observations  from  the  theor- 
etical conclusions  which  are  founded  upon  them.  What  we 
seek,  expressed  in  the  most  general  way,  is  of  a  triple  nature  : 
— the  distribution  of  heat  in  the  crust  of  the  earth  which  is 
accessible  to  us,  in  the  aqueous  covering  (the  ocean)  and  in 
the  atmosphere.  In  the  two  envelopes  of  the  body  of  the 
earth,  the  liquid  and  gaseous,  an  opposite  alteration  of  tem- 
perature (diminution  and  increase  in  the  superposed  strata) 
prevails  in  a  vertical  direction.  In  the  solid  parts  of  the 
body  of  the  earth  the  temperature  increases  with  the  depth ; 
the  alteration  is  in  the  same  direction,  although  in  a  very 
different  proportion,  as  in  the  aerial  ocean,  the  shallows  and 
rocks  of  which  are  formed  by  the  elevated  plateaux  and  mul- 
tiform mountain  peaks.  We  are  most  exactly  acquainted 
by  direct  experiments,  with  the  distribution  of  heat  in  the 
atmosphere, — geographically  by  local  determination  in  lati- 
tude and  longitude,  and  in  accordance  with  hypsometric  re- 
lations in  proportion  to  the  vertical  elevation  above  the  sur- 
face of  the  sea, — but  in  both  cases  almost  exclusively  in 
close  contact  with  the  solid  and  fluid  parts  of  the  surface  of 
our  planet.  Scientific  and  systematically  arranged  investi- 
gations by  aerostatic  voyages  in  the  free  aerial  ocean,  beyond 
the  near  action  of  the  earth,  are  still  very  rare,  and  there- 
fore but  little  adapted  to  furnish  the  numerical  data  of 
average  conditions  which  are  so  necessary.  Upon  the  de- 
crease of  heat  in  the  depths  of  the  ocean  observations  are 
not  wanting  ;  but  currents,  which  bring  in  water  of  different 
latitudes,  depths,  and  densities,  prevent  the  attainment  of 
general  results,  almost  to  a  greater  extent  than  currents  in 
the  atmosphere.  We  have  here  touched  preliminarily  upon 
the  thermic  conditions  of  the  envelopes  of  our  planet,  which 
will  be  treated  of  in  detail  hereafter,  in  order  to  consider  the 
influence  of  the  vertical  distribution  of  heat  in  the  solid 


190  COSMOS. 

crust  of  the  earth,  and  the  system  of  the  geo-isothermic 
lines,  not  in  too  isolated  a  condition,  but  as  a  part  of  the 
all-penetrating  motion  of  heat,  a  truly  cosmical  activity. 

Instructive  as  are,  in  many  respects,  observations  upon 
the  unequal  diminution  of  temperature  of  springs  which  do 
not  vary  with  the  seasons  as  the  height  of  their  point  of 
emergence  increases, — still  the  local  law  of  such  a  diminish- 
ing temperature  of  springs  cannot  be  regarded,  as  is  often 
done,  as  a  universal  geothermic  law.  If  we  were  certain 
that  waters  flowed  unmixed  in  a  horizontal  stratum  of  great 
extent,  we  might  certainly  suppose  that  they  have  gradually 
acquired  the  temperature  of  the  solid  ground,  but  in  the 
great  network  of  fissures  of  elevated  masses,  this  case  can 
rarely  occur.  Colder  and  more  elevated  waters  mix  with 
the  lower  ones.  Our  mining  operations,  inconsiderable  as 
may  be  the  depth  to  which  they  attain,  are  very  instruc- 
tive in  this  respect ;  but  we  should  only  obtain  a  direct 
knowledge  of  the  isogeothermal  lines,  if  thermometers  were 
buried,  according  to  Boussingault's  method,36  to  a  depth  below 
that  affected  by  the  influences  of  the  changes  of  temperature 
of  the  neighbouring  atmosphere,  and  at  very  different  eleva- 
tions above  the  sea.  From  the  forty-fifth  degree  of  latitude 
to  the  parts  of  the  tropical  regions  in  the  vicinity  of  the 
equator,  the  depth  at  which  the  stratum  of  invariable  tempe- 
rature commences,  diminishes  from  60  to  1^  or  2  feet.  Bury- 
ing the  geothermometer  at  a  small  depth  in  order  to  obtain  a 
knowledge  of  the  average  temperature  of  the  earth,  is  there- 
fore readily  practicable  only  between  the  tropics  or  in  the 
subtropical  zone.  The  excellent  expedient  of  Artesian  wells 
which  have  indicated  an  increase  of  heat  of  1°  F.  for  every 
54  to  58  feet  in  absolute  depths  of  from  745  to  2345 
feet  has  hitherto  only  been  afforded  to  the  physicist  in 
districts  not  much  more  than  1600  feet  above  the  level  of 
the  sea 37  I  have  visited  silver-mines  in  the  chain  of  the 
Andes,  6°45'  south  of  the  equator  at  an  elevation  of  nearly 
13,200  feet  and  found  the  temperature  of  the  water  pene- 
trating through  the  fissures  of  the  limestone  to  be  52°,3  F.88 
The  waters  which  were  heated  in  the  baths  of  the  Inca 

36  See  Cosmos,  vol.  i,  p.  218,  and  vol.  v,  p.  40,  Bohn's  edition. 

*7  See  above,  p.  37. 

88  Mina  de  Guadalupe,  one  of  the  Minas  de  Chota,  I.e.  sup.  p.  43, 


THERMAL  SPRINGS.  191 

Tupac  Yupanqui,  upon  the  ridge  of  the  Andes  (Paso  del 
Assuay},  probably  come  from  springs  of  the  Lad  era  de  Cad- 
lud,  where  I  have  traced  their  course,  near  which  the  old 
Peruvian  causeway  also  ran,  barometrically  to  an  elevation 
of  15,526  feet  (almost  that  of  Mont  Blanc).39  These  are  the 
highest  points  at  which  I  could  observe  spring  water  in 
South  America.  In  Europe  the  brothel's  Schlagintweit 
have  found  gallery-water  in  the  gold  mine  in  the  Eastern 
Alps  at  a  height  of  9442  feet,  and  found  that  the  tempera- 
ture of  small  springs  near  the  opening  of  the  gallery  of  only 
33°.4  F.,40  at  a  distance  from  any  snow  or  glacier  ice.  The 
highest  limits  of  springs  are  very  different  according  to  geo- 
graphical latitude,  the  elevation  of  the  snow  line  and  the  rela- 
tion of  the  hi^Uest  peaks  to  the  mountain  ridges  and  plateaux. 
If  the  radius  of  our  planet  were  to  be  increased  by  the 
height  of  the  Himalaya  at  the  Kintschindjun^a,  and  there- 
fore uniformly  over  the  whole  surface  by  28,175  feet  (4.34 
English  miles),  with  this  small  increase  of  only  -g-roth 
of  the  radius,  the  heat  in  the  surface  cooled  by  radiation, 
would  be  (according  to  Fourier's  analytical  theory),  almost 
the  same  as  it  now  is  in  the  upper  crust  of  the  earth. 
But  if  individual  parts  of  the  surface  raise  themselves  in 
mountain  chains  and  narrow  peaks,  like  rocks  upon  the 
bottom  of  the  aerial  ocean,  a  diminution  of  heat  takes  place 
in  the  interior  of  the  elevated  strata,  and  this  is  modified 
by  contact  with  strata  of  air  of  different  temperature,  by  the 
capacity  for  heat  and  conductive  power  of  heterogeneous 
kinds  of  rocks,  by  the  sun's  action  on  the  forest-clad 
summits  and  declivities,  by  the  greater  and  less  radiation 
of  the  mountains  in  accordance  with  their  form  (relief), 
their  massiveness)  or  their  conical  and  pyramidal  narrow- 
ness. The  special  elevations  of  the  region  of  clouds,  the 
snow  and  ice-coverings  at  various  elevations  of  the  snow 
line,  and  the  frequency  of  the  cool  currents  of  air  coming 
down  the  steep  declivities,  at  particular  times  of  the  day,  alter 
the  effect  of  the  terrestrial  radiation.  In  proportion  as  the 
towering  cones  of  the  summits  become  cooled,  a  weak  current 

»  Hximboldt,  Views  of  Nature,  p.  393. 

40  Mine  on  the  Great  Fleuss  in  the  Moll  Valley  of  the  Tauern,  se« 
Hermann  and  Adolph  Schlagintweit,  Untersuchungen  iOter  die  physifa- 
liwhe  Geographic  1#r  Alzen,  1850,  s.  242—273. 


192  COSMOS. 

of  heat  tending  towards,  but  never  reaching  an  equilibrium, 
sets  in  from  below  upwards.  The  recognition  of  so  many 
factors  acting  upon  the  vertical  distribution  of  heat,  leads  to 
well-founded  presumptions  regarding  the  connexion  of  com- 
plicated local  phenomena,  but  not  to  direct  numerical  deter- 
minations. In  the  mountain  springs  (and  the  higher  ones, 
being  important  to  the  chamois-hunter,  are  carefully  sought) 
there  so  often  remains  the  doubt  that  they  are  mixed  with 
waters,  which  by  sinking  down  introduce  the  colder  tem- 
perature of  higher  strata,  or  by  ascending  introduce  the 
warmer  temperature  of  lower  strata.  From  19  springs,  ob- 
served by  Wahlenberg,  Kamtz  draws  the  conclusion  that  in 
the  Alps  we  must  rise  from  960  to  1023  feet  in  order  to  *ee 
the  temperature  of  the  springs  sink  1°  C.  (1°.8  F.).  A  greater 
number  of  observations  selected  with  more  care  by  Hermann 
and  Adolph  Schlagintweit  in  the  eastern  Carinthian  Alps 
and  in  the  western  Swiss  Alps  on  the  Monte  Rosa,  give  only 
767  feet.  According  to  the  great  work41  of  these  excellent 
observers,  "  the  decrease  of  the  temperature  of  springs  is 
certainly  somewhat  more  gradual  than  that  of  the  average 
annual  temperature  of  the  air,  which  in  the  Alps  amounts 
to  about  320  feet  for  1°  F.  The  springs  there  are  in 
general  warmer  than  the  average  temperature  of  the  air  at 
the  same  level ;  and  the  difference  between  the  temperature 
of  the  air  and  springs  increases  with  the  elevation.  The 
temperature  of  the  soil  is  not  the  same  at  equal  elevations 
in  the  entire  range  of  the  Alps,  as  the  isothermal  surfaces 
which  unite  the  points  of  the  same  average  temperature  of 
springs,  rise  higher  above  the  level  of  the  sea,  independently 
of  the  influence  of  latitude,  in  proportion  to  the  average  con- 
vexity of  the  surrounding  soil ;  perfectly  in  accordance  with 
the  laws  of  the  distribution  of  heat  in  a  solid  body  of  vary- 
ing thickness,  with  which  the  relief  (the  mass-elevation)  of 
the  Alps  may  be  compared." 

In  the  chain  of  the  Andes,  and  indeed  in  those  volcanic 
parts  of  it  which  present  the  greatest  elevations,  the  bury- 
ing of  thermometers  may  in  particular  cases  lead  to  decep- 
tive results  by  the  influence  of  local  circumstances.  From 
the  opinion  formerly  held  by  me,  that  black  rocky  ridges, 
visible  at  a  great  distance,  which  penetrate  the  snowy 
41  Monte  Rosa,  1853,  chap,  vi,  s.  212—225. 


THERMAL  SPRINGS.  193 

region,  are  not  always  indebted  for  their  entire  freedom 
I'rom  snow  to  the  steepness  of  their  sides,  but  to  other 
causes,  I  buried  the  bulb  of  a  thermometer  only  three  inches 
deep  in  the  sand  which  filled  the  fissure  in  a  ridge  on  the 
Chimborazo  at  an  elevation  of  18,290  feet,  and  therefore 
3570  feet  above  the  summit  of  Mont  Blanc.  The  thermo- 
meter permanently  showed  10°.5  F.  above  the  freezing  point, 
whilst  the  air  was  only  4°.5  F.  above  that  point.  The  re- 
sult of  this  observation  is  of  some  importance  ;  for  even 
2558  feet  lower,  at  the  lower  limit  of  perpetual  snow  of  the 
volcano  of  Quito,  according  to  numerous  observations  col- 
lected by  Boussingault  and  myself,  the  average  temperature 
of  the  atmosphere  is  not  higher  than  34°. 9  F.  The  ground 
temperature  of  42^.5  must  therefore  be  ascribed  to  the  sub- 
terranean heat  of  the  doleritic  mountain  :  I  do  not  say  of 
the  entire  mass,  but  to  the  currents  of  air  ascending  in  it 
from  the  depths.  At  the  foot  of  Chimborazo,  at  an  eleva- 
tion of  9486  feet  towards  the  hamlet  of  Calpi,  there  is,  more- 
over, a  small  crater  of  eruption,  Yana-Urcu,  which,  as  indeed 
is  shown  by  its  black,  slag-like  rock  (augitic -porphyry),  ap- 
pears to  have  been  active  in  the  middle  of  the  fifteenth  cen- 
tury.48 

The  aridity  of  the  plain  from  which  Chimborazo  rises, 
and  the  subterranean  brook,  which  is  heard  rushing  under 
the  volcanic  hill  (Yana-Urcu)  just  mentioned,  have  led 
Boussingault  and  myself43  at  very  different  times  to  the  idea 
that  the  water  which  the  enormous  masses  of  snow  produce 
daily  by  melting  at  their  lower  limit,  sinks  into  the  depths 
through  the  fissures  and  chambers  of  the  elevated  volcano. 
These  waters  perpetually  produce  a  refrigeration  in  the 
.strata  through  which  they  run  down.  Without  them  the 
whole  of  the  doleritic  and  trachytic  mountains  would  ac- 
quire, even  at  times  when  no  near  eruption  is  foretold,  a  still 
higher  temperature  in  their  interior,  from  the  volcanic 
source,  perpetually  in  action,  although  perhaps  not  lying  at 
the  same  depth  in  all  latitudes.  Thus,  in  the  varying 
struggle  of  the  causes  of  heat  and  cold,  we  have  to  assume 
a  constant  tide  of  heat  upwards  and  downwards  in  those 
places  where  conical  solid  parts  ascend  into  the  atmosphere. 

4J  Humboldt,  Kleinere  Schriften,  Ed.  i,  pp.  139  and  147. 

'•'  Humboldt,  Op.  tit.,  s.  140  and  203. 

VOL.  V.  O 


194  COSMOS. 

As  regards  the  area  which  they  occupy,  however,  mountains 
and  elevated  peaks  form  a  very  small  phenomenon  in  the  relief 
formation  of  continents  ;  and  moreover  nearly  two-thirds  of 
the  entire  surface  of  the  earth  is  sea-bottom  (according  to 
the  present  state  of  geographical  discovery  in  the  polar  re- 
gions of  both  hemispheres,  we  may  assume  the  proportion  of 
sea  and  land  to  be  in  the  ratio  of  8  :  3).  This  is  directly  in 
contact  with  aqueous  strata,  which,  being  slightly  salt,  and 
depositing  themselves  in  accordance  with  the  maximum  of 
their  density  (at  38°.9),  possess  an  icy  coldness.  Exact  ob- 
servations by  Lenz  and  du  Petit-Thouars  have  shown  that 
within  the  tropics,  where  the  temperature  of  the  surface  of  the 
ocean  is  78°.8  to  80°.6,  water  of  the  temperature  of  36°.5  could 
be  drawn  up  from  a  depth  of  seven  or  eight  hundred  fathoms, 
— phenomena  which  prove  the  existence  of  under  currents 
from  the  polar  regions.  The  consequences  of  tliis  constant, 
suboceanic  refrigeration  of  by  far  the  greater  part  of  the 
crust  of  the  earth  deserve  a  degree  of  attention  which  they 
have  not  hitherto  received.  JRocks  and  islands  of  small  size, 
which  project,  like  cones,  from  the  sea-bottom  above  the  sur- 
face of  the  water,  and  narrow  isthmuses,  such  as  Panama  and 
Darien  washed  by  great  oceans,  must  present  a  distribution 
of  heat  in  their  rocky  strata,  different  from  that  of  parts  of 
equal  circumference  and  mass  in  the  interior  of  continents. 
In  a  veiy  elevated  mountainous  island,  the  submarine  part  is 
in  contact  with  a  fluid  which  has  an  increasing  temperature 
from  below  upwards.  But  as  the  strata  pass  into  the  atmo- 
sphere, unmoistened  by  the  sea,  they  come  in  contact,  under 
the  influence  of  insolation  and  free  radiation  of  dark  heat, 
with  a  gaseous  fluid  in  which  the  temperature  diminishes 
with  the  elevation.  Similar  thermic  conditions  of  opposed 
decrease  and  increase  of  temperature  in  a  vertical  direction 
are  repeated  between  two  large  inland  seas,  the  Caspian  and 
Aral  Sea,  in  the  narrow  Ust-tJrt,  which  separates  them  from, 
each  other.  In  order,  however,  to  clear  up  such  compli- 
cated phenomena,  the  only  means  to  be  employed  are  such 
as  borings  of  great  depth,  which  lead  directly  to  the  know- 
ledge of  the  internal  heat  of  the  earth,  and  not  merely  ob- 
servations of  springs,  or  of  the  temperature  of  the  air  in 
caves,  which  give  just  as  uncertain  results  as  the  air  in  the 
galleries  arid  chambers  of  mines. 


THERMAL   SPRINGS.  195 

\Vlien  a  low  plain  is  compared  with  a  mountain  chain  or 
plateau,  rising  boldly  to  a  height  of  many  thousand  feet,  the 
law  of  the  increase  and  diminution  of  temperature  does  not 
depend  simply  upon  the  relative  vertical  elevation  of  two 
points  on  the  earth's  surface  (in  the  plain  and  on  the  summit 
of  the  mountain).  If  we  should  calculate  from  the  supposi- 
tion of  a  definite  proportion  in  the  change  of  temperature  in 
a  certain  number  of  feet  from  the  plain  upwards  to  the  sum- 
mit, or  from  the  summit  downwards  to  the  stratum  in  the 
interior  of  the  mountain  mass  which  lies  at  the  same  level 
as  the  surface  of  the  plain,  we  should  in  the  one  case  find  the 
summit  too  cold,  and  in  the  other  the  stratum  in  the  in- 
terior of  the  mountain  far  too  hot.  The  distribution  of 
heat  in  a  gradually  sloping  mountain  (an  undulation  of  the 
surface  of  the  earth)  is  dependent,  as  has  already  been  re- 
marked, upon  form,  mass,  and  conductibility ;  upon  insola- 
tion, and  radiation  of  heat  towards  the  clear  or  cloudy 
strata  of  the  atmosphere  ;  and  upon  the  contact  and  play 
of  the  ascending  and  descending  currents  of  air.  According 
to  such  assumptions,  mountain  springs  must  be  very  abun- 
dant, even  at  very  moderate  elevations  of  four  or  five  ^hou- 
sand  feet,  where  the  temperature  would  exceed  the  average 
temperature  of  the  locality  by  72  or  90  degrees ;  and  how 
would  it  be  at  the  foot  of  mountains  under  the  tropics, 
which  at  an  elevation  of  14,900  feet  are  still  free  from 
perpetual  snow  ;  and  often  exhibit  no  volcanic  rock,  but 
only  gneiss  and  mica  schist  I44  The  great  mathematician, 
Fourier,  who  had  been  much  interested  in  the  fact  of  the 
volcano  of  Jorullo  having  been  upheaved,  in  a  plain,  where 
for  many  thousands  of  square  miles  around  no  unusual  ter- 
restrial heat  was  to  be  detected,  occupied  himself  at  my 
request  in  the  very  year  before  his  death  with  theoretical 
investigations  upon  the  question,  how  in  the  elevation  of 
mountains  and  alterations  in  the  surface  of  the  earth,  the 
isothermal  surfaces  are  brought  into  equilibrium  with  the 
new  form  of  the  soil.  The  lateral  radiation  from  strata 
which  lie  in  the  same  level,  but  are  differently  covered, 
44  I  differ  here  from  the  opinion  of  one  of  my  best  friends,  a  physi- 
cist \vhohas  done  excellent  Rervice  as  regards  the  distribution  of  telluric 
heat.  See  "  upon  the  cause  of  the  hot  springs  of  Leuck  and  Warm- 
brunn,"  Bischof,  Lehrbuch  der  chtfMMchcn  und  physikalisclien 
Bd.  i,  s.  127—133. 

o  2 


196  COSMOS. 

plays  in  this  case  a  more  important  part  -than  the  direction 
(inclination)  of  the  cleavage  planes  of  the  rock,  in  cases 
where  stratification  is  observable. 

I  have  already  elsewhere  mentioned45  how  the  hot  springs 
in  the  environs  of  ancient  Carthage,  probably  the  thermal 
springs  of  Pertusa  (aquce  calidce  of  Hammam-el  Enf )  led 
Bishop  Patricius,  the  martyr,  to  the  correct  view  of  the 
cause  of  the  higher  or  lower  temperature  of  the  bubbling 
waters.  When  the  Proconsul  Julius  tried  to  confuse  the 
accused  Bishop  by  the  mocking  question,  "  Quo  auctorefer- 
vens  hfpc  aqua  tantum  ebulliat  ? "  Patricius  set  forth  his 
theory  of  the  central  heat,  "  which  causes  the  fiery  eruptions 
of  Etna  arid  Vesuvius,  and  communicates  more  and  more 
heat  to  the  springs,  in  proportion  as  they  have  a  deeper 
origin."  With  the  learned  Bishop,  Plato's  Pyriphlegethon 
was  the  hell  of  sinners ;  and  a,s  though  he  desired  at  the 

45  With  regard  to  this  passage,  discovered  by  Bureau  de  la  Malle, 
see  Cosmos,  vol.  i,  pp,  220,  221.  "  Est  autem,"  says  Saint  Patricius, 
"  et  supra  firmamentum  cteli,  et  subter  terrain  ignis  atque  aqua ; 
et  quce  supra  terram  est  aqua,  coacta  in  unum,  appellationem  ma- 
rium :  quse  vero  infra,  abyssorum  suscepit ;  ex  qiiibus  ad  generis 
human!  usus  in  terram  velut  siphones  quidam  emittuntur  et  scatu- 
riunt.  Ex  iisdem  quoque  et  thermae  ex.sistunt  :  quarum  quge  ab  igne 
absunt  longius,  provida  boni  Dei  erga  nos  mente,  fnyidiores  ;  quce 
vero  propius  admodum,  ferventes  fluunt.  In  quibusdam  etiam  locis  et 
tepidse  aqua?  reperiuntur,  pro  ut  majore  ab  igue  intervallo  sunt  dis- 
junctac."  So  run  the  words  in  the  collection  : — Acta  Primorum  Mar- 
tyrum,  opera  et  studio  T/teodorici  Ruinart,  ed.  2,  Amstelaedami,  1713  fol. 
p.  555.  According  to  another  report  (A.  S.  Mazochii,  in  veins  marmo- 
reuin  sanctce  Neapolitans  Ecclesice  Kalendarium  commentaries,  vol.  ii, 
Neap.  1744,  4to,  p.  385),  Saint  Patricius  developed  nearly  the  same 
theory  of  telluric  heat  before  the  proconsul  Julius,  but  at  the  conclu- 
sion of  his  speech  the  cold  hell  is  more  distinctly  indicated :— - "  Nam 
quse  longius  ab  igne  subterraneo  absunt,  Dei  optimi  providentia  frigi- 
diores  erumpunt.  At  quD3  propiores  igni  sunt,  ab  eo  fervefactse,  into- 
lerabili  calore  procditae  promuntur  foras.  Sunt  et  alicubi  tepidse, 
quippe  non  parum  sed  longiuscule  ab  eo  igne  remotre.  Atque  ille  in- 
fernus  ignis  impiarum  est  animarum  carnin'cina  ;  non  secus  ac  subter- 
raneus  frigidissirnus  gurges,  in  glaciei  glebas  concretus,  qui  Tartarus 
nuncupatur."  The  Arabic  name,  Hamm&m-el-Enf,  signifies  nose-baths, 
and  is,  as  Temple  has  already  remarked,  derived  from  the  form  of  a 
neighbouring  promontory,  and  not  from  a  favourable  action  exerted  by 
this  thermal  water  upon  diseases  of  the  nose.  The  Arabic  nam-  has 
been  variously  altered  by  reporters: — Haminam  1'Enf  or  Lif,  Eruma- 
melif  (Peyssonel),  la  Mamelif  (Desfontaines).  See  Cumprecht,  Die  Mine' 
ralqudlen  auf  dem  FestlamJe  von  Africa  (1851),  s.  140 — 144. 


THERMAL  SPRINGS.  197 

same  time  to  remind  one  of  the  cold  hells  of  the  Buddhists, 
an  aqua  gelidissima  concrescens  in  glaciem  is  admitted, 
somewhat  unphysically  and  notwithstanding  the  depth,  for 
the  nunquam  jhiiendum  siipplicium  impiorum. 

Amongst  hot  springs,  those  which,  approaching  the  boil- 
ing heat  of  water,  attain  a  temperature  of  194°F.,  are  far  more 
rare  than  is  usually  supposed  in  consequence  of  inexact  ob- 
servations ;  least  of  all  do  they  occur  in  the  vicinity  of  still 
active  volcanoes.  I  was  so  fortunate,  during  my  American 
travels,  as  to  investigate  two  of  the  most  important  of  these 
springs,  both  between  the  tropics.  In  Mexico,  not  far  from 
the  rich  silver  mines  of  Guanaxuato,  in  21°  N.  lat.,  and  at  an 
elevation  of  about  6500  feet  above  the  surface  of  the  sea; 
near  Chichermquillo.46  the  Aquas  de  Comangillas  burst  forth 
from  a  mountain  of  basalt  and  basaltic  breccia.  In  Septem- 
ber, 1803, 1  found  their  temperature  to  be  205°.5  F.  This  mass 
of  basalt  has  broken  in  the  form  of  veins  through  a  columnar 
porphyry,  which  again  rests  upon  a  white  syenite  rich  in 
quartz.  At  a  greater  elevation,  but  not  far  from  this  nearly 
boiling  spring,  near  los  Jbares,  to  the  north  of  Santa  Rosa 
de  la  Sierra,  snow  falls  from  December  to  April  even  at  an 
elevation  of  8,700  feet,  and  the  inhabitants  prepare  ice  the 
whole  year  round,  by  radiation  in  artificial  basins.  On  the 
road  from  Nueva  Valencia  in  the  Valles  de  Aragua,  towards 
the  harbour  of  Portocabello  (in  about  10i°  of  latitude), 
on  the  northern  slope  of  the  coast  chain  of  Venezuela,  I  saw 
the  aquas  calientes  de  las  Trincheras  springing  from  a  strati- 
fied granite,  which  does  not  pass  at  all  into  gneiss.  I  found47 
the  springs  in  February,  1800,  at  194°.5  F.,  whilst  the 
Banos  de  Mariara  in  the  Valles  de  Aragua,,  which  belong  to 
the  gneiss,  showed  a  temperature  of  138°.7  F.  Twenty- 
three  years  later,  and  again  in  the  month  of  February,  Bous- 
singault  and  Rivero*8  found  in  the  Mariara  exactly  147°.2  F. ; 

46  Humboldt,  Essai  Politique  sur  la  Nouvelle  Espayne,  ed.  2,  t.  iii 
(1827),  p.  190. 

4?  Relation  Historique,  t.  ii,  p.  98;  Cosmos,  vol.  i,  p.  219.  The  hot 
springs  of  Carlsbad  also  originate  in  the  granite  (Leop.  von  Buch,  in 
Poggend.  Annalen,  Bd.  xii,  s.  230),  just  like  the  hot  springs  of  Momay, 
in  Thibet,  visited  by  Joseph  Hooker,  which  break  forth  near  Chan- 
grokhang,  at  an  elevation  of  16,000  feet  above  the  sea,  with  a  temper- 
ature  of  115°  (Himalayan  Journal,  vol.  ii,  p.  133). 

4'  Boussingault,  "  Considerations  sur  les  ea".x  thermales  des  Cordfi 


198  COSMOS. 

and  in  the  Trinoheras  de  Portocabello,  at  a  small  eleva- 
tion above  the  Caribbean  Sea,  in  one  basin  198°  F.,  in  the 
other  206°. 6  F.  The  temperature  of  these  hot  springs  had 
therefore  risen  unequally  in  the  short  interval  between  these 
two  periods  : — in  Mariara  about  8°. 5  F.,  and  in  the  Trincheras 
about  12°  1  F.  Boussingault  has  justly  called  attention  to 
ti  e  fact,  that  it  was  in  the  above  mentioned  interval  that  the 
fearful  earthquake  took  place,  which  overwhelmed  the  city 
of  Caraccas  on  the  26th  of  March,  1812.  The  commotion  at 
the  surface  was  indeed  not  so  strong  in  the  vicinity  of  the 
lake  of  Tacarigua  (Nueva  Valencia) ;  but  in  the  interior  of 
the  earth,  where  elastic  vapours  act  upon  fissures,  may  not  a 
movement  which  propagated  itself  so  far  and  so  powerfully, 
readily  alter  the  net-work  of  fissures  and  open  deeper  canals 
of  supply  ?  The  hot  waters  of  the  Trincheras,  rising  from  a 
granite  formation,  are  nearly  pure,  as  they  only  contain  traces 
of  silicic  acid,  a  little  sulphuretted  hydrogen  and  nitrogen  ; 
after  forming  numerous,  very  picturesque  cascades,  sur- 
rounded by  a  luxuriant  vegetation,  they  constitute  a  river, 
the  Rio  de  Aguas  calientes ;  and  this,  towards  the  coast,  is 
full  of  large  crocodiles,  to  which  the  warmth,  already  con- 
siderably diminished,  is  very  suitable.  In  the  most  northern 
parts  of  India  (30°  52'  N.  lat.),  and  also  from  granite,  issues 
the  very  hot  well  of  Jumnotri  which  attains  a  temperature 
of  194°  F.,  and  as  it  presents  this  high  temperature  at  an  ele- 
vation of  10,850  feet  almost  reaches  the  boiling  point  pro- 
per to  this  atmospheric  pressure.49 

Amongst  the  intermittent  hot  springs,  the  Icelandic  boil- 
ing fountains,  and  of  these  especially  the  Great  Geysir  and 
Strokkr,  have  justly  attained  the  greatest  celebrity.  Ac- 
cording to  the  admirable  recent  investigations  of  Bunsen. 
Sartorius  von  Waltershausen  and  Descloiseaux  the  tempe- 
rature of  the  streams  of  water  in  both  diminishes  in  a  remark- 
able manner  from  below  upwards.  The  Geysir  possesses  a 
truncated  cone  of  25  to  30  feet  in  height  formed  by  hori- 
zontal layers  of  silicious  sinter.  In  this  cone  there  lies  a 
shallow  basin  of  52  feet  in  diameter,  in  the  centre  of  which 

leres,"  in  the  Annales  de  Chimie  et  de  Physique,  t.  Hi,  1833,  pp.  188 — 
190. 

49  Captain  Newbold,  "  On  the  Temperature  of  the  Wells  and  Pavers 
in  India  and  Egypt"  (Phil.  Transact,  for  1845,  pt.  i,  p.  127). 


THERMAL  SPRINGS.  19D 

the  funnel  of  the  boiling  spring,  one -third  of  its  diameter,  and 
surrounded  by  perpendicular  walls,  goes  down  to  a  depth  of 
75  feet.  The  temperature  of  the  water  which  constantly 
fills  the  basin  is  180°.  At  very  regular  intervals  of  one  hour 
and  20  or  30  minutes  the  thunder  below  proclaims  the  com- 
mencement of  the  eruption.  The  jets  of  water,  of  9  feet 
in  thickness,  of  which  about  three  large  ones  follow  one 
another,  attain  a  height  of  100  and  sometimes  1#0  feet. 
The  temperature  of  the  water  ascending  in  the  funnel  has 
been  found  to  be  2 60°. 6  at  a  depth  of  72  feet  a  little  while 
before  the  eruption,  during  the  eruption  255°.5,  and  imme- 
diately after  it  251°.6  ;  at  the  surface  of  the  basin  it  is  only 
183° — 185°.  The  Strokkr,  which  is  also  situated  at  the  base 
of  the  Bjarnafell,  has  a  smaller  mass  of  water  than  the 
Geysir.  The  sinter  margin  of  its  basin  is  only  a  few  inches 
in  height  and  breadth.  The  eruptions  are  more  frequent 
than  in  the  Geysir,  but  do  not  announce  themselves  by  sub- 
terranean thunder.  In  the  Strokkr  the  temperature  during 
the  eruption  is  235°— 239°  at  a  depth  of  42  feet,  and  almost 
212°  at  the  surface.  -The  eruptions  of  the  intermittent  boil- 
ing springs,  and  the  slight  changes  in  the  type  of  the  pheno- 
mena are  perfectly  independent  of  the  eruptions  of  Hecla,  and 
were  by  no  means  disturbed  by  the  latter  in  the  years  1845 
and  1846.50  With  his  peculiar  acuteness  in  observation  and 
discussion,  Bun  sen  has  refuted  the  earlier  hypotheses  regard- 
ing the  periodicity  of  the  Geysir  eruptions  (subterranean 
cauldrons,  which,  as  steam-boilers,  are  filled  sometimes  with 
vapours  and  sometimes  with  water).  According  to  him  the 
eruptions  are  caused  by  a  port  ion  of  the  column  of  water  which 

50  Sartorius  von  Waltersbausen,  PhysiscTi-geographische  STcizze  von 
Island,  mit  besonderer  Riicksicht  auf  vullcanische  Erscheinungen,  1847, 
s.  128  — 132  ;  Bunsen  and  Descloiseaux,  in  the  Comptes  rendus  des 
Seances  de  VAcad.  des  Sciences,  t.  xxiii,  1846,  p.  935  ;  Bunsen,  in  the 
Annalen  der  Chemie  und  Pharmacie,  Bd.  Ixii,  1847,  s.  27 — 45.  Lottiu 
and  Robert  had  already  found  that  the  temperature  of  the  jet  of  water 
in  the  Geysir  diminishes  from  below  upwards.  Amongst  the  forty  sili- 
cious  bubbling  springs,  which  are  situated  in  the  vicinity  of  the  Great 
Geysir  and  Strokkr,  one  bears  the  name  of  the  Little  Geysir.  Its  jet 
of  water  only  rises  20  or  30  feet.  The  term  boiling  springs  (Koch- 
brunnen)  is  derived  from  the  word  Geysir,  which  is  connected  with  the 
Icelandic  giosa  (to  boil).  On  the  high  land  of  Thibet  also,  according  to 
the  report  of  Esoma  de  Koros,  there  is,  nenr  the  Alpine  lake  Mapham 
a  Geysir,  which  rises  to  the  height  of  12  feet. 


200  COSMOS. 

has  acquired  a  high  temperature  at  a  lower  point  under  great 
pressure  of  accumulated  vapours,  being  forced  upwards,  and 
thus  coming  under  a  pressure  which  does  not  correspond 
with  its  temperature.  In  this  way  "  the  Geysirs  are  natural 
collectors  of  steam  power." 

Of  the  hot  springs  a  few  approach  nearly  to  absolute 
purity  •  others  contain  solutions  of  8 — 12  parts  of  solid  or 
gaseous  matters.  Among  the  former  are  the  baths  of  Lux- 
eueil,  Pfeffer,  and  Gastein,  the  efficacy  of  which  may  appear 
so  mysterious  on  account  of  their  purity.81  As  all  springs 
are  fed  principally  by  meteoric  water,  they  contain  nitrogen, 
as  Boussingault  has  proved  in  the  very  pure82  springs  flowing 
from  the  granite  in  las  Trincheras  de  Portocabello,  and  Bun- 
sen63  in  the  Cornelius  spring  at  Aix  and  in  the  Geysir  of 
Iceland.  The  organic  matter  dissolved  in  many  springs  also 
contains  nitrogen,  and  is  even  sometimes  bituminous.  Until 
it  was  known  from  the  experiments  of  Gay-Lussac  and  my- 
self that  rain  and  snow-water  contain  more  oxygen  than 
the  atmosphere  (the  former  10,  and  the  latter  at  least  8  per 
cent,  more)  it  appeared  very  remarkable  that  a  gaseous  mix- 
ture, rich  in  oxygen,  could  be  evolved  from,  the  springs  of 
Nocera  in  the  Apennines.  The  analyses  made  by  Gay-Lus- 
sac during  our  stay  at  this  mountain  spring  showed  that  it 
only  contained  as  much  oxygen  as  might  have  been  furnished 
to  it  by  atmospheric  moisture.54  If  we  be  astonished  at  the 

51  Trommsdorf  finds  in  the  springs  of  Gastein  only  0.303  of  solid 
constituents  in   1000  parts;  Lowig,  0.291  in   Pfeffer;  and  Longchamp 
only  0.236  in  Luxeuil;  on  the  other  hand,  0.478  were  found  in  1000 
parts  of  common  well  water  in  Berne  ;  5.459  in  the  Carlsbad  bubbling 
spring;  and  even  7.454  in  Wiesbaden  (Studer,  P/iysikal.  Geographic und 
Geologic,  ed.  2,  1847,  cap.  i,  s.  92). 

52  «  The  hot  springs  which  gush  from  the  granite  of  the  Cordillera  of 
the  coast  (of  Venezuela),  are  nearly  pure ;  they  only  contain  a  small 
quantity  of  silica  in  solution,  and  hydrosulphuric  acid  gas,  mixed  with 
a  little  nitrogen.     Their  composition  is  identical  with  that  which  would 
result  from  the  action  of  water  upon  sulphuret  of  silicium"  (Annales  de 
Chimieet  de  Physique,  t.  lii,  1833,  p.  189).     Upon  the  great  quantity 
of  nitrogen  which  is  contained  in  the  hot  spring  of  Orense  (154°.4), 
see  Maria  Eubio,  Tratado  de  las  Fuentes  Minerales  de  Espaiia,  1853, 
p.  331. 

53  Sartorius  von  Waltershausen,  Skizze  von  Island,  s.  125. 

54  The  distinguished  chemist  Morechini  of  Rome,  had   stated  the 
oxygen  contained  in  the  spring  of  Nocera  (situated  2240  feet  above  the 
snati  to  be  0.43 j  Gay-Lnssac   (26  September,   1805)  found  the  exact 


THERMAL  SPBINGS.  201 

Bilicious  deposits  as  a  constructive  material  of  which  nature, 
as  it  were,  artificially  composes  the  apparatus  of  Geysirs,  we 
must  remember  that  silicic  acid  is  also  diffused  in  many  colci 
springs  which  contain  a  very  small  portion  of  carbonic  acid. 

Acid  springs  and  jets  of  carbonic  acid  gas,  which  were 
long  ascribed  to  deposits  of  coal  and  lignite,  appear  rather  to 
belong  entirely  to  the  processes  of  deep  volcanic  activity  : — 
an  activity  which  is  universally  disseminated,  and  therefore 
does  not  exert  itself  merely  in  those  places  where  volcanic 
rocks  testify  to  the  existence  of  ancient  local  fiery  eruptions. 
In  extinguished  volcanoes  jets  of  carbonic  acid  certainly  re- 
main longest  after  the  Plutonic  catastrophes  ;  they  follow 
the  stage  of  Solfatara  activity  ;  but  nevertheless  waters  im- 
pregnated with  carbonic  acid,  and  of  the  most  various  tem- 
peratures, burst  forth  from  granite,  gneiss,  and  old  and  new 
fioetz  mountains.  Acid  springs  become  impregnated  with 
alkaline  carbonates,  and  especially  with  carbonate  of  soda, 
wherever  water  impregnated  with  carbonic  acid  acts  upon 
rocks  containing  alkaline  silicates.55  In  the  north  of  Ger- 
many many  of  the  carbonic  acid  springs  and  gaseous  jets  are 
particularly  remarkable  for  the  dislocation  of  the  strata 
about  them  and  for  their  eruption  in  circular  valleys  (Pyr- 
mont,  Driburg)  which  are  usually  completely  closed.  Fried- 
rich  Hoffman  and  Buckland  have  almost  at  the  same  time 
very  characteristically  denominated  such  depressions  valleys 
of  elevation  (  Erhebu-ngs-Thaler). 

In  the  springs  to  which  the  name  of  sulphurous  waters  is 
given,  the  sulphur  by  no  means  constantly  occurs  combined 
in  the  same  way.  In  many,  which  contain  no  carbonate  of 
soda,  sulphuretted  hydrogen  is  probably  dissolved  ;  in  others, 
for  example  in  the  sulphurous  waters  of  Aix  (the  Kaiser, 
Cornelius,  Rose,  and  Quirinus  springs),  no  sulphuretted 
hydrogen  is  contained,  according  to  the  precise  experiments 
of  Bunsen  and  Liebig,  in  the  gases  obtained  by  boiling  the 

quantity  of  oxygen  to  be  only  0.299.  We  had  previously  found  0.31 
of  oxygen  in  meteoric  waters  (rain).  Upon  the  nitrogen  gas  con- 
tained in  the  acid  springs  of  Neris  and  Bourbon  1'Archambault,  seethe 
works  of  Anglade  and  Longchatnp(lS34),  and  on  carbonic  acid  exhala- 
tions in  general,  see  Bischof's  admirable  investigations  in  his  Ckemiscfte 
Geologic,  Bd.  i,  s.  243—350. 

55  Bunsen,  in  PoggendorfFs  Annalen,  Bd.  Ixxxiii,  s.  257;  Bischof, 
Geologic,  Bd.  i,  s.  271. 


202  COSMOS. 

waters  without  access  of  air  ;  indeed  the  Kaiserquelle  alonfl 
contains  0.31  per  cent,  of  sulphuretted  hydrogen  in  gas 
bubbles  which  rise  spontaneously  from  the  springs.56 

A  thermal  spring  which  gives  rise  to  an  entire  river  of 
water  acidified  by  sulphur,  the  Vinegar  river  (Rio  Vinagre), 
called  Pusambio  by  the  aborigines,  is  a  remarkable  pheno- 
menon to  which  I  first  called  attention.  The  Rio  Vinagre 
rises  at  an  elevation  of  about  10,660  feet  on  the  north- 
western declivity  of  the  volcano  of  Purace,  at  the  foot  of  which 
the  city  of  Popayan  is  situated.  It  forms  three  picturesque 
cascades.57  of  one  of  which  I  have  given  a  representation, 
falling  over  a  steep  trachytic  wall  probably  3.20  feet  in  per- 

Eendicular  height.  From  the  point  where  the  small  river 
Jls  into  the  Cauca,  this  great  river  for  a  distance  of  2 — 3 
miles  (from  8  to  12  English  miles)  downwards,  as  far  as  the 
junctions  of  the  Pindamon  and  Palace,  contains  no  fish  ; 
which  must  be  a  great  inconvenience  to  the  inhabitants  of 
Popayan,  who  are  strict  observers  of  fasts  !  According  to 
Boussingault's  subsequent  analysis,  the  waters  of  the  Pusam- 
bio contain  a  great  quantity  of  sulphuretted  hydrogen  and 
carbonic  ac.d,  with  some  sulphate  of  soda.  Near  the  source, 
Boussingault  found  the  temperature  to  be  163°.  The  upper 
part  of  the  Pusambio  runs  underground.  Degenhardt  (of 
Clausthal  in  the  Harz),  whose  early  death  has  caused  a 
great  loss  to  Geognosy,  discovered  a  hot  spring  in  1846  in 
the  Paramo  de  RVJ'Z,  on  the  declivity  of  the  volcano  of  the 
same  name,  at  the  sources  of  the  Rio  Guali,  and  at  an  alti- 
tude of  12,150  feet,  in  the  water  of  which  Boussingault 
found  three  times  as  much  sulphuric  acid  as  in  the  Rio 
Vinagre. 

The  equability  of  the  temperature  and  chemical  constitu- 

56  Liebig  and  Bunseu,  Untersuchung  der  Aachener  Scheivefelquetten,  in 
the  Annalen  der  Ckemie  und  Pharmacie,  Bd.  Ixxix  (1851),  s.  101.  In 
the  chemical  analyses  of  mineral  waters  which  contain  sulphuret  of 
sodium,  carbonate  of  soda  and  sulphuretted  hydrogen  are  often  stated 
to  occur  from  an  excess  of  cai-bonic  acid  being  present  in  those  waters. 

5~  One  of  these  cascades  is  represented  in  my  Vues  des  Cordilleres, 
pi.  xxx.  On  the  analysis  of  the  water  of  the  Eio  Vinagre,  see  Boussin- 
gault. in  the  .Annales  de  Ckimie  et  de  Physique,  2e,  s6rie,  t.  lii,  1833, 
p.  397.  and  Dumas.,  3e  serie,  t.  xviii,  1846,  p.  503;  on  the  spring  in  the 
Paramo  do  Ruiz,  see  Joaquin  Acosba,  Viajes  Cientificos  d  los  Andet 
Ecuatoriales,  1849,  p.  89. 


THERMAL    SPRINGS.  203 

tion  of  springs  as  far  as  we  can  ascertain  from  reliable  ob- 
servations, is  for  more  remarkable  thaD  the  instability58 
which  has  been  occasionally  detected.  The  hot  spring-waters, 
which,  during  their  long  and  tortuous  course,  take  up  such  a 
variety  of  constituents  from  the  rocks  with  which  they  are 
in  contact,  and  often  carry  them  to  places  where  they  are 
deficient  in  the  strata  through  which  the  springs  burst  forth, 
have  also  an  action  of  a  totally  different  nature.  They  exert 
a  transforming  and  at  the  same  time  a  formative  activity, 
and  in  this  respect  they  are  of  great  geognostic  importance. 
Senarmont  has  shown  with  wonderful  acuteness,  how  ex- 
tremely probable  it  is  that  many  vein-crevices  (ancient  courses 
of  thermal  waters)  have  been  filled  from  below  upwards  by 

58  The  examples  of  alteration  of  temperature  in  the  thermal  springs 
of  Mariara  and  las  Trincheras  lead  to  the  question  whether  the  Styx 
water,  whose  source,  so  difficult  of  access,  is  situated  in  the  wild 
Aroanie  Alps  of  Arcadia,  near  Nonacris,  in  the  district  of  Pheneos,  has 
lost  its  pernicious  qualities  by  alteration  in  the  subterranean  fissures  of 
supply  ?  or  whether  the  waters  of  the  Styx  have  only  occasionally  been 
injurious  to  the  wanderer  by  their  icy  coldness  ?  Perhaps  they  are 
indebted  for  their  evil  reputation,  which  has  been  transmitted  to  the 
present  inhabitants  of  Arcadia,  only  to  the  awful  wildness  and  desola- 
tion of  the  neighboxarhood,  and  to  the  myth  of  their  origin  from  Tar- 
tarus. A  young  and  learned  philologist,  Theodor  Schwab,  succeeded  a 
few  years  ago,  with  great  exertion,  in  penetrating  to  the  rocky  wall 
from  which  the  spring  trickles  down,  exactly  as  described  by  Homer, 
Hesiod,  and  Herodotus.  He  drank  some  of  the  water,  which  was  ex- 
tremely cold,  but  very  pure  to  the  taste,  without  perceiving  any  injuri- 
ous effects  (Schwab,  ArTcadien,  seine  Natur  und  Geschickte,  1852,  s.  15 — 
20).  Amongst  the  ancients  it  was  asserted  that  the  coldness  of  the 
water  of  the  Styx  burst  all  vessels  except  those  made  of  the  hoof  of  an 
ass.  The  legends  of  the  Styx  are  certainly  very  old,  but  the  report  of  the 
poisonous  properties  of  its  spring  appears  to  have  been  widely  dissemi- 
nated only  in  the  time  of  Aristotle.  According  to  a  statement  of 
Antigonus  of  Carystus  (IIi»t.  M'nab.  §  174),  it  was  contained  very  cir- 
cumstantially iu  a  book  of  Theophrastus,  which  has  been  lost  to  us. 
The  calumnious  fable  of  the  poisoning  of  Alexander  by  the  water  of 
the  Styx,  which  Aristotle  communicated  to  Cassander  by  Antipater,  was 
contradicted  by  Plutarch  and  Arriau,  and  disseminated  by  Vitruvius, 
Justin,  and  Quintus  Curtius,  but  without  mentioning  the  Stagirite 
(Stahr,  Aristotelia,  Th.  i,  1830,  s.  137  — 140).  Pliny  (xxx,  53)  says, 
somewhat  ambiguously  : — "  Magna  Aristotelia  infamia  excogitatum." 
See  Ernst  Curtius,  Pelvponnesiis  (1851),  Bd.  i,  s.  194  —  196,  and  212; 
St.  Croix,  Exainen  Critique  des  Anciens  Historiens  d'Alejrandre,  p.  496. 
A  representation  of  the  cascade  of  the  Styx,  drawn  from  a  distance,  ia 
contained  in  Fiedler's  Reise  durck  Griechenland,  Th.  i,s.  400. 


204  COSMOS. 

the  deposition  of  the  dissolved  elements.  By  changes  of  pres- 
sure and  temperature,  by  internal  electro-chemical  processes, 
and  the  specific  attraction  of  the  lateral  walls  (the  rock  tra- 
versed), sometimes  lamellar  deposits,  and  sometimes  masses 
of  concretion  are  produced  in  fissures  and  vesicular  cavities. 
In  this  way  druses  and  porous  amygdaloids  appear  to  have 
been  sometimes  formed.  Where  the  deposition  of  the  veins 
has  taken  place  in  parallel  zones,  these  zones  usually 
correspond  with  each  other  symmetrically  in  their  nature 
both  vertically  and  laterally.  Senarmont  has  succeeded  in 
preparing  a  considerable  number  of  minerals  artificially,  by 
perfectly  analogous  synthetical  methods.69 

One  of  my  intimate  friends,  a  highly  endowed  scientific 
observer,  will,  I  hope,  before  long  publish  a  new  and  impor- 
tant work  upon  the  conditions  of  temperature  of  springs,  and 
in  it  treat  with  great  acumen  and  universality,  by  induction 
from  a  long  series  of  recent  observations,  upon  the  involved 
phenomenon  of  disturbances.  In  the  determinations  of  tem- 
perature made  by  him  in  Germany  (on  the  Rhine)  and  in  Italy 
(in  the  vicinity  of  Rome,  in  the  Albanian  mountains  and 
the  Apennines)  from  the  year  1845  to  1853,  Eduard  Hall- 

59  «  Very  important  metalliferous  lodes,  perhaps  the  greater  number, 
appear  to  have  been  formed  by  solution,  while  the  veins  filled  witn 
concretions  of  metal  seem  to  be  nothing  but  immense  canals  more  or 
less  obstructed,  and  formerly  traversed  by  encrusting  thermal  waters. 
The  formation  of  a  great  number  of  minerals  which,  are  met  with  in 
these  lodes,  does  not  always  presuppose  conditions  or  agents  very  far 
removed  from  existing  causes.  The  two  principal  elements  of  the  most 
widely  diffused  thermal  waters,  the  alkaline  sulphurets  and  carbonates, 
have  enabled  me  to  reproduce  artificially,  by  very  simple  synthetic 
methods,  29  distinct  mineral  species,  nearly  all  crystallised,  belonging 
to  the  native  metals  (native  silver,  copper,  and  arsenic),  quartz,  specular 
iron,  carbonates  of  iron,  nickel,  zinc,  manganese,  sulphate  of  baryta, 
pyrites,  malachite,  copper  pyrites,  sulphuretof  copper,  red  arsenical  and 
antimonial  silver.  .  .  .  We  approach  as  closely  as  possible  to  the  pro- 
cesses of  nature,  if  we  succeed  in  reproducing  mineral?  in  their  conditions 
of  possible  association,  by  means  of  the  most  widely  diffused  natural 
chemical  agents,  and  by  imitating  the  phenomena  which  we  still  see 
realised  in  the  foci  in  which  the  mineral  creation  has  concentrated  the 
remains  of  that  activity  which  it  formerly  displayed  with  a  very  dif- 
ferent energy"  (H.  de  Senarmont,  Sur  la  Formation  des  Mineraux  pa,'.' 
la  Voie  Humide,  in  the  Annales  de  Chemie  et  de  Physique,  3eme  sdrie 
t.  xxxii,  1851,  p.  234  ;  see  also  Elie  de  Beaumont,  Sur  les  Emanations 
Volcaniques  e\  Metalliferes,  in  the  bulletin  de  la  Societe  Geologique  dt 
France,  2e  &e"rie,  t.  xv.  p.  129). 


THERMAL   SPRINGS.  205 

mann  distinguishes  : — 1.  Purely  meteorological  springs,  the 
average  temperature  of  which  is  not  increased  by  the  internal 
heat  of  the  earth  ;  2.  Meteorologico-geological  springs,  which, 
being  independent  of  the  distribution  of  rain,  and  warmer 
than  the  air,  only  undergo  such  alterations  of  temperature  as 
are  communicated  to  them  by  the  soil  through  which  they 
flow  out  ;  3.  Abnormally  cold  springs,  which  bring  down 
their  coldness  from  great  elevations.80  The  more  we  have 

60  "  In  order  to  ascertain  the  amount  of  variation  of  the  average  tem- 
perature of  springs  from  that  of  the  air,  Dr.  Ecluard  Hallmann  observed 
at  his  former  residence,  Marienberg,  near  Boppard,  on  the  Rhine,  the 
temperature  of  the  air,  the  amount  of  rain  and  the  temperature  of  seven 
springs  for  five  years,  from  the  1st  December,  1845,  to  the  30th  No- 
vember, 1850  ;  upon  these  observations  he  has  founded  a  new  elabora- 
tion of  the  relative  temperature  of  springs.  In  this  investigation  the 
springs  with  a  perfectly  constant  temperature  (the  purely  geological 
springs)  are  excluded.  On  the  other  hand,  all  those  springs  have  been 
made  the  subject  of  investigation  which  undergo  an  alteration  in  their 
temperature  according  to  the  seasons. 

"  The  variable  springs  fall  into  two  natural  groups  : — 

"  1.  Purely  meteorological  springs  :  that  is  to  say,  those  whose  ave- 
rage is  demonstrably  not  elevated  by  the  heat  of  the  earth.  In  these 
springs  the  amount  of  variation  of  the  average  from  the  aerial  average  is 
dependent  upon  the  distribution  of  the  animal  amount  of  rain  through 
the  12  months.  These  springs  are  on  the  average  colder  than  the  air 
when  the  proportion  of  rain  for  the  four  cold  months,  from  December 
to  March,  amounts  to  more  than  33^  per  cent.;  they  are  on  the  average 
warmer  than  the  air,  when  the  proportion  of  rain  for  the  four  warm 
months,  from  July  to  October,  amounts  to  more  than  33£  per  cent. 
The  negative  or  positive  difference  of  the  spring-average  from  the  air- 
average,  is  larger  in  proportion  to  the  excess  of  rain  in  the  above-men- 
tioned cold  or  warm  thirds  of  the  year.  Those  springs  in  which  the 
difference  of  the  average  from  that  of  the  air  is  in  accordance  with 
the  law,  that  is  to  say,  the  largest  possible  by  reason  of  the  distribution 
of  rain  in  the  year,  are  called  purely  meteorological  springs  of  undis- 
torted  average ;  but  those  in  which  the  amount  of  difference  of  the 
average  from  the  air  average  is  diminished  by  the  disturbing  action  of  the 
atmospheric  heat  during  the  seasons  which  are  free  from  rain  are  called 
purely  meteorological  springs  of  approximate  average.  The  approxima- 
tion of  the  average  to  the  aerial  average  is  caused  either  by  the  enclo- 
sure, especially  by  a  channel  at  the  lower  extremity  of  which  the  tem- 
perature of  the  spring  was  observed,  or  it  is  the  consequence  of  a  super- 
ficial course  and  the  poverty  of  the  feeders  of  the  spring.  In  each  year 
the  amount  of  difference  of  the  average  from  the  aerial  average  is 
similar  in  all  purely  meteorological  springs,  but  it  is  smaller  in  tho 
approximate  than  in  the  undistorted  springs,  and  indeed  is  smaller  in 
proportion  as  the  disturbing  action  of  the  atmospheric  heat  is  greater 


206  COSMOS. 

advanced  of  late  years,  by  the  successful  employment  of 
chemistry,  in  the  geognostic  investigation  of  the  formation 

Of  the  springs  of  Marienberg  4  belong  to  the  group  of  purely  meteoro- 
logical springs,  of  these  4  one  is  undistorted  in  its  average,  the  three 
others  are  approximated  in  various  degrees.  In  the  first  year  of  obser- 
vation the  portion  of  rain  of  the  cold  third  predominated,  and  all  four 
springs  were  on  the  average  colder  than  the  air.  In  the  four  following 
years  of  observation  the  rain  of  the  warm  third  predominated,  and  in 
these  all  the  four  springs  had  <t  higher  average  temperature  than  the 
air;  and  the  positive  variation  of.  the  average  of  the  spring  from  that 
of  the  air  was  higher,  the  greater  the  excess  of  rain  in  the  warm  third 
of  one  of  the  four  years.  . 

"  The  view  put  forward  in  the  year  1825,  by  Leopold  von  Buch,  that 
the  amount  of  variation  of  the  average  of  springs  from  that  of  the  air 
must  depend  upon  the  distribution  of  rain  in  the  seasons  of  the  year 
has  been  shown  to  be  perfectly  correct  by  Hallmann,  at  least  for  his 
place  of  observation,  Marienberg,  in  the  Rhenish  Grauwacke  mountains. 
The  purely  meteorological  springs  of  undistorted  average  alone  have 
any  value  for  scientific  climatology  ;  these  springs  are  to  be  sought  for 
everywhere,  and  to  be  distinguished  on  the  one  hand  from  the  purely 
meteorological  springs  with  an  approximate  average,  and  on  the  other 
from  the  rneteorologico-geological  springs. 

"2.  Meteorologico-ge-jlogical  springs:  that  is  to  s.ay,  those  of  which 
the  average  is  demonstrably  heightened  by  the  heat  of  the  earth.  What- 
ever the  distribution  of  rain  may  be,  these  springs  are  in  their  average 
warmer  than  the  air,  all  the  year  round  (the  alterations  of  temperature 
which  they  exhibit  in  the  course  of  the  year  are  communicated  to  them 
by  the  soil  through  which  they  flow).  The  amount  by  which  the 
average  of  a  rneteorologico-geological  spring  exceeds  the  atmospheric 
average,  depends  upon  the  depth  to  which  the  meteoric  waters  have 
sunk  down  into  the  interior  of  the  earth,  where  the  temperature  is  con- 
stant, before  they  again  make  their  appearance  in  the  form  of  a  spring ; 
this  amount  consequently  possesses  no  climatological  interest.  The 
clirnatologist  must,  however,  know  these  springs,  in  order  that  he  may 
not  mistake  them  for  purely  meteorological  springs.  The  meteorologico- 
geological  springs  may  also  be  approximated  to  the  aerial  average  by  an 
enclosure  or  channel.  The  springs  were  observed  on  particular  fixed 
days,  four  or  five  times  a  month.  The  elevation  above  the  sea,  both  of 
the  place  where  the  temperature  of  the  air  was  observed,  and  of  the 
different  springs  was  carefully  taken  into  account." 

After  the  completion  of  the  elaboration  of  his  observations  at  Marien- 
berg, Dr.  Hallmann  passed  the  winter  of  1852 — 1853  in  Italy,  and 
found  abnormally  cold  springs  in  the  vicinity  of  ordinary  ones.  This  is 
the  name  he  gives  "to  those  springs  which  demonstrably  bring  down 
cold  from  above.  These  springs  are  to  be  regarded  as  subterranean 
drains  of  open  lakes  or  subterranean  accumulations  of  water  situated 
at  a  great  elevation,  from  which  the  waters  pour  down  very  rapidly 
in  fissures  and  clefts,  and  break  forth  *t  the  foot  of  the  mountain  or 
chain  of  mountains  in  the  form  of  springs.  The  idea  of  the  abnormally 


SALSES.  207 

and  metamorphic  transformation  of  rocks,  the  greater  im- 
portance has  been  acquired  for  the  consideration  of  the 
waters  impregnated  with  gases  and  salts  which  circulate  in  the 
interior  of  the  earth,  and  which,  when  they  burst  forth  at  the 
surface  as  thermal  springs,  have  already  fulfilled  the  greater 
part  of  their  formative,  alterative,  or  destructive  activity. 

c.   Vapour  and  Gas  Springs,  Salses,  Mud-volcanoes, 
Naphtha-fire. 

(Amplification  of  the  Picture  of  Nature.      Cosmos, 
vol.  i.  pp.  221—223). 

In  the  General  Representation  of  Nature,  I  have  shown  by 
well  ascertained  examples,  which,  however,  have  not  been 
sufficiently  taken  into  consideration,  how  the  salses  in  the 
various  stages  through  which  they  pass,  from  the  first  erup- 
tions  accompanied  by  flames,  to  the  subsequent  condition  of 
simple  eruptions  of  mud,  form  as  it  were  an  intermediate 
step  between  hot  springs  and  true  volcanoes,  which  throw 
out  fused  earths,  either  in  the  form  of  disconnected  cinders, 
or  as  newly  formed  rocks,  often  arranged  in  many  beds  one 
over  the  other.  Like  all  transitions  and  intermediate  steps 
both  in  organic  and  inorganic  nature,  the  salses  and  mud- 
volcanoes  deserve  a  more  careful  consideration  than  was 
bestowed  upon  them  by  the  older  geognosists,  from  the  want 
of  special  knowledge  of  the  facts. 

The  salses  and  naphtha  springs  are  sometimes  arranged  in 
isolated  close  groups  :  like  the  Macalubi,  near  Girgenti,  in 
Sicily,  which  were  mentioned  even  by  Solinus,  those  nearPietra 
Mala,  Barigazzo,  and  on  the  Monte  Zibio,  not  far  from  Sas- 
suolo  in  the  north  of  Italy,  or  those  near  Turbaco  in  South 
America  ;  sometimes  they  appear  to  be  arranged  in  narrow 
chains,  and  these  are  the  most  instructive  and  important. 

cold  springs  is,  therefore,  as  follows : — They  are  too  cold  for  the  eleva- 
tion at  which  they  come  forth ;  or,  which  indicates  the  conditions  better, 
they  come  forth  at  too  low  a  part  of  the  mountain  for  their  low  tem- 
perature." These  views,  which  are  developed  in  the  first  volume  of 
Hallmann's  Temperaturvcrhaltnissen  der  Quellen,  have  been  modified  by 
the  author  in  his  second  volume  (s.  181 — 183),  because  in  every 
meteorological  spring,  however  superficial  it  may  be  there  must  bo 
some  telluric  heat. 


COSMOS. 

We  have  long  known 61  as  the  outermost  members  of  the 
Caucasus,  in  the  north-west  the  mud-volcanoes  of  Taman, 

61  Humboldt,  Asie  Centrale,  t.  ii,  p.  58.  Upon  the  reasons  which 
render  it  probable  that  the  Caucasus,  which  for  ft.hs  of  its  length,  be- 
tween the  Kasbegk  and  lilburuz,  runs  from  E.S.E.  to  W.N.W.  in  the 
mean  parallel  of  42°  50',  is  the  continuation  of  the  volcanic  fissure  of 
the  Asferah  (Aktagh)  and  Thian-schan,  see  the  work  cited  above,  pp.  54 
— 61.  Both  the  Asferah  and  Thian-schau  oscillate  between  the  parallels 
of  40f°  and  43°.  I  regard  the  great  Aralo-Caspian  depression,  the  sur- 
face of  which,  according  to  the  accurate  measurements  of  Slruve, 
exceeds  the  area  of  the  whole  of  France  by  nearly  107,520  geographical 
square  miles  (Op.  cit.  supra,  pp.  309 — 312),  as  more  ancient  than  the 
elevations  of  the  Altai  and  Thian-schan.  The  fissure  of  elevation  of 
the  last-mentioned  mountain  chain  has  not  been  continued  through  the 
great  depression.  It  is  only  to  the  west  of  the  Caspian  Sea  that  we  again 
meet  with  it,  with  some  alteration  in  its  direction,  as  the  chain  of  the 
Caucasus,  but  associated  with  trachytic  and  volcanic  phenomena.  This 
geognostic  connection  has  also  been  recognised  by  Abich,  and  confirmed 
by  valuable  observations.  In  a  treatise  on  the  connection  of  the  Thian- 
schan  with  the  Caucasus  by  this  great  geognosist,  which  is  in  my  pos- 
session, he  says  expressly  : — "  The  frequency  and  decided  predominance 
of  a  system  of  parallel  dislocations  and  lines  of  elevation  (nearly  from 
east  to  west)  distributed  over  the  whole  district  (between  the  Black  Sea 
and  the  Caspian)  brings  the  mean  axial  direction  of  the  great  latitu- 
dinal central  Asiatic  mass-elevations,  most  distinctly  westward  from  the 
Kosyurt  and  Bolar  system*  to  the  Caucasian  Isthmus.  The  mean 
direction  of  the  Caucasus,  S.E. — N.W.,  is  E.S.E. — W.N.W.  in  the  cen- 
tral parts  of  the  mountain  chain,  and  sometimes  even  exactly  E. — W.,  as 
in  the  Thian-schan.  The  lines  of  elevation  which  unite  Ararat  with  the 
trachytic  mountains  Dzerlydagh  and  Kargabassar  near  Erzeroum,  and  in 
the  southern  parallels  of  which  Mount  Argaeus,  Sepandagh,  and  Sabalan 
are  arranged,  constitute  the  most  decided  expression  of  a  mean  volcanic 
axial  direction,  that  is  to  say,  of  the  Thian-schau  being  prolonged  west- 
ward through  the  Caucasus.  Many  other  mountain-directions  of 
Central  Asia,  however,  also  revert  to  this  remarkable  space,  and  stand, 
as  elsewhere,  in  mutual  relation  to  each  other,  so  as  to  form  vast  moun- 
tain nuclei  and  maxima  of  elevation."  Pliny  (vi,  17),  says  : — "  Persse 
appellavere  Caucasum  montem  Graucasim  (var.  Graucasum,  Groucasim, 
Grocasurn),  hoc  est  nive  candidum  ;"  in  which  Bohleu  thought  the 
Sanscrit  words  Teds,  to  shine,  and  gravan,  rock,  were  to  be  recognised 
(see  my  Asie  Centrale,  t.  i,  p.  109).  As  Klausen  says,  in  his  investiga- 
tions on  the  wanderings  of  lo  (Rheinisckes  Museum  fur  Philoloyie, 
Jahrg  iii,  1845,  s.  298),  if  the  name  Graucasus  was  corrupted  into  Cau- 
casus, then  a  name  "  in  which  each  of  its  first  syllables  gave  the  Greeks 
the  idea  of  burning  might  certainly  characterise  a  burning  mountain, 
with  which  the  history  of  the  Fire-burner  (Fire-igniter,  -rrvoKatvi-)  would 
become  readily  and  almost  spontaneously  associated."  It  cannot  be  denied 
that  myths  sometimes  originate  from  names,  but  the  production  of  so 
great  and  important  a  fable,  as  the  Typhonico-caucasic,  can  certainly  not 


SALSES.  209 

and  in  the  south-east  of  the  great  mountain  chain,  the 
naphtha-springs  and  naphtha-fire  of  Baku  and  the  Caspian 
peninsula,  Apscheron.  The  magnitude  and  connection  of 
this  phenomenon  was,  however,  first  discovered  by  Abich, 
distinguished  by  his  profound  knowledge  of  this  part  of 
Asia.  According  to  him,  the  mud-volcanoes  and  naphtha- 
fires  of  the  Caucasus  are  arranged  in  a  distinctly  recognisable 
manner  in  certain  lines,  which  stand  in  unmistakeable  rela- 
tion with  the  axes  of  elevation  and  the  directions  of  dislo- 
cation of  the  strata  of  rock.  The  greatest  space,  of  nearly 
4,000  square  miles,  is  occupied  by  genetically  connected 
mud-volcanoes,  naphtha-emanations  and  saline  springs  in 
the  south-eastern  part  of  the  Caucacus,  in  an  isosceles 
triangle,  the  base  of  which  is  the  shore  of  the  Cas- 

be  derivable  from  the  accidental  similarity  of  sound  in  the  misunderstood 
name  of  a  mountain.  There  are  better  arguments,  of  which  Klausen  also 
mentions  one.  From  the  actual  association  of  Typhon  and  the  Caucasus, 
and  from  the  express  testimony  of  Pherecydes  of  Syros  (in  the  time  of 
the  58th  Olympiad),  it  is  clear  that  the  eastern  extremity  of  the  world 
was  regarded  as  a  volcanic  mountain.  According  to  one  of  the  Scholia 
to  Apollonius  (Scholia  in  Apoll.  Rhod.,  ed.  Schaeiferi,  1813,  v.  1210, 
p.  524),  Pherecydes  says,  in  the  Theogony,  "that  Typhon,  when  pur- 
sued, fled  to  the  Caucasus,  and  that  then  the  mountain  burnt  (or  was 
set  on  fire);  that  from  thence  Typhon  fled  to  Italy,  when  the  island 
Pithecusa  was  thrown  around  (as  it  were,  poured  around)  him."  But 
Pithecusa  is  the  island  ^Enaria  (now  Ischia),  upon  which  the  Epomeus 
(Epopon)  cast  forth  fire  and  lava,  according  to  Julius  Obsequens,  95 
years  before  our  era,  then  during  the  reigns  of  Titus  and  Diocletian, 
and  lastly,  in  the  year  1302,  according  to  the  statement  of  Tolomeo 
Fiadoni  of  Lucca,  who  was  at  that  time  Prior  of  Santa  Maria  Novella. 
"  It  is  singular,"  as  Boeckh,  the  profound  student  of  antiquity,  writes  to 
me,  "  that  Pherecydes  should  make  Typhon  fly  from  the  Caucasus 
because  it  burnt,  as  he  himself  is  the  originator  of  subterraneous  fire; 
but  that  his  residence  upon  the  Caucasus  rests  upon  the  occurrence  of 
volcanic  eruptions  there,  appears  to  me  to  be  undeniable."  Apollonius 
Rhodius  (Argon,  lib.  ii,  v.  1212 — 1217,  ed.  Beck)  in  speaking  of  the  birth 
of  the  Colchian  Dragon,  also  places  in  the  Caucasus  the  rock  of  Typhon, 
on  which  the  giant  was  struck  by  the  lightning  of  Jupiter.  Although  the 
lava-streams  and  crater-lakes  of  the  high  land  of  Kely,  the  eruptions  of 
Ararat  and  Elburuz,  or  the  currents  of  obsidian  and  pumice-stone  from 
the  old  craters  of  the  Puotandagh,  may  be  placed  in  a  pre-historic 
period,  still  the  many  hundred  flamos  which  even  now  break  forth 
from  fissures  in  the  Caucasus,  both  from  mountains  of  seven  or  eight 
thousand  feet  in  height  and  from  broad  plains,  may  have  been  a  suffi- 
cient reason  for  regarding  the  entire,  mountain  district  of  the  Caucasus 
as  a  Typhonic  seat  of  fire. 

VOL.  Y.  P 


210  COSMOS. 

plan  Sea  near  Balachani  (to  the  north  of  Baku)  and  one  of 
the  mouths  of  the  Kur  (Araxes),  near  the  hot  springs  of 
Sallian.  The  apex  of  such  a  triangle  is  situated  near  the 
Schagdagh  in  the  elevated  valley  of  Kinalughi.  There,  at 
the  boundary  of  a,  dolomitic  and  slate  formation,  at  an  ele- 
vation of  8350  feet  above  the  Caspian  Sea,  close  to  the 
village  of  Kinalughi  itself,  break  forth  the  perpetual  fires  of 
the  Schagdagh,  which  have  never  been  extinguished  by  me- 
teorological occurrences.  The  central  axis  of  this  triangle 
corresponds  with  the  direction  which  the  earthquakes,  so 
often  experienced  in  Schamacha  upon  the  banks  of  the 
Pyrsagat,  appear  constantly  to  follow.  When  the  north- 
western direction  just  indicated  is  traced  further,  it  strikes 
upon  the  hot  sulphurous  springs  of  Akti,  and  then  becomes 
the  line  of  strike  of  the  principal  crest  of  the  Caucasus  where 
It  rises  up  into  the  Kasbegk  and  bounds  Daghestan.  The 
salses  of  the  lower  region,  which  are  often  regularly  arranged 
in  series,  gradually  become  more  numerous  towards  the  shore 
of  the  Caspian,  between  Sallian,  the  mouth  of  the  Pyrsagat 
(near  the  island  of  Swinoi),  and  the  peninsula  of  Apscheron. 
They  present  traces  of  repeated  mud  eruptions  in  earlier 
times,  and  often  bear  at  their  summits  small  cones,  from 
which  combustible  and  often  spontaneously  ignited  gas  is 
poured  forth,  and  which  are  exactly  similar  in  form  to  the 
hornitos  of  Jortillo  in  Mexico.  Considerable  eruptions  of 
flame  were  particularly  frequent  between  1844  and  1849,  at 
the  Oudplidagh,  Nahalath,  and  Turandagh.  Close  to  the 
mouth  of  the  Pyrsagat  on  the  mud  volcano  Toprachali, 
"  black  marly  fragments,  which  at  the  first  glance  might  be 
confounded  with  dense  basalt,  and  extremely  fine-grained 
doleritic  rocks"  are  found  (a  proof  of  the  exceptional,  greatly 
increased  intensity  of  the  subterranean  heat).  At  other 
points  on  the  peninsula  of  Apscheron,  Lenz  found  slag-like 
fragments  as  products  of  eruption  ;  and  during  the  great 
eruption  of  flame  of  Backlichli  (7th  February,  1839),  small 
hollow  balls,  like  the  so-called  ashes  of  the  true  volcanoes, 
were  carried  by  the  wind  to  a  long  distance.62 

62  Humboldt,  Asie  Centrale,  t.  ii,  pp.  511  and  513.  I  Lave  already 
(t.  ii,  p.  201 )  called  attention  to  the  fact  that  Edrisi  does  not  mention 
the  fire  of  Baku,  although  it  is  described  diffusely  as  a  Nefala-land,  that 
is  to  say,  rich  in  burning  naphtha  swings,  by  Mass1*^/  *)othbeddin,  two 


SALSES.  211 

In  the  north-western  extremity  towards  the  Cimmerian 
Bosphorus  are  the  mud  volcanoes  of  the  peninsula  of  Taman, 
which  form,  one  group  with  those  of  Aklanisowka  and 
Jenikale  near  Kertsch.  One  of  the  salses  of  Taman  exhibited 
an  eruption  of  mud  and  gas  on  the  27th  of  February,  1793,  in 
which,  after  much  subterranean  noise,  a  column  of  fire  half 
enveloped  in  black  smoke  (dense  aqueous  vapour  ?)  rose  to  a 
height  of  several  hundred  feet.  It  is  a  remarkable  pheno- 
menon, and  instructive  as  regards  the  nature  of  the  Volcan- 
citos  de  Turbaco,  that  the  gas  of  Taman.  which  was  tested  in 
1811  by  Frederick  Parrot  and  Engelhardt,  was  not  inflam- 
mable -j  whilst  the  gas  collected  by  G-obel  in  the  same  place, 
23  years  later,  burnt,  from  the  mouth  of  a  glass  tube,  with 
a  bluish  flame  like  all  emanations  from  the  salses  in  the 
south-eastern  Caucasus,  but  also,  when  carefully  analysed, 
contained  in  100  parts  92.8  of  carburetted  hydrogen  and  5 
parts  of  carbonic  oxide  gas.63 

A  phenomenon  certainly  nearly  allied  to  these  in  its  origin, 
although  different  as  regards  the  matter  produced,  is  pre- 
sented by  the  eruptions  of  boracic  acid  vapours  in  the  Tuscan 
Maremma,  known  under  the  names  of  lagoni,  fiimmarole, 
soffioni,  and  even  volcani,  near  Possara,  Castel  Novo,  and 
Monte  Cerboli.  The  vapours  have  an  average  temperature 
of  205°  to  212°,  and  according  to  Pella,  in  certain  points,  as 
much  as  347°.  They  rise  in  part  directly  from  clefts  in  the 
rocks,  and  partly  from  stagnant  pools,  in  which  they  throw  up 
small  cones  of  fluid  clay.  They  are  seen  to  diffuse  them- 
selves in  the  air  in  whitish  eddies.  The  boracic  acid,  which 
is  brought  up  by  the  aqueous  vapours  from  the  bosom  of 
the  earth,  cannot  be  obtained  when  the  vapours  of  the 
sqffioni  are  condensed  in  very  wide  and  long  tubes,  but 
becomes  diffused  in  the  atmosphere  in  consequence  of  its 
volatility.  The  acid  is  only  procured  in  the  beautiful  esta- 
blishments of  Count  Larderel,  when  the  orifices  of  the 

hundred  years  before,  in  the  tenth  century  (see  Frahn,  Ibn  Fozlan, 
p.  245,  and  on  the  etymology  of  the  Median  word  naphtha,  Asiatic 
Journal,  vol.  xiii,  p.  124). 

6:5  Compare  Moritz  von  Engelhardt  and  F.  Parrot,  Reise  in  die  Krym 
und  den  Kaukasus,  1815,  Th.  i,  s.  71,  with  Gobel,  Reise  in  die  Steppen 
dex  xiid  lichen  Russlands,  1838,  Th.  i,  s.  249—253.  aud  Th.  ii,  s.  138 
—144, 

p  2 


212  COSMOS. 

sofnoni  are  covered  directly  by  the  fluid  of  the  basin.64 
.According  to  Payen's  excellent  analysis,  the  gaseous  emana- 
tions contain  0'57  of  carbonic  acid,  0'35  of  nitrogen,  and 
only  0'07  of  oxygen,  and  O001  of  sulphuric  acid.  Where 
the  boracic  acid  vapours  permeate  the  clefts  of  the  rock, 
they  deposit  sulphur.  According  to  Sir  "Roderick  Murchi- 
son's  investigations  the  rock  is  in  part  of  a  chalky  nature, 
and  in  part  an  eocene  formation,  containing  nummulites — a 
maciffno,  which  is  penetrated  by  the  uncovered  and  elevated 
serpentine 65  ol  the  neighbourhood  (near  Monte  Rotondo).  In 
this  case,  and  in  the  crater  of  Volcano,  asks  Bischof,  do 
not  hot  aqueous  vapours  act  upon  and  decompose  boracic 
minerals,  such  as  rocks  rich  in  datolithe,  axinite  or  tourma- 
line?66 

In  the  variety  and  grandeur  of  the  phenomena,  the  system 
of  somoni  in  Iceland  exceeds  anything  that  we  are  ac- 
quainted with  on  the  continent.  Actual  mud-springs  burst 
forth  in  the  fumarole-field  of  Krisuvek  and  Reykjalidh, 
from  small  basins  with  crater-like  margins  in  a  bluish  gray 

64  Payen,  De   I'acide  boracique   des  Suffioni   de  la   Toscane,  in   the 
Annaks  de  Chimie  et  de  Physique,  3me  se"rie,  t.  i,  1841,  pp.  247 — 255  ; 
Bischof,  Chem.  imd  Physik.   Geologic,  Bd.  i,  s.  669—691;  EtaUissements 
industriels  de  I'acide  boracique  en  Toscane,  by  the  Count  de  Larderel, 
p.  8. 

65  Sir  Eoderick  Impey  Murchison,  On  the  vents  of  hot  vapour  in  Tus- 
cany, 1850,  p.  7  (see  also  tl'e  earlier  geognostic  observations  of  Hoff- 
mann, in  Karstens  und  JJechens  Archiv  fur  Mineral.  Bd.  xiii,  1839, 
s.  19).     From  old  but  trustworthy  traditions,  Targioni  Tozzeti  asserts 
that  some  of  these  boracic  acid  springs  which  are  constantly  changing 
their  place  of  eruption  were  once  seen  to  be  luminous  (ignited)  at  night. 
In  order  to  increase  the  geological  interest  of  the  observations  of  Mur- 
chison and  Pareto  upon  the  volcanic  relations  of  the  serpentine  forma- 
tion in  Italy,  I  may  here  advert  to  the  fact  that  the  flame  of  the  Asiatic 
Chimcera  (near  the  town  of  Deliktasch,  the  ancient  Phaselis  in  Lycia, 
on  the  west  coast  of  the  Gulf  of  Adalia)  which  has  been  burning  lor 
several  thousand  years,  also  rises  from  a  hill  on  the  slope  of  the  Soli- 
mandagh,  in  which  serpentine  in  position  and  blocks  of  limestone  have 
been  found,    liather  more  to  the  south,  on  the  small  island  of  Gram- 
busa,  the  limestone  is  deposited  upon  dark-coloured  serpentine.     See 
the  important  work  of  Admiral  Beaufort  (Survey  of  the  Coasts  of  Cara- 
mania,  1818,  pp.  40  and  48),  whose  statements  are  confirmed  by  the 
specimens  of  rocks  just  brought  home  (May,  1854),  by  a  highly  talented 
artist,  Albrecht  Berg  (Pierre  de  Tchihatcheff,  Asie  Mineure,  1853,  t.  i, 
p.  407.) 

66  Bischof,  op.  cit.  s.  682. 


COSMOS.  213 

clay.67  Here  also  the  fissures  of  the  springs  may  be  traced 
in  determinate  directions.68  There  is  no  portion  of  the  earth, 
where  hot  springs,  salses  and  gas-eruptions  occur,  that  has 
been  made  the  subject  of  such  admirable  and  complete  che- 
mical investigations  as  those  on  Iceland,  which  we  owe  to 
the  acute  and  persevering  exertions  of  Bunsen.  Nowhere, 
perhaps,  in  such  a  great  extent  of  country,  or  so  near  the 
surface,  is  such  a  multifarious  spectacle  of  chemical  decom- 
positions, conversions,  and  new  formations  to  be  witnessed. 

Passing  from  Iceland  to  the  neighbouring  American  con- 
tinent we  find  in  the  State  of  New  York,  in  the  neighbour- 
hood of  Fredonia,  not  far  from  Lake  Erie,  a  multitude  of 
jets  of  inflammable  gas  (carburetted  hydrogen),  breaking  forth 
from  fissures  in  a  basin  of  Devonian  sandstone  strata,  and 
partly  employed  for  the  purpose  of  illumination.  Other 
springs  of  inflammable  gas,  near  Rushville,  assume  the  form 
of  mud  cones ;  and  others,  in  the  valley  of  the  Ohio,  in 
Virginia,  and  on  the  Kentucky  river,  also  contain  chloride 
of  sodium,  and  are  there  connected  with  weak  naphtha 
springs.  But  on  the  other  side  of  the  Caribbean  Sea,  on  the 
north  coast  of  South  America,  11^  miles  south-south-east 
from  the  harbour  of  Cartagena  de  Indias,  near  the  plea- 
sant village  of  Turbaco,  a  remarkable  group  of  salses  or 
mud- volcanoes  exhibits  phenomena,  which  I  was  the  first  to 
describe. 

In  the  neighbourhood  of  Turbaco,  where  one  enjoys  a 
magnificent  view  of  the  colossal  snowy  mountains  (Sierras 
Nevadas)  of  Santa  Marta,  on  a  desert  spot  in  the  midst  of 
the  primeval  forest,  rise  the  Volcancitos,  to  the  number  of 
18  or  20.  The  largest  of  the  cones,  which  consist  of  blackish 
gray  loam,  are  from  19  to  23  feet  in  height,  and  probably 
80  feet  in  diameter  at  the  base.  At  the  apex  of  each  cone 
is  a  circular  orifice  of  20  to  28  inches  in  diameter,  surrounded 
by  a  small  mud-wall.  The  gas  rushes  up  with  great  violence, 
as  in  Taman,  forming  bubbles,  each  of  which,  according  to 
my  measurements  in  graduated  vessels,  contains  10 — 12 
cubic  inches.  The  upper  part  of  the  funnel  is  filled  with 

67  Sartorius   von  "\Valtershausen,    Plnjsiscli-geoyrapliixclie   Sklz:.e  von 
Island,  1847,  R.  123;  Bunsen  "upon  the  processes  of  formation  of  the 
volcanic  rocks  of  Iceland,"  Pog^end.  Annalen,  Bd.  Ixxxiii,  s.  207. 

68  Waltershausen,  op.  cit.  s.  11  £. 


214  COSMOS. 

water,  which  rests  upon  a  compact  floor  of  mud.  The  erup- 
tions are  not  simultaneous  in  neighbouring  cones,  but  in 
each  one  a  certain  regularity  was  observable  in  the  periods 
of  the  eruptions.  Bonpland  and  I,  standing  on  the  outer- 
most parts  of  the  group,  counted  pretty  regularly  5  eruptions 
every  2  minutes.  On  beading  down  over  the  small  orifice 
of  the  crater  a  hollow  sound  is  perceived  in  the  interior  of 
the  earth,  far  below  the  base  of  the  cone,  usually  20  seconds 
before  each  eruption.  A  very  thin  burning  wax  taper  was 
instantly  extinguished  in  the  gas,  which  was  twice  collected 
with  great  care ;  this  was  also  the  case  with  a  glowing  chip 
of  the  wood  Bombax  Ceiba.  The  gas  could  not  be  ignited. 
Lime  water  was  not  rendered  turbid  by  it ;  no  absorption 
took  place.  When  tested  for  oxygen  with  nitrous  acid  gas, 
this  gas  showed  no  trace  of  the  former  in  one  experiment ; 
in  a  second  case,  when  the  gas  of  the  Yolcancitos  had  been 
confined  for  many  hours  in  a  bell  glass  with  water,  it  exhi- 
bited ratter  more  than  one  hundredth  of  oxygen,  which 
had  probably  been  evolved  from  the  water  and  accidentally 
intermixed. 

From  these  analytical  results  I  then  declared,  perhaps  not 
very  incorrectly,  that  the  gas  of  the  Volcancitos  of  Turbaco 
was  nitrogen  gas,  which  might  be  mixed  with  a  small 
quantity  of  hydrogen.  At  the  same  time  I  expressed  my 
regret  in  my  journal,  that  in  the  state  of  chemistry  at  that 
time  (April,  1801),  no  means  were  known  by  which,  in  a 
mixture  of  nitrogen  and  hydrogen  gases,  the  numerical 
proportions  of  the  mixture  might  be  determined.  The 
expedient,  by  the  employment  of  which  three  thousandths 
of  hydrogen  may  be  detected  in  a  gaseous  mixture,  was  only 
discovered  by  Gay-Lussac  and  myself  four  years  afterwards,69 
During  the  half-century  that  has  elapsed  since  my  residence 
in  Turbaco,  and  my  astronomical  survey  of  the  Magdalena 
river,  no  traveller  had  occupied  himself  scientifically  with 
the  small  mud-volcanoes  just  described,  until,  at  the  end  of 
December,  1850,  my  friend  Joaquin  Acosta,70  so  well  versed 

69  Humboldt  and  Gay-Lussac,  Memoire  sur  ^analyse  de  I'air  atmo- 
spherique  in  the  Journal  de  Physique,  par  Lametherie,  t.  Ix,  p.  151  (see 
my  Kleinere  Schriften,  Bd.  i,  s.  346). 

70  "  It  is  with  emotion  that  I  have  just  visited  a  place  which  you 
made  known  fifty  years  ago.     The  appearance  of  the  small  volcanoes  of 


SALSES.  215 

in  modern  geognosy  and  chemistry,  made  the  remarkable 
observation  that  at  present  "  the  cones  diffuse  a  bituminous 
odour ;"  (of  which  no  trace  existed  in  my  time) ;  "  that  some 
petroleum  floats  upon  the  surface  of  the  water  in  the  small 
orifices,  and  that  the  gas  pouring  out  may  be  ignited  upon 
every  mud-cone  of  Turbaco."  Does  this,  asks  Acosta,  indi- 
cate an  alteration  of  the  phenomena  brought  about  by 
internal  processes,  or  simply  an  error  in  the  earlier  experi- 
ments ?  I  would  admit  the  latter  freely,  if  I  had  not 
preserved  the  leaf  of  the  journal  on  which  the  experiments 
were  recorded  in  detail,71  on  the  very  morning  on  which 

Turbaco  is  such  as  you  have  described  ;  there  is  the  same  luxuriance 
of  vegetation,  the  same  form  of  cones  of  clay,  and  the  same  ejection  01 
liquid  and  muddy  matter ;  nothing  has  changed,  unless  it  be  the 
nature  of  the  gas  which  is  evolved.  I  had  with  me,  in  accordance 
with  the  advice  of  our  mutual  friend,  M.  Boussiugault,  all  that  was 
necesssary  for  the  chemical  analysis  of  the  gaseous  emanations,  and  even 
for  making  a  freezing  mixture  for  the  purpose  of  condensing  the  aqueous 
vapour,  as  the  doubt  had  been  expressed  to  me  that  nitrogen  might 
have  been  confounded  with  this  vapour.  But  this  apparatus  was  by 
no  means  necessary.  As  soon  as  I  arrived  at  the  Volcancitos,  the  dis- 
tinct odour  of  bitumen  set  me  in  the  right  course;  I  commenced  by 
lighting  the  gas  upon  the  very  orifice  of  each  small  crater.  Even  now 
one  sees  on  the  surface  of  the  liquid,  which  rises  intermittently,  a  deli- 
cate film  of  petroleum.  The  gas  collected  burns  away  entirely,  without 
any  residue  of  nitrog-en(?)  and  without  depositing  sulphur  (when  in 
contact  with  the  atmosphere).  Thus  the  nature  of  the  phenomenon  has 
completely  c/tanr/ed  since  your  journey,  unless  we  admit  an  error  of  obser- 
vation, justified  by  the  less  advanced  state  of  experimental  chemistry 
at  that  period.  I  no  longer  doubt  that  the  great  eruption  of  Galera 
Zamba,  which  illuminated  the  country  in  a  radius  of  100  kilometres 
(62  miles),  is  a  salses-like  phenomenon,  developed  on  a  great  scale,  since 
there  exist  hundreds  of  little  cones,  vomiting  saline  clay,  upon  a  surface 
of  400  square  leagues.  I  propose  examining  the  gaseous  products  of 
the  cones  of  Tubara,  which  are  the  most  distant  salses  from  your 
Volcancitos  of  Turbaco.  From  the  powerful  manifestations  which  have 
caused  the  disappearance  of  a  part  of  the  peninsula  of  Galera  Zamba, 
now  become  an  island,  and  from  the  appearance  of  a  new  island  raised 
from  the  bottom  of  the  sea  in  1848,  and  which  has  since  disappeared, 
I  am  led  to  think  that  it  is  near  Galera  Zamba,  to  the  west  of  the  delta 
of  the  Rio  Magdalena,  that  the  principal  focus  of  the  phenomenon  of 
salses  in  the  province  of  Carthagena  is  situated"  (from  a  letter  from 
Colonel  Acosta  to  A.  von  Huinboldt,  Turbaco,  21  December,  1850). 
See  also  Mosquera,  Memoria  politica  sobre  la  Nueva  Granada,  1852, 
p.  73  ;  and  Lionel  Gisborne,  The  Isthmus  of  Darien,  p.  48. 

71  During  the  whole  of  my  American  expedition  I  always  adhered 
strictly  to  the  advice  of  Yauquelin,  under  whom  I  worked  for  some  time 


216  COSMOS. 

they  were  made.     I  find  nothing  in  them  that  could  make 
me  at  all  doubtful  now ;  and  the  observation  already  referred 

before  my  voyage  :  to  write  down  and  preserve  the  details  of  every 
experiment  on  the  same  day.  From  my  journals  of  the  17th  and 
18th  April,  1801,  I  here  copy  the  following  : — "  As,  therefore,  the  gas 
showed  scarcely  0.01  of  oxygen  from  experiments  with  phosphorus 
and  nitrous  acid  gas,  and  not  0.02  of  carbonic  acid  with  lime-water,  the 
question  is,  what  are  the  other  97  hundredths?  I  supposed,  first  of  all, 
carburetted  and  sulphuretted  hydrogen ;  but  no  sul  phur  is  deposited 
on  the  margins  of  the  small  craters  in  contact  with  the  atmosphere, 
and  no  odour  of  sulphuretted  hydrogen  was  to  be  perceived.  The  pro- 
blematical part  might  appear  to  be  pure  nitrogen,  for,  as  above  men- 
tioned, nothing  was  ignited  by  a  burning  taper ;  but  I  know,  from  the 
time  of  my  analyses  of  fire-damp,  that  a  light  hydrogen  gas,  free  from 
any  carbonic  acid,  which  merely  stood  at  the  top  of  a  gallery  did  not 
ignite,  but  extinguished  the  pit  candles,  whilst  the  latter  burnt  clearly 
in  deep  places,  when  the  air  was  considerably  mixed  with  nitrogen  gas. 
The  residue  of  the  gas  of  the  Volcancitos  is,  therefore,  probably  to  be 
regarded  as  nitrogen,  with  a  portion  of  hj'drogen  gas,  the  quanti- 
tative amount  of  which ,we  do  not  at  present  know.  Does  the  same 
carbonaceous  schist  that  I  saw  further  westward  on  the  Rio  Sinu,  or 
marl  and  clay,  lie  below  the  Volcancitos  ?  Does  atmospheric  air  penetrate 
through  narrow  fissures  into  cavities  formed  by  water  and  become  de- 
composed in  contact  with  blackish  gray  loam,  as  in  the  pits  in  the 
saline  clay  of  Hallein  and  Berchtholdsgaden,  where  the  chambers  are 
filled  with  gases  which  extinguish  lights  ?  or  do  the  gases,  streaming  out 
tense  and  elastic,  prevent  the  penetration  of  atmospheric  air?"  These 
questions  were  sf't  down  by  me  in  Turbaco  53  years  ago.  According  to 
the  most  recent  observations  of  M.  Vauvert  de  Mdan  (1854)  the  inflam- 
mability of  the  gas  emitted  has  been  completely  retained.  The  traveller 
brought  with  him  samples  of  the  water  which  fills  the  small  orifice  of 
the  craters  of  the  Volcancitos.  In  this  Boussingault  found  in  the  litre: 
common  salt,  6.59  gr. ;  carbonate  of  soda,  0.31;  sulphate  of  soda,  0.20; 
and  also  traces  of  borate  of  soda  and  iodine.  In  the  mud  which  had 
fallen  to  the  bottom,  Ehrenberg,  by  a  careful  microscopic  examination, 
found  no  calcareous  parts  or  scoriaceous  matter,  but  quartz  granules 
mixed  with  micaceous  laminre,  and  many  small  crystalline  prisms  of 
black  Augite,  such  as  often  occurs  in  volcanic  tufa ;  no  trace  of  Spon- 
giolites  or  Polygastric  Infusoria,  and  nothing  to  indicate  the  vicinity 
of  the  sea,  but  on  the  contrary  many  remains  of  Dicotyledonous  plants 
and  grasses,  and  sporangia  of  lichens,  reminding  one  of  the  consti- 
tuents of  the  Moya  of  Pelileo.  Whilst  C.  Saiute-Claire,  Deville,  and 
George  Bornemann,  in  their  beautiful  analyses  of  the  Macalube  di 
Terrapilata,  found  0.99  of  carburetted  hydrogen  in  the  gas  emitted,  the 
gas  which  rises  in  the  Agua  Santa  di  Limosina,  near  Catanea,  gave 
them,  like  Turbaco  formerly,  0.98  of  nitrogen,  without  a  trace  of. 
oxygen  (Comptes  rendus  de  I'Acad.  des  Sciences,  t.  xliii,  1856,  pp.  361 
and  366). 


SALSES.  217 

to  (from  Parrot's  Keports),  that  "the  gas  of  the  mud- 
volcanoes  of  the  peninsula  of  Taman  in  1811  had  the 
property  of  preventing  combustion,  as  a  glowing  chip  was 
extinguished  in  the  gas,  and  even  the  ascending  bubbles,  a 
foot  in  diameter,  could  not  be  ignited  at  the  moment  of 
their  bursting,"  whilst  in  1834,  Gobel  saw  readily  inflam- 
mable gas  burning  with  a  bluish  flame  at  the  same  place, — 
leads  me  to  believe  that  the  emanations  undergo  chemical 
changes  in  different  stages.  Yery  recently  Mibscherlich  has, 
at  my  request,  determined  the  limits  of  inflammability  of 
artificially  prepared  mixtures  of  nitrogen  and  hydrogen 
gases.  It  appeared  that  mixtures  of  1  part  of  hydrogen 
gas  and  3  parts  of  nitrogen  gas,  not  only  took  fire  from  a 
light,  but  also  continued  to  burn.  When  the  quantity  of 
nitrogen  gas  was  increased,  so  that  the  mixture  consisted  oi 
1  part  of  hydrogen  and  3J  parts  of  nitrogen,  it  was  still 
inflammable,  but  did  not  continue  burning.  It  was  only 
ivitk  a  mixture  of\  part  nf  hydrogen  and  4  parts  of  nitrogen 
gas  tliat  no  ignition  too  place.  The  gaseous  emanations,  which 
from  their  ready  inflammability  and  the  colour  of  their 
flame  are  usually  called  emanations  of  pure  and  carburetted 
hydrogen,  need  therefore  consist  quantitatively  only  of  one- 
third  part  of  one  of  the  last-mentioned  gases.  With  mix- 
tures of  carbonic  acid  and  hydrogen,  which  occur  more 
rarely,  the  limits  of  inflammability  prove  different  again, 
on  account  of  the  capacity  for  heat  of  the  former.  Acosta 
justly  suggests  the  question: — "Whether  a  tradition  dis- 
seminated amongst  the  inhabitants  of  Turbaco,  descendants 
of  the  Indios  de  Taruaco,  according  to  which  the  Volcancitos 
formerly  all  burnt;  and  were  converted  from  Volcanes  de 
fucgo  into  Volcares  de  agua,  by  being  exorcised  and  sprinkled 
with  holywater  by  a  pious  monk72,  may  not  refer  to  a  con- 
dition which  has  now  returned  ?"  Single  great  eruptions  of 
flames  from  mud  volcanoes,  which  both  before  and  since 
have  been  very  inactive  (Tainan,  1793 ;  on  the  Caspian 
Sea,  near  Jokmali,  1827;  and  near  Baklichli,  1839;  near 

72  Humboldt,  Vues  des  Cordilleres  et  Monuments  dcs  pcuples  indigenes 
de  I'Amerique,  pi.  xli,  p.  239.  The  beautiful  drawing  of  the  Volcancitos 
de  Turbaco,  from  which  the  copperplate  was  engraved,  was  made  by  my 
young  fellow-traveller,  Louis  de  Rieux.  Upon  the  old  Taruaco  in  the 
first  period  of  the  Spanish  Conquista,  see  Herrera,  Dec.  i,  p.  251. 


218  COSMOS. 

Kuschtschy,  1846,  also  in  the  Caucasus),  present  analogous 
examples. 

The  apparently  unimportant  phenomenon  of  the  salses 
of  Turbaco,  has  gained  in  geological  interest  by  the  ter- 
rible eruption  of  flame,  and  the  terrestrial  changes  which 
occurred  in  1839,  more  than  32  geographical  miles  to  the 
N.N.E.  of  Cartagena  de  Indias,  between  this  harbour  and 
that  of  Sabanilla,  not  far  from  the  mouth  of  the  great 
Magdalena  river.  The  true  central  point  of  the  phenomenon 
was  the  Cape  Galera  Zamba,  which  projects  6 — 8  geo- 
graphical miles  into  the  sea,  in  the  form  of  a  narrow  penin- 
sula. For  the  knowledge  of  this  phenomenon  we  are  also 
indebted  to  Colonel  Acosta,  of  whom  science  has  unfor- 
tunately been  deprived  by  an  early  death.  In  the 
middle  of  the  tongue  of  land  there  stood  a  conical  hill, 
from  the  crater  of  which  smoke  (vapours)  and  gases  some- 
times poured  forth  with  such  violence  that  boards  and 
large  pieces  of  wood  which  were  thrown  into  it  were  cast 
back  again  to  a  great  distance.  In  the  year  1839  the 
cone  disappeared  during  a  considenible  eruption  of  fire,  and 
the  entire  peninsula  of  Galera  Zamba  became  an  island, 
separated  from  the  continent  by  a  channel  of  30  feet  in 
depth.  The  surface  of  the  sea  continued  in  this  peaceful 
state  until  on  the  7th  of  October,  1848,  at  the  place  of 
the  previous  breach,  a  second  terrible  eruption  of  flames 73 
appeared,  without  any  perceptible  earthquake  in  the 
vicinity,  lasted  for  several  days,  and  was  visible  at  a 
distance  of  from  40  to  50  miles.  The  salse  only  emitted  gases, 
but  no  solid  matters.  When  the  flames  had  disappeared 
the  sea-bottom  was  found  to  be  raised  into  a  small 
sandy  islet,  which  however  soon  disappeared  again.  More 
than  50  volcancitos  (cones  similar  to  those  of  Turbaco) 
now  surround  the  submarine  gas  volcano  of  Galera  Zamba, 
to  a  distance  of  from  18  to  '23  miles.  In  a  geological  point  of 
view  we  may  certainly  regard  this  as  the  principal  seat  of 
the  volcanic  activity  which  strives  to  place  itself  in  contact 
with  the  atmosphere,  over  the  whole  of  the  low  country 
from  Turbaco  to  beyond  the  delta  of  the  Bio  Grande  de  la 
Magdalena. 

73  Lettre  de  M.  Joaquin  Acosta  k  M.  Elie  de  Beaumont,  in  the 
Comptes  rendus  de  VAcad.  des  Sciences,  t.  xxix,  1849,  pp.  530 — 534. 


SALSES.  219 

The  uniformity  of  the  phenomena  which  are  presented  in 
the  various  stages  of  their  activity,  by  the  salses,  mud  vol- 
canoes, and  gas-springs  on  the  Italian  peninsula,  in  the 
Caucasus  and  in  South  America,  is  manifested  in  enormous 
tracts  of  land  in  the  Chinese  empire.  The  art  of  man  has 
there  from  the  most  ancient  periods  known  how  to  make  use 
of  this  treasure ;  nay,  even  led  to  the  ingenious  discovery  of 
the  Chinese  rope-boring,  which  has  only  of  late  become 
known  to  Europeans.  Borings  of  several  thousand  feet  in 
depth  are  produced  by  the  most  simple  application  of  human 
strength,  or  rather  of  the  weight  of  man.  I  have  elsewhere 74 
treated  in  detail  of  this  discovery,  and  also  of  the  "  fire 
springs,"  Ho-tsing,  and  "fiery  mountains,"  Ho-schan,  of 
Eastern  Asia.  They  bore  for  water,  brine-springs,  and  in- 
flammable gas,  from  the  south-western  provinces,  Yun-nan, 
Kuang-si,  and  Szu-tschuan  on  the  borders  of  Thibet,  to  the 
northern  province  Schan-si.  When  it  has  a  reddish  flame, 
the  gas  often  diffuses  a  bituminous  odour ;  it  is  transferred 
partly  in  portable  and  partly  in  lying  bamboo-tubes  to  re- 
mote places,  for  use  in  salt-boiling,  for  heating  the  houses,  or 
for  lighting  the  streets.  In  some  rare  cases  supply  of 
carburetted  hydrogen  gas  has  been  suddenly  exhausted,  or 
stopped  by  earthquakes.  Thus  we  know  that  a  celebrated 
Ho-tsing,  situated  to  the  south-west  of  the  town  of  Khiung- 
tscheu  (latitude  50°  27,'  longitude  101°  6'  East),  which  was 
a  salt  spring  burning  with  noise,  was  extinguished  in  the 
thirteenth  century,  after  it  had  illuminated  the  neighbour- 
hood from  the  second  century  of  our  era.  In  the  province 
of  Schan-si,  which  is  so  rich  in  coal,  there  are  some  ignited 
carbonaceous  strata.  Fiery  mountains  ( Ho-schan)  are  distri 
buted  over  a  great  part  of  China.  The  flames  often  rise  to  a 
great  height,  for  example,  in  the  mass  of  rock  of  the  Py-kia- 

<"4  Humboldt,  Asie  Centrale,  t.  ii,  pp.  519 — 540;  principally  from 
extracts  from  Chinese  works  by  Klaproth  and  Stanislas  Julien.  The  old 
Chinese  rope-boring,  which  was  repeatedly  employed,  and  sometimes 
with  advantage,  in  coal-pits  in  Belgium  and  Germany  between  1830  and 
1842,  had  been  described  (as  Jobard  has  discovered)  as  early  as  the 
17th  century,  in  the  Relation  of  the  Dutch  Ambassador,  Van  Hoorn, 
but  the  most  exact  account  of  this  method  of  boring  the  fire-springs 
(Ho-tsing)  is  given  by  the  French  missionary,  Imbert,  who  resided  so 
many  years  in  Kia-ting-fu  (see  Annales  de  la,  Propagation  de  la  Foy, 
1829,  pp.  369—381). 


220  COSMOS. 

schan,  at  the  foot  of  a  mountain  covered  with  perpetual  snow 
(lat.  31°  40'),  from  long,  open,  inaccessible  fissures  :  a  pheno- 
menon which  reminds  us  of  the  perpetual  fire  of  the  Shag- 
dagh  mountain  in  the  Caucasus. 

On  the  Inland  of  Java,  in  the  province  of  Samarang, 
at  a  distance  of  about  fourteen  miles  from  the  north  coast, 
there  are  salses  similar  to  those  of  Turbaco  and  Galera 
Zamba.  Very  variable  hills  of  25  to  30  feet  in  height, 
throw  out  mud,  salt-water,  and  a  singular  mixture  of 
hydrogen  gas  and  carbonic-acid76;  a  phenomenon  which  is 
not  to  be  confounded  with  the  vast  and  destructive  streams 
of  mud  which  are  poured  forth  during  the  rare  eruptions  of 
the  true,  colossal  volcanoes  of  Java  (Gununq  Kelut  and 
Gunung  Idjen).  Some  mofette-grottoes  or  sources  of  car- 
bonic acid  in  Java  are  also  very  celebrated,  particularly  in 
consequence  of  exaggerations  in  the  statements  of  some 
travellers,  as  also  from  their  connexion  with  the  myth  of  the 
Upas  poison-tree,  already  mentioned  by  Sykes  and  Loudon. 
The  most  remarkable  of  the  six  has  been  scientifically  de- 
scribed by  Junghuhn,  the  so-called  Vale  of  death  of  the 
island  (PaJcaraman)  in  the  mountain  Dieng,  near  Batur. 
It  is  a  funnel-shaped  sinking  on  the  declivity  of  a  moun- 
tain, a  depression  in  which  the  stratum  of  carbonic  acid 
emitted  attains  a  very  different  height  at  different  seasons. 
Skeletons  of  wild  hogs,  tigers,  and  birds  are  often  found  in 
it.76  The  poison-tree,  pohon  (or  better  puhn)  upas  of  the 
Malays  (Antiaris  toxicaria  of  the  traveller  Leschenault  de 

75  According  to  Diard,  Asie  Centrale,  t.  ii,  p.  515.  Besides  the  mud 
volcanoes  of  Damak  and  Surabaya,  there  are  upon  other  islands  of  the 
Indian  Archipelago  the  mud  volcanoes  of  Pulu-Semao,  Pulu-Kambing, 
and  Pulu-Koti :  see  Junghuhn,  Java,  seine  Gestalt  und  Pflanzendeckc, 
1852,  Abth.  iii,  s.  830. 

?6  Junghuhn,  Op.  cit.,  Abth.  i,  s.  201,  and  Abth.  iii,  s.  854—858. 
The  weaker  suffocating  caves  on  Java  are  Gua-Upas  and  Gua-Galan 
(the  first  word  is  the  Sanscrit,  gnhd,  cave).  As  there  can  certainly  be 
no  doubt  that  the  Grotto  del  Cane,  in  the  vicinity  of  the  Lago  di  Agnano 
is  the  same  that  Pliny  (ii,  cap.  93)  described  nearly  18  centuries  ago, 
"in  agro  Puteolano,"  as  "Charonea  scrobis  mortiferum  spiritum 
exhalans,"  we  must  certainly  share  in  the  surprise  felt  by  Scacchi 
(Memorie  geol.  sulla  Campania,  1849,  p.  48),  that  in  a  loose  soil,  so 
often  moved  by  earthquakes,  so  small  a  phenomenon  (the  supply  of 
a  small  quantity  of  carbonic  acid)  can  have  remained  unaltered  and  un- 
disturbed. 


SALSES.  221 

la  Tour),  with  its  harmless  exhalations,  has  nothing  to  do 
with  these  fatal  actions.77 

I  conclude  this  section  on  the  salses  and  steam  and  gas 
springs,  with  the  description  of  an  eruption  of  hot  sulphu- 
rous vapours,  which  may  attract  the  interest  of  geognosists 
on  account  of  the  kind  of  rock  from  which  they  are  evolved. 
During  my  delightful,  but  somewhat  fatiguing  passage  over 
the  central  Cordillera  of  Quindiu,  (it  took  me  14  or  15  days 
on  foot,  and  sleeping  constantly  in  the  open  air,  to  get  over 
the  mountain  crest  of  11.500  feet  from  the  valley  of  the  Rio 
Magdalena  into  the  Cauca  valley),  when  at  the  height  of 
6810  feet  I  visited  the  Azufral  to  the  west  of  the  station  el 
Moral.  In  a  mica-schist  of  a  rather  dark  colour,  which,  re- 
posing upon  a  gneiss  containing  garnets,  surrounds,  with  the 
latter,  the  elevated  granite  domes  of  la  Ceja  and  la  Garita 
del  Paramo,  I  saw  hot  sulphurous  vapours  flowing  out  from 
the  clefts  of  the  rocks  in  a  narrow  valley  (Quebrada  del 
Azufral).  As  they  are  mixed  with  sulphuretted  hydrogen 
gas  and  much  carbonic  acid,  a  stupefying  dizziness  is  expe- 
rienced on  stooping  down  to  measure  the  temperature,  and 
remaining  long  in  their  vicinity.  The  temperature  of  the 
sulphurous  vapours  was  117°  7  ;  that  of  the  air  69°  ;  and 
that  of  the  sulphurous  brook,  which  is  probably  cooled  in 
the  upper  parts  of  its  course  by  the  snow-waters  of  the 
volcano  of  Tolima,  84°.  6.  The  mica-schist,  which  contains 
some  pyrites,  is  permeated  by  numerous  fragments  of  sul- 
phur. The  sulphur  prepared  for  sale  is  principally  obtained 
from  an  ochre-yellow  loam,  mixed  with  native  sulphur  and 
weathered  mica-slate.  The  operatives  (Mestizoes)  suffer 
from  diseases  of  the  eyes  and  muscular  paralysis.  When 
Boussingault  visited  the  Azufral  de  Quindiu,  30  years  after 
me  (1831),  the  temperature  of  the  vapours  which  he  ana- 
lysed 78  had  so  greatly  diminished,  as  to  fall  below  that  of  the 
open  air  (7 1°!~6),  namely  to  66°—  68.°  The  same  excellent 
observer  saw  the  trachytic  rock  of  the  neighbouring  volcano 
of  Tolima,  breaking  through  the  mica-schist,  in  the  Quebrada 
de  Aguas  calientes  :  just  as  I  have  very  distinctly  seen  the 

77  Blume,  Rumphia  sire  Comment,  lotanicce,  t.  i  (1835),  pp.  47—59. 

"s  Humboldt,  Essai  r/eognostique  sur  le  gisement  des  Roches  dans  les 
deux  Hemispheres,  1823,  p.  76 ;  Boussingault,  in  the  Annales  de  Chimie 
tt  de  Physique,  t.  Hi,  1S33,  p.  11. 


222  COSMOS. 

equally  eruptive,  black  trachyte  of  the  volcano  of  Tungu- 
ragua  covering  a  greenish  mica-schist  containing  garnet  near 
the  rope-bridge  of  Penipe.  As  sulphur  has  hitherto  been 
found  in  Europe,  not  in  the  primitive  rocks  as  they  were 
formerly  called,  but  only  in  the  tertiary  limestone,  in  gypsum, 
in  conglomerates  and  in  true  volcanic  rocks,  its  occurrence 
in  the  Azufral  de  Quindiu  (4^°  N.  lat.)  is  the  more  remark- 
able, as  it  is  repeated  to  the  south  of  the  equator  between 
Quito  and  Cuenca,  on  the  northern  slope  of  the  Paramo  del 
Assuay.  In  the  Azufral  of  the  Cerro  Cuello  (2°  13'  S.  lat.). 
again  in  mica-schist,  at  an  elevation  of  7980  feet,  I  met 
with  a  vast  bed  of  quartz,79  in  which  the  sulphur  is  dissemi- 
nated abundantly  in  scattered  masses.  At  the  time  of  my 
journey  the  fragments  of  sulphur  measured  only  6  —  8  inches, 
but  they  were  formerly  found  of  as  much  as  3  —  4  feet  in 
diameter.  Even  a  naphtha  spring  rises  visibly  from  mica- 
schist  in  the  sea-bottom  in  the  gulf  of  Cariaco  near  Cumana. 
There  the  naphtha  gives  a  yellow  colour  to  the  surface  of  the 
sea  to  a  distance  of  more  than  a  thousand  feet,  and  I  found 
that  its  odour  was  diffused  as  far  as  the  interior  of  the  pen- 
insula of  Araya.80 

"9  With  regard  to  the  elevation  of  Alausi  (near  Ticsan)  on  the  Cerro 
Cuello,  see  the  "  Nivellement  barome'trique,  No.  206,"  in  my  Observ. 
Astron.  vol.  i,  p.  311. 

80  "  The  existence  of  a  naphtha  spring  issuing  at  the  bottom  of  the  sea 
from  a  mica-schist,  rich  in  garnets,  and  diffusing,  according  to  the  ex- 
pression of  the  historian  of,  the  Conquista,  Oviedo,  a  "  resinous,  aromatic, 
and  medicinal  liquid,"  is  an  extremely  remarkable  fact.  All  those 
hitherto  known  belong  to  secondary  mountains  ;  and  this  mode  of  stra- 
tification appeared  to  favour  the  idea  that  all  the  mineral  bitumens  (Hat- 
chett,  Transact.  Linncean  Society,  1798,  p.  129)  were  due  to  the  destruc- 
tion of  vegetable  and  animal  matters,  or  to  the  ignition  of  coal.  The 
phenomenon  of  the  Gulf  of  Cariaco  acquires  fresh  importance,  if  we 
bear  in  mind  that  the  same  so-called  primitive  stratum  contains  subter- 
ranean fires,  that  the  odour  of  petroleum  is  experienced  from  time  to 
time  at  the  edge  of  ignited  craters  (for  example,  in  the  eruption  of 
Vesuvius  in  1805,  when  the  volcano  threw  up  scoria?),  and  that  most  of 
the  very  hot  springs  of  South  America  issue  from  granite  (las  Trin- 
cheras,  near  Portocabello),  gneiss  and  micaceous  schist.  More  to  the 
eastward  of  the  meridian  of  Cumana,  in  descending  from  the  Sierra  de 
Meapire,  we  first  came  to  the  hollow  ground  (tierra  hueca),  which, 
during  the  great  earthquakes  of  1766,  threw  up  asphalte  enveloped  in 
viscous  petroleum  ;  and  afterwards,  beyond  this  ground,  to  an  infinity 
of  hydrosulphurous  hot  springs  (Humboldt,  Relation  Historique,  t,  i, 
pp.  136,  344,  347,  and  447). 


SALSES.  223 

If  we  now  cast  a  last  glance  at  the  kind  of  volcanic 
activity  which  manifests  itself  by  the  production  of  vapours 
and  gases,  either  with  or  without  phenomena  of  combustion, 
we  find  sometimes  a  great  affinity,  and  sometimes  a  remark- 
able difference  in  the  matters  escaping  from  fissures  of  the 
earth,  according  as  the  high  temperature  of  the  interior, 
modifying  the  action  of  the  affinities,  has  acted  upon  homo- 
geneous or  very  composite  materials.  The  matters  which 
are  driven  to  the  surface  by  this  low  degree  of  volcanic 
activity,  are  : — aqueous  vapour  in  great  quantity,  chloride  of 
sodium,  sulphur,  carburetted  and  sulphuretted  hydrogen, 
carbonic  acid  and  nitrogen  ;  naphtha  (colourless  or  yellowish, 
or  in  the  form  of  brown  petroleum)  ;  boracic  acid  and  alu- 
mina from  the  mud  volcanoes.  The  great  diversity  of  these 
matters,  of  which,  however,  some  (common  salt,  sulphuretted 
hydrogen  gas,  and  petroleum),  are  almost  always  associated 
together,  shows  the  unsuitableness  of  the  denomination 
salses,  which  originated  in  Italy,  where  Spallanzani  had  the 
great  merit  of  having  been  the  first  to  direct  the  attention 
of  geognosists  to  this  phenomenon,  which  had  been  long 
regarded  as  so  unimportant,  in  the  territory  of  Modena.  The 
name  vapour  and  gas  springs,  is  a  better  expression  of  the 
general  idea.  If  many  of  them,  such  as  the  Fumaroles, 
undoubtedly  stand  in  relation  to  extinct  volcanoes,  and  are 
even,  as  sources  of  carbonic  acid,  peculiarly  characteristic  of  a 
last  stage  of  such  volcanoes  ;  others,  on  the  contrary,  appear 
to  be  quite  independent  of  the  true  fiery  mountains  which 
vomit  forth  fused  earths.  Then,  as  Abich  has  already  shown 
in  the  Caucasus,  they  follow  definite  directions  in  large  tracts 
of  country,  breaking  out  of  fissures  in  rocks,  both  in  the  plains, 
even  in  the  deep  basin  of  the  Caspian  Sea,  and  in  moun- 
tain elevations  of  nearly  8500  feet.  Like  the  true  volcanoes, 
they  sometimes  suddenly  augment  their  apparently  dor- 
mant activity  by  the  eruption  of  columns  of  fire,  which 
spread  terror  all  around.  In  both  continents,  in  regions 
widely  separated,  they  exhibit  the  same  conditions  following 
one  upon  the  other  ;  but  no  observation  has  hitherto  justified 
us  in  supposing  that  they  are  the  forerunners  of  the  forma- 
tion of  true  volcanoes  vomiting  lava  and  cinders.  Their 
activity  is  of  another  kind,  perhaps  originating  at  a  smaller 
depth,  and  caused  by  different  chemical  processes. 


224  COSMOS. 

d  Volcanoes ,  according  to  the  difference  of  their  formation 
and  activity. — Action  ~by  fissures  and  cauldron-like  depres- 
sions.—  Circumvallation  of  the  craters  of  elevation. —  Vol- 
canic conical  and  hell-shaped  Mountains,  with  open  or 
closed  summits, — Difference  of  the  Rocks  through  which 
Volcanoes  act. 

(Amplification  of  the  Eepresentation  of  Nature : 
Cosmos,  vol.  i.,  pp.  225—247.) 

Amongst  the  various  specific  manifestations  of  force  in 
the  reaction  of  the  interior  of  our  planet  upon  its  uppermost 
strata,  the  mightiest  is  that  presented  by  the  true  Volcanoes  : 
— that  is  to  say,  those  openings  through  which,  besides 
gases,  solid  masses  of  various  materials  are  forced  up  from 
unmeasured  depths  to  the  surface,  either  in  a  state  of  igneous 
fusion,  as  lava  streams,  or  in  the  form  of  cinders,  or  as  pro- 
ducts of  the  finest  trituration  (ashes).  If  we  regard  the 
words  volcano  and  fiery  mountain  as  synonymous,  in  accord- 
ance with  the  old  usage  of  speech,  we  thus,  according  to  a 
preconceived  and  very  generally  diffused  opinion,  attach  to 
the  idea  of  volcanic  phenomena,  the  picture  of  an  isolated 
conical  mountain,  with  a  circular  or  oval  orifice  at  the 
summit.  Such  views,  however,  lose  their  universality  when 
the  observer  has  the  opportunity  of  wandering  through 
connected  volcanic  districts,  occupying  a  surface  of  many 
thousand  square  geographical  miles  ;  for  example,  the  entire 
central  part  of  the  highlands  of  Mexico,  between  the  Peak 
of  Orizaba,  Jorullo,  and  the  shores  of  the  South  Sea;  or 
Central  America ;  or  the  Cordilleras  of  New  Granada  and 
Quito,  between  the  Volcano  of  Purace",  near  Popayan,  that 
of  Pasto  and  Chimborazo ;  or  the  isthmian  chain  of  the 
Caucasus,  between  the  Kasbegk,  Elburuz  and  Ararat.  In 
lower  Italy,  between  the  Phlegraean  Fields  of  the  mainland 
of  Campania,  Sicily,  and  the  islands  of  Lipari  and  Ponza,  as 
also  in  the  Greek  Islands,  part  of  the  intervening  land  has 
not  been  elevated  with  the  volcanoes,  and  part  of  it  has 
been  swallowed  by  the  sea. 

In  the  above-mentioned  great  districts  of  America  and 
the  Caucasus,  masses  of  eruptions — (true  Trachytes,  and  not 


VOLCANOES.  225 

trachytic  conglomerates ;  streams  of  obsidian ;  quarried 
blocks  of  pumice -stone,  and  not  pumice  boulders  trans- 
ported and  deposited  by  water) — make  their  appearance, 
seeming  to  be  quite  independent  of  the  mountains,  which 
only  rise  at  a  considerable  distance.  Why  should  not  the 
surface  have  been  split  in  many  directions  during  the  pro- 
gressive refrigeration  of  the  upper  strata  of  the  earth  by 
radiation  of  heat,  before  the  elevation  of  isolated  mountains 
or  mountain  chains  had  yet  taken  place  ?  Why  should  not 
these  fissures  have  emitted  masses  in  a  state  of  igneous 
fusion,  which  have  hardened  into  rocks  and  eruptive  stones 
(trachyte,  dolerite,  melaphyre,  margarite,  obsidian,  and  pu- 
mice) ?  A  portion  of  these  trachytic  or  doleritic  strata  which 
have  broken  out  in  a  viscid  fluid  state,  as  if  from  earth- 
springs,81  and  which  were  originally  deposited  in  a  horizontal 
position,  have,  during  the  subsequent  elevation  of  volcanic 
cones  and  bell-shaped  mountains,  been  tilted  into  a  position 
which  by  no  means  belongs  to  the  more  recent  lavas,  pro- 
duced from  igneous  mountains.  Thus,  to  advert  in  the  first 
place  to  a  very  well-known  European  example,  in  the  Val 
del  Bove  on  Etna  (a  depression  which  cuts  deeply  into  the 
interior  of  the  mountain)  the  declination  of  the  strata  of 
lava,  which  alternate  very  regularly  with  masses  of  boulders,  is 
25°  to  30°,  whilst,  according  to  Elie  de  Beaumont's  exact 
determinations,  the  lava  streams  which  cover  the  surface  of 
Etna,  and  which  have  only  flowed  from  it  since  its  elevation 
in  the  form  of  a  mountain,  only  exhibit  a  declination  of  3° 
to  5°  on  an  average  of  30  streams.  These  conditions  indi- 
cate the  existence  of  very  ancient  volcanic  formations, 
which  have  broken  out  from  fissures,  before  the  production 
of  the  volcano  as  an  igneous  mountain.  A  remarkable  pheno- 
menon of  this  kind  is  also  presented  to  us  by  antiquity ;  a 
phenomenon  which  manifested  itself  on  Eubcea,  the  modern 
Negropout,  in  an  extended  plain,  situated  at  a  distance 
from  all  active  and  extinct  volcanoes.  "  The  violent  earth- 
quakes, which  partially  shook  the  island,  did  not  cease  until 
an  abyss,  which  had  opened  on  the  plain  of  Lelantus,  threw 
up  a  stream  of  glowing  mud  (lava)."*8 

81  Cosmos,  vol.  i,  p.  229. 

82  Strabo  i,  p.  58,  ed.  Casaub.     The  epithet  diairvpog,  proves  that  in 
this  case  mud-volcanoea  are  not  spoken  of.     Where  Plato,  in  his  geog- 

VOL.  V  Q. 


226  COSMOS. 

If  the  oldest  formations  of  eruptive  rock  (often  perfectly 
similar  to  the  more  recent  lavas  in  its  composition),  which 
also  in  part  occupy  veins,  are  to  be  ascribed  to  a  previous 
fissure  of  the  deeply  shaken  crust  of  the  earth,  as  I  have 
long  been  inclined  to  think,  both  these  fissures,  and  the  less 
simple  craters  of  elevation  subsequently  produced,  must  be 
regarded  only  as  volcanic  eruptive  orifices,  not  as  volcanoes 
themselves.  The  principal  character  of  these  last  consists 
in  a  connexion  of  the  deep-seated  focus  with  the  atmosphere, 
which  is  either  permanent,  or  at  least  renewed  from  time  to 
time.  For  this  purpose  the  volcano  requires  a  peculiar  frame- 
work ;  for,  as  Seneca  w  says  very  appropriately,  in  a  letter  to 
Lucilius,  "ignis  in  ipso  monte  non  alimentum  habet,  sed 
viam."  The  volcanic  activity  exerts,  therefore,  a  formative 
action  by  elevating  the  soil ;  and  not,  as  was  at  one  time  uni- 
versally and  exclusively  supposed,  a  building  action  by  the  ac- 
cumulation of  cinders,  and  new  strata  of  lava,  superposed  one 
upon  the  other.  The  resistance  experienced  in  the  canal  of 
eruption,  by  the  masses  in  a  state  of  igneous  fluidity  when 
forced  in  excessive  quantities  towards  the  surface,  gives  rise  to 
the  increase  in  the  heaving  force.  A  "  vesicular  inflation  of 
the  soil "  is  produced,  as  is  indicated  by  the  regular  outward 
declination  of  the  elevated  strata.  A  mine-like  explosion, 
the  bursting  of  the  central  and  highest  part  of  the  convex 
inflation  of  the  soil  gives  origin  sometimes  only  to  what 
Leopold  von  Buch  has  called  a  crater  of  elevation^  that  is 
nostic  phantasies,  alludes  to  these,  mixing  mythical  matter  with  ob- 
served facts,  he  says  distinctly  (in  opposition  to  the  phenomenon  de- 
scribed by  Strabo)  vypov  rrr)\ov  Trorajuot.  Upon  the  denominations 
TTJjXof  and  pua%,  as  volcanic  emissions,  I  have  treated  on  a  former 
occasion  (Cosmos,  vol.  i,  p.  236),  and  I  shall  only  advert  here  to 
another  passage  in  Strabo  (vi,  p.  269),  in  which  hardening  lava, 
called  71-77X6?  /iifXag,  is  most  distinctly  characterised.  In  the  description 
of  Etna  we  find : — "The  red-hot  stream  (pvaZ.)  in  the  act  of  solidifica- 
tion converts  the  surface  of  the  earth  into  stone  to  a  considerable 
depth,  so  that  whoever  wishes  to  uncover  it  must  undertake  the  labour 
of  quarrying.  For,  as  in  the  craters,  the  stone  is  molten  and  then  up- 
heaved, the  fluid  streaming  from  the  summit  is  a  black  excrementi- 
tious  mass  (Trr/Xot.)  falling  down  the  mountain,  which,  afterwards  har- 
dening, becomes  a  millstone,  and  retains  the  same  colour  that  it  had 
before." 

83  Cosmos,  vol.  i,  p.  238. 

84  Leopold  von  Buch,  On  Basaltic  Islands  and  Craters  of  Elevationt 
in  the  Abhandl.  der  kvnig.  Akad.  der  Wiss.  zu  Berlin,  1818 — 1819,  s.  51; 


CRATERS   OF   ELEVATION.  227 

to  say,  a  ci-ater-like,  round  or  oval  depression,  bounded  by  a 
circle  of  elevation,  a  ring-shaped  wall,  usually  broken  down 
in  places  ;  sometimes  (when  the  framework  of  a  perma- 
nent volcano  is  to  be  completed),  to  a  dome-shaped  or 
conical  mountain  in  the  middle  of  the  crater  of  elevation. 
The  latter  is  then  generally  open  at  its  summit,  and  on  the 
bottom  of  this  opening  (the  crater  of  the  permanent  volcano) 
rise  transitory  hills  of  eruption  and  hills  of  scoriae,  small  and 
large  cones  of  eruption,  which,  in  Vesuvius,  sometimes  far  ex- 
ceed  the  margins  of  the  crater  of  the  cone  of  elevation.  The 
signs  of  the  first  eruption,  the  old  framework,  are  not  however 
always  retained.  The  high  wall  of  rock  which  surrounds 
the  inner  circular  wall  (the  crater  of  elevation),  is  not  recog- 

and  Physicalische  Beschreibung  der  canarischen  Inseln,  1825,  s.  213, 
262,  284,  313,  323,  and  341.  This  work,  which  constitutes  an  era  in 
the  profound  knowledge  of  volcanic  phenomena,  is  the  fruit  of  a  voyage 
to  Madeira  and  Teneriffe  from  the  beginning  of  April  to  the  end  of 
October,  1815 ;  but  Naumann  indicates  with  much  justice,  in  his  Lekr- 
buch  der  Geognosie,  that  in  the  letters  written  in  1802  by  Leopold  von 
Buch,  from  Auvergne  (Geognostische  Beobacht.  auf  Reisen  durch  Deutsch- 
land  und  Italien,  Bd.  ii,  s.  282),  in  reference  to  the  description  of  Mont 
d'Or,  the  theory  of  craters  of  elevation  and  their  essential  difference 
from  the  true  volcanoes  was  already  expressed.  An  instructive  coun- 
terpart to  the  three  craters  of  elevation  of  the  Canary  Islands  (on  Gran 
Canaria,  Teneriffe,  and  Palma)  is  furnished  by  the  Azores.  The  admir- 
able maps  of  Captain  Vidal,  for  the  publication  of  which  we  are  in- 
debted to  the  English  Admiralty,  elucidate  the  wonderful  geognostic 
construction  of  these  islands.  On  San  Michael  is  situated  the  enormous 
Caldeira  das  sete  Cidades.  which  was  formed  in  the  year  1444,  almost 
under  Cabral's  eyes,  a  crater  of  elevation  which  encloses  two  lakes,  the 
Lagoa  grande  and  the  Lagoa  azul,  at  a  height  of  876  feet.  The  Cal- 
deira de  Corvo,  of  which  the  dry  part  of  the  bottom  is  1279  feet  high, 
is  almost  of  the  same  circumference.  Nearly  three  times  this  height  are 
the  craters  of  elevation  of  Fayal  and  Terceira.  To  the  same  kind  of 
eruptive  phenomena  belong  the  innumerable  but  ephemeral  platforms 
which  were  visible  only  by  day,  in  1691,  in  the  sea  around  the  island 
of  San  George,  and  in  1757  around  San  Michael.  The  periodical  inflation 
of  the  sea-bottom,  scarcely  four  miles  to  the  west  of  the  Caldeira  das 
sete  Cidades,  producing  a  larger  and  somewhat  more  permanent  island 
(Sabrina),  has  already  been  mentioned  (Cosmos,  vol.  i,  p.  241). 
Upon  the  crater  of  elevation  of  Astru»i,  in  the  Phlegnean  plains, 
and  the  trachytic  mass  driven  up  in  its  centre,  as  an  unopened  bell- 
shaped  hill,  see  Leopold  von  Buch,  in  Poggend.  Annalen.  Bd.  xxxvii, 
s.  171  and  182.  A  fine  crater  of  elevation  is  that  of  Rocca  Monfina. 
measured  and  figured  in  Abich's  Geolog.  Beobacht.  tiber  die  vulkan, 
Erschein.  in  Unter-und  Mittd  Italien,  1841,  Bd.  i,  s.  113,  Taf.  ii. 


228  COSMOS. 

nisable,  even  in  scattered  detritus,  on  many  of  the  largest 
and  most  active  volcanoes. 

It  is  a  great  merit  of  modern  times  not  only  to  have  more 
accurately  investigated  the  peculiar  conditions  of  the  forma- 
tion of  volcanoes  by  a  careful  comparison  of  those  which  are 
widely  separated  from  each  other,  but  also  to  have  intro- 
duced more  definite  expressions  into  language,  by  which  the 
heterogeneous  features  of  the  general  outline,  as  well  as 
the  manifestations  of  volcanic  activity  are  distinguished. 
If  we  are  not  decidedly  disinclined  to  all  classifications, 
because  in  the  endeavour  after  generalization  these  always 
rest  only  upon  imperfect  indications,  we  may  conceive  the 
bursting  forth  of  fused  masses  and  solid  matter,  vapours  and 
gases,  in  four  different  ways.  Proceeding  from  the  simple 
to  the  complex  phenomena,  we  may  first  mention  eruptions 
from  fissures,  not  forming  separate  series  of  cones,  but  pro- 
ducing volcanic  rocks  superlying  each  other,  in  a  fused 
and  viscid  state ;  secondly,  eruptions  through  heaped  up 
cones,  without  any  circumvallation,  and  yet  emitting  streams 
of  lava,  as  was  the  case  for  five  years  during  the  destruction 
of  the  Island  of  Lancerote,  in  the  first  half  of  the  last 
century  ;  thirdly,  craters  of  elevation,  with  up-heaved  strata, 
but  without  central  cones,  emitting  streams  of  lava  only  on 
the  outside  of  the  circumvallation,  never  from  the  interior, 
which  is  soon  closed  up  with  detritus  ;  fourthly,  closed  bell- 
shaped  mountains  or  cones  of  elevation,  open  at  the  summit, 
either  enclosed  by  a  circular  wall,  which  is  at  least  partially 
retained, — as  on  the  Pic  of  Teneriffe,  in  Fogo,  and  Rocca 
Monfina ;  or  entirely  without  circumvallation  or  crater  of 
elevation, — as  in  Iceland,85  in  the  Cordilleras  of  Quito,  and 
the  central  parts  of  Mexico.  The  open  cones  of  elevation  of 
this  fourth  class  maintain  a  permanent  connection  between 
the  fiery  interior  of  the  earth  and  the  atmosphere,  which  is 
more  or  less  effective  at  undetermined  intervals  of  time. 
Of  the  dome-shaped  and  bell-shaped  trachytic  and  doleritic 
mountains  which  have  remained  closed  at  the  summit,  there 
appear,  according  to  my  observations,  to  be  more  than  of 
the  open  cones  whether  active  or  extinct,  and  far  more 
than  of  the  true  volcanoes.  Dome-shaped  and  bell-shaped 

85  Sartorius  von  Waltershausen,  Physisch-geographische  Slcizze  vor 
Island,  1847,  s.  107. 


CRATERS   OP   ELEVATION.  229 

mountains,  such  as  Chimborazo,  Puy  de  Dome,  Sarcouy, 
Rocca  Monfina  and  Vultur,  give  the  landscape  a  peculiar 
character,  by  which  they  contrast  pleasingly  with  the  sch's* 
tose  peaks,  or  the  serrated  forms  of  limestone. 

In  the  tradition  preserved  to  us  so  picturesquely  by  Ovid 
regarding  the  great  volcanic  phenomenon  of  the  peninsula  of 
Methone,  the  production  of  such  a  bell-shaped  and  unopened 
mountain  is  indicated  with  methodical  clearness.  "  The 
force  of  the  winds  imprisoned  in  dark  caves  of  the  eartl , 
and  seeking  in  vain  for  an  opening,  drive  up  the  heaving 
soil  (extentam  tumefecit  humum),  as  when  one  fills  a  bladder 
or  leather  bag  with  air.  By  gradual  hardening,  the  high 
projecting  eminence  has  retained  the  form  of  a  hill."  I  have 
already  elsewhere  adverted  to  the  fact  of  how  completely 
different  this  Roman  representation  is  from  Aristotle's 
narration  of  the  volcanic  phenomenon  upon  Hiera,  a  newly 
formed  Aeolic  (Liparian)  Island,  in  which  "the  subterra- 
nean, mightily  urging  blast  does  indeed  also  raise  a  hill, 
but  afterwards  breaks  it  up  to  pour  forth  a  fiery  shower 
of  ashes."  The  elevation  is  here  clearly  represented  as 
preceding  the  eruption  of  flame  (Cosmos,  vol.  i,  p  240). 
According  to  Strabo,  the  elevated  dome-like  hill  of  Methana 
had  also  opened  in  fiery  eruptions,  at  the  close  of  which  an 
agreeable  odour  was  diffused  in  the  night  time.  It  is  very 
remarkable  that  the  latter  was  observed  under  exactly 
similar  circumstances  during  the  volcanic  eruption  of  San- 
torin,  in  the  autumn  of  1650,  and  was  denominated  "a 
consoling  sign,  that  God  would  not  yet  destroy  his  flock," 
in  the  penitential  sermon  delivered  and  written  shortly  after- 
wards by  a  monk.86  Does  not  this  pleasant  odour  afford 

86  It  has  been  a  much  disputed  point,  to  what  particular  locality  of 
the  plain  of  Troezen,  or  the  peninsula  of  Methana,  the  description  of 
the  Roman  poet  may  refer.  My  friend,  Ludwig  Ross,  the  great  Greek 
antiquarian  and  chorograph,  who  has  had  the  advantage  of  many  tra- 
vels, thinks  that  the  immediate  vicinity  of  Troezen  presents  no  locality 
which  can  be  referred  to  as  the  bladder-lifce  hills,  and  that,  by  a  poetic 
license,  Ovid  has  removed  the  phenomenon  described  with  such  truth 
to  nature,  to  the  plain.  "  To  the  south  of  the  peninsula  of  Methana, 
and  east  of  the  plain  of  Troezen,"  writes  Ross,  "lies  the  island  Calauria, 
well  known  as  the  place  where  Demosthenes,  being  pressed  by  the 
Macedonians,  took  poison  in  the  temple  of  Neptune.  A  narrow  arm  of 
the  sea  separates  the  limestone  rocks  of  Calauria  from  the  coast;  from 
this  arm  of  the  sea  (passage,  TTO^OI,')  the  town  and  island  take  their  present 


233  COSMOS. 

indications  of  naphtha  ?  The  same  thing  is  also  referred  to 
by  Kotzebue,  in  his  Russian  voyage  of  discovery,  in  connec- 
tion with  an  igneous  eruption  (1804)  of  the  volcanic  island  of 
Umnack,  newly  elevated  from  the  sea  in  the  Aleutian  Archi- 
pelago. During  the  great  eruption  of  Vesuvius,  on  the  12th 
August,  1805,  which  I  observed  in  company  with  Gay- 
Lussac,  the  latter  found  a  bituminous  odour  prevailing  at 
times  in  the  ignited  crater.  I  bring  together  these  little- 
noticed  facts,  because  they  contribute  to  confirm  the  close 
concatenation  of  all  manifestations  of  volcanic  activity,  the 
intimate  connection  of  the  weak  salses  and  naphtha  springs 
with  the  true  volcanoes. 

Circumvallations,  analogous  to  those  of  the  craters  of  ele- 
vafcion,  also  present  themselves  in  rocks  which  are  very 
different  from  trachyte,  basalt  and  porphyritic  schists,  for 
example  according  to  Elie  de  Beaumont's  acute  observation, 
in  the  granite  of  the  French  Alps.  The  mountain  mass  of 
Oisans,  to  which  the  highest 87  summit  of  France,  Mont 
name.  In  the  middle  of  the  strait,  united  with  Calauria  by  a  low  cause- 
way, probably  of  artificial  origin,  lies  a  small  conical  islet,  comparable 
in  form  to  an  egg  cut  through  the  middle.  It  is  volcanic  throughout, 
consisting  of  greyish  yellow  and  yellowish  red  trachyte,  mixed  with 
eruptions  of  lava  and  scoriae,  and  is  almost  entirely  destitute  of  vege- 
tation. Upon  this  islet  stands  the  present  town  of  Poros,  on  the  place 
of  the  ancient  Calauria.  The  formation  of  the  islet  is  exactly  similar 
to  that  of  the  more  recent  volcanic  islands  in  the  Bay  of  Thera  (Santo- 
rino).  In  his  animated  description,  Ovid  has  probably  followed  a 
Greek  original  or  an  old  tradition"  (Ludw.  Eoss,  in  a  letter  to  me  dated 
November,  1845).  As  a  member  of  the  French  scientific  expedition, 
Virlet  has  set  up  the  opinion  that  the  volcanic  upheaval  may  have  been 
only  a  subsequent  increase  of  the  trachytic  mass  of  the  peninsula  of 
Methana.  This  increase  occurs  in  the  north-west  extremity  of  the 
peninsula,  where  the  black  burnt  rock,  called  Kammeni-petra,  resem- 
bling the  Kammeni,  near  Santorin,  betrays  a  more  recent  origin.  Pau- 
sanias  communicates  the  tradition  of  the  inhabitants  of  Methana,  that, 
on  the  north  coast,  before  the  now  celebrated  sulphurous  springs  burst 
forth,  fire  rose  out  of  the  earth  (see  Curtius,  Pelopwinesos,  Bd.  i,  s.  42 
and  46).  On  the  "  indescribable  pleasant  odour"  which  followed  the 
stinking  sulphurous  odour,  near  Santorino  (Sept.  3650),  see  Ross, 
Reisen  auf  den  griech.  Inseln  des  agaiscken  Meeres,  Bd.  i,  s.  196.  Upon 
the  odour  of  naphtha  in  the  fumes  of  the  lava  of  the  Aleutian  island 
Umnack,  which  appeared  in  1796,  see  Kotzebue's  Entdeckungs-Reise, 
Bd.  ii,  s.  106,  and  Leopold  de  Buch,  Description  phys.  des  lies  Canaries, 
p.  458. 

87  The  highest  summit  of  the  Pyrenees,  that  is,  the  Pic  de  Nethou 
(the  eastern  and  highest  peak  of  the  Maladetta  or  Malahita  group),  has 


MAARS.  231 

Pelvoux,  near  Brianc,on,  (12,905  feet)  belongs,  forms  an  am- 
phitheatre of  thirty-two  geographical  miles  in  circumference, 
in  the  centre  of  which  is  situated  the  small  village  of  la 
Berarde.  The  steep  walls  of  this  circular  space  rise  to  a  height 
of  more  than  9600  feet.  The  circumvallation  itself  is  gneiss  , 
all  the  interior  is  granite.88  In  the  Swiss  and  Savoy  Alps,  the 
same  formation  presents  itself  repeatedly  in  small  dimensions. 
The  Grand-Plateau  of  Mont-Blanc,  in  which  Bravais  and 
Martins  encamped  for  several  days,  is  a  closed  amphi- 
theatre with  a  nearly  flat  bottom  at  an  elevation  of  nearly 
12,811  feet;  from  tne  midst  of  which  the  colossal  pyramid 
of  the  summit  rises.89  The  same  upheaving  forces  produce 
similar  forms,  although  modified  by  the  composition  of  the 
different  rocks.  The  annular  and  cauldron-like  valleys  (val- 
leys of  elevation),  described  by  Hoffman,  Buckland,  Mur- 
chison,  and  Thurmann,  in  the  sedimentary  rocks  of  the  north 
of  Germany,  in  Herefordshire,  and  the  Jura  mountains  of 
Porrentruy,  are  also  connected  with  the  phenomena  here 
described,  as  well  as,  although  with  a  less  degree  of  ana- 
logy, some  elevated  plains  of  the  Cordilleras  enclosed  on  all 
sides  by  mountain  masses,  in  which  are  situated  the  towns 
of  Caxamarca  (9362  feet),  Bogota  (8729  feet),  and  Mexico 
(7469  feet),  and  in  the  Himalayas  the  cauldron-like  valley 
of  Caschmir  (5819  feet). 

Less  related  to  the  craters  of  elevation  than  to  the  above 
described  simplest  form  of  volcanic  activity  (the  action  from 
mere  fissures),  are  the  numerous  Maars  amongst  the  extinct 
volcanoes  of  the  Eifel ;  cauldron-like  depressions  in  non- 
volcanic-rock  (Devonian  slate),  and  surrounded  by  slightly 
elevated  margins,  formed  by  themselves.  "  These  are  as 
been  twice  measured  trigonometrically ;  its  height,  according  to  Reboul, 
is  11,443  feet  (3481  metres),  and,  according  to  Coraboeui,  11,167  feet 
(3404  metres).  It  is,  therefore,  1705'  feet  lower  than  Mont  Pelvoux,  in 
the  French  Alps,  near  Brian9on.  The  next  in  height  to  the  Pic  de 
Nethou  in  the  Pyrenees,  are  the  Pic  Posets  or  Erist,  and  of  the  group 
of  the  Marbore",  the  Montperdu,  and  the  Cylindre. 

88  Mtmoire  pour  servir  a  la  Description  Geologique  dc  la  France,  t.  ii. 
p.  339.     Upon  "  valleys  of  elevation"  and  "  encircling  ridges"  in  the 
Silurian  formation,  see  the  admirable  description  of  Sir  Roderick  Mur- 
chison  in  "  The  Silurian  System,"  pt.  i,  pp.  427 — 442. 

89  Bravais   and    Martins,    Observ.  faites    au  Sommet   et    au   Grand 
Plateau  du  Mont-Blanc,  in  the  Annuaire  Meteorol.  de  la  France  pow 
1850,  p.  131. 


232  COSMOS. 

it  were  the  funnels  of  mines,  indications  of  mine-like  erup- 
tions," resembling  the  remarkable  phenomenon  described  by 
me  of  the  human  bones  scattered  upon  the  hill  of  la  Culca  *° 
during  the  earthquake  of  Riobamba  (4  February,  1797). 
When  single  Maars,  not  situated  at  any  great  height,  in  the 
Eifel,  in  Auvergne,  or  in  Java,  are  filled  with  water,  such 
former  craters  of  explosion  may  in  this  state  be  denominated 
crater es-lacs ;  but  it  seems  to  me  that  this  term  should  not 
be  taken  as  a  synonymous  name  for  Maar,  as  small  lakes 
have  been  found  by  Abich  and  myself  on  the  summits  of  the 
highest  volcanoes,  on  true  cones  of  elevation  in  extinguished 
craters  :  for  example,  on  the  Mexican  volcano  of  Toluca  at 
an  elevation  of  12,246  feet,  and  on  the  Caucasian  Elburuz  at 
19,717  feet.  In  the  volcanoes  of  the  Eifel  we  must  carefully 
distinguish  from  each  other  two  kinds  of  volcanic  activity  of 
very  unequal  age, — the  true  volcanoes  emitting  streams  of 
lava  ;  and  the  weaker  eruptive  phenomena  of  the  Maars. 
To  the  former  belong  the  basaltic  stream  of  lava,  rich  in 
olivine,  and  cleft  into  upright  columns,  in  the  valley  of 
Uesbach  near  Bertrich  ;w  the  volcano  of  Gerolstein,  which 
is  seated  in  a  limestone  containing  dolomite,  deposited  in  the 
form  of  a  basin  in  the  Devonian  grauwacke  schists  ;  and  the 
long  ridge  of  the  Mosenberg  (1753  feet  above  the  sea)  not 
far  from  Bettenfeld  to  the  west  of  Manderscheid.  The  last 
named  volcano  has  three  craters,  of  which  the  first  and 
second,  those  furthest  to  the  north,  are  perfectly  round,  and 
covered  with  peat  mosses ;  whilst  from  the  third  and  most 

90  Cosmos,   vol.  v,  p.   173.      I    have   twice    visited    the  volcanoes 
of    the    Eifel,  when    geognosy  was    in  very  different  states   of   de- 
velopment, in  the  autumn  of    1794,  and  in  August,  1845;   the  first 
time  in  the  vicinity  of  the  lake  of  Laach  and  the  monastery  there, 
which  was  then  still  inhabited  by  monks;    the  second  time,  in  the 
neighbourhood  of  Bertrich,    the  Mosenberg,  and  the  adjacent  Maars, 
but  never  for  more  than  a  few  days.     As  in  the  latter  excursion  I  had 
the  good  fortune  to  be  able  to  accompany  my  intimate  friend,  the 
mining  surveyor,  Von  Dechen,  I  have  been  enabled  by  many  years'  cor- 
respondence, and  the  communication  of  important  manuscript  memoirs 
to  make  free  use  of  the  observations  of  this  acute  geognosist.     I  have 
often  indicated  by  quotation  marks,  as  is  my  wont,  what  I  have  bor- 
rowed, word  for  word,  from  his  communications. 

91  H.  von  Dechen,  Geognost.  Uebersicht  der  Umgegend  von  Bad  £&>•• 
trick,  1847,  s.  11—51. 


MAARS,  233 

southern98  crater,  theie  flows  down  a  vast,  reddish  brown, 
deep  stream  of  lava,  separated  into  a  columnar  form,  towards 
the  valley  of  the  little  Kyll.  It  is  a  remarkable  pheno- 
menon, foreign  to  lava-producing  volcanoes  in  general,  that 
neither  on  the  Mosenberg  nor  on  the  Gerolstein,  nor  in 
other  true  volcanoes  of  the  Eifel  are  the  lava-eruptions 
visibly  surrounded  at  their  origin  by  a  trachytic  rock,  but, 
as  far  as  they  are  accessible  to  observation,  proceed  directly 
from  the  Devonian  strata.  The  surface  of  the  Mosenberg 
does  not  at  all  prove  what  is  hidden  in  its  depths.  The 
scoriae  containing  augite,  which  by  cohesion  pass  into 
basaltic  streams,  contain  small,  calcined  fragments  of  slate, 
but  no  trace  of  enclosed  trachyte.  Nor  is  the  latter  to  be 
found  enclosed  in  the  crater  of  the  Rodderberg,  notwith- 
standing that  it  lies  in  the  immediate  vicinity  of  the  Sieben- 
gebirge,  the  greatest  trachytic  mass  of  the  Rhine  district. 

"The  Maars  appear,"  as  the  mining  surveyor  Von  Dechen  has 
ingeniously  observed,  "  to  belong  in  their  formation  to  about 
the  same  epoch  as  the  eruption  of  the  lava-streams  of  the 
true  volcanoes.  Both  are  situated  in  the  vicinity  of  deeply 
cut  valleys.  The  lava-producing  volcanoes  were  decidedly 
active  at  a  time  when  the  valleys  had  already  attained  very 
nearly  their  present  form  ;  and  we  also  see  the  most  ancient 
lava-streams  of  this  district  pouring  down  into  the  valleys." 
The  Maars  are  surrounded  by  fragments  of  Devonian  slates 
and  by  heaps  of  gray  sand  and  tufa-margins.  The  Laacher 
lake,  wh  ether  it  be  regarded  as  a  large  Maar,  or,  with  my 
old  friend  C.  von  Oeynhausen,  as  part  of  a  large  cauldron- 
like  valley  in  the  clay  slate  (like  the  basin  of  Wehr),  ex- 
hibits some  volcanic  eruptions  of  scoriae  upon  the  ridge  sur- 
rounding it,  as  is  the  case  on  the  Krufter  Ofen,  the  Yeitskopf 
and  Laacher  Kopf.  It  is  not,  however,  merely  the  entire  want 
of  lava-streams,  such  as  are  to  be  observed  on  the  Canary 
Islands  upon  the  outer  margin  of  true  craters  of  elevation 
and  in  their  immediate  vicinity, — it  is  not  the  inconsiderable 

92  Stengel,  in  Ndggerath,  das  Gebirye  von  Rheinland  und  Westphalen, 
Bd.  i,  s.  79,  Taf.  iii.  See  also  C.  von  Oeynhauseii's  admirable  explana- 
tions of  his  geognostic  Map  of  the  Lake  of  Laach,  1847,  pp.  34,  39,  and 
42,  including  the  Eifel  and  the  basin  of  Neuwied.  Upon  the  Maars, 
see  Steininger,  Geognostische  Beschreibung  der  Eifel,  1853,  s.  113.  Hip 
earliest  meritorious  work,  "  Die  erloschenen  Vulkane  in  der  Eifel  und 
am  Niedcr-RItein,"  belongs  to  the  year  1820. 


234-  COSMOS. 

elevation  of  the  ridge  surrounding  the  Maar,  that  distin- 
guishes this  from  craters  of  elevation ;  the  margins  of  the 
Maars  are  destitute  of  a  regular  stratification  of  the  rock, 
falling,  in  consequence  of  the  upheaval,  constantly  outwards. 
The  Maars  sunk  in  the  Devonian  slate,  appear,  as  has  already 
been  observed,  like  the  craters  of  mines,  into  which,  after 
the  violent  explosion  of  hot  gases  and  vapours,  the  looser 
ejected  masses  (Bapillt),  have  for  the  most  part  fallen 
back.  As  examples  I  shall  only  mention  here  the  Immera- 
ther,  the  Pulverinaar,  and  theMeerfelder  Maar.  In  the  centre 
of  the  first  mentioned,  the  dry  bottom  of  which,  at  a  depth 
of  two  hundred  feet,  is  cultivated,  are  situated  the  two 
villages  of  Ober-  and  Unter-Immerath.  Here,  in  the  vol- 
canic tufa  of  the  vicinity,  exactly  as  on  the  Laacher  lake, 
mixtures  of  felspar  and  augite  occur  in  spheroids,  in  which 
particles  of  black  and  green  glass  are  scattered.  Similar 
spheroids  of  mica,  hornblende  and  augite,  full  of  vitrified 
portions  are  also  contained  in  the  tufa  veins  of  the  Pulver- 
maar  near  Gillenfeld,  which,  however,  is  entirely  converted 
into  a  deep  lake.  The  regularly  circular  Meerfelder  Maar, 
covered  partly  with  water  and  partly  with  peat,  is  character- 
ized geognostically  by  the  proximity  of  the  three  craters  of 
the  groat  Mosenberg,  the  most  southern  of  which  has  fur- 
nished a  stream  of  lava.  The  Maar,  however,  is  situated 
639  feet  below  the  long  ridge  of  the  volcano,  and  at  its 
northern  extremity,  not  in  the  axis  of  the  series  of  craters, 
but  more  to  the  north-west.  The  average  elevation  of  the 
Maars  of  the  Eifel  above  the  surface  of  the  sea  falls  be- 
tween 922  feet  (Laacher  lake  ?)  and  1588  feet  (Mosbrucher 
Maar). 

As  this  is  peculiarly  the  place  in  which  to  call  attention 
to  the  uniformity  and  agreement  exhibited  by  volcanic 
activity  in  its  production  of  material  results,  in  the 
most  different  forms  of  the  outer  framework  (as  Maars, 
as  circuinvallated  craters  of  elevation,  or  cones  opened 
at  the  summit),  I  may  mention  the  remarkable  abun- 
dance of  crystallized  minerals  which  have  been  thrown 
out  by  .the  Maars  in  their  first  explosion,  and  which  still 
in  part  lie  buried  in  the  tufas.  In  the  environs  of  the 
Laacher  lake  this  abundance  is  certainly  greatest,  but;  other 
Maars  also,  for  example  the  Immerather,  and  the  Meerfelder 


MAARS.  235 

Maar  so  rich  in  bombs  of  olivine,  contain  fine  crystallized 
masses.  We  may  here  mention,  zircon,  hauyne,  leucite,93  apa- 
tite, nosean,  olivine,  augite,  rhyacolite,  common  felspar 
(orthoclase) ,  glassy  felspar  (sanidine),  mica,  sodalite,  garnet, 
and  titanic  iron.  If  the  number  of  beautifully  crystallized 
minerals  on  Vesuvius  be  so  much  greater  (Scacchi  counts 
43  species),  we  must  not  forget,  that  very  few  of  them  are 
ejected  from  the  volcano,  and  that  the  greater  number  belongs 
to  the  portion  of  the  so-called  eruptive  matters  of  Vesu- 
vius, which,  according  to  the  opinion  of  Leopold  von  Buch,94 
"  are  quite  foreign  to  Vesuvius,  and  to  be  referred  to  a 
tufaceous  covering  diffused  far  beyond  Capua,  which  was  up- 
heaved by  the  rising  cone  of  Vesuvius,  and  has  probably 
been  produced  by  a  deeply-seated  submarine  volcanic  action." 
Certain  definite  directions  of  the  various  phenomena  of 
volcanic  activity  are  unmistakeable  even  in  the  Eifel.  "  The 
eruptions,  producing  lava-streams,  of  the  upper  Eifel  lie  in 
one  fissure,  nearly  32  English  miles  in  length,  from  Bert- 

93  Leucite  (of  the  same  kind  from  Vesuvius,  from  Rocoa  di  Papa  in 
the   Albanian    mountains,    from    Viterbo,    from   the   Rocca  Monfina, 
according  to  Pilla,  sometimes  of  more  than  3  inches  in  diameter,  and 
from  the  dolerite  of  the  Kaiserstuhl  in  the  Breisgau),  occurs  also  "  in 
position   as  leucite-rock  in  the  Eifel,  on  the  Burgberg,  near  Rieden. 
The  tufa  in  the  Eifel  incloses  large  blocks  of  leucitophyre  near  Boll 
and  Weibern."     I  cannot  resist  the  temptation  to  borrow  the  following 
important  observation  from  a  chemico-geognostic  memoir  read  by  Mits- 
cherlich  a  few  weeks  since  before  the  Academy  of  Berlin.     "Aqueous 
vapours  alone  may  have  effected  the  eruptions  of  the  Eifel ;  but  they 
would  have  divided  olivine  and  augite  into  the  finest  drops  and  pow- 
der, if  they  had   met  with   them  in  a  fluid  state.     With  the  funda- 
mental mass  of  the  erupted  matters  fragments  of  the  old,  broken  up  rock 
are  most  intimately  mixed,  for  example  on  the  Dreiser  Weiher,  and 
these  are  frequently  caked  together.     The  larger  olivine  masses  and  the 
masses  of  augite  even  usually  occur  surrounded  by  a  thick  crust  of 
this  mixture  ;  a  fragment  of  the  old  rock  never  occurs  in  the  olivine  or 
augite, — both  were  consequently  formed  before  they  reached  the  spot 
where  the  breaking  up  took  place.     Olivine  and  augite  had  therefore 
separated  from  the  fluid  basaltic  mass  before  this  met  with  an  accumu- 
lation of  water  or  a  spring  which  caused  its  expulsion."     See  also  upon 
the  bombs  an  older  memoir  by  Leonard  Homer,  in  the  Transactions  of 
the  Geological  Society,  2nd  series,  vol.  iv,  pt.  2,  1836,  p.  467. 

94  Leopold   von   Buch,   in   Poggend.    Annalen,    Ed.  xxxvii,  s.   17P. 
According  to  Scacchi,  the  eruptive  matters  belong  to  the  first  outbreak 
of  Vesuvius  in  the  year  79.     Leonhard's  Neues  Jahrbuch  fur  Mineral 
1853,  s.  259. 


236  COSMOS. 

rich  to  the  Goldberg  near  Ormond,  directed  from  south- 
east to  north-west ;  on  the  other  hand  the  Maars,  from  the 
Meerfelder  Maar  to  Mosbruch  and  the  Laacher  lake,  follow 
a  line  of  direction  from  south-west  to  north-east.  These 
two  primary  directions  intersect  each  other  in  the  three 
Maars  of  Daun.  In  the  neighbourhood  of  the  Laacher  lake 
trachyte  is  nowhere  visible  on  the  surface.  The  occurrence 
of  this  rock  below  the  surface  is  only  indicated  by  the  pecu- 
liar nature  of  the  perfectly  felspar-like  pumice-stone  of 
Laach,  and  by  the  bombs  of  augite  and  felspar  thrown  out. 
But  the  trachytes  of  the  Eifel,  composed  of  felspar  and 
large  crystals  of  hornblende,  are  only  visibly  distributed 
amongst  basaltic  mountains  :  as  in  the  Sellberg  (1893  feet) 
near  Quiddelbach,  in  the  rising  ground  of  Struth,  near 
Kelberg,  and  in  the  wall-like  mountain  chain  of  Reimerath 
near  Boos." 

Next  to  the  Lipari  and  Ponza  Islands  few  parts  of  Europe 
have  probably  produced  a  greater  mass  of  pumice-stone 
than  this  region  of  Germany,  which,  with  a  comparatively 
small  elevation,  presents  such  various  forms  of  volcanic 
activity  in  its  Maars  (crate res  d' explosion) ,  basaltic  rocks, 
and  lava-emitting  volcanoes.  The  principal  mass  of  the 
pumice-stone  is  situated  between  Nieder  Mendig  and  Sorge, 
Andernach  and  Hiibenach ;  the  principal  mass  of  the  duckstein, 
or  Trass  (a  very  recent  conglomerate,  deposited  by  water), 
lies  in  the  valley  of  Brohl,  from  its  opening  into  the  Rhine 
upwards  to  Burgbrohl,  near  Plaidt  and  Kruft.  The  Trass- 
formation  of  the  Brohl- valley  contains,  together  with  frag- 
ments of  grauwacke-slate  and  pieces  of  wood,  small  fragments 
of  pumice-stone,  differing  in  nothing  from  the  pumice-stone 
which  constitutes  the  superficial  covering  of  the  region,  and 
even  that  of  the  duckstein  itself.  Notwithstanding  some 
analogies  which  the  Cordilleras  appear  to  present,  I  have 
always  doubted  whether  the  Trass  can  be  ascribed  to  erup- 
tions of  mud  from  the  lava-producing  volcanoes  of  the  Eifel. 
I  rather  suppose,  with  H.  von  Dechen,  that  the  pumice- 
stone  was  thrown  out  dry,  and  that  the  Trass  was  formed  in 
the  same  way  as  other  conglomerates.  "Pumice-stone  is 
foreign  to  the  Siebengebirge;  and  the  great  pumice-eruption 
of  the  Eifel,  the  principal  mass  of  which-  still  lies  above  the 
loess  (Trass)  and  alternates  therewith  in  particular  parts, 


MAARS.  237 

may,  in  accordance  with  the  presumption  to  which  the  local 
conditions  lead,  have  taken  place  in  the  valley  of  the  Rhine, 
above  Neuwied,  in  the  great  Neuwied  basin,  perhaps  near 
Urmits,  on  the  leit  bank  of  the  Rhine.  From  the  friability 
of  the  material  the  place  of  eruption  may  have  disappeared 
without  leaving  any  ti-aces,  by  the  subsequent  action  of  the 
current  of  the  Rhine.  In  the  entire  tract  of  the  Maars  of 
the  Eifel,  as  in  that  of  its  volcanoes  from  Bertrich  to  Ormond, 
no  pumice-stone  is  found.  That  of  the  Laacher  lake  is  limited 
to  the  rocks  upon  its  margin ;  and  on  the  other  M  aars  the 
small  fragments  of  felspathic  rock,  which  lie  in  the  volcanic 
sand  and  tuff,  do  not  pass  into  pumice." 

We  have  already  touched  upon  the  relative  antiquity  of  the 
Maars  and  of  the  eruptions  of  the  lava-streams,  which  differ 
so  much  from  them,  compared  with  that  of  the  formation  of  the 
valleys.  "  The  trachyte  of  the  Siebengebirge  appears  to  be 
much  older  than  the  valley -formation,  and  even  older  than  the 
Rhenish  brown-coal.  Its  appearance  has  been  independent 
of  the  cutting  of  the  valley  of  the  Rhine,  even  if  we  should 
ascribe  this  valley  to  the  formation  of  a  fissure.  The  forma- 
tion of  the  valleys  is  more  recent  than  the  Rhenish  brown- 
coal,  and  more  recent  than  the  Rhenish  basalt ;  but  older 
than  the  volcanic  eruptions  with  lava-streams,  and  older 
than  the  great  pumice-eruption  and  the  Trass.  Basalt  for- 
mations decidedly  extend  to  a  more  recent  period  than  the 
formation  of  trachyte,  and  the  principal  mass  of  the  basalt  is, 
therefore,  to  be  regarded  £  younger  than  the  trachyte.  In 
the  present  declivities  \,f  the  valley  of  the  Rhine  many 
basaltic  groups  (the  quarry  of  Unkel,  Rolandseck,  Godes- 
berg),  were  only  laid  bare  by  the  opening. of  the  valley, 
as  up  to  that  time  they  were  probably  enclosed  in  the  Devo- 
nian grauwacke  rocks." 

The  Infusoria,  whose  universal  diffusion,  demonstrated  by 
Ehrenberg,  upon  the  continents,  in  the  greatest  depths  of  the 
sea  and  in  the  upper  strata  of  the  atmosphere,  is  one  of  the 
most  brilliant  discoveries  of  our  time,  have  their  principal 
seat  in  the  volcanic  Eifel,  in  the  Rapilli,  Trass-strata,  and 
pumice-conglomerates.  Organisms  with  silicious  shields  fill 
the  valley  of  Brohl  and  the  eruptive  matters  of  Hochsim- 
mer  ;  sometimes,  in  the  Trass,  they  are  mixed  with  uncar- 
bonised  twigs  of  coniferae.  According  to  Ehrenberg,  the 


238  COSMOS. 

whole  of  this  microcosm  is  of  fresh- water  formation,  and 
marine  Polythalamia95  only  show  themselves  exceptionally  in 
the  uppermost  deposit  of  the  friable,  yellowish  loess  at  the 
foot  and  on  the  declivities  of  the  Siebengebirge  (indicating 
its  former  brackish  coast-nature). 

Is  the  phenomenon  of  Maars  limited  to  Western  Ger- 
many ?  Count  Montlosier,  who  was  acquainted  with  the 
Eifel  by  personal  observations  in  1819,  and  who  pronounces 
the  Mosenberg  to  be  one  of  the  finest  volcanoes  that  he  ever 
saw,  (like  Rozet)  regards  the  Gouffre  de  Tazenat,  the  Lac 
J?avin  and  Lac  de  la  G-odivel,  in  Auvergne,  as  Maars  or 
craters  of  explosion.  They  are  cut  into  very  different  kinds 
of  rock, — in  granite,  basalt,  and  domite  (trachytic  rock),  and 
surrounded  at  the  margins  with  scoriae  and  rapilli.96 

The  frameworks  which  are  built  up  by  a  more  powerful 
eruptive  activity  of  volcanoes,  by  upheaval  of  the  soil  and 
emission  of  lava,  appear  in  at  least  six  different  forms,  and 
reappear  with  this  variety  in  their  forms  in  the  most  distant 
zones  of  the  earth.  Those  who  are  born  in  volcanic  districts 
amongst  basaltic  and  trachytic  mountains,  are  often  genially 
impressed  in  spots  where  the  same  forms  greet  them. 
Mountain  forms  are  amongst  the  most  important  deter- 
mining elements  of  the  physiognomy  of  nature, — they  give 
the  district  either  a  cheerful,  or  a  stern  and  magnificent  cha- 
racter, according  as  they  are  adorned  with  vegetation  or  sur- 
rounded by  a  dreary  barrenness.  I  have  quite  recently  endea- 

95  Upon  the  antiquity  of  formation  of  the  valley  of  the  Rhine,  see 
H.  von  Dechen,  Geognost.  Besdireibung  des  Siebengebirges,  in  the  Ver- 
handl.  des  Naturhist.  Vereins  der  Preuss.  Rheinlande  und  Westphalens, 
1852,  s.   556 — 559.      The  infusoria  of  the  Eifel    are  treated   of    by 
Ehrenberg   in   the   Monatsber.  der  Akad.  der   Wiss.  zu  Berlin,  1844, 
e.  337,  1845,  s.  133  and  148,  and   1846,   s.  161—171.      The  Trass  of 
Brohl,  which  is  filled  with  crumbs  of  pumice-stone  containing  infusoria, 
forms  hills  of  as  much  as  850  feet  in  height: 

96  See  Rozet,  in  the  Memoires  de  la  Societe  Geologique,  2me  serie,  t.  i, 
p.  119.     On  the  island  of  Java  also,  that  wonderful  seat  of  multifarious 
volcanic  activity,  there  occur  "  craters  without  cones,  as  it  were  flat 
volcanoes"  (Junghuhn,  Java,  seine  Gestalt  und  Pflanzendecke,  Lief,  vii, 
p.  640)  between  Gunung  Salak  and  Perwakti,  analogous  to  the  Maars 
as  "  craters  of  explosion."     Destitute  of  any  elevated  margins,  they  are 
situated  partly  in  perfectly  flat  districts  of  the  mountains,  have  angular 
fragments  of  the  burst  rocky  strata  scattered  around  them,  and  now 
only  emit  vapours  and  gases. 


TRUE    VOLCANOES.  239 

voured  to  bring  together,  in  a  separate  atlas,  a  number  of  out- 
lines of  the  Cordilleras  of  Quito  and  Mexico,  sketched  from  my 
own  drawings.  As  basalt  occurs  sometimes  in  conical  domes, 
somewhat  rounded  at  the  summit,  sometimes  in  the  form  ol 
closely-arranged  twin-mountains  of  unequal  elevation,  and 
sometimes  in  that  of  a  long  horizontal  ridge  bounded  at 
each  extremity  by  a  more  elevated  dome,  so  we  principally 
distinguish  in  trachyte  the  majestic  dome-form97  (Chim- 
borazo,  21,422  feet),  not  to  be  confounded  with  the  form 
of  the  unopened  but  less  massive  bell-shaped  mountains.  The 
conical  form  is  most  perfectly98  exhibited  in  Cotopaxi  (18,877 
feet),  and  next  to  this  in  Popocatepetl99  (17,727  feet),  as  seen 
on  the  beautiful  shores  of  the  lake  of  Tezcuco,  or  from  the 
summit  of  the  .ancient  Mexican  step-pyramid  of  Cholula; 
and  in  the  volcano  of  Orizaba100  (17,374  feet,  according  to 
Ferrer  17,879  feet).  A  strongly  truncated  conical  form1  is 
exhibited  by  the  Nevado  de  Cayambe-Urcu  (19,365  feet), 
which  is  intersected  by  the  equator,  and  by  the  volcano  of 
Tolima  (18,129  feet),  visible  above  the  primaeval  forest  at 
the  foot  of  the  Paramo  de  Quindiu,  near  the  little  town  of 
Ibague.2  To  the  astonishment  of  geognosists  an  elongated 
ridge  is  formed  by  the  volcano  of  Pichincha  (15,891  feet),  at 
the  less  elevated  extremity  of  which  the  broad,  still  ignited 
crater3  is  situated. 

Fallings  of  the  walls  of  craters,  induced  by  great  natural 
phenomena,  or  their  rupture  by  mine-like  explosion  from 

9'  Humboldt,  Umrisse  von  Vullcanen  der  Cordilleren  von  Quito  und 
Mexico,  ein  Beitrag  zur  Pliysiognomik  der  Natur,  Tafel  iv  (Kleinere 
Schriften,  Bd.  i,  s.  133—205). 

98  Umrisse  von  Vulkanen,  Tafel  vi. 

99  Op.  tit.  sup.    Tafel  viii  (Kleinere  Schriftin,  Bd.     i,  s.   463—467). 
On  the  topographical  position  of  Popocatepetl  (smoking  mountain,  in 
the  Aztec  language),  near  the  (recumbent)  White  woman,  Iztaccihuatl, 
and  its  geographical  relation  to  the  western  lake  of  Tezcuco  and  the 
pyramid  of  Cholula  situated  to  the  eastward,  see  ray  Atlas  Geographique 
et  Physique  de  la  Nouvelle  Espagve,  pi.  3. 

00  Umrisse  von  Vulkanen,  Tafel  ix;  the  Star-mountain,  in  the  Aztec 
language  Citlaltepetl ;  Kleinere  Schriften,  Bd.  i,  s.  467 — 470,  and  my 
Atlas  Geogr.  et  Phys.  de  la  Nouvelle  Espagne,  pi.  17. 

1  Umrisse  von  Vulkanen,  Tafel  ii. 

2  Humboldt,  Vues  dts  Cordilleres  et  Monumens  des  peuples  indigenes  de 
lAmerique  (fol.),  pl.lxii. 

3  Umrisse  von    Vidkanen.  Tafel  i  and  x  (Kleinere  Schriften,  Bd.  L 
a.  1-99). 


240  COSMOS. 

the  depths  of  the  interior  produce  remarkable  and  con- 
trasting forms  in  conical  mountains :  such  as  the  cleavage 
into  double  pyramids  of  a  more  or  less  regular  kind  in  the 
Carguairazo  (15,667  feet),  which  suddenly  fell  in4  on  the 
night  of  the  19th  July,  1698,  and  in  the  still  more  beautiful 
pyramids5  of  Ilinissa  (17,438  feet)  ;  and  a  crenulation  of  the 
upper  walls  of  the  crater,  in  which  two  very  similar  peaks, 
opposite  to  each  other,  betray  the  previous  primitive  form 
(Capac- Urcu,  Cerro  del  Altar,  now  only  17,456  feet  in 
height).  Amongst  the  aborigines  of  the  highlands  of  Quito, 
between  Chambo  and  Lican,  between  the  mountains  of 
Condorasto  and  Cuvillan,  the  tradition  has  been  universally 
preserved  that  fourteen  years  before  the  invasion  of  Huayna 
Capac,  the  son  of  the  Inca  Tupac  Yupanqui,  and  after  erup- 
tions which  lasted  uninterruptedly  for  seven  or  eight  years, 
the  summit  of  the  last-mentioned  volcano  fell  in,  and 
covered  the  entire  plateau,  in  which  New  Riobamba  is  situ- 
ated, with  pumice-stone  and  volcanic  ashes.  The  volcano, 
originally  higher  than  Chimborazo,  was  called  in  the  Inca 
or  Quichua  language,  capac,  the  kins'  or  prince  of  mountains 
(urcu),  because  the  natives  saw  its  summit  rise  to  a  greater 
height  above  the  lower  snow  line,  than  that  of  any  other  moun- 
tain of  the  neighbourhood.6  The  great  Ararat,  the  summit 

4  Umrisse  von  Vulkanen,  Tafel  iv. 

5  Ibid.  Tafel  iii,  and  vii. 

6  Long  before  the  visit  of  Bouguer  and  La  Condamine  (1736)  to  the 
plateau  of  Quito,  long  before  any  measurements  of  the  mountains  by 
astronomers,  the  natives  knew  that  Chimborazo  was  higher  than  any 
other  Nevado  in  that  region.     They  had  detected  two  lines  of  level 
which  remained  almost  exactly  the  same  all  the  year  round, — that  of 
the  lower  limit  of   perpetual    snow, — and  that    of   the   elevation    to 
which  a  single,  occasional  snow-fall  reached  down.    As  in  the  equatorial 
region  of  Quito,  the  snow-line,  as  I  have  proved  by  measurements  else- 
where (Asie  Centrale,  t.  iii,  p.  255),  only  varies  about  190  feet  in  eleva- 
tion on  six  of  the  most  colossal  peaks  ;  and  as  this  variation,  as  well  as 
smaller  ones  caused  by  local  conditions,  is  imperceptible  to  the  naked 
eye  when  seen  from  a  great  distance  (the  height  of  the  summit  of  Mont 
Blanc  is  the  same  as  that  of  the  lower  equatorial  snow-limit),  this  cir- 
cumstance gives  rise  within  the  tropics  to  an  apparently  uninterrupted 
regularity  of  the  snowy  covering,  that  is  to  say,  the  form  of  the  snow- 
line.     The  pictorial  representation  of  this  horizontally  is  astounding  to 
the  physicists   who  are  only  accustomed  to  the  irregularity  of  the 
enowy  covering  in  the  variable,  so-called  temperate  zones.     The  uni- 
formity of  elevation  of  the  snow  about  Quito,  and  the  knowledge  of  tlia 


TRUE   VOLCANOES.  241 

of  which  (17,084  feet)  was  reached  by  Friedrich  Parrot  in 
the  ytar  1829,  and  by  Abich  and  Chodzko  in  1845  and  1850, 
forms,  like  Chimborazo,  an  mi-opened  dome.  Its  vast  lava- 
streams  have  burst  forth  far  below  the  snow-line.  A  more 
important  character  in  the  formation  of  Ararat  is  a  lateral 
chasm,  the  deeply-cut  Valley  of  Jacob,  which  may  be  coin- 
pal  ed  with  the  Val  del  Bove  of  Etna.  In  this,  according  to 
Abich's  observation,  the  inner  structure  of  the  nucleus  of 
the  trachytic  dome-shaped  mountain,  first  becomes  really 
risible,  as  this  nucleus  and  the  upheaval  of  the  whole  of 
Ararat  are  much  more  ancient  than  the  lava-streams.7 
The  Kasbegk  and  Tschegem  which  have  broken  out  upon  the 
same  principal  Caucasian  mountain  ridge  (E.S.E. — W.N.W.) 
as  the  Elburuz  (19,716  feet)  are  also  cones  without  craters  at 
their  summits,  whilst  the  colossal  Elburuz  bears  a  crater-lake 
upon  its  summit. 

As  conical  and  dome-like  forms  are  by  far  the  most  fre- 
quent in  all  regions  of  the  earth,  the  isolated  occurrence 
of  the  long  ridge  of  the  volcano  of  Pichinch'a,  in  the  group 
of  volcanoes  of  Quito,  becomes  all  the  more  remarkable.  I 
have  occupied  myself  long  and  carefully  with  the  study  of 
its  structure,  and,  besides  its  profile  view,  founded  upon 

maximum  of  its  oscillation,  presents  perpendicular  bases  of  15,777  fee* 
above  the  surface  of  the  sea,  and  of  6396  feet  above  the  plateau  in 
which  the  cities  of  Quito,  Hambato,  and  Nuevo  Riobambaare  situated; 
bases  which,  combined  with  very  accurate  measurements  of  angles  of 
elevation,  may  be  employed  for  determining  distance  in  many  topogra- 
phical labours  which  are  to  be  rapidly  executed.  The  second  of  the 
level-lines  here  indicated,  the  horizontal  which  bounds  the  lower  por- 
tion of  a  single  occasional  snow-fall,  is  decisive  as  to  the  relative  height 
of  the  mountain  domes  which  do  not  reach  into  the  region  of  perpetual 
snow.  Of  a  long  chain  of  such  mountains,  which  have  been  erroneously 
supposed  to  be  of  equal  height,  many  are  below  the  temporary  snow- 
line,  and  thus  the  snow-fall  decides  as  to  the  relative  height.  I  have 
heard  such  considerations  as  these  upon  perpetual  and  accidental  snow- 
limits  from  the  mouths  of  rough  country  people  and  herdsmen  in  the 
mountains  of  Quito,  where  the  Sierras  Nevadas  are  often  close  together 
although  they  are  not  connected  by  the  same  line  of  perpetual  snow. 
Grandeur  of  nature  sharpens  the  perceptive  faculties  in  paiticular 
individuals  amongst  the  coloured  aborigines,  even  when  they  are  on 
the  lowest  steps  of  civilization. 

1  Abich.  Bulletin  de  la  Societe  de  Geographic,  4me  se'rie,  t.  i  (1851), 
p.  517,  with  a  very  beautiful  representation  of  the  form  of  the  old 
volcano. 

VOL.    V.  B 


242  COSMOS. 

numerous  angular  measurements,  have  also  published  a  topo- 
graphical sketch  of  its  transverse  valleys.8  Pichiricha  forms 
a  wall  of  black  trachytic  rock  (composed  of  augite  and  oligo- 
clase)  more  than  nine  miles  in  length,  elevated  upon  a  fissure 
in  the  most  western  Cordilleras,  near  the  South  Sea,  but 
without  the  axis  of  the  high  mountain  ridge  coinciding  in 
direction  with  that  of  the  Cordillera.  Upon  the  ridge  of 
the  wall,  the  three  domes,  set  up  like  castles,  follow  from 
S.W.  to  N.E.  :  Cuntur-guachana,  Guagua-Pichincha  (the 
child  of  the  old  volcano)  and  el  Picacho  de  los  Ladrillos. 
The  true  volcano  is  called  the  Father  or  the  Old  Man,  Eucu- 
Pichincha.  It  is  the  only  part  of  the  long  mountain  ridge 
that  reaches  into  the  region  of  perpetual  snow,  and  there- 
fore rises  to  an  elevation  which  exceeds  the  dome  of  Guagua- 
Pichincha;  the  child,  by  about  190  feet.  Three  tower-like 
rocks  surround  the  oval  crater,  which  lie  somewhat  to  the 
south-west,  and  therefore  beyond  the  axial  direction  of  a 
wall  which  is  on  the  average  15,406  feet  in  height.  In  the 
spring  of  1802, 1  reached  the  eastern  rocky  tower  accompanied 
only  by  the  Indian,  Felipe  Aldas.  We  stood  there  upon  the 
extreme  margin  of  the  crater,  about  2451  feet  above  the  bot- 
tom of  the  ignited  chasm.  Sebastian  Wisse,  to  whom  the  phy- 
sical sciences  are  indebted  for  so  many  interesting  observations 
during  his  long  residence  in  Quito,  had  the  courage  to  pass 
several  nights,  in  the  year  1845,  in  a  part  of  the  crater  where 
the  thermometer  fell  towards  sunrise  to  28°.  The  crater  is 
divided  into  two  portions  by  a  rocky  ridge,  covered  with 
vitrified  scoriae.  The  eastern  portion  lies  more  than  a 
thousand  ieet  deeper  than  the  western,  and  is  now  the  real 
seat  of  volcanic  activity.  Here  a  cone  of  eruption  rises  to 
a  height  of  266  feet.  It  is  surrounded  by  more  than  seventy 
ignited  fumaroles,  emitting  sulphurous  vapours.9  From  this 
circular  eastern  crater,  the  cooler  parts  of  which  are  now 
covered  with  tufts  of  rushy  grasses,  and  a  Pourretia  with 
Bromelia-like  leaves,  it  is  probable  that  the  eruptions  of 
fiery  scoriae,  pumice,  and  ashes  of  Rucu-Pichincha  took 
place  in  1539,  1560,  1566,  1577,  1580,  and  1660.  The  city 

8  Humboldt,    Vuts  de  Cordilleres,  p.  295,  pi.  Ixi,  and  Atlas  dt  la 
Mat.  Hist,  du  Voyage,  pi.  27. 
»  Kleinere  Schriften,  Bd.  i,  s.  61,  81,  83,  and  88. 


TRUE  VOLCANOES.  243 

of  Quito  was  then  frequently  enveloped  in  darkness  for  days 
together  by  the  falling,  dust-like  rapilli. 

To  the  rarer  class  oi  volcanic  forms  which  constitute  elon- 
gated ridges  belong,  in  the  old  world,  the  Galungung,  with  a 
large  crater,  in  the  western  part  of  Java  ;10  the  doleritic  mass 
of  the  Schiwelutsch,  in  Kamtschatka,  a  mountain- chain  upon 
the  ridge  of  which  single  domes  rise  to  a  height  of  10,170 
feet  ;n  Hec'a,  seen  from  the  north-west  side,  in  the  normal 
direction  upon  the  principal  and  longitudinal  fissure  over 
which  it  has  burst  forth,  as  a  broad  mountain-chain,  fur- 
nished with  various  small  peaks.  Since  the  last  eruptions  of 
1845  and  1846,  which  yielded  a  lava-stream  of  8  geographical 
miles  in  length  and  in  some  places  more  than  2  miles  in 
breadth,  similar  to  the  stream  from  Etna  in  1669,  five  caldron- 
like  craters  lie  in  a  row  upon  the  ridge  of  Hecla.  As  the 
principal  fissure  is  directed  N.  65J  E.,  the  volcano,  when  seen 
from  Selsundsfjall,  that  is  from  the  south-west  side,  and 
therefore  in  transverse  section,  appears  as  a  pointed  conical 
mountain.12 

If  the  forms  of  volcanoes  are  so  remarkably  different 
(Cotopaxi  and  Pichincha)  without  any  variation  in  the 
matters  thrown  out,  and  in  the  chemical  processes  taking  place 
in  the  depths  of  their  interior,  the  relative  position  of  the 
cones  of  elevation  is  sometimes  still  more  singular.  Upon 
the  island  of  Luzon,  in  the  group  of  the  Philippines,  the  still 
active  volcano  of  Taal,  the  most  destructive  eruption  oi' 
which  was  that  of  the  year  1754,  rises  in  the  midst  of  a 
If.rge  lake,  inhabited  by  crocodiles  (called  the  laguna  de 
Bomlon).  The  cone,  which  was  ascended  in  Kotzebue's 
voyage  of  discovery,  has  a  crater-lake,  from  which  again  a 
cone  of  eruption,  with  a  second  crater,  rises.13  This  descrip- 

10  Junghuhn,  Reise  durch  Java,  1845,  s.  215,  Tafel  xx. 

11  See  Adolf  Erraan's  Reise  um  die  Erde,  which  is  also  very  important 
in  a  geognostic  point  of  view,  Bd.  iii,  s.  271  and  207. 

12  Sartorius   von   Waltershausen,   Physisch-geographische  Skizze  von 
Island,  1847,  s.  107,  and  his  Geognostischer  Atlas  von  Island,  1853, 
Tafel  xv  and  xvi. 

13  Otto  von  Kotzebue,  Entdeckungs-Reise  in  die  Sildsee  und  in  die 
Berings-Strasse,  1815—1818,  Bd.  iii,  s.  68;  Reise- Atlas  von  Choris,  1820, 
Tafel  5;  Vicointe  d'Archiac,  Histoire  des  Progres  de  la  Geologie,  1847, 
t.  i,  p.  544 ;  and  Buzeta,  Diccionario  Geogr.  estad.  Historico  de  las  islat 
Filipinos,  t.ii  (Madrid,  1851),  pp.436  and  470—471,  in  which,  however, 


244  COSMOS. 

tion  reminds  one  involuntarily  of  Hanno's  journal  of  his 
voyage,  in  which  an  island  is  referred  to,  enclosing  a  small 
lake,  from  the  centre  of  which  a  second  island  rises.  The 
phenomenon  is  said  to  occur  twice,  once  in  the  Gulf  of  the 
Western  Horn,  and  again  in  the  Bay  of  the  Gorilla  Apes,  on 
the  West  African  coast.14  Such  particular  descriptions  may 
be  believed  to  rest  upon  actual  observation  of  nature ! 

The  smallest  and  greatest  elevation  of  the  points  at  which 
the  volcanic  energy  of  the  interior  of  the  earth  shows  itself 
permanently  active  at  the  surface,  is  a  hypsometric  considera- 
tion possessing  that  interest  for  the  physical  description  of 
th£  earth  which  belongs  to  all  facts  relating  to  the  reaction 
of  the  fluid  interior  of  the  planet  upon  its  surface.  The 
degree  of  the  upheaving  force16  is  certainly  evidenced  in  the 
height  of  volcanic  conical  mountains,  but  an  opinion  as  to 
the  influence  of  comparative  elevation  upon  the  frequency 
and  violence  of  eruptions  must  be  given  with  great  caution. 
Individual  contrasts  of  the  frequency  and  strength  of  similar 
actions  in  very  high  or  very  low  volcanoes,  cannot  be  deci- 
sive in  this  case,  and  our  knowledge  of  the  many  hundred 
active  volcanoes,  supposed  to  exist  upon  continents  and 
Islands,  is  still  so  exceedingly  imperfect  that  the  only  deci- 
sive method,  that  of  average  numbers,  is  as  yet  misapplied. 
But  such  average  numbers,  even  if  they  should  furnish  the 
definite  result  at  what  elevation  of  the  cones  a  quicker 
return  of  the  eruptions  is  manifested,  would  still  leave  room 
for  the  doubt  that  the  incalculable  contingencies  occurring 

the  double  encircling  of  a  crater  in  the  crater-lake,  mentioned  alike  accu- 
rately and  circumstantially  by  Delamare,  in  his  letter  to  Arago  (Novem- 
ber, 1842,  Comptes  rcndus  de  I'Acad.  des  Sciences,  t.  xvi,  p.  756)  is  not 
referred  to.  The  great  eruption  in  December,  1754  (a  previous  and 
more  violent  one  took  place  on  the  24th  September,  1716),  destroyed 
the  old  village  of  Taal,  situated  on  the  south-western  bank  of  the  lake, 
which  was  subsequently  rebuilt  at  a,  greater  distance  from  the  volcano. 
The  small  island  of  the  lake  upon  which  the  volcano  rises  is  called  Isla 
del  Volcan.  (Buzeta  loc.  cit.)  The  absolute  elevation  of  the  volcano  of 
Taal  is  scarcely  895  feet.  It  is,  therefore,  like  Cosima,  one  of  the  lowest. 
At  the  time  of  the  American  expedition  of  Captain  Wilkes  (1842)  it 
was  in  full  activity.  See  United  States  Exploring  Expedition,  vol.  v. 
P.  317. 

14  Humboldt,  Examen  Critique  de  I' Hist,  de  la  Geogr.  t.  iii,  p.  135; 
ffannonis  Periplus,  in  Hudson's  Geogr.  Greed  min.  t.  i,  p.  46. 

15  Cosmos,  vol.  i,  p.  227. 


TRUE    VOLCANOES.  245 

in  the  network  of  fissures,  which  may  be  stopped  up  with 
more  or  less  ease,  may  act  together  with  the  elevation ;  that 
is  to  say,  the  distance  from  the  volcanic  focus.  The  pheno- 
menon is  consequently  an  uncertain  one,  as  regards  its 
causal  connexion. 

Adhering  cautiously  to  matters  of  fact,  where  the  compli- 
cation of  the  natural  phenomena  and  the  deficiency  of  histo- 
rical records  as  to  the  number  of  eruptions  in  the  lapse  of 
ages  have  not  yet  allowed  us  to  discover  laws,  I  am  con- 
tented with  establishing  five  groups  for  the  comparative 
hypsometry  of  volcanoes,  in  which  the  classes  of  elevation  are 
characterised  by  a  small  but  certain  number  of  examples. 
In  these  five  groups  I  have  only  referred  to  conical  moun- 
tains rising  isolated  and  furnished  with  still  ignited  craters, 
and  consequently  to  true  and  still  active  volcanoes,  not  to 
unopened  dome-shaped  mountains,  such  as  Chimborazo.  All 
cones  of  eruption  which  are  dependent  upon  a  neighbouring 
volcano,  or  which,  when  at  a  distance  from  the  latter,  as 
upon  the  island  of  Lancerote,  and  in  the  Arso  on  the 
Epomeus  of  Ischia,  have  preserved  no  permanent  connection 
between  the  interior  of  the  earth  and  the  atmosphere,  are 
here  excluded.  According  to  the  testimony  of  the  most 
zealous  observer  of  the  vulcanicity  of  Etna,  Sartorius  von 
Waltershausen,  this  volcano  is  surrounded  by  nearly  700 
larger  and  smaller  cones  of  eruption.  As  the  measured  ele- 
vations of  the  summits  relate  to  the  level  of  the  sea,  the 
present  fluid  surface  of  the  planet,  it  is  of  importance  here 
to  advert  to  the  fact  that  insular  volcanoes, — of  which  some 
(such  as  the  Javanese  volcano  Cosima,16  at  the  entrance  of 
the  Straits  of  Tsugar,  described  by  Horner  and  Tilesius)  do 
not  project  a  thousand  feet,  and  others,  such  as  the  Peak  of 
Tenerifie,17  are  more  than  12,250  feet  above  the  surface  of 

16  For  the  position  of  this  volcano,  which  is  only  exceeded  in  small- 
noss  by  the  volcano  of  Tanna,  and  that  of  the  Mendaiia,  see  the  fine 
map  of  Japan  by  F.  von  Siebold,  1840. 

17  I  do  not  mention  here,  with  the  Peak  of  Teneriffe,  amongst  the 
insular  volcanoes,  that  of  Mauna-Roa,  the  conical  form  of  which  does 
not  agree  with  its  name.     In  the  language  of  the  Sandwich  Islanders, 
mauna   signifies  mountain,  and  roa,  both  long  and  much.     Nor  do  I 
mention  Hawaii,  upon  the  height  of  which  there  has  so  long  been  a 
dispute,  and  which  has  been  described  as  a  trachytic  dome  not  opened 
at  the  summit.     The  celebrated  crater  Kiraueah  (a  lake  of  molten, 


246  COSMOS. 

the  sea, — have  raised  themselves  by  volcanic  forces  above  a 
sea-bottom,  which  has  often  been  found  20,000  feet,  nay,  in 
one  case,  more  than  45,838  leet,  below  the  present  surface  of 
the  ocean.  To  avoid  an  error  in  the  numerical  proportions 
it  must  also  be  mentioned  that,  although  distinctions  of  the 
first  and  fourth  classes,— volcanoes  of  1000  and  18,000  feet 
(1066  and  19,188  English  feet)— appear  very  considerable  for 
volcanoes  on  continents,  the  ratios  of  these  numbers  are 
quite  changed  if  (from  Mitscherlich's  experiments  upon  the 
melting  point  of  granite,  and  the  not  very  probable  hypo- 
thesis of  the  uniform  increase  of  heat  in  proportion  to  the 
depth  in  arithmetical  progression)  we  infer  the  upper  limit 
of  the  fused  interior  of  the  earth  to  be  about  121,500  feet 
below  the  present  sea  level.  Considering  the  tension  of  elastic 
vapours,  which  is  vastly  increased  by  the  stopping  of  volcanic 
fissures,  the  differences  of  elevation  of  the  volcanoes  hitherto 
measured  are  certainly  not  considerable  enough  to  be 
regarded  as  a  hindrance  to  the  elevation  of  the  lava  and  other 
dense  masses  to  the  height  of  the  crater. 

Hypsometry  of  Volcanoes. 

First  group,  from  700  to  4000  Paris  or  746  to  4264  English 
feet  in  height. 

The  volcano  of  the  Japanese  i&land  Cosima,  to  the  south  of  Jezo: 

746  feet,  according  to  Horner. 
The  volcano  of  the  Liparian  island    Volcano:    1305  English  feet, 

according  to  F.  Hoffmann.18 
Gunung  Api  (signifying  Fiery  Mountain  in  the  Malay  language),  the 

volcano  of  the  island  of  Banda :  1949  feet. 

boiling  lava)  lies  to  the  eastward,  near  the  foot  of  the  Mauna-Eoa,  accord- 
ing to  Wilkes,  at  an  elevation  of  3970  feet.  See  the  excellent  description 
in  Charles  Wilkes'  Exploring  Expedition,  vol  iv,  pp.  165 — 196. 

18  Letter  from  F.  Hoffmann  to  Leopold  von  Buch,  upon  the  Geog- 
nostic  Constitution  of  the  Lipari  Islands,  in  Poggend.  Annalen,  Bd.  xxvi, 
1832,  s.  59.  Volcano,  1268  feet,  according  to  the  recent  measurement 
of  C.  Sainte-Claire  Deville,  had  violent  eruptions  of  scoriae  and  ashes  in 
the  year  1444,  at  the  end  of  the  16th  century,  in  1731,  1739,  and  1771. 
Its  fumaroles  contain  ammonia,  borate  of  selenium,  sulphuret  of 
arsenic,  phosphorus,  and,  according  to  Bornemann,  traces  of  iodine. 
The  last  three  substances  occur  here  for  the  first  tinip  amongst  vol- 
canic products  (Comptes  rendus  de  I'Acad.  des  Sciences,  t,  xliii,  1856, 
p.  683). 


TRUE  VOLCANOES.  247 

The  volcano  of  Izalco,19  in  the  state  of  San  Salvador  (in  Central 
America)  which  was  first  ascended  in  the  year  1770,  and  which 
is  in  a  state  of  almost  constant  eruption  :  2132  feet,  according 
to  Squier. 

Gunung  Ringgit,  the  lowest  volcano  of  Java :  2345  feet,  according  to 
Junghuhn.20 

Stromboli:  2958  feet,  according  to  F.  Hoffmann. 

Vesuvius,  the  Rocca  del  Palo,  on  the  highest  northern  margin  of  the 
crater  :  the  average  of  my  two  barometrical  measurements-1  of  1805 
and  1822  gives  3997  feet. 

The  volcano  of  Jorullo,  which  broke  out  in  the  elevated  plateau  of 
Mexico-  on  the  29th  September,  1759:  4266  feet. 

Second  group,  from  4000  to  8000  Paris  or  4264  to  8528 
English  feet  in  height. 

Mont  PeU,  of  Martinique  :  4707  feet,  according  to  Dupuget. 

The  Soufriere,  of  Guadaloupe:  4867  feet,  according  to  C.  Deville. 

Gunung  Lamongan,  in  the  most  eastern  part  of  Java:  5341  feet, 
according  to  Junghuhn. 

Gunung  Tengger,  which  has  the  largest  crater23  of  all  the  volcanoes  of 
Java:  height  at  the  cone  of  eruption  of  Bromo,  7547  feet,  accord- 
ing to  Junghuhn. 

The  volcano  of  Osorno  (Chili):  7550  feet,  according  to  Fitzroy. 

The  volcano  of  Pico24  (Azores)  :  7614  feet,  according  to  Captain 
Vidal. 

The  volcano  of  the  island  of  Bourbon:  8002  feet,  according  to 
Berth. 

19  Squier,  in  the  tenth  annual  meeting  of  the  American  Association, 
Newhaven,  1850. 

20  See  Franz  Junghuhn's  exceedingly  instructive  work,  Java,  seine 
Gestalt  und  Pflanzendecke,  1852,  Bd.  i,  s.  99.     Ringgit  has  been  nearly 
extinct,  since  its  fearful  eruption  in  the  year  1586,  which  cost  the  lives 
of  many  thousand  people. 

21  The  summit  of  Vesuvius  is,  therefore,  only  260  feet  higher  than 
the  Brock  en. 

22  Humboldt,    Vues   des   Cordilleres,    pi.  xliii,   and   Atlas  geogr.  et 
physique,  pi.  29. 

*3  Junghuhn,  Op.  cit.  sup.  Bd.  i,  s.  68  and  98. 

24  See  my  Relation  ffistorique,  t.  i,  p.  93,  especially  with  regard  to 
the  distance  at  which  the  summit  of  the  volcano  of  the  island  of  Pico 
has  sometimes  been  seen.  Ferrer's  old  measurement  gave  7918  feot, 
and  therefore  304  feet  more  than  the  certainly  more  careful  survey  of 
Obtain  Vidal  in  1843. 


248  COSMOS. 

Third  group,  from  8000  to  12,000  Paris  or  8528  to  12,792 
English  feet  in  height. 

The  volcano  of  Awatscha  (Peninsula  of  Kamtschatka),  not  to  be  con- 
founded25 with  the  rather  more  northern  Strjdoschnaja  Sopka, 
which  is  usually  called  the  volcano  of  Awatscha  by  the  English 
navigators:  8912  feet,  according  to  Erman. 

The  volcano  of  Antuco'26  or  Anto'io  (Chili):  8920  feet,  according  to 
Domeyko. 

The  volcano  of  the  island  of  FogcF  (Cape  Verd  Islands) :  91 54  feet, 
according  to  Charles  Deville. 

The  volcano  of  Schiwelutsch  (Kamtschntka) :  the  north-eastern 
summit  10,551  feet,  according  to  Erman.28 

25  Erman,  in  his  interesting  geognostic  description  of  the  volcanoes 
of  the  peninsula  of  Kamtschatka,  gives  the  Awatschinskaja  or  Gorelaja 
Sopka  as  8912  feet,  and  the  Strjeloschnaja  Sopka,  which  is  also  called 
Korjaskaja  Sopka,  as  11,822  feet  (Reise,  Bd.  iii,  s.  494  and  540).     See 
with  regard  to  these  two  volcanoes,  of  which  the  former  is  the  most 
active,  Leopold  de  Buch,  Descr.  Physique  des  Ites  Canaries,  pp.  447 — 
450.     Erman's  measurement  of  the  volcano  of  Awatscha  agrees  best 
with  the  earliest  measurements  of  Mongez  (8739)  during  the  expedition 
of  La  Perouse  (1787),  and  with  the  more  recent  one  of  Captain  Beechy 
(9057  feet).       Hofmann  in  Kotzebue's  voyage,  and  Lenz  in  Lutke's 
voyage,  found  only  8170  and  8214  feet ;   see  Lutke,  Voyage  autour  du 
Monde,  t.  iii,  pp.  67 — 84.     The  admiral's  measurement  of  the  Strjelo- 
schnaja Sopka  gave  11,222  feet. 

26  See  Pentland's  table  of   elevations   in  Mrs.  Somerville's  Physical 
Geography,  vol.  ii,  p.  452 ;  Sir  Woodbine  Parish,  Biienos-Ayres  and  the 
Province  of  the  Rio  de  la  Plata,  1852,  p.  343;  Poppig,  Reise  in  Chile  wid 
Peru,  Bd.  i,  s.  411—434. 

27  Is  it  probable  that  the  height  of  the  summit  of  this  remarkable 
volcano  is   gradually  diminishing  ?     A  barometrical  measurement  by 
Baldey,  Vidal,  and  Mudge,  in  the  year  1819,  gave  2975  metres  or  9760 
feet ;    whilst   a  very   accurate   and    practised  observer,    Sainte-Claire 
Deville,  who  has  done  such   important   service   to   the  geognosy   of 
volcanoes,   only   found    2790  metres  or   9154  feet  in  the  year  1842 
(Voyage  aux  lies  Antilles  et  a  Vile  de  Fogo,  p.  155).     Captain  King 
had  a  little  while  before   determined   the   height  of  the  volcano    of 
Fogo  to  be  only  2686  metres  or  8813  feet. 

28  Erman,  Reise,  Bd.  iii,  s.  271,  275,  and  297.     The  volcano  Schiwe- 
lutsch, like  Pichincha,  has  a  form  which  is  rare  amongst  active   vol- 
canoes, namely,  that  of  a  long  ridge  (chrebet),  upon  which  single  domes 
and  crests   (grebni)   rise.      Dome-shaped    and   conical   mountains  are 
always  indicated  in  the  volcanic  district  of  the  peninsula  by  the  name 
eopki. 


TRUE  VOLCANOES.  249 

Etna.39  according  to  Smyth,  10,871  feet. 

Peak  of  Tencriffe:  12.161  feet,  according  to  Charles  Deville.30 

The  volcano  Gunung  Semeru,  the  highest  of  all  mountains  on  the 

island  of  Java:  1^,237  feet,  according  to  Junghuhu's  barometrical 

measurement. 

The  volcano  Erebus,  lat.  77°  32',  the  nearest  to  the  south  pole  .31 
12,366  feet,  according  to  Sir  James  Rosa. 

The  volcano  Argceus,32  in  Cappadocia,  now  Erdschisch-Dagh,  south- 
south-east  of  Kaisarieh :  12,603  feet,  according  to  Peter  von 
Tschichatscheff. 

29  For  an  account  of  the  remarkable  agreement  of  the  trigonome- 
trical with  the  barometrical  measurement  of  Sir  John  Herschel,  see 
Cosmos,  vol.  i,  p.  6. 

30  The  barometrical  measurement  of  Sainte-Claire  Deville  (Voy.  aux 
Antilles,  pp.  102—118),  in  the  year  1842,  gave  3706  metres  or  12,161 
feet,  nearly  agreeing  with  the  result  (12,184  feet)  of  Borda's  second 
trigonometrical  measurement  in  the  year  1776,  which  I  was  enabled  to 
publish  for  the  first  time  from  the  manuscript  in  the  De'pot  de  la 
Marine  (Humboldt,   Voy.  aux  Regions  Equinox,  t.  i,  pp.  116  and  275 — 
287).     Borda's  first  trigonometrical  measurement,  undertaken  in  con- 
junction  with  Pingre"  in  the  year  1771,  gave,  instead  of  12,1 84  feet, 
only  11,142  feet.     The.  cause  of  the  error  was  the  false  reading  of  an 
angle  (33'  instead  of  53'),  as  was  told  me  by  Borda  himself,  to  whose 
great  personal  kindness  I  was  indebted  for  much  useful  advice  before 
my  voyage  on  the  Orinoco. 

31  I  follow  Peutland's   estimate  of  12,367  feet,  especially  because 
in  Sir   James   Ross'    Voyage   of  Discorery   in    the   Antarctic   Regions, 
vol.  i,  p.  216,  the  height  of  the  volcano,  the  eruptions  of  smoke  and 
flame  from  which  were  seen  even  in  the  day  time,  is  given  in  round 
numbers  at  12,400  feet. 

32  With  regard  to  Argseus,  which  Hamilton  was  the  first  to  ascend  and 
measure  barometrically  (at  12,708  feet  or  3905  metres),  see  Peter  von 
Tschichatscheff,  Asie  Mineure  (1853),  t.  i,  pp.  441—449,  and  571.    In  his 
excellent  work  (Researches  in  Asia  Minor),  William  Hamilton  obtained 
as  the  mean   of  one  barometrical  measurement  and  several  angles  of 
elevation  13,000  feet;  but  if  the  height  of  Kaisarieh  is  1000  feet  less 
than  he  supposes,  it  would  be  only  12,000  feet.    See  Hamilton,  in  Trans. 
Geolog.  Societi/,  vol.  v,  pt.  3,  1840,  p.  596.     Towards  the  south-east  from 
Argseus  (Erdschisch  Dagh)  in  the  great  plain  of  Eregli,  numerous  very 
email  cones  of  eruption  rise  to  the  south  of  the  village  of  Karabunar 
and  the  mountain  group  Karadscha-Dagh.      One  of  these,  furnished 
with  a  crater,  has  a  singular  shape  like  that  of  a  ship,  running  out  in 
front  like  a  beak.     This  crater  is  situated  in  a  salt  lake,  on  the  road 
from  Kambunar  to  Eregli,  at  a  distance  of  fully  four  miles  from  the 
former  place.    The  hill  bears  the  same  name  (Tschichatscheff,  t.  i,  p.  455; 
William  Hamilton,  Researches  in  Asia  Minor,  vol.  ii,  p.  217). 


250  COSMOS. 

Fourth  group,  from  12,000  to  16,000  Paris  or  12,792  to 
17,056  English  feet  in  lieigU. 

The  volcano  of  Tugiieres,33  in  the  highlands  of  the  Provincia  de  Ion 

Pastes:  12,824  feet,  according  to  Eoussingault. 
The  volcano  of  Pasto:™  13,453  feet,  according  to  Boussingault. 
The  volcano  Mauna-Roar*  13,761  feet,  according  to  Wilkes. 
The  volcano  of  Cumbal,™  in  the  Provincia  de  los  Pastos:   15,621 

feet,  according  to  Boussingault. 

The  volcano  KliutschewsW7  (Kamtschatka) :    15,766  feet,  according 
to  Erman. 

The  volcano  Rucu-Pichincha :  15,926  feet,  according  to  Humboldt'a 
barometrical  measurements. 

33  The  height  here  given  is  properly  that  of  the  grass-green  mountain 
lake,  Laguna  verde,  on  the  margin  of  which  is  situated  the  solfatara 
examined  by  Boussingault  (Acosta,  Viajes  Cientificos  a,  los  Andes  Ecuato- 
riales,  1849,  p.  75). 

34  Boussingault   succeeded  in  reaching  the  crater,   and  determined 
the  altitude  barometrically  ;  it  agrees  very  nearly  with  that  which  I 
made   known   approximately   23   years   before,    on  my  journey  from 
Popayau  to  Quito. 

35  The  altitude  qf  few  volcanoes  has  been  so  over-estimated  as  that 
of  the  Colossus  of  the  Sandwich  Islands.    We  see  it  gradually  fall  from 
18,410  feet  (the  estimate  given  in  Ccok's  third  voyage),  16,486  feet  in 
King's,  and  16,611  feet  in  Marchand's  measurement,  to  13,761  feet  by 
Captain  Wilkes,    and   13,524    feet  by  Horner  in  Kotzebue's   voyage. 
The  grounds  of  the  last-mentioned  result  were  first  made  known  by 
Leopold  von  Buch  in  the  Description  Physique  des  lies  Canaries,  p.  379. 
See  Wilkes,  Exploring  Expedition,  vol.  iv,  pp.  Ill — 162.     The  eastern 
margin  of  the  crater  is  only  13,442  feet.     The  assumption  of  a  greater 
height,  considering  the  asserted  freedom  from  snow  of  the  Mauna-Roa 
(lat.  19°  28';  would  also  be  in  contradiction  to  the  result  that  according 
to  my  measurements  in  the  Mexican  continent  in  the  same  latitude,  the 
limit  of  perpetual  snow  has  been   found  at  14,775  feet  (Humboldt, 
Voyage  aux  Regions  Equinox,  t.  i,  p.  97;  Asie  Centrale,  t.  iii,  p.  2C9  and 
359). 

36  The  volcano  rises  to  the  west  of  the  village  of  Cumbal,  which  is 
itself  situated  10,565  feet  above  the  sea-level  (Acosta,  p.  76). 

37  I  give  the  result  of  Erman's  repeated  measurements  in  September, 
1829.     The  height  of  the  margin  of  the  crater  is  exposed  to  alterations 
by  frequent  eruptions,  for  in  August,  1828,  measurements  which  might 
inspire  et^ual  confidence  gave  an  altitude  of    16,033  feet.      Compare 
Erman's  Physikalische  Beobaclitungen  auf  einer  Reise  um  die  Erde,  Bd.  i, 
s.  400  and  419,   with  the  historical   account  of  the  journey,    Bd.  iii, 
g.  358—360. 


TRUE  VOLCANOES.  251 

The  volcano  TunguraJiua :  16,494  feet,  according  to  a  trgonometrical 
measurement33  by  Kumboldt. 

The  volcano  of  Purace,39  near  Popayan:  17,010  feet,  according  to 
Jos£  Caldaa. 

Fifth  group,  from  16,000  to  more  than  20,000  Paris  or  from 
17,056  to  21,320  English  feet  in  height. 

The  volcano  Sangay,  to  the  south-west  of  Quito:  17,128  feet,  ac- 
cording to  Bouguer  and  La  Condamine.40 

The  volcano  Popocatepetl:41  17,729  feet,  according  to  a  trigonometri- 
cal measurement  by  Humboldt. 

The  volcano  of  Orizaba:4'2  17,783  feet,  according  to  Ferrer. 

38  Bouguer  and  La  Condamine,  in  the  inscription   at   Quito,   give 
16,777  feet  for  Tungurahua  before  the  great  eruption  of  1772,  and  the 
earthquake  of  Riobamba  (1797),  which  gave  rise  to  great  depressions  of 
mountains.     In  the  year  1802  I  found  the  summit  of  the  volcano  trigo- 
nometrically  to  be  ouiy  16,494  feet. 

39  The  barometrical  measurement  of  the  highest  peak  of  the  Volcan 
de  Purace"  by  Francisco  Jose  Caldas,  who,  like  my  dear  friend  and 
travelling  companion,  Carlos  Montufar,  fell  a  sacrifice  to  his  love  for 
the  independence   and  freedom  of   his  country,   is   given  by  Acosta 
(Viajes   Cientifaos,  p.   70)  at  5184  metres  (17,010  feet).     I  found  the 
height  of  the  small  crater,   which  emits  sulphureous  vapours  with  a 
violent  noise  (Aznfral  del  Boqueron)  to  be  14,427  feet;    Humboldt, 
Recueil  d'Observ.  Astronomiques  et  d' Operations  Trigonometriques,  vol.  i, 
p.  304. 

40  The  Sangay  is  extremely  remarkable  from  its  uninterrupted  activity 
and  its  position,  being  removed  somewhat  to  the  eastward  from  the 
eastern  Cordillera  of  Quito,  to  the  south  of  the  Rio  Pastaza,  and  at  a 
distance  of  120  miles  from  the  nearest  coast  of  the  Pacific, — a  position 
which  (like  that  of  the  volcanoes  of  the  Celestial  mountains  in  Asia) 
by  no  means  supports  the  theory  according  to  which  the  eastern  Cor- 
dilleras of  Chili  are  free  from  volcanic  eruptions  on  account  of  their 
distance  from  the  sea.     The  talented  Darwin  has  not  omitted  referring 
in  detail  to  this  old  and  widely  diffused  volcanic  littoral  theory  in  the 
Geological  Observations  on  South  America,  1846,  p.  185. 

41  I    measured    Popocatepetl,    which    is   also    called    the    Volcan 
Grande  de  Mexico,  in  the  plain  of  Tetimba,  near  the  Indian  village  San 
Nicolas  de  los  Ranchos.     It  seems  to  me  to  be  still  uncertain  which  of 
the  two  volcanoes,  Popocatepetl  or  the  pe;ik  of  Orizaba,  is  the  highest 
(see  Humboldt,  Receuil  d'Observ.  Astron.,  vol.  ii,  p.  543). 

42  The  peak  of  Orizaba,  clothed  with  perpetual  snow,  the  geogra- 
phical position  of  which  was  quite  erroneously  indicated  on  all  maps 
before  my  journey,  notwithstanding  the  importance  of  this  point  for 


252  COSMOS. 

ELias  Mount43  (on  the  west  coast  of  North  America):  17,855  feet, 
according  to  the  measurements  of  Quadra  and  Galeano. 

The  volcano  of  Tolima:**  18,143  feet,  according  to  a  trigonometrical 
measurement  by  Humboldt. 

The  volcano  of  Arequipa:45  18,883  feet,  according  to  a  trigonome- 
trical measurement  by  Dolley. 

navigation  near  the  landing-place  in  Vera  Cruz,  was  first  measured 
trigonometrically  from  the  Encero  by  Ferrer,  in  1796.  The  measure- 
ment gave  17,879  feet.  I  attempted  a  similar  operation  in  a  small 
plain  near  Xalapa.  I  found  only  17,375  feet,  but  the  angles  of  eleva- 
tion were  very  small,  and  the  base  line  difficult  to  level.  See  Humboldt, 
Essai  Politique  sur  la  Nouv.  Espagne,  2me  e"d.  t.  i,  1825,  p.  166  ;  Atlas 
du  Mexique  (Carte  des  fausses  positions),  pi.  x,  and  Kleinere  Schriften, 
Bd.  i,  s.  468. 

43  Humboldt,  Essai  sur  la  Geographic  des  Plantes,  1807,  p.  153.    The 
elevation  is  uncertain,  perhaps  more  than  ^th  too  high. 

44  I  measured  the  truncated  cone  of  the  volcano  of  Tolima,  situated  at 
the  northern  extremity  of  the  Paramo  de  Quindiu,  in  the  Valle  del 
Carvajal,  near  the  little  town  of  Ibague,  in  the  year  1802.     The  moun- 
tain is  also  seen  at  a  great  distance  upon  the  plateau  of  Bogota*.     At 
this  distance  Caldas  obtained  a  tolerably  approximate  result  (18,430 
feet)  by  a  somewhat  complicated  combination  in  the  year  1806  ;  Sem,a- 
nario  de  la  Nueva  Granada,  nueva  edition,  aumentada  por  J.  Acosta, 
1849,  p.  349. 

45  The  absolute  altitude  of  the  volcano  of  Arequipa  has  been  so 
variously  stated  that  it  becomes  difficult  to  distinguish  between  mere 
estimates  and  actual  measurements.     Dr.  Thaddaus  Hanke,  of  Prague, 
the  distinguished  botanist   of  Malaspina's  voyage   round   the   world, 
ascended  the  volcano  of  Arequipa  in  the  year  1796,  and  found  at  the 
summit  a  cross  which  had  been  ereuted  there  12  years  before.     By  a 
trigonometrical  operation  Hanke  found  the  volcano  to  be  3180  toises 
(20,235  feet)  above  the  sea.     Thih  altitude,  which  is  far  too  great,  was 
probably  the  result  of  an  erroneous  assumption  of  the  elevation  of  the 
town  of  Arequipa,  in  the  vicinity  of  which  the  operation  was  performed. 
Had  Hanke  been  provided  with  a  barometer,  a  botanist  entirely  unprac- 
tised in  trigonometrical  measurements,  would  certainly  not  have  resorted 
to  such  means  after  ascending  to  the  summit.     The  first  who  ascended 
the  volcano  after  Hanke  was  Samuel  Curzou,  from  the  United  States 
of  North  America    (Boston  Philosophical  Journal,    1823,    November, 
p.  168).     In  the  year  1830  Pentland  estimated  the  altitude  at  5600 
metres  (18,374  feet1),  and  I  have  adopted  this  number  (Annuaire  du 
Bureau  des  Longitudes,  1830,  p.  325)  for  my  Carte  Hypsometrique  de  la 
Cordillere  des  Andes,  1831.     There  is  a  satisfactory  agreement  (within 
Tyth)  between  this  and  the  trigonometrical  measurement  of  a  French 
naval  officer,  M.  Dolley,  for  which  I  was  indebted  in  1826  to  the  kind 
communication  of  Captain  Alphonse  de  Moges  in  Paris.     Dolley  found 


TRUE   VOLCANOES.  253 

The  volcano  Cotopaxi:*6  18,881  feet,  according  to  Bouguer. 

The  volcano  Sahama*7  (Bolivia)  :  22,354  feet,  according  r,o  Pentland, 

The  volcano  with  which  the  fifth  group  ends  is  more  than 

the  summit  of  the  volcano  of  Arequipa  (trigonometrically)  to  be 
11,031  feet,  and  the  summit  of  Charcani  11,860  feet  above  the  plateau 
in  which  the  town  of  Arequipa  is  situated.  If  now  we  fix  the  town  of 
Arequipa  at  7841  feet,  in  accordance  with  the  barometrical  measurements 
of  Pentland  and  Rivero  (Pentland,  7852  feet  in  the  Table  of  Altitudes 
to  the  Physical  Geography  of  Mrs.  Somerville,  3rd  ed.  vol.  ii,  p.  454; 
Rivero,  in  the  Memorial  de  Ciencias  Naturales,  t.  ii,  Lima,  1828,  p.  65  ; 
Meyen,  Reise  urn  die  Erde,  Theil.  ii,  1835,  s.  5),  Dolley's  trigonometrical 
operation  will  give  for  the  volcano  of  Arequipa  18,881  feet  (2952  toises), 
and  for  the  volcano  Charcani,,  19,702  feet  (3082  toises).  But  Pentland's 
Table  of  Altitudes,  above  cited,  gives  for  the  volcano  of  Arequipa 
20,320  English  feet,  6190  metres  (19,065  Paris  feet),  that  is  to  say, 
1945  feet  more  than  the  determination  of  1830,  and  somewhat  too  iden- 
tical with  Hanke's  trigonometrical  measurement  in  the  year  1796  !  In 
opposition  to  this  result  the  volcano  is  stated,  in  the  Anales  de  la  Uni- 
versidad  de  Chile,  1852,  p.  221,  only  at  5600  metres  or  18,378  feet:  con- 
sequently 590  metres  lower !  A  sad  condition  of  hypsometry  ! 

46  Boussingault,  accompanied  by  the  talented  Colonel  Hall,  has  nearly 
reached  the  summit  of  Cotopaxi.     He  attained,  according  to  barome- 
trical measurement,  to  an  altitude  of  5746  metres  or  18,855  feet.  There 
was  only  a  small  space  between  him  and  the  margin  of  the  crater,  but 
the  great  looseness  of  the  snow  prevented  his  ascending  further.     Per- 
haps Bouguer's  statement  of  altitude  is  rather  too  small,  as  his  compli- 
cated trigonometrical  calculation  depends  upon  the  hypothesis  as  to  the 
elevation  of  the  city  of  Quito. 

47  The  Sahama,  which  Pentland  (Annuaire  du  Bureau  des  Longi- 
tudes,   1830,   p.    321)   distinctly  calls  an   active  volcano,   is   situated, 
according  to  his  new  map  of  the  Vale  of  Titicaca  (1848),  to  the  east- 
ward of  Arica  in  the  western  Cordillera.     It  is  928  feet  higher  than 
Chimborazo,  and  the  relative  height  of  the  lowest  Japanese  volcano 
Cosima  to  the  Sahama  is  as  1  to  30.      I  have  hesitated  in  placing  the 
Chilian  Aconcagua,  which,  stated  by  Fitzroy  in  1835  at  23.204  feet, 
is,   according   to   Pentland's   correction,    23,911    feet,    and   according 
to  the   most  recent  measurement  (1845)   of  Captain  Kellet   of  the 
frigate   Herald,    23,004   feet,  in   the   fifth   group,    because   from    the 
contradictory  opinions  of  Miers  (  Voyage  to  Chili,  vol.  i,  p.  283)  and 
Charles  Darwin  (Journal  of  Researches  into  the  Geology  and  Natural 
History  of  the  Various  Countries  -visited  by  the  Beagle,  2nd  ed.  p.  291), 
it  remains  doubtful  whether  this  colossal  mountain  is  a  still  ignited 
volcano.     Mrs.  Somerville,  Pentland,  and  Gilliss  (Naval  Attr.  Exped. 
vol.  i,  p.  126),  also  deny  its  activity.      Darwin  says  : — "  I  was  surprised 
at  hearing   that  the  Aconcagua  was   in   action  the  same  night  (15th 
January,  1835),  because  this  mountain  most  rarely  shows  any  sign  of 
action." 


254  COSMOS. 

twice  as  high  as  Etna,  and  five  times  and  a  half  as  high  aa 
Vesuvius.  The  scale  of  volcanoes  that  I  have  suggested,  start- 
ing from  the  lowly  Maars  (mine-craters  without  a  raised 
framework,  which  have  cast  forth  olivine  bombs  surrounded 
by  half-fused  fragments  of  slate)  and  ascending  to  the  still 
burning  Bahama  22,354  feet  in  height,  has  shown  us  that 
there  is  no  necessary  connexion  between  the  maximum  oi 
elevation,  the  smaller  amount  of  the  volcanic  activity  and 
the  nature  of  the  visible  species  of  rock.  Observations  con- 
fined to  single  countries  may  readily  lead  us  to  erroneous 
conclusions.  For  example,  in  the  part  of  Mexico  which 
lies  in  the  torrid  zone,  all  the  snow-covered  mountains, 
that  is  to  say  the  culminating  points  of  the  whole  country, 
are  certainly  volcanoes  ;  and  this  is  also  usually  the  case 
in  the  Cordilleras  of  Quito,  if  the  dome-shaped  trachytic 
mountains,  not  opened  at  the  summit  (Chimborazo  and 
Corazon),  are  to  be  associated  with  volcanoes ;  on  the  other 
hand,  in  the  eastern  chain  of  the  Bolivian  Andes,  the 
highest  mountains  are  entirely  non- volcanic.  The  Uevados 
of  Sorata  (21,292  feet),  and  Illimani  (21, 153  feet)  consist  of 
grauwacke  schists,  which  are  penetrated  by  porphyritic 
masses,48  in  which  (as  a  proof  of  this  penetration),  fragments 
of  schist  are  enclosed.  In  the  eastern  Cordillera  of  Quito, 
south  of  the  parallel  of  1°  35'  the  high  summits  (Condorasto, 
Cuvillan.  and  the  Collanes)  lying  opposite  to  the  trachytes, 
and  also  entering  the  region  of  perpetual  snow,  are  also 
mica-slate  and  firestone.  According  to  our  present  know- 
ledge of  the  mineralogical  nature  of  the  most  elevated  parts 

48  These  penetrating  porpliyritic  masses  show  themselves  in  peculiar 
vastness,  near  the  Illimani,  in  Cenipampa  (15,949  feet)  and  Totora- 
pampa  (13,709  feet);  and  a  quartzose  porphyry  containing  mica,  and 
enclosing  garnets  and  at  the  same  time  angular  fragments  of  silicious 
schist  forms  the  superior  dome  of  the  celebrated  argentiferous  Cerro  de 
Potosi  (Pentland  in  MSS.  of  1832).  The  Illimani,  which  Pentland 
estimated  first  at  7315  (23,973  feet),  and  afterward  sat  6445  (21, 139  feet) 
metres,  has  also  been,  since  1847,  the  object  of  a  careful  measurement 
by  the  engineer  Pissis,  who,  on  the  occasion  of  his  great  trigonometrical 
survey  of  the  Llanura  de  "Bolivia,  found  the  Illimani  to  be  on  the  ave- 
rage 6509  metres  (21,349  feet)  in  height,  by  three  triangles  between 
Calamarca  and  La  Paz  :  this  only  differs  about  64  metres  (210  feet)  from 
Pentland' s  last  determination.  See  Investigadones  Sobre  la  Altitud  de 
los  Andes,  in  the  Anales  de  Chile,  1852,  p.  217  and  221. 


TRUE  VOLCANOES.  2.55 

of  the  Himalaya,  which  we  owe  to  the  meritorious  labours 
of  B.  H.  Hodgson,  Jacquemont,  Joseph  Dal  ton  Hooker, 
Thomson,  and  Henry  Strachey,  the  primary  rocks,  as  they 
were  formerly  called,  granite,  gneiss  and  mica-slate,  appear  to 
be  visible  here  also,  although  there  are  no  trachy tic  formations. 
In  Bolivia,  Pentland  has  found  fossil  shells  in  the  Silurian 
schists  on  the  Nevado  de  Antacaua,  17,482  feet  above  the 
sea,  between  La  Paz  and  Potosi.  •  The  enormous  height  to 
which  from  the  testimony  of  the  fossils  collected  by  Abich 
from  Daghestan,  and  by  myself  from  the  Peruvian  Cordil- 
leras (between  Guambos  and  Montan),  the  chalk  formation 
is  elevated,  reminds  us  very  vividly  that  non-volcanic  sedi- 
mentary strata,  full  of  organic  remains,  and  not  to  be  con- 
founded with  volcanic  tufaceous  strata,  show  themselves  in 
places  where  for  a  long  distance  around,  melaphyres,trachytes, 
dolerites,  and  other  pyroxenic  rocks,  which  we  regard  as  the 
seat  of  the  upheaving,  urging  forces,  remain  concealed  in  the 
depths.  In  what  immeasurable  tracts  of  the  Cordilleras  and 
the  districts  bordering  them  upon  the  east,  is  no  trace  of 
any  granitic  formation  visible ! 

The  frequency  of  the  eruptions  of  a  volcano,  appearing 
to  depend,  as  I  h:*ve  already  repeatedly  observed,  upon  mul- 
tifarious and  very  complicated  causes,  no  general  law  can 
safely  be  established  with  regard  to  the  relation  of  the  abso- 
lute elevation  to  the  frequency  and  degree  o"f  the  renewal  of 
combustion.  If  in  a  small  group  the  comparison  of  Strom- 
boli,  Vesuvius,  and  Etna,  may  mislead  us  into  the  belief 
that  the  number  of  eruptions  is  in  an  inverse  ratio  to  the 
elevation  of  the  volcanoes,  other  facts  stand  in  direct  con- 
tradiction to  this  proposition.  Sartorius  von  Waltershausen, 
who  has  done  such  good  service  to  our  knowledge  of  Etna, 
remarks  that  on  the  average  furnished  by  the  last  few  centu- 
ries,  an  eruption  of  this  volcano  is  to  be  expected  every  six 
years,  whilst  in  Iceland,  where  no  part  of  the  island  is  really 
secure  from  destruction  by  submarine  fire,  the  eruptions  of 
Hecla,  which  is  5756  feet  lower,  are  only  observed  every  70 
or  80  years.49  The  group  of  volcanoes  of  Quito  presents  a 
still  more  remarkable  contrast.  The  volcano  of  Sangay, 
17,000  feet  in  height,  is  far  more  active  than  the  little  conical 
mountain  Stromboli  (2958  feet)  ;  it  is  of  all  known  volca- 

49  Sartorius  von  Waltershausen,  Skizze  von  Island,  s.  103  and  107 


256  COSMOS. 

noes  the  one  which  exhibits,  every  quarter  of  an  houi,  the 
greatest  quantity  of  fiery,  widely-luminous  eruptions  of 
scoriae.  Instead  of  losing  ourselves  in  hypotheses  upon 
the  causal  relations  of  inaccessible  phenomena,  we  will  rather 
dwell  here  upon  the  consideration  of  six  points  of  the  surface 
of  the  earth,  which  are  peculiarly  important  and  instructive 
in  the  history  of  volcanic  activity, — Stromboli,  the  Lycian 
Chimoera,  the  old  volcano  of  JMJasaya,  the  very  recent  one 
of  Izalco,  the  volcano  Fogo  on  the  Cape  Verd  Islands,  and 
the  colossal  Sangay. 

The  Ghimara  in  Lycia,  and  Stromboli,  the  ancient  Stron- 
gyle,  are  the  two  igneous  manifestations  of  volcanic  activity, 
the  historic  proof  of  whose  permanence  extends  the  furthest 
back.  The  conical  hill  of  Stromboli,  a  doleritic  rock,  is 
twice  the  height  of  the  island  of  Volcano  (Hiera,  Thermessa), 
the  last  great  eruption  of  which  occurred  in  the  year  1775. 
The  uninterrupted  activity  of  Stromboli  is  compared  by 
Strabo  and  Pliny  with  that  of  the  island  of  Lipari,  the 
ancient  Meligunis  ;  but  they  ascribe  to  "  its  flame,"  that  is, 
its  erupted  scorise,  "  a  greater  purity  and  luminosity,  with 
less  heat." M  The  number  and  form  of  the  small  fiery 
chasms  are  very  variable.  Spallanzani's  description  of  the 
bottom  of  the  crater,  which  was  long  regarded  as  exaggerated 
has  been  completely  confirmed  by  an  experienced  geog- 
nosist,  Friedrich  Hoffmann,  and  also  very  recently,  by  an 
acute  naturalist,  A.  de  Quatrefages.  One  of  the  incandes- 
cent chasms  has  an  opening  of  only  20  feet  in  diameter ;  it 
resembles  the  pit  of  a  blast  furnace,  and  the  ascent  and 
overflow  of  the  fluid  lava,  are  seen  in  it  every  hour,  from  a 
position  on  the  margin  of  the  crater.  The  ancient,  perma- 
nent eruptions  of  Stromboli  still  sometimes  serve  for  the 
guidance  of  the  mariner,  and,  as  amongst  the  Greeks  and 
Romans,  afford  uncertain  predictions  of  the  weather,  by 
the  observation  of  the  direction  of  the  flame  and  of  the  ascend. 

50  Strabo,  lib.  vi,  p.  276,  ed.  Casaubon ;  Pliny,  Hist.  Nat.  iii,  9  : — 
"  Strongyle,  quae  a  Lipara  liquidiore  flainma  tantuaa  differt;  e  cujui 
fumo  quinam  flaturi  siiit  venti,  in  triduo  prsedicere  incolae  traduntur." 
See  also  Urlichs,  Vindicice  Pliniance,  1853,  Fasc.  i,  p.  39.  The  volcano 
of  Lipara  (in  the  north-eastern  part  of  the  island),  once  so  active, 
appears  to  rae  to  have  been  either  the  Monte  Campo  Bianco,  or  the 
Monte  di  Capo  Castagno.  (See  Hoffmann,  in  Poggend.  Annalen,  Bd.  xxvi, 
*.  49--54.) 


TBTTE   VOLCANOES.  257 

ing  column  of  vapour.  Polybius,  who  displays  a  singularly 
exact  knowledge  of  the  state  of  the  crater,  connects  the 
multifarious  signs  of  an  approaching  change  of  wind,  with 
the  myth  of  the  earliest  sojourn  of  JEolus  upon  Strongyle, 
and  still  more  with  observations  upon  the  then  violent  fire 
upon  Volcano  (the  "  holy  island  of  Hepha3stos").  The  fre- 
quency of  the  igneous  phenomena  has  of  late  exhibited  some 
irregularity.  The  activity  of  Stromboli,  like  that  of  Etna, 
according  to  Sartorius  von  Waltershausen,  is  greatest  in 
November  and  the  winter  months.  It  is  sometimes  inter- 
niDted  by  isolated  intervals  of  rest  j  but  these,  as  we  learn 
from  the  experience  of  centuries,  are  of  very  short  dura- 
tion. 

The  CTiimcera  in  Lycia,  which  has  been  so  admirably 
described  by  Admiral  Beaufort,  and  to  which  I  have  twice 
referred,51  is  no  volcano,  but  a  perpetual  burning  spring — a 
51  Cosmos,  vol.  i,  p.  220,  and  vol.  v,  p.  212.  Albert  Berg,  who  had 
previously  published  an  artistic  work,  Physiognomic  der  Tropischen 
Vegetation  von  Siidamerika,  visited  the  Lycian  Chimaera,  near  Delik- 
tasch  and  Yanartasch,  from  Rhodes  and  the  Gulf  of  Myra  in  1853. 
(The  Turkish  word  tdsch  signifies  stone,  as  ddgh  and  tdgh,  signify  moun- 
tain; deliktasch  signifies  perforated  stone,  from  the  Turkish,  delik,  a 
hole.}  The  traveller  first  saw  the  serpentine  rocks  near  Adrasau,  whilst 
Beaufort  met  with  the  dark-coloured  serpentine  deposited  upon  lime- 
stone, and  perhaps  deposited  in  it,  even  near  the  island  Garabusa  (not 
Grambusa),  to  the  south  of  Cape  Chelidonia.  "  Near  the  ruius  of  the 
ancient  temple  of  Vulcan  rise  the  remains  of  a  Christian  church  in  the 
later  Byzantine  style  :  the  remains  of  the  nave  and  of  two  side  chapels. 
In  a  fore-court,  situated  to  the  east,  the  flame  breaks  out  of  a  fire-place- 
like  opening  about  2  feet  broad  and  1  foot  high  in  the  serpentine  rock. 
It  rises  to  a  height  of  3  or  4  feet  and  (as  a  naphtha-spring  ?)  diffuses  a 
pleasant  odour,  which  is  perceptible  to  a  distance  of  40  paces.  Near 
this  large  flame,  and  without  the  chimney-like  opening,  numerous  very 
small,  constantly  ignited,  lambent  flames  make  their  appearance  from 
subordinate  fissures.  The  rock  which  is  in  contact  with  the  flame  is 
much  blackened,  and  the  soot  deposited  is  collected  to  alleviate 
smarting  of  the  eye-lids  and  especially  for  colouring  the  eye-brows. 
At  a  distance  of  three  paces  from  the  flame  of  the  Chimaera  the  heat 
which  it  diffuses  is  scarcely  endurable.  A  piece  of  dry  wood  ignites 
when  it  is  held  in  the  opening  and  brought  near  the  flame  without 
touching  it.  Where  the  old  ruined  walls  lean  against  the  rock,  gas  also 
pours  forth  from  the  interstices  of  the  stones  of  the  masonry,  and  this, 
probably  from  its  being  of  a  lower  temperature  or  differently  composed 
does  not  iguite  spontaneously,  but  whenever  it  is  brought  in  contact 
with  a  light.  Eight  feet  below  the  great  flame  in  the  interior  of  the 
ruins  there  is  a  *<Hind  opening,  6  feet  in  depth,  but  only  3  feet  wide, 

VOL.  V.  S 


258  COSMOS. 

gas  spring  always  ignited  by  the  volcanic  activity  of  the 
interior  of  the  earth.  It  was  visited  a  few  months  ago  by 
a  talented  artist,  Albert  Berg,  for  the  purpose  of  making  a 
picturesque  survey  of  this  locality,  celebrated  even  in  periods 
of  high  antiquity  (since  the  times  of  Ctesias  and  Scylax  of 
Caryanda),  and  of  collecting  the  rocks  from  which  the 
Chimsera  breaks  forth.  The  descriptions  of  Beaufort,  Pro- 
fessor Edward  Forbes,  and  Lieutenant  Spratt  in  the  "  Travels 
in  Lycia"  are  completely  confirmed.  An  eruptive  mass  of 
serpentine  rock  penetrates  the  dense  limestone  in  a  ravine, 
which  ascends  from  south-east  to  north-west.  At  the  north- 
western extremity  of  this  ravine,  the  serpentine  rocV  is  cut 
off,  or  perhaps  only  concealed,  by  a  curved  ridge  of  limestone 
rocks.  The  fragments  brought  home  are  partly  green  and 
fresh,  partly  brown  and  in  a  weathered  state.  In  both 
serpentines  diallage  is  clearly  recognisable. 

The  volcano  of  Masaya*-  the  fame  of  which  was  already 
widely  spread  in  the  beginning  of  the  16th  century,  under 
the  name  of  el  Injlerno  de  Masaya,  and  gave  occasion  for 
reports  to  the  Emperor  Charles  V.,  is  situated  between  the 
two  lakes  of  Nicaragua  and  Managua,  to  the  south-west  of 
the  charming  Indian  village  of  Nindiri.  For  centuries  to- 
gether it  presented  the  same  rare  phenomenon  that  we  have 

which  was  probably  arched  over  formerly,  as  a  spring  of  water  breaks 
out  in  it  in  the  wet  seasons,  near  a  fissure  over  which  a  small  flame 
plays."  (From  the  traveller's  manuscripts.)  On  a  plan  of  the  locality, 
Berg  shows  the  geographical  relations  of  the  alluvial  strata,  of  the 
(tertiary?)  limestone,  and  of  the  serpentine  rocks. 

52  The  oldest  and  most  important  notice  of  the  volcano  of  Masaya 
is  contained  in  a  manuscript  of  Oviedo's,  first  edited  fourteen  years  ago 
by  the  meritorious  historical  compiler,  Ternaux-Compans, — Historia  de 
Nicaragua  (cap.  v  to  x),  see  pp.  115 — 197.  The  French  translation 
forms  one  volume  of  the  Voyages,  Relations  et  Memoires  Originaux  pour 
iervir  a  VHistoire  et  a  la  Decouverte  de  I'Amerique.  See  also  Lopez  de 
Gomara,  Historia  General  de  las  Indias  (Zaragoza,  1553),  fol.  ex,  b;  and 
amongst  the  most  recent  works,  Squier,  Nicaragua,  its  People,  Scenery, 
and  Monuments,  1853,  vol.  i,  p.  211 — 223,  and  vol.  ii,  p.  17.  So  widely 
famed  was  the  incessantly  active  volcano  of  Masaya,  that  a  special 
monograph  of  this  mountain  exists  in  the  royal  library  at  Madrid, 
under  the  title  of  Entrada  y  Descubrimiento  del  Volcan  de  Masaya, 
gue  estd  en  la  Prov.  de  Nicaragua,  fecha  por  Juan  Sanchez  del 
Portero.  The  author  was  one  of  those  who  let  themselves  down  into 
the  crater  in  the  wonderful  expeditions  of  the  Dominican  monk,  Fray 
Bias  de  Inesta  (Oviedo,  Hist,  de  Nicaragua,  p.  141). 


TRUE  VOLCANOES.  259 

described  in  the  volcano  of  Stromboli.  From  the  margin  of 
the  crater,  the  waves  of  fluid  lava,  set  in  motion  by  vapours, 
were  seen  rising  and  falling  in  the  incandescent  chasm.  The 
Spanish  historian,  Gonzalez  Fernando  de  Oviedo,  first 
ascended  the  Masaya  in  July  1529,  and  made  comparisons 
with  Vesuvius,  which  he  had  previously  visited  (1501),  in 
the  suite  of  the  Queen  of  Naples  as  her  xefe  de  guardaropa. 
The  name  Masaya,  belongs  to  the  Chorotega  language 
of  ^Nicaragua,  and  signifies  burning  mountain.  The  volcano, 
surrounded  by  a  wide  lava-field  (mal-pays),  which  it  has 
probably  itself  produced,  was  at  that  time  reckoned  amongst 
the  mountain  group  of  the  "nine  burning  Maribios."  In  its 
ordinary  condition,  says  Oviedo,  the  surface  of  the  lava, 
upon  which  black  scoriae  float,  stands  several  hundred  feet 
below  the  margin  of  the  crater  ;  but  sometimes  the  ebullition 
is  suddenly  so  great,  that  the  lava  nearly  reaches  the  upper 
margin.  The  perpetual  luminous  phenomenon,  as  Oviedo 
definitely  and  acutely  states,  is  not  caused  by  an  actual 
flame,53  but  by  vapours  illuminated  from  below.  It  is  saiu  to 
have  been  of  such  intensity  that  on  the  road  from  the  volcano 
towards  Granada,  at  a  distance  of  more  than  three  leagues, 
the  illumination  of  the  district  was  almost  equal  to  that  of 
the  full  moon. 

Eight  years  after  Oviedo,  the  volcano  was  ascended  by 
the  Dominican  monk,  Fray  Bias  del  Castillo,  who  enter- 

53  In  the  French  translation  of  Ternaux-Compans  (the  Spanish 
original  has  never  been  published),  we  find  at  pp.  123  and  132  : — "It 
cannot,  however,  be  said  precisely  that  a  flame  issues  from  the  crater, 
but  a  smoke  as  hot  as  fire  ;  it  is  not  seen  from  far  during  the  day,  but 
is  well  seen  at  night.  The  volcano  gives  as  much  light  as  the  moon  a 
few  days  before  it  is  at  the  full."  This  old  observation  upon  the  pro- 
blematical mode  of  illumination  of  a  crater,  and  the  strata  of  air  lying 
above  it,  is  not  without  importance,  on  account  of  the  doubt,  so  often 
raised  in  recent  times,  as  to  the  disengagement  of  hydrogen  gas  from 
the  craters  of  volcanoes.  Although  in  the  ordinary  condition  here  indi- 
cated the  Hell  of  Masaya  did  not  throw  out  scoriae  or  ashes  (Gomara 
adds,  cosa  que  hazen  otros  volcanes],  it  has  nevertheless  sometimes  had 
true  eruptions  of  lava;  the  last  of  which  probably  occurred  in  the  year 
1670.  Since  that  date  the  volcano  has  been  quite  extinct,  after  a 
perpetual  luminosity  had  been  observed  for  140  years.  Stephens,  who 
ascended  it  in  1840,  found  no  perceptible  trace  of  ignition.  Upon  the 
Chorotega  language,  the  signification  of  the  word  Masaya,  and  the  Mari- 
bios,  see  Buschmann's  ingenious  ethnographical  researches,  Ueber  die 
Aztekischen  Ortsnamen,  s.  130,  140,  and  171. 

S  2 


260  COSMOS. 

tained  the  absurd  opinion  that  the  fluid  lava  in  the  crater 
was  liquid  gold,  and  associated  himself  with  an  equally  avari- 
cious Flemish  Franciscan,  Fray  Juan  de  Gandavo.  The 
pair  availing  themselves  of  the  credulity  of  the  Spanish 
settlers,  established  a  joint-stock  company  to  obtain  the 
metal  at  the  common  cost.  They  themselves,  Oviedo  adds 
satirically,  declared  that  as  ecclesiastics  they  were  free 
from  any  pecuniary  contributions.  The  report  upon  the 
execution  of  this  bold  undertaking,  which  was  sent  to  the 
Bishop  of  Castilla  del  Oro,  Thomas  de  Verlenga,  by  Fray 
Bias  del  Castillo  (the  same  person  who  is  denominated  Fray 
Bias  de  Tnesta  in  the  writings  of  Gomara,  Benzoni,  and 
Herrera),  was  only  made  known  (in  1840)  by  the  discovery 
of  Oviedo's  work  upon  ^Nicaragua.  Fray  Bias,  who  had  pre- 
viously served  on  board  ship  as  a  sailor,  proposed  to  imitate 
the  method  of  hanging  upon  ropes  over  the  sea,  by  which 
the  natives  of  the  Canary  Islands  collect  the  colouring  mat- 
ter of  the  Orchil  {Lichen  Roccella),  on  precipitous  rocks. 
For  months  together  all  sorts  of  preparations  were  made,  in 
order  to  let  down  a  beam  of  more  than  30  feet  in  length,  by 
means  of  a  windlass  and  crane,  so  that  it  might  project  over 
the  deep  abyss.  The  Dominican,  his  head  covered  with  an 
iron  helmet  and  a  crucifix  in  his  hand,  was  let  down  with 
three  other  members  of  the  association  ;  they  remained  for 
a  whole  night  in  this  part  of  the  solid  crater  bottom,  from 
which  they  made  vain  attempts  to  dip  out  the  supposed 
liquid  gold  with  earthen  vessels,  placed  in  an  iron  pot. 
Not  to  frighten  the  shareholders  they  agreed6*  that, 

54  «  The  three  companions  agreed  to  say  that  they  had  found  great 
riches ;  and  Fray  Bias,  whom  I  had  known  as  an  ambitious  man,  gives, 
in  his  relation,  the  oath  which  he  and  his  associates  took  upon  the 
Gospel,  to  persist  for  ever  in  their  opinion  that  the  volcano  contained 
gold  and  silver  in  a  state  of  fusion!"  Oviedo,  Descr.  de  Nicaragua,  cap.  x, 
pp.  186  and  196).  The  Cronista  de  las  Indias  is,  however,  very  indig- 
nant (cap.  5)  that  Fray  Bias  narrated  that  "  Oviedo  had  begged  the  Hell 
of  Masaja  from  the  Emperor  as  his  armorial  bearings."  Such  a  geog- 
nostic  memento  would  certainly  not  have  been  in  opposition  to  the 
heraldic  customs  of  the  period,  for  the  courageous  Diego  de  Ordaz,  who 
boasted  of  having  reached  the  crater  of  the  Popocatepetl  when  Cortez 
first  penetrated  into  the  valley  of  Mexico,  bore  this  volcano  as  an 
heraldic  distinction,  as  did  Oviedo  the  constellation  of  the  Southern 
Cross,  and  earliest  of  all  Columbus  (Exam.  crit.  t.  iv,  pp.  235 — 240),  a 
fragment  of  a  map  of  the  Antilles. 


TRUE  VOLCANOES.  261 

when  they  were  drawn  up  again  they  should  say  that  they 
had  found  great  riches,  and  that  the  Infierno  of  Masaya, 
deserved  in  future  to  be  called  el  Paraiso  del  Masaya.  The 
operation  was  afterwards  repeated  several  times,  until  the 
Governor  of  the  neighbouring  city  of  Granada,  conceived 
some  suspicion  of  the  deceit,  or  perhaps  of  a  fraud  upon  the 
revenue,  and  forbad  any  "  further  descents  on  ropes  into  the 
crater.'*  This  took  place  in  the  summer  of  1538 ;  but  in 
1551  Juan  Alvarez,  the  Dean  of  the  Chapter  of  Leon,  again 
received  from  Madrid  the  naive  permission  "to  open  the 
volcano,  and  procure  the  gold  that  it  contained."  Such  was 
the  popular  credulity  of  the  sixteenth  century !  But  even  in 
Naples  in  the  year  1822,  Monticelli  and  Covelli  were  obliged 
to  prove  by  chemical  analysis,  that  the  ashes  thrown  out 
from  Vesuvius  onthe  28th  October  contained  no  gold  ! M 

The  volcano  of  Jzalco,  situated  on  the  west  coast  of  Cen- 
tral America,  32  miles  northwards  from  San  Salvador,  and 
eastward  from  the  harbour  of  Sonsonate,  broke  out  1 1  years 
after  the  volcano  of  Jorullo,  deep  in  the  interior  of  Mexico. 
Both  eruptions  took  place  in  a  cultivated  plain,  and  after 
the  prevalence  of  earthquakes  and  subterranean  noises 
(bramidos)  for  several  mouths.  A  conical  hill  rose  in  the 
Llano  de  Izalco,  and  with  it  simultaneously  an  eruption  of 
lava  poured  from  its  summit  on  the  23rd  February,  1770.  It 
still  remains  undecided,  how  much  is  to  be  attributed,  in  the 
rapidly  increasing  height,  to  the  upheaval  of  the  soil,  and 
how  much  to  the  accumulation  of  erupted  scoriae,  ashes  and 
tufa-masses ;  only  this  much  is  certain,  that  since  the  first  erup- 
tion, the  new  volcano,  instead  of  soon  becoming  extinguished 
like  Jorullo,  has  remained  uninterruptedly  active,  and  often 
serves  as  a  beacon  light  for  mariners  near  the  landing  place 
in  the  Bay  of  Acajutla.  Four  fiery  eruptions  are  counted 
in  an  hour,  and  the  great  regularity  of  the  phenomenon  has 
astonished  its  few  accurate  observers.6*  The  violence  of  the 
eruptions  was  variable,  but  not  the  time  of  their  occurrence. 
The  elevation  which  the  volcano  of  Izalco  has  now  attained 
since  the  last  eruption  of  1825,  is  calculated  at  about  1600 
feet,  nearly  the  same  as  the  elevation  of  Jorullc  above  the 

55  Humboldt,  Views  of  Nature,  p.  368. 

56  Squier,  Nicaragua,  its  People  and  Monuments,  vol.  ii,  p.  104.  (John 
Bailey,  Central  America,  1850,  p.  75). 


262  COSMOS. 

original  cultivated  plain ;  but  almost  four  times  that  of 
the  crater  of  elevation  (Monte  Nuovo)  in  the  Phlegrsean 
Fields,  to  which  Scacchi67  ascribes  a  height  of  432  feec 
from  accurate  measurement.  The  permanent  activity  of 
the  volcano  of  Izalco,  which  was  long  considered  as  a 
safety-valve  for  the  neighbourhood  of  San  Salvador,  did 
not  however  preserve  the  town  from  complete  destruction 
on  Easter  eve  in  this  year  (1854). 

One  of  the  Cape  Yerd  Islands,  which  rises  between  S.  Jago 
and  Brava,  early  received  from  the  Portuguese  the  name  of 
llha  do  Fogo,  because,  like  Stromboli,  it  produced  fire  uninter- 
ruptedly from  1680  to  1713.  After  a  long  repose,  the  vol- 
cano of  this  island  resumed  its  activity  in  the  summer  of 
the  year  1798,  soon  after  the  last  lateral  eruption  of  the 
Peak  of  Teneriffe  in  the  crater  of  Chahorra,  which  is  errone- 
ously denominated  the  volcano  of  Chahorra  as  if  it  were  a 
distinct  mountain. 

The  most  active  of  the  South  American  volcanoes,  and 
indeed  of  all  those  which  I  have  here  specially  indicated,  is 
the  Sangay,  which  is  also  called  the  Volcan  de  Macas,  because 
the  remains  of  this  ancient  city,  so  populous  in  the  early 
period  of  the  Conquista,  are  situated  upon  the  Rio  TJpano, 
only  28  geog.  miles  to  the  south  of  it.  The  colossal  mountain, 
17,128  feet  in  height,  has  risen  on  the  eastern  declivity  of 
the  eastern  Cordillera,  between  two  systems  of  tributaries  of 
the  Amazons,  those  of  the  Pastaza  and  the  TJpano.  The 
grand  and  unequalled  fiery  phenomenon  which  it  now  ex- 
hibits, appears  only  to  have  commenced  in  the  year  1728. 
During  the  astronomical  measurements  of  degrees  by  Bou- 
guer  and  La  Condamine  (1738  to  1740),  the  Sangay  served 
as  a  perpetual  fire  signal.68  In  the  year  1802,  I  myself 
heard  its  thunder  for  months  together,  especially  in  the 
early  morning,  in  Chillo,  the  pleasant  country  seat  of  the 
Marquis  de  Selvaletjre  near  Quito,  as  half  a  century  pre- 
viously, Don  Jorge  Juan  had  perceived  the  ronquidos  del 

57  Memorie  geologiche  sulla  Campania,  1849,  p.  61.      I  found   the 
height  of  the  volcano  of  Jorullo  to  be  1682  feet  above  the  plain  in 
which  it  rose,  and  4266  feet  above  the  sea-level. 

58  La  Condamine,  Journal  du   Voyage  a  VEquateur,  p.  163;  and  in 
the  Mesure  de  Trois  Degres  de  la  Meridienne  de  I' Hemisphere  Austral, 
p.  56. 


TRUE  VOLCANOES.  263 

Sangay,  somewhat  further  towards  the  north-east,  near 
Pinibac,  at  the  foot  of  the  Antisana.59  In  the  years  1842 
and  1843,  when  the  eruptions  were  associated  with  most 
noise,  the  latter  was  heard  most  distinctly  not  only  in  the 
harbour  of  Guayaquil,  but  also  further  to  the  south  along 
the  coast  of  the  Pacific  Ocean,  as  far  as  Payta  and  San 

59  In  the  country  house  of  the  Marquis  of  Selvalegre,  the  father  of  my 
unfortunate  companion  and  friend,  Don  Carlos  Montufar,  one  was  often 
inclined  to  ascribe  the  bramidos,  which  resembled  the  discharge  of  a 
distant  battery  of  heavy  artillery,  and  which  with  the  same  wind,  the 
same  clearness  of  the  atmosphere  and  the  same  temperature,  were  so 
extremely  unequal  in  their  intensity,  not  to  the  Sangay,  but  to  the  Guaca- 
mayo,  a  mountain  forty  miles  nearer,  at  the  foot  of  which  a  road  leads 
from  Quito,  over  the  Hacienda  de  Antisana  to  the  plains  of  Archidona 
and  the  Rio  Napo.  (See  my  special  map  of  the  province  Quixos, 
No.  23  of  my  Atlas  geogr.  et  phys.  de  FAmerique,  1814 — 1834).  Don 
Jorge  Juan,  who  heard  the  Sangay  thundering  when  closer  to  it  than  I 
have  been,  says  decidedly  that  the  bramidos,  which  he  calls  ronquidos 
del  Volcan  (Relation  del  Viage  d  la  America  Meridional,  pt.  i,  t.  2, 
p.  569),  and  perceived  in  Pintac,  a  few  miles  from  the  Hacienda  de 
Chillo,  belong  to  the  Sangay  or  Volcan  de  Macas,  whose  voice,  if  I  may 
make  use  of  the  expression,  is  very  characteristic.  This  voice  appeared 
to  the  Spanish  astronomer  to  be  peculiarly  harsh,  for  which  reason  he 
calls  it  a  snore  (un  ronquido)  rather  than  a  roar  (bramido).  The  very 
disagreeable  noise  of  the  volcano  Pichincha,  which  I  have  frequently 
heard  at  night  in  the  city  of  Quito,  without  its  being  followed  by  any 
earthquake,  has  something  of  a  clear  rattling  sound  as  though  chains  were 
rattled,  and  masses  of  glass  were  falling  upon  each  other.  On  the  Sangay, 
Wisse  describes  the  noise  to  be,  sometimes  tike  rolling  thunder,  some- 
times distinct  and  sharp,  as  if  one  were  in  the  vicinity  of  platoon  firing. 
Payta  and  San  Buenaventura  (in  the  Choco)  where  the  bramidos  of  the 
Sangay,  that  is  to  say,  its  roaring,  were  heard,  are  distant  from  the 
summit  of  the  volcano  in  a  south-western  direction,  252  and  348  geog. 
miles.  (See  Carte  de  la  Prov.  Du  Choco,  and  Carte  hypsometrique  des  Cor- 
dilleres,  Nos.  23  and  3  of  my  A  tlas  Geogr.  et  Physique).  Thus,  in  this 
mighty  spectacle  of  nature,  reckoning  in  the  Tungurahua  and  the  Coto- 
paxi,  which  is  nearer  to  Quito,  and  the  roar  of  which  I  heard  in 
February,  1803,  in  the  Pacific  Ocean  (Kleinere  Schriften,  Bd.  i,  s.  384), 
the  voices  of  four  volcanoes  are  perceived  at  adjacent  points.  The 
ancients  also  mention  "  the  difference  of  the  noise,"  emitted  at  different 
times  on  the  ^Eolian  Islands  by  the  same  fiery  chasm  (Strabo,  lib.  vi. 
p.  276).  During  the  great  eruption  (23rd  January,  1835)  of  the 
volcano  of  Conseguina,  which  is  situated  on  the  coast  of  the  Pacific,  at, 
the  entrance  of  the  Bay  of  Fonseca,  in  Central  America,  the  subterranean 
propagation  of  the  sound  was  so  great,  that  it  was  most  distinctly  per- 
ceived on  the  plateau  of  Bogota",  at  a  distance  equal  to  that  from  Etna 
to  Hamburgh  (Acosta.  Viajes  Cicntificos  de  M.  Boussingault  d  los  Andes, 
1849,  a.  56). 


264  COSMOS. 

Buenaventura,  at  a  distance  equal  to  that  of  Berlin  from 
Basle,  the  Pyrenees  from  Fontainebleau,  or  London  from 
Aberdeen.  Although,  since  the  commencement  of  the  pre- 
sent century,  the  volcanoes  of  Mexico,  New  Granada,  Quito, 
Bolivia,  and  Chili  have  been  visited  by  some  geognosists,  the 
Sangay,  which  exceeds  the  Tungurahua  in  elevation,  has  un- 
fortunately remained  entirely  neglected,  in  consequence  of 
its  solitary  position,  at  a  distance  from  all  roads  of  commu- 
nication. It  was  only  in  December  1849  that  an  adventurous 
and  highly  informed  traveller,  Sebastian  Wisse,  after  a  sojourn 
of  five  years  on  the  chain  of  the  Andes,  ascended  it,  and 
nearly  reached  the  extreme  summit  of  the  snow-covered,  pre- 
cipitous cone.  He  not  only  made  an  accurate  chronometric 
determination  of  the  wonderful  frequency  of  the  eruptions, 
but  also  investigated  the  nature  of  the  trachyte  which,  con- 
fined to  such  a  limited  space,  breaks  through  the  gneiss.  As 
has  already  been  remarked,80  267  eruptions  were  counted  in 
one  hour,  each  lasting  on  an  average  13". 4,  and,  which  is 
very  remarkable,  unaccompanied  by  any  concussion  percep- 
tible on  the  ashy  cone.  The  erupted  matter,  enveloped  in 
much  smoke,  sometimes  of  a  gray  and  sometimes  of  an 
orange  colour,  is  principally  a  mixture  of  black  ashes  and 
rapilli,  but  it  also  consists  partly  of  cinders,  which  rise  per- 
pendiculai'ly,  are  of  a  globular  form  and  a  diameter  of  15  or 
16  inches.  In  one  of  the  more  violent  eruptions,  however, 
Wisse  counted  only  50  or  60  red  hot  stones  as  being  simul- 
taneously thrown  out.  They  usually  fall  back  again  into 
the  crater,  but  sometimes  they  cover  its  upper  margin,  or 
•  /isible  by  their  luminosity  at  a  distance,  glide  down  at  night, 
upon  a  portion  of  the  cone,  which,  when  seen  from  a  great 
way  off,  probably  gave  origin  to  the  erroneous  notion  of  La 
Condamine,  "  that  there  was  an  effusion  of  burning  sulphur 
and  bitumen."  The  stones  rise  singly  one  after  the  other,  so 
that  some  of  them  are  falling  down,  whilst  others  have  only 
just  left  the  crater.  By  an  exact  determination  of  time,  the 
visible  space  of  falling  (calculated  therefore  to  the  margin  of 
the  crater)  was  ascertained  to  be  on  the  average  only  786 
feet.  On  Etna,  according  to  the  measurements  of  Sartorius 
von  Waltershausen  and  the  astronomer  D.  Christian  Peters, 
the  ejected  stones  attain  an  elevation  of  as  much  as  2665 
60  Cosmos,  see  page  182. 


TRUE   VOLCANOES.  265 

feet  above  the  walls  of  the  crater.  Gemellaro's  estmates 
during  the  eruption  of  Etna  in  1832.  gave  even  three 
times  this  elevation !  The  black,  erupted  ashes  form  layers 
of  three  or  four  hundred  feet  in  thickness  upon  the  decli- 
vities of  the  Sari  ofay  for  a  circle  of  nearly  fourteen  miles  in 
circumference.  The  colour  of  the  ashes  and  rapilli  gives  the 
upper  part  of  the  cone  a  fearfully  stern  character.  We  must 
here  again  call  attention  to  the  colossal  size  of  this  volcano, 
which  is  six  times  greater  than  that  of  Stromboli,  as  this 
consideration  is  strongly  in  opposition  to  the  absolute  belief 
that  the  lower  volcanoes  always  have  the  most  frequent 
eruptions. 

The  grouping  of  volcanoes  is  of  more  importance  than 
their  form  and  elevation,  because  it  relates  to  the  great 
geological  phenomenon  of  upheaval  upon  fissures.  These 
groups,  whether  according  to  Leopold  von  Buch,  they  rise  in 
lines,  or  united  around  a  central  volcano,  indicate  the  parts 
of  the  crust  of  the  earth,  where  the  eruption  of  the  fused 
interior  has  found  the  least  resistance,  in  consequence  either 
of  the  reduced  thickness  of  the  rocky  strata,  of  their  natural 
structure,  or  of  their  having  been  originally  fissured.  Three 
degrees  of  latitude  are  occupied  by  the  space  in  which  the 
volcanic  energy  is  formidably  manifested  in  Etna,  in  the 
^Eolian  Islands,  in  Vesuvius,  and  the  parched  land  (the  Phle- 
grsean  Fields)  from  Puteoli  (Dic£earchia)  to  Cumse,  and  as  far 
as  the  fire- vomiting  Epopeus  on  Ischia,  the  Tyrrhenian  island 
of  Apes,  ^Enaria.  Such  a  connexion  of  analogous  phenomena 
could  not  escape  the  notice  of  the  Greeks.  Strabo  says,  "  The 
whole  sea  commencing  from  Cumse  as  far  as  Sicily  is  pene- 
trated by  fire,  and  has  in  its  depths  certain  conduits  commu- 
nicating with  each  other  and  with  the  continent.61  In  such  a 

61  See  Strabo,  lib.  v,  p.  248,  Casanbou  : — t\ti  KoiXmc  Tirdc;  and 
lib.  vi,  p.  276.  Upon  a  double  mode  of  production  of  islands  the 
geographer  of  Amasia  expresses  himself  (vi,  p.  258)  with  much  geolo- 
gical acumen.  "  Some  islands,"  says  he  (and  he  names  them),  "  are 
fragments  of  the  mainland ;  others  have  proceeded  from  the  sea,  as  still 
happens.  For  the  islands  of  the  high  sea  (those  which  lie  far  out  in 
the  sea)  were  probably  upheaved  from  the  depths ;  whilst,  on  the  con- 
trary, it  is  more  reasonable  to  consider  those  situated  at  promontories 
and  separated  by  a  strait,  as  torn  from  the  mainland."  The  small  group 
of  the  Pithecusae  consists  of  Ischia,  originally  called  ^Enaria,  and  Procida 
(Prochyta).  The  reason  why  this  group  was  considered  to  be  an  ancient 
habitation  of  apes,  why  the  Greeks  and  the  Italian  Tyrrhenians,  conse- 


266  COSMOS. 

(combustible)  nature,  as  all  describe  it,  appear,  not  only  Etna, 
bat  also  the  districts  around  JMcsearchia  and  Naples,  and 
around  Baiae  and  Pithecusa ;"  and  from  this  arose  the  fable 
that  Typhon  lay  under  Sicily,  and  that,  when  he  turned  him- 
self, flames  and  water  burst  forth,  nay  sometimes  even  small 
islands  with  boiling  water.  "  Frequently  between  Strongyle 
and  Lipara  (in  this  wide  district)  flames  have  been  seen  burst- 
ing forth  at  the  surface  of  the  sea,  the  fire  opening  itself  a 
passage  out  of  the  cavities  in  the  depths  and  pressing  upwards 
with  force."  According  to  Pindar69  the  body  of  Typhon  is  of 

quently  Etruscans,  gave  it  such  a  name  (apes  were  called  apipoi,  in  the 
Tyrrhenian;  Strabo,  lib.  xiii,  p.  626)  remains  very  obscure>  and  is  per- 
haps connected  with  the  myth,  according  to  which  the  old  inhabitants 
were  transformed  into  apes  by  Jxipiter.  The  name  of  the  apes,  aptpoi, 
might  relate  to  Arima  or  Arimer  of  Homer  (Iliad,  ii,  783)  and  Hesiod 
(Theog.  v.  301).  The  words  tiv  'Apt/ioic  of  Homer,  are  contracted  into 
one  word  in  some  codices,  and  in  this  contracted  form  we  find  the 
name  in  the  Roman  writers  (Virgil,  JEneid,  ix,  716 ;  Ovid,  Meta- 
morph.  xiv,  88).  Pliny  (Hist.  Nat.  iii,  5)  even  says  decidedly : — 
"  ^Enaria,  Homero  Inarime  dicta,  Grsecis  Pithecusa."  .... 
The  Homeric  country  of  the  Arimer,  Typhon's  resting-place,  was 
sought,  even  in  ancient  times  in  Cilicia,  Mysia,  Lydia,  in  the  volcanic 
Pithecusse,  at  the  crater  Puteolanus,  and  in  the  Phrygian  Phlegrsea, 
beneath  which  Typhon  once  lay,  and  even  in  the  Katakekaumene. 
That  apes  should  have  lived  within  historical  times  upon  Ischia,  at  such 
a  distance  from  the  African  coast  is  the  more  improbable,  because,  as 
I  have  already  observed  elsewhere,  the  ancient  presence  of  the  apes 
upon  the  Rock  of  Gibraltar  does  not  appear  to  be  proved,  since  Edrisi 
(in  the  12th  century)  and  other  Arabian  geographers,  who  describe  the 
Straits  of  Hercules  in  such  detail,  do  not  mention  them.  Pliny  also 
denies  the  apes  of  ^Enaria,  but  derives  the  name  of  the  Pithecusse  in  a 
most  improbable  manner  from  TtiQoQ,  dolium  (a  figlinis  doliorum). 
"  It  appears  to  me,"  says  Bockh,  "  to  be  the  main  point  in  this  investi- 
gation, that  Inarima  is  a  name  of  the  Pithecusse  produced  by  learned 
interpretation  and  fiction,  just  as  Corey ra  became  Scheria ;  and  that 
uEneas  was  probably  only  connected  with  the  Pithecusse  (JSneae 
insulse)  by  the  Romans,  who  find  their  progenitors  everywhere  in 
these  regions.  ISTaevius  also  testifies  to  their  connection  with  -5Cneas  in 
the  first  book  of  the  Punic  War." 

62  Pind.  Pyth.  i,  31.  See  Strabo,  v,  pp.  245  and  248,  and  xiii,  p.  627. 
We  have  already  observed  (Cosmos,  vol.  v,  p.  208),  that  Typhon  fled 
from  the  Caucasus  to  Lower  Italy,  as  though  the  myth  would 
indicate  that  the  volcanic  eruptions  in  the  latter  country  were  of 
leas  antiquity  than  those  upon  the  Caucasian  Isthmus.  The  consi- 
deration of  mythical  views  in  popular  belief  cannot  be  separated  either 
from  the  geography  or  the  history  of  volcanoes.  The  two  often  reci- 
procally illustrate  each  other.  That  which  was  regarded  upon  the 


TKUE  VOLCANOES.  267 

such  extent  that  "  Sicily  and  the  sea-girt  heights  above 
Cumse  (called  Phlegra,  or  the  burnt  field,)  lie  upon  the 
shaggy  breast  of  the  monster." 

Thus  Typhon  (the  raging  Enceladus)  was,  in  the  popular 
fancy  of  the  Greeks,  the  mythical  symbol  of  the  unknown 
cause  of  volcanic  phenomena  lying  deep  in  the  interior  of 
the  earth.  By  the  position  and  the  space  which  he  occupied 
were  indicated  the  limitation  and  the  co-operation  of  parti- 
cular volcanic  systems.  In  the  fanciful  geological  picture  of 
the  interior  of  the  earth,  in  the  great  contemplation  of  the 

surface  of  the  earth  as  the  mightiest  of  moving  forces  (Aristotle, 
Meteorol.  ii,  8,  3),  the  wind,  the  inclosed  pneuma,  was  recognised  as  the 
universal  cause  of  vulcanicity  (of  fire-vomiting  mountains  and  earth- 
quakes). Aristotle's  contemplation  of  nature  was  founded  upon  the 
mutual  action  of  the  external  and  the  internal  subterranean  air,  upon 
a  theory  of  transpiration,  upon  differences  of  heat  and  cold,  moisture 
and  dryness  (Aristotle,  Meteor,  ii,  8,  1,  25,  31,  and  ii,  9,  2).  The  greater 
the  mass  of  the  wind  inclosed  "  in  subterranean  and  submarine  pas- 
sages," and  the  more  it  is  obstructed  in  its  natural,  essential  property  of 
moving  far  and  quickly,  the  more  violent  are  the  eruptions.  "  Vis 
fera  ventorum,  csecis  iuclusa  cavernis"  (Ovid,  Metamorph.  xv,  299). 
Between  the  wind  and  the  fire  there  is  a  peculiar  relation.  (To  Tri'p 
orav  /itrd  TTVIVHCLTOQ  y,  yivtrai  <p\b%  KOI  (ptptrai  Ta\kw^  ;  Aristotle, 
Meteorol.  ii,  8,  3. — KCLI  yap  TO  irvp  olov  irvivfiaroQ  TIQ  <j>vait; ;  Theo- 
phrastus,  De  Igne,  §  30,  p.  715).  The  wind  (pneuma)  suddenly  set 
free  from  the  clouds,  sends  the  consuming  and  widely  luminous 
lightning  flash  (Tro/jcrrTyp).  "  In  the  Phlegrsea,  the  Katakekaumene  of 
Lydia,"  says  Strabo  (lib.  xiii,  p.  628),  "three  chasms,  fully  forty 
stadia  from  each  other,  are  still  shown,  which  are  called  the  wind- 
bags ;  above  them  lie  rough  hills,  which  are  probably  piled  up  by  the 
red-hot  masses  blown  up."  He  had  already  stated  (lib.  i,  p.  57)  "that 
between  the  Cyclades  (Thera  and  Therasia)  flames  of  fire  burst  forth 
from  the  sea  for  four  days  together,  so  that  the  whole  sea  boiled  and 
burnt ;  and  an  island  composed  of  calcined  masses  was  gradually  raised 
as  if  by  a  lever."  All  these  well  described  phenomena  are  ascribed 
to  the  compressed  wind,  acting  like  elastic  vapours.  Ancient  physical 
science  troubled  itself  but  little  about  the  peculiar  essentials  of  mate- 
rial bodies;  it  was  dynamic,  and  depended  on  the  measure  of  the  moving 
force.  We  find  the  opinion  that  the  increasing  heat  of  the  planet  with 
the  depth  is  the  cause  of  volcanoes  and  earthquakes,  first  expressed 
towards  the  close  of  the  third  century  by  a  Christian  bishop  in  Africa 
tinder  Diocletian  (Cosmos,  vol.  v,  p.  196).  The  Pyriphlegethon  of 
Plato,  as  a  stream  of  fire  circulating  in  the  interior  of  the  earth, 
nourishes  all  lava-giving  volcanoes,  as  we  have  already  mentioned 
in  the  text.  In  the  earliest  presentiments  of  humanity,  in  a  narrow 
circle  of  ideas,  lie  the  germs  of  that  which  we  now  think  we  may 
explain  under  the  form  of  other  symbols. 


268  COSMOS. 

universe  which  Plato  establishes  in  the  Phsedo  (p.  112 — • 
11 4)  this  co-operation  is  still  more  boldly  extended  to  all 
volcanic  systems.  The  lava-streams  derive  their  materials 
from  the  Pyriphlegethon,  which  "  after  it  has  repeatedly 
rolled  around  beneath  the  earth,"  pours  itself  into  Tartarus. 
Plato  says  expressly  that  the  fire-vomiting  mountains,  wher- 
ever such  occur  upon  the  earth,  blow  upwards  small  portions 
from  the  Pyriphlegethon  ("  OUTO?  Sea-rlv  ov  iTrovopa^ovai 
Tlvpi(f)\e?ye0oi>ra,  ov  KOI  ol  pvatce?  airoaTraa fiend  ava<J)va{caivt 
oirr)  av  Tv^wai  rrj<i  7^?").  This  expression  (p.  113  B.)  of  the 
expulsion  with  violence  refers  to  a  certain  extent  to  the 
moving  force  of  the  previously  enclosed  wind,  then  suddenly 
breaking  through,  upon  which  the  Stagirite  afterwards,  in 
the  Meteorology,  founded  his  entire  theory  of  vulcanicity. 

According  to  these  ancient  views  the  linear  arrangement  of 
volcanoes  is  more  distinctly  characterized  in  the  consideration 
of  the  entire  body  of  the  earth,  than  their  grouping  around  a 
central  volcano.  The  serial  arrangement  is  most  remarkable  in 
those  places  where  it  depends  upon  the  situation  and  exten- 
sion of  fissures,  which,  usually  parallel  to  each  other,  pass 
through  great  tracts  of  country  in  a  linear  direction  (like 
Cordilleras).  Thus,  to  mention  only  the  most  important 
series  of  closely  approximated  volcanoes,  we  find  in  the 
new  continent  those  of  Central  America,  with  their  appen- 
dages in  Mexico ;  those  of  New  Granada  and  Quito,  of  Peru, 
Bolivia,  and  Chili ;  in  the  old  continent  the  Sunda  Islands 
(the  Indian  Archipelago,  especially  Java),  the  peninsula  of 
Kamtschatka  and  its  continuation  in  the  Kurile  Islands, 
and  the  Aleutian  Islands,  which  bound  the  nearly  closed 
Behring's  Sea  on  the  south.  We  shall  dwell  upon  some  of 
the  principal  groups  ;  individual  details,  by  being  brought 
together,  lead  us  to  the  causes  of  phenomena. 

The  linear  volcanoes  of  Central  America,  according  to  the 
older  denominations  the  volcanoes  of  Costa  Rica,  Nicaragua, 
San  Salvador,  and  Guatemala,  extend  from  the  volcano 
Turrialva  near  Cartago  to  the  volcano  of  Soconusco,  over 
six  degrees  of  latitude,  between  10°  9  and  16°  2,  in  a  line 
the  general  direction  of  which  is  from  S.E.  to  N.W.,  and 
which,  with  the  few  curvatures  which  it  undergoes,  has  a 
length  of  540  geog.  miles.  This  length  is  about  equal  to  the 
distance  from  Vesuvius  to  Prague  The  most  closely  ap- 


TRUE  VOLCANOES.  269 

proximated  of  them,  as  if  they  had  broken  out  upon  one 
and  the  same  fissure  only  64  miles  in  length,  are  the  eight 
volcanoes,  situated  between  the  Laguna  de  Managua  and 
the  Bay  of  Fonseca,  between  the  volcano  of  Momotombo 
and  that  of  Conseguina,  the  subterranean  noise  of  which 
was  heard  in  Jamaica  and  on  the  highlands  of  Bogota  in 
the  year  1835  like  the  fire  of  artillery.  In  Central  America 
and  the  whole  southern  part  of  the  new  continent,  and 
generally  from  the  Chonos  Archipelago  in  Chili  to  the  most 
northern  volcanoes  of  Mount  Edgecombe  on  the  small  island 
near  Sitka,63  and  Mount  Elias  on  Prince  William's  Sound,  for 
a  length  of  6400  geog.  miles,  the  volcanic  fissures  have  every- 
where broken  out  in  the  western  part,  or  that  nearest  to  the 
Pacific  Ocean.  Where  the  line  of  the  Central  American  vol- 
canoes enters  with  the  volcano  of  Conchagua  into  the  state 
of  San  Salvador,  in  the  latitude  of  13^°  (to  the  north  of 
the  Bay  of  Fonseca)  the  direction  of  the  volcanoes  changes 
at  once  with  that  of  the  west  coast.  The  series  of  the 
former  then  strikes  E.S.E. — W.N.W.  ;  indeed,  where  the 
burning  mountains  are  again  so  closely  approximated  that 
five,  still  more  or  less  active,  are  counted  in  the  sliort  dis- 
tance of  120  miles,  the  direction  is  nearly  E. — W.  This 
deviation  corresponds  with  a  great  dilatation  of  the  conti- 
nent towards  the  east  in  the  peninsula  of  Honduras,  where 
the  coast  tends  also  suddenly,  exactly  east  and  west,  from 
Cape  Gracias  a  Dios  to  the  Gulf  of  Amatique  for  300  miles, 
after  it  had  been  previously  running  from  north  to  south 
for  the  same  distance.  In  the  group  of  elevated  volcanoes 
of  Guatemala  (lat.  14°  10')  the  series  again  acquires  its  old 
direction,  N.  45°  W.,  which  it  continues  as  far  as  the  Mexi- 
can boundary  towards  Chiapa  and  the  isthmus  of  Huasa- 
cualco.  North- West  of  the  volcano  of  Soconusco  to  that 

63  Mount  Edgecombe,  or  the  St.  Lazarus  mountain,  upon  the  small 
island  (Croze's  Island,  near  Lisiansky),  which  is  situated  to  the  west- 
ward, near  the  northern  half  of  the  larger  island  Sitka  or  Baranow,  in 
Norfolk  Sound,  was  seen  by  Cook,  and  is  a  hill  partly  composed  of 
basalt  abounding  in  olivine,  and  partly  of  felspathic  trachyte.  Its 
height  is  only  2770  feet.  Its  last  great  eruption,  which  produced 
much  pumice-stone,  was  in  the  year  1796  (Lutke*,  Voyage  autour 
dn  Monde,  1836,  t.  iii,  p.  15).  Eight  years  afterwards  Captain  Lisiansky 
reached  the  summit,  which  contains  a  crater-lake.  He  found  at  that 
time  no  signs  of  activity  anywhere  on  the  mountain. 


270  COSMOS. 

of  Tuxtla,  not  even  an  extinct  trachytic  cone  has  been 
discovered  ;  in  this  quarter,  granite  abounding  in  quartz 
and  mica-schist  predominate. 

The  volcanoes  of  Central  America  do  not  crown  the  ad- 
jacent mountain  chains,  but  rise  along  the  foot  of  the 
latter,  usually  completely  separated  from  each  other.  The 
greatest  elevations  lie  at  the  two  extremities  of  the  series. 
Towards  the  South,  in  Costa  Rica,  both  seas  are  visible 
from  the  summit  of  the  Irasu  (the  volcano  of  Cartago), 
to  which,  besides  its  elevation  (11,081  feet),  its  central 
position  contributes.  To  the  south-east  of  Cartago  there 
stand  mountains  of  ten  or  eleven  thousand  feet :  the 
CUriqui  (11,262  feet)  and  the  Pico  Blanco  (11,740  feet). 
We  know  nothing  of  the  nature  of  their  rock,  but  they 
are  probably  unopened  trachytic  cones.  Further  towards 
the  south-east,  the  elevations  diminish  in  Yeragua  to  six 
and  five  thousand  feet.  This  appears  also  to  be  the 
average  height  of  the  volcanoes  of  Nicaragua  and  San  Sal- 
vador; but  towards  the  north-western  extremity  of  the 
whole  series,  not  far  from  the  new  city  of  Guatemala,  two 
volcanoes  again  rise  above  13,000  feet.  The  maxima  con- 
sequently fall  into  the  third  group  of  my  attempted  hyp- 
sometric classification  of  volcanoes,  coinciding  with  Etna 
and  the  Peak  of  Teneriffe,  whilst  the  greater  number  of 
the  heights  lying  between  the  two  extremities,  scarcely 
exceed  Vesuvius  by  2000  feet.  The  volcanoes  of  Mexico, 
New  Granada,  and  Quito  belong  to  the  fifth  group,  and 
usually  attain  an  elevation  of  more  than  17,000  feet. 

Although  the  continent  of  Central  America  increases 
considerably  in  breadth  from  the  isthmus  of  Panama, 
through  Veragua,  Costa  Rica,  and  Nicaragua,  to  the  lati- 
tude of  11^°,  the  great  area  of  the  lake  of  Nicaragua  and 
the  small  elevation  of  its  surface  (scarcely  128  feet64  above 
the  two  seas),  gives  rise  to  such  a  degradation  of  the  land 
exactly  in  this  district,  that  by  it  an  overflow  of  air  from 
the  Caribbean  Sea  into  the  Great  South  Sea  is  often  caused, 
bringing  danger  to  the  voyager  in  the  so-called  Pacific 

84  Even  under  the  Spanish  Government  in  1781,  the  Spanish  engi- 
neer, Don  Jose"  Galisteo,  had  found  for  the  surface  of  the  Laguna  of 
Nicaragua  an  elevation  only  six  feet  greater  than  that  given  by  Baily  in  hia 
different  levellings  in  1838  (Humboldt,  Relation  Historique.  t.  iii,  p.  321). 


TRUE  VOLCANOES.  271 

The  north- east  storms  thus  excited  have  received 
the  name  of  Papagayos,  and  sometimes  rage  without  inter- 
mission for  four  or  five  days.  They  have  the  remarkable 
peculiarity  that,  during  their  continuance  the  sky  usually 
remains  quite  cloudless.  The  name  is  borrowed  from  the  part 
of  the  west  coast  of  Nicaragua  between  Brito  or  Cabo 
Desolado  and  Punta  S.  Elena  (from  11°  22'  to  10°  50'), 
which  is  called  Golfo  del  Papagayo,  and  includes  the  small 
bays  of  Salinas  and  S.  Elena  to  the  south  of  the  Puerto 
de  San  Juan  del  Sur.  On  my  voyage  from  Guayaquil  to 
Acapulco,  I  was  able  to  observe  the  Papagayos  in  all  their 
violence  and  peculiarity  for  more  than  two  whole  days 
(9th — llth  March,  1803),  although  rather  more  to  the 
south,  in  less  than  9°  13'  of  latitude.  The  waves  rose 
higher  than  I  have  ever  seen  them  ;  and  the  constant  visi- 
bility of  the  disc  of  the  sun  in  the  bright,  blue  arch  of  hea- 
ven, enabled  me  to  measure  the  height  of  the  waves  by  alti- 
tudes of  the  sun  taken  upon  the  ridge  of  the  wave  and 
in  the  trough,  by  a  method  which  had  not  been  tried  at 
that  time.  All  Spanish,  English65,  and  American  voyagers 
ascribe  the  above-described  storms  of  the  Southern  Ocean 
to  the  north-east  trade-wind  of  the  Atlantic. 

In  a  new  work*0  which  I  have  undertaken  with  much 

65  See  Sir  Edward  Belcher,   Voyage  round  the  World,  vol.  i,  p.  185. 
According  to  my  chronometric  longitude  I  was  in  the  Papagayo-storm 
19°  11'  to  the  west  of  the  meridian  of  Guayaquil,  and  consequently 
99°  9'  west,  and  880  miles  west  of  the  shore  of  Costa  Rica. 

66  My  earliest  work  upon  seventeen  linear  volcanoes  of  Guatemala 
and  Nicaragua  is  contained  in  the  Geographical  Journal  of  Berghaus 
(Hertha,  Bd.   vi,    1826,   pp.    131—161).      Besides  the  old  Chronista 
Fuentes  (lib.  ix,  cap.  9),  I  could  then  only  make  use  of  the  important 
work  of  Domingo  Juarros,  Compendia  de  la  Historia  de  la  Ciudad  dc 
Guatemala,  and  of  the  three  maps  by  Galisteo  (drawn  in  1781,  at  the 
command  of  the  Mexican  Viceroy,  Matias  de  Galvez),  by  Jose'  Rossi  y 
Rubi  (Alcalde  Mayor  de  Guatemala,  1800),  and  by  Joaquin  Ysasi  and 
Antonio  de  la  Cerda  (Alcalde  de  Granada)  which  I  possessed  princi- 
pally in  manuscript.     In  the  French  translation  of  his  work  upon  the 
Canary  Islands,  Leopold  von  Bnch  has  given  a  masterly  extension  of 
my  first  sketch  (Descr.  Physique  des  Isles  Canaries,  1836,  pp.  500 — 514  ), 
but  the  uncertainty  of  geographical  synonyms  and  the  confusion  of 
names  caused  thereby  gave  rise  to  many  doubts,  which  have  been  for 
the  most  part  removed  by  the  fine  maps  of  Baily  and  Saunders;  by 
Molina's  Bosquejo  de  la  Republica  de  Costa  Rica,  and  by  the  great  and 
very  meritorious  work  of  Squier  (Nicaragua,  its  People  and  Monuments, 


272  COSMOS. 

assiduity, — partly  from  materials  already  published,  and 
partly  from  manuscript  notes, — upon  the  linear  volcanoes 

•uith  Tables  of  the  Comparative  Heights  of  the  Mountains  in  Central 
America,  1852,  vol.  i,  p.  418,  and  vol.  ii,  p.  102).  The  important  work 
which  is  promised  us  by  Dr.  Oerstedt,  under  the  title  of  Schildernng 
der  Naturverhdltnisse  von  Nicaragua  und  Costa  Rica,  besides  the 
admirable  botanical  and  geological  disco verieKS  which  constitute  the 
primary  object  of  the  undertaking,  will  also  throw  light  upon  the 
geognostic  nat-ure  of  Central  America.  Dr.  Oersted  passed  through 
that  region  in  various  directions  from  1846  to  1848,  and  brought 
back  a  collection  of  rocks  to  Copenhagen.  I  am  indebted  to  his 
friendly  communications  for  interesting  corrections  of  my  fragmen- 
tary work.  From  a  careful  comparison  of  the  materials  with  which  I 
am  acquainted,  including  those  collected  by  Hesse,  the  Prussian 
Consul-General  in  Central  America,  which  are  of  great  value,  I  bring 
together  the  volcanoes  of  Central  America  in  the  following  manner, 
proceeding  from  south  to  north  : — 

Above  the  central  plateau  of  Cartago  (4648  feet),  in  the  republic  of 
Costa  Rica  (lat.  10°  9')  rise  the  three  volcanoes  of  Turrialva,  Irasu,  and 
Reventado,  of  which  the  first  two  are  still  ignited. 

Volcan  de  Turrialva*  (height  about  11,000  feet)  is,  according  to 
Oersted,  only  separated  from  the  Irasu  by  a  deep,  narrow  ravine. 
Its  summit,  from  which  columns  of  smoke  rise,  has  not  yet  been 
ascended. 

The  volcano  Irasu*,  also  called  the  volcano  of  Cartago  (11,100  feet) 
to  the  north-east  of  the  volcano  Reventado,  is  the  principal  vent 
of  volcanic  activity  in  Costa  Rica,  but  still  remarkably  accessible, 
and  towards  the  south  divided  into  terraces  in  such  a  manner  that 
one  may  on  horseback,  almost  reach  the  elevated  summit,  from 
which  the  two  oceans,  the  sea  of  the  Antilles  and  the  Pacific,  may  be 
geen  at  once.  The  cone  of  ashes  and  rapilli,  which  is  about  a  thou- 
sand feet  in  height,  rises  out  of  a  wall  of  circumvallation  (a  crater  of 
elevation).  In  the  flatter,  north-eastern  part  of  the  summit,  lies  the 
true  crater,  of  7500  feet  in  circumference,  which  has  never  emitted 
lava-streams.  Its  eruptions  of  scoriae  have  often  (1723,  1726,  1821, 
1847)  been  accompanied  by  destructive  earthquakes,  the  effect  of 
which  has  been  felt  from  Nicaragua  or  Rivas  to  Panama  (Oersted). 
During  a  very  recent  ascent  of  the  Irasu,  in  the  beginning  of  May, 
1855,  by  Dr.  Carl  Hoffmann,  the  crater  of  the  summit  and  its 
eruptive  orifices  have  been  more  accurately  investigated.  The 
altitude  of  the  volcano  is  stated  from  a  trigonometrical  measure- 
ment by  Galindo,  at  12,000  Spanish  feet,  or,  taking  the  vara 
ras£.=0.43  of  a  toise,  at  11,000  feet.  (Bonplandia,  Jahrgang,  1856, 
No.  3). 

El  Reventado  (about  9500  feet),  with  a  deep  crater,  of  which  the 
southern  margin  has  fallen  in,  and  which  was  formerly  filled  with 
water. 


TRUE  VOLCANOES.  273 

of  Central  America,  twenty-nine  volcanoes  are  numbered, 
whose  former   or   present   varied   activity   may   be   stated 

The  vol^.no  Barba  (more  than  8419  feet),  to  the  north  of  San 
Jose*,  the  capital  of  Costa  Rica;  with  a  crater  which  contains 
several  small  lakes. 

Between  the  volcanoes  Barba  and  Orosi,  there  follows  a  series  of 
volcanoes  which  intersects  the  principal  chain,  running  S.E. — N.W. 
in  Costa  Rica  and  Nicaragua,  almost  in  the  opposite  direction,  east  and 
west.  Upon  such  a  fissure  stand,  furthest  to  the  eastward,  Miravalles 
and  Tenorio  (each  of  these  volcanoes  is  about  4689  feet);  in  the  centre, 
to  the  south-east  of  Orosi,  the  volcano  Rincon,  also  called  Rincon  de  la 
Vieja*  (Squier,  vol.  ii,  p.  102)  which  exhibits  small  eruptions  of  ashes 
every  spring  at  the  commencement  of  the  rainy  season;  and  furthest  to 
the  westward,  near  the  little  town  of  Alajuela,  the  volcano  Votos* 
(7513  feet)  which  abounds  in  sulphur.  Dr.  Oersted  compares  this 
phenomenon  of  the  direction  of  volcanic  activity  upon  a  transverse 
fissure,  with  the  east  and  west  direction,  which  I  found  in  the  Mexican 
volcanoes  from  sea  to  sea. 

Orosi,*  still  active,  in  the  most  southern  part  of  the  State  of  Nica 
ragua  (5222  feet);  probably  the  Volcan  del  Papayayo,  on  the  chart  of 
the  Deposito  Hidrografico. 

The  two  volcanoes,  Mandeira  and  Ometepec*  (4157  and  5222  feet) 
upon  a  small  island  in  the  western  part  of  the  Laguna  de  Nicaragua, 
named  by  the  Aztec  inhabitants  of  the  district  after  these  two  moun- 
tains (ome  tepetl  signifies  two  mountains ;  see  Buschmann,  Aztekische 
Ortsnamen,  pp.  178  and  171).  The  insular  volcano  Ometepec,  erro- 
neously named  Ometep  by  Juarros  (Hist,  de  Guatemala,  t.  i,  p.  51),  is 
still  in  activity.  It  is  figured  by  Squier  (vol.  ii,  p.  235). 

The  extinct  crater  of  the  island  Zapatera,  but  little  elevated 
above  the  sea-level.  The  period  of  its  ancient  eruptions  is  quite 
unknown. 

The  volcano  of  Momobacho,  on  the  western  shore  of  the  Laguua  de 
Nicaragua,  somewhat  to  the  south  of  the  city  of  Granada.  As  this  city 
is  situated  between  the  volcanoes  of  Momobacho  (the  place  is  also 
called  Mombacho,  Oviedo,  Nicaragua,  ed.  Ternaux,  p.  245),  and  Masaya, 
the  pilots  indicate  sometimes  the  one  and  sometimes  the  other  of 
these  conical  mountains  by  the  indefinite  name  of  the  Volcano  of 
Granada. 

The  volcano  Massaya  (Masaya)  which  has  already  been  treated  of  in 
detail  (pp.258  —  261)  was  once  a  Stromboli,  but  has  been  extinct 
since  the  great  eruption  of  lava  in  1670.  According  to  the  interesting 
reports  of  Dr.  Scherzer  (Sitzungsberichtedcr  Philos.  Hist.  Classe  derAkad. 
der  Wiss.  zu  Wien,  Bd.  xx,  s.  58)  dense  clouds  of  vapour  were  again 
emitted  in  April,  1853,  from  a  newly  opened  crater.  The  volcano  of 
Massaya  is  situated  between  the  two  lakes  of  Nicaragua  and  Managua 
to  the  west  of  the  city  of  Granada.  Massaya  is  not  synonymous  with 
Nindiri ;  but,  as  Dr.  Oersted  expresses  himself,  Mcasaya  and  Nindiri* 
VOL.  V.  T 


274  COSMOS. 

with  certainty.  The  natives  make  the  number  more 
than  one-third  greater,  taking  into  account  a  quantity 

form  a  twin  volcano,  with  two  summits  and  two  distinct  craters,  both 
of  which  have  furnished  lava-streams.  The  lava-stream  of  1775  from 
the  Nindiri  reached  the  lake  of  Managua.  The  equal  height  of  these 
two  volcanoes,  situated  so  close  to  each  other,  is  stated  at  only  2450 
feet. 

Vokan  de  Momotombo*  (7034  feet),  burning,  and  often  giving  forth 
a  thundering  noise,  but  without  smoking,  in  lat.  12°  28',  at  the  north" 
ern  extremity  of  the  Laguna  de  Managua,  opposite  to  the  small  island 
Momotombito,  so  rich  in  sculptures  (see  the  representation  of  Momo- 
tombo in  Squier,  vol.  i,  pp.  233  and  302 — 312).  The  Laguna  de 
Managua  lies  28  feet  higher  than  the  Laguna  de  Nicaragua,  which 
is  more  than  double  its  size,  and  has  no  insular  volcano. 

From  hence,  to  the  Bay  of  Fonseca  or  Conchagua,  at  a  distance  of  23 
miles  from  the  coast  of  the  Pacific,  a  line  of  six  volcanoes  runs  from 
S.E.  to  N.W.;  closely  approximated  to  each  other  and  bearing  the 
common  name  of  los  Maribios  (Squier,  vol.  i,  p.  419;  vol.  ii,  p.  123). 

El  Nuevo,*  erroneously  called  Volcan  de  las  Pttas,  because  the  erup- 
tion of  the  12th  April,  1850,  took  place  at  the  foot  of  this  mountain;  a 
great  eruption  of  lava  almost  in  the  plain  itself!  (Squier,  vol.  ii, 
pp.  105—110). 

Volcan  de  Telica*  visited,  during  its  activity,  by  Oviedo  as  early  as 
the  sixteenth  century  (about  1529),  to  the  east  of  Chinendaga,  near 
Leon  de  Nicaragua,  and  consequently  a  little  out  of  the  direction 
previously  stated.  This  important  volcano,  which  emits  much  sul- 
phurous vapour  from  a  crater  320  feet  in  depth,  was  ascended,  a  few 
years  since,  by  my  scientific  and  talented  friend  Professor  Julius 
Frobel.  He  found  the  lava  composed  of  glassy  felspar  and  augite 
(Squier,  vol.  ii,  pp.  115 — 117).  At  the  summit,  at  an  elevation  of 
3517  feet,  there  is  a  crater,  in  which  the  vapours  deposit  great  masses 
of  sulphur.  At  the  foot  of  the  volcano  is  a  mud-spring  (Salse  ?). 

The  volcano  el  Viejo,*  the  northernmost  of  the  crowded  line  of 
six  volcanoes.  It  was  ascended  and  measured  in  the  year  1838  by 
Captain  Sir  Edward  Belcher.  The  result  of  the  measurement  was 
5559  feet.  A  more  recent  measurement,  by  Squier,  gave  6002  feet. 
This  volcano,  which  was  very  active  in  Dampier's  time,  is  still 
burning.  The  fiery  eruptions  of  scoriao  are  frequently  seen  in  the  city 
of  Leon. 

The  volcano  Guanacaure,  somewhat  to  the  north,  without  the  range 
from  el  Nuevo  to  the  Viejo,  at  a  distance  of  only  14  miles  from  the 
shore  of  the  Bay  of  Fonseca. 

The  volcano  Conseguina,*  upon  the  cape  which  projects  at  the  south- 
ern extremity  of  the  Bay  of  Fonseca  (lat.  12°  50'),  celebrated  for  the 
fearful  eruption,  preceded  by  earthquakes,  of  the  23rd  January,  1835. 
The  great  darkue.ss  during  the  fall  of  ashes,  similar  to  that  which  haa 


TRUE  VOLCANOES.  275 

of  old  eruptive  basins,  which  were  probably  only  lateral 
eruptions  on  the  declivity  of  one  and  the  same  mountain. 

sometimes  been  caused  by  the  volcano  Pichincha,  lasted  for  43  hours. 
At  a  distance  of  a  few  feet,  firebrands  could  not  be  perceived.  Respi- 
ration  was  obstructed,  and  a  subterranean  noise,  like  the  discharge  of 
heavy  artillery,  was  heard  not  only  in  Balize  on  the  peninsula  of 
Yucatan,  but  also  upon  the  coast  of  Jamaica,  and  upon  the  plateau  of 
Bogota",  in  the  latter  case  at  an  elevation  of  more  than  8500  feet  above 
the  sea,  and  at  a  distance  of  nearly  five  hundred  and  sixty  geographical 
miles  (Juan  Galindo,  in  Silliman's  American  Journal,  vol.  xxviii,  1835, 
pp.  332—336  ;  Acosta,  Viajes  a  los  Andes,  1849,  p.  56,  and  Squier, 
vol.  ii,  pp.  110 — 113;  figures  pp.  163  and  165).  Darwin  (Journal  of 
Researches  during  the  Voyage  of  the  Beagle,  1845,  p.  291)  calls  attention 
to  a  remarkable  coincidence  of  phenomena : — After  a  long  slumber, 
Conseguiua,  in  Central  America,  and  Aconcagua  and  Corcovado 
(S.  lat.  32f°  and  43^°)  in  Chili,  broke  out  on  the  same  day  (acci- 
dentally ?). 

Volcano  of  Conchagua,  or  of  Amalapa,  at  the  north  of  the  entrance 
to  the  Bay  of  Fonseca,  opposite  to  the  volcano  Conseguina,  near  the 
beautiful  Puerto  de  la  Union,  the  harbour  of  the  neighbouring  town  of 
San  Miguel. 

From  the  state  of  Costa  Rica  to  the  volcano  of  Conchagua,  there- 
fore, the  close  series  of  twenty  volcanoes  follows  a  direction  from  S.E.  to 
N.W.,  but  on  entering  near  Conchagua  into  the  State  of  San  Salvador 
which,  in  the  short  distance  of  160  geog.  miles  exhibits  five  still  more 
or  less  active  volcanoes,  the  line,  like  the  Pacific  coast  itself,  turns  more 
E.S.E. — W.N.W.,  and  indeed  almost  E. — W  ,  whilst  on  the  eastern, 
Caribbean  coast  (towards  the  Cape  Gracias  a"  Dios)  the  land  suddenly 
bulges  out  in  Honduras  and  los  Mosquitos  (see  above,  p.  269).  It  is 
only,  as  tlere  remarked,  to  the  north  of  the  high  volcanoes  of  Old 
Guatemala,  towards  the  Laguua  de  Atitlan,  that  the  former  general 
direction  N.  45°  W.  again  occurs,  until  at  last,  in  Chiapa,  and  on  the 
isthmus  of  Tehuantepec,  the  abnormal  direction  E. — W.  is  again  mani- 
fested, but  in  non-volcanic  chains.  Besides  Conchagua,  the  following 
four  volcanoes  belong  to  the  State  of  San  Salvador  : — 

The  volcano  of  San  Miguel  Bosotlan*  (lat.  13°  35'),  near  the  town  of 
the  same  name,  the  most  beautiful  and  regular  of  trachytic  cones 
next  to  the  insular  volcano  Ometepec,  in  the  lake  of  Nicaragua, 
(Squier,  vol.  ii,  p.  196).  The  volcanic  forces  are  very  active  in 
Bosotlan,  in  which  a  great  eruption  of  lava  occurred  on  the  20th  of 
July,  1844. 

Volcano  of  San  Vicente,*  to  the  west  of  the  Rio  de  Lempa,  between 
the  towns  of  Sacatecoluca  and  Sacatelepe.  A  great  eniption  of  ashes 
took  place,  according  to  Juarros,  in  1643  ;  and  in  January,  1835,  a 
long  continued  eruption  occurred  with  destructive  earthquakes. 

Volcano  of  San  Salvador  (lat.  13°  470,  near  the  city  of  the  eame 

T  2 


276  COSMOS. 

Amongst  the  isolated  conical  and  bell-shaped  mountains, 
which  are  there  called  volcanoes,  many  may,  indeed,  consist 

name.  The  last  eruption  was  that  of  1656.  The  whole  surrounding 
country  is  exposed  to  violent  earthquakes  ;  that  of  the  16th  of  April, 
1854,  which  was  preceded  by  no  noises,  overthrew  nearly  all  the 
buildings  in  San  Salvador. 

Volcano  of  Izalco,*  near  the  village  of  the  same  name,  often  pro- 
ducing ammonia.  The  first  eruption  recorded  in  history  occurred 
on  the  23rd  February,  1770;  the  last  widely-luminous  eruptions  were 
in  April,  1798,  1805  to  1807,  and  1825  (see  above,  p.  261,  and  Thomp- 
son, Official  Visit  to  Guatemala,  1829,  p.  512). 

Volcan  de  Pacaya*  (lat.  14°  23'),  about  14  miles  to  the  south-east 
of  the  city  of  New  Guatemala,  on  the  small  Alpine  lake  Amatitlan,  a 
very  active  and  often  flaming  volcano ;  an  extended  ridge  with  three 
domes.  The  great  eruptions  of  1565,  1651,  1671,  1677,  and  1775  are 
known ;  the  last,  which  produced  much  lava,  is  described  by  Juarros 
as  an  eye-witness. 

Next  follow  the  two  volcanoes  of  Old  Guatemala,  with  the  sin- 
gular appellations  de  Agua  and  de  Fuego,  near  the  coast,  in  latitude 
14°  12'. 

Volcan  de  Agua,  a  trachytic  cone  near  Escuintla,  higher  than  the 
Peak  of  Teneriffe,  surrounded  by  masses  of  obsidian  (indications  of  old 
eruptions?).  The  volcano,  which  reaches  into  the  region  of  perpetual 
snow,  has  received  its  name  from  the  circumstance  that,  in  September, 
1541,  a  great  inundation  (caused  by  earthquake  and  the  melting  of 
snow?)  was  ascribed  to  it;  this  destroyed  the  first  established  city  of 
Guatemala,  and  led  to  the  building  of  the  second  city,  situated  to  the 
north-north-west,  and  now  called  Antigua  Guatemala. 

Volcan  de  Fuego,*  near  Acatenango,  23  miles  in  a  west-north-west 
direction  from  the  so-called  water-volcano.  With  regard  to  their  rela- 
tive position,  see  the  rare  map  of  the  Alcalde  Mayor,  Don  Jose  Rossi  y 
Rubi,  engraved  in  Guatemala,  and  sent  to  me  thence  as  a  present : 
Bosquejo  del  espacio  que  media,  entre  los  estremos  de  la  Provincia  de 
Sucliitepeques  y  la  Capital  de  Guatemala,  1800.  The  Volcan  de  Fuego 
is  still  active,  but  now  much  less  so  than  formerly.  The  older  great 
eruptions  were  those  of  1581,  1586,  1623,  1705,  1710,  1717,1732,  1737, 
and  1799,  but  it  was  not  only  these  eruptions,  but  also  the  destruc- 
tive earthquakes  which  accompanied  them,  that  moved  the  Spanish 
Government  in  the  second  half  of  the  last  century  to  quit  the  second 
seat  of  the  city  (where  the  ruins  of  la  Antigua  Guatemala  now  stand), 
and  compel  the  inhabitants  to  settle  further  to  the  north,  in  the  new 
city  of  Santiago  de  Guatemala.  In  this  case,  as  at  the  removal  of 
Riobamba,  and  several  other  towns  near  the  volcanoes  of  the  chain  of 
the  Andes,  a  dogmatic  and  vehement  dispute  was  carried  on  in  reference 
to  the  difficult  selection  of  a  locality  "  of  which  it  might  be  asserted, 
t.  ^cording  to  previous  experience,  that  it  was  but  little  exposed  to  the 
action  of  neighbouring  volcanoes  (lava-streams,  eruptions  of  scoriae  and 


TRUE   VOLCANOES.  277 

of  trachyte  and  dolerite,  but  having  always  been  unopened, 
have  never  exhibited  any  ign«  ous  activity  since  the  time  of 
their  upheaval.  Eighteen  are  to  be  regarded  as  still  active  ; 
seven  of  these  have  thrown  up  flames,  scoria3  and  lava- 
streams  in  the  present  century  (1825,  1835,  1848,  and 
1850);  and  two*  at  the  end  of  the  last  century  (1775  and 
1799).  The  deficiency  of  lava-streams  in  the  mighty  vol- 
canoes of  the  Cordilleras  of  Quito  has  recently  given  occa- 
sion to  the  repeated  assertion  that  this  deficiency  is  equally 
general  in  the  volca.roes  of  Central  America.  Certainly, 
in  the  majority  of  cases,  eruptions  of  scoriae  and  ashes  have 
been  unaccompanied  by  any  effusion  of  lava — as  for  exam- 
earthquakes !)"  In  1852,  during  a  great  eruption,  the  Volcan  de  Fuego 
poured  forth  a  lava-stream  towards  the  shore  of  the  Pacific.  Captain 
Basil  Hall  measured,  under  sail,  both  the  volcanoes  of  Old  Guatemala, 
and  found  for  the  Volcan  de  Fuego  14,666  feet,  and  for  the  Volcan  de 
Agua,  14,903  feet.  The  foundation  of  this  measurement  has  been 
tested  by  Poggendorff.  He  found  the  mean  elevation  of  the  two  moun- 
tains to  be  less,  and  reduced  it  to  about  13,109  feet. 

Volcan  de  Quesaltenango*  (lat.  15°  10'),  burning  since  1821,  and 
smoking,  near  the  town  of  the  same  name ;  the  three  conical  moun- 
tains which  bound  the  Alpine  lake  Atitlan  (in  the  mountain  chain  of 
Solola)  on  the  south,  are  also  said  to  be  ignited.  The  volcano  of 
Tajamulco,  referred  to  by  Juarros,  certainly  cannot  be  identical  with 
the  volcano  of  Quesaltenango,  as  the  latter  is  at  a  distance  of  40  geog. 
miles  to  the  N.W.,  of  the  village  of  Tajamulco,  to  the  south  of  Tejutla. 

What  are  the  two  volcanoes  of  Sacatepeques  and  Sapotitlan,  men- 
tioned by  Funel,  or  Brue"s  Volcan  de  Amilpas? 

The  great  volcano  of  Soconusco,  situated  on  the  borders  of  Chiapa, 
28  geog.  miles  to  the  south  of  Ciudad  Real,  in  lat.  16°  2'. 

At  the  close  of  this  long  note  I  think  I  must  again  mention  that  the 
barometric  determinations  of  altitude  here  adduced  are  partly  derived 
from  Espinache,  and  partly  borrowed  from  the  writings  and  maps  of 
Baily,  Squier,  and  Molina. 

w  The  following  18  volcanoes,  constituting  therefore  nearly  the  half 
of  all  those  referred  to  by  me  as  active  in  former  or  present  times,  are 
to  be  regarded  as  at  present  more  or  less  active  : — Irasu  and  Turrialva, 
near  Cartago,  el  Rincon  de  la  Vieja,  Votos(?)  and  Orosi;  the  insular  vol- 
cano Ometepec,Nindiri,  Momotomba,  el  Nuevo,  at  the  foot  of  the  trachytic 
mountain  Las  Pilas,  Telica,  el  Viejo,  Conseguina,  San  Miguel  Bosotlan, 
.San  Vicente,  Izalco,  Pacaya,  Volcan  de  Fuego  (de  Guatemala),  and 
Quesaltenango.  The  most  recent  eruptions  are  those  of  el  Nuevo,  near 
las  Pilas,  on  the  18th  April,  1850  ;  San  Miguel  Bosotlan,  1848;  Conse- 
guina, and  San  Vicente,  1835;  Izalco,  1825;  Volcan  de  Fuego,  neajf 
New  Guatemala,  1799  and  1852;  and  Pacaya,  1775. 


278  COSMOS. 

pie,  at  present  in  the  volcano  of  Izalco ;  but  the  descrip- 
tions which  have  been  given  by  eye-witnesses  of  the  lava- 
producing  eruptions  of  the  four  volcanoes,  Nindiri,  el  Nuevo, 
Conseguina,  and  San  Miguel  de  Bosotlan,  give  an  opposite 
testimony68. 

I  have  purposely  dwelt  at  length  upon  the  details  of  the 
position  and  close  approximation  of  the  linear  volcanoes  of 
Central  America,  in  the  hope  that  some  day  a  geogaosist, 
who  has  previously  given  a  profound  study  to  the  active 
volcanoes  of  Europe,  and  the  extinct  ones  of  Auvergne, 
the  Vivarais  or  the  Eifel,  and  who  also  (this  is  of  the 
greatest  importance)  knows  how  to  describe  the  mineral- 
ogical  composition  of  the  different  rocks  in  accordance 
with  the  present  state  of  our  knowledge,  may  feel  himself 
impelled  to  visit  this  region,  which  is  so  near  and  so 
accessible.  Even  if  the  traveller  should  devote  himself 
exclusively  to  geognostic  investigations,  there  still  remains 
much  to  be  done  here, — especially  the  oryctognostic  deter- 
mination of  the  trachytic,  doleritic,  and  melaphyric  rocks  ; 
the  separation  of  the  primitive  mass  upheaved,  and  of  the 
portion  of  the  elevated  mass  which  has  been  covered  over 
by  subsequent  eruptions  ;  the  seeking  out  and  recognition 
of  true,  slender,  uninterrupted  lava-streams,  which  are  only 
too  frequently  confounded  with  accumulations  of  erupted 
scoriae.  Conical  mountains,  which  have  never  been  opened, 
rising  in  a  dome  or  bell-like  form,  such  as  Chimborazo,  are 
therefore  to  be  clearly  separated  from  volcanoes  which  have 
been,  or  still  are,  active,  throwing  out  scoriae  and  lava- 
streams,  like  Vesuvius  and  Etna,  or  scoriae  and  ashes  alone, 
like  Pichincha  or  Cotopaxi.  I  know  nothing  that  promises 
to  impart  a  more  brilliant  impetus  to  our  knowledge  of  vol- 
canic activity,  which  is  still  very  deficient  in  multiplicity 
of  observations  in  large  and  connected  continental  districts. 
As  the  material  results  of  such  a  labour,  collections  of 
rocks  would  be  brought  home  from  many  isolated,  true  vol- 

68  Compare  Squier,  Nicaragua,  vol.  ii,  p.  103,  with  pp.  106  and  111, 
as  also  his  previous  small  \vork  On  the  Volcanoes  of  Central  America, 
1850,  p.  7;  Leopold  de  Buch,  lies  Canaries,  p.  506,  where  reference 
is  made  to  the  lava-stream  which  broke  out  of  the  volcano  Nindiri  in 
1775,  and  which  has  been  recently  again  seen  by  a  very  scientific  ob- 
server, Dr.  Oersted, 


TRUE  VOLCANOES.  279 

canoes,  and  unopened  trachytic  cones,  together  with  the 
non-volcanic  masses  which  have  been  broken  through  by 
both ;  the  subsequent  chemical  analyses,  and  the  chemico- 
geological  inferences  deduced  from  the  analyses,  would  open 
a  field  equally  wide  and  fertile.  Central  America  and  Java 
have  the  unmistakeable  superiority  over  Mexico,  Quito,  and 
Chili,  that  in  a  greater  space  they  exhibit  the  most  variously 
formed  and  most  closely  approximated  stages  of  volcanic 
activity. 

At  the  point  where  the  characteristic  series  of  the  vol- 
canoes of  Central  America  terminates  on  the  borders  of 
Chiapa  with  the  volcano  of  Soconusco  (lat.  16°  2'),  there 
commences  a  perfectly  different  system  of  volcanoes — the 
Mexican.  The  isthmus  of  Huasacualco  and  Tehuantepec, 
so  important  for  the  trade  with  the  coast  of  the  Pacific, 
like  the  state  of  Oaxaca,  situated  to  the  north-west,  is  en- 
tirely without  volcanoes,  and,  perhaps,  even  destitute  of  un- 
opened trachytic  cones.  It  is  only  at  a  distance  of  160  geog. 
miles  from  the  volcano  of  Soconusco,  that  the  small  volcano  of 
Tuxtla  rises  near  the  coast  of  AJvarado  (lat.  18°  28').  Situated 
on  the  eastern  slope  of  the  Sierra  de  San  Martin,  it  had  a 
great  eruption  of  flames  and  ashes  on  the  2nd  of  March,  1793. 
An  exact  astronomical  determination  of  the  position  of  the 
colossal  snowy  mountains  and  volcanoes  in  the  interior  of 
Mexico  (the  old  Anahuac)  led  me,  after  my  return  to 
Europe,  while  inserting  the  maxima  of  elevations  in  my 
chart  of  New  Spain,  to  the  exceedingly  remarkable  result, 
that  there  is  in  this  place,  from  sea  to  sea,  a  parallel  of  the 
volcanoes  and  greatest  elevations  which  oscillates  by  only 
a  few  minutes  to  and  from  the  parallel  of  19°.  The  only 
volcanoes  and,  at  the  same  time,  the  only  mountains  covered 
with  perpetual  snow  in  the  country,  and  consequently  ele- 
vations varying  from  12,000  to  3,000  feet, — the  volcanoes 
of  Orizaba,  Popocatepetl,  Toluca,  and  Colima, — lie  between 
the  latitudes  of  18°  59'  and  19°  20',  and  thus  indicate  the 
direction  of  a  fissure  of  volcanic  activity  of  360  geog.  miles 
in  length69.  In  the  same  direction  (lat.  19°  9'),  between  the 

69  See  all  the  bases  of  these  Mexican  local  determinations,  and 
their  comparison  with  the  observations  of  Don  Joaquin  Ferrer,  in  my 
Recueil  d  Observations  Astron.  vol.  ii,  pp.  521,  529,  and  536 — 550,  and 
£gsai  Politique  sur  la  Nourelle-Espagne,  t.  i,  pp.  55 — 59,  and  176,  t.  ii. 


280  COSMOS. 

volcanoes  of  Toluca  and  Colima,  at  a  distance  of  116  and 
128  geog.  miles  from  them,  the  new  volcano  of  Jorullo  (4265 
feet)  rose  on  the  14th  September,  1759,  in  a  broad  plain, 
having  an  elevation  of  2583  feet.  The  local  position  of  this 
phenomenon  in  relation  to  the  situation  of  the  other  Mexican 
volcanoes,  and  the  circumstance  that  the  fissure  from  east 
to  west  which  I  here  indicate  intersects  the  direction  of 
the  great  mountain  chain  striking  from  south-south-east  to 
north-north-west  almost  at  right  angles,  are  geological 
phenomena  no  less  important  than  the  distance  of  the 
eruption  of  Jorullo  from  the  seas,  the  evidences  of  its  up- 
heaval which  I  have  represented  graphically  in  detail,  the 
innumerable  fuming  hornitos  which  surround  the  volcano, 
and  the  fragments  of  granite,  which  I  found  immersed  in 
the  lava  poured  forth  from  the  principal  volcano  of  Jorullo, 
in  a  district  which  is  destitute  of  granite  for  a  long  dis- 
tance. 

The  following  table  contains  the  special  local  determina- 
tions and  elevations  of  the  series  of  volcanoes  of  Ana- 
huac,  upon  a  fissure  which,  running  from  sea  to  sea,  inter- 
sects the  fissure  of  elevation  of  the  great  range  of  moun- 
tains : — 

p.  173.  I  had  myself  early  raised  doubts  with  regard  to  the  astrono- 
mical determination  of  the  position  of  the  volcano  of  Colima,  near  the 
coast  of  the  Pacific  (Essai  Polit.  t.  i,  p.  68,  t.  ii,  p.  180).  According  to 
angles  of  altitude  taken  by  Captain  Basil  Hall  while  under  sail,  the 
volcano  is  situated  in  lat.  19°  36',  and  consequently  half  a  degree  further 
north  than  I  concluded  to  be  its  position  from  Itineraries ;  certainly 
without  absolute  determinations  for  Selagua  and  Petatlan,  upon  which 
I  depended.  The  latitude,  19°  25',  which  I  have  given  in  the  text,  is, 
like  the  determination  of  altitude  (12,005  feet),  from  Captain  Beechey 
( Voyage,  pt.  ii,  p.  587).  The  most  recent  map  by  Laurie  (The  Mexican 
and  Central  States  of  America,  1853)  gives  19°  20'  for  the  latitude. 
The  latitude  of  Jorullo  may  also  be  wrong  by  2 — 3  minutes,  as  I  was 
then  occupied  entirely  with  geological  and  topographical  investigations, 
and  neither  the  sun  nor  stars  were  visible  for  determinations  of  latitude. 
(See  Basil  Hall,  Journal  written  on  the  Coast  of  Chili,  Peru,  and  Mexico, 
1824,  vol.  ii,  p.  379;  Beechey,  Voyage,  pt.  ii,  p.  587;  and  Humbolclt, 
Essai  Polit.  t.  i,  p.  68,  t.  ii,  p.  180).  In  the  true  and  exceedingly 
artistic  views  of  the  volcano  of  Colima,  drawn  by  Moritz  Kugendas, 
which  are  preserved  in  the  Berlin  Museum,  we  distinguish  two  adjacent 
mountains, — the  true  volcano,  which  constantly  emits  smoke,  and  is 
covered  with  but  little  snow,  and  the  more  elevated  Nevada,  which 
rises  far  into  the  region  of  perpetual  snow. 


TRUE   VOLCANOES. 


281 


Sequence  from  E.  to  W. 

Latitude. 

Elevation 
above  the  sea 
in  feet. 

Volcano  of  Orizaba.  .  .  . 
Nevado  Tztaccihuatl   .  . 
Volcano  Popocatepetl  .  . 
Volcano  of  Toluca  .... 
Volcano  of  Jorallo  .... 
Volcano  of  Colima  .... 

19°    2'   17" 
19    10      3 
18    59     47 
19    11     33 
19      9       0 
19    20       0 

17,879 
15705 
17726 
15168 
4265 
12005 

The  prolongation  of  the  parallel  of  volcanic  activity  in 
the  tropical  zone  of  Mexico,  leads,  at  a  distance  of  506 
miles  westward  from  the  shores  of  the  Pacific  to  the  insular 
group  Revillagigedo,  in  the  vicinity  of  which  Collnet  saw 
pumice-stone  floating,  and  perhaps  still  farther  on,  at  a  dis- 
tance of  3360  geog.  miles  to  the  great  volcano  Mauna  Roa 
(19°  28'),  without  causing  any  upheaval  of  islands  in  the 
intervening  space ! 

The  group  of  linear  volcanoes  of  Quito  and  New  Granada 
includes  a  volcanic  zone  which  extends  from  2°  S.  lat.  to 
nearly  5°  N.  lat.  The  extreme  boundaries  of  the  area  in 
which  the  reaction  of  the  interior  of  the  earth  upon  its  sur- 
face is  now  manifested,  are  the  uninterruptedly  active  San- 
gay,  and  the  Paramo  and  Volcan  de  Ruiz,  the  most  recent 
conflagration  of  which  was  in  the  year  1829,  and  which  was 
seen  smoking  by  Carl  Degenhardt  from  the  Mina  de  San- 
tana  in  the  province  of  Mariquita  in  1831  and  from  Mar- 
mato  in  1833.  The  most  remarkable  traces  of  great  erup- 
tive phenomena  next  to  the  Ruiz,  are  exhibited  from  north 
to  south,  by  the  truncated  cone  of  the  volcano  of  Tolima 
(18,129  feet),  celebrated  by  the  recollection  of  the  destruc- 
tive eruption  of  the  12th  March,  1595  ;  the  volcanoes  of 
Purace"  (17,006  feet)  and  Sotara  near  Popayan  ;  that  of 
Pasto  (13,450  feet),  near  the  city  of  the  same  name;  of 
the  Monte  de  Azufre  (12,821  feet),  near  Tuquerres ;  of 
Cumbal  (15,618  feet),  and  of  Chiles,  in  the  province  do  los 
Pastos  ;  then  follow  the  historically  celebrated  volcanoes  of 
the  true  high  land  of  Quito,  to  the  south  of  the  equator,  of 
which  four, — namely,  Pichincha,  Cotopaxi,  Tungu  rah.ua,  and 


282  cosuos. 

Sangay, — certainly  cannot  be  regarded  as  extinct  volcanoes. 
Although  to  the  north  of  the  mountain  group  of  the 
Robles,  near  Popayan,  as  we  shall  shortly  more  fully  show 
in  the  tripartition  of  the  vast  chain  of  the  Andes,  it 
is  only  the  central  Cordillera,  and  not  the  western  one, 
nearer  to  the  sea-coast,  that  exhibits  a  volcanic  activity  ; 
on  the  other  hand,  to  the  south  of  this  group,  where  the 
Andes  form  only  two  parallel  chains,  so  frequently  men- 
tioned by  Bouguer  and  La  Condamine  in  their  writings, 
volcanoes  are  so  equally  distributed,  that  the  four  volcanoes 
of  the  Pastes,  as  well  as  Cotocachi,  Pichincha,  Iliniza,  Car- 
guairazo,  and  Yana-Urcu,  at  the  foot  of  Chimborazo,  have 
broken  out  upon  the  western  chain,  nearest  to  the  sea  ;  and 
upon  the  eastern  Cordillera,  Imbabura,  Cayambe,  Antisana, 
Cotopaxi,  Tungurahua  (opposite  to  Chimborazo  towards  the 
east,  but  still  nearly  approximated  to  the  middle  of  the 
narrow  elevated  plateau),  the  Altar  de  los  Col  lanes  (Capac- 
Urcu),  and  Sangay.  If  we  include  the  northernmost  group 
of  the  linear  volcanoes  of  South  America  in  one  view,  the 
opinion  so  often  expressed  in  Quito,  and  to  a  certain  extent 
founded  on  historical  documents,  of  the  migration  of  the 
volcanic  activity  and  increase  of  intensity  from  north  to 
south,  acquires,  at  all  events,  a  certain  amount  of  proba- 
bility. It  is  true  that  in  the  south,  and  indeed  close  to  the 
colossal  Sangay,  which  acts  like  Stromboli,  we  find  the  ruins 
of  the  "  Prince  of  Mountains,"  Capac-Urcu,  which  is  said 
to  have  exceeded  Chimborazo  in  height,  but  which  fell  in 
and  became  extinct  in  the  latter  part  of  the  fifteenth  cen- 
tury (fourteen  years  before  the  capture  of  Quito  by  the  son 
of  the  Inca  Tupac  Yupangui),  and  has  never  again  resumed 
its  former  activity. 

The  space  of  the  chain  of  the  Andes  which  is  not  occupied 
by  groups  of  volcanoes  is  far  greater  than  is  usually  sup- 
posed. In  the  northern  part  of  South  America,  from  the 
volcan  de  E-uiz  and  the  conical  mountain  Tolima,  the  two 
most  northern  volcanoes  of  the  series  of  New  Granada  and 
Quito,  over  the  isthmus  of  Panama  as  far  as  the  vicinity 
of  Costa  Rica,  where  the  series  of  volcanoes  of  Central 
America  commences,  there  is  a  country  which  is  frequently 
and  violently  convulsed  by  earthquakes,  and  in  which 
flaming  salses,  but  no  true  volcanic  eruptions,  are  knovm. 


TRUE  VOLCANOES  283 

The  length  of  this  tract  amounts  to  628  geog.  miles.  Nearly- 
double  this  length  (occupying  a  space  of  968  geog.  miles)  is 
a  tract  of  country  free  from  volcanoes,  from  the  Sangay,  the 
southern  termination  of  the  group  of  New  Granada  and 
Quito,  to  the  Chacani,  near  Arequipa,  the  commencement  of 
the  series  of  volcanoes  of  Peru  and  Bolivia.  So  compli- 
cated and  various  in  the  same  mountain  chain,  must  have 
been  the  coincidence  of  the  conditions  upon  which  depend 
the  formation  of  permanently  open  fissures,  and  the  unim- 
peded communication  of  the  molten  interior  of  the  earth 
with  the  atmosphere.  Between  the  groups  of  trachytic  and 
doleritic  rocks,  through  which  the  volcanic  forces  become 
active,  lie  rather  shorter  spaces,  in  which  prevail  granite, 
syenite,  mica-schists,  clay-slates,  quartzose  porphyries,  sili- 
cious  conglomerates,  and  limestones,  of  which  (according  to 
Leopold  von  Buch's  investigation  of  the  organic  remains 
brought  home  by  Degenhardt  and  myself),  a  considerable 
portion  belong  to  the  chalk  formation.  The  gradually  in- 
creased frequency  of  labradoritic  rocks,  rich  in  pyroxene 
and  oligoclase,  announces  to  the  observant  traveller  (as  I 
have  already  elsewhere  shown)  the  transition  of  a  zone 
hitherto  closed  and  non-volcanic,  and  often  very  rich  in 
silver  in  porphyries,  destitute  of  quartz  and  full  of  glassy 
felspar,  into  the  volcanic  regions,  which  still  freely  commu- 
nicate with  the  interior  of  the  earth. 

The  more  accurate  knowledge  which  we  have  recently 
attained  of  the  position  and  boundaries  of  the  five  groups 
of  volcanoes  (the  groups  of  Anahuac  or  tropical  Mexico, 
of  Central  America,  of  New  Granada,  and  Quito,  of  Peru 
and  Bolivia,  and  of  Chili)  shows  that,  in  the  part  of  the 
Cordilleras  which  extends  from  19^°  north,  to  46°  south 
latitude,  (and,  consequently,  taking  into  account  the  curves 
caused  by  alterations  in  the  axial  direction,  for  a  distance 
of  nearly  5000  geog.  miles,)  not  much70  more  than  half 

70  The  following  is  the  result  of  the  determination  of  the  length  and 
latitude  of  the  five  groups  of  linear  volcanoes  in  the  chain  of  the  Andes, 
as  also  the  statement  of  the  distance  of  the  groups  from  each  other : 
a  statement  illustrating  the  relative  proportions  of  the  volcanic  and 
non-volcanic  areas. 

I.  Group  of  the  Mexican  Volcanoes:   The  fissure  upon  which  the 
volcanoes  have  broken  out  is  directed  from  east  to  west,  frou? 


284  k       COSMOS. 

(calculation  gives  2540  against  2428  geog.  miles)  is  occupied 
,  by  volcanoes.     If  we  examine  the  distribution  of  the  space 

the  Orizaba  to  the  Colima,  for  a  distance  of  392  geog.  miles,  be- 
tween latitudes  19°  and  19°  20'.  The  Volcano  of  Tuxtla  lies 
isolated  128  miles  to  the  east  of  Orizaba,  near  the  coast  of 
the  Gulf  of  Mexico,  and  in  a  parallel  (18°  28')  which  is  half  a 
degree  further  south. 

II.  Distance  of  the  Mexican  group  from   the  next  group,  that  of 
Central  America  (from  the  volcano  of  Orizaba  to  the  volcano  of 
Soconusco,  in  the  direction  E.S.E.— W.N.W.)  300  miles. 

III.  Group  of  the  Volcanoes  of  Central  America :  Its  length  from  S.E. 
to  N.W.,  from  the  volcano  of  Soconusco  to  Turrialva,  in  Costa 
Rica,  more  than  680  miles. 

IV.  Distance  of  the  group  of  Central  America  from  the  series  of 
volcanoes  of  New  Granada  and  Quito,  628  miles. 

V.  Group  of  the  Volcanoes  of  New  Granada  and  Quito :  Its  length 
from  the  eruption  in  the  Paramo  de  Ruiz  to  the  north  of  the 
Volcan  de  Tolima,   to  the  volcano  of  Sangay,   472  miles.     The 
portion  of  the  chain  of  the  Andes  between  the  volcano  of  Purac6, 
near  Popayan,  and  the  southern  part  of  the  volcanic  mountain 
group  of  Pasto  is  directed  N.N.E.— S.S.W.     Far  to  the  eastward 
from  the  volcanoes  of  Popayan,  at  the  sources  of  the  Rio  Fragua, 
there  is  a  very  isolated  volcano,  which  I  have  inserted  upon  my 
general    map   of  the    mountain  group   of   the  South  American 
Cordilleras,   from   the  statements   of  missionaries  from   Timana, 
which  were  communicated  to  me  :  distance  from  the  sea-shore, 
152  miles. 

VI.  Distance  of  the  volcanic  group  of  New  Granada  and  Quito,  from 
the  group  of  Peru  and  Bolivia,   960  miles,    the  greatest  length 
destitute  of  volcanoes. 

VII.  Group  of  the  Series  of  Volcanoes  of  Peru  and  Bolivia,  from  the 
Volcan  de   Chacani   and  Arequipa  to   the   volcano   of  Atacama 
(16i°— 21-1°)  420  miles. 

VIII.  Distance  of  the  group  of  Peru  and  Bolivia  from  the  volcanic 
group  of  Chili,  540  geog.  miles.     From  the  portion  of  the  desert  of 
Atacama,  on  the  border  of  which  the  volcano  of  San  Pedro  rises, 
to  far  beyond  Copiapo,  even  to  the  volcano  of  Coquimbo  (30°  5'), 
in  the  long  Cordillera  to  the  west  of  the  two  provinces  Catamarca 
and  Rioja,there  is  no  volcanic  cone. 

IX.  Group  of  Chili,  from  the  volcano  of  Coquimbo  to  the  volcano 
San  Clemente,  968  miles. 

These  estimates  of  the  length  of  the  Cordilleras,  with  the  curvature 
which  results  from  the  change  in  the  direction  of  the  axis,  from  the  pa- 
rallel of  the  Mexican  volcanoes  in  1 9^°  of  north  latitude,  to  the  volcano  of 
San  Clemente  in  Chili  (46°  8'  S.  lat.),  give  for  a  distance  of  4968  miles, 
a  space  of  2540  miles  which  is  covered  by  five  linear  groups  of  volcanoes 


TRtTE  VOLCANOES. 


285 


free  from  volcanoes  between  the  five  volcanic  groups,  we 
find  the  maximum  distance  of  two  groups  from  one  another 
between  the  volcanic  series  of  Quito  and  Peru.  This  is 
fully  960  miles,  whilst  the  most  closely  approximated 
groups  are  the  first  and  second,  those  of  Mexico  and  Cen- 
tral America.  The  four  interspaces  between  the  five  groups 
are  severally  300,  628,  960,  and  540  miles.  The  great  dis- 
tance of  the  southernmost  volcano  of  Quito  from  the  most 
northern  of  Peru,  is,  at  the  first  glance,  the  more  remark- 
able, because,  according  to  old  custom,  we  usually  term  the 
measurement  of  degrees  upon  the  high  land  of  Quito,  the 
Peruvian  measure-meat.  Only  a  small  southern  portion  of 
the  Peruvian  chain  of  the  Andes  is  volcanic.  The  number 
of  volcanoes,  according  to  the  lists  which  I  have  prepared 
after  a  careful  criticism  or  the  newest  materials,  is  as  fol- 
lows : — 


Names  of  the  five  groups  of  linear  Vol- 
canoes of  the  New  Continent,  from 
19°  25'  north,  to  46°  8'  south 
latitude. 

No.  of  Volca- 
noes included 
in  each  group. 

No.  of  Volca- 
noes which  are 
to  be  regarded 
as  still  ignited. 

G^oup  of  Mexico'1  

6 

4 

Group  of  Central  America73  .... 
Group  of  New  Granada  and    ) 
Quito73  J 

29 

18 

18 
10 

Group  of  Peru  and  Bolivia74.  .  .  . 
Group  of  Chili74  

14 

24 

3 
13 

(Mexico,  Central  America,  New  Granada  with  Quito,  Peru  with  Bolivia, 
and  Chili);  and  a  space  probably  quite  free  from  volcanoes  of  2428 
miles.  The  two  spaces  are  nearly  equal.  I  have  given  very  definite 
numerical  relations,  as  obtained  by  the  careful  criticism  of  my  own 
maps  and  those  of  others,  in  order  to  give  rise  to  a  greater  desire  to 
improve  them.  The  longest  portion  of  the  Cordilleras  free  from  vol- 
canoes is  that  between  the  groups  of  New  Granada  with  Quito  and 
Peru  with  Bolivia.  It  is  accidentally  equal  to  that  occupied  by  the 
volcanoes  of  Chili. 

71  The  group  of  volcanoes  of  Mexico  includes  the  volcanoes  of 
Orizaba,*  Popocatepetl,*  Toluca  (or  Cerro  de  San  Miguel  de  Tutucuitla- 
pilco),  Jorullo,*  Coliina,*  and  Tuxtla.*  Here,  as  in  similar  lists,  the 
still  active  volcanoes  are  indicated  by  asterisks. 


286  COSMOS. 

According  to  these  data  the  total  number  of  volcanoes  in 
the  five  American  groups  is  91,  of  which  56  belong  to  the 

72  The  series  of  volcanoes  of  Central  America  is  enumerated  iu  the 
notes  66  and  67. 

73  The  group  of  New  Granada  and  Quito  includes  the  Paramo  y 
Volcan  de  Ruiz,*  the  volcanoes  of  Tolima,  Purace",*  and  Sotara",  near 
Popayan ;  the  Volcan  del  Bio  Fragua,  an  affluent  of  the  Caqueta ;  the 
volcanoes  of  Paste,  el  Azufral,*  Cumbal,*  Tuquerres,*  Chiles,  Imba- 
buru,  Cotocachi,  Rucu-Pichincha,  Antisana(?),  Cotopaxi,*  Tungurahua,* 
Capac-Urcu,  or  Altar  de  los  Collanes(?),  and  Sangay.* 

74  The  group  of  Southern  Peru  and  Bolivia,  includes  from  north  to 
south  the  following  14  volcanoes : — 

Volcano  of  Chacani  (also  called  Charcani,  according  to  Curzon  and 
Meyen),  belonging  to  the  group  of  Arequipa  and  visible  from  the 
town ;  it  is  situated  on  the  right  bank  of  the  Rio  Quilca,  in 
lat.  16°  11',  according  to  Pentland,  the  most  accurate  geological 
observer  of  this  region,  32  miles  to  the  south  of  the  Nevado  de 
Chuquibamba,  which  is  estimated  at  more  than  19,000  feet  in 
height.  Manuscript  records  in  my  possession  give  the  volcano  of 
Chacani  a  height  of  fully  19,601  feet.  Curzon  saw  a  large  crater 
in  the  south-eastern  part  of  the  summit. 

Volcano  of  Arequipa*  lat.  16°  20',  12  miles  to  the  north-east 
of  the  town.  With  regard  to  its  height  (18,879  feet?)  see  p.  252. 
Thaddaus  Hanke,  the  botanist  of  the  expedition  of  Malaspina 
(1796),  Samuel  Curzon  from  the  United  States  of  North  America 
(1811)  and  Dr.  Weddell  (1847)  have  ascended  the  summit.  In 
August,  1831,  Meyen  saw  large  columns  of  smoke  rising;  a  year 
previously  the  volcano  had  thrown  out  scorise,  but  never  lava- 
streams  (Meyen' s  Reise  um  die  Erde,  Th.  ii,  s.  33). 

Volcan  de  Omato,  lat.  16°  50';  it  had  a  violent  eruption  in  the  year 
1667. 

Volcan  de  Uvillas  or  Uvinas,  to  the  south  of  Apo ;  its  last  eruptions 
were  in  the  sixteenth  century. 

Volcan  de  Pichu-PicJiu,  16  miles  to  the  east  of  the  town  of 
Arequipa  (lat.  16°  25'),  not  far  from  the  Pass  of  Cangallo,  9673  feet 
above  the  sea. 

Volcan  Viejo,  lat  16°  55',  an  enormous  crater,  with  lava-streams  and 
much  pumice-stone. 

The  six  volcanoes  just  mentioned,   constitute  the  group  of  Are- 
quipa. 

Volcan  de  Tacora  or  Chipicani,  according  to  Pentland's  fine  map  of 
the  lake  of  Titicaca,  lat.  17°  45',  height  19,738  feet. 

Volcan  de  Bahama*  22,354  leet  in  height,  lat.  18°  7';  a  truncated 
cone  of  the  most  regular  foim  ;  see  p.  253.  The  volcano  of 
Sahama  is  (according  to  Pentland)  927  feet  higher  than  tha 


TRUE  VOLCANOES.  287 

continent  of  Soutli  America.     I  reckon  as  volcanoes,  besides 
those  which  are   still   burning  and   active,  those  volcanic 

Chimborazo,  but  6650  feet  lower  than  Mount  Everest  in  the 
Himalaya,  which  is  now  regarded  as  the  highest  peak  of  Asia. 
According  to  the  last  official  report  of  Colonel  Waugh,  of  the 
1st  March,  1856,  the  four  highest  mountains  of  the  Himalayan 
chain  are :  —  Mount  Everest  (Gaurischanka)  to  the  north-east  of 
Katmandu,  29,000  feet,  —  the  Kuntschinjinga,  to  the  north  of 
Darjiling,  28,154  feet,— the  Dhaulagiri  (Dhavalagirir),  26,825  feet, 
and  Tschumalari  (Chamalari),  23,946  feet. 

Volcano  of  Pomarape,  21,699  feet,  lat.  18°  8',  almost  a  twin  moun- 
tain with  the  following  volcano. 

Volcano  of  Parinacota,  22,029  feet,  lat.  18°  12'. 

The  group  of  the  four  trachytic  cones  Sahama,  Pomarape,  Parinacota, 
and  Gualatieri,  lying  between  the  parallels  of  18°  7'  and  18°  25',  is, 
according  to  Pentland's  trigonometric  measurement,  higher  than  Chim- 
borazo, or  more  than  21,422  feet. 

Volcano  of  Gualatieri,*  21,962  feet,  lat.  18°  25',  in  the  Bolivian 
province  Carangas;  very  active,  according  to  Pentland  (Hertha, 
Bd.  xiii,  1829,  s.  21). 

Not  far  from  the  Bahama-group,  18°  7'  to  18°  25',  the  series  of 
volcanoes  and  the  entire  chain  of  the  Andes,  which  lies  to  the  westward 
of  it,  suddenly  change  their  strike,  and  pass  from  the  direction 
S.E. — N.W.  into  that  from  north  to  south,  which  becomes  general  as 
far  as  the  Straits  of  Magellan.  I  have  treated  of  this  important  turning 
point,  the  notch  in  the  shore  near  Arica  (18°  280  which  has  an  analogue 
on  the  west  coast  of  Africa  in  the  Gulf  of  Biafra,  in  the  first  volume  of 
Cosmos,  p.  296. 

Volcano  of  Isluga,  lat.  19°  20',  in  the  province  of  Tarapaca,  to  the 
west  of  Carangas. 

Volcan  de  San  Pedro  de  Atacama,  on  the  north-eastern  border  of  the 
Desierto  of  the  same  name,  in  lat.  22°  16',  according  to  the  new 
plan  of  the  arid  sandy  desert  (Desierto)  of  Atacama,  by  Dr. 
Philippi,  16  miles  to  the  north-east  of  the  small  town  of  San  Pedro, 
not  far  from  the  great  Nevado  de  Chorolque. 

There  is  no  volcano  from  204°  to  30°,  and  after  an  interruption  of 
more  than  568  miles,  the  volcanic  activity  first  reappears  in  the 
volcano  of  Coquimbo.  For  the  existence  of  a  volcano  of  Copiapo 
(lat.  27°  28')  is  denied  by  Meyen,  whilst  it  is  asserted  by  Philippi, 
who  is  well  acquainted  with  the  country. 

75  Our  geographical  and  geological  knowledge  of  the  group  of  vol- 
canoes, which  we  include  in  the  common  name  of  the  linear  volcanoes 
of  Chili,  is  indebted  for  the  first  incitement  to  its  completion,  and 
even  for  the  completion  itself,  to  the  acute  investigations  of  Captain 


288  COSMOS. 

formations  whose  old  eruptions  belong  to  historic  periods, 
or  of  which  the  structure  and  eruptive  masses  (craters  of 

Fitzroy  in  the  memorable  expedition  of  the  ships  Adventure  and 
Beagle,  and  to  the  ingenious  and  more  detailed  labours  of  Charles 
Darwin.  The  latter,  with  his  peculiar  generalizing  view,  has  grasped 
the  connexion  of  the  phenomena  of  earthquakes  and  eruptions  of 
volcanoes  under  one  point  of  view.  The  great  natural  phenomenon 
which  destroyed  the  town  of  Copiapo  on  the  22nd  of  November,  1822, 
was  accompanied  by  the  upheaval  of  a  considerable  tract  of  country 
on  the  coast ;  and  during  the  exactly  similar  phenomenon  of  the  20th 
February,  1835,  which  did  so  much  injury  to  the  city  of  Concepcion, 
a  submarine  volcano  broke  out  with  fiery  eruptions  near  the  shore  of 
the  island  of  Chiloe,  near  Bacalao  Head,  and  raged  for  a  day  and  a  half. 
All  this,  depending  upon  similar  conditions,  has  also  occurred  formerly, 
aud  strengthens  the  belief  that  the  series  of  rocky  islands  which  lies 
opposite  to  the  Fjords  of  the  mainland  to  the  south  of  Valdivia  and 
of  the  Fuerte  Maullin,  and  includes  Chiloe,  the  Archipelago  of  Chonos 
and  Huaytecas,  the  Peninsula  de  Tres  Monies,  and  the  Islas  de  la 
Campana,  de  la  Madre  de  Dios,  de  Santa  Lucia  and  los  Lobos,  from 
39°  53'  to  the  entrance  of  the  Straits  of  Magellan,  is  the  crest  of  a 
submerged  western  Cordillera  projecting  above  the  sea.  It  is  true  that 
no  open  trachytic  cone,  no  volcano,  belongs  to  these  fractis  excequore 
terris,  but  individual  submarine  eruptions,  sometimes  followed  and 
sometimes  preceded  by  mighty  earthquakes,  appear  to  indicate 
the  existence  of  this  western  fissure  (Darwin,  On  the  connexion  of 
volcanic  phenomena,  the  formation  of  mountain  chains,  and  the  effect  of 
the  same  powers,  by  which  continents  are  elevated  :  in  the  Trans.  Geol. 
Society,  2nd  series,  vol.  v,  pt.  3,  1840,  pp  606 — 615,  and  629—631  ; 
Humboldt,  Essai  Politique  sur  la  Nouvelle  Espagne,  t.  i.  p.  190,  and 
t.  ii.  p.  287). 

The  series  of  24  volcanoes  included  in  the  group  of  Chili  is  as 
follows,  counting  from  north  to  south,  from  the  parallel  of  Coquimbo 
to  46°  S.  lat.  :— 

(a.)  Between  the  parallels  of  Coquimbo  and  Valparaiso : — 

Volcan  de  Coquimbo  (lat.  30°  5') ;  Meyen,  th.  i.  s.  385. 

Volcano  of  Limari. 

Volcano  of  Chuapri. 

Volcano  of  Aconcagua*,  W.N",W.,  of  Mendoza,  lat.  32°  39';  altitude 
23,004  feet,  according  to  Kellet  (See  p.  253,  note),  but  according 
to  the  most  recent  trigonometric  measurement  of  the  engineer 
Amado  Pissis  (1854),  only  22,301  feet;  consequently,  rather  lower 
than  the  Sahama,  which  Pentland  now  assumes  to  be  22,350  feet 
(Gillis,  U.S.  Naval  Astron.  Exped.  to  Chili,  vol.  i.  p.  13).  The 
geodetic  basis  of  measurement  of  Aconcagua  at  6797  metres,  which 
required  eight  triangles,  has  been  developed  by  M.  Pissis,  in  the 
Anales  de  la  Universidad  de  Chile,  1852,  p.  219. 


TRUE    VOLCANOES.  289 

elevation   and   eruption,   lavas,   scoriae,    pumice-stones  and 
obsidians)  characterise  them,  without  reference  to  any  tra- 

The  Peak  of  Tupungato  is  stated  by  Gilliss  to  be  22,450  English,  or 
21,063  Paris,  feet  in  height,  and  in  lat.  33°  22' ;  but  in  the  map 
of  the  province  of  Santiago  by  Pissis  (Gilliss,  p.  45),  it  is  estimated 
at  22,016  English,  or  20,655  Paris,  feet.  The  latter  number  is  re- 
tained (as  6710  metres)  by  Pissis  in  the  Anales  de  Chile,  1850, 
p.  12. 

(b.)  Between  the  parallels  of  Valparaiso  and  Conception : 
Volcano  of  Maypu*,  according  to  Gilliss  (vol.i,  p.  13),  in  lat.  34°  17', 
(but  in  his  general  map  of  Chili,  33°  47',  certainly  erroneously), 
and  17,662  feet  in  height.  Ascended  by  Meyen.  The  trachytic 
rock  of  the  summit  has  broken  through  upper  Jurassic  strata,  in 
which  Leopold  von  Buch  detected  Exogyra  Couloni,  Trigonia  cos- 
tata  and  Ammonites  biplex  from  elevations  of  9600  feet  (Descrip- 
tion Physique  des  lies  Canaries,  1836,  p.  471).  No  lava  streams, 
but  eruptions  of  flame  and  scoriae  from  the  crater. 
Volcano  of  Peteroa*,  to  the  east  of  Talca,  in  lat.  34°  53' ;  a  volcano 
which  is  frequently  in  activity,  and  which,  according  to  Molina's 
description,  had  a  great  eruption  on  the  3rd  December,  1762.  It 
was  visited  in  1831  by  the  highly-gifted  naturalist,  Gay. 

Volcan  de  Chilian,  lat.  36°  2'  ;  a  region  which  has  been  described  by 
the  missionary  Havestadt  of  Minister.  In  its  vicinity  is  situated 
the  Nevado  Descabezado  (35°  1'),  which  was  ascended  by  Domeyko, 
and  which  Molina  declared  (erroneously)  to  be  the  highest  moun- 
tain of  Chili.  Its  height  has  been  estimated  by  Gilliss  at  13,100 
feet  (U.S.  Naval  Astr.  Exped.,  1855,  vol.  i.  pp.  16  and  371). 

Volcano  of  Tucapel,  to  the  west  of  the  city  of  Concepcion ;  also 
called  Sill  a  Veluda ;  perhaps  an  unopened  trachytic  mountain, 
which  is  in  connection  with  the  active  volcano  of  Antuco. 

(c)  Between  the  parallels  of  Conception  and  Valdima : 
Volcano  of  Antuco*,  lat.  37°  7';  geognostically  described  in  detail  by 
Poppig;  a  basaltic  crater  of  elevation,  from  the  interior  of 
which  a  trachytic  cone  ascends,  with  lava-streams,  which  break 
out  at  the  foot  of  the  cone,  and  more  rarely  from  the  crater  at  the 
summit  (Poppig,  Reise  in  Chile  and  Peru,  Bd.  i.  s.  364).  One  of 
these  streams  was  still  flowing  in  the  year  1828.  The  indefatig- 
able Domeyko  found  the  volcano  in  full  activity  in  1845,  and  its 
height  only  8920  feet  (Pentland,  in  Mary  Somerville's  Physical 
Geography,  vol.  i.  p.  186).  Gilliss  states  the  height  at  9242  feet, 
and  mentions  new  eruptions  in  the  year  1853.  According  to 
intelligence  communicated  to  me  by  the  distinguished  American 
astronomer,  Gilliss,  a  new  volcano  rose  out  of  the  depths  in  the 
interior  of  the  Cordillera  between  Antuco  and  the  Descabezado 
on  the  25th  of  November,  1847,  forming  a  hill*  of  320  feet.  The 
sulphureous  and  fiery  eruptions  were  seen  for  more  than  a  year 
VOL.  V.  U 


290  COSMOS. 

dition,  as  volcanoes  which  have  long  been  extinct.     Unopened 
trachytic  cones  and  domes,  or  unopened  long  trai-hytic  ridges, 
such  as  Chimborazo  and  Iztaccihuatl,  are  excluded.     This  is 
also  the  sense  given  to  the  word  volcano  by  Leopold  von 
Buch,  Charles  Darwin,  and  Friedrich  Naumaun  in  their  geo- 
graphical narratives.     I  give  the  name  of  still  active  vol- 
canoes to  those   which   when  seen   from   their   immediate 
vicinity,  still  exhibit  signs  of  greater  or  less  degrees  of  their 
activity,  and  some  which  have  also  presented  great  and  well- 
attested  eruptions  in  recent  times.     The  qualification  "  seen 
from  their  immediate  vicinity,"  is  of  great  importance,  as 
the  present  existence  of  activity  is  denied  to  many  volcanoes, 
because,  when  observed  from  the  plain,  the  thin  vapours, 
which   ascend  from  the   crater  at  a  great  height,  remain 
invisible  to  the  eye.    Thus  it  was  even  denied,  at  the  time  of 
my  American  travels,  that  Pichincha  and  the  great  volcano 
of  Mexico  (Popocatepetl)  were  still  active  although  an  enter- 
by  Domeyko.     Far  to  the  eastward  of  the  volcano  of  Antuco,  in 
a  parallel  chain  of  the  Andes,  Pop  pig  states  that  there  are  two 
other  active  volcanoes,—  Punhamuidda*  and  Unalavquen*. 
Volcano  of  Callaqui. 
Volcan  de  Villarica*,  lat.  39°  14'. 
Volcano  of  Chinal,  lat.  39°  35'. 

Volcan  de  Panguipulli*,  lat.  4 Of0,  according  to  Major  Philippi. 
(d)  Betiveen  the  Parallels  of  Valdivia  and  the  southernmost  Cape  of 
the  Island  of  Chiloe: 
Volcano  of  Ranco. 

Volcano  of  Osomo  or  Llanquihue;  lat.  41°  P';  height  7443  feet. 
Volcan  de  Calbuco*  lat.  41°  12'. 
Volcano  of  Guanahuca  (Guanegue?) 
Volcano  of  Minchinmadom,  lat.  42°  48',  height  7993  feet. 
Volcan  del  Corcovado*  lat.  43°  12',  height  7509  feet. 
Volcano  of  Yanteles  (Yntales),  lat.  43°  29',  height  8030  feet. 
Upon  the  last  four  volcanoes,  see  Captain  Fitzroy,  Exped.  of  the 

Beagle,  vol.  iii,  p.  275,  and  Gilliss,  vol.  i,  p.  13. 

Volcano  of  San  Clemente,  opposite  to  the  Peninsula  de  Tres  Montes, 
which  consists,  according  to  Darwin,  of  granite,  lat.  46°  8'.  On 
the  great  map  of  South  America,  by  La  Cruz,  a  more  southern 
volcano  de  los  Gigantes  is  given,  opposite  the  Archipelago  de  la 
Madre  de  Dios,  in  lat.  51°  4'.  Its  existence  is  very  doubtful. 
The  latitudes  in  the  foregoing  table  of  volcanoes  are  for  the  most 
part  derived  from  the  maps  of  Pissis,  Allan  Campbell,  and  Claude 
Gay,  in  the  admirable  work  of  Gilliss  (1855). 


TRUE  VOLCANOES.  291 

prising  traveller,  Sebastian  Wisse,76  counted  70  still  burning 
orifices  (fumaroles)  around  the  great  active  cone  of  eruption 
in  the  crater  of  Pichincha ;  and  I  was  myself  a  witness,77 
at  the  foot  of  the  volcano  in  the  Malpais  del  Llano  de 
Tetimpa,  in  which  I  had  to  measure  a  base-line,  of  an  ex- 
tremely distinct  eruption  of  ashes  from  Popocatepetl. 

In  the  series  of  volcanoes  of  New  Granada  and  Quito, 
which  in  18  volcanoes  includes  10  that  are  still  active,  and  is 
about  twice  the  length  of  the  Pyrenees,  we  may  indicate,  from 
^rth  to  south  as  four  smaller  groups  or  subdivisions : — 
the  Paramo  de  Ruiz  and  the  neighbouring  volcano  of  Tolima 
(latitude,  according  to  Acosta,  4°  55'  N.) ;  Purace  and  Sotara, 
near  Popayan  (lat.  2i°) ;  the  Volcanes  de  Pasto,  Tuquerres 
and  Cumbal  (lat.  2°  20'  to  0°  50') ;  and  the  series  of  volcanoes 
from  Pichincha,  near  Quito,  to  the  uniritermittently  active 
Sangay  (from  the  equator  to  2°  South  latitude).  This  last 
subdivision  of  the  active  group  is  not  particularly  remarkable 
amongst  the  volcanoes  of  the  New  World,  either  by  its  great 
length,  or  by  the  closeness  of  its  arrangement.  We  now 
know,  also,  that  it  does  not  include  the  highest  summit,  for 
the  Aconcagua  in  Chili  (lat.  32°  390,  of  23,003  feet,  according 
to  Kellet,  23,909  feet,  according  to  Fitzroy  and  Pentland, 
besides  the  Nevados  of  Sahama  (22,349  feet),  Parincota 
(22,030  feet),  Gualateiri  (21,962  feet),  and  Pomarape  (21,699 
feet),  all  from  between  18°  T  and  18°  25'  south  latitude,  are 
regarded  as  higher  than  Chimborazo  (21,422  feet).  Never- 
theless, of  all  the  volcanoes  of  the  new  continent,  the  vol- 
canoes of  Quito  enjoy  the  most  widely  spread  renown,  for 
to  these  mountains  of  the  chain  of  the  Andes,  to  this  high 
land  of  Quito,  attaches  the  memory  of  those  assiduous  astro- 
nomical, geodetical,  optical,  and  barometrical  labours,  directed 
to  important  ends,  which  are  associated  with  the  illustrious 
names  of  Bouguer  and  La  Condamine.  Wherever  intel- 
lectual tendencies  prevail,  wherever  a  rich  harvest  of  ideas 
has  been  excited,  leading  to  the  advancement  of  several 
sciences  at  the  same  time,  fame  remains  as  it  were  locally 
attached  for  a  long  time.  Such  fame  has  in  like  manner 
belonged  to  Mont  Blanc  in  the  Swiss  Alps, — not  on  account 

?6  Humboldt,  Kleinere  Schriften,  Bd.  i,  s.  90. 

77  24th  of  January,  1804.  See  my  Essai  Politique  sur  la  Nouvellt 
Espagne,  t.  i,  p.  166. 

u2 


292  COSMOS. 

of  its  height,  which  only  exceeds  that  of  Monte  Rosa  by 
about  557  feet, — not  on  account  of  the  danger  overcome 
in  its  ascent, — but  on  account  of  the  value  and  multiplicity 
of  the  physical  and  geological  views  which  ennoble  Saus- 
sure's  name,  and  the  scene  of  his  untiring  industry.  Nature 
appears  greatest  where,  besides  its  impression  on  the  senses, 
it  is  also  reflected  in  the  depths  of  thought. 

The  series  of  volcanoes  of  Peru  and  Bolivia,  still  entirely 
belonging  to  the  equinoctial  zone,  and  according  to  Pentland, 
only  covered  with  perpetual  snow  at  an  elevation  of  16,945 
feet  (Darwin,  Journal,  1845,  p.  244),  attains  the  maximum  of 
its  elevation  (22,349  feet)  at  about  the  middle  of  its  length' 
in  the  Sahama  group,  between  18°  7'  and  18°  25'  south  lati- 
tude. There,  in  the  neighbourhood  of  Arica,  appears  a  sin- 
gular, bay-like  bend  of  the  shore,  which  corresponds  with  a 
sudden  alteration  in  the  axial  direction  of  the  chain  of  the 
Andes,  and  of  the  series  of  volcanoes  lying  to  the  west  of  it. 
Thence,  towards  the  south,  the  coast  line,  and  also  the  vol- 
canic fissure,  no  longer  strike  from  south-east  to  north- 
west, but  in  the  direction  of  the  meridian,  a  direction  which 
is  maintained  until  near  the  western  entrance  into  the  Straits 
of  Magellan,  for  a  distance  of  more  than  two  thousand  miles. 
A  glance  at  the  map  of  the  ramifications  and  groups  of  moun- 
tains of  the  chain  of  the  Andes,  published  by  me  in  the  year 
1831,  exhibits  many  other  similar  agreements  between  the 
outline  of  the  New  Continent,  and  the  near  or  distant 
Cordilleras.  Thus  between  the  promontories  of  Aguja  and 
San  Lorenzo  (5^°  to  1°  south  latitude),  both  the  coast  line 
of  the  Pacific  and  the  Cordilleras  are  directed  from  south 
to  north,  after  being  directed  so  long  from  south-east  to 
north-west,  between  the  parallels  of  Arica  and  Caxamarca ; 
and  in  the  same  way  the  coast-line  and  the  Cordilleras  run 
from  south-west  to  north-east,  from  the  mountain  group  of 
Tmbaburu,  near  Quito,  to  that  of  los  Robles,78  near  Popayan. 

'3  The  mica  schist  mountain  group  de  los  Robles  (lat.  2°  2')  and  of  the 
Paramo  de  las  Papas  (lat.  2°  20')  contains  the  Alpine  lakes,  Laguna  de 
S.  lago  and  L.  del  Buey,  scarcely  six  miles  apart ;  from  the  former  springs 
the  Cauca,  and  from  the  latter  the  Magdalena,  which,  being  soon  sepa- 
rated by  a  central  mountain  chain,  only  unite  with  each  other  in  the 
parallel  of  9°  27',  in  the  plains  of  Mompox  and  Tenerife.  The  above- 
mentioned  mountain  group  between  Popayan,  Almaguer,  and  Timana 
IM  of  great  importance  in  connection  with  the  geological  question  whether 


TRUE  VOLCANOES.  293 

With  regard  to  the  geological  causal  connection  of  the  agree- 
ment, which  is  so  often  manifested  between  the  outlines  of 

the  volcanic  chain  of  the  Andes  of  Chili,  Peru,  Bolivia,  Quito,  and 
New  Granada,  be  connected  with  the  mountain  chain  of  the  Isthmus 
of  Panama,  and  in  this  way  with  that  of  Veragua  and  the  series  of  vol- 
canoes of  Costa  Pdca  and  Central  America  in  general.  In  my  maps 
of  1816,  1827,  and  1831,  the  mountain-systems  of  which  have  been 
made  more  generally  known  by  Bru£  in  Joaquin  Acosta's  fine  map  of 
New  Granada  (1847)  and  in  other  maps,  I  have  shown  how  the  chain 
of  the  Andes  undergoes  a  triple  division  under  the  northern  parallel 
of  2°  10';  the  western  Cordillera  running  between  the  valley  of  the 
Rio  Cauca  and  the  Rio  Atrato;  the  middle  one  between  the  Cauca  and 
the  Rio  Magdalena;  and  the  eastern  one  between  the  valley  of  the 
Magdalena  and  the  Llanos  (plains)  which  are  watered  by  the  affluents 
of  the  Maranon  and  Orinoco.  I  have  been  able  to  indicate  the  special 
direction  of  these  three  Cordilleras  from  a  great  number  of  points 
which  fall  in  the  series  of  astronomical  local  determinations,  of  which 
I  obtained  152  in  South  America  alone  by  culminations  of  stars. 

To  the  east  of  the  Rio  I^gua,  and  to  the  west  of  Cazeres,  Rolda- 
nilla,  Toro,  and  Anserma,  near  Cartago,  the  western  Cordillera  runs 
S.S.W.— N.N.E.,  as  far  as  the  Salto  de  San  Antonio  in  the  Rio  Cauca 
(lat.  5°  14')  which  lies  to  the  south-west  of  the  Vega  de  Supia.  Thence, 
as  far  as  the  Alto  del  Viento  (Cordillera  de  Abibe,  or  Avidi,  lat.  7°  12') 
9600  feet  in  height,  the  chain  increases  considerably  in  elevation  and 
bulk,  and  amalgamates,  in  the  province  of  Antioquia,  with  the  inter- 
mediate or  Central  Cordillera.  Further  to  the  north,  towards  the 
sources  of  the  Rios  Lucio  and  Guacuba,  the  chain  ceases,  dividing  into 
ranges  of  hills.  The  Cordillera  occidental,  which  is  scarcely  32  miles 
from  the  coast  of  the  Pacific  near  the  mouth  of  the  Dagua  in  the 
Bnhia  de  San  Buenaventura  (lat.  3°  50*)  is  twice  this  distance  in  the 
parallel  of  Quibdo  in  the  Choco  (lat.  5°  48').  This  observation  is  of 
some  importance,  because  we  must  not  confound  with  the  western 
chain  of  the  Andes,  the  country  with  high  hills,  and  the  range  of  hills, 
which  in  this  province,  so  rich  in  gold  dust,  runs  from  south  to  north 
from  Xovita  and  Tado  along  the  right  bank  of  the  Rio  San  Juan  and 
the  left  bank  of  the  great  Rio  Atrato.  It  is  this  inconsiderable  series  of 
hills  that  is  intersected  in  the  Quebrada  de  la  Raspadura,  by  the 
canal  of  Raspadura  (Canal  des  Monches),  which  unites  two  rivers  (the 
Rio  San  Juan  or  Noanama  and  the  Rio  Quibdo,  a  tributary  of  the 
Atrato)  and  by  their  means  two  oceans  (Humboldt,  Essai  Politique,^,.  i, 
p.  235);  it  was  this  also  which  was  seen  in  the  instructive  expedition  of 
Captain  Kellet  between  the  Bahia  de  Cupica  (lat.  6°  42*)  long  and  fruit- 
lessly extolled  by  me,  and  the  sources  of  the  Napipi,  which  falls 
into  the  Atrato.  (See  Humboldt,  Op.  cit.  t.  i,  p.  231 ;  and  Robert 
Fitzroy,  Congiderations  on  the  Great  Isthmus  of  Central  America,  in 
the  Journal  of  the  Royal  Gcogr.  Soc.  vol.  xx,  1851,  pp.  178,  180,  and 
186). 

The  middle  chain  of  the  Andes  (Cordillera  Central),  constantly  tha 
highest,  reaching  within  the  limit  of  perpetual  snow,  and  in  ita  entire 


294  COSMOS. 

continents  and  the  direction  of  near  mountain  chains  (South 
America,  Alleghanys,  Norway,  Apennines),  it  appears  diffi- 
cult to  come  to  any  decision. 

extent,  directed  nearly  from  south  to  north,  like  the  western  chain, 
commences  about  35  miles  to  the  north-east  of  Popayau  with  the 
Paramos  of  Guanacos,  Huila,  Iraca,  and  Chinche.  Further  on  towards 
the  north,  between  Buga  and  Chaparral,  rise  the  elongated  ridge  of  the 
Nevado  de  Baraguan  (lat.  4°  II7),  la  Montana  de  Quindio,  the  snow- 
capped, truncated  cone  of  Tolima,  the  Volcano  and  Paramo  de  Ruiz 
and  the  Mesa  de  Herveo.  These  high  and  rugged  mountain  deserts,  to 
which  the  name  of  Paramos  is  applied  in  Spanish,  are  distinguished  by 
their  temperature  and  a  peculiar  character  of  vegetation,  and  rise  in  the 
part  of  the  tropical  region  which  I  here  describe,  according  to  the  mean 
of  many  of  my  measurements,  from  10,000  to  11,700  feet  above  the 
\evel  of  the  sea.  In  the  parallel  of  Mariquita,  of  the  Herveo  and  the 
Salto  de  San  Antonio,  in  the  valley  of  the  Cauca,  there  commences  a 
union  of  the  western  and  central  chains,  of  which  mention  has  already 
been  made.  This  amalgamation  becomes  most  remarkable  between 
the  above-mentioned  Salto  and  the  Angostura  and  Cascada  de  Cara- 
manta,  near  Supia.  Here  is  situated  the  high  land  of  the  province  of 
Antioquia,  so  difficult  of  access,  which  extends,  according  to  Manuel 
Restrepo,  from  5^°  to  8°  34' ;  in  this  we  may  mention  as  points  of 
elevation  from  south  to  north :  Arrna,  Sonson,  to  the  north  of  the 
sources  of  the  Rio  Saiaana  :  Marinilla,  Rio  Negro  (6844  feet),  and 
Medellin  (4847  feet),  the  plateau  of  Santa  Rosa  (8466  feet)  and  Valle  de 
Osos.  Further  on,  beyond  Cazeres  and  Zaragoza,  towards  the  conflu- 
ence of  the  Cauca  and  iSechi,  the  true  mountain  chain  disappears,  and 
the  eastern  slope  of  the  Cerros  de  San  Lucar,  which  I  saw  from  Badillas 
(lat.  8°  I'),  and  Paturia  (lat.  7°  36'),  during  my  navigation  and  survey  of 
the  Magdalena,  is  only  perceptible  from  its  contrast  with  the  broad 
river-plain. 

The  eastern  Cordillera  possesses  a  geological  interest  in  as  much  as  it 
riot  only  separates  the  whole  northern  mountain  system  of  New  Granada 
from  the  lowland,  from  which  the  waters  flow  partly  by  the  Caguan 
and  Caqueta  to  the  Amazons,  and  partly  by  the  Guaviare,  Meta,  and 
Apure  to  the  Orinoco,  but  also  unites  itself  most  distinctly  with  the 
littoral  chain  of  Caraccas.  What  is  called  in  systems  of  veins  a  raking 
takes  place  there, — a  union  of  mountain  chains  which  have  been  ele- 
vated upon  two  fissures  of  very  different  directions,  and  probably  even 
at  very  different  times.  The  eastern  Cordillera  departs  far  more  than 
the  two  others  from  a  meridional  direction,  diverging  towards  the 
noi'th-east,  so  that  at  the  snowy  mountains  of  Merida  (lat.  8°  10')  ife 
already  lies  5  degrees  of  longitude  further  to  the  east,  than  at  its  issue 
from  the  mountain  group  de  los  Robles,  near  the  Ceja  and  Timana.  To 
the  north  of  the  Paramo  de  la  Suma  Paz,  to  the  east  of  the  Purificacion, 
on  the  western  declivity  of  the  Paramo  of  Chingaza,  at  an  altitude  of 
only  8760  feet,  rises,  over  an  oak  forest,  the  fine  but  treeless  and  stern 
plateau  of  Bogota  (lat.  4°  36').  It  occupies  about  288  geog.  square  miles 
and  its  position  presents  a  remarkable  similarity  to  that  of  the  basin 


TKUE  VOLCANOES.  295 

Although,  in  the  series  of  volcanoes  of  Bolivia  and  Chili, 
the  western  branch  of  the  chain  of  the  Ancles,  which 
approaches  nearest  to  the  Pacific,  at  present  exhibits  the 
greater  part  of  the  traces  of  still  existing  volcanic  activity, 
yet,  a  very  experienced  observer,  Pentland,  has  discovered, 
at  the  foot  of  the  eastern  chain,  more  than  180  geog.  miles 
from  the  sea-coast,  a  perfectly  preserved,  but  extinct  crater, 
with  unmistakeable  lava-streams.  This  is  situated  upon  the 
summit  of  a  conical  mountain,  near  San  Pedro  de  Cacha,  in 

of  Cashmere,  which,  however,  according  to  Victor  Jacquemont,  is 
about  3410  feet  lower  at  the  Wuller  lake,  and  belongs  to  the  south- 
western declivity  of  the  Himalayan  chain.  The  plateau  of  Bogota  and 
the  Paramo  de  Chingaza,  are  followed  in  the  eastern  Cordillera  of  the 
Andes  towards  the  north-east  by  the  Paramos  of  Guachaneque,  above 
Tunja;  of  Zoraca,  above  Sogamoso;  of  Chita  (16,000  feet?),  near  the 
sources  of  the  Eio  Casanare,  a  tributary  of  the  Meta;  of  the  Almorzadera 
(12,854  feet),  near  Socorro;  of  Cacota  (10,986  feet),  near  Pamplona;  of 
Laura  and  Porquera  near  la  Grita.  Here,  between  Pamplona,  Salazar, 
and  Rosario  (between  lat.  7°  8'  and  7°  50')  is  situated  the  small  moun- 
tain group,  from  which  a  crest  extends  from  south  to  north  towards 
Ocnfia  and  Valle  de  Upar,  to  the  west  of  the  Laguna  de  Maracaibo,  and 
unites  with  the  most  advanced  mountains  of  the  Sierra  Nevado  de  Santa 
Marta  (19,000  feet?).  The  more  elevated  and  vaster  crest  continues  in 
the  original  north-easterly  direction  towards  Merida,  Truxillo,  and  Bar- 
quisimeto,  to  unite  there,  to  the  eastward  of  the  Laguna  de  Maracaibo, 
with  the  granitic  littoral  chain  of  Venezuela,  to  the  west  of  Puerto  Cabello. 
From  the  Grita  and  the  Paramo  de  Porquera  the  eastern  Cordillera 
rises  again  at  once  to  an  extraordinary  height.  Between  the  parallels 
of  8°  5'  and  9°  7',  follow  the  Sierra  Nevada  de  Merida  (Mucuchies) 
examined  by  Boussingault  and  determined  by  Codazzi  trigonometri- 
cally  at  15,069  feet;  and  the  four  Paramos  de  Timotes,  Niquitao,  Bocon6, 
and  de  las  Rosas,  full  of  the  most  beautiful  Alpine  plants.  (See 
Codazzi,  Resumen  de  la  Geografia  de  Venezuela,  1841,  pp.  12  and  495; 
and  also  my  Asie  Centrale,  t.  iii,  pp.  258 — 262,  with  regard  to  the 
elevation  of  the  perpetual  snow  in  this  zone.)  The  western  Cordil- 
lera is  entirely  wanting  in  volcanic  activity,  which  is  peculiar  to  the 
central  Cordillera  as  far  as  the  Tolima  and  Paramo  de  Ruiz,  which,  how- 
ever, are  separated  from  the  volcano  of  Puracfi  by  nearly  three  degrees 
of  latitude.  The  eastern  Cordillera  has  a  smoking  hill  near  its  eastern 
declivity,  at  the  origin  of  the  Rio  Fragua,  to  the  north-east  of  Mocoa 
and  south-east  of  Timana,  at  a  greater  distance  from  the  shore  of  the 
Pacific,  than  any  other  still  active  volcano  of  the  New  World.  An 
accurate  knowledge  of  the  local  relations  of  the  volcanoes  to  the 
arrangement  of  the  mountain  chains  is  of  the  highest  importance  for 
the  completion  of  the  geology  of  volcanoes.  All  the  older  maps, 
with  the  single  exception  of  that  of  the  high  land  of 'Quito,  can  only  lead 
to  error. 


296  COSMOS. 

the  valley  of  Yucay,  at  an  elevation  of  nearly  12,000  feet 
(lat.  14°  8',  long.  71°  20'),  south-east  from  Cuzco,  where  the 
eastern  snowy  chain  of  Apolobamba,  Carabaya,  and  Vilcanoto 
extends  from  south-east  to  north-west.  This  remarkable 
point79  is  marked  by  the  ruins  of  a  famous  temple  of  the 
Inca  Viracocha.  The  distance  from  the  sea  of  this  old  lava- 
producing  volcano  is  far  greater  than  that  of  Sangay,  which 
also  belongs  to  an  eastern  Cordillera,  and  greater  than  that 
of  Orizaba  and  Jorullo. 

An  interval  of  540  miles  destitute  of  volcanoes  separates 
the  series  of  volcanoes  of  Peru  and  Bolivia  from  that  of  Chili. 
This  is  the  distance  of  the  eruption  in  the  desert  of  Atacama 
from*  the  volcano  of  Coquimbo.  At  2°  34'  further  to  the 
south,  as  already  remarked,  the  group  of  volcanoes  of  Chili 
attains  its  greatest  elevation  in  the  volcano  of  Aconcagua 
(23,003  feet),  which,  according  to  our  present  knowledge,  is 
also  the  maximum  of  all  the  summits  of  the  new  Continent. 
The  average  height  of  the  Bahama  group  is  22,008  feet ; 
consequently  586  feet  higher  than  Chimborazo.  Then  follow, 
diminishing  rapidly  in  elevation,  Cotopaxi,  Arequipa  (?),  and 
Tolima,  between  18,877  and  18,129  feet  in  height.  I  give, 
in  apparently  very  exact  numbers,  and  without  alteration, 
the  results  of  measurements  which  are  unfortunately  com- 
pounded from  barometrical  and  trigonometrical  determi- 
nations, because  in  this  way  the  greatest  inducement  will 
be  given  to  the  repetition  of  the  measurements  and  correc- 
tion of  the  results.  In  the  series  of  volcanoes  of  Chili,  of 
which  I  have  cited  24,  it  is  unfortunately  for  the  most  part 
only  the  southern  and  lower  ones,  from  Antuco  to  Yantales, 
between  the  parallels  of  37°  20'  and  43°  40',  that  have  been 
hypsometrically  determined.  These  have  the  inconsiderable 
elevation  of  from  six  to  eight  thousand  feet.  Even  in  Tierra 
del  Fuego  itself  the  summit  of  the  Sarmiento,  covered  with 
perpetual  snow,  only  rises,  according  to  Fitzroy,  to  6,821 
feet.  From  the  volcano  of  Coquimbo  to  that  of  San 
Clemente  the  distance  is  968  miles. 

79  Pentland,  in  Mrs.  Somerville's  Physical  Geography  (1851),  vol.  i, 
p.  185.  The  Peak  of  Vilcanoto  (17,020  feet),  situated  in  lat.  14°  28% 
forming  a  portion  of  the  vast  mountain  group  of  that  name,  closes  the 
northern  extremity  of  the  plateau,  in  which  the  lake  of  Titicaca,  a 
Mna]l  inland  sea  of  88  miles  in  length,  is  situated. 


TRUE  VOLCANOES  297 

With  regard  to  the  activity  of  the  volcanoes  of  Chili,  we 
have  the  important  testimony  of  Charles  Darwin,80  who 
refers  very  decidedly  to  Osorno,  Corcovado,  and  Aconcagua 
as  being  ignited ;  the  evidence  of  Meyen,  Poppig,  and 
G*y,  who  ascended  Maipu,  Antuco  and  Peteroa ;  and  that 
of  Domeyko,  the  astronomer  Gilliss,  and  Major  Philippi. 
The  number  of  active  craters  may  be  fixed  at  thirteen,  only 
five  fewer  than  in  the  group  of  Central  America. 

From  the  five  groups  of  serial  volcanoes  of  the  New  Con 
tinent,  which  we  have  been  able  to  describe  from  astrono- 
nomical  local  determinations,  and  for  the  most  part  also  hyp- 
sometrically  as  to  position  and  elevation,  let  us  now  turn  to 
the  Old  Continent,  in  which,  in  complete  opposition  to  the 
New  World,  the  greater  part  of  the  approximated  volcanoes 
belong  not  to  the  mainland  but  to  the  islands.  Most  of  the 
European  volcanoes  are  situated  in  the  Mediterranean  Sea, 
and  indeed  (if  we  include  the  great  and  repeatedly  active 
crater  between  Thera,  Therasia,  and  Aspronisi),  in  the  Tyr- 
rhenian and  ^Egsean  parts ;  in  Asia  the  most  mighty  vol- 
canoes are  situated  to  the  south  and  east  of  the  continent 
on  the  large  and  small  Sunda  Islands,  the  Moluccas,  and 
the  Philippines,  in  Japan,  and  the  Archipelagoes  of  the 
Kurile  and  Aleutian  Islands. 

In  no  other  region  of  the  earth's  surface  do  such  frequent 
and  such  fresh  traces  of  the  active  communication  between 
the  interior  and  exterior  of  our  planet  show  themselves,  as 
upon  the  narrow  space  of  scarcely  12,800  geographical  (16.928 
English)  square  miles  between  the  parallels  of  10°  south  and 
14°  north  latitude,  and  between  the  meridians  of  the  southern 
point  of  Malacca  and  the  western  point  of  the  Papuan  penin- 
sula of  New  Guinea.  The  area  of  this  volcanic  island- world 
scarcely  equals  that  of  Switzerland,  and  is  washed  by  the 
seas  of  Sunda,  Banda,  Solo,  and  Mindoro.  The  single  island 
of  Java  contains  a  greater  number  of  active  volcanoes  than 
the  entire  southern  half  of  America,  although  this  island 
is  only  544  miles  in  length,  that  is,  only  one-seventh  of  the 
length  of  South  America.  A  new  but  long-expected  light 
has  recently  been  diffused  over  the  geognostic  nature  of  Java 
(after  previous  very  imperfect  but  meritorious  works  by 

80  See  Darwin,  Journal  of  Researches  in  Natural  History  and  Geology 
during  the  Voyage  of  the  Beagle,  1845,  pp.  275,  291,  and  310. 


298  COSMOS. 

Horsfield,  Sir  Thomas  Stamford  Raffles  and  Reinwardt),  by 
a  learned,  bold,  and  untiringly  active  naturalist,  Franz 
Junghuhn.  After  a  residence  of  more  than  twelve  years  he 
has  given  the  entire  natural  history  of  the  country  in  an 
instructive  work,  Java,  its  form,  vegetable  covering,  and 
internal  structure.  More  than  400  elevations  are  carefully 
determined  barometrically;  the  volcanic  cones  and  bell-shaped 
mountains,  45  in  number,  are  represented  in  profile,  and  all 
but  three81  of  them  were  ascended  by  Junghuhn.  More  than 
half  (at  least  28)  were  found  to  be  still  burning  and  active ; 
their  remarkable  and  various  profiles  are  described  with 
extraordinary  clearness,  and  even  the  attainable  history  of 
their  eruptions  is  investigated.  No  less  important  than  the 
volcanic  phenomena  of  Java  are  its  sedimentary  formations 
of  the  Tertiary  period,  which  were  entirely  unknown  to  us 
before  the  appearance  of  the  complete  work  just  mentioned, 
although  they  cover  three- fiftlis  of  the  entire  area  of  the 
island,  especially  in  the  southern  parts.  In  many  districts 
of  Java  there  occur,  as  the  remains  of  former  widely-spread 
forests,  fragments,  from  three  to  seven  feet  in  length,  of  sili- 
cified  trunks  of  trees,  which  all  belong  to  the  Dicotyledons. 
For  a  country  in  which  at  present  an  abundance  of  palms 
and  tree  ferns  grows,  this  is  the  more  remarkable,  because 
in  the  Miocene  tertiary  rocks  of  the  brown-coal  formation 
of  Europe,  where  arborescent  Monocotyledons  no  longer 
thrive,  fossil  palms  are  not  unfrequently  met  with.82  By 
a  diligent  collection  of  the  impressions  of  leaves  and  fos- 
silized woods,  Junghuhn  has  been  enabled  to  give  us,  as 
the  first  example  of  the  fossil  Flora  of  a  purely  tropical 
region,  the  ancient  Flora  of  Java,  ingeniously  elaborated  by 
Goppert  from  his  collection. 

As  regards  the  elevation  to  which  they  attain,  the  vol- 
canoes of  Java  are  far  inferior  to  those  of  the  t/lncae  groups 

s1  Junghuhn,  Java,  Bd.  i,  s.  79. 

82  Op.  cit.  Bd.  iii,  s.  155,  and  Goppert,  Die  Tertiarflora  auf  der  Insel 
Java  nach  den  Entdeckungen  von  Fr.  Junghuhn  (1854),  s.  17.  The 
absence  of  Monocotyledons  is,  however,  peculiar  to  the  silicified  trunks 
of  trees  lying  scattered  upon  the  surface,  and  especially  in  the 
rivulets  of  the  district  of  Bantam;  in  the  subterranean  carbonaceous 
strata,  on  the  contrary,  there  are  remains  of  palm-wood,  belonging 
to  two  genera  (Flabellaria  and  Amesoneuron).  See  Goppert,  s.  31 
and  35. 


TRUE  VOLCANOES.  299 

of  Chili,  Bolivia,  and  Peru,  and  even  to  those  of  the  two 
groups  of  Quito  with  New  Granada,  and  of  Tropical  Mexico. 
The  maxima  attained  by  these  American  groups  are  : — For 
Chili,  Bolivia,  and  Quito,  21,000  to  23,000  feet,  and  for 
Mexico,  18,000  feet.  This  is  nearly  ten  thousand  feet 
(about  the  height  of  Etna),  more  than  the  greatest  elevation 
of  the  volcanoes  of  Sumatra  and  Java.  On  the  latter  island 
the  highest  still  burning  colossus  is  the  Gunung  Semeru, 
the  culminating  point  of  the  entire  Javanese  series  of  vol- 
canoes. Junghuhn  ascended  this  in  September,  1844  ;  the 
average  of  his  barometric  measurements  gave  12,233  feet 
above  the  surface  of  the  sea,  and  consequently  1748  feet 
more  than  the  summit  of  Etna,  At  night  the  centigrade 
thermometer  fell  below  6°.2  (43°.2  Fahr.).  The  old  Sanscrit 
name  of  Gunung  Semeru  was  MaM-Meru  (the  great  Meru) ; 
a  reminiscence  of  the  time  when  the  Malays  received  Indian 
civilisation, — a  reminiscence  of  the  Mountain  of  the  World 
in  the  north,  which,  according  to  the  Mahabharata,  is  the 
dwelling-place  of  Brahma,  Vishnu,  and  the  seven  Devarschi.8* 
It  is  remarkable  that,  as  the  natives  of  the  plateau  of  Quito 
had  guessed,  before  any  measurement,  that  Chimborazo  sur- 
passed all  the  other  snowy  mountains  -in  the  country,  the 
Javanese  also  knew  that  the  Holy  Mountain  Maha-Meru, 
which  is  but  at  a  short  distance  from  the  Gunung  Ajrdjuno 
(11,031  feet)  exhibited  the  maximum  of  elevation  upon  the 
island,  and  yet,  in  this  case,  in  a  country  free  from  snow,  the 
greater  distance  of  the  summit  from  the  level  of  the  lower 
limit  of  perpetual  snow  could  no  more  serve  as  a  guide  to 
the  judgment  than  the  height  of  an  occasional  temporary  fall 
of  snow.84 

The  elevation  of  the  Gunung  Semeru,  which  exceeds 
11,000  (11,726  English)  feet,  is  most  closely  approached 
by  four  other  mountains,  which  were  found  hypsometrically 
to  be  between  ten  and  eleven  thousand  feet.  These 
are:  Gunung89  Slamat,  or  mountain  of  Tegal  (11,116 

83  Upon  the  signification  of  the  word  Meru,  and  the  conjectures 
which  Burnouf  communicated  to  me  regarding  its    connection  with 
mira  (a  Sanscrit  word  for  sea],  see  my  Asie  Centrale,  t.  i,  pp.  114 — 116, 
and  Lassen's  Indische  Alterthumskunde,  Bd.  i,  s.  847.     The  latter  is 
inclined  to  regard  the  names  as  not  of  Sanscrit  origin. 

84  See  page  240. 

85  Gununrj  is  the  Javanese  word  for  mountain,  in  Malayan,  gHnongl 


SOO  COSMOS. 

feet),  Gunung  Ardjuno  (11,031  feet),  Gunung  Sumbing 
(11,029  feet),  and  Ginning  Lawn  (10,726  feet).  Seven 
other  volcanoes  of  Java  attain  a  height  of  nine  or  ten 
thousand  feet ;  a  result  which  is  of  the  more  importance  as 
no  summit  of  the  island  was  formerly  supposed  to  rise  higher 
than  six  thousand  feet.86  Of  the  five  groups  of  North  and 
South  American  volcanoes,  that  of  Guatemala  (Central 
America)  is  the  only  one  exceeded  in  mean  elevation  by 
the  Javanese  group.  Although  in  the  vicinity  of  Old 
Guatemala  the  Volcan  del  Fuego  attains  a  height  of  13,109 
feet  (according  to  the  calculation  and  reduction  of 
Poggendorff),  and  therefore  874  feet  more  than  Gunung 
Semeru,  the  remainder  of  the  Central  American  series  of 
volcanoes  only  varies  between  five  and  seven  thousand  feet, 
and  not  as  in  Java  between  seven  and  ten  thousand  feet. 
The  highest  volcano  of  Asia  is  not,  however,  to  be  sought 
in  the  Asiatic  Islands  (the  Archipelago  of  the  Sunda 
Islands),  but  upon  the  continent ;  for  upon  the  peninsula 
of  Kamtschatka  the  volcano  Kljutschewsk  rises  to  15,763 
feet,  or  nearly  to  the  height  of  the  Rucu-Pichincha,  in  the 
Cordilleras  of  Quito. 

which  singularly  enough  is  not  further  disseminated  over  the  enormous 
domain  of  the  Malayan  language ;  see  the  comparative  table  of  words  in 
my  brother's  woi'k  upon  the  Kawi  language,  vol.  ii,  s.  249,  No.  62.  As 
it  is  the  custom  to  place  this  word  gunung  before  the  names  of  moun- 
tains in  Java,  it  is  usually  indicated  in  the  text  by  a  simple  G. 

^  Leopold  de  Buch,  Description  Physique  des  lies  Canaries,  1836, 
p.  419.  Not  only  has  Java  (Junghuhn,  Th.  i.  s.  61,  and  Th.  ii.  s.  547) 
a  colossal  mountain,  the  Semeru  of  12,233  feet,  which  consequently 
exceeds  the  Peak  of  Teneriflfe  a  little  in  height,  but  an  elevation  of 
12,256  feet  is  also  attributed  to  the  Peak  of  Indrapura,  in  Sumatra, 
which  is  also  still  active,  but  does  not  appear  to  have  been  so  accu- 
rately measured  (Th.  i,  s.  78,  and  profile  Map  No.  1).  The  next  to 
this  in  Sumatra,  are  the  dome  of  Telainan,  which  is  only  one  of  the 
summits  of  Ophir  (not  13,834,  but  only  9603  feet  in  height),  and  the 
Merapi  (according  to  Dr.  Homer,  9571  feet)  the  most  active  of  the 
thirteen  volcanoes  of  Sumatra,  which,  however,  (Th.  ii.  s.  294,  and 
Juughuhn's  Battalander,  1847,  Th.  i,  s.  25)  is  not  to  be  confounded, 
from  the  similarity  of  the  names,  with  two  volcanoes  of  Java, — the 
celebrated  Merapi,  near  Jogjakerta  (9208  feet),  and  the  Merapi,  which 
forms  the  eastern  portion  of  the  summit  of  the  volcano  Idjen  (8595 
feet).  In  the  Merapi,  it  '.s  thought  that  the  holy  name  Meru  is  again 
to  be  detected,  combined  with  the  Malay  an  and  Javanese  word  a$i,  fira 


TRUE  VOLCANOES.  301 

Tbe  principal  axis87  of  the  closely  approximated  series  of 
the  Javanese  volcanoes  (more  than  45  in  number)  has  a 
direction  W.N.W  — E.S.E.  (exactly  W.  12°  K),  and  there- 
fore principally  parallel  to  the  series  of  volcanoes  of  the 
eastern  part  of  Sumatra,  but  not  to  the  longitudinal  axis  of 
the  island  of  Java.  This  general  direction  of  the  chain  of 
volcanoes  by  no  means  excludes  the  phenomenon  to  which 
attention  has  very  recently  been  directed  in  the  great  chain 
of  the  Himalaya,  that  three  or  four  individual  high  summits 
are  so  arranged  together,  that  the  small  axes  of  these  partial 
series  form  an  oblique  angle  with  the  primary  axis  of  the 
chain.  This  phenomenon  of  fissure,  which  has  been  observed 
and  partially  described b8  by  Hodgson,  Joseph  Hooker,  and 
Strachey,  is  of  great  interest.  The  small  axes  of  the  subsi- 
diary fissures  meet  the  great  axis,  sometimes  almost  at  a 
right  angle,  and  even  in  volcanic  chains,  the  actual  maxima 
of  elevation  are  often  situated  at  some  distance  from  the 
major  axis.  As  in  most  linear  volcanoes,  no  definite  pro- 
portion is  observed  in  Java,  between  the  elevation  and  the 
size  of  the  crater  at  the  summit.  The  two  largest  craters 
are  those  of  Gunung  Tengger  and  Gunung  Raon.  The  former 
of  these  is  a  mountain  of  the  third  class,  only  8704  feet  in 
height.  Its  circular  crater  is,  however,  more  than  21,315  feet, 
and  therefore  nearly  four  geographical  miles  in  diameter. 
The  flat  bottom  of  the  crater  is  a  sea  of  sand,  the  surface  of 
which  lies  1865  feet  below  the  highest  point  of  the  surrounding 
wall,  and  in  which  scoriaceous  lava-masses  project  here  and 
there  from  the  layer  of  pounded  rapilli.  Even  the  enormous 
crater  of  Kirauea,  in  Owhyhee,  which  is  filled  with  glowing 
lava,  does  not,  according  to  the  accurate  trigonometrical 
survey  of  Captain  Wilkes,  and  the  excellent  observations 
of  Dana,  attain  the  size  of  that  of  Gunung  Tengger.  In  the 
middle  of  the  crater  of  the  latter  there  rise  four  small  cones 
of  eruption,  actual  circumvallated  funnel-shaped  chasms,  of 
which  only  one,  Bromo  (the  mythical  name  Brahma,  a  word 
which  has  the  signification  of  fire,  in  the  Kawi  although 

87  Junghuhn,  Java,  Bd.  i.  s.  80. 

83  See  Joseph  Hooker,  Sketch-Map  of  SiJchim,  1850,  and  in  his 
Himalayan  Journals,  vol.  i,  1854,  Map  of  part  of  Bengal;  and  also 
Strachey,  Map  of  West-Nari,  in  his  Physical  Geography  of  Western 
Tibet,  1853. 


302  COSMOS. 

not  in  the  Sanscrit),  is  now  not  active.  Bromo  presents  the 
remarkable  phenomenon  that  from  1838  to  1842  a  lake  was 
formed  in  its  funnel,  of  which  Junghuhn  has  proved  that 
it  owes  its  origin  to  the  influx  of  atmospheric  waters,  which 
have  been  heated  and  acidulated  by  the  simultaneous  pene- 
tration of  sulphurous  vapours.89  Next  to  Gunung  Tengger, 
Gunung  Raon  has  the  largest  crater,  but  the  diameter  of 
this  is  about  one-half  less.  The  view  into  the  interior  is 
awe-inspiring.  It  appears  to  extend  to  a  depth  of  more 
than  2398  feet;  and  yet  the  remarkable  volcano,  10,178  feet 
in  height,  which  Junghuhn  has  ascended  and  so  carefully 
described,90  is  not  even  named  on  the  meritorious  map  of 
Raffles. 

Like  almost  all  linear  volcanoes,  the  volcanoes  of  Java 
exhibit  the  important  phenomenon,  that  a  simultaneity  of 
great  eruptions  is  observed  much  more  rarely  in  nearly  ap- 
proximated cones,  than  in  those  which  are  widely  separated. 
When,  in  the  night  of  the  llth  and  12th  of  August,  1772, 
the  volcano  Gunung  Pepandajan  (7034  feet)  burst  forth  the 
most  destructive  eruption  that  has  taken  place  upon  the 
island  within  historical  periods,  two  other  volcanoes,  the 
Gunung  Tjerimai  and  Gunung  Slamat,  became  ignited  on  the 
same  night,  although  they  lie  in  a  straight  line  at  a  distance 
of  J  34  and  352  miles  from  Pepandajan.91  Even  if  the  vol- 
can«res  of  a  series  all  stand  over  one  focus,  the  net  of  fissures 
through  which  they  communicate  is,  nevertheless,  certainly 
BO  constituted  that  the  obstruction  of  old  vapour-channels, 

89  Junghuhn,  Java,  Bd.  ii,  fig.  ix.  s.  572,  596,  and  601—604.    From 
1829  to  1848,  the  small  crater  of  eruption  of  the  Bromo  had  eight  fiery 
eruptions.     The  crater-lake,  which  had  disappeared  in  1842,  had  been 
again  formed  in  1848,  but  according  to  the  observations  of   B.  van 
Herwerden,  the  presence  of  the  water  in  the  chasm  of  the  cauldron 
had  no  effect  in  preventing  the  eruption  of  red-hot,  widely-scattered 
scoriae. 

90  Junghuhn,  Bd.  ii.  s.  624—641. 

91  The   G.  Pepandajan   was  ascended  in  1819  by  Reinwardt,  and  in 
1837  by  Junghuhn.     The  latter,  who  has  accurately  investigated  the 
vicinity  of  the  mountain,  consisting  of   detritus  intermingled   with 
numerous  angular,  erupted  blocks  of  lava,  and  compared  it  with  the 
earliest  reports,  regards  the  statement,  which  has  been  disseminated 
by  so  many  valuable  works,  that  a  portion  of  the  mountain  and  an 
area  of  several  square  miles   sank   during  the  eruption  of  1772,  as 
greatly  exaggerated  (Junghuhn,  Bd.  ii.  s.  98  and  100). 


TRUE   VOLCANOES.  303 

or  the  temporary  opening  of  new  ones,  in  the  course  of 
ages,  render  simultaneous  eruption  at  very  distant  points 
quite  conceivable.  I  may  again  advert  to  the  sudden  dis- 
appearance of  the  column  of  smoke  which  ascended  from 
the  volcano  of  Pasto,  when,  on  the  morning  of  the  4th  of 
February,  1797,  the  fearful  earthquake  of  Riobamba  con- 
vulsed the  plateau  of  Quito  between  Tunguragua  and  Coto- 
paxi.*8 

To  the  volcanoes  of  the  island  of  Java  generally,  a  cha- 
racter of  ribbed  formation  is  ascribed,  to  which  I  have  seen 
nothing  similar  in  the  Canary  Islands,  in  Mexico,  or  in  the 
Cordilleras  of  Quito.  The  most  recent  traveller,  to  whom 
we  are  indebted  for  such  admirable  observations  upon  the 
structure  of  the  volcanoes,  the  geography  of  plants,  and  the 
psychrometric  conditions  of  moisture,  has  described  the 
phenomenon  to  which  I  here  allude  with  such  decided  clear- 
ness that  I  must  not  omit  to  call  attention  to  this  regularity 
of-  form,  in  order  to  furnish  an  inducement  to  new  investi- 
gations. "  Although,"  says  Junghuhii,  "  the  surface  of  a  vol- 
cano 10,974  feet  in  height,  the  Gunung  Sumbing,  when  seen 
from  some  distance,  appears  as  an  uninterruptedly  smooth  and 
sloping  fkce  of  the  conical  mountain,  still,  on  a  closer  examina- 
tion, we  find  that  it  consists  entirely  of  separate  longitudinal 
ridges  or  ribs,  which  gradually  subdivide  and  become  broader 
as  they  advance  downwards  They  run  from  the  summit  of 
the  volcano,  or  more  frequently  from  an  elevation  several 
hundred  feet  below  the  summit,  down  to  the  foot  of  the 
mountain,  diverging  like  the  ribs  of  an  umbrella."  These 
rib-like  longitudinal  ridges  have  sometimes  a  tortuous  course 
for  a  short  distance,  but  are  all  formed  by  approximated 
clefts  of  three  or  four  hundred  feet  in  depth,  all  directed  in 
the  same  way,  and  becoming  broader  as  they  descend.  They 
are  furrows  of  the  surface  "  which  occur  on  the  lateral  slopes 
of  all  the  volcanoes  of  the  island  of  Java,  but  differ  consi- 
derably from  each  other  upon  the  various  conical  mountains, 
in  their  average  depth  and  the  distance  of  their  upper 
origin  from  the  margin  of  the  crater  or  from  an  unopened 
summit.  The  Gummg  Sumbing  (11,029  feet)  is  one  of  those 
volcanoes  which  exhibit  the  finest  and  most  regularly  formed 

92  Cosmos,  vol.  v,  p.  183,  and  Voyage  aux  Regions  Equinox,  t.  ii, 
p.  16. 


304  COSMOS. 

ribs,  as  the  mountain  is  bare  of  forest  trees  and  clothed  with 
grass."  According  to  the  measurements  given  by  Jung- 
huhn,93  the  number  of  ribs  increases  by  division  in  propor- 
tion as  the  declivity  decreases.  Above  the  zone  of  9000  feet 
there  are,  on  Gunung  Sumbing,  only  about  10  such  ribs  ;  at 
an  elevation  of  8,500  feet  there  are  32  ;  at  5500  feet,  72  ;  and 
at  3,000  feet,  more  than  95.  The  angle  of  inclination  at  the 
same  time  diminishes  from  37°  to  25°  and  10|°.  The  ribs 
are  almost  equally  regular  on  the  volcano  Gunung  Tengger 
(8702  feet),  whilst  on  the  Gunung  Ringgit  they  have  been 
disturbed  and  covered94  by  the  destructive  eruptions  which 
followed  the  year  1586.  The  production  of  these  peculiar 
longitudinal  ribs  and  the  mountain  fissures  lying  between 
them,  of  which  drawings  are  given,  is  ascribed  to "  erosion 
by  streams." 

It  is  certain  thac  the  mass  of  meteoric  water  in  this  tro- 
pical region  is  three  or  four  times  greater  than  in  the  tem- 
perate zone,  indeed  the  showers  are  often  like  waterspouts, 
for  although,  on  the  whole,  the  moisture  diminishes  with  the 
elevation  of  the  strata  of  air,  the  great  mountain  cones  exert 
on  the  other  hand  a  peculiar  attraction  upon  the  clouds, 
and,  as  I  have  already  remarked,  in  other  places,  volcanic 
eruptions  are  in  their  nature  productive  of  storms.  The 
clefts  and  valleys  (Barrancos),  in  the  volcanoes  of  the  Canary- 
Islands,  and  in  the  Cordilleras  of  South  America,  which  have 
become  of  importance  to  the  traveller  from  the  frequent 
descriptions  given  by  Leopold  von  Buch95  and  myself,  because 
they  open  up  to  him  the  interior  of  the  mountain,  and  some- 
times even  conduct  him  up  to  the  vicinity  of  the  highest 
summits,  and  to  the  circumvallation  of  a  crater  of  elevation, 
exhibit  analogous  phenomena ;  but  although  these  also  at 
times  carry  off  the  accumulated  meteoric  waters,  the  original 
formation  of  the  barrancas96  upon  the  slopes  of  the  volcanoes 

93  Junghuhn,  Bd.  ii.  s.  241 — 246. 

94  Op.  cit.  sup.  s.  566,  590  and  607—609. 

95  Leopold  von  Buch,  Phys.  Besckr.  der  Canariscken  Inseln,  a.  206. 
218,  248,  and  289. 

96  Barranco  and  Barranca,  both  of  the  same  meaning,  and  suffi- 
ciently in  use  in  Spanish  America,  certainly  indicate  properly  a  water- 
furrow  or  water-cleft :  la  quiebra  que  haceu  en  la  tierra  las  corrientea 
delas  aguas ; — "uua  torrente  que  hace  barrancas;"  but  they  also  indi- 


TRUE  VOLCANOES.  305 

is  probably  not  to  be  ascribed  to  these.  Fissures,  caused 
by  folding  in  the  trachytic  mass,  which  has  been  elevated 
whilst  soft  and  only  subsequently  hardened,  have  probably 
preceded  all  actions  of  erosion  and  the  impulse  of  water. 
But  in  those  places  where  deep  barrancos  appeared  in  the 
volcanic  districts  visited  by  me  on  the  declivities  of  bell 
shaped  or  conical  mountains  (en  lasfaldas  de  los  Cerros  bar- 
rancosos),  no  trace  was  to  be  detected  of  the  regularity,  or 
radiate  ramification  with  which  we  are  made  acquainted  by 
Junghuhn's  works  in  the  singular  outlines  of  the  volcanoes 
of  Java.97  The  greatest  analogy  with  the  form  here  re- 
ferred to  is  presented  by  the  phenomenon  to  which  Leopold 
von  Buch,  and  the  acute  observer  of  volcanoes,  Poulet 
Scrope,  have  already  directed  attention,  namely,  that  great 
fissures  almost  always  open  at  a  right  or  obtuse  angle  from 
the  centre  of  the  mountain,  radiating  (although  undivided), 
in  accordance  with  the  normal  direction  of  the  declivities, 
but  not  transversely  to  them. 

The  belief  in  the  complete  absence  of  lava-streams  upon 
the  island  of  Java,98  to  which  Leopold  von  Buch  appeared  to 

cate  any  chasm.  But  that  the  word  barranca  is  connected  with  barro, 
clay,  soft,  moist  loam,  and  also  road-scrapings,  is  doubtful. 

97  Lyell,  Manual  of  Elementary  Geology,  1855,  chap,  xxix,  p.  497. 
The  most  remarkable  analogy  with  the  phenomenon  of  regular  rib- 
bing in  Java,  is  presented  by  the  surface  of  the  Mantle  of  the  Somma 
of  Vesuvius,  upon  the  seventy  folds  of  which,  an  acute  and  accurate 
observer,  the  astronomer  Julius  Schmidt,  has  thrown  mv  Jo.  light  (Die 
Eruption  des  Vesuvs  im  Mai,  1855,  s.  101  — 109).  According  to 
Leopold  von  Buch,  these  valley-furrows  are  not  originally  rain-fur- 
rows (fiumare),  but  consequences  of  cracking  (folding,  etoilement)  dur- 
ing the  first  upheaval  of  the  volcano.  The  usually  radial  position 
of  the  lateral  eruptions  in  relation  to  the  axis  of  the  volcano,  also 
appears  to  be  connected  therewith  (s.  129). 

93  "  Obsidian,  and  consequently  pumice-stones,  are  as  rare  in  Java 
as  trachyte  itself.  Another  very  curious  fact  is  the  absence  of  any 
stream  of  lava  in  that  volcanic  island.  M.  Reinwardt,  who  has  him- 
self observed  a  great  number  of  eruptions,  says  expressly  that 
there  havn  never  been  instances  of  the  most  violent  and  destructive 
eruption  having  been  accompanied  by  lavas." — Leopold  de  Buch, 
Descr.  des  lies  Canaries,  p.  419.  Amongst  the  volcanic  rocks  of  Java, 
for  which  the  Cabinet  of  Minerals  at  Berlin  is  indebted  to  Dr.  Juug- 
huhn,  dioritic-trachytes  are  most  distinctly  recognizable  at  Burung- 
agung,  s.  255  of  the  Leidner  catalogue,  at  Tjinas,  s.  232,  and  in  the 
Gunung  Parang,  situated  in  the  district  Batu-gaugi.  This  is  couse- 
VOL.  V.  X 


306  COSMOS. 

incline  in  consequence  of  the  observations  of  Beinwardt,  has 
been  rendered  more  than  doubtful  by  recent  observations. 
Junghuhn,  indeed,  remarks  "  that  the  vast  volcano  Gunung 
Merapi  has  not  poured  forth  coherent,  compact  lava-streams 
within  the  historical  period  of  its  eruptions,  but  has  only 
thrown  out  fragments  of  lava  (rubbish),  or  incoherent  blocks 
of  stone,  although  for  nine  months,  in  the  year  1837,  fiery 
streams  were  seen  at  night  running  down  the  cone  of 
eruption."99  But  the  same  observant  traveller  has  distinctly 

quently  the  identical  formation  of  dioritic-trachyte  of  the  volcanoes 
of  Orizaba  and  Toluca  in  Mexico,  of  the  island  Panaria  in  the  Lipari 
Islands,  and  of  JEgina  in  the  JSgean  Sea  ! 

99  Junghuhn,  Bd.  ii.  s.  309  and  314.  The  fiery  streaks  which  were 
seen  on  the  volcano  G.  Merapi,  were  formed  by  closely  approximated 
streams  of  scoriae  (trainees  de  fragmens),  by  non-coherent  masses, 
which  roll  down  during  the  eruption  towards  the  same  side,  and  strike 
against  each  other  from  their  very  different  weights  on  the  steep 
declivity.  In  the  eruption  of  the  G.  Lamongau  on  the  26th  March, 
1847,  a  moving  line  of  scoriae  of  this  kind  divided  into  two  branches 
several  hundred  feet  below  its  point  of  origin.  "  The  fiery  streak," 
we  find  it  expressly  stated  (Bd.  ii.  s.  767),  "  did  not  consist  of  true 
fused  lava,  but  of  fragments  of  lava  rolling  closely  after  one  another." 
The  G.  Lamongan  and  the  G.  Semeru  are  the  two  volcanoes  of  the 
island  of  Java,  which  are  found  to  be  most  similar,  by  their  activity 
in  long  periods,  to  the  Stromboli,  which  is  only  about  2980  feet 
high,  as  they,  although  so  remarkably  different  in  height  (the  Lamon- 
gan being  5340  and  the  Semeru  12,235  feet  high),  exhibited  eruptions 
of  scoriae,  the  former  after  pauses  of  15  to  20  minutes  (eruptions  of 
July,  1838,  and  March,  1847),  and  the  second  of  1£  to  3  hours 
(eruptions  of  August,  1836,  and  September,  1844,)  (Bd.  ii.  s.  554  and 
765 — 769).  At  Stromboli  itself,  together  with  numerous  eruptions  of 
scoriae,  small,  but  rare  effusions  of  lava  also  occur,  which,  when 
detained  by  obstacles,  sometimes  harden  on  the  declivities  of  the 
cone.  I  lay  great  stress  upon  the  various  forms  of  continuity  or 
division,  under  which  completely  or  partially  fused  matters  are  thrown 
or  poured  out,  whether  from  the  same  or  different  volcanoes.  Ana- 
logous investigations,  undertaken  under  various  zones,  and  in  accord- 
ance with  guiding  ideas,  are  greatly  to  be  desired,  from  the  poverty 
and  great  one-sidedness  of  the  views,  to  which  the  four  active  Euro- 
pean volcanoes  lead.  The  question  raised  by  me  in  1802  and  by  my 
friend  Boussingault  in  1831, — whether  the  Antisana  in  the  Cordilleras 
of  Quito  has  furnished  lava-streams?  which  we  shall  touch  upon 
hereafter,  may  perhaps  find  its  solution  in  the  division  of  the  fluid 
matter.  The  essential  character  of  a  lava-stream  is  that  of  a  uniform, 
coherent  fluid, — a  band-like  stream,  from  the  surface  of  which  scales 
separate  during  its  cooling  and  hardening.  These  scales,  beneath 
which  the  nearly  homogeneous  lava  long  continues  to  flow,  upraise 


TRUE   VOLCANOES.  307 

described,  in  great  detail,  three  black,  basaltic  lava-streams 
on  three  volcanoes  : — Gunung  Tengger,  Gunung  Idjen,  and 
Slamat.100  On  the  latter  the  lava-stream,  after  giving  rise  to 
a  water-fall,  is  continued  into  the  tertiary  rocks.1  From  such 
true  effusions  of  lava,  which,  form  coherent  masses,  Junghuhn 
very  accurately  distinguishes,  in  the  eruption  of  Gunung 
Lamongan,2  on  the  6th  July,  1838,  what  he  calls  a  stone- 
stream,  consisting  of  glowing  and  usually  angular  fragments, 
erupted  in  a  row.  "  The  crash  was  heard  of  the  breaking 
stones,  which  rolled  down,  like  fiery  points,  either  in  a  line 
or  without  any  order."  1  purposely  direct  especial  attention 
to  the  very  various  modes  in  which  fiery  masses  appear  on 
the  slopes  of  a  volcano,  because  in  the  dispute  upon  the 
maximum  angle  of  fall  of  lava-streams,  glowing  streams  of 
stones  (masses  of  scoriae)  following  each  other  in  rows,  are 
sometimes  confounded  with  continuous  lava-streams. 

As  the  important  problem  of  the  rarity  or  complete  defici- 
ency of  lava-streams  in  Java, — a  problem  which  touches  on  the 

themselves  in  part,  obliquely  or  perpendicularly,  by  the  inequality  of 
the  internal  movement  and  the  evolution  of  hot  gases ;  and  when, 
in  this  way,  several  lava-streams,  flowing  together,  form  a  lava  lake, 
as  in  Iceland,  a  field  of  detritus  or  fragments  is  produced  on  their 
cooling.  The  Spaniards,  especially  in  Mexico,  call  such  a  district, 
which  is  very  disagreeable  to  pass  over,  a  malpais.  Such  lava-fields, 
which  are  often  found  in  the  plain  at  the  foot  of  a  volcano,  remind 
one  of  the  frozen  surface  of  a  lake,  with  short,  upraised  ice-blocks. 

100  The  name  G.  Idjen,  according  to  Buschmann,  may  be  explained 
by  the  Javanese  word  hidjdn,  singly,  alone,  separately  : — a  derivative 
from  the  substantive  hidji  or  widji,  grain,  seed,  which  with  sa  ex- 
presses the  number  one.  With  regard  to  the  etymology  of  G. 
Tengger,  see  the  important  work  of  my  brother  upon  the  connections 
between  Java  and  India  (Kawi-Sprache,  Bd.  i,  s.  188\  where  there 
is  a  reference  to  the  historical  importance  of  the  Tengger  Mountain, 
which  is  inhabited  by  a  small  tribe  of  people,  who,  opposed  to  the 
now  general  Mahomedanism  of  the  island,  have  retained  their  ancient 
Indo-Javanic  faith.  Junghuhn,  who  has  very  industriously  explained 
the  names  of  mountains  from  the  Kawi  language  says  (Th.  ii.  s.  554), 
that  in  the  Kawi,  Tengger  signifies  hill ;  the  word  also  receives  the 
same  signification  in  Gericke's  Javanese  Dictionary  (Javaansch-neder- 
duitsch  Woordenboek.  Amst.,  1847).  Slamat,  the  name  of  the  high 
volcano  of  Tegal,  is  the  well-known  Arabic  word  selamat,  which  sig- 
nifies happiness  and  safety. 

1  Junghuhn,  Bd.  ii.  Slamat,  8.  153  and  163  ;  Idjen,  ».  C98;  Tengger, 
a.  773. 

2  Bd.  ii.  s.  760—762. 

x  2 


308  COSMOS. 

internal  constitution  of  volcanoes,  and,  which  I  must  add,  has 
not  been  treated  with  sufficient  earnestness,  has  recently  been 
so  often  spoken  of.  the  present  appears  a  fitting  place  in  which 
to  bring  it  under  a  more  general  point  of  view.  Although 
it  is1  very  probable  that,  in  a  group  or  series  of  volcanoes  all 
the  members  stand  in  a  certain  common  relation  to  the 
general  focus,  the  molten  interior  of  the  earth,  still  each 
individual  presents  peculiar  physical  and  chemical  processes 
as  regards  strength  and  frequency  of  activity,  degree  and 
form  of  fluidity,  and  material  difference  of  products, — pecu- 
liarities which  cannot  be  explained  by  the  comparison  of  the 
form,  and  elevation  above  the  present  surface  of  the  sea. 
The  gigantic  mountain,  Sangay,  is  as  uninterruptedly 
active  as  the  lowly  Stromboli ;  of  two  neighbouring  vol- 
canoes, one  throws  out  pumice-stone  without  obsidian,  the 
other  both  at  once  ;  one  furnishes  only  loose  cinders,  the 
other  lava  flowing  in  narrow  streams.  These  characteristic 
processes,  moreover,  in  many  volcanoes  appear  not  to  have 
been  always  the  same  at  various  epochs  of  their  activity. 
To  neither  of  the  two  continents  is  rarity  or  total  absence  of 
lava  streams  to  be  peculiarly  ascribed.  Remarkable  distinc- 
tions only  occur  in  those  groups  with  regard  to  which  we 
must  confine  ourselves  to  definite  historical  periods  near  to 
our  own  times.  The  non-detection  of  single  lava-streams 
depends  simultaneously  upon  many  conditions.  Amongst 
these  we  may  instance  the  deposition  of  vast  layers  of  tufa, 
rapilli,  and  pumice-stone  ;  the  simultaneous  and  non-simul- 
taneous confluence  of  several  streams,  forming  a  widely  ex- 
tended lava-field  covered  with  detritus ;  the  circumstance  that 
in  a  wide  plain  the  small  conical  eruptive-cones,  the  volcanic 

Elatform,  as  it  were,  from  which,  as  at  Lancerote,  the  lava 
ad  flowed  forth  in  streams,  have  long  since  been  destroyed. 
In  the  most  ancient  conditions  of  our  unequally  cooling  planet, 
in  the  earliest  foldings  of  its  surface,  it  appears  to  me  very  pro- 
bable that  a  frequent  viscid  outflow  of  trachytic  and  doleritic 
rocks,  of  masses  of  pumice-stone  or  perlite,  containing  obsi- 
dian took  place  from  a  composite  network  of  fissures,  over 
which  no  platform  has  ever  been  elevated  or  built  up.  The 
problem  of  such  simple  effusions  from  fissures  deserves  the 
attention  of  geologists. 

In  the  series  of  Mexican  volcanoes,  the  greatest  and,  since 


TRUE   VOLCANOES.  309 

my  American  travels,  the  most  celebrated  phenomenon  is 
the  elevation  of  the  newly  produced  Jorullo,  and  its  effusion 
of  lava.  This  volcano,  the  topography  of  which,  founded 
on  measurements,  I  was  the  first  to  make  known3,  by  its 
position  between  the  two  volcanoes  of  Toluca  and  Colima, 
and  by  its  eruption  on  the  great  fissure  of  volcanic  activity*, 
which  extends  from  the  Atlantic  Ocean  to  the  Pacific,  pre- 
sents an  important  geognostic  phenomenon,  which  has  con- 
sequently been  all  the  more  the  subject  of  dispute.  Fol- 
lowing the  vast  lava-stream  which  the  new  volcano  poured 
out,  I  succeeded  in  getting  far  into  the  interior  of  the 
crater,  and  in  establishing  instruments  there.  The  eruption 
in  a  broad  and  long-peaceful  plain  in  the  former  province  of 
Michuacan,  in  the  ni<jht  from  the  28th  to  the  29th  of  Sep- 
tember, 1759,  at  a  distance  of  more  than  120  miles  from 
any  other  volcano,  was  preceded  for  fully  two  (?)  months, 
namely,  from  the  29th  June  in  the  same  year,  by  an  unin- 
terrupted subterranean  noise.  This  differed  from  the  won- 
derful bramidos  of  Guanaxuato,  which  I  have  elsewhere 
described5  by  the  circumstance  that  it  was,  as  is  usually 
the  case,  accompanied  by  earthquakes,  which  were  not 
felt  in  the  mountain  city  in  January,  1784.  The  erup- 
tion of  the  new  volcano,  about  3  o'clock  in  the  morning, 
was  foretold  the  day  before  by  a  phenomenon  which,  in 
other  eruptions,  does  not  indicate  their  commencement  but 
their  conclusion.  At  the  point  where  the  great  volcano  now 
stands,  there  was  formerly  a  thick  wood  of  the  Guayava 
(Psidium  pyriferum),  so  much  valued  by  the  natives  on  ac- 
count of  its  excellent  fruit.  Labourers  from  the  sugar-cane 
fields  (cafiaverales)  of  the  Hacienda  de  San  Pedro  Jorullo, 
belonging  to  the  rich  Don  Andres  Pimentel,  who  was  then 
living  in  Mexico,  had  gone  out  to  collect  the  fruit  of  the 
guayava.  When  they  returned  to  the  farm  (hacienda)  it 
was  remarked  with  astonishment  that  their  large  straw  hats 
were  covered  with  volcanic  ashes.  .Fissures  had,  conse- 
quently, already  opened  in  what  is  now  called  the  Malpais, 
probably  at  the  foot  of  the  high  basaltic  dome  el  Cuiche. 

3  Atlas  Gfeographique  et  Physique,  accompanying  the  Relation  His- 
torique,  1814,  pi.  28  and  29. 

4  Cosmos,  vol.  v.  pp.  279 — 280. 

*  Cosmos,  vol.  i.  p.  205,  and  vol.  v.  p.  179. 


310  COSMOS. 

which  threw  out  these  ashes  (rapilli)  before  any  change 
appears  to  have  occurred  in  the  plain.  From  a  letter  of 
Father  Joaquin  de  Ansogorri,  discovered  in  the  Episcopal 
archives  of  Valladolid,  which  was  written  three  weeks  after 
the  day  of  the  first  eruption,  it  appears  evident  that  Father 
Isidro  Molina,  sent  from  the  neighbouring  Jesuits'  College 
of  Patzcuaro  "  to  give  spiritual  comfort  to  the  inhabitants 
of  the  Playas  de  Jorullo,  who  were  extremely  disquieted  by 
the  subterranean  noise  and  earthquakes,"  was  the  first  to 
perceive  the  increasing  danger,  and  thus  caused  the  preser- 
vation of  the  small  population. 

In  the  first  hours  of  the  night  the  black  ashes  already  lay 
a  foot  deep  ;  every  one  fled  towards  the  hill  of  Aguasarco, 
a  small  Indian  village,  situated  2409  feet  higher  than  the 
old  plain  of  Jorullo.  From  this  height  (so  runs  the  tra- 
dition) a  large  tract  of  land  was  seen  in  a  state  of  fearful 
fiery  eruption,  and  "  in  the  midst  of  the  flames  (as  those 
who  witnessed  the  ascent  of  the  mountain  expressed  them- 
selves) there  appeared,  like  a  black  castle  (castillo  negro),  a 
great,  shapeless  mass  (bulto  grande)".  From  the  small  po- 
pulation of  the  district  (the  cultivation  of  indigo  and  cotton 
was  then  but  very  little  carried  on)  even  the  force  of  long- 
continued  earthquakes  cost  no  human  lives,  although,  as 
I  learn  from  manuscript  records6,  houses  were  over- 

6  In  my  JEssai  Politique  sur  la  Nouvelle-Espagne,  in  the  two  editions 
of  1811  and  1827  (in  the  latter,  t.  ii,  pp.  165 — 175),  I  have,  as  the  nature 
of  that  work  required,  only  given  a  condensed  abstract  from  my 
journal,  without  being  able  to  furnish  a  topographical  plan  of  the 
vicinity  or  a  chart  of  the  altitudes.  From  the  importance  which 
has  been  assigned  to  this  great  phenomenon  of  the  middle  of  the  last 
century,  I  have  thought  it  necessary  to  complete  this  abstract  here. 
I  am  indebted  for  particular  details  relating  to  the  new  volcano  of 
Jorullo  to  an  official  document,  written  three  weeks  after  the  day  of 
the  first  eruption,  but  only  discovered  in  the  year  1830  by  a  very 
scientific  Mexican  clergyman,  Don  Juan  Jose*  Pastor  Morales;  and 
also  to  oral  communications  from  my  companion,  the  Biscayan  Don 
Ramon  Espelde,  who  had  been  able  to  examine  living  eye-witnesses 
of  the  first  eruption.  Morales  discovered  in  the  Archives  of  the 
Bishop  of  Michuacan,  a  report  addressed  on  the  19th  of  October,  1759, 
by  Joaquin  de  Ansogorri,  Priest  in  the  Indian  village  la  Guacana,  to 
his  Bishop.  In  his  instructive  work  (Aufenthalt  undReisen  in  Mexico, 
1836)  Burkart  has  also  given  a  short  extract  from  it  (Bd.  i.  s.  230). 
At  the  time  of  my  journey,  Don  Ramon  Espelde  was  living  on  the 


TRUE   VOLCANOES.  311 

turned  by  them  near  the  copper  mines  of  Inguaran,  in  the 
small  town  of  Patzcuaro,  in  Santiago  de  Ario,  and  many 

plain  of  Jorullo,  and  has  the  merit  of  having  first  ascended  the 
summit  of  the  volcano.  Some  years  afterwards  he  attached  himself 
to  the  expedition  made  on  the  10th  March,  1789,  by  the  Intendente 
Corregidor,  Don  Juan  Antonio  de  Riano.  To  the  same  expedition 
belonged  a  well-informed  German,  Franz  Fischer,  who  had  entered  the 
Spanish  service  as  a  Mining  Commissary.  By  means  of  the  latter  the 
name  of  the  Jorullo  first  became  known  in  Germany,  as  he  mentioned 
\i  in  a  letter  in  the  Schriften  der  Gesellschaft  der  JBergbaukunde,  Bd.  ii., 
s.  441.  But  the  eruption  of  the  new  volcano  had  already  been  re- 
ferred to  in  Italy, — in  Clavigero's  Storia  antica  del  Messico  (Cesena, 
1780,  t.  i,  p.  42),  and  hi  the  poetical  work,  Rusticatio  Mexicana  of 
Father  Raphael  Landivar  (ed.  altera,  Bologna,  1782,  p.  17).  In  his 
valuable  work,  Clavigero  erroneously  places  the  production  of  the 
volcano,  which  he  writes  Juruyo,  in  the  year  1760,  and  enlarges  the 
description  of  the  eruption  by  accounts  of  the  shower  of  ashes,  ex- 
tending as  far  as  Queretaro,  which  had  been  communicated  to  him 
in  1766  by  Don  Juan  Manuel  de  Bustamente,  Governor  of  the  Pro- 
vince of  Valladolid  de  Michuacan,  as  an  eye-witness  of  the  pheno- 
menon. The  poet  Landivar,  an  enthusiastic  adherent,  like  Ovid,  of 
our  theory  of  upheaval,  makes  the  Colossus  rise,  in  euphonious  hexa- 
meters, to  the  full  height  of  3  milliaria,  and  finds  the  thermal  springs 
(after  the  fashion  of  the  ancients)  cold  by  day  and  warm  at  night. 
But  I  saw  the  thermometer  rise  to  126^°  in  the  water  of  the  Rio 
de  Cuitimba  about  noon. 

In  1789,  and  consequently  in  the  same  year  that  the  report  of  the 
Governor  Riano  and  the  Mining  Commissary  Franz  Fischer,  appeared  in 
the  Gazeta  de  Mexico,  in  the  fifth  part  of  his  large  and  useful  Diccionario 
geogrdfico-historico  de  las  Indias  Occidentals  6  America,  in  the  article 
Xurullo,  pp.  374 — 375)  Antonio  de  Alcedo  gave  the  interesting  infor- 
mation that,  when  the  earthquakes  commenced  (29th  June,  1759)  in 
the  Playas,  the  western  volcano  of  Colima,  which  was  in  eruption, 
suddenly  became  quiet,  although  it  is  at  a  distance  of  "  70  leguas"  (as 
Alcedo  says:  according  to  my  map  only  112  geog.  miles  !)  from  the 
Playas.  "  It  is  thought,"  he  adds,  "  that  the  materials  in  the 
bowels  of  the  earth  have  met  with  obstacles  to  their  following  their 
old  course ;  and  as  they  have  found  suitable  cavities  (to  the  east," 
they  have  broken  out  at  Jorullo — para  reventar  en  Xurullo). — 
Accurate  topographical  statements  regarding  the  neighbourhood  of 
the  volcano  occur  also  in  Juan  Jose"  Martinez  de  Lejarza's  geogra- 
phical sketch  of  the  ancient  Taraskian  country  :  A  ndlisis  estadistico 
de  la  provincia  de  Michuacan  en  1822  (Mexico,  1824),  pp.  125,  129, 
130,  and  131.  The  testimony  of  the  author,  living  at  Valladolid  in 
the  vicinity  of  Jorullo,  that,  since  my  residence  in  Mexico,  no  trace 
of  an  increased  activity  has  shown  itself  in  the  mountain  was  the 
earliest  contradiction  of  the  report  of  a  new  eruption  in  the  year 
1819  (Lyell,  Principles  of  Geology,  1855.  p.  430).  As  the  position  of 


512  COSMOS. 

miles  further,  but  not  beyond  San  Pedro  Churumucu.  In 
the  Hacienda  de  Jorullo,  during  the  general  nocturnal 
flight,  they  forgot  to  remove  a  deaf  and  dumb  negro  slave. 
A  mulatto  had  the  humanity  to  return  and  save  him, 
while  the  house  was  still  standing.  It  is  still  narrated 
that  he  was  found  kneeling,  with  a  consecrated  taper  in 
Jorullo  in  latitude  is  not  without  importance,  I  have  noticed  that 
Lejarza,  who  otherwise  always  follows  my  astronomical  determi- 
nations of  position,  and  who  gives  the  longitude  of  Jorullo  exactly 
like  myse.f  as  2°  25'  west  of  the  meridian  of  Mexico  (101°  29'  west 
of  Greenwich),  differs  from  me  in  the  latitude.  Is  the  latitude  attri- 
buted by  him  to  the  Jorullo  (18°  53'  30''),  which  comes  nearest  to 
that  of  the  volcano  of  Popocatepetl  (18°  59'  47"),  founded  upon  re- 
cent observations  unknown  to  me?  In  my  Recueil  d'Observ.  Astrono-. 
miques,  vol.  ii,  p.  521,  I  have  said  expressly,  "  Latitude  supposee,  19°  8', 
deduced  from  good  astronomical  observations  at  Valladolid,  which 
gave  19°  52'  8",  and  from  the  Itinerary  direction."  I  only  recognized 
the  importance  of  the  latitude  of  Jorullo,  when  subsequently  I  was 
drawing  up  the  great  map  of  Mexico  in  the  capital  city  and  inserting 
the  E. — W.  series  of  volcanoes. 

As  in  these  considerations  upon  the  origin  of  Jorullo,  I  have  repeat- 
edly mentioned  the  traditions  which  still  prevail  in  the  neighbourhood, 
I  will  conclude  this  long  note  by  referring  to  a  very  popular  tradition, 
which  I  have  already  touched  upon  in  another  work  (Essai  Politique 
sur  la  Nouvelle  Espagne,  t.  ii,  1827,  p.  172):—"  According  to  the  belief 
of  the  natives,  these  extraordinary  changes  which  we  have  just 
described,  are  the  work  of  the  monks,  the  greatest,  perhaps,  that  they 
have  produced  in  either  hemisphere.  At  the  Playas  de  Jorullo,  in 
the  hut  that  we  occupied,  our  Indian  host  told  us  that,  in  1759,  the 
Capuchins  belonging  to  the  mission  preached  at  the  station  or  San 
Pedro,  but  that,  not  having  been  favourably  received,  they  charged 
this  beautiful  and  fertile  plain,  with  the  most  horrible  and  compli- 
cated imprecations,  prophesying  that  first  of  all  the  house  would  be 
devoured  by  flames  which  would  issue  from  the  earth,  and  that  after- 
wards the  surrounding  air  would  become  cooled  to  such  a  degree  that 
the  neighbouring  mountains  wou^d  remain  eternally  covered  with 
snow  and  ice.  The  former  of  these  Maledictions  having  had  such  fatal 
consequences,  the  lower  class  of  Indians  already  see  in  the  gradual 
cooling  of  the  volcano,  the  presage  of  a  perpetual  winter." 

Next  to  that  of  the  poet,  Father  Landivar,  the  first  printed  account  of 
the  catastrophe  was  probably  that  already  mentioned  in  the  Gazeta  de 
Mexico  of  the  5th  May,  1789  (t.  iii,  Num.  30,  pp.  293—297) ;  it  bears 
the  modest  title,  Superficial  y  nada  facultativa  Description  del  estado 
en  que  se  hallaba  el  Volcdn  de  Jorullo  la  manana  del  dia  10  de  Marzo  de 
1789,  and  was  occasioned  by  the  expedition  of  Riano,  Franz  Fischer, 
and  Espelde.  Subsequently  (1791)  in  the  naval  astronomical  expedi- 
tion of  Malaspina,  the  botanists,  Mocino  and  Don  Martin  Sesse,  visited 
Jorullo,  from  the  Pacific  coast. 


TRUE   VOLCANOES.  313 

his  hand,  before  the  picture  of  Nuestra  Senora  de  Gua- 
dalupe. 

According  to  the  tradition,  widely  and  concordantly 
spread  amongst  the  natives,  the  eruption,  during  the  first 
days,  consisted  of  great  masses  of  rock,  scoriae,  sand,  and 
ashes,  but  always  combined  with  an  effusion  of  muddy  water. 
In  the  memorable  report,  already  mentioned,  of  the  19th 
of  October,  1759,  the  author  of  which  was  a  man  who, 
possessing  an  accurate  knowledge  of  the  locality,  describes 
what  had  only  just  taken  place,  it  is  expressly  said  :  Que 
espele  el  dicho  Volcan  arena,  ceniza  y  agua.  All  eye-witnesses 
relate  (I  translate  from  the  description  which  the  Inten- 
dant,  Colonel  Riano,  and  the  German  Mining  Commissary, 
Franz  Fischer,  who  had  passed  into  the  Spanish  service, 
have  given  of  the  condition  of  the  volcano  of  Jorullo  on 
the  10th  March,  1789),  "  that  before  the  terrible  mountain 
made  its  appearance  (antes  de  reventar  y  aparecerse  este 
terrible  Cerro),  the  earthquakes  and  subterranean  noises 
became  more  frequent ;  but  on  the  day  of  the  eruption 
itself  the  flat  soil  was  seen  to  rise  perpendicularly  (se  ob- 
servo,  que  el  plan  de  la  tierra  se  levantaba  perpendicular- 
mente),  and  the  whole  became  more  or  less  inflated,  so  that 
blisters  (vexigones)  appeared,  of  which  the  largest  is  now 
the  volcano  (de  los  que  el  mayor  es  hoy  el  Cerro  del  Vol- 
can). These  inflated  blisters,  of  very  various  sizes,  and 
partly  of  a  tolerably  regular,  conical  form,  subsequently 
burst  (estas  ampollas,  gruesas  vegigas  6  conos  diferente- 
mente  regulares  en  sus  figuras  y  tamanos,reventaron  despues), 
and  threw  boiling  hot  earthy  mud  from  their  orifices  (tierras 
hervidas  y  calientes),  as  well  as  scoriaceous  stony  masses  (pie- 
dras  cocidas  ?  y  fundidas),  which  are  still  found,  at  an 
immense  distance,  covered  with  black  stony  masses." 

These  historical  records,  which  we  might,  indeed,  wish  to 
see  more  complete,  agree  perfectly  with  what  I  learnt  from 
the  mouths  of  the  natives  14  years  after  the  ascent  of  An- 
tonio de  Riano.  To  the  questions,  whether  "the  castle 
mountain,"  was  seen  to  rise  gradually  for  months  or  years, 
or  whether  it  appeared  from  the  very  first  as  an  elevated 
peak,  no  answer  could  be  obtained.  Riano's  assertion  that 
further  eruptions  had  taken  place  in  the  first  16  or  17 
years,  and  therefore  up  to  1776,  was  declared  to  be  untrue. 


314  COSMOS. 

According  to  the  tradition,  the  phenomena  of  small  erup- 
tions of  water  and  mud  which  were  observed  during  the 
first  days  simultaneously  with  the  incandescent  scorias,  are 
ascribed  to  the  destruction  of  two  brooks,  which,  springing 
on  the  western  declivity  of  the  mountain  of  Santa  Ines,  and 
consequently  to  the  east  of  the  Cerro  de  Cuiche,  abundantly 
irrigated  the  cane-fields  of  the  former  Hacienda  de  San 
Pedro  de  Jorullo,  and  flowed  onwards  far  to  the  west  to  the 
Hacienda  de  la  Presentacion.  Near  their  origin,  the  point 
is  still  shown  where  they  disappeared  in  a  fissure  with  their 
formerly  cold  waters,  during  the  elevation  of  the  eastern 
border  of  the  Malpais.  Running  below  the  Hornitos,  they 
reappear,  according  to  the  general  opinion  of  the  people  of 
the  country,  heated,  in  two  thermal  springs.  As  the  ele- 
\  ated  part  of  the  Malpais  is  there  almost  perpendicular,  they 
form  two  small  waterfalls,  which  I  have  seen  and  represented 
in  my  drawing.  For  each  of  them  the  previous  name,  Rio 
de  San  Pedro  and  Rio  de  Cuitimba,  has  been  retained.  At 
this  point  I  found  the  temperature  of  the  steaming  water  to 
be  126°'8.  During  their  long  course  the  waters  are  only 
heated,  but  not  acidulated.  The  test  papers,  which  I  usually 
carried  about  with  me,  underwent  no  change ;  but  further 
on,  near  the  Hacienda  de  la  Presentacion,  towards  the 
Sierra  de  las  Canoas,  there  flows  a  spring  impregnated  with 
sulphuretted  hydrogen  gas,  which  forms  a  basin  of  20  feet 
in  breadth. 

In  order  to  acquire  a  clear  notion  of  the  complicated  outline 
and  general  form  of  the  surface  of  the  ground,  in  which  such 
remarkable  upheavals  have  taken  ^lace,  we  must  distinguish 
hypsometrically  and  morphologically  : — 1.  The  position  of 
the  volcanic  system  of  Jorullo  in  relation  to  the  average  level 
of  the  Mexican  plateau  ;  2.  The  convexity  of  the  Malpais, 
which  is  covered  by  thousands  of  hornitos  ;  3.  The  fissure 
upon  which  six  large,  volcanic,  mountain-masses  have  arisen. 

On  the  western  portion  of  the  Central  Cordillera  of  Mexico, 
which  strikes  from  S.S.E.  to  N.N.W.,  the  plain  of  the 
Playas  de  Jorullo,  at  an  elevation  of  only  2557  feet  above 
the  level  of  the  Pacific,  forms  one  of  the  horizontal  moun- 
tain terraces,  which,  everywhere  in  the  Cordilleras,  interrupt 
the  line  of  inclination  of  the  declivity,  and  consequently 
more  or  less  impede  the  decrease  of  heat  in  tho  superposed 


TRUE  VOLCANOES.  315 

strata  of  the  atmosphere.  On  descending  from  the  central 
plateau  of  Mexico  (whose  mean  elevation  is  7460  feet), 
to  the  corn-fields  of  Yalladolid  de  Michuacan,  to  the  charm- 
ing lake  of  Patzcuaro,  with  the  inhabited  islet  Janicho 
and  into  the  meadows  around  Santiago  de  Ario,  which 
Bonpland  and  I  found  adorned  with  the  dahlias  which  have 
since  become  so  well  known,  we  have  not  descended  more 
than  nine  hundred  or  a  thousand  feet.  But  in  parsing  from 
Ario  on  the  steep  declivity  over  Aguasarco  into  the  level  of 
the  old  plain  of  Jorullo,  we  diminish  the  absolute  elevation  in 
this  short  distance  by  from  a^O  to  4250  feet7.  The  roundish, 
convex  part  of  the  upheaved  plain  is  about  12,790  feet  in 
diameter,  so  that  its  area  is  more  than  seven  square  miles. 
The  true  volcano  of"  Jorullo  and  the  five  other  mountains 
which  rose  simultaneously  with  it  upon  the  same  fissure,  are 
so  situated  that  only  a  small  portion  of  the  Malpais  lies  to 
the  east  of  them.  Towards  the  west,  therefore,  the  number 
of  hornitos  is  much  larger,  and  when  in  early  morning  I 
issued  from  the  Indian  huts  of  the  Play  as  de  Jorullo,  or 
ascended  a  portion  of  the  Cerro  del  Mirador,  I  saw  the  black 
volcano  projecting  very  picturesquely  above  the  innumerable 
white  columns  of  smoke  of  the  "little  ovens"  (hornitos). 
Both  the  houses  of  the  Playas  and  the  basaltic  hill  Mira- 
dor are  situated  upon  the  level  of  the  old  non- volcanic,  or, 
to  speak  more  cautiously,  un-upheaved  soil.  Its  beautiful 
vegetation,  in  which  a  multitude  of  salvias  bloom  beneath 
the  shade  of  a  new  species  of  fan  palm  (CorypTia  pumos), 
and  of  a  new  alder  (Alnus  Jorullensis),  contrasts  with  the 
desert,  naked  aspect  of  the  Malpais.  The  comparison  of  the 
height  of  the  barometer8  at  the  point  where  the  upheaval 

"  My  barometric  measurements  give  for  Mexico  1168  toises  (7470 
feet),  Valladolid  1002  toises  (6409  feet),  Patzcuaro  1130  toises  (7227 
feet),  Ario  994  toises  (6358  feet),  Aguasarco  780  toises  (4^89  feet),  for 
the  old  plain  of  the  Playas  de  Jorullo  404  toises  (2584  fett)  (Humboldt, 
Observ.  Astron,  vol.  i,  p.  327,  Nivellement  Barometrique,  No.  366 — 370). 

8  If  the  old  plain  of  the  Playas  be  404  toises  (2584  feet),  I  find  for 
the  maximum  of  convexity  of  the  Malpais  above  the  sea-level  487 
toises  (3115  feet) ;  for  the  ridge  of  the  great  lava-strearn  600  toises 
(3838  feet);  for  the  highest  margin  of  the  crater  667  toises  (4266  feet): 
for  the  lowest  point  of  the  crater  at  which  we  could  establish  the 
barometer  644  toises  (4119  feet).  Consequently  the  elevation  of  the 
summit  of  Jorullo  above  the  old  plain  appeared  to  be  263  toises  or 
1682  feet. 


316  COSMOS. 

commences  in  the  Playas,  with  that  at  the  point  immediately 
at  the  foot  of  the  volcano,  gives  473  feet  of  relative  per- 
pendicular elevation.  The  house  that  we  inhabited  stood 
only  about  500  toises  (3197  feet)  from  the  border  of  the 
Malpais.  At  that  place  there  was  a  small  perpendicular  pre- 
cipice of  scarcely  12  feet  high,  from  which  the  heated  water 
of  the  brook  (Rio  de  San  Pedro)  falls  down.  The  portion 
of  the  inner  structure  of  the  soil  which  I  could  examine  at 
the  precipice,  showed  black,  horizontal,  loamy  strata,  mixed 
with  sand  (rapilli).  At  other  points  which  I  did  not  see, 
Burkart  has  observed  "on  the  perpendicular  boundary  of 
the  upheaved  soil,  where  the  ascent  of  this  is  difficult,  a  light 
gray  and  not  very  dense  (weathered)  basalt,  with  numerous 
grains  of  olivine."9  This  accurate  and  experienced  observer 
has,  however,10  like  myself,  on  the  spot,  conceived  the  idea  of 
a  vesicular  upheaval  of  the  surface  effected  by  elastic  va- 
pours, in  opposition  to  the  opinion  of  celebrated  geogno- 
sists11,  who  ascribe  the  convexity,  which  I  ascertained  by 
direct  measurement,  solely  to  the  greater  effusion  of  lava 
at  the  foot  of  the  volcano. 

The  many  thousand  small  eruptive  cones  (properly  rather 
of  a  roundish  or  somewhat  elongated,  oven-like  form)  which 
cover  the  upheaved  surface  pretty  uniformly,  are  on  the 
average  4  to  9  feet  in  height.  They  have  risen  almost  ex- 

9  Burkart,  Aufenthalt  und  Reisen  in  Mexico  in  den  JaJiren,  1825 — 
1834,  Bd.  i  (1836),  p.  227. 

10  Op.  tit.  sup.  Bd.  i,  pp.  227  and  230. 

11  Poulett  Scrope,  Considerations  on  Volcanoes,  p.  267;   Sir  Charles 
Lyell,  Principles  of  Geology,  1853,  p.  429;  Manual  of  Geolugy,  1855, 
p.  580  ;  Daubeny  on    Volcanoes,  p.  337.     See  also  "  on  the  elevation 
hypothesis,"  Dana,  Geology,  in  the  United  States  Exploring  Expedition, 
vol.  x,  p.  369.     Constant  Prevost,  in  the  Comptes  rendus,  t.  xli  (1855), 
pp.  866 — 876,  and  918 — 923  :  sur  les  eruptions  et  le  drapeau  de  I'infail- 
libilite."     See  also,  with  regard  to  Jorullo,  Carl  Pieschel's  instructive 
description  of  the  volcanoes  of  Mexico,  with  illustrations  by  Dr.  Gum- 
precht,  in  the  Zeitschrift  fur  Allg.  Erdkunde  of  the  Geographical  Society 
of  Berlin  (Bd.  vi,  s.  490 — 517);  and  the  newly  published  picturesque 
views   in   Pieschel's   Atlas  der  Vulkane  der  Republilc  Mexico,   1856, 
tab.  13,  14,  and  15.     The  Royal  Museum  of  Berlin,  in  the  department 
of  engravings  and  drawings,  possesses  a  splendid  and  numerous  col- 
lection of  representations  of  the  Mexican  volcanoes  (more  than  40 
sheets),  taken  from  nature  by  Moritz  Kugendas.     Of  the  most  western 
of  all  Mexican  volcanoes,  that  of  Colima  alone,  this  great  master  has 
furnished  fifteen  coloured  views. 


TRUE  VOLCANOES.  317 

clusively  on  the  western  side  of  the  great  volcano,  as  indeed, 
the  eastern  part  towards  the  Cerro  de  Cuiche,  scarcely  con- 
stitutes aV^  °f  the  entire  area  of  the  vesicular  elevation  of 
the  Playas.  Each  of  the  numerous  hornitos  is  composed  of 
weathered  basaltic  spheres,  with  fragments  separated  like 
concentric  shells  ;  I  was  frequently  able  to  count  from  24  to 
28  such  shells.  The  balls  are  flattened  into  a  somewhat 
spheroidal  form,  and  are  usually  15 — 18  inches  in  diameter, 
but  vary  from  1  to  3  feet.  The  black  basaltic  mass  is  pene- 
trated by  hot  vapours  and  broken  up  into  an  earthy  form, 
although  the  nucleus  is  of  greater  density,  whilst  the  shells, 
when  detached,  exhibit  yellow  spots  of  oxide  of  iron.  Even 
the  soft,  loamy  mass  which  unites  the  balls  is,  singularly 
enough,  divided  into  curved  lamellae,  which  wind  through 
all  the  interstices  of  the  balls.  At  the  first  glance  I  asked 
myself  whether  the  whole,  instead  of  weathered  basaltic 
spheroids,  containing  but  little  olivine,  did  not  perhaps  pre- 
sent masses  disturbed  in  the  course  of  their  formation.  But 
in  opposition  to  this  we  have  the  analogy  of  the  hills  of  glo- 
bular basalt,  mixed  with  layers  of  clay  and  marl,  which  are 
found,  often  of  very  small  dimensions,  in  the  central  chain  of 
Bohemia,  sometimes  isolated  and  sometimes  crowning  long 
basaltic  ridges  at  both  extremities.  Some  of  the  hornitos 
are  so  much  broken  up,  or  have  such  large  internal  cavities, 
that  mules  when  compelled  to  place  their  fore-feet  upon  the 
flatter  ones,  sink  in  deeply,  whilst  in  similar  experiments 
which  I  made,  the  hills  constructed  by  the  termites,  re- 
sisted. 

In  the  basaltic  mass  of  the  hornitos  I  found  no  immersed 
scoria?,  or  fragments  of  old  rocks  which  had  been  penetrated, 
AS  is  the  case  in  the  lavas  of  the  great  Jorullo.  The  appel- 
lation Hornos  or  Hornitos  is  especially  justified  by  the  cir- 
cumstance that  in  each  of  them  (I  speak  of  the  period  when 
I  travelled  over  the  Playas  de  Jorullo  and  wrote  my  journal, 
18  September,  1803,)  the  columns  of  smoke  break  out,  not 
from  the  summit,  but  laterally.  In  the  year  1780,  cigars 
might  still  be  lighted  when  they  were  fastened  to  a  stick 
and  pushed  in  to  a  depth  of  2  or  3  inches  ;  in  some  places 
the  air  was  at  that  time  so  much  heated  by  the  vicinity  of 
the  hornitos,  that  it  was  necessary  to  turn  away  from 
one's  proposed  course.  Notwithstanding  the  refrigeration 


318  COSMOS. 

which,  according  to  the  universal  testimony  of  the  Indians, 
the  district  had  undergone  within  20  years,  I  found  the 
temperature  in  the  fissures  of  the  hornitos  to  range  between 
199°  and  203°  ;  and  at  a  distance  of  twenty  feet  from  some 
hills,  the  temperature  of  the  air  was  still  108°'5  and  1160>2, 
at  a  point  where  no  vapours  reached  me ;  the  true  tem- 
perature of  the  atmosphere  of  the  Playas  being  at  the  same 
time  scarcely  77°.  The  weak  sulphuric  vapours  decolo- 
rized strips  of  test  paper,  and  rose  visibly,  for  some  hours 
after  sunrise,  to  a  height  of  fully  60  feet.  The  view  of 
the  columns  of  smoke  was  most  remarkable  early  in  a  cool 
morning.  Towards  midday,  and  even  after  11  o'clock,  they 
had  become  very  low  and  were  visible  only  from  their  imme- 
diate vicinity.  In  the  interior  of  many  of  the  hornitos  we 
heard  a  rushing  sound  like  the  fall  of  water.  The  small  ba- 
saltic hornitos  are,  as  already  remarked,  easily  destructible. 
When  Burkart  visited  the  Malpais,  24  years  after  me,  he 
found  that  none  of  the  hornitos  were  still  smoking ;  their 
temperature  being  in  most  cases  the  same  as  that  of  the 
surrounding  air,  while  many  of  them  had  lost  all  regularity 
of  form  by  heavy  rains  and  meteoric  influences.  Near  the 
principal  volcano  Burkart  found  small  cones,  which  were 
composed  of  a  brownish-red  conglomerate  of  rounded  or 
angular  fragments  of  lava,  and  only  loosely  coherent.  In 
the  midst  of  the  upheaved  area,  covered  with  hornitos,  there 
is  still  to  be  seen  a  remnant  of  the  old  elevation  on  which 
the  buildings  of  the  farm  of  San  Pedro  rested.  The  hill, 
which  I  have  indicated  in  my  plan,  forms  a  ridge  directed 
east  and  west,  and  its  preservation  at  the  foot  of  the  great 
volcano  is  most  astonishing.  Only  a  part  of  it  is  covered 
with  dense  sand  (burnt  rapilli).  The  projecting  basaltic 
rock,  grown  over  with  ancient  trunks  of  Ficus  indica  and 
Psidium,  is,  certainly,  like  that  of  the  Cerro  del  Mirador 
and  the  high  mountain  masses  which  bound  the  plain  to 
the  eastward,  to  be  regarded  as  having  existed  before  the 
catastrophe. 

It  remains  for  me  to  describe  the  vast  fissure  upon  which 
a  series  of  six  volcanoes  has  risen,  in  the  general  direction 
from  south-south-west  to  north-north-east.  The  partial 
direction  of  the  first  three,  less  elevated  volcanoes  situated 
most  southerly  is  S.W — N.E. ;  that  of  the  three  following 


TRUE   VOLCANOES.  319 

near  S. — N.  The  fissure  lias  consequently  been  curved, 
and  has  changed  its  strike  throughout  its  total  length 
of  10,871  feet.  The  direction  here  indicated  of  the  linear 
but  not  contiguous  mountains  is  certainly  nearly  at  right 
angles  with  the  line  upon  which,  according  to  my  observation, 
the  Mexican  volcanoes  follow  each  other  from  sea  to  sea. 
But  this  difference  is  the  less  surprising  if  we  consider  that 
a  great  geognostic  phenomenon  (the  relation  of  the  principal 
masses  to  each  other  across  a  continent)  is  not  to  be  con- 
founded with  the  local  conditions  and  direction  of  a  single 
group.  The  long  ridge  of  the  great  volcano  of  Pichincha 
also,  is  not  in  the  same  direction  as  the  series  of  volcanoes 
of  Quito ;  and  in  non- volcanic  chains,  for  example  in  the 
Himalaya,  the  culminating  points  are  often  situated,  as 
I  have  already  pointed  out,  at  a  distance  from  the  general 
line  of  elevation  of  the  chain.  They  are  situated  upon  par- 
tial snowy  ridges  which  even  form  nearly  a  right  angle  with 
this  general  line  of  upheaval. 

Of  the  six  volcanic  hills  which  have  risen  upon  the  above- 
mentioned  fissure,  the  first  three,  the  more  southern  ones, 
between  which  the  road  to  the  copper  mines  of  Inguaran 
passes,  appear,  in  their  present  condition,  to  be  of  least  im- 
portance. They  are  no  longer  open,  and  are  entirely  covered 
with  grayish  white,  volcanic  sand,  which  however  does  not 
consist  of  pumice-stone,  for  I  have  seen  nothing  either  of 
pumice  or  obsidian  in  this  region.  At  Jorullo  also,  as  at 
Vesuvius  according  to  the  assertion  of  Leopold  von  Buch  and 
Monticelli,  the  last  covering-fall  of  ashes  appears  to  have  been 
the  white  one.  The  fourth,  more  northern  mountain  is  the 
large,  true  volcano  of  Jorullo,  the  summit  of  which,  not- 
withstanding its  small  elevation  (4265  feet  above  the  sea 
level,  1151  feet  above  the  Malpais  at  the  foot  of  the  volcano, 
and  1681  feet  above  the  old  soil  of  the  Playas),  I  had 
some  difficulty  in  reaching,  when  I  ascended  it  with  Bon- 
pland  and  Carlos  Montufar  on  the  19th  September,  1803. 
We  thought  we  should  be  most  certain  of  getting  into  the 
crater,  which  was  still  filled  with  hot  sulphurous  vapours, 
by  ascending  the  steep  ridge  of  the  vast  lava-stream,  which 
burst  forth  from  the  very  summit.  The  course  passed  over  a 
crisp,  scoriaceous,  clear-sounding  lava,  swelled  up  in  a  coke- 
like,  or  rather  cauliflower-like  form.  Some  parts  of  it  have 


320  COSMOS. 

a  metallic  lustre  :  other,?  are  basaltic  and  full  of  small  gra- 
nules of  olivine.  When  we  had  thus  ascended  to  the  upper 
surface  of  the  lava-stream  at  a  perpendicular  elevation  of 
711  feet,  we  turned  to  the  white  ash  cone,  on  which,  from 
its  great  steepness,  we  could  not  but  fear  that  during  fre- 
quent and  rapid  slips  we  might  be  seriously  wounded  by  the 
rugged  lava.  The  upper  margin  of  the  crater,  on  the  south 
western  part  of  which  we  placed  the  instruments,  forms 
a  ring  of  a  few  feet  in  width.  We  carried  the  barometer 
from  the  margin  into  the  oval  crater  of  the  truncated  cone. 
At  an  open  fissure  air  streams  forth  of  a  temperature  of 
200°'6.  We  now  stood  149  feet  in  perpendicular  height 
below  the  margin  of  the  crater ;  and  the  deepest  point  of 
the  chasm,  the  attainment  of  which  we  were  compelled  to 
give  up  on  account  of  the  dense  sulphurous  vapours,  ap- 
peared to  be  only  about  twice  this  depth.  The  geognostic 
discovery  which  had  the  most  interest  for  us,  was  the  find- 
ing of  several  white  fragments,  three  or  four  inches  in  dia- 
meter, of  a  rock  rich  in  felspar  baked  into  the  black  basaltic 
lava.  I  regarded  these  at  first"  as  syenite,  but  from  the 

12  "  M.  Bonpland  and  myself  were  particularly  astonished  at  finding, 
encased  in  the  basaltic,  lithoid  and  scorified  lavas  of  the  volcano  of 
Jorullo,  white  or  greenish  white  angular  fragments  of  Syenite,  com- 
posed of  a  little  amphibole  and  a  great  quantity  of  lamellar  felspar. 
Where  these  masses  have  been  split  by  heat,  the  felspar  has  become 
filamentous,  so  that  the  margins  of  the  crack  are  united  in  some  places 
by  fibres  elongated  from  the  mass.  In  the  Cordilleras  of  South 
America,  between  Popayan  and  Almaguer,  at  the  foot  of  the  Cerro 
Broncoso,  I  have  found  actual  fragments  of  gneiss  encased  in  a  trachyte 
abounding  in  pyroxene.  These  phenomena  prove  that  the  trachytic 
formations  have  issued  from  beneath  the  granitic  crust  of  the  globe. 
Analogous  phenomena  are  presented  by  the  trachytes  of  the  Siebenge- 
Mrge  on  the  banks  of  the  Khine,  and  by  the  inferior  strata  of  Phono- 
lite  (Porphyrschiefer)  of  the  Biliner  Stein  in  Bohemia."  (Humboldt, 
Essai  Geognostique  sur  le  Gisement  des  Roches,  1823,  pp.  133  and  339. 
Burkart  also  (Aufenthalt  und  Reisen  in  Mexico,  Bd.  i,  s.  230)  detected 
enclosed  in  the  black  lava,  abounding  in  olivine,  of  Jorullo  :  "  Blocks 
of  a  metamorphosed  syenite.  Hornblende  is  rarely  to  be  recognized 
distinctly.  The  blocks  of  syenite  may  certainly  furnish  an  incontro- 
vertible proof,  that  the  seat  of  the  focus  of  the  volcano  of  Jorullo  is 
either  in  or  below  the  syenite,  which  shows  itself  in  considerable 
extent,  a  few  miles  (leguas)  further  south,  on  the  left  bank  of  the  Rio 
de  las  Balsas,  flowing  into  the  Pacific  Ocean."  Dolomieu,  and,  in  1832, 
the  excellent  geognosist,  Friedrich  Hoffmann,  found  in  Lipari,  neai 


TRUE  VOLCANOES.  321 


exact  examination  by  Gustav  RO-SP,  of  a  fragment  which  I 
brought  with  me,  they  prohably  belong  rather  to  the  granite 
formation,  which  Bnrkart  has  also  seen  emerging  from 
below  the  syenite  of  the  Rio  de  las  Balsas.  "  The  inclosure 
is  a  mixture  of  quartz  and  felspar.  The  blackish  green  spots 
appear  to  be  not  hornblende,  but  mica  fused  with  some 
felspar.  The  white  fragment  baked  in  is  split  by  volcanic 
heat,  and  in  the  crack  white,  tooth-like,  fused  threads  run 
from  one  margin  to  the  other." 

To  the  north  of  the  great  volcano  and  the  scoriaceous 
lava  mountain  which  it  has  vomited  forth  in  the  direction 
of  the  old  basalt  of  the  Cerro  del  Mortero,  follow  the  two 
last  of  the  six  often-mentioned  eruptions.  These  hills  also 
were  originally  very  active,  for  the  people  still  call  the  ex- 
treme mountain  of  ashes,  el  Volcancito.  -A.  broad  fissure 
opened  towards  the  west,  bears  the  traces  of  a  destroyed 
crater.  The  great  volcano,  like  the  Epomeo  in  Ischia,  ap- 
pears to  have  only  once  poured  out  a  mighty  lava-stream. 
That  its  lava-pouring  activity  endured  after  the  period  01 
its  first  eruption,  is  not  proved  historically  ;  for  the  valuable 
letter,  so  happily  discovered,  of  Father  Joaquin  de  Ansogorri, 
written  scarcely  three  weeks  after  the  first  eruption,  treats 
almost  exclusively  of  the  means  of  making  "  arrangements 
for  the  better  pastoral  care  of  the  country  people  who  had 
fled  from  the  catastrophe  and  become  dispersed  ;"  and  for  the 
following  thirty  years  we  have  no  records.  As  the  tradition 
speaks  very  generally  of  fires  which  covered  so  great  a  sur- 
face, it  is  certainly  to  be  supposed  that  all  the  six  hills  upon 
the  great  fissure,  and  the  portion  of  the  Malpais  itself  in 
which  the  Hornitos  have  appeared,  were  simultaneously  in 
combustion.  The  temperature  of  the  surrounding  air,  which 
I  measured,  allows  us  to  judge  of  the  heat  which  prevailed 
there  43  years  previously  ;  they  remind  one  of  the  former 
condition  of  our  planet,  in  which  the  temperature  of  its 
atmospheric  envelope,  and  with  this  the  distribution  of 
organic  life,  might  be  modified  by  the  thermic  action  of  the 
interior  by  means  of  deep  fissures  (under  any  latitude  and 
for  long  periods  of  time). 

Caneto,  fragments  of  granite,  formed  of  pale  red  felspar,  black  mica, 
and  a  little  pale  gray  quartz,  enclosed  in  compact  masses  of  obsidiau 
(Poggendorfl's  Annalen  der  Physik,  Bd.  xxvi,  s.  49). 

VOL.  V.  Y 


322  COSMOS. 

Since  I  described  the  Hornitos  which  surround  the  vol* 
cano  of  Jorullo,  many  analogous  platforms  in  various  regions 
of  the  world,  have  been  compared  with  these  oven-like  little 
hills,  To  me,  the  Mexican  ones,  from  their  interior  con- 
formation, appear  still  to  stand  in  a  very  contrasting  and 
isolated  condition.  If  all  upheavals  which  emit  vapours  are 
to  be  called  eruptive -cones,  the  Hornitos  certainly  deserve 
the  appellation  of  Fumaroles.  But  the  denomination,  erup- 
tive-cones, would  lead  to  the  erroneous  notion  that  there  is 
evidence  that  the  Hornitos  have  thrown  out  scoriae,  or  even, 
like  many  eruptive-cones,  poured  forth  lava.  Yery  different, 
for  example  (to  advert  to  a  great  phenomenon)  are  the  three 
chasms  in  Asia  Minor,  upon  the  former  boundaries  of  Mysia 
and  Phrygia,  in  the  ancient  burning  country  (Katake- 
kaumene)  "  where  it  is  dangerous  to  dwell  (on  account  of 
the  earthquakes),"  which  Strabo  calls  (fivaai,  or  wind-bags, 
and  which  the  meritorious  traveller,  William  Hamilton,  has 
rediscovered.13  Eruptive  cones  such  as  are  exhibited  by  the 
island  of  Lancerote  near  Tinguaton,  or  by  Lower  Italy,  or 
(ot  hardly  20  feet  in  height)  by  the  declivity  of  the  great 
Kamtschatkan  volcano,  Awatscha,14  which  was  ascended  in 
July,  1824,  by  my  friend  and  Siberian  companion,  Ernst 
Hofmann,  consist  of  scoriae  and  ashes  surrounding  a  small 
crater,  which  has  thrown  them  out,  and  has  been  in  return 
buried  by  them.  In  the  Hornitos  nothing  like  a  crater  is  to 
be  seen,  and  they  consist — and  this  is  an  important  charac- 
ter— merely  of  basaltic  balls,  with  shell-like  separated  frag- 
ments, without  any  admixture  of  loose  angular  scoriae.  At 
the  foot  of  Vesuvius,  during  the  great  eruption  of  1794  (and 

15  Strabo,  lib.  xiii,  pp.  579  and  628  ;  Hamilton,  Researches  in  Asia 
Minor,  vol.  ii,  chap.  39.  The  most  western  of  the  three  cones,  now 
called  Kara  Devlit,  is  raised  532  feet  above  the  plain,  and  has  emitted 
a  great  lava-stream  in  the  direction  of  Koula.  Hamilton  counted  more 
than  thirty  small  cones  in  the  vicinity.  The  three  chasms  (fioOpw  and 
<j>vaai  of  Strabo)  are  craters  situated  upon  conical  mountains  composed 
of  scorice  and  lavas. 

14  Erman,  Reiseum  die  JSrde,  Bd.  iii,  s.  538  ;  Cosmos,  vol.  v,  p.  248, 
Postels  ( Voyage  autour  du  Monde  par  le  Cap.  Lutke,  partie  hist.  fc.  iii, 
p.  76)  and  Leopold  von  Buch  (.Description  Physique  des  lies  Canaries, 
p.  448)  mention  the  similarity  to  the  Hornitos  of  Jorullo.  In  a  manu- 
script most  kindly  communicated  to  me,  Erman  describes  a  great 
number  of  truncated  cones  of  scoriae  in  the  immense  lava-field  to  the 
east  of  the  Baidar  Mountains  on  the  peninsula  of  Kamtschatka. 


TRUE   VOLCANOES.  323 

also  in  earlier  times),  eight  different,  small  craters  of  erup- 
tion, (bocche  nuove)  were  formed,  arranged  upon  a  longitu- 
dinal fissure  ;  they  are  the  so-called  parasitic  cones  of  erup- 
tion, which  poured  forth  lava,  and  are  even  by  this  circum- 
stance entirely  distinct  from  the  Hornitos  of  Jorullo. 
"  Your  Hornitos,"  wrote  Leopold  von  Buch  to  me,  "  are 
not  cones  accumulated  by  erupted  matters  ;  they  have  been 
upheaved  directly  from  the  interior  of  the  earth."  The 
production  of  the  volcano  of  Jorullo  itself  was  compared  by 
this  great  geologist  with  that  of  the  Monte  Nuovo  in  the 
Phlegrsean  fields.  The  same  notion  of  the  upheaval  of  six 
volcanic  mountains  upon  a  longitudinal  fissure  forced  itself 
as  the  most  probable  upon  Colonel  Riano  and  the  mining 
commissary  Fischer  in  1789  (see  ante,  p.  313),  upon  myself 
at  the  first  glance  in  1803,  and  upon  Burkart  in  1827. 
With  both  the  new  mountains,  produced  in  1538  and  1759, 
the  same  questions  repeat  themselves.  Upon  that  of  South- 
ern Italy,  the  testimonies  of  Falconi,  Pietro  Griacomo  di 
Toledo,  Francesco  del  Nero  and  Porzio,  are  circumstantial, 
near  the  time  of  the  catastrophe  and  prepared  by  educated 
observers.  The  celebrated  Porzio,  who  was  the  most 
learned  of  these  observers,  says  :  —  "Magnus  terrse  tractus, 
qui  inter  radices  montis,  quern  Barbarum  incolae  appellant, 
et  mare  juxta  Avernum  jacet,  sese  erigere  videbatur  et  montis 
subito  nascentis  figuram  iinitari.  Iste  terras  cumulus  aperto 
veluti  ore  magnos  ignes  evomuit,  pumicesque  et  lapides, 
cineresque."  15 

From  the  geognostic  description  here  completed  of  the 
volcano  of  Jorullo,  we  will  pass  to  the  more  eastern  parts 
of  Central  Mexico  (Anahuac).  Unmistakeable  lava-streams, 
the  principal  mass  of  which  is  usually  basaltic,  have  been 
poured  out  by  the  peak  of  Orizaba  according  to  the  most  recent, 

15  Porzio,  Opera  omnia,  Med.,  Phil,  et  Mathem.  in  unum  collect  a, 
1736:  according  to  Dufre*noy,  Memoires  pour  servir  a  une  Description 
Geologique  de  la  France,  t.  iv,  p.  272.  All  the  genetic  questions  are 
discussed  very  completely  and  with  praiseworthy  impartiality  in  the 
9th  edition  of  Sir  Charles  Lyell's  Principles  of  Geology,  1853,  p.  369. 
Even  Bouguer  (Figure  de  la  Terre,  1749,  p.  Ixvi)  was  not  disinclined 
to  the  idea  of  the  upheaval  of  the  volcano  of  Pichincha.  He  says  : — 
"  It  is  not  impossible  that  the  rock,  which  is  burnt  and  black,  may 
have  been  elevated  by  the  action  of  subterranean  fire."  See  also 
p.  xci. 

Y  * 


324  COSMOS. 

interesting  observations  of  Pieschel  (March,  1854)leand  H. 
de  Saussure.  The  rock  of  the  peak  of  Orizaba,  like  that  of  the 
volcano  of  Toluca17  which  I  ascended,  is  composed  of  horn- 
blende, oligoclase,  and  a  little  obsidian;  whilst  the  funda- 
mental mass  of  Popocatepetl  is  a  Chimborazo-rock,  composed 
of  very  small  crystals  of  oligoclase  and  augite.  At  the  foot  of 
the  eastern  slope  of  Popocatepetl,  westward  of  the  town 
la  Puebla  de  los  Angeles,  in  the  Llano  de  Tetimpa,  where  I 
measured  the  base  for  the  determination  of  the  elevation  of 
the  two  great  Nevados  (Popocatepetl  and  Iztaccihuatl) 
which  bound  the  valley  of  Mexico,  I  found,  at  a  height 
of  7000  feet  above  the  sea,  an  extensive  and  myste- 
rious kind  of  lava-field  It  is  called  the  Malpais  (rough 
rubbish-field)  of  Atlachayacatl,  a  low  trachytic  dome,  on 
the  declivity  of  which  the  river  Atlaco  rises  and  runs  at 
an  elevation  of  from  60  to  85  feet  above  the  adjacent  plain, 
from  east  to  west,  and  consequently  at  right  angles  to  the 
volcanoes.  From  the  Indian  village  of  San  Nicolas  de 
los  Ranchos,  to  San  Buenaventura,  I  calculated  the  length 
of  the  Malpais  at  more  than  19,200  feet,  and  its  breadth  at 
6400  feet.  It  consists  of  black,  partially  upraised  lava- 
blocks  of  a  fearfully  wild  appearance,  and  only  sparingly 
coated  here  and  there  with  lichens,  contrasting  with  the  yel- 
lowish white  coat  of  pumice-stone  which  covers  everything 
for  a  long  distance  round.  The  latter  consists  here  of  coarsely 
fibrous  fragments  of  two  or  three  inches  in  diameter,  in 
which  hornblende  crystals  sometimes  lie.  This  coarser 
pumice-stone  sand,  is  different  from  the  very  finely  granular 
sand,  which,  near  the  rock  el  Frayle  and  at  the  limit  of  per- 
petual snow,  on  the  volcano  Popocatepetl,  renders  the  ascent 
so  dangerous,  because,  when  it  is  set  in  motion  on  steep  decli- 
vities, the  sand-mass,  rolling  down,  threatens  to  overwhelm 
everything.  Whether  this  lava  field  of  fragments  (in 
Spanish  JUalpais,  in  Sicily  Sciarra  viva,  in  Iceland  Odaada- 
Ilraun,}  is  due  to  ancient  lateral  eruptions  of  Popocate- 
petl, situated  one  above  the  other,  or  to  the  somewhat 
rounded  cone  of  Tetlijolo  (Cerro  del  Corazon  de  Piedra)  I 

16  Zeitschrift  fur  Allgemeine  Erdkunde,  Bd.  iv,  s.  398. 

1'  For  the  more  certain  determination  of  the  minerals  of  which  the 
Mexican  volcanoes  are  composed,  old  and  recent  collections  made 
by  myself  and  Pieschel  have  been  compared. 


TRUE    VOLCANOES.  325 

cannot  determine.  It  is  also  geognostically  remarkable  that, 
further  to  the  east,  on  the  road  towards  the  small  fortress 
Perote,  the  ancient  Aztec  Pinahuizapan,  between  Ojo  de 
Agua,  Yenta  de  Soto  and  el  Portachuelo,  the  volcanic  forma- 
tion of  coarsely  fibrous,  white,  friable  perlite  18  rises 
beside  a  limestone  (Marmol  de  la  Puebla)  which  is  probably 
tertiary.  This  perlite  is  very  similar  to  that  of  the  conical 
hill  of  Zinapecuaro  (between  Mexico  and  Valladolid)  ;  and 
contains,  bet-ides  laminae  of  mica,  and  lumps  of  immersed 
obsidian,  a  glassy,  bluish- gray,  or  sometimes  red,  jasper-like 
streaking.  The  wide  "  perlite  district "  is  here  covered  with 
a  finely  granular  sand  of  weathered  perlite,  which  might  be 
taken,  at  the  first  glance,  for  granitic  sand,  and  which,  not- 
withstanding its  allied  origin,  is  still  easily  distinguishable 
from  the  true,  grayish  white  pumice-stone  sand.  The  latter 
is  more  proper  to  the  immediate  vicinity  of  Perote, — the  pla- 
teau 7460  feet  in  height  between  the  two  volcanic  chains  of 
Popocatepetl  and  Orizaba,  which  strike  north  and  south. 

When,  on  the  road  from  Mexico  to  Yera  Cruz,  we  begin 
to  descend  from  the  heights  of  the  non-quartzose,  trachytic 
porphyry  of  the  Yigas  towards  Canoas  and  Jalapa,  we  again 
twice  pass  over  fields  of  fragments  and  scoriaceous  lava  : — 
the  first  time  between  the  station  Parage  de  Garros  and  Canoas 
or  Tochtlacuaya,  and  the  second,  between  Canoas  and  the 
station  Casas  de  la  Hoya.  The  first  point  is  called  Loma  de 
Tobias  on  account  of  the  numerous  upraised,  basaltic  blocks 
of  lava  containing  abundance  of  olivine ;  the  second  simply 
el  Malpais.  A  small  ridge  of  the  same  trachytic  porphyry, 
full  of  glassy  felspar,  which  forms  the  eastern  limit  of  the 
Arenal  (the  perlitic  sand-fields)  near  la  Cruz  Blanca 
and  Rio  Frio  (on  the  western  declivity  of  the  heights  of 
las  Yigas)  separates  the  two  branches  of  the  lava-field 
which  have  just  been  mentioned, — the  Loma  de  Tablas,  and 
the  much  broader  Malpais.  Those  of  the  country  people 
who  are  well  acquainted  with  the  district  assert  that  the 
band  of  scoriae  is  elongated  towards  the  south-south-east, 
and  consequently  towards  the  Cofre  de  Perote.  As  I  have 

18  The  beautiful  marble  of  la  Puebla  comes  from  the  quarries  of 
Tecali,  Totomehuacan  and  Portachuelo,  to  the  south  of  the  high 
trachytic  mountain,  el  Pizarro.  I  have  also  seen  limestone  cropping 
out  near  the  terrace-pyramid  of  Cholula,  on  the  way  to  la  Puebla. 


326  COSMOS. 

myself  ascended  the  Cofre  and  made  many  measurements 
on  it,19  I  have  been  but  little  inclined  to  conclude,  from  a 
19  The  Cofre  de  Perote  stands  nearly  isolated  to  the  south-east  of 
the  Fuerte  or  Castillo  de  Perote,  near  the  eastern  slope  of  the 
great  plateau  of  Mexico;  but  its  great  mass  belongs  to  an  impor- 
tant range  of  heights,  which,  forming  the  margin  of  the  slope, 
extends  in  a  north  and  south  direction,  from  Cruz  Blanca  and  Rio 
Frio  towards  las  Vigas  (lat.  19°  37'  37")  past  the  Cofre  de  Perote 
(lat.  19°  28'  57",  long.  97°  7' 20")  to  the  westward  of  Xicochimalco 
and  Achilchotla  to  the  Peak  of  Orizaba  (lat.  19°  2'  17",  long. 
97°  13'  56"),  parallel  to  the  chain  (Popocatepetl — Iztaccihuatl) 
which  separates  the  cauldron-valley  of  the  Mexican  lakes  from 
the  plain  of  la  Puebla.  (For  the  grounds  of  these  determinations 
see  my  Recueil  d'Observ.  Astron,  vol.  ii,  pp.  529—532  and  547,  and 
also  Analyse  de  I 'Atlas  du  Mexique,  or  Essai  Politique  sur  la  Nou- 
velle  Espagne,  t.  i,  pp.  55 — 60).  As  the  Cofre  has  raised  itself 
abruptly  in  a  field  of  pumice-stone  many  miles  in  width,  it  appeared 
to  me  in  my  winter  ascent  (the  thermometer  fell  at  the  summit,  on 
the  7th  February,  1804,  to  28°'4)  to  be  extremely  interesting,  that 
the  covering  of  pumice-stone,  the  thickness  and  height  of  which  I 
measured  barometically  at  several  points  both  in  ascending  and  de- 
scending, rose  more  than  780  feet.  The  lower  limit  of  the  pumice- 
stone,  in  the  plain  between  Perote  and  Rio  Frio,  is  1187  toises  (7590 
i'eet)  above  the  level  of  the  sea ;  the  upper  limit  on  the  northern 
declivity  of  the  Cofre  1309  toises  (8370  feet);  thence  through  the 
Pinahuast,  the  Alto  de  los  Caxones  (1954  toises  =  12,4 96  feet),  where  I 
could  determine  the  latitude  by  the  sun's  meridian  altitude  up  to  the 
summit  itself,  no  trace  of  pumice-stone  was  to  be  seen.  During  the 
upheaval  of  the  mountain,  a  portion  of  the  coat  of  pumice-stone  of 
the  great  Arenal,  which  has  probably  been  levelled  in  strata  by  water, 
was  carried  up.  I  inserted  a  drawing  of  this  zone  of  pumice-stone 
in  my  journal  (February,  1804)  on  the  spot.  It  is  the  same  impor- 
tant phenomenon  which  was  described  by  Leopold  von  Buch  in  the 
year  1834  on  Vesuvius,  where  horizontal  strata  of  pumice-tufa  were 
raised  by  the  elevation  of  the  volcano  to  a  greater  height  indeed, 
1900  or  2000  feet  towards  the  Hermitage  del  Salvatore  (Pog- 
gendorfs  Annalen,  Bd.  xxxvii,  s.  175 — 179).  The  surface  of 
the  dioritic  trachyte  rock  on  the  Cofre,  at  the  point  where  I  found 
the  highest  pumice-stone,  was  not  withdrawn  from  observation  by 
snow.  The  limit  of  perpetual  snow  lies  in  Mexico  under  the  latitudes 
of  19°  or  191°,  only  at  the  average  elevation  of  2310  toises  (14,770 
feet),  and  the  summit  of  the  Cofre,  up  to  the  foot  of  the  small,  house- 
like  cubical  rock  where  I  set  up  the  instruments,  reaches  2098 
toises,  or  13,418  feet  above  the  sea  level.  According  to  angles  of 
altitude  the  cubical  rock  is  21  toi.ses  or  134  feet  in  height ;  conse- 
quently the  total  altitude,  which  cannot  be  reached  on  account  of 
the  perpendicular  wall  of  the  rock  is  13,552  feet  above  the  sea.  I 
found  only  single  spots  of  sporadic  snow,  the  lower  limit  of  which 
was  12,150  feet;  about  700  or  800  feet  below  the  upper  limit  of 


TRUE  VOLCANOES.  327 

prolongation  of  the  lava-stream  which  is  certainly  very  pro- 
bable (it  is  so  represented  in  my  Profiles  tab.  9  and  11,  and 
in  the  Nivellement  Barometrique),  that  it  may  have  flowed 
from  this  mountain,  the  form  of  which  is  so  remarkable. 
The  Cofre  de  Perote,  which  is  nearly  1400  feet  higher  than 
the  peak  of  Teneriffe,  but  inconsiderable  in  comparison  with 
the  giants  Popocatepetl  and  Orizaba,  forms,  like  Pichincha, 
a  long  rocky  ridge,  upon  the  southern  extremity  of  which 
stands  the  small  cubical  rock  (la  Pen  a),  the  form  of  which 
gave  origin  to  the  ancient  Aztec  name  of  Nauhcampatepetl. 
In  ascending  the  mountain  I  saw  no  trace  of  the  falling  in 
of  a  crater,  or  of  eruptive  orifices  on  its  declivities ;  no 
masses  of  scoriae,  and  no  obsidians,  perlites  or  pumice-stones 
belonging  to  it.  The  blackish  gray  rock  is  very  uniformly 
composed  of  much  hornblende  and  a  species  of  felspar,  which 
is  not  glassy  felspar  (sanidinr)  but  oligoclase ;  this  would 
show  the  entire  rock,  which  is  not  porous,  to  be  a  dioritic 
trachyte.  I  describe  the  impressions  which  I  experienced. 

forest-trees  in  beautiful  pine-trees  :  Pinus  occidentalis,  mixed  with 
Cupressus  sabinoides  and  Arbutus  Madrono.  The  oak,  Quercus  xala- 
pensis,  had  accpmpanied  us  only  to  an  absolute  elevation  of  10,340 
feet.  (Humboldt,  Nivellement  barometr.  des  Cordilleres,  Nos.  414 — 
429).  The  name  of  Nauhcampatepetl,  which  the  mountain  bears  in 
the  Mexican  language,  is  derived  from  its  peculiar  form,  which  also 
induced  the  Spaniards  to  give  it  the  name  of  Cofre.  It  signifies 
"  quadrangular  mountain"  for  nauhcampa,  formed  from  nahui,  the 
numeral  four,  signifies,  as  an  adverb  from  four  sides,  but  as  an  adjec- 
tive (although  the  Dictionaries  do  not  state  this),  undoubtedly  quad- 
rangular or  four -sided,  as  this  signification  is  attached  to  the  com- 
pound  nauhcampa  ixquich.  An  observer,  very  well  acquainted  with 
the  country,  M.  Pieschel,  supposes  the  existence  of  an  old  crater- 
opening  on  the  eastern  declivity  of  the  Cofre  de  Perote  (Zeitschrift 
filr  Allgem.  Erdkunde,  herausg,  von  Gumprecht,  Bd.  v,  s.  125).  I 
drew  the  view  of  the  Cofre,  given  in  my  Vues  des  Cordilleres,  pi.  xxxiv, 
in  the  vicinity  of  the  castle  of  San  Carlos  de  Perote,  at  a  distance  of 
about  eight  miles.  The  ancient  Aztek  name  of  Perote  was  Pinahui- 
zapan,  and  signifies  (according  to  Buschmann)  the  beetle  pinaJiuiztli 
(regarded  as  an  evil  omen,  and  employed  superstitiously  in  fortune- 
telling  :  see  Sahagun,  Historia  Gen.  de  las  Cosas  de  Nueva  Espana, 
t.  ii,  1829,  pp.  10 — 11)  on  the  water ;  the  name  of  this  beetle  is  derived 
from  pinahua,  to  be  ashamed.  From  the  same  verb  is  derived  the 
above-mentioned  local  name  Pinahuast  (pinahuaztli)  of  this  district; 
as  well  as  the  name  of  a  ehrub  (Mimosaceae  '?)  pinahuihuiztli,  trans- 
lated herba  verecunda  by  Hernandez,  the  leaves  of  which  fall  down 
when  touched. 


328  COSMOS. 

If  the  terrible,  black  lava-field — Malpais — (upon  which  I 
have  here  purposely  dwelt  in  order  to  counteract  the  too 
one-sided  consideration  of  exertions  of  volcanic  force  from 
the  interior),  did  not  flow  from  the  Cofre  de  Perote  itself  at  a 
lateral  opening,  still  the  upheaval  of  this  isolated  mountain 
13,553  feet  in  height,  may  have  caused  the  formation  of  the 
Loma  de  Tablas.  During  such  an  upheaval,  longitudinal 
fissures  and  networks  of  fissures  may  be  produced  far  and 
wide  by  folding  of  the  soil,  and  from  these,  molten  masses 
may  have  poured  directly,  sometimes  as  dense  masses,  and 
sometimes  as  scoriaceous  lava,  without  any  formation  of  true 
mountain  platforms  (open  cones  or  craters  of  elevation). 
Do  we  not  seek  in  vain  in  the  great  mountains  of  basalt  and 
porphyritic-slate,  for  central  points  (crater-mountains)  or  lower, 
circumvallated,  circular  chasms,  to  which  their  common  pro- 
duction might  be  ascribed  ?  The  careful  separation  of  that 
which  is  genetically  different  in  phenomena : — the  forma- 
tion of  conical  mountains  with  permanently  open  craters 
and  lateral  openings ;  of  circumvallated  craters  of  elevation 
and  Maars  ;  of  upraised  closed  bell-shaped  mountains  or  open 
cones,  or  matters  poured  out  from  coalescent  fissures — 
is  a  gain  to  science.  It  is  so  because  the  multiplicity  of 
opinions  which  is  necessarily  called  forth  by  an  enlarged 
ho-izon  of  observation,  and  the  strict  critical  comparison  of 
that  which  exists,  with  that  which  is  asserted  to  be  the 
only  mode  of  production,  are  most  powerful  inducements 
to  investigation.  Even  upon  European  soil,  however,  on  the 
island  of  Eubcea,  so  rich  in  hot  springs,  a  vast  lava-stream 
has  been  poured  out,80  within  the  historical  period,  from 
a  chasm  in  the  great  plain  of  Lelanton,  at  a  distance  from 
any  mountain. 

In  the  volcanic  group  of  Central  America,  which  follows 
the  Mexican  group  towards  the  south,  and  in  which  eighteen 
conical  and  bell-shaped  mountains  may  be  regarded  as  still 
active,  four  (Nindiri,  el  Nuevo,  Conseguina,  and  San  Miguel 
de  Bosotlan)  have  been  recognized  as  producing  lava.81  The 
mountains  of  the  third  volcanic  group,  that  of  Popayan  and 
Quito,  have  already  for  more  than  a  century  enjoyed  the  re- 

20  Strabo,  lib.  i,  p.  58,  lib.  vi,  ,».  269,  ed.  Casaubon;  Cosmos,  vol.  i, 
p.  236,  and  vol.  v,  p.  225. 
31  See  page  278. 


TRUE  VOLCANOES.  329 

putati^n  of  furnishing  no  lava-streams,  but  only  incoherent, 
glowing  scoriaceous  masses,  thrown  out  of  the  single  summital 
crater,  and  often  rolling  down  in  a  linear  arrangement.  This 
was  even  the  opinion22  of  La  Condamine,  when  he  left  the 
highlands  of  Quito  and  Cuen$a  in  the  spring  of  1743.  Four- 
teen years  afterwards,  when  he  returned  from  an  ascent  of 
Vesuvius  (4th  June,  1755),  in  which  he  accompanied  the 
sister  of  Frederick  the  Great,  the  Margravine  of  Baireuth, 
he  had  the  opportunity  of  expressing  himself  warmly,  in  a 
meeting  of  the  French  Academy,  upon  the  want  of  true 
lava-streams  (laves  coulees  par  torrens  de  matieres  liquefiees) 
22  "  I  have  never  known,"  says  La  Condamine,  "lava-like  matter  in 
America,  although  M.  Bouguer  and  myself  have  encamped  for  whole 
weeks  and  months  upon  the  volcanoes,  and  especially  upon  those  of 
Pichincha,  Cotopaxi,  and  Chimborazo.  Upon  these  mountains  I  have 
only  seen  traces  of  calcination,  without  liquefaction.  Nevertheless,  the 
kind  of  blackish  crystal,  commonly  called  Piedra  de  Gallinafo  in  Peru 
(obsidian),  of  which  I  have  brought  home  several  fragments,  and  of 
which  a  polished  lens  of  seven  or  eight  inches  in  diameter,  may  be  seen 
in  the  cabinet  of  the  Jardin  du  Roi,  is  nothing  but  a  glass  formed 
by  volcanic  action.  The  materials  of  the  stream  of  fire  which  flows 
continually  from  that  of  Sangai,  in  the  province  of  Macas,  to  the  south- 
east of  Quito,  are  no  doubt  lava,  but  we  have  only  seen  this  mountain 
from  a  distance,  and  I  was  no  longer  at  Quito  at  the  time  of  the  last 
eruptions  of  the  volcano  of  Cotopaxi,  when  vents  opened  upon  its 
flanks,  from  which  ignited  and  liquid  matters  were  seen  to  issue  in 
streams,  which  must  have  been  of  a  similar  nature  to  the  lava  of 
Vesuvius"  (La  Condamine,  Journal  de  Voyage  en  Italic,  in  the 
Hemoires  de  VAcad.  des  Sciences,  1757,  p.  357,  Historic,  p.  12).  The 
two  examples,  especiallythe  first,  are  not  happily  chosen.  The  Sangay 
was  first  scientifically  examined  in  December  of  the  year  1849,  by 
Sebastian  Wisse ;  what  La  Condamine,  at  a  distance  of  108  miles, 
took  for  luminous  lava  flowing  down,  and  "an  effusion  of  burning 
sulphur  and  bitumen,"  consists  of  red-hot  stones  and  scoriaceous 
masses,  which  sometimes,  pressed  closely  together,  slip  down  on  the 
steep  declivities  of  the  cone  of  ashes  (Cosmos,  see  above,  p.  264).  On 
Cotopaxi,  as  on  Tungurahua,  Chimborazo,  and  Pichincha,  or  on 
Purace,  and  Sotara  near  Popayan,  I  have  seen  nothing  that  could  be 
looked  upon  as  narrow  lava-streams,  which  had  flowed  from  these 
colossal  mountains.  The  incoherent,  glowing  masses  of  5 — 6  feet  in 
diameter,  often  containing  obsidian,  which  Cotopaxi  has  scattered 
abroad  during  its  eruptions,  impelled  by  floods  of  melting  snow  and 
ice,  have  reached  far  into  the  plain,  where  they  form  rows  partially 
diverging  in  a  radiate  form.  La  Condamine  also  says  very  truly  else- 
where (Journal  du  Voyage  a  T Equateur,  p.  160): — '''These  fragments  of 
rock,  as  large  as  the  hut  of  an  Indian,  form  series  of  rays,  which  start 
from  the  volcano  as  from  a  common  centre." 


330  COSMOS. 

from  the  volcanoes  of  Quito.  The  Journal  d'uti  Voyage  en 
Italie,  which  was  read  at  the  meeting  of  the  20th  April, 
1757,  only  appeared  in  1762  in  the  Memoires  of  the  Aca- 
demy of  Paris,  and  is  of  some  geognostic  importance  in  the 
history  of  the  recognition  of  old  extinct  volcanoes  in  France, 
because  in  this  journal,  La  Condamine,  with  his  peculiar 
acuteness,  and  without  knowing  of  the  certainly  earlier  ob- 
servations of  Guettard,23  expresses  himself  very  decidedly 
upon  the  existence  of  ancient  crater-lakes  and  extinct  vol- 
canoes in  middle  and  northern  Italy  and  in  the  south 
of  France. 

This  remarkable  contrast  between  the  narrow  and  un- 
doubted lava-streams  of  Auvergne  thus  early  recognized, 
and  the  often  too  absolutely  asserted  absence  of  any  effusion 
of  lava  in  the  Cordilleras,  occupied  me  seriously  during  the 
whole  period  of  my  expedition.  All  my  journals  are  full  of 
considerations  upon  this  problem,  the  solution  of  which  I 
long  sought  in  the  absolute  elevation  of  the  summits  and  in 
the  vastness  of  the  circumvallation,  that  is  to  say,  the  sink- 
ing of  trachytic  conical  mountains  from  mountain-plains  of 
eight  or  nine  thousand  (8500—9600  English)  feet  in  eleva- 
tion and  of  great  breadth.  We  now  know,  however,  that  a 
volcano  of  Quito,  17,000  feet  in  height,  which  throws  out 
scoriae  (that  of  Macas),  is  uninterruptedly  much  more 
active  than  the  low  volcanoes  Izaleo  and  Stromboli;  we 
know  that  the  eastern  dome-shaped  and  conical  mountains, 
Antisana  and  Sangay,  have  free  slopes  towards  the  plains  of 
the  Napo  and  Pastaza ;  and  the  western  ones,  Pichincha, 
Iliniza,  and  Chimborazo,  towards  the  affluents  of  the  Pacific 
Ocean.  In  many  also  the  upper  part  projects  without  cir- 
cumvallation eight  or  nine  thousand  feet  above  the  elevated 
plateaux.  Moreover,  all  these  elevations  above  the  sea-level, 
which  is  regarded,  although  not  quite  correctly,  as  the  mean 
elevation  of  the  earth's  surface,  are  certainly  inconsiderable 
as  compared  with  the  depth  which  we  may  assume  to  be 
that  of  the  seat  of  volcanic  activity,  and  of  the  necessary 
temperature  for  the  fusion  of  rock-masses. 

23  Guettard's  memoir  on  the  extinct  volcanoes  was  read  at  the 
Academy  in  1752,  consequently  three  years  before  La  Condamine's 
journey  into  Italy;  but  only  printed  in  1756,  consequently  during  the 
Italian  travels  of  the  astronomer. 


TRUE   VOLCANOES.  331 

The  only  phenomena  resembling  narrow  lava-eruptions 
which  I  discovered  in  the  Cordilleras  of  Quito,  are  those 
presented  by  the  colossal  mountain  Antisana,  the  height  of 
which  I  determined  to  be  19,137  feet  (5833  metres),  by  a 
trigonometrical  measurement.  As  the  structure  furnishes 
the  most  important  criterion  here,  I  will  avoid  the  systematic 
denomination  lava,  which  confines  the  idea  of  the  mode  of 
production  within  too  narrow  limits,  and  make  use,  but 
quite  provisionally,  of  the  names  "rock-debris  "  (Felstrum- 
inern)  or  "  detritus  dykes"  (Schuttivallen,  trainees  de  masses 
volcaniques).  The  mighty  mountain  of  Antisana,  at  an  ele- 
vation of  13,458  feet,  forms  a  nearly  oval  plain,  more  than 
12,5(30  toises  (79,950  feet)  in  long  diameter,  from  which  the 
portion  of  the  mountain  covered  with  perpetual  snow  rises 
like  an  island.  The  highest  summit  is  rounded  off  and 
dome-shaped.  The  dome  is  united  by  a  short  jagged  ridge 
with  a  truncated  cone  lying  towards  the  north.  In  the 
plateau,  partly  desert  and  sandy,  partly  covered  with  grass 
(the  dwelling-place  of  a  very  spirited  race  of  cattle,  which, 
owing  to  the  slight  atmospheric  pressure,  easily  expel  blood 
from  the  mouth  and  nostrils  when  excited  to  any  great  mus- 
cular exertion),  is  situated  a  small  farm  (Hacienda),  a  single 
house  in  which  we  passed  four  days  in  a  temperature  varying 
between  38°'6and  48C*2.  The  great  plain, which  is  bynomeans 
circumvallated  as  in  craters  of  elevation,  bears  the  traces  of  an 
ancient  sea-bottom.  The  Laguna  Mica,  to  the  westward  of  the 
Altos  de  la  Moya,  is  to  be  regarded  as  the  residue  of  the  old 
covering  of  water.  At  the  margin  of  the  limit  of  perpetual 
snow,  the  Rio  Tinajillas  bursts  forth,  subsequently,  under  the 
name  of  Rio  de  Quixos,  becoming  a  tributary  of  the  Maspa, 
the  Napo,  and  the  Amazon.  Two  narrow,  wall-like  dykes,  or 
elevations,  which  I  have  indicated  upon  the  plan  of  Anti- 
sana, drawn  by  me,  as  coulees  de  laves,  and  which  are  called 
by  the  natives  Volcan  de  la  Hacienda  and  Yana  Yolcan 
(  Tana  signifies  black  or  brown  in  the  Qquechhua  language), 
pass  like  bands  from  the  foot  of  the  volcano  at  the  lower 
margin  of  the  perpetual  snow-line,  and  extend,  apparently 
with  a  very  moderate  declivity,  in  a  direction  N.E. — S.W., 
for  more  than  2000  toises  (12,792  feet)  into  the  plain. 
With  very  little  breadth  they  have  probably  an  elevation 
of  192  to  213  feet  above  the  soil  of  the  Llanos  de  la  Ha- 


332  COSMOS. 

cienda,  de  Santa  Lucia,  and  del  Cuvillan.  Their  declivities 
are  everywhere  very  rugged  and  steep,  even  at  the  extremi- 
ties. In  their  present  state  they  consist  of  conchoidal  and 
usually  sharp-edged  fragments  of  a  black  basaltic  rock,  with- 
out olivine  or  hornblende,  but  containing  a  few  small  white 
crystals  of  felspar.  The  fundamental  mass  has  frequently  a 
lustre  like  that  of  pitch  stone,  and  contains  an  admixture 
of  obsidian,  which  was  especially  recognizable  in  very 
large  quantity,  and  more  distinctly,  in  the  so-called  Cueva  de 
Antisana,  the  elevation  of  which  we  found  to  be  15,942  feet. 
This  is  not  a  true  cavern,  but  a  shed  formed  by  blocks  of 
rock  which  had  fallen  against  and  mutually  supported  each 
other,  and  which  preserved  the  mountain  cowherds  and  also 
ourselves  during  a  fearful  hailstorm.  The  Cueva  lies  somewhat 
to  the  north  of  the  Yolcan  de  la  Hacienda.  In  the  two 
narrow  dykes,  which  have  the  appearance  of  cooled  lava- 
streams,  the  tables  and  blocks  appear  in  part  inflated  like 
cinders  or  even  spongy  at  the  edges,  and  in  part  weathered 
and  mixed  with  earthy  detritus. 

Analogous  but  more  complicated  phenomena  are  presented 
by  another  also  band-like  mass  of  rocks.  On  the  eastern 
declivity  of  the  Antisana,  probably  about  1280  feet  per- 
pendicularly below  the  plain  of  the  Hacienda  in  the  direction 
of  Pinantura  and  Pintac,  there  lie  two  small  round  lakes,  of 
which  the  more  northern  is  called  Ansango,  and  the  southern 
Lecheyacu.  The  former  has  an  insular  rock,  and  is  sur- 
rounded by  rolled  pumice-stone,  a  very  important  point. 
Each  of  these  lakes  marks  the  commencement  of  a  valley ;  the 
two  valleys  unite,  and  their  enlarged  continuation  bears  the 
name  of  Volcan  de  Ansango,  because  from  the  margins  of 
the  two  lakes  narrow  lines  of  rock  debris,  exactly  like 
the  two  dykes  of  the  plateau  which  we  have  described  above, 
do  not,  indeed,  fill  up  the  valley,  but  rise  in  its  midsb  like 
dams  to  a  height  of  213  and  266  feet.  A  glance  at  the  local 
plan  which  I  published  in  the  "  Geographical  and  Physical 
Atlas"  of  my  American  travels  (pi.  26),  will  illustrate  these 
conditions.  The  blocks  are  again  partly  sharp-edged,  and 
partly  scorified  and  even  burnt  like  coke  at  the  edges.  It  is 
a  basaltic,  black,  fundamental  mass,  with  sparingly  scattered 
glassy  felspar  ;  some  fragments  are  blackish  brown  and  of  a 
dull  pitch  stone-like  lustre.  Basaltic  as  the  fundamental  mass 


TRUE  VOLCANOES.  333 

appears,  however,  it  is  entirely  destitute  of  the  olivine  which 
occurs  so  abundantly  on  the  Rio  Pisque  and  near  Gualla- 
bamba,  where  1  saw  basaltic  columns  of  72  feet  in  height 
And  3  feet  thick,  which  contained  both  olivine  and  horn- 
blende scattered  in  them.  In  the  dyke  of  Ansango  nume- 
rous tablets,  cleft  by  weathering,  indicate  porphvritic  slates. 
All  the  blocks  have  a  yellowish  gray  crust  from  weathering. 
As  the  detritus-ridge  (called  los  derrumbamientos,  la  reven- 
tnzon,  by  the  natives,  who  speak  Spanish),  may  be  traced 
from  the  Eio  del  Molina,  not  far  from  the  farm  of  Pintac, 
up  to  the  small  crater-lakes  surrounded  by  pumice-stone 
(chasms  filled  with  water),  the  opinion  has  grown  up  natu- 
rally, and,  as  it  were,  of  itself,  that  the  lakes  are  the  openings 
from  which  the  blocks  of  stone  came  to  the  surface.  A  few 
years  before  my  visiting  the  district,  the  ridge  of  fragments 
was  in  motion  for  weeks  upon  the  inclined  surface,  without 
any  perceptible  previous  earthquake,  and  some  houses  near 
Pintac  were  destroyed  by  the  pressure  and  shock  of  the 
blocks  of  stone.  The  detritus-ridge  of  Ansango  is  still  with- 
out any  trace  of  vegetation,  which  is  found,  although  very 
sparingly,  upon  the  two  more  weathered  and  certainly  older 
eruptions  of  the  plateau  of  Antisana. 

How  is  this  mode  of  manifestation  of  volcanic  activity, 
the  action  of  which  I  am  describing,  to  be  denominated?24 
Have  we  here  to  do  with  lava-streams  ?  or  only  with  semi- 
scorified  and  ignited  masses,  which  are  thrown  out  uncon- 
nected, but  in  chains  pressed  closely  upon  each  other  (as  on 
Cotapaxi  in  very  recent  times)?  Have  the  dykes  of  Yana 
Volcan  and  Ansango  been  perhaps  merely  solid  fragmentary 
masses,  which  burst  forth  without  any  fresh  elevation  of 
temperature  from  the  interior  of  a  volcanic  conical  mountain, 
in  which  they  lay  loosely  accumulated  and  therefore  badly 
supported,  their  movement  being  caused  by  the  concussion 
of  an  earthquake,  impelled  by  shocks  or  falls  and  giving  rise 
to  small  local  earthquakes  ?  Is  no  one  of  the  three  manifes- 

24  "  There  are  few  volcanoes  in  the  chain  of  the  Andes,"  says  Leopold 
von  Buch,  "which  have  presented  streams  of  lava,  and  none  have 
ever  been  seen  around  the  volcanoes  of  Quito.  Antisana,  upon  the 
eastern  chain  of  the  Andes,  is  the  only  volcano  of  Quito  upon  whii/j 
M.  de  Huniboldt  saw,  near  the  summit,  something  analogous  to  7 
stream  of  lava ;  this  stream  was  exactly  like  obsidian"  (Descr.  dea  II* 
Canaries,  1836,  pp.  468  and  488). 


334  COSMOS. 

tations  of  volcanic  activity  here  indicated,  different  as  they 
are,  applicable  in  this  case  ?  and  have  the  linear  accumula- 
tions of  rock-detritus  been  upheaved  upon  fissures  in  the 
spots  where  they  now  lie  (at  the  foot  and  in  the  vicinity  of 
a  volcano)?  The  two  dykes  of  fragments,  in  this  so  slightly 
inclined  plateau,  called  Volcan  de  la  Hacienda  and  Yana 
Volcan,  which  I  once  considered,  although  only  conjecturally, 
as  cooled  lava-streams,  now  appear  to  me,  as  far  as  I  can 
remember,  to  present  but  little  in  support  of  the  latter  opi- 
nion. In  the  Yolcan  de  Ansango,  where  the  line  of  frag- 
ments may  be  traced  without  interruption,  like  a  river-bed, 
to  the  pumice  margins  of  two  small  lakes,  the  fall,  or  differ- 
ence of  level  between  Pinantura  1482  toises  (9476  feet),  and 
Lecheyacu  1900  toises  (12,150  feet),  in  a  distance  of  about 
7700  toises  (49,239  feet),  by  no  means  contradicts  what  we 
now  believe  we  know  of  the  small  average  angles  of  inclina- 
tion of.  lava-streams.  Prom  the  difference  of  level  of  418 
toises  (2674  feet),  there  is  an  inclination  of  3°  6'.  A  partial 
elevation  of  the  soil  in  the  middle  of  the  floor  of  the  valley 
would  not  appear  to  be  any  hindrance,  because  the  back 
swell  of  fluid  masses  impelled  up  valleys  has  been  ob- 
served elsewhere,  for  example,  in  the  eruption  of  Scaptar 
Jokul  in  Iceland,  in  1783  (Naumann,  Geognosie,  Bd.  i, 
s.  160). 

The  word  lava  indicates  no  peculiar  mineral  composition 
of  the  rock  ;  and  when  Leopold  von  Buch  says  that  every- 
thing is  lava  that  flows  in  the  volcano  and  attains  new  posi- 
tions by  its  fluidity,  I  add  that  that  which  has  not  again  be- 
come fluid,  but  is  contained  in  the  interior  of  a  volcanic 
cone,  may  change  its  position.  Even  in  the  first  description2* 
of  my  attempt  to  ascend  the  summit  of  Chimborazo  (only 
published  in  1837,  in  Schumacher's  Astronomisclie  Jahr- 
buch),  I  expressed  this  opinion  in  speaking  of  the  remarkable 
"fragments  of  augitic  porphyry  which  1  collected  on  the 
23rd  June,  1802,  in  loose  pieces  of  from  twelve  to  fourteen 
inches  in  diameter,  upon  the  narrow  ridge  of  rock  leading 
to  the  summit  at  an  elevation  of  19,000  feet.  They 
had  small,  shining  cells,  and  were  porous  and  of  a  red 
colour.  The  blackest  of  them  are  sometimes  light  like 
pumice-stone,  and  as  though  freshly  altered  by  fire.  They 
25  Humboldt,  Kldnere  Sclirijten,  Bd.  i,  s.  161. 


TRUE  VOLCANOES.  335 

have  not,  however,  flowed  out  in  streams  like  lava,  but  have 
probably  been  expelled  at  fissures  on  the  declivity  of  the 
previously  upheaved,  bell-shaped  mountain."  This  genetic 
explanation  might  find  abundant  support  in  the  assumptions 
of  Boussingault,  who  regards  the  volcanic  cones  themselves 
"  as  an  accumulation  of  angular  trachytic  fragments,  upheaved 
in  a  solid  condition,  and  heaped  up  without  any  order.  As 
after  the  upheaval  the  broken  rocky  masses  occupy  a  greater 
space  than  before  they  were  shattered,  great  cavities  remain 
amongst  them,  movement  being  produced  by  pressure  and 
shock  (the  action  of  the  volcanic  vapour-force  being  ab- 
stracted)." I  am  far  from  doubting  the  partial  occurrence  of 
such  fragments  and  cavities,  which  become  filled  with  water 
in  the  Nevados,  although  the  beautiful,  regular,  and,  for  the 
most  part,  perfectly  perpendicular  trachytic  columns  of  the 
Pico  de  los  Ladrillos,  and  Tablahuma  on  Pichincha,  and, 
above  all,  over  the  small  basin.  Yana-Cocha  on  Chimborazo, 
appear  to  me  to  have  been  formed  on  the  spot.  My  old 
and  valued  friend,  Boussingault,  whose  chemico-geognostic 
and  meteorological  opinions  I  am  always  ready  to  adopt, 
regards  what  is  called  the  Yolcan  de  Ansango,  and  what 
now  appears  to  me  as  an  eruption  of  fragments  from  two 
small  lateral  craters  (on  the  western  Antisana.  below  Chus- 
sulongo)  as  upheavals  of  blocks20  upon  long  fissures.  As 
26  « \ye  differ  entirely  with  regard  to  the  pretended  stream  of 
Antisana  towards  Pinantura.  I  regard  this  stream  (coulee]  as  a  recent 
upheaval  analogous  to  those  of  Calpi  (Yana  Urcu).  Pisque,  and  Jorullo. 
The  trachytic  fragments  have  acquired  a  greater  thickness  towards  the 
middle  of  the  stream.  Their  stratum  is  thicker  towards  Pinantura 
than  at  points  nearer  Antisana.  The  fragmentary  condition  is  an 
effect  of  local  upheaval,  and  in  the  Cordillera  of  the  Andes  earth- 
quakes may  often  be  produced  by  heaping  up  "  (letter  from  M.  Bous- 
eingault,  dated  August,  1834).  See  page  270.  In  the  description 
of  his  ascent  of  Chimborazo  (December,  1831),  Boussingault  says  : 
— "  The  mass  of  the  mountain  consists,  in  my  opinion,  of  a 
heap  of  trachytic  ruins  piled  up  on  each  other  without  any  order. 
These  trachytic  fragments  of  a  volcano,  which  are  often  of  enormous 
size,  are  upheaved  in  the  solid  state ;  their  edges  are  sharp,  and  nothing 
indicates  that  they  had  been  in  a  fused  or  even  a  softened  condition. 
Nowhere,  on  any  of  the  equatorial  volcanoes,  do  we  observe  anything 
that  would  allow  us  to  infer  a  lava-stream.  Nothing  has  ever  been 
thrown  out  from  these  craters  except  masses  of  mud,  elastic  fluids  and 
ignited,  more  or  less  scorified  trachytic  blocks,  which  have  frequently 
been  scattered  to  considerable  distances"  (Hurnboldt,  Kleinere  Schriftent 


336  COSMOS. 

he  has  acutely  investigated  this  region  30  years  after  myself 
he  insists  upon  the  analogy  which  appears  to  him  to  be 
presented  by  the  geognostic  relations  of  the  eruption  of 
Ansango  to  Antisana,  and  those  of  Yana  Urcu  (of  which 
I  made  a  particular  plan)  to  Chimborazo.  I  was  the  less 
inclined  to  believe  in  a  direct  upheaval  upon  fissures  through- 
out the  entire  linear  extent  of  the  tract  of  fragments  at 
Ansango,  because  this,  as  I  have  already  repeatedly  mentioned, 
leads  at  its  upper  extremity,  to  the  two  chasms  now  filled 
with  water.  Non-fragmentary,  wall-like  upheavals  of  great 
length  and  uniform  direction,  are  however  not  unknown  to 
me,  as  I  have  seen  and  described  them  in  our  hemisphere, 
in  Chinese  Mongolia,  in  granite  banks  with  a  floetz-like 
bedding27. 

Antisana  had  an  eruption28  in  the  year  1580,  and 
another  in  the  beginning  of  the  last  century,  probably  in 
1728.  Near  the  summit,  on  the  north»north-east  side,  we 
observe  a  black  mass  of  rock,  upon  which  even  freshly 
fallen  snow  does  not  adhere.  At  this  point,  a  black  column 
of  smoke  was  seen  ascending  for  several  days  in  the  spring 
of  1801,  at  a  time  when  the  summit  was  on  all  sides  per- 
fectly free  from  clouds.  On  the  16th  March,  1802,  Bon- 
pland,  Carlos  Montufar,  and  myself  reached  a  ridge  of 
rock,  covered  with  pumice-stone,  and  black,  basaltic  scoriae 
in  the  region  of  perpetual  snow,  at  an  elevation  of  2837 
toises  (18,142  feet),  and  consequently  2358  feet  higher  than 
Montblanc.  The  snow  was  firm  enough  to  bear  us  on 

Bd.  i,  s.  200).  With  regard  to  the  first  origin  of  the  opinion  of  the 
upheaval  of  solid  masses  in  the  form  of  heaped-up  blocks,  see  Acosta, 
in  the  Viajes  d  los  Andes  Ecuatoriales  par  M.  Boussingault,  1849, 
pp.  222 — 223.  The  movement  of  the  heaped-up  fragments,  induced  by 
earth-shocks  and  other  causes,  and  the  gradual  filling  up  of  the  inter- 
stices, may,  according  to  the  assumptions  of  the  celebrated  traveller, 
produce  a  gradual  sinking  of  volcanic  mountain  peaks. 

^  Humboldt,  Asie  Centrale,  t.  ii,  pp.  296—301  (Gustav  Rose,  mineral- 
geognostische  JReise  nach  dem  Ural,  dem  Altai  und  dem  Kasp.  Meere, 
Bd.  i,  s.  599).  Narrow,  much  elongated  granitic  walls  may  have  risen, 
during  the  earliest  foldings  of  the  earth's  crust,  over  fissures  analo- 
gous to  the  remarkable,  still  open  ones,  which  are  found  at  the  foot  of 
the  volcano  of  Pichincha:  as  the  Guaycos  of  the  city  of  Quito,  of  30 — 
40  feet  in  width  (see  my  Kleinere  Schriften,  Bd.  i,  s.  24). 

28  La  Gondamine,  Mesure  des  trois  premiers  Degr$s  du  Meridien  dant 
¥  Hemisphere  Austral,  1751,  p.  56. 


TRUE   VOLCANOES.  337 

many  points  near  the  ridge  of  rock,  which  is  so  rare  under 
the  tropics  (temperature  of  the  atmosphere,  280>8 — 34°'5). 
On  the  southern  declivity,  which  we  did  not  ascend,  at  the 
Piedro  de  Azufre,  where  scales  of  rock  sometimes  separate 
of  themselves  by  weathering,  masses  of  pure  sulphur  of 
10 — 12  feet  in  length,  and  2  feet  in  thickness,  are  found; 
sulphurous  springs  are  wanting  in  the  vicinity. 

Although  in  the  eastern  Cordillera  the  volcano  of  Anti- 
sana, and  especially  its  western  declivity  (from  Ansango 
and  Pinantura,  towards  the  village  of  Pedregal)  is  sepa- 
rated from  Cotopaxi  by  the  extinct  volcano  of  Passuchoa2' 
with  its  widely  distinguishable  crater  (la  Peila),  by  the 
Nevado  Sinchulahua  and  by  the  lower  Ruminaui,  there  is 
still  a  certain  resemblance  between  the  rocks  of  the  two 
giants.  From  Quinche  onwards  the  whole  eastern  chain 
of  the  Andes  has  produced  obsidian,  and  yet  el  Quinche, 
Antisana,  and  Passuchoa  belong  to  the  basin  in  which  the 
city  of  Quito  is  situated ;  whilst  Cotopaxi  bounds  another 
basin,  that  of  Lactacunga,  Hambato  and  Riobamba.  The 
small  knot  of  mountains  of  the  Altos  of  Chisinche  sepa- 
rates the  two  basins  like  a  dam  ;  and  what  is  remarkable 

'x  Passuchoa,  separated  by  the  farm  el  Tambillo  from  the  Atacazo, 
does  not  any  more  than  the  latter  attain  the  region  of  perpetual  snow. 
The  elevated  margin  of  the  crater,  la  Peila,  has  fallen  in  towards  the 
west,  but  projects  towards  the  east  like  an  amphitheatre.  The  tradi- 
tion runs  that  at  the  end  of  the  sixteenth  century,  the  Passuchoa, 
which  had  previously  been  active,  ceased  its  manifestations  of  activity 
on  the  occasion  of  an  eruption  of  Pichincha,  which  proves  the  communi- 
cation between  the  vents  of  the  opposite  eastern  and  western  Cordilleras. 
The  true  basin  of  Quito,  closed  like  a  dam, — on  the  north  by  a  moun- 
tain group  between  Cotocachi  and  Imbaburo,  and  on  the  south, 
by  the  Altos  de  Chisinche  (between  0°  20'  N.  and  0°  41'  S.),  is  for  the 
most  part  divided  longitudinally  by  the  mountain  ridges  of  Ichimbio 
and  Poingasi.  To  the  eastward  lies  the  valley  of  Puembo  and  Chillo  ; 
to  the  westward  the  plain  of  Inaquito  and  Turubamba.  In  the  eastern 
Cordillera  follow  from  north  to  south, — Imbaburo,  the  Faldas  de 
Guamani,  and  Antisana,  Sinchulahua,  and  the  perpendicular,  black 
wall,  crowned  with  turret-iike  points,  of  Ruminaui  (Stone-eye);  in  the 
western  Cordillera,  Cotocachi,  Casitagua,  Pichincha,  Atacazo,  and 
Corazon,  upon  the  slopes  of  which  blooms  the  splendid  Alpine  plant, 
the  red  Ranunculus  Gusmani.  This  has  appeared  to  me  to  be  the  place 
to  give,  in  brief  terms,  a  morphological  representation,  drawn  from  my 
owii  experience,  of  the  form  of  a  spot  which  is  so  important  and 
classical  in  respect  to  volcanic  geology. 

VOL.    V.  Z 


338  COSMOS. 

enough,  considering  its  smallness,  the  waters  of  the  nor- 
thern slope  of  Chisinche  pass  by  the  Rios  de  San  Pedro, 
de  Pito,  and  de  Guallabamba  into  the  Pacific,  whilst  those 
Df  the  southern  declivity  flow  through  the  Rio  Alaques  and 
the  Rio  de  San  Felipe  into  the  Amazons  and  Atlantic 
Ocean.  The  union  of  the  Cordilleras  by  mountain  knots 
and  dykes  (sometimes  low,  like  the  Altos  just  mentioned ; 
sometimes  equal  to  Mont  Blanc  in  height,  as  on  the  road 
over  the  Paso  del  Assuay)  appears  to  be  a  more  recent 
and  also  a  less  important  phenomenon  than  the  upheaval 
of  the  divided  parallel  mountain  chain  itself.  As  Cotopaxi, 
the  greatest  of  the  volcanoes  of  Quito,  presents  much 
analogy  in  its  trachytic  rock  with  the  Antisana,  so  also 
we  again  meet  with  the  rows  of  blocks  (lines  of  fragments) 
which  have  already  occupied  us  so  long,  even  in  greater 
number  upon  the  slopes  of  Cotopaxi. 

It  was  especially  our  business  when  travelling  to  trace 
these  rows  to  their  origin,  or  rather  to  the  point  where  they 
are  concealed  beneath  the  perpetual  covering  of  snow.  Wo 
ascended  upon  the  south-western  declivity  of  the  volcano 
from  Mulalo  (Mulahalo),  along  the  Rio  Alaques,  which  is 
formed  of  the  Rio  de  los  Bafios  and  the  Rio  Barrancas,  up  to 
Pansache  (12,066  feet),  where  we  inhabited  the  spacious 
Casa  del  Paramo  in  the  grassy  plain  (el  Pajonal).  Although 
up  to  this  time  much  snow  had  fallen  at  night,  we  never- 
theless got  to  the  eastward  of  the  celebrated  Cabeza  del 
Inga,  first  into  the  Quebrada  and  Reventazoii  de  las  Minas, 
and  afterwards  still  further  to  the  east  over  the  Alto  de 
Suniguaicu  to  the  chasm  of  the  Lion  Mountain  (Puma- 
Urcu),  where  the  barometer  only  showed  an  elevation  of 
2263  toises,  or  14,471  feet.  Another  line  of  fragments 
which,  however,  we  only  saw  from  a  distance,  has  moved 
from,  the  eastern  part  of  the  snow-clad  ash-cone  towards  the 
Rio  Negro  (an  affluent  of  the  Amazon)  and  Yalle  vicioso.  It 
is  uncertain  whether  these  blocks  were  all  thrown  out  of  the 
crater  at  the  summit  to  a  great  height  in  the  air,  as  glow- 
ing, scoriaceous  masses  fused  only  at  the  edges  (some  angular, 
some  rounded,  of  6  or  8  feet  in  diameter,  rarely  conchoidal 
like  those  of  Antisana),  falling  oil  the  declivity  of  Cotopaxi 
and,  hastened  in  their  movement  by  the  rush  of  the  melted 
snow  water  ;  or  whether,  without  passing  through  the  air 


TRUE  VOLCANOES.  335 

they  were  forced  out  through  lateral  fissures  of  the  volcano, 
as  the  word  reventazon  would  indicate.  Soon  returning 
from  Suuiguaicu  and  the  Quebrada  del  Vi  estizo.  we  examined 
the  long  and  broad  ridge  which,  striking  from  N.W.  to  S.E., 
unites  Cotopaxi  with  the  Nevado  de  Quelenclaila.  Here  the 
blocks  arranged  in  rows  are  wanting,  and  the  whole  appears  to 
be  a  darn-like  upheaval,  upon  the  ridge  of  which  are  situated 
the  small  conical  mountain  el  Morro  and,  nearer  to  the  horse- 
shoe shaped  Quelendaria,  seAreral  marshes  and  two  small 
lakes  (Lagunas  de  Yauricocha  and  de  Verdecocha).  The 
rock  of  el  Morro  and  of  the  entire  linear  volcanic  upheaval 
was  greenish-gray  porphyritic  slate,  separated  into  layers  of 
eight  inches  thick,  which  dipped  very  regularly  towards  the 
east  at  60°.  Nowhere  was  there  any  trace  of  true  lava- 
streams?0. 

30  It  is  particularly  remarkable  that  the  vast  volcano  of  Coto- 
paxi, which  manifests  an  enormous  activity,  although,  indeed,  usually 
only  after  long  periods,  and  acts  destructively  upon  the  neighbour- 
hood, especially  by  the  inundations  which  it  produces,  exhibits  no 
visible  vapours  between  its  periodical  eruptions,  when  seen  either  in  the 
plateau  of  Lactacunga,  or  from  the  Paramo  de  Pansache.  From  several 
comparisons  with  other  colossal  volcanoes,  such  a  phenomenon  is 
certainly  not  to  be  explained  from  its  height  of  19,180  feet,  and  the 
great  tenuity  of  the  strata  of  air  and  vapour  corresponding  with  this 
elevation.  No  other  Nevado  of  the  equatorial  Cordilleras  shows 
itself  so  often  free  from  clouds  and  in  such  great  beauty  as  the  trun- 
cated cone  of  Cotopaxi,  that  is  to  say  the  portion  which  rises  above 
the  limit  of  perpetual  snow.  The  uninterrupted  regularity  of  this 
ash-cone  is  much  greater  than  that  of  the  ash-cone  of  the  Peak  of 
Teueriffe,  on  which  a  narrow  projecting  rib  of  obsidian  runs  down 
like  a  wall.  Only  the  upper  part  of  the  Tungurahua  is  said  for- 
merly to  have  been  distinguished  in  an  almost  equal  degree  by  the 
regularity  of  its  form,  but  the  terrible  earthquake  of  the  4th  Feb- 
ruary, 1797,  called  the  Catastrophe  of  Riobamba,  has  deformed  the 
mountain  cone  of  Tungurahua  by  fissures  and  the  falling  in  of  parts 
and  the  descent  of  loosened  wooded  fragments,  as  also  by  the  accu- 
mulation of  debris.  At  Cotopaxi,  as  even  Bouguer  observed,  the 
enow  is  mixed  in  particular  spots  with  crumbs  of  pumice-stoue, 
when  it  forms  a  nearly  solid  mass.  A  slight  inequality  in  the 
mantle  of  snow  is  visible  towards  the  north-west,  whei-e  two  fissure- 
like  valleys  run  down.  Black  rocky  ridges  ascending  to  the  summit 
are  seen  nowhere  from  afar,  although  in  the  eruptions  of  the  24th 
Juno  and  9th  December,  1742,  a  lateral  opening  showed  itself  halfway 
up  the  snow-covered  ash-cone.  "  There  opened,"  says  Bouguer  (Fiyui't. 
de  la  Terre,  p.  Ixviii ;  see  also  La  Condarniue,  Journal  du  Voyage  a 
I'EquatcUr,  p.  159),  "  a  new  mouth  towards  the  middle  of  the  paii 

Z2 


340  COSMOS. 

In  the  island  of  Lipari,  which  abounds  in  pumice- 
stone,  a  lava-stream  of  pumice-stone  and  obsidian  runs 
constantly  covered  with,  snow,  whilst  the  flame  always  issued  at  the 
top  of  the  truncated  cone."  Quite  at  the  top,  close  to  the  summit,  some 
horizontal,  black  streaks,  parallel  to  each  other,  but  interrupted,  are 
detected.  When  examined  with  the  telescope  under  various  illumi- 
nations they  appeared  to  me  to  be  rocky  ridges.  The  whole  of  this 
upper  part  is  steeper,  and  almost  close  to  the  truncation  of*  the  cone 
forms  a  wall-like  ring  of  unequal  height,  which,  however,  is  not 
visible  at  a  great  distance  with  the  naked  eye.  My  description  of  this 
nearly  perpendicular  uppermost  circumvallation,  has  already  attracted 
the  particular  attention  of  two  distinguished  geologists, — Darwin  ( Vol- 
canic Islands,  1844,  p.  83),  and  Dana  (Geology  of  the  U.S.  Explor.  Exped., 
1849,  p.  356).  The  volcanoes  of  the  Galapagos  Islands,  Diana's  Peak 
in  St.  Helena,  Teneriffe,  and  Cotopaxi,  present  analogous  formations. 
The  highest  point  which  I  determined  by  angles  of  altitude  in  the 
trigonometrical  measurement  of  Cotopaxi,  was  situated  in  a  black 
convexity.  It  is,  perhaps,  the  inner  wall  of  the  higher  and  more 
distant  margin  of  the  crater;  or  is  the  freedom  from  snow  of  the  pro- 
truding rock  caused  at  once  by  steepness  and  the  heat  of  the  crater? 
In  the  autumn  of  the  year  1800,  the  whole  upper  part  of  the  ash- 
cone  was  seen  to  be  luminous,  although  no  eruption,  or  even  emission 
of  visible  vapours  followed.  On  the  other  hand,  in  the  violent  erup- 
tion of  Cotopaxi  on  the  4th  January.  1803,  when  during  my  residence 
on  the  Pacific  coast  the  thundering  noise  of  the  volcano  shook  the 
windows  in  the  harbour  of  Guayaquil  (at  a  distance  of  148  geog. 
miles),  the  ash-cone  had  entirely  lost  its  snow,  and  presented  a 
most  threatening  appearance.  Was  such  a  heating  ever  observed 
before  ?  Even  very  recently,  as  we  learn  from  that  admirable,  and 
courageous  female  traveller,  Ida  Pfeiffer  (Meine  zweite  Weltreise,  Bd.  iii, 
s.  170),  the  Cotopaxi  had,  in  the  beginning  of  April,  1854,  a  violent 
eruption  of  thick  columns  of  smoke,  "through  which  the  fire  wound 
itself  like  flashing  flames."  May  this  luminous  phenomenon  have 
been  a  consequence  of  the  volcanic  lightning  excited  by  vaporization  ? 
The  eruptions  have  been  frequent  since  1851. 

The  great  regularity  of  the  snow-covered,  truncated  cone  itself, 
renders  it  the  more  remarkable  that  to  the  south-west  of  the  summit 
there  is  a  small,  grotesquely-notched,  rocky  mass  with  three  or  four 
points  at  the  lower  limit  of  the  region  of  perpetual  snow,  where 
the  conical  form  commences.  The  snow  remains  upon  it  only  in 
small  patches,  probably  on  account  of  its  steepness.  A  glance  at  my 
representation  (Atlas  Pittoresque  du  Voyage,  pi.  10),  shows  its  relation 
to  the  ash-cone  most  distinctly.  I  approached  nearest  to  this  blackish- 
gray,  probably  basaltic  rocky  mass,  in  the  Quebrada  and  Reventazon 
de  Minas.  Although  this  widely  visible  hill,  of  very  strange  appear- 
ance, has  been  generally  known  for  centuries  in  the  whole  province 
as  the  Cabeza  del  Inga,  two  very  different  hypotheses,  nevertheless, 
prevail  with  regard  to  its  origin  amongst  the  coloured  aborigines 
(fndios), — according  to  the  one,  it  is  merely  asserted,  that  the  rock 


TRUE   VOLCANOES.  341 

down  to  the  north  of  Caneto,  from  the  well-preserved, 
extinct  crater  of  the  Monte  di  Campo  Bianco  towards  the 
sea,  in  which  the  fibres  of  the  former  substance  run,  singu- 
larly enough,  parallel  to  the  direction  of  the  stream31.  The 

is  the  fallen  summit  of  the  volcano,  which  formerly  ended  in  a  point, 
without  any  statement  of  the  date  at  which  the  occurrence  took 
place;  according  to  the  second  hypothesis,  this  is  placed  in  the  year 
(1533)  in  which  the  Inca  Atahuallpa  was  strangled  in  Caxamarca, 
and  thus  connected  with  the  terrible  fiery  eruption  of  Cotopaxi, 
described  by  Herrera,  which  took  place  in  the  same  year,  and  also 
with  the  obscure  prophecy  of  Atahuallpa's  father,  Huayna  Capac, 
regarding  th«  approaching  fall  of  the  Peruvian  Empire.  Is  that 
\vhich  is  common  to  both  hypotheses, — namely,  the  opinion  that  this 
fragment  of  rock  formerly  constituted  the  apex  of  the  cone,—  the  tra- 
ditional echo,  or  obscure  remembrance  of  an  actual  occurrence  ?  The 
aborigines,  it  may  be  said,  in  their  uncultivated  state,  would  probably 
notice  facts  and  preserve  them  in  remembrance,  but  would  be  unable 
to  rise  to  geoguostic  combinations.  I  doubt  the  correctness  of  this 
objection.  The  idea  that  a  truncated  cone,  "  in  losing  its  apex,"  may 
have  thrown  it  off  unbroken,  as  large  blocks  were  thrown  out  during 
subsequent  eruptions,  may  present  itself  even  to  very  uncultivated 
minds.  The  terraced  pyramid  of  Cholula,  a  work  of  the  Tolteks,  is 
truncated.  The  natives  could  not  suppose  that  the  pyramid  was  not 
originally  completed.  They  therefore  invented  the  fable  that  an 
aerolite,  falling  from  heaven,  destroyed  the  apex ;  nay,  portions  of  the 
aerolite  were  shown  to  the  Spanish  conquerors.  Moreover,  how  can  we 
place  the  first  eruption  of  the  volcano  of  Cotopaxi  at  a  period  when 
the  ash-cone  (the  result  of  a  series  of  eruptions)  was  already  in  exist- 
ence ?  It  seems  probable  to  me,  that  that  the  Cabeza  del  Inga,  was  pro- 
duced at  the  spot  which  it  now  occupies ;  that  it  was  upheaved  there, 
like  the  Yana-Urcu  at  the  foot  of  Chimborazo,  and  like  the  Morro  on 
Cotopaxi  itself,  to  the  south  of  Suniguaica,  and  to  the  north-west  of 
the  small  lake  Yurak-cocha  (in  the  Qquechhua  language,  the  White 
Lake). 

With  regard  to  the  name  of  the  Cotopaxi,  I  have  stated  in  the 
first  volume  of  my  Kleinere  Schriften,  (s.  463,)  that  only  the  first  pai-t 
of  it  could  be  explained  from  the  Qquechhua  language,  being  the  word 
ccotto,  heap  or  mass,  but  that  pacsi  was  unknown.  La  Condamine 
(p.  53)  explains  the  whole  name  of  the  mountain,  saying  "  in  the  lan- 
guage of  the  Incas,  the  name  signifies  shining  mass"  Buachmann, 
however,  remarks  that,  in  this  case,  pacsi  is  replaced  by  the  word 
pacsa,  which  is  certainly  quite  different  from  it,  and  which  signifies 
lustre,  brilliancy,  especially  the  mild  lustre  of  the  moon  ;  to  express 
"  shining  mass,"  moreover,  in  accordance  with  the  spirit  of  the 
Qquechhua  language,  the  position  of  the  two  words  would  have  to  be 
reversed, — pacsaccotto. 

31  Friedrich  Hoffmann,  in  Poggendorff's  Annalen,  Bd.  xxvi,  1832, 
s.  48. 


342  COSMOS. 

extended  pumice  quarries,  four  miles  and  a  half  from  Lao 
tacunga,  present,  according  to  my  investigation  of  the  local 
conditions,  an  analogy  with  this  occurrence  on  Lipari.  These 
quarries,  in  which  the  pumice-stone,  divided  into  horizontal 
beds,  has  exactly  the  appearance  of  a  rock  in  position,  ex- 
cited even  the  astonishment  of  Bouguer  in  173732.  "On  vol- 
canic mountains,"  he  says,  "  we  only  find  simple  fragments 
of  pumice-stone  of  a  certain  size  ;  but  at  seven  leagues  to 
the  south  of  Cotopaxi;  in  a  point  which  corresponds  with 
our  tenth  triangle,  pumice-stone  forms  entire  rocks,  ranged  in 
parallel  banks  of  5  to  6  feet  in  thickness  in  a  space  of  more 
than  a  square  league.  Its  depth  is  not  known.  Imagine 
what  a  heat  it  must  have  required  to  fuse  this  enormous 
mass,  and  in  the  very  spot  where  it  now  occurs  ;  for  it  is 
easily  seen  that  it  has  not  been  deranged,  and  that  it  has 
cooled  in  the  place  where  it  was  liquefied.  The  inhabitants 
of  the  neighbourhood  have  profited  by  this  immense  quarry, 
for  the  small  town  of  Lactacunga,  with  some  very  pretty 
buildings,  has  been  entirely  constructed  of  pumice-stone,  since 
the  earthquake  which  overturned  it  in  1698." 

The  pumice  quarries  are  situated  near  the  Indian  vil- 
lage of  San  Felipe,  in  the  hills  of  Guapulo  and  Zumbalica, 
which  are  elevated  512  feet  above  the  plateau  and  9990  feet 
above  the  sea  level.  The  uppermost  layers  of  pumice-stone 
are,  therefore,  five  or  six  hundred  feet  below  the  level  of 
Mulalo,  the  once  beautiful  villa  of  the  Marquis  of  Maenza 
(at  the  foot  of  Cotopaxi),  also  constructed  of  blocks  of 
pumice-stone,  but  now  completely  destroyed  by  frequent 
earthquakes.  The  subterranean  quarries  are  at  unequal 
distances  from  the  two  active  volcanoes,  Tungurahua  and 
32  Bouguer,  Figure  de  la  Terre,  p.  Ixviii.  How  often,  since  the  earth- 
quake of  the  19th  July,  1698,  has  the  little  town  of  Lactacunga  been 
destroyed  and  rebuilt  with  blocks  of  pumice-stone  from  the  subterra- 
nean quarries  of  Zumbalica !  According  to  historical  documents  com- 
municated to  me  during  my  sojourn  in  the  country,  from  copies  of  the 
old  ones  which  have  been  destroyed,  and  from  more  recent  original 
documents  partially  preserved  in  the  archives  of  the  town,  the  destruc- 
tions occurred  in  the  years  1703  and  1736,  on  tho  9th  December, 
1742,  30th  November,  1744,  22nd  February,  1757,  10th  February, 
1766,  and  4th  April,  1768, — therefore  seven  times  in  65  years!  In 
the  year  1802  I  found  four-fifths  of  the  town  still  in  ruins  in  conse- 
quence of  the  great  earthquake  of  Riobamba  on  the  4th  February, 
1797. 


TRUE   VOLCANOES.  348 

Cotonaxi :  32  miles  from  the  former,  and  about  half  that  dis- 
tance from  the  latter.  They  are  reached  by  a  gallery.  The 
workmen  assert  that  from  the  horizontal  solid  layers,  of 
which  a  few  are  surrounded  by  loamy  pumice  fragments, 
quadrangular  blocks  of  20  feet,  divided  by  no  transverse  fis- 
sures, might  be  procured.  The  pumice-stone,  which  is  partly 
white  and  partly  bluish  gray,  consists  of  very  fine  and  long 
fibres,  with  a  silky  lustre.  The  parallel  fibres  have  some- 
times a  knotted  appearance,  and  then  exhibit  a  singular 
structure.  The  knots  are  formed  by  roundish  particles  of 
finely  porous  pumice-stone,  from  1 — 1^  line  in  breadth, 
around  which  long  fibres  curve  so  as  to  inclose  them. 
Brownish  black  mica  in  small  six-sided  tables,  white 
crystals  of  oligoclase,  and  black  hornblende  are  sparingly 
scattered  in  it ;  on  the  other  hand,  the  glassy  felspar,  which 
elsewhere  (Camaldoli,  near  Naples)  occurs  in  pumice-stone, 
is  entirely  wanting.  The  pumice-stone  of  Cotopaxi  is  very 
different  from  that  of  the  quarries  of  Zumbalica33 :  its  fibres 
are  short,  not  parallel,  but  curved  in  a  confused  man- 
ner. Magnesia-mica,  however,  is  not  peculiar  to  pumice- 
stone,  for  it  is  also  found  in  the  fundamental  mass  of  the 
trachyte34  of  Cotopaxi.  At  the  more  southern  volcano, 
Tungurahua,  pumice-stone  appears  to  be  entirely  wanting. 
There  is  no  trace  of  obsidian  in  the  vicinity  of  the  quar- 

33  This  difference  has  also  been   recognized   by  the    acute    Abich, 
(Ueber    Natur    und    Zusammenhang    vulkanischer    B'ddunyen,     1841, 
s.  83). 

34  The  rock  of  Cotopaxi  has  essentially  the  same  mineralogical  com- 
position, as  that  of  the  nearest  volcanoes,  Antisana  and  Tuugurahua. 
It  is  a  trachyte,  composed  of  oligoclase  and  augite,  and  consequently 
a  Chimborazo-rock  :  a  proof  of  the  identity  of  the  same  kind  of  volcanic 
mountain  in  masses  in  the  opposite  Cordilleras.     In  the  specimens  col- 
lected by  me  in  1802,  and  by  Boussingault  in  1831,  the  fundamental 
mass  is  partly  light  or  greenish  gray,  with  a  pitchstone-like  lustre  and 
translucent  at  the  edges  ;  partly  black,  nearly  resembling  basalt,  with 
large  and  small  pores,  which  possess  shining  walls.     The  inclosed  oligo- 
clase is  distinctly  limited ;  sometimes  in  very  brilliant  crystals,  very  dis- 
tinctly striated  on  the  cleavage  planes;  sometimes  in  small  fragments 
and  difficult  of  detection.     The  intermixed  augites  are  brownish  and 
blackish  green  and  of  very  variable  size.     Dark  laminae  of  mica  and 
black  metallic  grains  of  magnetic  iron  are  rarely  and  probably  quite 
accidentally  sprinkled  through  the  mass.      In  the  pores  of  a  mass  con- 
taining  much   oligoclase,   there   was   some   native   sulphur,  probably 
deposited  by  the  all- penetrating  sulphurous  vapours. 


344  COSMOS. 

ries  of  Zumbalica,  but  I  have  found  black  obsidian  with  a 
conchoidal  fracture  in  very  large  masses,  immersed  in  bluish 
gray  weathered  perlite,  amongst  the  blocks  thrown  out 
from  Cotopaxi  and  lying  near  Mulalo.  Of  this,  fragments 
are  preserved  in  the  Royal  Collection  of  Minerals  at  Berlin. 
The  pumice-stone  quarries  here  described,  at  a  distance  of 
sixteen  miles  from  the  foot  of  Cotopaxi,  appear  therefore, 
to  judge  from  their  mineralogical  nature,  to  be  quite  fo- 
reign to  that  mountain,  and  only  to  stand  in  the  same 
relation  to  it,  which  all  the  volcanoes  of  Pasto  and  Quito, 
occupying  many  thousand  square  miles,  present  to  the  vol- 
canic focus  of  the  equatorial  Cordilleras.  Have  these 
pumice-stones  been  the  centre  and  interior  of  a  proper 
crater  of  elevation,  the  external  wall  of  which  has  been 
destroyed  in  the  numerous  convulsions  which  the  surface 
of  the  earth  has  here  undergone  ?  or  have  they  been  depo- 
sited here  upon  fissures  in  apparent  rest,  during  the  most 
ancient  foldings  of  the  earth's  crust  ?  For  the  assump- 
tion of  aqueous  sedimentary  alluvia,  such  as  are  often  exhi- 
bited in  volcanic  tufaceous  masses  mixed  with  remains  of 
plants  and  shells,  is  attended  with  still  greater  difficul- 
ties. 

The  same  questions  are  suggested  by  the  great  mass  of 
pumice-stone,  at  a  distance  from  all  intuniescent  volcanic 
platforms,  which  I  found  on  the  Rio  Mayo  in  the  Cordil- 
lera of  Pasto,  between  Mamendoy  and  the  Cerro  del  Pul- 
pito,  36  miles  from  the  active  volcano  of  Pasto.  Leopold 
von  Buch  has  also  called  attention  to  a  similar  perfectly 
isolated  eruption  of  pumice-stone  described  by  Meyen,  which, 
consisting  of  boulders,  forms  a  hill  of  320  feet  in  height, 
near  the  village  of  Tollo,  to  the  east  of  Valparaiso,  in  Chili. 
The  volcano  Maypo,  which  upheaves  Jurassic  strata  in  its 
rise,  is  two  full  days' journey  from  this  eruption  of  pumice- 
stone  **.  The  Prussian  Ambassador  in  Washington,  Fried- 
rich  von  Gerolt,  to  whom  we  are  indebted  for  the  first 

35  "The  volcano  of  Maypo  (S.  lat.  34°  150  which  has  never  ejected 
pumice-stone,  is  at  a  distance  of  two  days'  journey  from  the  ridge  of 
Tollo,  which  is  320  feet  in  height  and  entirely  composed  of  pumice- 
stone,  inclosing  vitreous  felspar,  brown  crystals  of  mica,  and  small 
fragments  of  obsidian.  It  is,  therefore,  an  (independent)  isolated  erup- 
tion, quite  at  the  foot  of  the  Andes  and  close  to  the  plain."  Leop.  de 
Buch,  Desc.  Phys.  des  lies  Canaries,  1836,  p.  470. 


TRUE  VOLCANOES.  345 

coloured  geognostic  map  of  Mexico,  also  mentions  "a  subter- 
ranean quarry  of  pumice-stone  at  Bauten,"  near  Huichapa, 
32  miles  to  the  south-east  of  Queretaro,  at  a  distance  from 
all  volcanoes36.  The  geological  explorer  of  the  Caucasus, 
Abich,  is  inclined  to  believe  from  his  own  observations, 
that  the  vast  eruption  of  pumice-stone  near  the  village 
Tschegem,  in  the  little  Kabarda,  on  the  northern  declivity  of 
the  central  chain  of  the  Elburuz,  is,  as  an  effect  of  fissure, 
much  older  than  the  elevation  of  the  very  distant  conical 
mountain  just  menioned. 

If,  therefore,  the  volcanic  activity  of  the  earth,  by  radia- 
tion of  heat  into  space  during  the  diminution  of  its  original 
temperature,  and  in  the  contraction  of  the  superior  cooling 
strata,  produces  fissures  and  wrinkles  (fractures  et  rides), 
and  therefore  simultaneous  sinking  of  the  upper  and  up- 
heaval of  the  lower  parts37,  we  must  naturally  regard,  as 
the  measure  and  evidence  of  this  activity  in  the  various 
regions  of  the  earth,  the  number  of  recognizable  volcanic, 
platforms  (open,  conical,  and  dome-shaped  mountains)  up- 
heaved upon  fissures.  This  enumeration  has  been  repeat- 
edly and  often  very  imperfectly  attempted :  eruptive  hills 

36  Federico  de  Gerolt,  Cartas  Geognosticas  de  los  Principaks  Distritos 
Mineralcs  de  Mexico,  1827,  p.  5. 

37  On  the  solidification  and  formation  of  the  crusts  of  the  earth,  see 
Cosmos,  vol.  i,  pp.  164 — 166.      The  experiments  of  Bischof,  Charles 
Deville,  and  Delesse  have  thrown  a  new  light  upon  the  folding  of  the 
body  of  the  earth.      See  also  the  older,  ingenious  considerations  of 
Babbage,  on  the  occasion  of  his  thermit;  explanation  of  the  problem 
presented  by  the  temple  of  Serapis  to  the  north  of  Puzzuoli,  in  the 
Quarterly  Journal  of  the  Geological  Society  of  London,  voL  iii,  1847, 
p.  186 ;  Charles  Deville,  Sur  la  Diminution  de  Densite  dans  les  Roches 
en  passant  de  I'etat  cristallin  a  I'etat  vitreux,  in  the  Comptes  rendus 
de  VAcad.  des  Sciences,  t.  xx,  1845,  p.  1453;  Delesse,  Sur  les  Effets  de  la 
fusion,  t.  xxv,  1847,  p.  455;  Louis  Frapolli  Sur  la  Caractere  Geologique, 
in  the  Bull  de  la  Soc.  Geol.  de  France,  2me  se>ie,  t.  iv,  1847,  p.  627;  and 
above  all,  Elie  de  Beaumont,  in  his  important  work,  Notice  sur  les 
Systemes   de   Montagnes,    1852,   t.  iii.      The   following  three  sections 
deserve  the  particular  attention  of  geologists  :   Considerations  sur  les 
Soulevements  diis  a  une  diminution  lente  et  progressive  du  volume  de  la 
Terre,  p.  1330  ;   Sur  1'Ecrasement  Transversal  nomme  refoulement  par 
Saussure,  comme  une  des  causes  dc  V elevation  des  Chalnes  de  Montagnes, 
pp.  1317,  1333,  and  1346;  Sur  la  Contraction  que  les  Roches  fondues 
cprouvent  en  cristallisant,  tendant  des  le  commencement  du  rejroidisse- 
ment  du  Globe  a  rendre  sa  masse  interne  plus  petite  que  la  capadte  dt 
ton  enveloppe  exterieure,  p.  1235. 


346  COSMOS. 

and  solfataras,  belonging  to  one  and  the  same  system,  have 
been  referred  to  as  distinct  volcanoes.  The  magnitude 
of  the  space  in  the  interior  of  continents  which  has 
hitherto  remained  closed  to  all  scientific  investigation,  has 
not  been  so  great  an  obstacle  to  the  solidity  of  this  work  as 
is  commonly  supposed,  as  islands  and  regions  near  the  coast 
are  generally  the  principal  seat  of  volcanoes.  In  a  numerical 
investigation,  which  cannot  be  brought  to  a  -full  conclusion 
in  the  present  state  of  our  knowledge,  much  is  already 
gained  when  we  attain  to  a  result  which  is  to  be  regarded 
as  a  lower  limit,  and  when  we  can  determine  with  great 
probability  upon  how  many  points  the  fluid  interior  of  our 
earth  has  remained  in  active  communication  with  the  atmo- 
sphere within  the  historical  period.  Such  an  activity 
usually  manifests  itself  simultaneously  in  eruptions  from 
volcanic  platforms  (conical  mountains),  in  the  increasing  heat 
and  inflammability  of  thermal  springs  and  naphtha  wells, 
and  in  the  increased  extent  of  circles  of  commotion,  phe- 
nomena which  all  stand  in  intimate  connection  and  in  mu- 
tual dependence38.  Here  again,  also,  Leopold  von  Buch  has 
the  great  merit  of  having  (in  the  supplements  to  the  Phy- 
sical Description  of  the  Canary  Islands]  for  the  first  time 
undertaken  to  bring  the  volcanic  system  of  the  whole  earth, 
after  the  fundamental  distinction  of  Central  and  Linear  Vol- 
canoes, under  one  cosmical  point  of  view.  My  own  more 
recent,  and,  probably  for  this  reason,  more  complete  enumera- 
tion, undertaken  in  accordance  with  principles  which  I  have 
already  indicated  (pp.  245  and  271)  and  therefore  excluding 
unopened  bell-shaped  mountains  and  mere  eruptive  cones, 
gives,  as  the  probable  lower  numerical  limit  (noinbre  limite 
inferieur),  a  result  which  differs  considerably  from  all  pre- 

33  "  The  hot  springs  of  Saragyn  at  the  height  of  fully  5600  feet  are  re- 
markable for  the  part  played  by  the  carbonic  acid  gas  which  traverses 
them  at  the  period  of  earthquakes.  At  this  epoch,  the  gas,  like  the  car- 
bonated hydrogen  of  the  peninsula  of  Apscheron,  increases  in  volume 
and  becomes  heated,  before  and  during  the  earthquakes  in  the  plain  of 
Ardebil.  In  the  peninsula  of  Apscheron,  the  temperature  rises  36°, 
until  spontaneous  inflammation  occurs  at  the  moment  when  and  the 
spot  where  an  igneous  eruption  takes  place,  which  is  always  prognosti- 
cated by  earthquakes  in  the  provinces  of  Chemakhi  and  Apscheron." 
Abich,  in  the  Melanges  Physiques  et  Chimiques,  t.  ii,  1855,  pp.  364 — 36a 
(see  Cosmos,  vol.  v,  p.  175). 


TRUE  VOLCANOES.  347 

vious  ones.      It  is  an  attempt  to  indicate  the   volcanoes 
which  have  been  active  within  the  historical  period. 

The  question  has  been  repeatedly  raised  whether  in  those 
parts  of  the  earth's  surface,  in  which  the  greatest  number 
of  volcanoes  are  crowded  together,  and  the  reaction  of  the 
interior  of  the  earth  upon  the  hard  (solid)  crust  manifests 
the  most  activity,  the  fused  part  may  not  lie  nearer  to 
the  surface  ?  Whatever  be  the  course  adopted  to  determine 
the  average  thickness  of  the  solid  crust  of  the  earth  in  its 
maximum  :  whether  it  be  the  purely  mathematical'  one 
which  is  presented  by  theoretical  astronomy39,  or  the  simpler 
course,  founded  upon  the  law  of  the  increase  of  heat  with 
depth  and  the  temperature  of  fusion  of  rocks40,  still  the 
.solution  of  this  problem  presents  a  great  number  of  values 
which  are  at  present  undetermined.  Amongst  these  we 

39  W.  Hopkins,  Researches  on  Physical  Geology  in  the  Phil.  Transact, 
for  1839,  pt.  ii,  p,  311,  for  1840,  pt.  i,  p.  193,  and  for  1842,  pt.  i,  p.  43 ; 
also  with  regard  to  the  necessary  relations  of  stability  of  the  external 
surface;  Theory  of  Volcanoes  in  the  British  Association  Report  for  1847, 
pp.  45—49. 

40  Cosmos,  vol.  v.  pp.  35 — 37 ;  Naumann,  Geogncsie,  Bd.  i,  pp.  66 — 76  ; 
Bischof,  Wdrmelehre,  s.  382  ;  Lyell,  Principles  of  Geology,  1853,  pp.  536 
— 547  and  562.     In  the  very  interesting  and  instructive  work,  Sou- 
renirs  dun  Naturaliste,  by  A.  de  Quatrefages,   1854,  t.  ii,  p.  469,  the 
upper  limit  of  the  fused  liquid  strata,  is  brought  up  to  the  small  depth 
of  20  kilometres  :  "  as  most  of  the  silicates  fuse  at  1231°."     "  This  low 
estimate,"  as  Gustav  Rose  observes,    "  is  founded  in  an  error.     The 
temperature  of  2372°,  which  is  given  by  Mitscherlich  as  the  melting 
point  of  granite  (Cosmos,  vol.  i,  p.  26)  is  certainly  the  minimum  that  we 
can  admit.     I  have  repeatedly  had  granite  placed  in  the  hottest  parts  of 
a  porcelain  furnace,  and  it  was  always  but  imperfectly  fused.     The 
mica  alone  fuses  with  the  felspar  to  form  a  vesicular  glass ;  the  quartz 
becomes  opaque,  but  does  not  fuse.     This  is  the  case  with  all  rocks 
which  contain  quartz  ;  and  this  means  may  even  be  made  use  of  for 
the  detection  of  quartz  in  rocks,  in  which  its  quantity  is  so  small  that 
it   cannot   be   discovered   with   the  naked  eye, — for   example   in   the 
syenite  of  Plauen,  and  in  the  diorite,  which  we  brought  in  1829  from 
Alapajewsk  in  the  Ural.      All  rocks  which  contain  no  quartz,  or  any 
other  minerals  so  rich  in  silica  as  granite,  such  as  basalt  for  example, 
fuse  more  readily  than  granite  to  form  a  perfect  glass  in  the  porcelain 
furnace ;  but  not  over  the  spirit  lamp  with  a  double  current,  which  is 
nevertheless  certainly  capable  of  producing  a  temperature  of  1231°." 
In  Bischof  s    remarkable  experiments,  on  the  fusion  of   a  globule  of 
basalt,  even  this  mineral  appeared,  from  some  hypothetical  assumptions 
to  require  a  temperature  264°  higher  than  the  melting  point  of  copper. 
(Wdrmelekre  des  Jnnern  unsers  Erdkbrpcrs,  s.  473). 


348  COSMOS. 

have  to  mention  :  the  influence  of  an  enormous  pressure 
upon  fusibility, — the  different  conduction  of  heat  by  hetero- 
geneous rocks, — the  remarkable  enfeebling  of  conductibility 
with  a  great  increase  of  temperature,  treated  of  by  Edward 
Forbes, — the  unequal  depth  of  the  oceanic  basin, — and  the 
local  accidents  in  the  connection  and  nature  of  the  fissures, 
which  lead  down  to  the  fluid  interior !  If  the  greater  vici- 
nity of  the  upper  limit  of  the  fluid  interior  in  particular 
regions  of  the  earth  may  explain  the  frequency  of  volcanoes 
and  the  greater  multiplicity  of  communication  between  the 
depths  and  the  atmosphere,  this  vicinity  again  may  depend 
either  upon  the  relative  average  differences  of  elevation  of 
the  sea-bottom  and  the  continents,  or  upon  the  unequal 
perpendicular  depth  at  which  the  surface  of  the  molten  fluid 
mass  occurs,  in  various  geographical  longitudes  and  latitudes. 
But  where  does  such  a  surface  commence  ?  Are  there  not 
intermediate  degrees  between  perfect  solidity  and  perfect 
mobility  of  the  parts  ? — states  of  transition  which  have 
frequently  been  referred  to  in  the  discussions  relative  to 
the  plasticity  of  some  Plutonic  and  volcanic  rocks  which 
have  been  elevated  to  the  surface,  and  also  with  regard  to 
the  movement  of  glaciers.  Such  intermediate  states  abstract 
themselves  from  mathematical  considerations,  just  as  much 
as  the  condition  of  the  so-called  fluid  interior  under  an 
enormous  pressure.  If  it  be  not  even  very  probable  that 
the  temperature  everywhere  continues  to  increase  with  the 
depth  in  arithmetical  progression,  local  intermediate  dis- 
turbances may  also  occur,  for  example,  by  subterranean 
basins  (cavities  in  the  hard  mass),  which  are  from  time  to 
time  partially-filled  from  below  with  fluid  lava  and  vapours 
resting  upon  it41.  Even  the  immortal  author  of  the  Pro- 
togcea  allows  these  cavities  to  play  a  part  in  the  theory  of 
the  diminishing  ceotral  heat : — "  Postremo  credibile  est  con- 
trahentem  se  refrigeratione  crustam  bullas  reliquisse,  ingentes 
pro  rei  magnitudine  id  est  sub  vastis  fornicibus  cavitates"1* 

41  Cosmos,  vol.  v,  p.  168.     See  also  with  regard  to  the  unequal  dis- 
tribution of  the  icy  soil,  and  the  depth  at  which  it  commences,  inde- 
pendently  of  geographical  latitude,   the    remarkable    observations  of 
Captain  Franklin,  Errimn,  Kupffer,  and  especially  of  Middendorff  (loc, 
eit.  sup,  s.  42,  47  and  167). 

42  Leibnitz  in  the  Protugcea,  §  4. 


TRUE   VOLCANOES.  349 

The  more  improbable  it  is  that  the  thickness  of  the  crust 
already  solidified  is  the  same  in  all  regions,  the  more  impor- 
tant is  the  consideration  of  the  number  and  geographical 
position  of  the  volcanoes  which  have  been  open  in  his- 
torical periods.  Such  an  examination  of  the  geography  of 
volcanoes  can  only  be  perfected  by  frequently  renewed 
attempts. 


I.  EUROPE. 

Etna, 

Volcano  in  the  Liparis, 

Sfromboh, 

Iscliia, 

Vesuvius, 

Santorin, 

Lemnos, 

All  belong  to  the  great  basin  of  the  Mediterranean,  but 
to  its  European  and  not  to  its  African  shores ;  and  all  these 
seven  volcanoes  are  still  or  have  been  active  in  known  histo- 
rical periods  ;  the  burning  mountain  Mosychlos  in  Leninos, 
which  Homer  names  the  favourite  seat  of  Hephaestos  was 
only  destroyed  and  sunk  beneath  the  wraves  of  the  sea  by 
earthquakes,  together  with  the  island  of  Chryse,  after  the  time 
of  the  great  Macedonian  (Cosmos,  vol.  i,  p.  246;  Ukert,  Geogr. 
der  Griechen  und  Rdmer,  Th.  ii,  Abth.  1,  s.  198).  The 
great  upheaval  of  the  three  Kaimenes  in  the  middle  of 
the  Gulf  of  Santorin  (partly  inclosed  by  Thera,  Therasia, 
and  Aspronisi)  which  has  been  repeated  several  times  within 
about  1900  years  (from  186  B.C.  to  1712  of  our  epoch)  had  in 
their  production  and  disappearance  a  remarkable  similarity 
with  the  relatively  unimportant  phenomenon  of  the  tem- 
porary formation  of  the  islands  which  were  called  Graham, 
Julia,  and  Ferdinandea,  between  Sciacca  and  Pantellaria. 
Upon  the  peninsula  of  Methana,  which  has  already  been 
frequently  mentioned  (Cosmos,  vol.  i,  p.  239  ;  vol.  v,  p.  229), 
there  are  distinct  traces  of  volcanic  eruptions  in  the  reddish 
brown  trachyte  which  rises  from  the  limestone  near  Kai 
menochari  and  Kaimeno  (Curtius,  Pelop.  Bd.ii.  s.  439). 
Of  prehistoric  Volcanoes  with  frcFh  traces  of  the  emissioD 


350  COSMOS. 

of  lava,  from  craters  there  are,  counting  from  north  to  south, 
those  of  the  Eifel  (Mosenberg,  Geroldstein)  furthest  to  the 
north ;  the  great  crater  of  elevation  in  which  Schemnitz  is 
situated;  Auvergne  (Ghame  des  Puys  or  of  the  Monts 
Domes,  le  Gone  du  Cantal,  les  Monts-Dore}  ;  Vivarais,  in 
which  the  ancient  lavas  have  broken  out  from  gneiss  (Coupe 
d'yAsac,  and  the  cone  of  Montpezat)  ;  Yelay :  eruptions  of 
scorise  from  which  no  lavas  issue ;  the  Euganean  hills ;  the 
Alban  mountains,  Rocca  Monfina  and  Vultur,  near  Teano  and 
Melfi  ;  the  extinct  volcanoes  about  Olot  and  Castell  Follit 
in  Catalonia  j43  the  island  group,  las  Columbretes,  near  the 
coast  of  Valencia  (the  sickle-shaped  larger  island  Colum- 
braria  of  the  Romans,  upon  which  Montcolibre,  latitude 
39°54'  according  to  Captain  Smyth,  is  full  of  obsidian  and 
cellular  trachyte);  the  Greek  island  "Nisyros,  one  of  the 
Carpathian  Sporades,  of  a  perfectly  round  form,  in  the 
middle  of  which,  at  an  elevation  of  2270  feet  according  to 
Ross,  there  is  a  deep,  walled  cauldron  with  a  strongly  deto- 
nating solfatara,  from  which  at  one  time  radiating  lava- 
streams  poured  themselves  into  the  sea,  where  they  now 
form  small  promontories,  and  furnished  volcanic  millstones 
in  Strabo's  time  (Ross,  JReisen  auf  den  qriecliischen  Inseln, 
Bd.  ii,  s.  69  and  72—78).  For  the  British  islands  we 
have  here  still  to  mention,  on  account  of  the  antiquity  of 
the  formations,  the  remarkable  effects  of  submarine  vol- 
canoes upon  the  strata  of  the  lower  Silurian  formation 
(Llandeilo  strata)  cellular  volcanic  fragments  being  baked 
into  these  strata,  whilst,  according  to  Sir  Roderick  Murchi- 
son's  important  observation,  even  eruptive  trapp-masses  pene- 
trate into  lower  Silurian  strata  in  the  Corndon  mountains 
(Shropshire  and  Montgomeryshire)  ;**  the  dyke-phenomena 
of  the  isle  of  Arran  ;  and  the  other  points  in  which  the  in- 
terference of  volcanic  activity  is  visible,  although  no  traces 
of  true  platforms  are  to  be  discovered. 

43  With  regard  to  Vivarais  and  Velay,  see  the  very  recent  and  accu- 
rate researches  of  Girard  in  his  GeologiscJien  Wandcrungen,  Bd.  i, 
(1856)  s.  161,  173  and  214.  The  ancient  volcanoes  of  Olot  were 
discovered  by  the  American  geologist  Maclure  in  1808,  visited  by  Lyell 
in  1830,  and  well  described  and  figured  by  the  latter  in  his  Manual  of 
Geology  1855,  pp.  535 — 542. 

41  Sir  Roderick  Murchison,  Siluria,  pp.  20  and  55—58  (Lyell, 
Manual,  p.  563). 


TKUE  VOLCANOES. 


II.  ISLANDS  OP  THE  ATLANTIC  OCEAN. 

The  volcano  Esk,  upon  the  island  of  Jan  Mayen,  ascended 
by  the  meritorious  Scoresby  and  named  after  his  ship; 
height  scarcely  1600  feet.  An  open,  not  ignited  summit- 
crater  ;  basalt,  rich  in  pyroxene  and  trass. 

South-west  of  the  Esk,  near  the  North  Cape  of  Egg  Island, 
another  volcano,  which,  in  April  1818,  presented  high  erup- 
tions of  ashes  every  four  months. 

The  Beerenberg,  6874  feet  in  height,  in  the  broad,  north- 
eastern part  of  Jan  Mayen  (lat.  71°  4")  is  not  known  to  be  a 
volcano.46 

Volcanoes  of  Iceland :  Oerafa,  Hecla,  Rauda-Kamba  .  .  . 

Volcano  of  the  island  of  Pico46  in  the  Azores  :  a  great 
eruption  of  lava  from  the  1st  May  to  the  5th  June,  1800. 

The  Peak  of  Teneriffe. 

Volcano  of  Fogo,41  ono  of  the  Cape  de  Verde  Islands. 

Prehistoric  volcanic  activity. — This  on  Iceland  is  less  defi- 
nitely attached  to  certain  centres.  If  we  divide  the  volcanoes 
of  the  island,  with  Sartorius  von  Waltershausen,  into  two 
classes,  of  which  those  of  the  one  have  only  had  a  single 
eruption,  whilst  those  of  the  other  repeatedly  emit  lava- 
streams  at  the  same  principal  fissure,  we  must  refer  to  the 
former,  ftauda-Kamba,  Scaptar,  Ellidavatan,  to  the  south- 
east of  Reykjavik  .  .  .  . ;  to  the  second,  which  exhibits  a 
permanent  individuality,  the  two  highest  volcanoes  of  Ice- 
land Oerafa  (more  than  6390  feet)  and  Snaefiall,  Hecla,  <fcc. 
Snaefiall  has  not  been  in  activity  within  the  memory  of  man, 
whilst  Oerafa  is  known  by  the  fearful  eruptions  of  1362  and 
1727  (Sart.  von  Waltershausen,  Skizze  von  Island,  a.  108 

45  Scoresby,  Account  of  the  Arctic  Regions,  vol.  i,  pp.  155 — 169,  tab. 
v  and  vi. 

46  Leop.  von  Buch,  Descr.  des  lies  Canaries,  pp.  357 — 369,  and  Land- 
grebe,  Naturgcschichte  der   Vulkane,  1855,  Bd.  i,  s.  121 — 136  :  and  with 
regard  to  the  circumvallations  of  the  craters  of  elevation   (Caldeiras) 
upon  the  Islands  of  Saint  Michael,  Fayal  and  Terceira  (from  the  maps 
of  Captain  Vidal)  (see  page  226).     The  eruptions  of  Fayal  (1672)  and 
Saint  George  (1580  and  1808)  appear  to  be  dependent  upon  the  prin- 
cipal volcano,  the  Pico. 

*  See  pages  248  and  262. 


352  COSMOS. 

and  112).  In  Madeira,48  the  two  highest  mountains,  the 
conical  Pico  Huivo,  6060  feet  in  height,  and  the  Pico  de 
Torres,  which  is  but  little  known,  covered  on  their  steep 
declivities  with  scoriaceous  lavas,  cannot  be  regarded  as  the 
central  point  of  the  former  volcanic  activity  on  the  whole 
island,  as  in  many  parts  of  the  latter,  especially  towards  the 
coasts,  eruptive-orifices  and  even  a  large  crater,  that  of  the 
Lagoa,  near  Machico,  are  met  with.  The  lavas,  thickened 
by  confluence,  cannot  be  traced  far  as  separate  streams. 
Remains  of  ancient  Dicotyledonous  and  .Fern -like  vegeta- 
tion, carefully  investigated  by  Charles  Bunbury,  are  found 
buried  in  upheaved  strata  of  volcanic  tufa  and  loam,  some- 
times covered  by  more  recent  basalt.  Fernando  de  Noronha, 
lat.  3°  50'  S.  and  2°  27'  to  the  east  of  Pernambuco  :  a  group 
of  very  small  islands ;  phonolitic  rocks  containing  horn- 
blende,— no  crater,  but  vein-fissures  filled  with  trachyte 
and  basaltic  amygdaloid,  penetrating  white  tufa  layers.49 
The  island  of  Ascension  ;  highest  summit  2868  feet ;  basal- 
tic lavas  with  more  glassy  felspar  than  olivine  sprinkled 
through  them,  and  well  bounded  streams  traceable  up  to  the 
eruptive  cone  of  trachyte.  The  latter  rock  of  light  colours, 
often  broken  up  like  tufa,  predominates  in  the  interior  and 
south-east  of  the  island.  The  masses  of  scoriae  thrown  out 
from  Green  Mountain,  inclose  immersed  angular  fragments60 
containing  syenite  and  granite,  which  remind  one  of  the 
lavas  of  Jorullo.  To  the  westward  of  Green  Mountain, 
there  is  a  large  open  crater.  Volcanic  bombs,  partly  hollow, 
of  as  much  as  10  inches  in  diameter  lie  scattered  about  in 
innumerable  quantities,  together  with  large  masses  of  obsi- 
dian. Saint  Helena  :  the  whole  island  volcanic,  the  beds  ol 
lava  in  the  interior  rather  felspathic ;  basaltic  towards  the 
coast,  penetrated  by  innumerable  dykes  as  at  Flagstaff  Hill. 
Between  Diana  Peak  and  JS"estlodge,  in  the  central  series  of 
mountains,  is  the  curved  and  crescentic  shaped  fragments 
of  a  wider,  destroyed  crater  full  of  scoriae  and  cellular  lava 

48  Results  of  the  observations  upon  Madeira  by  Sir  Charles  Lyell  and 
Hartung  in  the  Manual  of  Geology  1855,  pp.  515 — 525. 

49  Darwin,  Volcanic  Islands  1844,  p.  23,  and  Lieutenant  Lee,  Cruise 
of  the  U.S.  Brig  Dolphin,  1 854,  p.  80. 

50  See  the  admirable  description  of  Ascension  in  Darwin's  Volcanic 
Islands,  pp.  40  and  41. 


TRUE   VOLCANOES.  353 

"the  mere  wreck51  of  one  great  crater  is  left  ").  The  beds  of 
lava  are  not  limited  and  consequently  cannot  be  traced  as  true 
streams  of  small  breadth.  Tristan  da  Cuiiha  (kt.  37°  3'  S., 
long.  11°26'W.)  discovered  as  early  as  1506  by  the  Portuguese  -, 
a  small  circular  island  of  six  miles  in  diameter,  in  the 
centre  of  which  a  conical  mountain  is  situated,  described  by 
Captain  Denham  as  about  8300  feet  in  height  and  composed 
of  volcanic  rock  (Dr.  Petermann's  Geogr.  Mittheil.  1855, 
No.  iii,  s.  84).  To  the  south-east,  but'  in  53°  S.  latitude, 
lies  the  equally  volcanic  Thompson's  Island  and  between 
the  two  in  the  same  direction,  Gough  Island,  &lso  called 
Diego  Alvarez.  Deception  Island,  a  slender,  narrowly 
opened  ring  (S.  lat.  62°  55'),  and  Bridgeman's  Island  belong- 
ing to  the  South  Shetlands  group ;  both  volcanic,  with  layers 
of  ice,  pumice-stone,  black  ashes  and  obsidian ;  perpetual 
eruption  of  hot  vapours  (Kendal,  Journal  of  the  Geographical 
Society,  vol.  i,  1831,  p.  62).  In  February,  1842,  Deception 
Island  was  seen  to  produce  flames  simultaneously  at  13 
points  in  the  ring  (Dana  in  United  States  Explor.  Exped. 
vol.  x,  p.  548).  It  is  remarkable  that,  as  so  many  islands  in 
the  Atlantic  Ocean  are  volcanic,  neither  the  entire  flat  islet 
of  Saint  Paul52  (Penedo  de  S.  Pedro),  one  decree  to  the  north 
of  the  equator  ;  nor  the  Falklands  (with  thin  quartzose 
clay-slate),  South  Georgia  or  Sandwich  land,  appear  to  offer 
any  volcanic  rock.  On  the  other  hand  a  region  of  the 
Atlantic  Ocean,  about  0°  20'  to  the  south  of  the  equator, 
longitude  22°  W.,  is  regarded  as  the  seat  of  a  submarine 
volcano.53  In  this  vicinity  Krusenstern  saw  black  columns 
of  smoke  rise  out  of  the  sea  (19th  May  1806),  and  in  1836 
volcanic  ashes  collected  at  the  same  point  (south-east  from 
the  above  mentioned  rock  of  Saint  Paul)  on  two  occasions, 

51  Darwin,  pp.  84  and  92,  with  regard  to  "  the  great  hollow  space  or 
valley  southward  of  the  central  curved  ridge,  across  which  the  half  of 
the  crater  must  once  have  extended.     It  is  interesting  to  trace  the  steps, 
by  which  the  structure  of  a  volcanic  district  becomes  obscured  and 
finally   obliterated"  (See  also  Scale,  Geognosy  of  the  Island  of  Sain 
Helena,  p.  28). 

52  St.  Paul's  Rocks.    (See  Darwin,  pp.  31—33  and  125). 

53  Daussy  on  the  probable  existence  of  a  submarine  volcano  in  the 
Atlantic,   in  the  Comptes  rendus  de  I' A  cad.  des  Sciences,  t.  vi,  1858, 
p.  512 ;  Darwin,   Volcanic  Islands,  p.  92  ;  Lee,  Cruise  of  the  U.S.  Brig 
Dolphin,  pp.  2—55  and  61. 

VOL.  V.  2  A 


354:  COSMOS. 

were  exhibited  to  the  Asiatic  Society  of  Calcutta.  According 
to  very  accurate  investigations  by  Daussy,  singular  shocks 
and  agitation  of  the  sea,  ascribed  to  the  commotion  of  the 
sea-bottoin  by  earthquakes,  have  been  observed  in  this  vol- 
canic region,  as  it  is  called  in  the  new  and  beautiful  American 
chart  of  Lieutenant  Samuel  Lee  (Track  of  the  Surveying  Brig 
Dolphin,  1854),  five  times  between  1747  and  Krusenstern's 
circumnavigation  of  the  globe  and  seven  times  from  1806  to 
1836.  But  during  the  recent  expedition  of  the  brig  Dol- 
phin (January  1852),  as  previously  (1838),  during  Wilkes's 
exploring  expedition,  nothing  remarkable  was  observed, 
although  the  brig  was  ordered  "  on  account  of  Krusenstern's 
volcano  "  to  make  investigations  with  the  lead  between  the 
equator  and  7°  S.  latitude,  and  about  18°  to  27°  longitude. 

III.  AFRICA. 

It  is  stated  by  Captain  Allan  that  the  volcano  Mongo-ma 
Leba  in  the  Cameroon  Mountains  (4°  12'  N.  lat.),  westward 
of  the  mouth  of  the  river  of  the  same  name  in  the  Bight  of 
Biafra,  and  eastward  of  the  Delta  of  the  Kowara,  or  Niger, 
emitted  an  eruption  of  lava  in  the  year  1838.  The  four 
high  volcanic  islands  of  Annabon,  St.  Thomas,  Isla  do 
Principe,  and  San  Fernando  Po,  which  run  on  a  fissure 
in  a  direct  linear  series  from  SS.W.  to  NN.E.,  point  to  the 
Cameroons,  which,  according  to  the  measurements  of  Captain 
Owen  and  Lieutenant  Boteler,  rises  to  the  great  altitude  of 
nearly  13,000  feet.64 

A  volcano  (?)  a  little  to  the  west  of  the  Snowy  Mountain 
Kignea  in  Eastern  Africa,  about  1°20'  S.  lat.  was  discovered 
by  the  missionary  Krapf  in  1849,  near  the  source  of  the 
River  Dana,  about  320  geographical  miles  north-west  of  the 
coast  of  Mombas.  In  a  parallel  nearly  two  degrees  more 
southerly  than  the  Kignea  is  situated  another  snowy  moun- 
tain, the  Kilimandjaro,  which  was  discovered  by  the  mis- 
sionary Rebmann  in  1847,  perhaps  scarcely  200  geographical 
miles  from  the  same  coast.  A  little  to  the  westward  lies  a 
third  snowy  mountain,  the  Doengo  Engai,  seen  by  Captain 

54  Gumprecht,  Die  vulkanische  ThatigTceit  auf  dem  Festlande  von 
Afrtfca,  in  Arabien  und  auf  den  Insdn  des  rothen  Meeres,  1849,  s.  18. 


TRUE  VOLCANOES.  355 

Short.     The  knowledge  of  the  existence  of  these  mountains 
is  the  result  of  laborious  and  hazardous  researches. 

Evidences  of  pre-historical  volcanic  action  in  the  great 
continent,  the  interior  of  which  between  the  seventh  degree 
north  and  the  twelfth  degree  south  latitude  (the  parallels  of 
Adamaua  and  the  Lubalo  Mountain,  which  acts  as  a  water- 
shed,) still  remains  so  unexplored,  are  furnished,  according 
to  Ruppell,  by  the  country  surrounding  the  Lake  Tzana,  in 
the  kingdom  of  Gondar,  as  well  as  by  the  basaltic  lavas, 
trachytes,  and  obsidian  strata  of  Shoa,  according  to  Rochet 
d'Hericourt,  whose  mineralogical  specimens,  quite  analogous 
to  those  of  Cantal  and  Mont  Dore,  may  have  been  exa- 
mined by  Dufrenoy  (Comptes  rendus,  t.  xxii.  pp.  806 — 810). 
Though  the  conical  mountain  Koldghi  in  Cordofan  is  not 
now  seen  either  in  a  burning  or  smoking  state,  yet  it  ap- 
pears that  the  existence  of  a  black,  porous,  and  vitrified  rock 
has  been  ascertained  there.65 

In  Adamaua,  south  of  the  great  Benue  river,  rise  the 
isolated  mountain-masses  of  Bagele  and  Alantika,  which 
from  their  conical  and  dome-like  forms  appeared  to  Dr.  Earth, 
on  his  journey  from  Kuka  to  lola,  to  resemble  trachyte 
mountains.  According  to  Petermann's  notices  from  the  note- 
books of  Overweg,  (of  whose  researches  natural  science  was 
so  early  deprived)  that  traveller  found  in  the  district  of 
Gudsheba,  westward  of  the  lake  of  Tshad,  separate  basaltic 
cones,  rich  in  olivine  and  columnar  in  form,  which  were 
sometimes  intersected  by  layers  of  the  red,  clayey-sandstone, 
and  sometimes  by  those  of  quartzose  granite. 

The  small  number  of  now  ignited  volcanoes  in  the  undi- 
vided continents,  whose  coast-lands  are  sufficiently  known, 
is  a  very  remarkable  phenomenon.  Can  it  be  that  in  the 
unknown  regions  of  Central  Africa,  especially  south  of  the 
equator,  large  basins  of  water  exist,  analogous  to  Lake 
TJniames  (formerly  called  by  Dr.  Cooley,  N 'yassi),  on  whose 
shores  rise  volcanoes,  like  the  Demavend  near  the  Caspian 
Sea  ?  Much  as  the  natives  are  accustomed  to  move  about 
over  the  country,  none  of  them  have  hitherto  brought  us  the 
least  notice  of  any  such  thing  ! 

55  Cosmos,  vol.  1,  p.  244,  note  J.  For  the  whole  of  the  phenomena 
hitherto  known  in  Africa,  see  Landgrebe,  Natwyescltichte  der  Vulkanc, 
Bd.  i,  B.  195—219. 

2  A2 


356  COSMOS. 


IV.  ASIA. 

a.  The  Western  and  Central  part. 

The  volcano  of  Demavend,66  in  a  state  of  ignition,  but, 
according  to  the  accounts  of  Olivier,  Morier  and  Taylor 
Thomson  (1837),  smoking  only  moderately,  and  not  uninter- 
ruptedly. 

The  volcano  of  Medina  (eruption  of  lava  in  1276). 

The  volcano  of  Djebel  el  Tir  (Tair  or  Tehr),  an  insular 
mountain  895  feet  high,  between  Loheia  and  Massaua  in  the 
Red  Sea. 

The  volcano  of  Peshan,  northward  of  Kutsche  in  the  great 
mountain-chain  of  the  Thian-schan  or  Celestial  Mountains  in 
Central  Asia ;  eruptions  of  lava  within  the  true  historical 
period,  from  the  year  89  up  to  the  beginning  of  the  seventh 
centuiy  of  our  era. 

The  volcano  of  Ho-cheu,  called  also  sometimes  in  the  very 
circumstantial  Chinese  geographies  the  volcano  of  Turfan ; 
120  geographical  miles  from  the  great  Solfatara  of  Urumtsi, 
near  the  eastern  extremity  of  the  Thian-schan,  in  the  direc- 
tion of  the  beautiful  fruit  country  of  Hami. 

The  volcano  of  Demavend,  which  rises  to  a  height  of  up- 

56  The  height  of  Demavend  above  the  sea  was  given  by  Ainsworth 
at  14,695,  but  after  correcting  a  barometrical  result,  probably  attri- 
butable to  an  error  of  the  pen  (Asie  Centrale,  t.  iii,  p.  327),  it  amounts, 
according  to  Ottman's  tables  to  fully  18,633  feet.  A  somewhat  greater 
elevation,  20,085  feet,  is  given  by  the  angles  of  altitude  worked  by  my 
friend,  Captain  Lemm,  of  the  Russian  navy,  in  the  year  1839,  and 
which  are  certainly  very  correct,  but  the  distance  is  not  trigonome- 
trically  laid  down,  and  rests  on  the  presumption  that  the  volcano 
of  Demavend  is  66  versts  distant  from  Teheran  (one  equatorial 
degree  being  equal  to  104^y  versts).  Hence  it  would  appear  that  the 
Persian  volcano  of  Demavend,  covered  with  perpetual  snow,  situated  so 
near  the  southern  shore  of  the  Caspian  Sea,  but  distant  600  geogra- 
phical miles  from  the  Colchian  coast  of  the  Black  Sea,  is  higher  than 
the  great  Ararat  by  about  2989  feet  and  the  Caucasian  Elburuz  by 
probably  1600  feet.  On  the  Demavend,  see  Hitter,  Erdkunde  von 
Asien,  Bd.  vi,  Abth.  i,  s.  551 — 571,  and  on  the  connection  of  the  name 
Albordj,  taken  from  the  mythic  and  therefore  vague  geography  of  the 
Zend-nation,  with  the  modern  name  Elburz  (Koh  Alburz  of  Kazwini) 
and  Elburuz,  see  ibid.  s.  43—49,  424,  552,  and  555. 


TRUE  VOLCANOES.  357 

wards  of  19,000  feet,  lies  nearly  36  geographical  miles  from 
the  southern  shore  of  the  Caspian  Sea,  in  Mazeuderan,  and 
almost  at  the  same  distance  from  Resht  and  Asterabad,  on 
the  chain  of  the  Hindu-kho  which  slopes  suddenly  down 
to  the  west  in  the  direction  of  Herat  and  Mesh  id.  I  have 
elsewhere  (Asie  Centrale,  t.  i,  pp  124 — 129  ;  t.  iii,  pp.  433— 
435)  mentioned  the  probability  that  the  Hindu-kho  of 
Chitral  and  Kafiristan  is  a  westerly  continuation  of  the 
mighty  Kuen-lim,  which  bounds  Tibet  towards  the  north 
and  intersects  the  Bolor  Mountains  in  the  Tsungling.  The 
Demavend  belongs  to  the  Persian  or  Caspian  Elburz,  a  sys- 
tem of  mountains  which  must  not  be  confounded  with  the 
Caucasian  ridge  of  the  same  name  (now  called  Elburuz),  and 
which  lies  7£°  further  north  and  10°  further  west.  The 
word  Elburz  is  a  corruption  of  Alborj,  or  Mountain  of  the 
World,  which  is  connected  with  the  ancient  cosmogony  of 
the  Zends. 

While  the  volcano  of  Demavend,  according  to  the  gene- 
rality of  geognostic  views  on  the  direction  of  the  mountain- 
chains  of  Central  Asia,  bounds  the  great  Kuen-lun  chain 
near  its  western  extremity,  another  igneous  appearance  at 
its  eastern  extremity,  the  existence  of  which  I  was  the  first 
to  announce  (Asie  Centrale,  t.  ii,  pp.  427  and  483),  deserves 
particular  notice.  In  the  course  of  the  important  researches 
which  T  recommended  to  my  respected  friend  and  colleague 
in  the  Institute,  Stanislas  Julien,  with  the  view  of  deriving 
information  from  the  rich  geographical  sources  of  old  Chinese 
literature  on  the  subject  of  the  Bolor,  the  Kuen-lun,  and  the 
Sea  of  Stars,  that  intelligent  investigator  discovered  in  the 
great  Dictionary  published  in  the  beginning  of  the  eighteenth 
century  by  the  Emperor  Yong-ching  a  description  of  the 
"  eternal  flame "  which  issues  from  an  opening  in  the  hill 
called  Shin-khien,  on  the  eastern  slope  of  the  Kuen-lun. 
This  luminous  phenomenon,  however  deeply  seated  it  may 
be,  cannot  well  be  termed  a  volcano.  It  appears  to  me 
rather  to  present  an  analogy  with  the  Chimaera  in  Lycia, 
near  Deliktash  and  Yanartash,  which  was  so  early  known 
to  the  Greeks.  This  is  a  stream  of  fire,  an  issue  of  gas  con- 
stantly kindled  by  volcanic  action  in  the  interior  of  the 
earth  (See  page  256,  note  50). 

Arabian  writers  inform   us,  though  lor  the   most   part 


358  COSMOS. 

without  quoting  any  precise  year,  that  lava-ei  uptions  have 
taken  place  during  the  middle  ages  on  the  south-western 
shore  of  Arabia,  in  the  insular  chain  of  the  Zobayr,  in  the 
Straits  of  Bab-el-Mandeb  and  Aden  (Wellsted,  Travels  in 
Arabia,  vol.  ii,  pp.  466 — 468),  in  Hadhramaut,  in  the  Strait 
of  Ormuz,  and  at  different  points  in  the  western  portion  of 
the  Persian  Gulf.  These  eruptions  have  always  occurred  on 
a  soil  which  had  already  been  in  pre-historical  times  the  seat 
of  volcanic  action.  The  date  of  the  eruption  of  a  volcano  at 
Medina  itself,  12|°  northward  of  the  Straits  of  Bab-el- 
Mandeb,  was  found  by  Burckhardt  in  Samhudy's  Chronicle 
of  the  famous  city  of  that  name  in  the  Hedjaz.  It  took 
place  on  the  2nd  November,  1276.  According  to  Seetzen, 
however,  Abulmahasen  states  that  an  igneous  eruption  had 
occurred  there  in  1254,  which  is  twenty-two  years  earlier 
(see  Cosmos,  vol.  i,  p.  246).  The  volcanic  island  of  Djebel- 
tair,  in  which  Vincent  recognized  the  "  burnt-out  island  "  of 
the  Periplus  Maria  lErytJircei,  is  still  active  and  emits  smoke, 
according  to  Botta  and  the  accounts  collected  by  Ehrenberg 
and  Russegger  (Jteisen  in  Europa,  Asien  und  Africa,  Bd.  ii, 
Th,  1,  1843,  s.  54).  For  information  respecting  the  entire 
district  of  the  Straits  of  Bab-el-Mandeb,  with  the  basaltic 
island  of  Perini, — the  crater-like  circumvallation,  within 
which  lies  the  town  of  Aden, — the  island  of  Seerah  with 
streams  of  obsidian,  covered  with  pumice, — the  island- 
groupes  of  the  Zobayr  and  the  Farsan  (the  volcanic  nature 
of  the  latter  was  discovered  by  Ehrenberg  in  1825)  I  refer 
my  readers  to  the  interesting  researches  of  Ritter  in  his 
Erdkunde  von  Asien,  Bd.  viii,  Abth.  1,  s.  664—707,  889— 
891,  and  1021—1034. 

The  volcanic  mountain-chain  of  the  Thian-schan  (Asie 
Centrale,  t.  i,  pp.  201 — 203  ;  t.  ii,  pp.  7 — 51),  a  range  which 
intersects  Central  Asia  between  Altai  and  Kuen-lun  from 
east  to  west,  formed  at  one  period  the  particular  object  of 
my  investigations,  so  that  I  have  been  enabled  to  add  to  the 
few  notices  obtained  by  Abel-Remusat  from  the  Japanese 
Encyclopaedia,  some  fragments  of  greater  importance  dis- 
covered by  Klaproth,  Neumann,  and  Stanislas  Julien  (Asie 
Centrale,  t.  ii,  pp.  39—50  and  335—364).  The  length  of 
the  Thian-schan  is  eight  times  greater  than  that  of  the 
Pyrenees,  if  we  include  the  Asferah  which  is  on  the  other 


TKUE  VOLCANOES.  359 

side  of  the  intersected  meridian-chain  of  the  Kusyurt-Bolor, 
stretching  westward  as  far  as  the  meridian  of  Samarcand, 
and  in  which  Ibn  Haukal  and  Ibn-al-Vardi  describe  streams 
of  fire,  and  notice  luminous  (?)  fissures  emitting  sal  am- 
moniac (see  the  account  of  Mount  Botom,  ut  supra).  In 
the  history  of  the  dynasty  of  Thang  it  is  expressly  stated 
that  on  one  of  the  slopes  of  the  Pe-shan,  which  continually 
emits  fire  and  smoke,  the  rocks  burn,  melt  and  flow  to  the 
distance  of  several  li,  like  a  "  stream  of  melted  fat.  The 
soft  mass  hardens  as  it  cools."  It  is  impossible  to  describe 
more  characteristically  the  appearance  of  a  stream  of  lava. 
Moreover,  in  the  forty-ninth  book  of  the  great  geography  of 
the  Chinese  empire,  which  was  printed  at  Pekin  from  1789 
to  1804  at  the  expense  of  the  state,  the  burning  mountains 
of  the  Thian-schan  are  described  as  "  still  active."  Their 
position  is  very  central,  being  nearly  equi-distant  (1520  geo- 
graphical miles)  from  the  nearest  shore  of  the  Frozen  Ocean 
and  from  the  mouth  of  the  Indus  and  Ganges,  1020  miles 
from  the  Sea  of  Aral,  172  and  208  miles  from  the  salt-lakes 
of  Issikal  and  Balkasch.  Information  respecting  the  flames 
issuing  from  the  mountain  of  Turfan  (Hotscheu)  has  also 
been  furnished  by  the  pilgrims  of  Mecca,  who  were  ofiicially 
examined  at  Bombay  in  the  year  1835  (Journal  of  the  Asiatic 
Soc.  of  Bengal,  vol.  iv,  1835",  pp.  657—664).  When  may  we 
hope  to  see  the  volcanoes  of  Peschan  and  Turfan,  Barkul  and 
Hami  explored  by  some  scientific  traveller,  by  way  of 
Gouldja  on  the  Ili,  which  may  be  easily  reached. 

The  better  knowledge  now  possessed  of  the  position  of  the 
volcanic  mountain  chain  of  the  Thian-schan  has  very  naturally 
given  rise  to  the  question  whether  the  fabulous  territory  of 
Gog  and  Magog  where  "  eternal  fire  "  is  said  to  burn  at  the 
bottom  of  the  River  El  Macher,  is  not  in  some  way  con- 
nected with  the  eruptions  of  the  Peschan  or  the  volcano  of 
Turfan.  This  oriental  myth,  which  had  its  origin  westward 
of  the  Caspian  Sea,  in  the  Pylis  Albanian  near  Derbend,  has 
travelled,  like  all  other  myths,  far  towards  the  East.  Edrisi 
gives  an  account  of  the  journeying  of  one  Salam  el  Terdje- 
man.  the  dragoman  of  one  of  the  Abbasside-Chalifs,  in  the 
first  half  of  the  ninth  century,  from  Bagdad  to  the  Land  of 
Darkness.  He  proceeded  through  the  steppe  of  Baschkir  to 
the  snowy-mountain  of  Cocaia,  which  is  surrounded  by  the 


360  COSMOS. 

great  wall  of  Magog  (Madjoudj).  Ame"de"e  Jaubert,  to  whom 
we  are  indebted  for  important  supplements  to  the  Nubian 
geographers,  has  shown  that  the  fires  which  burn  on  the 
slope  of  the  Coca'ia  have  nothing  volcanic  in  their  nature 
(Asie  Centrale,  t.  ii,  p.  99).  Edrisi  places  the  Lake  of  Te- 
hama  further  to  the  south.  I  think  I  have  said  enough  to 
show  the  probability  of  the  Tehama  being  identical  with  the 
great  Lake  of  Balkasch,  into  which  the  Hi  flows,  and  which 
is  only  180  miles  further  south.  A  century  and  a  half  later 
than  Edrisi,  Marco  Polo  placed  the  wall  of  Magog  among 
the  mountains  of  In-schan,  to  the  east  of  the  elevated  plain  of 
Gobi,  in  the  direction  of  the  River  Hoang-ho  and  the  Chinese 
wall,  respecting  which,  singularly  enough,  the  famous  Vene- 
tian traveller  is  as  silent  as  he  is  on  the  subject  of  the  use  of 
tea.  The  In-shan,  the  limit  of  the  territory  of  Prester  John, 
may  be  regarded  as  the  eastern  prolongation  of  the  Thian- 
schan  (Asie  Centrale,  t.  ii,  pp.  92—104). 

The  two  conical  volcanic  mountains,  the  Petschan  and 
Hotshen  of  Turfan,  which  formerly  emitted  lava,  and  which 
are  separated  from  each  other  at  a  distance  of  about  420 
geographical  miles  by  the  gigantic  block  of  mountains  called 
the  Bogdo-Oola,  crowned  with  eternal  snow  and  ice,  have 
long  been  erroneously  considered  an  isolated  volcanic  group. 
I  think  I  have  shown  that  the  volcanic  action  north  and 
south  of  the  long  chain  of  the  Thian-schan  here,  as  well  as 
in  the  Caucasus,  stands  in  close  geognostic  connection  with 
the  limits  of  the  circle  of  terrestrial  commotion,  the  hot- 
springs,  the  solfataras,  the  sal-ammoniacal  fissures  and  beds 
of  rock-salt. 

According  to  the  view  I  have  already  frequently  ex- 
pressed, and  in  which  the  writer  most  profoundly  acquainted 
with  the  Caucasian  mountain  system  (Abich)  now  coin- 
cides, the  Caucasus  itself  is  only  a  continuation  of  the  ridge 
of  the  volcanic  Thian-schan  and  Asferah  on  the  other  side 
of  the  great  Aralo- Caspian  depression.67  This  is  therefore 
the  place,  in  connection  with  the  phenomena  of  the  Thian- 
shan,  to  cite  as  belonging  to  pre-historical  periods  the  four 
extinct  volcanoes  of  Elburuz,  18,494  feet  in  height,  Ararat 
17,112  feet,  Kasbegk  16,532  feet,  and  Savalan  15,760  feet 

i7  Asie  Centrale,  t.  ii,  pp.  9,  and  54—58.  See  also  page  208, 
note  61,  of  the  present  volume. 


TRUE  VOLCANOES.  361 

hiu'h."  In  point  of  height  these  mountains  stand  between 
Cotopaxi  and  Mont  Blanc.  The  Great  Ararat  (Agri-dagh), 
ascended  for  the  first  time  on  the  27th  September,  1829,  by 
Friedrich  von  Parrot,  several  times  during  1844  and  1845 
by  Abich,  and  lastly  in  1850  by  Colonel  Cbodzko,  is  dome- 
shaped,  like  Chimborazo,  with  two  extremely  small  eleva- 
tions on  the  border  of  the  summit,  but  without  any  crater 
at  the  apex.  The  most  extensive  and  probably  the  latest 
pre-historical  lava-eruptions  of  Ararat  have  all  issued  below 
the  limit  of  perpetual  snow.  The  nature  of  these  eruptions 
is  two-fold ;  they  are  sometimes  trachytic  with  glassy  feld- 
spar, interspersed  with  pyrites  which  readily  weather,  and 
sometimes  doleritic,  composed  of  labradorite  and  augite,  like 
the  lavas  of  Etna.  The  doleritic  lavas  of  Ararat  are  con- 
sidered by  Abich  to  be  more  recent  than  the  trachytic.  The 
points  of  emission  of  the  lava-streams,  which  are  all  beneath 
the  limit  of  perpetual  snow,  are  frequently  indicated  (as,  for 
example,  in  the  extensive  grassy  plain  of  Kip-ghioll,  on  the 
north-western  slope)  by  eruptive  cones  and  by  small  craters 
encircled  by  scoriae.  Although  the  deep  valley  of  St.  James 
which  extends  to  the  very  summit  of  Ararat,  and  gives  a 
peculiar  character  to  its  form,  even  when  seen  at  a  distance, 
exhibits  much  resemblance  to  the  Yal  del  Bove  on  Etna,  and 
displays  the  internal  structure  of  the  Dome,  yet  there  is  this 
striking  difference  between  them,  that  in  the  valley  of  St. 
James  massive  trachytic  rock  alone  is  found,  and  no  streams  of 
lava,  beds  of  scori*  or  rapilli.69  The  Great  and  Little  Ararat, 
the  first  of  which  is  shown  by  the  geodetic  labours  of  Wasili 
Fedorow,  to  be  3'4"  more  northerly  and  6'42"  more  westerly 
than  the  other,  rise  on  the  southern  edge  of  the  great  plain 

58  Elburuz,   Kasbegk,   and   Ararat,   according  to   communications 
from  Struve,  Asie  Centrale,  t.  ii,  p.  57.     The  height  of  the  extinct 
volcano  of  Savalan,    westward  of  Ardebil,  as  given  in  the  text  is 
founded  on  a  measurement  of  Chanykow.     See  Abich  in  the  Melanges 
Phys.  et  Chini,  t.  ii,  p.  361.     To  save  tedious  repetition  in  the  citation 
of  the  sources  on  which  I  have  drawn,  I  would  here  explain  that 
everything  in  the  geological  section  of  Cosmos,  relating  to  the  impor- 
tant Caucasian  isthmus,  is  borrowed  from  manuscript  essays  of  the 
years  1852  and  1855  communicated  to  me  by  Abich  in  the  kindest 
and  friendliest  manner  for  my  unrestricted  use. 

59  Abich,  Notice  Explicative  d'une  Vue  de  £  Ararat,  in  the  Bulletin  de 
la  Soc.  de  Geographic  de  France,  4eme  s^rie,  t.  i,  p.  516. 


362  COSMOS. 

through  which  the  Araxes  flows  in  a  large  bend.  They  both 
stand  on  an  elliptic  volcanic  plateau,  whose  major  axis  runs 
south-east  and  north-west.  The  Kasbegk  and  the  Tshegem 
have  likewise  no  summit  crater,  although  the  former  has 
thrown  out  vast  eruptions  towards  the  north,  in  the  direc- 
tion of  Wladikaukas.  The  greatest  of  all  these  extinct  vol- 
canoes, the  trachytic  cone  of  the  Elburuz,  which  has  risen 
out  of  the  talc  and  dioritic  schistous  mouutains,  rich  in 
granite,  of  the  valley  of  the  lliver  Backsan,  has  a  crater-lake. 
Similar  crater-lakes  occur  in  the  rugged  highlands  of  Kely, 
from  which  streams  of  lava  flow  out  between  eruption-cones. 
Moreover,  the  basalts  are  here,  as  well  as  in  the  Cordilleras 
of  Quito,  widely  separated  from  the  trachyte- system  ;  they 
commence  from  twenty-four  to  thirty-two  miles  south  of  the 
chain  of  the  Elburuz,  and  of  the  Tschegem  on  the  Upper 
Phasis  or  Rhion  valley. 

P  .  The  north-eastern  portion  (the  Peninsula  of 
KamtscTiatka). 

The  peninsula  of  Kamtschatka,  from  Cape  Lopatka, 
which,  according  to  Krusenstern  is  in  lat.  51°3',  as  far  north 
as  to  Cape  Ukinsk,  belongs,  in  common  with  the  island  of 
Java,  Chili  and  Central  America,  to  those  regions  in  which 
the  greatest  number  of  volcanoes,  and,  it  may  be  added,  of 
still  active  volcanoes,  are  compressed  within  a  very  small 
area.  Fourteen  of  these  are  reckoned  in  Kamtschatka 
within  a  range  of  420  geographical  miles.  In  Central  Ame- 
rica I  find  in  a  space  of  680  miles,  from  the  volcano  of 
Coconusco  to  Turrialva  in  Costa  Rica,  twenty-nine  volcanoes, 
eighteen  of  which  are  still  burning ;  in  Peru  and  Bolivia, 
over  a  space  of  420  miles,  from  the  volcano  Chacani  to 
that  of  San  Pedro  de  Atacama,  fourteen  volcanoes,  of  which 
only  three  are  at  present  active,  and  in  Chili,  over  a  space 
of  960  miles,  from  the  volcano  of  Coquimbo  to  that  of  San 
Clemente,  twenty-four  volcanoes.  Of  the  latter,  thirteen  are 
known  to  have  been  active  within  the  periods  of  time  em- 
braced in  historical  records 

Our  acquaintance  with  the  Kamtschatkan  volcanoes,  in 
respect  to  their  form,  the  astronomical  determination  of  their 
position  and  their  height,  has  been  vastly  extended  in  recent 


TRUE  VOLCANOES.  363 

times  by  Krusenstern,  Horner,  Hofmann,  Lenz,  Liitke, 
Postels,  Captain  Beechey,  and  above  all  by  Adolph  Erman. 
The  peninsula  is  intersected  lengthwise  by  two  parallel 
mountain  chains,  in  the  most  easterly  of  which  the  volcanoes 
are  accumulated.  The  loftiest  of  these  attain  a  height  of 
from  11,190  to  15,773  feet.  They  lie  in  the  following  order 
from  south  to  north  : 

The  Opalinskian  volcano  (the  Pic  Koscheleff  of  Admiral 
Krusenstern)  lat.  51°  21'.  According  to  Captain  Chwostow, 
this  mountain  rises  to  the  height  of  the  Peak  of  Tenerifie, 
and  was  extremely  active  at  the  close  of  the  18th  century. 

The  Hodutka  Sopka  (51°  35').  Between  this  and  the  one 
just  noticed,  there  lies  an  unnamed  volcanic  cone  (51°  32'), 
which,  however,  according  to  Postels,  seems,  like  the  Ho- 
dutka, to  be  extinct. 

Poworotnaja  Sopka  (52°  22'),  according  to  Captain 
Beechey,  7930  feet  high  (Erman's  Eeise,  t.  iii,  p.  253; 
Leop.  von  Buch,  Hes  Can.  p.  447). 

Assatschinskaja  Sopka  (52°  2')  ;  great  discharges  of  ashes, 
particularly  in  the  year  1828. 

The  Wiljutschinsker  volcano  (52°  52')  ;  according  to 
Captain  Beechey  7373  feet,  according  to  Admiral  Liitke 
6744  feet  high.  Distant  only  20  geographical  miles  from 
the  harbour  of  Petropolowski  on  the  north  side  of  the  Bay 
of  Torinsk. 

Awatschinskaja  or  Gorelaja  Sopka  (53°  17'),  according  to 
Erman,  8910  feet  high  ;  first  ascended  during  the  expedition 
of  La  Perouse  in  1787  by  Mongez  andBernizet ;  afterwards 
by  my  dear  friend  and  Siberian  fellow-traveller,  Ernst  Hof- 
mann (in  July,  1824,  during  the  circumnavigation  of  the 
globe  by  Kotzebue ;  by  Postels  and  Lenz  during  the  ex- 
pedition of  Admiral  Liitke  in  1828,  and  by  Erman  in 
September  1829.  The  latter  made  the  important  geog- 
nostic  observation  that  the  uphea\mg  trachyte  had  pierced 
through  slate  and  grey-wacke  (a  silurian  rock).  The  still 
smoking  volcano  had  a  terrific  eruption  in  October  1837, 
there  having  previously  been  a  slight  one  in  April,  1828 
(Postels  in  Lutke,  Voyage,  t.  Bd.  s,  67 — 84 ;  Erman,  Reise, 
Hist.  Eericht,  Bd.  iii,  s.  494  and  534—540). 

In  the  immediate  neighbourhood  of  the  Awatscha-vol- 
cano  (see  page  248)  lies  the  Koriatikaja  or  Strjeloschnaja 


364  COSMOS. 

Sopka  (lat.  53°  19'),  11,210  feet  high,  according  to  Lutke, 
t.  iii,  p.  84.  This  mountain  is  rich  in  obsidian,  which  the 
Kamtschatkans  so  late  as  the  last  century  made  into  arrow- 
heads, as  the  Mexicans  and  the  ancient  Greeks  used  to  do. 

Jupanowa  Sopka,  lat.  according  to  Erman's  calculation 
(Reise,  Bd.  iii,  s.  469)  53°  32'.  The  summit  is  pretty  flat, 
and  the  traveller  just  mentioned  expressly  states  "  that  this 
Sopka,  on  account  of  the  smoke  it  emits,  and  its  perceptible 
subterranean  rumbling,  is  always  compared  to  the  mighty 
Schiwelutsch,  and  reckoned  among  the  undoubted  igneous 
mountains."  Its  height,  as  measured  by  Liitke  from  the 
sea,  is  9055  feet. 

Kronotskaja  Sopka,  10,609  feet,  at  the  lake  of  the  same 
name,  lat.  54°  8' ;  a  smoking  crater  on  the  summit  of  the 
very  sharp-pointed  conical  mountain  (Liitke,  Voyage,  t.  iii, 
p.  85). 

The  volcano  Schiwelutsch,  20  miles  south-east  of  Jelowka, 
respecting  which  we  possess  an  admirable  work  by  Erman 
(Reise,  Bd.  iii,  s.  261—317,  and  Phys.  Beob.,  Bd.  i,  s.  400 
— 403)  previous  to  whose  journey  the  mountain  was  almost 
unknown.  Northern  peak,  lat.  56°  40',  height  10,544  feet ; 
southern  peak,  lat.  56°  39',  height  8793  feet.  When  Erman 
ascended  the  Schiwelutsch  in  September,  1829,  he  found  it 
smoking  vehemently.  Great  eruptions  took  place  in  1739, 
and  between  1790  and  1810;  the  latter  consisting,  not  of 
flowing,  melted  lava,  but  of  ejections  of  loose  volcanic  stones. 
C.  von  Dittmar  relates  that  the  northern  peak  fell  in  during 
the  night  from  the  17th  to  18th  February  1854.  At  that 
time  an  eruption  which  still  continues  took  place,  accom- 
panied by  genuine  streams  of  lava. 

Tolbatschinskaja  Sopka  ;  smoking  violently,  but  in  earlier 
times  frequently  changing  the  openings  through  which  it 
ejected  its  ashes.  According  to  Erman,  lat.  55°  51'  and 
height  8313  feet. 

TJschinskaja  Sopka;  closely  connected  with  the  Kliuts- 
chewsker  volcano  ;  lat.  56°  0',  height  11,723  feet  (Buch,  Can. 
p.  452  ;  Landgrebe,  Volkane,  vol.  i,  p.  375). 

Kliutschewskaja  Sopka  (56°  4')  :  the  highest  and  most  ac- 
tive of  all  the  volcanoes  of  the  peninsula  of  Kamtschatka  ; 
thoroughly  examined  by  Erman,  both  geologically  and  hyp- 
sonietrically.  According  to  KraschenikofFs  report,  the 


TRUE  VOLCANOES.  365 

Kliutschewsk  had  great  igneous  eruptions  from  1727  to 
1731,  as  also  in  1767  and  1795.  On  the  llth  of  September 
1829,  Erman  performed  the  hazardous  feat  of  ascending  the 
volcano,  and  was  an  eye-witness  of  the  ejection  of  red-hot 
stones,  ashes,  and  vapour  from  the  summit,  while  at  a  great 
distance  below  it  an  immense  stream  of  lava  flowed  from 
a  Assure  on  the  western  declivity.  Here  also  the  lava  is  rich 
in  obsidian.  According  to  Erman  (Beob.,  vol.  i,  pp.  400 — 
403  and  419)  the  geographical  latitude  of  the  volcano  is  56D4', 
and  its  height  in  September  1829  was,  on  a  very  accurate 
talculation,  15,763  feet.  In  August  1828;  on  the  other  hand, 
Admiral  Liitke,  on  taking  angles  of  altitude  at  sea,  at  a 
distance  of  160  knots  (40  nautical  miles)  found  the  summit 
of  Kliutschewsk  16,498  feet  high  (Voyage,*,  iii,  p.  86; 
Landgrebe,  Vulkane,  Bd.  i,  s.  375—386).  This  measure- 
ment, and  a  comparison  of  the  admirable  outline  drawings. 
of  Baron  von  Kittlitz,  who  accompanied  Lutke's  expedition 
on  board  the  Seniawin,  with  what  Erman  himself  observed 
in  September  1829,  led  the  latter  to  the  conclusion  that,  in 
this  short  period  of  thirteen  months,  great  changes  had  taken 
place  in  the  form  and  height  of  the  summit.  "I  am  of 
opinion,"  says  Erman  (Reise,vol.  iii,  p.  359),  "that  we  can 
scarcely  be  wrong  in  assuming  the  height  of  the  summit  in 
August  1828,  to  have  been  266  feet  more  than  in  September 
1829,  during  my  stay  in  the  neighbourhood  of  Kliutschi, 
and  that  therefore  its  height  at  the  former  of  these  periods 
must  have  been  16,029  feet."  In  the  case  of  Vesuvius  I 
found,  by  my  own  calculations  (founded  on  Saussure's 
barometrical  measurement  in  1773),  of  the  Rocca  del  Palo, 
the  highest  northern  margin  of  the  crater,  that  up  to  the 
year  1805,  that  is  to  say,  in  the  course  of  thirty-two  years, 
this  northern  margin  of  the  crater  had  sunk  35  \  feet,  while 
from  1773  to  1822,  or  forty-nine  years,  it  had  risen  (appa- 
rently) 102  feet  (Views  of  Nature,  1850,  pp.  376—378).  In 
the  year  1822,  Monticelli  and  Covelli  calculated  the  Rocca 
del  Palo  at  3990  feet,  and  I  at  4022  feet ;  I  then  gave 
3996  as  the  most  probable  result  for  that  period.  In  the 
spring  of  1855,  thirty -three  years  later,  the  delicate  baro- 
metrical measurements  of  the  Olmutz  astronomer,  Julius 
Schmidt,  again  brought  out  3990  feet  (Neue  Bestimm.  am 
Vesuv.  1856,  s.  i,  16  and  33).  It  would  be  curious  to 


366  COSMOS. 

know  how  much  should  here  be  attributed  to  imperfec- 
tion of  measurement  and  barometrical  formula.  Investiga- 
tions of  this  kind  might  be  multiplied  on  a  larger  scale 
and  with  greater  certainty  if,  instead  of  often  repeated  com- 
plete trigonometrical  operations  or,  in  the  case  of  acces- 
sible summits,  the  more  practicable,  though  less  satisfactory 
barometrical  measurements,  operators  would  confine  them- 
selves to  determining,  even  to  fractions  of  seconds,  at  com- 
parative periods  of  twenty-five  or  fifty  years,  the  simple 
angle  of  altitude  of  the  margin  of  the  summit,  from  the 
same  point  of  observation,  and  one  which  could  with  cer- 
tainty be  found  again.  On  account  of  the  influence  of 
terrestrial  refraction,  I  would  recommend  that,  in  each  of 
the  normal  epochs,  the  mean  result  of  three  days'  observa- 
tions at  different  hours  should  be  taken.  In  order  to  obtain, 
not  only  the  general  result  of  the  increase  or  diminution  of 
the  angle,  but  also  the  absolute  amount  of  the  change  in 
feet,  the  distance  would  require  to  be  determined  previously 
only  once  for  all.  What  a  rich  source  of  knowledge  relative 
to  the  twenty  volcanic  Colossi  of  the  Cordilleras  of  Quito, 
would  not  the  angles  of  altitude,  determined  for  more  than  a 
century  by  the  labours  of  Bouguer  and  La  Condamine  have 
provided,  had  those  travellers  accurately  designated  as  fixed 
and  permanent  points  the  stations  whence  they  measured 
the  angles  of  altitude  of  the  summits.  According  to 
C.  von  Dittmar  the  Kliutschewsk  was  entirely  quiescent 
since  the  eruption  of  1841  until  the  lava  burst  forth  again 
in  1853.  The  falling  in,  however,  of  the  summit  of  the 
Schiwelutsch  interrupted  the  new  action  {Bulletin  de  la 
Clause  Physico-Mathem.  de  V  Acad.  des  Sc.  de  St.  Petersbourg, 
t.  xiv,  1856,  p.  246). 

Pour  more  volcanoes,  mentioned  in  part  by  Admiral 
Liitke,  and  in  part  by  Postels,  namely  the  Apalsk,  still 
smoking,  to  the  south-east  of  the  village  of  Bolscheretski, 
the  Schischapinskaja  Sopka  (lat.  55°  11'),  the  cone  of  fvres- 
towsk  (lat.  56°  4'),  near  the  Kliutschewsk  group,  and  the 
Uschkowsk,  I  have  not  cited  in  the  foregoing  series  from 
want  of  more  exact  specification.  The  central  mountain- 
range  of  Kamtschatka,  especially  in  the  plain  of  Baidaren, 
lat.  57°  20',  eastward  of  Sedanka,  presents  (as  if  it  bad  been 
"the  field  of  an  ancient  crater  of  about  four  wersts,  that  is 


TRUE  VOLCANOES.  367 

to  say,  the  same  number  of  kilometres,  in  diameter"),  the 
remarkable  geological  phenomenon  of  effusions  of  lava  and 
scoriae  from  a  blistery  and  often  brick-coloured  volcanic 
rock,  which  in  its  turn  has  penetrated  through  fissures  in  the 
earth,  at  the  greatest  possible  distance  from  any  frame- 
work of  raised  cones  (Erman,  Beise,  Bd.  iii,  s.  221,  228 
and  273  ;  Buch,  lies  Canaries  p.  454).  The  analogy  is  here 
very  striking  with  what  I  have  already  circumstantially 
explained  regarding  the  Malpays,  the  problematic  fields  of 
debris  in  the  elevated  plain  of  Mexico  (see  page  315). 

V.  ISLANDS  OF  EASTERN  ASIA. 

From  Torres  Strait,  which,  in  the  10th  degree  of  southern 
latitude,  separates  New-Guinea  and  Australia,  and  from 
the  smoking  volcano  of  Flores  to  the  most  northern  of  the 
Aleutian  Isles  (lat.  55°)  there  is  a  multitude  of  islands, 
for  the  most  part  volcanic,  which,  considered  in  a  general 
geological  point  of  view,  it  would  be  somewhat  difnciilt,  on 
account  of  their  genetic  connection,  to  divide  into  separate 
groups,  and  which  increase  considerably  in  circumference 
towards  the  south.  Beginning  at  the  north  we  first  observe 
that  the  curved  series60  of  the  Aleutians,  issuing  from  the 
American  peninsula  of  Alaska,  connect  the  old  and  the  new 
continents  together  by  means  of  the  island  Attu,  near 
Copper  Island  and  Behring's  Island,  while  to  the  south  they 
close  in  the  waters  of  Behring's  Sea.  From  Cape  Lopatka, 
at  the  southern  extremity  of  the  peninsula  of  Karntschatka, 
we  find  succeeding  each  other  in  the  direction  from  north  to 
south  first,  the  Archipelago  of  the  Kuriles,  bounding  on  the 
east  the  Saghalien  or  Ochotsk  Sea,  rendered  famous  by  La 
Perouse,  next  Jesso,  probably  in  former  times  connected 
with  the  island  of  Krafto61  (Saghalin,  or  Tschoka),  and 

60  See  Dana's  remarks  on  the  curvatures  of  ranges  of  islands,  whose 
convexity  in  the  South  Sea  is  almost  always  directed  towards  the 
Bouth  or  south-east,  in  the  United  States'  Explor.  Exped.  by  Wilkes, 
vol.  x  (Geology  by  James  Dana),  1849,  p.  419. 

61  The  island  of  Saghalin,  Tschoka,  or  Tarakai,  is  called  by  the  Ja- 
panese mai-iners  Krafto  (written  Karafuto).    It  lies  opposite  the  mouth 
of  the  Amoor  (the  Black  River,  Saghalian  Ula),  and  is  inhabited  by  the 
Ainos,  a  race  mild  in  disposition,  dark  in  colour,  and  sometimes  rather 
hairy.     Admiral  Kruseiistern  was  of  opinion,  as  were  also  previously 


368  COSMOS 

lastly  the  tri-insular  empire  of  Japan,  across  the  narrow 
Strait  of  Saugar  (Niphon,  Sitkok  and  Kiu-Siu,  according  to 
Siebold's  admirable  map,  between  41°  32'  and  30°  18').  From 
the  volcano  of  Kliutschewsk,  the  northernmost  on  the  east 
coast  of  the  peninsula  of  Kamtschatka,  to  the  most  southern 
Japanese  volcano-island  of  Tanega-Sima,  in  the  Van  Die- 
men's  Channel,  explored  by  Krusenstern,  the  direction  of 
the  igneous  action  as  indicated  in  the  numerous  rents  of  the 
earth's  crust,  is  precisely  from  north-east  to  south-west.  The 
range  is  carried  on  by  the  island  of  Jakuno-Sima,  on  which 
a  conical  mountain  rises  to  the  height  of  5838  feet  (1780 
metres),  and  which  separates  the  two  straits  of  Yan  Die- 
men  and  Colnet, — by  the  Linschote  Archipelago  of  Siebold, 
— by  Captain  Basil  Hall's  sulphur  island,  Lung-Huang- 
Schan,  and  by  the  small  group  of  the  Loo-choo  and  Majico- 
sima,  which  latter  approaches  within  a  distance  of  92 
geographical  miles  the  eastern  margin  of  the  great  island  of 
the  Chinese  coasts,  Formosa  or  Tay-wan. 

the  companions  of  La  Pe'rouse  (1787)  and  Broughton  (1797),  that 
Saghalin  was  connected  with  the  Asiatic  continent  by  a  narrow,  sandy 
isthmus  (lat.  52°  50 ;  but  from  the  important  Japanese  notices  com- 
municated by  Franz  von  Siebold,  it  appears  that,  according  to  a  chart 
drawn  up  in  the  year  1808,  by  Mamia  Rinso,  the  chief  of  an  Imperial 
Japanese  commission,  Krafto  is  not  a  peninsula,  but  an  island  sur- 
rounded on  all  sides  by  the  sea  (Ritter,  Erdkunde  von  Asien,  vol.  ii, 
p.  488).  The  conclusion  of  Mamia  Rinso  has  been  very  recently  com- 
pletely verified,  as  mentioned  by  Siebold,  when  the  Russian  fleet  lay 
at  anchor  in  the  year  1855,  in  the  Baie  de  Castries  (lat.  51°  29')  near 
Alexandrowsk,  and  consequently  to  the  south  of  the  conjectured 
isthmus,  and  yet  was  able  to  retire  into  the  mouth  of  the  Amoor  (lat. 
52°  24').  In  the  narrow  channel  in  which  the  isthmus  was  formerly 
supposed  to  be,  there  were  in  some  places  only  5  fathoms  water.  The 
island  is  beginning  to  acquire  some  political  importance  on  account  of 
the  proximity  of  the  great  stream  of  Amoor  or  Saghalin.  Its  name, 
pronounced  Karafto  or  Krafto,  is  a  contraction  of  Kara-fu-to,  which 
signifies,  according  to  Siebold,  "  the  island  bordering  on  Kara."  In 
the  Japano-Chinese  language  Kara  denotes  the  most  northerly  part  of 
China  (Tartary),  and  fu,  according  to  the  learned  writer  just  men- 
tioned, signifies  "  lying  close  by."  Tschoka  is  a  corruption  of  Tsyokai, 
and  Tarakai  originates  from  a  mistake  in  the  name  of  a  single  village 
called  Taraika.  According  to  Klaproth  (Asia  Polyglotla,  p.  301), 
Taraikai,  or  Tarakai,  is  the  native  Aino  name  of  the  whole  island. 
Compare  Leopold  Schrenk's  and  Captain  Bernard  Wittingham's  re- 
marks in  Petermann's  Geogr.  Mittheilungen,  1856,  s.  176  and!84.  See 
also  Perry,  Exped.  to  Japan,  vol.  i,  p.  468. 


TRUE  VOLCANOES.  369 

Here  at  Formosa  (N.  lat.  25°— 26°)  is  the  important 
point  where,  instead  of  the  lines  of  elevation  from  N.E. 
to  S.W.  those  in  the  direction  from  north  to  south  com- 
mence, and  continue  nearly  as  far  as  the  parallel  of  5°  or  6° 
of  southern  latitude.  They  are  recognizable  in  Formosa 
and  in  the  Philippines  (Luzon  and  Mindanao)  over  a  space 
of  fully  twenty  degrees  of  latitude,  intersecting  the  coasts, 
sometimes  on  one  side  and  sometimes  on  both,  in  the  direc- 
tion of  the  meridian.  They  are  likewise  visible  on  the  east 
coast  of  the  great  island  of  Borneo,  which  is  connected  by 
the  So-lo  Archipelago  with  Mindanao,  and  by  the  long 
narrow  island  of  Palawan  with  Mindoro.  So  also  in  the 
western  portions  of  the  Celebes,  with  their  varied  outline, 
and  Gilolo,  and  lastly  (which  is  especially  remarkable)  in 
the  longitudinal  fissures  on  which,  at  a  distance  of  1400 
geographical  miles  eastward  of  the  group  of  the  Philippines 
and  in  the  same  latitude,  the  range  of  volcanic  and  coral 
islands  of  Marian  or  the  Ladrones  have  been  upheaved. 
Their  general  direction62  is  north  and  10°  east. 

Having  pointed  out  in  the  parallel  of  the  carboniferous 
island  of  Formosa,  the  turning  point  at  which  the  direction 
of  the  Kuriles  from  N.E.  to  S.W.  is  changed  to  that  from 
north  to  south,  I  must  now  observe  that  a  new  system  of 
fissures  commences  to  the  south  of  Celebes  and  the  south 
coasts  of  Borneo,  which,  as  we  have  already  seen,  is  cut 
from  east  to  west.  The  greater  and  lesser  Sunda  islands, 
from  Timor-lant  to  West-Bali,  follow  chiefly  for  the  space 
of  18°  of  longitude,  the  mean  parallel  of  8°  south  lati- 
tude. At  the  western  extremity  of  Java  the  mean  axis 
runs  somewhat  more  towards  the  north,  nearly  E.S.E.  and 
W.N.W.,  while  from  the  Strait  of  Sunda  to  the  southern- 
most of  the  Nicobar  Isles  the  direction  is  from  S.E.  to 
N.W.  The  whole  volcanic  fissure  of  elevation  (E.  to  \V. 
and  S.E.  to  N.W.),  has  consequently  an  extent  of  about 
2700  geographical  miles,  or  eleven  times  the  length  of  the 

82  Dana,  Geoloyy  of  the  Pacific  Ocean,  p.  16.  Corresponding  with 
the  meridian  lines  of  the  south-east  Asiatic  island-world,  the  shore* 
of  Cochin-China  from  the  gulph  of  Tonquiu,  those  of  Malacca  from 
the  gulph  of  Siam,  and  even  those  of  New  Holland  south  of  the  25th 
degree  of  lat.,  are  for  the  most  part  cut  off  as  it  were  in  the  directioa 
from  north  to  south. 

VOL.  V.  2   B 


370  COSMOS. 

Pyrenees.  Of  this  space,  if  we  disregard  the  slight  devia- 
tion towards  the  north  in  Java,  1620  miles  belong  to  the 
east  and  west  direction,  and  1080  to  the  south-east  and 
north-west. 

Thus  do  general  geological  considerations  on  form  and 
range  lead  uninterruptedly  in  the  island-world  on  the 
east  coast  of  Asia  (over  the  immense  space  of  68°  of 
latitude)  from  the  Aleutian  Isles  and  Behring's  Sea  to  the 
Moluccas  and  the  Great  and  Little  Sunda  lies.  The  greatest 
variety  in  the  configuration  of  the  land  is  met  with  in  the 
parallel-zone  of  5°  north  and  10°  south  latitude.  It  is  very 
remarkable  how  generally  the  line  of  eruption  in  the  larger 
portions  is  repeated  in  a  neighboring  smaller  portion.  Thus 
a  long  range  of  islands  lies  near  the  south  coast  of  Sumatra 
and  parallel  to  it.  We  find  the  same  appearances  in  the 
smaller  phenomena  of  the  mineral  veins  as  in  the  greater 
ones  of  the  mountain  ranges  of  whole  continents.  Accom- 
panying debris  running  by  the  side  of  the  principal  vein, 
and  secondary  chains  (chaines  accompagnantes)  lie  frequently 
at  considerable  distances  from  each  other.  They  indicate 
similar  causes  and  similar  tendencies  of  the  formative  action 
in  the  folding  in  of  the  crust  of  the  earth.  The  conflict  of 
powers  in  the  contemporaneous  openings  of  fissures  in  op- 
posite directions  appears  sometimes  to  occasion  strange 
formations  in  juxtaposition,  as  may  be  seen  in  the  Molucca 
Islands,  Celebes,  and  Kilolo. 

After  developing  the  internal  geological  connection  of  the 
East  and  South  A.siatic  insular  system,  in  order  not  to  deviate 
from  the  long-adopted,  though  somewhat  arbitrary,  geo- 
graphical divisions  and  nomenclature,  we  place  the  southern 
limit  of  the  Eastern  Asiatic  insular  range  (the  turning  point) 
at  Formosa,  where  the  line  of  direction  runs  off  from  the 
N.E.—S.W.  to  the  N.— S.,  in  the  24th  degree  of  north 
latitude.  The  enumeration  proceeds  again  from  north  to 
south,  beginning  with  the  eastern,  and  more  American, 
Aleutian  Islands. 

The  Aleutian  Isles,  which  abound  in  volcanoes,  include,  in 
the  direction  from  east  to  west,  the  Fox  Islands,  among 
which  are  the  largest  of  all,  Unimak,  Unalaschka,  and 
TJmnak ; — the  Andrejanowsk  Isles,  of  which  the  most 
famous  are  Atcha,  with  three  smoking  volcanoes,  and  the 


TRUE  VOLCANOES.  371 

great  volcano  of  Tanaga,  already  delineated  by  Sauer; — 
the  Rat  Islands,  and  the  somewhat  distant  islands  of  B'ynia, 
among  which,  as  has  been  already  observed,  Attu  forms  the 
connecting  link  to  the  Commander  group  (Copper  and 
Behring's  Isles)  near  Asia.  There  seems  no  ground  for  the 
often-repeated  conjecture  that  the  range  of  continental  vol- 
canoes in  the  direction  of  NN.E.  and  SS.W.  on  the  penin- 
sula of  Kamtschatka  first  commences  where  the  volcanic 
fissure  of  upheaval  in  the  Aleutian  Islands  intersects  the 
peninsula  beneath  the  ocean,  the  Aleutian-fissure  thus  form- 
ing, as  it  were,  a  channel  of  conduction.  According  to 
Admiral  Liitke's  chart  of  the  Kamtschatkan  Sea  (Behring's- 
Sea)  the  island  of  Attu,  the  western  extremity  of  the  Aleu- 
tian range,  lies  in  lat.  52°  46',  and  the  non-volcanic  Cop- 
per and  Behring's  Islands  in  lat.  54°  30'  to  55°  20',  while  the 
volcanic  range  of  Kamtschatka  commences  under  the  paral- 
lel of  56°  40'  with  the  great  volcano  of  Schiwelutsch,  to  the 
west  of  Cape  Stolbowoy.  Besides,  the  direction  of  the 
fissures  of  eruption  is  very  different,  indeed,  almost  opposite. 
The  highest  of  the  Aleutian  volcanoes,  on  Unimak,  is  8076 
feet,  according  to  Liitke.  Near  the  northern  extremity  of 
Umnak,  in  the  month  of  May,  1796,  there  arose  from  the 
sea.  under  very  remarkable  circumstances,  which  have  been 
admirably  described  in  Otto  von  Kotzebue's  "  Entdeckungs- 
reise"  (Bd.  ii,  s.  106),  the  island  of  Agaschagokh  (or  St. 
Johannes  Theologus)  which  continued  burning  for  nearly 
eight  years.  According  to  a  report  published  by  Krusen- 
stern,  this  island  was,  in  the  year  1819,  nearly  sixteen 
geographical  miles  in  circumference,  and  was  nearly  2240  feet 
high.  On  the  island  of  Unalaschka  the  proportions  of  the 
trachyte,  containing  much  hornblende,  of  the  volcano  of 
Matuschkin  (5474  feet)  to  the  black  porphyry  (?)  and  the 
neighbouring  g  anite,  as  given  by  Chamisso,  would  deserve 
to  be  investigated  by  some  scientific  observer  acquainted 
with  the  conditions  of  modern  geology,  and  able  to  examine 
carefully  the  mineralogical  character  of  the  different  kinds 
of  rocks.  Of  the  two  contiguous  islands  of  the  Pribytow 
group,  which  lie  isolated  in  the  Kamtschafckan  sea,  that  of 
St.  Paul  is  entirely  volcanic,  abounding  in  lava  and  pumice, 
while  St.  George's  Island,  on  the  contrary,  contains  only 
granite  and  gneiss. 

2  B  2 


372  COSMOS. 

According  to  the  most  exact  enumeration  we  yet  possess, 
the  range  of  the  Aleutian  Isles,  stretching  over  960  geo- 
graphical miles,  seems  to  contain  above  thirty-four  volcanoes, 
the  greater  part  ol  them  active  in  modern  historical  times. 
Thus  we  see  here  (in  54°  and  60°  latitude,  and  160°— 
196°  west  longitude)  a  stripe  of  the  whole  floor  of  the 
ocean  between  two  great  continents  in  a  constant  state  of 
formative  and  destructive  activity.  How  many  islands  in 
the  course  of  centuries,  as  in  the  group  of  the  Azores, 
may  there  not  be  near  becoming  visible  above  the  surface  of 
the  ocean,  and  how  many  more  which,  after  having  long 
appeared,  have  sunk  either  wholly  or  partially  unobserved ! 
For  the  mingling  of  races,  and  the  migration  of  nations, 
the  range  of  the  Aleutian  Islands  furnishes  a  channel  from 
thirteen  to  fourteen  degrees  more  southerly  than  that  of 
Behring's  Straits,  by  which  the  Tchutches  seem  to  have 
crossed  from  America  to  Asia,  and  even  to  the  other  side  of 
the  river  Anadir. 

The  range  of  the  Kurile  Islands,  from  the  extreme  point 
of  Kamtschatka  to  Cape  Brought  on  (the  northernmost  pro- 
montory of  Jesso)  in  a  longitudinal  space  of  720  geographi- 
cal miles,  exhibits  from  eight  to  ten  volcanoes,  still  for  the 
most  part  in  a  state  of  ignition.  The  northernmost  of 
these,  on  the  island  of  Alaid,  known  for  its  great  eruptions 
in  the  years  1770  and  1793,  is  well  worthy  of  being  accu- 
rately measured,  its  height  being  calculated  at  from  12,000 
to  15,000  feet.  The  much  less  lofty  Pic  Sarytshew  (4193 
feet  according  to  Horner)  on  Mataua,  and  the  southernmost 
Japanese  Kuriles,  Urup,  Jetorop,  and  Kunasiri,  have  also 
been  very  active  volcanoes. 

We  now  come  in  the  order  of  succession  of  the  volcanic 
range  to  Jesso,  and  the  three  larger  Japanese  Islands,  re- 
specting which  the  celebrated  traveller,  Herr  von  Siebold, 
has  kindly  communicated  to  me  a  large  and  important  work 
for  assistance  in  my  Cosmos.  This  will  serve  to  correct  what- 
ever was  defective  in  the  notices  which  I  borrowed  from  the 
great  Japanese  Encyclopedia  in  my  Fraqmens  de  Geologic 
et  de  Climatologie  Asiatiques  (t.  i,  pp.  217 — 234),  and  in 
Asie  Centrale  (t.  ii,  pp.  540—552). 

The  large  island  of  Jesso,  which  is  very  quadrangular  in 
its  northern  portion  (lat.  41^°  to  45jJ°),  separated  by  the 


TRUE   VOLCANOES.  373 

Strait  of  Saugar,  or  Tsugar,  from  Niphon,  and  by  that  of  la 
Perouse  from  the  island  of  Krafto  (Ksra-fu-to),  bounds  by 
its  north-east  cape  the  Archipelago  of  the  Kuriles ;  but  not 
far  from  the  North  west  Cape  Komanzow  on  Jesso,  which 
stretches  a  degree  and  a  half  more  northward  in  the  strait 
of  La  Perouse.  lies,  in  latitude  45°  11',  the  volcanic  Pic  de 
Langle  (5350  feet)  on  the  little  island  of  Bisiri.  Jesso 
itself  seems  also  to  be  intersected  by  a  range  of  volcanoes, 
from  Broughton's  Southern  Volcano  Bay  nearly  all  the  way 
to  the  North  Cape,  a  circumstance  the  more  remark- 
able as,  on  the  narrow  island  of  Krafto  which  is  almost 
a  continuation  of  Jesso,  the  naturalists  of  la  Perouse's  ex- 
pedition found  in  the  JBaie  de  Castries  fields  of  red  porous 
lava  and  scoriae.  On  Jesso  itself  Siebold  counted  seventeen 
conical  mountains,  the  greater  number  of  which  appear  to 
be  extinct  volcanoes.  The  Kiaka,  called  by  the  Japanese 
Usuga-Take,  or  Mortar-mountain,  on  account  of  a  deeply- 
nollowed  crater,  and  the  Kajo-hori  are  both  said  to  be 
still  in  a  state  of  ignition.  (Commodore  Perry  noticed 
two  volcanoes  from  Volcano  Bay  near  the  harbour  of  En- 
derrno,  lat.  42°  17').  The  lofty  Man  ye  ( Krusenstem's 
conical  mountain  Pallas)  lies  in  the  middle  of  the  island  of 
Jesso,  nearly  in  lat.  44°,  somewhat  to  the  E.N.E.  of  Bay 
Strogonow. 

"  The  historical  books  of  Japan  mention  only  six  active 
volcanoes  before  and  since  our  era,  namely,  two  on  the  island 
of  Niphon,  and  four  on  the  island  of  Kiu-siu.  The  vol- 
canoes of  Kiu-siu,  the  nearest  to  the  peninsula  of  Corea. 
reckoning  them  in  their  geographical  position  from  south  to 
north,  are  (1)  the  volcano  of  Mitake,  on  the  islet  of 
Sayura-sima,  in  the  bay  of  Kagosima  (province  of  Satsuma), 
which  lies  open  to  the  south,  lat.  3 1°  33',  long.  130°  41'; 
(2)  the  volcano  Kirisima  (lat.  31°  45')  in  the  district 
of  Naka,  province  of  JFinga  ;  3rd,  the  volcano  A  so  jama,  in 
the  district  Aso  (lat.  32°  45'),  province  of  Figo ;  4th, 
the  volcano  of  Yunzen,  on  the  peninsula  of  Simabara  (lat. 
32°  44'),  in  the  district  of  Takaku.  The  height  of  this 
volcano,  amounts,  according  to  a  barometrical  measurement, 
only  to  1253  metres,  or  4110  English  feet,  so  that  it  is 
scarcely  a  hundred  feet  higher  than  Vesuvius  (Rocca  del 
Palo).  The  most  violent  eruption  of  the  volcano  of  Vunzen 


374 


COSMOS. 


on  record  is  that  of  February  1793.  Vunzen  and  Aso  jama 
both  lie  east-south-east  of  Nangasaki." 

"  The  volcanoes  of  the  great  island  of  Niphon,  again 
reckoning  from  south  to  north,  are  (1)  the  volcano  of  Fusi 
jama,  scarcely  16  geographical  miles  distant  from  the 
southern  coast,  in  the  district  Fusi,  province  of  Suruga 
(lat.  35°  18',  long.  138°  35').  Its  height,  measured  in  the 
same  way  as  the  volcano  of  Yunzen,  or  Kiusiu,  by  some 
young  Japanese,  instructed  by  Siebold,  amounts  to  3793 
metres,  or  12,441  feet ;  it  is  therefore  fully  320  feet  higher 
than  the  Peak  of  Teneriffe,  with  which  it  has  been  already 
compared  by  Kampfer  (Wilhelm  Heine,  Reise  nach  Japan, 
1856,  Bd.  ii,  s.  4).  The  upheaval  of  this  conical  moun- 
tain is  recorded  in  the  fifth  year  of  the  reign  of  Mikado  VI 
(286  years  before  our  era)  in  these  (geognostically  remark- 
able) words  : — '  In  the  country  of  Omi  a  considerable  tract 
of  land  sinks,  an  inland  lake  is  formed,  and  the  volcano 
Fusi  makes  its  appearance  '  The  most  violent  historically 
recorded  eruptions  within  the  Christian  era  are  those  of 
799,  800,  863,  937,  1032,  1083,  and  1707  ;  since  the  latter 
period  the  mountain  has  been  tranquil.  2nd.  The  volcano 
of  Asama  jama,  the  most  central  of  the  active  volcanoes  in 
the  interior  of  the  country,  distant  80  geographical  miles 
from  the  south-south-cast,  52  miles  from  the  north-north- 
west coast,  in  the  district  of  Saku  (province  of  Sinano), 
lat.  36°  22',  long.  138°  38';  thus  lying  between  the  meri- 
dians of  the  two  capitals,  Mijako  and  Jeddo.  The  Asama 
jama  had  an  eruption  as  early  as  the  year  864,  contempora- 
neously with  the  Fusi  jama  ;  that  of  the  month  of  July 
1783  was  particularly  violent  and  destructive.  Since  that 
time  the  Asama  jama  has  maintained  a  constant  state  of 
activity. 

"Besides  these  volcanoes  two  other  small  islands  with 
smoking  craters  have  been  observed  by  European  mariners, 
namely,  3rd.  The  small  island  of  Iv6gasima  or  Ivosima  (sima 
signifies  island,  and  ivo  sulphur ;  ga  is  merely  an  affix  mark- 
ing the  nominative),  Krusenstern's  lie  du  Volcan,  south  of 
Kiu-siu,  in  Van  Diemen's  Strait,  30°.43'jN".  lat.  and  130°  18' 
E.  long.,  distant  only  fifty-four  miles  from  the  above-men- 
tioned volcano  of  Mitake  ;  the  height  of  the  volcano  is  2364 
feet  (715  met).  This  island  is  mentioned  by  Linschoten  so 


TRUE   VOLCANOES.  375 

early  as  1596  in  these  words  :  i  The  island  has  a  volcano, 
which  is  a  sulphur,  or  fiery  mountain.'  It  occurs  also  on 
the  oldest  Dutch  sea-charts  under  the  name  of  Vulcanus 
(Fr.  von  Siebold,  Atlas  vom  Jap.  Seiche,  Tab.  xi).  Kru- 
senstern  saw  it  smoking  in  1804,  as  did  Captain  Blake  in 
1838,  and  Gue"rin  and  De  la  Roche  Poncie  in  1846.  The 
height  of  the  cone,  according  to  the  latter  navigator,  is  2345 
feet  (715  met.)  The  rocky  islet  mentioned  as  a  volcano  by 
Landgrebe  in  the  NaturgeschicJite  der  VulJcane  (Bd.  i, 
s.  355),  and  which,  according  to  Kampfer,  is  near  Firato 
(Firando),  is  imdoubtedly  Ivo-sima,  for  the  group  to  which 
Ivo-sima  belongs  is  called  Kiusiu  ku  sima,  i.e.,  the  nine 
islands  of  Kiusiu,  and  not  the  ninty-nine  islands.  A  group 
of  this  description  occurs  near  Firato,  northward  of  Naga- 
saki, and  no  where  else  in  Japan.  (4)  The  island  of  Ohosima 
(Barneveld's  Island;  Krusenstern's  He  de  Vries),  which  is 
considered  part  of  the  province  of  Idsu,  on  Niphon,  and 
lies  in  front  of  the  Bay  of  Yodavara,  in  34°  42'  N.  lat.  and 
139°  26'  E.  long.  Broughton  saw  smoke  issuing  from  the 
crater  in  1797,  a  violent  eruption  of  the  volcano  having 
taken  place  a  short  time  previous.  From  this  island  a  range 
of  smaller  volcanic  isles  stretches  out  in  a  southerly  direction 
as  far  as  Fatsi-syo  (33°  6'  N.  lat.),  and  continues  as  far  as  the 
Bonin  Islands  (26°  30'  N.  lat.  and  142°  5'  E.  long.),  which, 
according  to  A.  Postels  (Liitke,  Voyage  autour  du  Monde 
dans  les  annees  1826 — 29,  t.  iii,  p.  117)  are  likewise  vol- 
canic and  are  subject  to  veiy  violent  earthquakes." 

"  These,  then,  are  the  eight  volcanoes  historically  known 
to  be  active  in  Japan  Proper,  in  and  near  the  islands  of 
Kiusiu  and  Niphon.  But  in  addition  to  these  volcanoes  a 
range  of  conical  mountains  must  also  be  cited,  some  of  which, 
marked  by  very  distinct  and  often  deeply  indented  craters, 
appear  to  be  volcanoes  long  since  extinct.  One  of  these  is 
the  conical  mountain  of  Kaimon,  Krusenstern's  Pic  Homer 
in  the  southernmost  part  of  the  island  of  Kiusiu,  on  the 
coast  of  Yan  Diemen's  Strait,  in  the  province  of  Satsum 
(lat.  31°  9'),  scarcely  six  geographical  miles  SSW.  from 
the  active  volcano  of  Mitake.  Another  is  the  Kofusi,  or 
Little  Fusi,  on  Sikok ;  and  another  is  on  the  islet  of 
Kutsuriasima.  in  the  province  of  Ijo  (lat.  33°  45'),  on  the 
eastern  coast  of  the  great  straits  of  Suvo  Nada  or  Yan  der 


376  COSMOS. 

Capellen,  which  separate  the  three  great  portions  of  the 
Japanese  empire,  Kiusiu,  Sikon,  and  Niphon.  On  the 
latter,  or  principal  island,  nine  such  conical  mountains,  pro- 
bably trachytic,  are  reckoned,  the  most  remarkable  of  which 
are,  the  Sira  jama  (or  White  Mountain)  in  the  province  of 
Kaga,  lat.  36°5',  and  the  Tsyo  Kai-san,  in  the  province  of 
Deva  (lat.  39°10'),  both  of  which  are  considered  loftier  than 
the  southerly  volcano  of  Fusi  jama,  which  is  upwards  of 
12,360  feet  high.  Between  these  two,  in  the  province  of 
Jetsigo,  lies  the  Jaki  jama  (or  Flame  Mountain,  lat.  3G°o3'). 
The  two  northernmost  conical  mountaims  in  the  Saugar  Strait, 
in  sight  of  the  great  island  of  Jesso,  are,  (1)  The  Ivaki 
jama,  called  by  Krusenstern,  whose  illustrations  of  the  geo- 
graphy of  Japan  have  gained  him  immortal  honour,  the  Pic 
Tilesius  (lat.  40°  42')  ;  and  (2)  The  Jake  jama  (the  Burning 
Mountain,  lat.  41°  20'),  in  Nambu,  at  the  north-eastern  ex- 
tremity of  Niphon,  with  igneous  eruptions  from  the  remotest 
times." 

In  the  continental  portion  of  the  neighbouring  peninsula 
of  Corea,  or  Korai  (which,  in  the  parallels  of  34°  and 
34^°,  is  almost  united  with  Kiusiu  by  the  islands  Tsu  sima 
and  Iki),  notwithstanding  its  great  similarity  in  form  to  the 
peninsula  of  Kanitschatka,  no  volcanoes  have  hitherto  been 
discovered.  The  volcanic  action  seems  to  be  confined  to 
the  adjoining  islands.  Thus,  in  the  year  1007,  the  island- 
volcano  of  Tsininura,  called  by  the  Chinese,  Tanlo,  rose  from 
the  sea.  A  learned  Chinese,  named  Tien-kong-chi,  was  sent 
to  describe  the  phenomenon  and  to  execute  a  picture  of  it.63 
But  it  is  especially  on  the  island  of  Se-he-sure  (the  Quel- 
paerts  of  the  Dutch)  that  the  mountains  exhibit  everywhere 
a  volcanic  conical  form.  The  central  mountain  rises,  ac- 
cording to  Broughfcon  and  La  Perouse,  to  the  height  of  6395 
feet.  How  many  volcanic  effects  may  there  not  yet  remain 
to  be  discovered  in  the  Western  Archipelago,  where  the 
King  of  the  Coreans  styles  himself  the  Sovereign  of  10,000 
Islands ! 

From  the  Pic  Homer  (Kaimon  ga  take)  on  the  west  side 
of  the  southern  extremity  of  the  Kiusiu,  in  the  Japanese 
tri-insular  empire,  there  stretches  out  in  a  curve  which  lies 

63  Compare  the  translations  of  Stanislas  Julien  from  the  Japanese 
Encyclopaedia  in  my  Asie  Centrale,  t.  ii,  p.  551. 


TRUE   VOLCANOES.  377 

open  towards  the  west,  a  small  range  of  volcanic  islands, 
comprising,  first,  between  the  Var  Diemen  and  Colnet 
Straits,  the  Jakuno  sima  and  the  Tanega  sima;  second 
south  of  the  Strait  of  Colnet  in  the  Li  nschot en-group64  of 
Siebold  (the  Archipel  Cecile  of  Captain  G-uerin),  which  ex- 
tends as  far  as  the  parallel  of  29°,  the  island  of  Suvase  sima, 
the  volcano  island  of  Captain  Belcher  (lat.  29°39'  and  long. 
129°  41')  rising,  according  to  De  la  Roche  Poncie,  to  a  height 
of  2800  feet  (855  met.)  ;  third,  Basil  Hall's  sulphur  island, 
the  Tori-sima,  or  Bird  Island,  of  the  Japanese,  the  Lung- 
hoang-shan  of  Pere  Gaubil,  in  lat.  27°  51'  and  long.  128°  14', 
as  fixed  by  Captain  De  la  Roche  Poncie  in  1848.  As  this 
island  is  also  called  Iwosima,  care  must  be  taken  not  to  con- 
found it  with  its  more  northerly  namesake  in  Van  Diemen's 
Straits.  It  has  been  admirably  described  by  Captain  Basil  Hall. 
Between  the  parallel  of  26J  and  27°  of  latitude  comes  in  suc- 
cession the  group  of  the  Lieu-thieu,  or  Loo-choo  Islands,  as 
the  natives  call  them,  of  which  Klaproth  published  a  separate 
map  in  1824,  and  more  to  the  south-west  the  small  Archi- 
pelago of  Majicosima,  which  approaches  the  great  island  of 
Formosa,  and  is  considered  by  me  to  be  the  closing  point  of 
the  eastern  Asiatic  islands.  Close  to  the  east  coast  of  Formosa 
(lat.  24°)  a  great  volcanic  eruption  in  the  sea  was  observed 
by  Lieutenant  Boyle  in  1853  (Commodore  Perry,  Exped.  to 
Japan,  vol.  i,  p.  500).  Among  the  Benin  Islands  ( Buna- 
sima  of  the  Japanese,  lat.  26|°  to  27f°  and  long.  142°  15') 
that  called  Peel's  Island  has  several  craters  abounding  in 
sulphur  and  scorise,  which  do  not  appear  to  have  been  long 
extinct  (Perry,  i,  pp.  200  and  209). 

VI.  ISLANDS  OF  SOUTHERN  ASIA. 

We  comprehend  under  this  division  Formosa  (Tayvan), 
the  Philippines,  the  Sunda  Islands  and  the  Moluccas.  Klap- 
roth first  made  us  acquainted  with  the  volcanoes  of  Formosa 
by  information  extracted  from  Chinese  sjurces,  which  are 
always  so  copious  in 'their  descriptions  of  nature.06  They 

64  Compare  Kaart  van  den  Zuid-en  Zuidwest-Kust  van  Japan  door 
F.  von  Siebold,  1851. 

®  Compare  my  Fragment  de  Geologie  et  de  Climmologie  Asiatiques, 
t  i,  p.  82,  which  appeared  immediately  after  my  return  from  my 


378  COSMOS. 

are  four  in  number,  and  of  these  the  Chy-kang  (Red  Moun- 
tain), whose  crater  contains  a  hot-water  lake,  has  experi- 
enced great  igneous  eruptions.  The  small  Baschi  Islands 
and  the  Babuyans,  which  so  late  as  1831,  according  to 
Meyen's  testimony,  experienced  a  violent  eruption  of  fire, 
connect  Formosa  with  the  Philippines,  of  which  the  smallest 
and  most  broken  islands  abound  most  in  volcanoes.  Leo- 
pold von  Buch  enumerates  nineteen  lofty  isolated  conical 
mountains  upon  them,  which  in  the  country  are  called  vol- 
canes,  though  probably  some  of  them  are  closed  trachytic 
domes.  Dana  is  of  opinion  that  in  southern  Luzon  there 
are  now  only  two  active  volcanoes, — that  of  Taal,  which 
rises  in  the  Laguna  de  Bongbong,  with  an  encircling  escarp- 
ment which  incloses  another  lagoon  (see  page  243) ;  and  in 
the  southern  portion  of  the  peninsula  of  Camarines  the  vol- 
cano of  Albay,  or  Mayon,  which  the  natives  call  Isaroe. 
The  latter,  which  is  3197  feet  high,  experienced  great  erup- 
tions in  the  years  1800  and  1814.  In  the  northern  portion 
of  Luzon  granite  and  mica- slate,  and  even  sedimentary 
formations  together  with  coal  are  diffused.66 

The  far-stretching  group  of  the  Soolo  (Solo)  islands,  which 
are  fully  100  in  number,  and  which  connect  Mindanao  and 
Borneo,  is  partly  volcanic,  and  partly  intersected  by  coral- 
reefs.  Isolated  unopened,  trachytic,  cone-shaped  peaks  are 
indeed  often  called  Vulcanes  by  the  Spaniards. 

If  we  carefully  examine  all  that  lies  to  the  south  of  the 
fifth  degree  of  north  latitude  (to  the  south  of  the  Philippines), 
between  the  meridians  of  the  Nicobars  and  the  north-west 
of  New  Guinea,  thus  taking  in  the  Sunda  Islands,  great  and 
Siberian  expedition,  and  the  Asie  Centrale,  in  which  the  opinion  ex- 
pressed by  Klaproth,  and  which  I  formerly  adopted,  respecting  the 
probability  of  the  connection  of  the  snowy  mountains  of  the  Himalaya 
with  the  Chinese  province  of  Yunan  and  with  Nanling  north  westward 
of  Canton,  has  been  confuted  by  me.  The  mountains  of  Formosa, 
upwards  of  11,000  feet  high,  as  well  as  Ta-yu-ling  which  bounds 
Fukian  to  the  westward,  belong  to  the  system  of  meridian  fissures  in 
Upper  Assam,  in  the  country  of  the  Burmese,  and  in  the  group  of 
the  Philippines. 

66  Dana's  Geology,  in  the  Explor.  Exped.,  vol.  x,  p.  540 — 545  ;  Ernest 
Hofmann,  Geogn.  Beob.  auf  der  Reise  von  Otto  v.  Kotzebue,  p.  70  ;  Leop. 
de  Buch,  Description  Physique  des  lies  Canaries,  pp.  435—439.  See 
the  large  and  admirable  chart  of  the  Islas  Filipinas,  by  the  Pilot  Don 
Antonio  Morati  (Madrid,  1852),  in  two  plates. 


TRUE  VOLCANOES.  379 

email,  and  the  Moluccas,  we  shall  find  as  the  result,  given  in 
the  great  work  of  Dr.  Junghuhn,  that  "  in  a  circle  of  islands 
which  surround  the  almost  continental  Borneo,  there  are 
109  lofty  fire-emitting  mountains,  and  10  mud-volcanoes." 
This  is  not  merely  an  approximate  calculation,  but  an  actual 
enumeration. 

Borneo,  the  Giava  Maggiore  of  Marco  Polo,67  has  hitherto 
furnished  us  with  no  certain  proofs  of  the  existence  of  any 
active  volcano  upon  it ;  but,  indeed,  it  is  only  a  few  narrow 
strips  of  the  shore  that  we  are  acquainted  with  (on  the 
north-west  side  as  far  as  the  small  coast- island  of  Labuan, 
and  as  far  as  Cape  Balambangan;  on  the  west  coast  at 
the  mouth  of  the  Pontianak ;  and  on  the  south-eastern 
point  in  the  district  of  Banjermas-Sing,  on  account  of  the 
gold,  diamond  and  platinum  washings).  It  is  not  even  be- 
lieved that  the  highest  mountain  of  the  whole  island,  and 
perhaps  even  of  the  whole  South  Asiatic  island-world,  the 
double-peaked  Kina  Bailu  at  the  northern  extremity,  dis- 
tant only  thirty-two  geographical  miles  from  the  Pirate- 
coasts,  is  a  volcano.  Captain  Belcher  makes  it  13,695  feet 
high,  which  is  nearly  4000  feet  higher  than  the  Gunung 
Pasaman  (Ophir)  of  Sumatra.68  On  the  other  hand,  Rajah 

6'  Marco  Polo  distinguishes  (Part  iii,  cap.  5  and  8)  Giava  Minore 
(Sumatra),  where  he  remained  for  five  months,  and  where  he  describes 
the  elephants,  which  were  not  to  be  found  in  Java  itself  (Humboldt, 
Examen.  Grit,  de  VHist.  de  la  Georg.,  t.  ii,  p.  218),  from  what  he  had 
before  described  as  Giava  (Maggiore),  la  quale,  secondo  dicono  i  mari- 
nai,  che  bene  to  sanno,  e  Visola  piu  grande  che  sia  al  mondo, — (which 
as  the  sailors  say,  who  know  it  well,  is  the  largest  island  in  the  world. 
This  assertion  is  even  to  this  day  true.  From  the  outlines  of  the  chart 
of  Borneo  and  Celebes  by  James  Brooke  and  Captain  Rodney  Mundy, 
I  find  the  area  of  Borneo  51,680  square  geographical  miles,  nearly 
equal  to  that  of  the  island  of  New  Guinea,  but  only  one-tenth  of  the 
continent  of  New  Holland.  Marco  Polo's  account  of  the  great  quantity 
of  gold  and  treasure  which  the  "Mercanti  di  Zaiton  e  del  Mangi"  ex- 
ported from  thence,  shows  that  by  Giava  Maggiore  he  meant  Borneo, 
(as  did  also  Martin  Behaim  on  the  Niirnberg  globe  of  1492,  and  Johann 
Ruysch  in  the  Roman  edition  of  Ptolemy,  dated  1508,  which  is  so 
important  for  the  history  of  the  discoveiy  of  America). 

68  Captain  Mundy's  chart  (coast  of  Borneo  Proper,  1847,)  gives,  it  is 
true,  14,000  English  feet.  See  a  doubt  of  this  datum  in  Junghuhn's 
Java,  Bd.  ii,  s.  580.  The  colossal  Kina  Bailu  is  not  a  conical  moun- 
tain. In  shape  it  much  more  resembles  the  basaltic  mountains  which 
occur  under  all  latitudes,  and  which  form  a  long  ridge  with  two 
terminal  summits. 


380  COSMOS. 

Brooke  mentions  a  much  lower  mountain  in  the  province  of 
Sarawak,  whose  name,  Gunung  Api  (Fire  Mountain  in  the 
Malay  tongue)  as  well  as  the  scorite  which  lie  around  it, 
lead  to  the  conclusion  that  it  was  once  volcanically  active. 
Large  deposits  of  gold- sand  between  quartz-veins,  the  abun- 
dance of  tin  washed  down  on  both  shores  of  the  rivers,  and 
the  feldspathic  porphyry69  of  the  Carambo  Mountains,  indi- 
cate a  great  extension  of  what  are  called  primitive  and 
transition  rocks.  According  to  the  only  certain  information 
which  we  possess  from  a  geologist  (Dr.  Ludwig  Horner, 
son  of  the  meritorious  Zurich  astronomer  and  circumnavi- 
gator of  the  globe),  there  are  found  in  the  south-eastern 
portion  of  Borneo  united  in  several  profitably  worked  wash- 
ings, precisely  as  in  the  Siberian  Ural,  gold,  diamonds,  plati- 
num, osmium,  and  iridium  (but  not  yet  palladium).  Forma- 
tions of  serpentine,  euphotide,  and  syenite,  lying  in  great 
proximity,  belong  to  a  range  of  rocks  3411  feet  high,  that 
of  the  Ratuhs  Mountains.70 

The  still  active  volcanoes  on  the  remaining  three  great 
Sunda  Islands  are  reckoned  by  Junghuhu  as  follows  :—  On 
Sumatra  from  six  to  seven,  on  Java  from  twenty  to  twenty- 
three,  on  Celebes  eleven,  and  on  Flores  six.  Of  the  vol- 
canoes of  the  island  of  J&va  we  have  already  (see  above 
page  298)  treated  in  detail.  In  Sumatra,  which  has  not 
hitherto  been  completely  investigated,  out  of  nineteen  con- 
ical mountains  of  volcanic  appearance  there  are  six  still 
active.71  Those  ascertained  to  be  so  are  the  following  : — 
The  Gunung  Indrapura,  about  12,256  feet  in  height,  accord- 
ing to  angles  of  altitude  measured  from  the  sea,  and  pro- 
bably of  equal  height  with  the  more  accurately  measured 
Semeru  or  Maha-Meru  on  Java; — the  Gunung  Pasaman, 
called  also  Ophir  (9602  feet),  with  a  nearly  extinguished 
crater,  ascended  by  Dr.  L.  Horner ; — the  sulphureous  Gun- 
ung Salasi,  with  eruptions  of  ashes  in  1833  and  1845  ; — 
the  Gunung  Merapi  (9751  feet),  also  ascended  by  Dr.  L. 
Horner,  accompanied  by  Dr.  Korthal,  in  the  year  1834,  the 

69  Brooke's  Borneo  and  Celebes,  vol.  ii,  pp.  382,  384,  aad  386. 

70  Homer,  in  the   Verhandelingen  van  het  Bataviaasch  Genootschap 
vcm  Kunsten  en  Wetensckappen,  Deel  xvii  (1839),  s.  281 ;  Asie  Centrale, 
t.  iii,  pp.  534—537. 

71  Junghuhn,  Java,  Bd.  ii,  e.  809 ;  (Battalander,  Bd.  i,  s.  39). 


TRUE   VOLCANOES.  3&1 

active  of  all  the  volcanoes  of  Sumatra,  tind  not  to  be 
confounded  with  the  two  similarly  named  mountains  of 
Java  ;72 — the  Chiming  Ipu,  a  smoking  truncated  cone  ; — and 
the  Gunung  Dernpo,  in  the  inland  country  of  Benkula, 
reckoned  at  9940  feet  high. 

Four  islets  forming  trachytic  cones,  of  which  the  Pic  Kecata 
and  Panahitam  (Prince's  Island)  are  the  highest,  rise  above 
the  sea  in  the  Strait  of  Sunda,  and  connect  the  volcanic  range 
of  Sumatra  with  the  crowded  field  of  Java,  and  in  like  man- 
ner the  eastern  extremity  of  Java,  with  its  volcano  of  Idjen, 
forms,  through  the  medium  of  the  active  volcanoes  Gunung 
Batur  and  Gunung  Agung  on  the  neighbouring  island  of 
Bali,  a  connection  with  the  long  chain  of  the  smaller  Sunda 
Islands.  Here  again  the  range  is  continued  eastward  from 
Bali,  by  the  smoking  volcano  of  Rindjani  on  the  island  of 
Lombok,  12.363  feet  high,  according  to  the  trigonometrical 
measurement  of  M.  Melville  de  Carnbee ; — by  the  Temboro 
(5862  feet)  on  the  Sumbava,  or  Sambava,  whose  eruption  of 
ashes  and  pumice  in  April,  1815,  obscured  the  surrounding 
atmosphere,  and  was  one  of  the  greatest  which  history  has 
recorded;73 — and  by  six  conical  mountains  still  partially 
smoking,  on  Flores 

The  large  and  many  armed  island  of  Celebes  contains  six 
volcanoes,  which  are  not  yet  all  extinct ;  they  lie  all  together 
on  the  narrow  north-eastern  peninsula  of  Menado.  Beside 
it  spout  out  streams  of  hot  melted  sulphur,  into  the  orifice 
of  one  of  which,  near  the  road  from  Sender  to  Lamovang,  a 
great  traveller  and  intrepid  observer,  Count  Carlo  Vidua, 
my  Piedmontese  friend,  sank  and  met  his  death  from  the 
burns  he  received.  As  the  small  island  of  Banda  in  the 
Moluccas  consists  of  the  volcano  of  Guning  Api,  which  was 
active  from  1586  to  1824,  and  is  about  1812  feet  high,  in 
the  same  way  the  larger  island  of  Ternate  is  likewise  formed 
by  a  single  conical  mountain,  5756  feet  high,  the  Gunung 
Gama  Lama,  whose  violent  eruptions  from  1838  to  1849, 
after  more  than  a  century  and  a  half  of  entire  quiescence  are 
described  at  ten  different  periods.  During  the  eruption  of 
the  3rd  February,  1840,  according  to  Junghuhn,  a  stream  of 
lava  poured  out  of  a  fissure  near  the  fort  of  Toluko,  and 

72  See  page  300,  note  86.  »  Java,  Bd.  ii,  B.  818—828. 


S82  COSMOS. 

flowed  down  to  the  shore,74  "  partly  issuing  in  the  form  of 
a  connected  and  thoroughly  molten  stream,  and  partly 
consisting  of  glowing  fragments  which  rolled  down  and  were 
forced  along  the  plain  by  the  weight  of  the  succeeding 
masses."  If  to  the  more  important  volcanic  cones  here  in- 
dividually mentioned  we  add  the  numerous  small  island  vol- 
canoes which  cannot  be  here  noticed,  the  total  number  of 
the  igneous  mountains  situated  to  the  southward  of  the 
parallel  of  Cape  Serangami  on  Mindanao,  one  of  the  Philip- 
pines, and  between  the  meridians  of  the  north-west  Cape  of 
New  Guinea  on  the  east  and  of  the  Nicobar  and  Andaman 
groups  on  the  west,  amounts,  as  has  been  already  stated,  to 
the  large  number  of  109.76  This  calculation  is  made  in  the 
belief  that  *'  on  Java  forty-five  volcanoes,  for  the  most  part 
cone-shaped,  and  provided  with  craters,  may  be  counted." 
Of  these,  however,  only  21,  and  only  from  42  to  45, 
of  the  whole  number  of  109,  are  recognized  as  now  active, 
or  as  having  been  so,  at  any  period  within  the  reach  of 
history.  The  mighty  Pic  of  Timor  formerly  served  like 
Stromboli  as  a  light-house  to  mariners.  On  the  small  island 
of  Pulu  Batu  (called  also  P.  Komba),  a  little  to  the  north 
of  Floris,  a  volcano  was  seen  in  1850  to  pour  a  stream  of 
glowing  lava  down  to  the  sea-shore.  The  same  thing  was 
observed  in  1812,  and  again  in  the  spring  of  1856,  in 
respect  to  the  Pic  on  the  greater  Sangir  Island,  between 
Magindanao  and  Celebes.  Junghuhn  doubts  whether  the 
famous  conical  mountain  of  Yavani  or  Ateti,  on  Amboina, 
ejected  anything  more  than  hot  mud  in  1674,  and  considers 
the  island  at  present  as  only  a  solfatara.  The  great  group 
of  the  South  Asiatic  Islands  is  connected  by  the  division  of 
the  Western  Sunda  Islands  with  the  Nicobar  and  Andaman, 
Isles  of  the  Indian  Ocean,  and  by  the  division  of  the  Mo- 
luccas and  Philippines  with  the  Papuas,  the  Pellew  Islands 
and  Carolinas  of  the  South  Sea.  We  shall  first,  however, 
proceed  with  the  less  numerous  and  more  dispersed  groups 
of  the  Indian  Ocean. 

VII.  THE  INDIAN  OCEAN. 

This  comprehends  the  space  between  the  west  coast  of 
»  Junghuhn's  Java,  vol.  ii,  pp.  840—842.  ?5  Ibid,  p.  853. 


TRUE   VOLCANOES.  383 

the  peninsula  of  Malacca,  or  of  the  Birman  country  to  the 
east  coast  of  Africa,  thus  inclosing  in  its  northern  division 
the  Bay  of  Bengal  and  the  Arabian  and  Red  Seas.  We 
pursue  the  chain  of  volcanic  activity  in  the  Indian  Ocean  in 
the  direction  from  north-east  to  south-west. 

Barren  Island,  in  the  Bay  of  Bengal,  a  little  to  the  east 
of  the  great  Andaman  Island  (lat.  12°  15'),  is  correctly  con- 
sidered an  active  cone  of  eruption,  issuing  out  of  a  crater  of 
upheaval.  The  sea  forces  its  way  through  a  narrow  opening 
and  fills  an  internal  basin.  The  appearance  presented  by 
this  island,  which  was  discovered  by  Horsburgh  in  1791,  is 
exceedingly  instructive  for  the  theory  of  the  formation  of 
volcanic  structures.  We  sec  here  in  a  complete  and  per- 
manent form  what  nature  exhibits  in  only  a  cursory  way  at 
Santorin,  and  at  other  points  of  the  earth's  surface.76  The 
eruptions  in  November  1803  were,  like  those  of  Sangay  in 
the  Cordilleras  of  Quito,  very  distinctly  periodical,  recurring 
at  intervals  often  minutes  (Leop.  von  Buch  in  the  Abhandl. 
der  Berl.  Akademie,  1818—1819,  s.  62). 

The  island  of  Narcondam,  to  the  north  of  Barren  Island, 
has  likewise  exhibited  volcanic  action  at  a  former  period,  as 
has  also  the  cone-mountain  of  the  island  of  Cheduba,  which 
lies  more  to  the  north,  near  the  shore  of  Arracan  (10°  52'). 
(Silliman's  American  Journal,  vol.  xxxviii,  p.  385). 

The  most  active  volcano,  judging  from  the  frequency  of 
the  lava-eruptions,  not  only  in  the  Indian  Ocean  but  in 
almost  the  whole  of  the  south  hemisphere  between  the  meri- 
dians of  the  west  coast  of  New  Holland  and  the  east  coast 
of  America,  is  that  on  the  island  of  Bourbon  in  the  group 
of  the  Mascareignes.  The  greater  part  of  the  island,  parti- 
cularly the  western  portion  and  the  interior,  is  basaltic. 
Recent  veins  of  basalt,  with  little  admixture  of  olivine,  run 
through  the  older  rock,  which  abounds  in  olivine ;  beds  of 
lignite  are  also  enclosed  in  the  basalt.  The  culminating 
points  of  the  Mountain  Island  are  the  Gros  Mornr  and  the 
Trois  Salazes,  the  height  of  which  La  Caille  over-estimated 
at  10,658.  The  volcanic  action  is  now  limited  to  the  southern- 
most portion,  the  "  Grand  pays  brule."  The  summit  of  the 

7fi  Leop.  v.  Buch,  in  the  Abhandl.  der  Akad.  der  Wiss.  zu  Berlin, 
1818  and  1819,  s.  62;  Lyell,  Princ.  of  Geology.  (1853),  p.  447,  where  a 
fine  representation  of  the  volcano  is  given. 


384  COSMOS. 

volcano  of  Bourbon,  which  Hubert  describes  as  emitting, 
nearly  every  year,  two  streams  of  lava  which  frequently  ex- 
tend to  the  sea,  is,  according  to  Berth's  measurement,  8000 
feet  high.77  It  exhibits  several  cones  of  eruption  which  have 
received  distinct  names,  and  which  alternately  send  forth 
eruptions.  The  eruptions  from  the  summit  are  infrequent. 
The  lavas  contain  glassy  feld-spar,  and  are  therefore  rather 
trachytic  than  basaltic.  The  shower  of  ashes  frequently  con- 
tains olivine  in  long,  fine  threads,  a  phenomenon  which  like- 
wise occurs  at  the  volcano  of  Owhyhee.  A  violent  eruption 
of  these  glassy  threads,  covering  the  whole  island  of  Bour- 
bori,  occurred  in  the  year  1821. 

All  that  we  know  of  the  great  neighbouring  terra  incog- 
nita of  Madagascar  is  the  extensive  dispersion  of  pumice  at 
Tintingue,  opposite  the  French  island  of  St.  Marie,  and  the 
occurrence  of  basalt,  to  the  south  of  the  bay  of  Diego  Suarez, 
near  the  northernmost  Cap  d'Ambre,  surrounded  by  granite 
aud  gneiss.  The  southern  central-ridge  of  the  Ambohist- 
raene  Mountains  is  calculated  (though  with  little  certainty) 
at  about  11,000  feet.  Westward  of  Madagascar,  in  the 
northern  outlet  of  the  Mozambique  Channel,  the  largest 
of  the  Comoro  Islands  has  a  burning  volcano  (Darwin, 
Coral  Reefs,  p.  122). 

The  small  volcanic  island  of  St.  Paul  (38°  38'),  south  of 
Amsterdam,  is  considered  volcanic,  not  only  on  account  of 
its  form,  which  strongly  reminds  one  of  that  of  Santorin, 
Barren  Island,  and  Deception  Island,  in  the  group  of  the 
New  Shetland  Isles,  but  likewise  on  account  of  the  repeat- 
edly ob&erved  eruptions  of  fire  and  vapour  in  modern  times. 
The  very  characteristic  drawing  given  by  Yalentyn  in  hia 
work  on  the  Banda  Islands,  relative  to  the  expedition  of 
Willein  de  Vlaming  (November  1696)  corresponds  exactly, 
as  do  also  the  statements  of  the  latitudes,  with  the  repre- 
sentations in  the  atlas  of  Macartney's  expedition,  and  Cap- 
tain Blackwood's  survey  (1842).  The  crater-shaped,  circular 
bay,  nearly  an  English  mile  across,  is  everywhere  surrounded 
by  precipitate  rocks  which  fall  perpendicularly  in  the  in- 
terior, with  the  exception  of  a  narrow  opening,  through 
which  the  sea  enters  at  flood-tide ;  while  those  which  form 

77  Bory  de  St.  Vincent,  Voyage  aux  Quatre  Isles  d'Afrique,  t.  iL 
p.  429. 


TRUE  VOLCANOES.  385 

the  margin  of  the  crater  fall  away  externally  with  a  gentle 
slope.78 

The  island  of  Amsterdam  which  lies  50'  of  latitude  farther 
towards  the  north  (37°  48')  consists,  according  to  Valentyn's 
representation,  of  a  single,  well-wooded,  somewhat  rounded 
mountain,  from  the  highest  ridge  of  which  rises  a  small 
cubical  rock,  almost  the  same  as  at  the  Cofre  de  Perote  on 
the  higher  plains  of  Mexico.  During  the  expedition  of  D'En- 
trecasteaux  (March  1792),  the  island  was  seen  for  two  whole 
days  entirely  enveloped  in  flames  and  smoke.  The  smell  of 
the  smoke  seemed  to  indicate  the  combustion  of  wood  and 
earth  ;  columns  of  vapour  were,  indeed,  thought  to  rise  here 
and  there  from  the  ground  near  the  shore,  but  the  natural- 
ists who  accompanied  the  expedition  were  decidedly  of 
opinion  that  the  mysterious  phenomenon  could  by  no  means 
be  ascribed  to  an  eruption  79  of  the  high  mountain,  like  that 

73  Valentyn,  Beschryving  van  Oud  en  Nieuw  Oost  Indien,  Deel  iii, 
(1726),  p.  70  ;  Het  Eyland  St.  Paulo.  (Compare  Lyell,  Princ.  p.  446). 

79  "\Ve  were  unable,"  says  D'Entrecasteaux,  "  to  form  any  conjecture 
as  to  the  cause  of  the  burning  on  the  island  of  Amsterdam.  The 
island  was  in  flames  throughout  its  whole  extent,  and  we  recognized 
distinctly  the  smell  of  burnt  wood  and  earth.  We  had  felt  nothing  to 
lead  us  to  suppose  that  the  fire  was  the  effect  of  a  volcano"  (t.  i, 
p.  45).  A  few  pages  before,  he  says,  "  We  remarked,  however,  as  we 
sailed  along  the  coast,  from  which  the  flames  were  rather  distant, 
little  puffs  of  smoke  which  seemed  to  come  from  the  earth  like  jets  ; 
yet  we  could  not  distinguish  the  least  trace  of  fire  around  them, 
though  we  were  very  close  to  the  laud.  These  jets  of  smoke  which 
appeared  at  intervals,  were  considered  by  the  naturalists  of  the  expedi- 
tion as  certain  proofs  of  subterranean  fire."  Are  we  to  conclude  from 
this  that  there  were  actual  combustions  of  earth, — conflagrations  of 
lignite,  the  beds  of  which,  covered  with  basalt  and  tufa,  occur  in  such 
abundance  on  volcanic  islands  (as  Bourbon,  Kerguelen-land,  and  Ice- 
land) ?  The  Surtarbrand,  on  the  latter  island,  derives  its  name  from 
the  Scandinavian  myth  of  the  fire-giant  Surtr  causing  the  conflagra- 
tion of  the  world.  The  combustion  of  earth,  however,  causes  no  flame 
in  general.  As  in  modern  times  the  names  of  the  islands  Amsterdam 
and  St.  Paul  are  unfortunately  often  confounded  on  charts,  I  would 
here  observe,  in  order  to  prevent  mistakes  in  ascribing  to  one  observa- 
tions which  apply  to  the  other,  they  being  very  different  in  formation 
though  lying  almost  under  one  and  the  same  meridian,  that  originally 
(as  early  as  the  end  of  the  17th  century)  the  south  island  was  called 
St.  Paul  and  the  northern  one  Amsterdam.  Vlaming,  their  discoverer, 
assigned  to  the  first  the  latitude  of  38°40',  and  to  the  second  thatof  37°48' 
south  of  the  equator.  This  corresponds  in  a  remarkable  manner  with 
VOL.  V.  "2  C 


386  COSMOS. 

of  a  volcano.  More  certain  evidences  of  former  genuine 
volcanic  action  on  the  island  of  Amsterdam  may  be  found  in 
the  calculation  made  by  D'Entrecasteaux  a  century  later  on  the  occa- 
sion of  the  expedition  in  search  of  La  Pgrouse  ( Voyage,  t.  i,  p.  43  —45). 
namely,  for  Amsterdam,  according  to  Beautemps  Beaupre,  37°  47' 46" 
(long.  77°  71'),  for  St.  Paul  38°  38'.  This  near  coincidence  must  be  con- 
sidered accidental,  as  the  points  of  observation  were  certainly  not  ex- 
actly the  same.  On  the  other  hand  Captain  Blackwood  in  his  Ad- 
miralty chart  of  1842  gives  38°" 44'  and  longitude  77°  37'  for  St.  Paul. 
On  the  charts  given  in  the  original  editions  of  the  voyages  of  the  im- 
mortal circumnavigator  Cook,  those  for  instance  of  the  first  and  second 
expedition  ( Voyage  to  the  South  Pole  and  Round  the  World,  London, 
1777,  p.  1),  as  well  as  of  the  third  and  last  voyage  (Voyage  to  the 
Pacific  Ocean,  published  by  the  Admiralty,  London,  1784,  in  2nd  edi- 
tion, 1785),  and  even  of  all  the  three  expeditions  (A  General  Chart, 
exhibiting  the  Discoveries  of  Captain  Cook  in  his  Third  and  Two  Pre- 
ceding Voyages,  by  Lieut.  Henry  Roberts),  the  island  of  St.  Paul  is 
very  correctly  laid  down  as  the  most  southernly  of  the  two ;  but  in 
the  text  of  the  voyage  of  D'Entrecasteaux  (t.  i,  p.  44),  it  is  mentioned 
by  way  of  censure  (whether  with  justice  or  not  I  am  unable  to  say, 
although  I  have  sought  after  the  editions  in  the  libraries  of  Paris, 
Berlin,  and  Gb'ttingen),  "that  on  the  special  chart  of  Cook's  last  expe- 
dition the  island  of  Amsterdam  is  set  down  as  more  to  the  south  than 
St.  Paul."  A  similar  reversal  of  the  appellations,  quite  opposed  to 
the  intention  of  the  discoverer,  Willem  de  Vlamiug,  was  frequent  in 
the  first  third  of  the  present  century,  as  for  example  on  the  older  and 
excellent  maps  of  the  world  by  Arrowsmith  and  Purdy  (1833),  but 
there  was  more  than  a  special  chart  of  Cook's  third  voyage  operating 
to  cause  it.  There  was,  1st,  the  arbitrary  entry  on  the  maps  of  Cox 
and  Mortimer ;  2nd,  the  circumstance  that,  in  the  atlas  of  Lord  Mac- 
artney's voyage  to  China,  though  the  beautiful  volcanic  island  repre- 
sented smoking  is  very  correctly  named  St.  Paul,  under  Lit.  38°  42', 
yet  it  is  absurdly  added,  "  commonly  called  Amsterdam,"  and  what 
is  still  worse,  in  the  narrative  of  the  voyage  itself,  Staunton  and. 
Dr.  Gillau  uniformly  called  this  "  island  still  in  a  state  of  inflamma- 
tion "  Amsterdam,  and,  they  even  add  (p.  226,  after  having  given  the 
correct  latitude  in  p.  219)  "  that  St.  Paul  is  lying  to  the  northward  of 
Amsterdam  ;"  and  3rdly,  there  is  the  same  confusion  of  names  by 
Barrow  (Voyage  to  Cochin  China  in  the  Years  1792  and  1793,  pp.  140 — 
157),  who  also  gives  the  name  of  Amsterdam  to  the  southern  island, 
emitting  smoke  and  flames,  assigning  to  it  at  the  same  time  the  lati- 
tude 38°  42'.  Malte  Brun  (Precis  de  la  Geographic  Universelle,  t.  v, 
1817,  p.  146),  very  properly  blames  Barrow,  but  he  errs  in  also 
blaming,  M.  de  Rossel  and  Beautemps-Beaupre\  Both  of  the  latter 
writers  give  as  the  latitude  of  the  island  of  Amsterdam,  which  is  the 
only  one  they  represent,  37°  47',  and  that  of  the  island  of  St.  Paul, 
because  it  lies  50'  more  to  the  south,  38°  38'  (  Voy.  de  D' Entrecastreaux, 
1808,  t.  1,  pp.  40 — 46),  and  to  show  that  the  design  represents  the 
true  island  of  Amsterdam,  discovered  by  Willem  de  Vlaming,  Beau- 


TRUE  VOLCANOES.  387 

the  beds  of  pumice-stone  (uitgebranden  puimsteen),  mention 
of  which  is  made  so  early  as  by  Valentyn,  according  to 
Vlaming's  Ship  Journal  of  1696. 

To  the  south-east  of  the  Cape  of  Good  Hope  lie  Marion's, 
or  Prince  Edward's  Island  (47°  2').  and  Possession  Island 
(lat.  46°  28'  and  long.  51°  56'),  forming  part  of  the  Crozet 
group.  Both  of  them  exhibit  traces  of  former  volcanic 
action,— small  conical  hills,80  with  eruption-openings  sur- 
rounded by  columnar  basalt. 

More  eastward,  and  almost  in  the  same  latitude,  we  come 
to  Kerguelen's  island  (Cook's  Island  of  Desolation),  for  the 
first  geological  account  of  which  we  are  indebted  to  the  suc- 
cessful and  important  expedition  of  Sir  James  Ross.  In  the 
harbour  called  by  Cook  Christmas  Harbour  (lat.  48°  41', 
long.  69°  2'),  basaltic  lavas,  several  feet  thick,  are  found  en- 
closing the  fossil  trunks  of  trees ;  there  also  is  seen  the  sin- 
gular and  ^picturesque  Arched  Rock,  a  natural  passage  through 
a  narrow  projecting  wall  of  basalt.  In  the  neighbourhood 
are  conical-mountains,  the  highest  of  which  rise  to  2664  feet, 
with  extinct  craters, —  masses  of  green-stone  and  porphyry, 
traversed  ky  beds  of  basalt, — and  amygdaloid  with  dnisv 
masses  of  quartz  at  Cumberland  Bay.  The  most  remarkable 
of  all  are  the  numerous  beds  of  coal,  covered  with  trap- rock 
(dolerite,  as  at  Meissner  in  Hesse  ?),  of  a  thickness  of 
from  a  few  inches  to  four  feet  at  the  outcrop.81 

If  we  take  a  general  survey  of  the  Indian  Ocean,  we  shall 
find  the  north-westerly  extremity  of  the  Sunda  range  in 
Sumatra,  which  is  curved,  carried  on  through  the  Nicobars 
and  the  Great  and  Little  Andamans,  while  the  volcanoes  of 
Barren  Island,  Narcondam,  and  Cheduba,  almost  parallel 

temps-Beaupre  adds  in  his  atlas  a  copy  of  the  thickly-wooded  island 
of  Amsterdam  from  Valentyn.  I  may  here  observe  that  the  cele- 
brated navigator,  Abel  Tasman  having  in  1642,  along  with  Middel- 
burg,  called  the  island  of  Tonga-Tabu  (lat.  21-i°)  in  the  Tonga  group, 
by  the  name  of  Amsterdam  (Burney,  Chronolog.  Hist,  of  the  Voyages 
and  Discoveries  in  the  South  Sea  or  Pacific  Ocean,  Part  iii,  pp.  81  and 
437)  ;  he  has  also  been  sometimes  erroneously  cited  as  the  discoverer 
of  Amsterdam  and  St.  Paul  in  the  Indian  Ocean.  See  Leidenfroet, 
Ilhtor.  Handwortenbuch,  Bd.  v,  s.  310. 

80  Sir  James  Ross,  Vogage  in  the  boutnem  and  Antarctic  Reg  long 
vol.  i,  pp.  46,  and  50 — 56. 

»  Ibid.  p.  63—82. 

2c  2 


388  COSMOS. 

to  the  coasts  of  Malacca  and  Tenasseriin,  run  into  the 
eastern  portion  of  the  Bay  of  Bengal.  Along  the  shores  of 
Orissa  and  Coromandel,  the  eastern  portion  of  the  bay  is 
destitute  of  islands,  the  great  island  of  Ceylon  bearing,  like 
that  of  Madagascar,  more  of  the  character  of  a  continent. 
Opposite  the  western  shore  of  the  Indian  peninsula  (the 
elevated  plain  of  Neilgherry  and  the  coasts  of  Ganara  and 
Malabar)  a  range  of  three  archipelagos  lying  in  a  direction 
from  north  to  south,  and  extending  from  14°  north  to  8° 
south  latitude  (the  Laccadives,  the  Maldives,  and  the  Chagos) 
is  connected  by  the  shallows  of  Sahia  de  Malha  and  Car- 
gados  Carajos  with  the  volcanic  group  of  the  Mascareignes 
and  Madagascar.  The  whole  of  this  chain,  so  far  as  can  be 
seen,  is  the  work  of  coral-polypes, — true  Atolls,  or  lagoon- 
reefs  ;  in  accordance  with  Darwin's  ingenious  conjecture 
that  at  this  part  a  large  extent  of  the  floor  of  the  ocean 
forms,  not  an  area  of  upheaval,  but  an  area  of  subsidence. 

VIII.  THE  SOUTH  SEA,  OR  PACIFIC. 

If  we  compare  that  portion  of  the  earth's  surface  now 
covered  with  water  with  the  aggregate  area  of  the  terra 
firma,  (nearly82  in  the  proportion  of  2.7  to  1),  we  cannot  but 
be  astonished  in  a  geological  point  of  view  at  the  small 
number  of  volcanoes  which  still  continue  active  in  the 
oceanic  region.  The  South  Sea,  the  superficies  of  which  is 
nearly  one-sixth  greater  than  that  of  the  whole  terra  firma 
of  our  planet, —  which  in  the  equinoctial  region,  from  the 
archipelago  of  Galapagos  to  the  Pellew  Islands,  is  nearly 
two-fifths  of  the  whole  circumference  of  the  earth  in  breadth, 
— exhibits  fewer  smoking  volcanoes,  fewer  openings  through 
which  the  interior  of  the  planet  still  continues  in  active 
communion  with  its  atmospheric  envelope  than  does  the 
single  island  of  Java.  Mr.  James  Dana,  the  talented  geo- 
logist of  the  great  American  exploring  expedition  (1838 — 
1842),  under  the  command  of  Charles  Wilkes,  basing  his 
views  on  his  own  personal  investigations,  aided  by  a  careful 
comparison  of  all  previous  reliable  observations,  and  espe- 

82  The  result  of  Prof.  Rigaud'a  "  weighings  "  at  Oxford,  according  to 
Halley'a  old  method.  See  my  Asie  Centrale,  t.  i,  p.  189. 


TRUE  VOLCANOES.  389 

cially  by  a  comprehensive  examination  of  the  different  opi- 
nions on  the  forms,  the  distribution  and  the  axial  direction 
of  the  island  groups,  on  the  character  of  the  different  kinds  of 
rocks,  and  the  periods  of  the  subsidence  and  upheaval  of  ex- 
tensive tracts  of  the  floor  of  the  ocean,  has  the  indisputable 
merit  of  having  shed  a  new  light  over  the  island-world  of 
the  South  Sea.  In  availing  myself  of  his  work,  as  well  as 
of  the  admirable  writings  of  Charles  Darwin,  the  geologist  of 
Captain  Fitzroy's  expedition  (1832 — 1836),  without  always 
particularizing  them,  I  trust  that  the  high  respect  in  which 
I  have  for  so  many  years  held  those  gentlemen,  will  secure 
me  from  the  chance  of  having  my  motives  misinterpreted. 

It  is  my  intention  to  avoid  altogether  the  divisional  terms 
of  Polynesia,  Micronesia,  Melanesia,  and  Malaisia,83  which 
are  not  only  extremely  arbitrary,  but  founded  on  totally 
different  principles  drawn  from  the  number  and  size,  or  the 
complexion  and  descent  of  the  inhabitants,  and  to  com- 
mence the  enumeration  of  the  still  active  volcanoes  of  the 
South  Sea  with  those  which  lie  to  the  north  of  the  equator. 
I  shall  afterwards  proceed  in  the  direction  from  east  to 
west  to  the  islands  situated  between  the  equator  and  the 
parallel  of  30°  south  latitude.  The  numerous  basaltic  and 
trachytic  islands,  with  their  countless  craters,  formerly  at 
different  times  eruptive,  must  on  no  account  be  said  to  be 
indiscriminately  scattered.84  It  is  admitted  with  respect  to 
the  greater  number  of  them  that  their  upheaval  has  taken 

s3  D'Urville,  Voy.  de  la  Corvette  I' Astrolabe,  1826—1829,  Atlas,  pi.  i. 
— 1st,  Polynesia  is  considered  to  contain  the  eastern  portion  of  the 
South  Sea  (the  Sandwich  Islands,  Tahiti,  and  the  Tonga  Archipelago  ; 
and  also  New  Zealand) ;  2nd,  Micronesia  and  Melanesia  form  the  west- 
ern portion  of  the  South  Sea ;  the  former  extends  from  Kauai,  the 
westernmost  island  of  the  Sandwich  group,  to  near  Japan  and  the 
Philippines,  and  reaches  south  to  the  equator,  comprehending  the 
Marians  (Ladrones),  the  Carolinas  and  the  Pellew  Islands ;  3rd,  Me- 
lanesia, so  called  from  its  dark-haired  inhabitants,  bordering  on  the 
Malaisia  to  the  north-west,  embraces  the  small  archipelago  of  Viti,  or 
Feejee,  the  New  Hebrides  and  Solomon's  Islands;  likewise  the  larger 
islands  of  New  Caledonia,  New  Britain,  New  Ireland,  and  New 
Guinea.  The  terms  Oceania  and  Polynesia,  often  so  contradictory  iu 
a  geographical  point  of  view,  are  taken  from  Malte-Brun  (1813)  and 
from  Le*soii  (1 828). 

84  "  The  epithet  scattered,  as  applied  to  the  islands  of  the  ocean  (in 
the  arrangement  of  the  groups)  conveys  a  very  incorrect  idea  of  thei* 


390  COSMOS. 

place  on  widely  extended  fissures  and  submarine  mountain- 
chains,  which  run  in  directions  governed  by  fixed  laws  of 
region  and  grouping,  and  which,  just  as  we  see  in  the  conti- 
nental mountain  chains  of  Central  Asia,  and  of  the  Caucasus, 
belong  to  different  systems ;  but  the  circumstances  which 
govern  the  area  over  which  at  any  one  particular  time  the 
openings  are  simultaneously  active,  probably  depend,  from 
the  extremely  limited  number  of  such  openings,  on  entirely 
local  disturbances  to  which  the  conducting  fissures  are  sub- 
jected. The  attempt  to  draw  lines  through  three  now 
simultaneously  active  volcanoes,  whose  respective  distances 
amount  to  between  2400  and  3000  geographical  miles 
asunder,  without  any  intervening  cases  of  eruption  (I  refer 
to  three  volcanoes  now  in  a  state  of  ignition, — Mouna  Loa, 
with  Kilauea  on  its  eastern  declivity, — the  cone-mountain 
of  Tanna,  in  the  new  Hebrides  ;  and  Assumption  Island  in 
the  North  Ladrones),  would  afford  us  no  information  in  re- 
gard to  the  general  formation  of  volcanoes  in  the  basin  of 
the  South  Sea.  The  case  is  quite  different  if  we  limit  our- 
selves to  single  groups  of  islands,  and  look  back  to  remote, 
perhaps  pre-historic,  epochs  when  the  numerous  linearly 
arranged,  though  now  extinct,  craters  of  the  Ladrones 
(Marian  Islands),  the  New  Hebrides  and  the  Solomon's 
Islands  were  active,  but  which  certainly  did  not  become 

positions.  There  is  a  system  in  their  arrangement  as  regular  as  in 
the  mountain  heights  of  a  continent,  and  ranges  of  elevation  are  indi- 
cated, as  grand  and  extensive  as  any  continent  presents."  Geology, 
by  J.  Dana,  United  States'  Exploring  Expedition,  under  command  of 
Charles  Wilkes,  vol.  x,  (1849)  p.  12.  Dana  calculates  that  there  are 
in  the  whole  of  the  South  Sea,  exclusive  of  the  small  rock-islands, 
about  350  basaltic  or  trachytic  and  290  coral  islands.  He  divide? 
them  into  twenty-five  groups,  of  which  nineteen  in  the  centre 
have  the  direction  of  their  axis  N.  50° — 60°  W.,  and  the  remaining 
N.  20° — 30°  E.  It  is  particularly  remarkable  that  these  numerous 
islands,  with  a  few  exceptions,  such  as  the  Sandwich  Islands  and  New 
Zealand,  all  lie  between  23°  23'  of  north  and  south  latitude,  and  that 
there  is  such  an  immense  space  devoid  of  islands  eastward  from  the 
Sandwich  and  the  Nukahiva  groups  as  far  as  the  American  shores  of 
Mexico  and  Peru.  Dana  likewise  draws  attention  to  a  circumstance 
which  forms  a  contrast  to  the  insignificant  number  of  the  now  active 
volcanoes,  namely,  that  if,  as  is  probable,  the  Coral  Islands,  when  lying 
between  entirely  basaltic  islands,  have  likewise  a  basaltic  foundation, 
the  number  of  submarine  and  subae'rial  volcanic  openings  may  be  esti- 
mated at  more  than  a  thousand  (pp.  17  and  24). 


TRUE  VOLCANOES.  391 

gradually  extinguished  in  a  direction  either  from  south- 
east to  north-west  or  from  north  to  south.  Though  I 
here  name  only  volcanic  island-chains  of  the  high  seas,  yet 
the  Aleutes  and  other  true  coastian  islands  are  analogous 
to  them.  General  conclusions  as  to  the  direction  of  a  cool- 
ing process  are  deceptive,  as  the  state  of  the  conducting 
medium  must  operate  temporarily  upon  it,  according  as  it  is 
open  or  interrupted. 

Mouna  Loa,  ascertained  by  the  exact  measurement8'  of 
the  American  exploring  expedition  under  Captain  Wilkes 
to  be  13,758  feet  in  height,  and  consequently  1600  feet 
higher  than  the  Peak  of  Teneriffe,  is  the  largest  volcano  of 
the  South  Sea  Islands,  and  the  only  one  that  still  remains 
really  active  in  the  whole  volcanic  archipelago  of  the  Hawaii 
or  Sandwich  Islands.  The  summit-craters,  the  largest 
of  which  is  nearly  13,000  feet  in  diameter,  exhibit  in 
their  ordinary  state  a  solid  bottom,  composed  of  hardened 
lava  and  scoriae,  out  of  which  rise  small  cones  of  eruption, 
exhaling  vapour.  The  summit  openings  are  on  the  whole 
not  very  active,  though  in  June  1832  and  in  January 
1843,  they  emitted  eruptions  of  several  weeks'  duration,  and 
even  streams  of  lava  of  from  20  to  28  geographical  miles  in 
length,  extending  to  the  foot  of  Monna  Kea.  The  fall  (in- 
clination) of  the  perfectly  connected  flowing  stream86  was 
chiefly  6U,  frequently  10°,  15°,  and  even  25°.  The  conforma- 
tion of  the  Mouna  Loa  is  very  remarkable  from  the  circum- 
stance of  its  having  no  cone  of  ashes,  like  the  Peak  of 
Teneriffe,  Cotopaxi,  and  so  many  other  volcanoes ;  it  is 
likewise  almost  entirely  deficient  in  pumice87  though  the 
blackish-grey,  and  more  trachy  tic  than  basaltic,  lavas  of  the 

85  See  Cosmos,  vol.  v,  p.  250,  note  35. 

so  Dana,  Geology  of  the  U.  St.  Explor.  Exped.,  pp.  208  and  210. 

87  Dana,  pp.  193  and  201.  The  absence  of  cinder-cones  is  likewise 
very  remarkable  in  those  volcanoes  of  the  Eifel  which  emit  streams  of 
lava.  Reliable  information,  however,  received  by  the  Missionary  Dib- 
ble from  the  mouths  of  eye-witnesses,  proves  that  an  eruption  of  ashes 
may  notwithstanding  occur  from  the  summit-crater  of  Mouna  Loa,  for 
he  was  told  that,  during  the  war  carried  on  by  Kamehameha  against 
the  insurgents  in  the  year  1789,  an  eruption  of  hot  ashes,  accompanied 
by  an  earthquake,  enveloped  the  surrounding  country  in  the  darkness 
of  night  (p.  183).  On  the  volcanic  glass  threads  (the  hair  of  the  god- 
dess Pele,  who  before  she  went  to  settle  at  Hawaii  inhabited  the  now 


592  COSMOS. 

summit  abound  in  felspar.  The  extraordinary  fluidity  of 
the  lavas  of  Mouna  Loa,  whether  issuing  from  the  summit- 
crater  (Mokna-weo-weo)  or  from  the  sea  of  lava  (on  the 
eastern  declivity  of  the  volcano,  at  a  height  of  only  3969  feet 
above  the  sea),  is  testified  by  the  glass  threads,  sometimes 
smooth  and  sometimes  crisped  or  curled,  which  are  dispersed 
by  the  wind  all  over  the  island.  This  hair  glass,  which  is 
likewise  thrown  out  by  the  volcano  of  Bourbon,  is  called 
Pele's  hair  by  the  Hawaiians,  after  the  tutelary  goddess  of 
the  countiy. 

Dana  has  ably  demonstrated  that  Mouna  Loa  is  not  the 
central  volcano  of  the  Sandwich  Islands,  and  that  Kilauea  is 
not  a  solfatara.88  The  basin  of  Kilauea  is  16,000  feet  (about 
2-|  geographical  miles)  across  its  long  diameter,  and  7460 
feet  across  its  shorter  one.  The  steaming,  bubbling,  and 
foaming  mass  which  forms  the  true  lava-pool  does  not, 
however,  under  ordinary  circumstances,  fill  the  whole  of 
this  cavity,  but  merely  a  space  whose  long  diameter  mea- 
sures 14,000  feet  and  its  breadth  5000  feet.  The  descent  to 
the  edge  of  the  crater  is  gi"aduated.  This  great  phenomenon 
produces  a  wonderful  impression  of  silence  and  solemn  re- 
pose. The  approach  of  an  eruption  is  not  here  indicated 
by  earthquakes  or  subterranean  noises,  but  merely  by  a 
sudden  rising  and  falling  of  the  surface  of  the  lava,  some- 
times to  the  extent  of  from  300  or  400  feet  up  to  the 
complete  filling  of  the  whole  basin.  If,  disregarding  the 
immense  difference  in  size,  we  were  to  compare  the  gigantic 
basin  of  Kilauea  with  the  small  side-craters,  (first  described 
by  Spallanzani),  on  the  declivity  of  Stromboli  at  four-fifths 
of  the  height  of  the  mountain,  the  summit  of  which  has 

extinct  volcano  of  Hale-a-Kala — or  the  House  of  the  Sun — on  the  island 
of  Mani).     See  pp.  179  and  199—200. 

88  Dana,  p.  205.  "The  term  Solfatara  is  wholly  misapplied.  A 
solfatara  is  an  area  with  steairing  fissures  and  escaping  sulphur  vapours, 
and  without  proper  lava  ejections  ;  while  Kilauea  is  a  vast  crater  with 
extensive  lava  ejections  and  no  sulphur,  except  that  of  the  sulphur 
banks,  beyond  what  necessarily  accompanies,  as  at  Vesuvius,  violent 
volcanic  action."  The  structural  frame  of  Kilauea,  the  mass  of  the 
great  lava-basin,  consists  also,  not  of  beds  of  ashes  or  fragmentary 
rocks,  but  of  horizontal  layers  of  lava,  arranged  like  lime-stone.  Dana, 
p.  193.  (Compare  Strzelecki,  Phys.  Descr.  of  New  South  Wales,  1845, 
p.  105-111). 


TRUE  VOLCANOES.  393 

no  opening — that  is  to  say,  with  basins  of  boiling  lava  of 
from  30  to  200  feet  in  diameter  only — we  must  not  forget 
that  the  fiery  gulfs  on  the  slope  of  Stromboli  throw  out 
ashes  to  a  great  height,  and  even  pour  out  lava.  Though 
the  great  lava-lake  of  Kilauea  (the  lower  and  secondary 
crater  of  the  active  volcano  of  Mouna  Loa)  sometimes 
threatens  to  overflow  its  margin,  yet  it  never  actually  runs 
over  so  as  to  produce  true  streams  of  lava.  These  occur  by 
currents  from  below,  through  subterranean  channels,  and 
the  formation  of  new  eruptive-openings  at  a  distance  of 
from  16  to  20  geographical  miles,  consequently  at  points 
very  much  lower  than  the  basin.  After  these  eruptions, 
occasioned  by  the  pressure  of  the  immense  mass  of  lava 
in  the  basin  of  Kilauea,  the  fluid  surface  sinks  in  the 
basin.89 

Of  the  two  other  high  mountains  of  Hawaii,  Mouna  Lea 
and  Mouna  Hualalai,  the  former  is,  according  to  Captain 
Wilkes,  190  feet  higher  than  Mouna  Loa.  It  is  a  conical 
mountain  on  whose  summit  there  no  longer  exists  any 
terminal-crater,  but  only  long  extinct  mounds  of  scoriae. 
Mouna  Hualalai*  is  fully  10,000  feet  high,  and  is  still  burn- 
ing. In  the  year  1801  an  eruption  took  place,  during  which 
the  lava  reached  the  sea  on  the  western  side.  It  is  to 
the  three  colossal  mountains  of  Loa,  Kea  and  Hualalai, 
which  rose  from  the  bottom  of  the  sea,  that  the  island  of 
Hawaii  owes  its  origin.  In  the  accounts  given  of  the  nume- 
rous ascents  of  Mouna  Loa,  among  which  that  of  the  expedi- 

89  This  remarkable  sinking  of  the  surface  of  the  lava  is  confirmed 
by  the  relations  of  numerous  voyagere,  from  Ellis,  Stewart,  and  Doug- 
las to  the  meritorious  Count  Strzelecki,  Wilkes's  expedition  and  the 
remarkably  observant  Missionary  Coan.  During  the  great  eruption  of 
June,  1840,  the  connection  of  the  rise  of  the  lava  in  the  Kilauea  with 
the  sudden  inflammation  of  the  crater  of  Arare,  situated  so  far  below 
it,  was  most  decidedly  shown.  The  disappearance  of  the  lava  poured 
forth  from  Arare,  its  renewed  subterranean  course,  and  final  re-ap- 
pearance in  greater  quantity,  do  not  quite  admit  of  an  absolute  con- 
clusion as  to  identity  because  numerous  lava-yielding  longitudinal 
fissures  opened  simultaneously  below  the  line  of  the  floor  of  the 
Kilauea  basin.  It  is  likewise  very  worthy  of  observation,  as  bearing 
on  the  internal  constitution  of  this  singular  volcano  of  Hawahi,  that 
in  June,  1832,  both  craters,  that  of  the  summit  and  that  of  Kilauea, 
poured  out  and  occasioned  streams  of  lava,  so  that  they  were  simul- 
taneously active.  (Compare  Dana,  pp.  184,  188,  193,  and  196). 


394  COSMOS. 

tior  of  Captain  "Wilkes  was  based  on  investigations  of  twenty- 
eight  days'  duration,  mention  is  made  of  falls  of  snow  with  a 
degree  of  cold  from  23  to  17^-  F.  above  zero,  and  of  single 
patches  of  snow,  which  could  be  distinguished  with  the  aid 
of  the  telescope  at  the  summit  of  the  volcano,  but  nothing 
is  ever  said  of  perpetual  snow.90  I  have  already  observed  in 
a  former  part  of  this  work  that  the  Mouna  Loa  (13,758  feet) 
and  the  Mouna  Kea  (13,950  feet)  are  respectively  more  than 
1000  and  821  feet  lower  than  the  lowest  limit  of  perpetual 
snow  as  found  by  me  in  the  continental  mountains  of  Mexico 
under  19  4°  latitude.  On  a  small  island  the  line  of  perpetual 
snow  should  lie  somewhat  lower,  on  account  of  the  less  ele- 
vated temperature  of  the  lower  strata  of  air  in  the  hottest 
season  of  the  tropical  zone,  and  on  account  of  the  greater 
quantity  of  water  held  in  solution  in  the  upper  atmosphere. 

The  volcanoes  of  Tafoa*  and  Amargura*1  in  the  Tonga- 
group  are  both  active,  and  the  latter  had  a  considerable 
eruption  of  lava  on  the  9th  of  July  1847.91  It  is  extremely 
remarkable  and  is  in  entire  accordance  with  the  stories  of 
the  coral  animals  avoiding  the  shores  of  volcanoes  either 
at  the  time  or  shortly  before  in  a  state  of  ignition,  that  the 
Tonga  islands  of  Tafoa  and  the  cone  of  Kao,  which  abound 
in  coral-reefs  are  entirely  destitute  of  those  creatures.92 

Next  follow  the  volcanoes  of  Tanna*  and  Ambrym,*  the 
latter  westward  of  Mallicollo  in  the  archipelago  of  the  New 
Hebrides.  The  volcano  of  Tanna,  first  described  by  Rein- 
hold  Forster,  was  found  in  a  full  state  of  eruption  on  Cook's 
discovery  of  the  island  in  1774.  It  has  since  remained  con- 
stantly active.  Its  height  being  only  458  feet,  it  is  one  of 
the  lowest  fire-emitting  cones,  along  with  the  volcano  of 
Mendana,  hereafter  to  be  noticed,  and  the  Japanese  volcano 
of  Kosima.  There  is  a  great,  quantity  of  pumice  on  Mall- 
icollo. 

Matthew's  Rock  ;  *  a  very  small  smoking  rock-island, 
about  1183  feet  high,  the  eruption  of  which  was  observed 

90  Wilkes,    pp.   114,  140,  and  157;  Dana,  p.  221.     From  the  per- 
petual transmutation  of  the  r  and  the  I,   Mauna  Loa  is  often  written 
Koa,  and  Kilauea,  Kirauea. 

91  Dana,  pp.  25  and  138. 

92  Dana,    Geology  of  the  U.  States  Exploring  Exped.,   p.  138.   (See 
Darwin,  Structure  of  Coral  Reefs,  p.  60). 


TRUE  VOLCANOES.  395 

by  D'Urville  in  January  1828.  It  lies  eastward  of  the 
southern  point  of  New  Caledonia. 

The  volcano  of  Tinakoro*  in  the  group  of  Yanikoro  or 
Santa  Cruz. 

In  the  same  archipelago  of  Santa  Cruz,  fully  80  geo- 
graphical miles  NN.W.  of  Tinakoro,  the  volcano*  seen  by 
Mendana  so  early  as  1595,  rises  out  of  the  sea  to  a  height  of 
about  213  feet  (lat.  10°  23'  S.).  Its  eruptions  have  some- 
times been  periodical,  occurring  every  ten  minutes,  and  at 
other  times,  as  on  the  occasion  of  the  expedition  of  D'Entre- 
casteaux,  the  crater  itself  and  the  column  of  vapour  were 
uudistinguishable  from  each  other. 

In  the  Solomon' s-group  the  volcano  of  the  island  of 
Sesarga*  is  in  a  state  of  ignition.  On  the  coast  of  Guadal- 
canal', in  this  neighbourhood,  and  therefore  also  at  the 
south-east  end  of  the  long  range  of  islands  towards  the 
Vanikoro  or  Santa  Cruz  group,  volcanic  eruptive  action 
has  likewise  been  observed. 

In  the  Ladrones,  or  Marian  Islands,  at  the  north  end  of 
the  range,  which  seems  to  have  been  upheaved  from  a  meri- 
dian fissure,  Guguan,*  Pagon,*  and  the  Volcan  grande  of 
Asuncion  are  said  to  be  still  in  a  state  of  activity. 

The  direction  of  the  coasts  of  the  small  continent  of  New 
Holland,  and  particularly  the  deviation  from  that  direction 
seen  in  the  east  coast  in  25°  south  latitude  (between  Cape  Her- 
vey  and  Moreton  Bay),  seem  to  be  reflected  in  the  zone  of  the 
neighbouring  eastern  islands.  The  great  southern  island  of 
New  Zealand,  and  the  Kermadec  and  Tonga  groups  stretch 
from  the  south-west  to  the  north-east,  while,  on  the  other 
hand,  the  northern  portion  of  the  north  island  of  New  Zea- 
land (from  the  Bay  of  Plenty  to  Cape  Oton),  New  Caledonia 
and  New  Guinea,  the  New  Hebrides,  the  Solomon's  Isles, 
New  Ireland  and  New  Britain  run  in  a  direction  from  south- 
east to  north-west,  chiefly  N.  48°  W.  Leopold  von  Buch9* 
first  drew  attention  to  this  relation  between  continental 
masses  and  neighbouring  islands  in  the  Greek  Archipelago 
and  the  Australian  Coral  Sea.  The  islands  of  the  latter  sea, 
too,  are  not  deficient,  as  both  Forster  (Cook's  companion)  and 
La  Billardiere  formerly  observed,  in  granite  and  mica-slate, 

53  Ldop.  von  Buch,  Description  phys.  des  iles  Canaries,  1836,  pp.  393 
and  403—405. 


396  COSMOS. 

the  quart zose  rocks  formerly  called  primeval.  Dana  has  like- 
wise collected  them  on  the  northern  island  of  New  Zealand, 
to  the  west  of  Tipuna,  in  the  Bay  of  Islands.94 

New  Holland  exhibits  only  on  its  southern  extremity 
(Australia  Felix),  at  the  foot  and  to  the  south  of  the  Gram- 
pian Mountains,  fresh  traces  of  former  igneous  action,  for 
we  learn  from  Dana  that  a  number  of  volcanic  cones  and  de- 
posits of  lava  are  found  to  the  north-west  of  Port  Phillip, 
as  also  in  the  direction  of  the  Murray  river  (Dana,  p.  453). 

On  New  Britain*  there  are  at  least  three  cones  on  the 
west  coast,  which  have  been  observed  within  the  historical 
era,  by  Tasman,  Dampier,  Carteret  and  La  Billardiere,  in  a 
state  of  ignition  and  throwing  out  lava. 

There  are  two  active  volcanoes  on  New  Guinea,*  on  the 
north-eastern  coast,  opposite  New  Britain  and  the  Admiralty 
Islands/ which  abound  in  obsidian. 

In  New  Zealand,  of  which  the  geology  of  the  north  island 
at  least,  has  been  illustrated  by  the  important  work  of  Ernst 
Dieffenbach,  and  the  admirable  investigations  of  Dana,  ba- 
saltic and  trachytic  rocks  at  various  points  break  through  the 
generally  diffused  plutonic  and  sedimentary  rocks.  This  ex- 
ample is  the  case  in  a  very  limited  area  near  the  Bay  of  Islands 
(lat.  35°  2'),  where  the  ash-cones,  crowned  with  extinct  craters, 
Turoto  and  Poerua  rise  ;  and  again,  more  to  the  south-east, 
(between  37-^-°  and  39^-°  lat.),  where  the  volcanic  floor  runs 
quite  across  the  centre  of  the  north  island,  a  distance  of  more 
than  160  geographical  miles  from  north-east  to  south-west, 
from  the  Bay  of  Plenty  on  the  east  to  Cape  Egmont  on  the 
west.  This  zone  of  volcanic  action  here  traverses,  (as  we 
have  already  seen  it  to  do  on  a  much  larger  scale  in  the  Mexi- 
can Continent)  in  a  diagonal  fissure  from  north-east  to  south- 
west, the  interior  chain  of  mountains  which  runs  lengthwise 
in  a  north  and  south  direction,  and  which  seems  to  give  its 
form  to  the  whole  island.  On  the  ridge  of  this  chain  stand, 
as  it  were,  at  the  points  of  intersection,  the  lofty  cone  of  Ton- 
gariro*  (6198  feet),  whose  crater  is  found  on  the  top  of  the 
ash-cone,  Bidwill,  and,  somewhat  more  to  the  south,  Ruapahu 

94  See  Dana,  ibid.  p.  438 — 446,  and  on  the  fresh  traces  of  ancient  vol- 
canic action  in  New  Holland,  pp.  453  and  457  ;  also  on  the  many  basal- 
tic columns  in  New  South  Wales  and  Van  Diemen's  Land,  p.  495 — 510 ; 
and  E.  de  Strzelecki,  Phys.  Descr.  of  New  South  Wales,  p.  112. 


TRUE  VOLCANOES.  397 

(9006  feet).  The  north-east  end  of  the  zone  is  formed  in 
the  Bay  of  Plenty  (lat.  38-^),  by  a  constantly  smoking  solfa- 
tara,  the  island -volcano  of  Puhia-i-wakati*95  (White  Island). 
Next  follow  to  the  south-west,  on  the  shore  itself,  the  extinct 
volcano  of  Putawaki  (Mount  Edgecombe),  8838  feet  high, 
probably  the  highest  snowy  mountain  on  New  Zealand,  and 
in  the  interior,  between  Mount  Edgecombe  and  the  still 
burning  Tongariro,*  which  has  poured  fourth  some  streams 
of  lava,  a  lengthened  chain  of  lakes,  partly  consisting  of 
boiling  water.  The  lake  of  Taupo,  which  is  surrounded  by 
beautiful  glistening  leucite  and  sanidine  sand,  as  well  as  by 
mounds  of  pumice,  is  nearly  24  geographical  miles  long,  and 
lies  in  the  centre  of  the  north  island  of  New  Zealand,  at  an 
elevation,  according  to  Dieffenbach,  of  1337  feet  above  the 
surface  of  the  sea.  The  ground  for  two  English  square 
miles  round,  is  entirely  covered  with  solfataras,  vapour-holes, 
and  thermal-springs,  the  latter  of  which  form,  as  at  the  Gey- 
ser in  Iceland,  a  variety  of  siliceous  precipitates96.  West- 
ward of  Tongariro,*  the  chief  seat  of  volcanic  action,  whose 
crater  still  ejects  vapours  and  pumice-stone  ashes,  and  at  a  dis- 
tance of  only  sixteen  miles  from  the  western  shore,  rises  the 
volcano  of  Taranaki  (Mount  Egmont),  8838  feet  high,  which 
was  first  ascended  and  measured  by  Dr.  Ernst  Dieffenbach  in 
November,  1840.  The  summit  of  the  cone,  which  in  its  out- 
line more  resembles  Tolima  than  Cotopaxi,  terminates  in  a 
plain,  out  of  which  rises  a  steep  ash-cone.  No  traces  of 
present  activity,  such  as  are  seen  on  the  volcano  of  the  White 
Island*  and  on  Tongariro*  are  visible,  nor  any  connected 
stream  of  lava.  The  substance  composed  of  very  thin  scales, 
and  having  a  ringing  sound,  which  is  seen  projecting  with 
sharp  points  like  fish-bones,  from  among  the  scoriae,  in  the 
same  manner  as  on  one  side  of  the  Peak  of  Teneriffe,  re- 
sembles porphyritic  schist,  or  clink-stone. 

A  narrow,  long-extended,  uninterrupted  accumulation  of 
island-groups,  erupted  from  north-western  fissures,  such  as 

95  Ernest  Dieffenbach,  Travels  in  New  Zealand,  1843,  vol.  i,  pp.  337, 
355  and  401.    Dieffenbach  calls  White  Island  "a  smoking solfatara,  but 
still  in  volcanic  activity"  (pp.  358  and  407),  and  on  the  chart,  "  in  con- 
tinual ignition." 

96  Dana,  pp.  445—448  ;  Dieffenbach,  vol.  i,  pp.  331 ;  339—341  and  397 
On  Mount  Egmont,  bee  vol.  i,  pp.  131 — 157. 


398  COSMOS. 

New  Caledonia  and  New  Guinea,  the  New  Hebrides  and 
Solomon's  Island,  Pttcairn,  Tahiti  and  the  Pauuiotu  Islands, 
traverses  the  great  Ocean  in  the  Southern  hemisphere  in  a 
direction  from  west  to  east,  for  a  length  of  5400  geographi- 
cal miles,  between  the  parallels  of  latitude  of  12°  and  27°, 
from  the  meridian  of  the  east  coast  of  Australia  as  far  as 
Easter  Island,  and  the  rock  of  Sala  y  Gomez.  The  western 
portions  of  this  crowd  of  islands  (New  Britain*  the  New 
Hebrides,*  Vanikoro*  in  the  Archipelago  of  Santa  Cruz,  and 
the  Tonga-group*)  exhibit  at  the  present  time  in  the  middle 
of  the  nineteenth  century,  inflammation  and  igneous  action. 
New  Caledonia,  though  surrounded  by  basaltic  and  other 
volcanic  islands,  has  nevertheless  nothing  but  Plutonic  rock, OT 
as  is  the  case  with  Santa  Maria98  in  the  Azores,  according  to 
Leopold  von  Buch,  and  with  Flores  and  Graciosa,  according 
to  Count  Bedemar.  It  is  to  this  absence  of  volcanic  action 
in  New  Caledonia,  where  sedimentary  formations  with  seams 
of  coal  have  lately  been  discovered,  that  the  great  develope- 
ment  of  living  coral  reefs  on  its  shores  is  ascribed.  The  Ar- 
chipelago of  the  Viti,  or  Feedjee  Islands  is  at  once  basaltic 
and  trachytic,  though  distinguished  only  by  hot  springs  in 
the  Savu  Bay  on  Vanua  Lebu."  The  Samoa  group  (Navi- 
gator's Islands),  north-east  of  the  Feedjee  Islands,  and  nearly 
north  of  the  still  active  Tonga-archipelago  is  likewise  basal- 
tic, and  is  moreover  characterised  by  a  countless  number 
of  eruption-craters  linearly  arranged,  which  are  surrounded 
by  tufa-beds  with  pieces  of  coral  baked  into  them.  The  Peak 
of  Tafua,  on  the  island  of  Upolu,  one  of  the  Samoa-group, 
presents  a  remarkable  degree  of  geognostic  interest.  It  must 
not,  however,  be  confounded  Avith  the  still  enkindled  peak  of 
Tafua,  south  of  Amargura  in  the  Tonga-archipelago.  The 
Peak  of  Tafua  (2138  feet),  which  Dana  first100  ascended  and 
measured,  has  a  large  crater  entirely  filled  with  a  thick  forest, 

9?  Darwin,  Volcanic  Islands,  p.  125;  Dana,  p.  140. 

98  L.  de  Buch,  Descr.  des  I.  Can.  p.  365.     On  the  three  islands  here 
named,  however,  phonolite  and  basaltic  rock  are  also  found  along  with 
plutonic  and  sedimentary  strata.     But  these  rocks  may  have  made  their 
a/ppearance  above  the  surface  of  the  sea  on  the  first  volcanic  up-heaval 
of  the  island  from  the  bed  of  the  ocean.     No  traces  are  said  to  have 
been  found  of  fiery  eruptions  or  of  extinct  craters. 

99  Dana,  pp.  343—350. 

m  Dana,  pp.  312,  318,  320  and  323. 


TRUE   VOLCANOES.  399 

and  crowned  by  a  regularly  rounded  ash-cone.  There  is  here 
no  trace  of  any  stream  of  lava ;  yet  on  the  conical  moun- 
tain of  Apia  (2576  feet),  which  is  likewise  on  Upolu,  as 
•well  as  on  the  Peak  of  Fao  (3197  feet)  we  meet  with  fields 
of  scoriaceous  lava  (Malpais  of  the  Spaniards),  the  surface 
of  which  is  as  it  were  crimped,  and  often  twisted  like  a 
rope.  The  lava-fields  of  Apia  contain  narrow  subterranean 
cavities. 

Tahiti,  in  the  centre  of  the  Society's  Islands,  far  more  tra- 
chytic  than  basaltic,  exhibits,  strictly  speaking,  only  the  ruins 
of  its  former  volcanic  frame- work,  and  it  is  difficult  to  trace 
the  original  form  of  the  volcano  in  those  enormous  masses 
looking  like  ramparts  and  chevaux-de-frise,  with  perpendicu- 
lar precipices  of  several  thousand  feet  in  depth.  Of  its  two 
highest  summits,  Aorai  and  Orohena,  the  former  was  first 
ascended  and  investigated  by  that  profound  geologist  Dana.1 
The  trachytic  mountain,  Orohena,  is  said  to  equal  Etna  in 
height.  Thus,  next  to  the  active  group  of  the  Sandwich 
Islands,  Tahiti  contains  the  highest  rock  of  eruption  in  the 
whole  range  of  the  Ocean  between  the  Continents  of  Ame- 
rica and  Asia.  There  is  a  felspathic  rock  on  the  small 
islands  of  Borabora  and  Maurua,  near  Tahiti,  designated  by 
late  travellers  with  the  name  of  syenite,  and  by  Ellis  in  his 
Polynesian  researches  described  as  a  granitic  aggregate  of 
felspar  and  quartz,  which,  on  account  of  the  breaking  out 
of  porous,  scoriaceous  basalt  in  the  immediate  neighbour- 
hood, merits  a  much  more  complete  mineralogical  investiga- 
tion. Extinct  craters  and  lava-streams  are  not  now  to  be 
met  with  on  the  Society  Islands.  The  question  occurs, — 
are  the  craters  on  the  mountain  tops  destroyed, — or  did  the 
high  and  ancient  structures,  now  riven  and  transformed,  con- 
tinue closed  at  the  top  like  a  dome,  while  the  veins  of  basalt 
and  trachyte  poured  immediately  forth  from  fissures  in  the 
earth,  as  has  probably  been  the  case  at  many  other  points  of 
the  sea's  bottom?  Extremes  of  great  viscidity  or  great 
fluidity  in  the  matter  poured  out,  as  well  as  the  varying 
width,  or  narrowness  of  the  fissures  through  which  the  effu- 
sion takes  place,  modify  the  shapes  of  the  self-forming  vol- 

1  Leop.  von  Buch,  p.  383 ;  Darwin,  Vole.  hi.  p.  25 ;  Darwin,  Coral 
Reefs,  p.  138 ;  Dana,  pp.  286—305  and  364. 


400  COSMOS. 

came  mountain-strata,  and  where  friction  produces  what  is 
called  ashes  and  fragmentary  sub-division,  give  rise  to  small 
and  for  the  most  part  transitory  cones  of  ejection,  which  are 
not  to  be  confounded  with  the  great  terminal  cinder-cones  of 
the  permanent  structural  frames. 

Close  by  the  Society  Islands,  in  an  easterly  direction,  are 
the  Low  Islands,  or  Paumotu.  These  are  merely  coral  islands, 
with  the  remarkable  exception  of  the  small  basaltic  group 
of  Gambier's  and  Pitcairn's  Islands.2  Volcanic  rock,  similar 
to  the  latter,  is  also  found  in  the  same  parallel  (between  25° 
and  27°  south  latitude);  12 60  geographical  miles  farther  to 
the  east,  in  the  Easter  Island  (Waihu),  and  probably  also 
240  miles  farther  east,  in  the  rocks  Sala  y  Gomez.  On 
Waihu,  where  the  loftiest  conical  peaks  are  scarcely  a  thou- 
sand feet  high,  Captain  Beechey  remarked  a  range  of  craters, 
none  of  which  appeared,  however,  to  be  burning. 

In  the  extreme  east  towards  the  New  Continent,  the  range 
of  the  South  Sea  Island  terminates  with  one  of  the  most 
active  of  all  island  groups,  the  Archipelago  of  Galapagos, 
composed  of  five  great  islands.  Scarcely  anywhere  else,  on 
a  small  space  of  barely  120  or  140  geographical  miles  in  dia- 
meter, has  such  a  countless  number  of  conical  mountains  and 
extinct  craters  (the  traces  of  former  communication  between 
the  interior  of  the  earth  and  the  atmosphere),  remained 
visible.  Darwin  calculates  the  number  of  the  craters  at  nearly 
two  thousand.  When  that  talented  observer  visited  the 
Galapagos  in  the  expedition  of  the  "  Beagle,"  under  Captain 
Fitzroy,  two  of  the  craters  were  simultaneously  in  a  state  of 
igneous  eruption.  On  all  the  islands,  streams  of  a  very 
fluid  lava  may  be  seen  which  have  forked  off  into  different 
channels  and  have  often  run  into  the  sea.  Almost  all  are 
rich  in  augite  and  olivine  ;  some  of  which  are  more  of  a  trachy- 
tic  character,  are  said  to  contain  albite3  in  large  crystals.  It 

3  Dana,  p.  137. 

3  Darwin,  Vole,  hi.,  pp.  104,  110—112,  and  114.  When  Darwin 
says  so  decidedly  that  there  is  no  trachyte  on  the  Galapagos,  it  is  be- 
cause he  limits  the  term  trachyte  to  the  common  felspar,  i.e.  to  or- 
thoklase,  or  orthoklase  and  sanidine  (glassy  felspar).  The  enigmati- 
cal fragments  imbaked  in  the  lava  of  the  small  and  entirely  basaltic 
crater  of  James  Island  contain  no  quartz,  although  they  appear  to  rest 
on  a  plutonic  rock  (See  above,  p.  367  et  seq).  Several  of  the  volcanic 
cone-mountains  on  the  Galapagos  Islands,  have  at  the  orifice  a  narrow 


TRUE    VOLCANOES.  401 

would  be  well,  in  the  perfection  to  which  mineralogical 
science  is  now  brought,  to  institute  investigations  for  the 
purpose  of  discovering  whether  oligoclase  is  not  contained  in 
these  porphyritic  trachytes,  as  at  Teneriffe,  Popocatepetl  and 
Chimborazo,  or  else  labradorite,  as  at  Etna  and  Stromboli. 
Pumice  is  entirely  wanting  on  the  Galapagos,  as  at  Vesuvius, 
where  although  it  may  be  present,  it  is  not  produced,  nor 
is  hornblende  anywhere  mentioned  to  have  been  found 
in  them. ;  consequently  the  trachyte  formation  of  Toluca, 
Orizaba,  and  some  of  the  volcanoes  of  Java,  from  which  Dr. 
Junghuhn  has  sent  me  some  well-selected  solid  pieces  of 
lava  for  examination  by  Gustav  Rose,  does  not  prevail  here. 
On  the  largest  and  most  westerly  island  of  the  Galapagos 
group,  Albemarle,  the  cone-mountains  are  ranged  in  a  line, 
and  consequently  OR  fissures.  Their  greatest  height,  however, 
reaches  only  to  4636  feet.  The  Western  Bay,  in  which  the 
Peak  of  Narborough,  so  violently  inflamed  in  1825,  rises  in 
the  form  of  an  island,  is  described  by  Leopold  von  Buch4  as 
a  crater  of  up-heaval,  and  compared  to  Santorino.  Many 
margins  of  craters  on  the  Galapagos  are  formed  of  beds  of 
tufa,  which  slope  off  in  every  direction.  It  is  a  very  re- 
markable circumstance,  seeming  to  indicate  the  simul- 
taneous operation  of  some  great  and  wide-spread  catas- 
trophe, that  the  margins  of  all  the  craters  are  disrupted  or 
entirely  destroyed  towards  the  south.  A  part  of  what  in 
the  older  descriptions  is  called  tufa,  consists  of  palagonite 
beds,  exactly  similar  to  those  of  Iceland  and  Italy,  as  Bun- 
sen  has  ascertained  by  an  exact  analysis  of  the  tufas  of 
Chatham  Island.6  This  island,  the  most  easterly  of  the 
whole  group,  and  whose  situation  is  fixed  by  careful  astro- 
nomical observations  by  Captain  Beechey,  is,  according  to 
my  determination  of  the  longitude  of  the  city  of  Quito 
(783  44'  8'),  and  according  to  Acosta's  Mapa  de  la  Nueva 
Granada  of  1849,  536  geographical  miles  distant  from  the 
Punta  de  S.  Francisco. 

cylindrical,  annular  addition,  exactly  like  what  I  saw  on  Cotopaxi; — 
"  in  some  parts  the  ridge  is  surmounted  by  a  wall  or  parapet  perpen- 
dicular on  both  sides."  Darwin,  Vole.  Isl.  p.  83. 

4  L.  von  Buch,  p.  376. 

5  Bunsen,  in  LeonharcCs  Jahrb.  fur  Mineralvgie,  1851,  s.  856 ;  also 
in  Poggend,  Annalcn  der  Physik,  Bd.  Ixxxiii,  s.  223. 

VOL.    V.  2    D 


402  COSMOS. 


IX.  MEXICO. 

The  six  Mexican  Volcanoes,  Tuxtla,*  Orizaba,  Popoca- 
tepetl,* Toluca,  Jorullo*  and  Colima,*  four  of  which  have 
been  in  a  state  of  igneous  activity  within  the  historical  era, 
were  enumerated  in  a  former  place,6  and  described  in  their 
geognostically  remarkable  relative  position.  According  to 
recent  investigations  by  Gustav  Rose,  the  formation  of 
Chimborazo  is  repeated  in  the  rock  of  Popocatepetl,  or 
Great  volcano  of  Mexico.  This  rock  also  consists  of  oligo- 
clase  and  augite.  Even  in  the  almost  black  beds  of 
trachyte,  resembling  pitch-stone,  the  oligoclase  is  recognis- 
able in  veiy  small  acute-angled  crystals.  To  this  same  Chim- 
borazo and  Teiieriffe  formation  belongs  the  volcano  of  Co- 
lima,  which  lies  far  to  the  west,  near  the  shore  of  the  South 
Sea.  I  have  not  myself  seen  this  volcano,  but  we  are  indebted 
to  Herr  Pieschel *  (since  the  spring  of  1855)  for  a  very 
instructive  view  of  the  different  kinds  of  rocks  collected  by 

6  See  above,  pp.  279 — 281. 

7  See  Pieschel,  Ueber  die  Vullcane  von  Mexico,  in  the  Geitschrfft  fur 
allgem.    Erdkunde,  Bd.  vi,  1856,  s.  86  and  489—532.     The  assertion 
there  made  (p.  86)  "  that  never  mortal  has  ascended  the  steep  summit 
of  the  Pico  del  Fraile,"  that  is  to  say,  the  highest  Peak  of  the  Volcano 
of  Toluca,  has  been  confuted  by  my  barometrical  measurement  made 
upon  that  very  summit,  (which  is,  by  the  way,  scarcely  10  feet  in  width,) 
on  the  29th  September,  1803,  and  published  first  in  1807,  and  again 
recently  by  Dr.  Gumprecht  in  the  same  volume  of  the  journal  above 
referred  to  (p.  489).     The  doubt  raised  on  this  point  was  the  more  sin- 
gular as  it  was  from  this  very  summit  of  the  Pico  del  Fraile,  whose 
tower-like  sides  are  certainly  not  very  easy  to  climb,  and  at  a  height 
scarcely  600  feet  less  than  that  of  Mont  Blanc,  that  I  struck  off  the 
masses  of  trachyte  which  are  hollowed  out  by  the  lightning,  and  which 
are  glazed  on  the  inside  like  vitreous  tubes.     An  essay  was  inserted  so 
early  as  1819  by  Gilbert  in  volume  Ix  of  his  Annalen  der  Physik, 
(s.  261)  on  the  specimens  placed  by  me  in  the  Berlin  Museum  as  well 
as  in  several  Parisian  collections  (see  also  Annales  de  Chimie  et  de 
Physique,  t.  xix,  1822,  p.  298).  In  some  places  the  lightning  has  bored 
such  regular  cylindrical  tubes  (as  much  as  3  inches  in  length,)  that  they 
can  be  looked  through  from  end  to  end,  and  in  those  cases  the  rock 
surrounding  the  openings  is  likewise  vitrified.     I  have  also  brought 
with  me  pieces  of  trachyte  in  my  collections,  in  which  the  whole  sur- 
face is  vitrified  without  any  tube-like  perforation,  as  is  the  case  at  the 
little  Ararat  and  at  Mont  Blanc.     Herr    Pieschel  first  ascended  the 
double-peaked  volcano  of  Colirna,  in  October,  1852,  and  reached  the 


TRUE    VOLCANOES.  403 

him,  as  well  as  for  his  interesting  geological  notices  on  the 
volcanoes  of  the  \vhole  Mexican  highlands,  all  of  which  he 
has  personally  visited.  The  volcano  of  Toluca,  whose 
highest  summit  (the  Pico  del  Frayle),  though  narrow  and 
difficult  to  climb,  I  ascended  on  the  29th  September,  1803. 
and  found  barometrically  to  be  15,166  feet  high,  has  a  totally 
different  mineralogical  composition  from  the  still  active  Po- 
pocatepetl and  the  igneous  mountain  of  Colima ;  this  must 
not,  however,  be  confounded  with  another,  still  higher  sum-  - 
mit,  called  the  Snow-mountain.  The  volcano  of  Toluca 
consists,  like  the  Peak  of  Orizaba,  the  Puy  de  Chaumont  in 
the  Auvergne  and  .^Egina,  of  a  combination  of  oligoclase 
and  hornblende.  From  this  brief  sketch  it  will  be  seen, 
and  it  is  well  deserving  of  notice,  that  in  the  long  range  of 
volcanoes  which  extend  from  ocean  to  ocean,  there  are  not 
two  immediately  succeeding  each  other  which  are  of  similar 
mineralogical  composition. 

X.  THE  NORTH-WESTERN  DISTRICTS  OF  AMERICA 
(northward  of  the  parallel  of  Rio  Gila) . 

In  the  section  which  treats  of  the  volcanic  action  on  the 
eastern  Asiatic  Islands,8  particular  notice  has  been  drawn 
to  the  bow-like  curve  in  the  direction  of  the  fissure  of  up- 
beaval  from  which  the  Aleutian  Islands  have  risen,  and 
which  manifests  an  immediate  connection  between  the 
Asiatic  and  American  continents,  — between  the  two  volcanic 
peninsulas  Kamtschatka  and  Aliaska.  At  this  point  is  the 
outlet,  or  rather  the  northern  boundary,  of  a  mighty  gulf 
of  the  Pacific  Ocean,  which  from  the  150  degrees  of  longi- 
tude embraced  by  it  under  the  equator,  narrows  itself  down 
between  the  terminal  points  of  these  two  peninsulas  to  37C 

crater,  from  which  he  then  saw  nothing  but  sulphuretted-hydrogen  va- 
pour rising  in  a  cloud  ;  but  Sonneschmid,  who  vainly  attempted  to 
ascend  Colima,  in  February,  1796,  gives  an  account  of  an  immense 
ejection  of  ashes  in  the  year  1770.  In  the  month  of  March  1795,  on 
the  other  hand,  red-hot  scorire  were  visibly  thrown  out  in  a  column  of 
fire  at  night.  — "  To  the  north-west  of  the  volcano  of  Colima,  a  vol- 
canic branch-fissure  runs  along  the  shore  of  the  South  Sea.  Extinct 
craters  and  ancient  lava-streams  are  recognised  in  what  are  called  the 
Volcanoes  of  Ahuacatlan  (on  the  road  from  Guadalaxara  to  San  Bias) 
and  Tepic."  (Pieschel,  ibid.  p.  529). 
8  See  above,  pp.  367—372. 

2  D  2 


404  COSMOS. 

ot*  longitude.  On  the  American  continent,  near  the  sea- 
shore, a  number  of  more  or  less  active  volcanoes  has  become 
known  to  mariners  within  the  last  seventy  or  eighty  years, 
but  this  group  lay  hitherto  as  it  were  isolated,  and  uncon- 
nected with  the  volcanic  range  of  the  Mexican  tropical 
region,  or  with  the  volcanoes  which  were  believed  to  exist 
on  the  peninsula  of  California.  If  we  include  the  range  of 
extinct  trachytic  cones  as  intermediate  links,  we  may  be 
said  to  have  obtained  insight  into  their  important  geo- 
logical connection  over  a  gap  of  more  than  28°  of  latitude, 
between  Durango  and  the  new  Washington  territory,  north- 
ward of  West  Oregon.  The  study  of  the  physical  condi- 
tion of  the  earth  owes  this  important  step  in  advance  to  the 
scientifically  well-prepared  expeditions,  which  the  govern- 
ment of  the  United  States  has  fitted  out  for  the  discovery 
of  the  best  road  from  the  plains  of  the  Mississippi  to  the 
shores  of  the  South  Sea.  All  the  departments  of  natural 
history  have  derived  advantage  from  those  undertakings. 
Great  tracts  of  country  have  been  found,  in  the  now  ex- 
plored terra-incognita  of  this  intermediate  space,  from  very 
near  the  Rocky  Mountains  on  their  eastern  slope,  to  a  great 
distance  beyond  their  western  descent,  covered  with  evi- 
dences of  extinct  or  still  active  volcanoes  (as  for  instance 
in  the  Cascade  Mountains).  Thus,  yetting  out  from  New 
Zealand  and  ascending  first  a  long  way  to  the  north-west 
through  New  Guinea,  the  Sunda  Islands,  the  Philippines 
and  Eastern  Asia,  to  the  Aleutians,  and  then  descending 
towards  the  south  through  the  north-western,  the  Mexican, 
the  Central  American,  and  South  American  territories  to 
the  terminating  point  of  Chili,  we  find  the  entire  circuit 
of  the  basin  of  the  'Pacific  Ocean,  throughout  an  extent  of 
26,400  geographical  miles,  surrounded  by  a  range  of  recog- 
nisable memorials  of  volcanic  action.  Without  entering 
into  the  details  of  exact  geographical  bearings  and  of  the 
perfected  nomenclature,  a  cosmical  view  such  as  this  could 
never  have  been  obtained. 

Of  the  circuit  of  the  great  oceanic9  basin  here  indicated 
(or,  as  there  is  but  one  united  mass  of  water  over  the 

9  The  term  "Grand  Ocean/'  used  to  designate  the  basin  of  the 
South  Sea  by  that  learned  geographer,  my  friend  Contre-Amiral  de 
Fleurieu,  the  editor  of  the  Introduction  Historique  au  Voyage  dt 


TRUE    VOLCANOES.  405 

whole  earth,  we  ought  rather  to  say  the  circumference  of  the 
largest  of  those  portions  oi  it  which  penetrate  between  con- 
tinents) it  remains  for  us  now  to  describe  the  tract  of  country 
which  extends  from  Rio  Gila  to  Norton's  and  Kotzebue's 
Sounds.  Analogies  drawn  in  Euro]  e  from  the  Pyrenees  or  the 
Alpine  chain,  and  in  South  America  from  the  Cordilleras  of 
the  Andes,  from  South  Chili  to  the  fifth  degree  of  north  lati- 
tude in  New  Grenada,  supported  by  tanciful  delineations  in 
maps,  have  propagated  the  erroneous  opinion  that  the  Mexi- 
can mountains,  or  at  least  their  highest  ridge,  can  be  traced 
along  like  a  wail,  under  the  name  of  the  Sierra  Madre,  from 
south-east  to  north- west.  But  though  the  mountainous 
part  of  Mexico  is  a  mighty  swelling  of  the  land  running 
connectedly  in  the  direction  above  stated  between  two  seas 
to  the  height  of  from  5000  to  7000  feet,  yet  on  the 
top  of  this,  in  the  same  way  as  in  the  Caucasus  and  in 
Central  Asia,  still  loftier  ranges  of  mountains,  running  in 
partial  and  very  various  directions,  rise  to  about  15,000  and 
17,800  feet.  The  arrangement  of  these  partial  groups, 
erupted  irom  fissures  not  parallel  to  each  other,  is  in  its 
bearings  for  the  most  part  independent  of  the  ideal  axis 
which  may  be  drawn  through  the  entire  swell  of  the  undu- 
lating flattened  ridge.  These  remarkable  features  in  the 
formation  of  the  soil  give  rise  to  a  deception  which  is 
strengthened  by  the  pictorial  effect  of  the  beautiful  country. 
The  colossal  mountains  covered  with  perpetual  snow  seem  as  it 
were,  to  rise  out  of  a  plain.  The  spectator  confounds  the 
ridge  of  the  soft  swelling  land,  the  elevated  plain,  with  the 
plain  of  the  low  lands,  and  it  is  only  from  the  change 
of  climate,  the  lowering  of  the  temperature,  under  the  same 
degree  of  latitude,  that  he  is  reminded  of  the  height  to 
which  he  has  ascended.  The  fissure  of  upheaval,  frequently 
before  mentioned,  of  the  volcano  of  Anahuac  (running  in  a 
direction  from  east  to  west  between  19°  and  19£°  lat.)  inter- 
sects10 the  general  axis  of  the  swelling  land  almost  at  right 
angles. 

Marchand,  confounds  the  whole  with  a  part,  and  consequently  leads 
to  misapprehension. 

10  On  the  axes  of  the  greatest  elevations  and  of  the  volcanoes  in 
the  tropical  zone  of  Mexico,  see  above  pp.  279  and  319.  Compare 
also  Essai  Pol.  sur  la  Nouv.-Etp.  t.  i,  pp.  257—268,  t.  ii,  p.  173 ;  Vieic* 
of  Nature,  p.  37. 


406  COSMOS. 

The  conformation  here  described  of  a  considerable  portion 
of  the  surface  of  the  earth,  which  only  began  to  be  established 
by  careful  measurements  since  the  year  1803,  must  not  be 
confounded  with  those  swellings  of  the  soil  which  are  met 
with  enclosed  between  two  mountain- chains  which  bound 
them  as  it  were  like  walls,  as  in  Bolivia  at  the  Lake  of 
Titicaca,  and  in  Central  Asia,  between  the  Himalaya  and 
Kuen-lim.  The  former  of  these,  the  South  American  eleva- 
tion, which  at  the  same  time  forms  the  bottom  of  a  valley, 
is  on  an  average  according  to  Pentland,  12.847  feet  above  the 
level  of  the  sea,— the  latter,  or  Thibetian,  according  to 
Captain  Henry  Strachey,  Joseph  Hooker,  and  Thomas 
Thomson,  is  upwards  of  14,996.  The  wish  expressed  by 
me  half  a  century  since  in  my  circumstantial  "  Analyse  de 
T Atlas  Geographique  et  Physique  du  Hoyaume  de  la  Nouvelle- 
Espagne  (§  xiv),  that  my  profile  of  the  elevated  plain  be- 
tween Mexico  and  Guanaxuato  might  be  continued  by 
measurements  over  Durango  and  Chihuahua  as  far  as 
Santa  Fe  del  Nuevo  Mexico,  is  now  completely  realized. 
The  length  of  way,  reckoning  only  one-fourth  for  the  inflec- 
tions, amounts  to  far  more  than  1200  geographical  miles,  and 
the  characteristic  feature  of  this  so  long  unobserved  con- 
figuration of  the  earth  (the  soft  undulation  of  the  swelling, 
audits  breadth  in  a  transverse  section,  amounting  sometimes 
to  240  or  280  geographical  miles)  is  manifested  by  the  fact 
that  the  distance  (from  Mexico  to  Santa  Fe),  comprising  a 
difference  of  parallels  of  fully  16°  20;  about  the  same  as  that 
from  Stockholm  to  Florence,  is  travelled  over  in  four- 
wheeled  carriages,  on  the  ridge  of  the  table-land,  without  the 
advantage  of  artificially  prepared  roads.  The  possibility 
of  such  a  medium  of  intercourse  was  known  to  the  Spaniards 
so  early  as  the  end  of  the  16th  century,  when  the  Viceroy, 
the  Coude  de  Monterey,11  planned  the  first  settlements  from 
Zacatecas. 

In  confirm ...it-ion  of  what  has  been  stated  in  a  general  way 

11  By  Juan  de  Onate,  1594.  Memoir  of  a  Tour  to  Northern  Mexico 
in  1846  and  1847  by  Dr.  Wislizenus.  On  the  influence  of  the  con- 
figuration of  the  soil  (the  wonderful  extent  of  the  table-land)  on  the 
internal  commerce  and  the  intercourse  of  the  tropical  zone  with  the 
north,  when  once  civic  order,  legal  freedom  and  industry  increase  ia 
these  parts,  see  Essai  Pol.,  t.  iv.,  p.  38,  and  Dana,  p.  612. 


TRUE    VOLCANOES.  407 

respecting  the  relative  heights  between  the  capital  of  Mexico 
and  Sante  Fe  del  Nuevo  Mexico,  I  here  insert  the  chief 
elements  of  the  barometrical  leveJlings.  which  have  been  com- 
pleted from  1803  to  1847.  I  take  them  in  the  direction 
from  north  to  south,  so  that  the  most  northerly,  placed  at 
the  top  of  the  list,  may  correspond  more  readily  with  the 
bearings  of  our  charts  :12 

12  In  this  survey  of  the  elevations  of  the  soil  between  Mexico  and 
Sante  Fe  del  Nuevo  Mexico,  as  well  as  in  the  similar,  but  more  im- 
perfect table  which  I  have  given  in  the  Views  of  Nature,  p.  208,  the 
letters  Ws,  Bt,  and  Ht,  attached  to  the  numerals,  denote  the  names  of 
the  observer.  Thus,  Ws  stands  for  Dr.  Wislizeuus,  editor  of  the  very 
instructive  and  scientific  Memoir  of  a  Tour  to  Northern  Mexico,  con- 
nected with  Col.  Doniphan's  Expedition,  in  1846  and  1847  (Washing- 
ton, 1848),  Bt  the  Chief  Counsellor  of  Mines,  Burkart,  and  Ht 
for  myself.  At  the  time  when  I  was  occupied  from  March  1803 
to  February  1804  with  the  astronomical  determinations  of  places 
in  the  tropical  part  of  New  Spain,  and  ventured,  from  the  materials  I 
could  discover  and  examine,  to  design  a  map  of  that  country,  of  which 
my  respected  friend,  Thomas  Jefferson,  then  President  of  the  United 
States,  during  my  residence  in  Washington,  caused  a  copy  to  be  made, 
there  existed  as  yet  in  the  interior  of  the  country  on  the  road  to 
Santa  Fe",  no  determinations  of  latitude  north  of  Durango  (lat.  24°  25'). 
According  to  the  two  manuscript  journals  of  the  engineers  Rivera, 
Laforaaad  Mascard,  of  the  years  1724  and  1765,  discovered  by  me  in 
the  archives  of  Mexico,  and  which  contained  directions  of  the  com- 
pass and  computed  partial  distances,  a  careful  calculation  showed  for 
the  important  station  of  Santa  Fe",  according  to  Don  Pedro  de  Rivera, 
lat.  36°  12'  and  long.  105°  52'  30''.  (See  my  Atlas  Geogr.  et  Phys.  du. 
Me.nquc,  Tab.  6,  and  Essai  Pol.  t.  i,  pp.  75 — 82).  I  took  the  precaution 
in  the  analysis  of  my  map,  to  note  this  result  as  a  very  uncertain  one 
seeing  that  in  the  valuations  of  the  distances  as  well  as  in  the  direc- 
tions of  the  compass,  uncorrected  for  the  magnetic  variation,  and 
unaided  by  objects  in  treeless  plains,  destitute  of  human  habitations, 
over  an  extent  of  more  than  1200  geographical  miles,  all  the  errors 
cannot  be  compensated  (t.  i,  pp.  127 — 131).  It  happens  that  the 
result  here  given,  as  compared  with  the  most  recent  astronomical 
observations,  turns  out  to  be  much  more  erroneous  in  the  latitude 
than  in  the  longitude, — being  in  the  former  about  thirty-one  and  in 
the  latter  scarcely  twenty-three  minutes.  I  was  likewise  fortunate 
enough  to  determine,  nearly  correctly,  the  geographical  position  of  the 
Lake  Timpanogos,  now  generally  called  the  Great  Salt  Lake,  while  the 
name  of  Timpanogos  is  now  only  applied  to  the  river  which  falls  into 
the  little  Utah-lake,  a  fresh  water  lake.  In  che  language  of  the  Utah 
Indians  a  river  is  called  og-wahbe,  and  by  contraction  ogo  alone  ;  tim- 
pan  means  rock,  so  that  Timpan-ogo  signifies  rock-river  (Fremont, 
Expl.  Exped.  1845,  p.  273).  Buschmann  explains  the  word  timpa  as 


408  COSMOS. 

Santa  F6  del  Nuevo  Mexico  (lat.  35°  41'),  height  7047 
feet,  Ws. 

Albuquerque13  (lat.  35°  8'),  height  4849  feet,  Ws. 

Paso  del  Norte14  on  the  Rio  Grande  del  Norte  (lat.  29°  48'), 
height  3790  feet,  Ws. 

Chihuahua  (lat.  28°  32'),  4638  feet,  Ws. 

Cosiquiriachi,  G273  feet,  Ws. 

Mapimi,  in  the  Bolson  de  Mapimi  (lat  25°  54'),  4782  feet. 
Ws. 

Parras  (lat.  25°  32'),  4986  feet,  Ws. 

Saltillo  (lat.  25°  10'),  5240  feet,  Ws. 

Durango  (lat.  24°  25'),  6849  feet,  according  to  Oteiza. 

Eresnillo  (lat.  23°  10'),  7244  feet,  Bt. 

Zacatecas  (lat.  22°  50'),  9012  feet,  Bt. 

San  Luis  Potosi  (lat.  22°  8'),  6090  feet,  Bt. 

Aguas  calientes  (lat.  21°  53'),  6261  feet,  Bt. 

derived  from  the  Mexican  tetl,  stone,  while  in  pa  he  finds  a  substantive 
termination  of  the  native  North-Mexican  languages ;  to  ogo  he  attri- 
butes the  general  signification  of  water;  see  his  work,-  —  Die Spuren 
der  Aztekitchen  Sprache  im  nordlichen  Mexico,  s.  354—356  and  351 
Compare  Expedition  to  the  Valley  of  the  Great  Salt  Lake  of  Utah,  by 
Captain  Howard  Stansbury,  1852,  p.  300,  and  Humboldt,  Views  of 
Nature,  p.  206.  My  map  gives  to  the  Montagnes  de  Sel  gemme,  some- 
what to  the  east  of  the  Laguna  de  Timpanogos,  lat.  40°  7',  long.  111° 
48'  30";  consequently  my  first  conjecture  differs  39  minutes  in  lati- 
tude, and  17  in  longitude.  The  most  recent  determinations  of  the 
position  of  Santa  F6,  the  Capital  of  New  Mexico,  with  which  I  am 
acquainted,  are  1st,  by  Lieutenant  Emory  (1846)  from  numerous 
astronomical  observations,  lab.  35°  44'  6",  and  2nd,  by  Gregg  and 
Dr.  Wislizenus  (1848),  perhaps  in  another  locality,  35°  41'  6".  The 
longitude,  according  to  Emory,  is  7h  4'  18",  in  time  from  Greenwich, 
and  therefore  106°  5' in  the  equatorial  circle  ;  according  to  Wislizenus, 
108°  22'  from  Paris  (New  Mexico  and  California,  by  Emory,  Docum. 
No.  41,  p.  36  ;  Wisl.  p,  29).  Most  maps  err  in  making  the  latitudes  of 
places  in  the  neighbourhood  of  Santa  Fe'  too  far  to  the  north.  The 
height  of  the  city  of  Santa  F6  above  the  level  of  the  sea,  according 
to  Emory,  is  6844,  according  to  Wislizenus  fully  7046  feet  (mean 
measurement  6950) ;  it  therefore  resembles  that  of  the  Spliigen  and 
Gotthard  passes  in  the  Swiss  Alps. 

13  The  latitude  of  Albuquerque  is  taken  from  the  beautiful  special 
map  entitled,  Map  of  the  Territory  of  New   Mexico  by  Kern,  1851. 
Its  height,  according  to  Emory  (p.  166),  is  4749  feet;  according  to  Wis- 
lizenus (p.  122),  4858. 

14  For  the  latitude  of  the  Paso  del  Norte  compare  Wisliz.  p.   125 
Met.  Tables  8—12,  Aug.  1846. 


TRUE  VOLCANOES.  409 

Lagos  (lat.  21°  20'),  6376  feet,  Bt. 

Villa  de  Leon  (lat.  21C  7'),  6134  feet,  Bfc. 

Silao,  5911  feet,  Bt. 

Guanaxuato  (lat.  21°  0'  15"),  6836  feet,  Ht. 

Salamanca  (lat.  20°  40°).  5762  feet,  Ht.    . 

Celaya  (lat.  20°  38'),  6017  feet,  Ht. 

Queretaro  (lat.  20°  36'  39"),  6363  feet,  Ht. 

San  Juan  del  Rio,  in  the  State  of  Queretaro  (lat.  20°  SO'). 
6490  feet,  Ht. 

Tula  (lat.  19°  57'),  6733  feet,  Ht. 

Pachuca,  8140  feet,  lit. 

Moran,  near  Real  del  Monte,  8511  feet,  Ht. 

Huehuetoca,  at  the  northern  extremity  of  the  great  plain 
of  Mexico  (lat.  19°  48'),  7533  feet,  Ht. 

Mexico  (lat.  19°  25'  45"),  7469  feet,  Ht. 

Toluca  (lat.  19°  16'),  8825  feet,  Ht. 

Venta  de  Chalco,  at  the  south-eastern  extremity  of  the 
great  plain  of  Puebla,  7712  feet,  Ht. 

San  Francisco  Ocotlan,  at  the  western  extremity  of  the 
great  plain  of  Puebla,  7680  feet,  Ht. 

Cholula,  at  the  foot  of  the  ancient  graduated  Pyramid 
(lat.  19C  2'),  6906  feet,  Ht. 

La  Puebla  de  los  Angeles  (lat.  19°  0'  15"),  7201  feet,  Ht. 

(The  village  of  las  Vigas  marks  the  eastern  extremity  of 
the  elevated  plain  of  Anahuac,  lat.  19°  37' ;  the  height  of 
the  village  is  7814  feet,  Ht). 

Thus,  though  previous  to  the  commencement  of  the  19th 
century  not  a  single  altitude  had  been  barometrically  taken 
in  the  whole  of  JS"evv  Spain,  the  hypsometrical  and  in  most 
cases  also  astronomical  observations  for  thirty-two  places  in 
the  direction  from  north  to  south,  in  a  zone  of  nearly  16^° 
of  latitude,  between  the  town  of  Santa  Fe  and  the  capital 
of  Mexico,  have  been  accomplished.  We  thus  see  that  the 
surface  of  the  wide  elevated  plain  of  Mexico  assumes  an 
undulating  form  varying  in  the  centre  from  5850  to  7500 
feet  in  height.  The  lowest  portion  of  the  road  from  Parras 
to  Albuquerque  is  even  1066  feet  higher  than  the  highest 
point  of  Vesuvius. 

The  great,  though  gentle,15  swelling  of  the  soil,  whose 

15  Compare  Fremont,  Report  of  the  Exploring  Exped.  in  1842,  p.  60; 
Dana,  Geology  of  the  United  States  Expl.  Exped.  pp.  611— t>13;  aud  fof 


110  COSMOS. 

highest  portion  we  have  just  surveyed,  and  which  from 
south  to  north,  from  the  tropical  part  to  the  parallels 
of  42°  and  44°,  so  increases  in  extent  from  east  to  west 
that  the  Great  Basin,  westward  of  the  great  Salt  Lake  of 
the  Mormons,  has  a  diameter  of  upwards  of  340  geogra- 
phical miles,  with  a  mean  elevation  of  nearly  5800  feet, 
differs  very  considerably  from  the  rampart-like  mountain- 
chains  by  which  it  is  surmounted.  Our  knowledge  of  this 
configuration  is  one  of  the  chief  poinits  of  Fremont's  great 
hypsometrical  investigations  in  the  years  1842  and  1844. 
This  swelling  of  the  soil  belongs  to  a  different  epoch 
from  that  late  upheaval  which  we  call  mountain-chains 
and  systems  of  varied  direction.  At  the  point  where, 
about  32°  lat.,  the  mountain-mass  of  Chihuahua,  accord- 
ing to  the  present  settlement  of  the  boundaries,  enters  the 
western  territory  of  the  United  States  (in  the  provinces 
taken  from  Mexico),  it  begins  to  bear  the  not  very  definite 
title  of  the  Sierra  Madre.  A  decided  bifurcation,16  however, 
occurs  in  the  neighbourhood  of  Albuquerque,  and  at  this 
bifurcation  the  western  chain  still  maintains  the  general 

South  America,  Alcide  D'Orbigny,  Voy.  dans  I'Amerique  merid.  Atlas, 
pi.  viii.  de  Geologic  spfoiale,  fig.  i. 

16  For  this  bifurcation  and  the  correct  denomination  of  the  east 
f.nd  west  chains  see  the  large  special  map  of  the  Territory  of  Neiv 
Mexico,  by  Parke  and  Kern,  1851  :  Edwin  Johnson's  Map  of  .Railroads, 
1854;  John  Bartlett's  Map  of  the  Boundary  Commission,  1854  :  Ex- 
plorations and  Surveys  from  the  Mississippi  to  the  Pacific  in  1853 
and,  1854,  vol.  i,  p.  15;  and,  above  all,  the  admirable  and  comprehensive 
work  of  Jules  Marcou,  Geologist  of  the  Southern  Pacific  R.  R.  Survey, 
under  the  command  of  Lieutenant  Whipple,  entitled  Resume  explicatif 
dune  Carte  geologique  des  Etats  Unis  et  d'un  Profil  geologique  allant  de 
la  vallee  du  Mississippi,  aux  cdtes  del' Ocean  Pacifique,  pp.  113 — 116; 
also  in  the  Bulletin  de  la  Societe  geologique  de  la  France,  2e  Se"rie,  t.  xii, 
p.  813.  In  the  elongated  valley  closed  by  the  Sierra  Madre,  or  Rocky 
Mountains,  lat.  35° — 38i°,  the  separate  groups  of  which  the  western 
chain  of  the  Sierra  Madre  and  the  eastern  chain  of  the  Rocky  Moun- 
tains (Sierra  de  Sandia)  consist  bear  different  names.  To  the  first  chain 
belong,  reckoning  from  south  to  north,  the  Sierra  de  las  Grullas,  the 
S.  de  los  Mimbres  (Wislizenus,  pp.  22  and  54),  Mount  Taylor  (lat.  35° 
15'),  the  S.  de  Jemez  and  the  S.  de  San  Juan  ;  in  the  eastern  chain  the 
Moro  Peaks,  or  Sierra  de  la  Sangre  de  Cristo,  are  distinguished  from 
the  Spanish  Peaks  (lat.  37°  32')  and  the  north  westerly  tending  White 
Mountains,  which  close  the  elongated  valley  of  Taosand  Santa  Fe.  Pro- 
fessor Julius  Frobel,  whose  examination  of  the  volcanoes  of  Central 
America  I  have  already  noticed  (Cosmos,  above,  p.  274),  has  with  rnuuh 


TRUE  VOLCANOES.  411 

title  of  the  Sierra  Madre,  while  the  eastern  branch  has  re- 
ceived from  lat.  36°  10'  forward  (a  little  to  the  north  of 
Santa  Fe)  from  American  and  English  travellers  the  equally 
ill-chosen,  but  now  universally  accepted  title  of  the  Kocky 
Mountains.  The  two  chains  form  a  lengthened  valley,  in 
which  Albuquerque,  Santa  Fe  and  Taos  lie,  and  through 
which  the  Rio  Grande  del  Norte  flows.  In  lat.  38 1°  this 
valley  is  closed  by  a  chain  running  east  and  west  for  the 
space  of  88  geographical  miles,  while  the  rocky  mountains 
extend  undivided  in  a  meridional  direction  as  far  as  lat.  41°. 
In  this  intermediate  space  rise  somewhat  to  the  east  the 
Spanish  Peaks,  Pike's  Peak  (5800  feet),  which  has  been 

ability  elucidated  the  indefinite  geographical  appellation  of  Sierra 
Madre  on  the  older  maps,  but  he  has  at  the  same  time,  in  a  treatise 
entitled  Remarks  contributing  to  the  Physical  Geography  of  the  North 
American  Continent  (9th  Annual  Report  of  the  Smithsonian  Institution, 
1855,  pp.  272 — 281),  given  expression  to  a  conjecture  which,  after 
having  examined  all  the  materials  within  my  reach,  I  am  unable  to 
assent  to,  namely,  that  the  Rocky  Mountains  are  not  to  be  regarded  as 
a  continuation  of  the  Mexican  Mountain  range  in  the  tropical  zone  of 
Anahuac.  Uninterrupted  mountain  chains,  like  those  of  the  Apennines, 
the  Swiss  Jura,  the  Pyrenees,  and  a  great  part  of  the  German  Alps, 
certainly  do  not  exist  from  the  19th  to  the  44th  degrees  of  latitude, 
from  Popocatepetl  in  Anahuac  as  far  as  to  the  north  of  Fremont's  Peak 
in  the  Rocky  Mountains,  in  the  direction  from  SS.E.  to  NN.W.,  but  the 
immense  swelling  of  the  surface  of  the  land  which  goes  on  increasing 
in  breadth  towards  the  north  and  north-west,  is  continuous  from 
tropical  Mexico  to  Oregon,  and  on  this  swelling  (or  elevated  plain), 
which  is  itself  the  great  geognostic  phenomenon,  separate  groups  of 
mountains,  running  in  often  varying  directions,  rise  over  fissures  which 
have  been  formed  more  recently  and  at  different  periods.  These  super- 
imposed groups  of  mountains,  which,  however,  in  the  Rocky  Mountains 
are  for  an  extent  of  8  degrees  of  latitude  connected  together  almost  like 
a  rampart,  and  rendered  visible  to  a  great  distance  by  conical  moun- 
tains, chiefly  trachytic,  from  10,000  to  12,000  feet  high,  produce  an 
impression  on  the  uiind  of  the  traveller  which  is  only  the  more  profound 
from  the  circumstance  that  the  elevated  plateau  which  stretches  far 
and  wide  around  him  assumes  in  his  eyes  the  appearance  of  a  plain  of 
the  level  country.  Though  in  reference  to  the  Cordilleras  of  South 
America,  a  considerable  part  of  which  is  known  to  me  by  personal 
inspection,  we  speak  of  double  and  triple  ranges  (in  fact  the  Spanish 
expression  las  Cordilleras  de  los  Andes  refers  to  such  a  disposition  and 
partition  of  the  chain),  we  must  not  forget  that  even  here  the  direc- 
tions of  the  separate  ranges  of  mountain  groups,  whether  in  long  ridges 
or  in  consecutive  domes,  are  by  no  means  parallel,  either  to  one 
mother,  or  to  the  direction  of  the  entire  swell  of  tb«  land. 


412  COSMOS. 

beautifully  delineated  by  Fremont,  James'  Peak  (11,434  feet), 
and  the  three  Park  Mountains,  all  of  which  enclose  three 
deep  valleys,  the  lateral  walls  of  which  rise  up,  along  with 
the  eastern  Long's  Peak,  or  Big  Horn,  to  a  height  of  9060 
and  11,191  feet.17  On  the  eastern  boundary,  between 
Middle  and  North  Park,  the  mountain  chain  all  at  once 
changes  its  direction  and  runs  from  lat.  40|-0  to  44°  for  a 
distance  of  about  260  geographical  miles  from  south-east  to 
north-west.  In  this  intermediate  space  lie  the  south  Pass 
(7490  feet),  and  the  famous  Wind  Biver  Mountains,  so 
singularly  sharp  pointed,  together  with  Fremont's  Peak 
(lat.  43°  8'),  which  reaches  the  height  of  13,567  feet.  In 
the  parallel  of  44,°  in  the  neighbourhood  of  the  Three 
Tetons.  where  the  north-westerly  direction  ceases,  the  meri- 
dian direction  of  the  Hocky  Mountains  begins  again,  and 
continues  about  as  far  as  Lewis  and  Clarke's  Pass,  which 
lies  in  lat.  47°  2'  and  long.  112°  9'  30/'  Even  at  this  point, 
the  chain  of  the  Rocky  Mountains  maintains  a  considerable 
height  (5977  feet),  but  from  the  many  deep  river-beds  in 
the  direction  of  Flathead  River  (Clarke's  Fork),  it  soon 

tf  Frdmont,  Explor.  Exped.  pp.  281 — 288.  Pike's  Peak,  lat.  38°  50', 
delineated,  at  p.  114;  Long's  Peak,  40°  15';  ascent  of  Fremont's  Peak 
(13,570  feet)  p.  70.  The  Wind  River  Mountains  take  their  name  from 
the  source  of  a  tributary  to  the  Big  Horn  River,  whose  waters  unite 
with  those  of  the  Yellow  Stone  River,  which  falls  into  the  Upper  Mis- 
souri (lat.  47°  58',  long.  103°  6'  30").  See  the  delineations  of  the  Alpine 
range,  rich  in  mica-slate  and  granite,  pp.  66  and  70.  I  have  in  all  cases 
retained  the  English  names  given  by  the  North  American  Geographers, 
as- their  translation  into  a  pure  German  nomenclature  has  often  proved 
a  rich  source  of  confusion.  To  help  the  comparison  of  the  direction 
and  length  of  the  meridian-chain  of  the  Ural,  which,  according  to  the 
careful  investigations  of  my  friend  and  travelling  companion,  Colonel 
Ernst  Hofmann,  takes  a  curve  at  the  northern  extremity  towards  the 
east,  and  which,  from  the  Truchmenian  Mountain  Airuk-Tagh  (48f  °) 
to  the  Sablja  Mountains  (65°),  is  fully  1020  geographical  miles  in  length, 
with  those  of  the  Rocky  Mountains,  I  would  here  remind  the  reader 
that  the  latter  chain  runs,  between  the  parallels  of  Pike's  Peak  and 
Lewis  and  Clarke's  Pass,  from  105°  9'  30"  into  112°  y'  BO"  of  longitude. 
The  chain  of  the  Ural  which,  within  the  same  space  of  17  degrees  of 
latitude,  deviates  little  from  the  meridian  of  59°  0'  30",  likewise  changes 
its  direction  under  the  parallel  of  65°,  and  attains,  under  lat,  67^°  the 
meridian  of  66°  5'  30".  Compare  Ernst  Hofmann,  der  nordlicke  Ural 
und  das  Kustengebirge  Pac-Ckoi,  1856,  s.  191  and  297—305,  with 
Humboldt,  Asie  centrale  (1843)  t.  i.  p.  447. 


TRUE   VOLCANOES.  413 

decreases  to  a  more  regular  level.  Clarke's  Fork  and  Lewis 
or  Snake  River  unite  in  forming  the  great  Columbia  River, 
which  will  one  day  prove  an  important  channel  for  com- 
merce. (Explorations  for  a  railroad  from  tlie  Mississippi 
River  to  the  Pacific  Ocean,  made  in  1853 — 1854,  vol.  i,  p. 
107.) 

As  in  Bolivia,  the  eastern  chain  of  the  Andes  furthest 
removed  from  the  sea,  that  of  Sorata  (21,287  feet)  and 
Illimani  (21,148  feet),  furnish  no  volcano  now  in  a  state 
of  ignition,  so  also  in  the  western  parts  of  the  United 
States,  the  volcanic  action  on  the  coast-chain  of  California 
and  Oregon  is  at  present  very  limited.  The  long  chain  of 
the  Rocky  Mountains,  at  a  distance  from  the  shores  of  the 
South  Sea  varying  from  480  to  800  geographical  miles, 
without  any  trace  of  still  existing  volcanic  action,  neverthe- 
less shows,  like  the  eastern  chain  of  Bolivia  in  the  vale  of 
Yucay,18  on  both  of  its  slopes  volcanic  rock,  extinct  craters, 
and  even  lavas  inclosing  obsidian,  and  beds  of  scoriae.  In 
the  chain  of  the  Rocky  Mountains  which  we  have  here 
geographically  described  in  accordance  with  the  admirable 
observations  of  Fremont,  Emory,  Abbot,  Wislizenus,  Dana, 
and  Jules  Marcou,  the  latter,  a  distinguished  geologist, 
reckons  three  groups  of  old  volcanic  rock  on  the  two  slopes. 
For  the  earliest  notices  of  the  vulcanicity  of  this  district  we 
are-  also  indebted  to  the  investigations  made  by  Fremont 
since  the  years  1842  and  1843  (Report  of  the  Exploring  Ex- 
pedition to  the  Rocky  Mountains  in  1842,  and  to  Oregon  and 
North  California  in  1843-44,  pp.  164,  184-187,  and  193). 

On  the  eastern  slope  of  the  Rocky  Mountains,  on  the 
south-western  road  from  Bent's  Fort,  on  the  Arkansas  River 
to  Santa  Fe  del  Nuevo  Mexico,  lie  two  extinct  volcanoes,  the 
Raton  Mountains19  with  Fisher's  Peak,  and  the  hill  of  El 
Cerrito  between  Galisteo  and  Pcna  Blanca.  The  lavas  of  the 
former  cover  the  whole  district  between  the  Upper  Arkansas 
and  the  Canadian  River.  The  Peperino  and  the  volcanic 
sconce,  which  are  first  met  with  even  in  the  prairies,  on 

18  See  above  p.  295. 

19  According  to  the  road-map  of  1855,  attached  to  the  general  repor1; 
of  the  Secretary  of  State,  Jefferson  Davis,  the  Raton  Pass  rises  to  an 
elevation  of  as  much  as  7180  feet  above  the  level  of  the  sea.     Compare, 
also,  Marcou,  Resume  explicatif  d'une  Carte  GcoL,  1855,  p.  113. 


414  COSMOS. 

approaching  the  Rocky  Mountains  from  the  east,  belong 
perhaps  to  old  eruptions  of  the  Cerrito,  or  of  the  stupendous 
Spanish  Peaks  (37°  32').  This  easterly  volcanic  district  of 
the  isolated  Raton  Mountains  forms  an  area  of  80  geogra- 
phical miles  in  diameter ;  its  centre  lies  nearly  in  latitude 
36°  50'. 

On  the  western  slope  most  unmistakeable  evidences  of 
ancient  volcanic  action  are  discernible  over  a  wider  space, 
which  has  been  traversed  by  the  important  expedition  of 
Lieutenant  Whipple  throughout  its  whole  breadth  from 
east  to  west.  This  variously  shaped  district,  though  inter- 
rupted for  fully  120  geographical  miles  to  the  north  of  the 
Sierra  de  Mogoyon,  is  comprised  (always  on  the  authority 
of  Marcou's  geological  chart)  between  latitude  33°  48'  and 
35°  40',  so  that  instances  of  eruption  occur  further  south 
than  those  of  the  Raton  Mountains.  Its  centre  falls  nearly 
in  the  parallel  of  Albuquerque.  The  area  here  designated 
divides  into  two  sections,  that  of  the  crest  of  the  Rocky 
Mountains  nearer  Mount  Taylor,  which  terminates  at  the 
Sierra  de  Zuni,30  and  the  western  section,  called  the  Sierra 
de  San  Francisco.  The  conical  mountain  of  Mount  Taylor, 
12,256  feet  high,  is  surrounded  by  radiating  lava-streams, 
which,  like  Malpays  still  destitute  of  all  vegetation,  covered 
over  with  scoriae  and  pumice-stone,  wind  along  to  a  distance 
of  several  miles,  precisely  as  in  the  district  around  Hecla. 
About  72  geographical  miles  to  the  west  of  the  present  Pueblo 
de  Zuni  rises  the  lofty  volcanic  mountain  of  San  Francisco 
itself.  It  has  a  peak  which  has  been  calculated  at  more 
than  16,000  feet  high,  and  stretches  away  southward  from 
the  Rio  Colorado  Chiquito,  where,  farther  to  the  west,  the 

20  We  must  be  careful  to  distinguish,  to  the  west  of  the  mountain- 
ridge  of  Zuni,  where  the  Paso  de  Zuni  attains  an  elevation  of  as  much 
as  7943  feet,  between  Zuni  viejo,  the  old  dilapidated  town  delineated 
by  Mollhausen  on  Whipple's  expedition,  and  the  still  inhabited  Pueblo 
de  Zuiii.  Forty  geographical  miles  north  of  the  latter,  near  Fort 
Defiance,  there  still  exists  a  very  small  and  isolated  volcanic  district. 
Between  the  village  of  Zuni  and  the  descent  to  the  Rio  Colorado 
chiquito  (Little  Colorado)  lies  exposed  the  petrified  forest  which 
Mollhausen  admirably  delineated  in  1853,  and  described  in  a  treatise 
which  he  sent  to  the  Geographical  Society  of  Berlin.  According  to 
Marcou  (Presume  explic.  d'une  Carte  Geol.,  p.  59),  fossil  trees  and  ferna 
are  mingled  with  the  silicified  coniferse. 


OF  THE 

(TY 
or 

TEUE    VOLCA&Om^*****  415 

Bill  William  Mountain,  the  Aztec  Pass  (6279  feet),  and  the 
Aquarius  Mountains  (8526  feet)  follow.  The  volcanic  rock 
does  not  terminate  at  the  confluence  of  the  Bill  William 
Fork  with  the  great  Colorado,  near  the  village  of  the  Mohave 
Indians  (lat.  34°,  long.  114°),  for,  on  the  other  side  of  the 
Rio  Colorado  at  the  Soda  Lake,  several  extinct,  but  still  open 
craters  of  eruption,  may  be  recognized.21 

Thus  we  find  here  in  the  present  New  Mexico,  in  the 
volcanic  group  commencing  at  the  Sierra  de  San  Francisco, 
and  ending  a  little  to  the  westward  of  the  Rio  Colorado 
Grande,  or  del  Occidente  (into  which  the  Gila  falls),  over  a 
distance  of  180  geographical  miles,  the  old  volcanic  district 
of  the  Auvergne  and  the  Vivarais  repeated,  and  a  new  and 
wide  field  opened  up  for  geological  investigation. 

Likewise  on  the  western  slope,  but  540  geographical  miles 
more  to  the  north,  lies  the  third  ancient  volcanic  group  of 
the  Rocky  Mountains,  that  of  Fremont's  Peak,  and  the  two 
triple-mountains,  whose  names,  the  Trois  Te"tons  and  the 
Three  Buttes,22  correspond  well  with  their  conical  forms. 
The  former  lie  more  to  the  west  than  the  latter,  and  con- 
sequently farther  from  the  mountain  chain.  They  exhibit 
wide-spread,  black  banks  of  lava,  very  much  rent,  and  with 
a  scorified  surface.23 

Parallel  with  the  chain  of  the  Rocky  Mountains,  some- 
times single  and  sometimes  double,  run  several  ranges  in 
which  their  northern  portion  from  lat.  46°  12',  are  still  the 
seat  of  volcanic  action.  First,  from  San  Diego  to  Monterey 
(32^°  to  36f°),  there  is  the  coast-range,  specially  so-called,  a 
continuation  of  the  ridge  of  land  on  the  peninsula  of  Old,  or 
Lower,  California ;  then,  for  the  most  part  80  geographical 

21  All  on  the  authority  of  the  profiles  of  Marcou  and  the  above-cited 
road-map  of  1855. 

"  The  French  appellations,  introduced  by  the  Canadian  fur-hunters, 
are  generally  used  in  the  country  and  on  English  maps.  According  to 
the  most  recent  calculations,  the  relative  positions  of  the  extinct  vol- 
canoes are  as  follows  :—  Fremont's  Peak,  lat.  43°  5',  long.  110°  9'  30"; 
Trois  Tenons,  lat.  43°  38',  long.  110°  49'  30";  Three  Buttes,  lat.  43°  20', 
long.  112°  41'  30";  Fort  Hall,  lat.  43°  0',  long.  111°  24'  30". 

-3  Lieut.  Mullan,  on  Volcanic  Formation,  in  the  Reports  of  Explor. 
and  Surveys,  vol.  i  (1855),  pp.  330  and  348;  see  also  Lambert's  and 
Tinkham's  Reports  on  the  Three  Buttes,  ibid.  pp.  167  and  226—230 
and  Jules  Marcou,  p.  115, 


413  COSMOS. 

miles  distant  from  the  shore  of  the  South  Sea,  the  Sierra 
Nevada  (de  Alta  California)  from  36°  to  40f° ;  then  again, 
commencing  from  the  lofty  Shasty  Mountains  in  the  parallel 
of  Trinidad  Bay  (lat.  41°  10'),  the  Cascade  range,  which 
contains  the  highest  still  ignited  peak,  and  which,  at  a 
distance  of  104  miles  from  the  coast,  extends  from  south  to 
north  far  beyond  the  parallel  of  the  Fuca  Strait.  Similar  in 
their  course  to  this  latter  chain  (lat.  43°— 46°),  but  280 
miles  distant  from  the  shore,  are  the  Blue  Mountains,24  which 
rise  in  their  centre  to  a  height  of  from  7000  to  8000  feet. 
In  the  central  portion  of  Old  California,  a  little  farther  to 
the  north,  near  the  eastern  coast  or  bay  in  the  neighbour- 
hood of  the  former  Mission  of  San  Ignacio,  in  about  28° 
north  latitude,  stands  the  extinct  volcano,  known  as  the 
"  Volcanes  de  las  Virgenes,"  which  I  have  given  on  my  chart 
of  Mexico.  This  volcano  had  its  last  eruption  in  1746;  but 
we  possess  no  reliable  information  either  regarding  it  or  any 
of  the  surrounding  districts ;  (See  Venegas,  Noticia  de  la 
California,  1757,  t.  i,  p.  27  ;  and  Duflot  de  Moras,  Exploration 
de  I' Oregon  et  de  la  Calif ornie,  1844,  t.  i,  pp.  218  and  239). 
Ancient  volcanic  rock  has  already  been  found  in  the  coast- 
range  near  the  harbour  of  San  Francisco,  in  the  Monte  del 
Diablo,  which  Dr.  Trask  investigated  (3673  feet),  and  in  the 
auriferous  elongated  valley  of  the  Rio  del  Sacramento  in  a 
trachytic  crater  now  fallen  in,  called  the  Sacramento  Butt, 
which  Dana  has  delineated.  Farther  to  the  north,  the ' 
Shasty,  or  Tshashtl  Mountains,  contain  basaltic  lavas,  obsi- 
dian, of  which  the  natives  make  arrow-heads,  and  the  talc- 
like  serpentine  which  makes  its  appearance  on  many  points 
of  the  earth's  surface,  and  appears  to  be  closely  allied  to  the 
volcanic  formations.  But  the  true  seat  of  the  still  existing 
igneous  action  is  the  Cascade  Mountain  range,  in  which, 
covered  with  eternal  snow,  several  of  the  peaks  rise  to  the 
height  of  16,000  feet.  I  shall  here  give  a  list  of  these,  pro- 
ceeding from  south  to  north.  The  now  ignited,  and  more  or 
less  active  volcanoes,  will  be  (on  the  plan  heretofore  adopted) 

-4  Dana,  p.  616—620  ;  Blue  Mountains,  p.  649—651 ;  Sacramento 
Butt,  p.  630—643;  Shasty  Mountains,  p.  614;  Cascade  range.  On  the 
Monte  Diablo  range,  perforated  by  volcanic  rock,  see  also  John  Trask, 
on  the  Geology  of  the  Coast  Mountains  and  the  Sierra  Nevada,  1854, 
pp.  13—18. 


TRUE  VOLCANOES.  417 

(see  above,  p.  61,  note  71)  distinguished  by  a  star.  The  high 
conical  mountains  not  so  distinguished,  are  probably  partly 
extinct  volcanoes,  and  partly  unopened  trachytic  domes. 

Mount  Pitt,  or  M'Laughlin  ;  lat.  4&°  30',  a  little  to  the 
west  of  Lake  Tlamat ;  height  9548  feet. 

Mount  Jefferson,  or  Vancouver  (lat.  44°  35'),  a  conical 
mountain. 

Mount  Hood  (lat.  45°  10'),  decidedly  an  extinct  volcano, 
covered  with  cellular  lava.  According  to  Dana  this  moun- 
tain, as  well  as  Mount  St.  Helen's,  which  lies  more 
northerly  in  the  volcano  range,  is  between  15.000  and 
16,000  feet  high,  though  somewhat  lower25  than  the  latter. 
Mount  Hood  was  ascended  in  August,  1853,  by  Lake,  Tra- 
vaillot,  and  Heller. 

Mount  Swalahos,  or  Saddle  Hill,  S.S.E.  of  Astoria38, 
with  a  fallen  in,  extinct  crater. 

Mount  St.  Helen's,*  north  of  the  Columbia  river 
(lat.  46°  12').  According  to  Dana,  not  less  than  15,000 
feet  high27.  Still  burning  and  always  smoking  from  the 
summit-crater.  A  volcano  of  very  beautiful,  regular,  co- 
nical form  and  covered  with  perpetual  snow.  There  was  a 
great  eruption  on  the  23rd  November,  1842  ;  which,  ac- 
cording to  Fremont,  covered  everything-to  a  great  distance 
round  with  ashes  and  pumice. 

Mount  Adams  (lat.  46°  18'),  almost  exactly  east  of  the 
volcano  of  St.  Helen's,  more  than  112  geographical  miles 
distant  from  the  coast,  if  it  be  true  that  the  last-named 
and  still  active  mountain,  is  only  76  of  those  miles  inland. 

25  Dana  (pp.  615  and  640)  estimated  the  rolcano  of  St.  Helen's  at 
16,000  feet,  and  Mount  Hood  of  course  under  that  height,  while 
according  to  others  Mount  Hood  is  said  to  attain  the  great  height  of 
18,316  feet,  which  is  2521  feet  higher  than  the  summit  of  Mont  Blanc, 
and  4730  feet  higher  than  Fremont's  Peak  in  the  Rocky  Mountains. 
According  to  this  estimate,  (Langrebe,  Naturgesckichte  der  Vulkane, 
Bd.  i,  s.  497),  Mount  Hood  would  be  only  571  feet-  lower  than  the 
volcano  Cotopaxi ;  on  the  other  hand  Mount  Hood,  according  to 
Dana,  exceeds  the  highest  summit  of  the  Rocky  Mountains  by  2586 
feet  at  the  utmost.  I  am  always  desirous  of  drawing  attention  to 
variantes  lectiones  such  as  these. 

36  Dana,  Geol.  o)  the  U.S.  Expl.  Exped.,  pp.  640  and  643—645. 

*  Variously  estimated  previously  at  10,178  feet  by  Wilkes,  and  13,535 
leet  by  Simpson. 

VOL.  V.  2    E 


418  COSMOS. 

Mount  Regnier,*  also  written  Mount  Rainier  (lat. 
46°  48')  E.S.E.  of  Fort  Nisqually,  on  Puget's  Sound,  which 
is  connected  with  the  Fuca  Strait.  A  burning  volcano  ; 
according  to  Edwin  Johnson's  road-map  of  1854,  12,330 
feet  high.  It  experienced  severe  eruptions  in  1841  and!843. 

Mount  Olympus  (lat.  47°  50').  Only  24  geographical 
miles  south  of  the  strait  of  San  Juan  de  Fuca,  long  so 
famous  in  the  history  of  the  South  Sea  discoveries. 

Mount  Baker,*  a  large  and  still  active  volcano,  situated 
in  the  territory  of  Washington  (lat.  48°  48'),  of  great 
(unmeasured  ?)  height  (not  yet  determined),  and  regular 
conical  form. 

Mount  Brown  (16,000  feet?)  and,  a  little  more  to  the 
east,  Mount  Hooker  (16,750  feet  ?),  are  cited  by  Johnson 
as  lofty,  old-volcanic  trachytic  mountains,  under  lat.  52£°, 
and  long.  117°  40'  and  119°  40'.  They  are  therefore  re- 
markable as  being  more  than  300  geographical  miles 
distant  from  the  coast. 

Mount  Edgecombe,*  on  the  small  Lazarus  Island,  near 
Sitka  (lat.  57°  3').  Its  violent  igneous  eruption  in  1796, 
has  already  been  mentioned  by  me  (see  above,  p.  269). 
Captain  Lisiansky,  who  ascended  it  in  the  first  years  of 
the  present  century,  found  the  volcano  then  unignited. 
Its  height28  reaches,  according  to  Ernst  Hofmann,  3039 
feet,  according  to  Lisiansky,  2801  feet.  Near  it  are  hot 
springs  which  issue  from  granite,  as  on  the  road  from  the 
Valles  de  Aragua  to  Portocabello. 

Mount  Fairweather,  or  Cerro  de  Buen  Tiempo  ;  accord- 
ing to  Malaspina,  4489  metres,  or  14,710  feet  high29.  In 
lat.  58G  45'.  Covered  with  pumice-stone,  and  probably 
ignited  up  to  a  short  time  back,  like  Mount  Elias. 

The  volcano  of  Cook's  Inlet  (lat.  60°  8').  According 
to  Admiral  Wrangel  12,065  feet  high,  and  considered  by 
that  intelligent  mariner,  as  well  as  by  Vancouver,  to  be 
an  active  volcano30. 

23  Karsten's  Arcldv.  fur  Mineralogie,  Bd.  i,  1829,  s.  243. 

29  Humboldt,  Lssai  Polit.  sur  la  Nouv.  Esp.,  t.  i,  p.  266.  torn,  ii,  p.  310. 

30  According  to  a  manuscript  which  I  was  permitted  to  examine  in 
the  year  1803,  in  the  Archives  of  Mexico,  the  whole  coast  of  Nutka, 
as  far  as  what  was  afterwards  called  "  Cook's  Inlet,"  was  visited  during 
the  expedition  of  Juan  Perez,  and  Estevan  Jose"  Martinez,  in  the  year 
1774. 


TRUE   VOLCANOES.  419 

Mount  Elias,  lat.  60°  17' ;  long.  136°  10  30".  Accord- 
ing to  Malaspina's  manuscripts,  which  I  found  in  the 
Archives  of  Mexico,  5441  metres,  or  17,854  feet.  Ac- 
cording to  Captain  Denham's  chart,  from  1853  to  1856, 
the  height  is  only  14,970  feet. 

What  M'Clure,  in  his  account  of  the  North- West  Passage, 
calls  the  Volcano  of  Franklin's  Bay  (lat.  69°  57' ;  long  127°) 
eastward  of  the  mouth  of  the  Mackenzie  river,  seems  to  be 
a  kind  of  earth-fire.,  or  salses,  throwing  out  hot,  sulphurous 
vapours.  An  eye-witness,  the  Missionary  Miertsching,  in- 
terpreter to  the  expedition  on  board  the  ship  "Investigator," 
found  from  thirty  to  forty  columns  of  smoke  rising  from 
fissures  in  the  earth,  or  from  small  conical  mounds  of  clays 
of  various  colours.  The  sulphurous  odour  was  so  strong 
that  it  was  scarcely  possible  to  approach  the  columns  of 
smoke  within  a  distance  of  twelve  paces.  No  rock  or 
other  solid  masses  could  be  discovered  in  the  immediate 
vicinity.  Lights  were  seen  from  the  ship  at  night,  no  ejec- 
tions of  mud,  but  great  heat  of  the  bed  of  the  sea,  and 
small  pools  of  water  containing  sulphuric  acid  were  observed. 
The  district  merits  a  careful  investigation,  and  the  pheno- 
menon stands  quite  unconnected  there,  like  the  volcanic 
action  of  the  Cerro  de  Buen  Tiempo,  or  of  Mount  Elias  in 
the  Californian  Cascade  range  (M'Clure,  Discovery  of  the 
N.  W.  Passage,  p.  99  ;  Papers  relative  to  the  Arctic  Ex- 
pedition, 1854,  p.  34;  Miertsching's  Reise-Tagebuch  ; 
Gnadau,  1855,  s.  46). 

1  have  hitherto  treated  the  volcanic  vital  activities  of  our 
planet  in  their  intimate  connections,  as  if  forming  an  ascending 
scale  of  the  great  and  mysterious  phenomenon  of  a  reaction 
of  its  fused  interior  upon  its  surface,  clothed  with  animal  and 
vegetable  organisms.  I  have  considered  next  in  order  to  the 
almost  purely  dynamic  effects  of  the  earthquake  (the  wave 
of  concussion)  the  thermal  springs  and  salses,  that  is  to  say, 
phenomena  produced,  with  or  without  spontaneous  ignition, 
by  the  permanent  elevation  of  temperature  communicated  to 
the  water-springs  and  streams  of  gas,  as  well  as  by  diversity 
of  chemical  mixture.  The  highest,  and  in  its  expressions, 
the  most  complicated  grade  of  the  scale,  is  presented  by  the 
volcanoes,  which  call  into  action  the  great  and  varied  pro- 
cesses of  crystalline  rock-formation  by  the  dry  method,  and 

2  E  2 


120  COSMOS. 

which  consequently  do  not  simply  reduce  and  destroy,  but 
appear  in  the  character  of  creative  powers,  and  form  the 
materials  for  new  combinations.  A  considerable  portion  -of 
very  recent,  if  not  of  the  most  recent,  mountain-strata,  is  the 
work  of  volcanic  action,  whether  effected,  as  in  the  present 
day,  by  the  pouring  forth  of  molten  masses  at  many  points 
of  the  earth  from  peculiar  conical,  or  dome-shaped  elevated 
stages,  or,  as  in  the  early  years  of  our  planet's  existence, 
by  the  immediate  issuing  forth  of  basaltic  and  trachytic  rock 
by  the  side  of  the  sedimentary  strata,  from  a  net-work  of  open 
fissures,  without  the  intervention  of  any  such  structures. 

In  the  preceding  pages  I  have  most  carefully  endeavoured 
to  determine  the  locality  of  the  points  at  which  a  commu- 
nication has  long  continued  open  between  the  fluid  interior 
of  the  earth  and  the  atmosphere.  It  now  remains  to  sum 
up  the  number  of  these  points,  to  separate  out  of  the  rich 
abundance  of  the  volcanoes  which  have  been  active  in  very 
remote  historical  periods,  those  which  are  still  ignited  at  the 
present  day,  and  to  consider  these  according  to  their  division 
into  Continental  and  Insular  Volcanoes.  If  all  those  which, 
in  this  enumeration,  I  think  I  may  venture  to  consider  the 
lowest  limit  of  the  number,  were  simultaneously  in  action, 
their  influence  on  the  condition  of  the  atmosphere,  and  its 
climatic,  and  especially  its  electric  relations,  would  certainly 
be  extremely  perceptible  ;  but  as  the  eruptions  do  not  take 
place  simultaneously,  but  at  different  times,  their  effect  is 
diminished  and  is  confined  within  very  narrow  and  chiefly 
mere  local  limits.  In  great  eruptions  there  occur  around  the 
crater,  as  a  consequence  of  the  exhalation,  volcanic  storms, 
which  being  accompanied  by  lightning  and  torrents  of  rain, 
often  occasion  great  ravages ;  but  these  atmospheric  pheno- 
mena have  no  generally  extended  results.  For  that  the  re- 
markable obscurity  (known  by  the  name  o  ithe  dry  fog) 
which  for  the  space  of  several  months,  from  May  to  August 
of  the  year  1783,  overspread  a  very  considerable  part  of 
Europe  and  A  sia,  as  well  as  the  North  of  Africa — while  the 
sky  was  seen  pure  and  untroubled  at  the  top  oi  the  lofty 
mountains  of  Switzerland — could  have  been  occasioned  by  the 
unusual  activity  of  the  Icelandic  volcanicity,  and  the  earth- 
quakes of  Calabria,  as  is  even  now  sometimes  maintained, 
seems  to  me  very  improbable  on  account  of  the  magnitude  of 


TRUE   VOLCANOES.  421 

the  effect  produced.*  Yet  a  certain  apparent  influence  of 
earthquakes,  in  cases  where  they  occupy  much  space  in 
changing  the  commencement  of  the  rainy  season,  as  in  the 
highland  of  Quito  and  Riobamba  (in  February,  1797),  or  in 
the  south-eastern  countries  of  Europe  and  Asia  Minor  (in  the 
Autumn  of  1856),  might  indeed  be  viewed  as  the  isolated 
influence  of  a  volcanic  eruption. 

In  the  following  table  the  first  figures  denote  the  number 
of  the  volcanoes  cited  in  the  preceding  pages,  while  the  second 
figures,  inclosed  in  parentheses,  denote  the  number  of  those 
which  in  recent  times  have  given  evidence  of  their  igneous 
activity. 

Number  of  Volcanoes  on  the  Earth. 
I  Europe  (above,  p.  349, 350)         ...  ...  ...         7       (4) 

II  Islands  of  the  Atlantic  Ocean  (p.  351—354)  ...       14       (8) 

III  Africa  (p.  354,  355)       ...  3      (1) 

IV  Asia— Continental  25     (15) 

(1)  Western  and  Central  (p.  356—362)  ...       11       (6) 

(2)  The  Peninsula  of  Kamtschatka  (p.  362—367)       14       (9) 
V  Eastern  Asiatic  Islands  (p.  367—377)       ...  ..       69     (54) 

VI  South  Asiatic  Islands  (p.  297— 308,  377— 382)  ...  120  (56) 
VII  Indian  Ocean  (p.  382—388,  and  note  79  at  p.  385,  386)  9  (5) 
VIII  South  Sea  (p.  388—401,  notes  83—85  at  p.  389—391)  40  (26j 

IX  America— Continental  115     (53) 

(1)  South  America     56     (26) 

(a)  Chili  (p.  285,  note  75  at  p.  287— 290)      ...       24     (13) 

(b)  Peru  and  Bolivia  (p.  285—291,  note  74  at 

p.  286,  287)  14      (3) 

(c)  Quito  and  New  Granada  (p.  285,  note  73 

at  p.  286) 18     (10) 

(2)  Central  America  (p.  258,  268—279,  285,  328, 

notes  66—68  at  p.  271—278)       29    (18) 

(3)  Mexico,  south  of  the  Rio  Gila  (p.  279,  281, 

285,  308—328,  and  notes  6—13  at  p.  310— 

322,  401—429,  notes  7—14  at  p.  402—408)          6      (4) 

(4)  North-  Western  America,  north   of  the   Gila 

(p.  409—419) 24      (5) 

The  Antilles^1          5       (3) 

Total    407    (225) 

*  [A  similar  fog  overspread  the  Tyrol  and  Switzerland  in  1755,  just 
before  the  great  earthquake  which  destroyed  Lisbon.  It  appeared  to 
be  composed  of  earthy  particles  reduced  to  an  extreme  degree  of  fine- 
ness.]— TR. 

31  In  the  Antilles  the  volcanic  activity  is  confined  to  what  are 
called  the  "  Little  Antilles,"  three  or  four  still  active  volcanoes  having 


422  COSMOS. 

The  result  of  this  laborious  work,  on  which  I  have  long 

broken  out  on  a  somewhat  curvilinear  fissure  running  from  South  to 
north,  nearly  parallel  to  the  volcanic  fissure  of  Central  America.  In 
the  course  of  the  considerations  induced  by  the  simultaueousness  of 
the  earthquakes  in  the  valleys  of  the  rivers  Ohio,  Mississippi,  and  Ar- 
kansa,s,  with  those  of  the  Orinoco,  and  of  the  shore  of  Venezuela,  I  have 
already  described  the  little  sea  of  the  Antilles,  in  its  connection  with 
the  Gulf  of  Mexico  and  the  great  plain  of  Louisiana,  between  the  Alle- 
ghanys  and  the  Rocky  Mountains,  on  geognostic  views,  as  a  single 
ancient  basin  {Voyage  aux  Regions  Eqmnoxiales,  t.  ii,  pp.  5 and  19;  see 
also  above,  p.  6).  This  basin  is  intersected  in  its  centre,  between  18° 
and  22°  lat.  by  a  plutonic  mountain-range  from  Cape  Catoche  of  the 
peninsula  of  Yucatan  to  Tortola  and  Virgen  gorda.  Cuba,  Haiti,  and 
Porto  Rico,  form  a  range  running  from  west  to  east,  parallel  with 
the  granite  and  gneiss  chain  of  Caraccas.  On  the  other  hand,  the  Little 
Antilles,  which  are  for  the  most  part  volcanic,  unite  together  the  plu- 
tonic chain  just  alluded  to  (that  of  the  Great  Antilles)  and  that  of 
the  shore  of  Venezuela,  closing  the  southern  portion  of  the  basin  on  the 
east.  The  still  active  volcanoes  of  the  Little  Antilles  lie  between  the 
parallels  of  13°  to  16£°,  in  the  following  order,  reckoning  from  south 
to  north  :  — 

The  volcano  of  the  island  of  St.  Vincent,  stated  sometimes  at  3197 
and  sometimes  at  5052  feet  high.  Since  the  eruption  of  1718  all  re- 
mained quiet,  until  an  immense  ejection  of  lava  took  place  on  the  27th 
April,  1812.  The  first  commotions  commenced  as  early  as  May,  1811, 
near  the  Crater,  three  months  after  the  island  of  Sabrina  in  the 
Azores  had  risen  from  the  sea.  They  began  faintly  in  the  mountain- 
valley  of  Caraccas,  3496  feet  above  the  surface  of  the  sea,  in  December 
of  the  same  year.  The  complete  destruction  of  the  great  city  took 
place  on  the  26th  March,  1812.  As  the  earthquake  which  destroyed 
Cumana  pn  the  14th  December,  1796,  was  with  justice  ascribed  to  the 
eruption  of  the  volcano  of  Guadaloupe  (the  end  of  September,  17S6), 
in  like  manner  the  destruction  of  Caraccas  appears  to  have  been  the  effect 
of  the  reaction  of  asoutherly  volcano  of  the  Antilles, — that  of  St.  Vincent. 
The  frightful  subterranean  noise,  like  the  thundering  of  cannon,  pro- 
duced by  a  violent  eruption  of  the  latter  volcano  on  the  30th  April, 
1812,  was  heard  on  the  distant  grass-plains  (Llanos)  of  Calabozo,  and 
on  the  shores  of  the  Rio  Apure,  192  geographical  miles  farther  to  the 
west  than  its  junction  with  the  Orinoco  (Humboldt,  Voy.  t.  ii,  p.  14). 
The  volcano  of  St.  Vincent  had  thrown  out  no  lava  since  1718,  but  on 
the  30th  April,  a  stream  of  lava  flowed  from  the  summit  crater,  and  in 
four  hours  reached  the  sea  shore.  It  was  a  very  striking  circumstance, 
and  one  which  has  been  confirmed  to  me  by  very  intelligent  coasting 
mariners,  that  the  noise  was  very  much  stronger  on  the  open  sea,  far 
from  the  island,  than  near  the  shore. 

The  volcano  of  the  island  S.  Lucia,  commonly  called  only  a  solfa- 
tara,  is  scarcely  1200  to  1800  feet  high.  In  the  crater  are  several  small 
basins  periodically  filled  with  boiling  water.  In  the  year  1766,  an 
ejection  of  scorise  and  cinders  is  said  to  have  been  observed,  which  if 


TRUE  VOLCANOES.  423 

been  occnpied,  having  in  all  cases  consulted   the  original 

certainly  an  unusual  phenomenon  in  a  solfatara,  for  although  the 
careful  investigations  of  James  Forbes  and  Poulett  Scrope,  leave  no 
room  to  doubt  that  an  eruption  took  place  from  the  Solfatara  of  Poz- 
zuoli  in  the  year  1198,  yet  one  might  be  inclined  to  consider  that  event 
as  a  collateral  effect  produced  by  the  great  neighbouring  volcano,  Vesu 
vius  (See  Forbes  in  the  Edinb.  Journal  of  Science,  vol.  i,  p.  128,  and 
Poulett  Scrope  in  the  Transact,  of  the  Geol.  Soc.  2nd  Ser.  vol.  ii,  p.  346). 
Lancerote,  Hawaii  and  the  Sunda  Islands  furnish  us  with  analogous 
examples  of  eruptions  at  exceedingly  great  distances  from  the  summit 
craters,  the  peculiar  seat  of  action.  It  is  true  the  solfataraof  Pozzuoli  was 
not  disturbed  on  the  occasion  of  great  eruptions  of  Vesuvius  in  the 
years  1794, 1822,  1850  and  1855,  (Julius  Schmidt,  Ueber  die  Eruption  des 
Vesuvs.  in  Mai,  1855,  p.  156),  though  Strabo  (lib.  v,  p.  245),  long  before 
the  eruption  of  Vesuvius,  speaks  of  fire,  somewhat  vaguely  it  is  true,  in 
the  scorched  plains  of  Dicaarchia,  near  Curncea  and  Phlegra.  Dicaarchia 
in  Hannibal's  time  received  the  name  of  Puteoli  from  the  Romans  who 
colonised  it.  "  Some  are  of  opinion,"  continues  Strabo,  "  on  account  of 
the  bad  smell  of  the  water  that  the  whole  of  that  district  as  far  as 
Baise  and  Cumoea  is  so  called,  because  it  is  full  of  sulphur,  fire  and 
warm  water.  Some  think  that  on  this  account  Cumoea  (Cumanus  ager) 
is  called  also  Phlegra  .  .  .  ."  and  then  again  Strabo  mentions  discharges 
of  fire  and  water,  "  irpo\oaQ  TOV  TTVOOQ  Kai  TOV  r^'arog)." 

The  recent  volcanic  action  of  the  island  of  Martinique  in  the  Mon- 
tagne  Pelee  (according  to  Dupuget,  4706  feet  high),  the  Vauclin  and  the 
Pitons  du  Carbet  is  still  more  doubtful.  The  great  eruption  of  vapour 
on  the  22nd  January,  1792,  described  by  Chisholm,  and  the  shower  of 
ashes  of  the  5th  August,  1851,  deserve  to  be  more  thoroughly  inquired 
into. 

The  Soufriere  de  la  Guadeloupe,  accoi'ding  to  the  older  measure- 
ments of  Amic  and  Le  Boucher,  5435  and  5109  feet  high,  but  accord- 
ing to  the  latest  and  very  correct  calculations  of  Charles  Sainte-Claire 
Deville,  only  4867  feet  high,  exhibited  itself  on  the  28th  September, 
1797,  78  days  before  the  great  earthquake  and  the  destruction  of  the 
town  of  Cumana,  as  a  volcano  ejecting  pumice  (Rapport  fait  au  Ge'ne'ral 
Victor  Hugues  par  Amic  et  Hapel  sur  le  Volcan  de  la  Basse  Terre, 
dans  la  nuit  du  7  au  8  Vendimiaire,  an  6,  pag.  46;  Humboldt,  Voyage, 
t.  i,  p.  316).  The  lower  part  of  the  mountain  is  dioritic  rock,  the  vol- 
canic cone,  the  summit  of  which  is  open,  is  trachyte,  containing  labra- 
dorite.  Lava  does  not  appear  even  to  have  flowed  in  streams  from  the 
mountain  called  on  account  of  its  usual  condition,  the  Soufriere,  either 
from  the  summit  crater,  or  from  the  lateral  fissures,  but  the  ashes  of 
the  eruptions  of  Sept.  1797,  Dec.  1836,  and  Feb.  1837,  examined  by 
the  excellent  and  much  lamented  Dufrenoy,  with  his  peculiar  accuracy, 
were  found  to  be  finely  pulverised  fragments  of  lava,  in  which  fel- 
spathic  minerals  (labradorite,  rhyakolite  and  sanidine)  were  recognisable 
together  with  pyroxene.  (See  Lherminier,  Daver,  Elie  de  Beaumont 
and  Dufrenoy,  in  the  Comptes  rend  us  de  V Acad.  des  Sc.  t.  iv,  1837, 
pp.  294;  651  and  743—749).  Small  fragments  of  quartz  have  also 


424  COSMOS. 

sources  of   information    (the   geological   and  geographical 

been  recognised  by  Deville  in  the  trachytes  of  the  soufriere,  together 
with  the  crystals  of  labradorite  (Comptes  rendus,  t.  xxxii,  p.  675),  while 
Gustav  Rose  even  iound  hexagonal-dodecahfidra  of  quartz  in  the  tra- 
chytes of  the  volcano  of  Arequipa  (Meyen,  Reise  um  dieErde,  Bd. ii,  s.  23). 
The  phenomena  here  described,  of  the  temporary  ejection  of  very 
various  mineral  productions  from  the  fissure-openings  of  a  sou- 
friere, remind  us  very  forcibly  that  what  we  are  accustomed  to  deno- 
minate a  solfatara,  soufriere  or  fumarole,  denotes  properly  speaking 
only  certain  conditions  of  volcanic  action.  Volcanoes  which  have  once 
emitted  lava ;  or,  when  that  failed,  have  ejected  loose  scoriae  of  con- 
siderable volume,  or  finally  the  same  scoriae  pulverised  by  trituration, 
pass  on  a  diminution  of  their  activity,  into  a  state  in  which  they 
yield  only  sulphur  sublimates  of  sulphurous  acid  and  aqueous  vapour. 
If  as  such  we  were  to  call  them  semi- volcanoes,  it  would  readily  convey 
the  idea  that  they  are  a  peculiar  class  of  volcanoes.  Bunsen,  to  whom 
along  with  Boussingault,  Senarmont,  Charles  Deville  and  Danbree 
science  is  indebted  for  such  important  advances  for  their  ingenious 
and  happy  application  of  chemistry  to  geology,  and  especially  to  the 
volcanic  processes,  shows  "  how,  when  in  sulphur  sublimations, 
which  almost  always  accompany  volcanic  eruptions,  the  masses  of  sul- 
phur in  the  form  of  vapour  come  in  contact  with  the  glowing  pyroxene 
rocks,  the  sulphurous  a^id  is  generated  by  the  partial  decomposition  of 
the  oxyde  of  iron  contained  in  those  rocks.  If  the  volcanic  action  then 
sinks  to  a  lower  temperature,  the  chemical  action  of  that  zone  then 
enters  into  a  new  phase.  The  sulphurous  combinations  of  iron  and 
perhaps  of  metals  of  the  earths  and  alkalies  there  produced,  commence 
their  operation  on  the  aqueous  vapour,  and  the  result  of  the  alternate 
action  is  the  generation  of  sulphuretted  hydrogen  and  the  products  of 
its  decomposition,  disengaged  hydrogen  and  sulphur  vapour." — The 
sulphur  fumaroles  outlive  the  great  volcanic  eruptions  for  centuries. 
The  muriatic  acid  fumaroles  belong  to  a  different  and  later  period. 
They  seldom  assume  the  character  of  permanent  phenomena.  The 
muriatic  acid  in  the  gases  of  craters  is  generated  in  this  way  ;  the 
common  salt  which  so  often  occurs  as  a  product  of  sublimation  in  vol- 
canoes, particularly  in  Vesuvius,  is  decomposed  in  higher  temperatures, 
itnder  the  co-operation  of  aqueous  vapour  and  silicates,  and  forms 
muriatic  acid  and  soda,  the  latter  combining  with  the  silicates  pre- 
sent. Muriatic  acid  fumaroles  which,  in  Italian  volcanoes,  are  not  un- 
frequently  on  the  most  extensive  scale,  and  are  then  generally  accom- 
panied by  immense  sublimations  of  common  salt,  seem  to  be  of  a  very 
unimportant  character  in  Iceland.  The  concluding  stages  in  the  chro- 
nological series  of  all  these  phenomena  consist  in  mere  emanations  of 
carbonic  acid.  The  hydrogen  contained  in  the  volcanic  gases  has 
hitherto  been  almost  entirely  overlooked.  It  is  present  in  the  vapour, 
springs  of  the  great  solfataras  of  Krisuvik  and  Reykjalidh  in  Iceland, 
and  is  indeed  at  both  those  places  combined  with  sulphuretted  hydro- 
gen. When  the  latter  corne  in  contact  with  sulphuric  acid,  they  are 
both  mutually  decomposed  by  the  separation  of  the  sulphur,  so  that 


TRUE   VOLCANOES.  425 

accounts  of  travels),  is  that,  out  of  407  volcanoes  cited  by 

they  can  never  occur  together.  They  are  however  not  unfrequently 
met  with  on  one  and  the  same  field  of  fumaroles  in  close  proximity  to 
each  other.  Unrecognisable  as  was  the  sulphuretted  hydrogen  gas  in 
the  Icelandic  solfataras  just  mentioned,  it  failed  on  the  other  hand  en- 
tirely in  the  solfataric  condition  assumed  by  the  crater  of  Hecla  shortly 
after  the  eruption  of  the  year  1845, — that  is  to  say,  in  the  first  phase 
of  the  volcanic  secondary  action.  Not  the  smallest  trace  of  sulphuretted 
Hydrogen  could  be  detected,  either  by  the  smell  or  by  re-agents,  while 
che  copious  sublimation  of  sulphur,  the  smell  of  which  extended  to  a 
great  distance,  afforded  indisputable  evidence  of  the  presence  of  sul- 
phurous acid.  In  fact,  on  the  approach  of  a  lighted  cigar  to  one  of  these 
fumaroles  those  thick  clouds  of  smoke  were  produced  which  Melloni 
and  Piria  have  noticed  as  a  test  of  the  smallest  trace  of  sulphuretted 
hydrogen  (Comptes  rendus,  t.  xi,  1840,  p.  352,  and  Poggendorff's  Anna- 
len,  Erganzungsband,  1842,  s.  511).  As  it  may  however  be  easily 
seen  by  experiment  that  even  sulphur  itself,  when  sublimated  with 
aqueous  vapour,  produces  the  same  phenomenon,  it  remains  doubtful 
whether  any  trace  whatever  of  sulphuretted  hydrogen  accompanied 
the  emanations  from  the  crater  of  Hecla  in  1845,  and  of  Vesuvius  in 
1843  (compare  Robert  Bunsen's  admirable  and  geologically  important 
treatise  on  the  processes  of  formation  of  the  volcanic  rock  of  Iceland, 
in  Poggend.  Annal.  Bd.  Ixxxiii,  1851.  s.  241,  244,  246,  248,  254 
and  256  ;  serving  as  an  extension  and  rectification  of  the  treatises 
of  1847  in  Wohler's  and  Liebig's  Annalen  der  Chemie  und  Phar- 
macie.  Bd.  Ixii,  s.  19).  That  the  emanations  from  the  solfatara  of 
Pozzuoli  are  not  sulphuretted  hydrogen,  and  that  no  sulphur  is 
deposited  from  them  by  contact  with  the  atmosphere,  as  Breislak  has 
conjectured  (Essai  Mineralogique  sur  la  Soufri&re  de  Pozzuoli, 
1792,  p.  128—130),  was  remarked  by  Gay-Lussac  when  I  visited  the 
Phlegrsean  Fields  with  him  at  the  time  of  the  great  eruption  of  lava  in 
the  year  1805.  That  acute  observer,  Archangelo  Scacchi  likewise  de- 
cidedly denies  the  existence  of  sulphuretted  hydrogen  (Memorie  geo- 
logiche  suUa  Campania,  1849,  p.  49 — 121),  Piria's  test  seeming  to  him 
only  to  prove  the  presence  of  aqueous  vapour ;  —  '•  Son  di  avviso  che  lo 
solfo  emane  mescolato  a  i  vapori  acquei  senza  esserein  chimica  combi- 
nazione  con  altre  sostanze," — "  I  am  of  opinion  that  the  sulphur  ema- 
nates mixed  with  aqueous  vapours  without  being  in  combination  with 
other  substances."  An  actual  analysis,  however,  long  looked  for  by  me, 
of  the  gases  ejected  by  the  solfatara  of  Pozzuoli.  has  been  very  recently 
published  by  Charles  Sainte-Claire  Deville  and  Leblanc,  and  has  com- 
pletely established  the  absence  of  sulphuretted  hydrogen  (Comptes 
rendus  de  I'Acad.  d.  Sc.  t.  xliii,  1856,  p.  746).  Sartorius  von  Waltershau- 
sen,  on  the  other  hand,  observed  on  cones  of  eruption  of  Etna,  in  1811, 
a  strong  smell  of  sulphuretted  hydrogen,  where  in  other  years  sulphu- 
rous acid  only  was  perceived.  Nor  did  Charles  Deville  discover  any  sul- 
phuretted hydrogen  at  Girgenti,  or  in  the  Macalube,  but  a  small  por- 
tion of  it  on  the  eastern  declivity  of  Etna,  in  the  spring  of  Santa 
Veneriiia.  It  is  remarkable,  that  throughout  the  important  series  o/ 


426  COSMOS. 

me,  225  have  exhibited  proofs  of  activity  in  modern  times. 
Previous  statements  of  the  number32  of  active  volcanoes 
have  given  sometimes  about  30  and  sometimes  about  50 
less,  because  they  were  prepared  on  different  principles. 
In  the  division  made  by  me.  I  have  confined  myself  to  those 
volcanoes  which  still  emit  vapours,  or  which  have  had 
historically  certain  eruptions  in  the  19th  or  in  the  latter 
half  of  the  18th  century.  There  are  doubtless  instances 
of  the  intermission  of  eruptions  which  extend  over  four 
centuries  and  more,  but  these  phenomena  are  of  very  rare 
occurrence.  We  are  acquainted  with  the  lengthened  series 
of  the  eruptions  of  Vesuvius  in  the  years  79,  203,  512,  652, 
983,  1138,  and  1500.  Previous  to  the  great  eruption  of 
Epomeo  on  Ischia  in  the  year  1302,  we  are  acquainted  only 
with  those  which  occurred  in  the  36th  and  45th  years  before 
our  era,  that  is  to  say,  55  years  before  the  eruption  of 
Vesuvius. 

Strabo,  who  died  at  the  age  of  90  under  Tiberius  (99  years 
after  the  occupation  of  Vesuvius  by  Spartacus),  and  whom 
no  historical  account  of  any  former  eruption  had  ever  reached, 
describes  Vesuvius  notwithstanding  as  an  ancient  and  long 
extinct  volcano.  "  Above  the  places "  (Herculaneum  and 
Pompeii),  he  says,  "lies  the  Mount  Vesuios,  covered  round 
by  the  most  beautiful  farms,  except  on  the  summit.  This  is 
indeed  for  the  most  part  pretty  smooth,  but  on  the  whole 
chemical  analyses  made  by  Boussingault  on  gas-exhaling  volcanoes  of 
the  Andes  (from  Purace'  and  Tolima  to  the  elevated  plains  of  las  Pastes 
and  Quito),  both  muriatic  acid  and  sulphuretted  hydrogen  (hydrogene 
sulf  ureux)  are  wanting. 

32  The  following  numbers  are  given  in  older  works  as  those  of  the 
volcanoes  still  in  a  state  of  activity : — by  Werner,  193 ;  by  Caesar  von 
Leonhard,  187;  by  Arago,  175  (Astronomic  Populaire,  t.  iii,  p.  170); 
variations  which,  as  compared  with  my  results,  all  show  a  difference 
ranging  from  £  to  TV  in  a  downward  direction,  occasioned  partly  by 
diversity  of  principle  in  judging  of  the  igneous  state  of  a  volcano,  and 
partly  by  a  deficiency  of  materials  for  forming  a  correct  judgment.  It 
is  well  known,  as  I  have  previously  remarked,  and  as  we  learn  from 
historical  experience,  that  volcanoes  which  have  been  held  to  be  extinct 
have,  after  the  lapse  of  very  long  periods,  again  become  active,  and 
therefore  the  result,  which  I  have  obtained  must  be  considered  as 
rather  too  low  than  too  high.  Leopold  von  Buch,  in  the  supplement 
to  his  masterly  description  of  the  Canary  Isles,  and  Landgrebe,  in 
his  Geography  of  Volcanoes,  have  not  attempted  to  give  any  general 
numerical  result^ 


TRUE  VOLCANOES.  427 

unfruitful,  and  having  an  ashy  appearance.  It  exhibits 
fissured  hollows  of  red-coloured  rock,  as  if  it  were  corroded 
by  fire,  so  that  it  might  be  supposed  that  this  place  had 
formerly  burned  and  had  gulphs  of  fire,  which,  however,  had 
died  away  when  the  fuel  became  consumed."  (Strabo,  lib.  v. 
page  247,  Casaub.)  This  description  of  the  primitive  form 
of  Vesuvius  indicates  neither  a  cone  of  cinders  nor  a  crater- 
like  hollowing33  of  the  ancient  summit,  such  as,  being  walled 
in,  could  have  served  Spartacus34  and  his  gladiators  for  a 
defensive  stronghold. 

33  This  description  is  therefore  totally  at  variance  with  the  often 
repeated  representation  of  Vesuvius,  according  to  Strabo,  given  in 
Poggendorffs  Annalen  der  Physik,  Bd.  xxxvii,  s.  190,  Tafel  1.  It 
is  a  very  late  writer,  Dio  Cassius,  under  Septimius  Severus,  who 
first  speaks,  not  (as  is  frequently  supposed)  of  the  production  of 
several  summits,  but  of  the  changes  of  form  which  the  summits 
have  undergone  in  the  course  of  time.  He  records  (quite  in  con- 
firmation of  Strabo)  that  the  mountain  formerly  had  everywhere  a 
flat  summit.  His  words  are  as  follows  (lib.  Ixvi,  cap.  21,  ed.  Sturz, 
vol.  iv,  1824,  p.  240): — "For  Vesuvius  is  situated  by  the  sea  near 
Naples,  and  has  numerous  sources  of  fire.  The  whole  mountain  was 
formerly  of  uniform  height,  and  the  fire  arose  from  its  centre,  for  at 
this  part  only  is  it  in  a  state  of  combustion.  Outwardly,  however,  the 
whole  of  it  is  still  down  to  our  times  devoid  of  fire.  But,  while  the 
exterior  is  always  without  conflagration,  and  the  centre  is  dried  up 
(heated)  and  converted  into  cinders,  the  peaks  round  about  it  have  still 
their  ancient  height.  But  the  whole  of  the  igneous  part,  being  con- 
sumed by  length  of  time,  has  become  hollow  by  sinking  in,  so  that  the 
whole  mountain  (if  we  may  compare  a  small  thing  with  a  great) 
resembles  an  amphitheatre."  (Comp.  Sturz,  vol.  vi,  Annot,  ii,  p.  568). 
This  is  a  clear  description  of  those  mountain-masses  which,  since  the 
year  79,  have  formed  the  margins  of  the  crater.  The  explanation  of 
this  passage,  by  referring  it  to  the  Atrio  del  Cavallo,  appears  to  me 
erroneous.  According  to  the  large  and  excellent  hypsometrical  work 
of  that  distinguished  Olmutz  astronomer,  Julius  Schmidt,  for  the  year 
1855,  the  Punta  Nasone  of  the  Somma  is  3771  feet,  the  Atrio  del 
Cavallo,  at  the  foot  of  the  Punta  Nasone,  2661,  and  the  Punta  or 
Rocca  del  Palo  (the  highest  edge  of  the  crater  of  Vesuvius  to  the 
north,  pp.  112—116;  3992  feet  high.  My  barometrical  measurements 
of  1822  (Views  of  Nature,  pp.  376—377)  gave  for  the  same  three  points 
3747  feet,  2577  feet,  and  4022  feet— showing  a  difference  of  24,  84,  and 
30  feet  respectively.  The  floor  of  the  Atrio  del  Cavallo  has,  according 
to  Julius  Schmidt  (Eruption  des  Vesuvs  im  Mai  1855,  p.  95),  undergone 
great  alterations  of  level  since  the  eruption  of  Feb.  1850. 

14  Velleius  Paterculus,  who  died  under  Tiberius,  mentions  Vesuvius, 
it  is  true,  as  the  mountain  which  Spartacus  occupied  with  his  gladiators 
(ii.  30),  while  Plutarch,  in  his  Biography  of  Crassus,  cap.  ii,  speaks  only 


428  COSMOS. 

Diodorus  Siculus,  likewise  (lib.  iv.  cap.  21,  5),  who  lived 
tinder  Caesar  and  Augustus,  in  his  account  of  the  progress  of 
-Hercules  and  his  battles  with  the  giants  in  the  Phlegreean 
Fields,  describes  "  what  is  now  called  Vesuvius  as  a  Xo'0os, 
which,  like  Etna  in  Sicily,  once  emitted  a  great  deal  of  fire, 
and  (still)  shows  traces  of  its  former  ignition."  He  calls  the 
whole  space  between  Cumse  and  Naples  the  Phlegrsean  Fields, 
as  Polybius  does  the  still  greater  space  between  Capua  and 
Nola  (lib.  ii,  cap.  17),  while  Strabo  (lib.  v,  page  246)  describes 
with  much  local  truth  the  neighbourhood  of  Puteoli  (Dic«- 
archia),  where  the  great  Solfatara  lies,  and  calls  it  '  Upaiarov 
(i ryopd.  In  later  times  the  name  of  TO,  (pXe^oam  TreSi'a  is 
ordinarily  confined  to  this  district,  as  at  this  day  geologists 
place  the  mineralogical  composition  of  the  lavas  of  the 
Phlegrsean  Fields  in  opposition  to  those  from  the  neighbour- 
hood of  Vesuvius.  The  same  opinion  that  in  ancient  times 
there  was  fire  burning  within  Vesuvius,  and  that  that 
mountain  had  formerly  had  eruptions,  is  most  distinctly 
expressed  in  the  architectural  work  of  Vitruvius  (lib.  ii, 
cap.  6),  in  a  passage  which  has  hitherto  not  been  sufficiently 
regarded : — "  Non  minus  etiam  memoratur,  antiquitus  crevisse 
ardores  et  abundavisse  sub  Vesuvio  monte,  et  inde  evomuisse 
circa  agros  flammam.  Ideoque  nunc  qui  spongia  sive  pumex 
Pompejanus  vocatur,  excoctus  ex  alio  genere  lapidis,  in  hanc 
redactus  esse  videtur  generis  qualitatem.  Id  autem  genus 
spongise,  quod  inde  eximitur,  non  in  omnibus  locis  nascitur, 
nisi  circurn  ^Etnam,  et  collibus  Mysise,  qui  a  Graecis  /caTa/ee- 
Kavuevoi  nominantur."  It  is  also  related  that  in  ancient 
times  the  fire  increased  and  abounded  beneath  Mount 
Vesuvius,  and  vomited  out  flame  from  thence  on  the  fields 
around.  So  that  now  what  is  called  spongia,  or  Pompeian 
pumex,  baked  out  of  some  other  kind  of  stone,  seems  to  have 
been  reduced  to  this  kind  of  substance.  But  that  kind  of 
spongia  which  is  got  out  of  there  is  not  produced  in  all 
of  a  rocky  district,  having  a  single  narrow  entrance.  The  servile  war 
of  Spartacus  took  place  in  the  681st  year  of  Rome,  or  152  years  before  the 
eruption  of  Vesuvius  described  by  Pliny  (24th  August,  79,  A.D.).  The 
circumstance  that  Floras,  a  writer  who  lived  in  the  time  of  Trajan,  and 
who,  being  acquainted  with  the  eruption  just  referred  to,  knew  what 
was  hidden  in  the  interior  of  the  mountain,  calls  it  "cavus,"  proves 
nothing,  as  others  have  already  observed,  for  its  earlier  configuration 
(Florus,  lib.  i,  cap.  16,  "Vesuvius  mons,  ^Etnsei  ignis  imitator;"  lib. iii, 
cap.  20,-" fauces  cavi  mentis)." 


TRUE  VOLCANOES.  429 

places,  only  around  ^Etna  and  on  the  hills  of  Mysia,  which 
are  called  by  the  Greeks  KaraKeKavpevoi.)  Now,  it  can  no 
longer  be  doubted,  since  the  investigations  of  Bockh  and 
Hirt,  that  Vitruvius  lived  in  the  time  of  Augustus,36  and 
consequently  a  full  century  before  the  eruption  of  Vesuvius, 
at  which  the  elder  Pliny  met  his  death.  The  passage  thus 
quoted,  therefore,  and  the  expression  pumex  Pompeianus 
(thus  connecting  pumice-stone  with  Pompeii),  present  a 
special  geological  interest  in  relation  to  the  question  raised 
as  to  whether,  according  to  the  acute  conjecture  of  Leopold 
von  Buch,36  Pompeii  was  overwhelmed  only  by  the  pumiceous 
tufa-beds  thrown  up  on  the  first  formation  of  Mount  Somma; 
these  beds,  which  are  of  submarine  formation,  covering  in 
horizontal  layers  the  whole  level  between  the  Apennine 
range  and  the  west  coast  of  Capua  as  far  as  Sorento,  and 
from  Nola  to  the  other  side  of  Naples, — or  whether  Vesuvius 
itself,  entirely  contrary  to  its  present  habit,  ejected  the 
pumice  from  its  interior. 

Both  Carmine  Lippi,37  who  (1816)  describes  the  tufa 
covering  of  Pompeii  as  an  aqueous  deposit,  and  his  ingenious 
opponent  Archangelo  Scacchi,38  in  the  letter  addressed  to  the 
Cavaliere  Francesco  Avellino  (1843),  have  directed  attention 
to  the  remarkable  phenomenon  that  a  portion  of  the  pumice 
of  Pompeii  and  Mount  Somma  contains  small  fragments 
of  chalk  which  have  not  lost  their  carbonic  acid,  a  circum- 
stance which,  on  the  supposition  that  they  have  been  exposed 
to  a  great  pressure  during  their  igneous  formation,  can 
excite  but  little  surprise.  I  have  myself  had  the  opportunity 

35  At  all  events  Vitruvius  wrote  earlier  than  the  elder  Pliny,  as  is 
evident,  not  merely  because  he  is  three  separate  times  cited  by  Pliny 
in  his  list  of  authorities,  so  unjustly  attacked  by  the  English  translator 
Newton  (lib.  xvi,  xxxv,  and  xxxvi),  but  because  in  book  xxxv,  cap.  14, 
s.  170 — 172,  as  has  been   distinctly  proved  by  Sillig   (vol.  v,    1851, 
p.  277)  and  Brunn  (Diss.  de  auctorum  indicibus  Plinianis,  Bonnae,  1856, 
pp.  55 — 60),  a  passage  has  actually  been  extracted  from  Vitruvius  by 
Pliny  himself.     See  also  Sillig's  edition  of  Pliny,  vol.  v,  p.  272.     Hirt, 
in  his  Essay  on  the  Pantheon,  places  the  date  of  Vitruvius's  writings  on 
Architecture  between  the  years  16  and  14  of  our  era. 

36  Poggendorff  s  Annalen,  Bd.  xxxvii,  s.  175 — 180. 

3^  Carmine  Lippi :  Fu  il  fuoco  o  Vacqua  eke  sottcrd  Pompei  ed 
Ercolanol  (1816)  p.  10. 

'•&  Scacchi,  Osservaziom  cntichc  sulla  maniera  come  fu  seppcllita 
fAntica  Pompei,  1843,  pp.  8—10. 


430  COSMOS. 

of  seeing  specimens  of  this  pumice-stone  in  the  interesting 
geological  collections  of  my  learned  friend  and  academical 
colleague,  Dr.  Ewald.  The  similarity  of  the  mineralogical 
constitution  at  two  opposite  points  naturally  gives  rise  to 
the  question, — whether  that  which  covers  Pompeii  has  been 
thrown  down,  as  Leopold  vcn  Buch  supposes,  during  the 
eruption  of  the  year  79,  from  the  declivities  of  Somma, — or 
whether,  as  Scacchi  maintains,  the  newly-opened  crater  of 
Vesuvius  has  ejected  pumice  simultaneously  on  Pompeii  aiid 
on  Somma?  What  was  known  as  pumex  Pompejanus  in 
the  time  of  Vitruvius,  under  Augustus  ,carries  us  back  to 
eruptions  before  the  time  of  Pliny,  and  from  the  experience 
we  have  respecting  the  variable  nature  of  the  formations  in 
different  ages  and  different  circumstances  of  volcanic  activity, 
we  should  be  as  little  warranted  in  absolutely  denying  that, 
since  its  first  existence,  Vesuvius  could  have  ejected  pumice, 
as  we  should  be  in  absolutely  taking  it  for  granted  that 
pumice — that  is  to  say,  the  fibrous  or  porous  condition  of  a 
pyrogenous  mineral — could  only  be  formed  where  obsidian 
or  trachyte  with  vitreous  felspar  (sanidine)  were  present. 

Although,  from  the  examples  which  have  been  cited  of  the 
length  of  the  periods  at  which  the  revival  of  a  slumbering 
volcano  may  take  place,  it  is  evident  that  much  uncertainty 
must  still  remain,  yet  it  is  of  great  importance  to  verify 
the  geographical  distribution  of  burning  volcanoes  for  a 
determinate  period.  Of  the  225  open  craters  through  which, 
in  the  middle  of  the  19th  century,  the  molten  interior  of 
the  earth  maintains  a  volcanic  communication  with  the 
atmosphere,  70,  that  is  to  say,  one-third,  are  situated  on  the 
continents,  and  155,  or  two-thirds,  on  the  islands  of  our 
globe.  Of  the  70  continental  volcanoes,  53,  or  three-fourths, 
belong  to  America,  15  to  Asia,  1  to  Europe,  and  1  or  2  to 
that  portion  of  the  continent  of  Africa  hitherto  known  to  us. 
In  the  South-Asiatic  islands  (the  Sundas  and  Moluccas),  as 
well  as  in  the  Aleutian  and  Kurile  Islands,  the  greatest  num- 
ber of  the  island  volcanoes  are  situated  in  a  very  limited 
space.  The  Aleutian  Isles  contain,  perhaps,  more  volcanoes 
active  in  late  historical  times  than  the  whole  continent  of 
South-America.  On  the  whole  surface  of  the  earth,  the  tract 
containing  the  greatest  number  of  volcanoes  is  that  which 
ranges  between  73°  west  and  127°  east  longitude,  and 


TRUE  VOLCANOES.  431 

between  47°  south  and  66°  north  latitude,  in  a  direction 
from  south-east  to  north-west. 

If  we  suppose  the  great  gulph  of  the  sea,  known  under 
the  name  of  the  South  Sea,  or  South  Pacific  Ocean,  to  be 
cosmically  bounded  by  the  parallel  of  Behring's  Straits,  and 
that  of  New  Zealand,  which  is  also  the  parallel  of  South 
Chili  and  North  Patagonia,  we  shall  find — and  this  result 
is  very  remarkable — in  the  interior  of  the  basin,  as  well 
as  around  it  (on  its  Asiatic  and  American  continental  boun- 
daries), 198,  or  nearly  seven-eighths  of  the  225  still  active 
volcanoes  of  the  whole  earth.  The  volcanoes  nearest  the 
poles  are,  so  far  as  our  present  geographical  knowledge  goes, 
in  the  northern  hemisphere  the  volcano  Esk,  on  the  small 
island  of  Jan  Meyen,  in  lat.  71°  1',  and  west  long.  7°  30' 30", 
and  in  the  southern  hemisphere  Mount  Erebus,  whose  red 
flames  are  visible  even  by  day,  and  which  Sir  James  Ross,39 
on  his  great  southern  voyage  of  discovery  in  1841,  found  to 
be  12,400  feet  high,  or  about  240  feet  higher  than  the  Peak 
of  Teneriffe,  in  lat.  77°  33',  and  long.  166°  58'  30"  east. 

The  great  number  of  volcanoes  on  the  islands  and  on 
the  shores  of  continents  must  have  early  led  to  the  investi- 
gation by  geologists  of  the  causes  of  this  phenomenon.  I 
have  already,  in  another  place  (Cosmos,  vol.  i,  p.  242),  men- 
tioned the  confused  theory  of  Trogus  Pompeius  under  Augus- 
tus, who  supposed  that  the  sea- water  excited  the  volcanic  fire. 
Chemical  and  mechanical  reasons  for  this  supposed  effect  of 
the  sea  have  been  adduced  to  the  latest  times.  The  old 
hypothesis  of  the  sea- water  penetrating  into  the  volcanic 
focus  seemed  to  acquire  a  firmer  foundation  at  the  time  of  the 
discovery  of  the  metals  of  the  earth  by  Davy,  but  the  great 
discoverer  himself  soon  abandoned  the  theory  to  which  even 
Gay-Lussac  inclined,40  in  spite  of  the  rare  occurrence,  or  total 
absence  of  hydrogen  gas.  Mechanical,  or  rather  dynamical 
causes,  whether  sought  for  in  the  contraction  of  the  upper 
crust  of  the  earth  and  the  rising  of  continents,  or  in  the 
locally  diminished  thickness  of  the  inflexible  portion  of  the 

39  Sir  James  Ross,  Voyage  to  the  Antartic  Regions,  vol.  i,  pp.  217, 
220,  and  3C4. 

40  Gay-Lussac,  Reflexions  sur  les  Volcans  in  the  Annales  dc  Chimie  ct 
de  Physique,  t.  xxii,  1823,  p.  429 ;  see  above,  p.  169 ;  Arago,  (Euvret 
completes,  t.  iii,  p.  47. 


432  COSMOS. 

earth's  crust,  might,  in  my  opinion,  offer  a  greater  appearance 
of  probability.  It  is  not  difficult  to  imagine  that  at  the 
margins  of  the  up-heaving  continents  which  now  form  the 
more  or  less  precipitous  littoral  boundary  visible  over  the 
surface  of  the  sea,  fissures  have  been  produced  by  the  simul- 
taneous sinking  of  the  adjoining  bottom  of  the  sea,  through 
which  the  communication  with  the  molten  interior  is  pro- 
moted. On  the  ridge  of  the  elevations,  far  from  that  area 
of  depression  in  the  oceanic  basin,  the  same  occasion  for 
the  existence  of  such  rents  does  not  exist.  Volcanoes  follow 
the  present  sea-shore  in  single,  sometimes  double,  and  some- 
times even  triple  parallel  rows.  These  are  connected  by 
short  chains  of  mountains,  raised  on  transverse  fissures,  and 
forming  mountain-nodes.  The  range  nearest  to  the  shore  is 
frequently  (but  by  110  means  always)  the  most  active,  while 
the  more  distant,  those  more  in  the  interior  of  the  country, 
appear  to  be  extinct  or  approaching  extinction.  It  is  some- 
times thought  that,  in  a  particular  direction  in  one  and  the 
same  range  of  volcanoes,  an  increase  or  diminution  in  the 
frequency  of  the  eruptions  may  be  perceived,  but  the  pheno- 
mena of  renewed  activity  after  long  intervals  of  rest  render 
this  perception  very  uncertain. 

As  many  incorrect  statements  of  the  distance  of  volcanic 
activity  from  the  sea  are  circulated,  either  through  ignorance 
of,  or  inattention  to,  the  exact  localities  both  of  the  volcanoes 
and  of  the  nearest  points  of  the  coast,  I  shall  here  give  the 
following  distances  in  geographical  miles  (each  being  equal 
to  about  2030  yards,  or  60  to  a  degree)  : — In  the  Cordilleras 
of  Quito,  the  volcano  of  Sangay,  which  discharges  uninter- 
ruptedly, is  situated  in  the  most  easterly  direction,  but  its 
distance  from  the  sea  is  still  112  miles.  Some  very  intelli- 
gent monks  attached  to  the  mission  of  the  Indies  Andaquies 
at  the  Alto  Putumayo  have  assured  me  that  on  the  upper 
Rio  de  la  Fragua,41  a  tributary  of  the  Caqueta,  to  the  eastward 
of  the  Ceja,  they  had  seen  smoke  issue  from  a  conical  moun- 

41  The  position  of  the  Volcan  de  la  Fragua,  as  reduced  at  Timana,  is 
N.  L.  1°  48',  long.  75°  30'  nearly.  Compare  the  Carte  Hypsometrique 
des  Nceuds  de  Montagnes  dans  les  Cordilleres,  in  the  large  atlas  of  my 
travels,  1831,  pi.  5,  see  also  pi.  22  and  24.  This  mountain,  lying 
isolated  and  so  far  to  the  east,  ought  to  be  visited  by  a  geologist 
capable  of  determining  the  longitude  and  latitude  astronomically. 


TRUE  VOLCANOES.  433 

tain  of  no  great  height,  and  whose  distance  from  the  coast 
must  have  been  160  miles.  The  Mexican  volcano  of  Jorullo, 
which  was  elevated  above  the  surface  in  September,  1759,  is 
84  miles  from  the  nearest  point  of  the  sea-shore  (see  above, 
pp.  314-321) ;  the  volcano  of  Popocatepetl  is  132  miles;  an 
extinct  volcano  in  the  eastern  Cordilleras  of  Bolivia,  near  S. 
Pedro  de  Cacha,  in  the  vale  of  Yucay  (see  above,  p.  295), 
is  upwards  of  180  miles ;  the  volcanoes  of  the  Siebenge- 
birge,  near  Bonn,  and  of  the  Eifel  (see  above,  p.  231 — 238), 
are  from  132  to  152  miles;  those  of  Auvergne,  Velay,  and 
Vivarais,43  distributing  them  into  three  separate  groups  (the 
group  of  the  Puy  de  Dome,  near  Clermont,  with  the  Mont 
Dore,  the  group  of  the  Cantal.  and  the  group  of  the  Puy  and 
Mezenc),  are  severally  148,  116,  and  84  miles  distant  from 
the  sea.  The  extinct  volcanoes  of  Olofc,  south  of  the  Pyrenees, 
west  of  Gerona,  with  their  distinct  and  sometimes  divided 
lava-streams,  are  distant  only  28  miles  from  the  Catalonian 
shores  of  the  Mediterranean,  while,  on  the  other  hand,  the 
undoubted,  and  to  all  appearances  very  lately  extinct,  vol- 
canoes in  the  long  chain  of  the  Rocky  Mountains,  in  the 
north-vest  of  America,  are  situated  at  a  distance  of  from  600 
to  680  miles  from  the  shore  of  the  Pacific. 

A  very  abnormal  phenomenon  in  the  geographical  distri- 
bution of  volcanoes  is  the  existence  in  historical  times  of 
active,  and  partially,  perhaps,  even  of  burning  volcanoes  in 
the  mountain-chain  of  the  Thian-shan  (the  Celestial  Moun- 
tains), between  the  two  parallel  chains  of  the  Altai  and  the 
Kueii-lun.  The  existence  of  these  volcanoes  was  first  made 
known  by  Abel-Rernusat  and  Klaproth,  and  I  have  been 
enabled,  by  the  aid  of  the  able  and  laborious  investigations  of 

42  In  these  three  groups  which,  according  to  the  old  geographical 
nomenclature,  belong  to  Auvergne,  the  Vivarais,  and  the  Velay,  the 
distances  given  in  the  text  are  those  of  the  northernmost  parts  of  each 
group  as  taken  from  the  Mediterranean  Sea  (between  the  Golfe  d'Aigues 
Mortes  and  Cette).  In  the  first  group,  that  of  the  Puy  de  Dome,  a 
crater  erupted  in  the  granite  near  Man/at,  called  Le  Gour  de  Tazena, 
is  taken  as  the  most  northerly  point  (Rozet.  in  the  Mem.  de  la  Societe 
Geol.  de  France,  t.  i,  1844,  p.  119).  Farther  south  than  the  group  of 
the  Cantal,  and  therefore  nearest  the  sea-shore,  lies  the  small  volcanic 
district  of  la  Guiolle  near  the  Monts  d'Aubrac,  norta-west  of  Chirac, 
and  distant  scarcely  72  geographical  miles  from  the  sea.  Compare  tL» 
Carte  Geotoyique  de  la  France,  1841. 

VOL.    V.  2  F 


434  COSMOS. 

Stanislas  Julien,  to  treat  of  them  fully  in  my  work  on  Central 
Asia.43     The  relative  distances  of  the  volcano  of  Pe-.shan 

43  Humboldt,  Asie  Centrale,  t.  ii,  pp.  7 — 61,  216,  and  335—364; 
Cosmos,  vol.  i,  p.  244.  The  mountain-lake  of  Issikul,  on  the  northern 
slope  of  the  Thian-shan,  which  was  lately  visited  for  the  first  time  by 
Eussian  travellers,  I  found  marked  on  the  famous  Catalonian  map  of 
1374,*  which  is  preserved  as  a  treasure  among  the  manuscripts  of  the 
Paris  library.  Strahlenberg,  in  his  work  entitled  Der  nb'rdliche  und 
ostliclie  Theil  von  Europa  und  Asien  (Stockholm,  1730,  s.  327),  has  the 
merit  of  having  first  represented  the  Thian-shan  as  a  peculiar  and  inde- 
pendent chain,  without  however  being  aware  of  its  volcanic  action.  He 
gives  it  the  very  indefinite  name  of  Mousart,  which, — as  the  Bolor  was 
designated  by  the  general  title  of  M  us  tag,  which  particularizes  nothing, 
and  merely  indicates  snow, — has  for  a  whole  century  occasioned  an 
erroneous  representation,  and  an  absurd  and  confused  nomenclature  of 
the  mountain-ranges  to  the  north  of  the  Himalaya,  confounding  meridian 
and  parallel-chains  with  each  other.  Mousart  is  a  corruption  of  the 
Tartaric  word  Muztay,  synonymous  with  our  expression  snowy  chain, 
the  Sierra  Nevada  of  the  Spaniards,  the  Himalaya  in  the  Institutes  of 
Menu, — signifying  the  habitation  (alaya)o£  snow(/ama),  and  the  Sineshan 
of  the  Chinese.  Eleven  hundred  years  before  Strahleuberg  wrote,  under 
the  dynasty  of  Sui,  in  the  time  of  Dagobert,  king  of  the  Franks,  the 
Chinese  possessed  maps,  constructed  by  order  of  the  Government,  of 
the  countries  lying  between  the  Yellow  River  and  the  Caspian 
Sea,  on  which  the  Kuen-liin  and  the  Thian-shan  were  marked.  It  was 
undoubtedly  these  two  chains,  but  especially  the  first,  as  I  think  I  have 
shown  in  another  place  (Asie  Centr.  t.  i,  pp.  118 — 129,  194—203,  and 
t.  ii,  p.  413—425),  which,  when  the  march  of  the  Macedonian  army 
had  brought  the  Greeks  into  closer  acquaintance  with  the  interior  of 
.Asia,  spread  among  their  geographers  the  knowledge  of  a  belt  of 
mountains  extending  from  Asia  Minor  to  the  eastern  sea,  from  India 
and  Scythia  to  Thin®,  thus  cutting  the  whole  continent  into  two 
halves  (Strabo,  lib.  i,  p.  68,  lib.  xi,  p.  490).  Dicsearchus,  and  after  him 
Eratosthenes,  denominated  this  chain  the  elongated  Taurus;  the 
Himalaya  chain  is  included  under  this  appellation.  "  That  which 
bounds  India  on  the  north,"  we  are  expressly  told  by  Strabo  (lib.  xv, 
p.  689),  "  from  Ariane  to  the  eastern  sea,  is  the  extremest  portions  of 
the  Taurus,  which  are  separately  called  by  the  natives  Paropamisos, 
Emodon,  Imaon,  and  other  names,  but  which  the  Macedonians  call  the 
Caucasus."  In  a  previous  part  of  the  book,  in  describing  Pactriana  and 
Sogdiana  (lib.  xi,  p.  519),  he  says,  "the  last  portion  of  the  Taurus, 
which  is  called  Imaon,  touches  the  Indian  (eastern)  Sea."  The  terms 
"on  this  side  and  on  that  side  the  Taurus,"  had  reference  to  what  was 


[*  This  curious  Spanish  map  was  the  result  of  the  great  commercial 
relations  which  existed  at  that  time  between  Majorca  and  Italy,  Egypt 
and  India.  See  a  more  full  notice  of  it  in  Asie  Centrale,  loc.  cit. — TK.] 


TRUE   VOLCANOES.  435 

(Mont  Blanc)  with  its  lava-streams,  and  the  still  burning 

believed  to  be  a  single  range  running  east  and  west ;  that  is  to  say,  a 
parallel-chain.  Strabo  was  aware  of  this,  for  he  says,  "  the  Greeks  call 
the  half  of  the  region  of  Asia  looking  to  the  north  this  side  the  Taurus, 
and  the  half  towards  the  south  that  side"  (lib.  ii,  p.  129).  In  the  later 
times  of  Ptolemy,  however,  when  commerce  in  general,  and  particularly 
the  silk-trade,  became  animated,  the  appellation  of  Imaus  was  trans- 
ferred to  a  meridian  chain,  the  Bolor,  as  many  passages  of  the  6th  book 
show  (Asie  Centr.  t.  i,  pp.  146—162).  The  line  in  which,  parallel  to  the 
equator,  the  Taurus  range  intersects  the  whole  region,  according  to 
Hellenic  ideas,  was  first  called  by  Dicaearchus,  a  pupil  of  the  Stagirite, 
a  Diaphragma  (partition-wall),  because,  by  means  of  perpendicular  lines 
drawn  from  it,  the  geographical  width  of  other  points  could  be  measured. 
The  diaphragma  was  the  parallel  of  Rhodes,  extended  on  the  west  to 
the  pillars  of  Hercules,  and  on  the  east  to  the  coast  of  Thinse  (Agathe- 
meros  in  Hudson's  Geogr.  Gr.  Min.,  vol.  ii,  p.  4).  The  divisional  line  of 
Dicaearchus,  equally  interesting  in  a  geological  and  an  orographical  point 
of  view,  passed  into  the  work  of  Eratosthenes,  who  mentions  it  in  the 
3rd  book  of  his  description  of  the  earth,  in  illustration  of  his  table  of 
the  inhabited  world.  Strabo  places  so  much  importance  on  this  direc- 
tion and  partition  line  of  Eratosthenes  that  he  (lib.  i,  p.  65)  thinks  it 
possible  "  that  on  its  eastern  extension,  which  at  Thinse  passes  through 
the  Atlantic  Sea,  there  might  be  the  site  of  another  inhabited  world, 
or  even  of  several  worlds ;"  although  he  does  not  exactly  predict  that 
they  will  be  found  to  exist.  The  expression  "Atlantic  Sea"  may 
seem  remarkable  as  used  instead  of  the  "  eastern  sea,"  as  the  south  sea 
(the  Pacific)  is  usually  called,  but  as  our  Indian  Ocean,  south  of  Bengal, 
is  called  in  Strabo  the  Atlantic  South  Sea,  so  were  both  seas  to  the 
south-east  of  India  considered  to  be  connected,  and  were  frequently 
confounded  together.  Thus,  we  read,  lib.  ii,  p.  130,  "  India,  the  largest 
and  most  favoured  country,  which  terminates  at  the  eastern  sea  and 
at  t'iie  Atlantic  South  Sea,"  and  again,  lib.  xv,  p.  689,  "the  southern 
and  eastern  sides  of  India,  which  are  much  larger  than  the  other  sides, 
run  into  the  Atlantic  Sea,"  in  which  passage,  as  well  as  in  the  one 
above  quoted  regarding  Thinse  (lib.  i,  p.  65),  the  expression  "  eastern  sea" 
is  even  avoided.  Having  been  uninterruptedly  occupied  since  the  year 
1792  with  the  strike  and  inclination  of  the  mountain-strata,  and  their 
relation  to  the  bearings  of  the  ranges  of  mountains,  I  have  thought 
it  right  to  point  attention  to  the  fact  that,  taken  in  the  mean,  the 
equatorial  distance  of  the  Kuen-liin,  throughout  its  whole  extent,  as 
well  as  in  its  western  prolongation  by  the  Hindu-Kho,  points  towards 
the  basin  of  the  Mediterranean  Sea  and  the  Straits  of  Gibraltar  (Asie 
Centr.,  t.  i,  pp.  118 — 127,  and  t.  ii,  pp.  115 — 118),  and  that  the  sinking 
of  the  bed  of  the  sea  in  a  great  basin  which  is  volcanic,  especially  on 
the  northern  margin,  may  very  possibly  be  connected  with  this  up- 
heaval and  folding  in.  My  friend,  Elie  de  Beaumont,  so  thoroughly 
acquainted  with  all  that  relates  to  geological  bearing?,  is  opposed  to 
these  views  on  loxodromical  principles  (Notice  sur  les  Syttcmcs  de 
Afontagnes,  1852,  t.  ii,  p.  667). 

2F2 


436  COSMOS. 

igneous  mountain  (Hot&cheu)  of  Turfan,  from  the  shores  of 
the  Polar  Sea  and  the  Indian  Ocean,  are  almost  equally  great, 
about  1480  and  1520  miles.  On  the  other  hand,  the  distance 
of  Pe-shan,  whose  eruptions  of  lava  are  separately  recorded, 
from  the  year  89  of  our  era  up  to  the  7th  century,  in  Chinese 
works,  from  the  great  mountain-lake  of  Issikul  to  the  descent 
of  the  Temurtutagh  (a  western  portion  of  the  Thian-shan)  is 
only  172  miles,  while  from  the  more  northerly  situated  lake 
of  Balkasch,  148  miles  in  length,  it  is  208  miles  distant.4* 
•  The  great  Dsaisang  lake,  in  the  neighbourhood  of  which  I  was 
during  my  stay  in  the  Chinese  Dsungarei  in  1829,  is  360  miles 
distant  from  the  volcanoes  of  Thian-shan.  Inland  waters 
are  therefore  not  wanting,  but  they  are  certainly  not  in  such 
propinquity  as  that  which  the  Caspian  Sea  bears  to  the  still 
active  volcano  of  Demavend  in  the  Persian  Mazenderan. 

While,  however,  basins  of  water,  whether  oceanic  or  in- 
land, may  not  be  requisite  for  the  maintenance  of  volcanic 
activity,  —  yet,  if  islands  and  coasts,  as  I  am  inclined  to 
believe,  abound  more  in  volcanoes  only  because  the  elevation 
of  the  latter,  produced  by  internal  elastic  forces,  is  accom- 
panied by  a  neighbouring  depression  in  the  basin  of  the  sea,45 
so  that  an  area  of  elevation  borders  on  an  area  of  depres- 
sion, and  that  at  this  bordering-line  large  and  deeply  pene- 
trating fissures  and  rents  are  produced,  —  it  may  be  supposed 
that  in  the  central  Asiatic  zone,  between  the  parallels  of 
41°  and  48,°  the  great  Aralo-Caspian  area  of  depression,  as 
well  as  the  large  number  of  lakes,  whether  disposed  in  ranges 
or  otherwise,  between  the  Thian-shan  and  the  Altai-Kurts- 
chum,  may  have  given  rise  to  littoral  phenomena.  We  know 
from  tradition  that  many  small  basins  now  ranged  in  a  row 
like  a  string  of  beads  (lacs  a  chapelet}  once  upon  a  time 
formed  a  single  large  basin.  Many  large  lakes  are  seen  to 
divide  and  form  smaller  ones  from  the  disproportion  be- 
tween precipitation  and  evaporation.  A  very  experienced 
observer  of  the  Kirghis  Steppe,  General  Genz  of  Oren- 
burg, has  conjectured  that  there  formerly  existed  a  water- 


44  See  above,  p.  358. 

45  See  Arago,  Sur  la  cause  de  la  depression  d'une  grande  partie 
de  1'Asie  et  sur  le  phenomene  que  les  pentes  les  plus  rapides  des 
chaines  de  montagnes   sont  (ge'ueralement)  tourne'es  vers  la  r 

plus  voisine,  in  his  Astronomie  Populaire,  t.  iii.  pp.  1266—1274. 


rner    la 


TRUE   VOLCANOES.  437 

communication  between  the  Sea  of  Aral,  the  Aksakal, 
the  Sary-Kupa  and  the  Tschagli.  A  great  furrow  is 
observed,  running  from  south-west  to  north-east,  which 
may  be  traced  by  the  way  of  Omsk,  between  Irtisch  and 
Obi,  through  the  steppe  of  Barabinsk,  which  abounds  in 
lakes,  towards  the  moory  plains  of  the  Samoiedes,  towards 
Beresow  and  the  shore  of  the  Arctic  Ocean.  With  this 
furrow  is  probably  connected  the  ancient  and  wide-spread 
tradition  of  a  Sitter  Lake  (called  also  the  Dried  Lake, 
Hanhai)  which  extended  eastward  and  southward  from 
Hanii,  and  in  which '  a  portion  of  the  Gobi,  whose  salt  and 
reedy  centre  was  found  by  Dr.  von  Bunge's  careful  baro- 
metrical measurement  to  be  only  2558  feet  above  the  level 
of  the  sea,  rose  in  the  form  of  an  island.46  It  is  a  geological 
fact,  which  has  not  hitherto  received  its  due  share  of  atten- 
tion, that  seals,  exactly  similar  to  those  which  inhabit  the 
Caspian  Sea  and  the  Baikal  in  shoals,  are  found  upwards  of 
400  miles  to  the  east  of  the  Baikal  in  the  small  fresh-water 
lake  of  Oron,  only  a  few  miles  in  circumference.  The  lake 
is  connected  with  the  Witim,  a  tributary  of  the  Lena,  in 
which  there  are  no  seals.47  The  present  isolation  of  these 
animals  and  their  distance  from  the  mouth  of  the  Volga 
(fully  3600  geographical  miles)  form  a  remarkable  geological 
phenomenon,  indicative  of  an  ancient  and  extensive  con- 
nection of  waters.  Can  it  be  that  the  numerous  depressions 
to  which,  throughout  a  large  tract  of  country,  this  central 
part  of  Asia  has  been  exposed,  have  called  forth  exception- 
ally, on  the  convexity  of  the  continental  swelling,  conditions 
similar  to  those  pi^oduced  on  the  littoral  borders  of  the  fis- 
sures of  elevation  ? 

From  reliable  accounts  rendered  to  the  Emperor  Kanghi, 
we  are  acquainted  with  the  existence  of  an  extinct  volcano 
far  to  the  east,  iu  the  north-western  Mantschurei,  in  the 
neighbourhood  of  Mergen  (probably  in  lat.  48^°  and  long. 
122°  20'  east).  The  eruption  of  scoriae  and  lava  from  the 
mountain  of  Bo-shan  or  Ujun-Holdongi  (the  Nine  Hills) 

46  Klaproth,  Asia  Polyglotta,  p.  232,  and  Memoires  relatifs  &  TAsie 
(from  the  Chinese  Encyclopedia,  published  by  command  of  the  Em- 
peror Kang-hi,  in  1711),  t.  ii.  p.  342  ;  Humboldt,  Asie  Centrale,  t.  ii, 
pp.  125  and  135—143. 

4?  Pallas,  Zoographia  Rosso-Asiatica,  1811,  p.  115. 


438  COSMOS. 

from  12  to  16  miles  in  a  south-westerly  direction  from 
Margen,  took  place  in  January  1721.  The  mounds  of  scoriae 
thrown  out  on  that  occasion,  according  to  the  report  of  the 
persons  sent  by  the  Emperor  Kanghi  to  investigate  the  cir- 
cumstances, were  24  geographical  miles  in  circumference  ;  it 
was  likewise  mentioned  that  a  stream  of  lava,  damming  up 
the  water  of  the  river  Udelin,  had  formed  a  lake.  In  the 
7th  century  of  our  era  the  Bo-shan  is  said  to  have  had  a 
previous  igneous  eruption.  Its  distance  from  the  sea  is 
about  420  geographical  miles,  similar  to  that  of  the  Him- 
alaya/8 so  that  it  is  upwards  of  three  times  more  distant  than 

B  It  is  not  in  the  Himalaya  range,  near  the  sea  (some  portions  of  it 
between  the  colossai  Kunchinjinga  and  Shamalari,  approach  the  shore 
of  the  Bay  of  Bengal  within  428  aud  376  geographical  miles),  that  the 
volcanic  action  has  first  burst  forth,  but  in  the  third,  or  interior, 
parallel  chain,  the  Thian-shan,  nearly  four  times  as  far  removed  from 
the  same  shore,  and  that  under  very  special  circumstances,  the  subsi- 
dence of  ground  in  the  neighbourhood  deranging  strata  and  causing 
fissures.  We  learn  from  the  study  of  the  geographical  works  of  the 
Chinese,  first  instigated  by  me  and  afterwards  continued  by  my  friend 
Stanislas  Julien,  that  the  Kuen-lun,  the  northern  boundary  range  of 
Tibet,  the  Tsi-shi-shan  of  the  Mongols,  also  possesses  in  the  hill  of 
Shin-Khieu  a  cavern  emitting  uninterrupted  flames  (Asie  Centrale,  t.  ii, 
pp.  427 — 467  and  483).  The  phenomenon  seems  to  be  quite  analogous 
to  the  Chimasra  in  Lycia,  which  has  now  been  burning  for  several 
thousands  of  years  (see  above,  p.  256 — 7,  and  note  51) ;  it  is  not  a 
volcano,  but  a  fire-spring,  diffusing  to  a  great  distance  an  agreeable 
odour  (probably  from  containing  r aphtha?).  The  Kuen-liin  which, 
like  me  in  the  Asie  Centrale  (t.  i,  p.  127  and  t.  ii,  p.  431),  Dr.  Thomas 
Thomson,  the  learned  botanist  of  Western  Tibet  (Flora  Indica,  1855, 
p.  253),  describes  as  a  continuation  of  the  Hindu-Kho,  which  is 
joined  from  the  south-east  by  the  Himalaya  chain,  approaches  this 
chain  at  its  western  extremity  to  such  a  degree  that  my  excellent 
friend,  Adolph  Schlagintweit,  designates  "  the  Kuen-liin  and  the 
Himalaya  on  the  west  side  of  the  Indus,  not  as  separate  chains,  but 
as  one  mass  of  mountains."  (Report  No.  ix  of  the  Magnetic  Survey  in 
India  ly  Ad.  Schlagintweit,  1856,  p.  61).  In  the  whole  extent  towards 
the  east,  however,  as  far  as  92°  20'  east  longitude,  in  the  direction  of 
the  starry  lake,  the  Kuen-liin  forms,  as  was  shown  so  early  as  the  7th 
century  of  our  era  by  minute  descriptions  given  under  the  Dynasty  of 
Sai  (Klaproth,  Tableaux  Historiques  de  I' Asie,  p.  204),  an  independent 
chain  running  east  and  west  parallel  to  the  Himalaya  at  a  distance  of 
about  7^  degrees  of  latitude.  The  brothers  Hermann  and  Robert 
Schlagintweit  are  the  first  who  have  had  the  courage  and  the  good 
fortune  to  traverse  the  chain  of  the  Kuen-liin,  setting  out  from  Ladak 
and  reaching  the  territory  of  Khotau  in  the  months  of  July  and  Sep- 
tember, 1856.  According  to  their  observations,  which  are  always 


TRUE  VOLCANOES.  439 

the  volcano  of  Jorullo.  We  are  indebted  for  these  remark- 
able geosnostic  accounts  from  the  Mantschurei  to  the  in- 
dustry of  W.  P.  Wassiljew  (Q-eog.  Bote,  1855,  Heft,  v,  s.  31) 
and  to  an  essay  by  M.  Semenow  (the  learned  translator  of 
Carl  Hitter's  great  work  on  Geology)  in  the  17th  vol.  of  the 
Proceedings  of  the  Imperial  Russian  Geographical  Society. 

In  the  course  of  the  investigations  into  the  geographical 
distribution  of  volcanoes,  and  their  frequent  occurrence  on 
islands  and  sea-coasts,  that  is  to  say,  on  the  margins  of  con- 
tinental elevations,  the  probable  great  inequality  in  the 
depth  to  which  the  crust  of  the  earth  has  hitherto  been 
penetrated  has  also  been  frequently  brought  under  con- 
sideration. One  is  disposed  to  believe  that  the  surface  of 
the  internal  molten  mass  of  the  earth's  body  lies  nearest  to 
those  points  at  which  the  volcanoes  have  burst  forth.  But 
as  it  may  be  conceived  that  there  are  many  intermediate 
degrees  of  consistency  in  the  solidifying  mass,  it  is  difficult 
to  form  a  clear  idea  of  any  such  surface  of  the  molten 
matter ;  if  a  change  in  the  comprehensive  capacity  of  the 
external  firm  and  already  solidified  shell,  be  supposed  to 
be  the  chief  cause  ot  all  the  subversions,  fissures,  upheavals 
and  basin-like  depressions.  If  we  might  be  allowed  to 
determine  what  is  called  the  thickness  of  the  earth's  crust 
in  an  arithmetical  ratio  deduced  from  experiments  drawn 
from.  Artesian  wells,  and  from  the  fusion-point  of  granite, 
that  is  to  say,  by  taking  equal  geothermal  degrees  of 
depth,49  we  should  find  it  to  be  20  ^  geographical  miles 
or  3-y^th  of  the  Polar  diameter.60  But  the  influences  of 

extremely  careful,  the  highest  water-shedding  mountain-chain  is  that 
on  which  is  situated* the  Karakorum  pass  (18,304  feet)  which,  stretching 
from  south-east  to  north-west,  lies  parallel  to  the  opposite  southerly 
portion  of  the  Himalaya  (to  the  west  of  Dhawalagiri).  The  rivers 
Yarkland  and  Karakasch,  which  form  a  part  of  the  great  water  system 
of  the  Tarim  and  Lake  Lop,  rise  on  the  north-eastern  slope  of  the 
Karakorum  chain.  From  this  region  of  water-springs  the  travellers 
arrived  by  way  of  Kissilkorum  and  the  hot  springs  (120°  F.)  at  the 
small  mountain  lake  of  Kiuk-kiul,  on  the  chain  of  the  Kuen-liin 
which  stretches  east  and  west  (Report  Xo.  viii,  Agra,  1857,  p.  6). 

4%J  Cosmos,  vol.  i,  pp.  26,  167;  see  above,  pp.  34 — 38. 

50  Arago  (Astron.  Populaire,  t.  iii,  p.  248)  adopts  nearly  the  same 
thickness  of  the  earth's  crust,  namely,  40,000  metres,  or  about  22 
miles;  Elie  de  Beaumont  (Systemes  de  Montagncs,  t.  iii,  p.  1237),  cal- 
culates the  thickness  at  about  £  more.  The  oldest  calculation  is  that 


440  COSMOS. 

the  pressure  and  of  the  power  of  conducting  heat  exercised 
by  various  kinds  of  rock,  render  it  likely  that  the  geo- 
thermal  degrees  of  depth  increase  in  value  in  proportion  as 
the  depth  itself  increases. 

Notwithstanding  the  ve'ry  limited  number  of  points  at 
which  the  fused  interior  of  our  planet  now  maintains  an 
active  communication  with  the  atmosphere,  it  is  still  not 
unimportant  to  inquire  in  what  manner  and  to  what  extent 
the  volcanic  exhalations  of  gas  operate  on  the  chemical 
composition  of  the  atmosphere,  and  through  it,  on  the  or- 
ganic life  developed  on  the  earth's  surface.  We  must,  in  the 
first  place,  bear  in  mind  that  it  is  not  so  much  the  summit- 
craters  themselves  as  the  small  cones  of  ejection  and  the 
fumaroles,  which  occupy  large  spaces  and  surround  so  many 
volcanoes,  that  exhale  gases, — and  that  even  whole  tracts  of 
country  in  Iceland,  in  the  Caucasus,  in  the  high  land  of 
Armenia,  on  Java,  the  Galapagos,  the  Sandwich  Islands  and 
New  Zealand,  exhibit  a  constant  state  of  activity  through 
solfataras,  naphtha-springs,  and  salses.  Volcanic  districts, 
which  are  now  reckoned  among  those  which  are  extinct,  are 
likewise  to  be  regarded  as  sources  of  gas,  and  the  silent 
working  of  the  subterranean  forces,  whether  destructive 
or  formative,  within  them  is,  with  regard  to  quantity,  pro- 
bably more  productive  than  the  great,  noisy,  and  more  rare 
eruptions  of  volcanoes,  although  their  lava-fields  continue  to 
smoke  either  visibly  or  invisibly  for  years  at  a  time.  If  it 
be  said  that  the  effects  of  these  small  chemical  processes 
can  be  but  little  regarded,  for  that  the  immense  volume  of 
the  atmosphere,  constantly  kept  in  motion  by  currents  of 
air,  could  only  be  affected  in  its  primitive  mixture  to  a  very 
small  extent  through  means  of  such  apparently  unimportant 
additions,61  it  will  be  necessary  to  bear  in  mind  the  powerful 
of  Cordier,  in  mean  value  56  geographical  miles,  an  amount  which, 
according  to  Hopkins's  mathematical  theory  of  stability,  would  have 
to  be  multiplied  fourteen  times,  and  would  give  between  688  and 
860  geographical  miles.  I  quite  concur  on  geological  grounds  in  the 
doubts  raised  by  Naumann  in  his  admirable  Lelirluch  der  Geognosie 
(vol.  i,  p.  62 — 64,  73 — 76  and  289),  against  this  enormous  distance  of 
the  fluid  interior  from  the  craters  of  the  active  volcanoes. 

11  A  remarkable  example  of  the  way  in  which  perceptible  changes 
of  mixture  are  produced  in  nature  by  very  minute,  but  continuous, 
accumulation  is  afforded  by  the  presence  of  silver  in  sea-water, 
which  was  discovered  by  Malaguti  and  confirmed  by  Field.  Not- 


TRUE  VOLCANOES.  441 

influence  exerted,  according  to  the  admirable  investigations 
of  Percival,  Saussure,  Boussingault  and  Liebig,  by  three  01 
four  ten-thousandth  parts  of  carbonic  acid  in  our  atmo- 
sphere on  the  existence  of  the  vegetable  organism.  From 
Bunsen's  excellent  work  on  the  different  kinds  of  volcanic 
gas,  it  appears  that  among  the  fumaroles  of  different  stages 
of  activity  and  local  diversity,  some  (as  for  example  at  Hecla) 
yield  from  0.81  to  0.83  of  nitrogen,  and  in  the  lava-streams 
of  the  mountain  0.78,  with  mere  traces  (0.01  to  0.02)  of 
carbonic  acid,  while  others  in  Iceland,  as  for  instance  near 
Krisuvik,  on  the  contrary,  yield  from  0.86  to  0.87  of  car- 
bonic acid,  with  scarcely  0.01  of  nitrogen.62  We  find  like- 
wise in  the  important  work  on  the  emanations  of  gas  in 
Southern  Italy  and  Sicily  by  Charles  Sainte-Claire  Deville 
and  Bornemann,  that  there  is  an  immense  proportion  of 
nitrogen  gas  (0.98)  in  the  exhalations  of  a  fissure  situated 
low  down  in  the  crater  of  Vulcano,  while  the  sulphuric 
acid  vapours  show  a  mixture  of  74.7  nitrogen  gas  and  18.5 
oxygen,  a  proportion  which  approaches  pretty  nearly  to  the 
composition  of  the  atmospheric  air.  On  the  other  hand  the 
gas  which  rises  from  the  spring  of  Acqua  Santa53  in  Catania 
is  pure  nitrogen  gas,  as  was  also  the  gas  of  the  Yolcancifcos 
de  Turbaco  at  the  time  of  my  American  journey.64 

Are  we  to  conclude  that  the  great  quantity  of  nitrogen 
dispersed  through  the  medium  of  volcanic  action  consists  of 
that  alone  which  is  imparted  to  the  volcanoes  by  meteoric 
water  ? — or  are  there  internal  and  deeply-seated  sources  of 
nitrogen  ?  It  must  also  be  borne  in  mind  that  the  air  dis- 
solved in  rain-water  does  not  contain,  like  the  atmosphere, 
0.79  of  nitrogen,  but  according  to  my  own  experiments,  only 

withstanding  the  immense  extent  of  the  ocean  and  the  trifling 
amount  of  surface  presented  to  it  by  the  ships  which  traverse  it, 
yet  the  trace  of  silver  in  the  sea-water  has  in  recent  times  become 
observable  on  the  copper-sheeting  of  ships. 

62  Bunsen,  Ueber  die  chemischen  Prozesse  der  rullcanischen  Gesteins- 
bildungen  in  Poggend.  Annalen,  Bd.  Ixxxiii,  s.  242  and  246. 

53  Comptes  rendus  de  FAcad.  des  Sciences,  t.  xliii,  1856,  pp.  366 
and  689.  The  first  correct  analysis  of  the  gas  which  rushes  with  noise 
from  the  great  solfatara  of  Pozzuoli,  and  which  was  collected  with 
great  difficulty  by  M.  Ch.  St.-Claire  Deville,  gave  the  following  results : 
— sulphurous  acid  (acide  sulfureux)  24.5, — oxygen  14.5, — and  nitrogen 
61.4. 

*  See  above,  pp.  211-    218. 


COSMOS. 

O.G9.  Nitrogen  is  a  source  of  increased  fertility,58  by  the 
formation  of  ammonia,  through  the  medium  of  the  almost 
daily  electrical  explosions  in  tropical  countries.  The  influ- 
ence of  nitrogen  on  vegetation  is  similar  to  that  of  the  sub- 
stratum of  atmospheric  carbonic  acid. 

In  analysing  the  different  gases  of  the  volcanoes  which 
lie  nearest  to  the  equator  (Tolima,  Purace,  Pasto,  Tuqueres 
and  Cunibal)  Boussingault  has  discovered,  along  with  a  great 
deal  of  aqueous  vapour,  carbonic  acid  and  sulphuretted 
hydrogen  gas,  but  no  muriatic  acid,  no  nitrogen  and  no  free 
hydrogen.56  The  influence  still  exercised  by  the  interior  of 
our  planet  on  the  chemical  composition  of  the  atmosphere 
in  withdrawing  this  matter  in  order  to  give  it  out  again 
under  other  forms,  is  certainly  but  an  insignificant  part  of 
the  chemical  revolutions  which  the  atmosphere  must  have 
undergone  in  remote  ages  on  the  eruption  of  great  masses  of 
rock  from  open  fissures.  The  conjecture  as  to  the  probability 
of  a  very  large  portion  of  carbonic  acid  gas  in  the  ancient 

55  Boussingault,  Economic  rurale  (1851),  t.  ii,  p.  724 — 726; — "The 
permanency  of  storms  in  the  interior  of  the  atmosphere  (within  the 
tropics)  is  an  interesting  fact,  being  connected  with  one  of  the  most 
important  questions  in  the  physical  history  of  the  globe,  namely,  that 
of  the  fixation  of  the  nitrogen  of  the  air  in  organised  beings.  When- 
ever a  series  of  electric  sparks  passes  through  the  humid  atmosphere, 
the  production  and  combination  of  nitric  acid  and  ammonia  take  place. 
The  nitrate  of  ammonia  uniformly  accompanies  the  rain  during  a  storm, 
and  being  by  nature  fixed,  it  cannot  maintain  itself  in  the  state  of 
vapour;  carbonate  of  ammonia  is  found  in  the  air,  and  the  ammonia 
of  the  nitrate  is  carried  to  the  earth  by  the  rain.  Thus  it  appears,  in 
fact,  to  be  an  electric  action  which  disposes  the  nitrogen  of  the  atmo- 
sphere to  become  assimilated  by  organised  beings.  In  the  equinoxial 
zone,  throughout  the  whole  year,  every  day,  and  probably  even  every 
moment,  there  is  a  continual  succession  of  electric  discharges  going  on. 
An  observer,  stationed  at  the  equator,  if  he  were  endowed  with  organs 
sufficiently  sensitive,  would  hear  without  intermission  the  noise  of  thun- 
der." Sal  ammoniac,  however,  together  with  common  salt,  are  from 
time  to  time  found  as  products  of  sublimation,  even  in  lava-streams, — 
on  Hecla,  Vesuvius,  and  Etna,  in  the  volcanic  chain  of  Guatemala  (the 
volcano  of  Izalco),  and  above  all  in  Asia  in  the  volcanic  chain  of  the 
Thian-shan.  The  inhabitants  of  the  country  between  Kutsch,  Turfan, 
and  Kami  pay  their  tribute  to  the  Emperor  of  China  in  certain  years 
in  sal  ammoniac  (in  Chinese  nao-sha,  in  Persian  nushadcn),  which  is  an 
important  article  of  internal  trade.  (Asie  Centrale,  t.  ii,  pp.  33,  38,  45, 
and  428.) 

M  Viajcs  de  Boussingault  (1849)  p.  78. 


TRUE  VOLCANOES.  443 

aeriform  envelope  is  strengthened  by  a  comparison  of  the 
thickness  of  the  present  seams  of  coals  with  that  of  the 
thin  coal-strata  (seven  lines  in  thickness)  which,  according 
to  Chevandier's  calculations,  our  thickest  woods  in  the 
temperate  zone  would  yield  to  the  soil  in  the  course  of 
100  years.57 

In  the  infancy  of  geognosy,  previous  to  Do'lomieu's  ingenious 
conjectures,  the  source  of  volcanic  action  was  not  placed 
below  the  most  ancient  rock-formations,  which  were  then 
generally  supposed  to  be  granite  and  gneiss.  Besting  on 
some  feeble  analogies  of  inflammability,  it  was  long  believed 
that  the  source  of  volcanic  eruptions,  and  the  emanations  of 
gas  to  which .  they  for  many  centuries  give  rise,  was  to  be 
sought  for  in  the  later,  upper-silurian  floetz-strata,  containing 
combustible  matter.  A  more  general  acquaintance  with 
the  earth's  surface,  profounder  and  more  strictly  conducted 
geological  investigations,  together  with  the  beneficial  influence 
which  the  great  advances  made  by  modern  chemistry  have 
exercised  on  the  study  of  geology,  have  taught  us  that  the 
three  great  groups  of  volcanic  or  eruptive  rock  (trachyte, 
phonolite,  and  basalt),  when  viewed  as  large  masses,  appear 
when  compared  together  to  be  of  different  ages,  and  for  the 
most  part  widely  separated  from  each  other.  All  three,  how- 
ever, have  come  later  to  the  surface  than  the  Plutonic  gra- 
nite, the  diorite,  and  the  quartz-porphyry, — later  than  all  the 
silurian,  secondary,  tertiary,  and  quartary  (pleistocene)  for- 
mations,— and  that  they  frequently  traverse  the  loose  strata 
of  the  diluvial  formations  and  bone-breccias.  A  striking 
variety68  of  these  intersections,  compressed  into  a  small  space, 
is  exhibited,  as  we  learn  from  Rozet's  observations,  in  Au- 
vergne.  While  the  great  trachytic  mountain -masses  of  the 
Cantal,  Mont-Dore,  and  Puy  de  Dome,  penetrate  the  granite 

57  Cosmos,  vol.  i,  pp.  283 — 5. 

53  Kozet,  Memoire  sur  les  Volcans  d'Auvergne,  in  the  Memoires  de  la, 
Soc.  Geol.  de  France,  2me  Serie,  t.  i,  1844,  pp.  64  and  120—130  :— "The 
basalts  (like  the  trachytes)  have  penetrated  through  the  gneiss,  the 
granite,  the  coal  formations,  the  tertiary  formations,  and  the  oldest 
diiuvian  beds.  The  basalts  are  even  frequently  seen  overlying  masses 
of  basaltic  boulders  j  they  have  issued  from  an  infinite  number  of 
openings,  several  of  which  are  still  perfectly  recognisable.  Many  of 
them  exhibit  cones  of  scorise  more  or  less  considerable,  but  nowhere  do 
we  find  craters  similar  to  those  which  have  given  out  streams  of  lava." 


414  COSMOS. 

itself,  and  at  the  same  time  enclose  in  some  parts  (for  ex- 
ample, between  Vic  and  Aurillac,  and  at  the  Giou  de  Mamon) 
large  fragments  of  gneiss59  and  limestone,  we  find  also  the 
trachyte  and  basalt  intersecting  as  dykes  the  gneiss,  and  the 
coal-beds  of  the  tertiary  and  diluvial  strata.  Basalt  and 
phonolite,  closely  allied  to  each  other,  as  the  Auvergne  and  the 
central  mountains  of  Bohemia  prove,  are  both  of  more  recent 
formation  than  the  trachytes,  which  are  frequently  tra- 
versed in  layers  by  basalts.60  The  phonolites  are,  on  the 
other  hand,  more  ancient  than  the  basalts ;  where  they  pro- 
bably never  form  dykes,  but  on  the  contrary  dykes  of  basalt 
frequently  intersect  the  porphyritic-schist  (phonolite).  In 
the  chain  of  the  Andes  belonging  to  Quito,  I  have  found  the 
basalt-formation  a  great  distance  apart  from  the  prevailing 
trachytes ;  almost  solely  at  the  Rio  Pisque  and  in  the  valley 
of  Guaillabamba.61 

As  in  the  volcanic  elevated  plain  of  Quito  everything  is 
covered  with  trachytes,  trachytic-conglomerates,  and  tufas,  it 
was  my  most  earnest  endeavour  to  discover,  if  possible,  some 
point  at  which  it  might  be  clearly  seen  on  which  of  the  older 
rocks  the  mighty  cone  and  bell- shaped  mountains  are  placed, 
or,  to  speak  more  precisely,  through  which  of  them  they 
had  broken  forth.  Such  a  point  I  was  so  fortunate  as  to 
discover  in  the  month  of  June  1802,  on  my  way  from  Rio- 
bamba  Nuevo  (9483  feet  above  the  surface  of  the  South 
Pacific)  when  I  attempted  to  ascend  the  Tunguragua  on  the 

59  Resembling  the  granitic  fragments  imbedded  in  the  trachyte  of 
Jorullo.     See  above,  p.  321. 

60  Also  in  the  Eifel,  according  to  the  important  testimony  of  the 
mine-director,  Von  Dechen.     See  above,  p.  237. 

61  See   above,  p.  333.      The  Rio  de   Guaillabamba  flows  into  the 
Rio  de  las  Esmeraldas.     The  village  of   Guaillabamba,  near  which  I 
found  the  isolated  oliviniferous  basalt,  is  only  6430  feet  above  the  level 
of  the  sea.     An  intolerable  heat  prevails  in  the  valley,  which  is  still 
more  intense  in  the  Valle  de  Chota,  between  Tusa  and  the  Villa  cle 
Ibarra,  the  sole  of  which  sinks  to  5288  feet,  and  which  is  rather  a  chasm 
than  a  valley,  being  scarcely  9600  feet  wide  and  4800  feet  deep  (Hum- 
boldt,  Rec.  d' Observations  Astronomiques,  vol.  i,  p.  307),     The  rubbish- 
ejecting  Volcan  de  Ansango,  on  the  descent  of  the  Antisana,  does  not 
belong  to  the  basalt-formation  at  all ;  it  is  an  oligoclase-trachyte  resem- 
bling basalt  (compare,  for  the  distances,  Antagonisme  des  Basalt.es  et  des 
Trachytes,  my  Essai  Geognostique  sur  le  gisement  des  Roches,  1823,  pp. 
848  and  359,  and  generally,  pp.  327—336). 


TRUE  VOLCANOES.  445 

side  of  the  Cucliilla  de  Guandisava.  I  proceeded  from  the 
delightful  village  of  Penipe  over  the  swinging  rope-bridge 
(puente  de  maroma)  of  t'he  Rio  Puela  to  the  isolated  Ha- 
cienda de  Guansce  (7929  feet),  where  to  the  south-east,  op- 
posite the  point  at  which  the  Rio  Blanco  falls  into  the  Rio 
Chambo,  rises  a  splendid  colonnade  of  black  trachyte  resem- 
bling pitch-stone.  It  looks  at  a  distance  like  the  basalt- 
quarry  at  Unkel.  At  Chiruborazo,  a  little  higher  than  the 
basin  of  Yana-Cocha,  I  saw  a  similar  group  of  trachytic 
columns  of  greater  height  but  less  regularity.  The  columns  to 
the  south-east  of  Penipe  are  mostly  pentagonal,  only  14  inches 
in  diameter,  and  frequently  bent  and  diverging.  At  the  foot 
of  this  black  trachyte  of  Penipe,  not  far  from  the  mouth  of 
the  Rio  Blanco,  a  very  unexpected  phenomenon  presents 
itself  in  this  part  of  the  Cordilleras  j — greenish- white  mica- 
slate  with  garnets  interspersed  in  it,  and  farther  on,  beyond 
the  shallow  stream  of  Bascaguan,  at  the  hacienda  of  Guansce, 
near  the  shore  of  the  Rio  Puela,  and  probably  dipping  be 
low  the  mica-slate  granite  of  a  middling-sized  grain,  with 
light  reddish  felspar,  a  small  quantity  of  blackish  green  mica 
and  a  great  deal  of  greyish  white  quartz.  There  is  no  horn- 
blend,  nor  is  there  any  syenite.  Thus  it  appears  that  the 
trachytes  of  the  volcano  of  Tungurahua,  resembling  those 
of  Chimborazo  in  their  mineralogical  condition,  that  is  to 
say,  consisting  of  a  mixture  of  oligoclase  and  augite, 
have  here  penetrated  granite  and  mica-slate.  Farther 
towards  the  south,  and  a  little  to  the  east  of  the  road 
leading  from  Riobamba  Nuevo  to  Guamote  and  Ticsan,  in 
that  part  of  the  Cordilleras  which  recedes  from  the  sea-shore, 
the  rocks  formerly  called  primitive,  mica-slate  and  gneiss, 
make  their  appearance  everywhere,  towards  the  foot  of  the 
colossal  altar  de  los  Collanes,  the  Cuvillan,  and  the  Paramo 
del  Hatillo.  Previous  to  the  arrival  of  the  Spaniards;  and 
even  before  the  dominion  of  the  Incas  extended  so  far  to  the 
north,  the  natives  are.  said  to  have  worked  metalliferous 
beds  in  the  neighbourhood  of  the  volcanoes.  A  little  to  the 
south  of  San  Luis  numerous  dykes  of  quartz  are  observed 
running  through  a  greenish  clay-slute.  At  Guamote,  at  the 
entrance  to  the  grassy-plain  of  Tiocaxa,  we  found  large  masses 
of  rock  consisting  of  quartzites  very  poor  in  mica,  of  a  dis- 
tinct linear  parallel  structure,  running  reg^arly  at  an  angle 


446  COSMOS. 

of  70  degrees  to  the  north.  Farther  to  the  south  at  Ticsan, 
not  far  from  Alausi,  the  Cerro  Cuello  de  Ticsan  shows 
large  masses  of  sulphur  imbedded  in  a  layer  of  quartz, 
subordinate  to  the  neighbouring  mica-slate.  So  great  a  diffu- 
sion of  quartz  in  the  neighbourhood  of  trachytic  volcanoes 
appears  at  first  sight  somewhat  strange.  The  observations 
which  I  made,  however,  of  the  overlying,  or  rather  of  the 
breaking  forth  of  trachyte  from  mica-slate  and  granite  at  the 
loot  of  the  Tungurahua  (a  phenomenon  as  rare  in  the  Cor- 
dilleras as  frequent  in  Auvergne)  have  been  confirmed,  after 
an  interval  of  47  years,  by  the  admirable  investigations  of 
the  French  Geologist  Sebastian  Wisse  at  the  Sangay. 

That  colossal  volcano,  1343  feet  higher  than  Mont-Blanc, 
entirely  destitute  of  lava-streams  (which  Charles  Deville  de- 
clares are  also  wanting  in  the  equally  active  Stromboli)  but 
ejecting  uninterruptedly,  at  least  since  the  year  1728,  a  black, 
and  frequently  brightly  glowing  rock,  forms  a  trachy tic- 
island  of  scarcely  8  geographical  miles  in  diameter62  in  the 
midst  of  beds  of  granite  and  gneiss.  A  totally  opposite 
condition  of  stratification  is  exhibited  in  the  volcanic  district 

62  S^bastien  Wisse,  Exploration  du  Volcan  de  Sangay,  in  the  Comptes 
rendus  de  I'Acad.  des  Sciences,  t.  xxxvi,  1853,  p.  721 ;  comp.  also  above, 
p.  251. 

According  to  Bo  ussingault,  the  ejected  fragments  of  trachy te  brought 
home  by  Wisse  and  collected  on  the  upper  descent  of  the  cone  (the 
traveller  reached  an  elevation  of  960  feet  below  the  summit,  which  is 
itself  485  feet  in  diameter),  consist  of  a  black,  pitch-like  fundamental 
mass,  in  which  are  imbedded  crystals  of  glassy  (?)  felspar.  It  is  a  very 
remarkable  phenomenon,  and  one  which  up  to  the  present  time  seems 
to  stand  alone  in  the  history  of  volcanic  ejections  that,  along  with  these 
large  black  pieces  of  trachyte,  small  sharp-edged  fragments  of  pure 
quartz  are  thrown  out.  According  to  a  letter  from  my  friend  Boussin- 
gault,  dated  January  1851,  these  fragments  are  no  longer  than  4  cubic 
centimetres  in  bulk.  No  quartz  is  found  disseminated  in  the  trachytic 
mass  itself.  All  the  volcanic  trachytes  which  I  have  examined  in  the 
Cordilleras  of  South  America  and  Mexico,  and  even  the  trachytic  por- 
phyries in  which  the  rich  silver  veins  of  Real  del  Monte,  Moran  and 
Regla  are  contained,  to  the  north  of  the  elevated  valley  of  Mexico,  are 
entirely  destitute  of  quartz.  Notwithstanding  this  seeming  antagonism, 
however,  of  quartz  and  trachyte  in  still-active  volcanoes,  I  am  by  no 
means  inclined  to  deny  the  volcanic  origin  of  the  "  trachytes  et  porphy- 
res  meulieres  (mill-stone  trachytes)"  to  which  Beudant  first  drew  atten- 
tion. The  mode,  however,  in  which  these  are  formed,  being  erupted 
frcrn  fissures,  is  entirely  different  from  the  formation  of  the  conical  and 
dome-like  trachyte  structures. 


TRUE  VOLCANOES.  447 

of  Eifel,  as  I  have  already  observed,  both  from  the  activity 
which  once  manifested  itself  in  the  Maars  (or  mine-funnels) 
sunk  in  the  Devonian-schist,  and  that  shown  in  the  raised 
structures  from  which  lava-streams  flow,  as  on  the  long  ridge 
of  the  Mosenberg  and  Gerolstein.  The  surface  does  not  here 
indicate  what  is  hidden  in  the  interior.  The  absence  of  tra- 
chyte in  volcanoes  which  were  so  active  thousands  of  years 
ago,  is  a  still  more  striking  phenomenon.  The  augitiferous 
scoriae  of  the  Mosenberg,  which  partly  accompany  the  basaltic 
lava-stream,  contain  small  burnt  pieces  of  schist,  but  no 
fragments  of  trachyte,  and  in  the  neighbourhood  the  tra- 
chytes are  absent.  This  species  of  rock  is  only  to  be  seen 
in  the  Eifel  in  a  state  of  entire  isolation63  far  from  the  Maars 
and  lava-yielding  volcanoes,  as  in  the  Seliberg  at  Quiddel- 
bach,  and  in  the  mountain-chain  of  Reimerath.  The  different 
nature  of  the  formations  through  which  the  volcanoes  force 
their  way  so  as  to  operate  with  power  on  the  outer  crust  of 
the  earth  is  geologically  as  important  as  the  material  which 
they  throw  out. 

The  conditions  of  configuration  in  those  rocky  structures 
through  which  volcanic  action  manifests  itself,  or  has  en- 
deavoured to  do  so,  have  at  length  been  in  modern  times  far 
more  completely  investigated  and  described  in  their  often 
very  complicated  variations  in  the  most  distant  quarters  of 
the  globe  than  in  the  previous  century,  when  the  entire 
morphology  of  volcanoes  was  limited  to  conical  and  bell- 
shaped  mountains.  There  are  many  volcanoes  whose  confi- 
guration, altitude  and  range  (what  the  talented  Carl  Frie- 
drich  JSTaumann  calls  the  geotectonics),64  we  now  know  in 
the  most  satisfactory  manner,  while  we  continue  in  the 
greatest  ignorance  regarding  the  composition  of  their  diffe- 
rent rocks  and  the  association  of  the  mineral  species  which 
characterise  their  trachytes,  and  which  are  recognisable 

63  See  above,  pp.  232—6. 

64  The  fullest  information  we  possess  on  any  volcanic  district,  founded 
on  actual  measurements  of  altitudes,  angles  of  inclination,  and  profile 
views,  is  contained  in  the  beautiful  work  of  the  Astronomer  of  Olmiitz, 
Julius  Schmidt,  on  Vesuvius,  the  solfatara,  Monte  Nuovo,  the  Astroni, 
Eocca  Monfina  and  the  old  volcanoes  of  the  Papal  territory  (in  the  A> 
banian  Mountains,  Lago  Bracciano,  and  Lago  di  Bolsena).     See  his  hyp- 
Eometrical  work,  Die  Eruption  dcs   Vcsuvs  im  Mai,  1855,  with  Atlas, 
plates  iii,  iv.  iz. 


4i8  COSMOS. 

apart  from  the  principal  mass.  Both  kinds  of  knowledge, 
however, — the  morphology  of  the  rocky  piles  and  the  oryc- 
tognosy  of  their  composition, — are  equally  necessary  to  the 
perfect  understanding  of  volcanic  action  ;  nay,  the  latter, 
founded  on  crystallisation  and  chemical  analysis,  on  account 
of  the  connection  with  plutonic  rocks  (porphyritic  quartz, 
greenstone  and  serpentine)  is  of  even  greater  geognostic  im- 
portance. The  little  we  believe  we  know  of  what  is  called 
the  volcanicity  of  the  Moon  depends  too,  from  the  very  na- 
ture of  the  knowledge,  on  configuration  alone65. 

65  The  progressive  perfection  of  our  acquaintance  with  the  formation 
of  the  surface  of  the  Moon  as  derived  from  numerous  observers,  from 
Tobias  Mayer  down  to  Lohrmann,  Miidler  and  Julius  Schmidt,  has 
tended  on  the  whole  rather  to  diminish  than  to  strengthen  our  belief 
in  great  analogies  between  the  volcanic  structures  of  the  earth  and 
those  of  the  moon ;  not  so  much  on  account  of  the  conditions  of  di- 
mension and  the  early  recognised  ranging  of  so  many  ring-shaped 
mountains,  as  on  account  of  the  nature  of  the  rills  and  of  the  system  of 
rays  which  cast  no  shadows  (radiations  of  light)  of  more  than  400  miles 
in  length  and  from  2  to  16  miles  in  breadth,  as  in  Tycho,  Copernicus, 
Kepler  and  Aristarchus.  It  is  remarkable,  however,  that  Galileo,  in  his 
letter  to  Father  Christoph  Grienberger,  SMe  montuosita  della  Luna, 
should  have  thought  of  comparing  annular  mountains,  whose  diameter 
he  considered  greater  than  they  actually  are,  to  the  circumvallated 
district  of  Bohemia,  and  that  the  ingenious  Robert  Hooke  in  his 
"  Micrography "  attributes  the  type  of  circular  formation  almost  uni- 
versally prevalent  on  the  moon  to  the  reaction  of  the  interior  of  its 
body  on  the  exterior  (vol.  ii,  p.  701,  and  vol.  iv,  p  496).  With  respect 
to  the  annular  mountain  ranges  of  the  moon,  I  have  been  of  late  much 
interested  with  the  relation  between  the  height  of  the  central  mountain 
and  that  of  the  circumvallation  or  margins  of  the  crater,  as  well  as  by 
the  existence  of  parasitic  craters  on  the  circumvallation  itself.  The 
result  of  all  the  careful  observations  of  Julius  Schmidt,  who  is  occupied 
with  the  continuation  and  completion  of  Lohrmami's  Topography  of 
the  Moon,  establishes  "that  no  single  central-mountain  attains  the 
height  of  the  wall  of  its  crater,  but  that  in  all  cases  it  probably  even 
lies  together  with  its  summit  considerably  below  that  surface  of  the 
inoon  from  which  the  crater  is  erupted.  While  the  cone  of  ashes  in  the 
crater  of  Vesuvius  which  rose  on  the  22nd  of  October  1822,  according 
to  Brioschi's  trigonometrical  measurement,  exceeds  in  height  the  Punta 
del  Palo,  the  highest  edge  of  the  crater  on  the  north  (618  toises  above 
the  sea),  by  about  30  feet,  and  was  visible  at  Naples,  many  of  the 
central  mo'intains  of  the  moon,  measured  by  Madler  and  the  Olmiitz 
Astronomer,  lie  fully  6400  feet  lower  than  the  mean  margin  of  cir 
cumvallation,  nay,  even  100  toises  below  what  may  be  taken  as 
t/ie  mean  surface-level  in  that  part  of  the  moon  to  which  they  respec« 
tival  belong  {Madler,  iu  Schumacher  s  Jahrbuchfur  1841,  pp.  272  aud 


TRUE  VOLCANOES.  449 

If,  as  I  would  fain  hope,  what  I  here  propound  regarding 
the  classification  of  the  volcanic  rocks  ;  or,  to  speak  more 
precisely,  on  the  arrangement  of  the  trachytes  according  to 
their  composition,  excites  any  particular  interest,  the  merit 
of  this  classification  is  entirely  due  to  my  friend  and  Sibe- 
rian fellow-traveller,  Gustav  Rose.  His  accurate  observa- 
tion of  nature,  and  the  happy  combination  which  he  possesses 

274,  and  Jul.  Schmidt;  Der  Mond,  1856,  s.  62).  In  general,  the  central 
mountains,  or  central  mountain-masses  of  the  moon  have  several  sum- 
mits, as  in  Theophilus,  Petavius  and  Bulliald.  In  Copernicus  there  are 
6  central  mountains,  and  Alphonsus  alcyie  exhibits  a  true  central  sharp 
pointed  peak.  This  state  of  things  recalls  to  mind  the  Astroni  in  the 
Phlegraean  fields,  on  whose  dome-formed  central  masses  Leopold  von 
Buch  justly  lays  much  stress.  "  These  masses,"  he  says,  "  like  those 
in  the  centre  of  the  annular  mountains  of  the  moon,  did  not  break  forth. 
There  existed  no  permanent  connection  with  the  interior, — no  volcano, 
but  they  rather  appeared  like  models  of  the  great  trachytic  unopened 
domes  so  abundantly  dispersed  over  the  earth's  crust,  such  as  the  Puy 
de  Dome  and  Chimborazo."  (Poggendorffs  Annalen,  Bd.  xxxvii,  1836, 
p.  183.)  The  circumvallation  of  the  Astroni  is  of  an  elliptic  form,  closed 
all  round,  and  rises  in  no  part  higher  than  830  feet  above  the  level  of 
the  sea.  The  tops  of  the  central  summits  lie  more  than  660  feet  lower 
than  the  maximum  of  the  south-western  wall  of  the  crater.  The  sum- 
mits form  two  parallel  ridges,  covered  with  thick  bushes  (Julius  Schmidt, 
Eruption  des  Vesuvs.  s.  147,  and  Der  Mond,  s.  70  and  103).  One  of 
the  most  remarkable  objects,  however,  on  the  whole  surface  of  the  moon 
is  the  annular  mountain-range  of  Petavius,  in  which  the  whole  internal 
floor  of  the  crater  expands  convexly  in  the  form  of  a  tumour  or  cupola, 
and  is  crowned  besides  with  a  central  mountain.  The  convexity  here 
is  a  permanent  form.  In  our  terrestrial  volcanoes  the  flooring  of  the 
crater  is  only  temporarily  raised  by  the  force  of  internal  vapours  some- 
times almost  to  the  height  of  the  margin  of  the  crater,  but  as  soon  as 
the  vapours  force  their  way  through,  the  floor  sinks  down  again.  The 
largest  diameters  of  craters  on  the  earth  are,— the  Caldeira  de  Fogo,  ac- 
cording to  Charles  Deville  4100  toises  (4 '32  geogi-aphical  miles)  and  the 
Caldeira  de  Palma,  according  to  Leop.  v.  Buch  3100  toises,  while  on 
the  moon,  Theophilus  is  50,000  toises,  and  Tycho  45,000  toises,  or 
respectively,  52  and  45  geogr.  miles  in  diameter.  Parasitic  craters, 
erupted  from  a  marginal  wall  of  the  great  crater,  are  of  very  frequent 
occurrence  on  the  moon.  The  base  of  these  parasitic  craters  is  usually 
empty,  as  on  the  great  rent  margin  of  the  Maurolycus ;  sometimes,  but 
more  rarely,  a  smaller  central  mountain,  perhaps  a  cone  of  eruption,  is 
seen  in  them,  as  in  Logomontauus.  In  a  beautiful  sketch  of  the 
crater-system  of  Etna,  which  my  friend  Christian  Peters  the  Astro- 
nomer (now  in  Albany,  North-America)  sent  me  from  Flensburg  in 
August  1854,  the  parasitic  marginal  crater,  called  the  Pozzo  di  Fuoco, 
which  was  formed  in  January  1833,  on  the  east-south-east  side,  and 
which  had  several  violent  eruptions  of  lava,  is  distinctly  recognisable, 
VOL.  V.  2  G 


4-50  COSMOS. 

of  chemical,  crystal!  o-mineralogical  and  geological  knowledge, 
have  rendered  him  peculiarly  well  qualified  to  promulgate  new 
views  on  that  set  of  minerals  whose  varied,  but  frequently 
recurring  association  is  the  product  of  volcanic  action.  This 
great  geologist,  partly  at  my  instigation,  has  with  the 
greatest  kindness,  especially  since  the  year  1834,  repeatedly 
examined  the  fragments  which  I  brought  from  the  slopes  of 
the  volcanoes  of  New  Granada,  los  Pastos,  Quito,  and  the 
high  land  of  Mexico,  and  compared  them  with  the  spe- 
cimens from  other  parts  of  the  globe  contained  in  the  rich 
mineral-collection  of  the  Berlin  Cabinet.  Before  my  collec- 
tions were  separated  from  those  of  my  companion  Aime  Bon- 
pland,  Leopold  von  Buch  had  examined  them  microscopically 
with  persevering  diligence  (in  Paris,  1810 — 1811,  between 
his  return  from  Norway  and  his  voyage  to  Teneriffe).  He 
had  also,  at  an  earlier  period,  during  my  residence  with  Gay 
Lussac  at  Rome  (in  the  Summer  of  1805)  as  well  as  after- 
wards in  France,  made  himself  acquainted  with  what  I  had 
noted  down  in  my  travelling  journal  on  the  spot,  in  the 
month  of  July  1802,  respecting  certain  volcanoes,  and  in 
general  on  the  affinity  between  volcanoes  and  certain  porphy- 
ries destitute  of  quartz66.  I  preserve  as  a  memorial  which  I 

6(3  The  unspecific  and  indefinite  term  "trachyte"  (Rauhstein),  which 
is  now  so  generally  applied  to  the  rock  in  which  the  volcanoes  break 
out,  was  first  given  to  a  rock  of  Auvergne,  in  the  year  1822  by  Hauy  in 
the  second  edition  of  his  Traite  de  Mineralogie,  vol.  iv,  p.  579,  with  a 
mere  notice  of  the  derivation  of  the  word  and  a  short  description  in 
which  the  older  appellations  of  granite  chauffe  en  place  of  Desmarets), 
trap-porphyry  and  domite  are  not  even  mentioned.  It  was  only  by 
oral  communication,  originating  in  Hauy's  Lectures  in  the  Jardin  des 
Plantes,  that  the  term  "  trachyte  "  was  propagated  previous  to  1822,  for 
example,  in  Leopold  von  Buch's  treatise  on  basaltic  islands  and  craters 
of  upheaval,  published  iu  1818,  in  Daubuisson's  Traite  de  Mineralogie, 
1819,  and  in  Beudant's  important  work,  Voyage  en  Hongrie.  From 
letters  lately  received  by  me  from  M.  Elie  de  Beaumont,  I  find  that 
the  recollections  of  M.  Delafosse,  formerly  Aide-Naturaliste  to  Hauy, 
and  now  Member  of  the  Institute,  fix  the  application  of  the  term  "  tra- 
chyte "  between  the  years  1813  and  1816.  The  publication  of  the  term 
"domite"  by  Leop.  v.  Buch,  seems  according  to  Ewald,  to  have  occurred 
in  the  year  1809;  it  is  first  mentioned  in  the  third  letter  to  Karsten 
(Geognost.  Beolaclit.  auf  Reisen  durch  Deutschl.  undItalien,~Bd.u,  1809, 
s.  244).  "  The  porphyry  of  the  Puy  de  Dome,"  it -is  there  stated,  "is 
a  peculiar,  and  hitherto  nameless  rock,  consisting  of  crystals  of  fel- 
spar with  a  glassy  lustre,  hornblende  and  small  laminse  of  black  mica. 
In  the  clefts  of  this  kind  of  rock,  which  I  provisionally  term  domite, 


TRUE  VOLCANOES.  451 

consider  invaluable,  some  sheets  with  remarks  on  the  volcanic 
products  of  the  elevated  plateaux  of  Quito  and  Mexico,  which 
the  great  geologist  communicated  to  me  for  my  information 
more  than  46  years  ago.  Travellers,  as  I  have  elsewhere17 
said,  being  merely  the  bearers  of  the  imperfect  knowledge  of 

I  find  beautiful  drusic  cavities,  the  walls  of  which  are  covered  with 
crystals  of  iron-glance.  Through  the  whole  length  of  the  Puy,  cones 
of  dornite  alternate  with  cones  of  cinders."  The  second  volume  of 
the  Travels,  containing  the  letters  from  Auvergne,  was  printed  in  1806, 
but  not  published  till  1809,  so  that  the  publication  of  the  name  of 
domite  properly  belongs  to  the  latter  year.  It  is  singular  that  four 
years  later,  in  Leopold  von  Buch's  treatise  on  the  trap-porphyry, 
domite  is  not  even  mentioned. — In  referring  to  a  drawing  of  the  pro- 
file of  the  Cordilleras,  contained  in  the  journal  of  my  travels  in  the 
month  of  July  1802,  and  included  between  the  4th  degree  north  and 
4th  degree  south  latitude  under  the  inscription  "  Affinite'  entre  le  feu 
volcanique  et  les  porphyres,"  my  only  object  was  to  mention  that  this 
profile,  which  represents  the  three  breakings  through  of  the  volcanic 
groups  of  Popayan,  Los  Pastos  and  Quito,  as  well  as  the  eruption  of 
the  trap-porphyry  in  the  granite  and  mica-slate  of  the  Paramo  de 
Assuay  (on  the  great  road  from  Cadlud,  at  a  height  of  15,526  feet), 
led  Leopold  von  Buch,  too  kindly  and  too  distinctly,  to  ascribe  to 
me  the  merit  of  having  first  noticed  "  that  all  the  volcanoes  of  the 
chain  of  the  Andes  have  their  foundation  in  a  porphyry  which  is  a 
peculiar  kind  of  rock  and  belongs  essentially  to  the  volcanic  forma- 
tions" (Abhandlungen  der  ATchademie  der  Wissenscli.  zu  Berlin,  aus  den 
Jahren,  1812—1813,  s.  131,  151  and  153).  I  may  indeed  have  noticed 
the  phenomenon  in  a  general  way,  but  it  had  already,  as  early  as  1789, 
been  remarked  by  Nose,  whose  merits  have  long  been  too  little  appre- 
ciated, in  his  Orographical  Letters,  that  the  volcanic  rock  of  the  Sie- 
bengebirge  is  "a  peculiarly  Rhenish  kind  of  porphyry,  closely  allied 
to  basalt  and  porphyritic  schist."  He  says  '*  that  this  formation  i.s 
especially  characterised  by  glassy  felspar,"  which  he  proposes  should 
be  called  sanidine,  and  that  it  belongs,  judging  from  the  age  of  its 
formation,  to  the  middle  floetz-rocks  (Niederrheinische  Rdse,  Th.  i, 
s.  26,  28  and  47  ;  Th.  ii,  s.  428).  I  do  not  find  any  grounds  for 
Leopold  von  Buch's  conjecture  that  Nose  considered  this  porphyry- 
formation,  which  he  not  very  happily  terms  granite-porphyry,  as 
well  as  the  basalts,  to  be  of  later  date  than  the  most  recent  floetz- 
rocks.  "  The  whole  of  this  rock,"  says  the  great  geologist,  so  early 
removed  from  among  us,  "  should  be  named  after  the  glassy  felspars 
(therefore  sanidine-porphyry)  had  it  not  already  received  the  name  of 
trap-porphyry"  (Abh.  der  Berl.  AJcad.  aus  den  J.  1812—13,  s.  134). 
The  history  of  the  systematic  nomenclature  of  a  science  is  so  far  of 
importance  as  the  succession  of  prevalent  opinions  is  found  reflected 
in  it. 

67  Humboldt,  Kldnere  ScJiriftcn,  Bd.  i,  Vorrede,  s.  iii. — v, 

2G2 


452  COSMOS. 

their  age,  and  their  observations  being  deficient  in  many  of 
the  leading  ideas,  that  is  to  say,  those  discriminating  marks 
which  are  the  fruits  of  an  advancing  knowledge,  the  mate- 
rials which  have  been  carefully  collected  and  geographically 
arranged,  will  almost  alone  maintain  an  enduring  value. 

To  confine  the  term  trachyte,  as  is  frequently  done  (on 
account  of  its  earliest  application  to  the  rocks  of  Auvergne 
and  of  the  Siebengebirge,  near  Bonn)  to  a  volcanic  rock  con- 
taining felspar,  especially  Werner's  vitreous  felspar,  Nose's 
and  Abioh's  sanidine,  is  fruitlessly  to  break  asunder  that  in- 
timate concatenation  of  volcanic  rock  which  leads  to  higher 
geological  views.  Such  a  limitation  might  justify  the  ex- 
pression "  that  in  Etna,  so  rich  in  labradorite,  no  trachyte 
occurs."  Indeed  my  own  collections  are  said  to  prove  that 
"  no  single  individual  of  the  countless  volcanoes  of  the  Andes 
consists  of  trachyte ;  that  in  fact  the  subtance  of  which 
they  are  composed  is  albite,  and  that  therefore,  as  oligoclase 
was  at  that  time  (1835)  always  erroneously  considered  to  be 
albite,  all  kinds  of  volcanic  rock  should  be  designated  an- 
desite  (consisting  of  albite  with  a  small  quantity  of  horn- 
blende)".68 Gustav  Rose  has  taken  the  same  view  that  I  my- 
self adopted,  from  the  impressions  which  I  brought  back 
with  me  from  my  journeys,  on  the  common  nature  of  all  vol- 
canoes, notwithstanding  a  mineralogical  variation  in  their  in- 
ternal composition  ;  on  the  principle  developed  in  his  admi- 
rable essay  on  the  felspar  groups,69  in  his  classification  of 
the  trachytes,  he  generalizes  orthoclase,  sanidine,  the  anor- 
thite  of  Mount  Somma,  albite,  labradorite  and  oligoclase,  as 
forming  the  felspathic  ingredient  of  the  volcanic  rocks. 
Brief  appellations  which  are  supposed  to  contain  definitions 
lead  to  many  obscurities  in  orology  as  well  as  in  chemistry.  I 
was  myself  for  a  long  time  inclined  to  adopt  the  expressions 
orthoclase-trachytes,  or  labrador-trachytes,  or  oligoclase-tra- 

68L£op.  v.  Buch  in  Poggend,  Annalen,  Bd.  xxxvii,  1836,  s.  188,  190. 

69  Gustav  Rose  in  Gilbert's  Annalen,  Bd.  Ixxiii,  1823,  s.  173,  and 
Annales  de  Chimie  et  de  Physique,  t.  xxiv,  1823,  p.  16.  Oligoclase  was 
first  held  by  Breithaupt  as  a  new  mineral  species  (Poggendorff's  Annalen, 
Bd.  viii,  1826,  s.  238).  It  afterwards  appeared  that  oligoclase  was  iden- 
tical with  a  mineral  which  Berzelius  had  observed  in  a  granite  dyke 
resting  upon  gneiss  near  Stockholm,  and  which,  on  account  of  the  re- 
semblance in  ita  chemical  composition  he  had  called  ''  Natron  Spodu- 
men."  (Poggendorff's  Annal.  Bd.  ix,  1827,  s.  281). 


TRUE  VOLCANOES.  '    453 

chyles,  thus  comprehending  the  glassy  felspar  (sanidine),  on 
account  of  its  chemical  composition,  under  the  species  ortho- 
clase  (common  felspar).  The  terms  were  at  least  well-sound- 
ing and  simple,  but  their  very  simplicity  must  have  induced 
error,  for  though  labrador-trachyte  points  to  Etna  and  to 
Stromboli,  yet  oligoclase-trachyte,  in  its  important  twofold 
combination  with  augite  and  hornblende,  would  erroneously 
connect  the  widely  diffused  and  very  dissimilar  formations 
of  Chimborazo  and  the  volcano  of  Toluca.  It  is  the  asso- 
ciation of  a  felspathic  element  with  one  or  two  others  which 
here  forms  the  characteristic  feature,  as  it  does  in  the  forma- 
tion of  some  mineral-dykes. 

The  following  is  a  view  of  the  divisions  into  which  Gustav 
Rose,  subsequently  to  the  winter  of  1852,  distributes  the 
trachytes,  in  reference  to  the  crystals  enclosed  in  them,  and 
separately  recognisable.  The  chief  results  of  this  work,  in 
which  there  is  no  confounding  of  oligoclase  with  albite,  were 
obtained  ten  years  earlier ;  when  my  friend  discovered,  in 
the  course  of  his  geognostic  investigations  in  the  Riesenge- 
birge,  that  the  oligoclase  there  formed  an  essential  ingredient 
of  the  granite,  and  his  attention  being  thus  directed  to  the 
importance  of  oligoclase  as  an  ingredient  of  that  rock,  he 
was  induced  to  look  for  it  likewise  in  other  rocks.70  This 
examination  led  to  the  important  result  (Poggend.  Ann. 
Bd.  Ixvi,  1845,  s.  109)  that  albite  never  forms  a  part  in  the 
mixed  composition  of  any  rock. 

First  division.  "  The  principal  mass  contains  only  crystals 
of  glassy  felspar,  which  are  laminar,  and  in  general  large. 
Hornblende  and  mica  either  do  not  occur  in  it  at  all,  or  in 
extremely  small  quantity,  and  as  an  entirely  unessential  ad- 
mixture. To  this  division  belongs  the  trachyte  of  the  Phle- 
"°  See  Gustav  Rose  on  the  granite  of  the  Riesengebirge,  in  Poggen- 
dorff's  Ann.  Bd.  Ivi,  1842,  s.  617.  Berzelius  had  found  the  oligoclase, 
his  "  Natron  Spodumen,"  only  in  a  dyke  of  granite  ;  in  the  treatise  just 
cited  it  is  for  the  first  time  spoken  of  as  an  ingredient  in  the  composi- 
tion of  granite  (the  mineral  itself).  Gustav  Rose  here  determined  the 
oligoclase  according  to  its  specific  gravity,  the  greater  proportion  of 
lime  contained  in  it  as  compared  with  albite,  and  its  greater  fusibility. 
The  same  compound  with  which  he  had  found  the  specific  gravity  to 
be  2.682  was  analysed  by  Rammelsberg  (Handworterbuch  der  Mineralog. 
eupplem.  i,  s.  104,  and  G.  Rose  Ueber  die  zur  Granitgruppe  gehorenden 
Gebirgsarten,  in  the  Zeitschr.  der  Deutschen  geol.  Gesellschajt,  Bd.  i,  1849, 
B.  364). 


COSMOS. 

grsean  Fields  (Monte  Olibano  near  Pozzuoli),  that  of  Ischia 
and  of  La  Tolfa,  as  also  a  part  of  tlie  Mont-Dore  (the  Grande 
Cascade).  A  ugite  is  but  very  rarely  found  in  small  crystals 
in  trachytes  of  the  Mont-Dore71 — never,  in  the  Phlegrsean 
Fields  together  with  hornblende  ;  nor  is  leucite,  of  which 
last  however,  Hoffmann  collected  some  pieces  on  the  Lago 
Averno  (on  the  road  to  Cuinse),  while  I  found  some  on  the 
slope  of  the  Monte  Nuovo72  (in  the  autumn  of  1822). 
Leucite-ophyr  in  loose  fragments  is  more  frequent  in  the 
island  of  Procida  and  the  adjoining  Scoglio  di  S.  Martino." 

Second  Division.  "  The  ground-mass  contains  some  de- 
tached crystals  of  glassy  felspar,  and  a  profusion  of  small 
snow-white  crystals  of  oligoclase.  The  latter  are  frequently 
overspread  with  the  glassy  felspar  in  regular  order,  and 
form  a  covering  about  the  felspar,  as  is  so  frequently  seen 
in  G.  Hose's  granitite  (the  principal  mass  of  the  Eiesen- 
gebirge  and  Iser-gebirge,  consisting  of  granite  with  red 
felspar,  particularly  rich  in  oligoclase  and  magnesian-mica, 
but  without  any  white  potash-mica).  Hornblende  and  mica, 
and  in  some  modifications  augite,  occasionally  appear  in 
small  quantity.  To  this  division  belong  the  trachytes  of  the 
Drachenfels  and  of  the  Perlenhardt  in  the  Siebengebirge73 
near  Bonn,  and  many  modifications  of  the  Mont-Dore  and 
Cantal ;  some  trachytes  also  of  Asia  Minor  (for  which  we 
are  indebted  to  that  industrious  traveller  Peter  von  Tschi- 

71  Eozet,  Sur  les  montagnes  de  1'Auvergne,  in  the  Mem.  de  la  Soc. 
Geol.de  France,  2me  SeVie,  t.  i,  partie  i,  1844,  p.  69. 

72  Fragments  of  Leucite-ophyr,  collected  by  me  at  the  Monte  Nuovo, 
are  described  by  Gustav  Hose  in  Fried.  Hoffmann's  Geoynosticheii  Beo- 
backtungen,  1839,  s.  219.     On  the  trachyte  of  the  Monte  di  Procida  of 
the  island  of  the  same  name,  and  the  rock  of  San  Martino,  see  Roth, 
Monographic  des  Vesuvs.  1857,  s.  519 — 522,  tab.  viii. — The  trachyte  of 
the  island  of  Ischia  contains  in  the  Arso,  or  stream  of  Cremate  (1301) 
vitreous  felspar,  brown  mica,  green  augite,  magnetic  iron  and  olivine 
(s.  528),  but  no  leucite. 

73  The  geologico-topographical  conditions  of  the  Siebengebirge  near 
Bonn,  have  been  developed  with  comprehensive  talent  and  great  exact- 
ness by  my  friend  H.  von  Dechen,  director  of  mines,  in  the  9th  annual 
volume  of  the  Verhandlungcn  des  Naturhistorischen  Vereines  der  Preuss, 
RkcMandeund  Westphalens,  1852,  s.  289—567.     All  the  chemical  ana- 
lyses  of  the  trachytes  of  the  Siebengebirge  which  hf>ve  hitherto  ap- 
peared are  there  collected  (p.  323 — 356);  mention  is  also  made  of  the 
trachytes  of  the  Drachenfels  and  Rottchen,  in  which,  besides  the  large 
crystals  of  sanidine,  several  small  crystalline  particles  may  be  distm- 


TRUE   VOLCANOES.  455 

ehatscheff),  of  Afran  Karahissar  (famous  for  the  culture  of  the 
poppy)  and  Menammed-kyoe  in  Phrygia,  and  of  Kayadschyk 
and  Donanlar  in  Mysia,  in  which  glassy  felspar,  with  a  great 
deal  of  oligoclase,  some  hornblende,  and  brown  mica  are 
mingled." 

guisbed  in  the  fundamental  mass.  "  These  portions  have  been  found 
by  I)r.  Bothe,  on  chemical  analysis  in  Mitscherlich's  Laboratory,  to 
be  oligoclase,  corresponding  exactly  with  the  oligoclase  of  Danvikszoll 
(near  Stockholm)  noticed  by  Berzelius."  (Dechen,  s.  340 — 346).  The 
Wolkenburg  and  the  Stenzelberg  are  destitute  of  glassy  felspar  (s.  357 
and  363),  and  belong,  not  to  the  second  division,  but  to  the  third  ;  they 
contain  a  Toluca-rock.  That  section  of  the  geological  description  of 
the  Siebengebirge  which  treats  of  the  relative  age  of  trachyte-conglo- 
merate and  basalt  conglomerate  contains  many  new  views  (p.  405 — 461). 
"  With  the  more  rare  dykes  of  trachyte  in  the  trachyte-conglomerates, 
which  prove  that  the  formation  of  trachyte  has  still  continued  after  the 
deposit  of  the  conglomerate  (s.  413),  are  associated  a  great  number  of 
basalt  courses  (s.  416).  The  basalt-formation  extends  decidedly  into  a 
later  basalt  than  the  trachyte-formation,  and  the  principal  mass  of  the 
basalt  is  here  more  recent  than  the  trachyte.  On  the  other  hand  a  portion 
of  this  basalt  only,  and  not  of  all  basalts  (s.  323)  is  more  recent  than  the 
great  mass  of  the  brown-coal  rocks.  Both  formations,  the  basalt  and 
the  brown-coal  rocks,  run  into  each  other  in  the  Siebengebirge  as  well 
as  in  many  other  places,  and  must  be  considered  in  the  aggregate  as 
contemporaneous."  Where  very  small  crystals  of  quartz  occur  by 
way  of  rarity  in  the  trachytes  of  the  Siebengebirge,  as  (according 
to  Noggerath  and  Bischof)  in  the  Drachenfels  and  in  the  valley  of 
Rhondorf,  they  fill  up  cavities  and  seem  to  be  of  later  formation  (p.  361 
and  370) ;  caused  perhaps  by  efflorescence  of  the  sanidiue.  On  Chim- 
borazo  I  have  on  one  solitary  occasion  seen  similar  deposits  of  quartz, 
though  very  thin,  on  the  internal  surfaces  of  the  cavities  of  some  very 
porous,  brick-red  masses  of  trachyte  at  an  elevation  of  about  17,000 
feet  (Humboldt,  Gisement  des  Roches,  1823,  p.  336).  These  fragments, 
which  are  frequently  mentioned  in  my  journal,  are  not  deposited  in  the 
Berlin  collections.  Efflorescence  of  oligoclase,  or  of  the  whole  funda- 
mental mass  of  the  rock  may  also  yield  such  traces  of  disengaged  silicic 
acid.  Some  points  of  the  Siebengebirge  still  merit  renewed  and  perse- 
vering investigation.  The  highest  summit,  the  Lowenburg,  represented 
as  basalt,  seems,  from  the  analysis  of  Bischof  and  Kjerulf,  to  be  a  do- 
leritic  rock  (H.  v.  Dechen,  s.  383,  386,  393).  The  rock  of  the  little 
Rosenau,  which  has  sometimes  been  called  Sanido-phyre,  belongs,  ac- 
cording to  G.  Rose,  to  the  first  division  of  his  trachytes,  and  is  very 
closely  allied  to  many  of  the  trachytes  of  the  Ponga  Islands.  The 
trachyte  of  the  Drachenfels  with  large  crystals  of  glassy  felspar  seems, 
according  to  Abich's  yet  unpublished  investigations,  most  nearly  to 
resemble  the  Dsyndserly-dagh  which  rises  to  a  height  of  8526  feet,  to 
the  north  of  the  great  Ararat,  from  a  formation  of  iiummulites  under- 
dipped  by  Devonian  strata. 


456  COSMOS. 

Third  Division.  "The  ground-mass  of  this  dioritic  tra- 
chyte contains  many  small  crystals  of  oligoclase  with  black 
hornblende  and  brown  magnesian-mica.  To  this  belong 
the  trachytes  of  ^gina,74  of  the  valley  of  Kozelnik  near 
Schemnitz75,  of  Nagyag  in  Transylvania,  of  Montabaur  in 
the  Duchy  of  Nassau,  of  the  Stenzelberg  and  the  Wolken- 
biirg  in  the  Siabengebirge  near  Bonn,  of  the  Puy  de  Chau- 
mout,  near  Clermont  in  Auvergne,  and  of  the  Liorant  in 
Cantal;  also  the  Kasbegk  in  the  Caucasus,  the  Mexican  vol- 
canoes of  Toluca76  and  Orizaba,  the  volcano  of  Purace  and  the 
splendid  columns  of  Pisoje77  near  Popayan,  though  whether 
the  latter  are  trachytes  is  very  uncertain.  The  domites 
of  Leopold  von  Buch  belong  likewise  to  this  third  di- 
vision. In  the  white,  fine-grained  fundamental  mass  of 
the  trachytes  of  the  Puy  de  Dome  are  found  glassy  crys- 
tals, which  were  constantly  taken  for  felspar,  but  which  are 
always  streaked  on  the  most  distinct  cleavage  surface,  and 
are  oligoclase ;  hornblende  and  some  mica  are  also  present. 
Judging  from  the  volcanic  specimens  for  which  the  royal 

74  From  the   close   propinquity  of   Cape   Perdica  of  the  island  of 
JEgma,  to  the  long  famous  red-brown  Trozen-trachytes  (Cosmos,  see 
above,  p.  229)  of  the  peninsula  of  Methana,  and  from  the  sulphur- 
springs  of  Bromolimni,  it  is  probable  that  the  trachytes  of  Methana,  as 
well  as  those  of  the  island  of  Kalauria,  near  the  small  town  of  Poros, 
belong  to  the  same  third  division  of  Gustav   Rose   (oligoclase  with 
hornblende  and   inica)   (Curtius,   Peloponnesos,    Bd.   ii,   s.   439,   446, 
tab.  xiv). 

75  See  the  admirable  geological  map  of  the  district  of  Schemnitz  by 
Bergrath,  Johann  von    Peltko,  1852,  and  the  Abhandlungen  dtr  Jc.  k. 
yeologischen  Reichsanstalt,  Bd.  ii,  1855,  Abth.  i,  s.  3. 

76  Cosmos,  see  above,  pp.  401 — 2. 

77  The  basaltic  columns  of  Pisoje,  the  felspathic  part  of  which  has  been 
analysed  by  Francis  (Poggend.  Annal.  Bd.  lii,  1841,  s.  471),  near  the 

banks  of  the  Cauca,  in  the  plain  of  Amolanga  (not  far  from  the  Pueblos 
of  Sta.  Barbara  and  Marmato),  consist  of  a  somewhat  modified  oligo- 
clase in  large  beautiful  crystals,  and  small  crystals  of  hornblende. 
Nearly  allied  to  this  mixture  are,  the  quartz,  containing  dioritic-por- 
phyry  of  Marmato,  brought  home  by  Degenhardt,  the  felspathic  part  of 
which  was  named  by  Abich  Andesine, — the  rock,  destitute  of  quartz, 
of  Cucurusape,  near  Marmato,  in  Boussingault's  collection  (Charles 
Ste.-Cl.  Deville,  Etudes  de  Lithologie,  p.  29),  the  rock  which  I  found  12 
geographical  miles  eastward  of  Chimborazo,  below  the  ruins  of  old 
lliobamba  (Humboldt,  Kleinere  Scliriften,  Bd.  i,  s.  161),  and  lastly,  the 
rock  of  the  Esterel  Mountains  in  the  department  of  the  Var  (Elie  da 
Beaumont,  Explic.  de  la,  Carte  Geol.  de  France,  t.  i,  p.  473). 


TRUE  VOLCANOES.  457 

collection  is  indebted  to  Herr  Mollhausen,  the  draughtsman 
and  topographist  of  Lieut.  Whipple's  exploring  expedition, 
the  third  division,  or  that  of  the  dioritic  Toluca-trachytes, 
also  includes  those  of  Mount  Taylor,  between  Santa  Fe  del 
Nuevo  Mexico  and  Albuquerque,  as  well  as  those  of  Ciene- 
guilla  on  the  western  slope  of  the  Rocky  Mountains,  where, 
according  to  the  able  observations  of  Jules  Marcou,  black  lava- 
streams  overflow  the  Jura-formation."  The  same  mixture  of 
oligoclase  and  hornblende  which  I  saw  in  the  Azteck  high- 
lands, in  Anahuac  proper,  but  not  in  the  Cordilleras  of  South 
America,  are  also  found  far  to  the  west  of  the  Rocky  Moun- 
tains and  of  Zuni,  near  the  Mohave  river,  a  tributary  of  the  Rio 
Colorado  (see  Marcou,  Resume  of  a  geological  reconnaissance 
from  the  Arkansas  to  California,  July,  1854,  pp.  46 — 48.  See 
also  two  important  French  treatises, — Resume  explicatif  d*  une 
Carte  Geologique  des  Etats-Unis,  1855,  pp.  113 — 116,  and  Ex- 
quisse  d  une  Classification  des  Chames  de  J&Lontaqnes  de  T  A.me- 
rique  du  Nord,  1855  ;  Sierra  de  S.  Francisco  et  Mount  Taylor, 
p.  23).  Among  the  trachytes  cf  Java,  for  specimer  „  of  which 
I  am  indebted  to  my  friend  Dr.  Junghuhn,  we  have  likewise 
recognised  those  of  the  third  division  in  three  volcanic  dis- 
tricts, namely,  Burung-agung,  Tyinas  and  Gurung  Parang 
(in  the  Batugangi  district). 

Fourth  division.    "  The  leading  mass  contains  augite  with 
oligoclase  : — the  Peak  of  Teixcrilie,78  the  Mexican  volcanoes 

"8  The  felspar  in  the  trachytes  of  Teneriffe  was  first  recognised  in 
1842  by  Charles  Deville,  who  visited  the  Canaiy  Islands  in  the  autumn 
of  that  year  ;  see  that  distinguished  geologist's  Voyage  Geologique  aux 
Antilles  et  aux  lies  de  Teneriffe  et  de  Fogo,  1848,  pp.  14,  74,  and  169  ; 
also  Analyse  du  Feldspath  de  Te'neriffe,  in  the  Comptes  rendus  deVAcad. 
des  Sciences,  t.  xix,  1844,  p.  46.  "  The  labours  of  Messrs.  Gustav  Rose 
and  H.  Abich,"  he  says,  "  have  contributed  in  no  small  degree,  both 
crystallographically  and  chemically,  to  throw  light  on  the  numerous 
varieties  of  minerals  which  were  comprised  under  the  vague  denomina- 
tion of  felspar.  I  have  succeeded  in  submitting  to  analysis  carefully 
isolated  crystals  whose  density  in  different  specimens  was  very  uni- 
formly 2-593,  2-594,  and  2'586.  This  is  the  first  time  that  the  oligo- 
clase felspar  has  been  indicated  in  volcanic  regions,  with  the  excep- 
tion perhaps  of  some  of  the  great  masses  of  the  Cordillera  of  the 
Andes.  It  was  not  detected,  at  least  with  any  certainty,  except  in  the 
ancient  eruptive  rocks  (plutouic,  granite,  syenite,  syenitic  porphyry 
),  but  in  the  trachytes  of  the  Peak  of  Teneriffe  it  plays  a 
part  analogous  to  that  of  the  labrador  in  the  doleritic  masses  of 


458  COSMOS. 

Popocatepetl79  and  Colima,  the  South  American  volcanoes, 
Tolima  (with  the  Paranio  de  Ruiz),  Purace  near  Popayan, 

Etna."  Compare  also  Rammelsberg,  in  the  Zeitschr.  der  Deutscken 
geol.  Gesettschaft,  Bd.  v,  1853,  s.  691,  and  the  4th  Supplement  of 
his  ffandwb'rterbuchs  der  chem.  Mineralogie,  s.  245. 

5-9  The  first  determination  of  height  of  the  great  volcano  of  Mexico, 
Popocatepetl  is,  so  far  as  I  am  aware,  the  trigonometrical  measure- 
ment already  mentioned  (see  above,  p.  41,  note  42),  executed  by  me  on 
24th  January,  1804,  in  the  Llano  de  Tetimba.  The  summit  was  found 
to  be  1536  toises  above  the  Llano,  and  as  the  latter  lies  barometrically 
1234  toises  above  the  coast  of  Vera  Cruz,  we  obtain  2770  toises,  or 
17.728  English  feet,  as  the  absolute  height  of  the  volcano.  The  baro- 
metrical mersurements  which  have  succeeded  my  trigonometrical  cal- 
culation lead  me  to  conjecture  that  the  volcano  is  still  higher  than  I 
have  made  it  in  the  Essai  sur  la  Geographic  des  Plantes,  1807,  p.  148, 
and  in  the  Essai  Politique  sur  la  Nouv.  Espagne,  t.  i,  1825,  p.  185. 
William  Glennie,  who  first  reached  the  margin  of  the  crater  on  the 
20th  April,  1827,  found  it,  according  to  his  own  calculation  (Gazcta 
del  Sol,  published  in  Mexico,  No.  1432),  17,884  feet,  equal  to  2796 
toises,  but,  as  corrected  by  the  mining  director,  Burkart,  who  has 
acquired  so  high  a  reputation  in  the  department  of  American  hypso- 
metry,  and  who  compared  the  calculation  in  Vera  Cruz  with  barome- 
trical observations  taken  nearly  at  the  same  time,  it  cornea  out 
fully  18,017  feet.  On  the  other  hand,  a  barometrical  measurement 
by  Samuel  Birbeck  (10th  Nov.  1827),  calculated  according  to  the  tables 
of  Oltmanns,  gave  only  17,854  feet,  and  the  measurement  of  Alex. 
Doignon  (Gumprecht,  Zeitsclirift  fur  Allg.  Erdkunde,  Bd.  iv,  1855, 
s.  390) ;  coinciding  almost  too  precisely  with  the  trigonometrical 
measurement  of  Tetimba,  gives  5403  metres,  equal  to  17,726  feet. 
The  talented  Herr  von  Gerolt,  the  present  Prussian  ambassador  in 
Washington,  accompanied  by  Baron  Gros,  likewise  visited  the  sum- 
mit of  Popocatepetl  ^2Sth  May,  1833),  and  found,  by  an  exact  barome- 
trical measurement,  the  Roca  del  Fraile,  below  the  crater,  16,896  feet 
above  the  sea.  Singularly  contrasted  with  these  chronologically-stated 
hypsometrical  results  appears  a  carefully-conducted  barometrical  mea- 
surement by  M.  Craveri,  published  by  Petermann  in  his  valuable 
Mittheilungen  iiber  wiclitige  neue  Erforschungen  der  Geographic,  1856 
(Heft  x),  s.  358—361.  That  traveller  found,  in  September,  1855,  the 
height  of  the  highest  margin  of  the  crater,  the  north-west,  compared 
with  what  he  considered  the  mean  height  of  the  atmospheric  pressure 
in  Vera  Cruz,  only  5230  metres,  or  17,159  feet,  which  is  555 
feet  (£%  of  the  whole  height  under  measurement)  less  than  I 
found  it  by  trigonometrical  measurement  half  a  century  previous. 
Craveri  likewise  makes  the  height  of  the  city  of  Mexico  above  the  sea 
.196  feet  less  than  Burkart  and  I  have  found  it  to  be  at  very  different 
times  ;  he  reckons  it  at  only  2217  metres,  or  7274  feet,  instead  of 
2277  metres,  or  7471  feet.  In  Dr.  Petermann's  periodical  above 
reierred  to,  p.  479 — 481,  I  have  explained  myself  more  particularly  on 


TRUE  VOLCANOES.  459 

Pasto  and   Cumbal   (according   to  specimens  collected  by 

the  subject  of  these  variations  plus  or  minus,  as  compared  with  the 
result  of  my  trigonometrical  measurement,  which  unfortunately  has 
never  been  repeated.  The  453  determinations  of  height  which  I  made 
from  September,  1799,  to  February,  1804,  in  Venezuela,  on  the  woody 
shores  of  the  Orinoco,  the  Rio  de  la  Magdalena,  and  the  river  Amazon ; 
in  the  Cordilleras  of  New  Granada,  Quito,  and  Peru,  and  in  the  tropical 
region  of  Mexico,  all  of  which,  re-calculated  by  Professor  Oltmanns, 
uniformly  according  to  the  formula  of  Laplace  and  the  co-efficients 
of  Ramond,  have  been  published  in  my  Nivelkment  JSarometrique  et  Geo- 
logique,  1810  (Recueil  d'Olserv.  Astronom.  t.  i,  pp.  295—334)  were^  per- 
formed without  exception  with  Ramsden's  cistern-barometers  "a  niveau 
constant,"  and  not  with  apparatus  in  which  several  fresh-filled  Torricel- 
lian tubes  may  be  inserted  one  after  another,  nor  by  the  instrument,  pro- 
jected by  myself,  described  in  Lametherie's  Journal  de  Physique,  t.  iv, 
p.  468,  and  occasionally  used  in  Germany  and  France  during  the  years 
1796  and  1797.  Gay-Lussan  and  I  made  use,  to  our  mutual  satisfaction, 
of  a  portable  Ramsden  cistern-barometer  exactly  similar  in  construc- 
tion, in  the  year  1805,  during  our  journey  through  Italy  and  Swit- 
zerland. The  admirable  observations  of  the  Olmutz  astronomer, 
Julius  Schmidt,  on  the  margins  of  the  crater  of  Vesuvius  (Beschreib un y 
der  Eruption  im  Mai,  1855,  s.  114 — 116)  furnish  from  their  similarity 
additional  motives  of  satisfaction.  As  I  never  have  ascended  the  sum- 
mit of  Popocatepetl,  but  measured  it  trigonometrically,  there  is  no 
foundation  whatever  for  the  extraordinary  criticism  (Craven,  in  Peter- 
maun's  Geogr.  Mittheilungen,  Heft  x,  s.  359),  " that  the  height  of  the 
mountain  as  described  by  me  is  unsatisfactory,  because,  as  I  my- 
self stated,  I  had  made  use  of  fresh-filled  Torricellian  tubes."  The 
apparatus  with  several  tubes  ought  never  to  be  used  in  the  open  air, 
more  especially  on  the  summit  of  a  mountain.  It  is  one  of  those 
means  which,  from  the  conveniences  furnished  by  large  towns,  may 
be  employed  at  long  intervals,  when  the  opeiator  feels  anxious  as  to 
the  state  of  his  barometer.  For  my  own  part,  I  have  had  recourse  to 
it  only  on  very  rare  occasions,  but  I  would  nevertheless  still  recom- 
mend it  to  travellers,  accompanied  by  a  comparison  with  the  boiling 
point,  as  warmly  as  I  did  in  my  Observations  Astronomiques  (vol.  i, 
pp.  363 — 373): — "As  it  is  better  not  to  observe  at  all  than  to  make  bad 
observations,  we  ought  to  be  less  afraid  of  breaking  the  barometer  than 
of  putting  it  out  of  order.  M.  Bonpland  and  I  having  four  different 
times  traversed  the  Cordilleras  of  the  Andes,  the  determinations  which 
chiefly  interested  us  were  repeated  at  different  times,  as  we  returned 
to  the  places  which  seemed  doubtful.  We  occasionally  employed  the 
apparatus  of  Mutis,  in  which  Torricelli's  primary  experiment  is  per- 
formed, by  applying- successively  three  or  four  strongly  heated  tubeK, 
filled  with  mercury  recently  boiled  in  a  stoneware  crucible.  When 
there  is  no  possibility  of  replacing  the  tubes,  it  is  perhaps  prudent 
not  to  boil  the  mercury  in  the  tubes  themselves.  In  this  way 
I  have  found,  in  experiments  made  in  conjunction  with  Lindner, 


iGO  COSMOS. 

Boussingault),  Rucu-Piehincha,  Antisana,  Cotopaxi,  Chim- 

Professor  of  Chemistry  at  the  School  of  Mines  in  Mexico,  the  height  of 
the  column  of  mercury  at  Mexico  in  six  tubes,  as  follows  :— 

259.7  lines  (old  Paris  foot) 

259.5 

259.9 

259.9 

260.0 

259.9 

"  The  two  last  tubes  alone  had,  by  means  of  heat,  been  deprived  of  air 
by  Bellardoni,  the  instrument  maker  at  Mexico.  As  the  exactness  of 
the  experiment  depends  partly  on  the  perfect  cleanliness  of  the  inside 
of  the  empty  tubes,  which  are  so  easily  carried,  it  is  a  good  plan  to  seal 
them  hermetically  over  a  lamp."  As  the  angles  of  altitude  cannot,  in 
mountainous  districts,  be  taken  from  the  sea-shore,  and  the  trigono- 
metrical measurements  are  of  a  mixed  nature  and  to  a  considerable 
extent  (frequently  as  much  as  i  or  -^y  of  the  whole  height)  baro- 
metrical, the  determination  of  the  height  of  the  elevated  plain  in  which 
the  base  line  may  be  measured  is  of  great  importance.  As  cor- 
responding barometrical  observations  at  sea  are  seldom  obtained,  or  for 
the  most  part  only  at  too  great  a  distance,  travellers  are  too  often  in- 
duced to  take  the  results  they  have  obtained  from  a  few  days'  obser- 
vations, conducted  by  them  at  different  seasons  of  the  year,  as  the 
mean  height  of  the  pressure  of  the  atmosphere  on  the  elevated  plain 
and  at  the  seashore.  u  In  wishing  to  know  whether  a  measurement 
made  by  means  of  the  barometer  possesses  the  exactness  of  trigono- 
metrical operations,  it  is  only  necessary  to  ascertain  whether,  in  a  given 
case,  the  two  kinds  of  measurement  have  been  taken  under  equally 
favourable  circumstances,  that  is  to  say,  by  fulfilling  those  con- 
ditions which  both  theory  and  long  experience  have  prescribed.  The 
mathematical  experimenter  dreads  the  effect  of  terrestrial  refrac- 
tions, while  the  physical  experimenter  has  reason  to  fear  the 
unequal  and  far  from  simultaneous  distribution  of  the  temperature 
in  the  column  of  air  at  the  extremities  of  which  the  two  barometers 
are  placed.  It  is  probable  enough  that  near  the  surface  of  the  earth 
the  decrease  of  caloric  is  slower  than  at  greater  elevations,  and  in 
order  to  ascertain  with  precision  the  mean  density  of  the  whole  column 
of  air,  it  would  be  necessary  to  ascend  in  a  balloon  so  as  to  examine  the 
temperature  of  each  successive  stratum  or  layer  of  the  superimposed 
air"  (Humboldt,  Recueil  d'  Observ.  Astron.  vol.  i,  p.  138;  see  also  371,  in 
the  appendix  on  refraction  and  barometrical  measurements).  While 
the  barometrical  measurement  of  M.  M.  Truqui  and  Craveri  gives  only 
17,159  feet  to  the  summit  of  Popocatepetl,  whereas  Glennie  gives 
17,889  feet,  I  find  that  the  lately  published  measurement  of  Professor 
Carl  Heller  of  Olmiitz,  who  has  thoroughly  investigated  the  district 
surrounding  Mexico,  as  well  as  the  provinces  of  Yucatan  and  Chiapa, 


TRUE  VOLCANOES.  461 

borazo,80  Tunguragua,  and  trachyte  rocks  which  are 
covered  by  the  ruins  of  Old  Riobamba.  In  the  Tunguragiia, 
besides  the  augites  there  occur  also  separate  blackish  green 

corresponds  to  within  32  feet  of  my  own.  (Compare  my  Essay  on  th« 
If  eight  of  the  Mexican  Volcano  Popocatepetl,  in  Dr.  Petermann's 
Mittheilungen  aus  Justus  Perthes  Geographischer  Anstalt,  1856,  s.  479 
—481). 

80  In  the  Chimborazo  rock  it  is  not  possible,  as  in  the  Etna  rock, 
to  separate  mechanically  the  felspathic  crystals  from  the  ground- 
mass  in  which  they  lie,  but  the  large  proportion  of  silicic  acid  which 
it  contains,  along  with  the  fact  connected  therewith  of  the  small 
specific  gravity  of  the  rock,  make  it  apparent  that  the  felspathic 
constituent  is  oligoclase.  The  quantity  of  silicic  acid  which  a  mineral 
contains  and  its  specific  gravity  are  generally  in  an  inverse  ratio ; 
in  oligoclase  and  labradorite  the  former  is  64  and  53  per  cent, 
while  the  latter  is  2.66  and  2.71.  Anorthite,  with  only  44  per  cent,  of 
silicic  acid,  has  the  great  specific  gravity  of  2.76.  This  inverse  pro- 
portion between  the  quantity  of  silicic  acid  and  the  specific  gravity 
does  not  occur,  as  Gustav  Rose  remarks,  in  the  felspathic  minerals, 
which  are  also  isomorphous,  but  with  a  different  crystalline  form. 
Thus  felspar  and  leucite,  for  instance,  have  the  same  component 
parts, — potash,  alumina,  and  silicic  acid.  The  felspar,  however,  con- 
tains 65  and  the  leucite  only  56  per  cent,  of  silicic  acid,  yet  the 
former  has  a  higher  specific  gravity,  namely,  2.56,  than  the  latter, 
whose  specific  gravity  is  only  2.48. 

Being  desirous  in  the  spring  of  1854  to  obtain  a  fresh  analysis  of 
the  trachyte  of  Chimborazo,  Professor  Rammelsberg  kindly  undertook 
the  task,  and  performed  it  with  his  usual  accuracy.  I  here  give  the 
results  of  this  analysis,  as  they  were  communicated  to  me  by  Gustav 
Hose,  in  a  letter  in  the  month  of  June,  1854.  He  says  :  "  The  Chim« 
borazo  rock,  submitted  to  a  careful  analysis  by  Professor  Rammels- 
berg, was  broken  from  a  specimen  belonging  to  your  collection,  which 
you  had  brought  home  from  the  narrow  rocky  ridge  at  a  height  of 
more  than  19,000  feet  above  the  sea." 

Rammelsberys  Analysis. 
(Height  19,194  English  feet;  spec.  grav.  2.806.) 


Oxygen. 

Silicic  acid   59.12          ...  30.70         2.33 

Alumina  13.48          ...  6.30 

Protoxide  of  irou    7.27 

Lime    (5.50 

Magnesia 5.41         2.13}    T.93 

Soda ......     3.46 

Potash 2.64 

97.83 


V.fU  ^.O< 

6.30  j       ... 
6.93  J 


462  COSMOS. 

crystals  of  uralite,  of  from  half  a  line  to  five  lines  in  length, 
with  a  perfect  augite  form  and  the  cleavage  of  hornblende 
(see  Rose,  Reise  nacJi  dem  Ural,  Bd.  ii,  s.  353)."  I  brought 

Alick's  Analysis. 

(Height  16,179  English  feet;  spec.  grav.  2.685.) 

Oxygen. 

Silicic  acid  65.09  ...  33.81  .     2.63 

Alumina  15.58  ...  7.27 

Oxide  of  iron  3.83  ...  1.16 

Protoxide 1.73  ...  0.39 

Lime 2.61          ...  0.73 

Magnesia 4.10  ...  1.58 

Soda 4.46  ...  1.14 

Potash 1.99  ...  0.33 

Chlorine,  and  loss  by  )   «... 
heat     J 

99.80 

In  explanation  of  these  figures  it  must  be  observed,  that  the  first 
series  gives  the  ingredients  in  a  per  eentage,  the  second  and  third  give 
the  oxygen  contained  in  them.  The  second  space  shows  only  the 
oxygen  of  the  stronger  oxides  (those  which  contain  1  atom  of  oxygen). 
In  the  third  space  this  is  recapitulated,  so  as  to  offer  a  comparison 
with  that  of  the  alumina  earth  (which  is  a  weak  oxide)  and  of  the 
silicic  acid.  The  fourth  space  gives  the  proportion  of  the  oxygen  of 
the  silicic  acid  to  the  oxygen  of  the  aggregate  bases,  which  latter 
are  fixed  =  1.  In  the  trachyte  of  Chimborazo  thia  proportion 
is -2.33:1. 

"  The  differences  between  the  analyses  of  Rarnmelsberg  and  of 
Abich  are  certainly  important.  Both  analysed  minerals  from  Chim- 
borazo,  from  the  relative  heights  of  19,194  and  16,179  feet,  which 
wei'e  broken  off  by  you  and  were  taken  from  your  geological  collection 
in  the  Royal  Mineral  Cabinet  at  Berlin.  The  mineral  from  the  lower 
elevation  (scarcely  400  feet  higher  than  the  summit  of  Mont  Blanc) 
which  Abich  has  analysed,  posseses  a  smaller  specific  gravity,  and  in 
correspondence  therewith  a  greater  quantity  of  silicic  acid,  than  the 
mineral  taken  from  a  point  2918  feet  higher,  analysed  by  Ram- 
nielsberg.  Assuming  that  the  argillaceous  earth  belongs  only  to  the 
felspathic  ingredient,  we  may  reckon  in  the  analysis  of  Rammels- 
berg  :— 

Oligoclase 58.66 

Augite   34.14 

Silicic  acid 4.08 

As  thus,  by  the  assumption  of  oligoclase,  a  portion  of  silicic  acid 
remains  over  uncombined,  it  is  probable  that  the  felspathic  ingredient 
is  oligoclase  and  not  labradorite.  The  latter  does  not  occur  witb 


TRUE  VOLCANOES. 


463 


a  similar  fragment,  with  distinct  uralite  crystals,  from  tlie 
slope  of  the  Tunguragua  at  an  elevation  of  13,260  feet. 
Gustav  Hose  considers  this  specimen  strikingly  different 

uncouibined  silicic  acid,  and  if  we  were  to  suppose  labradorite  in  the 
rock,  a  greater  quantity  of  silicic  acid  would  remain  over." 

A  careful  comparison  of  several  analyses  for  which  I  am  indebted 
to  the  friendship  of  M.  Charles  Sainte-Claire  Deville,  to  whom  the 
valuable  geological  collections  of  our  mutual  friend  Boussingault  are 
accessible  for  chemical  experiment,  shows  that  the  quantity  of  silicic 
acid  contained  in  the  fundamental  mass  of  the  trachytic  rocks  is  gene- 
rally greater  than  in  the  felspars  which  they  contain.  The  table  kindly 
communicated  to  me  by  the  compiler  himself  in  the  month  of  June, 
1857,  contains  only  five  of  the  great  volcanoes  of  the  chain  of  the 
Andes : —  ' 


Nnmes  of 
the  Volcanoes. 

Structure  and  Colour  of  the  Mass. 

Silicic  Acid 
in  the  whole  Mass. 

."232 

*1! 

£~  3 
i».S  * 

Chimborazo 

;  semi-vitrified,  brownish  grey 
j  semi-vitreous,  and  black  
i  crystalline,  compact,  grey  
J  grey-black 

Go.  09  Abich    } 
63.19  Deville  I 
62.66  Deville  ) 
64  26  Abich    i 

58.26 

Antisana 

63  23  Abich    j 

58.26 

J  vitreous  and  brownish 

69  28  Abich    ) 

Cotopaxi 

63  98  Abich    j 

Pichincha 

black,  vitreous    

67  07  Abich 

Puracd 

nearly  bottle  green  

68.80  Deville 

55  40 

Guadaloupe 
Bourbon 

grey,  granulated,  and  cellular 
crystalline,  grey,  porous    

57.95  Deville 
50.90  Deville 

54.25 
49.06 

"  These  differences,  as  far  as  regards  the  relative  richness  in  silica  of 
the  ground-mass  (and  the  felspar),"  continues  Charles  Deville,  "  will 
appear  still  more  striking  when  it  is  considered  that,  in  analysing  a, 
rock  en  masse,  there  are  included  in  the  analysis,  along  with  the  basis 
properly  so  called,  not  only  fragments  of  felspar  similar  to  those  which 
have  been  extracted,  but  even  such  minerals  as  amphibole,  pyroxene, 
and  especially  peridote,  which  are  less  rich  in  silica  than  the  felspar. 
This  excess  of  silica  manifests  itself  sometimes  by  the  presence  of  iso- 
lated grains  of  quartz,  which  M.  Abich  has  detected  in  the  trachytes 
of  the  Drachenfels  (Siebengebirge,  near  Bonn),  and  which  I  have  myself 
observed  with  some  surprise  in  the  trachytic  dolerite  of  Guadaloupe." 

"  If,"  observes  Gustav  Rose,  "  we  add  to  this  remarkable  synopsis  of 
the  silicic  acid  contained  in  Chimborazo  the  result  of  the  latest  analysis, 


cosmos. 

from  the  seven  fragments  of  trachyte  from  the  same  volcano 
which  are  contained  in  my  cabinet.  It  recalls  to  mind  the 
formation  of  green  slate  (schistose  augitic-porphyry)  which  we 

that  of  Rammelsberg  in  May,  1854,  we  shall  find  that  the  result 
obtained  by  Deville  occupies  exactly  the  mean  between  those  of  Abich 
and  Rammelsberg.  Thus  : — 

Cliimborazo-rock. 

Silicic  acid  65.09  Abich  (spec.  grav.  2.685) 
63.19  Deville 
62.66      do. 
59.12  Rammelsberg  (spec.  grav.  2.806)" 

In  the  Echo  du  Patifique  of  the  5th  January,  1857,  published  at 
San  Francisco  in  California,  an  account  is  given  of  a  French  traveller, 
named  M.  Jules  Re"my,  having  succeeded,  on  the  3rd  November,  1856, 
in  company  with  an  Englishman,  Mr.  Brencklay,  in  reaching  the 
summit  of  Chimborazo,  which  was  "  however,  enveloped  in  a  cloud,  so 
that  we  ascended  without  perceiving  it."  He  observed,  it  is  stated, 
the  boiling  point  of  water  at  171°.5  F.,  with  the  temperature  of  the 
air  at  31°.9  F.,  on  calculating  upon  these  data,  the  height  he 
had  attained  by  a  hypsometrical  rule  tested  by  him  in  repeated 
journeys  in  the  Haway  Archipelago,  he  was  astonished  at  the  result 
brought  out.  He  found,  in  fact,  that  he  was  at  an  elevation  of  21,467 
feet,  that  is  to  say,  at  a  height  differing  by  only  40  feet  from  that 
given  by  my  trigonometrical  measurement  at  Riobamba  Nuevo  in  the 
elevated  plain  of  Tapia,  in  June,  1803,  as  the  height  of  the  summit 
of  Chimborazo, — namely,  21,426  feet.  This  correspondence  of  a  trigo- 
nometrical measurement  of  the  summit  with  one  founded  on  the 
boiling  point  is  the  more  surprising,  as  my  trigonometrical  measure- 
ment, like  all  measurements  of  mountains  in  the  Cordilleras,  involves 
a  barometrical  portion,  and  from  the  want  of  corresponding  observa- 
tions on  the  shore  of  the  South  Sea,  my  barometrical  determination  of 
the  height  of  the  Llano  de  Tapia,  9484  feet,  cannct  possess  all  the 
exactness  that  could  be  desired.  (For  the  details  of  my  trigonometrical 
measurement,  see  my  Recueil  d' Observations  Aslron.,  vol.  i,  pp.  72  aud 
74).  Professor  Poggendorff  kindly  undertook  to  ascertain  what  result 
under  the  most  probable  hypotheses  a  rational  mode  of  calculation 
would  produce.  He  found,  reckoning  under  both  hypotheses,  that 
the  prevailing  temperature  of  the  atmosphere  at  the  sea  being  81C.5  F., 
or  79°.7  F.,  and  the  barometer  marking  29.922  inches,  with  the  ther- 
mometer at  the  freezing  point,  the  following  result  is  obtained  by 
Regnault's  table  : — the  boiling  point  at  the  summit  at  171°.5  F.  answers 
to  12,677  inches  of  the  barometer  at  32°  temperature  ;  the  tempera- 
ture of  the  air  may  therefore  be  taken  at  35°.3  F.  =  34°.7  F. 
According  to  these  data,  Oltmanns'  tables  give,  for  the  height  ascended, 
under  the  first  hypothesis  (81°.5),  =  7328'".2,  or  24,043  feet,  and  under 
the  second  (79°.7),  =  7314m.5,  or  23,998  English  feet,  showing  an 


TRUE  VOLCANOES.  4G5 

have  found  so  diffused  on  the  Asiatic  side  of  the  Ural 
(Ibid.  s.  544). 

Fifth  division.  "  A  mixture  of  labradorite81  and  augite,*3 
a  doleritic  trachyte  :  Etna,  Stromboli ;  and,  according  to 
the  admirable  works  on  the  trachytes  of  the  Antilles  by 
Charles  Saint e-Claire  Deville,  the  Soufriere  de  la  Guadeloupe, 
as  well  as  the  three  great  cirques  which  surround  the  Pic  de 
Salazu,  on  Bourbon." 

Sixth  division.  "The  ground-mass,  often  of  a  grey 
colour,  in  which  crystals  of  leucite  and  augite  lie  imbedded, 
with  very  little  olivine  : — Vesuvius  and  Sornma ;  also  the 
extinct  volcanoes  of  Yultur,  Kocca  Monfina,  the  Albanian 
hills  and  Borghetto.  In  the  older  mass  (for  example,  in  the 
wall  and  paving-stones  of  Pompeii)  the  crystals  of  leucite  are 
more  considerable  in  size  and  more  numerous  than  the  augite. 

average  of  777m.,  or  2549  English  feet,  more  than  my  barometrical 
measurement.  To  have  corresponded  with  this,  the  boiling  point, 
should  have  been  found  about  2°.25  cent,  higher,  if  the  summit  of 
Chimborazo  bad  actually  been  reached.  Poggendorffs  Annalen,  Bd.  c, 
1857,  s.  479. 

bl  That  the  trachytic  rocks  of  Etna  contain  labradorite  was  demon  • 
strated  by  Gustav  Rose  in  1833,  when  he  exhibited  to  his  friends  the  rich 
Sicilian  collections  of  Friedrich  Hoffmann  in  the  Berlin  Mineralogical 
cabinet.  In  his  treatise  on  the  minerals  known  by  the  names  of  green- 
stone and  green-stone  porphyry  (Poggend.  Annal.,  Bd.  xxxiv,  1835, 
p.  29),  Gustav  Rose  mentions  the  lavas  of  Etna,  which  contain  augite 
and  labradorite  (compare  Abich  in  his  interesting  treatise  on  the  whole 
felspathic-family,  (Poggend.  Annul.,  1840,  Bd.  1,  s.  347).  Leopold  von 
Buch  describes  the  rock  of  Etna  as  analogous  to  the  dolerite  of  the 
basalt-formation  (Poggend.  Annal.,  Bd.  xxxvii,  1836,  s.  188). 

82  Sartorius  von  Waltershausen,  who  has  for  many  years  carefully 
investigated  the  trachytes  of  Etna,  makes  the  following  important 
observations  : — "  the  hornblende  there  belongs  especially  to  the  older 
masses, — the  green-stone  veins  in  the  Val  del  Bove,  as  well  as  the 
white  and  red  trachytes,  which  form  the  ground  mass  of  Etna  in 
the  Serra  Giannicola.  Black  hornblende  and  bright  yellowish-green 
augite  are  there  found  side  by  side.  The  more  recent  lava-streams 
from  1669  (especially  those  of  1787,  1809,  1811,  1819,  1832,  1838, 
and  1842),  show  angiie,  but  no  hornblende.  The  latter  seems  to  be 
generated  only  after  a  longer  period  of  cooling'' (Waltershausen,  Ueber 
die  vulkainscken  Getteine  ron  SiciUen  und  Island,  1853,  s.  Ill — 114). 
Ill  the  augitiferous  trachytes  of  the  fourth  division  in  the  chain  of  the 
Andes,  along  with  the  abundant  augites,  I  have  indeed  sometimes  found 
none,  but  sometimes,  as  at  Cotopaxi  (at  an  elevation  of  14,068  feet)  and 
at  Rucu-Pichincha,  at  a  height  of  15,304  feet,  distinct  black  hornblende- 
crystals  in  small  quantities. 

VOL.  V.  2  H 


46(5  COSMOS. 

In  the  present  lavas,  on  the  contrary,  the  atigites  predomi- 
nate and  the  leucites  are  on  the  whole  very  scarce,  although 
the  lava-stream  of  the  2 2nd  April,  1845,  has  furnished  them 
in  abundance.83  Fragments  of  trachytes  of  the  first  division, 
containing  glassy  felspar  (Leopold  von  Buch's  trachyte 
proper),  are  imbedded  in  the  tufas  of  Monte  Sornma ;  they 
also  occur  detached  in  the  layer  of  pumice  which  covers 
Pompeii.  The  leucite-ophyr- trachytes  of  the  sixth  division 
must  be  carefully  distinguished  from  the  trachytes  of  the 
first  division,  although  leucites  occur  in  the  westernmost 
part  of  the  Phlegraean  fields  and  on  the  island  of  Procida, 
as  has  been  already  mentioned." 

The  talented  originator  of  the  above  classification  of  vol- 
canoes, according  to  the  association  of  the  simple  minerals 
which  they  present,  does  not  by  any  means  suppose  that  he 
has  completed  the  grouping  of  all  that  are  found  on  the 
surface  of  the  earth,  which  is  still  on  the  whole  so  very 

83  See  Pilla,  in  the  Compfes  rendus  de  VAcad.  des  Sc.,  t.  xx,  1845, 
p.  324.  In  the  leucite-crystals  of  the  Rocca  Monfina,  Pilla  has  found 
the  surface  covered  with  worm-tubes  (scrpulcu),  indicating  a  submarine 
volcanic  formation.  On  the  leucite  of  the  Eifel,  in  the  trachyte  of  the 
Burgberg  near  Riedeu,  and  that  of  Albano,  Lago  Bracciano,  and  Bor- 
ghetto,  to  the  north  of  Rome,  see  above,  page  32,  note  93.  In 
the  centre  of  large  crystals  of  leucite,  Leop.  v.  Buch  has  generally 
found  the  fi-agment  of  a  crystal  of  augite,  round  which  the  leucite- 
crystallisation  has  formed,  "  a  circumstance  which,  considering  the 
ready  fusibility  of  the  augite,  and  the  infusibility  of  the  leucite,  is 
somewhat  singular.  More  frequently  still  are  fragments  of  the  funda- 
mental mass  itself  enclosed  like  a  nucleus  iu  leucite-porphyry."  Olivine 
is  likewise  found  in  lavas,  as  in  the  cavities  of  the  obsidian,  which  I 
brought  from  the  Cerro  del  Jacal  in  Mexico  (Cosmos,  vol.  i,  p.  268, 
note  J),  and  yet,  strange  to  say,  also  in  the  hypersthene  rock  of 
Elfdal  (Berzelius,  Sechster  Jahrexbericht,  1827,  s.  302),  which  was 
long  considered  to  be  syenite.  A  similar  contrast  in  the  nature  of  the 
places  where  it  is  found  is  exhibited  by  oligoclase,  which  occurs  in  the 
trachytes  of  still  burning  volcanoes  (the  Peak  of  Teneriffe  and  Cotopaxi), 
and  yet  at  the  same  time  also  in  the  granite  and  granitite  of  Schreiber- 
FHU  and  Warmbrunn  in  the  Silesian  Riesengebirge  (Gustav  Rose,  in 
the  minerals  belonging  to  the  granite-group,  in  the  Zeitscliriften  d. 
Deutsch.  geoL  Geselhch.,  zu  Berlin,  Bd.  i,  s.  364).  This  is  not  the  case 
with  the  leucite  in  the  Plutonic  rocks,  for  the  statement  that  leucite 
has  been  found  disseminated  in  the  mica-slate  and  gneiss  of  the 
Pyrenees  near  Gavarnie  (an  assertion  which  even  Hauy  has  repeated) 
lias  been  found  erroneous,  after  many  years'  investigation,  by  Dufreuoy 
(Traits  de  Mincralogie,  t.  iii,  p.  399). 


TRUE  VOLCANOES.  467 

imperfectly  investigated  in  a  scientifically  geological  and 
chemical  sense.  Modifications  in  the  nomenclature  of  the 
associated  minerals,  as  well  as  additions  to  the  trachyte- 
formations  themselves,  are  to  be  expected  in  two  ways,  both 
from  the  progressive  improvement  of  mineralogy  itself  (in  a 
more  exact  specific  distinction  both  with  regard  to  form  and 
chemical  composition),  and  from  the  increased  number  of 
collections,  which  are  for  the  most  part  so  incomplete  and 
so  aimless.  Here,  as  in  all  other  cases  where  the  governing 
law  in  cosmical  investigations  can  only  be  discovered  by  a 
widely-extended  comparison  of  individual  cases,  we  must 
proceed  on  the  principle  that  everything  which,  in  the 
present  condition  of  science,  we  think  we  know,  is  but  a 
small  portion  of  what  the  next  century  will  bring  to  light. 
The  means  of  early  acquiring  this  advantage  lie  in  profusion 
before  us,  but  the  investigation  of  the  trachytic  portion  of 
the  dry  surface  of  the  earth,  whether  raised,  depressed,  or 
opened  up  by  fissures,  has  hitherto  been  very  deficient  in  the 
employment  of  thoroughly  exhaustive  methods. 

Though  similar  in  form,  in  the  construction  of  their  frame- 
work and  their  geotectonic  relations,  volcanoes  situated 
very  near  each  other  have  frequently  a  very  different  indi- 
vidual character  in  regard  to  the  composition  and  association 
of  their  mineral  aggregate.  On  the  great  transverse  fissure 
which,  extending  from  sea  to  sea,  almost  entirely  in  a  direc- 
tion from  west  to  east,  intersects  a  chain  of  mountains,  or, 
more  properly  speaking,  an  uninterrupted  mountainous  swell, 
running  from  south-east  to  north-west,  the  volcanoes  occur 
in  the  following  order  :-— Colima  (13,003  feet),  Jorullo  (4265 
feet),  Toluca  (15168  feet),  Popocatepetl  (17,726  feet),  and 
Orizaba  (17,884  feet).  Those  situated  nearest  to  each  other 
are  dissimilar  in  the  composition  which  characterizes  them, 
a  similarity  of  trachyte  occurring  only  alternately.  Colima 
and  Popocatepetl  consist  of  oligoclase  with  augite,  and  conse- 
quently have  the  trachyte  of  Chirnborazo  or  Teneriife; 
Toluca  and  Orizaba  consist  of  oligoclase  with  hornblende, 
and  consequently  have  the  rock  of  ^gina  and  Kozelnik. 
The  recently  formed  volcano  of  Jorullo,  which  is  scarcely 
more  than  a  large  eruptive  hill,  consists  almost  alone  of 
scoriaceous  lavas,  resembling  basalt  and  pitchstone,  and 
seems  more  like  the  trachte  of  Toluca  than  that  of  Colima. 


4G8  COSMOS. 

In  these  considerations  on  the  individual  diversity  of  tho 
mineralogical  constitution  of  neighbouring  volcanoes,  we  find 
a  condemnation  of  the  mischievous  attempt  to  introduce  a 
name  for  a  species  of  trachyte,  derived  from  a  mountain- 
chain,  chiefly  volcanic,  of  more  than  7200  geographical  miles 
in  length.  The  name  of  Jura  limestone,  which  I  was  the 
first  to  introduce,8^  is  unobjectionable,  because  it  is  taken 
from  a  simple  unmixed  rock ;  from  a  chain  of  mountains 
whose  antiquity  is  characterised  by  its  containing  organic 
remains.  It  would  in  like  manner  be  unobjectionable  to 
designate  trachyte-formations  after  particular  mountains, — 
to  make  use  of  the  expression  Teneriffe-trachyte  or  Etna- 
trachyte  for  decided  oligoclase  or  labradorite  formations. 
So  long  as  there  was  an  inclination  among  geologists  to  find 
albite  everywhere  among  the  veiy  different  kinds  of  felspar 
which  are  peculiar  to  the  chain  of  the  Andes,  every  rock  in 
which  albite  was  supposed  to  exist  was  called  andesite.  I 
first  meet  with  the  name  of  this  mineral,  with  the  distinct 
definition  that  "andesite  is  composed  of  a  preponderating 
quantity  of  albite  and  a  small  quantity  of  hornblende,"  in 
the  important  treatise  written  in  the  beginning  of  the  year 
1835  by  my  friend  Leopold  von  Buch  on  "Craters  of  upheaval 
and  volcanoes"**  This  tendency  to  find  albite  every  where 

84  In  the  course  of  a  geological  tour  which  I  made,  in  1795,  through 
the  south  of  France,  western  Switzerland,  and  the  north  of  Italy,  I  had 
satisfied  myself  that  the  Jura  limestone,  which  Werner  reckoned  among 
his   Muschel-kalk,  constituted  a  peculiar  formation.     In  my  treatise 
on  subterranean  gases,  published  by  my  brother,  Wilhelm  von  Hum- 
boldt,  in  1799,  during  my  residence  in  South  America,  this  formation, 
which  I  provisionally  designated  as  Jura  limestone,  was  for  the  first 
time  mentioned  (s.  39).    This  account  of  the  new  formation  was  imme- 
diately transferred  to  the  Oberbergrath  Karsteu's  miueralogical  table?, 
at  that  time  so  generally  read  (1800,  p.  64,  and  preface,  p.  vii),   I  named 
none  of  the  petrifactions  which  characterise  the  Jura  formation,  and  in 
relation  to  which    Leopold   von   Buch  has  acquired  so  much  credit 
(1839) ;  I  erred  likewise  in  the  age  ascribed  by  me  to  the  Jura  forma- 
tion, supposing  it  to  be  older  than  muschel-kalk,  on  account  of   its 
propinquity  to  the  Alps,  which  were  considered  older  than  Zechstein. 
In  the  earliest  tables  of  Bucklancl,  on  the  Superposition  of  strata  in  the 
British  Islands,  the  Jura  limestone  of  Humboldt  is  reckoned  as  belong- 
ing to  the  upper  oolite.     Compare  my  Essai  Geogn.  sur  le  Gisement  des 
Roches,  1823,  p.  281. 

85  The  name  of  Andesite  first  occurrs  in  print  in  Leopold  von  Buch's 
treatise,  read  on  the  26th  March,  1835,  at  the  Berlin  Academy.     That 


TRUE  VOLCAN03S.  469 

lasted  for  five  or  six  years,  until  renewed  investigations  of  a 

great  geologist  limits  the  appellation  of  trachyte  to  those  cases  in  which 
glassy  felspar  is  contained,  and  thus  speaks  in  the  above  treatise, 
which  was  not  printed  till  1836  (Poggend.  Annal.,  Bd.  xxxvii,  s. 
188 — 190): — "The  discoveries  of  Gustav  Rose,  relating  to  felspar, 
have  shed  a  new  light  on  volcanoes  and  geology  in  general,  and  the 
minerals  of  volcanoes  have  in  consequence  presented  a  new  and  totally 
unexpected  aspect.  After  many  careful  investigations  in  the  neigh- 
bourhood of  Catanea  and  at  Etna,  Elie  de  Beaumont  and  I  have  con- 
vinced ourselves  that  felspar  is  not  to  be  met  with  on  Etna,  and 
consequently  there  is  no  trachyte  either.  All  the  lava-streams,  as  well 
as  all  the  strata  in  the  interior  of  the  mountain,  consist  of  a  mixture  of 
augite  and  labradorite.  Another  important  difference  in  the  minerals 
of  volcanoes  is  manifested  when  albite  takes  the  place  of  felspar,  in 
which  case  a  new  mineral  is  formed,  which  can  no  longer  be  denomi- 
nated trachyte.  According  to  G.  Rose's  (present)  investigations,  it  may 
be  considered  tolerably  certain  that  not  one  of  the  almost  innumer- 
able volcanoes  of  the  Andes  consists  of  trachyte,  but  that  they  all 
contain  albite  in  their  constituent  mass.  This  conjecture  seems  a  very 
bold  one,  but  it  loses  that  appearance  when  we  consider  that  we  have 
become  acquainted,  through  Huinboldt's  journeys  alone,  with  one-half 
of  these  volcanoes  and  their  products  in  both  hemispheres.  Through 
Meyen  we  are  acquainted  with  these  albitiferous  minerals  in  Bolivia 
and  the  northern  part  of  Chili;  through  Poppig,  as  far  as  the  southern- 
most limit  of  the  same  country ;  through  Erman,  in  the  volcanoes  of 
Kamtschatka.  Their  presence  being  so  widely  diffused  and  so  distinctly 
marked,  seems  sufficiently  to  justify  the  name  of  andesite,  under  which 
this  mineral,  composed  of  a  preponderance  of  albite  and  a  small  quan- 
tity of  hornblende,  has  already  been  sometimes  noticed."  Almost  at 
the  same  time  that  this  appeared,  Leopold  von  Buch  enters  more  into 
the  detail  of  the  subject  in  the  addenda  with  which,  in  1836,  he  so 
greatly  enriched  the  French  edition  of  his  work  on  the  Canary  Islands. 
The  volcanoes  Pichincha,  Cotopaxi,  Tungurahua,  and  Chimborazo,  are 
all  said  to  consist  of  andesite,  while  the  Mexican  volcanoes  were  called 
genuine  (sanidiniferous)  trachytes  (Description  physique  des  lies  Canaries, 
1836,  pp.  486,  487,  490,  and  515).  This  lithological  classification  of  the 
volcanoes  of  the  Andes  and  those  of  Mexico  shows  that,  in  a  scientific 
point  of  view,  such  a  similarity  of  mineralogical  constitution  and  the 
possibility  of  a  general  denomination  derived  from  a  large  extent  of 
country,  cannot  be  thought  of.  A  year  later,  when  Leopold  von  Buch 
first  made  mention,  in  Poggendorjfs  Annalen,  of  the  name  of  Andesite, 
which  has  been  the  occasion  of  so  much  confusion,  I  committed  the 
mistake  myself  of  making  use  of  it  on  two  occasions; — once,  in  1836, 
in  the  account  of  my  attempt  to  ascend  Chimborazo,  in  Schumacher's 
Jakrbuch,  1837,  s.  204,  205  (reprinted  in  my  Kleinere  Schriften, 
Bd.  i,  s.  160,  161),  and  again,  in  1837,  in  the  treatise  on  the  high- 
land of  Quito  (in  Poggend.  Ann.,  Bd.  xl,  s.  165).  "Recent  times  have 
taught  us,"  I  observed,  already  strongly  opposing  my  friend's  conjecture 
as  to  the  similar  constitution  of  all  the  Andes-volcanoes,  "  that  the 


4:70  COSMOS. 

more  profound  and  less  prejudiced  character  led  to  the  recog- 

diffevenfc  zones  do  not  always  present  the  same  (mineralogical)  composi- 
tion,  or  the  same  component  parts.  Sometimes  we  find  trachytes, 
properly  so  called,  characterised  by  the  glassy  felspar,  as  at  the  Peak 
of  Tenerifie  and  in  the  Siebengebirge  near  Bonn,  where  a  little  albite  ia 
associated  with  the  felspar,  —  felspathic  trachytes,  which,  as  active 
volcanoes,  exhibit  abundance  of  obsidian  and  pumice ;  sometimes 
melaphyre,  and  doleritic  mixtures  of  labradorite  and  augite,  more 
nearly  resembling  the  basalt  formation,  as  at  Etna,  Stromboli,  and 
Chimborazo ;  sometimes  albite  with  hornblende  prevails,  as  iu  the 
lately  so-called  andesites  of  Chili  and  the  splendid  columns,  described 
as  dioritic-porphyry,  at  Pisoje  near  Popayan,  at  the  foot  of  the  volcano 
of  Purace",  or  in  the  Mexican  volcano  of  Jorullo ;  finally,  they  s-re  some- 
times leucite-ophyrs,  a  mixture  of  leucite  and  augite,  as  in  the  Somma, 
the  ancient  wall  of  the  crater  of  elevation  of  Vesuvius."  By  an  acci- 
dental misinterpretation  of  this  passage,  which  shows  many  traces  of 
the  then  imperfect  state  of  geological  knowledge  (felspar  being  still 
ascribed  to  the  Peak  of  Teneriffe  instead  of  oligoclase,  labradorite  to 
Chimborazo,  and  albite  to  the  volcano  of  Toluca),  that  talented  investi- 
gator Abich,  who  is  both  a  chemist  and  a  geologist,  has  erroneously 
attributed  to  myself  the  invention  of  the  term  andesite  as  applied  to  a 
trachj'tic,  widely-dispersed  rock,  rich  in  albite  (Pogysnd.  Ann., 
Bd.  ii,  1840,  s.  523),  and  has  given  the  name  of  andesine  to  a  new 
species  of  felspar,  first  analysed  by  him,  but  still  somewhat  enigmati- 
cal in  its  nature,  "with  reference  to  the  mineral  (from  Marmato,  uear 
Popayan)  in  which  it  was  first  observed."  The  andesine  (pseudo-albite 
in  andesite)  is  supposed  to  occupy  a  middle  position  between  labradorite 
and  oligoclase  ;  at  the  temperature  of  55°.7  its  specific  gravity  is  2.733', 
while  that  of  the  andesite  in  which  the  andesine  occurred  is  3.593. 
Gustav  Rose  doubts,  as  did  subsequently  Charles  Deville  (Etudes  de 
Lithoiogie,  p.  30),  the  individuality  of  andesine,  as  it  rests  only  on  a 
single  analysis  of  Abich,  and  because  the  analysis  of  the  felspathic 
ingredient  in  the  beautiful  dioritic-porphyry  of  Pisoje  near  Popayan, 
brought  by  me  from  South  America,  which  was  performed  by  Francis 
(Poggend.,  Bd.  lii,  1841,  s.  472)  in  the  laboratory  of  Heinrich  Rose, 
while  it  certainly  shows  a  great  resemblance  to  the  andesine  of  Mar- 
mato, as  analysed  by  Abich,  is,  notwithstanding,  of  a  different  com- 
position. Still  more  uncertain  is  the  andesine  in  the  syenite  of 
the  Vosges  (from  the  Ballon  de  Servance,  and  Coravillers,  which  Delesse 
has  analysed).  Compare  G.  Rose,  in  the  already  often-cited  Zeitschrift 
cler  Deutscken  geologischen  Gesdlschaft,  Bd.  i,  for  the  year  1849,  s.  369. 
It  is  not  unimportant  to  remark  here  that  the  name  andesine,  intro- 
duced by  Abich  as  that  of  a  simple  mineral,  appears  for  the  first  time 
in  his  valuable  treatise  entitled,  Beitrag  zur  Eenntniss  des  Feldspaths 
(in  Poggend.  Ann.,  Bd.  1,  s.  125,  341,  Bd.  li,  s.  519),  in  the  year 
1840,  which  is  at  least  five  years  after  the  adoption  of  the  name  ande- 
site, instead  of  being  prior  to  the  designation  of  the  mineral  from  which 
it  is  taken,  as  has  been  sometimes  erroneously  supposed.  In  the  forma- 
tions of  Chili  which  Darwin  BO  frequently  calls  andesitic  granite 


TRUE  VOLCANOES.  47 1 

aition  of  the  trachytic  albites  as  oligoclase.83  Gustav  Host. 
has  come  to  the  general  conclusion  that  it  is  very  doubtful 
whether  albite  occurs  at  all  among  the  minerals  as  a  real  and 
essential  element  of  commixture  ;  consequently,  according  to 
the  old  conception  of  andesite,  this  mineral  would  actually 
be  wanting  in  the  chain  of  the  Andes. 

The  mineralogical  condition  of  the  trachytes  is  imperfectly 
recognised  if  the  porphyritically  enclosed  crystals  cannot  be 
separately  examined  and  measured,  in  which  case,  the  in- 
vestigator must  have  recourse  to  the  numerical  proportions 
of  the  earths,  alkalies  and  metallic  oxides,  which  the  result 
of  the  analysis  furnishes,  as  well  as  to  the  specific  gravity  of 

and  andesitic  porphry  rich  in  albite  (Geological  Observations  on  South 
America,  1846,  p.  174),  oligoclase  may  also  very  likely  be  obtained. 
Gustav  Rose,  whose  treatise  on  the  nomenclature  of  the  minerals  allied 
to  greenstone  and  greenstone-porphyry  (in  Poggendorff's  Ann.,  Bel. 
xxxiv,  s.  1 — 30)  appeared  in  the  same  year,  1835,  in  which  Leopold  von 
Buch  employed  the  name  of  andesite,  has  not,  either  in  the  treatise  just 
mentioned,  or  in  any  later  work,  made  use  of  this  term,  the  true  defini- 
tion of  which  is,  not  albite  with  hornblende,  but  in  the  Cordilleras  of 
South  America,  oligoclase  with  augae.  The  now  obsolete  account  of 
the  designation  of  andesite,  of  Avhich  I  have  perhaps  treated  too  cir- 
cumstantially, helps  to  show,  like  many  other  examples  in  the  history 
of  the  development  of  our  physical  knowledge,  that  erroneous  or 
insufficiently  grounded  conjectures  (as,  for  instance,  the  tendency  to 
enumerate  varieties  as  species)  frequently  turn  out  advantageous  to 
science,  by  inducing  more  exact  observations. 

86  So  early  as  1840,  Abich  described  oligoclase-trachyte  from  the 
summit-rock  of  the  Kasbegk  and  a  part  of  the  Ararat  (Ueber  die  Natur 
und  die  Zusammensetzung  der  Vulkan-B'ddungen,  s.  46),  and  even  in 
1835,  Gustav  Hose  had  the  foresight  to  say  that  though  "he  had  not 
hitherto  in  his  definitions  taken  notice  of  oligoclase  and  pericline,  yet 
that  they  probably  also  occur  as  ingredients  of  admixture."  The  belief 
formerly  so  generally  entertained  that  a  decided  preponderance  of 
augite  or  of  hornblende  might  be  taken  to  denote  a  distinct  species  of 
the  felspar  family,  such  as  glassy  orthoclase  (sanidine),  labradorite  or 
oligoclase,  appears  to  be  very  much  ?haken  by  a  comparison  of  the 
trachytes  of  the  Chimborazo  and  Toluca  rocks,  belonging  to  the  fourth 
and  third  division.  In  the  basalt-formatiou,  hornblende  and  a«gite 
often  occur  in  equal  abundance,  which  is  by  no  means  the  case  in  the 
trachytes;  but  I  have  met  with  augite  crystals,  quite  isolated,  in 
Toluca  rock,  and  a  few  hornblende  crystals  in  portions  of  the  Chim- 
borazo, Pichincha,  Purace,  and  Teneriffe  rocks.  Olivines,  which  are  so 
very  rarely  absent  in  the  basalts,  are  as  great  a  rarity  in  trachytes  as 
they  are  in  phonolites ;  yet  we  sometimes  find,  in  certain  lava-streams, 
olivines  formed  in  great  abundance  by  the  side  of  augites.  Mica  is  on  the 


472  COSMOS. 

the  seemingly  amorphous  mass  to  be  analysed.  The  result 
is  obtained  in  a  more  convincing  and  more  certain  manner 
if  the  principal  mass,  as  well  as  the  chief  elements  of  the 
mixture,  can  be  singly  investigated  both  mineralogically  and 
chemically.  This  is  the  case  with  the  trachytes  of  the  Peak 
of  Teneriffe  and  those  of  Etna.  The  supposition  that  the 
principal  mass  consists  of  the  same  small,  inseparable,  com- 
ponent parts  which  we  recognise  in  the  large  crystals  appears 
to  be  by  no  means  well  grounded,  for,  as  we  have  already 
noticed,  as  shown  in  Charles  Deville's  work,  the  apparently 
amorphous  principal  mass  generally  furnishes  more  silicic 
acid  than  would  be  expected  from  the  nature  of  the  felspar 
and  the  other  visible  commixed  elements.  Among  the 
leucite-ophyrs,  as  Gustav  Rose  observes,  a  striking  contrast  is 
exhibited,  even  in  the  specific  difference  of  the  prevailing 
alkalies  (of  the  potash  containing  interspersed  leucites)  and 
the  almost  exclusively  natroniferous  principal  mass.87 

But  along  with  these  associations  of  augite  with  oligoclaee, 
augite  with  labradorite,  and  hornblende  with  oligoclase,  which 
are  referred  to  in  our  classification  of  the  trachytes,  and  which 
especially  characterise  them,  there  exist  likewise  in  each  vol- 

whole  very  unusual  in  basalt,  and  yet  some  of  the  basaltic  summits  of 
the  Bohemian  central  mountains,  first  described  by  Reuss,  Freieslebeu, 
and  myself,  contain  plenty  of  it.  The  unusual  isolation  of  certain 
mineral  bodies,  and  the  causes  of  their  legitimate  specific  association, 
probably  depend  on  many  still  undiscovered  causes  of  pressure,  tempe- 
rature, fluidity,  and  rapidity  in  cooling.  The  specific  differences  of  the 
.association  are,  however,  of  great  importance,  both  in  the  mixed  rocks 
and  in  the  masses  of  mineral  veins ;  and  in  geological  descriptions,  noted 
down  in  the  open  air,  in  sight  of  the  object  described,  the  observer 
should  be  careful  not  to  make  any  mistake  as  to  what  may  be  a  prevail- 
ing, or  at  least  a  rarely  absent  member  of  the  association,  and  what 
may  be  sparingly  or  only  accidentally  combined.  The  diversity  which 
prevails  in  the  elements  of  a  mixture, — for  instance,  in  the  trachytes, — 
is  repeated,  as  I  have  already  noticed,  in  the  rocks  themselves.  In  both 
continents  there  exist  large  tracts  of  country  in  which  trachyte  forma- 
tions and  basalt  formations  as  it  were  repel  each  other,  as  basalts  and 
phonolites;  and  there  are  other  countries  in  which  trachytes  and 
basalts  alternate  with  each  other  in  tolerably  close  proximity  (see 
Gustav  Jenzsch,  MonograpJiie  der  bohmischen  Pkonolithe,  1856,  s. 
1—7). 

s"  See  Bischof,  Chemische  und  pkysikalische  Geologic,  Bd.  ii, 
185],  &  2288,  2297;  Roth,  Monographic  des  Vesuvs.  1857,  s, 
805. 


TRUE  VOLCANOES.  473 

cano  other  easily  recognisable,  unessential  elements  of  com- 
mixture, whose  presence  in  large  quantities  or  total  absence 
in  different  volcanoes,  often  situated  very  near  to  each  other, 
is  very  striking.  Their  occurrence,  either  in  frequent  abun- 
dance, or  else  at  long  and  separate  intervals,  depends  probably 
in  one  and  the  same  natural  laboratory  on  various  conditions 
of  the  depth  from  which  the  matter  originally  came,  the  tem- 
perature, the  pressure,  the  fluidity,  or  the  quicker  or  slower 
process  of  cooling.  The  fact  of  the  specific  occurrence  or  the 
absence  of  certain  ingredients  is  opposed  to  certain  theories, 
such  as  the  derivation  of  pumice  from  glassy  felspar  or 
from  obsidian.  These  views,  which  have  not  been  altogether 
lately  adopted,  but  originated  as  early  as  the  end  of  the  1 8th 
century  from  a  comparison  of  the  trachytes  of  Hungary  and 
of  Teiieriffe,  engaged  my  attention  for  several  years  in  Mexico 
and  the  Cordilleras,  as  my  journals  will  testify.  From  the 
great  advancement  which  lithology  has  undeniably  made  in 
modern  times,  the  more  imperfect  definitions  of  the  mineral 
species,  made  by  me  during  my  journey  have,  through  Gustav 
Hose's  careful  mineralogical  elaboration  of  my  collections, 
been  improved  and  accurately  certified. 

MICA. 

Black  or  dark-green  magnesian  mica  is  very  abundant  in 
the  trachytes  of  the  Cotopaxi,  at  an  elevation  of  14,470  feet 
between  Suniguaicu  and  Quelendafia,  as  also  in  the  subter- 
ranean pumice-beds  of  Guapu]o  and  Zumbalica  at  the  foot 
of  Cotopaxi,88  but  16  miles  distant  from  the  same.  The 
trachytes  of  the  volcano  of  Toluca  are  likewise  rich  in  mag- 
nesian mica,  which  is  wanting  in  the  Chimborazo.89  In  the 
Continent  of  Europe  micas  have  shown  themselves  in  abun- 
d  ;nce  :  at  Vesuvius  (for  example  in  the  eruptions  of  1821 — 
1823,  according  to  Monticelli  and  Covelli) ;  in  the  Eifel  in 
the  old  volcanic  Bombs  of  the  Lacher  Lake  ;*°  in  the  basalt 

88  Cosmos,  see  above,  p.  343. 

89  It  is  almost  superfluous  to  mention  that  the  term  wanting  signifies 
only  that,  in  the  investigation  of  a  not  inconsiderable  portion  of  vol- 
canoes of  large  extent,  a  particular  sort  of  mineral  has  hitherto  been 
vainly  sought  for.    I  wish  to  distinguish  between  what  is  wanting  (not 
being  found),  being  of  very  rare  admixture,  and  what,  though  more 
abundant,  is  still  not  normally  characteristic. 

90  Carl  vou  Oeynhausen,  Erkl  der  yeogn.  Karte  des  Lacher  Sees.  1847, 
B.3S. 


474  COSMOS. 

of  the  Meronitz,  of  the  marly  Kausawer  Mountain  and  espe« 
cially  of  the  Camay  er  summit91  of  the  central  Bohemian 
chain  j  more  rarely  in  the  phonolite,93  as  well  as  in  the  dole- 
rite  of  the  Kaiserstuhl  near  Freiburg.  It  is  remarkable 
that  in  the  trachytes  and  lavas  of  both  continents  not  only 
no  white  (chiefly  bi-axal)  potash-mica  is  observable,  but 
that  it  is  entirely  dark-coloured  (chiefly  uni-axal)  magnesian- 
mica,  and  that  this  exceptional  occurrence  of  the  magnesia- 
mica  is  extended  to  many  other  rocks  of  eruption  and  plu- 
tonic  rocks,  such  as  basalt,  phonolite,  syenite,  syenitic- 
slate,  and  even  granitite,  while  the  granite  proper  contains 
at  one  and  the  same  time,  white  alkaline-mica  and  black  or 
brown  magnesia-mica.93 

GLASSY  FELSPAR. 

This  kind  of  felspar,  which  plays  so  important  a  part 
in  the  action  of  European  volcanoes  ;  in  the  trachytes  of 
the  first  and  second  division  (for  example,  on  Ischia,  in  the 
Phlegrsean  Fields,  or  the  Siebengebirge  near  Bonn),  is  proba- 
bly entirely  wanting  in  the  New  Continent,  in  the  trachytes 
of  active  volcanoes.  This  circumstance  is  the  more  striking 
as  sanidine  (glassy  felspar)  belongs  essentially  to  the  argen- 
tiferous, non-quartzose  Mexican  porphyries  of  Moran,  Pa- 
chuca,  Villalpando  and  Acaquisotla,  the  first  of  which  are 
connected  with  the  obsidians  of  Jacal. 94 

91  See  the  Berymannisches  Journal,  von  Kohler  und  Hofmann,  5ter 
Jahrgang,  Bd.   i,  1792,   s.  244,  251,  265.     Basalt  rich   in  mica,   as  on 
the  Gamayer  summit  in  the  Bohemian  centre  mountains,  is  a  rarity.     I 
visited  this  part  of  the  Bohemian  central  range  in  the  summer  of  1792, 
in  company  with  Carl  Freiesleben,  afterwards  my  companion  in  my 
Swiss  tour,  who  has  exercised  so  great  an  influence  over  rny  geological 
and  mining  education.     Bischof  doubts  all  production  of  mica  by  the 
igneous  method,  and  considers  it  a  metamorphic  product  by  the  moist 
method.     See  his  Lehrbuch  der  ckem.  und  physikal.   Geologic,  Bd.  ii, 
s.  1426,  1439. 

92  Jenzsch,  JBeitraye  zurKenntn/ss  der  Pkonolithe,  in  der  Zeitschrift  der 
Dcutschen  Geoloyischen  Gesellsckaft,  Bd.  viii,  1856,  s.  36. 

93  Gustav  Rose,  Ueber  die  zur  Granitgruppe  yehoriyen  Gzbirysarten, 
ibi'.l,,  Bd.  i,  1849,  s.  359. 

!4  The  porphyries  of  Moran,  Real  del  Monte  and  Regla  (the  latter 
celebrated  for  the  rich  silver  mines  of  the  Veta  Biscayna,  and 
the  vicinity  of  the  obsidians  and  pearlstones  of  the  Cerro  del  Jacal 
and  the  Messerberg,  Cerro  de  las  Navajas),  like  almost  all  the  metal- 
liferous porphyries  of  America,  are  quite  destitute  of  quartz  (ou 
and  other  analogous  phenomena  in  Hungary,  see  Humboldt, 


TBUE  VOLCANOES.  475 

HOR^BLEN'DE   AND    AUGITE. 

In  this  account  of  the  characteristics  of  six  different  divi- 
sions of  the  trachytes,  it  has  been  already  observed  how  the 
same  minerals  which  occur  as  essential  elements  of  commix- 
ture (for  example,  hornblende  in  the  third  division,  or  tha 
Toluca  rock),  appear  in  other  divisions  in  a  separate  or  spo- 
radic condition  (as  in  the  fourth  and  fifth  divisions,  in  the 
rock  of  Pichincha  and  of  Etna).  I  have  found  hornblende,, 


(jeognostique  sur  le  Gisement  des  Roches,  pp.  179  —  188  and 
190  —  193).  The  porphyries  of  Acaquisotla,  however,  on  the  road 
from  Acapulco  to  Chilpanzingo,  as  well  as  those  of  Villalpando  to 
the  North  of  Guauaxuato,  which  are  penetrated  by  auriferous  veins, 
along  with  the  sauidine  contain  also  grains  of  brownish  quartz.  —  » 
The  small  inclosures  of  grains  of  obsidian  and  glassy  felspar  being 
on  the  whole  rare  in  the  volcanic  rocks  at  the  Cerro  de  las  Navajas, 
arid  in  the  Valie  de  Santiago,  so  rich  in  basalt  and  pearl  -stone, 
which  is  traversed  in  going  from  Valladolid  to  the  volcano  of  Jorullo, 
I  was  the  more  astonished  at  finding  at  Capula  and  Pazcuaro,  and 
especially  near  Yurisapundaro,  all  the  ant-hills  filled  with  beautifully 
shining  grains  of  obsidian  and  sanidine.  This  was  in  the  month  of 
September,  1803  (Nivellement  barometr.  p.  327,  No.  366,  and  Essai 
geoynost.  sur  le  Gisement  des  Roches,  p.  356).  I  was  amazed  that  Such 
small  insects  should  be  able  to  drag  the  minerals  to  such  a  distance. 
It  has  given  me  great  pleasure  to  find  that  an  active  investigator,  M. 
Jules  Marcou,  has  observed  something  exactly  similar.  "  There  exists," 
he  says,  "  on  the  high  plateaux  of  the  Rocky  Mountains,  and  particu- 
larly in  the  neighbourhood  of  Fort  Defiance  (to  the  west  of  Mount 
Taylor),  a  species  of  ant  which,  instead  of  using  fragments  of  wood 
and  vegetable  remains  for  the  purpose  of  building  its  dwelling,  employs 
only  small  stones  of  the  size  of  a  grain  of  maize.  Its  instinct  leads  it 
to  select  the  most  brilliant  fragments  of  stones,  and  thus  the  ant-hill 
is  frequently  filled  with  magnificent  transparent  garnets  and  very  pure 
grains  of  quartz."  (Jules  Marcou,  Resume  explicatif  d'une  Carte  geogn. 
des  Etats-unis,  1855,  p.  3.) 

Glassy  felspar  is  very  rare  in  the  present  lavas  of  Vesuvius,  but 
this  is  uot  the  case  in  the  old  lavas,  for  instance  in  those  of  the  eruption 
of  1631,  where  it  occurs  along  with  crystals  of  leucite.  Sanidine  is 
also  found  in  abundance  in  the  Arso  lava-stream,  from  Cremate  towards 
Ischia,  of  the  year  1301,  without  any  leucite  ;  but  this  must  not  be  con- 
founded with  the  older  stream,  described  by  Strabo,  near  Montag* 
none  and  Rotaro  (Cosmos,  see  above,  pp.  265,  427).  Glassy  fel- 
spar is  not  only  rare  in  the  trachytes  of  Cotopaxi  and  other  vol- 
canoes of  the  Cordilleras  generally,  but  is  equally  so  in  the  subterranean 
pumice-quarries  at  the  foot  of  the  Cotopaxi.  What  was  formerly  de- 
scribed aa  sanidine  are  crystals  of  oligoclaae. 


476  COSMOS. 

though  not  in  large  quantities,  in  the  trachytes  of  the  vol- 
canoes of  Cotopaxi,  Rucu-Pichincha,  Tungurahua  and  Anti- 
sana,  along  with  augite  and  oligoclase,  but  scarcely  ever  along 
with  these  two  minerals  on  the  slope  of  the  Chimborazo  up 
to  a  height  of  more  than  19,000  feet.  Among  the  many  speci- 
mens which  I  brought  from  Chimborazo,  hornblende  is  recog- 
nized only  in  two,  and  even  then  in  small  quantity.  In  the 
eruptions  of  Vesuvius  in  the  years  1822  and  1850,  augite 
and  crystals  of  hornblende  (these  nearly  9  Parisian  lines  in 
length)  were  contemporaneously  formed  by  exhalations  of 
vapours  on  fissures.95  The  hornblende  of  Etna,  as  Sar  borius  von 
Waltershausen  observes,  belongs  especially  to  the  older  lavas. 
That  remarkable  mineral,  so  widely  diffused  in  Western  A  sia 
and  at  several  points  of  Europe,  which  Gustav  Rose  has  de- 
nominated Uralite,  being  allied  in  structure  and  crystalline 
form  to  hornblende  and  augite,96  I  here  once  more  gladly 
point  attention  to  the  first  occurrence  of  uralite  crystals  in 
the  New  Continent ; — they  were  recognised  by  Rose  in  a 
piece  of  trachyte  which  I  abstracted  from  the  slope  of  the 
Tungurahua,  3200  feet  below  the  summit. 

LEUCITE. 

Leucites,  which  in  Europe  belong  exclusively  to  Vesuvius, 
the  Rocca  Monfina,  the  Albanian  Mountains  near  Rome,  the 
Kaiserstuhl  in  the  Breisgau,  and  the  Eifel  (in  the  western 
environs  of  the  Lachar  Lake  in  blocks,  and  not  in  the  con- 
tiguous rock,  as  in  the  Burgberge  near  Rieden),  have  never 
yet  been  found  in  volcanic  rocks  of  the  New  Continent,  or 
the  Asiatic  portion  of  the  old.  Leopold  von  Buch  discovered 
them  round  an  augite-crystal  as  early  as  the  year  1798,  and 
described  in  an  admirable  treatise  their  frequent  forma- 
tion.97 The  augite-crystal  round  which,  according  to  this 
great  geologist,  the  leucite  is  formed,  is  seldom  wanting,  but 
appears  to  me  to  be  sometimes  replaced  by  a  small  grain  or 
morsel  of  trachyte.  The  unequal  degrees  of  fusibility,  be- 
tween the  grain  of  trachyte  and  the  surrounding  mass  of 

95  Roth,  Monographic  des  Vesuvs.  s.  267,  382. 

96  See  above,  note  82  ;  Rose,  Reise  nach  dein    Ural.,  Bd.  ii,   s.  369 ; 
Bischof,  Ckem.  und  PhysiTc.  Geologic,  Bd.  ii,  s.  528—571. 

'#  Gilbert's  Annalen  der  PhysiTc.,  Bd.  vi,  1800,  B.  53;— Bischof; 
Geologic,  Bd.  ii,  s.  2265—2303. 


TRUE   VOLCANOES.  477 

leucite  raise  some  chemical  difficulties  to  the  explanation  of 
the  mode  in  which  the  integumental  covering  is  formed. 
Leucites,  partly  detached,  ace  ording  to  Scacchi,  and  partly- 
mixed  with  lava,  were  extremely  abundant  in  the  recent 
eruptions  of  Vesuvius  in  1822,  1828,  1832,  1845  and  1847. 

OLIVINE. 

Olivine  being  very  abundant  in  the  old  lavas  of  Vesuvius98 
(especially  in  the  leucite-ophyrs  of  the  Sornma)  in  the  Arso  of 
Ischia,  in  the  eruption  of  1301,  mixed  with  glassy  felspar, 
brown  mica,  green  augite  and  magnetic  iron,  in  the  volcanoes 
of  the  Eifel  which  emit  lava-streams  (for  example,  in  the 
Mosenberge  westward  of  Manderscheid),99  and  in  the  south- 
eastern portion  of  TenerifTe  in  the  lava-eruption  of  Guimar 
in  the  year  1704,  I  have  also  searched  for  it  very  diligently, 
but  in  vain,  in  the  trachytes  of  the  volcanoes  of  Mexico, 
New  Granada  and  Quito.  Our  Berlin  collections  contain 
sixty-eight  specimens  of  trachyte  of  the  four  volcanoes,  Tun- 
gurahua,  Antisana,  Chimborazo  and  Pichincha  alone,  48  of 

)s  The  recent  lavas  of  Vesuvius  contain  neither  olivine,  nor  glassy 
felspar ;  Roth.  Mon,  des  Vesuvs.  s.  139.  According  to  Leopold  von 
Buch,  the  lava-stream  of  the  Peak  of  Teneriffe  of  1704,  described  by 
Viera  and  Glas,  is  the  only  one  which  contains  olivine  (Descr.  des  lies 
Canaries,  p.  207).  The  supposition  that  the  eruption  of  1704  was  the 
first  which  had  taken  place  since  the  conquest  of  the  Canary  Islands 
at  the  end  of  the  loth  Century,  has  been  shown  by  me  in  another 
place  (Examen  Critique  de  I'Histoire  de  la  Geoymphie,  t.iii,  pp.  143 — 146) 
to  be  erroneous.  Columbus  saw  the  eruption  of  fire  on  Teneriffe,  at 
the  time  of  his  first  voyage  of  discovery,  on  the  nights  from  the  21st  to 
the  25th  August,  when  he  went  in  search  of  Dona  Beatriz  de  Bobadilla, 
on  the  Gran  Canaria.  It  is  thus  noticed  in  the  Admiral's  journal, 
under  the  Rubric  of  "  Jueves,  9  de  Agosto,"  which  contains  notices  up 
to  the  2d  September, — "  Vieron  salir  gran  fuego  de  la  Sierra  de  la 
Isla  de  Tenerife,  que  es  muy  alta  en  gran  in  an  era," — "  they  saw  a  great 
deal  of  fire  rising  with  a  grand  appearance  out  of  the  mountain  of  the 
Island  of  Teneritfe,  which  is  very  high  ;"  Navarrete,  Col.  de  los  Viayes 
de  los  Espanoles,  t.  i,  p.  5.  The  lady  above  named  must  not  be 
confounded  with  Dona  Beatriz  Henriquez  of  Cordova, — the  mother  of 
his  illegitimate  son,  the  learned  Don  Fernando  Colon,  the  historian  of 
his  father, — whose  pregnancy  in  the  year  1488  so  materially  contributed 
to  detain  Columbits  in  Spain,  and  to  lead  to  the  discovery  of  the  New 
World  being  made  on  account  of  Castille  and  Leon,  and  not  for  Portu- 
gal, France,  or  England  (see  my  Examen  Critique,  t.  iii,  pp.  350 
and  367). 

99  Cosmos,  see  above,  p.  232. 


478  COSMOS. 

which  were  contributed  by  me  and  20  by  Boussingault.10* 
In  the  basalt  formations  of  the  jN"ew  World,  olivine  along 
with  augite  is  as  abundant  as  in  Europe  ;  but  the  black,  ba- 
saltic trachyte  of  Yana  Urcu,  near  Calpi  at  the  foot  of  the 
Chimborazo,1  as  well  as  those  enigmatical  trachytes  called  la 
reventazon  del  volcan  de  Anzango,2  contain  no  olivine.  It  was 
only  in  the  great,  brown-black  lava-stream,  with  a  crisp, 
scoriaceous  surface  raised  like  a  cauliflower,  whose  track 
we  followed  in  order  to  reach  the  crater  of  the  volcano  of 
Jorullo,  that  we  met  with  small  grains  of  olivine  imbedded.3 
The  prevailing  scarcity  of  olivine  in  the  modern  lavas  and 
the  greater  part  of  the  trachytes  seems  less  striking  when  we 
recollect  that,  essential  as  olivine  appears  to  be  for  basalt  in 
general,  yet  (according  to  Krug  von  Nidda  and  Sartor ius 
von  Waltershausen)  in  Iceland  and  in  the  German  Rhone 
Mountains  the  basalt  destitute  of  olivine  is  not  distinguish- 
able from  that  which  abounds  in  it.  The  former  it  has  been 
the  custom  from  the  earliest  times  to  call  trap  and  waclce,  the 
latter  we  have  in  modern  times  denominated  Anemasitc^ 
Olivines,  which  sometimes  occur  as  large  as  a  man's  head  in 
the  basalts  of  Rentieres  in  the  Auvergne,  attain  also  in  the 
Tinkler  quarries,  which  were  the  object  of  my  first  youthful 
researches  to  the  size  of  6  inches  in  diameter.  The  beautiful 
Jrypersthene  rock  of  Elfdalen  in  Sweden,  much  employed 

100  A  considerable  portion  of  the  minerals  collected  during  my  Ame- 
rican Expedition,  has  been  sent  to  the  Spanish  Mineral  Cabinet,  to  the 
King  of  Etruria,  to  England  and  to  France.  I  do  not  refer  to  the  geologi- 
cal and  botanical  collections  which  my  worthy  friend  and  fellow-labourer 
Bonpland  possesses,  with  the  twofold  right  of  self-collection  and  self- 
discovery.  This  extensive  dispersion  of  the  materials,  (which,  from  the 
very  exact  account  given  of  the  places  in  which  they  originated,  does 
not  prevent  the  maintenance  of  the  groups  in  their  geographical  rela- 
tions,) has  this  advantage  that  it  facilitates  the  most  comprehensive  and 
exact  definition  of  those  minerals  whose  substantial  and  habitual  asso- 
ciation characterises  the  different  kinds  of  rocks. 

1  Humboldt,  Kldnere  Schriften,  Bd.  i,  s.  139. 

2  Ibid,  s.  202,  and  Cosmos,  see  ab^ve,  p.  232. 

3  Humboldt,  Kl.  Schr.  vol.  i,  p.  344.     I  have  also  found  a  great  deal 
of  olivine  in  the  Tezontle  (cellular  lava,  or  basaltic  amygdaloid  ? — in 
Mexican,  tetzontli,  i.e.,  stone-hair,  from  tetl,  stone,  and  tzontli,  hair) 
belonging  to  the  Cerro  de  Axusco  in  Mexico. 

4  Sartorius  von  Waltershausen,   Physisch-ycographische    £kizze  von 
Island,  s.  64. 


TRUE   VOLCANOES.  479 

for  ornamental  purposes,*  a  granulated  mixture  of  hyper- 
sthene  arid  labradorite,  which  Berzelius  has  described  as  sye- 
nite, likewise  contains  olivine,6  as  does  also  (though  more 
rarely)  the  phonolite  of  the  Pic  de  Griou,  in  the  Cantal.6 
While,  according  to  Stromeyer,  nickel  is  a  very  constant  ac- 
companiment of  olivine,  Kumler  has  on  the  other  hand 
discovered  arsenic  in  it,7  a  metal  which  has  been  found  in  the 
most  recent  times  widely  diffused  in  so  many  mineral  springs, 
and  even  in  sea-water.  The  occurrence  of  olivine  in  meteoric 
stones8  and  in  artificial  scoria^  as  investigated  by  Sefstrom," 
I  have  already  mentioned. 

OBSIDIAN. 

As  early  as  in  the  spring  and  summer  of  1799,  while  I  was 
preparing  in  Spain  for  my  voyage  to  the  Canary  Isles,  there 
prevailed  generally  among  the  mineralogists  in  Madrid, — 
Hergen,  Don  Jose  Clavijo,  and  others, — the  opinion  that 
pumice  was  entirely  derived  from  obsidian.  This  opinion 
had  been  founded  on  the  study  of  some  fine  geological 
collections  from  the  Peak  of  Teneriffe,  and  a  comparison  of 
them  with  the  phenomena  which  Hungary  furnishes,  although 
the  latter  were  at  that  time  explained  chiefly  in  accordance 
with  the  jSTeptunian  views  of  the  Freiberg  school.  Doubts 
of  the  correctness  of  this  theory  of  formation,  awakened  at  an 
early  period  in  my  mind  by  my  observations  in  the  Canary 
Isles,  the  Cordilleras  of  Quito,  and  in  the  range  of  Mexican 
volcanoes,10  impelled  me  to  direct  my  most  earnest  attention 

[*  It  is  there  cut  into  vases,  sometimes  of  a  considerable  size,  and 
other  ornamental  objects.  From  the  high  polish  it  takes,  and  the 
contrast  of  its  colours,  it  is  one  of  the  most  beautiful  stones  in 
existence.— Tr.] 

5  Berzeliufe,  Sechster  Jaltresbemcht,  1827,   p.    392;  Gustav   Rose,   in 
Poggend.  Ann.  vol.  xxxiv,  1835,  p.  14  (Cosmos,  vol.  i,  p.  464). 

6  Jenzsch,  Pkonolithe,  1856,  p.  37,  and  Seuft,  in  his  important  work, 
Classification  der  Felsarten,  1857,  p.  187.     According  to  Scacchi  olivine 
occurs  also,  along  with  mica  and  augite,  in  the  lime-blocks  of  the 
Somma.     I  call  these  remarkable  masses  erupted  blocks,  not  lavas,  for 
the  Somroa  appears  never  to  have  ejected  the  latter. 

'  Poggend.  Annul.  Bd.  xlix,  1840,  s.  591,  and  Bd.  Ixxxiv,  s.  302; 
Daubrde  in  the  Annales  des  Mines,  4me  Serie,  t.  xix,  1851,  p.  669. 

8  Cosmos,  vol.  i,  p.  119,  and  vol.  iv,  p.  595. 

9  Ibid.  vol.  i,  p.  269,  note*. 

10  Humboldt,  Personal  Naraiive,  vol.  i,  p.  113  (Bohn's  Edition). 


ISO  COSMOS. 

to  two  groups  of  facts ; — first,  the  different  nature  of  the  en- 
closures of  obsidians  and  pumice  in  general,  and  secondly, 
the  frequency  of  the  association  or  entire  separation  of  them 
in  well  investigated,  active  volcanic  structures.  My  journals 
are  filled  with  notices  on  this  subject,  and  the  specific  defi- 
nition of  the  imbedded  minerals  has  been  ascertained  by  the 
most  varied  and  most  recent  investigations  of  my  ever  ready 
and  obliging  friend,  Gustav  Rose. 

Both  glassy  felspar  and  oligoclase  occur  in  obsidian  as 
well  as  in  pumice,  and  frequently  both  of  them  together. 
As  examples  may  be  cited, — the  Mexican  obsidians  of  the 
Cerro  de  las  Navajas  on  the  eastern  slope  of  the  Jacal, 
collected  by  me. — those  of  Chico,  with  many  crystals  of 
mica, — those  of  Zimapan  to  the  S.  S.  W.  of  the  capital  of 
Mexico,  mixed  with  small  distinct  crystals  of  quartz,  and  the 
pumice  of  the  Rio  Mayo  (on  the  mountain-road  from  Popayan 
to  Pasto)  as  well  as  those  of  the  extinct  volcano  of  Sorata, 
near  Popayan.  The  subterranean  pumice  quarries  near 
Liactagunga11  contain  a  large  quantity  of  mica,  oligoclase, 
and  (which  is  very  rare  in  pumice  and  obsidian),  hornblende 
also  ;  the  latter,  however,  is  also  found  in  the  pumice  of  the 
volcano  of  Arequipa.  Common  felspar  (orthoclase)  never 
occurs  in  pumice  along  with  saiiidine,  nor  is  augite  ever 
present.  The  Somma,  not  the  cone  of  Vesuvius  itself,  con- 
tains pumice,  enclosing  earthy  masses  of  carbonate  of  lirne. 
It  is  by  this  remarkable  variety  of  a  calcareous  pumice  that 
Pompeii  was  overwhelmed.1*  Obsidians  are  rare  in  genuine 
lava-like  streams  ;  they  belong  almost  solely  to  the  Peak  of 
Teneriffe,  Ltpari,  and  Volcano. 

Passing  now  to  the  association  of  obsidian  and  pumice  in 
one  and  the  same  volcano,  the  following  facts  appear. 
Pichincha  possesses  large  pumice-fields  and  no  obsidian. 
Chimborazo,  like  Etna,  whose  trachytes,  however,  have  a 

11  See  above,  p.  342. 

12  Scacchi,  Oaservazioni  criticJte  sulla  manicra  come  fu  scpellito  Tantica, 
Pompei,  1843,  p.  10,  in  opposition  to  the  theory  proposed  by  Carmine 
Lippi,  and  afterwards  shared  by  Tondi,  Tenore,  Pilla,  and  Dufrenoy, 
that    Pompeii  and    Herculaneum  were  not   overwhelmed   by   rapilli 
and    ashes   direct   from  the    Somma,   but  that  they   were  conveyed 
there    by    water.      Iloth,  Monogr.    cks     Vesuvs.    1857,    5.    458,    sea 
above,  p.  429. 


TliUE  VOLCANOES.  481 

totally  different  composition  (containing  labraclorite  instead 
of  oligoclase),  shows  neither  obsidian  nor  pumice  ;  this  same 
deficiency  I  observed  on  my  ascent  of  the  Tungurahua.  The 
volcano  Purace,  near  Popayan,  has  a  great  deal  of  obsidian 
mixed  in  its  trachytes,  but  has  never  yielded  any  pumice. 
The  immense  plains  out  of  which  rise  the  Ilinissa,  Carguai- 
razo,  and  Altar  are  covered  with  pumice.  The  subterranean 
pumice- quarries  near  Lactacunga,  as  well  as  those  of 
Huichapa  south-east  of  Queretaro;  and  the  accumulations 
of  pumice  at  the  Rio  Mayo,13  those  near  Tschegem  in  the 
Caucasus,14  and  near  Tollo15  in  Chili,  at  a  distance  from  active 
volcanic  structures,  appear  to  me  to  belong  to  the  phenomena 
of  eruption  from  the  numerous  fissures  in  the  level  surface  of 
the  earth.  Another  Chilian  volcano,  that  of  Antuco,16  (of 
which  Poppig  has  given  a  description  as  scientifically  impor- 
tant as  it  is  agreeably  written)  produces,  like  Vesuvius, 
ashes,  triturated  rapilli  (sand),  but  gives  out  no  pumice, 
no  vitrified  or  obsidian-like  mineral.  Without  the  presence 
of  either  obsidian  or  glassy  felspar,  we  sometimes  meet  with 
pumice  in  trachytes  of  very  dissimilar  composition,  although 
in  many  cases  it  is  not  present.  Pumice,  as  Charles  Darwin 
observes,  is  entirely  wanting  in  those  of  the  Archipelago  of 
the  Galapagos.  We  have  already  remarked  in  another  place 
that  cones  of  cinders  are  wanting  in  the  mighty  volcano  of 
Mauna  Loa  in  the  Sandwich  Islands,  as  well  as  in  the  vol- 
canoes of  the  Eifel "  which  once  emitted  lava-streams. 
Though  the  island  of  Java  contains  a  series  of  more  than 
forty  volcanoes,  of  which  as  many  as  twenty-three  are  still 
active,  yet  Junghuhn  was  only  able  to  discover  two  points 
in  the  volcano  of  Gunung  Guntur,  near  Bandong  and  the 
great  Tengger  Mountains,18  in  which  masses  of  obsidian  have 
been  formed.  These  do  not  appear  to  have  given  occasion 

13  Nivellement  Barometrique,  in  Humboldt,  Observat.  Astron.,  vol.  i, 
p.  305,  No.  149. 

14  See  above,  p.  345. 

15  For  an  account  of  the  pumice-bill  of  Tollo,  at  a  distance  of  two 
days'  journey  from  tbe  active  volcano  of  Maypu,  which  has  itself  never 
ejected  a  fragment  of  such  pumice,  see  Meyen,  Reise  urn  die  Erde, 
Th.  i,  s.  338  und  358. 

16  Poppig,  Reise  in  Chile  und  Peru,  Ed.  i,  s.  426. 

17  See  above,  p.  392,  and  notes,  pp.  320 — 3. 

18  Franz  Junghuhn,  Java,  Bd.  ii,  s.  388,  592. 

VOL.    V.  2   I 


482  COSMOS. 

to  the  formation  of  pumice.  The  sand-lakes  of  Dasar, 
which  lie  about  6828  feet  above  the  mean  level  of  the  sea, 
are  not  covered  with  pumice,  but  with  a  layer  of  rapilli, 
described  as  being  obsidian-like,  semi-vitrified  fragments  of 
basalt.  The  cone  of  Vesuvius,  which  never  emits  pumice, 
gave  out  from  the  24th  to  the  28th  October,  1822,  a  layer 
18  inches  thick  of  sand-like  ashes,  consisting  of  pulverised 
trachytic-rapilli,  which  has  never  been  mistaken  for  pumice. 
The  cavities  and  air-holes  of  obsidian  in  which  crystals  of 
olivine,  probably  precipitated  from  vapours,  have  formed,  as, 
for  example,  in  the  Mexican  Cerro  del  Jacal,  are  sometimes 
ibund  in  both  hemispheres  to  contain  another  kind  of  en- 
closures, which  seem  to  indicate  the  manner  of  their  origin 
and  formation.  In  the  wider  portions  of  these  long-extended, 
and  for  the  most  part  very  regularly  parallel  cavities,  frag- 
ments of  half-decomposed  earthy  trachyte  are  found  embedded 
Beyond  these  the  cavity  runs  on  in  the  form  of  a  tail,  as  if  a 
gas-like  elastic  fluid  had  been  developed  by  volcanic  heat 
in  the  still  soft  mass.  This  phenomenon  particularly  attrac- 
ted the  attention  of  Leopold  von  Buch  when  he  visited  the 
Thomson  collection  of  minerals  at  Naples  in  company  with 
Gay-Lussac  and  myself  in  the  year  1805.19  The  inflation  of 
obsidian  by  the  operation  of  fire,  which  did  not  escape  atten- 
tion in  the  early  period  of  Grecian  antiquity,20  is  certainly 
caused  by  some  such  development  of  gas.  According  to 
Abich,  obsidians  pass  the  more  easily  into  cellular  (not 
parallel-porous)  pumice,  the  poorer  they  are  in  silicic  acid 
and  the  richer  they  are  in  alkalies.  It  remains,  however,  very 
uncertain,  according  to  Rammelsberg's  researches,21  whether 
the  tumefaction  is  to  be  ascribed  to  the  volatilisation  of 
potash  or  hydrochloric  acid.  It  is  probable  that  similar 
phenomena  of  inflation  in  trachytes  rich  in  obsidian  and 
sanidine,  in  porous  basalts  and  amygdaloids  in  pitch-stone, 
tourmaline,  and  that  dark-brown  flint  which  loses  its  colour, 
may  have  very  different  causes  in  the  different  materials 

19  Leopold  von  Buch,  in  the  Abkandl.  der  Akademie  der  Wiss.  zu 
Berlin,  for  the  years  1812—1813  (Berlin,  1816),  s.  128. 

20  Theopkrastus  de  lapidibus,  s.  14  and  15  (Opera  ed.  Schneider,  t.  i, 
1818,  p.  689,  t.  ii,  p.  426,  and  t.  iv,  p.  551),  says  this  of  the  "liparian 
stone"  (Ai7Ttt()aio£). 

21  Rammelsberg,  in  Poggend.  Annal.,  Bd.  Ixxx,  1850,  s.   464,  and 
fourth  supplement  to  his  Chemische  Handworterbuch,  s.  169;  compare 
also  Bischof.  GeoL,  Bd.  ii,  s.  2224,  2232,  2280. 


TRUE  VOLCANOES.  483 

themselves.  An  investigation  which  has  now  been  long 
looked  for  in  vain,  founded  on  accurate  experiments,  ex- 
clasively  directed  to  these  escaping  gaseous  fluids,  would 
lead  to  an  invaluable  extension  of  our  knowledge  of  the 
geology  of  volcanoes,  if  at  the  same  time  attention  were  paid 
to  the  operation  of  the  sea- water  in  subterranean  formations, 
and  to  the  great  quantity  of  carburetted  hydrogen  belonging 
to  the  commingled  organic  substances. 

The  facts  which  I  have  brought  together  at  the  end  of  this 
section,  the  enumeration  of  those  volcanoes  which  produce 
pumice  without  obsidian,  and  those  which  yield  a  great  deal 
of  obsidian  and  no  pumice, — the  remarkable,  not  constant, 
but  very  diversified  association  of  obsidian  and  pumice  with 
certain  other  minerals,  early  led  me,  during  my  residence  in 
the  Cordilleras  of  Quito,  to  the  conclusion  that  the  formation 
of  pumice  is  the  result  of  a  chemical  process,  which  may  be 
verified  in  trachytes  of  very  heterogeneous  composition, 
without  the  necessity  of  a  previous  intervention  of  obsidian 
(that  is  to  say,  without  its  pre-existence  in  large  masses). 
The  conditions  under  which  such  a  process  is  performed  on  a 
large  scale,  are  perhaps  founded  (I  would  here  repeat)  less  on 
the  diversity  of  the  material  than  on  the  gradation  of  heat, 
the  pressure  determined  by  the  depth,  the  fluidity,  and  the 
length  of  time  occupied  in  solidification.  The  striking,  though 
rare,  phenomena  presented  by  the  isolation  of  immense  sub- 
terraneous pumice-quarries,  far  from  any  volcanic  structures 
(conical  and  bell-shaped  mountains),  lead  me  at  the  same  time 
to  conjecture22  that  a  not  inconsiderable — perhaps  even,  in 
regard  to  volume,  the  greater,  number  of  the  volcanic  rocks 
have  been  erupted,  not  from  upraised  volcanic  structures, 
but  from  a  net-work  of  fissures  on  the  surface  of  the  earth 
frequently  covering  over  in  the  form  of  strata  a  space  of  many 
square  miles.  To  these  probably  belong  those  masses  of 
trap  of  the  lower  Silurian  formation  of  the  south-west  of 
England,  by  the  chronometric  determination  of  which  my 
worthy  friend,  Sir  Roderic  Murchison,  has  so  greatly  in- 
creased and  heightened  our  acquaintance  with  the  geological 
construction  of  the  globe. 

22  See  above,  pp.  308,  330  332 — 336,  344 — 346,  354.  For  particulars 
respecting  the  geographical  distribution  of  pumice  and  obsidian  in 
the  tropical  zone  of  the  New  Continent,  see  Humboldt,  Essai  G&ognos- 
tigue  sur  le  gisement  des  Roches,  <kc.,  1823,  pp.  340—342,  and  344—347, 

2  i  2 


INDEX  TO  VOL.  V. 


ABTOH  on  volcanic  phenomena  in 
Ghilan,  175;  his  views  on  the 
Caucasian  mountain  system,  209, 
360  ;  analysis  of  the  Chimborazo 
rock,  462. 

Aconcagua,  volcano  of,  measure- 
ment of,  288. 

Acosta  on  the  volcaucitos  of  Tur- 
baco,  214. 

Adanis,  Mount,  a  volcano,  417. 

JSnaria,  the  island  of  Apes,  265. 

^Eolus,  residence  of,  on  Strongyle, 
257. 

Africa,  determination  of  the  mag- 
netic equator  in,  by  Sabine,  103  ; 
its  translation,  106 ;  snowy 
mountains  in,  354;  volcanoes 
in,  354 ;  their  small  number, 
355. 

African  magnetic  node,  its  varying 
position,  103. 

Agaschagokh,  island  of,  371. 

Agreeable  odour  diffused  from 
certain  volcanoes,  229. 

Agua,  Volcan  de,  described,  276. 

Airy,  density  of  the  earth  deter- 
mined by,  vii ;  on  terrestrial 
magnetism,  79. 

Alaid,  great  eruptions  of  the  vol- 
cano on  the  isle  of,  372. 

Albite,  469. 

Aleutian  islands,  numerous  volca- 
noes in,  370. 

Alps,  temperature  of  springs  in 
the,  192. 

America.  See  Central  America, 
Chili,  Mexico,  North-west  Ame- 
rica, Peru  and  Bolivia,  Rocky 
Mountains,  South  Sea. 

Ampere  on  the  cause  of  earth- 
quakes, 168. 

Ampolletas,  56. 

Amsterdam,  volcanic  island  of, 
385. 


Anahuac,  series  of  volcanoes  of, 
280. 

Anaxagoras,  maxim  of,  verified,  7. 

Andaman  isles,  volcanic  pheno- 
mena in  the,  383. 

Andes,  large  spaces  in  the  chain 
of,  destitute  of  volcanoes,  282; 
groups  and  distances,  283  ;  spe- 
cial direction  of  the  three  Cor- 
dilleras, 292. 

Andesite,  468,  471. 

Andrea  Bianco,  his  early  charts, 
exhibit  the  magnetic  variation, 
54. 

Anemasite,  478. 

Annular  valleys,  231. 

Ansango,  lake  of,  3. 

Ansogorri,  Father  Joaquin,  his  de- 
scription of  the  rise  of  the  vol- 
cano Jorullo,  310. 

Ant-hills,  in  the  Rocky  Mountains, 
their  remarkable  construction, 
475. 

Antilles,  Little,  volcanoes  of  the, 
described,  421. 

Antisana,  the  colossal  mountain, 
described,  331 ,  its  dykes,  331 ; 
lakes,  332. 

Antuco,  volcano  of,  289. 

Aphron,  the  northern  pole  of  the 
magnetic  needle,  53. 

Apparatus  employed  by  Humboldt 
for  his  453  determinations  of 
height  in  the  New  World,  459. 

Arabia,  lava  eniptions  in,  357. 

Arago  on  magnetic  inclination, 
107  ;  his  series  of  magnetic  ob- 
servations, vii. 

Ararat,  as  a  volcano,  361. 

Arare,  crater  of,  393. 

Arequipa,  volcano  of,  286. 

Ai'gaeus,  the  volcano,  249. 

Arimer,  country  of  the,  266. 

Aristotle    on    the     fundamental 


IXDEX. 


485 


principles  of  nature,  5 ;  volcanic 
phenomenon  upon  Hiera  de- 
scribed by,  229. 

Arran,  volcanic  phenomena  in, 
350. 

Artesian  wells,  Walferdin's  obser- 
vations on,  35. 

Ascension,  volcanic  phenomena  of 
the  island  of,  352. 

Asia,  situation  of  the  principal 
volcanoes  in,  297  ;  volcanoes  of 
the  western  and  central  parts, 
356 ;  of  Kamtschatka,  362 ;  of 
the  islands  of  Eastern  Asia,  367; 
of  the  islands  of  Southern  Asia, 
377;  of  the  Indian  Ocean,  382. 

Atlantic  Ocean,  volcanoes  of  the 
islands  of  the,  351;  presumed 
submarine  volcano,  353. 

Atlantis  of  Solon,  179. 

Atolls,  or  lagoon  reefs,  388. 

Attraction  of  the  magnet  known 
to  the  Greeks  and  Romans,  50. 

Augite,  475. 

Aurora  borealis,  152 ;  observa- 
tions of  the  black  segment,  152; 
colours  observed  in  high  lati- 
tudes, 1 54  ;  accompanying  flee- 
cy clouds,  155 ;  influence  on 
terrestrial  magnetism,  157;  ob- 
servations at  Berlin  and  at  Edin- 
burgh, 158. 

Auvergne,  extinct  volcanoes  of, 
238,  278. 

Azores,  craters  of  elevation  in  the, 
227  ;  the  volcano  Pico,  247. 

Azufral  de  Quindiu,  Humboldt's 
visit  to  the,  221 ;  change  of  tem- 
perature observed  by  Boussin- 
gault,  221. 

Baily  on  the  density  of  the  earth, 
31,  32. 

Baker,  Mount,  a  volcano,  418. 

Banda,  a  volcanic  island,  381. 

Barba,  the  volcano,  described, 
273. 

Barile,  earthquake  at,  173. 

Barrancos  on  the  slopes  of  vol- 
canoes, 304. 


Barren  Island,  one  of  the  Anda- 
mans,  appearance  of,  as  de- 
scribed by  Horsburgh,  383. 

Basalt-like  columns  of  Pisoje,  456. 

Beaufort,  Admiral,  the  Chimsera 
described  by,  257. 

Beauvais,  Vincent  of,  on  the  mag- 
netic needle,  53. 

Belcher,  Sir  E.,  magnetic  observa- 
tions by,  113. 

Bell-shaped  volcanic  mountains, 
228. 

Berg,  Albert,  his  description  of 
the  burning  spring,  Chimsera, 
257. 

Berlin,  aurora  observed  at,  by 
Humboldt,  158. 

Bessel,  determination  of  the  size 
and  figure  of  the  earth,  14,  27. 

Biot,  pendulum  measurements  by, 
23. 

Bolivia.     See  Peru. 

Borda,  his  services  in  equipping 
the  expedition  of  La  Perouse, 
61. 

Borneo,  the  Giava  Maggiore  of 
Marco  Polo,  379  ;  doubtful 
whether  volcanoes  exist  there 
379 ;  great  number  of  volcanoes 
in  its  vicinity,  379. 

Bo-shan,  eruption  of  the  volcano, 
437. 

Bouguer's  experiments  on  the  de- 
viation of  the  plummet,  30 ;  on 
the  pumice-quarries  of  Lactu- 
cunga,  342. 

Boxirbon,  volcanoes  of  the  isle  of, 
383. 

Boussingault's  method  of  deter- 
mining the  mean  temperature, 
40 ;  on  the  cause  of  earthquakes, 
170 ;  on  the  matters  ejected  from 
volcanoes,  335  ;  on  gases,  442. 

Bove,  Val  del,  on  Etna,  225,  241. 

Bramidos  de  Guanaxuato,  178. 

Bravais  on  Artesian  wells,  37;  on 
the  black  segment  of  the  Au- 
rora, 153. 

Brisbane,  Sir  Thomas,  his  observa* 
tory  at  Makerstoun,  123, 124. 


486 


INDEX. 


British  isles,  volcanic  phenomena 

in  the,  350,  483. 
Bromo,    a  volcano    in  Java,    its 

crater  lake,  302. 
Brooke,   Eajah,   on  the    volcanic 

appearances  in  Borneo,  380. 
Brooks  of  cold  water  said  to  be 

converted  into  thermal  springs, 

314. 

Brown,  Mount,  a  volcano,  418. 
Buch,   Leopold  von,  his  work  on 

basaltic  islands  and  craters  of 

elevation,  226  ;  on  the  erupted 

matters  of  Vesuvius,  235 ;   on 

the  trachytes  of  Etna,  469. 
Buddhist  fancy  as  to  the  causa  of 

earthquakes,  177. 
Bun'sen  on  fumaroles,  424. 
Burkart,  his  visit  to  Jorullo,  318. 

Calabria,  earthquake  in,  in  1783, 
172. 

Calamatico,  el,  an  ancient  name  for 
the  magnetic  pole,  56. 

Calbuco,  Volcan  de,  290. 

California,  list  of  the  volcanoes  of, 
417. 

Callaqui,  volcano  of,  290. 

Canary  Islands,  eruptions  in  the, 
477. 

Capac-Urcu,an  extinct  volcano  282. 

Cape  of  Good  Hope,  magnetic 
observations  at,  113. 

Carbonic  acid  gas,  considerations 
on,  442. 

Carbonic  acid  gas,  jets  of,  201. 

Cascade  Mountain  range,  in  Cali  - 
fornia,  416. 

Castillo,  Fray  Bias  del,  explores 
the  crater  of  Masaya,  260. 

Catalans,  advanced  state  of  navi- 
gation among  the,  53,  54. 

Caucasus,  volcanic  phenomena  of 
the,  208  ;  a  continuation  of 
the  Thian-schan,  360;  its  ex- 
tinct volcanoes,  360. 

Cauldron-like  depressions  of  volca- 
noes, 231. 

Cavanilles,  his  account  of  the 
earthquake  of  Riobamba,  1 73. 


Celebes,  volcanoes  of,  381. 

Central  America,  linear  volcanoes 
of,  268,  272 ;  number  of  volca- 
noes in,  273;  recommended  for 
further  examination,  278. 

Chacani  or  Charcani,  volcano  of, 
286. 

Chahorra,  the  crater  of,  on  the 
Peak  of  Teneriffe,  262. 

Chatham  Island,  its  position,  401 . 

Chili,  group  of  volcanoes  in,  288 ; 
their  greatest  elevation,  where 
attained,  296. 

Chilian,  Volcan  de,  289. 

Chiloe,  submarine  volcano  near, 
288. 

Chimborazo,  majestic  dome,  form 
of,  2  ;  ascent  of,  464  ;  conside- 
rations on  the  height  of  the 
mountain,  464. 

Chimborazo  rock,  Rammelsberg's 
analysis  of,  461,  Abich's,  462; 
remarks  on  the  differences  be- 
tween them,  463. 

Chimsera,  in  Lycia,  not  a  volcano, 
but  a  perpetual  burning  spring, 
212,257;  analogous  phenomenon 
in  the  Kuen-lun,  438. 

Chinal,  volcano  of,  290. 

Chinese,  early  acquainted  with 
the  polarity  of  the  magnet,  50  f. 
rope-boring,  219;  early  maps 
of  the,  434. 

Chuapri,  volcano  of,  288. 

Cinders,  cones  of,  wanting  in  seve- 
ral volcanoes  which  once  emit- 
ted lava-streams,  481;  thickness 
of  the  layers  of,  on  Sangay,  265. 

Circumvallations,  volcanic,  230 ; 
that  of  Oisans,  in  France,  its 
great  extent,  231  ;  of  Mont 
Blanc,  231. 

Coal  strata,  443. 

Coan,  the  missionary,  on  the  basin 
of  Kilauea,  393. 

Coast  Kange  mountains,  in  Cali- 
fornia, old  volcanic  rocks  of  the, 
416. 

Cofre  de  Perote,  Humboldt'a 
ascent  of.  326. 


INDEX. 


487 


Columbus  determines  astronomi- 
cally a  line  of  no  variation,  54  ; 
notice  of  an  eruption  on  Tene- 
riffe,  by,  477. 

Comangillas,  Aguas  de,  a  hot 
spring,  197. 

Commotion,  waves  of,  in  earth- 
quakes, 171;  theory  of,  172; 
attempt  to  explain  the  rotatory 
shocks  experienced  in  Calabria, 
172. 

Commotions  of  the  earth  in  earth- 
quakes often  confined  within 
narrovr  limits,  182. 

Comoro  islands,  burning  volcano 
in  the,  384. 

Compass.    See  Mariner's  Compass. 

Compression,  polar,  29. 

Couchagua,  a  volcano,  275. 

Conical  volcanic  mountains,  239. 

Conseguira,  eruption  of,  274. 

Copiapo,  destruction  of  the  town 
of,  288. 

Coquimbo,  volcano  of,  288. 

Coral  islands,  number  of,  in  the 
Pacific,  according  to  Dana,  390. 

Corcovado,  Volcan  de,  290. 

Cordilleras.     See  Andes. 

Corea,  volcanoes  of,  376. 

Cosima,  small  elevation  of  the 
volcano  of,  245. 

Costa,  Col.  A.,  his  experiments  on 
mean  annual  temperature,  41. 

Cotopaxi,  mineralogical  composi- 
tion of,  343. 

Craters  of  elevation,  226 ;  distin- 

fuished    from   true   volcanoes, 
27.     See  also  Volcanoes. 
Crozet's  group,  traces  of  former 

volcanic  action  in,  387. 
Crust  of  the  earth,  considerations 

on  its  varying  thickness,  439. 
Crystallized  minerals  of  the  Maars, 

234 ;  greater  number  found  on 

Vesuvius,  235. 
Cueva  de  Autisana,  332. 
Cyclades,  volcanic  phenomena  in 

the,  267. 

Dana,    James,    his    valuable    re- 


searches in  the  Pacific,  388 ; 
his  grouping  of  the  basaltic  and 
coral  islands,  390  ;  on  the  vol- 
canoes of  the  Sandwich  Islands, 
392. 

Darwin,  Charles,  his  enlarged 
views  on  earthquakes  and  erup- 
tions of  volcanoes,  288  ;  general 
acknowledgment  of  obligations 
of  science  to,  389. 

Dasar,  sand-lakes  of,  482 

Dechen,  H.  von,  on  volcanic  phe- 
nomena  in  the  Eifel,  236 

Declination.     See  Magnetism. 

Degree,  table  of  the  increase  in 
length  of  the,  from  the  equator 
to  the  pole,  17. 

Demavend,  volcano  of,  356,  357  ; 
question  of  its  altitude,  356. 

Density  of  the  earth,  experiments 
to  determine,  30;  Airy 's  results, 
vii. 

Detritus  dykes,  331. 

Deville,  on  the  structure  and 
colour  of  the  mass  in  certain 
volcanoes,  463. 

Devonian  slate,  231. 

Diablo,  Monte  del,  in  California, 
416. 

Diamagnetism,  its  discovery  by 
Faraday,  49,  78. 

Dio  Cassius  on  the  eruptions  of 
Vesuvius,  427. 

Diodorus  Siculus  on  the  Phlegrsean 
fields,  428. 

Disturbances,  magnetic,  table  of, 
134. 

Djebel  el  Tir,  a  volcano,  356. 

Dome-shaped  and  bell-shaped 
mountains  peculiar  aspect  given 
by,  to  the  landscape,  229. 

Domite,  origin  of  the  term,  450. 

Dry  fog  of  the  summer  of  1783, 
421. 

Duperrey,  his  observations  on  the 
magnetic  equatoi*,  104. 

Earth,  its  size,  configuration  and 
density,  vii,  9 ;  interior  heat, 
34,  246  ;  magnetic  activity,  49; 


488 


IND2X. 


magnetic  storms,  141 ;  polar 
light,  151  ;  reaction  of  the 
interior  on  the  surface,  162 
(see  also  Earthquakes,  Volcanoes); 
thickness  of  the  crust  of,  pro- 
bably very  unequal,  169. 

Earthquakes,  variety  of  views  as 
to  their  cause,  167  ;  the  impulse, 
167  ;  translatory  movements, 
173;  subterranean  noises,  178; 
velocity  of  propagation,  179 ; 
distinguished,  but  improperly, 
aa  Plutonic  and  Volcanic,  180 ; 
three  groups  of  phenomena 
which  indicate  the  existence  of 
one  general  cause,  183  ;  list  of 
memorable  examples  of  these 
phenomena,  183. 

Earth-waves  in  volcanic  phe- 
nomena, 171. 

Eastern  Asia,  volcanoes  of  the 
islands  of,  367. 

Eclgecombe,  Mount,  a  volcano, 
269,  418;  another  in  New 
Zealand,  397. 

Edinburgh,  beautiful  aurora  ob- 
served at,  158. 

Edrisi  on  the  land  of  Gog  and 
Magog,  359. 

Eifel,  extinct  volcanoes  of  the, 
231  ;  two  kinds  of  volcanic 
activity  distinguishable,  232 ; 
Mitscherlich  on  the  minerals, 
235 ;  Ehrenberg  on  the  infusoria, 
237. 

Elburuz,  as  an  extinct  volcano,  362. 

Elevation,  question  of  the  in- 
fluence of,  on  magnetic  dip  and 
intensity,  114 ;  craters  of,  dis- 
tinguished from  true  volcanoes, 
227. 

Elias,  Mount,  a  volcano,  252,  419. 

Elliot,  Capt.,  on  the  magnetic 
equator,  105. 

Ellipticity  of  the  earth,  specula- 
tions of  the  ancients  on  the,  26 ; 
Bessel's  determination,  27. 

El  Nuevo,  a  volcano,  274. 

El  Viejo,  a  volcano,  measurements 
of,  274. 


El  Volcancito,  now  a  mountain  of 
ashes,  321. 

Emanations  from  fumaroles,  their 
nature,  424. 

Enceladus.     See  Typhon. 

England,  volcanic  phenomena  in, 
350,  483. 

Equator,  magnetic.  See  Magnetic 
equator. 

Erebus,  Mount,  the  volcano,  103, 
249. 

Ermau  on  the  magnetic  equator, 
105  ;  his  researches  on  the  vol- 
canoes of  Kamtschatka,  363. 

Erupted  blocks,  479. 

Eruption,  masses  of,  considera- 
tions on,  225;  craters  of,  226. 

Eruptions  of  volcanoes,  considera- 
tions on  the  general  laws  of, 
255 ;  varying  heights  to  which 
matters  are  cast,  264. 

Etna,  eruptions  of,  usually  occur 
within  a  space  of  six  years,  255  ; 
periods  of  its  greatest  activity, 
257 ;  height  to  which  ejected 
matters  attain,  265 ;  its  tra- 
chytes, 165. 

Euboea,  Strabo's  description  of  an 
earthquake  in,  225. 

Europe,  active  volcanoes  of,  349 ; 
extinct  volcanoes  and  volcanic 
phenomena,  231,  238,  350,  483. 

Faraday's  discovery  of  the  para- 
magnetic force  of  oxygen,  78 ; 
important  results  expected  from 
it,  82,  99;  on  diamagnetism, 
49,  78. 

Fairweather,  Mount,  a  volcano,  4 1 8. 

Felspar,  variety  of  minerals  com- 
prised under  the  denomination 
of,  457,  474. 

Ferdinandea,  the  volcanic  island, 
349. 

Figure  of  the  earth,  attempts  to 
solve  the  problem,  13  ;  deter- 
minations of  Bessel,  14  ;  earlier 
observations,  16. 

Fissures  caused  by  earthquakes, 
173;  volcanic,  226,  228;  vol- 


INDEX. 


489 


canoes  upheaved  on  fissures, 
265.  See  Volcanoes. 

Fitzroy's  magnetic  observations, 
71. 

Floods  in  rivers,  prognostication 
of,  187. 

Forbes,  on  the  conductive  power 
of  different  rocks,  38. 

Fogo,  volcano  of  the  Ilha  do, 
262. 

Formosa,  the  turning-point  of  the 
lines  of  volcanic  elevation  in 
the  islands  of  Eastern  Asia,  369  ; 
its  volcanoes,  377. 

Foucault's  apparatus  for  demons- 
trating the  rotation  of  the 
earth,  25. 

France,  extinct  volcanoes  of,  238, 
278. 

Franklin  on  frozen  earth  in  the 
north-west  of  America,  48  ;  his 
Arctic  voyages,  65  ;  search  for 
him,  65. 

Franklin's  Bay,  volcano  of, 
more  properly  a  salse,  419. 

Fredonia,  near  Lake  Erie,  springs 
of  inflammable  gas  at,  213. 

Fremont's  hypsometrical  investiga- 
tions in  North- West  America, 
410. 

Fremont's  Peak,  415. 

French  Alps,  highest  summit  of 
the,  230. 

Frozen  earth,  its  geographical  ex- 
tension, 46. 

Fse-nan,  a  Chinese  magnetic  appa- 
ratus, 50. 

Fuego,  Volcan  de,  described,  276. 

Fumaroles,  various  classes  of,  424; 
Bunsen  on  their  products,  424. 

Fummarole  of  the  Tuscan  Ma- 
remma,  211. 

Fused  interior  of  the  earth,  246. 

Galapagos,   the,    countless    cones 

and  extinct  craters,  400  ;  pumice 

not  found  there,  401. 
Gal  era  Zamba,  terrible   eruptions 

of  flames  and  terrestrial  changes 

at,  218. 


Gandavo,  Fray  Juan  de,  explores 
the  crater  of  Masaya,  260. 

Gas,  volcanic  exhalations  of,  in- 
quiry into,  441.  See  also 
Springs. 

Gauss,  his  theory  of  terrestrial 
magnetism,  62. 

Gay  Lussaconthe  chemical  causes 
of  volcanic  phenomena,  169 ; 
on  waves  of  commotion  and 
oscillation,  171. 

Gemellaro,  his  estimate  of  the 
height  to  which  erupted  bodies 
ascend  from  Etna,  265. 

Geographical  distribution  of  vol- 
canoes, 421  ;  an  abnormal  phe- 
nomenon in,  noticed,  433. 

Geological  terms,  origin  of  some, 
450. 

Geysirs,  the,  of  Iceland  described, 
199. 

Gilbert,  William,  lays  down  com- 
prehensive views  on  the  mag- 
netic force  of  the  earth,  57. 

Glassy  felspar.     See  Felspar. 

Godivel,  Lac  de  la,  an  extinct 
volcano,  238. 

Gog  and  Magog,  oriental  myth  of, 
359. 

Gold,  believed  to  be  found  in 
volcanoes,  261  ;  descent  into 
Masaya  in  search  of  it,  261. 

Graham,  his  observation  of  the 
hourly  variations  of  the  mag- 
netic force,  60. 

Graham  Island,  temporary  for- 
mation of,  349. 

Grand  Ocean,  a  term  for  the  basin 
of  the  South  Sea,  objected  to, 
404. 

Granite,Mitscherlich's  experiments 
on  the  melting  point  of,  246. 

Greece,  has  frequently  suffered 
from  earthquakes,  177;  great 
number  of  thermal  springs,  177. 

Grenelle,  the  Artesian  well  of,  36. 

Ground  temperature,  observations 
on,  1 90.  See  also  Frozen  earth. 

Guadeloupe,  the  Soufriere  of,  de- 
scribed, 423. 


490 


INDEX. 


Quagua-Pichincha,    its    meaning, 

242. 

Gualatieri,  volcano  of,  287. 
Guanacaure,  a  volcano,  274. 
Guanahuca  (Guanegue?)  volcano 

of,  290. 
Guettard's  observations  on  extinct 

volcanoes,  330. 
Gunung,  the   Javanese  term   for 

mountain,  299. 
Gunung   Tengger,   a    volcano   in 

Java,  vast  size  of  its  crater,  301. 
Guyot  of  Provins,  his  mention  of 

the  magnetic  needle,  53. 

Hair-glass,  a  volcanic  product, 
392. 

Hall,  Capt.  Basil,  experiments  to 
determine  the  mean  tempera- 
ture of  places  within  the  tropics, 
40;  measurement  of  the  vol- 
canoes of  Old  Guatemala,  277  ; 
his  admirable  description  of 
Sulphur  Island,  377. 

Halley's  theory  of  four  magnetic 
poles,  58. 

Hallmann,  his  classification  of 
springs,  205. 

Hansteen  on  the  magnetism  of 
the  earth,  66. 

Harton,  pendulum  experiments 
at,  relative  to  the  density  of  the 
earth,  vii. 

Hawaii,  the  volcanoes  of,  de- 
scribed, 395. 

Heat,  distribution  of,  in  the  in- 
terior of  our  globe,  34  ;  hypo- 
thesis of  the  depth  of  the  fused 
interior  of  the  earth  below  the 
present  sea  level,  246. 

Hecla,  the  volcano,  its  aspect, 
243  ;  infrequency  of  its  erup- 
tions, 255 ;  how  classified  by 
Waltershausen,  351. 

Helena,  St.,  volcanic  phenomena 
of,  352. 

Helen's,  St.,  Mount,  a  vclcano, 
417. 

Hell,  the  cold,  of  the  Buddhists 
196. 


Hephsestos,  Volcano,  the  holy  isle 
of,  257. 

Herefordshire,  sedimentary  rocks 
of,  231. 

Hesse,  on  the  volcanoes  of  Central 
America,  272. 

Hiera,  volcanic  phenomena  upon, 
described  by  Aristotle,  229. 

Himalayan  chain,  four  highest 
mountains  of  the,  287  ;  known 
to  the  Greeks  as  the  elongated 
Taurus,  434. 

Hobarton,  magnetic  observations 
at,  100. 

Ho-cheu,  a  volcano,  also  called 
Turfan,  356. 

Hood,  Mount,  an  extinct  volcano, 
417. 

Hooker,  Joseph,  on  the  hot  springs 
of  Momay,  197. 

Hopkins  on  earthquakes,  168,  171, 
174. 

Horary  variation  of  the  declina- 
tion not  ascribable  to  the  heat 
of  the  sun,  82;  maxima  and 
minima,  at  various  magnetic 
stations,  109. 

Hornblende  and  augite,  475. 

Hornos  or  Hornitos.  See  Hornitos. 

Hornitos,  low  volcanic  cones,  1 83 ; 
further  notices  of  them,  316, 
322. 

Horsburgh,  description  of  Barren 
Island  by,  383. 

Ho-schan  and  Ho-tsing,  of  Eastern 
Asia,  219. 

Humboldt,  Alexander  von,  ob- 
servations of  temperature  in 
Mexico  and  Peru,  41 ;  magnetic 
observations  by,  70,  96 ;  his 
determination  of  the  magnetic 
equator,  104  ;  observations  of 
polar  bands,  155  ;  visit  to  the 
scene  of  the  earthquake  of 
Kiobamba,  1 73 ;  observations  of 
the  phenomena  of  an  eruption 
of  Vesuvius,  181  ;  barometrical 
measurements  of  the  same 
mountain,  247 ;  his  definition 
of  the  term  "volcano,"  287; 


INDEX. 


491 


his  visit  to  Joruilo,  313,  319; 
the  name  Jura  limestone  intro- 
duced by,  468 ;  apparatus  em- 
ployed by,  in  the  New  World, 
459 ;  his  mineralogical  collec- 
tions, 477 ;  on  the  formation  of 
pumice,  483. 

lumboldt,  Alexander  von,  works 
by,  cited  in  the  text  or  notes : — 

Asie  Centrale,  51,  101,  116, 
148,  149,  176,  208,  210, 
219,  220,  250,  295,  336, 
356,  358,  360,  361,  372, 
376,  438. 

Atlas  Geographique  et  Phy- 
sique de  la  Nouvelle  Es- 
pagiie,  239,  247,  263,  309, 
432. 

Essai  Geognostique  sur  le 
Gisement  des  Roches,  221, 
320, 444,  454,  468,  475,  483. 

Essai  sur  la  Geographic  des 
Plantes,  252,  458. 

Essai  Politique  sur  la  Nou- 
velle  Espagne,  42,  197,  279, 
280,  293,  310,  312,  326, 
406,  418,  458. 

Examen  Critique  de  l?His- 
toire  de  la  Geographic,  51, 
119,  126,  180,  244,  260. 

Fragmens  de  Ge'ologie  et  de 
Climatologie  Asiatique, 
372,  377. 

Kleinere  Schriften,  171,  214, 
239,  291,  332,  336,  341, 
451,  478. 

Recueil  d'  Observation  s  As- 
tronomiques,  41,  104,  143, 
222,  251,  279,  315,  326, 
444,  459,  464,  481. 

Relation  Historiquedu  Voyage 
aux  Regions  equinoxiales 
(Personal  Narrative,  Bonn's 
edit.,  1852-3),  97,  112,115, 
117,  173,  175,  187,  249, 
250,  303,  422,  423,  479. 

Views  of  Nature,  261,  365, 
408,  427. 

Vues  des  Cordilleres,  217, 
239,  242,  247. 


Hypersthene  rock,  its  employment 

for  ornamental  purposes,  478. 
Hypsometry.  of    volcanoes,    first 

group,  246  ;  second  group,  247 ; 

third  group,  248 ;  fourth  group, 

250 ;  fifth  group,  251. 

Iceland,  the  Geysirs  of,  198  ;  mud 
springs,  212  ;  volcanoes,  351. 

Ilha  do  Fogo,  one  of  the  Cape 
Verd  Islands,  so  called,  262. 

Impulse  in  volcanic  phenomena, 
summary  of  views  on,  167. 

Inarima,  266. 

Inclination,  magnetic,  102 ;  max- 
ima and  minima,  109 ;  secular 
variation,  111. 

Indian  Ocean,  volcanoes  of  the, 
382,  387. 

Infusoria,  universal  diffusion  of 
the,  237. 

Intensity  of  the  magnetic  ter- 
restrial force,  57,  61,  87. 

Interior  of  the  earth,  its  reaction 
•on  the  surface,  162.  See  also 
Earthquakes,  Volcanoes. 

Invariable  temperature,  stratum 
of,  39. 

Ischia,  265. 

Island  of  Desolation.  See  Ker- 
guelen's  Island. 

Islands,  temporary,  enumerated, 
349. 

Islands  and  the  shores  of  conti- 
nents, great  number  of  vol- 
canoes found  on,  431. 

Islands  of  the  Pacific,  Dana's 
classification  of,  390. 

Isluga,  volcano  of,  287. 

Izalco,  volcano  of,  described,  261  ; 
its  eruptions,  276, 

Iztaccihuatl,  a  volcano,  meaning 
of  the  name,  239. 

Jacob,  valley  of,  on  Ararat,  241. 

Jakutsk,  mean  annual  tempera- 
ture of,  45:  extreme  variations. 
45. 

Jan  Mayen,  volcanoes  of  the  island 
of,  351. 


402 


INDEX. 


Japan,  notice  of  the  volcanoes  of, 
communicated  by  Sielbold,  373. 

Jaques  de  Vitry,  his  mention  of 
the  magnetic  needle,  53. 

Java,  large  number  of  volcanoes 
in,  297;  their  comparatively 
low  elevation,  299;  direction  of 
the  principal  axis,  301 ;  vast 
craters  of  some,  301 ;  ribbed 
formation,  303 ;  lava  streams, 
305 ;  salses  of,  and  mofette 
grottoes,  described  by  Jung- 
huhn,  220 ;  tertiary  formations, 
298. 

Javanese  names  of  mountains  ex- 
plained, 307. 

Jefferson,  Mount,  417. 

Jesso,  island  of,  372 ;  its  nume- 
rous volcanoes,  373. 

Jorullo,  rise  of  the  volcano,  280, 
309 ;  description  of,  by  eye-wit- 
nesses, 310 ;  visit  of  Humboldt 
to,  313,  319;  visit  of  Buckart, 
and  changes  noticed  by  him, 
318. 

Juan  Jayme,  his  scientific  voyage, 
55. 

Julia  the  volcanic  island,  349. 

Julius,  the  proconsul,  196. 

Jumnotri,  hot  well  of,  198. 

Junghuhn,  his  researches  in  Java, 
220,  298. 

Jura  limestone,  name  introduced 
by  Humboldt,  468. 

Kaimenes,  upheaval  of  the  three, 
349. 

Kamtschatka,  the  loftiest  volcano 
of  Asia  found  in,  300;  de- 
scribed, 362. 

Kerguelen's  Island,  extinct  craters 
of,  387. 

Kilauea,  the  great  crater  of,  not  a 
solfatara,  392. 

Kina  Bailu,  a  lofty  mountain  of 
Borneo,  379. 

Kirgish  Steppe,  former  water- 
courses of  the,  437. 

Kljutschewsk,  the  highest  Asiatic 
volcano,  300. 


Korai.     See  Corea. 

Kotzebue  on  the  volcanic  island 
of  Umnack,  230. 

Krapf,  discovery  of  a  volcano  in 
Eastern  Africa  by,  354. 

Krafto.     See  Saglialin. 

Krasnajazarki,  polar  bands  ob- 
served by  Humboldt  at,  155. 

Kreil  on  the  magnetism  of  the 
moon,  85. 

Krusenstern  on  a  presumed  sub- 
marine volcano,  353. 

Kuen-lun,  fire-springs  of  the, 
438  ;  the  chain  visited  by  the 
brothers  Schlagintweit,  438. 

Kuopho  on  the  magnetic  needle, 
51. 

Kupffer  on  the  frozen  soil  of 
Northern  Asia,  48. 

Kurile  isles,  active  volcanoes  of 
the,  372. 

La  Berarde,  remarkable  position 
of  the  village  of,  231. 

Lactacunga,  repeated  destruction 
of  the  town  of,  342 ;  subter- 
ranean pumice  quarries  of,  342, 
481. 

Ladrone  islands,  volcanoes  of,  395. 

Lagoni  of  the  Tuscan  Maremma, 
211. 

Lamont  deduces  the  law  of  the 
period  of  alterations  of  decli- 
nation, 84. 

Lancerote,  destruction  of  the 
island  of,  228. 

Lava,  recent,  often  perfectly  simi- 
lar to  the  oldest  formations  of 
eruptive  rock,  226;  important 
conclusion  drawn  therefrom, 
226. 

Lava  fields,  various  names  for,  324. 

Lava  streams  rare  in  the  volcanoes 
of  the  Cordilleras  of  Quito,  277; 
discovered  in  the  eastern  chain 
of  the  Andes,  295  ;  also  in  Java, 
306;  their  essential  character, 
306 ;  of  Auverge,  330 ;  of  Etna, 
465;  of  Hecla,  243;  of  Ter» 
nate,  381. 


INDEX. 


493 


Lazarus,  St.  Mount,  volcano,  269. 
Lelantus,  in  Euboea,  eruption  at, 

225. 
Lemnos,  destruction  of  the  moun 

tain  Mosychlos  in,  349. 
Letronne  on  earthquakes  in  Egypt? 

177. 

Leucite,  466,  476. 
Limari,  volcano  of,  288. 
Linschoten,  notices  the  volcanoes 

of  Japan,  375. 
Lipara,    the  volcano,  question  of 

its  identity,  256. 
Lipari,  the  ancient  Meligunis,  256; 

lava  stream  found  in,  341. 
Llandeilo    strata,    volcanic    frag- 
ments found  in  the,  350. 
Llanquihue,  volcano  of,  290. 
Log,  ship's,  introduction  of  the, 

an  important  era  in  navigation, 

56. 
Lombok,  volcano  on  the  isle  of, 

331. 

Lucia,  St.,  the  volcano  of,  422. 
Lunar-diurnal  magnetic  variation, 

viii. 
Liitke,  Admiral,  on  the  volcanoes 

of  Kamtschatka,  363. 
Luzon,  active  volcano  in,  243. 

Maars,  in  Germany,  231 ,  in  Au- 
vergne,  238. 

Macas.    See  Sangay. 

McLaughlin,  Mount,  its  height, 
417. 

Madagascar,  volcanic  indications 
in,  384. 

Madeira,  volcanic  phenomena  of, 
352. 

Magnet,  attraction,  but  not  pola- 
rity of  the,  known  to  the  Greeks 
and  Romans,  50;  variations  of 
the,  early  known  to  the  Chinese, 
52  ;  variation  charts,  54 ;  horary 
periodical  alterations,  60. 

Magnetic  disturbances,  table  of, 
134. 

Magnetic  equator,  its  position  and 
change  of  form,  103 ;  Hum- 
boldt'a  determinations,  1-J4 ; 


Puperrey's  observations,  104; 
Elliot's,  105. 

Magnetic  intensity,  61 ;  the  know- 
ledge of,  due  to  Borda,  61 ;  in- 
clination chart,  61. 

Magnetic  needle,  early  known  to 
the  Chinese,  50 ;  its  introduction 
to  Europe,  52  ;  decimation,  54. 

Magnetic  observatories,  62. 

Magnetic  storms,  134. 

Magnetic  waggon,  the,  of  the 
Chinese,  51. 

Magnetism,  early  researches  in, 
55,  57 ;  increased  activity  of 
observation  in  the  1 9th  century, 
62 ;  table  of  magnetic  investi- 
gations, 63;  influence  of  the 
moon,  viii. 

Magnetism  of  mountain  masses, 
159. 

Makerstoun,  Sir  Thomas  Bris- 
bane's observatory  at,  123,  124. 

Malpais,  a  term  applied  to  lava 
fields,  307. 

Mandeira,  the  volcano,  273. 

Mantschurei,  extinct  volcano  in, 
437. 

Marco  Polo,  date  of  his  travels,  53 ; 
the  mariner's  compass  known  in 
Europe  before  his  time,  53. 

Marcou,  on  the  anthills  in  the 
Eocky  Mountains,  475. 

Maribios,  los,  a  line  of  six  vol- 
canoes, 274. 

Mariner's  compass  known  in  Eu- 
rope in  the  12th  century,  53; 
English  ships  guided  by  it,  in 
1345,  56. 

Marion's  Island,  traces  of  former 
volcanic  action  on,  387. 

Martinique,  recent  volcanic  action 
in  the  island  of,  423. 

Masaya,  volcano  of,  described, 
258  ;  descent  into  the  crater  of, 
260. 

Mauna-Roa,  a  volcano  of  the  Sand- 
wich Islands,  250;  its  height 
greatly  exaggerated,  250;  mean- 
ing of  the  name,  245;  described, 
391;  the  largest  volcano  of  tha 


494 


INDEX. 


South  Seas,  391;  called  also 
Mouna  Loa,  391;  its  lava-lake 
of  Kilauea,  393. 

Maypu,  volcano  of,  289. 

Medina,  volcano  of,  356. 

Meligunis.     See  Lipari. 

Methone,  volcanic  phenomena  of 
the  peninsula  of,  229. 

Mexico,  list  of  elevations  of  the 
table  land  of,  408  ;  volcano  of, 
402 ;  considerations  on  the 
mountain  chains,  405.  See  also 
New  Mexico. 

Mica,  473. 

Micuipampa,  mean  annual  tempe- 
rature of,  41,  42. 

Middendorf's  two  Siberian  expe- 
ditions, 43 ;  on  the  frozen  soil 
of  Northern  Asia,  47. 

Minchinmadom,  volcano  of,  290. 

Mines,  observations  in,  on  mag- 
netic dip  and  intensity,  116. 

Mitscherlich  on  the  minerals  of  the 
Eifel,  235 ;  on  the  melting  point 
of  granite,  246. 

Mofette-grottoes  of  Java,  described 
by  Junghuhn,  220. 

Momay,  hot  springs  of,  197. 

Momobacho,  the  volcano,  273. 

Momotombo,  the  volcano,  274. 

Monkwearmouth,  the  coal  mine  at, 
37. 

Mont  Blanc,  the  Grand  Plateau 
of,  231. 

Mont  Pelvoux,  the  highest  summit 
of  the  French  Alps,  230. 

Monte  del  Diablo,  in  California, 
416. 

Moon,  extent  of  our  acquaintance 
with  the  surface  of  the,  448; 
volcanoes  and  parasitic  craters, 
449 ;  magnetism  of  the  Kreil 
on  the,  85 ;  investigation  of 
the  subject  by  General  Sabine, 
viii. 

Mormons,  Great  Salt  Lake  of  the, 
410. 

Mortero,  Cerro  del,  321. 

Mosenberg,  the,  an  extinct  vol- 
cano, 232,  238. 


Mosychlos,  the  mountain,  destruc- 
tion of,  349. 

Mouna  Loa.     See  Mauna  Roa. 
Mountain  masses,  magnetism  of, 

159. 
Mountain   peaks,   comparison   of, 

with  the  bulging  of  the  earth's 

surface,  28. 
Mousart  (corruption  of  Muztag), 

equivalent    to    Sierra    Nevada, 

434. 

Moya  cones  of  Pelileo,  172,  216. 
Mud-springs  of  Iceland,  212. 
Mud- volcanoes,  217,  379. 
Murchison,    Sir    R.,  on    eruptive 

trap  masses,  350,  483. 
Muriatic  acid  fumaroles,  424. 
Mutis,  apparatus  of,  459. 

Naphtha  springs,  207. 

Negropont.     See  Eubcea. 

Neptune,  connexion  of,  with  earth- 
quakes, 179. 

New  Britain,  volcanoes  of,  396. 

New  Caledonia,  volcanic  action 
absent  from,  398. 

New  Guinea,  volcanoes  of,  396. 

New  Mexico,  barometric  levellings 
in,  407;  list  of  heights,  408. 

New  Zealand,  geology  of,  396; 
volcanoes,  397. 

Niphon,  recorded  volcanic  erup- 
tions in,  374. 

Nodes,  magnetic,  their  changes  of 
position,  103.  106. 

Noises  from  volcanoes,  differences 
observed  in,  263  ;  extraordinary 
distances  at  which  heard,  264. 

Norman,  Robert,  determines  the 
inclination  of  the  magnetic 
needle  in  London,  57. 

North-west  America,  volcanoes  of, 
403  ;  hypsometry  of,  408. 

No  variation  (magnetic),  points 
ami  lines  of,  54,  58. 

Obsidian,   479 ;    its   cavities    and 

airholes,  482. 
Oeriifa,  in   Iceland,  fearful  erup» 

tions  of,  351. 


INDEX. 


495 


Oeynhausen,  temperature  of  the 

salt  spring  at,  36. 
Oisans,  natural  amphitheatre   of, 

its  vast  extent,  231. 
Oligoclase,  471. 

Olot,  extinct  volcanoes  of,  433. 
Olympus,    Mount,    in    America, 

418. 

Omato,  Volcan  de,  286. 
Ometepec,  an  active  volcano,  273. 
Orinoco,  high  temperature  of  its 

waters  at  certain  seasons,  186. 
Orizaba,  a  volcano,  measurement 

of  the  peak  of,  251 ;  lava  field 

of,  3-24. 
Oron,   fresh-water  lake   of,    seals 

found  in  the,  437. 
Orosi,  the  volcano,  273. 
Orthoclase,  480. 
Osomo,  volcano  of,  290. 
Overweg's  researches  on  volcanic 

phenomena  in  Africa,  355. 
Ovid,  volcanic  phenomena  clearly 

described  by,  229. 
Owhyhee.     See  Haivaii. 

Pacaya,  eruptions  of,  276. 

Pacific  Ocean,  the  term  "Grand 
Ocean,"  improperly  applied  to 
the,  404;  comparatively  small 
number  of  active  volcanoes, 
388  ,  grouping  of  its  islands  by 
Dana,  390.  See  also  South 
Pacific  Ocean,  South  Sea. 

Panguipulli,  Volcan  de,  290. 

Papagayos,  remarkable  storms  so 
called,  271. 

Paramos,  their  elevation  and  vege- 
tation, 294. 

Paramagnetism  exhibited  by  oxy- 
gen gas,  49  ;  importance  of  the 
discovery,  78,  82,  99. 

Parasitic  craters  of  the  Moon, 
449. 

Parinacota,  volcano  of,  287. 

Passuchoa,  the  extinct  volcano  of, 
337. 

Patricius,  the  bishop,  his  theory  of 
central  heat,  196. 

Paul,  St.,  volcanic  island  of,  384. 


Pele's  hair,  volcanic  glass  so  called, 
392. 

Pelileo,  eruption  of  the  Maya  of, 
172,216. 

Pendulum,  vibrations  of  the,  ap- 
plied to  determine  the  figure  of 
the  earth,  1 9  ;  Sabine's  expedi- 
tion, 22  ;  other  observers,  23  ; 
the  form  of  the  earth  not  ex- 
actly determinable  by  such 
means,  25 ;  Airy's  experiments 
at  Harton,  vii. 

Pentland,  his  discovery  of  lava- 
streams  in  the  eastern  chain  of 
the  Andes,  295. 

Perlite,  344. 

Pertusa,  hot  springs  of,  196. 

Peru  and  Bolivia,  series  of  voles- 
noes  of,  292. 

Peshan,  volcano  of,  356,  434. 

Peteroa,  volcano  of,  289. 

Peterman's  notices  from  Overweg, 
of  volcanic  phenomena  in  Africa, 
355. 

Phaselis,  flame  of  the  Chimgera, 
near,  212. 

Philippines,  volcanoes  of  the,  243. 

Phlegreean  fields,  ancient  descrip- 
tions of  the,  428. 

Pic  de  Xethou,  the  highest  sum- 
mit of  the  Pyrenees,  230. 

Pic  of  Timor,  formerly  an  ever- 
active  volcano,  382. 

Pichincha,  remarkable  form  of, 
241 ;  ascent  of,  by  Humboldt, 
242  ;  visited  by  Wisse,  242 ;  its 
height,  250. 

Pichu-Pichu,  Volcaii  de,  286. 

Pico,  the  volcano,  247 ;  eruptions 
of  other  volcanoes  in  the  Azores 
apparently  dependant  on,  351. 

Piedmont,  trembling  of  the  earth 
in,  183. 

Pill  a,  on  the  leucite-crystals  of 
Kocca  Monfina,  466. 

Pisoje,  basalt-like  columns  of, 
456. 

Pithecusse,  Bokh  on  the,  266. 

Pitt,  Mo\mt,  in  America,  417. 

Plato,  on  the  Pyriphlegethon,  35, 


40G 


INDEX. 


208  ;  on  the  magnetic  chain  of 
rings,  50. 

Polar  light.     See  Aurora. 

Polarity,  the  force  of,  unknown  to 
the  Greeks  and  Romans,  50. 

Poles,  magnetic,  traditions  regard- 
ing, 55  ;  Halley's  variation 
chnrt,  59. 

Polybius,  his  knowledge  of  Stron- 


gyle,  257. 
oly 


Polynesia  and  similar  divisional 
terms,  objected  to,  389. 

Pomarape,  volcano  of,  287. 

Popocatepetl,  a  volcano,  251  ; 
meaning  of  the  name,  239  ;  de- 
terminations of  the  height  of, 
458. 

Porphyries  of  America,  475. 

Porphyry  of  the  Puy  de  D6me, 
its  peculiar  character,  450. 

Portobello,  hot  springs  of,  193. 

Pozzuoli,  eruption  from  the  solfa- 
tara  of,  423. 

Procida  or  Prochyta,  265. 

Proclus  on  earthquakes,  179. 

Pulu  Batu,  lava-sti-eams  of,  382. 

Pumex  Pompeianus,  430. 

Pumice  not  found  at  Jorullo,  319; 
abundant  in  Lipari,  340;  the 
pumice  quarries  of  Lactacuuga, 
342 ;  of  Cotopaxi,  343  ;  isolated 
eruptions  of,  344 ;  found  in 
Madagascar,  384 ;  and  in  the 
island  of  Amsterdam,  387;  Hum- 
boldt's  view  of  its  formation, 
483. 

Pumice  eruption  of  the  Eifel,  236. 

Punhamuidda,  volcano  of,  290. 

Pusambio,  the  river,  acidified  by 
sulphur,  202. 

Pyrenees,  highest  summits  of  the, 
230,  231. 

Pyriphlegethon,  Plato's  geognostic 
myth,  35,  268. 

Quelpaert's  island,  a  volcano,  376. 
Quesaltenango,  Volcan  de,  277. 
Quetelet   on    daily    variations    of 

temperature,  38. 
Qaludiu.    See  Azufrol  de  Quindiu. 


Quito,  observations  on  the  older 
rocks  of  the  volcanic  elevated 
plains  of,  444. 

Quito  and  New  Granada,  the 
group  of  volcanoes  of,  281. 

Rainier  (or  Regnier)  Mount,  an 
active  volcano,  418. 

Rains,  regions  of  summer,  autumn, 
and  winter,  188. 

Raking  of  mountain  chains  ex- 
plained, 294. 

Rammelsberg's  analysis  of  the 
Chimborazo  rock,  461. 

Ranco,  volcano  of,  290. 

Rapilli,  234. 

Raton  Mountains,  extinct  volca- 
noes of  the,  413. 

Regnier,  Mount,  an  active  volcano, 
418. 

Rehme,  the  Artesian  well  at,  36. 

Reich's  experiments  to  determine 
the  density  of  the  earth,  31;  the 
subject  more  lately  investigated 
by  Airy,  vii. 

Results  of  observation  in  the  tel- 
luric portion  of  the  physical 
description  of  the  universe,  8. 

Revillagigedo,  volcanic  islands  of, 
281. 

Ribbed  formation  of  the  volcanoes 
of  the  island  of  Java,  303  ;  ana- 
logous phenomena  of  the  mantle 
of  the  Sornma  of  Vesuvius, 
305. 

Richer,  observations  on  the  pen- 
dulum, by,  19. 

Rigaud,  Professor,  on  the  propor- 
tion of  water  and  terra  firm  a, 
388. 

Riudjana,  a  volcano,  its  height, 
881. 

Riobamba,  terrible  earthquake  at, 
167,  172,  173. 

Rio  Vinagre,  described,  202. 

Rock-debris,  331. 

Rocky  Mountains,  the  chain  de- 
scribed, 411;  traces  of  ancient 
volcanic  action,  414  ;  parallel 
coast  ranges,  still  volcanic,  4 1  Jv 


INDEX, 


497 


Ronquido  and  Iramido,  distin- 
guished, 263. 

Rope-boricg  of  the  Chinese,  219. 

Rose,  Gustav,  his  classification  of 
volcanic  rocks,  449,  453. 

Ross,  Sir  James  Clark,  his  Ant- 
arctic voyage,  75,  145. 

Ross,  John,  his  Polar  voyages,  65. 

Rucu-Pichincha,  its  meaning,  242. 

Ruido,  el  gran,  172. 

Sabine,  Major- General,  his  pendu- 
lum expedition,  22 ;  on  the 
horary  and  annual  variations, 
82 ;  on  the  influence  of  the 
moon  on  terrestrial  magnetism, 
viii. 

Sacramento  Butt,  an  extinct 
crater,  416. 

Saghalin,  called  Krafto  by  the 
Japanese,  367. 

Bahama,  Volcan  de,  286. 

Salses  and  naphtha  springs,  207. 

Salt  Lake,  Great,  of  the  Mormons, 
410. 

San  Bruno,  rotatory  motion  of  the 
obelisks  before  the  monastery 
of,  in  Calabria,  172. 

San  Clemen te,  volcano  of,  290. 

Sandwich  Islands,  a  volcanic  ar- 
chipelago, 391 ;  the  volcanoes, 
245 ;  height  of  some  greatly 
exaggerated,  250. 

Sangai  or  Sangay,  the  volcano, 
251 ;  its  position,  251  ;  the  most 
active  of  tho  South  American 
volcanoes,  262;  its  eruptions 
observed  by  Wisse,  182. 

Sanidine,  475. 

San  Miguel  Bosotlan,  a  volcano, 
275. 

San  Pedro  de  Atacama,  Volcan  de, 
287. 

San  Salvador,  a  volcano,  eruptions 
of,  275. 

Santa  Cruz,  volcano  of  395. 

San  Vicente,  a  volcano,  eruptions 
of,  275. 

Santorin,  volcanic  eruption  of, 
229. 

VOL.   V. 


I   Saragyn,  hot  springs  of,  346. 

Sawelieff  on  magnetic  inclination, 
113. 

Schagdagh,  the  perpetual  fires  of 
the,  210. 

Schergin's  shaft,  at  Jakutsk,  43. 

Schiwelutsch,  a  volcano,  its  pecu- 
liar form,  248 

Schlagintweits,  the  brothers,  ob' 
servations  on  springs,  191;  tra 
verse  the  Kuen-lun,  439. 

Schrenk,  on  the  frozen  soil  in  the 
country  of  the  Samojedes,  46. 

Sea,  distance  of  volcanic  activity 
from  the,  statements  of,  exa- 
mined, 432 ;  volcanic  eruption 
observed  in  the,  377 

Seals  found  in  the  Caspian  Sea, 
and  the  Sea  of  Baikal,  437;  also 
in  the  distant  fresh-water  lake 
of  Oron,  437. 

Secular  variation  of  the  magneti 
inclination,  111. 

Semi-volcanoes,  424. 

Senarmont,  his  preparation  of 
artificial  minerals,  204. 

Seneca  on  volcanoes,  226. 

Sesaya,  volcano  of,  395. 

Shasty  mountains,  basaltic  lavas 
found  in  the,  416. 

Siebengebirge,  trachyte  of  the, 
237 ;  geological  topography,  454. 

Siebold  on  the  volcanoes  of  Japan, 
373. 

Sierra  Madre,  erroneous  notions 
regarding  the,  405,  410  ;  east 
and  west  chains,  410. 

Silla  Veluda,  volcano  of,  289. 

Silurian  and  Lower  Silurian  for- 
mations, eruptive  trap  masses 
of  the,  350,  483. 

Silver  in  sea-water,  its  presence 
how  manifested,  440. 

Sitka  or  Baranove,  43,  269. 

Smyth,  Capt.,  on  the  Columbretes, 
350  ;  determination  of  the 
height  of  Etna,  249. 

Society  Islands,  the  geology  of, 
recommend***!  for  investigation, 
399. 

2K 


498 


INDEX. 


Soconusco,  the  great  volcano  of, 
277. 

Soffioni,the,  of  Tuscany,  211. 

Soil,  frozen,  in  Northern  Asia,  42  ; 
its  geographical  extension,  47. 

Solfatara,  the  term  inapplicable 
to  the  crater  of  Kilauea,  392. 

Solo  islands,  character  of  the,  378. 

Solomon's  islands.     See  Sesarga. 

Soufriere  de  la  Guadeloupe,  the, 
described,  423. 

South  Pacific  Ocean,  great  num- 
ber of  volcanoes  of  the,  431. 

South  Sea,  volcanoes  of  the,  388  ; 
its  islands  incorrectly  described 
as  scattered,  389 ;  the  term 
"Grand  Ocean"  objected  to, 
404. 

Southern  Asia,  volcanoes  of  the 
islands  of,  377. 

Spain,  extinct  volcanoes  of, 
433. 

Spartacus  and  his  gladiators,  their 
encampment  on  Vesuvius,  427. 

Special  results  of  observation  in 
the  domain  of  telluric  pheno- 
mena, 1. 

Springs,  rise  of  temperature  in, 
during  earthquakes,  175 ;  diffi- 
culty of  classifying  into  hot  and 
cold,  185 ;  method  proposed, 
185 ;  considerations  on  tempe- 
rature, 187;  heights  at  which 
they  are  found,  190;  boiling 
springs  rare,  197;  the  Geysirs 
and  Strokkr,  198;  gases,  201; 
Hallmann's  classification,  205 ; 
vapour  and  gas  springs,  salses, 
207. 

Stokes,  on  the  density  of  the 
earth,  vii. 

Stone  streams  distinguished  from 
lava  streams,  306. 

Strabo,  on  the  figure  of  the  earth, 
27 ;  on  lava,  226 ;  on  a  double 
mode  of  production  of  islands, 
265. 

Strokkr,  the,  of  Iceland,  described, 
199. 

Stromboli,    description    of,   256; 


periods  of  its  greatest  activity 
257. 

Strongyle,  described  by  Polybius, 
257. 

Strzelecki,  Count,  on  the  basin  of 
Kilauea,  393. 

Styx,  the  waters  of,  203 ;  visits  to 
their  source,  203. 

Submarine  volcano,  presumed,  in 
the  Atlantic  Ocean,  353 ;  one 
observed  in  the  Pacific  near 
Chiloe,  288. 

Subterranean  noises,  178  ;  at- 
tempts to  determine  the  rate  of 
their  transmission,  179. 

Sulphur  Island,  described  by  Cap- 
tain Basil  Hall,  377. 

Sulphuretted  hydrogen,  question 
as  to  its  existence  in  certain 
fumaroles,  425. 

Sumatra,  the  Giava  Minore  of 
Marco  Polo,  379. 

Sumbava,  violent  eruption  of  the 
volcano  of,  381. 

Sun,  magnetism  of  the,  85. 

Sunda  islands,  volcanoes  of  the, 
380,  381. 

Swalahos,  Mount,  an  extinct  vol- 
cano, 417. 

Taal,  active  volcano  of,  its  sin- 
gular position,  243;  small  ele- 
vation, 244. 

Table-land  of  South  America,  of 
Mexico,  and  Thibet,  406;  list 
of  elevations,  408. 

Tacora,  Volcan  de,  286. 

Tafua,  the  peak  of,  398. 

Tahiti,  the  geology  of,  recom- 
mended for  investigation,  399. 

Tajamulco,  the  volcano  of,  277. 

Taman,  mud  volcanoes  of  the  pen- 
insula of,  217. 

Taranaki,  a  volcano  in  New  Zea- 
land, 397. 

Taurus,  elongated,  theThian-schan, 
inchiding  the  Himalayas,  known 
as  the,  to  the  Greeks,  434. 

Tazenat,  Gouffre  de,  an  extinct 
yolcano,  238. 


499 


Telica,  Volcan  de,  described,  274. 

Telluric  phenomena,  special  re- 
sults of  observation  in  the  do- 
main of,  1. 

Temboro,  a  volcano,  its  violent 
eruption,  in  1815,  381. 

Temperature,  invariable,  stratum 
of,  39 ;  mean  annual,  how  de- 
termined in  the  tropics,  40; 
observations  of,  in  Mexico  and 
Peru,  by  Humboldt,  41 ;  frozen 
soil  in  Northern  Asia,  42; 
Schergin's  shaft,  43.  See  Interior 
of  the  Earth. 

Temperature,  rise  of,  in  springs, 
during  earthquakes,  175. 

Teneriffe,  the  felspar  of  the  tra- 
chytes of,  457;  notice  of  an  erup- 
tion on,  by  Columbus,  477. 

Ternate,  violent  eruptions  and 
lava  streams  in,  381. 

Tertiary  formations  in  Java,  298. 

Thermal  springs,  their  connexion 
with  earthquakes,  177. 

Thian-schan,  the  volcanic  moun- 
tain chain  of,  358 ;  peculiarity 
of  the  position  of  the  volcano, 
433 ;  the  chain  known  to  the 
Greeks  as  the  elongated  Taurus, 
434. 

Thibet,  hot  springs  of,  197;  gey- 
sir,  199. 

Tierra  del  Fuego,  volcanoes  of, 
296. 

Timor,  Pic  of,  formerly  an  ever- 
active  volcano,  382. 

Tollo,  the  pumice  hill  of,  481. 

Tonga  Islands,  active  volcanoes  of 
the,  394. 

Toronto,  magnetic  observations 
at,  100. 

Trachyte,  origin  of  the  word,  450; 
frequently  used  in  too  confined 
a  sense,  452;  further  remarks, 
468. 

Tractus  chalyboeliticos,  what,  59. 

Translatory  movements  in  earth- 
quakes, 173. 

Trap,  masses  of,  Sir  R.  Murchison 
on,  350,  483. 


Trass,  formation,  236. 

Trincheras,  hot  springs  of,  197. 

Tristan  da  Cunha,  a  volcanic 
island,  353. 

Tshashtl  mountains,  basaltic  lavas 
of  the,  416. 

Tucapel,  volcano  of,  289. 

Tupungato,  measurement  of  the 
peak  of,  289. 

Turbaco,  the  Volcancitos  of,  213. 

Tuscan  Maremma,  volcanic  pheno- 
mena of  the,  211. 

Typhon,  fable  of,  266. 

Umnack,  volcanic  island  of,  230. 

Unalavquen,  volcano  of,  290. 

Under  currents  of  cold  water  in 
the  tropics,  194. 

United  States'  scientific  expedi- 
tions, benefits  to  natural  history 
from  the,  404. 

Uvillas  or  Uvinas,  Volcan  de,  286. 

Val  del  Bove,  on  Etna,  remarkable 
inference  regarding,  225. 

Valleys  of  elevation,  what,  201. 

Vancouver,  Mount,  417. 

Vapour  and  gas  springs,  222. 

Variation  charts,  their  early  date, 
54. 

Vegetation,  limit  of.  in  Northern 
Asia,  43. 

Vesuvius,  phenomena  of  an  erup- 
tion of,  as  observed  by  Hum- 
boldt, 181;  barometrical  mea- 
surements by  the  same,  247  ; 
lengthened  series  of  eruptions 
of,  426;  described  by  Strabo, 
426;  by  Dio  Cassius,  427;  by 
Diodorus  Siculus,  428 ;  by 
Vitruvius,  428 ;  difference  of 
constitution  of  the  old  and  the 
recent  lavas,  477 ;  encampment 
of  Spartacus  and  his  gladiators 
on,  427. 

Vesuvius,  valley  furrows  on  the 
mantle  of  the  Somma  of,  305. 

Vidua,  Count  Carlo,  his  melan- 
choly death,  381. 

Vilcanoto,  peak  of,  296. 


500 


INDEX. 


Villarica,  Volcan  de,  290. 

Vincent,  St.,  the  volcano  of,  422. 

Vincent  of  Beauvais,  his  mention 
of  the  magnetic  needle,  53. 

Virgenes,  las,  extinct  volcanoes  in 
Old  California,  416. 

Vitruvius,  notice  of  Vesuvius  by, 
428. 

Vivarais,  extinct  volcanoes  of  the, 
278. 

Volcan  Viejo,  a  crater  in  Southern 
Peru,  286. 

Volcancitos  of  Turbaco,  described, 
213. 

Volcanic  districts,  different  aspects 
presented  by,  224. 

Volcanic  islands  in  the  South 
Atlantic  Ocean,  353. 

Volcanic  reaction,  bands  of,  176. 

Volcano,  what  intended  under  the 
term,  by  Humboldt,  287. 

Volcano,  the  island  styled  "the 
holy  isle  of  Hephsestos,"  257. 

Volcanoes,  considered  according 
to  the  difference  of  their  forma- 
tion and  activity,  224 ;  definite 
language  of  modern  science, 
228 ;  number  of,  on  the  earth, 
421 ;  their  great  number  in  the 
Eastern  Archipelago,  379  ;  hyp- 
sometry  of,  246  ;  linear  arrange- 
ment of,  268;  table  of  dif- 
ferences in  structure  and  colour 
of  the  mass  in  certain,  463  ;  the 
Mexican  system,  279 ;  sequence, 
latitude,  and  elevation,  281 ; 
particulars  of  the  five  groups  of, 
in  the  New  Continent,  285 ; 


list  of  active,  277  ;  geography  of 
active,  examined,  349  :  geogra- 
phical distribution  of,  430;  open 
in  historical  periods,  list  of,  35 1 ; 
semi-volcanoes,  424. 

Volcanoes  of  the  moon,  448. 

Vulcanicity,  definition  of,  163. 

Wales,  volcanic  phenomena  in, 
350. 

Walferdin  on  Artesian  wells,  35, 

Waltershausen,  his  classification 
of  the  volcanoes  of  Iceland, 
351 ;  remarks  on  the  period  of 
recurrence  of  eruptions  in 
various  volcanoes,  255,  on  the 
trachytes  of  Etna,  465. 

Wilkes,  Captain,  commander  of 
the  American  expedition,  105, 
388. 

Wislizenus,  positions  in  North- 
West  America  ascertained  by, 
408. 

Wisse,  his  observations  of  the 
eruptions  of  the  volcano  of 
Sangai,  182;  264;  his  visit  to 
Pichincha,  242. 

Yana-Urcu,  a  volcanic  hill,  193. 
Yanteles   (Yntales),    volcano    of, 
290. 

Zapatera,    extinct  crater    of  the 

island,  273. 
Zohron,  the  southern  pole  of  the 

magnetic  needle,  53. 
Zone  of  volcanic  activity,  176. 
Zuni,  petrified  forest  near,  414. 


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27 


A    CATALOGUE  0" 


PIauo:,  ^^alogues,  an  Analysis   and 
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DAT. 

Plautus's  Comedies.    Literally  Trans-  1 
lated,  with  Notes,  by  H.  T.  BILBT,  B.A. 
In  2  vols. 

Pliny's  Natural  History.    Translated,  j 
with  Copious  Notes,  by  the  late  JOHN    | 
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B.A.    In  6  vols. 

Propertius,  Petrouius,  and  Johannes 

SecunduB.  Literally  Translated,  and  ac- 
companied by  Poetical  Versions,  from 
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Quintilian's  Institutes  of  Oratory. 

Literally  Translated,  with  Notes,  &o,  by 
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Sallust,  Florus,  and  Velleius  Pater- 

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Sophocles.  The  (Uford  Translation 
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Standard  Library  Atlas  of  Classical 
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Suetonius'    Lives   of    the   Twelve 

Cassars,  and  other    Works.      Thomson's 
Translation,  revised,   with  Notes,  by  T. 

FOBESTEB. 

Tacitus.     Literally  Translated,   with 
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Vol.  l.  The  Annals. 
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cola,  &c.    With  Index. 

Terence  and  Fhaedrus.    By  H.  T. 

RlLET,  B.A. 

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Tyrtajus.    By  J.  BANKS,  M.A.    With  the 
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BOW,  M.A.  And  a  Geographical  Com- 
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Handbook  of  Domestic  Medicine,  Po- 
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Games.-  j&y  various  Amateurs 

and  Professors/  "  Comprising  tfeatises 
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above  40  games  (the  Whist,  Draughts, 
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Lewndes'  Bibliographer's  Manual  of 

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