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NEW   YORK  ,   HARPER     &     R  ROl  H  E  RS    .  I  8bO  . 


COSMOS: 


A  SKETCH 


OP 


A  PHYSICAL  DESCRIPTION  OF  THE  UNIVERSE. 


BY 


ALEXANDER  VON  HUMBOLDT. 


TRANSLATED   FROM  THE  GERMAN, 

BY   E.   a  OTTE. 


MatarsB  vero  rerura  vis  atque  majestas  in  omnibus  momentis  fide  caret,  si  qiiia  modo 
partes  ejus  ac  non  totara  complectatur  animo. — Plin.,  Hist.  Nat.,  lib.  viL,  c.  1. 


IN     TWO     VOLUMES. 

VOL.   L 


NEW    YORK: 

HARPER   &  BROTHERS,   PUBLISHERS 

329   &   331   PEARL    STREET, 
FRANKLIN    SQUARE. 

18  56. 


TRANSLATOR'S  PREFACE. 


I  CAN  not  more  appropriately  introduce  the  Cosmos  than 
by  presenting  a  brief  sketch  of  the  life  of  its  illustrious  au- 
thor.* While  the  name  of  Alexander  von  Humboldt  is  fa- 
miliar to  every  one,  few,  perhaps,  are  aware  of  the  peculiar 
circumstances  of  his  scientific  career  and  of  the  extent  of  his 
labors  in  almost  every  department  of  physical  knowledge.  He 
was  bom  on  the  14th  of  September,  1769,  and  is,  therefore, 
now  in  his  80th  year.  After  going  through  the  ordinary 
course  of  education  at  Gottingen,  and  having  made  a  rapid 
tour  through  Holland,  England,  and  France,  he  became  a  pu- 
pil of  Werner  at  the  mining  school  of  Freyburg,  and  in  his 
21st  year  published  an  "Essay  on  the  Basalts  of  the  Rhine." 
Though  he  soon  became  officially  connected  with  the  mining 
corps,  he  was  enabled  to  continue  his  excursions  in  foreign 
comitries,  for,  during  the  six  or  seven  years  succeeding  the 
publication  of  his  first  essay,  he  seems  to  have  visited  Austria, 
Switzerland,  Italy,  and  France.  His  attention  to  mining  did 
not,  however,  prevent  him  from  devoting  his  attention  to  oth- 
er scientific  pursuits,  among  which  botany  and  the  then  re- 
cent discovery  of  galvanism  may  be  especially  noticed.  Bot- 
any, indeed,  we  know  from  his  own  authority,  occupied  him 
almost  exclusively  for  some  years ;  but  even  at  this  time  he 
was  practicing  the  use  of  those  astronomical  and  physical  in- 
struments which  he  afterward  turned  to  so  singularly  excel- 
lent an  account. 

The  political  disturbances  of  the  civilized  world  at  the  close 

*  For  the  following  remarks  I  am  mainly  indebted  to  the  articles  on 
the  Cosmos  in  the  two  leading  Quarterly  Reviews. 


iv  translator's  preface. 

of  the  last  century  prevented  our  author  from  carrying  out 
various  plans  of  foreign  travel  which  he  had  contemplated, 
and  detained  him  an  unwilling  prisoner  in  Europe.  In  the 
year  1799  he  went  to  Spain,  with  the  hope  of  entering  Africa 
from  Cadiz,  but  the  unexpected  patronage  which  he  received 
at  the  court  of  Madrid  led  to  a  great  alteration  in  his  plans, 
and  decided  him  to  proceed  directly  to  the  Spanish  posses- 
sions in  America,  "  and  there  gratify  the  longings  for  foreign 
adventure,  and  the  scenery  of  the  tropics,  which  had  haunted 
him  from  boyhood,  but  had  all  along  been  turned  in  the  dia- 
metrically opposite  direction  of  Asia."  After  encountering 
various  risks  of  capture,  he  succeeded  in  reaching  America, 
and  from  1799  to  1804  prosecuted  there  extensive  researches 
in  the  physical  geography  of  the  New  World,  which  have  in- 
delibly stamped  his  name  in  the  undying  records  of  science. 

Excepting  an  excursion  to  Naples  with  Gay-Lussac  and 
Von  Buch  in  1805  (the  year  after  his  return  from  America), 
the  succeeding  twenty  years  of  his  life  were  spent  in  Paris,  and 
were  almost  exclusively  employed  in  editing  the  results  of  his 
American  journey.  In  order  to  bring  these  results  before  the 
world  in  a  manner  worthy  of  their  importance,  he  commenced 
a  series  of  gigantic  publications  in  almost  every  branch  of 
science  on  which  he  had  instituted  observations.  In  1817, 
after  twelve  years  of  incessant  toil,  four  fifths  were  completed, 
and  an  ordinary  copy  of  the  part  then  in  print  cost  considera- 
bly more  than  one  hundred  pounds  sterling.  Smce  that  time 
the  publication  has  gone  on  more  slowly,  and  even  now,  after 
the  lapse  of  nearly  half  a  century,  it  remains,  and  probably 
ever  will  remain,  incomplete. 

In  the  year  1828,  when  the  greatest  portion  of  his  literary 
labor  had  been  accomplished,  he  undertook  a  scientific  journey 
to  Siberia,  under  the  special  protection  of  the  Russian  govern- 
ment. In  this  journey — a  journey  for  which  he  had  prepared 
himself  by  a  course  of  study  unparalleled  in  the  history  of 
travel — he  was  accompanied  by  two  companions  hardly  less 
distinguished  than  himself,  Ehrenberg  and  Gustav  Rose,  and 


translator's  preface.  v 

the  results  obtained  during  their  expedition  are  recorded  by 
our  author  in  his  Frag?nents  Asiatiques,  and  in  his  Asie 
Ce7itrale,  and  by  Rose  in  his  Reise  nach  dem  Oural.  If  the 
Asie  Centrale  had  been  his  only  work,  constituting,  as  it 
does,  an  epitome  of  all  the  knowledge  acquired  by  himself  and 
by  former  travelers  on  the  physical  geography  of  Northern 
and  Central  Asia,  that  work  alone  would  have  sufficed  to 
form  a  reputation  of  the  highest  order. 

I  proceed  to  offer  a  few  remarks  on  the  work  of  which  I 
now  present  a  new  translation  to  the  English  pubHc,  a  work 
intended  by  its  author  "  to  embrace  a  summary  of  physical 
knowledge,  as  connected  with  a  delineation  of  the  material 
universe." 

The  idea  of  such  a  physical  description  of  the  universe  had, 
it  appears,  been  present  to  his  mind  from  a  very  early  epoch. 
It  was  a  work  which  he  felt  he  must  accomplish,  and  he  de- 
voted almost  a  lifetime  to  the  accumulation  of  materials  for 
it.  For  almost  half  a  century  it  had  occupied  his  thoughts  ; 
and  at  length,  in  the  evening  of  life,  he  felt  himself  rich 
enough  in  the  accumulation  of  thought,  travel,  reading,  and 
experimental  research,  to  reduce  into  form  and  reaUty  the 
undefined  vision  that  has  so  long  floated  before  him.  The 
w;ork,  when  completed,  wiU  form  three  volumes.  The  first 
volume  comprises  a  sketch  of  all  that  is  at  present  Imown  of 
the  physical  phenomena  of  the  universe  ;  the  second  compre- 
hends two  distinct  parts,  the  first  of  which  treats  of  the  in- 
citements to  the  study  of  nature,  afforded  in  descriptive  poet- 
ry, landscape  painting,  and  the  cultivation  of  exotic  plants ; 
while  the  second  and  larger  part  enters  into  the  consideration 
of  the  different  epochs  in  the  progress  of  discovery  and  of  the 
corresponding  stages  of  advance  in  human  civilization.  The 
third  volume,  the  publication  of  which,  as  M.  Humboldt  him- 
self informs  me  in  a  letter  addressed  to  my  learned  friend  and 
publisher,  Mr.  H.  G.  Bohn,  "  has  been  somewhat  delayed, 
owing  to  the  present  state  of  public  affairs,  will  comprise  the 
special  and  scientific  development  of  the  s;reat  Picture  of  Na- 


vi  translator's  preface. 

ture."  Each  of  the  three  parts  of  the  Cosmos  is  therefore,  to 
a  certain  extent,  distinct  in  its  object,  and  may  be  considered 
complete  in  itself.  We  can  not  better  terminate  this  brief 
notice  than  in  the  words  of  one  of  the  most  eminent  philos 
ophers  of  our  own  country,  that,  "  should  the  conclusion  cor- 
respond (as  we  doubt  not)  with  these  beginnings,  a  work  will 
have  been  accomplished  every  way  worthy  of  the  author's 
fame,  and  a  crowning  laurel  added  to  that  wreath  with  which 
Europe  will  always  delight  to  surround  the  name  of  Alexan 
der  von  Humboldt." 

In  venturing  to  appear  before  the  English  public  as  the  in- 
terpreter of  "  the  great  ivork  of  our  age,^'^  I  have  been  en- 
couraged by  the  assistance  of  many  kind  literary  and  scientific 
friends,  and  I  gladly  avail  myself  of  this  opportunity  of  ex- 
pressing my  deep  obligations  to  Mr.  Brooke,  Dr.  Day,  Pro 
fessor  Edward  Forbes,  Mr.  Hind,  Mr.  Glaisher,  Dr.  Percy,  and 
Mr.  Ronalds,  for  the  valuable  aid  they  have  afforded  me. 

It  would  be  scarcely  right  to  conclude  these  remarks  with- 
out a  reference  to  the  translations  that  have  preceded  mine. 
The  translation  executed  by  Mrs.  Sabine  is  singularly  accu- 
rate and  elegant.  The  other  translation  is  remarkable  for 
the  opposite  qualities,  and  may  therefore  be  passed  over  in  si- 
lence. The  present  volumes  differ  from  those  of  Mrs.  Sabine 
in  having  all  the  foreign  measures  converted  into  correspond- 
ing English  terms,  in  being  published  at  considerably  less 
than  one  third  of  the  price,  and  in  being  a  translation  of  the 
entire  work,  for  I  have  not  conceived  myself  justified  in  omit- 
ting passages,  sometimes  amounting  to  pages,  simply  because 
they  might  be  deemed  slightly  obnoxious  to  our  national  prej- 
udices. 

*  The  expression  applied  to  the  Cosmos  by  the  learned  Bunsen,  in 
his  late  Report  on  Ethnology,  in  the  Report  of  the  British  Association 
for  1847,  p.  265. 


AUTHOR'S   PREFACE. 


In  the  late  evening  of  an  active  life  I  offer  to  the  German 
public  a  work,  whose  undefined  image  has  floated  before  my 
mind  for  almost  half  a  century.  I  have  frequently  looked 
upon  its  completion  as  impracticable,  but  as  often  as  I  have 
been  disposed  to  relinquish  the  undertaking,  I  have  again — 
although  perhaps  imprudently — resumed  the  task.  This  work 
I  now  present  to  my  cotemporaries  with  a  diffidence  inspired 
by  a  just  mistrust  of  my  own  powers,  while  I  would  willingly 
forget  that  writings  long  expected  are  usually  received  mth 
less  indulgence. 

Although  the  outward  relations  of  life,  and  an  irresistible 
impulse  toward  knowledge  of  various  kinds,  have  led  me  to 
occupy  myself  for  many  years — and  apparently  exclusively — 
with  separate  branches  of  science,  as,  for  instance,  with  de- 
scriptive botany,  geognosy,  chemistry,  astronomical  determin- 
ations of  position,  and  terrestrial  magnetism,  in  order  that  I 
might  the  better  prepare  myself  for  the  extensive  travels  in 
which  I  was  desirous  of  engaging,  the  actual  object  of  my 
studies  has  nevertheless  been  of  a  higher  character.  The 
principal  impulse  by  which  I  was  directed  was  the  earnest 
endeavor  to  comprehend  the  phenomena  of  physical  objects  in 
their  general  connection,  and  to  represent  nature  as  one  great 
whole,  moved  and  animated  by  internal  forces.  My  inter 
course  with  highly-gifted  men  early  led  me  to  discover  that, 
without  an  earnest  striving  to  attain  to  a  knowledge  of  special 
branches  of  study,  all  attempts  to  give  a  grand  and  general 
view  of  the  universe  would  be  nothing  more  than  a  vain  illu- 
sion.    These  special  departments  in  the  great  domain  of  nat- 


v'lii  author's  preface. 


iiral  science  are,  moreover,  capable  of  being  reciprocally  fruc- 
tified by  means  of  the  appropriative  forces  by  which  they  are 
endowed.  Descriptive  botany,  no  longer  confined  to  the  nar- 
row circle  of  the  determination  of  genera  and  species,  leads 
the  observer  who  traverses  distant  lands  and  lofty  mountains 
to  the  study  of  the  geographical  distribution  of  plants  over  the 
earth's  surface,  according  to  distance  from  the  equator  and  ver- 
tical elevation  above  the  sea.  It  is  further  necessary  to  in- 
vestigate the  laws  which  regulate  the  differences  of  tempera- 
ture and  climate,  and  the  meteorological  processes  of  the  at- 
mosphere, before  we  can  hope  to  explain  the  involved  causes 
of  vegetable  distribution  ;  and  it  is  thus  that  the  observer  who 
earnestly  pursues  the  path  of  knowledge  is  led  from  one  class 
of  phenomena  to  another,  by  means  of  the  mutual  dependence 
and  connection  existing  between  them. 

I  have  enjoyed  an  advantage  which  few  scientific  travelers 
have  shared  to  an  equal  extent,  viz.,  that  of  having  seen  not 
only  littoral  districts,  such  as  are  alone  visited  by  the  majority 
of  those  who  take  part  in  voyages  of  circumnavigation,  but 
also  those  portions  of  the  interior  of  two  vast  continents  which 
present  the  most  striking  contrasts  manifested  in  the  Alpine 
tropical  landscapes  of  South  America,  and  the  dreary  wastes 
of  the  steppes  in  Northern  Asia.  Travels,  undertaken  in  dis- 
tricts such  as  these,  could  not  fail  to  encourage  the  natural 
tendency  of  my  mind  toward  a  generalization  of  views,  and  to 
encourage  me  to  attempt,  m  a  special  work,  to  treat  of  the 
knowledge  which  we  at  present  possess,  regarding  the  sidereal 
and  terrestrial  phenomena  of  the  Cosmos  in  their  empirical 
relations.  The  hitherto  undefined  idea  of  a  physical  geog- 
raphy has  thus,  by  an  extended  and  perhaps  too  boldly  imag- 
ined a  plan,  been  comprehended  under  the  idea  of  a  physical 
description  of  the  universe,  embracing  all  created  things  in  the 
regions  of  space  and  in  the  earth. 

The  very  abundance  of  the  materials  which  are  presented 
to  the  mind  for  arrangement  and  definition,  necessarily  impart 
uo  inconsiderable  difficulties  in  the  choice  of  the  form  utidev 


AUTHOR  S    PREFACE.  *  IX 

which  such  a  work  must  be  presented,  if  it  would  aspire  to 
the  honor  of  being  regarded  as  a  Hterary  composition.  De- 
scriptions of  nature  ought  not  to  be  deficient  in  a  tone  of  life- 
like truthfulness,  while  the  mere  enumeration  of  a  series  of 
general  results  is  productive  of  a  no  less  wearying  impression 
than  the  elaborate  accumulation  of  the  individual  data  of  ob- 
servation, i  scarcely  venture  to  hope  that  I  have  succeeded 
in  satisfying  these  various  requirements  of  composition,  or  that 
I  have  myself  avoided  the  shoals  and  breakers  which  I  have 
known  how  to  indicate  to  others.  My  faint  hope  of  success 
rests  upon  the  special  indulgence  which  the  German  public 
have  hestowed  upon  a  small  work  bearing  the  title  of  Ansich- 
ten  der  Natur,  which  I  pubhshed  soon  after  my  return  from 
Mexico.  This  work  treats,  under  general  points  of  view,  of 
separate  branches  of  physical  geography  (such  as  the  forms  of 
vegetation,  g;rassy  plains,  and  deserts).  The  efiect  produced 
by  this  small  volimie  has  doubtlessly  been  more  powerfully 
manifested  in  the  influence  it  has  exercised  on  the  sensitive 
minds  of  the  young,  whose  imaginative  faculties  are  so  strong- 
ly manifested,  than  by  means  of  any  thing  which  it  could  it- 
self impart.  In  the  work  on  the  Cosmos  on  which  I  am  now 
engaged,  I  have  endeavored  to  show,  as  in  that  entitled  An- 
sichten  der  Natur,  that  a  certain  degree  of  scientific  com- 
pleteness in  the  treatment  of  individual  facts  is  not  wholly 
incompatible  with  a  picturesque  animation  of  style. 

Since  public  lectures  seemed  to  me  to  present  an  easy  and 
efficient  means  of  testing  the  more  or  less  successful  manner 
of  connecting  together  the  detached  branches  of  any  one  sci- 
ence, I  undertook,  for  many  months  consecutively,  first  in  the 
French  language,  at  Paris,  and  afterward  in  my  own  native 
German,  at  Berhn  (almost  simultaneously  at  two  different 
places  of  assembly),  to  deUver  a  course  of  lectures  on  the  phys- 
ical description  of  the  universe,  according  to  my  conception 
of  the  science.  My  lectures  were  given  extemporaneously, 
both  in  French  and  German,  and  without  the  aid  of  written 
notes,  nor  have  I,  in  any  way,  made  use,  in  the  present  work, 


author's  preface. 


of  those  portioiis  of  my  discourses  which  have  been  preserved 
by  the  industry  of  certain  attentive  auditors.  V/ith  the  ex- 
ception of  the  first  forty  pages,  the  whole  of  the  present  work 
was  written,  for  the  first  time,  in  the  years  1843  and  1844. 

A  character  of  unity,  freshness,  and  animation  must,  I 
think,  be  derived  from  an  association  with  some  definite 
epoch,  where  the  object  of  the  writer  is  to  delineate  the  pres- 
ent condition  of  knowledge  and  opinions.  Since  the  addi- 
tions constantly  made  to  the  latter  give  rise  to  fundamental 
changes  in  pre-existing  views,  my  lectures  and  the  Cosmos 
have  nothing  in  common  beyond  the  succession  in  which  the 
various  facts  are  treated.  The  first  portion  of  my  work  con 
tains  introductory  considerations  regarding  the  diversity  in 
the  degrees  of  enjoyment  to  be  derived  from  nature,  and  the 
knowledge  of  the  laws  by  which  the  universe  is  governed ;  it 
also  considers  the  limitation  and  scientific  mode  of  treatinjr  a 
physical  description  of  the  universe,  and  gives  a  general  pic- 
ture of  nature  which  contains  a  view  of  all  the  phenomena 
comprised  in  the  Cosmos. 

This  general  picture  of  nature,  which  embraces  within  its 
wide  scope  the  remotest  nebulous  spots,  and  the  revolving 
double  stars  in  the  regions  of  space,  no  less  than  the  telluric 
phenomena  included  under  the  department  of  the  geography 
of  organic  forms  (such  as  plants,  animals,  and  races  of  men), 
comprises  all  that  I  deem  most  specially  important  vdth  re- 
gard to  the  connection  existing  between  generalities  and  spe- 
cialities, while  it  moreover  exemplifies,  by  the  form  and  style 
of  the  composition,  the  mode  of  treatment  pursued  in  the  se- 
lection of  the  results  obtained  from  experimental  knowledge. 
The  two  succeeding  volumes  will  contain  a  consideration  of 
the  particular  means  of  incitement  toward  the  study  of  na- 
ture (consisting  in  animated  delineations,  landscape  painting, 
and  the  arrangement  and  cultivation  of  exotic  vegetable 
forms),  of  the  history  of  the  contemplation  of  the  universe,  or 
the  gradual  development  of  the  reciprocal  action  of  natural 
forces  constituting  one  natural  whole  ;  and,  lastly,  of  the  spe- 


AUTHOR  ^^    PREFACE-.  XI 

cial  branches  of  the  several  departments  of  scienet,  whose 
mutual  connection  is  indicated  in  the  beginning  of  the  work. 
Wherever  it  has  been  possible  to  do  so,  I  have  adduced  the  au- 
thorities from  whence  I  derived  my  facts,  with  a  view  of  afibrd- 
ing  testimony  both  to  the  accuracy  of  my  statements  and  to  the 
value  of  the  observations  to  which  reference  was  made.  In 
those  instances  where  I  have  quoted  from  my  own  writings 
(the  facts  contained  in  which  being,  from  their  very  nature,  scat- 
tered through  different  portions  of  my  works),  I  have  always 
referred  to  the  original  editions,  owing  to  the  importance  of 
accuracy  with  regard  to  numerical  relations,  and  to  my  own 
distrust  of  the  care  and  correctness  of  translators.  In  the  few 
cases  where  I  have  extracted  short  passages  from  the  works 
of  my  friends,  I  have  indicated  them  by  marks  of  quotation  ; 
and,  in  imitation  of  the  practice  of  the  ancients,  I  have  inva- 
riably preferred  the  repetition  of  the  same  words  to  any  arbi- 
ti'ary  substitution  of  my  own  paraphrases.  The  much-con- 
tested question  of  priority  of  claim  to  a  first  discovery,  which 
it  is  so  dangerous  to  treat  of  in  a  work  of  this  uncontroversial 
kind,  has  rarely  been  touched  upon.  Where  I  have  occasion- 
ally referred  to  classical  antiquity,  and  to  that  happy  period 
of  transition  which  has  rendered  the  sixteenth  and  seventeenth 
centuries  so  celebrated,  owing  to  the  great  geographical  dis- 
coveries by  which  the  age  was  characterized,  I  have  been  sim- 
ply led  to  adopt  this  mode  of  treatment,  from  the  desire  we 
experience  from  time  to  time,  when  considering  the  general 
views  of  nature,  to  escape  from  the  circle  of  more  strictly  dog- 
matical modern  opinions,  and  enter  the  free  and  fanciful  do- 
main of  earlier  presentiments. 

It  has  frequently  been  regarded  as  a  subject  of  discouraging 
consideration,  that  while  purely  literary  products  of  intellect 
ual  activity  are  rooted  in  the  depths  of  feeling,  and  interwoven 
with  the  creative  force  of  imagination,  all  works  treating  of 
empirical  knowledge,  and  of  the  connection  of  natural  phe- 
nomena and  physical  laws,  are  subject  to  the  most  marked 
modifications  of  form  in  the  lapse  of  short  periods  of  time,  both 


xii  author's  preface. 


by  the  improvement  in  the  instruments  used,  and  by  the  con- 
sequent expansion  of  the  field  of  view  opened  to  rational  ob- 
servation, and  that  those  scientific  works  which  have,  to  use 
a  common  expression,  become  mitiquated  by  the  acquisition 
of  new  funds  of  knowledge,  are  thus  continually  being  con- 
signed to  oblivion  as  unreadable.  However  discouraging  such 
a  prospect  must  be,  no  one  who  is  animated  by  a  genuine  love 
of  nature,  and  by  a  sense  of  the  dignity  attached  to  its  study, 
can  view  with  regret  any  thing  which  promises  future  addi- 
tions and  a  greater  degree  of  perfection  to  general  knowledge. 
Many  important  branches  of  knowledge  have  been  based  upon 
a  solid  foundation  which  will  not  easily  be  shaken,  both  as  re- 
gards the  phenomena  in  the  regions  of  space  and  on  the  earth  ; 
while  there  are  other  portions  of  science  in  which  general 
views  will  undoubtedly  take  the  place  of  merely  special ; 
where  new  forces  will  be  discovered  and  new  substances  will 
be  made  known,  and  where  those  which  are  now  considered 
as  simple  will  be  decomposed.  I  would,  therefore,  venture  to 
hope  that  an  attempt  to  delineate  nature  in  all  its  vivid  ani- 
mation and  exalted  grandeur,  and  to  trace  the  stahle  amid  the 
vacillating,  ever-recurring  alternation  of  physical  metamorph- 
oses, will  not  be  wholly  disregarded  even  at  a  future  age. 
PoUdam,  Nov.,  1844. 


CONTENTS  OF  VOL.  I. 


Page 

The  Translator's  Preface iii 

The  Author's  Preface vii 

Summary xv 

INTRODUCTION. 

The  Results  of  the  Study  of  Physical  Phenomena 23 

The  different  Epochs  of  the  Contemplation  of  the  external  World.  24 
The  different  Degrees  of  Enjoyment  presented  by  the  Contempla- 
tion of  Nature 25 

Instances  of  this  Species  of  Enjoyment 26 

Means  by  which  it  is  induced 26 

The  Elevations  and  climatic  Relations  of  many  of  the  most  cele- 
brated Mountains  in  the  World,  considered  with  Reference  to  the 

Effect  produced  on  the  Mind  of  the  Observer 27-33 

The  Impressions  awakened  by  the  Aspect  of  tropical  Regions  ...  34 
The  more  accurate  Knowledge  of  the  Physical  Forces  of  the  Uni- 
verse, acquired  by  the  Inhabitants  of  a  small  Section  of  the  tem- 
perate Zone 36 

The  earliest  Dawn  of  the  Science  of  the  Cosmos 36 

The  Difficulties  that  opposed  the  Progress  of  Inquiry 37 

Consideration  of  the  Effect  produced  on  the  Mind  by  the  Observa- 
tion of  Nature,  and  the  Fear  entertained  by  some  of  its  injurious 

Influence 40 

Illustrations  of  the  Manner  in  which  many  recent  Discoveries  have 
tended  to  Remove  the  groundless  Fears  entertained  regarding 

the  Agency  of  certain  Natural  Phenomena 43 

The  Amount  of  Scientific  Knowledge  required  to  enter  on  the 

Consideration  of  Physical  Phenomena 47 

The  Object  held  in  View  by  the  present  Work 49 

The  Nature  of  the  Study  of  the  Cosmos 50 

The  special  Requirements  of  the  present  Age 53 

Limits  and  Method  of  Exposition  of  the  Physical  Description  of  the 

Universe 56 

Considerations  on  the  terms  Physiology  and  Physics 58 

Physical  Geography 59 

Celestial  Phenomena 63 

The  Natural  Philosophy  of  the  Ancients  directed  more  to  Celestial 

than  to  Terrestrial  Phenomena 65 

The  able  Treatises  of  Varenius  and  Carl  Ritter 66,  61 

Signification  of  the  Word  Cosmos .-. .    68—70 

The  Domain  embraced  by  Cosmography 71 

Empiricism  and  Experiments 74 

The  Process  of  Reason  and  Induction 77 


XIV  CONTENTS. 

GENERAL  REVIEW  OF  NATIJRAL  PHENOMENA. 

Connection  betweei^  the  Material  and  the  Ideal  World 80 

Delineation  of  Nature 82 

Celestial  Phenomena 83 

Sidereal  Systems 89 

Planetary  Systems 90 

Comets 99 

Aerolites Ill 

Zodiacal  Light 137 

Translatory  Motion  of  the  Solar  System 145 

The  Milky  Way 150 

Starless  Open'ngs 152 

Terrestrial  Phenomena 154 

Geographical  Distribution 161 

Fio-ure  of  the  Earth 163 

Density  of  the  Earth 169 

Internal  Heat  of  the  Earth 172 

Mean  Temperature  of  the  Earth 175 

Terrestrial  Magnetism 177 

Magnetism 183 

Aurora  Borealis 193 

Geoo-nostic  Phenomena 202 

Earthquakes 204 

Gaseous  Emanations , 217 

Hot  Springs 221 

Salses 224 

Volcanoes 227 

Rocks 247 

PalfEontology 270 

Geognostic  Periods 286 

Physical  Geography 287 

Meteorology " 311 

Atmospheric  Pressure 315 

Climatology 317 

The  Snow-line 329 

Hygrometry 332 

Atmospheric  Electricity 335 

Organic  Life 339 

Motion  in  Plants 341 

Universality  of  Animal  Life 342 

Geography  of  Plants  and  Animals 346 

Floras  of  different  Countries 350 

Man 352 

Races 353 

Language 357 

Conclusion  of  the  Subject < 359 


SUMMARY. 

Translator's  Preface. 
Author's  Preface. 

« 

Vol.  I. 

GENERAL    SUMMARY    OF    THE    CONTENTS. 

Introduction. — Rejlections  on  the  different  Degrees  of  Enjoyment  pre' 
sented  to  us  by  the  Aspect  of  Nature  and  the  scientific  Exposition  of 
the  Laws  of  the  Universe Page  23-78 

Insight  mto  the  connection  of  phenomena  as  the  aim  of  all  natural 
investigation.  Nature  presents  itself  to  meditative  contemplation  as  a 
jnity  in  diversity.  Differences  in  the  grades  of  enjoyment  yielded  by 
nature.  Effect  of  contact  with  free  nature ;  enjoyment  derived  from 
nature  independently  of  a  knowledge  of  the  action  of  natural  forces,  or 
of  the  effect  produced  by  the  individual  character  of  a  locality.  Effect 
of  the  physiognomy  and  configuration  of  the  surface,  or  of  the  character 
of  vegetation.  Reminiscences  of  the  woody  valleys  of  the  Cordilleras 
and  of  the  Peak  of  Teneriffe.  Advantages  of  the  mountainous  region 
near  the  equator,  where  the  multiplicity  of  natural  impressions  attains 
its  maximum  within  the  most  circumscribed  limits,  and  where  it  is 
permitted  to  man  simultaneously  to  behold  all  the  stars  of  the  firma- 
ment and  all  the  forms  of  vegetation — p.  23-33. 

Tendency  toward  the  investigation  of  the  causes  of  physical  phenom 
ena.  Erroneous  views  of  the  character  of  natural  forces  arising  from 
an  imperfect  mode  of  observation  or  of  induction.  The  crude  accu- 
mulation of  physical  dogmas  transmitted  from  one  century  to  another. 
Their  diffusion  among  the  higher  classes.  Scientific  physics  are  asso- 
ciated with  another  and  a  deep-rooted  system  of  untried  and  misunder- 
stood experimental  positions.  Investigation  of  natural  laws.  Appre- 
hension that  nature  may  lose  a  portion  of  its  secret  charm  by  an  inquiry 
into  the  internal  character  of  its  forces,  and  that  the  enjoyment  of  na 
ture  must  necessarily  be  weakened  by  a  study  of  its  domain.  Advant 
ages  of  general  views  which  impart  an  exalted  and  solemn  character 
to  natural  science.  The  possibility  of  separating  generalities  from 
specialities.  Examples  drawn  from  astronomy,  recent  optical  discov 
eries,  physical  geognosy,  and  the  geography  of  plants.  Practicabil 
ity  of  the  study  of  physical  cosmography — p.  33-54.  Misunderstood 
popular  knowledge,  confounding  cosmography  with  a  mere  encyclope- 
dic enumeration  of  natural  sciences.  Necessity  for  a  simultaneous  re- 
gard for  all  branches  of  natural  science.  Influence  of  this  study  on 
national  prosperity  and  the  welfare  of  nations ;  its  more  earnest  and 
characteristic  aim  is  an  inner  one,  arising  from  exalted  mental  activity. 
Mode  of  treatment  with  regard  to  the  object  and  presentation ;  recip- 
rocal connection  existing  between  thought  and  speech — p.  54-5C 

The  notes  to  p.  28-33.  Comparative  hypsometrical  data  of  the  eleva- 
tions of  the  Dhawalagiri,  Jawahir,  Chimborazo,  iEtna  (according  to  the 
measureraeutof  Sir  John  Herschel),  the  Swiss  Alps,  &c. — p.  28.     Rarity 


XVI  SUMMARY    OF    THE    CONTENTS. 

of  palms  and  ferns  in  the  Himalaya  Mountains — p.  29.  European  vz- 
etable  forms  in  the  Indian  Mountains — p.  30.  Northern  and  southern 
limits  of  perpetual  snow  on  the  Himalaya ;  influence  of  the  elevated 
plateau  of  Thibet — p.  30-33.     Fishes  of  an  earlier  world — p.  46. 

Limits  and  Method  of  Exposition  of  the  ^Physical  Description  of  the 

Universe Page  56-78 

Subjects  embraced  by  the  study  of  the  Cosmos  or  of  physical  cosmog 
raphy.  Separation  of  other  kindred  studies — p.  56-62.  The  urano- 
logical  portion  of  the  Cosmos  is  more  simple  than  the  telluric  ;  the  im- 
possibility of  ascertaining  the  diversity  of  matter  simplifies  the  study 
of  the  mechanism  of  the  heavens.  Origin  of  the  word  Cosmos,  its  sig- 
nification of  adornment  and  order  of  the  universe.  The  existijig  can 
not  be  absolutely  separated  in  our  contemplation  of  nature  from  the 
future.  Histoiy  of  the  world  and  description  of  the  world — p.  62-73. 
Attempts  to  embrace  the  multiplicity  of  the  phenomena  of  the  Cos- 
mos in  the  unity  of  thought  and  under  the  form  of  a  purely  rational 
combination.  Natural  philosophy,  which  preceded  all  exact  observa- 
tion in  antiquity,  is  a  natural,  but  not  unfrequently  ill-directed,  eftbrt 
of  reason.  Two  forms  of  abstraction  rule  the  whole  mass  of  knowl- 
edge, viz.:  the  quantitative,  relative  deteraiinations  according  to  num- 
ber and  magnitude,  and  qualitative,  material  characters.  Means  of 
submitting  phenomena  to  calculation.  Atoms,  mechanical  methods  of 
construction.  Figurative  representatiojus  ;  mythical  conception  of  im- 
ponderable matters,  and  the  peculiar  vital  forces  in  every  organism. 
That  which  is  attained  by  obsex-vation  and  experiment  (calling  forth 
phenomena)  leads,  by  analogy  and  induction,  to  a  knowledge  of  empir- 
ical laws;  their  gradual  simplification  and  generalization.  Arrange- 
ment of  the  facts  discovered  in  accordance  with  leading  ideas.  The 
treasure  of  empirical  contemplation,  collected  through  ages,  is  in  no  dan- 
ger of  experiencing  any  hostile  agency  from  philosophy — p.  73-78. 

[In  the  notes  appended  to  p.  66-70  are  considerations  of  the  general 
and  comparative  geography  of  Varenius.  Philological  investigation 
into  the  meaning  of  the  words  Koafiog  and  mundus.'] 

Delineation  of  Nature.     General  Review  of  Natural  Phenomena 

p.  79-359 

Introduction — p.  79-83.  A  descriptive  delineation  of  the  world 
embraces  the  whole  universe  {to  tt&v)  in  the  celestial  and  terrestrial 
spheres.  Form  and  course  of  the  representation.  It  begins  with  the 
depths  of  space,  of  which  we  know  little  beyond  the  existence  of 
laws  of  gravitation,  and  with  the  region  of  the  remotest  nebulous  spots 
and  double  stars,  and  then,  gradually  descending  through  the  starry 
stratum  to  w^hich  our  solar  system  belongs,  it  contemplates  this  terres- 
trial spheroid,  surrounded  by  air  and  water,  and,  finally,  proceeds  to 
the  consideration  of  the  form  of  our  planet,  its  temperature  and  mag- 
netic tension,  and  the  fullness  of  organic  vitality  which  is  unfolded  on 
its  surface  under  the  action  of  light.  Partial  insight  into  the  relative 
dependence  existing  among  all  phenomena.  Amid  all  the  mobile  and 
unstable  elements  in  space,  mean  numerical  vahces  are  the  ultimate  aim 
of  investigation,  being  the  expression  of  the  physical  laws,  or  forces  of 
the  Cosmos.  The  delineation  of  the  universe  does  not  begin  with  the 
eai'th,  from  which  a  merely  subjective  point  of  view  might  have  led  ua 
to  start,  but  rather  with  the  objects  comprised  in  the  regions  of  space. 
Distribution  of  matter,  which  is  partially  conglomerated  into  rotating 


SUMMARY    OF    THE    CONTENTS.  XVil 

nnd  circling  heavenly  bodies  of  veiy  different  density  and  magnitude, 
and  partly  scattered  as  self-luminous  vapor.  Review  of  the  separate 
portions  of  the  picture  of  nature,  for  the  purpose  of  explaining  the  re- 
ciprocal connection  of  all  phenomena. 

I.    Celestial  Portion  of  the  Cosmos Page  83-154 

II.    Terrestrial  Portion,  of  the  Cosmos p.  154-359 

a.  Form  of  the  earth,  its  mean  density,  quantity  of  heat,  electro-mag- 
netic activity,  process  of  light — p.  154-202. 

b.  Vital  activity  of  the  earth  toward  its  external  surface.  Reaction 
of  the  interior  of  a  planet  on  its  crust  and  surface.  Subterranean  noise 
without  waves  of  concussion.  Earthquakes  dynamic  phenomena — 
p.  202-217. 

c.  Mateiial  pi'oducts  which  frequently  accompany  earthquakes.  Gas- 
eous and  aqueous  springs.  Salses  and  mud  volcanoes  Upheavals  of 
the  soil  by  elastic  forces — p.  217-228. 

d.  Fire-emitting  mountains.  Craters  of  elevation.  Distribution  of 
volcanoes  on  the  earth — p.  228-247. 

e.  Volcanic  foi'ces  form  new  kinds  of  rock,  and  metamorphose  those 
already  existing.  Geognostical  classification  of  rocks  into  four  groups. 
Phenomena  of  contact.  Fossiliferous  strata ;  their  vertical  arrangement. 
The  faunas  and  floras  of  an  earlier  world.  Distribution  of  masses  of 
rock— p.  247-284. 

/.  Geognostical  epochs,  which  are  indicated  by  the  mineralogical  dif- 
ference of  rocks,  have  determined  the  distnbution  of  solids  and  fluids 
into  continents  and  seas.  Individual  configuration  of  solids  into  hori- 
zontal expansion  and  vertical  elevation.  Relations  of  area.  Articula- 
tion. Probability  of  the  continued  elevation  of  the  earth's  crust  in 
ridges— p.  284-301. 

0-.  Liquid  and  aenform  envelopes  of  the  solid  surface  of  our  planet. 
Distribution  of  heat  in  both.  The  sea.  The  tides.  CuiTents  and  their 
effects— p.  301-311. 

h.  The  atmosphere.  Its  chemical  composition.  Fluctuations  in  its 
density.  Law  of  the  direction  of  the  winds.  Mean  temperature.  Enu- 
meration of  the  causes  which  tend  to  raise  and  lower  the  temperature. 
Continental  and  insular  climates.  East  and  west  coasts.  Cause  of  the 
curvature  of  the  isothermal  lines.  Limits  of  perpetual  snow.  Quantity 
of  vapor.  Electricity  in  the  atmosphere.  Forms  of  the  clouds — p. 
311-339. 

i.  Separation  of  inorganic  terrestrial  life  from  the  geogi-aphy  of  vital 
organisms;  the  geography  of  vegetables  and  animals.  Physical  grada- 
tions of  the  human  race — p.  339-359. 

Special  Analysis  of  the  Delineation  of  Nature,  including  References  to  the 

Subjects  treated  of  in  the  Notes. 

[.  Celestial  Portion  of  the  Cosmos p.  83-154 

The  universe  and  all  that  it  compnses — multiform  nebulous  spots, 
planetary  vapor,  and  nebulous  stai-s.  The  pictui'esque  charm  of  a 
southern  sky — note,  p.  85.  Conjectures  on  the  position  in  space  of 
the  world.  Our  stellar  masses.  A  cosmical  island.  Gauging  stars. 
Double  stars  revolving  round  a  common  center.  Distance  of  the  star  6 1 
Cygui — p.  88  and  note.  Our  solar  system  more  complicated  than  was 
conjectured  at  the  close  of  the  last  century.  Primary  planets  with  Nep- 
tune, Astrea,  Hebe,  Iris,  and  Flora,  now  constitute  16 ;  secondary  plan- 
ets 18 ;  myriads  of  comets  of  which  many  of  the  inner  ones  are  inclosed 


XVm  SUMMARY    OF  THE    CONTENTS. 

in  the  orbits  of  the  planets ;  a  rotating  ring  (the  zodiacal  light)  and  me- 
teoric stones,  probably  to  be  regarded  as  small  cosmical  bodies.  The 
telescopic  planets,  Vesta,  Junoj  Ceres,  Pallas,  Astrea,  Hebe,  Iris,  and 
Flora,  with  their  frequently  intersecting,  strongly  inclined,  and  more 
eccentric  orbits,  constitute  a  central  group  of  separation  between  the 
inner  planetary  group  (Mercury,  Venus,  the  Earth,  and  Mars)  and  the 
outer  group  (Jupiter,  Saturn,  Uranus,  and  Neptune).  Contrasts  of  these 
planetary  groups.  Relations  of  distance  from  one  central  body.  Dif- 
fei'ences  of  absolute  magnitude,  density,  period  of  revolution,  eccentric- 
ity, and  inclination  of  the  orbits.  The  so-called  law  of  the  distances  of 
the  planets  from  their  central  sun.  The  planets  which  have  the  largest 
number  of  moons — p.  96  and  note.  Relations  in  space,  both  absolute 
and  relative,  of  the  secondary  planets.  Largest  and  smallest  of  the 
moons.  Greatest  appi'oximation  to  a  primary  planet.  Retrogressive 
movement  of  the  moons  of  Uranus.  Libration  of  the  Earth's  satellite — 
p.  98  and  note.  Comets ;  the  nucleus  and  tail ;  various  forms  and  di- 
rections of  the  emanations  in  conoidal  envelopes,  with  more  or  less 
dense  walls.  Several  tails  inclined  toward  the  sun ;  change  of  form  of 
the  tail;  its  conjectured  rotation.  Nature  of  light.  Occultations  of  the 
fixed  stars  by  the  nuclei  of  comets.  Eccentricity  of  their  orbits  and 
periods  of  revolution.  Greatest  distance  and  greatest  approximation 
of  comets.  Passage  through  the  system  of  Jupiter's  satellites.  Comets 
of  short  periods  of  revolution,  more  correctly  termed  inner  comets 
(Encke,  Biela,  Faye) — p.  107  and  note.  Revolving  a6rolites  (meteoric 
stones,  fire-balls,  falling  stars).  Their  planetary  velocity,  magnitude, 
form,  observed  height.  Periodic  return  in  streams;  the  November 
stream  and  the  stream  of  St.  Lawrence.  Chemical  composition  of  me- 
teoric asteroids — p.  130  and  notes.  Ring  of  zodiacal  light.  Limita- 
tion of  the  present  solar  atmosphere — p.  141  and  note.  Translatory 
motion  of  the  whole  solar  system — p.  145-149  and  note.  The  exist- 
ence of  the  law  of  gravitation  beyond  our  solar  system.  The  milky 
way  of  stars  and  its  conjectured  breaking  up.  Milky  way  of  nebulous 
spots,  at  right  angles  with  that  of  the  stars.  Periods  of  revolutions  of 
bi-colored  double  stars.  Canopy  of  stars;  openings  in  the  stellar  stra- 
tum. Events  in  the  universe ;  the  apparition  of  new  stars.  Propaga- 
tion of  light,  the  aspect  of  the  stai'ry  vault  of  the  heavens  conveys  to  the 
mind  an  idea  of  inequality  of  time — p.  149-154  and  notes. 

II.   Terrestrial  Portion  of  the  Cosmos Page  154-359 

a.  Figure  of  the  earth.  Density,  quantity  of  heat,  electro-magnetic 
tension,  and  terrestrial  light — p.  154-202  and  note.  Knowledge  of 
the  compression  and  curvature  of  the  earth's  surface  acquired  by  meas- 
urements of  degrees,  pendulum  oscillations,  and  certain  inequalities  in 
the  moon's  orbit.  Mean  density  of  the  earth.  The  earth's  crust,  and 
the  depth  to  which  we  are  able  to  penetrate — p.  159, 160,  note.  Three- 
fold movement  of  the  heat  of  the  earth  ;  its  thermic  condition.  Law 
of  the  increase  of  heat  with  the  increase  of  depth — p.  160, 161  and  note. 
Magnetism  electricity  in  motion.  Periodical  variation  of  terrestrial 
magnetism.  Disturbance  of  the  regular  course  of  the  magnetic  needle. 
Magnetic  stoiins ;  extension  of  their  action.  Manifestations  of  magnet- 
ic force  on  the  earth's  surface  presented  under  three  classes  of  phe- 
nomena, namely,  lines  of  equal  force  (isodynamic),  equal  inclination 
(isoclinic),  and  equal  deviation  (isogenic).  Position  of  the  magnetic 
pole.  Its  probable  connection  with  the  poles  of  cold.  Change  of  all 
the  magnetic  phenomena  of  the  earth.     Erection  of  magnetic  observa- 


SUMMARY    OF    THE    CONTENTS.  XIX 

toi-ies  since  1828 ;  a  far-extending  net-work  of  magnetic  stations — p. 
190  and  note.  Development  of  light  at  the  magnetic  poles;  terrestrial 
light  as  a  consequence  of  the  electro-magnetic  activity  of  our  planet. 
Elevation  of  polar  light.  Whether  magnetic  storms  are  accompanied 
by  noise.  Connection  of  polar  light  (an  electro-magnetic  development 
of  light)  with  the  formation  of  cirrus  clouds.  Other  examples  of  the 
generation  of  terrestrial  light — p.  202  and  note. 

b.  The  vital  activity  of  a  planet  manifested  from  within  outward,  the 
principal  source  of  geognostic  phenomena.  Connection  between  mere- 
ly dynamic  concussions  or  the  upheaval  of  whole  portions  of  the  earth's 
crust,  accompanied  by  the  eflfusion  of  matter,  and  the  generation  of 
gaseous  and  liquid  fluids,  of  hot  mud  and  fused  earths,  which  solidify 
into  rocks.  Volcanic  action,  in  the  most  general  conception  of  the  idea, 
is  the  reaction  of  the  interior  of  a  planet  on  its  outer  surface.  Earth- 
quakes. Extent  of  the  circles  of  commotion  and  their  gradual  increase. 
Whether  there  exists  any  connection  between  the  changes  in  terres- 
trial magnetism  and  the  processes  of  the  atmosphere.  Noises,  subter- 
ranean thunder  without  any  perceptible  concussion.  The  rocks  which 
modify  the  propagation  of  the  waves  of  concussion.  Upheavals ;  erup- 
tion of  water,  hot  steam,  mud  mofettes,  smoke,  and  flame  during  au 
earthquake — p.  202-218  and  notes. 

c.  Closer  consideration  of  material  products  as  a  consequence  of 
internal  planetary  activity.  There  rise  from  the  depths  of  the  earth, 
through  fissures  and  cones  of  eruption,  various  gases,  liquid  fluids  (pure 
or  acidulated),  mud,  and  molten  earths.  Volcanoes  are  a  species  of 
intermittent  spring.  Temperature  of  thermal  springs;  their  constancy 
and  change.  Depth  of  the  foci — p.  219-224  and  notes.  Salses,  mud 
volcanoes.  While  fire-emitting  mountains,  being  sources  of  molten 
earths,  produce  volcanic  rocks,  spring  water  forms,  by  precipitation, 
strata  of  limestone.  Continued  generation  of  sedimentary  rocks — p 
228  and  note. 

d.  Diversity  of  volcanic  elevations.  Dome-like  closed  trachytic 
mountains.  Actual  volcanoes  which  are  formed  from  craters  of  eleva- 
tion or  among  the  detritus  of  their  original  structure.  Permanent  con- 
nection of  the  interior  of  our  earth  with  the  atmosphere.  Relation  to 
certain  rocks.  Influence  of  the  relations  of  height  on  the  frequency  of 
the  eruptions.  Height  of  the  cone  of  cinders.  Characteristics  of  those 
volcanoes  v^'hich  rise  above  the  snow-line.  Columns  of  ashes  and  fire. 
Volcanic  storm  during  the  eruption.  Mineral  composition  of  lavas — 
p.  236  and  notes.  Distribution  of  volcanoes  on  the  earth's  surface ; 
central  and  linear  volcanoes  ;  insular  and  littoral  volcanoes.  Distance 
of  volcanoes  from  the  sea-coast.  Extinction  of  volcanic  forces — p.  246 
and  notes. 

e.  Relation  of  volcanoes  to  the  character  of  rocks.  Volcanic  forces 
form  new  rocks,  and  metamorphose  the  more  ancient  ones.  The  study 
of  these  relations  leads,  by  a  double  course,  to  the  mineral  portion  of 
geognosy  (the  study  of  the  textures  and  of  the  position  of  the  earth's 
strata),  and  to  the  configuration  of  continents  and  insular  groups  ele- 
vated above  the  level  of  the  sea  (the  study  of  the  geographical  form 
and  outlines  of  the  different  pai*ts  of  the  earth).  Classification  of  rocks 
according  to  the  scale  of  the  phenomena  of  structure  and  metamorpho- 
sis, which  are  still  passing  before  our  eyes.  Rocks  of  eruption,  sedi- 
mentary rocks,  changed  (metamorphosed)  rocks,  conglomerates — com- 
pound rocks  are  definite  associations  of  oryctognostically  simple  fossils 
There  are  four  phases  in  the  formative  condition:  rocks  of  eruption. 


XX  SUMIMARY    OF    THE    CONTENTS. 

endogenous  (granite,  sienite,  porphyry,  greenstone,  hypersthene,  rockj 
eupliotide,  melapbyre,  basalt,  and  phonolithe);  sedimentary  rocks  (si- 
lurian  schist,  coal  measures,  limestone,  travertino,  infusorial  deposit) ; 
metamorphosed  rock,  which  contains  also,  together  with  the  detritus 
of  the  rocks  of  eruption  and  sedimentary  rocks,  the  remains  of  gneiss, 
mica  schist,  and  more  ancient  metamorphic  masses.  Aggregate  and 
sandstone  formations.  The  phenomenon  of  contact  explained  by  the 
artificial  imitation  of  minerals.  Effects  of  pressure  and  the  various  ra- 
pidity of  cooling.  Origin  of  granular  or  saccharoidal  marble,  silicifica- 
tion  of  schist  into  ribbon  jasper.  Metamorphosis  of  calcareous  marl 
into  micaceous  schist  through  granite.  Conversion  of  dolomite  and 
granite  into  argillaceous  schist,  by  contact  with  basaltic  and  doleritie 
rocks.  Filling  up  of  the  veins  from  below.  Processes  of  cementation 
in  agglomerate  structures.  Friction  conglomerates — p.  269  and  note. 
Relative  age  of  rocks,  chronometry  of  the  earth's  crust.  Fossiliferous 
strata.  Relative  age  of  organisms.  Simplicity  of  the  first  \atal  forms. 
Dependence  of  physiological  gradations  on  the  age  of  the  formations. 
Geognostic  horizon,  whose  careful  investigation  may  yield  certain  data 
regarding  the  identity  or  the  relative  age  of  formations,  the  periodic 
recurrence  of  certain  strata,  their  parallelism,  or  their  total  suppression. 
Types  of  the  sedimentary  structures  considered  in  their  most  simple 
and  general  characters ;  silurian  and  devonian  formations  (formerly 
known  as  rocks  of  transition);  the  lower  trias  (mountain  limestone, 
coal  measures,  together  with  todtliegende  and  zechstein) ;  the  upper 
ti'ias  (bunter  sandstone,  muschelkalk,  and  keuper) ;  Jura  limestone  (lias 
and  oolite) ;  freestone,  lower  and  upper  chalk,  as  the  last  of  the  flotz 
strata,  which  begin  with  mountain  limestone ;  tertiaiy  formations  in 
three  divisions,  which  are  designated  by  granular  limestone,  lignite, 
and  south  Apennine  gravel — p.  269-278. 

The  faunas  and  floras  of  an  earlier  world,  and  their  relations  to  exist- 
ing organisms.  Colossal  bones  of  antediluvian  mammalia  in  the  upper 
alluvium.  Vegetation  of  an  earlier  world  ;  monuments  of  the  history 
of  its  vegetation.  The  points  at  which  certain  vegetable  groups  attain 
their  maximum;  cycadeae  in  the  keuper  and  lias,  and  coniferae  in  the 
bunter  sandstone.  Lignite  and  coal  measures  (amber-tree).  Deposition 
of  large  masses  of  rock ;  doubts  regarding  their  origin — p.  285  and  note 

/.  The  knowledge  of  geognostic  epochs — of  the  upheaval  of  mount- 
ain chains  and  elevated  plateaux,  by  which  lands  are  both  formed  and 
destroyed,  leads,  by  an  internal  causal  connection,  to  the  distribution 
into  solids  and  fluids,  and  to  the  peculiarities  in  the  natural  configura- 
tion of  the  earth's  surface.  Existing  areal  relations  of  the  solid  to  the 
fluid  differ  considerably  from  those  presented  by  the  maps  of  the  phys- 
ical portion  of  a  more  ancient  geography.  Importance  of  the  eruption 
of  quartzose  porphyry  with  reference  to  the  then  existing  configuration 
of  continental  masses.  Individual  conformation  in  horizontal  exten- 
sion (relations  of  articulation)  and  in  vertical  elevation  (hypsometrical 
views).  Influence  of  the  relations  of  the  area  of  land  and  sea  on  the 
temperature,  direction  of  the  winds,  abundance  or  scarcity  of  organic 
products,  and  on  all  meteorological  processes  collectively.  Direction 
of  the  major  axes  of  continental  masses.  Articulation  and  pyramidal 
termination  toward  the  south.  Series  of  peninsulas.  Valley-like  form- 
ation of  the  Atlantic  Ocean.  Forms  which  frequently  recur — p.  285- 
293  and  notes.  Ramifications  and  systems  of  mountain  chains,  and  tho 
means  of  determining  their  relative  ages.  Attempts  to  determine  the 
*enter  of  gravity  of  the  volume  of  the  lauds  upheaved  above  the  level 


SUMMARY    OF    THE    CONTENTS.  XXI 

of  the  sea.  The  elevation  of  continents  is  still  progressing  slowly,  and 
is  being  compensated  for  at  some  definite  points  by  a  perceptible  sink- 
ing. All  geognostic  phenomena  indicate  a  periodical  alternation  of 
activity  in  the  interior  of  our  planet.  Probability  of  new^  elevations  of 
ridges — p.  293-301  and  notes. 

g.  The  solid  surface  of  the  earth  has  two  envelopes,  one  liquid,  and 
tlie  other  aeriform.  Contrasts  and  analogies  which  these  envelopes— 
tlie  sea  and  the  atmosphere — present  in  their  conditions  of  aggrega^ 
tion  and  electricity,  and  in  their  relations  of  currents  and  temperature. 
Depths  of  the  ocean  and  of  the  atmosphei-e,  the  shoals  of  which  consti 
tute  our  highlands  and  mountain  chains.  The  degree  of  heat  at  the 
surface  of  the  sea  in  different  latitudes  and  in  the  lower  strata.  Tend- 
ency of  the  sea  to  maintain  the  temperature  of  the  surface  in  the  strata 
nearest  to  the  atmosphere,  in  consequence  of  the  mobility  of  its  j)arti- 
cles  and  the  alteration  in  its  density.  Maximum  of  the  density  of  salt 
water.  Position  of  the  zones  of  the  hottest  water,  and  of  those  having 
the  greatest  saline  contents.  Thermic  influence  of  the  lower  polar  cur- 
rent and  the  counter  currents  in  the  straits  of  the  sea — p.  302-304  and 
notes.  General  level  of  the  sea,  and  permanent  local  disturbances  of 
equilibrium  ;  the  periodic  disturbances  manifested  as  tides.  Oceanic 
currents;  the  equatorial  or  rotation  current,  the  Atlantic  warm  Gulf 
Stream,  and  the  further  impulse  which  it  receives;  the  cold  Peruvian 
stream  in  the  eastern  portion  of  the  Pacific  Ocean  of  the  southern  zone. 
Temperature  of  shoals.  The  universal  diffusion  of  life  in  the  ocean. 
Influence  of  the  small  submarine  sylvan  region  at  the  bottom  of  beds 
of  rooted  algse,  or  on  far-extending  floating  layers  of  fucus — p.  302-311 
and  notes. 

k.  The  gaseous  envelope  of  our  planet,  the  atmosphere.  Chemical 
composition  of  the  atmosphere,  its  transparency,  its  polarization,  pres 
sure,  temperature,  humidity,  and  electric  tension.  Relation  of  oxygen 
to  nitrogen ;  amount  of  carbonic  acid;  carbureted  hydrogen;  ammo- 
niacal  vapors.  Miasmata.  Regular  (horaiy)  changes  in  the  pressure 
of  the  atmosphere.  Mean  barometrical  height  at  the  level  of  the  sea 
in  different  zones  of  the  earth.  Isobarometx'ical  curves.  Barometrical 
windroses.  Law  of  rotation  of  the  winds,  and  its  importance  with  ref- 
erence to  the  knowledge  of  many  meteorological  processes.  Land  and 
sea  winds,  trade  winds  and  monsoons — p.  311-317.  Climatic  distribu- 
tion of  heat  in  the  atmosphere,  as  the  effect  of  the  relative  position  of 
transparent  and  opaque  masses  (fluid  and  solid  superficial  area),  and 
of  the  hypsometrical  configuration  of  continents.  Curvature  of  the  iso- 
thermal lines  in  a  horizontal  and  vertical  direction,  on  the  earth's  sur- 
face and  in  the  superimposed  strata  of  air.  Convexity  and  concavity 
of  the  isothermal  lines.  Mean  heat  of  the  year,  seasons,  months,  and 
days.  Enumeration  of  the  causes  which  produce  disturbances  in  the 
form  of  the  isothermal  lines,  i.  e.,  their  deviation  from  the  position  of  the 
geographical  parallels.  Isochimenal  and  isotheral  lines  are  the  lines  of 
equal  winter  and  summer  heat.  Causes  which  raise  or  lower  the  tem- 
perature. Radiation  of  the  earth's  surface,  according  to  its  inclination, 
color,  density,  dryness,  and  chemical  composition.  The  form  of  the 
cloud  which  announces  what  is  passing  in  the  upper  strata  of  the  atmos- 
phere  is  the  image  of  the  strongly  radiating  ground  projected  on  a  hot 
summer  sky.  Contrast  between  an  insular  or  littoral  climate,  such  as 
is  experienced  by  all  deeply-articulated  continents,  and  the  climate  of 
the  interior  of  large  tracts  of  land.  East  and  west  coasts.  Ditlerence 
between  the  southern  and  northern  hemispheres.     Thennal  scales  of 


XXll  SUMMARY    OF    THE    CONTENTS. 

cultivated  plants,  going  down  from  the  vanilla,  cacoa,  and  musacese,  to 
citrons  and  olives,  and  to  vines  yielding  potable  wines.  The  influence 
which  these  scales  exercise  on  the  geographical  distribution  of  culti- 
vated plants.  The  favorable  ripening  and  the  immaturity  of  fruits  are 
essentially  influenced  by  the  difference  in  the  action  of  direct  or  scat- 
tered light  in  a  clear  sky  or  in  one  overcast  with  mist.  General  sum- 
mary of  the  causes  which  yield  a  more  genial  climate  to  the  greater 
portion  of  Europe  considered  as  the  western  peninsula  of  Asia — ^p.  326. 
Determination  of  the  changes  in  the  mean  annual  and  summer  temper- 
ature, which  correspond  to  one  degree  of  geographical  latitude.  Equal- 
ity of  the  mean  temperature  of  a  mountain  station,  and  of  the  polar  dis- 
tance of  any  point  lying  at  the  level  of  the  sea.  Decrease  of  tempera- 
ture with  the  decrease  in  elevation.  Limits  of  perpetual  snow,  and  the 
fluctuations  in  these  limits.  Causes  of  disturbance  in  the  regularity  of 
the  phenomenon.  Northern  and  southern  chains  of  the  Himalaya;  hab- 
itability  of  the  elevated  plateaux  of  Thibet — p.  33 1 .  Quantity  of  moist- 
ure in  the  atmosphere,  according  to  the  hours  of  the  day,  the  seasons  of 
the  year,  degrees  of  latitude,  and  elevation.  Greatest  dryness  of  the 
atmosphere  observed  in  Northern  Asia,  between  the  river  disti-icts  of 
the  Irtysch  and  the  Obi.  Dew,  a  consequence  of  radiation.  Quantity 
of  rain — p.  335.  Electricity  of  the  atmosphere,  and  disturbance  of  the 
electric  tension.  Geographical  distribution  of  storms.  Predetermina 
tion  of  atmospheric  changes.  The  most  important  climatic  disturbances 
can  not  be  traced,  at  the  place  of  observation,  to  any  local  cause,  but  are 
rather  the  consequence  of  some  occurrence  by  which  the  equilibrium 
in  the  atmospheric  currents  has  been  destroyed  at  some  considerable 
distance — p.  335-339. 

i.  Physical  geography  is  not  limited  to  elementary  inorganic  terres- 
trial life,  but,  elevated  to  a  higher  point  of  view,  it  embraces  the  sphere 
of  organic  life,  and  the  numerous  gradations  of  its  typical  development. 
Animal  and  vegetable  life.     General  diffusion  of  life  in  the  sea  and  on 
the  land;  microscopic  vital  forms  discovered  in  the  polar  ice  no  less 
than  in  the  depths  of  the  ocean  within  the  tropics.     Extension  imparted 
to  the  horizon  of  life  by  Ehrenberg's  discoveries.     Estimation  of  the 
mass  (volume)  of  animal  and  vegetable  organisms — p.  339-346.     Geog- 
raphy of  plants  and  animals.     Migrations  of  organisms  in  the  ovum,  or 
by  means  of  organs  capable  of  spontaneous  motion.     Spheres  of  distri- 
bution depending  on  climatic  relations.     Regions  of  vegetation,  and 
classification  of  the  genera  of  animals.     Isolated  and  social  living  plants 
and  animals.     The  character  of  floras  and  faunas  is  not  deteimined  so 
much  by  the  predominance  of  separate  families,  in  certain  parallels  of 
latitude,  as  by  the  highly  complicated  relations  of  the  association  of  many 
families,  and  the  relative  numerical  value  of  their  species.     The  forms 
of  natural  families  which  increase  or  decrease  from  the  equator  to  the 
poles.     Investigations  into  the  numerical  relation  existing  in  different 
districts  of  the  earth  between  each  one  of  the  large  families  to  the 
whole  mass  of  phanerogamia — p.  346-351.    The  human  race  considered 
according  to  its  physical  gradations,  and  the  geographical  distribution 
of  its  simultaneously  occurring  types.     Races  and  varieties.     All  races 
of  men  are  forms  of  one  single  species.     Unity  of  the  human  race. 
Languages  considered  as  the  intellectual  creations  of  mankind,  or  as 
portions  of  the  history  of  mental  activity,  manifest  a  character  of  nation- 
ality, although  certain  historical  occurrences  have  been  the  means  of 
diffusing  idioms  of  the  same  family  of  languages  among  nations  of  wholb^ 
different  descent — p.  351-359. 


INTRODUCTION. 


REFLECTIONS  ON  THE  DIFFERENT  DEGREES  OF  ENJOYMENT  PRE- 
SENTED  TO  US  BY  THE  ASPECT  OF  NATURE  AND  THE  STUDY  OF  HER 
LAWS. 

In  attempting,  after  a  long  absence  from  my  native  coun- 
try, to  develop  the  physical  phenomena  of  the  globe,  and  the 
simultaneous  action  of  the  forces  that  pervade  the  regions  of 
space,  I  experience  a  two-fold  cause  of  anxiety.  The  subject 
before  me  is  so  inexhaustible  and  so  varied,  that  I  fear  either 
to  fall  into  the  superficiality  of  the  encyclopedist,  or  to  weary 
the  mind  of  my  reader  by  aphorisms  consisting  of  mere  gener- 
alities clothed  in  dry  and  dogmatical  forms.  Undue  concise- 
ness often  checks  the  flow  of  expression,  while  diffuseness  is 
alike  detrimental  to  a  clear  and  precise  exposition  of  our  ideas. 
Nature  is  a  free  domain,  and  the  profound  conceptions  and 
enjoyments  she  awakens  within  us  can  only  be  vividly  deline- 
ated by  thought  clothed  in  exalted  forms  of  speech,  worthy  of 
bearing  witness  to  the  majesty  and  greatness  of  the  creation. 

In  considering  the  study  of  physical  phenomena,  not  mere- 
ly in  its  bearings  on  the  material  wants  of  life,  but  in  its  gen- 
eral influence  on  the  mtellectual  advancement  of  rnankmd, 
we  find  its  noblest  and  most  important  result  to  be  a  knowl- 
edge of  the  chain  of  connection,  by  which  all  natural  forces 
are  linked  together,  and  made  mutually  dependent  upon  each 
other ;  and  it  is  the  perception  of  these  relations  that  exalts 
our  views  and  ennobles  our  enjoyments.  Such  a  result  can, 
however,  only  be  reaped  as  the  fruit  of  observation  and  intel- 
lect, combined  wdth  the  spirit  of  the  age,  in  which  are  reflect- 
ed all  the  varied  phases  of  thought.  He  who  can  trace, 
through  by-gone  times,  the  stream  of  our  knowledge  to  its 
primitive  source,  will  learn  from  history  how,  for  thousands 
of  years,  man  has  labored,  amid  the  ever-recurring  changes 
of  form,  to  recognize  the  invariability  of  natural  laws,  and 
has  thus,  by  the  force  of  mind,  gradually  subdued  a  great  por- 
tion of  the  physical  world  to  his  dominion.  In  interrogating 
the  history  of  the  past,  we  trace  the  mysterious  course  of  ideas 
yielding  the  first  glimmering  perception  of  the  same  imag'i  of 


24  COSMOS. 

a  Cosmos,  or  harmoniously  ordered  whole,  which,  dimly  shad- 
owed forth  to  the  human  mind  in  the  primitive  ages  of  the 
world,  is  now  fully  revealed  to  the  maturer  intellect  of  man 
kind  as  the  result  of  long  and  laborious  observation. 

Each  of  these  epochs  of  the  contemplation  of  the  external 
Vorld — the  earliest  dawn  of  thought  and  the  advanced  stage 
of  civilization — has  its  oWii  source  of  enjoyment.  In  the 
former,  this  enjoyment,  in  accordance  with  the  simplicity  of 
the  primitive  ages,  flowed  from  an  intuitive  feeling  of  the  or 
der  that  was  proclaimed  by  the  invariable  and  successive  re- 
appearance of  the  heavenly  bodies,  and  by  the  progressive  de- 
velopment of  organized  beings  ;  while  in  the  latter,  this  sense 
of  enjoyment  springs  from  a  definite  knowledge  of  the  phe- 
nomena of  nature.  When  man  began  to  interrogate  nature, 
and,  not  conteijt  with  observing,  learned  to  evoke  phenomena 
under  definite  conditions  ;  when  once  he  sought  to  collect  and 
record  facts,  in  order  that  the  fruit  of  liis  labors  might  aid  in- 
vestigation after  his  own  brief  existence  had  passed  aw^ay,  the 
philosophy  of  Nature  cast  aside  the  vague  and  poetic  garb 
in  which  she  had  been  enveloped  from  her  origin,  and,  having 
assumed  a  severer  aspect,  she  now  w^eighs  the  value  of  ob- 
servations, and  substitutes  induction  and  reasoning  for  con- 
jecture and  assumption.  The  dogmas  of  former  ages  survive 
now  only  in  the  superstitions  of  the  people  and  the  prejudices 
of  the  ignorant,  or  are  perpetuated  in  a  few  systems,  which, 
conscious  of  their  weakness,  shroud  themselves  in  a  vail  of 
mystery.  We  may  also  trace  the  same  primitive  intuitions 
in  lanffuaofes  exuberant  in  fisfurative  exDressions  ;  and  a  few 
of  the  best  chosen  symbols  engendered  by  the  happy  inspira- 
tion of  the  earliest  ages,  having  by  degrees  lost  their  vague- 
ness through  a  better  mode  of  interpretation,  are  still  preserved 
among  our  scientific  terms. 

Nature  considered  rationally,  that  is  to  say,  submitted  to 
the  process  of  thought,  is  a  unity  in  diversity  of  phenomena  ; 
a  harmony,  blending  together  all  created  things,  however  dis- 
similar in  form  and  attributes  ;  one  great  whole  {to  -rrdv)  an- 
imated by  the  breath  of  life.  The  most  important  result  of 
a  rational  inquiry  into  nature  is,  therefore,  to  establish  the 
unity  and  harmony  of  this  stupendous  mass  of  force  and  mat- 
ter, to  determine  with  impartial  justice  what  is  due  to  the 
discoveries  of  the  past  and  to  those  of  the  present,  and  to  an- 
alyze the  individual  parts  of  natural  phenomena  without  suo- 
cumbing  beneath  the  weight  of  the  whole.  Thus,  and  thus 
alone,  is  it  permitted  to  man,  while  mindful  of  the  high  des- 


INTRODUCTION.  25 

tiny  of  his  race,  to  comprehend  nature,  to  lift  the  vail  that 
shrouds  her  phenomena,  and,  as  it  were,  submit  the  results  of 
observation  to  the  test  of  reason  and  of  intellect. 

In  reflecting  upon  the  different  degrees  of  enjoyment  pre- 
sented to  us  in  the  contemplation  of  nature,  we  find  that  the 
ftrst  place  must  be  assigned  to  a  sensation,  which  is  wholly 
mdependent  of  an  intimate  acquaintance  with  the  physical 
phenomena  presented  to  our  view,  or  of  the  peculiar  character 
of  the  region  surrounding  us.  In  the  uniform  plain  bounded 
only  by  a  distant  horizon,  where  the  lowly  heather,  the  cistus, 
or  waving  grasses,  deck  the  soil ;  on  the  ocean  shore,  where 
the  waves,  softly  rippling  over  the  beach,  leave  a  track,  green 
with  the  weeds  of  the  sea ;  every  where,  the  mind  is  penetra- 
ted by  the  same  sense  of  the  grandeur  and  vast  expanse  of 
nature,  revealing  to  the  soul,  by  a  mysterious  inspiration,  the 
existence  of  laws  that  regulate  the  forces  of  the  universe. 
Mere  communion  with  nature,  mere  contact  with  the  free  air, 
exercise  a  soothing  yet  strengthening  influence  on  the  wearied 
spirit,  calm  the  storm  of  passion,  and  soften  the  heart  when 
shaken  by  sorrow  to  its  inmost  depths.  Every  where,  in  ev 
ery  region  of  the  globe,  in  every  stage  of  intellectual  culture, 
the  same  sources  of  enjoyment  are  alike  vouchsafed  to  man. 
The  earnest  and  solemn  thoughts  awakened  by  a  communion 
with  nature  intuitively  arise  from  a  presentiment  of  the  order 
and  harmony  pervading  the  whole  universe,  and  from  the 
contrast  we  draw  between  the  narrow  limits  of  our  own  ex- 
istence and  the  image  of  infinity  revealed  on  every  side,  wheth- 
er we  look  upward  to  the  starry  vault  of  heaven,  scan  the  far- 
stretching  plain  before  us,  or  seek  to  trace  the  dim  horizon 
across  the  vast  expanse  of  ocean. 

The  contemplation  of  the  individual  characteristics  of  the 
landscape,  and  of  the  conformation  of  the  land  in  any  definite 
region  of  the  earth,  gives  rise  to  a  different  source  of  enjoy- 
ment, awakening  impressions  that  are  more  vivid,  better  de- 
fined, and  more  congenial  to  certain  phases  of  the  mind,  than 
those  of  which  we  have  already  spoken.  At  one  time  the 
hiiart  is  stirred  by  a  sense  of  the  grandeur  of  the  face  of  na- 
ture, by  the  strife  of  the  elements,  or,  as  in  Northern  Asia,  by 
the  aspect  of  the  dreary  barrenness  of  the  far-stretching  steppes ; 
at  another  time,  softer  emotions  are  excited  by  the  contempla- 
tion of  rich  harvests  wrested  by  the  hand  of  man  from  the 
wild  fertility  of  nature,  or  by  the  sight  of  human  habitations 
raised  beside  some  wild  and  foaming  torrent.  Here  I  regard 
less  the  degree  of  intensity  than  the  difference  existing  in  the 

Vol.  I.— B 


26  COSMOS. 

various  sensations  that  derive  their  charm  and  peimauencf 
from  the  pecuhar  character  of  the  scene. 

If  I  might  be  allowed  to  abandon  myself  to  the  recollections 
»f  my  own  distant  travels,  I  would  instance,  among  the  most 
•■■triking  scenes  of  nature,  the  calm  sublimity  of  a  tropical  night, 
ivhen  the  stars,  not  sparkling,  as  in  our  northern  skies,  shed 
cheir  soft  and  planetary  light  over  the  gently-heaving  ocean ; 
)r  I  would  recall  the  deep  valleys  of  the  Cordilleras,  where 
",he  tall  and  slender  palms  pierce  the  leafy  vail  around  them, 
ind  waving  on  high  their  feathery  and  arrow-like  branches, 
';brm,  as  it  were,  "  a  forest  above  a  forest  ;"*  or  I  would  de- 
scribe the  summit  of  the  Peak  of  TenerifTe,  when  a  horizontal 
.ayer  of  clouds,  dazzling  in  whiteness,  has  separated  the  cone 
)f  cinders  from  the  plain  below,  and  suddenly  the  ascending 
iurrent  pierces  the  cloudy  vail,  so  that  the  eye  of  the  traveler 
may  range  from  the  brink  of  the  crater,  along  the  vine-clad 
slopes  of  Orotava,  to  the  orange  gardens  and  banana  groves 
that  skirt  the  shore.  In  scenes  like  these,  it  is  not  the  peace- 
ful charm  uniformly  spread  over  the  face  of  nature  that  moves 
the  heart,  but  rather  the  peculiar  physiognomy  and  conforma- 
tion of  the  land,  the  features  of  the  landscape,  the  ever-vary- 
ing outline  of  the  clouds,  and  their  blending  with  the  horizon 
of  the  sea,  whether  it  lies  spread  before  us  like  a  smooth  and 
shining  mirror,  or  is  dimly  seen  through  the  morning  mist. 
All  that  the  senses  can  but  imperfectly  comprehend,  all  that 
is  most  awful  in  such  romantic  scenes  of  nature,  may  become 
1  source  of  enjoyment  to  man,  by  opening  a  wide  field  to  the 
creative  powers  of  his  imagination.  Impressions  change  with 
the  varying  movements  of  the  mind,  and  we  are  led  by  a  hap- 
py illusion  to  believe  that  we  receive  from  the  external  world 
that  with  which  we  have  ourselves  invested  it. 

When  far  from  our  native  country,  after  a  long  voyage,  we 
;read  for  the  first  time  the  soil  of  a  tropical  land,  v/e  expe- 
•ience  a  certain  feeling  of  surprise  and  gratification  in  recog- 
lizing,  in  the  rocks  that  surround  us,  the  same  inclined  schis- 
I  ose  strata,  and  the  same  columnar  basalt  covered  with  cellu- 
iar  amygdaloids,  that  we  had  left  in  Europe,  and  whose  iden- 
iity  of  character,  in.  latitudes  so  widely  different,  reminds  us 
!.hat  the  solidification  of  the  earth's  crust  is  altogether  inde- 
[leudent  of  climatic  influences.  But  these  rocky  masses  of 
schist  and  of  basalt  are  covered  with  vogetation  of  a  character 
with  wluch  we  are  unacquainted,  and  of  a  physiognomy  wholly 

*  This  expression  is  taken  from  a  beautiful  description  of  tropical 
forest  sceiieiy  iu  Paul  and  Virginia,  by  Bernardin  de  Saint  Pierre. 


INTRODUCTION.  27 

unknown  to  us  ;  and  it  is  then,  amid  the  colossal  and  majestic 
forms  of  an  exotic  flora,  that  we  feel  how  wonderfully  the  flex- 
ibility of  our  nature  fits  us  to  receive  new  impressions,  linked 
together  by  a  certain  secret  analogy.  We  so  readily  perceive 
the  affinity  existing  among  all  the  forms  of  organic  life,  thai 
although  the  sight  of  a  vegetation  similar  to  that  of  our  native 
country  might  at  first  be  most  welcome  to  the  eye,  as  the  sweel 
familiar  sounds  of  our  mother  tongue  are  to  the  ear,  we  nev- 
ertheless, by  degrees,  and  almost  imperceptibly,  become  famil 
iarized  with  a  new  home  and  a  new  climate.  As  a  true  citi 
zen  of  the  world,  man  eveiy  where  habituates  himself  to  tha' 
which  surrounds  him  ;  yet  fearful,  as  it  were,  of  breaking  tl  ^ 
links  of  association  that  bind  him  to  the  home  of  his  childhood, 
the  colonist  applies  to  some  few  plants  in  a  far-distant  clime  the 
names  he  had  been  familiar  Avith  in  his  native  land ;  and  by 
the  mysterious  relations  existing  among  all  types  of  organiza- 
tion, the  forms  of  exotic  vegetation  present  themselves  to  his 
mind  as  nobler  and  more  perfect  developments  of  those  he  had 
loved  in  earher  days.  Thus  do  the  spontaneous  impressions 
of  the  untutored  mind  lead,  like  the  laborious  deductions  of 
cultivated  intellect,  to  the  same  intimate  persuasion,  that  one 
sole  and  indissoluble  chain  binds  together  all  nature. 

It  may  seem  a  rash  attempt  to  endeavor  to  separate,  into 
its  different  elements,  the  magic  power  exercised  upon  our 
minds  by.  the  physical  world,  since  the  character  of  the  land- 
scape, and  of  every  imposing  scene  in  nature,  depends  so  ma- 
terially upon  the  mutual  relation  of  the  ideas  and  sentiments 
simultaneously  excited  in  the  mind  of  the  observer. 

The  powerful  effect  exercised  by  nature  springs,  as  it  were, 
from  the  connection  and  unity  of  the  impressions  and  emo- 
tions produced  ;  and  we  can  only  trace  their  different  sources 
by  analyzing  the  individuality  of  objects  and  the  diversity  of 
forces. 

The  richest  and  most  varied  elements  for  pursuing  an  anal- 
ysis of  this  nature  present  themselves  to  the  eyes  of  the  trav- 
eler in  the  scenery  of  Southern  Asia,  in  the  Great  Indian 
Archipelago,  and  more  especially,  too,  in  the  New  Continent, 
where  the  summits  of  the  lofty  Cordilleras  penetrate  the  con- 
fines of  the  aerial  ocean  surrounding  our  globe,  and  where  the 
same  subterranean  forces  that  once  raised  these  mountain 
chains  still  shake  them  to  their  foundation  and  threaten  their 
downfall. 

Graphic  delineations  of  nature,  arranged  according  to  sys- 
teraatic  views,  are  not  only  suited  to  please  the  imagination, 


28  COSMOS. 

but  may  also,  when  properly  considered,  indicate  the  grades 
of  the  impressions  of  which  I  have  spoken,  from  the  miiform- 
ity  of  the  sea-shore,  or  the  barren  steppes  of  Siberia,  to  the 
inexhaustible  fertility  of  the  torrid  zone.  If  we  were  even  to 
picture  to  ourselves  Mount  Pilatus  placed  on  the  Schreck- 
horn,*  or  the  Schneekoppe  of  Silesia  on  Mont  Blanc,  we  should 

*  These  comparisons  are  only  approximative.     The  several  eleva- 
tions above  the  level  of  the  sea  are,  in  accurate  numbers,  as  follows : 

The  Schneekoppe  or  Riesenkoppe,  in  Silesia,  about  5270  feet,  ac- 
cording to  Hallaschka.  The  Righi,  5902  feet,  taking  the  height  of  the 
Lake  of  Lucerne  at  1426  feet,  according  to  Eschman.  (See  Compte 
Rendu  des  Mesures  Ti-igonometriques  en  Suisse,  1840,  p.  230.)  Mount 
Athos,  6775  feet,  according  to  Captain  Gaultier;  Mount  Pilatus,  7546 
feet;  Mount  ^Etna,  10,871  feet,  according  to  Captain  Smyth;  or  10,874 
feet,  according  to  the  barometrical  measurement  made  by  Sir  John 
Herschel,  and  communicated  to  me  in  writing  in  1825,  and  10,899  feet, 
according  to  angles  of  altitude  taken  by  Cacciatore  at  Palermo  (calcu- 
lated by  assuming  the  terrestrial  refraction  to  be  0'076) ;  the  Schreck 
horn,  12,383  feet;  the  Jungfrau,  13,720  feet,  according  to  TraUes ;  Mont 
Blanc,  15,775  feet,  according  to  the  diflferent  measurements  considered 
by  Roger  {Bibl.  Univ.,  May,  1828,  p.  24-53),  15,733  feet,  according  to 
the  measurements  taken  from  Mount  Columbier  by  Carlini  in  1821,  and 
15,748  feet,  as  measured  by  the  Austrian  engineers  from  Trelod  and 
the  Glacier  d'Ambin. 

The  actual  height  of  the  Swiss  mountains  fluctuates,  according  to 
Eschman's  observations,  as  much  as  25  English  feet,  owing  to  the  vary- 
ing thickness  of  the  stratum  of  snow  that  covers  the  summits.  Chim- 
borazo  is,  according  to  my  trigonometrical  measurements,  21,421  feet 
(see  Humboldt,  Recueil  d^Obs.  Astr.,  tome  i.,  p.  73),  and  Dhawalagiri, 
28,074  feet.  As  there  is  a  dilference  of  445  feet  between  the  determin- 
ations of  Blake  and  Webb,  the  elevation  assigned  to  the  Dhawalagiri 
(or  white  mountain,  from  the  Sanscrit  dhawala,  white,  and  giri,  mount- 
ain) can  not  be  received  with  the  same  confidence  as  that  of  the  Jawa- 
hir,  25,749  feet,  since  the  latter  rests  on  a  complete  trigonometrical 
measurement  (see  Herbert  and  Hodgson  in  the  Asiat.  Res.,  vol.  xiv., 
p.  189,  and  Suppl.  to  Encycl.  Brit.,  vol.  iv.,  p.  643).  I  have  shown 
elsewhere  {Ann.  des  Sciences  Naturelles,  Mars,  1825)  that  the  height  of 
the  Dhawalagiri  (28,074  feet)  depends  on  several  elements  that  have 
not  been  ascertained  with  certainty,  as  azimuths  and  latitudes  (Hum- 
boldt, Asie  Centrale,  t.  iii.,  p.  282).  It  has  been  believed,  but  without 
foundation,  that  in  the  Tartaric  chain,  north  of  Thibet,  opposite  to  the 
chain  of  Kuen-lun,  there  are  several  snowy  summits,  whose  elevation 
is  about  30,000  English  feet  (almost  twice  that  of  Mont  Blanc),  or,  at 
any  rate,  29,000  feet  (see  Captain  Alexander  Gerard's  and  John  Gerard's 
J(>-  '•ney  to  the  Boorendo  Pass,  1840,  vol.  i.,  p.  143  and  311).  Chimbo- 
ru-^o  is  spoken  of  in  the  text  only  as  one  of  the  highest  summits  of  the 
chain  of  the  Andes;  for  in  the  year  1827,  the  learned  and  highly-gifted 
traveler,  Pentland,  in  his  memorable  expedition  to  Upper  Peru  (Bolivia), 
measured  the  elevation  of  two  mountains  situated  to  the  east  of  Lake 
Titicaca,  viz.,  the  Sorata,  25,200  feet,  and  the  Illimani,  24,000  feet,  both 
greatly  exceeding  th«  height  of  Chimborazo,  which  is  only  21,421  feet, 
and  being  nearly  equal  in  elevation  to  the  Jawahir,  which  is  the  highest 
mouutaia  in  the  Himalaya  that  has  as  yet  been  accurately  measured. 


INTRODUCTION.  29 

not  have  attained  to  the  height  of  that  great  Colossus  of  the 
Andes,  the  Chimhorazo,  whose  height  is  twice  that  of  Mount 
^tna;  and  we  must  pile  the  Righi,  or  Mount  Athos,  on  the 
summit  of  the  Chimhorazo,  in  order  to  form  a  just  estimate 
of  the  elevation  of  the  Dhawalagiri,  the  highest  point  of  the 
Himalaya.  But  although  the  mountains  of  India  greatly  sur- 
pass the  Cordilleras  of  South  America  hy  their  astonishing  el- 
evation (which,  after  heing  long  contested,  has  at  last  been 
confirmed  by  accurate  measurements),  they  can  not,  from  their 
geographical  position,  present  the  same  inexhaustible  variety 
of  phenomena  by  which  the  latter  are  characterized.  The 
impression  produced  by  the  grander  aspects  of  nature  does  not 
depend  exclusively  on  height.  The  chain  of  the  Himalaya  is 
placed  far  beyond  the  limits  of  the  torrid  zone,  and  scarcely  is 
a  solitary  palm-tree  to  be  found  in  the  beautiful  valleys  of 
Kumaoun  and  Garhwal.*  On  the  southern  slope  of  the  an- 
cient Paropamisus,  in  the  latitudes  of  28^  and  34°,  nature  no 
longer  displays  the  same  abundance  of  tree-ferns  and  arbores- 
cent grasses,  heliconias  and  orchideous  plants,  which  in  tropic- 

Thus  Mont  Blanc  is  5646  feet  below  Chimborazo ;  Chimhorazo,  3770 
feet  below  the  Sorata ;  the  Sorata,  549  feet  below  the  Jawahir,  and  prob 
ably  about  2880  feet  below  the  Dhawalagiri.  According  to  a  new 
measurement  of  the  Illimani,  by  Pentland,  in  1838,  the  elevation  of  this 
mountain  is  given  at  23,868  feet,  varying  only  133  feet  from  the  meas- 
urement taken  in  1827.  The  elevations  have  been  given  in  this  note 
with  minute  exactness,  as  erroneous  numbers  have  been  introduced 
into  many  maps  and  tables  recently  published,  owing  to  incorrect  re- 
ductions of  the  measux'ements. 

[In  the  preceding  note,  taken  from  those  appended  to  the  Introduc- 
tion in  the  French  translation,  rewritten  by  Humboldt  himself,  the 
measurements  are  given  in  meters,  but  these  have  been  convei'ted  into 
English  feet,  for  the  greater  convenience  of  the  general  reader.] — Tr. 

*  The  absence  of  palms  and  tree-ferns  on  the  temperate  slopes  of  the 
Himalaya  is  shown  in  Don's  Flora  Nepalensis,  1825,  and  in  the  remark- 
able series  of  lithographs  of  WalUch's  Flora  Indica,  whose  catalogue 
contains  the  enormous  number  of  7683  Himalaya  species,  almost  all 
phanerogamic  plants,  which  have  as  yet  been  but  imperfectly  classified. 
In  Nepaul  (lat.  26^°  to  27^°)  there  has  hitherto  been  observed  only  one 
species  of  palm,  Chamaerops  martiana,  Wall.  {Plaidce  Asiat.,  lib.  iii.,  p 
5,  211),  which  is  found  at  the  height  of  5250  English  feet  above  the  level 
of  the  sea,  in  the  shady  valley  of  Bunipa.  The  magnificent  tree-fern, 
Alsophila  bmnoniaua,  Wall,  (of  which  a  stem  48  feet  long  has  been  in 
the  possession  of  the  British  Museum  since  1831),  does  not  grow  in  Ne- 
paul, but  is  found  on  the  mountains  of  Silhet,  to  the  northwest  of  Cal- 
cutta, in  lat.  24°  50'.  The  Nepaul  fern,  Paranema'cyathoides,  Don, 
formerly  known  as  Sphaeroptera  barbata,  Wall.  {Plantce  Asiat.,  lib.  i., 
p.  42,  48).  is,  indeed,  nearly  related  to  Cyathea,  a  species  of  which  I 
have  seen  in  the  South  American  Missions  of  Caripe,  measm-ing  33  feet 
in  height;  this  is  not,  however,  properly  speaking,  a  tree. 


30  CO&MOS. 

al  regions  are  to  be  found  even  on  the  highest  plateaux  of  the 
mountains.  On  the  slope  of  the  Himalaya,  under  the  shade 
of  the  Deodora  and  the  broad-leaved  oak,  peculiar  to  these 
Indian  Alps,  the  rocks  of  granite  and  of  mica  schist  are  cov- 
ered with  vegetable  forms  almost  similar  to  those  which  char- 
acterize Europe  and  Northern  Asia.  The  species  are  not 
identical,  but  closely  analogous  in  aspect  and  physiognomy,  as, 
for  instance,  the  juniper,  the  alpine  birch,  the  gentian,  the 
marsh  parnassia,  and  the  prickly  species  of  Ribes.*  The 
chain  of  the  Himalaya  is  also  wanting  in  the  imposing  phe- 
nomena of  volcanoes,  which  in  the  Andes  and  in  the  Indian 
Archipelago  often  reveal  to  the  inhabitants,  under  the  most 
terrific  forms,  the  existence  of  the  forces  pervading  the  inte- 
rior of  our  planet. 

Moreover,  on  the  southern  declivity  of  the  Himalaya,  where 
the  ascending  current  deposits  the  exhalations  rising  from  a 
vigorous  Indian  vegetation,  the  region  of  perpetual  snow  be- 
gins at  an  elevation  of  11,000  or  12,000  feet  above  the  level 
of  the  sea,t  thus  setting  a  limit  to  the  development  of  organic 

**  Ribes  iiubicola,  R.  glaciale,  R.  grossularia.  The  species  which 
compose  the  vegetation  of  the  Himalaya  are  four  pines,  notwithstanding 
the  assertion  of  the  ancients  regarding  Eastern  Asia  (Strabo,  lib.  11,  p. 
510,  Cas.),  twenly-five  oaks,  four  birches,  two  chestnuts,  seven  maples, 
twelve  willows,  fourteen  roses,  three  species  of  strawberry,  seven  spe- 
cies of  Alpine  roses  (rhododendra),  one  of  which  attains  a  height  of  20 
feet,  and  many  other  northern  genera.  Large  white  apes,  having  black 
faces,  inhabit  the  wild  chestnut-tree  of  Kashmir,  which  grows  to  a  height 
of  100  feet,  in  lat.  33°  (see  Carl  von  HUgel's  Kasckmir,  1840,  2d  pt. 
249).  Among  the  Coniferae,  we  find  the  Pinus  deodwara,  or  deodara 
(in  Sanscrit,  dewa-dar^i,  the  timber  of  the  gods),  which  is  nearly  allied 
to  Pinus  cedrus.  Near  the  limit  of  perpetual  snow  flourish  the  large 
and  showy  flowers  of  the  Gentiana  venusta,  G.  Moorcroftiaua,  Swertia 
purpurescens,  S.  speciosa,  Parnassia  armata,  P.  nubicola,  Poeonia  Emo- 
di,  Tulipa  stellata;  and,  besides  varieties  of  European  genera  peculiar 
to  these  Indian  mountains,  true  European  species,  as  Leontodon  tarax- 
acum, Prunella  vulgaris,  Galium  aparine,  and  Thlaspi  arvense.  The 
heath  mentioned  by  §aunders,  in  Turner's  Travels,  and  which  had  been 
confounded  with  Calluna  vulgaris,  is  an  Andromeda,  a  fact  of  the  great- 
est importance  in  the  geography  of  Asiatic  plants.  If  I  have  made  use, 
in  this  work,  of  the  uuphilosophical  expressions  of  Ejiropean  genera, 
European  species,  growing  wild  in  Asia,  &c.,  it  has  been  in  consequence 
of  the  old  botanical  language,  which,  instead  of  the  idea  of  a  large  dis- 
semination, or,  rather,  of  the  coexistence  of  organic  productions,  has 
dogmatically  substituted  the  false  hypothesis  of  a  migration,  which, 
fi'om  predilection*for  Europe,  is  further  assumed  to  have  been  from  west 
to  east, 

t  On  the  southern  declivity  of  the  Himalaya,  the  limit  of  perpetual 
Buow  is  12,978  feet  above  the  level  of  the  sea;  on  the  northern  decliv- 
ity, or,  rather,  on  the  peaks  which  rise  above  the  Thibet,  or  Tartarian 


INTKUIJUCIION.  3) 

ahi  in  a  zone  that  is  nearly  3000  feet  lower  than  that  to  which 
it  attains  in  the  equinoctial  region  of  the  Cordilleras. 

plateau,  this  limit  is  at  16,625  feet  from  20^°  to  32°  of  latitude,  whilt 
Bt  the  equator,  iu  the  Andes  of  Quito,  it  is  15,790  feet.     Such  is  the 
resuh  I  have  deduced  from  the  combiuatiou  of  numerous  data  famished 
by  Webb,  Gerard,  Herbert,  and  Moorcroft.     (See  my  two  memoirs  on 
the  mountains  of  India,  in  1816  and  1820,  iu  the  Ann.  de  CJdmie  et  di 
Physique,  t.  iii.,  p-  303  ;  t.  xiv.,  p.  6,  22,  50.)     The  greater  elevation  to 
which  the  Hmit  of  perpetual  snow  recedes  on  the  Tartarian  declivity 
is  owing  to  tlie  radiation  of  heat  from  the  neighboring  elevated  plains, 
to  tlie  purity  of  the  atmosphere,  and  to  the  infrequent  formation  of  snow 
in  an  air  which  is  both  very  cold  and  veiy  dry.     (Humboldt,  Asie  Cen 
trale,  t.  iii.,  p.  281-326.)     My  opinion  on  the  ditference  of  height  of 
the  snow-line  on  the  two  sides  of  the  Himalaya  has  the  high  authority 
of  Colebrooke  in  its  favor.     He  wrote  to  me  in  June,  1824,  as  follows: 
"  I  also  find,  from  the  data  in  my  possession,  that  the  elevation  of  the 
iiue  of  perpetual  snow  is  13,000  feet.     On  the  southern  declivity,  and 
at  latitude  31*^,  Webb's  measurements  give  me  13,500  feet,  consequently 
500  i'eet  more  than  the  height  deduced  from  Captain  Hodgson's  oh 
servations.     Gerard's  measurements  fully  confirm  your  opinion  tha' 
the  hue  of  snow  is  higher  on  the  northern  than  on  the  southern  side.' 
<t  was  not  until  the  present  year  (1840)  that  we  obtained  the  complett 
and  collected  journal  of  the  brothers  Gerard,  published  under  the  su 
pervision  of  Mr.  Lloyd.     {Narrative  of  a  Journey  from  Caionpoor  h 
the  Boorendo  Pass,  in  the  Himalaya,  by  Captain  Alexander  Gerard  ant 
John  Gerard,  edited  by  George  Lloyd,  vol.  i.,  p.  291,  311,  320,  327,  an< 
^Ml.)     Many  interesting  details  regarding  some  localities  may  be  fount  ■ 
in  tlie  narrative  of  A  Visit  to  the  Shatool,for  the  Ptirpose  of  determinin. 
the  Line  of  Perpetual  Stiow  on  the  southern  face  of  the  Himalaya,  in  At 
gust,  1822.     Unfortunately,  however,  these  travelers  always  confoun 
the  elevation  at  which  sporadic  snow  falls  with  the  maximum  of  th 
height  that  the  snow-line  attains  on  the  Thibetian  plateau.     Captaii 
Gerard  distinguishes  between  the  summits  that  rise  in  the  middle  o 
the  plateau,  where  he  states  the  elevation  of  the  snow-line  to  be  b( 
*ween  18,000  and  19,000  feet,  and  the  northern  slopes  of  the  chain  o 
»he  Himalaya,  which  border  on  the  defile  of  the  Sutledge,  and  can  ri 
diate  but  little  heat,  owing  to  the  deep  ravines  with  which  they  ai  ^ 
intersected.     The  elevation  of  the  village  of  Tangno  is  given  at  onl » 
9300  feet,  while  that  of  the  plateau  surrounding  the  sacred  lake  of  Mj. 
nasa  is  17,000  feet.     Captain  Geraixl  finds  the  snow^-line  500  feet  lowt  >. 
on  the  northern  slopes,  where  the  chain  of  the  Himalaya  is  broke  i 
through,  than  toward  the  southern  declivities  facing  Hindostan,  and  h  • 
'.here  estimates  the  line  of  perpetual  snow  at  15,000  feet.     The  moi 
striking  difierences  are  presented  between  the  vegetation  on  the  Thil 
etian  plateau  and  that  characteristic  of  the  southern  slopes  ot  the  Hin 
alaya.     On  the  latter  the  cultivation  of  grain  is  arrested  at  9974  fee. 
and  even  there  the  corn  has  often  to  be  cut  when  the  blades  are  sti., 
green.     The  extreme  limit  of  forests  of  tali  oaks  and  deodars  is  11,900 
feet ;  that  of  dwarf  birches,  12,983  feet.     On  the  plains.  Captain  Gerard 
found  pastures  up  to  the  height  of  17,000  feet;  the  cereals  will  grow  ui 
14,100  feet,  or  even  at  18,540  feet;  birches  with  tall  stems  at  14,100 
feet,  and  copse  or  brush  wood  applicable  for  fuel  is  found  at  an  elevti 
tioa  of  upward  of  17,000  feet,  that  is  to  say,  1280  feet  above  the  lowej 
limits  of  the  snow-line  at  the  equator,  in  the  province  of  Quito.     It  is- 


H2  cosMv  s. 

But  the  countries  bordering  on  the  equator  possess  anoihei 
advantage,  to  which  sufficient  attentign  has  not  hitherto  been 

very  desirable  that  the  mean  elevation  of  the  Thibetiaii  plateau,  which 
I  have  estimated  at  ouly  about  8200  feet  between  the  Himalaya  and 
the  Kuen-lun,  and  the  difference  in  the  height  of  the  line  of  perpetual 
snow  on  the  southern  and  on  the  northern  slopes  of  the  Himalaya,  should 
be  again  ihvestigated  by  travelers  who  are  accustomed  to  judge  of  the 
general  conformation  of  the  land.  Hitherto  simple  calculations  have  too 
often  been  confounded  with  actual  measurements,  and  the  elevations 
of  isolated  summits  with  that  of  the  surrounding  plateau.  (Compare 
Carl  Zimmerman's  excellent  Hypsometrical  Kemarks  in  his  Geograph- 
isclien  Analyse  der  Karte  von  Inner  Asien,  1841,  s.  08.)  Lord  draws 
attention  to  the  difference  presented  by  the  two  faces  of  the  Himalaya 
and  those  of  the  Alpine  chain  of  Hindoo-Coosh,  with  respect  to  the 
limits  of  the  snow-line.  "  The  latter  chain,"  he  says,  "has  the  table- 
land to  the  south,  in  consequence  of  which  the  snow-line  is  higher  on 
the  southern  side,  contrary  to  what  we  find  to  be  the  case  with  respect 
to  the  Himalaya,  which  is  bounded  on  the  south  by  sheltered  plains, 
as  Hindoo-Coosh  is  on  the  north."  It  must,hov/ever,be  admitted  that 
the  hypsometrical  data  on  which  these  statements  are  based  require  a 
critical  revision  with  regard  to  several  of  their  details;  but  still  they 
sufSce  to  establish  the  main  fact,  that  the  remarkable  configuration  of 
the  laud  in  Central  Asia  affords  man  all  that  is  essential  to  the  mainte- 
nance of  life,  as  habitation,  food,  and  fuel,  at  an  elevation  above  the 
level  of  the  sea  which  in  almost  all  other  parts  of  the  globe  is  covered 
with  perpetual  ice.  We  must  except  the  very  dry  districts  of  Bolivia, 
where  snow  is  so  rarely  met  with,  and  where  Pentland  (in  1838)  fixed 
the  snov/-line  at  15,667  feet,  between  16°  and  17|°  south  latitude.  The 
opinion  that  I  had  advanced  regarding  the  difference  in  the  snow-line 
on  the  two  faces  of  the  Himalaya  has  heen  most  fully  confirmed  by  the 
barometrical  observations  of  Victor  Jacquemont,  who  fell  an  early  sac- 
I'ifice  to  his  noble  and  unwearied  ardor.  (See  his  Correspondanc& 
pendant  son  Voyage  dans  V Inde,  1828  a  1832,  hv.  23,  p.  290,  296,299.) 
"  Perpetual  snow,"  says  Jacquemont,  "  descends  lower  on  the  southern 
than  on  the  northern  slopes  of  the  Himalaya,  and  the  limit  constantly? 
rises  as  we  advance  to  the  north  of  the  chain  bordering  on  India.  On 
the  Kioubrong,  about  18,317  feet  in  elevation,  according  to  Captain 
Gerard,  I  was  still  considerably  below  the  limit  of  perpetual  snow, 
which  I  believe  to  be  19,690  feet  in  this  part  of  Hindostan."  (This 
estimate  I  consider  much  too  high.) 

The  same  ti-aveler  says,  "  To  whatever  height  we  rise  on  the  south- 
ern declivity  of  the  Himalaya,  the  climate  retains  the  same  character, 
and  the  same  division  of  the  seasons  as  in  the  plains  of  India ;  the  sum- 
mer solstice  being  eveiy  year  marked  by  the  same  prevalence  of  rain, 
w^hich  continues  to  fall  without  intermission  until  the  autumnal  equi- 
nox. But  a  new,  a  totally  different  climate  begins  at  Kashmir,  whose 
elevation  I  estimate  to  be  5350  feet,  nearly  equal  to  that  of  the  cities 
of  Mexico  and  Popayan"  {Correspond,  de  Jacquemont,  t.  ii.,  p.  58  et  74), 
The  warm  and  humid  air  of  the  sea,  as  Leopold  von  Buch  well  observes, 
is  carried  by  the  monsoons  across  the  plains  of  India  to  the  skirts  of 
the  Himalaya,  which  arrest  its  couise,  and  hinder  it  from  diverging  to 
the  Thibetian  districts  of  Ladak  and  Lassa.  Carl  von  HUgel  estimates 
the  elevation  of  the  Valley  of  Kashmir  above  the  level  of  the  sea  at 
5818  feet,  and  bases  his  observation  on  the  determination  of  the  boiling 


INTRODUCTION.  33 

directed.  This  portion  of  the  surface  of  the  globe  affords  in 
the  smallest  space  the  greatest  possible  variety  of  impressions 
from  the  contemplation  of  nature.  Among  the  colossal  mount- 
ains of  Cundinamarca,  of  Quito,  and  of  Peru,  furrowed  by 
deep  ravines,  man  is  enabled  to  contemplate  alike  all  the  fam- 
ilies of  plants,  and  all  the  stars  of  the  firmament.  There,  at 
a  single  glance,  the  eye  surveys  majestic  palms,  humid  forests 
of  bambusa,  and  the  varied  species  of  Musacese,  while  above 
these  forms  of  tropical  vegetation  appear  oaks,  medlars,  the 
sweet-brier,  and  umbelliferous  plants,  as  in  our  European 
homes.  There,  as  the  traveler  turns  his  eyes  to  the  vault  of 
heaven,  a  single  glance  embraces  the  constellation  of  the  South- 
ern Cross,  the  Magellanic  clouds,  and  the  guiding  stars  of  the 
constellation  of  the  Bear,  as  they  circle  round  the  arctic  pole. 
There  the  depths  of  the  earth  and  the  vaults  of  heaven  dis- 
play all  the  richness  of  their  forms  and  the  variety  of  their 
phenomena.  There  the  different  climates  are  ranged  the  one 
above  the  other,  stage  by  stage,  like  the  vegetable  zones,  whose 
succession  they  limit  ;  and  there  the  observer  may  readily 
trace  the  laws  that  regulate  the  diminution  of  heat,  as  they 
stand  indelibly  inscribed  on  the  rocky  walls  and  abrupt  decliv- 
ities of  the  Cordilleras. 

Not  to  M'-eary  the  reader  with  the  details  of  the  phenomena 
which  I  long  since  endeavored  graphically  to  represent,*  I 
will  here  limit  myself  to  the  consideration  of  a  few  of  the  gen- 
eral results  whose  combination  constitutes  the  i^liy^ical  delhie- 
ation  of  the  torrid  zone.     That  which,  m  the  vagueness  of  our 

point  of  water  (see  theil  11,  s.  155,  and  Journal  of  Geog.  Soc,  vol.  vi., 
p.  215).  In  this  valley,  where  the  atmosphere  is  scarcely  ever  agita- 
ted by  storms,  and  in  34°  7'  lat.,  snow^  is  found,  several  feet  in  thick- 
ness, from  December  to  March. 

*  See,  generally,  my  Essai  sur  la  Geographie  des  Plantes,  et  le  Ta- 
bleau physique  des  Regions  Equinoxiales,  1807,  p.  80-88.  On  the  diur- 
nal and  nocturnal  variations  of  temperatui'e,  see  Plate  9  of  my  Atlas 
Geogr.  et  Phys.  du  Nouveau  Continent;  and  the  Tables  in  my  work, 
entitled  De  distributione  Geographica  Plantarum,  secundum  cosli  tempe- 
riem,  et  altitudinem  Montium,  1817,  p.  90-116  ;  the  meteorological  por- 
tion of  my  Asie  Centrale,  t.  iii.,  p.  212,  224;  and,  finally,  the  more 
receut  and  far  more  exact  exposition  of  the  variations  of  temperature 
experienced  in  correspondence  with  the  increase  of  altitude  on  the  chain 
of  the  Andes,  given  in  Boussiugault's  Memoir,  Sur  la  profondeur  a  la- 
quelle  on  trouve,  sous  les  Tropiques,  la  coucke  de  Temperature  Invaria- 
ble. (Ann.  de  Chimie  et  de  Physique,  1833,  t.  liii.,  p.  225-247.)  This 
treatise  contains  the  elevations  of  128  points,  included  between  the 
level  of  the  sea  and  the  declivity  of  the  Antisana  (17,900  feet),  as  well 
as  the  mean  temperature  of  the  atmosphere,  which  varies  with  the 
height  between  81°  and  35°  F. 

B2 


34  COSMOS. 

impressions,  loses  all  distinctness  of  form,  like  some  distant 
mountain  shrouded  from  view  by  a  vail  of  mist,  is  clearly  re- 
vealed by  the  light  of  mind,  which,  by  its  scrutiny  into  the 
causes  of  phenomena,  learns  to  resolve  and  analyze  their  dif- 
ferent elements,  assigning  to  each  its  individual  character. 
Thus,  in  the  sphere  of  natural  investigation,  as  in  poetry  and 
painting,  the  delineation  of  that  which  appeals  most  strong- 
ly to  the  imagination,  derives  its  collective  interest  from  the 
vivid  truthfulness  with  which  the  individual  features  are  por- 
trayed. 

The  regions  of  the  torrid  zone  not  only  give  rise  to  the 
most  powerful  impressions  by  their  organic  richness  and  their 
abundant  fertility,  but  they  likewise  afford  the  inestimable 
advantage  of  revealing  to  man,  by  the  uniformity  of  the  vari- 
ations of  the  atmosphere  and  the  development  of  vital  forces, 
and  by  the  contrasts  of  climate  and  vegetation  exhibited  at 
different  elevations,  the  invariability  of  the  laws  that  regulate 
the  course  of  the  heavenly  bodies,  reflected,  as  it  were,  in  ter- 
restrial phenomena.  Let  us  dwell,  then,  for  a  few  moments, 
on  the  proofs  of  this  regularity,  which  is  such  that  it  may  be 
submitted  to  numerical  calculation  and  computation. 

In  the  burning  plains  that  rise  but  little  above  the  level  of 
the  sea,  reign  the  families  of  the  banana,  the  cycas,  and  the 
palm,  of  wliich  the  number  of  species  comprised  in  the  flora 
of  tropical  regions  has  been  so  wonderfully  increased  in  the 
present  day  by  the  zeal  of  botanical  travelers.  To  these 
groups  succeed,  in  the  Alpine  valleys,  and  the  humid  and 
shaded  clefts  on  the  slopes  of  the  Cordilleras,  the  tree-ferns, 
whose  thick  cylindrical  trunks  and  delicate  lace-like  foliage 
stand  out  in  bold  relief  against  the  azure  of  the  sky,  and  the 
cinchona,  from  which  we  derive  the  febrifuge  bark.  The 
medicinal  strength  of  this  bark  is  said  to  increase  in  propor- 
tion to  the  degree  of  moisture  imparted  to  the  foliage  of  the 
tree  by  the  light  mists  which  form  the  upper  surface  of  the 
clouds  resting  over  the  plains.  Every  where  around,  the  con- 
fines of  the  forest  are  encircled  by  broad  bands  of  social  plants, 
as  the  delicate  aralia,  the  thibaudia,  and  the  myrtle-leaved 
Andromeda,  while  the  Alpine  rose,  the  magnificent  befaria, 
weaves  a  purple  girdle  round  the  spiry  peaks.  In  the  cold 
regions  of  the  Paramos,  which  is  continually  exposed  to  the 
fury  of  storms  and  winds,  we  find  that  flowering  shrubs  and 
herbaceous  plants,  bearing  large  and  variegated  blossoms, 
h^ve  given  place  to  monocotyledons,  whose  slender  spikes  con- 
it"*,ute  the  sole  covering  of  the  soil.     This  is  the  zone  of  the 


INTRODUCTION.  35 

glasses,  one  vast  savannah  extending  over  the  immense  mount- 
ain-plateaux,  and  reflecting  a  yellow,  almost  golden  tinge,  tc 
the  slopes  of  the  Cordilleras,  on  which  graze  the  lama  and  the 
cattle  domesticated  by  the  European  colonist.  Where  the 
naked  trachyte  rock  pierces  the  grassy  turf,  and  penetrates  into 
those  higher  strata  of  air  which  are  supposed  to  be  less  charged 
with  carbonic  acid,  we  meet  only  with  plants  of  an  inferior  or- 
ganization, as  lichens,  lecideas,  and  the  brightly-colored,  dust- 
like lepraria,  scattered  around  in  circular  patches.  Islets  of 
fresh-fallen  snow,  varying  in  form  and  extent,  arrest  the  last 
feeble  traces  of  vegetable  development,  and  to  these  succeeds 
the  region  of  perpetual  snow,  whose  elevation  undergoes  but 
little  change,  and  may  be  easily  determined.  It  is  but  rarely 
that  the  elastic  forces  at  work  within  the  interior  of  our  globe 
have  succeeded  in  breaking  through  the  spiral  domes,  which, 
resplendent  in  the  brightness  of  eternal  snow,  crown  the  sum- 
mits of  the  Cordilleras  ;  and  even  where  these  subterranean 
forces  have  opened  a  permanent  communication  with  the  at- 
mosphere, through  circular  craters  or  long  fissures,  they  rarelj 
send  forth  currents  of  lava,  but  merely  eject  ignited  scoriae, 
steam,  sulphureted  hydrogen  gas,  and  jets  of.  carbonic  acid. 

In  the  earhest  stages  of  civilization,  the  grand  and  imposing 
spectacle  presented  to  the  minds  of  the  inhabitants  of  the  trop- 
ics could  only  awaken  feelings  of  astonishment  and  awe.  Il 
might,  perhaps,  be  supposed,  as  we  have  already  said,  that  the 
periodical  return  of  the  same  phenomena,  and  the  uniform  man- 
ner in  which  they  arrange  themselves  in  successive  groups, 
would  have  enabled  man  more  readily  to  attain  to  a  knowl- 
edge of  the  laws  of  nature  ;  but,  as  far  as  tradition  and  history 
guide  us,  we  do  not  find  that  any  application  was  made  of  the 
advantages  presented  by  these  favored  regions.  Recent  re- 
searches have  rendered  it  very  doubtful  whether  the  primitive 
seat  of  Hindoo  civihzation — one  of  the  most  remarkable  phase.' 
in  the  progress  of  mankind — was  actually  within  the  tropics 
Airyana  Vaedjo,  the  ancient  cradle  of  the  Zend,  was  situatec 
to  the  northwest  of  the  upper  Indus,  and  after  the  great  re 
ligious  schism,  that  is  to  say,  after  the  separation  of  the  Ir:i 
uians  from  the  Brahminical  institution,  the  language  that  ha« 
previously  been  common  to  them  and  to  the  Hindoos  assume' 
among  the  latter  people  (together  with  the  hterature,  habit: 
and  condition  of  society)  an  individual  form  in  the  Magodha  oi 
Madhya  Desa,*  a  district  that  is  bounded"  by  the  great  chaii. 

*  See,  on  the  Madhjadecja,  properly  so  called,  Lassen's  exceilei 
work,  entitled  Indische  Altcrthumskun'de,  bd.  i.,  s.  92.     The  Chinest 


S6  cosivros. 

oi'  Himalaya  and  the  smaller  range  of  the  Vindhya.  In  less 
ancient  times  the  Sanscrit  language  and  civilization  advanced 
tovi^ard  the  southeast,  penetrating  further  within  the  torrid  zone, 
as  my  brother  Wilhelm  von  Humboldt  has  shov^^n  in  his  great 
work  on  the  Kavi  and  other  languages  of  analogous  structure.* 

Notwithstanding  the  obstacles  opposed  in  northern  latitudes 
to  the  discovery  of  the  laws  of  nature,  owing  to  the  excessive 
complication  of  phenomena,  and  the  perpetual  local  variations 
that,  in  these  climates,  afiect  the  movements  of  the  atmosphere 
and  the  distribution  of  organic  forms,  it  is  to  the  inhabitants 
of  a  small  section  of  the  temperate  zone  that  the  rest  of  man- 
kind owe  the  earliest  revelation  of  an  intimate  and  rational 
acquaintance  with  the  forces  governing  the  physical  world. 
Moreover,  it  is  from  the  same  zone  (which  is  apparently  more 
favorable  to  the  progress  of  reason,  the  softening  of  manners, 
and  the  security  of  public  liberty)  that  the  germs  of  civiliza- 
tion have  been  carried  to  the  regions  of  the  tropics,  as  much 
by  the  migratory  movement  of  races  as  by  the  establishment 
of  colonies,  differing  widely  in  their  institution  from  those  of 
the  Phoenicians  or  Greeks. 

In  speaking  of  the  influence  exercised  by  the  succession  of 
phenomena  on  the  greater  or  lesser  facility  of  recognizing  the 
causes  producing  them,  I  have  touched  upon  that  important 
stage  of  our  communion  with  the  external  world,  when  the  en- 
joyment arising  from  a  knowledge  of  the  laws,  and  the  mutual 
connection  of  phenomena,  associates  itself  with  the  charm  of 
a  simple  contemplation  of  nature.  That  which  for  a  long 
time  remains  merely  an  object  of  vague  intuition,  by  degrees 
acquires  the  certainty  of  positive  truth  ;  and  man,  as  an  im- 
mortal poet  has  said,  in  our  own  tongue — Amid  ceaseless 
change  seeks  the  unchanging  pole.f 

In  order  to  trace  to  its  primitive  source  the  enjoyment  de- 
rived from  the  exercise  of  thought,  it  is  sufficient  to  cast  a 
J:apid  glance  on  the  earliest  dawnings  of  the  philosophy  of  na- 
ture, or  of  the  ancient  doctrine  of  the  Cosmos.     We  find  even 

give  the  name  of  Mo-kie-thi  to  the  southern  Bahar,  situated  to  the 
south  of  the  Ganges  (see  Foe-Koue-Ki,  by  Chy-Fa-Hian,  1836,  p.  256). 
Djambu-dwipa  is  the  name  given  to  the  whole  of  India;  but  the  words 
also  indicate  one  of  the  four  Buddhist  continents. 

*  Ueber  die  Kawi  Sprache  aiif  der  Insel  Java,  nebst  einer  Einleiijinff 
iiber  die  Verschiedenheit  des  menschlichen  Spra^'hbaiies  und  ihren  Ein 
fluss  auf  die  geistige  Entwickelung  des  Mensckengeschlechf  s,  von  Wil 
helm  V.  Humboldt,  1836,  bd.  i.,  s.  5-510. 

t  This  verse  occurs  in  a  poem  of  Schiller,  entitled  Der  Spaziergayig 
which  first  appeared  in  1795,  in  the  Horen. 


INTRODUCTION.  37 

among  the  most  savage  nations  (as  my  own  travels  enable  me 
to  attest)  a  certain  vague,  terror-stricken  sense  of  the  all-pow- 
erful unity  of  natural  forces,  and  of  the  existence  of  an  invisi- 
ble, spiritual  essence  manifested  in  these  forces,  whether  in 
unfolding  the  flower  and  maturing  the  fruit  of  the  nutrient 
tree,  in  upheaving  the  soil  of  the  forest,  or  in  rending  the  clouds 
with  the  might  of  the  storm.  We  may  here  trace  the  revela- 
tion of  a  bond  of  union,  linking  together  the  visible  world  and 
that  higher  spiritual  world  which  escapes  the  grasp  of  the 
senses.  The  two  become  unconsciously  blended  together,  de- 
veloping in  the  mind  of  man,  as  a  simple  product  of  ideal  con- 
ception, and  independently  of  the  aid  of  observation,  the  first 
germ  of  a  Fhiloioiohy  of  Nature. 

Among  nations  least  advanced  in  civilization,  the  imagina- 
tion revels  in  strange  and  fantastic  creations,  and,  by  its  pre- 
dilection for  symbols,  alike  influences  ideas  and  language.  In- 
stead of  examining,  men  are  led  to  conjecture,  dogmatize,  and 
interpret  supposed  facts  that  have  never  been  observed.  The 
inner  world  of  thought  and  of  feelins:  does  not  reflect  the  imajje 
of  the  external  world  in  its  primitive  purity.  That  which  in 
some  regions  of  the  earth  manifested  itself  as  the  rudiments 
of  natural  philosophy,  only  to  a  small  number  of  persons  en- 
dowed with  superior  inteUigence,  appears  in  other  regions,  and 
among  entire  races  of  men,  to  be  the  result  of  mystic  tenden- 
cies and  instinctive  intuitions.  An  intimate  communion  with 
nature,  and  the  vivid  and  deep  emotions  thus  awakened,  are 
likewise  the  source  from  which  have  sprung  the  first  impulses 
toward  the  worship  and  deification  of  the  destroying  and  pre- 
serving forces  of  the  universe.  But  by  degrees,  as  man,  after 
having  passed  through  the  different  gradations  of  intellectual 
development,  arrives  at  the  free  enjo}rment  of  the  regulating 
power  of  reflection,  and  learns  by  gradual  progress,  as  it  were, 
to  separate  the  world  of  ideas  from  that  of  sensations,  he  no 
longer  rests  satisfied  merely  with  a  vague  presentiment  of  the 
harmonious  unity  of  natural  forces ;  thought  begins  to  fulfill 
its  noble  mission  ;  and  observation,  aided  by  reason,  endeav- 
ors to  trace  phenomena  to  the  causes  from  which  they  spring 

The  history  of  science  teaches  us  the  difficulties  that  have 
opposed  the  progress  of  this  active  spirit  of  inquiry.  Inaccu 
rate  and  imperfect  observations  have  led,  by  false  inductions, 
to  the  great  number  of  physical  views  that  have  been  perpet- 
uated as  popular  prejudices  among  all  classes  of  society.  Thus 
by  the  side  of  a  solid  and  scientific  knowledge  of  natural  phe- 
nomena there  has  been  preserved  a  system  of  the  pretended 


38  COSMOS. 

results  of  observation,  which  is  so  much  the  more  difficult  to 
shake,  as  it  denies  the  vahdity  of  the  facts  by  which  it  may 
be  refuted.  This  empiricism,  the  melancholy  heritage  trans- 
mitted to  us  from  former  times,  invariably  contends  for  the 
truth  of  its  axioms  with  the  arrogance  of  a  narrow-minded 
spirit.  Physical  philosophy,  on  the  other  hand,  when  based 
upon  science,  doubts  because  it  seeks  to  investigate,  distin- 
guishes between  that  which  is  certain  and  that  which  is  mere- 
ly probable,  and  strives  incessantly  to  perfect  theory  by  ex- 
tending the  circle  of  observation. 

This  assemblage  of  imperfect  dogmas,  bequeathed  by  one- 
age  to  another — this  physical  philosophy,  which  is  composed 
of  popular  prejudices — is  not  only  injurious  because  it  perpet- 
uates error  with  the  obstinacy  engendered  by  the  evidence  of 
ill-observed  facts,  but  also  because  it  hinders  the  mind  from 
attaining  to  higher  views  of  nature.  Instead  of  seeking  to 
discover  the  mean  or  medium  point,  around  which  oscillate, 
in  apparent  iiidependence  offerees,  all  the  phenomena  of  the 
external  world,  this  system  delights  in  multiplying  exceptions 
to  the  law,  and  seeks,  amid  phenomena  and  in  organic  forms, 
for  something  beyond  the  marvel  of  a  regular  succession,  and 
an  internal  and  progressive  development.  Ever  inclined  to 
beheve  that  the  order  of  nature  is  disturbed,  it  refuses  to  rec 
ognize  in  the  present  any  analogy  with  the  past,  and,  guided 
by  its  own  varying  hypotheses,  seeks  at  hazard,  either  in  the 
interior  of  the  globe  or  in  the  regions  of  space,  for  the  cause 
of  these  pretended  perturbations. 

It  is  the  special  object  of  the  present  work  to  combat  those 
errors  which  derive  their  source  Irom  a  vicious  empiricism  and 
from  imperfect  inductions.  The  higher  enjoyments  yielded  by 
the  study  of  nature  depend  upon  the  correctness  and  the  depth 
of  our  views,  and  upon  the  extent  of  the  subjects  that  maybe 
comprehended  in  a  single  glance.  Increased  mental  cultiva- 
tion has  given  rise,  in  all  classes  of  society,  to  an  increased  de- 
sire of  embellishing  life  by  augmenting  the  mass  of  ideas,  and 
by  multiplying  means  for  their  generalization  ;  and  this  sen- 
timent fully  refutes  the  vague  accusations  advanced  against 
the  age  in  which  we  live,  showing  that  other  interests,  be- 
sides the  material  wants  of  life,  occupy  the  minds  of  men. 

It  is  almost  with  reluctance  that  I  am  about  to  speak  of  a 
sentiment,  which  appears  to  arise  from  narrow-minded  views, 
or  from  a  certain  weak  and  morbid  sentimentality — I  alludo 
to  thejTear  entertained  by  some  persons,  that  nature  rnay  by 
degrees  lose  a  portion  of  the  charm  and  magic  of  her  power. 


INTRODUCTION.  39 

4S  we  learn  more  and  more  how  to  nnvail  her  secrets,  com- 
prehend the  mechanism  of  the  movements  of  the  heavenly 
bodies,  and  estimate  numerically  the  intensity  of  natural  forces. 
It  is  true  that,  properly  speaking,  the  forces  of  nature  can  only 
exercise  a  magical  power  over  us  as  long  as  their  action  is 
ehrouded  in  mystery  and  darkness,  and  does  not  admit  of  be- 
mg  classed  among  the  conditions  with  which  experience  has 
made  us  acquainted.  The  effect  of  such  a  power  is,  there- 
fore, to  excite  the  imagination,  but  that,  assuredly,  is  not  the 
faculty  of  mind  we  would  evoke  to  preside  over  the  laborious 
and  elaborate  observations  by  which  we  strive  to  attain  to  a 
knowledge  of  the  greatness  and  excellence  of  the  laws  of  the 
universe. 

The  astronomer  who,  by  the  aid  of  the  heliometer  or  a 
double-refracting  prism,*  determines  the  diameter  of  planetary 
bodies  ;  who  measures  patiently,  year  after  year,  the  meridian 
altitude  and  the  relative  distances  of  stars,  or  who  seeks  a  tel 
escopic  comet  in  a  group  of  nebulae,  does  not  feel  his  imagina- 
tion more  excited — and  this  is  the  very  guarantee  of  the  pre- 
cision of  his  labors — than  the  botanist  who  counts  the  divi- 
sions of  the  calyx,  or  the  number  of  stamens  in  a  flower,  or  ex- 
amines the  connected  or  the  separate  teeth  of  the  peristoma 
surrounding  the  capsule  of  a  moss.  Yet  the  multiplied  an- 
gular measurements  on  the  one  hand,  and  the  detail  of  organic 
relations  on  the  other,  alike  aid  in  preparing  the  way  for  the 
attainment  of  higher  views  of  the  laws  of  the  universe. 

We  must  not  confound  the  disposition  of  mind  in  the  ob- 
server at  the  time  he  is  pursuing  his  labors,  with  the  ulterior 
greatness  of  the  views  resulting  from  investigation  and  the 
exercise  of  thought.  The  physical  philosopher  measures  with 
admirable  sagacity  the  waves  of  light  of  unequal  length  which 
by  interference  mutually  strengthen  or  destroy  each  other, 
even  with  respect  to  their  chemical  actions  ;  the  astronomer, 
armed  with  powerful  telescopes,  penetrates  the  regions  of 
space,  contemplates,  on  the  extremest  confines  of  our  solar 
system,  the  satellites  of  Uranus,  or  decomposes  faintly  spark- 
ling points  into  double  stars  differing  in  color.  The  botanist 
discovers  the  constancy  of  the  gyratory  motion  of  the  chara  in 
the  greater  number  of  vegetable  cells,  and  recognizes  in  the 
genera  and  natural  families  of  plants  the  intimate  relations 
of  organic  forms.     The  vault  of  heaven,  studded  with  nebu- 

*  Arago's  ocular  micrometer,  a  happy  improvement  upon  Rochou'a 
prismatic  or  double-refraction  micrometer.  See  M.  Mathieu's  note  ii 
Delambre's  Histoire  de  V Astronomic  au  dix-huUieme  Siecle,  1827. 


40  COSMOS 

IsL'  and  stars,  and  the  rich  vegetable  mantle  that  covers  the 
soil  in  the  climate  of  palms,  can  not  surely  fail  to  produce  on 
the  minds  of  these  laborious  observers  of  nature  an  impression 
more  imposing  and  more  w^orthy  of  the  majesty  of  creation 
than  on  those  who  are  unaccustomed  to  investigate  the  great 
mutual  relations  of  phenomena.  I  can  not,  therefore,  agree 
with  Burke  when  he  says,  "it  is  our  ignorance  of  natural 
things  that  causes  all  our  admiration,  and  chiefly  excites  our 
passions." 

While  the  illusion  of  the  senses  would  make  the  stars  sta- 
tionary in  the  vault  of  heaven.  Astronomy,  by  her  aspiring  la- 
bors, has  assigned  indefinite  bounds  to  space  ;  and  if  she  have 
set  limits  to  the  great  nebula  to  which  our  solar  system  be- 
longs, it  has  only  been  to  show  us  in  those  remote  regions  of 
space,  which  appear  to  expand  in  proportion  to  the  increase 
of  our  optic  powers,  islet  on  islet  of  scattered  nebulce.  The 
feeling  of  the  sublime,  so  far  as  it  arises  from  a  contemplation 
of  the  distance  of  the  stars,  of  their  greatness  and  physical  ex- 
tent, reflects  itself  in  the  feeling  of  the  infinite,  which  belongs 
to  another  sphere  of  ideas  included  in  the  domain  of  mind. 
The  solemn  and  imposing  impressions  excited  by  this  senti- 
ment are  owing  to  the  combination  of  which  we  have  spoken, 
and  to  the  analogous  character  of  the  enjoyment  and  emotions 
awakened  in  us,  whether  we  float  on  the  surface  of  the  great 
deep,  stand  on  some  lonely  mountain  summit  enveloped  in  the 
half  transparent  vapory  vail  of  the  atmosphere,  or  by  the  aid 
of  powerful  optical  instruments  scan  the  regions  of  space,  and 
see  the  remote  nebulous  mass  resolve  itself  into  worlds  of  stars. 

The  mere  accumulation  of  unconnected  observations  of  de- 
tails, devoid  of  generalization  of  ideas,  may  doubtlessly  have 
tended  to  create  and  foster  the  deeply-rooted  prejudice,  that 
the  study  of  the  exact  sciences  must  necessarily  chill  the  feel- 
ings, and  diminish  the  nobler  enjoyments  attendant  upon  a 
contemplation  of  nature.  Those  who  still  cherish  such  erro 
neous  views  in  the  present  age,  and  amid  the  progress  of  pub- 
lic opinion,  and  the  advancement  of  all  branches  of  knowledge, 
fail  in  duly  appreciating  the  value  of  every  enlargement  of  th(; 
sphere  of  intellect,  and  the  importance  of  the  detail  of  isolated 
facts  in  leading  us  on  to  general  results.  The  fear  of  sacri 
ficing  the  free  enjoyment  of  nature,  under  the  influence  of"  sci- 
entific reasoning,  is  often  associated  with  an  apprehension 
that  every  mind  may  not  be  capable  of  grasping  the  truths 
of  the  philosophy  of  nature.  It  is  certainly  true  that  in  the 
midst  of  the  universal  fluctuation  of  phenomena  and  vital 


INTRODUCTION.  41 

forces — ill  that  inextricable  net- work  of  organisms  by  turns 
developed  and  destroyed — each  step  that  we  make  in  the 
more  intimate  knowledge  of  nature  leads  us  to  the  entrance 
of  new  labyrinths  ;  but  the  excitement  produced  by  a  presenti- 
ment of  discovery,  the  vague  intuition  of  the  mysteries  to  be 
unfolded,  and  the  multiplicity  of  the  paths  before  us,  all  tend 
to  stimulate  the  exercise  of  thought  in  every  stage  of  knowl- 
edge. The  discovery  of  each  separate  law  of  nature  leads  to 
the  establishment  of  some  other  more  general  law,  or  at  least 
indicates  to  the  intelligent  observer  its  existence.  Nature,  as 
a  celebrated  physiologist*  has  defined  it,  and  as  the  word  was 
interpreted  by  the  Greeks  and  Romans,  is  "  that  which  is  ever 
growing  and  ever  unfolding  itself  in  new  forms." 

The  series  of  organic  types  becomes  extended  or  perfected 
in  proportion  as  hitherto  unknown  regions  are  laid  open  to  our 
view  by  the  labors  and  researches  of  travelers  and  observers  ; 
as  living  organisms  are  compared  with  those  which  have  dis- 
appeared in  the  great  revolutions  of  our  planet ;  and  as  micro- 
scopes are  made  more  perfect,  and  are  more  extensively  and 
efficiently  employed.  In  the  midst  of  this  immense  variety, 
and  this  periodic  transformation  of  animal  and  vegetable  pro- 
ductions, we  see  incessantly  revealed  the  primordial  mystery 
of  all  organic  development,  that  same  great  problem  of  meta- 
Tnorpliosis  which  Gothe  has  treated  with  more  than  common 
sagacity,  and  to  the  solution  of  which  man  is  urged  by  his 
desire  of  reducuiEr  vital  forms  to  the  smallest  number  of  fun- 
damental  types.  As  men  contemplate  the  riches  of  nature, 
and  see  the  mass  of  observations  incessantly  increasing  be- 
fore them,  they  become  impressed  with  the  intimate  convic- 
tion that  the  surface  and  the  interior  of  the  earth,  the  depths 
of  the  ocean,  and  the  regions  of  air  will  still,  when  thousands 
and  thousands  of  years  have  passed  away,  open  to  the  scien- 
tific observer  untrodden  paths  of  discovery.  The  regret  of 
Alexander  can  not  be  appUed  to  the  progress  of  observation 
and  intelligence.!  General  considerations,  whether  they  treat 
of  the  agglomeration  of  matter  in  the  heavenly  bodies,  or  of 
the  geographical  distribution  of  terrestrial  organisms,  are  not 
only  in  themselves  more  attractive  than  special  studies,  but 
they  also  afford  superior  advantages  to  those  who  are  unable 
to  devote  much  time  to  occupations  of  this  nature.  The  dif- 
ferent branches  of  the  study  of  natural  history  are  only  accessi- 
ble in  certain  positions  of  social  life,  and  do  not,  at  every  sea- 

*  Cams,  Von  den  Urtheilen  des  Knochen  und  Schalen  Gerustes,  18"2^ 
$  6  +  Plut.,  in  Vita  Alex.  Magni,  cap.  7 


42  COSMOS. 

son  and  m  every  climate,  present  like  enjoyments.  Thus,  in 
the  dreary  regions  of  the  north,  man  is  deprived  for  a  long 
period  of  the  year  of  the  spectacle  presented  by  the  activity 
of  the  productive  forces  of  organic  nature  ;  and  if  the  mind 
be  directed  to  one  sole  class  of  objects,  the  most  animated 
narratives  of  voyages  in  distant  lands  w^ill  fail  to  interest  and 
attract  us,  if  they  do  not  touch  upon  the  subjects  to  v^^hich 
we  are  most  partial. 

As  the  history  of  nations — if  it  were  always  able  to  trace 
events  to  their  true  causes — might  solve  the  ever-recurring 
enigma  of  the  oscillations  experienced  by  the  alternately  pro- 
gressive and  retrograde  movement  of  human  society,  so  might 
also  the  physical  description  of  the  world,  the  science  of  the 
Co&inos,  if  it  were  grasped  by  a  powerful  intellect,  and  based 
upon  a  knowledge  of  all  the  results  of  discovery  up  to  a  giv- 
en period,  succeed  in  dispelling  a  portion  of  the  contradictions 
which,  at  first  sight,  appear  to  arise  from  the  complication  oi 
phenomena  and  the  multitude  of  the  perturbations  simultane- 
ously manifested. 

The  knowledge  of  the  laws  of  nature,  whether  we  can 
trace  them  in  the  alternate  ebb  and  flow  of  the  ocean,  in  the 
measured  path  of  comets,  or  in  the  mutual  attractions  of  mul- 
tiple stars,  alike  increases  our  sense  of  the  calm  of  nature, 
while  the  chimera  so  long  cherished  by  the  human  mind  in 
its  early  and  intuitive  contemplations,  the  belief  in  a  "discord 
of  the  elements,"  seems  gradually  to  vanish  in  proportion  as 
science  extends  her  empire.  General  views  lead  us  habitu- 
ally to  consider  each  organism  as  a  part  of  the  entire  creation, 
and  to  recognize  in  the  plant  or  the  animal  not  merely  an 
isolated  species,  but  a  form  linked  in  the  chain  of  being  to 
other  forms  either  living  or  extinct.  They  aid  us  in  compre- 
hending the  relations  that  exist  between  the  most  recent  dis 
coveries  and  those  which  have  prepared  the  way  for  them. 
Although  fixed  to  one  point  of  space,  we  eagerly  grasp  at  a 
knowledge  of  that  wliich  has  been  observed  in  different  and 
far-distant  regions.  We  delight  in  tracking  the  course  of  the 
bold  mariner  through  seas  of  polar  ice,  or  in  following  him  to 
the  summit  of  that  volcano  of  the  antarctic  pole,  whose  fires 
may  be  seen  from  afar,  even  at  mid-day.  It  is  by  an  ac- 
quaintance with  the  results  of  distant  voyages  that  we  may 
learn  to  comprehend  some  of  the  marvels  of"  terrestrial  mag- 
netism, and  be  thus  led  to  appreciate  the  importance  of  the 
estal  lishments  of  the  numerous  observatories  which  in  the 
present  day  cover  both  hemispheres,  and  are  designed  to  note 


INTRODUCTION.  43 

the  simullaiieous  occurrence  of  perturbations,  and  the  frequen- 
cy and  duration  of  tnagnetic  storms. 

Let  me  be  permitted  here  to  touch  upon  a  few  points  con- 
nected with  discoveries,  whose  importance  can  only  be  esti- 
mated by  those  who  have  devoted  themselves  to  the  study 
of  the  physical  sciences  generally.  Examples  chosen  from 
among  the  phenomena  to  which  special  attention  has  been 
directed  in  recent  times,  will  throw  additional  light  upon  the 
preceding  considerations.  Without  a  preHminary  knowledge 
of  the  orbits  of  comets,  we  should  be  unable  duly  to  appre- 
ciate the  importance  attached  to  the  discovery  of  one  of  these 
bodies,  whose  elliptical  orbit  is  included  in  the  narrow  limits 
of  our  solar  system,  and  which  has  revealed  the  existence  of 
an  ethereal  fluid,  tending  to  diminish  its  centrifugal  force  and 
the  period  of  its  revolution. 

The  superficial  half-knowledge,  so  characteristic  of  the 
present  day,  which  leads  to  the  introduction  of  vaguely  com- 
prehended scientific  views  into  general  conversation,  also  gives 
rise,  under  various  forms,  to  the  expression  of  alarm  at  the 
supposed  danger  of  a  collision  between  the  celestial  bodies,  or 
of  disturbance  in  the  climatic  relations  of  our  globe.  These 
phantoms  of  the  imagination  are  so  much  the  more  injurious 
as  they  derive  their  source  from  dogmatic  pretensions  to  true 
science.  The  history  of  the  atmosphere,  and  of  the  annual 
variations  of  its  temperature,  extends  already  sufficiently  far 
back  to  show  the  recurrence  of  shglit  disturbances  in  the 
mean  temperature  of  any  given  place,  and  thus  afibrds  suffi- 
cient guarantee  against  the  exaggerated  apprehension  of  a 
general  and  progressive  deterioration  of  the  climates  of  Eu- 
rope. Encke's  comet,  which  is  one  of  the  three  interior 
comets,  completes  its  course  in  1200  days,  but  from  the  form 
and  position  of  its  orbit  it  is  as  little  dangerous  to  the  earth 
as  Halley's  great  comet,  whose  revolution  is  not  completed  in 
less  than  seventy-six  years  (and  which  appeared  less  brilliant 
in  1835  than  it  had  done  in  1759) :  the  interior  comet  of 
Biela  intersects  the  earth's  orbit,  it  is  true,  but  it  can  only 
approach  our  globe  when  its  proximity  to  the  sun  coincides 
with  our  winter  solstice. 

The  quantity  of  heat  received  by  a  planet,  and  whose  un- 
equal distribution  determines  the  meteorological  variations 
of  its  atmosphere,  depends  alike  upon  the  light-engendering 
force  of  the  sun  ;  that  is  to  say,  upon  the  conditio-i  of  its 
gaseous  coverings,  and  upon  the  relative  position  of  the  planet 
and  the  central  body. 


44  COSMOS. 

There  are  variations,  it  is  true,  which,  in  obedience  to  the 
laws  of  universal  gravitation,  affect  the  form  of  the  earth's  or- 
bit and  the  inclination  of  the  ecliptic,  that  is,  the  angle  M^hich 
the  axis  of  the  earth  makes  with  the  plane  of  its  orbit ;  but 
these  periodical  variations  are  so  slow,  and  are  restricted  with- 
in such  narrow  limits,  that  their  thermic  effects  would  hardly 
be  appreciable  by  our  instruments  in  many  thousands  of  years. 
The  astronomical  causes  of  a  refrigeration  of  our  globe,  and 
of  the  diminution  of  moisture  at  its  surface,  and  the  nature 
and  frequency  of  certain  epidemics — phenomena  which  are 
often  discussed  in  the  present  4ay  according  to  the  benighted 
views  of  the  Middle  Ages — ought  to  be  considered  as  beyond 
the  range  of  our  experience  in  physics  and  chemistry. 

Physical  astronomy  presents  us  with  other  phenomena, 
which  can  not  be  fully  comprehended  in  all  their  vastness 
without  a  previous  acquirement  of  general  views  regarding 
the  forces  that  govern  the  universe.  Such,  for  instance,  are 
the  innumerable  double  stars,  or  rather  suns,  which  revolve 
round  one  common  center  of  gravity,  and  thus  reveal  in  dis- 
tant worlds  the  existence  of  the  Newtonian  law  ;  the  larger 
or  smaller  number  of  spots  upon  the  sun,  that  is  to  say,  the 
openings  formed  through  the  luminous  and  opaque  atmosphere 
surrounding  the  solid  nucleus  ;  and  the  regular  appearance, 
about  the  13th  of  November  and  the  1 1th  of  August,  of  shoot- 
ing stars,  which  probably  form  part  of  a  belt  of  asteroids,  in- 
tersecting the  earth's  orbit,  and  moving  with  planetary  ve- 
locity. 

Descending  from  the  celestial  regions  to  the  earth,  we 
would  fain  inquire  into  the  relations  that  exist  between  the 
oscillations  of  the  pendulum  in  air  (the  theory  of  which  ha.s 
been  perfected  by  Bessel)  and  the  density  of  our  planet  ;  and 
how  the  pendulum,  acting  the  part  of  a  plummet,  can,  to  a 
certain  extent,  throw  light  upon  the  geological  constitution 
of  strata  at  great  depths  1  By  means  of  this  instrument  we 
are  enabled  to  trace  the  striking  analogy  which  exists  be- 
tween the  formation  of  the  granular  rocks  composing  the 
lava  currents  ejected  from  active  volcanoes,  and  those  endog- 
enous misses  of  granite,  porphyry,  and  serpentine,  which,  is- 
suing from  the  interior  of  the  earth,  have  broken,  as  erup- 
tive rocks,  through  the  secondary  strata,  and  modified  them 
by  contact,  either  in  rendering  them  harder  by  the  introduc- 
tion of  silex,  or  reducing  them  into  dolomite,  or,  finally,  by 
inducing  within  them  the  formation  of  crystals  of  the  most 
varied  composition.     The  elevation  of  sporadic  islands,  of , 


INTKODUCTtON.  45 

domes  of  trachyte,  and  cones  of  basalt,  by  the  elastic  forces 
emanating  from  the  fluid  interior  of  our  globe,  has  led  one 
of  the  first  geologists  of  the  age,  Leopold  von  Buch,  to  the 
theory  of  the  elevation  of  continents,  and  of  mountain  chains 
generally.  This  action  of  subterranean  forces  in  breaking 
through  and  elevating  strata  of  sedimentary  rocks,  of  which 
the  coast  of  Chili,  in  consequence  of  a  great  earthquake,  fur- 
nished a  recent  example,  leads  to  the  assumption  that  the 
pelagic  shells  found  by  M.  Bonpland  and  myself  on  the  ridge 
of  the  Andes,  at  an  elevation  of  more  than  15,000  English 
feet,  may  have  been  conveyed  to  so  extraordinary  a  position, 
not  by  a  rising  of  the  ocean,  but  by  the  agency  of  volcanic 
forces  capable  of  elevating  into  ridges  the  softened  crust  of 
the  earth. 

I  apply  the  term  volcanic^  in  the  widest  sense  of  the  word, 
to  every  action  exercised  by  the  interior  of  a  planet  on  its 
external  crust.  The  surface  of  our  globe,  and  that  of  the 
moon,  manifest  traces  of  this  action,  which  in  the  former,  at 
least,  has  varied  during  the  course  of  ages.  Those  who  are 
ignorant  of  tlio  fact  that  the  internal  heat  of  the  earth  in- 
creases so  rapidly  with  the  increase  of  depth  that  granite  is 
m  a  state  of  fusion  about  twenty  or  thirty  geographical  miles 
below  the  surface,*  can  not  have  a  clear  conception  of  the 
causes,  and  the  simultaneous  occurrence  of  volcanic  eruptions 
at  places  widely  removed  from  one  another,  or  of  the  extent 
and  intersection  of  circles  of  commotion  in  earthquakes,  or  of 
the  uniformity  of  temperature,  and  equality  of  chemical  com- 
position observed  in  thermal  springs  during  a  long  course  of 
years.  The  quantity  of  heat  peculiar  to  a  planet  is,  however, 
a  matter  of  such  importance — being  the  result  of  its  primitive 
condensation,  and  varying  according  to  the  nature  and  dura- 
tion of  the  radiation  —  that  the  study  of  this  subject  may 
throw  some  degree  of  light  on  the  history  of  the  atmosphere, 
and  the  distribution  of  the  organic  bodies  imbedded  in  the 
solid  crust  of  the  earth.  This  study  enables  us  to  understand 
how  a  tropical  temperature,  independent  of  latitude  (that  is, 
of  the  distance  from  the  poles),  may  have  been  produced  by 
deep  fissures  remaining  open,  and  exhaling  heat  from  the  in- 

*  The  determinations  usually  given  of  the  point  of  fusion  are  in 
general  much  too  high  for  refracting  substances.  According  to  the  very 
accurate  researches  of  Mitscherlich,  the  melting  point  of  granite  can 
hardly  exceed  2372°  F. 

[Dr.  Mantell  states  in  The  Wonders  of  Geology,  1848,  vol.  i.,  p.  34, 
that  this  increase  of  temperature  amounts  to  1°  of  Fahrenheit  for  eveiy 
fifty-four  feet  of  vertical  depth,"} — Tr. 


46  coSxMos. 

terior  of  the  globe,  at  a  period  when  the  earth's  crust  we^ 
still  furrowed  and  rent,  and  only  in  a  state  of  semi-solidifica- 
tion ;  and  a  primordial  condition  is  thus  revealed  to  us,  in 
which  the  temperature  of  the  atmosphere,  and  climates  gen- 
erally, were  owing  rather  to  a  liberation  of  caloric  and  of  dif- 
ferent gaseous  emanations  (that  is  to  say,  rather  to  the  ener- 
getic reaction  of  the  interior  on  the  exterior)  than  to  the  posi- 
tion of  the  earth  with  respect  to  the  central  body,  the  sun. 

The  cold  regions  of  the  earth  contain,  deposited  in  sedi- 
mentary strata,  the  products  of  tropical  climates  ;  thus,  in 
the  coal  formations,  we  find  the  trunks  of  palms  standing  up- 
right amid  coniferee,  tree  ferns,  goniatites,  and  fishes  having 
rhomboidal  osseous  scales  ;*  in  the  Jura  limestone,  colossal 
skeletons  of  crocodiles,  plesiosauri,  planulites,  and  stems  of  the 
cycadese  ;  in  the  chalk  formations,  small  polythalamia  and 
bryozoa,  whose  species  still  exist  in  our  seas  ;  in  tripoli,  or 
polishing  slate,  in  the  semi-opal  and  the  farina-like  opal  or 
mountain  meal,  agglomerations  of  siliceous  infusoria,  which 
have  been  brought  to  light  by  the  powerful  microscope  of 
Ehrenberg;t  and,  lastly,  in  transported  soils,  and  in  certain 
caves,  the  bones  of  elephants,  hyenas,  and  lions.  An  intimate 
acquaintance  with  the  physical  phenomena  of  the  universe 
leads  us  to  regard  the  products  of  warm  latitudes  that  are 
thus  found  in  a  fossil  condition  in  northern  regions  not  merely 
as  incentives  to  barren  curiosity,  but  as  subjects  awakening 
deep  reflection,  and  opening  new  sources  of  study. 

The  number  and  the  variety  of  the  objects  I  have  alluded 
to  give  rise  to  the  question  whether  general  considerations  of 
physical  phenomena  can  be  made  sufficiently  clear  to  persons 
who  have  not  acquired  a  detailed  and  special  knowledge  of 

*  See  the  classical  woik  on  the  fislies  of  the  Old  World  by  Agassiz, 
Reck,  sur  les  Poissons  Fossiles,  1834,  vol.  i.,  p.  38;  vol.  ii.,  p.  3,  28, 
34,  App.,  p.  6.  The  whole  genus  of  Amblypterus,  Ag.,  nearly  allied 
to  Palaeouiscus  (called  also  Palueothrissum),  lies  buried  beneath  the 
Jura  formations  in  the  old  carboniferous  strata.  Scales  which,  in  some 
fishes,  as  in  the  family  of  Lepidoides  (ordei*  of  Ganoides),  are  formed 
like  teeth,  and  covered  in  certain  pai'ts  with  enamel,  belong,  after  the 
Placoides,  to  the  oldest  forms  of  fossil  fishes  ;  their  living  representa- 
tives are  still  found  in  two  genera,  the  Bichir  of  the  Nile  and  Senegal, 
and  the  Lepidosteus  of  the  Ohio. 

\  [The  polishing  slate  of  Bilin  is  stated  by  M.  Ehrenberg  to  form  a 
series  of  strata  fourteen  feet  in  thickness,  entirely  made  up  of  the  sili- 
ceous shells  of  GaillonellcB,  of  such  extreme  minuteness  that  a  cubic 
inch  of  the  stone  contains  forty-one  thousand  millions  !  The  Bergmehl 
(mountain  meal  ov  fossil  farina)  of  San  Flora,  in  Tuscany,  is  one  mass 
of  auimalculites.  See  the  interesting  work  of  G.  A  Manlell,  On  Ik^f 
Medals  of  Creation,  vol.  i.,  p.  223.]— jTr. 


INTRODUCTJOX.  47 

descriptive  natural  history,  geology,  or  mathematical  astron- 
omy ?  I  think  we  ought  to  distinguish  here  between  him 
whose  task  it  is  to  collect  the  individual  details  of"  various 
observations,  and  study  the  mutual  relations  existing  among 
them,  and  him  to  whom  these  relations  are  to  be  revealed, 
under  the  form  of  general  results.  The  former  should  be  aT5- 
quainted  with  the  specialities  of  phenomena,  that  he  may  ar- 
rive at  a  generalization  of  ideas  as  the  result,  at  least  in  part, 
of  his  own  observations,  experiments,  and  calculations.  It 
can  not  be  denied,  that  where  there  is  an  absence  of  positive 
knowledge  of  physical  phenomena,  the  general  results  which 
impart  so  great  a  charm  to  the  study  of  nature  can  not  all 
be  made  equally  clear  and  intelligible  to  the  reader,  but  still 
I  venture  to  hope,  that  in  the  work  which  I  am  now  prepar- 
ing on  the  physical  laws  of  the  universe,  the  greater  part  of 
the  facts  advanced  can  be  made  manifest  without  the  neces- 
sity of  appealing  to  fundamental  views  and  principles.  The 
picture  of  nature  thus  drawn,  notmthstanding  the  want  of 
distinctness  of  some  of  its  outlines,  will  not  be  the  less  able  to 
enrich  the  intellect,  enlarge  the  sphere  of  ideas,  and  nourish 
and  vivify  the  imagiuation. 

There  is,  perhaps,  some  truth  in  the  accusation  advanced 
against  many  German  scientific  works,  that  they 'lessen  the 
value  of  general  views  by  an  accumulation  of  detail,  and  do 
not  sufficiently  distinguish  between  those  great  results  which 
form,  as  it  were,  the  beacon  lights  of  science,  and  the  long 
series  of  means  by  which  they  have  been  attained.  This 
method  of  treating  scientific  subjects  led  the  most  illustrious 
of  our  poets*  to  exclaim  with  impatience,  "  The  Germans 
have  the  art  of  making  science  inaccessible."  An  edifice  can 
not  produce  a  striking  efTect  until  the  scaffolding  is  removed, 
that  had  of  necessity  been  used  during  its  erection.  Thus  the 
uniformity  of  figure  observed  in  the  distribution  of  continental 
masses,  which  all  terminate  toward  the  south  in  a  pyramidal 
form,  and  expand  toward  the  north  (a  law  that  determines 
the  nature  of  climates,  the  direction  of  currents  in  the  ocean 
and  the  atmosphere,  and  the  transition  of  certain  types  of 
tropical  vegetation  toward  the  southern  temperate  zone),  may 
be  clearly  apprehended  without  any  knowledge  of  the  geo- 
desical  and  astronomical  operations  by  means  of  which  these 
pyramidal  forms  of  continents  have  been  determiued.  In  like 
manner,  physical  geography  teaches  us  by  how  many  leagues 

*  Gotlie,  iu  Die  Aphorismen  ilbcr  NaturwisscJischaft,  bd.  I.,  .s,  155 
(  Werke  kleine  Ausgabe,  von  1833.) 


48  COSMOS. 

the  equatorial  axis  exceeds  the  polar  axis  of  the  globe,  and 
shows  us  the  mean  equality  of  the  flattening  of  the  two  hemi- 
spheres, without  entaiUng  on  us  the  necessity  of  giving  the 
detail  of  the  measurement  of  the  degrees  in  the  meridian,  or 
the  observations  on  the  pendulum,  which  have  led  us  to  know 
that  the  true  figure  of  our  globe  is  not  exactly  that  of  a  regu- 
lar ellipsoid  of  revolution,  and  that  this  irregularity  is  reflect- 
ed in  the  corresponding  irregularity  of  the  movements  of  the 
moon. 

The  views  of  comparative  geography  have  been  specially 
enlarged  by  that  admirable  work,  Erdkunde  im  Verhciltniss 
zur  Natur  und  zur  Geschichte,  in  which  Carl  Emitter  so  ably 
delineates  the  physiognomy  of  our  globe,  and  shows  the  influ- 
ence of  its  external  configuration  on  the  physical  phenomena 
on  its  surface,  on  the  migrations,  laws,  and  manners  of  nations, 
and  on  all  the  principal  historical  events  enacted  upon  the  face 
of  the  earth. 

France  possesses  an  immortal  work,  L' Exjoosition  du  Sijs- 
te?7ie  dtc  Monde,  in  which  the  author  has  combined  the  results 
of  the  highest  astronomical  and  mathematical  labors,  and  pre- 
sented them  to  his  readers  free  from  all  processes  of  demon- 
stration. The  structure  of  the  heavens  is  here  reduced  to  the 
simple  solution  of  a  great  problem  in  mechanics  ;  yet  Laplace's 
work  has  never  yet  been  accused  of  incompleteness  and  want 
of  profundity. 

The  distinction  between  dissimilar  subjects,  and  the  sepa- 
ration of  the  general  from  the  special,  are  not  only  conducive 
to  the  attainment  of  perspicuity  in  the  composition  of  a  phys- 
i'-al  history  of  the  universe,  but  are  also  the  means  by  which 
a  character  of  greater  elevation  may  be  imparted  to  the  study 
of  nature.  By  the  suppression  of  all  unnecessary  detail,  the 
great  masses  are  better  seen,  and  the  reasoning  faculty  is  ena- 
bled to  grasp  all  that  might  otherwise  escape  the  limited  range 
of  the  senses. 

The  exposition  of  general  results  has,  it  must  be  owned,  been 
singularly  facilitated  by  the  happy  revolution  experienced  since 
•he  close  of  the  last  century,  in  the  condition  of  all  the  special 
sciences,  more  particularly  of  geology,  chemistry,  and  descrip- 
t.ive  natural  history.  In  proportion  as  laws  admit  of  more 
.general  application,  and  as  sciences  mutually  enrich  each  other, 
md  by  their  extension  become  connected  together  in  more  im- 
oierous  and  more  intimate  relations,  the  development  of  gen- 
eral truths  may  be  given  with  conciseness  devoid  of  superfici- 
ality.    On  being  first  examined,  all  phenomena  appear  to  be 


INTRODUCTION.  49 

isolated,  and  it  is  only  by  the  result  of  a  multiplicity  of  obser- 
vations, combined  by  reason,  that  we  are  able  to  trace  the 
mutual  relations  existing  between  them.  If,  however,  in  the 
present  age,  which  is  so  strongly  characterized  by  a  brilliant 
course  of  scientific  discoveries,  we  perceive  a  w-ant  of  connec- 
tion in  the  phenomena  of  certain  sciences,  we  may  anticipate 
the  revelation  of  new  facts,  whose  importance  will  probably 
be  commensurate  with  the  attention  directed  to  these  branches 
of  study.  Expectations  of  this  nature  may  be  entertained  with 
regard  to  meteorology,  several  parts  of  optics,  and  to  radiating 
heat,  and  electro-magnetism,  since  the  admirable  discoveries 
of  Melloni  and  Faraday.  A  fertile  field  is  here  opened  to  dis- 
covery, although  the  voltaic  pile  has  already  taught  us  the 
intimate  connection  existing  between  electric,  magnetic,  and 
chemical  phenomena.  Who  will  venture  to  affirm  that  we 
have  any  precise  knowledge,  in  the  present  day,  of  that  part 
of  the  atmosphere  which  is  not  oxygen,  or  that  thousands  of 
gaseous  substances  affecting  our  organs  may  not  be  mixed  with 
the  nitrogen,  or,  finally,  that  we  have  even  discovered  the  whole 
number  of  the  forces  which  pervade  the  universe  ? 

It  is  not  the  purpose  of  this  essay  on  the  physical  history  of 
the  world  to  reduce  all  sensible  phenomena  to  a  small  number 
of  abstract  principles,  based  on  reason  only.  The  physical 
history  of  the  universe,  whose  exposition  I  attempt  to  develop, 
does  not  pretend  to  rise  to  the  perilous  abstractions  of  a  purely 
rational  science  of  nature,  and  is  simply  a  phydcal  geography, 
combined  icith  a  descrijotion  of  the  regions  of  space  and  the 
bodies  occujnjing  them.  Devoid  of  the  profoundness  of  a  purely 
speculative  philosophy,  my  essay  on  the  Cos^nos  treats  of  the 
contemplation  of  the  universe,  and  is  based  upon  a  rational 
empiricism,  that  is  to  say,  upon  the  results  of  the  facts  regis- 
tered by  science,  and  tested  by  the  operations  of  the  intellect. 
It  is  within  these  limits  alone  that  the  work,  which  I  now 
venture  to  undertake,  appertains  to  the  sphere  of  labor  to 
which  I  have  devoted  myself  throughout  the  course  of  my 
long  scientific  career.  The  path  of  inquiry  is  not  unknown 
to  me,  although  it  may  be  pursued  by  others  with  greater 
success.  The  unity  which  I  seek  to  attain  in  the  development 
of  the  great  phenomena  of  the  universe  is  analogous  to  that 
which  historical  composition  is  capable  of  acquiring.  All 
points  relating  to  the  accidental  individuahties,  and  the  essen- 
tial variations  of  the  actual,  whether  in  the  form  and  arrange- 
ment of  natural  objects  in  the  struggle  of  man  against  the 
elements,  or  of  nations  against  nations,  do  not  admit  of  being 

Vol.  I— C 


50  COSMOS. 

based  only  on  a  rational  foundation — that  is  to  say,  of  being 
deduced  from  ideas  alone. 

It  seems  to  me  that  a  like  degree  of  empiricism  attaches  to 
the  Description  of  the  Universe  and  to  Civil  History  ;  but  in 
reflecting  upon  physical  phenomena  and  events,  and  tracing 
their  causes  by  the  process  of  reason,  we  become  more  and 
more  convinced  of  the  truth  of  the  ancient  doctrine,  that  the 
forces  inherent  in  matter,  and  those  which  govel'n  the  moral 
world,  exercise  their  action  under  the  control  of  primordial 
necessity,  and  in  accordance  with  movements  occurring  period- 
ically after  longer  or  shorter  intervals. 

It  is  this  necessity,  this  occult  but  permanent  connection, 
this  periodical  recurrence  in  the  progressive  development  of 
forms,  phenomena,  and  events,  which  constitute  nature,  obe- 
dient to  the  first  impulse  imparted  to  it.  Physics,  as  the  term 
signifies,  is  limited  to  the  explanation  of  the  phenomena  of  the 
material  world  by  the  properties  of  matter.  The  ultimate 
object  of  the  experimental  sciences  is,  therefore,  to  discover 
laws,  and  to  trace  their  progressive  generalization.  All  that 
exceeds  this  goes  beyond  the  province  of  the  physical  descrip- 
tion of  the  universe,  and  appertains  to  a  range  of  higher  spec- 
ulative views. 

Emanuel  Kant,  one  of  the  few  philosophers  who  have  es- 
caped the  imputation  of  impiety,  has  defined  with  rare  sagac- 
ity the  limits  of  physical  explanations,  in  his  celebrated  essay 
On  the  Theory  and  Strncture  of  the  Heaven?,,  published  at 
Konigsberg  in  1755. 

The  study  of  a  science  that  promises  to  lead  us  through  the 
vast  range  of  creation  may  be  compared  to  a  journey  in  a  far- 
distant  land.  Before  w^e  set  forth,  we  consider,  and  often 
with  distrust,  our  own  strength,  and  that  of  the  guide  we  have 
chosen.  But  the  apprehensions  which  have  originated  in  the 
abundance  and  the  difficulties  attached  to  the  subjects  we 
would  embrace,  recede  from  view  as  we  remember  that  with 
the  increase  of  observations  in  the  present  day  there  has  also 
arisen  a  more  intimate  knowledge  of  the  connection  existing 
among  all  phenomena.  It  has  not  unfrequently  happened, 
that  the  researches  made  at  remote  distances  have  often  and 
unexpectedly  thrown  light  upon  subjects  which  had  long  re- 
sisted the  attempts  made  to  explain  them  within  the  narrow 
limits  of  our  own  sphere  of  observation.  Organic  forms  tliat 
had  long  remained  isolated,  both  in  the  animal  and  vegetable 
kingdom,  have  been  connected  by  the  discovery  of  intermediate 
links  or  stages  of  transition.    The  geography  of  beings  endov/ 


INTRODUCTION.  51 

ed  with  life  attains  completeness  as  we  see  the  species,  genera, 
and  entire  families  belonging  to  one  hemisphere,  reflected,  as 
it  were,  in  analogous  animal  and  vegetable  forms  in  the  oppo- 
site liemisphere.  These  are,  so  to  speak,  the  equivalents  w^hich 
mutually  personate  and  replace  one  another  in  the  great  series 
of  organisms.  These  connecting  links  and  stages  of  transition 
may  be  traced,  alternately,  in  a  deficiency  or  an  excess  of  de- 
velopment of  certain  parts,  in  the  mode  of  junction  of  distinct 
organs,  in  the  differences  in  the  balance  of  forces,  or  in  a  re- 
semblance to  intermediate  forms  which  are  not  permanent, 
but  merely  characteristic  of  certain  phases  of  normal  devel- 
opment. Passing  from  the  consideration  of  beings  endowed 
with  life  to  that  of  inorganic  bodies,  we  find  many  striking 
illustrations  of  the  high  state  of  advancement  to  which  modern 
geology  has  attained.  We  thus  see,  according  to  the  grand 
views  of  Elie  de  Beaumont,  how  chains  of  mountains  dividing 
different  climates  and  floras  and  different  races  of  men,  reveal 
to  us  their  relative  age,  both  by  the  character  of  the  sediment- 
ary strata  they  have  uplifted,  and  by  the  directions  which 
they  follow  over  the  long  fissures  with  which  the  earth's  crust 
is  furrowed.  Relations  of  superposition  of  trachyte  and  of 
syenitic  porphyry,  of  diorite  and  of  serpentine,  which  remuin 
doubtful  when  considered  in  the  auriferous  soil  of  Hungary, 
in  the  rich  platinum  districts  of  the  Oural,  and  on  the  south- 
western declivity  of  the  Siberian  Altai,  are  elucidated  by  the 
observations  that  have  been  made  on  the  plateaux  of  Mexico 
and  Antioquia,  and  in  the  unhealthy  ravines  of  Choco.  The 
most  important  facts  on  which  the  physical  history  of  the 
world  has  been  based  in  modern  times,  have  not  been  accu- 
mulated by  chance.  It  has  at  length  been  fully  acknowledg- 
ed, and  the  conviction  is  characteristic  of  the  age,  that  the 
narratives  of  distant  travels,  too  long  occupied  in  the  mere 
recital  of  hazardous  adventures,  can  only  be  made  a  source  of 
instruction  where  the  traveler  is  acquainted  with  the  condi- 
tion of  the  science  he  would  enlarge,  and  is  guided  by  reason 
in  his  researches. 

It  is  by  this  tendency  to  generalization,  which  is  only  dan- 
gerous in  its  abuse,  that  a  great  portion  of  the  physical  knowl- 
edge already  acquired  may  be  made  the  common  property  of 
all  classes  of  society ;  but,  in  order  to  render  the  instruction 
imparted  by  these  means  commensurate  with  the  importance 
of  the  subject,  it  is  desirable  to  deviate  as  widely  as  possible 
from  the  imperfect  compilations  designated,  till  the  close  of 
the  eighteenth  century,  by  t^e  inappropriate  term  of  popula? 


52  cosjMos. 

knowledge.  I  take  pleasure  in  persuading  myself  that  scien- 
tific subjects  may  be  treated  of  in  language  at  once  dignified, 
grave,  and  animated,  and  that  those  who  are  restricted  with- 
in the  circumscribed  limits  of  ordinary  life,  and  have  long  re- 
mained strangers  to  an  intimate  communion  with  nature, 
may  thus  have  opened  to  them  one  of  the  richest  sources  of 
enjoyment,  by  which  the  mind  is  invigorated  by  the  acquisi- 
tion of  new  ideas.  Communion  with  nature  awakens  within 
us  perceptive  faculties  that  bad  long  lain  dormant ;  and  we 
thus  comprehend  at  a  single  glance  the  influence  exercised  by 
physical  discoveries  on  the  enlargement  of  the  sphere  of  intel- 
lect, and  perceive  how  a  judicious  application  of  mechanics, 
chemistry,  and  other  sciences  may  be  made  conducive  to  na- 
tional prosperity. 

A  more  accurate  knowledge  of  the  connection  of  physical 
phenomena  will  also  tend  to  remove  the  prevalent  error  that 
all  branches  of  natural  science  are  not  equally  important  in 
relation  to  general  cultivation  and  industrial  progress.  An 
arbitrary  distinction  is  frequently  made  between  the  various 
degrees  of  importance  appertaining  to  mathematical  sciences, 
to  the  study  of  organized  beings,  the  knowledge  of  electro-" 
magnetism,  and  investigations  of  the  general  properties  of  mat- 
ter in  its  different  conditions  of  molecular  aggregation  ;  and  it 
is  not  uncommon  presumptuously  to  affix  a  supposed  stigma 
upon  researches  of  this  nature,  by  terming  them  "  purely  the- 
oretical," forgetting,  although  the  fact  has  been  long  attested, 
that  in  the  observation  of  a  phenomenon,  which  at  first  sight 
appears  to  be  wholly  isolated,  may  be  concealed  the  germ  of  a 
great  discovery.  When  Aloysio  Galvani  first  stimulated  the 
nervous  fiber  by  the  accidental  contact  of  two  heterogeneous 
metals,  his  cotemporaries  could  never  have  anticipated  that 
the  action  of  the  voltaic  pile  would  discover  to  us,  in  the  al- 
kalies, metals  of  a  silvery  luster,  so  light  as  to  swim  on  wa- 
ter, and  eminently  inflammable  ;  or  that  it  would  become  a 
powerful  instrument  of  chemical  analysis,  and  at  the  same 
time  a  thermoscope  and  a  magnet.  When  Huygens  first  ob- 
served, in  1678,  the  phenomenon  of  the  polarization  of  light, 
exhibited  in  the  difference  between  the  two  rays  into  which 
a  pencil  of  light  divides  itself  in  passing  through  a  doubly 
refracting  crystal,  it  could  not  have  been  foreseen  that,  a 
century  and  a  half  later,  the  great  philosopher  Arago  would, 
by  his  discovery  of  chromatic  ijolarization,  be  led  to  discern, 
by  means  of  a  small  fragment  of  Iceland  spar,  whether  solar 
light  emanates  from  a  solid  body  or  a  gaseous  covering,  oi 


INTRODUCTION.  53 

whether  comets  transmit  light  directly  or  merely  by  reflec- 
tion.* 

An  equal  appreciation  of  all  branches  of  the  mathematical^ 
physical,  and  natural  sciences  is  a  special  requirement  of  the 
present  age,  in  which  the  material  wealth  and  the  growing 
prosperity  of  nations  are  principally  based  upon  a  more  en- 
lightened employment  of  the  products  and  forces  of  nature. 
The  most  superficial  glance  at  the  present  condition  of  Europe 
shows  that  a  diminution,  or  even  a  total  annihilation  of  na- 
tional prosperity,  must  be  the  award  of  those  states  who  shrink 
with  slothful  indifierence  from  the  great  struggle  of  rival  na- 
tions in  the  career  of  the  industrial  arts.  It  is  with  nations 
as  with  nature,  which,  according  to  a  happy  expression  of 
G6the,t  "  knows  no  pause  in  progress  and  development,  and 
attaches  her  curse  on  all  inaction."  The  propagation  of  an 
earnest  and  sound  knowledge  of  science  can  therefore  alone 
avert  the  dangers  of  which  I  have  spoken.  Man  can  not  act 
upon  nature,  or  appropriate  her  forces  to  his  own  use,  without 
comprehending  their  full  extent,  and  having  an  intimate  ac- 
quaintance with  the  laws  of  the  physical  world.  Bacon  has 
said  that,  in  human  societies,  knowledge  is  power.  Both  must 
rise  and  sink  together.  But  the  knowledge  that  results  from 
the  free  action  of  thought  is  at  once  the  delight  and  the  in- 
destructible prerogative  of  man  ;  and  in  forming  part  of  the 
wealth  of  mankind,  it  not  unfrequently  serves  as  a  substitute 
for  the  natural  riches,  which  are  but  spariiigly  scattered  over 
the  earth.  Those  states  which  take  no  active  part  in  the 
general  industrial  movement,  in  the  choice  and  preparation  of 
natural  substances,  or  in  the  application  of  mechanics  and 
chemistry,  and  among  whom  this  activity  is  not  appreciated 
by  all  classes  of  society,  will  infallibly  see  their  prosperity  di- 
minish in  proportion  as  neighboring  countries  become  strength- 
ened and  invigorated  under  the  genial  influence  of  arts  and 
sciences. 

As  in  nobler  spheres  of  thought  and  sentiment,  in  philosophy, 
poetry,  and  the  fine  arts,  the  object  at  which  we  aim  ought  to 
be  an  inwaid  one — an  ennoblement  of  the  intellect — so  ought 
we  likevidse,  in  our  pursuit  of  science,  to  strive  after  a  knowl- 
edge of  the  laws  and  the  principles  of  unity  that  pervade  the 
vital  forces  of  the  universe  ;  and  it  is  by  such  a  course  that 

*  Ai'ago's  Discoveries  ia  the  year  1811. — Delambre's  Histoire  de 
V Ait.,  p.  652.     (Passage  already  quoted.) 

t  Gothe,  ill  Die  AphoHsmen  uber  Naturwissenschaft. —  Werke,  bd.  1... 
B.  4 


54  COSMOS. 

physical  studies  may  be  made  subservient  to  the  progress  of  in- 
dustry, which  is  a  conquest  of  mind  over  matter.  By  a  hap- 
py connection  of  causes  and  effects,  we  often  see  the  useful  link- 
ed to  the  beautiful  and  the  exalted.  The  improvement  of  agri- 
culture in  the  hands  of  freemen,  and  on  properties  of  a  mod- 
erate extent — the  flourishing  state  of  the  mechanical  arts  freed 
from  the  trammels  of  municipal  restrictions — the  increased 
impetus  imparted  to  commerce  by  the  multiplied  means  of 
contact  of  nations  v^^ith  each  other,  are  all  brilliant  results  of 
the  intellectual  progress  of  mankind,  and  of  the  amelioration 
of  political  institutions,  in  which  this  progress  is  reflected. 
The  picture  presented  by  modern  history  ought  to  convince 
those  who  are  tardy  in  awakening  to  the  truth  of  the  lesson 
it  teaches. 

Nor  let  it  be  feared  that  the  marked  predilection  for  the 
study  of  nature,  and  for  industrial  progress,  which  is  so  char- 
acteristic of  the  present  age,  should  necessarily  have  a  tenden- 
cy to  retard  the  noble  exertions  of  the  intellect  in  the  domains 
of  philosophy,  classical  history,  and  antiquity,  or  to  deprive 
the  arts  by  which  life  is  embellished  of  the  vivifying  breath  of 
imagination.  Where  all  the  germs  of  civilization  are  devel- 
oped beneath  the  ff^gis  of  free  institutions  and  wise  legislation, 
there  is  no  cause  for  apprehending  that  any  one  branch  of 
knowledge  should  be  cultivated  to  the  prejudice  of  others. 
All  afford  the  state  precious  fruits,  whether  they  yield  nourish- 
ment to  man  and  constitute  his  physical  wealth,  or  whether, 
more  permanent  in  their  nature,  they  transmit  in  the  works 
of  mind  the  glory  of  nations  to  remotest  posterity.  The  Spar- 
tans, notwithstanding  their  Doric  austerity,  prayed  the  gods 
to  grant  them  "  the  beautiful  with  the  good."* 

I  will  no  longer  dwell  upon  the  considerations  of  the  influ- 
ence exercised  by  the  mathematical  and  physical  sciences  on 
all  that  appertains  to  the  material  wants  of  social  life,  for  the 
vast  extent  of  the  course  on  which  I  am  entering  forbids  me 
to  insist  further  upon  the  utility  of  these  applications.  Ac- 
customed to  distant  excursions,  I  may,  perhaps,  have  erred  in 
describing  the  path  before  us  as  more  smooth  and  pleasant 
than  it  really  is,  for  such  is  wont  to  be  the  practice  of  those 
who  delight  in  guiding  others  to  the  summits  of  lofty  mount- 
ains :  they  praise  the  view  even  when  great  part  of  the  dis- 
tant plains  lie  hidden  by  clouds,  knowing  that  this  half-trans- 
parent vapory  vail  imparts  to  the  scene  a  certain  charm  from 

*  Pseudo-Plato. — Alcib.,  xi.,  p.  184,  ed.  Steph. ;  Plut.,  Instituta  La- 
conica,  p.  253,  ed.  Hutten. 


,  j\TKoDi;(  rrox.  oa 

the  power  exercised  by  the  imagination  over  the  domani  of  the 
senses.  In  like  manner,  from  the  height  occupied  by  the  phys- 
ical history  of  the  world,  all  parts  of  the  horizon  will  not  ap- 
pear equally  clear  and  well  defined.  This  indistinctness  will 
not,  however,  be  wholly  owing  to  the  present  imperfect  state 
of  some  of  the  sciences,  but  in  part,  likewise,  to  the  unskill- 
fulness  of  the  guide  who  has  imprudently  ventured  to  ascend 
these  lofty  summits. 

The  object  of  this  introductory  notice  is  not,  however,  solely 
to  draw  attention  to  the  importance  and  greatness  of  the  phys- 
ical history  of  the  universe,  for  in  the  present  day  these  are  too 
well  understood  to  be  contested,  but  likewise  to  prove  how, 
without  detriment  to  the  stability  of  special  studies,  we  may 
be  enabled  to  generalize  our  ideas  by  concentrating  them  in 
one  conmion  focus,  and  thus  arrive  at  a  point  of  view  from 
w^hich  all  the  organisms  and  forces  of  nature  may  be  seen  as 
one  Hving,  active  whole,  animated  by  one  sole  impulse,  "  Na- 
ture," as  Schelling  remarks  in  his  poetic  discourse  on  art,  "is 
not  an  inert  mass  ;  and  to  him  who  can  comprehend  her  vast 
sublimity,  she  reveals  herself  as  the  creative  force  of  the  uni- 
verse— before  all  time,  eternal,  ever  active,  she  calls  to  life  all 
things,  whether  perishable  or  imperishable." 

By  uniting,  under  one  point  of  view,  both  the  phenomena 
of  our  own  globe  and  those  presented  in  the  regions  of  space, 
we  embrace  the  limits  of  the  science  of  the  Cosmos,  and  con- 
vert the  physical  history  of  the  globe  into  the  physical  history 
of  the  universe,  the  one  term  being  modeled  upon  that  of  the 
other.  This  science  of  the  Cosmos  is  not,  however,  to  be  re- 
garded as  a.  mere  encyclopedic  aggregation  of  the  most  im- 
portant and  general  results  that  have  been  collected  together 
from  special  branches  of  knowledge.  These  results  are  noth- 
ing more  than  the  materials  for  a  vast  edifice,  and  their  com- 
bination can  not  constitute  the  physical  history  of  the  w^orld, 
whose  exalted  part  it  is  to  show  the  simultaneous  action  and 
the  connecting  links  of  the  forces  which  pervade  the  universe. 
The  distribution  of  organic  types  in  different  climates  and  at 
different  elevations — that  is  to  say,  the  geography  of  plants 
and  animals — differs  as  widely  from  botany  and  descriptive 
zoology  as  geology  does  from  mineralogy,  properly  so  called. 
The  physical  history  of  the  universe  must  not,  therefore,  be 
confounded  with  the  Encyclopedias  of  the  Natural  Sciences, 
as  they  have  hitherto  been  compiled,  and  whose  title  is  as 
vao-ue  as  their  limits  are  ill  defined.  In  the  work  before  us, 
partial  facts  will  be  considered  only  in  relation  to  the  whole 


5(j  COSMOS. 

The  higher  the  point  of  view,  the  greater  is  the  nece*,sity  lor 
a  systematic  mode  of  treating  the  subject  in  language  at  once 
animated  and  picturesque. 

But  thought  and  language  have  ever  been  most  intimately 
allied.  If  langiiage,  by  its  originality  of  structure  and  its 
native  richness,  can,  in  its  delineations,  interpret  thought  M^ith 
grace  and  clearness,  and  if,  by  its  happy  flexibility,  it  can  paint 
with  vivid  truthfulness  the  objects  of  the  external  world,  it 
reacts  at  the  same  time  upon  thought,  and  animates  it,  as  it 
were,  with  the  breath  of  life.  It  is  this  mutual  reaction  which 
makes  words  more  than  mere  signs  and  forms  of  thought ;  and 
the  beneficent  influence  of  a  language  is  most  strikingly  man- 
ifested on  its  native  soil,  where  it  has  sprung  spontaneously 
from  the  minds  of  the  people,  whose  character  it  embodies. 
Proud  of  a  country  that  seeks  to  concentrate  her  strength  in 
intellectual  unity,  the  writer  recalls  with  delight  the  advant- 
ages he  has  enjoyed  in  being  permitted  to  express  his  thoughts 
in  his  native  language  ;  and  truly  happy  is  he  who,  in  at- 
tempting to  give  a  lucid  exposition  of  the  great  phenomena  of 
the  universe,  is  able  to  draw  from  the  depths  of  a  language, 
which,  through  the  free  exercise  of  thought,  and  by  the  efiii- 
sions  of  creative  fancy,  has  for  centuries  past  exercised  so  pow- 
erful an  influence  over  the  destinies  of  man. 


M.MITS  AND  METHOD  OF  EXPOSITION  OF  THE  PHYSICAL  DESCRIPTION 

OF  THE   UNIVERSE. 

I  HAVE  endeavored,  in  the  preceding  part  of  my  work,  to 
explain  and  illustrate,  by  various  examples,  how  the  enjoy- 
ments presented  by  the  aspect  of  nature,  varying  as  they  do 
in  the  sources  from  whence  they  flow,  may  be  multiplied  and 
ennobled  by  an  acquaintance  with  the  connection  of  phenom- 
ena and  the  laws  by  which  they  are  regulated.  It  remains, 
then,  for  me  to  examine  the  spirit  of  the  method  in  which  the 
exposition  of  the  physical  descriiJtion  of  the  utiiverse  should 
be  conducted,  and  to  indicate  the  limits  of  this  science  in  ac- 
cordance with  the  views  I  have  acquired  in  the  course  of  my 
studies  and  travels  in  various  parts  of  the  earth.  I  trust  I 
may  flatter  myself  with  a  hope  that  a  treatise  of  this  nature 
will  justify  the  title  I  have  ventured  to  adopt  for  my  work, 
and  exonerate  me  from  the  reproach  of  a  presumption  that 
would  be  doubly  reprehensible  in  a  scientific  discussion. 

Before  entering  upon  the  delineation  of  the  partial  phenom- 


INTRODUCTION.  57 

ena  which  are  found  to  be  distributed  in  various  g^roups,  I  would 
consider  a  few  general  questions  intimately  connected  together, 
and  bearing  upon  the  nature  of  our  kno^vledge  of  the  external 
world  and  its  different  relations,  in  all  epochs  of  history  and  in 
all  phases  of  intellectual  advancement.  Under  this  head  will 
be  comprised  the  following  considerations  : 

1 .  The  precise  limits  of  the  physical  description  of  the  uni- 
verse, considered  as  a  distinct  science. 

2.  A  brief  enumeration  of  the  totality  of  natural  phenomena, 
presented  under  the  form  of  a  general  delineatioii  of  nature. 

3.  The  influence  of  the  external  world  on  the  imagination 
and  feelings,  which  has  acted  in  modern  times  as  a  powerful 
impulse  toward  the  study  of  natural  science,  by  giving  anima- 
tion to  the  description  of  distant  regions  and  to  the  delineation 
of  natural  scenery,  as  far  as  it  is  characterized  by  vegetable 
physiognomy  and  by  the  cultivation  of  exotic  plants,  and  their 
arrangement  in  well- contrasted  groups. 

4.  The  history  of  the  contemplation  of  nature,  or  the  pro- 
gressive development  of  the  idea  of  the  Cosmos,  considered 
with  reference  to  the  historical  and  geographical  facts  that 
have  led  to  the  discovery  of  the  connection  of  phenomena. 

The  higher  the  point  of  view  from  which  natural  phenome- 
na may  be  considered,  the  more  necessary  it  is  to  circumscribe 
the  science  within  its  just  limits,  and  to  distinguish  it  from  all 
other  analogous  or  auxiliary  studies. 

Physical  cosmography  is  founded  on  the  contemplation  of  all 
created  things-:-all  that  exists  in  space,  whether  as  substances 
or  forces — that  is,  all  the  material  beings  that  constitute  the 
universe.  The  science  which  I  would  attempt  to  define  pre- 
sents itself,  therefore,  to  man,  as  the  inhabitant  of  the  earth, 
under  a  two-fold  form — as  the  earth  itself  and  the  reo-ions  of 
space.  It  is  with  a  view  of  showing  the  actual  character  and 
the  independence  of  the  study  of  physical  cosmography,  and  at 
the  saraie  time  indicating  the  nature  of  its  relations  to  general 
fhysics,  descrij)tive  natural  history,  geology,  and  comparative 
geography,  that  I  will  pause  for  a  few  moments  to  consider 
that  portion  of  the  science  of  the  Cosmos  which  concerns  the 
earth.  As  the  history  of  philosophy  does  not  consist  of  a  mere 
material  enumeration  of  the  philosophical  views  entertained 
in  different  ages,  neither  should  the  physical  description  of  the 
universe  be  a  simple  encyclopedic  compilation  of  the  sciences 
we  have  enumerated.  The  difficulty  of  defining  the  limits  of 
intimately-connected  studies  has  been  increased,  because  for 
centuries  it  has  been  customary  to  designate  various  branches 

C2 


58  COSMOS. 

of  empirical  knowledge  by  terms  which  admit  either  ot  too 
wide  or  too  limited  a  definition  of  the  ideas  which  they  were 
intended  to  convey,  and  arc,  besides,  objectionable  from  hav- 
ing had  a  different  signification  in  those  classical  languages  of 
antiquity  from  which  they  have  been  borrowed.  The  terms 
physiology,  physics,  natural  history,  geology,  and  geography 
arose,  and  were  commonly  used,  long  before  clear  ideas  were 
entertained  of  the  diversity  of  objects  embraced  by  these 
sciences,  and  consequently  of  their  reciprocal  limitation.  Such 
is  the  influence  of  long  habit  upon  language,  that  by  one  of 
the  nations  of  Europe  most  advanced  in  civilization  the  word 
"  physic"  is  applied  to  medicine,  while  in  a  society  of  justly 
deserved  universal  reputation,  technical  chemistry,  geology, 
and  astronomy  (purely  experimental  sciences)  are  comprised 
under  the  head  of"  Philosophical  Transactions." 

An  attempt  has  often  been  made,  and  almost  always  in  vain, 
to  substitute  new  and  more  appropriate  terms  for  these  ancient 
designations,  which,  notwithstanding  their  undoubted  vague- 
ness, are  now  generally  understood.  These  changes  have  been 
proposed,  for  the  most  part,  by  those  who  have  occupied  them- 
selves with  the  general  classification  of  the  various  branches 
of  knowledge,  from  the  first  appearance  of  the  great  encyclo- 
pedia [Margarita  Pliilosophica)  of  Gregory  Reisch,*  prior  of 
the  Chartreuse  at  Freiburg,  toward  the  close  of  the  fifteenth 
century,  to  Lord  Bacon,  and  from  Bacon  to  D'Alembert ;  and 
in  recent  times  to  an  eminent  physicist,  Andre  Marie  Ampere. t 

*  The  Margarita  PhilosopJiica  of  Gregory  Reisch,  prior  of  the  Char- 
treuse at  Freiburg,  first  appeared  under  the  following  title :  Epitome 
omnis  Philosophice,  alias  Margarita  PhilosopJiica,  tractans  de  omni  generi 
scibili.  The  Heidelberg  edition  (1486),  and  that  of  Strasburg  (1504), 
both  bear  this  title,  but  the  first  part  was  suppi'essed  in  the  Freiburg 
edition  of  the  same  year,  as  well  as  in  the  twelve  subsequent  editions, 
vvhich  succeeded  one  another,  at  short  intervals,  till  1.535.  This  work 
exercised  a  great  influence  on  the  ditfusion  of  mathematical  and  physic- 
al sciences  toward  the  beginning  of  the  sixteenth  century,  and  CLas^es, 
the  learned  author  of  L'Apercu  Historique  des  Methodes  en  GeomHrtc 
(1837),  has  shown  the  great  importance  of  Reisch's  Encyclopedia  in 
the  history  of  mathematics  in  the  Middle  Ages.  I  have  had  recourse 
to  a  passage  in  the  Margarita  PhilosopTiica,  found  only  in  the  edition 
of  1513,  to  elucidate  the  important  question  of  the  relations  between 
the  statements  of  the  geographer  of  Saint-Die,  Hylacomilus  (Martin 
VValdseemiiller),  the  first  who  gave  the  name  of  America  to  the  New 
Continent,  and  those  of  Amerigo  Vespucci,  Rene,  King  of  Jerusalem 
and  Duke  of  Lorraine,  as  also  those  contained  in  the  celebrated  editions 
of  Ptolemy  of  1513  and  1522.  See  my  Examen  Critique  de  la  G^o- 
grapkip.  du  Nouveau  Continent,  et  des  Progres  de  V Astronomie  Nautiqtie 
aux  15e  et  16e  Siecles,  t.  iv.,  p.  99-125. 

t  Ampere,  Essai  sn.r  la  Phil,  des  Sciences,  1834,  p.  25.     Whewell, 


IXTHODITTroW  59 

The  selection  of  an  inappropriate  Greek  nomenclature  has  per- 
haps been  even  more  prejudicial  to  the  last  of  these  attempts 
than  the  injudicious  use  of  binary  divisions  and  the  excessive 
multiplication  of  groups. 

The  physical  description  of  the  world,  considering  the  uni- 
verse as  an  object  of  the  external  senses,  does  undoubtedly  re- 
quire the  aid  of  general  physics  and  of  descriptive  natural  histo- 
ly,  but  the  contemplation  of  all  created  thmgs,  which  are  hnked 
together,  and  form  one  luhole,  animated  by  internal  forces,  gives 
to  the  science  we  are  considering  a  peculiar  character.  Phys- 
ical science  considers  only  the  general  properties  of  bodies  ;  it 
is  the  product  of  abstraction — a  generalization  of  perceptible 
phenomena ;  and  even  in  the  work  in  which  were  laid  the 
first  foundations  of  general  physics,  in  the  eight  books  on 
physics  of  Aristotle,*  all  the  phenomena  of  nature  are  consid- 
ered as  depending  upon  the  primitive  and  vital  action  of  one 
sole  force,  from  which  emanate  all  the  movements  of  the  uni- 
verse. The  terrestrial  portion  of  physical  cosmography,  for 
which  I  would  willingly  retain  the  expressive  designation  of 
'physical  geograjjhij,  treats  of  the  distribution  of  magnetism  in 
our  planet  with  relation  to  its  intensity  and  direction,  but  does 
not  enter  into  a  consideration  of  the  laws  of  attraction  or  re- 
pulsion of  the  poles,  or  the  means  of  eliciting  either  permanent 
or  transitory  electro-magnetic  currents.  Physical  geography 
depicts  in  broad  outlines  the  even  or  irregular  configuration  of 
continents,  the  relations  of  superficial  area,  and  the  distribution 
of  continental  masses  in  the  two  hemispheres,  a  distribution 
which  exercises  a  powerful  influence  on  the  diversity  of  climate 
and  the  meteorological  modifications  of  the  atmosphere  ;  this 
science  defines  the  character  of  mountain  chains,  which,  hav- 
ing been  elevated  at  different  epochs,  constitute  distinct  sys- 
tems, whether  they  run  in  parallel  lines  or  intersect  one  an- 
other ;  determines  the  mean  height  of  continents  above  the 
level  of  the  sea,  the  position  of  the  center  of  gravity  of  their 
volume,  and  the  relation  of  the  highest  summits  of  mountain 
chains  to  the  mean  elevation  of  their  crests,  or  to  their  prox- 
imity with  the  sea-shore.  It  depicts  the  eruptive  rocks  as 
principles  of  movement,  acting  upon  the  sedimentary  rocks  by 
traversing,  uplifting,  and  inchning  them  at  various  angles  ;  it 

Philosophy  of  the  Inductive  Sciences,  volt  ii.,  p.  277.    Park,  Pantoiogy^ 

*  All  changes  in  the  physical  world  may  be  reduced  to  motion. 
Aristot.,  Phys.  Ansc,  iii.,  1  and  4,  p.  200,  201.  Bekker,  viii.,  1,  8,  and 
9,  p.  250,  262,  265.  De  Genere  et  Corr.,  ii.,  10,  p.  336.  Psendo-Aris- 
tot.,  De  Mundo.  cap.  vi.,  p.  398. 


.«|HX^ 


60  COSMOS. 

considers  volcanoes  either  as  isolated,  or  ranged  in  single  or  in 
double  series,  and  extending  their  sphere  of  action  to  various 
distances,  either  by  raising  long  and  narrow  lines  of  rocks,  or 
by  means  of  circles  of  commotion,  which  expand  or  diminish 
in  diameter  in  the  course  of  ages.  This  terrestrial  portion  ot 
the  science  of  the  Cosmos  describes  the  strife  of  the  liquid  ele- 
ment with  the  solid  land  ;  it  indicates  the  features  possessed 
in  common  by  all  great  rivers  in  the  upper  and  lower  portion 
of  their  course,  and  in  their  mode  of  bifurcation  when  their 
basins  are  unclosed  ;  and  shows  us  rivers  breaking  through 
the  highest  mountain  chains,  or  following  for  a  long  time  a 
course  parallel  to  them,  either  at  their  base,  or  at  a  consider- 
able distance,  Avhere  the  elevation  of  the  strata  of  the  mount- 
ain system  and  the  direction  of  their  inclination  correspond 
to  the  configuration  of  the  table-land.  It  is  only  the  general 
results  of  comparative  orography  and  hydrography  that  belong 
to  the  science  whose  true  limits  I  am  desirous  of  determining, 
and  not  the  special  enumeration  of  the  greatest  elevations  of 
our  globe,  of  active  volcanoes,  of  rivers,  and  the  number  of 
their  tributaries,  these  details  falling  rather  within  the  domain 
of  geography,  properly  so  called.  We  would  here  only  con- 
sider phenomena  in  their  mutual  connection,  and  in  their  re- 
lations to  different  zones  of  our  planet,  and  to  its  physical  con- 
stitution generally.  The  specialities  both  of  inorganic  and  or- 
ganized matter,  classed  according  to  analogy  of  form  and  com- 
position, undoubtedly  constitute  a  most  interesting  branch  of 
study,  but  they  appertain  to  a  sphere  of  ideas  having  no  affin- 
ity with  the  subject  of  this  work. 

The  description  of  different  countries  certainly  furnishes  us 
with  the  most  important  materials  for  the  composition  of  a 
physical  geography  ;  but  the  combination  of  these  differenl 
descriptions,  ranged  in  series,  would  as  little  give  us  a  tru« 
image  of  the  general  conformation  of  the  irregular  surface  of 
our  globe,  as  a  succession  of  all  the  floras  of  different  region? 
would  constitute  that  M^iich  I  designate  as  a  Geogra2)hy  of 
Plants.  It  is  by  subjecting  isolated  observations  to  the  process 
of  thought,  and  by  combining  and  comparing  them,  that  we 
are  enabled  to  discover  the  relations  existing  in  common  be 
tween  the  climatic  distribution  of  beings  and  the  individualitj 
of  organic  forms  (in  the  morphology  or  descriptive  natural  his- 
tory of  plants  and  animals)  ;  and  it  is  by  induction  that  we 
are  led  to  comprehend  numerical  laws,  the  proportion  of  nat- 
ural families  to  the  whole  number  of  species,  and  to  desig-nate 
the  latitude  or  geographical  position  of  the  zones  in  whose 


INTRODUCTION.  61 

plains  each  org:anic  form  attains  the  maximum  of  its  develop- 
ment. Considerations  of  this  nature,  by  their  tendency  to 
generalization,  impress  a  nobler  character  on  the  physical  de- 
scription of  the  globe,  and  enable  us  to  undfrstand  how  the 
aspect  of  the  scenery,  that  is  to  say,  the  impression  produced 
upon  the  mind  by  the  physiognomy  of  the  vegetation,  depends 
upon  the  local  distribution,  the  number,  and  the  luxuriance  of 
growth  of  the  vegetable  forms  predominating  in  the  general 
mass.  The  catalogues  of  organized  beings,  to  which  was  for- 
merly given  the  pompous  title  of  Systems  of  Nature,  present 
us  with  an  admirably  connected  arrangement  by  analogies  of 
structure,  either  in  the  perfected  development  of  these  beings, 
or  in  the  different  phases  which,  in  accordance  with  the  views 
of  a  spiral  evolution,  affect  in  vegetables  the  leaves,  bracts, 
calyx,  corolla,  and  fructifying  organs ;  and  in  animals,  with 
more  or  less  symmetrical  regularity,  the  cellular  and  fibrous 
tissues,  and  their  perfect  or  but  obscurely  developed  articula- 
tions. But  these  pretended  systems  of  nature,  however  ingen- 
ious their  mode  of  classification  may  be,  do  not  show  us  or- 
ganic beings  as  they  are  distributed  in  groups  throughout  our 
planet,  according  to  their  difierent  relations  of  latitude  and 
elevation  above  the  level  of  the  sea,  and  to  climatic  influences, 
which  are  owing  to  general  and  often  very  remote  causes. 
The  ultimate  aim  of  physical  geography  is,  however,  as  we 
have  already  said,  to  recognize  unity  in  the  vast  diversity  of 
phenomena,  and  by  the  exercise  of  thought  and  the  combina- 
tion of  observations,  to  discern  the  constancy  of  phenomena 
in  the  midst  of  apparent  changes.  In  the  exposition  of  the 
terrestrial  portion  of  the  Cosmos,  it  will  occasionally  be  neces- 
sary to  descend  to  veiy  special  facts  ;  but  this  will  only  be  in 
order  to  recall  the  connection  existing  betM^een  the  actual  dis- 
tribution of  organic  beings  over  the  globe,  and  the  laws  of  the 
ideal  classification  by  natural  families,  analogy  of  internal  or- 
ganization, and  progressive  evolution. 

It  follows  from  these  discussions  on  the  limits  of  the  various 
sciences,  and  more  particularly  from  the  distinction  which  must 
necessarily  be  made  between  descriptive  botany  (morphology 
of  vegetables)  and  the  geography  of  plants,  that  in  the  phys 
ical  history  of  the  globe,  the  innumerable  multitude  of  organ- 
ized bodies  which  embellish  creation  are  considered  rather  ac- 
cording to  zones  of  habitation  or  stations,  and  to  differently 
inflected  isothermal  bands,  than  with  reference  to  the  princi- 
ples of  gradation  in  the  development  of  internal  organism. 
Notwithstanding  this,  botany  and  zoology,  which  constitute 


62  COSMOS. 

the  descriptive  natural  history  of  all  organized  beings,  are  the 
fruitful  sources  whence  we  draw  the  materials  necessary  to 
give  a  solid  basis  to  the  study  of  the  mutual  relations  and 
connection  of  phenomena. 

We  will  here  subjoin  one  important  observation  by  way  of 
elucidating  the  connection  of  which  we  have  spoken.  The 
first  general  glance  over  the  vegetation  of  a  vast  extent  of  a 
continent  shows  us  forms  the  most  dissimilar — Graminese  and 
Orchideee,  Coniferse  and  oaks,  in  local  approximation  to  one 
another  ;  while  natural  families  and  genera,  instead  of  being 
locally  associated,  are  dispersed  as  if  by  chance.  This  disper- 
sion is,  however,  only  apparent.  The  physical  description  of 
the  globe  teaches  us  that  vegetation  every  where  presents  nu- 
merically constant  relations  in  the  development  of  its  forms 
and  types  ;  that  in  the  same  climates,  the  species  which  are 
wanting  in  one  country  are  replaced  in  a  neighboring  one  by 
other  species  of  the  same  family  ;  and  that  this  laiv  of  substi- 
tution, which  seems  to  depend  upon  some  inherent  mysteries 
of  the  organism,  considered  with  reference  to  its  origin,  main- 
tains in  contiguous  regions  a  numerical  relation  between  the 
species  of  various  great  families  and  the  general  mass  of  the 
phanerogamic  plants  constituting  the  two  floras.  We  thus 
find  a  principle  of  unity  and  a  primitive  plan  of  distribution 
revealed  in  the  multiplicity  of  the  distinct  organizations  by 
which  these  regions  are  occupied  ;  and  we  also  discover  in 
each  zone,  and  diversified  according  to  the  families  of  plants, 
a  slow  but  continuous  action  on  the  aerial  ocean,  depending 
upon  the  influence  of  light — the  primary  condition  of  all  or- 
ganic vitality — on  the  solid  and  liquid  surface  of  our  planet. 
It  might  be  said,  in  accordance  with  a  beautiful  expression  of 
Lavoisier,  that  the  ancient  marvel  of  the  myth  of  Prometheus 
was  incessantly  renewed  before  our  eyes. 

If  we  extend  the  course  which  we  have  proposed,  following 
in  the  exposition  of  the  physical  description  of  the  earth  to  the 
sidereal  part  of  the  science  of  the  Cosmos,  the  delineation  of 
the  regions  of  space  and  the  bodies  by  which  they  are  occupied, 
we  shall  find  our  task  simplified  in  no  common  degree.  If,  ac- 
cording to  ancient  but  unphilosophical  forms  of  nomenclature, 
we  would  distinguish  between  physics,  that  is  to  say,  general 
considerations  on  the  essence  of  matter,  and  the  forces  by  which 
it  is  actuated,  and  chemistry,  which  treats  of  the  nature  of 
substances,  their  elementary  composition,  and  those  attrac- 
tions that  are  not  determined  solely  by  the  relations  of  mass, 
we  must  admit  that  the  description  of  the  earth  comprises  at 


INTRODUCTION.  (53 

once  physical  and  chejiiical  actions.  In  addition  to  gravita- 
tion, which  must  be  considered  as  a  primitive  force  in  nature, 
we  observe  that  attractions  of  another  kind  are  at  work  around 
us,  both  in  the  interior  of  our  planet  and  on  its  surface.  These 
forces,  to  which  we  apply  the  term  chemical  ajjinity,  act  upon 
molecules  in  contact,  or  at  infinitely  minute  distances  from  one 
another,*  and  which,  being  differently  modified  by  electricity, 
heat,  condensation  in  porous  bodies,  or  by  the  contact  of  an 
intermediate  substance,  animate  equally  the  inorganic  world 
and  animal  and  vegetable  tissues.  If  we  except  the  small 
asteroids,  which  appear  to  us  under  the  forms  of  aerolites  and 
shooting  stars,  the  regions  of  space  have  hitherto  presented  to 
our  direct  observation  physical  phenomena  alone  ;  and  in  the 
case  of  these,  we  know  only  with  certainty  the  effects  depend- 
ing upon  the  quantitative  relations  of  matter  or  the  distribu- 
tion of  masses.  The  phenomena  of  the  regions  of  space  may 
consequently  be  considered  as  influenced  by  simple  dynamical 
laws — the  laws  of  motion. 

The  effects  that  may  arise  from  the  specific  difference  and 
the  heteroofeneous  nature  of  matter  have  not  hitherto  entered 
into  our  calculations  of  the  mechanism  of  the  heavens.  The 
only  means  by  which  the  inhabitants  of  our  planet  can  enter 
into  relation  with  the  matter  contained  within  the  regions  of 
space,  whether  existing  in  scattered  forms  or  united  into  large 
spheroids,  is  by  the  phenomena  of  light,  the  propagation  of 
luminous  waves,  and  by  the  influence  universally  exercised  by 
the  force  of  gravitation  or  the  attraction  of  masses.  The  ex- 
istence of  a  periodical  action  of  the  sun  and  moon  on  the  va- 
riations of  terrestrial  magnetism  is  even  at  the  present  day 
extremely  problematical.  We  have  no  direct  experimental 
knowdedge  regarding  the  properties  and  specific  qualities  of 
the  masses  circulating  in  space,  or  of  the  matter  of  w^hich  they 
are  probably  composed,  if  we  except  what  may  be  derived  from 
the  fall  of  aerolites  or  meteoric  stones,  wdiich,  as  we  have  al- 
ready observed,  enter  within  the  limits  of  our  terrestrial  sphere. 
It  will  be  sufficient  here  to  remark,  that  the  direction  and  the 
excessive  velocity  of  projection  (a  velocity  wholly  planetary) 
manifested  by  these  masses,  render  it  more  than  probable  that 

*  On  the  question  already  discussed  by  Newton,  regarding  the  differ- 
ence existing  between  the  atti-action  of  masses  and  molecular  attraction, 
see  Laplace,  Exposition  du  Systeme  du  Monde,  p.  384,  and  supplement 
to  book  X.  of  the  Mecanique  Celeste,  p,  3,  4 ;  Kant,  Metaph.  AnfangR. 
grunde  der  Naturwissenschaft,  Sam.  Werke,  1839,  bd.  v.,  s.  309  (Meta- 
physical Principles  of  the  Natural  Sciences)  ;  Pectet,  Physique,  1838- 
vol,  i.,  p.  59-63. 


64  COSMOS. 

they  are  small  celestial  bodies,  which,  being  attracted  by  out 
planet,  are  made  to  deviate  from  their  original  course,  and  thus 
reach  the  earth  enveloped  in  vapors,  and  in  a  high  state  of 
actual  incandescence.  The  familiar  aspect  of  these  asteroids, 
and  the  analogies  which  they  present  with  the  minerals  com- 
posing the  earth's  crust,  undoubtedly  afford  ample  grounds  for 
surprise  ;*  but,  in  my  opinion,  the  only  conclusion  to  be  drawn 
from  these  facts  is,  that,  in  general,  planets  and  other  sidereal 
masses,  which,  by  the  influence  of  a  central  body,  have  been 
agglomerated  into  rings  of  vapor,  and  subsequently  into  sphe- 
roids, being  integrant  parts  of  the  same  system,  and  having 
one  common  origin,  may  likewise  be  composed  of  substances 
chemically  identical.  Again,  experiments  with  the  pendulum, 
particularly  those  prosecuted  with  such  rare  precision  by  Bes- 
sel,  confirm  the  Newtonian  axiom,  that  bodies  the  most  hete- 
rogeneous in  their  nature  (as  water,  gold,  quartz,  granular 
limestone,  and  diflerent  masses  of  aerolites)  experience  a  per- 
fectly similar  degree  of  acceleration  from  the  attraction  of  the 
earth.  To  the  experiments  of  the  pendulum  may  be  added 
the  proofs  furnished  by  purely  astronomical  observations.  The 
almost  perfect  identity  of  the  mass  of  Jupiter,  deduced  from  the 
influence  exercised  by  this  stupendous  planet  on  its  own  satel- 
lites, on  Encke's  comet  of  short  period,  and  on  the  small  planets 
Vesta,  Juno,  Ceres,  and  Pallas,  indicates  with  equal  certain- 
ty that  within  the  limits  of  actual  observation  attraction  is 
determined  solely  by  the  quantity  of  matter. t 

This  absence  of  any  perceptible  difierence  in  the  nature  of 
matter,  alike  proved  by  direct  observation  and  theoretical  de- 
ductions, imparts  a  high  degree  of  simplicity  to  the  mechanism 
of  the  heavens.  The  immeasurable  extent  of  the  regions  of 
space  being  subjected  to  laws  of  motion  alone,  the  sidereal 
portion  of  the  science  of  the  Cosmos  is  based  on  the  pure  and 
abundant  source  of  mathematical  astronomy,  as  is  the  terres- 
trial portion  on  physics,  chemistry,  and  organic  morphology  ; 
but  the  domain  of  these  three  last-named  sciences  embraces 

*  [The  analysis  of  an  aeroHte  which  fell  a  few  years  since  in  Mary 
land.  United  States,  and  was  examined  by  Professor  Silliman,  of  New 
Haven,  Connecticut,  gave  the  following  results:  Oxyd  of  iron,  24 ;  ox- 
yd  of  nickel,  1*25 ;  silica,  with  earthy  matter,  3*46  ;   sulphur,  a  trace 
=28-71.    Dr.  Mantell's  Wonders  of  Geology,  1848,  vol.  i..  p.  51.]— 7V. 

t  Poisson,    Connaissances  des    Temps  pour  V Annee   1836,  p.  (j4-6(). 
Bessel,  Poggeudorf 's  Annalen,  bd.  xxv.,  s.  417.     Encke,  Abhandhingen 
der  Berliner  Academie  (Trans,  of  the  Berlin  Academy),  1826,  s.  257. 
Mitscherlich,  Lehrbuck  der  Chemie  (Manual  of  Chemistry),  1837   bd.  i. 
8.  352. 


INTRODUCTION.  65 

the  consideration  of  phenomena  which  are  so  complicated, 
and  have,  up  to  the  present  time,  been  found  so  little  suscep- 
tible of  the  application  of  rigorous  method,  that  tht)  physical 
science  of  the  earth  can  not  boast  of  the  same  certainty  and 
simplicity  in  the  exposition  of  facts  and  their  mutual  connec- 
tion which  characterize  the  celestial  portion  of  the  Cosmos. 
It  is  not  improbable  that  the  difference  to  which  we  allude 
may  furnish  an  explanation  of  the  cause  which,  in  the  earliest 
ages  of  intellectual  culture  among  the  Greeks,  directed  the 
natural  philosophy  of  the  Pythagoreans  with  more  ardor  to  the 
heavenly  bodies  and  the  regions  of  space  than  to  the  earth 
and  its  productions,  and  how  through  Philolaiis,  and  subse- 
quently through  the  analogous  views  of  Aristarchus  of  Samos, 
and  of  Seleucus  of  Erythrea,  this  science  has  been  made  more 
conducive  to  the  attainment  of  a  knowledge  of  the  true  system 
of  the  world  than  the  natural  philosophy  of  the  Ionian  school 
could  ever  be  to  the  physical  history  of  the  earth.  Giving  but 
little  attention  to  the  properties  and  specific  differences  of 
matter  filling  space,  the  great  Italian  school,  in  its  Doric 
gravity,  turned  by  preference  toward  all  that  relates  to  meas- 
ure, to  the  form  of  bodies,  and  to  the  number  and  distances  of 
the  planets,*"  while  the  Ionian  physicists  directed  their  atten 
tion  to  the  qualities  of  matter,  its  true  or  supposed  metamor 
phoses,  and  to  relations  of  origin.  It  was  reserved  for  the 
powerful  genius  of  Aristotle,  alike  profoundly  speculative  and 
practical,  to  sound  with  equal  success  the  depths  of  abstraction 
and  the  inexhaustible  resources  of  vital  activity  pervading  the 
material  world. 

Several  highly  distinguished  treatises  on  physical  geography 
are  prefaced  by  an  introduction,  whose  purely  astronomical 
sections  are  directed  to  the  consideration  of  the  earth  in  its 
planetary  dependence,  and  as  constituting  a  part  of  that  great 
system  which  is  animated  by  one  central  body,  the  sun.  This 
course  is  diametrically  opposed  to  the  one  which  I  propose 
following.  In  order  adequately  to  estimate  the  dignity  of  the 
Cosmos,  it  is  requisite  that  the  sidereal  portion,  termed  by 
Kant  the  oiaturaL  history  of  the  heavens,  should  not  be  made 
subordinate  to  the  terrestrial.  In  the  science  of  the  Cosmos, 
according  to  the  expression  of  Aristarchus  of  Samos,  the  pio- 
neer cf  •the  Copernican  system,  the  sun,  with  its  satellites, 
was  nothing  more  than  one  of  the  innumerable  stars  by  which 
space  is  occupied.  The  physical  history  of  the  world  must, 
therefore,  begin  with  the  description  of  the  heavenly  bodies, 
*  Compare  Otfried  MUller's  Dorien,  bd.  i.,  s.  365. 


■U6  ^  COSMOS. 

and  with  a  geographical  sketch  of  the  universe,  or,  I  would 
rather  say,  a  true  map  of  the  ivorld,  such  as  was  traced  by 
the  bold  hand  of  the  elder  Herschel.  If,  notwithstanding  the 
sraallness  of  our  planet,  the  most  considerable  space  and  the 
most  attentive  consideration  be  here  afforded  to  that  which 
exclusively  concerns  it,  this  arises  solely  from  the  disproportion 
in  the  extent  of  our  knowledge  of  that  which  is  accessible  and 
of  that  which  is  closed  to  our  observation.  This  subordina- 
tion of  the  celestial  to  the  terrestrial  portion  is  met  with  in  the 
great  work  of  Bernard  Varenius,'*  w^hich  appeared  in  the  mid- 

*  Geographia  Generalis  iii  qua  affectiones  generales  telluris  expli- 
cantur.  The  oldest  Elzevir  edition  bears  date  1650,  the  second  1672, 
and  the  third  1681 ;  these  were  published  at  Cambridge,  under  New- 
ton's supervision.  This  excellent  work  by  Varenius  is,  in  the  true 
sense  of  the  words,  a  physical  description  of  the  earth.  Since  the  work 
Hlstoria  Natural  de  las  Indias,  1590,  in  which  the  Jesuit  Joseph  de 
Acosta  sketched  in  so  masterly  a  manner  the  delineation  of  the  New 
Continent,  questions  relating  to  the  physical  history  of  the  earth  have 
never  been  considered  with  such  admirable  generality.  Acosta  is  rich- 
er in  original  observations,  while  Varenius  embraces  a  wider  circle  of 
ideas,  since  his  sojourn  in  Holland,  which  was  at  that  period  the  center 
of  vast  commercial  relations,  had  brought  him  in  contact  with  a  great 
number  of  w^ell-informed  travelers.  Generalis  sive  Universalis  Geo- 
graphia dicitJir  qute  tellurem  in  genere  considerat  atque  affectiones  ex' 
plicat,  non^  habita  particulariitm  regionum  ratione.  The  general  de- 
scription of  the  earth  by  Varenius  {Pars  Ahsoluta,  cap.  i.-xxii.)  maybe 
considered  as  a  treatise  of  comparative  geography,  if  we  adopt  the  term 
used  by  the  author  h.\m?,e\i  {Geographia  Comparativa,  cap.xxxiii.-xl.), 
although  this  must  be  understood  in  a  limited  acceptation.  We  may 
cite  the  following  among  the  most  remarkable  passages  of  this  book : 
the  enumeration  of  the  systems  of  mountains  ;  the  examination  of  the 
relations  existing  between  their  directions  and  the  general  form  of  con- 
tinents (p.  66,  76,  ed.  Cantab.,  1681);  a  list  of  extinct  volcanoes,  and 
such  as  were  still  in  a  state  of  activity  ;  the  discussion  of  facts  relative 
to  the  general  distribution  of  islands  and  archipelagoes  (p.  220)  ;  the 
depth  of  the  ocean  I'elatively  to  the  height  of  neighboring  coasts  (p.  103) ; 
the  uniformity  of  level  observed  in  all  open  seas  (p.  97)  ;  the  depend- 
ence of  currents  on  the  prevailing  winds;  the  unequal  saltness  of  the 
sea;  the  configuration  of  shores  (p.  139);  the  direction  of  the  winds  as 
the  result  of  ditferences  of  temperature,  &c.  We  may  further  instance 
the  remarkable  considerations  of  Varenius  regarding  the  equinoctial 
current  from  east  to  west,  to  which  he  attributes  the  origin  of  the  Gulf 
Stream,  beginning  at  Cape  St.  Augustiu,  and  issuing  forth  between 
Cuba  and  Florida  (p.  140).  Nothing  can  be  more  accurate  than  his 
description  of  the  current  which  skirts  the  western  coast  of  Africa,  be- 
tween Cape  Verde  and  the  island  of  Fernando  Po  in  the  Gulf  of  Guinea. 
Varenius  explains  the  formation  of  sporadic  islands  by  supposing  them 
to  be  *'  the  raised  bottom  of  the  sea:"  magna  spirihium  inclusorum  vi, 
sicut  aliquando  monies  e  terra  protttsos  esse  quidam  scribunt  (p.  225). 
The  edition  published  by  Newton  in  1681  {auciior  et  emendatior)  un^ 
fortunately  contains  no  additions  from  this  great  authority;  and  there 
is  not  even  mention  made  of  the  polar  compression  of  the  globe,  al- 


IXTIIODUCTIOX.  07 

d\e  of  the  seventeenth  century.  He  was  tlie  first  to  distinguish 
between  general  a?id  special  geography,  the  former  of  which 
he  subdivides  into  an  absolute,  or,  properly  speaking,  terres- 
trial part,  and  a  relative  or  planetary  portion,  according  to 
the  mode  of  considering  our  planet  either  with  reference  to  its 
surface  in  its  diliereiit  zones,  or  to  its  relations  to  the  sun  and 
moon.  It  redounds  to  the  glory  of  Varenius  that  his  work  on 
General  and  Comparative  Geography  should  in  so  high  a 
degree  have  arrested  the  attention,  of  Newton.  The  imper- 
fect state  of  many  of  the  auxiliary  sciences  from  which  this 
.  writer  was  obliged  to  draw  his  materials  prevented  his  work 
from  corresponduig  to  the  greatness  of  the  design,  and  it  was 
reserved  for  the  present  age,  and  for  my  own  country,  to  see 
the  delineation  of  comparative  geography,  drawn  in  its  full 
extent,  and  in  all  its  relations  with  the  history  of  man,  by  the 
skillful  hand  of  Carl  Ritter.* 

The  enumeration  of  the  most  important  results  of  the  as- 
tronomical and  physical  sciences  which  in  the  history  of  the 
Cosmos  radiate  toward  one  common  focus,  may  perhaps,  to  a 
certain  degree,  justify  the  designation  I  have  given  to  my 
work,  and,  considered  within  the  circumscribed  limits  I  have 
proposed  to  myself,  the  undertaking  may  be  esteemed  less  ad- 
venturous than  the  title.  The  introduction  of  new  terms,  es- 
pecially with  reference  to  the  general  results  of  a  science  which 

-  though  the  experiments  on  the  pendulum  by  Richer  had  been  made 
nine  years  prior  to  the  appearance  of  the  Cambridge  edition.  Newton's 
Principia  Mathematica  Philosojjhice  Natnralis  were  not  communicated 
in  manuscript  to  tlie  Royal  Society  until  April,  1G80.  Much  uncer- 
tainty seems  to  prevail  regarding  the  birth-place  of  Varenius.  Ja;cher 
says  it  was  England,  while,  according  to  La  Biographie  Universclle 
(b.  xlvii.,  p.  495),  he  is  stated  to  have  been  bom  at  Amsterdam;  but 
it  would  appear,  from  the  dedicatory  address  to  the  burgomaster  ol 
that  city  (see  his  Geographia  Comparativa),  that  both  suppositions  ai'e 
false.  Varenius  expressly  says  that  lie  had  sought  refuge  in  Amsterdam, 
*'  because  his  native  city  had  been  burned  and  completely  destroyed 
during  a  long  war,"  words  which  appear  to  apply  to  the  north  of  Ger- 
many, and  to  the  devastations  of  the  Thirty  Years'  War.  In  his  dedica- 
tion of  another  work,  Descriptio  regni  Japonic^  (Amst.,  1649),  to  the 
Senate  of  Hamburgh,  Varenius  says  that  he  prosecuted  his  elementary 
mathematical  studies  in  the  gymnasium  of  that  city.  There  is,  there- 
fore, every  reason  to  believe  that  this  admirable  geographer  was  a 
native  of  Germany,  and  was  probajjly  born  at  Luneburg  (  TFV/^e?i.  Mem. 
Theol.,  1685,  p.  2142;  Zedler,  Universal  Lexicon,  vol.  xlvi.,  1745.  p. 
187). 

*  Carl  Ritter's  Erdkundeim  VerhuUniss  zur  Naturund  zvr  Geschichte 
des  Menschen,  oder  allgemeine  vergleichende  Geographic  (Geojjraphy  in 
relation  to  Nature  and  the  History  o'  Man,  or  general  Comparativo 
Geography). 


68  COSMOS. 

ought  to  be  accessible  to  all,  has  always  been  greatly  in  oppo- 
sition to  my  own  practice  ;  and  whenever  I  have  enlarged 
upon  the  established  nomenclature,  it  has  only  been  in  the 
specialities  of  descriptive  botany  and  zoology,  where  the  in- 
troduction of  hitherto  unknown  objects  rendered  new  names 
necessary.  The  denominations  of  physical  descriptions  of  the 
universe,  or  physical  cosmography,  which  I  use  indiscrimin- 
ately, have  been  modeled  upon  those  o{  physical  descriptio?is 
of  the  earth,  that  is  to  say,  physical  geography,  terms  that 
have  lonor  heen  in  common  use.  Descartes,  whose  o^enius  was 
one  of  the  most  powerful  manifested  in  any  age,  has  left  us  a 
few  fragments  of  a  great  work,  which  he  intended  publishing 
under  the  title  of  Monde,  and  for  which  he  had  prepared  him- 
self by  special  studies,  including  even  that  of  human  anatomy. 
The  uncommon,  but  definite  expression  of  the  science  of  the 
Cosmos  recalls  to  the  mind  of  the  inhabitant  of  the  earth  that 
we  are  treating  of  a  more  wddely-extended  horizon — of  the 
assemblage  of  all  things  with  which  space  is  filled,  from  the 
remotest  nebula?  to  the  climatic  distribution  of  those  delicate 
tissues  of  vegetable  matter  which  spread  a  variegated  cover- 
ins:  over  the  surface  of  our  rocks. 

The  influence  of  narrow-minded  views  peculiar  to  the  ear- 
lier ages  of  civilization  led  in  all  languages  to  a  confusion  of 
ideas  in  the  synonymic  use  of  the  words  earth  and  tvorld, 
while  the  common  expressions  voyages  round  the  ivorld,  map 
of  the  ivorld,  and  neiu  ivorld,  afford  further  illustrations  of  the 
same  confusion.  The  more  noble  and  precisely-defined  ex- 
pressions of  system  of  the  ivorld,  the  planetary  ivorld,  and 
creation  and  age  of  the  ivorld,  relate  either  to  the  totality  of 
the  substances  by  which  space  is  filled,  or  to  the  origin  of"  the 
whole  universe. 

It  was  natural  that,  in  the  midst  of  the  extreme  variability 
of  phenomena  presented  by  the  surface  of  our  globe,  and  the 
aerial  ocean  by  which  it  is  surrounded,  man  should  have  been 
impressed  by  the  aspect  of  the  vault  of  heaven,  and  the  uni- 
form and  regular  movements  of  the  sun  and  planets.  Thus 
the  word  Cosmos,  which  primitively,  in  the  Homeric  ages,  in- 
dicated an  idea  of  order  and  harmony,  was  subsequently  adopt- 
ed in  scientific  language,  where  it  was  gradually  applied  to 
the  order  observed  in  the  movements  of  the  heavenly  bodies, 
to  the  whole  universe,  and  then  finally  to  the  world  in  which 
this  harmony  was  reflected  to  us.  According  to  the  assertion 
of  Philolaiis,  whose  fragmentary  works  have  been  so  ably  com- 
mented upon  by  Bockh,  and  conformably  to  the  general  testi- 


INTRODUCTION.  69 

mony  of  antiquity,  Pythagoras  was  the  first  who  used  the 
word  Cosmos  to  designate  the  order  that  reigns  in  the  uni- 
verse, or  entire  world.* 

*  Koofioc,  in  the  most  ancient,  and  at  the  same  time  most  precise, 
definition  of  the  word,  signified  ornament  (as  an  adornment  for  a  man, 
a  woman,  or  a  horse) ;  taken  figuratively  for  evra^ia,  it  implied,  the  or- 
der or  adornment  of  a  discourse.  According  to  the  testimony  of  all  the 
ancients,  it  was  Pythagoras  who  first  used  the  word  to  designate  the 
order  in  the  universe,  and  the  universe  itself.  Pythagoras  left  no  writ- 
ings ;  but  ancient  attestation  to  the  truth  of  this  assertion  is  to  be  found 
in  several  passages  of  the  fragmentary  works  of  Philolatis  (Stob.,  Eclog., 
p.  360  and  460,  Heeren),  p.  62,  90,  in  Bockh's  German  edition.  I  do 
not,  according  to  the  example  of  Niike,  cite  Tim.'eus  of  Locris,  since  hia 
authenticity  is  doubtful.  Plutarch  {De  plac.  Phil.,  ii.,  1)  says,  in  the 
most  express  manner,  that  Pythagoras  gave  the  name  of  Cosmos  to  the 
universe  on  account  of  the  order  which  reigned  throughout  it;  so  like- 
wise does  Galen  {Hist.  Phil.,  p.  429).  This  word,  together  with  its 
novel  signification,  passed  from  the  schools  of  philosophy  into  the  lan- 
guage ot  poets  and  prose  writers.  Plato  designates  the  heavenly  bod- 
ies by  the  name  of  Uranos,  but  the  order  pervading  the  regions  of  space 
he  too  terms  the  Cosmos,  and  in  his  Timmus  (p.  30,  b.)  he  says  that  the 
world  is  an  animal  endowed  tcith  a  soul  {KOCfiov  ^cjou  kiiypv^ov).  Com- 
pare Anaxag.  Claz.,  ed.  Schaubach,  p.  Ill,  and  Plut.  {De  plac.  Phil., 
ii.,  3),  on  spirit  apart  from  matter,  as  the  ordaining  power  of  nature. 
In  Aristotle  {De  Casio,  1,  9),  Cosmos  signifies  "  the  universe  and  the 
order  pervading  it,"  but  it  is  likewise  considered  as  divided  in  space 
into  two  parts — the  sublunary  world,  and  the  world  above  the  moon. 
{Meteor.,  I.,  2,  1,  and  I.,  3,  13,  p.  339,  a,  and  340,  b,  Bekk.)  The  def- 
inition of  Cosmos,  which  I  have  already  cited,  is  taken  from  Pseudo-Ar- 
istoteles  de  Mundo,  cap.  ii.  (p.  391);  tte  passage  referred  to  is  as  fol- 
lows: Koa^og  earl  nvoTijua  kg  ovpavov  koL  yfjg  Kul  tuv  ev  Tovrotg  Trepte- 
XOfiivuif  (pvaeov.  AeyeTac  de  Kal  eKepcog  K6a2,og  rj  ribv  bT^uv  rd^ig  re  kuI 
6iaK6(yfj,r]aig,  vno  t^euv  re  Kai  did  d^aijv  (pv/iaTTOfiivri.  Most  of  the  pas- 
sages occurring  in  Greek  writers  on  the  word  Cosmos  may  be  found 
collected  together  in  the  controversy  between  Richard  Bentley  and 
Charles  Boyle  {Opuscula  Philologica,  1781,  p.  347,  445;  Dissertation 
iipon  the  Epistles  of  Phalaris,  1817,  p.  254)  ;  on  the  histoiical  existence 
of  Zaleucus,  legislator  of  Leucris,  in  Nake's  excellent  work,  Sched. 
Crit.,  1812,  p.  9,  15;  and,  finally,  in  Thcophilus  Schmidt,  ad  Cleom. 
Cycl.  Theor.,  met.  I.,  1,  p.  ix.,  1,  and  99.  Taken  in  a  more  limited 
sense,  the  word  Cosmos  is  also  used  in  the  plural  (Plut.,  1,  5),  either  to 
designate  the  stars  (Stob.,  1,  p.  514;  Plut.,  11, 13),  or  the  innumerable 
systems  scattered  like  Islands  through  the  immensity  of  space,  and  each 
composed  of  a  sun  and  a  moon.  (Anax.  Claz.,  Fragm.,  p.  89,  93,  120; 
Brandis,  Gesck.  der  Griechisck-Romischen  Philosophie,  h.  i.,  s.  252  (His- 
tory of  the  Greco-Roman  Philosophy).  Each  of  these  groups  forming 
thus  a  Cosmos,  the  universe,  to  ttuv,  the  word  must  be  understood  in  a 
wider  sense  (Pint.,  ii.,  1).  It  was  not  until  long  after  the  time  of  the 
Ptolemies  that  the  word  was  applied  to  the  earth.  Bockh  has  made 
known  inscnptions  in  praise  of  Trajan  and  Adrian  (  Corpus  Inscr.  Grcec., 
1,  n.  334  and  1036),  in  which  Koafiog  occurs  for  oLKOVjiivrj,  in  the  same 
manner  as  we  still  use  the  term  world  to  signify  the  earth  alone.  We 
have  already  mentioned  the  singular  division  of  the  regions  of  space 


70  COSMOS. 

From  the  Italian  school  of  philosophy,  the  expression  pass- 
ed, in  this  signification,  into  the  language  of  those  early  poets 

into  three  parts,  the  Olympus,  Cosmos,  and  Oui\tnos  (Stob.,  i.,  p.  488; 
Philolatis,  p.  94,  202)  ;  this  division  applies  to  the  dilTerent  regions  sur 
i-Qunding  that  mysterious  focus  of  the  universe,  the  'Earia  rov  iravTot, 
of  the  Pythagoreans.     In  the  fragmentary  passage  in  which  this  divi- 
sion is  found,  the  term  Ouranos  designates  the  innermost  region,  situ- 
ated between  the   moon  and  earth ;  this  is  the  domain  of  changing 
things.     The  middle  region,  where  the  planets  circulate  in  an  invaria- 
ble and  harmonious  order,  is,  in  accordance  with  the  special  coucep- 
tions  entertained  of  tlie  universe,  exclusively  termed  Cosmos,  while  the 
word  Olympus  is  used  to  express  the  exterior  or  igneous  region.     13opp, 
the  profound  philologist,  has  remarked,  that  we  may  deduce,  as  Pott 
has  done,  Etymol.  Forschungeii,  th.  i.,  s.  39  and  252  {Eiymol.  Research- 
es), the  word  Koa^og  from  the  Sanscrit  root  'sud\  purificari,  by  assum- 
ing  two  conditions;  first,  that  the  Greek  k  in  koo^oq  comes  from  the 
palatial  c,  which  Bopp  represents  by  's  and  Pott  by  c  (in  the  same  man- 
ner as  diKa,  decern,  taih^m  in  Gothic,  comes  from  the  Indian  word  del- 
ean),  and,  next,  that  the  Indian  d'  corresponds,  as  a  general  rule,  with 
the  Greek  6  (  Vergleichende  Grammatik,  $  99 — Comparative  Grammar), 
which  shows  the  relation  of  Koa/xoc  (for  Kodfxog)  with  the  Sanscrit  root 
^sud\  whence  is  also  derived  Kada^ibg.     Another  Indian  term  for  the 
world  is  gagat  (pronounced  dschagat),  which  is,  properly  speaking,  the 
present  participle  of  the  verb  gagdmi  (I  go),  the  root  of  which  is  gd. 
In  restricting  ourselves  to  the  circle  of  Hellenic  etymologies,  we  find 
{Etymol.  M.,  p.  532, 12)  that  Koojiog  is  intimately  associated  with  wafw, 
or  rather  with  Kacvvfiac,  whence  we  have  KeKaafievog  or  KCKac^fxEvog. 
Welcker  (Eine  Kretische  Col.  in  Thebcn,  s.  23 — A  Cretan  Colony  in 
Thebes)  combines  with  this  the  name  Kadjiog,  as  in  Hesychius  Kud/nog 
signifies  a  Cretan  suit  of  anus.    When  the  scientific  language  of  Greece 
w^as  introduced  among  the  Romans,  the  word  mundus,  which  at  first  had 
only  the  primary  meaning  of /cda/^of  (female  ornament),  was  applied  to 
designate  the  entire  universe.     Ennius  seems  to  have  been  the  first 
who  ventui-ed  upon  this  innovation.     In  one  of  the  fragments  of  this 
poet,  preserved  by  Macrobius,  on  the  occasion  of  his  quarrel  with  Vir- 
gil, we  fiud  the  word  used  in  its  novel  mode  of  acceptation :  "  Micitdus 
coeli  vastus  constitit  silentio''^  (Sat.,  vi.,  2).     Cicero  also  says,  ^'Qvem  nos 
lucentem  mundum  vocamus^^  (Timajus,  S.  de   Univer.,  cap.  x.).     The 
Sanscrit  root  mand,  from  which  Pott  derives  the  Latin  mundus  {Etym. 
Forsch.,  th.  i.,s.  240),  combines  the  double  signification  of  shining  and 
adorning.    Loka  designates  in  Sanscrit  the  world  and  people  in  general, 
in  the  same  manner  as  the  French  word  monde,  and  is  derived,  accord- 
ing to  Bopp,  from  Idk  (to  see  and  shine);  it  is  the  same  with  the  Scla- 
vonic root  swjet,  which  means  both  light  and  icorld.    (Grimm,  Deutsche 
Gramm.,  b.  iii.,  s.  394 — German  Grammar.)     The  word  icelt,  which 
the  Germans  make  use  of  at  the  present  day,  and  which  was  weralt  in 
old  German,  toorold  in  old  Saxon,  and  veruld  in  Anglo-Saxon,  was,  ac- 
cording to  .Tames  Grimm's  interpi-etation,  a  period  ol  time,  an  age  (««- 
cnlum),  rather  than  a  term  used  for  the  world  in  space.    The  Etruscans 
figured  to  themselves  mundus  as  an  inverted  dome,  symmetrically  op- 
posed to  the  celestial  vault  (Otfried  MUller's  Etrusken,  th.  ii.,  s.  96, 
&c.).     Taken  in  a  still  more  hmited  sense,  the  word  appears  to  have 
signified  among  the  Goths  the  terrestrial  surface  girded  by  seas  (marei, 
meri),  the  merigard,  literally,  garden  of  seas. 


INTRODUCTION.  71 

of  nature,  Parmenides  and  Empedocles.  and  from  thence  into 
the  works  of  prose  writers.  We  will  not  here  enter  into  a 
discussion  of  the  manner  in  which,  according  to  the  Pythago- 
rean views,  Philolaiis  distinguishes  between  Olympus,  Uranus, 
or  the  heavens,  and  Cosmos,  or  how  the  same  word,  used  in 
a  plural  sense,  could  be  applied  to  certain  heavenly  bodies 
(the  planets)  revolving  round  one  central  focus  of  the  world, 
or  to  groups  of  stars.  In  this  work  I  use  the  word  Cosmos  in 
conformity  with  the  Hellenic  usage  of  the  term  subsequently 
to  the  time  of  Pythagoras,  and  in  accordance  with  the  precise 
definition  given  of  it  in  the  treatise  entitled  De  Mmido,  which 
was  long  erroneously  attributed  to  Aristotle.  It  is  the  assem- 
blage of  all  things  in  heaven  and  earth,  the  universality  of 
created  things  constituting  the  perceptible  world.  If  scientific 
terms  had  not  long  been  diverted  from  their  true  verbal  sig- 
nification,  the  present  work  ought  rather  to  have  borne  the 
title  of  Cosmography,  divided  into  Uranography  and  Geog- 
raj)hy.  The  Romans,  in  their  feeble  essays  on  philosophy,  ^ 
imitated  the  Greeks  by  applying  to  the  universe  the  term 
inundus,  which,  in  its  primary  meaning,  indicated  nothing 
more  than  ornament,  and  did  not  even  imply  order  or  regu- 
larity in  the  disposition  of  parts.  It  is  probable  that  the  in- 
troduction into  the  language  of  Latium  of  this  technical  term 
as  an  equivalent  for  Cosmos,  in  its  double  signification,  is  due 
to  Ennius,*  who  was  a  follower  of  the  Italian  school,  and  the 
translator  of  the  writings  of  Epicharmus  and  some  of  his  pu 
pils  on  the  Pythagorean  philosophy. 

We  would  first  distinguish  between  the  physical  history  and 
the  physical  description  of  the  world.  The  former,  conceived 
in  the  most  general  sense  of  the  word,  ought,  if  materials  for 
writing  it  existed,  to  trace  the  variations  experienced  by  the 
universe  in  the  course  of  ages  from  the  new  stars  which  have 
suddenly  appeared  and  disappeared  in  the  vault  of  heaven, 
from  nebula}  dissolving  or  condensing — to  the  first  stratum  of 
cryptogamic  vegetation  on  the  still  imperfectly  cooled  surface 
of  the  earth,  or  on  a  reef  of  coral  uplifted  from  the  depths  of 
ocean.  The  physical  description  of  the  ivorld  presents  a  pic- 
ture of  all  that  exists  in  space — of  the  simultaneous  action  of 

*  See,  on  Ennius,  the  ingenious  researches  of  Leopold  Krahnev,  in 
liis  Grundlinien  ziir  GeschicJite  des  Verfalls  der  Romischen  Staats-Rcii 
gion,  1837,  s.  41-45  (Outlines  of  the  History  of  the  Decay  of  the  EstaU 
lished  Religion  among  the  Romans).     In  all  probability,  Ennius  did  not 
quote  from  writings  of  Epicharmus  himself,  but  from  poems  composed 
La  the  name  of  that  philosopher,  and  in  accordance  wi'h  his  views 


72  COSMOS. 

natural  forces,  together  with  the  phenomena  which  they  pro- 
duce. 

But  if  we  would  correctly  comprehend  nature,  we  must  not 
entirely  or  absolutely  separate  the  consideration  of  the  present 
state  of  things  from  that  of  the  successive  phases  through 
which  they  have  passed.  We  can  not  form  a  just  conception 
of  their  nature  without  looking  back  on  the  mode  of  their  for- 
mation. It  is  not  organic  matter  alone  that  is  continually  un- 
dergoing change,  and  being  dissolved  to  form  new  combina- 
tions. The  globe  itself  reveals  at  every  phase  of  its  existence 
the  mystery  of  its  former  conditions. 

We  can  not  survey  the  crust  of  our  planet  without  recog- 
nizing the  traces  of  the  prior  existence  and  destruction  of  an 
organic  world.  The  sedimentary  rocks  present  a  succession 
of  organic  forms,  associated  in  groups,  Avhich  have  successive- 
ly displaced  and  succeeded  each  other.  The  different  super 
imposed  strata  thus  display  to  us  the  faunas  and  floras  of  dif- 
ferent epochs.  In  this  sense  the  description  of  nature  is  inti 
mately  connected  with  its  history  ;  and  the  geologist,  who  is 
guided  by  the  connection  existing  among  the  facts  observed, 
can  not  form  a  conception  of  the  present  without  pursuing, 
through  countless  ages,  the  history  of  the  past.  In  tracing 
the  physical  delineation  of  the  globe,  we  behold  the  present 
and  the  past  reciprocally  incorporated,  as  it  were,  with  one 
another  ;  for  the  domain  of  nature  is  like  that  of  languages,  in 
which  etymological  research  reveals  a  successive  development, 
by  showing  us  the  primary  condition  of  an  idiom  reflected  in 
the  forms  of  speech  in  use  at  the  present  day.  The  study  of 
the  material  world  renders  this  reflection  of  the  past  peculiar- 
ly manifest,  by  displaying  in  the  process  of  formation  rocks  of 
eruption  and  sedimentary  strata  similar  to  those  of  former 
ages.  If  I  may  be  allowed  to  borrow  a  striking  illustration 
from  the  geological  relations  by  which  the  physiognomy  of  a 
country  is  determined,  I  would  say  that  domes  of  trachyte, 
cones  of  basalt,  lava  streams  {coulees)  of  amygdaloid  with 
elongated  and  parallel  pores,  and  white  deposits  of  pumice, 
intermixed  with  black  scoriae,  animate  the  scenery  by  the  as- 
sociations of  the  past  which  they  awaken,  actmg  upon  the 
imagination  of  the  enlightened  observer  like  traditional  records 
of  an  earlier  world.     Their  form  is  their  history. 

The  sense  in  which  the  Greeks  and  Romans  originally  em- 
ployed the  word  history  proves  that  they  too  were  intimately 
convinced  that,  to  form  a  complete  idea  of  the  present  state 
of  the  universe,  it  was  necessary  to  consider  it  in  its  successive 


INTRODUCTION.  73^ 

phases.  It  is  not,  however,  in  the  definition  given  by  Vale- 
lius  Flaccus,*'  but  in  the  zoological  writings  of  Aristotle,  that 
the  word  history  presents  itself  as  an  exposition  of  the  results 
of  experience  and  observation.  The  physical  description  of 
the  word  by  Pliny  the  elder  bears  the  title  of  Natural  His- 
tory, while  in  the  letters  of  his  nephew  it  is  designated  by  the 
nobler  terra  of  History  of  Nature.  The  earlier  Greek  his- 
torians did  not  separate  the  descriptions  of  countries  from  the 
narrative  of  events  of  which  they  had  been  the  theater.  With 
these  writers,  physical  geography  and  history  were  long  inti- 
mately associated,  and  remained  simply  but  elegantly  blended 
until  the  period  of  the  development  of  political  interests,  when 
the  agitation  in  which  the  lives  of  men  were  passed  caused 
the  geographical  portion  to  be  banished  from  the  history  of 
nations,  and  raised  into  an  independent  science. 

It  remains  to  be  considered  whether,  by  the  operation  of 
thought,  we  may  hope  to  reduce  the  immense  diversity  of 
phenomena  comprised  by  the  Cosmos  to  the  unity  of  a  princi- 
ple, and  the  evidence  ajSbrded  by  rational  truths.  In  the 
present  state  of  empirical  knowledge,  we  can  scarcely  flatter 
ourselves  Avith  such  a  hope.  Experimental  sciences,  based 
on  the  observation  of  the  external  world,  can  not  aspire  to 
completeness  ;  the  nature  of  things,  and  the  imperfection  of 
our  organs,  are  alike  opposed  to  it.  We  shall  never  succeed 
in  exhausting  the  immeasurable  riches  of  nature  ;  and  no  gen- 
eration of  men  will  ever  have  cause  to  boast  of  bavins:  com- 
prehended  the  total  aggregation  of  phenomena.  It  is  only  by 
distributing  them  into  groups  that  we  have  been  able,  in  the 
case  of  a  few,  to  discover  the  empire  of  certain  natural  laws, 
grand  and  simple  as  nature  itself.  The  extent  of  this  empire 
will  no  doubt  increase  in  proportion  as  physical  sciences  are 
more  perfectly  developed.  Striking  proofs  of  this  advance- 
ment have  been  made  manifest  in  our  own  day,  in  the  phe- 
nomena of  electro-magnetism,  the  propagation  of  luminous 
waves  and  radiating  heat.  In  the  same  manner,  the  fruitful 
doctrine  of  evolution  shows  us  how,  in  organic  development, 
all  that  is  formed  is  sketched  out  beforehand,  and  how  the 
tissues  of  vegetable  and  animal  matter  uniformly  arise  from 
the  multiplication  and  transformation  of  cells. 

The  generalization  of  laws,  which,  being  at  first  bounded 
by  narrow  limits,  had  been  applied  solely  to  isolated  groups 
of  phenomena,  acquires  in  time  more  marked  gradations,  and 
gains  in  extent  and  certainty  as  long  as  the  process  of  reason* 

*  Aul.  Gell..  Noct.  Alt.,  v.,  18. 

Vol.  I— D 


74  COSMOS. 

ing  is  applied  strictly  to  analogous  phenomena ;  but  as  soon 
as  dynamical  views  prove  insufficient  M'here  the  specific  prop- 
erties and  heterogeneous  nature  of  matter  come  into  play,  it  is 
to  he  feared  that,  by  persisting  in  the  pursuit  of  laws,  we  may 
find  our  course  suddenly  arrested  by  .an  impassable  chasm. 
The  principle  of  unity  is  lost  sight  of,  and  the  guiding  clew 
is  rent  asunder  whenever  any  specific  and  peculiar  kind  of 
action  manifests  itself  amid  the  active  forces  of  nature.  The 
law  of  equivalents  and  the  numerical  proportions  of  composi- 
tion, so  happily  recognized  by  modern  chemists,  and  proclaimed 
under  the  ancient  form  of  atomic  symbols,  still  remains  isola- 
ted and  independent  of  mathematical  laws  of  motion  and  grav- 
itation. 

Those  productions  of  nature  which  are  objects  of  direct  ob- 
servation may  be  logically  distributed  in  classes,  orders,  and 
families.  This  form  of  distribution  undoubtedly  sheds  some 
light  on  descriptive  natural  history,  but  the  study  of  organized 
bodies,  considered  in  their  linear  connection,  although  it  may 
impart  a  greater  degree  of  unity  and  simplicity  to  the  distri- 
bution of  groups,  can  not  rise  to  the  height  of  a  classification 
based  on  one  sole  principle  of  composition  and  internal  organ- 
ization. As  different  gradations  are  presented  by  the  laws 
of  nature  according  to  the  extent  of  the  horizon,  or  the  limits 
of  the  phenomena  to  be  considered,  so  there  are  likewise  dif- 
ferently graduated  phases  in  the  investigation  of  the  external 
world.  Empiricism  originates  in  isolated  views,  which  are 
subsequently  grouped  according  to  their  analogy  or  dissimilar- 
ity. To  direct  observation  succeeds,  although  long  afterward, 
the  wish  to  prosecute  experiments  ;  that  is  to  say,  to  evoke 
phenomena  under  different  determined  conditions.  The  ra- 
tional experimentalist  does  not  proceed  at  hazard,  but  acts 
under  the  guidance  of  hypotheses,  founded  on  a  half  indistinct 
and  more  or  less  just  intuition  of  the  connection  existing  among 
natural  objects  or  forces.  That  which  has  been  conquered 
by  observation  or  by  means  of  experiments,  leads,  by  analysis 
and  induction,  to  the  discovery  of  empirical  laws.  These  are 
the  phases  in  human  intellect  that  have  marked  the  different 
epochs  in  the  life  of  nations,  and  by  means  of  which  that  great 
mass  of  facts  has  been  accumulated  which  constitutes  at  the 
present  day  the  solid  basis  of  the  natural  sciences. 

Two  forms  of  abstraction  conjointly  regulate  our  knowl- 
edge, namely,  relations  of  quantity,  comprising  ideas  of  num- 
ber and  size,  and  relations  of  quality,  embracing  the  consider- 
ation of  the  specific  properties  and  the  heterogeneous  nature 


INTRODUCTION.  76 

of  matter.  The  former,  as  being  more  accessible  to  the  exer 
cise  of  thought,  appertains  to  mathematics  ;  the  latter,  from 
its  apparent  mysteries  and  greater  difficulties,  falls  under  the 
domain  of  the  chemical  sciences.  In  order  to  submit  phe- 
nomena to  calculation,  recourse  is  had  to  a  hypothetical  con- 
struction of  matter  by  a  combination  of  molecules  and  atoms, 
whose  number,  form,  position,  and  polarity  determine,  modify, 
or  vary  phenomena. 

The  mythical  ideas  long  entertained  of  the  imponderable 
substances  and  vital  forces  peculiar  to  each  mode  of  organiza- 
tion, have  complicated  our  views  generally,  and  shed  an  un- 
certain light  on  the  path  we  ought  to  pursue. 

The  most  various  forms  of  intuition  have  thus,  age  aftei 
age,  aided  in  augmenting  the  prodigious  mass  of  empirical 
knowledge,  which  in  our  own  day  has  been  enlarged  with 
ever-increasing  rapidity.  The  investigating  spirit  of  man 
strives  from  time  to  time,  with  varying  success,  to  break 
through  those  ancient  forms  and  symbols  invented,  to  subject 
rebellious  matter  to  rules  of  mechanical  construction. 

We  are  still  very  far  from  the  time  when  it  will  be  possi- 
ble for  us  to  reduce,  by  the  operation  of  thought,  all  that  we 
perceive  by  the  senses,  to  the  unity  of  a  rational  principle. 
It  may  even  be  doubted  if  such  a  victory  could  ever  be 
achieved  in  the  field  of  natural  philosophy.  The  complica- 
tion of  phenomena,  and  the  vast  extent  of  the  Cosmos,  would 
seem  to  oppose  such  a  result ;  but  even  a  partial  solution  of 
the  problem — the  tendency  toward  a  comprehension  of  the 
phenomena  of  the  universe — will  not  the  less  remain  the  eter- 
nal and  sublime  aim  of  every  investigation  of  nature. 

In  conformity  with  the  character  of  my  former  writings,  as 
well  as  with  the  labors  in  which  I  have  been  engaged  during 
my  scientific  career,  in  measurements,  experiments,  and  the 
investigation  of  facts,  I  limit  myself  to  the  domain  of  empirical 
ideas. 

The  exposition  of  mutually  connected  facts  does  not  exclude 
the  classification  of  phenomena  according  to  their  rational  con- 
nection, the  generalization  of  many  specialities  in  the  great 
mass  of  observations,  or  the  attempt  to  discover  laws.  Con- 
ceptions of  the  universe  solely  based  upon  reason,  and  the 
principles  of  speculative  philosophy,  would  no  doubt  assign  a 
still  more  exalted  aim  to  the  science  of  the  Cosmos.  I  am  far 
from  blaming  the  efforts  of  others  solely  because  their  success 
has  hitherto  remained  very  doubtful.  Contrary  to  the  wishes 
and  counsels  of  those  profound  and  powerful  thinkers  who 


76  COSMOS. 

have  given  new  life  to  speculations  which  were  already  fa- 
miliar to  the  ancients,  systems  of  natural  philosophy  have  in 
our  own  country  for  some  time  past  turned  aside  the  minds 
of  men  from  the  graver  study  of  mathematical  and  physical 
sciences.  The  abuse  of  better  powers,  which  has  led  many 
of  our  noble  but  ill-judging  youth  into  the  saturnalia  of  a  pure- 
ly ideal  science  of  nature,  has  been  signalized  by  the  intoxica- 
tion of  pretended  conquests,  by  a  novel  and  fantastically  sym- 
bolical phraseology,  and  by  a  predilection  for  the  formulae  of 
a  scholastic  rationalism,  more  contracted  in  its  views  than 
any  known  to  the  Middle  Ages.  I  use  the  expression  "  abuse 
of  better  powers,"  because  superior  intellects  devoted  to  phil- 
osophical pursuits  and  experimental  sciences  have  remained 
strangers  to  these  saturnalia.  The  results  yielded  by  an  earn- 
est investigation  in  the  path  of  experinient  can  not  be  at  va- 
riance with  a  true  philosophy  of  nature.  If  there  be  any 
contradiction,  the  fault  must  lie  either  in  the  unsoundness  of 
speculation,  or  in  the  exaggerated  pretensions  of  empiricism, 
which  thinks  that  more  is  proved  by  experiment  than  is  act- 
ually derivable  from  it. 

External  nature  may  be  opposed  to  the  intellectual  world, 
as  if  the  latter  were  not  comprised  within  the  limits  of  the 
former,  or  nature  may  be  opposed  to  art  when  the  latter  is 
defined  as  a  manifestation  of  the  intellectual  power  of  man  ; 
but  these  contrasts,  which  we  find  reflected  in  the  most  cul- 
tivated languages,  must  not  lead  us  to  separate  the  sphere  of 
nature  from  that  of  mind,  since  such  a  separation  would  re- 
duce the  physical  science  of  the  world  to  a  mere  aggregation 
of  empirical  specialities.  Science  does  not  present  its.elf  to 
man  until  mind  conquers  matter  in  striving  to  subject  the 
result  of  experimental  investigation  to  rational  combinations. 
Science  is  the  labor  of  mind  applied  to  nature,  but  the  ex- 
ternal world  has  no  real  existence  for  us  beyond  the  image 
reflected  within  ourselves  through  the  medium  of  the  senses. 
As  intelligence  and  forms  of  speech,  thought  and  its  verbal 
symbols,  are  united  by  secret  and  indissoluble  links,  so  does 
the  external  world  blend  almost  unconsciously  to  ourselves 
with  our  ideas  and  feelings.  "  External  phenomena,"  says 
Hegel,  in  his  Philosophy  of  History,  "  are  in  some  degree 
translated  in  our  inner  representations. ' '  The  objective  world, 
conceived  and  reflected,  within  us  by  thought,  is  subjected  to 
the  eternal  and  necessary  conditions  of  our  intellectual  being. 
The  activity  of  the  mind  exercises  itself  on  the  elements  fur- 
nished to  it  by  the  perceptions  of  the  senses.      Thus,  in  the 


INTRODUCTION.  77 

early  ages  of  mankind,  there  manifests  itself  in  the  simple  in- 
tuition of  natm*al  facts,  and  in  the  efforts  made  to  compre- 
hend them,  the  germ  of  the  philosophy  of  nature.  These 
ideal  tendencies  vary,  and  are  more  or  less  powerful,  accord- 
ing to  the  individual  characteristics  and  moral  dispositions  of 
nations,  and  to  the  degrees  of  their  mental  culture,  whether 
attained  amid  scenes  of  nature  that  excite  or  chill  the  imag- 
ination. 

History  has  preserved  the  record  of  the  numerous  attempts 
that  have  been  made  to  form  a  rational  conception  of  the 
whole  world  of  phenomena,  and  to  recognize  in  the  universe 
the  action  of  one  sole  active  force  by  which  matter  is  pene- 
trated, transformed,  and  animated.  These  attempts  are  traced 
in  classical  antiquity  in  those  treatises  on  the  principles  of 
things  which  emanated  from  the  Ionian  school,  and  in  which 
all  the  phenomena  of  nature  were  subjected  to  hazardous 
speculations,  based  upon  a  small  number  of  observations.  By 
degrees,  as  the  influence  of  great  historical  events  has  favored 
the  development  of  every  branch  of  science  supported  by  ob- 
servation, that  ardor  has  cooled  which  formerly  led  men  to 
seek  the  essential  nature  and  connection  of  things  by  ideal 
construction  and  in  purely  rational  principles.  In  recent 
times,  the  mathematical  portion  of  natural  philosophy  has 
been  most  remarkably  and  admirably  enlarged.  The  method 
and  the  instrument  (analysis)  have  been  simultaneously  per- 
fected. That  which  has  been  acquired  by  means  so  different 
— by  the  ingenious  application  of  atomic  suppositions,  by  the 
more  general  and  intimate  study  of  phenomena,  and  by  the 
improved  construction  of  new  apparatus — is  the  common  prop- 
erty of  mankind,  and  should  not,  in  our  opinion,  now,  more 
than  in  ancient  times,  be  withdrawn  from  the  free  exercise  of 
speculative  thought. 

It  can  not  be  denied  that  in  this  process  of  thought  the 
results  of  experience  have  had  to  contend  with  many  disad- 
vantages ;  we  must  not,  therefore,  be  surprised  if,  in  the  per- 
petual vicissitude  of  theoretical  views,  as  is  ingeniously  ex- 
pressed by  the  author  of  Giordano  Bi'uno,^  "  most  men  see 
nothing  in  philosophy  but  a  succession  of  passing  meteors, 
while  even  the  grander  forms  in  which  she  has  revealed  her- 
self share  the  fate  of  comets,  bodies  that  do  not  rank  in  pop- 
ular opinion  among  the  eternal  and  permanent  works  of  na- 

*  SchelUug's  Bruno,  TJeher  das  Goitliche  und  Naturaliche  Princip 
der  Dingc,  $  181  (Bruno,  on  the  Divine  and  Natural  Principle  of 
Things) 


78  coSxMos. 

ture,  but  are  regarded  as  mere  fugitive  apparitions  of  igiioo«/s 
vapor."  We  would  here  remark  that  the  abuse  of  thought, 
and  the  false  track  it  too  often  pursues,  ought  not  to  sanctian 
an  opinion  derogatory  to  intellect,  vi^hich  would  imply  that 
the  domain  of  mind  is  essentially  a  world  of  vague  fantastic 
illusions,  and  that  the  treasures  accumulated  by  laborious  ob- 
servations in  philosophy  are  powers  hostile  to  its  own  empire. 
It  does  not  become  the  spirit  which  characterizes  the  present 
age  distrustfully  to  reject  every  generalization  of  views  and 
every  attempt  to  examine  into  the  nature  of  things  by  the 
process  of  reason  and  induction.  It  would  be  a  denial  of  the 
dignity  of  human  nature  and  the  relative  importance  of  the 
faculties  with  which  we  are  endowed,  were  we  to  condemn 
at  one  time  austere  reason  engaged  in  investigating  causes 
and  their  mutual  connections,  and  at  another  that  exercise  of 
the  imagination  which  prompts  and  excites  discoveries  by  its 
creative  powers. 


COSMOS. 


DELINEATION  OF  NATURE.  GENERAL  REVIEW  OF 
NATURAL  PHENOMENA. 

When  the  human  mind  first  attempts  to  subject  to  its  con- 
trol the  world  of  physical  phenomena,  and  strives  by  medita- 
tive contemplation  to  penetrate  the  rich  luxuriance  of  living 
nature,  and  the  mingled  web  of  free  and  restricted  natural 
forces,  man  feels  himself  raised  to  a  height  from  whence,  as 
he  embraces  the  vast  horizon,  individual  things  blend  together 
in  varied  groups,  and  appear  as  if  shrouded  in  a  vapory  vail. 
These  figurative  expressions  are  used  in  order  to  illustrate  the 
point  of  view  from  whence  we  would  consider  the  universe 
both  in  its  celestial  and  terrestrial  sphere.  I  am  not  insen- 
sible of  the  boldness  of  such  an  undertaking.  Among  all  the 
forms  of  exposition  to  which  these  pages  are  devoted,  there 
is  none  more  difficult  than  the  general  delineation  of  nature, 
which  we  purpose  sketching,  since  we  must  not  allow  our- 
selves to  be  overpowered  by  a  sense  of  the  stupendous  rich- 
ness and  variety  of  the  forms  presented  to  us,  but  must  dwell 
only  on  the  consideration  of  masses  either  possessing  actual 
magnitude,  or  borrowing  its  semblance  from  the  associations 
aAvakened  within  the  subjective  sphere  of  ideas.  It  is  by  a 
separation  and  classification  of  phenomena,  by  an  intuitive  in- 
sight into  the  play  of  obscure  forces,  and  b/  animated  expres- 
sions, in  which  the  perceptible  spectacle  is  i\  fleeted  with  vivid 
truthfulness,  that  we  may  hope  to  compreh^^nd  and  describe 
the  universal  all  (to  Tray)  in  a  manner  worthy  of  the  dignity 
of  the  word  Cosmos  m  its  signification  of  tiniverse,  order  of 
the  U'orld,  and  adornment  of  this  universal  order.  May  the 
ijumeasurable  diversity  of  phenomena  which  crowd  into  the 
picture  of  nature  in  no  way  detract  from  that  harmonious  im- 
pression of  rest  and  unity  v/hich  is  the  ultimate  object  of  every 
literary  or  purely  artistical  composition. 

Beginning  with  the  depths  of  space  and  the  regions  of  re- 
motest nebulse,  Vv-e  will  gradually  descend  through  the  starry 
zone  to  which  our  solar  system  belongs,  to  our  own  terrestrial 
spheroid,  circled  by  air  and  ocean,  there  to  direct  our  atten- 


80  COSMOS 

tion  to  its  form,  temperature,  and  magnetic  tension,  and  to 
consi'ler  the  fullness  of  organic  life  unfolding  itself  upon  its 
surface  beneath  the  vivifying  influence  of  light.  In  this  man- 
ner a  picture  of  the  world  may,  with  a  few  strokes,  be  made 
to  include  the  realms  of  infinity  no  less  than  the  minute  mi- 
croscopic animal  and  vegetable  organisms  which  exist  in  stand- 
ing waters  and  on  the  weather-beaten  surface  of  our  rocks. 
All  that  can  be  perceived  by  the  senses,  and  all  that  has  been 
accumulated  up  to  the  present  day  by  an  attentive  and  vari- 
ously directed  study  of  nature,  constitute  the  materials  from 
which  this  representation  is  to  be  drawn,  whose  character  is 
an  evidence  of  its  fidelity  and  truth.  But  the  descriptive  pic- 
ture of  nature  which  we  purpose  drawing  must  not  enter  too 
fully  into  detail,  since  a  minute  enumeration  of  all  vital  forms, 
natural  objects,  and  processes  is  not  requisite  to  the  complete- 
ness of  the  undertaking.  The  delineator  of  nature  must  re- 
sist the  tendency  toward  endless  division,  in  order  to  avoid 
the  dangers  presented  by  the  very  abundance  of  our  empirical 
knowledge.  A  considerable  portion  of  the  qualitative  proper^, 
ties  of  matter — -or,  to  speak  more  in  accordance  with  the  lan- 
guage of  natural  philosophy,  of  the  qualitative  expression  of 
forces — is  doubtlessly  still  unknown  to  us,  and  the  attempt 
perfectly  to  represent  unity  in  diversity  must  therefore  neces- 
sarily prove  unsuccessful.  Thus,  besides  the  pleasure  derived 
from  acquired  knowledge,  there  lurks  in  the  mind  of  man, 
and  tinged  with  a  shade  of  sadness,  an  unsatisfied  longing  for 
something  beyond  the  present — a  striving  towaixl  regions  yet 
unknown  and  unopened.  Such  a  sense  of  longing  binds  still 
■aster  the  links  which,  in  accordance  with  the  supreme  laws 
of  our  being,  connect  the  material  with  the  ideal  world,  and 
animates  the  mysterious  relation  existing  between  that  which 
the  mind  receive^  from  without,  and  that  which  it  reflects 
from  its  own  dej  ths  to  the  external  world.  If,  then,  nature 
(understanding  by  the  term  all  natural  objects  and  phenomena) 
be  illimitable  in  extent  and  contents,  it  likewise  presents  it- 
self to  the  haman  intellect  as  a  problem  which  can  not  be 
grasped,  a.nd  whose  solution  is  impossible,  since  it  requires  a 
knowledge  of  che  combined  action  of  all  natural  forces.  Such 
an  acknowledgment  is  due  where  the  actual  state  and  pro- 
spective development  of  phenomena  constitute  the  sole  objects 
of  direct  investigation,  which  does  not  venture  to  depart  from 
the  strict  rules  of  induction.  But,  although  the  incessant  ef- 
fort to  embrace  nature  in  its  universality  may  remain  unsatis- 
fied, the  history  of  the  contemplation  of  the  universe  (which 


DELINEATION    OF    NATURE.  81 

Will  be  considered  in  another  part  of  this  work)  will  teach  us 
how,  in  the  course  of  ages,  mankind  has  gradually  attained 
to  a  partial  insight  into  the  relative  dependence  of  phenomena. 
My  duty  is  to  depict  the  results  of  our  knowledge  in  all  their 
bearings  with  reference  to  the  present.  In  all  that  is  subject 
to  motion  and  change  in  space,  the  ultimate  aim,  the  very  ex- 
pression of  physical  laws,  depend  upon  inean  mimerical  value?,. 
which  show  us  the  constant  amid  change,  and  the  stable  amid 
apparent  fluctuations  of  phenomena.  Thus  the  progress  of 
modern  physical  science  is  especially  characterized  by  the  at- 
tainment and  the  rectification  of  the  mean  values  of  certain 
quantities  by  means  of  the  processes  of  weighing  and  meas- 
uring ;  and  it  may  be  said,  that  the  only  remaining  and  wide- 
ly-difiused  hieroglyphic  characters  still  in  our  writing — nimi- 
bers — appear  to  us  again,  as  powers  of  the  Cosmos,  although 
in  a  wider  sense  than  that  applied  to  them  by  the  Italian 
School. 

The  earnest  investigator  delights  in  the  simplicity  of  nu- 
merical relations,  indicating  the  dimensions  of  the  celestial 
regions,  the  magnitudes  and  periodical  disturbances   of  the 
heavenly  bodies,  the  triple  elements  of  terrestrial  magnetism, 
the  mean  pressure  of  the  atmosphere,  and  the  quantity  of  heat 
which  the  sun  imparts  in  each  year,  and  in  every  season  of  the 
year,  to  all  points  of  the  solid  and  liquid  surface  of  our  planet. 
These  sources  of  enjoyment  do  not,  however,  satisfy  the  poet 
of  Nature,  or  the  mind  of  the  inquiring  many.     To  both  of 
these  the  present  state  of  science  appears  as  a  blank,  now  that 
she  answers  doubtingly,  or  wholly  rejects  as  unanswerable, 
questions  to  which  former   ages  deemed  they  could  furnish 
satisfactory  rephes.     In  her  severer  aspect,  and  clothed  with 
less  luxuriance,  she  shows  herself  deprived  of  that  seductive 
charm  with  which  a  dogmatizing  and  symbolizing  physical 
philosophy  knew  how  to  deceive  the  understanding  and  give 
the  rein  to  imagination.     Long  before  the  discovery  of  the 
New  World,  it  was  believed  that  new  lands  in  the  Far  West 
might  be  seen  from  the  shores  of  the  Canaries  and  the  Azores. 
These  illusive  images  were  owing,  not  to  any  extraordinary 
refraction  of  the  rays  of  light,  but  produced  by  an  eager  long- 
ing for  the  distant  and  the  unattained.     The  philosophy  of 
the  Greeks,  the  physical  views  of  the  Middle  Ages,  and  even 
those  of  a  more  recent  period,  have  been  eminently  imbued 
with  the  charm  springing  from  similar  illusive  phantoms  of 
the  imagination.     At  the  limits  of  circumscribed  knowledge, 
as  from  some  lofty  island  shore,  the  eye  delights  to  penetrate 

D2 


82  COSMOS. 

to  distant  regions.  The  belief  in  the  uncommon  and  the  won- 
derful lends  a  definite  outline  to  every  manifestation  of  ideal 
creation  ;  and  the  realm  of  fancy — a  fairy-land  of  cosmolog- 
ical,  geognostical,  and  magnetic  visions — becomes  thus  invol- 
untarily blended  vv^ith  the  domain  of  reaUty. 

Nature,  in  the  manifold  signification  of  the  word — whether 
considered  as  the  universality  of  all  that  is  and  ever  will  be — 
as  the  inner  moving  force  of  all  phenomena,  or  as  their  mys- 
terious prototype — reveals  itself  to  the  simple  mind  and  feel- 
ings of  man  as  something  earthly,  and  closely  allied  to  him- 
self It  is  only  within  the  animated  circles  of  organic  struc- 
ture that  we  feel  ourselves  peculiarly  at  home.  Thus, 
wherever  the  earth  unfolds  her  fruits  and  flowers,  and  gives 
food  to  countless  tribes  of  animals,  there  the  image  of  nature 
impresses  itself  most  vividly  upon  our  senses.  The  impression 
thus  produced  upon  our  minds  limits  itself  almost  exclusively 
to  the  reflection  of  the  earthly.  The  starry  vault  and  the 
wide  expanse  of  the  heavens  belong  to  a  picture  of  the  uni- 
verse, in  which  the  magnitude  of  masses,  the  number  of  con- 
gregated suns  and  faintly  glimmering  nebulae,  although  they 
excite  our  wonder  and  astonishment,  manifest  themselves  to 
us  in  apparent  isolation,  and  as  utterly  devoid  of  all  evidence 
of  their  being  the  scenes  of  organic  life.  Thus,  even  in  the 
earliest  physical  views  of  mankind,  heaven  and  earth  have 
been  separated  and  opposed  to  one  another  as  an  upper  and 
lower  portion  of  space.  If,  then,  a  picture  of  nature  were  to 
correspond  to  the  requirements  of  contemplation  by  the  senses, 
it  ought  to  begin  with  a  delineation  of  our  native  earth.  It 
should  depict,  first,  the  terrestrial  planet  as  to  its  size  and 
form ;  its  increasing  density  and  heat  at  increasing  depths  in 
its  superimposed  solid  and  liquid  strata  ;  the  separation  of  sea 
and  land,  and  the  vital  forms  animating  both,  developed  in 
the  cellular  tissues  of  plants  and  animals ;  the  atmospheric 
ocean,  with  its  waves  and  currents,  through  which  pierce  the 
forest-crowned  summits  of  our  mountain  chains.  After  this 
delineation  of  purely  telluric  relations,  the  eye  would  rise  to 
the  celestial  regions,  and  the  Earth  would  then,  as  the  well- 
known  seat  of  organic  development,  be  considered  as  a  planet, 
occupying  a  place  in  the  series  of  those  heavenly  bodies  which 
circle  round  one  of  the  innumerable  host  of  self-luminous  stars. 
This  succession  of  ideas  indicates  the  course  pursued  in  the 
earliest  stages  of  perceptive  contemplation,  and  reminds  us  of 
the  ancient  conception  of  the  "  sea-girt  disk  of  earth,"  sup- 
porting the  vault  of  heaven.     It  begins  to  exercise  its  action 


at  the  spot  where  it  originated,  and  passes  from  the  consider- 
ation of  the  known  to  the  unknown,  of  the  near  to  the  distant 
It  corresponds  with  the  method  pursued  in  our  elementary 
works  on  astronomy  (and  which  is  so  admirable  in  a  mathe- 
matical point  of  view),  of  proceeding  from  the  apparent  to  the 
real  movements  of  the  heavenly  bodies. 

Another  course  of  ideas  must,  however,  be  pursued  in  a 
work  which  proposes  merely  to  give  an  exposition  of  what  is 
known — of  what  may  in  the  present  state  of  our  knowledge 
be  regarded  as  certain,  or  as  merely  probable  in  a  greater  or 
lesser  deofree — and  does  not  enter  into  a  consideration  of  the 
proofs  on  which  such  results  have  been  based.  Here,  there- 
fore, we  do  not  proceed  from  the  subjective  point  of  view  of 
human  interests.  The  terrestrial  must  be  treated  only  as  a 
part,  subject  to  the  whole.  The  view  of  nature  ought  to  be 
grand  and  free,  uninfluenced  by  motives  of  proximity,  social 
sympathy,  or  relative  utility.  A  physical  cosmography — a 
picture  of  the  universe — does  not  begin,  therefore,  with  the 
terrestrial,  but  with  that  which  fills  the  regions  of  space.  But 
as  the  sphere  of  contemplation  contracts  in  dimension  our  per- 
ception of  the  richness  of  individual  parts,  the  fullness  of  phys- 
ical phenomena,  and  of  the  heterogeneous  properties  of  mat- 
ter becomes  enlarged.  From  the  regions  in  which  we  rec- 
ognize only  the  dominion  of  the  laws  of  attraction,  Ave  de- 
scend to  our  own  planet,  and  to  the  intricate  play  of  terrestrial 
forces.  The  method  here  described  for  the  delineation  of  na- 
ture is  opposed  to  that  which  must  be  pursued  in  establish- 
ino-  conclusive  results.  The  one  enumerates  what  the  other 
demonstrates. 

Man  learns  to  know  the  external  world  through  the  organs 
of  the  senses.  Phenomena  of  light  proclaim  the  existence  of 
matter  in  remotest  space,  and  the  eye  is  thus  made  the  me- 
dium through  which  we  may  contemplate  the  universe.  The 
discovery  of  telescopic  vision  more  than  two  centuries  ago,  has 
transmitted  to  latest  generations  a  power  whose  limits  are  as 
yet  unattained. 

The  first  and  most  general  consideration  in  the  Cosmos  is 
that  of  the  contents  of  space — the  distribution  of  matter,  or 
of  creation,  as  we  are  wont  to  designate  the  assemblage  of  all 
that  is  and  ever  will  be  developed.  We  see  matter  either 
agglomerated  into  rotating,  revolving  spheres  of  different  dens- 
ity and  size,  or  scattered  through  space  in  the  form  of  self- 
luminous  vapor.  If  we  consider  first  the  cosmical  vapor  dis 
persed  in  definite  nebulous  spots,  its  state  of  aggregation  will 


84  COSMOS. 

appear  constantly  to  vary,  sometimes  appearing  separated  into 
round  or  elliptical  disks,  single  or  in  pairs,  occasionally  con- 
nected by  a  thread  of  light  ;  while,  at  another  time,  these* 
nebulae  occur  in  forms  of  larger  dimensions,  and  are  either 
elongated,  or  variously  branched,  or  fan-shaped,  or  appear  like 
well-defined  rings,  inclosing  a  dark  interior.  It  is  conjectured 
that  these  bodies  are  undergoing  variously  developed  formative 
processes,  as  the  cosmical  vapor  becomes  condensed  in  con- 
formity with  the  laws  of  attraction,  either  round  one  or  more 
of  the  nuclei.  Between  two  and  three  thousand  of  such  un- 
resolvabie  nebulae,  in  which  the  most  powerful  telescopes  have 
hitherto  been  unable  to  distinguish  the  presence  of  stars,  have 
been  counted,  and  their  positions  determined. 

The  genetic  evolution — that  perpetual  state  of  development 
which  seems  to  affect  this  portion  of  the  regions  of  space — 
has  led  philosophical  observers  to  the  discovery  of  the  analogy 
existing  among  organic  phenomena.  As  in  our  forests  we  see 
the  same  kind  of  tree  in  all  the  various  stages  of  its  growth, 
and  are  thus  enabled  to  form  an  idea  of  progressive,  vital  de- 
velopment, so  do  we  also,  in  the  great  garden  of  the  universe, 
recognize  the  most  different  phases  of  sidereal  formation.  The 
process  of  condensation,  which  formed  a  part  of  the  doctrines 
of  Anaximenes  and  of  the  Ionian  School,  appears  to  be  going 
on  before  our  eyes.  This  subject  of  investigation  and  conject- 
ure is  especially  attractive  to  the  imagination,  for  in  the  study 
of  the  animated  circles  of  nature,  and  of  the  action  of  all  the 
moving  forces  of  the  universe,  the  charm  that  exercises  the 
most  powerful  influence  on  the  mind  is  derived  less  from  a 
knowledge  of  that  which  is  than  from  a  perception  of  that 
which  will  be,  even  though  the  latter  be  nothing  more  than 
a  new  condition  of  a  known  material  existence  ;  for  of  actual 
creation,  of  origin,  the  beginning  of  existence  from  non-exist- 
ence, we  have  no  experience,  and  can  therefore  form  no  con- 
ception. 

A  comparison  of  the  various  causes  influencing  the  develop- 
ment manifested  by  the  greater  or  less  degree  of  condensation 
in  the  interior  of  nebulae,  no  less  than  a  successive  course  of 
direct  observations,  have  led  to  the  belief  that  changes  of  form 
have  been  recognized  first  in  Andromeda,  next  in  the  constel- 
lation Argo,  and  in  the  isolated  filamentous  portion  of  the 
nebula  in  Orion.  But  want  of  uniformity  in  the  power  of  the 
instruments  employed,  different  conditions  of  our  atmosphere, 
and  other  optical  relations,  render  a  part  of  the  results  invalid 
as  historical  evidence. 


CELESTIAL  PHENOMENA.  85 

Nebulous  stars  must  not  be  confounded  either  with  irreffu- 
larly-shaped  nebulous  spots,  properly  so  called,  whose  separate 
parts  have  an  unequal  degree  of  brightness  (and  which  may, 
perhaps,  become  concentrated  into  stars  as  their  circumference 
contracts),  nor  with  the  so-called  planetary  nebulae,  whose  cir- 
cular or  slightly  oval  disks  manifest  in  all  their  parts  a  per- 
fectly uniform  degree  of  faint  light.  Nebulous  stars  are  not 
merely  accidental  bodies  projected  upon  a  nebulous  ground, 
but  are  a  part  of  the  nebulous  matter  constituting  one  mass 
with  the  body  which  it  surrounds.  The  not  unfrequently  con- 
siderable magnitude  of  their  apparent  diameter,  and  the  re- 
mote distance  from  which  they  are  revealed  to  us,  show  that 
both  the  planetary  nebulte  and  the  nebulous  stars  must  be  of 
enormous  dimensions.  New  and  ingenious  considerations  of 
the  different  influence  exercised  by  distance^  on  the  intensity 
of  light  of  a  disk  of  appreciable  diameter,  and  of  a  single  self- 
luminous  point,  render  it  not  improbable  that  the  planetary 
nebula?  are  very  remote  nebulous  stars,  in  which  the  differ- 
ence between  the  central  body  and  the  surrounding  nebulous 
covering  can  no  longer  be  detected  by  our  telescopic  instru- 
ments. 

The  magnificent  zones  of  the  southern  heavens,  between 
50°  and  80°,  are  especially  rich  in  nebulous  stars,  and  in  com- 
pressed unresolvable  nebulae.  The  larger  of  the  two  Magel- 
lanic clouds,  which  circle  round  the  starless,  desert  pole  of  the 
south,  appears,  according  to  the  most  recent  researches,!  as 
"  a  collection  of  clusters  of  stars,  composed  of  globular  clusters 
and  nebulae  of  different  magnitude,  and  of  large  nebulous  spots 

*  The  optical  cousiderations  relative  to  the  difTerence  presented  by 
a  single  luminous  point,  and  by  a  disk  subtending  an  appreciable  angle, 
in  which  the  intensity  of  light  is  constant  at  every  distance,  are  explain- 
ed in  Arago's  Analyse  des  Travaux  de  Sir  William  Herschel  (Annuaire 
du  Bvreaii  des  Lang.,  1842,  p.  410-412,  and  441). 

t  The  twro  Magellanic  clouds,  Nubecula  major  and  Nubecula  minor, 
are  very  remarkable  objects.  The  larger  of  the  two  is  an  accumulated 
mass  of  stars,  and  consists  of  clusters  of  stars  of  irregular  form,  either 
conical  masses  or  nebulae  of  different  magnitudes  and  degrees  of  con- 
densation. This  is  interspersed  with  nebulous  spots,  not  resolvable 
into  stars,  but  which  are  probably  star  dust,  appearing  only  as  a  general 
radiance  upon  the  telescopic  field  of  a  twenty-feet  reflector,  and  form- 
ing a  luminous  ground  on  which  other  objects  of  striking  and  inde- 
scribable form  are  scattered.  In  no  other  portion  of  the  heavens  are 
so  many  nebulous  and  stellar  masses  thronged  together  in  an  equally 
small  space.  Nubecula  minor  is  much  less  beautiful,  has  more  unre- 
solvable nebulous  light,  while  the  stellar  masses  are  fewer  and  fainter 
in  intensity. — (From  a  letter  of  Sir  John  Herschel,  Feldhuysen,  Cape 
of  Good  Hope,  13th  June,  1836.) 


86  COSMOS. 

not  resolvable,  which,  producing  a  general  brightness  in  the 
field  of  view,  form,  as  it  were,  the  back-ground  of  the  picture." 
The  appearance  of  these  clouds,  of  the  brightly-beaming  con- 
stellation Argo,  of  the  Milky  Way  between  Scorpio,  the  Cen- 
taur, and  the  Southern  Cross,  the  picturesque  beauty,  if  one 
may  so  speak,  of  the  whole  expanse  of  the  southern  celestial 
hemisphere,  has  left  upon  my  mind  an  ineffaceable  impression. 
The  zodiacal  light,  which  rises  in  a  pyramidal  form,  and  con- 
stantly contributes,  by  its  mild  radiance,  to  the  external  beauty 
of  the  tropical  nights,  is  either  a  vast  nebulous  ring,  rotating 
between  the  Earth  and  Mars,  or,  less  probably,  the  exterior 
stratum  of  the  solar  atmosphere.  Besides  these  luminous  clouds 
and  nebulse  of  definite  form,  exact  and  corresponding  observa* 
tions  indi^ccxe  the  existence  and  the  general  distribution  of  an 
apparently  non-luminous,  infinitely-divided  matter,  which  pos 
sesses  a  force  of  resistance,  and  manifests  its  presence  in  Encke's, 
and  perhaps  also  in  Biela's  comet,  by  diminishing  their  eccen- 
tricity and  shortening  their  period  of  revolution.  Of  this  im- 
peding, ethereal,  and  cosmical  matter,  it  may  be  supposed  that 
it  is  in  motion  ;  that  it  gravitates,  notwithstanding  its  original 
tenuity  ;  that  it  is  condensed  in  the  vicinity  of  the  great  mass 
of  the  Sun  ;  and,  finally,  that  it  may,  for  myriads  of  ages, 
have  been  augmented  by  the  vapor  emanating  from  the  tails 
of  comets. 

If  we  now  pass  from  the  consideration  of  the  vaporous  mat- 
ter of  the  immeasurable  regions  of  space  {ovpavov  ^oprog)* 
— whether,  scattered  without  definite  form  and  limits,  it  ex- 
ists as  a  cosmical  ether,  or  is  condensed  into  nebulous  spots, 
and  becomes  comprised  among  the  solid  agglomerated  bodies 
of  the  universe — we  approach  a  class  of  phenomena  exclusive- 
ly designated  by  the  term  of  stars,  or  as  the  sidereal  world. 

*  I  should  have  made  use,  in  the  place  of  garden  of  the  universe,  of 
the  beautiful  expression  xoprog  ovpavov,  borrowed  by  Hesychius  fi-om 
an  unknown  poet,  if  ;:j;6prof  had  not  rather  signified  in  general  an  in- 
closed space.  The  connection  with  the  German  garten  and  the  En- 
glish garden,  gards  in  Gothic  (derived,  according  to  Jacob  Grimm,  from 
gairdan,  to  gird),  is,  however,  evident,  as  is  likewise  the  affinity  with 
the  Sclavonic  grad,  gorod,  and  as  Pott  remarks,  in  his  Etymol.  Forschun- 
gen,  th.  i.,  s.  144  (Etymol.  Researches),  with  the  Latin  chars,  whence 
we  have  the  Spanish  corte,  the  French  cour,  and  the  English  word  court, 
together  with  the  Ossetic  khart.  To  these  may  be  further  added  the 
Scandinavian  gard,^  gdrd,  a  place  inclosed,  as  a  court,  or  a  country 
seat,  and  the  Persian  gerd,  gird,  a  district,  a  circle,  a  princely  country 
Beat,  a  castle  or  city,  as  we  find  the  term  applied  to  the  names  of  places 
in  Firdusi's  Schahnameh,  as  Siyawakschgird,  Darabgird,  &c. 

*  (This  word  is  written  ^aarrf  in  the  Danish.] — TV.  ^ 


CELESTIAL    PHENOMENA.  87 

Here,  too,  we  find  diflerences  existing  in  the  solidity  or  density 
of  the  spheroid  ally  agglomerated  matter.  Our  own  solar  sys- 
tem presents  all  stages  of  mean  density  (or  of  the  relation  of 
volume  to  7?iass.)  On  comparing  the  planets  from  Mercury 
to  Mars  with  the  Sun  and  with  Jupiter,  and  these  two  last 
named  with  the  yet  inferior  density  of  Saturn,  we  arrive,  by 
a  descendino-  scale — to  draw  our  illustration  from  terrestrial 
substances — at  the  respective  densities  of  antimony,  honey, 
water,  and  pine  wood.  In  comets,  which  actually  constitute 
the  most  considerable  portion  of  our  solar  system  with  respect 
to  the  number  of  individual  forms,  the  concentrated  part, 
usually  termed  the  head,  or  nucleus,  transmits  sidereal  light 
unimpaired.  The  mass  of  a  comet  probably  in  no  case  equals 
the  five  thousandth  part  of  that  of  the  earth,  so  dissimilar  are 
the  formative  processes  manifested  in  the  original  and  perhaps 
still  progressive  agglomerations  of  matter.  In  proceeding  from 
general  to  special  considerations,  it  was  particularly  desirable 
to  draw  attention  to  this  diversity,  not  merely  as  a  possible, 
but  as  an  actually  proved  fact. 

The  purely  speculative  conclusions  arrived  at  by  Wright, 
Kant,  and  Lambert,  concerning  the  general  structural  ar- 
rangement of  the  universe,  and  of  the  distribution  of  matter 
in  space,  have  been  confirmed  by  Sir  William  Herschel,  on 
the  more  certain  path'  of  observation  and  measurement.  That 
great  and  enthusiastic,  although  cautious  observer,  was  the 
first  to  sound  the  depths  of  heaven  in  order  to  determine  the 
limits  and  form  of  the  starry  stratum  which  we  inhabit,  and 
he,  too,  was  the  first  who  ventured  to  throw  the  light  of  inves- 
tigation upon  the  relations  existing  between  the  position  and 
distance  of  remote  nebulae  and  our  own  portion  of  the  sidereal 
universe.  William  Herschel,  as  is  well  expressed  in  the  ele- 
gant inscription  on  his  monument  at  Upton,  broke  through  the 
inclosures  of  heaven  {codorum  perrupit  claustra),  and,  like 
another  Columbus,  penetrated  into  an  unknown  ocean,  from 
which  he  beheld  coasts  and  groups  of  islands,  whose  true  po- 
sition it  remains  for  future  ages  to  determine. 

Considerations  regarding  the  different  intensity  of  light  in 
stars,  and  their  relative  number,  that  is  to  say,  their  numeric- 
al frequency  on  telescopic  fields  of  equal  magnitude,  have  led 
to  the  assumption  of  unequal  distances  and  distribution  in  space 
in  the  strata  which  they  compose.  Such  assumptions,  in  as 
far  as  they  may  lead  us  to  draw  the  limits  of  the  individual 
portions  of  the  universe,  can  not  ofi^er  the  same  degree  of  math- 
ematical certainty  as  that  which  may  be  attained  in  all  that 


88  COSMOS. 

relaies  to  our  solar  system,  whether  we  consider  the  rotation 
of  double  stars  with  unequal  velocity  round  one  common  cen- 
ter of  gravity,  or  the  apparent  or  true  movements  of  all  the 
heavenly  bodies.  If  we  take  up  the  physical  description  of 
the  universe  from  the  remotest  nebulae,  we  may  be  inclined 
to  compare  it  with  the  mythical  portions  of  history.  The  one 
begins  L-  the  obscurity  of  antiquity,  the  other  in  that  of  inac- 
cessible space  ;  and  at  the  point  where  reality  seems  to  flee 
before  us,  imagination  becomes  doubly  incited  to  draw  from 
its  own  fullness,  and  give  definite  outline  and  permanence  to 
the  changing  forms  of  objects. 

If  we  compare  the  regions  of  the  universe  with  one  of  the 
island- studded  seas  of  our  own  planet,  we  may  imagine  mat- 
ter to  be  distributed  in  groups,  either  as  unresolvable  nebulaj 
of  different  ages,  condensed  around  one  or  more  nuclei,  or  as 
already  agglomerated  into  clusters  of  stars,  or  isolated  sphe- 
roidal bodies.  The  cluster  of  stars,  to  which  our  cosmical  isl- 
and belongs,  forms  a  lens-shaped,  flattened  stratum,  detached 
on  every  side,  whose  major  axis  is  estimated  at  seven  or  eight 
hundred,  and  its  minor  one  at  a  hundred  and  fifty  times  the 
distance  of  Sirius.  It  would  appear,  on  the  supposition  that 
the  parallax  of  Sirius  is  not  greater  than  that  accurately  de- 
termined for  the  brightest  star  in  the  Centaur  (0"-9128),  that 
hght  traverses  one  distance  of  Sirius  in  three  years,  while  it 
also  follows,  from  Bessel's  earlier  excellent  Memoir*  on  the 
parallax  of  the  remarkable  star  61  Cygni  (0"-3483),  (whose 
considerable  motion  might  lead  to  the  inference  of  great  prox- 
imity), that  a  period  of  nine  years  and  a  quarter  is  required 
for  the  transmission  of  light  Irom  this  star  to  our  planet.  Our 
starry  stratum  is  a  disk  of  inconsiderable  thickness,  divided  a 

*  See  Maclear's  "  Results  from  1839  to  1840,"  in  the  Trans,  of  the 
Astronomical  Soc,  vol.  xii.,  p.  370,  on  a  Centauri,  the  probable  mean' 
error  being  0"-0640.  For  61  Cygni,  see  Bessel,  in  Schumacher's  Jahr- 
buch,  1839,  s.  47,  and  Schumacher's  Astron.  Nachr.,  bd.  xviu.,  s.  401, 
402,  probable  mean  error,  0"-0141.  With  reference  to  the  relative 
distances  of  stars  of  different  magnitudes,  how  those  of  the  third  mag- 
nitude may  probably  be  three  times  more  remote,  and  the  manner  in 
which  we  represent  to  ourselves  the  material  arrangenient  of  the  starry 
strata,  I  have  found  the  following  remarkable  passage  in  Kepler's 
Epitome  Astronomies  Copernicance,  1618,  t.  i.,  lib.  1,  p.  34-39:  ''Sol 
hie  noster  nil  aliud  est  quam  una  ex  fixis,  nobis  major  et  clarior  visa, 
quia,  propior  quam  fix  a.  Pone  terram  stare  ad  latus,  una  semi-diamctro 
vim  lactece,  tunc  hcsc  via  lactea  apparebit  circulus  parvus,  vet  ellipsis  par- 
va,  tota  declinans  ad  latus  alterum;  eritque  simul  uno  intuitu  conspicua, 
qucB  nunc  non  potest  nisi  dimidia  corispici  quovis  momcnto.  Itaque  fix' 
arum  sphcera  non  tantum  orhe  stellarum,  sed  etiam  circulo  lactis  versus 
nos  deorsum  est  terminata.^^ 


SIDEREAL    SYSTEMS.  89 

third  oi'its  length  into  two  branches  ;  it  is  supposed  that  we 
are  near  this  division,  and  nearer  to  the  region  of  Sirius  than 
to  the  constellation  Aquila,  almost  in  the  middle  of  the  stra- 
tum in  the  line  of  its  thickness  or  minor  axis. 

This  position  of  our  solar  system,  and  the  form  of  the  whole 
discoidal  stratum,  have  been  inferred  from  sidereal  scales,  that 
is  to  say,  from  that  method  of  counting  the  stars  to  which  I 
have  already  alluded,  and  which  is  based  upon  the  equidistant 
subdivision  of  the  telescopic  field  of  view.  The  relative  depth 
of  the  stratum  in  all  directions  is  measured  by  the  greater  or 
smaller  number  of  stars  appearing  in  each  division.  These 
divisions  give  the  length  of  the  ray  of  vision  in  the  same  man- 
ner as  we  measure  the  depth  to  which  the  plummet  has  been 
thrown,  before  it  reaches  the  bottom,  although  in  the  case  of 
a  starry  stratum  there  can  not,  correctly  speaking,  be  any  idea 
of  depth,  but  merely  of  outer  limits.  In  the  direction  of  the 
longer  axis,  where  the  stars  lie  behind  one  another,  the  more 
remote  ones  appear  closely  crowded  together,  united,  as  it  were, 
by  a  milky- white  radiance  or  luminous  vapor,  and  are  perspec- 
tively  grouped,  encircling,  as  in  a  zone,  the  visible  vault  of 
heaven.  This  narrow  and  branched  girdle,  studded  with  ra- 
diant light,  and  here  and  there  interrupted  by  dark  spots,  de- 
viates only  by  a  few  degrees  from  forming  a  perfect  large  cir- 
cle round  the  concave  sphere  of  heaven,  owing  to  our  being 
near  the  center  of  the  large  starry  cluster,  and  almost  on  the 
plane  of  the  Milky  Way.  If  our  planetary  system  were  far 
outside  this  cluster,  the  Milky  Way  would  appear  to  tele- 
scopic vision  as  a  ring,  and  at  a  still  greater  distance  as  a  re- 
solvable discoidal  nebula. 

Among  the  many  self-luminous  moving  suns,  erroneously 
called  fixed  stag's,  which  constitute  our  cosmical  island,  our 
own  sun  is  the  only  one  known  by  direct  observation  to  be  a 
central  body  in  its  relations  to  spherical  agglomerations  of 
matter  directly  depending  upon  and  revolving  round  it,  either 
in  the  form  of  planets,  comets,  or  aerolite  asteroids.  As  far 
as  we  have  hitherto  been  able  to  investigate  midtiple  stars 
(double  stars  or  suns),  these  bodies  are  not  subject,  with  re- 
spect to  relative  motion  and  illumination,  to  the  same  planet- 
ary dependence  that  .characterizes  our  own  solar  system.  Two 
or  more  self-luminous  bodies,  whose  planets  and  moon,  if  such 
exist,  have  hitherto  escaped  our  telescopic  powers  of  vision, 
certainly  revolve  around  one  common  center  of  gravity  ;  but 
this  is  in  a  portion  of  space  which  is  probably  occupied  merely 
by  unagglomerated  matter  or  cosmical  vapor,  while  in  our  sys- 


90  COSMOS. 

tern  the  center  of  gravity  is  often  comprised  within  the  inner- 
most limits  of  a  visible  central  body.  If,  therefore,  we  regard 
the  Sun  and  the  Earth,  or  the  Earth  and  the  Moon,  as  double 
stars,  and  the  whole  of  our  planetary  solar  system  as  a  multi- 
ple cluster  of  stars,  the  analogy  thus  suggested  must  be  limit  • 
ed  to  the  universality  of  the  laws  of  attraction  in  different  sys- 
tems, being  alike  applicable  to  the  independent  processes  of 
light  and  to  the  method  of  illumination. 

For  the  generalization  of  cosmical  views,  corresponding  with 
the  plan  we  have  proposed  to  follow  in  giving  a  delineation  of 
nature  or  of  the  universe,  the  solar  system  to  which  the  Earth 
belongs  may  be  considered  in  a  two-fold  relation  :  first,  with 
respect  to  the  different  classes  of  individually  agglomerated 
matter,  and  the  relative  size,  conformation,  density,  and  dis- 
tance of  the  heavenly  bodies  of  this  system  ;  and,  secondly, 
with  reference  to  other  portions  of  our  starry  cluster,  and  of 
the  changes  of  position  of  its  central  body,  the  Sun. 

The  solar  system,  that  is  to  say,  the  variously-formed  matter 
circling  round  the  Sun,  consists,  according  to  the  present  state 
of  our  knowledge,  of  eleven  'primary  j^lcmets*  eighteen  satel- 

*  [Since  the  publication  of  Bavon  Humboldt's  work  in  1845,  several 
other  planets  have  been  discovered,  making  the  number  of  those  be- 
longing to  our  planetary  system  sixteen  instead  of  eleven.  Of  these, 
Astrea,  Hebe,  Flora,  and  Iris  are  members  of  the  remarkable  group 
of  astei'oids  between  Mars  and  Jupiter.  Astrea  and  Hebe  were  dis- 
covered by  Hencke  at  Driesen,  the  one  in  1846  and  the  other  in  1847 ; 
Flora  and  Iris  were  both  discovered  in  1847  by  Mr.  Hind,  at  the  South 
Villa  Observatory,  Regent's  Park.  It  would  appear  from  the  latest  de- 
terminations of  their  elements,  that  the  small  planets  have  the  following 
order  with  respect  to  mean  distance  from  the  Sun :  Flora,  Iris,  Vesta, 
Hebe,  Astrea,  Juno,  Ceres,  Pallas.  Of  these,  Flora  has  the  shortest 
period  (about  34  years).  The  planet  Neptune, 'which,  after  having 
been  predicted  by  several  astronomers,  was  actually  observed  on  the 
25th  of  September,  1846,  is  situated  on  the  confines  of  our  planetary 
system  beyond  Uranus.  The  discovery  of  this  planet  is  not  only  highly 
interesting  from  the  importance  attached  to  it  as  a  question  of  science^ 
but  also  from  the  evidence  it  affords  of  the  care  and  unremitting  labor 
evinced  by  modern  astronomers  in  the  investigatioji  and  comparison  of 
the  older  calculations,  and  the  ingenious  application  of  the  results  thus 
obtained  to  the  observation  of  new  facts.  The  merit  of  having  paved 
the  way  for  the  discovery  of  the  planet  Neptune  is  due  to  M.  Bouvard. 
who,  in  his  persevering  and  assiduous  efforts  to  deduce  the  entire  orbit 
of  Uranus  from  observations  made  during  the  forty  years  that  succeed- 
ed the  discovery  of  that  planet  in  1781,  found  the  results  yielded  by 
theory  to  be  at  variance  with  fact,  in  a  degree  that  had  no  parallel  in 
the  history  of  astronomy.  This  startling  discrepancy,  which  seemed 
only  to  gain  additional  weight  from  every  attempt  made  by  M.  Bouvard 
to  correct  his  calculations,  led  Leverrier,  after  a  careful  modification  of 
the  tables  of  Bouvard.  to  establish  the  proposition  that  there  was  "  a 


PLANETARY    SYSTEMS.  91 

iites  or  secondary  planets,  and  myriads  of  comets,  three  of 
which,  known  as  the  "planetary  comets,"  do  not  pass  beyond 
the  narrow  limits  of  the  orbits  described  by  the  principal 
planets.  We  may,  with  no  inconsiderable  degree  of  proba- 
bility, include  within  the  domain  of  our  Sun,  in  the  immedi- 
ate sphere  of  its  central  force,  a  rotating  ring  of  vaporous  mat- 
ter, lying  probably  between  the  orbits  of  Venus  and  Mars,  but 
certainly  beyond  that  of  the  Earth,=^  which  appears  to  us  in 

formal  incompatibility  between  the  observed  motions  of  Uranus  and 
the  hypothesis  that  he  was  acted  on  ojily  by  the  Sun  and  known  plan- 
ets, according  to  the  law  of  universal  gravitation."  Pursuing  this  idea, 
Leverrier  arrived  at  the  conclusion  that  the  disturbing  cause  must  be  a 
planet,  and,  finally,  after  an  amount  of  labor  that  seems  perfectly  over- 
whelming, he,  on  the  31st  of  August,  1846,  laid  before  the  French  In- 
stitute a  paper,  in  w^hich  he  indicated  the  exact  spot  in  the  heavens 
where  this  new  planetaiy  body  would  be  found,  giving  the  following 
data  for  its  various  elements  :  mean  distance  from  the  Sun,  36-154  times 
that  of  the  Earth;  period  of  revolution,  217'387  years;  mean  long., 
Jan.  1st,  1847,  318^  47';  mass,  ^  3V0 ^h  5  heliocentric  long.,  Jan.  1st, 
1847,  326°  32'.  Essential  difficulties  still  intervened,  however,  and  as 
the  remoteness  of  the  planet  rendered  it  improbable  that  its  disk  would 
be  discernible  by  any  telescopic  instrument,  no  other  means  remained 
for  detecting  the  suspected  body  but  its  planetary  motion,  which  could 
only  be  ascertained  by  mapping,  after  every  observation,  the  quarter 
of  the  heavens  scanned,  and  by  a  comparison  of  the  various  maps. 
Fortunately  for  the  verification  of  Leverrier's  predictions,  Dr.  Bremiker 
had  just  completed  a  map  of  the  precise  region  in  which  it  was  expect- 
ed the  new  planet  would  appear,  this  being  one  of  a  series  of  maps 
made  for  the  Academy  of  Berlin,  of  the  small  stars  along  the  entire  zo- 
diac. By  means  of  this  valuable  assistance,  Dr.  Galle,  of  the  Berlin 
Observatory,  was  led,  on  the  25th  of  September,  184G,  by  the  discov- 
ery of  a  star  of  the  eighth  magnitude,  not  recorded  in  Dr.  Bremiker's 
map,  to  make  the  first  observation  of  the  planet  predicted  by  Leverrier. 
By  a  singular  coincidence,  Mr.  Adams,  of  Cambridge,  had  predicted 
the  appearance  of  the  planet  simultaneously  with  M.  Leverrier;  but 
by  the  concurrence  of  several  circumstances  much  to  be  regretted,  the 
world  at  large  were  not  made  acquainted  with  Mr.  Adams's  valuable 
discovery  until  subsequently  to  the  period  at  which  Leverrier  published 
his  observations.  As  the  data  of  Leverrier  and  Adams  stand  at  present, 
there  is  a  discrepancy  between  the  predicted  and  the  true  distance,  and 
in  some  other  elements  of  the  planet ;  it  remains,  therefore,  for  these 
or  future  astronomers  to  reconcile  theory  with  fact,  or  perhaps,  as  in 
the  case  of  Uranus,  to  make  the  new  planet  the  means  of  lea-ding  to  yet 
greater  discoveries.  It  would  appear  from  the  most  recent  observations, 
that  the  mass  of  Neptune,  instead  of  being,  as  at  first  stated,  ^  jq  o^h,  is 
only  about  _^__th  that  of  the  Sun,  while  its  periodic  time  is  now  given 
w^ith  a  greater  probability  at  166  years,  and  its  mean  distance  from  the 
Sun  nearly  30.  The  planet  appears  to  have  a  ring,  but  as  yet  no  ac- 
curate observations  have  been  inade  regarding  its  system  of  satellites. 
See  Trans.  Astron.  Soc,  and  The  Planai  Neptune,  1848,  by  J .  P.  Nicholl.  1 
—  Tr. 

*  "  If  there  should  be  molecules  in  the  zones  diffused  by  the  atmo» 


92  COSMOS 

a  pyramidal  form,  and  is  known  as  the  Zodiacal  Light ;  and 
a  host  of  very  small  asteroids,  whose  orbits  either  intersect,  or 
very  nearly  approach,  that  of  our  earth,  and  which  present  us 
with  the  phenomena  of  aerolites  and  falling  or  shooting  stars. 
When  we  consider  the  complication  of  variously-formed  bodies 
which  revolve  round  the  Sun  in  orbits  of  such  dissimilar  ec- 
centricity— although  we  may  not  be  disposed,  with  the  im- 
mortal author  of  the  Mecanique  Celeste,  to  regard  the  larger 
number  of  comets  as  nebulous  stars,  passing  from  one  central 
system  to  another,*  we  yet  can  not  fail  to  acknowledge  that 
the  planetary  system,  especially  so  called  (that  is,  the  group 
of  heavenly  bodies  which,  together  with  their  satellites,  re- 
volve with  but  slightly  eccentric  orbits  round  the  Sun),  con- 
stitutes but  a  small  portion  of  the  whole  system  with  respect 
to  individual  numbers,  if  not  to  mass. 

It  has  been  proposed  to  consider  the  telescopic  planets,  Ves- 
ta, Juno,  Ceres,  and  Pallas,  with  their  more  closely  intersect- 
ing, inclined,  and  eccentric  orbits,  as  a  zone  of  separation,  or 
as  a  middle  group  in  space  ;  and  if  this  view  be  adopted,  we 
shall  discover  that  the  interior  planetary  group  (consisting  of 
Mercury,  Venus,  the  Earth,  and  Mars)  presents  several  very 
striking  contrasts!  when  compared  with  the  exterior  group, 
comprising  Jupiter,  Saturn,  and  Uranus.  The  planets  near- 
est the  Sun,  and  consequently  included  in  the  inner  group,  are 
of  more  moderate  size,  denser,  rotate  more  slowly  and  with 
nearly  equal  velocity  (their  periods  of  revolution  being  almost 
all  about  24  hours),  are  less  compressed  at  the  poles,  and,  with 
the  exception  of  one,  are  without  satellites.  The  exterior 
planets,  which  are  further  removed  from  the  Sun,  are  very 
considerably  larger,  have  a  density  five  times  less,  more  than 
twice  as  great  a  velocity  in  the  period  of  their  rotation  round 
their  axes,  are  more  compressed  at  the  poles,  and  if  six  satel- 
lites may  be  ascribed  to  Uranus,  have  a  quantitative  prepon- 
derance in  the  number  of  their  attendant  moons,  which  is  as 
seventeen  to  one. 

phere  of  the  Sun  of  too  volatile  a  nature  either  to  combine  Avith  one 
another  or  with  the  planets,  we  must  suppose  that  they  would,  in  cir- 
cling round  that  luminary,  present  all  the  appearances  of  zodiacal  light, 
without  opposing  any  appreciable  resistance  to  the  different  bodies  com- 
posing the  planetary  system,  either  owing  to  their  extreme  rarity,  oi* 
to  the  similarity  existing  between  their  motion  and  that  of  the  planets 
with  which  they  come  in  contact." — Laplace,  Expos,  du  Syst.  du  MondAi 
(ed.  5),  p.  415. 

*  Laplace,  Exp.  du  Syst.  du  Monde,  p.  396,  414. 

t  Littrow,  Astronomic,  l8iJ5,  bd.  xi.,  §  107.  Madler,  Astron.,  1841, 
$  212.     Laplace,  Exp.  d*.  Syst.  du  Monde,  p.  210. 


PLANETARY    SYSTEMS.  93 

Such  general  considerations  regarding  certain  characteristic 
properties  appertaining  to  whole  groups,  can  not,  however,  be 
applied  with  equal  justice  to  the  individual  planets  of  every 
group,  nor  to  the  relations  between  the  distances  of  the  revolv- 
nig  planets  from  the  central  body,  and  their  absolute  size, 
density,  period  of  rotation,  eccentricity,  and  the  inclination  of 
their  orbits  and  the  axes.  We  know  as  yet  of  no  inherent  ne- 
cessity, no  mechanical  natural  law,  similar  to  the  one  which 
teaches  us  that  the  squares  of  the  periodic  times  are  propor- 
tional to  the  cubes  of  the  major  axes,  by  which  the  above- 
named  six  elements  of  the  planetary  bodies  and  the  form  of 
their  orbit  are  made  dependent  either  on  one  another,  or  on 
their  mean  distance  from  the  Sun.  Mars  is  smaller  than  the 
Earth  and  Venus,  although  further  removed  from  the  Sun 
than  these  last-named  planets,  approaching  most  nearly  in  size 
to  Mercury,  the  nearest  planet  to  the  Sun.  Saturn  is  smaller 
than  Jupiter,  and  yet  much  larger  than  Uranus.  The  zone 
of  the  telescopic  planets,  which  have  so  inconsiderable  a  vol 
ume,  immediately  precede  Jupiter  (the  greatest  in  size  of  an) 
of  the  planetary  bodies),  if  we  consider  them  with  regard  to 
distance  from  the  Sun  ;  and  yet  the  disks  of  these  small  aster- 
oids, which  scarcely  admit  of  measurement,  have  an  areal  sur- 
face not  much  more  than  half  that  of  France,  Madagascar,  or 
Borneo.  However  striking  may  be  the  extremely  small  dens- 
ity of  all  the  colossal  planets,  which  are  furthest  removed  from 
the  Sun,  we  are  yet  unable  in  this  respect  to  recognize  any 
regular  succession.*  Uranus  appears  to  be  denser  than  Sat- 
urn, even  if  we  adopt  the  smaller  mass,  -34  o  o  5>  assumed  by 
Lament ;  and,  notwithstanding  the  inconsiderable  difference 
of  density  observed  in  the  mnermost  planetary  group,t  we  find 
both  Venus  and  Mars  less  dense  than  the  Earth,  which  lies 
between  them.  The  time  of  rotation  certainly  diminishes 
with  increasing  solar  distance,  but  yet  it  is  greater  in  Mars 
than  in  the  Earth,  and  in  Saturn  than  in  Jupiter.     The  el- 

*  See  Kepler,  on  the  increasing  density  and  volume  of  the  planets  in 
proportion  with  their  increase  of  distance  from  the  Sun,  which  is  de- 
scribed as  the  densest  of  all  the  heavenly  bodies ;  in  the  Epitome  As- 
iron.  Copern.  in  vii.  libros  digesta,  1618-1622,  p.  420.  Leibnitz  also  in- 
clined to  the  opinions  of  Kepler  and  Otto  von  Guericke,  that  the  plan- 
ets increase  in  volume  in  proportion  to  their  increase  of  distance  from 
the  Sun.  See  his  letter  to  the  Magdeburg  Burgomaster  (Mayence, 
1671),  in  Leibnitz,  Deutschen  Schriften,  herausg.  von  Guhrauer,  th.  i., 
I  264. 

t  On  the  arrangement  of  masses,  see  Encke,  in  Schum.,  Astr.  Nachr. 
1843  Nr.  488,  $  114. 


94  COSMOS. 

liptic  orbits  of  Juno,  Pallas,  and  Mercury  have  the  greatest 
degree  of  eccentricity,  and  Mars  and  Venus,  which  immedi- 
ately follow  each  other,  have  the  least.  Mercury  and  Venus 
exhibit  the  same  contrasts  that  may  be  observed  in  the  four 
smaller  planets,  or  asteroids,  whose  paths  are  so  closely  inter- 
woven. 

The  eccentricities  of  Juno  and  Pallas  are  very  nearly  iden- 
tical, and  are  each  three  times  as  great  as  those  of  Ceres  and 
Vesta.  The  same  may  be  said  of  the  inclination  of  the  orbits 
of  the  planets  toward  the  plane  of  projection  of  the  ecliptic,  or 
in  the  position  of  their  axes  of  rotation  with  relation  to  their 
orbits,  a  position  on  which  the  relations  of  chmate,  seasons  of 
the  year,  and  length  of  the  days  depend,  more  than  on  eccen- 
tricity. Those  planets  that  have  the  most  elongated  elliptic 
orbits,  as  Juno,  Pallas,  and  Mercury,  have  also,  although  not 
to  the  same  degree,  their  orbits  most  strongly  inclined  toward 
the  ecliptic.  Pallas  has  a  comet-like  inclination  nearly  twen- 
ty-six times  greater  than  that  of  Jupiter,  while  in  the  little 
planet  Vesta,  which  is  so  near  Pallas,  the  angle  of  inclination 
scarcely  by  six  times  exceeds  that  of  Jupiter.  An  equally  ir- 
regular succession  is  observed  in  the  position  of  the  axes  of 
the  few  planets  (four  or  five)  whose  planes  of  rotation  we 
know  with  any  degree  of  certainty.  It  would  appear  from 
the  position  of  the  satellites  of  Uranus,  two  of  which,  the  sec- 
ond and  fourth,  have  been  recently  observed  with  certainty, 
that  the  axis  of  this,  the  outermost  of  all  the  planets,  is  scarce- 
ly incHned  as  much  as  11°  toward  the  plane  of  its  orbit,  while 
Saturn  is  placed  between  this  planet,  whose  axis  almost  coin- 
cides with  the  plane  of  its  orbit,  and  J  upiter,  whose  axis  of 
rotation  is  nearly  perpendicular  to  it. 

In  this  enumeration  of  the  forms  which  compose  the  world 
in  space,  we  have  delineated  them  as  possessing  an  actual  ex- 
istence, and  not  as  objects  of  intellectual  contemplation,  or  as 
mere  links  of  a  mental  and  causal  chain  of  connection.  The 
planetary  system,  in  its  relations  of  absolute  size  and  relative 
position  of  the  axes,  density,  time  of  rotation,  and  different  de- 
gress of  eccentricity  of  the  orbits,  does  not  appear  to  offer  to 
our  apprehension  any  stronger  evidence  of  a  natural  necessity 
than  the  proportion  observed  in  the  distribution  of  land  and 
water  on  the  Earth,  the  configuration  of  continents,  or  the 
height  of  mountain  chains.  In  these  respects  we  can  discover 
no  common  law  in  the  regions  of  space  or  in  the  inequalities 
of  the  earth's  crust.  They  are  facts  in  nature  that  have 
arisen  firgm  the  conflict  of  manifold  forces  acting  under  un- 


PLANET  All  V    SYriTEMS.  95 

known  conditions,  although  nian  considers  as  accidental  what- 
ever he  is  unable  to  explain  in  the  planetary  formation  on  pure- 
ly genetic  principles.  If  the  planets  have  been  formed  out  of 
separate  rings  of  vaporous  matter  revolving  round  the  Sun, 
we  may  conjecture  that  the  different  thickness,  unequal  dens- 
ity, temperature,  and  electro-magnetic  tension  of  these  rings 
may  have  given  occasion  to  the  most  various  agglomerations 
of  matter,  in  the  same  manner  as  the  amount  of  tangential 
velocity  and  small  variations  in  its  direction  have  produced  so 
great  a  difference  in  the  forms  and  inclinations  of  the  elliptic 
orbits.  Attractions  of  mass  and  laws  of  gravitation  have  no 
doubt  exercised  an  influence  here,  no  less  than  in  the  geog- 
nostic  relations  of  the  elevations  of  continents  ;  but  we  are  un- 
able from  present  forms  to  draw  any  conclusions  regarding  the 
series  of  conditions  through  which  they  have  passed.  Even 
the  so-called  law  of  the  distances  of  the  planets  from  the  Sun, 
the  law  of  progression  (which  led  Kepler  to  conjecture  the  ex- 
istence of  a  planet  supplying  the  link  that  was  wanting  in  the 
chain  of  connection  between  Mars  and  Jupiter),  has  been  found 
numerically  inexact  for  the  distances  between  Mercury,  Venus, 
and  the  Earth,  and  at  variance  with  the  conception  of  a  series, 
owing  to  the  necessity  for  a  supposition  in  the  case  of  the  first 
member. 

The  hitherto  discovered  principal  planets  that  revolve  round 
our  Sun  are  attended  certainly  by  fourteen,  and  probably  by 
eighteen  secondary  planets  (moons  or  satellites).  The  princi- 
pal planets  are,  therefore,  themselves  the  central  bodies  of  sub- 
ordinate systems.  We  seem  to  recognize  in  the  fabric  of  the 
universe  the  same  process  of  arrangement  so  frequently  ex- 
hibited in  the  development  of  organic  life,  where  we  find  in 
the  manifold  combinations  of  groups  of  plants  or  animals  the 
same  typical  form  repeated  in  the  suhoi'dinate  classes.  The 
secondary  planets  or  satellites  are  more  frequent  in  the  extern- 
al region  of"  the  planetary  system,  lying  beyond  the  intersect- 
ing orbits  of  the  smaller  planets  or  asteroids  ;  in  the  inner  re- 
gion none  of  the  planets  are  attended  by  satellites,  with  the 
exception  of  the  Earth,  whose  moon  is  relatively  of  great  mag- 
nitude, since  its  diameter  is  equal  to  a  fourth  of  that  of  the 
Earth,  while  the  diameter  of  the  largest  of  all  known  second- 
ary planets — the  sixth  satellite  of  Saturn — is  probably  about 
one  seventeenth,  and  the  largest  of  Jupiter's  moons,  the  third, 
only  about  one  twenty-sixth  part  that  of  the  primary  planet 
or  central  body.  The  planets  which  are  attended  by  the 
largest  number  of  satelhtes  are  most  remote  from  the  Sun, 


96  COSMOS. 

and  are  at  the  same  time  the  largest,  most  compressed  at  the 
poles,  and  the  least  dense.  According  to  the  most  recent 
measurements  of  Madler,  Uranus  has  a  greater  planetary 
compression  than  any  other  of  the  planets,  viz.,  -g-.^^d.  In  our 
Earth  and  her  moon,  whose  mean  distance  from  one  another 
amounts  to  207,200  miles,  we  find  that  the  difierences  of 
mass*  and  diameter  between  the  two  are  much  less  consider- 
able than  are  usually  observed  to  exist  between  the  principal 
planets  and  their  attendant  satellites,  or  between  bodies  of 
difi'erent  orders  in  the  solar  system.  While  the  density  of  the 
Moon  is  five  ninths  less  than  that  of  the  Earth,  it  would  ap- 
pear, if  we  may  sufficiently  depend  upon  the  determinations 
of  their  magnitudes  and  masses,  that  the  second  of  Jupiter's 
moons  is  actually  denser  than  that  great  planet  itself.  Among 
the  fourteen  satelHtes  that  have  been  investigated  with  any 
degree  of  certainty,  the  system  of  the  seven  satellites  of  Saturn 
presents  an  instance  of  the  greatest  possible  contrast,  both  in 
absolute  magnitude  and  in  distance  from  the  central  body. 
The  sixth  of  these  satellites  is  probably  not  much  smaller  than 
Mars,  while  our  moon  has  a  diameter  which  does  not  amount 
to  more  than  half  that  of  the  latter  planet.  With  respect  to 
volume,  the  two  outer,  the  sixth  and  seventh  of  Saturn's  satel- 
lites, approach  the  nearest  to  the  third  and  brightest  of  Jupi- 
ter's moons.  The  two  innermost  of  these  satellites  belong 
perhaps,  together  with  the  remote  moons  of  Uranus,  to  the 
smallest  cosmical  bodies  of  our  solar  system,  being  only  made 
visible  under  favorable  circumstances  by  the  most  powerful 
instruments.  They  were  first  discovered  by  the  ibrty-foot 
telescope  of  William  Herschel  in  1789,  and  were  seen  again 
by  John  Herschel  at  the  Cape  of  Good  Hope,  by  Vice  at  Rome, 
and  by  Lamont  at  Munich.  Determinations  of  the  true  di- 
ameter of  satellites,  made  by  the  measurement  of  the  apparent 
size  of  their  small  disks,  are  subjected  to  many  optical  diffi- 
culties ;  but  numerical  astronomy,  whose  task  it  is  to  prede- 
termine by  calculation  the  motions  of  the  heavenly  bodies  as 
they  will  appear  when  viewed  from  the  Earth,  is  directed  al- 

*  If,  according  to  Burckhardt's  determination,  the  Moon's  radius  be 
0.2725  and  its  volume  _-J;_-^th,  its  density  will  be  0*5596,  or  nearly  five 
ninths.  Compare,  also,  Willi.  Beer  und  H.  Madler,  der  Mond,  §  2, 
10,  and  Madler,  Ast.,  §  157.  The  material  contents  of  the  Moon  are, 
according  to  Hansen,  nearly  ^^th  (and  according  to  Madler  ^i._-th) 
that  of  the  Earth,  and  its  mass  equal  to  g^.^^d  that  of  the  Earth.  lu 
the  largest  of  Jupiter's  moons,  the  third,  the  relations  of  volume  to  the 
central  body  are  -r^^..-„th,  and  of  mass  --A_._th.     On  the  polar  flatten- 

,  *'  1   .■>  .<  7  0  1   1  J  0  U  * 

mg  ot  Uranus,  see  Schum.,  Aalron.  Nachr.,  1844,  No.  493. 


PLANETARY    SYSTEMS.  97 

most,  exclusively  to  motion  and  mass,  and  but  little  to  volume. 
The  absolute  distance  of  a  satellite  from  its  central  body  is 
greatest  in  the  case  of  the  outermost  or  seventh  satellite  of 
Saturn,  its  distance  from  the  body  round  vv^hich  it  revolves 
amounting  to  more  than  two  millions  of  miles,  or  ten  times  as 
great  a  distance  as  that  of  our  moon  from  the  Earth.  In  the 
case  of  Jupiter  we  find  that  the  outermost  or  fourth  attendant 
moon  is  only  1,040,000  miles  from  that  planet,  while  the  dis- 
tance between  Uranus  and  its  sixth  satellite  (if  the  latter  real- 
ly exist)  amounts  to  as  much  as  1,360,000  miles.  If  we  com- 
pare, in  each  of  these  subordinate  systems,  the  volume  of  the 
main  planet  with  the  distance  of  the  orbit  of  its  most  remote 
satellite,  we  discover  the  existence  of  entirely  new  numerical 
relations.  The  distances  of  the  outermost  satellites  of  Uranus, 
Saturn,  and  Jupiter  are,  when  expressed  in  semi-diameters 
of  the  main  planets,  as  91,  64,  and  27.  The  outermost  satel- 
lite of  Saturn  appears,  therefore,  to  be  removed  only  about 
one  fifteenth  further  from  the  center  of  that  planet  than  our 
moon  is  from  the  Earth.  The  first  or  innermost  of  Saturn's 
satellites  is  nearer  to  its  central  body  than  any  other  of  the 
secondary  planets,  and  presents,  moreover,  the  only  instance 
of  a  period  of  revolution  of  less  than  twenty-four  hours.  Its 
distance  from  the  center  of  Saturn  may,  according  to  Madler 
and  Wilhelm  Beer,  be  expressed  as  2-47  semi-diameters  of  that 
planet,  or  as  80,088  miles.  Its  distance  from  the  surface  of 
the  main  planet  is  therefore  47,480  miles,  and  from  the  outer- 
most edge  of  the  ring  only  4916  miles.  The  traveler  may 
form  to  himself  an  estimate  of  the  smallness  of  this  amount 
by  remembering  the  statement  of  an  enterprising  navigator, 
Captain  Beechey,  that  he  had  in  three  years  passed  over  72,800 
miles.  If,  instead  of  absolute  distances,  we  take  the  semi-di- 
ameters of  the  principal  planets,  we  shall  find  that  even  the 
first  or  nearest  of  the  moons  of  Jupiter  (which  is  26,000  miles 
further  removed  from  the  center  of  that  planet  than  our  moon 
is  from  that  of  the  Earth)  is  only  six  semi-diameters  of  Jupiter 
from  its  center,  while  our  moon  is  removed  from  us  fully  60  ^d 
semi-diameters  of  the  Earth. 

In  the  subordinate  systems  of  satellites,  we  find  that  the 
same  laws  of  gravitation  which  regulate  the  revolutions  of  the 
principal  planets  round  the  Sun  hkewise  govern  the  mutual 
relations  existing  between  these  planets  among  one  another 
and  with  reference  to  their  attendant  satellites.  The  twelve 
moons  of  Saturn,  Jupiter,  and  the  Earth  all  move  like  the 
primary  planets  from  west  to  east,  and  in  elliptic  orbits,  do- 

Vol.  I.— E 


98  COSMOS. 

viatiiig  but  little  from  circles.  It  is  only  in  the  case  of  ouf 
moon,  and  perhaps  in  that  of  the  first  and  innermost  of  tha 
satellites  of  Saturn  (0'068),  that  we  discover  an  eccentricity 
greater  than  that  of  Jupiter ;  according  to  the  very  exact  ob- 
servations of  Bessel,  the  eccentricity  of  the  sixth  of  Saturn's 
satellites  (0'029)  exceeds  that  of  the  Earth.  On  the  extremes! 
limits  of  the  planetary  system,  vv^here,  at  a  distance  nineteen 
times  greater  than  that  of  our  Earth,  the  centripetal  force  of 
the  Sun  is  greatly  diminished,  the  satellites  of  Uranus  (which 
have  certainly  been  but  imperfectly  investigated)  exhibit  tht 
most  striking  contrasts  from  the  facts  observed  with  regard  t(? 
other  secondary  planets.  Instead,  as  in  all  other  satellites,  of 
having  their  orbits  but  slightly  inclined  toward  the  ecliptic 
and  (not  excepting  even  Saturn's  ring,  which  may  be  regard- 
ed as  a  fusion  of  agglomerated  satellites)  moving  from  west  tc 
east,  the  satellites  of  Uranus  are  almost  perpendicular  to  the 
ecliptic,  and  move  retrogressively  from  east  to  west,  as  Sir 
John  Herschel  has  proved  by  observations  continued  during 
many  years  If  the  primary  and  secondary  planets  have  been 
formed  by  the  condensation  of  rotating  rings  of  solar  and  plan- 
etary atmospheric  vapor,  there  must  have  existed  singular 
causes  of  retardation  or  impediment  in  the  vaporous  rings  re- 
volving round  Uranus,  by  which,  under  relations  with  which 
we  are  unacquainted,  the  revolution  of  the  second  and  fourth 
of  its  satellites  was  made  to  assume  a  direction  opposite  to  that 
of  the  rotation  of  the  central  planet. 

It  seems  highly  probable  that  the  period  of  rotation  of  all 
secondary  planets  is  equal  to  that  of  their  revolution  round 
the  main  planet,  and  therefore  that  they  always  present  to 
the  latter  the  same  side.  Inequalities,  occasioned  by  slight 
variations  in  the  revolution,  give  rise  -to  fluctuations  of  from 
6'^  to  8*^,  or  to  an  apparent  libration  in  longitude  as  well  as 
in  latitude.  Thus,  in  the  case  of  our  moon,  we  sometimes 
observe  more  than  the  half  of  its  surface,  the  eastern  and 
northern  edges  being  more  visible  at  one  time,  and  tlie  west- 
ern or  southern  at  another.  By  means  of  this  libration*  we 
ave  enabled  to  see  the  annular  mountain  Malapert  (which  oc- 
casionally conceals  the  Moon's  south  pole),  the  arctic  land- 
scape round  the  crater  of  Gioja,  and  the  largf  gray  plane  near 
Endymion,  which  exceeds  in  superficial  extent  the  Mare  Va- 
pormn.     Three  sevenths  of  the  Moon's  surface  arc  entirelj 

*  Beer  and  Madler,  op.  cit.,  $  185,  s.  208,  and  *;j  347,  s  33-J ;  ,muI  u 
their  Phys.  Kemiiniss  der  liimml.  Korper,  s.  4  uiiiJ  69.  Tab.  1  ( l*hy&Jo 
al  History  of  the  Heavenly  Bodies). 


COMETS.  9i> 

concealed  from  our  observation,  and  must  always  remain  so, 
unless  new  and  unexpected  disturbing  causes  come  into  play. 
These  cosmical  relations  involuntarily  remind  us  of  nearly 
similar  conditions  in  the  intellectual  world,  where,  in  the  do- 
main of  deep  research  into  the  mysteries  and  the  primeval 
creative  forces  of  nature,  there  are  regions  similarly  turned 
away  from  us,  and  apparently  unattainable,  of  which  only  a 
narrow  margin  has  revealed  itself,  for  thousands  of  years,  toi 
the  human  mind,  appearing,  from  time  to  time,  either  glim- 
mering in  true  or  delusive  hght.  We  have  hitherto  consid- 
ered the  primary  planets,  their  satellites,  and  the  concentric 
rings  which  belong  to  one,  at  least,  of  the  outermost  planets, 
as  products  of  tangential  force,  and  as  closely  connected  to- 
gether by  mutual  attraction ;  it  therefore  now  only  remains 
lor  us  to  speak  of  the  unnumbered  host  of  comets  which  con- 
stitute a  portion  of  the  cosmical  bodies  revolving  in  independ- 
ent orbits  round  the  Sun.  If  we  assume  an  equable  distribu- 
tion of  their  orbits,  and  the  limits  of  their  perihelia,  or  greatest 
proximities  to  the  Sun,  and  the  possibility  of  their  remaining 
invisible  to  the  inhabitants  of  the  Earth,  and  base  our  esti- 
mates on  the  rules  of  the  calculus  of  probabilities,  we  shall 
obtain  as  the  result  an  amount  of  myriads  perfectly  astonish- 
ing. Kepler,  with  his  usual  animation  of  expression,  said  that 
there  were  more  comets  in  the  regions  of  space  than  fishes  in 
the  depths  of  the  ocean.  As  yet,  however,  there  are  scarcely 
one  hundred  and  fifty  whose  paths  have  been  calculated,  if 
we  may  assume  at  six  or  seven  hundred  the  number  of  comets 
whose  appearance  and  passage  through  known  constellations 
have  been  ascertained  by  more  or  less  precise  observations. 
While  the  so-called  classical  nations  of  the  West,  the  Greeks 
and  Romans,  although  they  may  occasionally  have  indicated 
the  position  in  which  a  comet  first  appeared,  never  afford  any 
information  regarding  its  apparent  path,  the  copious  literature 
of  the  Chinese  (who  observed  nature  carefully,  and  recorded 
with  accuracy  what  they  saw)  contains  circumstantial  notices 
of  the  constellations  through  which  each  comet  was  observed 
to  pass.  These  notices  go  back  to  more  than  five  hundred 
years  before  the  Christian  era,  and  many  of  them  are  still 
found  to  be  of  value  in  astronomical  observations.  =^ 

*  The  first  comets  of  whose  orbits  we  have  any  knowledge,  and 
which  were  calculated  from  Chinese  observations,  are  those  of  240  (un- 
der Gordian  III.),  539  (under  Justinian),  56-5,  568,  574,  837,  1337,  and 
1385.  See  John  Russell  Hind, in  Schiini.,  Astron.  Nachr.,  1843,  No.  498. 
While  ihe  comet  of  837  (which,  a^cordin^  to  Du  Sejour,  continued  dur- 


100  COSMOS. 

Although  comets  have  a  smaller  mass  than  anj^  other  oos- 
mical  bodies — being,  according  to  our  present  knowledge,  prob- 
ably not  equal  to  joVo^h  part  of  the  Earth's  mass — yet  they 
occupy  the  largest  space,  as  their  tails  in  several  instances  ex- 
tend over  many  millions  of  miles.  The  cone  of  luminous  va- 
por which  radiates  from  them  has  been  found,  in  some  cases 
(as  in  1680  and  1811),  to  equal  the  length  of  the  Earth's 
distance  from  the  Sun,  forming  a  line  that  intersects  both  the 
orbits  of  Venus  and  Mercury.  It  is  even  probable  that  the 
vapor  of  the  tails  of  comets  mingled  with  our  atmosphere  in 
the  years  1819  and  1823. 

Comets  exhibit  such  diversities  of  form,  which  appear  rath 
er  to  appertain  to  the  individual  than  the  class,  that  a  de- 
scription of  one  of  these  "  wandering  light-clouds,"  as  they 
were  already  called  by  Xenophanes  and  Theon  of  Alexandria, 
cotemporaries  of  Pappus,  can  only  be  applied  with  caution  to 
another.  The  faintest  telescopic  comets  are  generally  devoid 
of  visible  tails,  and  resemble  Herschel's  nebulous  stars.  They 
appear  like  circular  nebulae  of  faintly-glimmering  vapor,  with 
the  light  concentrated  toward  the  middle.  This  is  the  most 
simple  type  ;  but  it  can  not,  however,  be  regarded  as  rudi- 
mentary, since  it  might  equally  be  the  type  of  an  older  cos 
mical  body,  exhausted  by  exhalation.  In  the  larger  comets 
we  may  distinguish  both  the  so-called  "head"  or  "nucleus," 
and  the  single  or  multiple  tail,  which  is  characteristically  de 
nominated  by  the  Chinese  astronomers  "  the  brush"  [sui). 
The  nucleus  generally  presents  no  definite  outline,  although, 
in  a  few  rare  cases,  it  appears  like  a  star  of  the  first  or  second 
magnitude,  and  has  even  been  seen  in  bright  sunshine  ;^  as, 

ing  twenty-four  hours  within  a  distance  of  2,000,000  miles  from  the 
Earth)  terrified  Louis  I.  of  France  to  that  degree  that  he  busied  him 
self  in  building  churches  and  founding  monastic  establishments,  in  the 
hope  of  appeasing  the  evils  threatened  by  its  appearance,  the  Chinese 
astronomers  made  observations  on  the  path  of  this  cosmical  body,  whose 
tail  extended  over  a  space  of  60°,  appearing  sometimes  single  and 
sometimes  multiple.  The  first  comet  that  has  been  calculated  solely 
from  European  observations  was  that  of  1456,  known  as  Halley's  cor.Ti- 
et,  from  the  belief  long,  but  erroneously,  entertained  that  the  period 
when  it  was  first  observed  by  that  astronomer  was  its  first  and  only 
well-attested  appearance.  See  Arago,  in  the  Annuaire,  1836,  p.  204, 
and  Laugier,  Comptes  Rendus  des  Stances  de  VAcad.,  1843,  t.  xvi., 
1006. 

*  Arago,  Annuaire,  1832,  p.  209,  211.  The  phenomenon  of  the  tail 
of  a  comet  being  visible  in  bright  sunshine,  which  is  recorded  of  the 
comet  of  1402,  occurred  again  in  the  case  of  the  large  comet  of  1843, 
whose  nucleus  and  tail  were  seen  in  North  America  on  the  28th  of  Feb- 
raary  (according  to  the  testimony  of  J.  G.  Clarke,  of  Portland,  state  of 


COMETS.  101 

lor  instance,  in  the  large  comets  of  1402,  1532,  1577,  1744, 
and  1843.  This  latter  circumstance  indicates,  in  particular 
individuals,  a  denser  mass,  capable  of  reflecting  Ught  with 
greater  intensity.  Even  in  Herschel's  large  telescope,  only 
two  comets,  that  discovered  in  Sicily  in  1807,  and  the  splen- 
did one  of  1811,  exhibited  well-defined  disks  ;*  the  one  at  an 
angle  of  1",  and  the  other  at  0""77,  whence  the  true  diame- 
ters are  assumed  to  be  536  and  428  miles.  The  diameters 
of  the  less  well-defined  nuclei  of  the  comets  of  1798  and  1805 
did  not  appear  to  exceed  24  or  28  miles. 

In  several  comets  that  have  been  investigated  with  great 
care,  especially  in  the  above-named  one  of  1811,  which  con- 
tinued visible  for  so  long  a  period,  the  nucleus  and  its  nebu- 
lous envelope  were  entirely  separated  from  the  tail  by  a  darker 
space.  The  intensity  of  light  in  the  nucleus  of  comets  does 
not  augment  toward  the  center  in  any  uniform  degree,  bright- 
ly shining  zones  being  in  many  cases  separated  by  concentric 
nebulous  envelopes.  The  tails  sometimes  appear  single,  some- 
times, although  more  rarely,  double  ;  and  in  the  comets  of- 
1807  and  1843  the  branches  were  of  difierent  leno^ths  ;  in 
one  instance  (1744)  the  tail  had  six  branches,  the  whole 
forming  an  angle  of  60^.  The  tails  have  been  sometimes 
straight,  sometimes  curved,  either  toward  both  sides,  or  to- 
ward the  side  appearing  to  us  as  the  exterior  (as  in  1811),  or 
convex  toward  the  direction  in  which  the  comet  is  moving 
(as  in  that  of  1618) ;  and  sometimes  the  tail  has  even  ap- 
peared like  a  flame  in  motion.  The  tails  are  always  turned 
away  from  the  sun,  so  that  their  line  of  prolongation  passes 
through  its  center ;  a  fact  which,  according  to  Edward  Biot, 
was  noticed  by  the  Chinese  astronomers  as  early  as  837,  but 
was  first  generally  made  known  in  Europe  by  Fracastoro  and 
Peter  Apian  in  the  sixteenth  century.  These  emanations 
may  be  regarded  as  conoidal  envelopes  of  greater  or  less  thick- 

Maiue),  between  1  and  3  o'clock  in  the  afternoon.*  The  distance  of 
the  very  dense  nucleus  from  the  sun's  light  admitted  of  being  measured 
with  much  exactness.  The  nucleus  and  tail  a{)peared  like  a  very  pure 
white  cloud,  a  darker  space  intervemng  between  the  tail  and  the  nu- 
cleus.    {Amer-  Journ.  of  Science,  vol.  xlv.,  No.  1,  p.  229.) 

*  Phil.  Trans,  for  1808,  Part  ii.,  p.  155,  and  for  1812,  Part  i.,  p.  118 
The  diameters  found  by  Herschel  for  the  nuclei  were  538  <inJ  428  En 
glish  miles.     For  the  magnitudes  of  the  comets  of  1798  and  ISOJ.  st;e 
Arago,  Annnaire,  1832,  p.  203. 

a  [The  translator  was  at  New  Bedford,  Massachusetts,  U.  S.,  on  the  2Sth  Februa- 
ry, 1843,  and  distinctly  saw  the  comet,  between  1  and  2  in  the  afternoon.  The  skj 
at  the  time  was  intensely  blue,  and  the  sun  shining  with  a  dazzling  brightnoos  un- 
known in  European  climates.] — Tr 


102  *  COSMOS. 

ness,  and,  considered  in  this  manner,  they  furnish  a  simple 
explanation  of  many  of  the  remarkable  optical  phenomena  al- 
ready spoken  of. 

Comets  are  not  only  characteristically  different  in  form, 
some  being  entirely  without  a  visible  tail,  while  others  have 
a  tail  of  immense  length  (as  in  the  instance  of  the  comet  of 
1618,  whose  tail  measured  104°),  but  we  also  see  the  same 
comets  undergoing  successive  and  rapidly-changing  processes 
of  configuration.  These  variations  of  form  have  been  most 
accurately  and  admirably  described  in  the  comet  of  1744,  by 
Hensius,  at  St.  Petersburg,  and  in  Halley's  comet,  on  its  last 
reappearance  in  1835,  by  Bessel,  at  Konigsberg.  A  more  or 
less  well-defined  tuft  of  rays  emanated  from  that  part  of  the 
nucleus  which  was  turned  toward  the  Sun  ;  and  the  rays  be- 
ing bent  backward,  formed  a  part  of  the  tail.  The  nucleus 
of  Halley's  comet,  with  its  emanations,  presented  the  appear- 
ance of  a  burning  rocket,  the  end  of  which  was  turned  side- 
ways by  the  force  of  the  wind.  The  rays  issuing  from  the 
head  were  seen  by  Arago  and  myself,  at  the  Observatory  at 
Paris,  to  assume  very  different  forms  on  successive  nights.* 
The  great  Konigsberg  astronomer  concluded  from  many  meas- 
urements, and  from  theoretical  considerations,  "  that  the  cone 
of  light  issuing  from  the  comet  deviated  considerably  both  to 
the  right  and  the  left  of  the  true  direction  of  the  Sun,  but 
that  it  always  returned  to  that  direction,  and  passed  over  to 
the  opposite  side,  so  that  both  the  cone  of  light  and  the  body 
of  the  comet  from  whence  it  emanated  experienced  a  rotatory, 
or,  rather,  a  vibratory  motion  in  the  plane  of  the  orbit."  He 
finds  that  "  the  attractive  force  exercised  by  the  Sun  on  heavy 
bodies  is  inadequate  to  explain  such  vibrations,  and  is  of  opin- 
ion that  they  indicate  a  polar  force,  which  turns  one  semi-di- 
ameter of  the  comet  toward  the  Sun,  and  strives  to  turn  the 
opposite  side  away  from  that  luminary.  The  magnetic  polar- 
ity possessed  by  the  Earth  may  present  some  analogy  to  this ; 
and,  should  the  Sun  have  an  opposite  polarity,  an  influence 
might  be  manifested,  resulting  in  the  precession  of  the  equi- 
noxes." This  is  not  the  place  to  enter  more  fully  upon  the 
grounds  on  which  explanations  of  this  subject  have  been  bas- 
ed ;  but  observations  so  remarkable,!  and  views  of  so  exalted 

*  Arago,  Des  Changemenis  physiques  de  la  Comete  de  Halley  du  15- 
23  Oct.,  1835.  Annnaire,  1836,  p.  218,  221.  The  ordinary  direction 
of  the  emanations  was  noticed  even  in  Nero's  time.  "  Comce  radios  sO' 
lis  effugiunt.^^ — Seneca,  Nat.  Qucest.,  vii.,  20. 

t  Bessel,  in  Schumacher,  Astr.  Nachr.,  1836,  No.  300-302,  s.  188, 192, 


COMETS.  103 

I  character,  regarding  the  most  wonderful  class  of  the  cosmic- 
al  bodies  belonging  to  our  solar  system,  ought  not  to  be  en- 
tirely passed  over  in  this  sketch  of  a  general  picture  of  nature. 

Although,  as  a  rule,  the  tails  of  comets  increase  in  magni- 
tude and  brilliancy  in  the  vicinity  of  the  sun,  and  are  directed 
away  from  that  central  body,  yet  the  comet  of  1823  ofiered 
the  remarkable  example  of  two  tails,  one  of  which  was  turned 
toward  the  sun,  and  the  other  away  from  it,  forming  with 
each  other  an  angle  of  160°.  Modifications  of  polarity  and 
the  unequal  manner  of  its  distribution,  and  of  the  direction  in 
which  it  is  conducted,  may  in  this  rare  instance  have  occa- 
sioned a  double,  unchecked,  continuous  emanation  of  nebulous 
matter,* 

Aristotle,  in  his  Natural  Philosophy^  makes  these  emana- 
tions the  means  of  bringing  the  phenomena  of  comets  into  a 
singular  connection  with  the  existence  of  the  Milky  Way. 
According  to  his  views,  the  innumerable  quantity  of  stars 
which  compose  this  starry  zone  give  out  a  self-luminous,  in- 
candescent matter.  The  nebulous  belt  which  separates  the 
different  portions  of  the  vault  of  heaven  was  therefore  regard- 
ed by  the  Stagirite  as  a  large  comet,  the  substance  of  which 
was  incessantly  being  renewed.! 

197,  200,  20-2,  und  230.  Also  in  Schumacher,  Jahrb.,  1837,  s.  149, 168. 
William  Herschel,  in  his  observations  on  the  beautiful  comet  of  1811, 
believed  that  he  had  discovered  evidences  of  the  rotation  of  the  nucleus 
and  tail  {Phil.  Trans,  for  1812,  Part  i.,  p.  140).  Duulop,  at  Paramat- 
ta, thought  the  same  with  reference  to  the  third  comet  of  1825. 

*  Bessel,  in  Astr.  Nachr.,  1836,  No.  302,  s.  231.  Schum.,  Jahrb.,  1837. 
s.  175.  See,  also,  Lehmaun,  Ueber  Cometenschiceife  (On  the  Tails  of 
Comets),  in  Bode,  Astron.  Jahrb.  fur  1826,  s.  168. 

t  Aristot.,  Meteor.,  i.,  8,  11-14,  und  19-21  (ed.  Ideler,  t.  i.,  p.  32-34). 
Biese,  Phil,  des  Aristoteles,  bd.  ii.,  s.  86.  Since  Aristotle  exercised  so 
great  an  influence  throughout  the  whole  of  the  Middle  Ages,  it  is  very 
much  to  be  regretted  that  he  was  so  averse  to  those  grander  views  of 
the  elder  Pythagoreans,  which  inculcated  ideas  so  nearly  approxima- 
ting to  truth  respecting  the  structure  of  the  universe.  He  asserts  that 
comets  are  transitory  meteors  ^belonging  to  our  atmosphere  in  the  very 
book  in  which  he  cites  the  opinion  of  the  Pythagorean  school,  accord- 
ing to  which  these  cosmical  bodies  are  supposed  to  be  planets  having 
long  periods  of  revolution.  (Aristot.,  i.,  6,  2.)  This  Pythagorean  doc- 
trine, which,  according  to  the  testimony  of  ApoUonius  Myndius,  was 
still  more  ancient,  having  oingiuated  with  the  Chaldeans,  ])a3scd  over 
to  the  Romans,  who  in  this  instance,  as  was  their  usual  practice,  were 
merely  the  copiers  of  others.  The  Myndian  philosopher  describes  the 
path  of  comets  as  directed  toward  the  upper  and  remote  regions  of 
heaven.  Hence  Seneca  says,  in  his  Nat.  Qucest.,  vii.,  17:  ^^  Comeles 
pon  est  species  falsa,  sed  propHum  sidus  sicnt  solis  et  lunce  :  altiora  mnn- 
di  secat  et  tunc  demum  apparct  quum  in  imum  cwrsum  stii  venil;^'  and 
'Again  (at  vii.,  27),  "  Cometes  ceternos  esse  et  sortis  ejvsdem,  cvjns  ctr.tera 


104  C0SM09. 

The  occultat.ion  of  the  fixed  stars  by  the  nucleus  of  a  com 
et,  or  by  its  innermost  vaporous  envelopes,  might  throw  some 
light  on  the  physical  character  of  these  wonderful  bodies  ;  but 
we  are  unfortunately  deficient  in  observations  by  which  we 
may  be  assured*  that  the  occultation  was  perfectly  central ; 
for,  as  it  has  already  been  observed,  the  parts  of  the  envelope 
contiguous  to  the  nucleus  are  alternately  composed  of  layers 
of  dense  or  very  attenuated  vapor.  On  the  other  hand,  the 
carefully  conducted  measurements  of  Bessel  prove,  beyond  all 
doubt,  that  on  the  29th  of  September,  1835,  the  light  of  a 
star  of  the  tenth  magnitude,  which  was  then  at  a  distance  of 
7"-78  from  the  central  point  of  the  head  of  Halley's  comet, 
passed  through  very  dense  nebulous  matter,  without  experi- 
encing any  deflection  during  its  passage.!  If  such  an  absence 
of  refracting  power  must  be  ascribed  to  the  nucleus  of  a  com- 
et, tve  can  scarcely  regard  the  matter  composing  comets  as  a 
gaseous  fluid.  The  question  here  arises  whether  this  absence 
of  refracting  power  may  not  be  owing  to  the  extreme  tenuity 
of  the  fluid  ;  or  does  the  comet  consist  of  separated  particles 
constituting  a  cosmical  stratum  of  clouds,  which,  like  the 
clouds  of  our  atmosphere,  that  exercise  no  influence  on  the 

{sidera),  etiamsi  faciem  illis  non  habent  similemJ'''  Pliny  (ii.,  25)  also  re- 
fers to  Apollonius  Myndius,  when  he  says,  "-Sunt  qui  et  kcBC  sidera  per- 
petua  esse  credant  sitoque  amhitu  ire,  sed  non  nisi  relicta  a  sole  cerniy 

*  Olbers,  in  Asir.  Nachr.,  1828,  s.  157,  184.  Arago,  De  la  Constitu- 
tion physique  des  C o metes ;  Annuaire  de  1832,  p.  203,  208.  The  an- 
cients were  struck  by  the  phenomenon  that  it  was  possible  to  see 
through  comets  as  throusrh  a  flame.  The  earliest  evidence  to  be  met 
with  of  stars  having  been  seen  throngh  comets  is  that  of  Democntus 
(Aristot.,  Metear.,  i.,  6,  11),  and  the  statement  leads  Aristotle  to  make 
the  not  miimportant  remark,  that  he  himself  had  observed  the  occulta- 
tion of  one  of  the  stars  of  Gemini  by  Jupiter.  Seneca  only  speaks  de- 
cidedly of  the  transparence  of  the  tail  of  comets.  "  We  may  see,"  says 
he,  "stars  through  a  comet  as  through  a  cloud  (Nat.  Qucest.,  vii.,  18); 
but  we  can  only  see  through  the  rays  of  tlie  tail,  and  not  through  the 
body  of  the  comet  itself:  non  in  ea  parte  qua  sidns  ipsum  est  spissi  et 
:^olidi  ignis,  sed  qua  varus  splendor  occurrit  et  in  crines  dispergitur.  Per 
intervalla  ignium,  non  per  ipsos,  vides"  (vii.,  26).  The  last  remark  is 
unnecessary,  since,  as  Galileo  observed  in  the  Saggialore  {Lettera  a 
Monsignor  CesaHni,  1G19),  we  can  certainly  see  through  a  flame  when 
it  is  not  of  too  great  a  thickness. 

t  Bessel,  in  the  Astron.  Nachr.,  1836,  No.  301,  s.  204,  206.  Struve, 
in  Recueil  des  Mim.  de  V Acad,  dc  St.  Petcrsh.,  1836,  p.  140,  143,  and 
Astr.  Nachr.,  1836,  No.  303,  s.  238,  writes  as  follows:  "At  Dorpat  the 
star  was  in  conjunction  only  2"*2  from  the  Imghtest  point  of  the  comet. 
The  star  remained  continually  visible,  and  its  hght  was  not  perceptibly 
diminished,  while  the  nucleus  of  the  comet  tfeemed  to  be  almost  extin 
guished  before  the  radiance  of  the  small  star  of  the  ninth  or  tenth  mag 
nitude." 


COMETS.  105 

zenith  distance  of  the  stars,  does  not  affect  the  ray  of  light 
passing  through  it  ?  In  the  passage  of  a  comet  over  a  star,  a 
more  or  less  considerable  diminution  of  light  has  often  been 
observed  ;  but  this  has  been  justly  ascribed  to  the  brightness 
of  the  ground  from  which  the  star  seems  to  stand  forth  during 
the  passage  of  the  comet. 

The  most  important  and  decisive  observations  that  we  pos- 
sess on  the  nature  and  the  light  of  comets  are  due  to  Arago's 
polarization  experiments.  His  polariscope  instructs  us  re- 
garding the  physical  constitution  of  thfe  Sun  and  comets,  indi- 
cating whether  a  ray  that  reaches  us  from  a  distance  of  many 
millions  of  miles  transmits  light  directly  or  by  reflection  ;  and 
if  the  former,  whether  the  source  of  light  is  a  sofld,  a  liquid, 
or  a  gaseous  body.  His  apparatus  was  used  at  the  Paris  Ob- 
servatory in  examining  the  hght  of  Capella  and  that  of  the 
great  comet  of  1819.  The  latter  shov/ed  polarized,  and  there- 
fore reflected  hght,  while  the  fixed  star,  as  was  to  be  expect- 
ed, appeared  to  be  a  self-luminous  sun.*  The  existence  of 
polarized  cometary  light  announced  itself  not  only  by  the  in- 
equality of  the  images,  but  was  proved  with  greater  certainty 
on  the  reappearance  of  Halley's  comet,  in  the  year  1835,  by 
the  more  striking  contrast  of  the  complementary  colors,  de- 
duced from  the  laws  of  chromatic  polarization  discovered  by 
Arago  in  1811.  These  beautiful  experiments  still  leave  it 
undecided  whether,  in  addition  to  this  reflected  solar  light, 
comets  may  not  have  light  of  their  own.  Even  in  the  case 
of  the  planets,  as.  for  instance,  in  Venus,  an  evolution  of  ui- 
dependent  light  seems  very  probable. 

The  variable  intensity  of  light  in  comets  can  not  always  be 

*  On  the  3d  of  July,  1819,  Arago  made  the  first  attempt  to  analyze 
the  light  of  comets  by  polarization,  on  the  evening  of  the  sudden  ap 
pearance  of  the  great  comet.  I  was  present  at  the  Paris  Observatory, 
and  was  fully  convinced,  as  were  also  Matthieu  and  the  late  Bouvard, 
of  the  dissimilarity  in  the  intensity  of  the  light  seen  in  the  polariscope, 
when  the  instrument  received  cometary  light.  When  it  received  light 
from  Capella,  which  was  near  the  comet,  and  at  an  equal  altitude,  the 
images  were  of  equal  intensity.  On  the  reappearance  of  Halley's  com- 
et in  1835,  the  instrument  was  altered  so  as  to  give,  according  to  Ara- 
go's chromatic  polarization,  two  images  of  complementary  colors  (gieen 
and  red).  {Annates  de  Chimie,  t.  xiii.,  p.  108;  Annuaire,  1832,  p.  216.) 
"  We  must  conclude  from  these  observations,"  says  Arago,  "  that  the 
cometary  light  was  not  entirely  composed  of  rays  having  the  properties 
of  direct  light,  there  being  light  which  was  reflected  specularly  or  po- 
larized, that  is,  coming  from  the  sun.  It  can  not  be  stated  with  abso- 
lute certainty  that  comets  shine  only  with  borrowed  light,  for  bodies,, 
in  becoming  self-luminous,  do  not,  on  that  account,  lose  the  power  of 
reflecting  foreign  light." 

E  2 


106  COSMOS. 

explained  by  tlie  position  of  their  orbits  and  their  distance  from 
the  Sun.  It  would  seem  to  indicate,  in  some  individuals,  the 
existence  of  an  inherent  process  of  condensation,  and  an  in- 
creased or  diminished  capacity  of  reflecting  borrowed  light. 
In  the  comet  of  1618,  and  in  that  which  has  a  period  of  three 
years,  it  was  observed  first  by  Hevelius  that  the  nucleus  of 
the  comet  diminished  at  its  perihelion  and  enlarged  at  its 
aphelion,  a  fact  which,  after  remaining  long  unheeded,  was 
again  noticed  by  the  talented  astronomer  Valz  at  Nismes. 
The  regularity  of  the  change  of  volume,  according  to  the  dif- 
ferent degrees  of  distance  from  the  Sun,  appears  very  striking. 
The  physical  explanation  of  the  phenomenon  can  not,  howev- 
er, be  sought  in  the  condensed  layers  of  cosmical  vapor  occur- 
ring in  the  vicinity  of  the  Sun,  since  it  is  difficult  to  imagine 
the  nebulous  envelope  of  the  nucleus  of  the  comet  to  be  vesic- 
ular and  impervious  to  the  ether.* 

The  dissimilar  eccentricity  of  the  orbits  of  comets  has,  in 
recent  times  (1819),  in  the  most  brilliant  manner  enriched  our 
knowledge  of"  the  solar  system.  Encke  has  discovered  the  ex- 
istence of  a  comet  of  so  short  a  period  of  revolution  that  it  re- 
mains entirely  within  the  limits  of  our  planetary  system,  at- 
taining its  aphelion  between  the  orbits  of  the  smaller  planets 
and  that  of  Jupiter.  Its  eccentricity  must  be  assumed  at  0*845, 
that  of  Juno  (which  has  the  greatest  eccentricity  of  any  of  the 
planets)  being  0*255.  Encke's  comet  has  several  times,  al- 
though with  difficulty,  been  observed  by  the  naked  eye,  as  in 
Europe  in  1819,  and,  according  to  Riimker,  in  New  Holland 
in  1822.  Its  period  of  revolution  is  about  S^d  years;  but, 
from  a  careful  comparison  of  the  epochs  of  its  return  to  its 
perihelion,  the  remarkable  fact  has  been  discovered  that  these 
periods  have  diminished  in  the  most  regular  manner  between 
the  years  1786  and  1838,  the  diminution  amounting,  in  the 
course  of  52  years,  to  about  lyVl^h.  days.  The  attempt  to 
brmg  into  unison  the  results  of  observation  and  calculation  in 
the  investigation  of  all  the  planetary  disturbances,  with  the 
view  of  explaining  this  phenomenon,  has  led  to  the  adoption 
of  the  very  probable  hypothesis  that  there  exists  dispersed  in 
space  a  vaporous  substance  capable  of  acting  as  a  resisting 
medium.  This  matter  diminishes  the  tangential  force,  and 
with  it  the  major  axis  of  the  comet's  orbit.  The  value  of  the 
constant  of  the  resistance  appears  to  be  somewhat  different 
before  and  after  the  perihelion  ;  and  this  may,  perhaps,  be  as- 

*  Arago,  in  the  Anniiaire,  1832,  p.  217-220.     Sir  John  Herschel, 
Asiron.,  §  488. 


COMElfc'.  107 

bribed  to  tlie  altered  form  of  the  small  nebulous  star  in  the 
vi(dnity  of  the  Sun,  and  to  the  action  of  the  unequal  density 
of  the  strata  of  cosmical  ether. ^  These  facts,  and  the  inves- 
tigations to  which  they  have  led,  belong  to  the  most  interest- 
ng  results  of  modern  astronomy.  Encke's  comet  has  been 
the  means  of  leading  astronomers  to  a  more  exact  investiga- 
tion of  Jupiter's  mass  (a  most  important  point  with  reference 
\o  the  calculation  of  perturbations)  ;  and,  more  recently,  the 
eourse  of  this  comet  has  obtained  for  us  the  first  determina- 
tion, although  only  an  approximative  one,  of  a  smaller  mass  for 
Mercury. 

The  discovery  of  Encke's  comet,  which  had  a  period  of  only 
3id  years,  was  speedily  followed,  in  1826,  by  that  of  another, 
Biela'a  comet,  whose  period  of  revolution  is  6|th  years,  and 
which  is  likewise  planetary,  having  its  aphelion  beyond  the 
orbit  of  Jupiter,  but  within  that  of  Saturn.  It  has  a  fainter 
light  than  Encke's  comet,  and,  like  the  latter,  its  motion  is 
direct,  while  Halley's  comet  moves  in  a  course  opposite  to  that 
pursued  by  the  planets.  Biela's  comet  presents  the  first  cer- 
tain example  of  the  orbit  of  a  comet  intersecting  that  of  the 
Earth.  This  position,  with  reference  to  our  planet,  may  there- 
fore be  productive  of  danger,  if  we  can  associate  an  idea  of 
danger  with  so  extraordinary  a  natural  phenomenon,  whose 
history  presents  no  parallel,  and  the  results  of  which  we  are 
consequently  unable  correctly  to  estimate.  Small  masses  en- 
dowed with  enormous  velocity  may  certainly  exercise  a  con- 
siderable power  ;  but  Laplace  has  shovi^i  that  the  mass  of  the 
comet  of  1770  is  probably  not  equal  to  jo'oo'tb  of  that  of  the 
Earth,  estimating  further  with  apparent  correctness  the  incan 
mass  of  comets  as  much  below  yoo-Vo  nth  that  of  the  Earth, 
or  about  yoVo^b  that  of  the  Moon.f  We  must  not  confound 
the  passage  of  Biela's  comet  through  the  Earth's  orbit  with 
its  proximity  to,  or  collision  with,  our  globe.  When  this  pas- 
sage took  place,  on  the  29th  of  October,  1832,  it  required  a 
full  month  before  the  Earth  would  reach  the  point  of  inter- 
section of  the  two  orbits.  These  two  comets  oi"  short  periods 
of  revolution  also  intersect  each  other,  and  it  has  been  justly 
observed,!  that  amid  the  many  perturbations  experienced  by 

*  Encke,  in.  the  Astronomische  Nachrichf en,  1843,  No.  489,  s.  130-132. 

■hLaplace,  Expos,  du  S^/st.  du  Monde,  p.  216,  237. 

X  Littrow,  Beschreibende  Asiron,,  1835,  s.  274.  On  the  inner  comet 
recently  discovered  by  M.  Faye,  at  the  Observatory  of  Paris,  and  whose 
eccentricity  is  0-551,  its  distance  at  its  perihelion  1-690,  and  its  distance 
at  its  aphelion  5-832,  see  Schumacher,  Asiron.  Nachr.,  1844,  No.  495. 
Regarding  the  supposed  identity  of  the  comet  of  1766  with  the  third 


108  COSMOS. 

such  small  bodies  from  the  larger  planets,  there  is  di.  possibility 
— supposing"  a  meeting  of  these  comets  to  occur  in  October — • 
that  the  inhabitants  of  the  Earth  may  witness  the  extraordi- 
nary spectacle  of  an  encounter  between  two  cosmical  bodies, 
and  possibly  of  their  reciprocal  penetration  and  amalgamation, 
or  of  their  destruction  by  means  of  exhausting  emanations. 
Events  of  this  nature,  resulting  either  from  deflection  occa- 
sioned by  disturbing  masses  or  primevally  intersecting  orbits, 
must  have  been  of  frequent  occurrence  in  the  course  of  mill- 
ions of  years  in  the  immeasurable  regions  of  ethereal  space  ; 
but  they  must  be  regarded  as  isolated  occurrences,  exercising 
no  more  general  or  alterative  effects  on  cosmical  relations  than 
the  breaking  forth  or  extinction  of  a  volcano  within  the  limit- 
ed sphere  of  our  Earth. 

A  third  interior  comet,  having  likev/ise  a  short  period  of 
revolution,  was  discovered  by  Faye  on  the  22d  of  November, 
1843,  at  the  Observatory  at  Paris.  Its  elliptic  path,  which 
approaches  much  more  nearly  to  a  circle  than  that  of  any 
other  known  comet,  is  included  within  the  orbits  of  Mars  and 
Saturn.  This  comet,  therefore,  which,  according  to  Gold- 
schmidt,  passes  beyond  the  orbit  of  Jupiter,  is  one  of  the  few 
whose  perihelia  are  beyond  Mars.  Its  period  of  revolution  is 
7y-/o  years,  and  it  is  not  improbable  that  the  form  of  its  pres- 
ent orbit  may  be  owing  to  its  great  approximation  to  Jupiter 
at  the  close  of  the  year  1839. 

If  we  consider  the  comets  in  their  inclosed  elliptic  orbits  as 
members  of  our  solar  system,  and  with  respect  to  the  length 
of  their  major  axes,  the  amount  of  their  eccentricity,  and  their 
periods  of  revolution,  we  shall  probably  find  that  the  three 
planetary  comets  of  Encke,  Biela,  and  Faye  are  most  nearly 
approached  in  these  respects,  first,  by  the  comet  discovered  in 
1766  by  Messier,  and  which  is  regarded  by  Clausen  as  iden- 
tical with  the  third  comet  of  1819;  and,  next,  by  the  fourth 
comet  of  the  last-mentioned  year,  discovered  by  Blaupain,  but 
considered  by  Clausen  as  identical  with  that  of  the  year  1743, 
and  whose  orbit  appears,  like  that  of  Lexell's  comet,  to  have 
suffered  great  variations  from  the  proximity  and  attraction  of 
Jupiter.  The  two  last-named  comets  would  likewise  seem  to 
have  a  period  of  revolution  not  exceeding  five  or  six  years,  and 
their  aphelia  are  in  the  vicinity  of  Jupiter's  orbit.  Among 
the  comets  that  have  a  period  of  revolution  of  from  seventy  to 

comet  of  1819,  see  Astr.  Nachr.,  1833,  No.  239  ;  and  on  the  identity  of 
the  comet  of  1743  and  the  fourth  comet  of  1819,  see  No.  237  of  the  last 
mentioned  work. 


COMETS.  109 

seventy-six  years,  the  first  in  point  of  importance  with  respect 
to  theoretical  and  physical  astronomy  is  Halley's  comet,  whose 
last  appearance,  in  1835,  was  much  less  brilliant  than  was  to 
be  expected  from  preceding  ones ;  next  we  would  notice  Ol- 
bers's  comet,  discovered  on  the  6th  of  March,  1815  ;  and, 
lastly,  the  comet  discovered  by  Pons  in  the  year  1812,  and 
whose  elliptic  orbit  has  been  determined  by  Encke.  The  two 
latter  comets  were  invisible  to  the  naked  eye.  We  now  know 
with  certainty  of  nine  returns  of  Halley's  large  comet,  it  hav- 
ing recently  been  proved  by  Laugier's  calculations,*  that  in 
the  Chinese  table  of  comets,  first  made  known  to  us  by  Ed- 
ward Biot,  the  comet  of  1378  is  identical  with  Halley's  ;  its 
periods  of  revolution  have  varied  in  the  interval  between  1378 
and  1835  from  74-91  to  77-58  years,  the  mean  being  76-1. 

A  host  of  other  comets  may  be  contrasted  with  the  cosmical 
bodies  of  which  we  have  spoken,  requiring  several  thousand 
years  to  perform  their  orbits,  which  it  is  difficult  to  determine 
with  any  degree  of  certainty.  The  beautiful  comet  of  1811 
requires,  according  to  Argelander,  a  period  of  3065  years  for 
its  revolution,  and  the  colossal  one  of  1680  as  much  as  8800 
years,  according  to  Encke's  calculation.  These  bodies  respect- 
ively recede,  therefore,  21  and  44  times  further  than  Uranus 
from  the  Sun,  that  is  to  say,  33,600  and  70,400  millions  of 
miles.  At  this  enormous  distance  the  attractive  force  of  the 
Sun  is  still  manifested ;  but  while  the  velocity  of  the  comet 
of  1680  at  its  perihelion  is  212  miles  in  a  second,  that  is, 
thirteen  times  greater  than  that  of  the  Earth,  it  scarcely 
moves  ten  feet  in  the  second  when  at  its  aphelion.  This  ve- 
locity is  only  three  times  greater  than  that  of  water  in  our 
most  sluggish  European  rivers,  and  equal  only  to  half  that 
which  I  have  observed  in  the  Cassiquiare,  a  branch  of  the 
Orinoco.  It  is  highly  probable  that,  among  the  innumerable 
host  of  uncalculated  or  undiscovered  comets,  there  are  many 
whose  major  axes  greatly  exceed  that  of  the  comet  of  1680. 
In  order  to  form  some  idea  by  numbers,  I  do  not  say  of  the 
sphere  of  attraction,  but  of  the  distance  in  space  of  a  fixed  star 
or  other  sun,  from  the  aphelion  of  the  comet  of  1680  (the  fur- 
thest receding  cosmical  body  with  which  we  are  acquainted 
in  our  solar  system),  it  must  be  remembered  that,  according 
to  the  most  recent  determinations  of  parallaxes,  the  nearest 
fixed  star  is  full  250  times  further  removed  from  our  sun  than 
the  comet  in  its  aphelion.     The  comet's  distance  is  only  44 

*  Laugier,  in  the  Comptes  Rendus  des  Stances  de  f  Academie,  18431 
t  xvi.,  p.  1006. 


110  COSMOS. 

times  that  of  Uranus,  while  a  Centaiiri  is  11,000,  and  61 
Cygni  31,000  times  that  of  Uranus,  according  to  Bessel's  de- 
terminations. 

Having  considered  the  greatest  distances  of  comets  from 
the  central  body,  it  now  remains  for  us  to  notice  instances  of 
the  greatest  proximity  hitherto  measured.  Lexell  and  Burck- 
hardt's  comet  of  1770,  so  celebrated  on  account  of  the  disturb- 
ances it  experienced  from  Jupiter,  has  approached  the  Earth 
within  a  smaller  distance  than  any  other  comet.  On  the  28th 
of  June,  1770,  its  distance  from  the  Earth  was  only  six  times 
that  of  the  Moon.  The  same  comet  passed  twice,  viz.,  in 
]769  and  1779,  through  the  sj^stem  of  Jupiter's  four  satellites 
without  producing  the  slightest  notable  change  in  the  well- 
known  orbits  of  these  bodies.  The  great  comet  of  1680  ap- 
proached at  its  perihelion  eight  or  nine  times  nearer  to  the 
surface  of  the  Sun  than  Lexell's  comet  did  to  that  of  our 
Earth,  being  on  the  17th  of  December  a  sixth  part  of  the 
Sun's  diameter,  or  seven  tenths  of  the  distance  of  the  Moon 
from  that  luminary.  Perihelia  occurring  beyond  the  orbit  of 
Mars  can  seldom  be  observed  by  the  inhabitants  of  the  Earth, 
owing  to  the  faintness  of  the  light  of  distant  comets ;  and 
among  those  already  calculated,  the  comet  of  1729  is  the  only 
one  which  has  its  perihelion  between  the  orbits  of  Pallas  and 
Jupiter ;  it  was  even  observed  beyond  the  latter. 

Since  scientific  knowledge,  although  frequently  blended  with 
vague  and  superficial  views,  has  been  more  extensively  diffused 
through  wider  circles  of  social  life,  apprehensions  of  the  possi- 
ble evils  threatened  by  comets  have  acquired  more  weight  as 
their  direction  has  become  more  defuiite.  The  certainty  that 
there  are  within  the  known  planetary  orbits  comets  which  re- 
visit our  regions  of  space  at  short  intervals — that  great  dis- 
turbances have  been  produced  by  Jupiter  and  Saturn  in  their 
orbits,  by  which  such  as  were  apparently  harmless  have  been 
converted  into  dangerous  bodies — the  intersection  of  the  Earth's 
orbit  by  Biela's  comet — the  cosmical  vapor,  which,  acting  as 
a  resisting  and  impeding  medium,  tends  to  contract  all  orbits 
— the  individual  difference  of  comets,  which  would  seem  to 
indicate  considerable  decreasing  gradations  in  the  quantity  of 
the  mass  of  the  nucleus,  are  all  considerations  more  than  equiv- 
alent, both  as  to  number  and  variety,  to  the  vague  fears  en- 
tertained in  early  ages  of  the  general  conflagration  of  the  world 
hy  Jiammg  stvords,  and  stars  with  fieri/  streaming  hair.  As 
the  cons'Dlatory  considerations  which  may  be  derived  from  the 
calculus  of  probabilities  address  themselves  to  reason  and  to 


AEROLITES.  Ill 

meditative  understanding  only,  and  not  to  the  imagination  or 
to  a  desponding  condition  of  mind,  modern  science  has  been 
accused,  and  not  entirely  without  reason,  of  not  attempting  to 
allay  apprehensions  which  it  has  been  the  very  means  of  ex- 
citino-.  It  is  an  inherent  attribute  of  the  human  mind  to  ex- 
perience  fear,  and  not  hope  or  joy,  at  the  aspect  of  that  which 
is  unexpected  and  extraordinary.*  The  strange  form  of  a  large 
comet,  its  faint  nebulous  light,  and  its  sudden  appearance  in 
the  vault  of  heaven,  have  in  all  regions  been  almost  invariably 
regarded  by  the  people  at  large  as  some  new  and  formidable 
agent  inimical  to  the  existing  state  of  things.  The  sudden 
occurrence  and  short  duration  of  the  phenomenon  lead  to  the 
belief  of  some  equally  rapid  reflection  of  its  agency  in  terres- 
trial matters,  whose  varied  nature  renders  it  easy  to  find  events 
that  may  be  regarded  as  the  fulfillment  of  the  evil  foretold  by 
the  appearance  of  these  mysterious  cosmical  bodies.  In  our 
own  day,  however,  the  public  mind  has  taken  another  and 
more  cheerful,  although  singular,  turn  with  regard  to  comets ; 
and  in  the  German  vineyards  in  the  beautiful  valleys  of  the 
Rhine  and  Moselle,  a  belief  has  arisen,  ascribing  to  these  once 
ill-omened  bodies  a  beneficial  influence  on  the  ripening  of  the 
vine.  The  evidence  yielded  by  experience,  of  which  there  is 
no  lack  in  these  days,  when  comets  may  so  frequently  be  ob- 
served, has  not  been  able  to  shake  the  common  belief  in  the 
meteorological  myth  of  the  existence  of  wandering  stars  capa- 
ble of  radiating  heat. 

From  comets  I  would  pass  to  the  consideration  of  a  far  more 
enigmatical  class  of  agglomerated  matter — the  smallest  of  all 
asteroids,  to  which  we  apply  the  name  aeTolites,  or  meteoric 
stones,^  when  they  reach  our  atmosphere  in  a  fragmentary 
condition.  If  I  should  seem  to  dwell  on  the  specific  enumer- 
ation of  these  bodies,  and  of  comets,  longer  than  the  general 
nature  of  this  work  might  w^arrant,  I  have  not  done  so  unde- 
signedly. The  diversity  existing  in  the  individual  character- 
istics of  comets  has  already  been  noticed.  The  imperfect 
knowledge  we  possess  of  their  physical  character  renders  it 

*  Fries,  Vorlesungen  uber  die  SternJcunde,  1833,  s.  262-267  (Lectures 
on  the  Science  of  Astronomy).  An  infeUcitously  chosen  instance  of  the 
good  omen  of  a  comet  may  be  found  in  Seneca,  Nat.  Qucest.,  vii.,  17  and 
21.  The  philosopher  thus  writes  of  the  comet:  "  Quern  7ios  Neronis 
principatu  Icetissimo  vidimus  et  qui  cometis  detraxit  infamiam.^' 

t  [Much  valuable  information  may  be  obtained  regarding  the  origin 
and  composition  of  aerolites  or  meteoric  stones  in  Memoirs  on  the  sub- 
ject, by  Baumbeer  and  other  writers,  in  the  numbers  of  Poggendorf's 
Annalen,  from  1845  to  the  present  time.] — Tr. 


1 12  COSMOS. 

difficult;  in  a  work  like  the  present,  to  give  the  proper  def^ree 
of  circumstantiality  to  the  phenomena,  which,  althougL  of 
frequent  recurrence,  have  been  observed  with  such  various  de- 
grees of  accuracy,  or  to  separate  the  necessary  from  the  acci- 
dental. It  is  only  with  respect  to  measurements  and  compu- 
tations that  the  astronomy  of  comets  has  made  any  marked 
advancement,  and,  consequently,  a  scientific  consideration  of 
these  bodies  must  be  limited  to  a  specification  of  the  differencef 
of  physiognomy  and  conformation  in  the  nucleus  and  tail,  the 
instances  of  great  approximation  to  other  cosmical  bodies,  and 
of  the  extremes  in  the  length  of  their  orbits  and  in  their  periods 
of  revolution.  A  faithful  delineation  of  these  phenomena,  as 
well  as  of  those  which  we  proceed  to  consider,  can  only  be 
given  by  sketching  individual  features  with  the  animated  cir- 
cumstantiality of  reality. 

Shooting  stars,  fire-balls,  and  meteoric  stones  are,  with  great 
probability,  regarded  as  small  bodies  moving  with  planetary 
velocity,  and  revolving  in  obedience  to  the  laws  of  general 
gravity  in  conic  sections  round  the  Sun.  When  these  masses 
meet  the  Earth  in  their  course,  and  are  attracted  by  it,  they 
enter  within  the  limits  of  our  atmosphere  in  a  luminous  con- 
dition, and  frequently  let  fall  more  or  less  strongly  heated  stony 
fragments,  covered  with  a  shining  black  crust.  When  we 
enter  mto  a  careful  investigation  of  the  facts  observed  at  those 
epochs  when  showers  of  shooting  stars  fell  periodically  in  Cu- 
mana  in  1799,  and  in  North  America  during  the  years  1833 
and  1834,  we  shall  find  XhdX  fire-balls  can  not  be  considered 
separately  from  shooting  stars.  Both  these  phenomena  are 
frequently  not  only  simultaneous  and  blended  together,  but 
they  likewise  are  often  found  to  merge  into  one  another,  the 
one  phenomenon  gradually  assuming  the  character  of  the  other 
alike  with  respect  to  the  size  of  their  disks,  the  emanation  of 
sparks,  and  the  velocities  of  their  motion.  Although  explod- 
ing smoking  luminous  fire-balls  are  sometimes  seen,  even  in 
the  brightness  of  tropical  daylight,*  equaling  in  size  the  ap- 

*  A  friend  of  mine,  much  accustomed  to  exact  trigonometrical  meas- 
urements, was  in  the  year  1788  at  Popayan,  a  city  which  is  2^  26' 
north  latitude,  lying  at  an  elevation  of  5583  feet  above  the  level  of  the 
sea,  and  at  noon,  when  the  sun  was  shining  brightly  in  a  cloudless  sky, 
saw  his  room  lighted  up  by  a  fire-ball.  He  had  his  back  to  tlie  window 
at  the  time,  and  on  turning  round,  perceived  that  great  part  of  the  path 
traversed  by  the  fire-ball  was  still  illuminated  by  the  brightest  radiance 
Different  nations  have  had  the  most  various  terms  to  exjiress  the^e  i>iie- 
uomena :  the  Germans  use  the  w^ord  Sternschnnppe,  literally  star  savff 
—an  expression  well  suited  to  the  physical  views  of  the  vulgar  in  former 


AEROLITES.  1]3 

parent  diameter  of  the  Moon,  innumerable  quantities  of  shoot- 
ing stars  have,  on  the  other  hand,  been  observed  to  fall  in 
forms  of  such  extremely  small  dimensions  that  they  appear 
only  as  moving  points  or  pliosiohorescent  lines.^ 

It  still  remains  undetermined  whether  the  many  luminous 
bodies  that  shoot  across  the  sky  may  not  vary  in  their  nature. 
On  my  return  from  the  equinoctial  zones,  I  was  impressed 
with  an  idea  that  in  the  torrid  regions  of  the  tropics  I  had 
more  frequently  than  in  our  colder  latitudes  seen  shooting 
stars  fall  as  if  from  a  height  of  twelve  or  fifteen  thousand  feet ; 
that  they  were  of  brighter  colors,  and  left  a  more  brilliant  line 
of  light  in  their  track  ;  but  this  impression  was  no  doubt  owing 
to  the  greater  transparency  of  the  tropical  atmosphere,!  which 

times,  according  to  which,  the  lights  in  the  finnament  were  said  to  under 
go  a  process  of  snuffing  or  cleaning  ;  and  other  nations  generally  adopt  a 
term  expressive  of  a  shot  ov  fall  of  stars,  as  the  Swedish  stjernjfall,  the 
Italian  stella  cadente,  and  the  English  star  shoot.  In  the  woody  district 
of  the  Orinoco,  on  tlie  dreary  banks  of  the  Cassiquiare,  I  heard  the  na- 
tives in  the  Mission  of  Vasiva  use  terms  still  more  inelegant  than  the 
German  star  snnff.  {Relation  Historique  du  Voy.  aux  Rigions  Equhwx., 
t.  ii.,  p.  513.)  These  same  tribes  term  the  pearly  drops  of  dew  which 
cover  the  beautiful  leaves  of  the  heliconia  star  spit.  In  the  Lithuanian 
mythology,  the  imagination  of  the  people  has  embodied  its  ideas  of  the 
nature  and  signification  of  falling  stars  under  nobler  and  more  graceful 
symbols.  The  Parcse,  Werpeja,  weave  in  heaven  for  the  new-born 
child  its  thread  of  fate,  attaching  each  separate  thread  to  a  star.  When 
death  approaches  the  person,  the  thread  is  rent,  and  the  star  wanes  and 
sinks  to  the  earth.     Jacob  Grimm,  Deutsche  Mytlwlogie,  1843,  s.  685. 

*  According  to  the  testimony  of  Professor  Denison  Olmsted,  of  Yale 
College,  New  Haven,  Connecticut.  (See  Poggend.,  Annalen  der  Physik, 
bd.  XXX.,  s.  194.)  Kepler,  who  excluded  tire-balls  and  shooting  stars 
from  the  domain  of  astronomy,  because  they  were,  according  to  his 
views,  -'meteors  arising  from  the  exhalations  of  the  earth,  and  blend- 
ing with  the  higher  ether,"  expresses  himself,  however,  generally  with 
much  caution.  He  says:  "  Stellce  cadentes  sunt  materia  viscida  inflam- 
mata.  Eai"nm  aliqufs  inter  cadendum  absumuntur,  aliquce  vere  in  terram 
cadunt.  pondere  sua  tractce.  Nee  est  dissimile  vero,  quasdam  conglohataa 
esse  ex  materia  fcecidentd,  in  ipsam  auram  atheream  immixta :  exque 
aetheris  regione,  tractu  rectilineo,  per  aerem  trajicerc,  ceu  minutos  com- 
etas,  occulta  causa  motus  utrorumque.^^ — Kepler,  Epit.  Astron.  Coper- 
nicance,  t.  i.,  p.  80. 

t  Relation  Historique,  t.  i.,  p.  80,  213,  527.  If  in  falling  stars,  as  in 
comets,  we  distinguish  between  the  head  or  nucleus  and  the  tail,  we 
shall  find  that  the  gi-eater  transparency  of  the  atmosphere  in  tropical 
climates  is  evinced  in  the  greater  length  and  brilliancy  of  the  tail  which 
may  be  observed  in  those  latitudes.  The  phenomenon  is  therefore  not 
necessarily  more  frequent  there,  because  it  is  oftener  seen  and  contin- 
ues longer  visible.  The  influence  exercised  on  shooting  stars  by  the 
character  of  the  atmosphere  is  shown  occasionally  even  in  our  temper- 
ate zone,  and  at  veiy  small  distances  apart.  Wartmann  relates  that  on 
the  occasion  of  a  November  phenomenon  at  two  places  lying  very  near 


114  COSMOS. 

enables  the  eye  to  penetrate  furtlier  into  distance.  Sir  Alex- 
ander Burnes  likewise  extols  as  a  consequence  of  the  purity  of 
the  atmosphere  in  Bokhara  the  enchanting  and  constantly-re- 
curring spectacle  of  variously-colored  shooting  stars. 

The  connection  of  meteoric  stones  with  the  grander  phe- 
nomenon of  fire-halls — the  former  being  known  to  be  project- 
ed from  the  latter  with  such  force  as  to  penetrate  from  ten 
to  fifteen  feet  into  the  earth — has  been  proved,  among  many 
other  instances,  in  the  falls  of  aerolites  at  Barbotan,  in  the 
Department  des  Landes  (24th  July,  1790),  at  Siena  (16th 
June,  1794),  at  Weston,  in  Connecticut,  U.  S.  (14th  Decem- 
ber, 1807),  and  at  Jnvenas,  in  the  Department  of  Ardeche 
(15th  June,  1821).  Meteoric  stones  are  in  some  instances 
thrown  from  dark  clouds  suddenly  formed  in  a  clear  sky,  and 
fall  with  a  noise  resembling  thunder.  Whole  districts  have 
thus  occasionally  been  covered  with  thousands  of  fragmentary 
masses,  of  uniform  character  but  unequal  magnitudes,  that 

each  other,  Geneva  and  Aux  Plancliettes,  the  number  of  the  meteors 
counted  wei'e  as  1  to  7.  (Wartmann,  Mem.  sur  les  Eloiles  Jilanies,  p. 
17.)  The  tail  of  a  shooting  star  (or  its  train),  on  the  subject  of  which 
Brandes  has  made  so  many  exact  and  delicate  observations,  is  in  no 
way  to  be  ascribed  to  the  continuance  of  the  impression  produced  by 
light  on  the  retina.  It  sometimes  continues  visible  a  w^hole  minute, 
and  in  some  rare  instances  longer  than  the  light  of  the  nucleus  of  the 
shooting  star;  in  which  case  the  luminous  track  remains  motionless. 
(Gilb.,  Ann.,  bd.  xiv.,  s.  251.)  This  circumstance  further  indicates  the 
analogy  between  large  shooting  stars  and  fire-balls.  Admiral  Krusen- 
stern  saw,  in  his  voyage  round  the  world,  the  train  of  a  fire-ball  shine 
for  an  hour  after  the  luminous  body  itself  had  disappeared,  and  scarce- 
ly move  throughout  the  whole  time.  {Reise,  th.  i.,  s.  58.)  Sir  Alex- 
ander Bumes  gives  a  charming  description  of  the  transparency  of  the 
clear  atmosphere  of  Bokhara,  which  was  once  so  favorable  to  the  pur- 
suit of  astronomical  observations.  Bokhara  is  situated  in  39°  43'  north 
latitude,  and  at  an  elevation  of  1280  feet  above  the  level  of  the  sea. 
"  There  is  a  constant  serenity  in  its  atmosphere,  and  an  admirable  clear- 
ness in  the  sky.  At  night,  the  stars  have  uncommon  luster,  and  the 
Milky  Way  shines  gloriously  in  the  firmament.  There  is  also  a  never- 
ceasing  display  of  the  most  brilliant  meteors,  which  dart  like  rockets 
in  the  sky ;  ten  or  twelve  of  them  are  sometimes  seen  in  an  hour,  as- 
suming every  color — fiery  red,  blue,  pale,  and  faint.  It  is  a  noble 
country  for  astronomical  science,  and  great  must  have  been  the  ad- 
vantage enjoyed  by  the  famed  observatory  of  Samarkand."  (Burnes, 
Travels  into  Bokhara,  vol.  ii.  (1834),  p.  158.)  A  mere  traveler  must 
not  be  reproached  for  calling  ten  or  twelve  shooting  stars  in  an  hour 
*'  many,"  since  it  is  only  recently  that  we  have  learned,  from  careful 
observations  on  this  subject  in  Europe,  that  eight  is  the  mean  number 
which  may  be  seen  in  an  hour  in  the  field  of  vision  of  one  individual 
(Quetelet,  Corresp.  Mathim.,  Novem.,  1837,  p.  447);  this  number  is, 
however,  limited  to  five  or  six  by  that  diligent  observer,  Olbers. 
(Schum.,  Jahrh.,  1838,  s.  325.) 


AEROLITES.  115 

nave  been  liiirled  from  one  of  these  moving  clouds.  In  less 
frequent  cases,  as  in  that  which  occurred  on  the  16th  of  Sep- 
tember, 1843,  at  Kleinwenden,  near  Miililhausen,  a  large 
aerolite  fell  with  a  thundering  crash  while  the  sky  was  clear 
and  cloudless.  The  intimate  affinity  between  fire-balls  and 
shooting  stars  is  further  proved  by  the  fact  that  fire-balls,  from 
which  meteoric  stones  have  been  thrown,  have  occasionally 
been  found,  as  at  Angers,  on  the  9th  of  June,  1822,  having  a 
iiameter  scarcely  equal  to  that  of  the  small  fire-works  called 
Eloraan  candles. 

The  formative  power,  and  the  nature  of  the  physical  and 
chemical  processes  involved  in  these  phenomena,  are  questions 
ill  equally  shrouded  in  mystery,  and  we  are  as  yet  ignorant 
tvdiether  the  particles  composing  the  dense  mass  of  meteoric 
itones  are  originally,  as  in  comets,  separated  from  one  another 
\n  the  form  of  vapor,  and  only  condensed  v/ithin  the  fiery  ball 
when  they  become  luminous  to  our  sight,  or  whether,  in  the 
ease  of  smaller  shooting  stars,  any  compact  substance  actually 
Tails,  or,  finally,  whether  a  meteor  is  composed  only  of  a  smoke- 
like dust,  "containing  iron  and  nickel ;  while  w^e  are  wholly 
ignorant  of  what  takes  place  within  the  dark  cloud  from  which 
a  noise  like  thunder  is  often  heard  for  many  minutes  before 
the  stones  fall.* 

*  Oil  meteoric  dust,  see  Arago,  in  the  Annuaire  for  1832,  p.  254.  1 
have  very  recently  endeavored  to  show,  in  another  work  {Asie  Centrale, 
t.  i.,  p.  408),  how  the  Scythian  saga  of  the  sacred  gold,  which  fell  burn- 
ing from  heaven,  and  remained  in'the  possession  of  the  Golden  Horde 
of  the  ParalattB  (Herod.,  iv.,  5-7),  probably  originated  in  the  vague  rec- 
ollection of  the  fall  of  an  aSrolite.  The  ancients  had  also  some  strange 
fictions  (Dio  Cassius,  Ixxv.,  1259)  of  silver  which  had  fallen  from  heav- 
en, and  with  which  it  had  been  attempted,  under  the  Emperor  Seve- 
rus,  to  cover  bronze  coins ;  metallic  iron  was,  however,  known  to  exist 
hi  meteoric  stones.  (Plin.,  ii.,  56.)  The  frequently-recui'ring  expres- 
sion lapidibus  phiit  must  not  always  be  understood  to  refer  to  falls  of 
aSrolites.  In  Liv.,  xxv.,  7,  it  probably  refers  to  pumice  (rapil/i)  eject- 
ed from  the  volcano,  Mount  Albanus  (Monte  Cavo),  which  vC-as  not 
wholly  extinguished  at  the  time.  (See  Heyne,  Opuscula  Acad.,  t.  iii., 
p.  261 ;  and  my  Relation  Hist.,  t.  i.,  p.  394.)  The  contest  of  Hercules 
with  the  Ligyans,  on  the  road  from  the  Caucasus  to  the  Hesperides, 
belongs  to  a  different  sphere  of  ideas,  being  an  attempt  to  explain  myth- 
ically the  origin  of  the  round  quartz  blocks  in  the  Ligyan  field  of  stones 
at  the  mouth  of  the  Rhone,  which  Aristotle  supposes  to  have  been  eject- 
ed from  a  fissure  during  an  earthquake,  and  Posidonius  to  have  been 
caused  by  the  force  of  the  waves  of  an  inland  piece  of  water.  In  the 
fragments  that  we  still  possess  of  the  play  of  ^Eschylus,  the  Promeihetis 
Delivered,  every  thing  proceeds,  however,  in  part  of  the  narration,  as 
in  a  fall  of  aerolites,  for  Jupiter  draws  together  a  cloud,  and  causes  the 
"district  around  to  be  covered  by  a  shower  of  round  stones  "     Posido- 


116  COSMOS. 

We  can  ascertain  by  measurement  the  enormous,  wonder, 
ful,  and  wholly  planetary  velocity  of  shooting  stars,  fire-balls, 
and  meteoric  stones,  and  we  can  gain  a  knowledge  of  what  is 
the  general  and  uniform  character  of  the  phenomenon,  but 
not  of  the  genetically  cosmical  process  and  the  results  of  the 
metamorphoses.  If  meteoric  stones  while  revolving  in  space 
are  already  consolidated  into  dense  masses,*  less  dense,  how- 

uius  even  ventured  to  deride  the  geognostic  myth  of  the  blocks  and 
stones.  The  Lygian  field  of  stones  was,  however,  very  naturally  and 
well  described  iSy  the  ancients.  The  district  is  now  known  as  La  Crau. 
(See  Guerin,  Mesures  Baromitriques  dans  les  Alpes,  et  Metiorologie 
d^ Avignon,  1829,  chap,  xii.,  p.  115.) 

*  The  specific  weight  of  aerolites  varies  from  1-9  (Alais)  to  4-3 
(Tabor).  Their  general  density  maybe  set  down  as  3,  water  being  1. 
As  to  wliat  has  been  said  in  the  text  of  the  actual  diameters  of  fire-balls, 
we  must  remark,  that  the  numbers  have  been  taken  froin  the  few 
measurl&ments  that  can  be  relied  upon  as  correct.  These  give  for  the 
fire-ball  of  Weston,  Connecticut  (14th  December,  1807),  only  500;  for 
that  observed  by  Le  Roi  (10th  July,  1771)  about  1000,  and  for  that 
estimated  by  Sir  Charles  Blagden  (18th  January,  1783)  2600  feet  iu 
diameter.  Brandes  {UnterhaltHugen,  bd.  i.,  s.  42)  ascribes  a  diameter 
varying  from  80  to  120  feet  to  shooting  stars,  and  a  luminous  train  ex- 
tending from  12  to  16  miles.  There  are,  however,  ample  optical  caus- 
es for  supposing  that  the  appai'ent  diameter  of  fire-balls  and  shooting 
stars  has  been  very  much  overrated.  The  volume  of  the  largest  fiie- 
ball  yet  observed  can  not  be  compared  with  that  rf  Ceres,  estimating 
this  planet  to  have  a  diameter  of  only  7J  English  miles.  (See  the 
generally  so  exact  and  admirable  treatise,  i )n  the  Connection  of  the 
Physical  Sciences,  1835,  p.  411.)  With  the  view  of  elucidating  what 
has  been  stated  in  the  text  regarding  the  large  aerolite  that  fell  into 
the  bed  of  the  River  Narni,  but  has  not  again  been  found,  I  will  give 
the  passage  made  known  by  Pertz,  trom  the  Chronicon  Benedicti,  Man- 
achi  Sancti  Andrece  in  Monte  Soracte,  a  MS.  belonging  to  the  tenth 
century,  and  preserved  in  the  Chigi  Library  at  Rome.  The  barbaious 
Latiji  of  that  age  has  been  left  unchanged.  '^^  Anno  921,  temporihns 
domini  Johannis  Decimi  pape,  in  anno  pontificatus  illius  7  visa  sunt  sig- 
na.  Nam  juxta  urbem  Romani  lapides  plurimi  de  cailo  cadere  visi  sunt. 
In  civitate  qua;  vocatur  Narnia  tarn  diri  ac  tetri,  ut  7iihil  aliitd  credatur, 
quarn  de  infernalibiis  locis  dedncti  essent.  Nam  ila  ex  illis  lapidibus 
umis  omnium  maximns  est,  ut  d-]cidens  in  fluuien  Narnvs,  ad  mensuram 
unius  c'uhiti  super  aquas  fiumim  ',  usque  hodie  videretur.  Nam  et  ignitiB 
faculce  de  coslo  plurimoe  omnibus  in  hac  civitate  Romani  popuH  vis<e  S7int, 
ita  ut  pene  terra  contingeret.  Alice  cadentes,^''  &c.  (Pertz,  Mmivm. 
Germ.  Hist.  Scriptores,  t.  iii.,  p.  715.)  On  the  aerolites  of  ^gos.  I'ota- 
mos,  which  fell,  according  to  the  Parian  Chronicle,  in  the  78  1  Olym- 
piad, see  Bockh,  Corp.  Jnscr.  Graec,  t.  ii.,  p.  302,  320,  340;  also  Aris- 
tot.,  Meteor.,  i.,  7  (Ideler's  Comm.,  t.  i.,  p.  404-407)  ;  Stob.,  Eel.  Phys., 
I.,  25,  p.  508  (Heeren);  Pint.,  Lys.,  c.  12;  Diog.  Laert.,  ii.,  10;  and 
see,  also,  subsequent  notes  in  this  work.  According  to  a  Moui^oliun 
tradition,  a  black  fragment  of  a  rock,  forty  feet  in  height,  fell  iVoni 
heaven  on  a  plain  near  the  source  of  the  Great  Yellow  River  in  West- 
ern China.  (Abel  Remusat,  in  Lametherie,  Jour,  de  Phys.,  1819,  Mai 
p.  264.) 


AEROLITES.  117 

ever,  than  the  mean  density  of  the  earth,  they  must  be  very 
small  nuclei,  which,  surrounded  by  inflammable  vapor  or  gas, 
form  the  innermost  part  of  fire-balls,  from  the  height  and  ap- 
parent diameter  of  which  we  may,  in  the  case  of  the  largest, 
estimate  that  the  actual  diameter  varies  from  500  to  about 
2800  feet.  The  largest  meteoric  masses  as  yet  known  are 
those  of  Otumpa,  in  Chaco,  and  of  Bahia,  in  Brazil,  described 
by  Rubi  de  Celis  as  being  from  7  to  7|-  feet  in  length.  The 
meteoric  stone  of  ^gos  Potamos,  celebrated  in  antiquity,  and 
even  mentioned  in  the  Chronicle  of  the  Parian  Marbles,  which 
fell  about  the  year  m  which  Socrates  was  born,  has  been  de- 
scribed as  of  the  size  of  two  mill-stones,  and  equal  in  weight 
to  a  full  wagon  load.  Notwithstanding  the  failure  that  has 
attended  the  efforts  of  the  African  traveler.  Brown,  I  do  not 
wholly  relinquish  the  hope  that,  even  after  the  lapse  of  2312 
years,  this  Thracian  meteoric  mass,  which  it  would  be  so  dif- 
ficult to  destroy,  may  be  found,  since  the  region  in  which  it 
fell  is  now  become  so  easy  of  access  to  European  travelers. 
The  huge  aerolite  which  in  the  beginning  of  the  tenth  centu- 
ry fell  into  the  river  at  Narni,  projected  between  three  and 
four  feet  above  the  surface  of  the  water,  as  we  learn  from  a 
document  lately  discovered  by  Pertz.  It  must  be  remarked 
that  these  meteoric  bodies,  whether  in  ancient  or  modern  times, 
can  only  be  regarded  as  the  principal  fragments  of  masses  that 
have  been  broken  up  by  the  explosion  either  of  a  fire-ball  or 
a  dark  cloud. 

On  considering  the  enormous  velocity  with  \Vhich,  as  has 
been  mathematically  proved,  meteoric  stones  reach  the  earth 
from  the  extremest  confines  of  the  atmosphere,  and  the  length- 
ened course  traversed  by  fire-balls  through  the  denser  strata 
of  the  air,  it  seems  more  than  improbable  that  these  metallif- 
erous stony  masses,  containing  perfectly-formed  crystals  of  oli- 
vine, labradorite,  and  pyroxene,  should  in  so  short  a  period  of 
time  have  been  converted  from  a  vaporous  condition  to  a  solid 
nucleus.  Moreover,  that  which  falls  from  meteoric  masses, 
even  where  the  internal  composition  is  chemically  difierent, 
exhibits  almost  always  the  peculiar  character  of  a  fragment, 
being  of  a  prismatic  or  truncated  pyramidal  form,  with  broad, 
somewhat  curved  faces,  and  rounded  angles.  But  whence 
comes  this  form,  which  was  first  recognized  by  Schreiber  as 
characteristic  of  the  severed  part  of  a  rotating  planetary  body  1 
Here,  as  in  the  sphere  of  organic  life,  all  that  appertains  to 
the  history  of  development  remains  hidden  in  obscurity.  Me- 
teoric masses  become  luminous  and  kindle  at  heights  which 


118  COSMOS. 

must  be  regarded  as  almost  devoid  of  air,  or  occupied  by  an 
atmosphere  that  does  not  even  contain  To"oVoo*h  part  of  oxy 
gen.  The  recent  investigations  of  Biot  on  the  important  phe 
nomenon  of  twihght=^  have  considerably  lowered  the  lines 
which  had,  perhaps  with  some  degree  of  temerity,  been  usual 
ly  termed  the  boundaries  of  the  atmosphere ;  but  processes  of 
hght  may  be  evolved  independently  of  the  presence  of  oxygen, 
and  Poisson  conjectured  that  aerolites  were  ignited  far  beyond 
the  range  of  our  atmosphere.  Numerical  calculation  and  geo- 
metrical measurement  are  the  only  means  by  which,  as  in  the 
case  of  the  larger  bodies  of  our  solar  system,  we  are  enabled  to 
impart  a  firm  and  safe  basis  to  our  investigations  of  meteoric 
stones.  Although  Halley  pronounced  the  great  fire-ball  of  1686, 
whose  motion  was  opposite  to  that  of  the  earth  in  its  orbit,  f  to 
be  a  cosmical  body,  Chladni,  in  1794,  first  recognized,  with 
ready  acuteness  of  mind,  the  connection  between  fire-balls  and 
the  stones  projected  from  the  atmosphere,  and  the  motions  of  the 
former  bodies  in  space. J  A  brilliant  confirmation  of  the  cos- 
mical origin  of  these  phenomena  has  been  afforded  by  Denison 
Olmsted,  at  New  Haven,  Connecticut,  who  has  shown,  on  the 
concurrent  authority  of  all  eye-witnesses,  that  during  the  cele- 
brated fall  of  shooting  stars  on  the  night  between  the  12th 

*  Biot,  TraiU  d' Astro7iomie  Physique  (3eme  6d.),  1841,  t.  i.,  p.  149, 
177,  238,  312.  My  lamented  frieud  Poisson  endeavored,  in  a  singular 
manner,  to  solve  the  difficulty  attending  an  assumption  of  the  sponta- 
neous ignition  of  meteoric  stones  at  an  elevation  where  the  density  of 
the  atmosphere  is  almost  null.  These  are  his  words  :  ''  It  is  difficult  to 
attribute,  as  is  usually  done,  the  incandescence  of  aerolites  to  friction 
against  the  molecules  of  the  atmosphere  at  an  elevation  above  the  earth 
where  the  density  of  the  air  is  almost  null.  May  we  not  suppose  that 
the  electric  fluid,  in  a  neutral  condition,  forms  a  kind  of  atmosphere,  ex- 
tending far  beyond  the  mass  of  our  atmosphere,  yet  subject  to  terres- 
trial attraction,  although  physically  imponderable,  and  consequently 
following  our  globe  in  its  motion  ?  According  to  this  hypothesis,  the 
bodies  of  which  we  have  been  speaking  would,  on  entering  this  im- 
ponderable atmosphere,  decompose  the  neutral  fluid  by  their  unequal 
action  on  the  two  electricities,  and  they  would  thus  be  heated,  and  in 
a  state  of  incandescence,  by  becoming  electrified."  (Poisson,  Rech.  sur 
la  Probability  des  Jugements,  1837,  p.  6.) 

t  Philos.  Transact.,  vol.  xxix.,  p.  lGl-163. 

X  The  first  edition  of  Chladni's  important  treatise,    Ueber  den   Ur- 
sprung  der  von  Pallas  gefundenen  nnd  anderen  Eisenmassen  (On  the 
Origin  of  the  masses  of  Iron  found  by  Pallas,  and  other  similar  masses), 
appeared  two  months  prior  to  the  shower  of  stones  at  Siena,  and  two 
years  before  Lichtenberg  stated,  in  the  Gottingen  Taschenbnch,  tha 
"  stones  reach  our  atmosphere   from  the  remoter  regions  of  space.' 
Comp.,  also,  Olbers's  letter  to  Benzenberg,  18th  Nov.,  1837,  in  Ben 
zenberg's  Treatise  on  Shooting  Stars,  p.  186. 


AEROLITES.  119 

and  13th  of  November,  1833,  the  fire-balls  and  shooting  stars 
all  emerged  from  one  and  the  same  quarter  of  the  heavens, 
namely,  in  the  vicinity  of  the  star  y  in  the  constellation  Leo, 
and  did  not  deviate  from  this  point,  although  the  star  changed 
its  apparent  height  and  azimuth  during  the  time  of  the  observ- 
ation. Such  an  independence  of  the, Earth's  rotation  shows 
that  the  luminous  body  must  have  reached  our  atmosphere  from 
witlwut.     According  to  Encke's  computation*  of  the  whole 

*  Eucke,  \i\Vo^§,end.,  Annalen,  bd.  xxxiii.  (1834),  s.  213.  Arago, 
in  the  Annuaire.  for  1836,  p.  291.  Two  letters  which  I  wrote  to  Ben- 
zenberg,  May  19  and  October  22,  1837,  on  the  conjectural  precession 
of  the  nodes  in  the  orbit  of  periodical  falls  of  shooting  stai's.  (Benzen- 
berg's  Sternsch.,  s.  207  and  209.)  Olbers  subsequently  adopted  this 
opinion  of  the  gradual  retardation  of  the  November  phenomenon. 
{Astron.  Nachr.,  1838,  No.  372,  s.  180.)  If  I  may  venture  to  combine 
two  of  the  falls  of  shooting  stars  mentioned  by  the  Arabian  writers 
with  the  epochs  found  by  Boguslawski  for  the  fourteenth  century,  I 
obtain  the  following  more  or  less  accordant  elements  of  the  movements 
of  the  nodes : 

In  Oct.,  902,  on  the  night  in  which  King  Ibrahim  ben  Ahmed  died, 
there  fell  a  heavy  shower  of  shooting  stars,  **  like  a  fiery  rain ;"  and 
this  year  was,  therefore,  called  the  year  of  stars.  (Conde,  Hist,  de  la 
Domin.  de  los  Arabes,  p.  346.) 

On  the  19th  of  Oct.,  1202,  the  stars  were  in  motion  all  night.  "  They 
fell  like  locusts."  {Comptes  Rendus,  1837,  t.  i.,  p.  294  ;  and  Fryehn,  in 
the  Bull,  de  V  Academie  de  St.  PHershourg,  t.  iii.,  p.  308.') 

On  the  21st  Oct.,  O.S.,  1366,  "  die  sequente  post  festum  XL  ynillia  Vir- 
ginum  ab  hora  matutiyia  usque  ad  Tioram  primam  visce  sunt  quasi  stellce 
de  coilo  cadere  contiinio,  et  in  tanta  multitudine,  quod  nemo  narrare  suf 
jicit.''''  This  remarkable  notice,  of  which  we  shall  speak  more  fully  in 
the  subsequent  part  of  this  w^ork,  was  found  by  the  younger  Von  Bo- 
guslawski, in  Benesse  (de  Horowic)  de  Weitmil  or  Weithmiil,  Chron- 
icon  Ecclesice  Pragensis,  p.  389.  This  chronicle  may  also  be  found  in 
the  second  part  of  ScHptores  rerum  Bghemicarum,  by  Pelzel  and  Do- 
browsky,  1784.     (Schum.,  Astr.  Nachr.,  Dec,  1839.) 

On  the  night  between  the  9th  and  10th  of  November,  1787,  many  fall- 
ing stars  were  observed  at  Manheira,  Southern  Germany,  by  Hemmer. 
(Kamtz,  Meteor.,  th.  iii.,  s.  237.) 

After  midnight,  on  the  12th  of  November,  1799,  occurred  the  extra- 
ordinary fall  of  stars  at  Cumana,  which  Bonpland  and  myself  have  de 
scribed,  and  which  was  observed  over  a  great  part  of  the  earth.    (Relat. 
Hist.,  t.  i.,  p.  519-527.) 

Between  the  12th  and  13th  of  November,  1822,  shooting  stars,  inter- 
mingled with  fire-balls,  were  seen  in  large  numbers  by  Kloden,  at 
Potsdam.     (Gilbei-t's  Ann.,  bd.  Ixxii.,  s.  291.) 

On  the  I3th  of  November,  1831,  at  4  o'clock  in  the  morning,  a  great 
shower  of  falling  stars  was  seen  by  Captain  Berard,  on  the  Spanish 
coast,  near  Carthagena  del  Levante.     {Annuaire,  1836,  p.  297.) 

In  the  night  between  the  12th  and  13tli  of  November,  1833,  occurred 
the  phenomenon  so  admirably  described  by  Professor  Olmsted,  iu 
North  America. 

In  the  night  of  the  13-14th  of  November,  1834,  a  similar  fall  of  shoot- 


120  COSMOS. 

Qumber  of  observations  made  in  the  United  States  of  North 
America,  between  the  thirty-fifth  and  the  forty-second  degrees 
of  latitude,  it  would  appear  that  all  these  meteors  came  from 
the  same  point  of  space  in  the  direction  in  which  the  Earth 
was  moving  at  the  time.  On  the  recurrence  of  falls  of  shoot- 
ing stars  in  North  America,  in  the  month  of  November  of  the 
years  1834  and  1837,  and  in  the  analogous  falls  observed  at 
Bremen  in  1838,  a  like  general  parallelism  of  the  orbits,  and 
the  same  direction  of  the  meteors  from  the  constellation  Leo, 
were  again  noticed.  It  has  been  supposed  that  a  greater 
parallelism  was  observable  in  the  direction  of  periodic  falls  of 
shooting  stars  than  in  those  of  sporadic  occurrence  ;  and  it  has 
further  been  remarked,  that  in  the  periodically-recurring  falls 
in  the  month  of  August,  as,  for  instance,  in  the  year  1839,  the 
meteors  came  principally  from  one  point  between  Perseus  and 
Taurus,  toward  the  latter  of  which  constellations  the  Earth 
was  then  moving.  This  peculiarity  of  the  phenomenon,  mani- 
fested in  the  retrograde  direction  of  the  orbits  in  November 
and  August,  should  be  thoroughly  investigated  by  accurate 
observations,  in  order  that  it  may  either  be  fully  confirmed  or 
refuted. 

The  heights  of  shooting  stars,  that  is  to  say,  the  heights  of 
the  points  at  which  they  begin  and  cease  to  be  visible,  vary 
exceedingly,  fluctuating  between  16  and  140  miles.  This 
important  result,  and  the  enormous  velocity  of  these  problem- 
atical asteroids,  were  first  ascertained  by  Benzenberg  and 
Brandes,  by  simultaneous  observations  and  determinations  of 
parallax  at  the  extremities  of  a  base  line  of  49,020  feet  in 
length. =^  The  relative  velocity  of  motion  is  from  18  to  36 
miles  in  a  second,  and  consequently  equal  to  planetary  velocity. 
This  planetary  velocity,!  as  well  as  the  direction  of  the  orbits 

jng  stars  was  seen  in  North  America,  although  the  numbers  were  not 
quite  so  considerable.     (Poggend.,  Annalen,  bd.  xxxiv.,  s.  129.) 

On  the  13th  of  November,  1835,  a  barn  was  set  on  fire  by  the  fall  of 
a  sporadic  fire-ball,  at  Belley,  in  the  Department  de  I'Ain.  {Annuaire, 
1836,  p.  296.) 

In  the  year  1838,  the  stream  showed  itself  most  decidedly  on  the 
night  of  the  13-14th  of  November.     {Astron.  Nachr.,  1838,  No.  372.) 

*  I  am  well  aware  tliat,  amoug  the  62  shooting  stars  simultaneously 
observed  in  Silesia,  in  1823,  at  the  suggestion  of  Professor  Brandes 
some  appeared  to  have  an  elevation  of  183  to  240,  or  even  400  miles. 
(Bi'andes,  Unterhaltungen  fur  Frennde  der  Astronomic  mid  Physik,  heft 
i.,  s.  48.  Instructive  Nairatives  for  the  Lovers  of  Astronomy  and  Phys- 
ics.) But  Olbers  considered  that  all  determinations  for  elevations  be- 
yond 120  miles  must  be  doubtfid,  owing  to  the  smallness  of  the  parallax. 

t  The  planetary  velocity  of  translation,  the  movement  in  the  orbit,  is 
in  Mercury  26-4,  in  Venus  19-2,  and  in  the  Earth  16-4  miles  in  a  second 


AEROLITES.  121 

of  fire-balls  and  shooting  stars,  wliicli  has  frequently  been  ob- 
served to  be  opposite  to  that  of"  the  Earth,  ma}^  be  considered 
as  conclusive  arguments  against  the  hypothesis  that  aerolites 
derive  their  origin  from  the  so-called  active  lunar  volcanoes. 
Numerical  views  regarding  a  greater  or  lesser  volcanic  force 
on  a  small  cosmical  body,  not  surrounded  by  any  atmosphere, 
must,  from  their  nature,  be  wholly  arbitrary.  We  may  imag- 
ine the  reaction  of  the  interior  of  a  planet  on  its  crust  ten  or 
even  a  hundred  times  greater  than  that  of  our  present  terres- 
•  trial  volcanoes  ;  the  direction  of  masses  projected  from  a  satel- 
lite revolving  from  west  to  east  might  appear  retrogressive, 
owing  to  the  Earth  in  its  orbit  subsequently  reaching  that 
point  of  space  at  which  these  bodies  fall.  If  we  examine  the 
whole  sphere  of  relations  which  I  have  touched  upon  in  this 
work,  in  order  to  escape  the  charge  of  having  made  unproved 
assertions,  we  shall  find  that  the  hypothesis  of  the  selenic  ori- 
gin of  meteoric  stones*  depends  upon  a  number  of  conditions 

*  Chladui  states  that  an  Italian  physicist,  Paolo  Maria  Terzago,  on 
the  occasion  of  the  fall  of  an  aerolite  at  Milan  in  1660,  by  which  a  Fran- 
ciscan monk  was  killed,  was  the  first  who  surmised  that  aerolites  were 
of  selenic  origin.    He  says,  in  a  memoir  entitled  Musceuvi  Septalianum, 
Manfredi  Septalcs,  Patricii  Mediolanensis,  indjistrioso  labore  conslruciurn 
(Tortona,  1664,  p.  44),  '^Labant  philosophorum  meutes  sub  horum  lapidum 
ponderibus ;  ni  dicire  velimus,  lunam  terram  alteram,  sine  mundum  esse, 
ex  cujus  montibus  dwisa  frustra  in  inferior  em  nostrum  hunc  orbe^n  dela 
bantury     Without  any  previous  knowledge  of  this  conjecture,  Olbers 
was  led,  in  the  year  1795  (after  the  celebrated  fall  at  Siena  on  the  16th 
of  June,  1794),  into  an  investigation  of  the  amount  of  the  initial  tangen- 
tial force  that  would  be  requisite  to  bring  to  the  Earth  masses  project- 
ed from  the  Moon.     This  ballistic  problem  occupied,  during  ten  or 
twelve  years,  the  attention  of  the  geometricians  Laplace,  Biot,  Brandes, 
and  Poisson.     The  opinion  which  w^as  then  so  prevalent,  but  which  has 
since  been  abandoned,  of  the  existence  of  active  volcanoes  in  the  Moon, 
where  air  and  water  are  absent,  led  to  a  confusion  in  the  minds  of  the 
generality  of  persons  between  mathematical  possibilities  and  physical 
probabilities.    Olbers,  Brandes,  and  Chladni  thought  *'  that  the  velocity 
of  16  to  32  miles,  with  which  fire-balls  and  shooting  stars  entered  our 
atmosphere,"  furnished  a  refutation  to  the  view  of  their  selenic  origin. 
According  to  Olbers,  it  would  require  to  reach  the  Earth,  setting  aside 
the  resistance  of  the  air,  an  initial  velocity  of  8292  feet  in  the  second ; 
according  to  Laplace,  7862  ;  to  Biot,  8282 ;  and  to  Poisson,  7595.     La- 
place states  that  this  velocity  is  only  five  or  six  times  as  great  as  that  of 
a  cannon  ball;  but  Olbers  has  sliown  "that,  with  such  an  initial  veloc- 
ity as  7500  or  8000  feet  in  a  second,  meteoric  stones  would  arrive  at  the 
surface  of  our  earth  with  a  velocity  of  only  35.000  feet  (or  1-53  German 
geogi'aphical  mile).     But  the  measured  velocity  of  meteoric  stones  av- 
erages five  such  miles,  or  upward  of  114,000  feet  to  a  second  ;  and, 
consequently,  the  original  velocity  of  projection  from  the  Moon  must 
be  almost  110,000  feet,  and  therefore  fourteen  times  greater  than  La- 
place asserted."     (Olbers,  in  Sebum.,  Jahrb.,  1837,  p.  52-58;  and  in 
Vol.  I.— F 


12*2  COSMOS. 

whose  accidental  coincidence  could  alone  convert  a  possible 
into  an  actual  fact.     The  view  of  the  orighial  existence  of 

Gehlei-,  NeuesPhyslk.  Worterbuche,  bd.  yi.,  abth.  3,  s.  2129-2130.)^    If 
we  could  assume  volcanic  forces  to  be  still  active  on  the  Moon's  surface, 
the  absence  of  atmospheric  resistance  would  certainly  give  to  their 
projectile  force  an  advantage  over  that  of  our  terrestrial  volcanoes  ;  but 
even  in  respect  to  the  measure  of  the  latter  force  (the  projectile  force 
of  our  own  volcanoes),  we  have  no  observations  on  which  any  reliance 
can  be  placed,  and  it  has  probably  been  exceedingly  overrated.     Dr. 
Peters,  who  accurately  observed  and  measured  the  phenomena  present- 
ed by  Mtna,  found  that  the  greatest  velocity  of  any  of  the  stones  pro- ' 
jected  from  the  crater  was  only  1250  feet  to  a  second.     Observations 
on  the  Peak  of  TenerifFe,  in  1798,  gave  3000  feet.     Although  Laplace, 
at  the  end  of  his  work  (Expos,  du  Syst.  du  Monde,  ed.  de  1824,  p.  399).. 
cautiously  observes,  regarding  aerolites,  "  that  in  all  probability  they 
come  from  the  depths  of  space,"  yet  we  see  from  another  passage 
(chap,  vi.,  p.  233)  that,  being  probably  unacquainted  with  the  extra- 
ordinary planetary  velocity  of  meteoric  stones,  he  inclines  to  the  hy- 
pothesis of  their  lunar  origin,  always,  however,  assuming  that  the  stones 
projected  from  the  Moon  "  become  satellites  of  our  Earth,  describing 
around  it  more  or  less  eccentric  orbits,  and  thus  not  reaching  its  atmos- 
phere until  several  or  even  many  revolutions  have  been  accomplished." 
As  an  Italian  at  Tortona  had  the  fancy  that  aerolites  came  from  the 
Moon,  so  some  of  the  Greek  philosophers  thought  they  came  from  the 
Sun.     This  was  the  opinion  of  Diogenes  Laertius  (ii.,  9)  regarding  the 
origin  of  the  mass  that  fell  at  iEgos  Potamos  (see  note,  p.  116).    Pliny, 
whose  labors  in  recording  the  opinions  and  statements  of  preceding 
writei'S  are  astonishing,  repeats  the  theoiy,  and  derides  it  the  more 
freely,  because  he,  with  earlier  writers  (Diog.  Laert.,  3  and  5,  p.  99, 
Hiibner),  accuses  Anaxagoras  of  having  predicted  the  fall  of  aerolites 
from  the  Sun:  "Celebrant  Grseci  Anaxagoram  Clazomenium  Olyra- 
piadis  septuagesimae  octavse  secundo  anno  praedixisse  caelestium  littera- 
rum  scientia,  quibus  diebus  saxum  casurum  esse  e  sole,  idque  factum 
interdiu  in  Thracife  parte  ad  iEgos  flumen.     Quod  si  quis  prsedictum 
credat,  simul  fateatur  necesse  est,  majoris  miraculi  divinitatem  Anax- 
agorae  faisse,  solvique  rerum  naturae  intellectum,  et  confundi  omnia,  si 
aut  ipse  Sol  lapis  esse  aut  unquam  lapidem  in  eo  fuisse  credatur;  de- 
cidere  tamen  crebro  non  erit  dubium."     The  fall  of  a  moderate-sized 
stone,  which  is  pi'eserved  in  the  Gymnasium  at  Abydos,  is  also  report- 
ed to  have  been  foretold  by  Anaxagoras.    The  fall  of  aerolites  in  bright 
sunshine,  and  when  the  Moon's  disk  was  invisible,  probably  led  to  the 
idea  of  sun-stones.    Moreovev,  according  to  one  of  the  physical  dogmas 
of  Anaxagoras,.  which  brought  on  him  the  persecution  of  the  theologians 
(even  as  they  have  attacked  the  geologists  of  our  own  times),  the  Sun 
was  regarded  as  "  a  molten  fiery  mass"  (fivdpoc  dtdTvvpo^).     In  accord- 
ance with  these  views  of  Anaxagoras,  we  find  Euripides,  in  Phaeton, 
terming  the  Sun  "a  golden  mass;"  that  is  to  say,  a  tire-colored,  bright- 
ly-shining matter,  but  not  leading  to  the  inference  that  aerolites  are 
golden  suu-stones.      (See  note  to  page  115.)      Compare  Valckenaer, 
Diatribe  in  Eurip.  perd.  Dram.  Reliqnias,  17G7,  p.  30.      Diog.  Laert., 
ii.,  40.     Hence,  among  the  Greek  philosophers,  we  find  four  hypotheses 
regarding  the  origin  of  falling  stars :  a  telluric  origin  from  ascending 
exhalations;  masses  of  stone  raised  by  hurricane  (see  Aristot.,  il/e/'cor., 
lib.  i.,  cap.  iv.,  2-13,  and  cap.  vii.,  9);  a  solar  origin;  and.  lastly,  an 


AEROLITES.  123 

Email  planetary  masses  in  space  is  simpler,  and,  at  the  same 
time,  more  analogous  with  those  entertained  concerning  the 
formation  of  other  portions  of  the  solar  system. 

It  is  very  probable  that  a  large  number  of  these  cosmical 
bodies  traverse  space  undestroyed  by  the  vicinity  of  our  at- 
mosphere, and  revolve  round  the  Sun  without  experiencing 
any  alteration  but  a  slight  increase  in  the  eccentricity  of  their 
orbits,  occasioned  by  the  attraction  of  the  Earth's  mass.  We 
may,  consequently,  suppose  the  possibility  of  these  bodies  re- 
maining invisible  to  us  during  many  years  and  frequent  revo- 
lutions. The  supposed  phenomenon  of  ascending  shooting 
stars  and  fire-balls,  which  Chladni  has  unsuccessfully  endeav- 
ored to  explain  on  the  hypothesis  of  the  reflection  of  strongly 
compressed  air,  appears  at  first  sight  as  the  consequence  of 
some  unknown  tangential  force  propelling  bodies  from  the 
earth  ;  but  Bessel  has  sho^\^l  by  theoretical  deductions,  con- 
firmed by  Feldt's  carefully-conducted  calculations,  that,  owing 
to  the  absence  of  any  proofs  of  the  simultaneous  occurrence 
of  the  observed  disappearances,  the  assumption  of  an  ascent 
of  shooting  stars  was  rendered  wholly  improbable,  and  inad- 
missible as  a  result  of  observation. *"  The  opinion  advanced 
by  Olbers  that  the  explosion  of  shooting  stars  and  ignited  fire- 
balls not  moving  in  straight  lines  may  impel  meteors  upward 
in  the  manner  of  rockets,  and  influence  the  direction  of  their 
orbits,  must  be  made  the  subject  of  future  researches. 

Shooting  stars  fall  either  separately  and  in  inconsiderable 
numbers,  that  is,  sporadically,  or  in  swarms  of  many  thou- 

origin  in  the  regions  of  space,  as  heavenly  bodies  which  had  long  re- 
mained invisible.  Respecting  this  last  opinion,  which  is  that  of  Diog- 
enes of  Apollonia,  and  entirely  accords  with  that  of  the  px'esent  day, 
see  pages  124  and  125.  It  is  worthy  of  remark,  that  in  Syria,  as  I  have 
been  assured  by  a  learned  Orientalist,  now  resident  at  Smyrna,  Andrea 
de  Nericat,  who  instructed  me  in  Persian,  there  is  a  popular  belief  that 
aerolites  chiefly  fall  on  clear  moonlight  nights.  The  ancients,  on  the 
contrary,  especially  looked  for  their  fall  during  lunar  eclipses.  (See 
Pliny,  xxxvii.,  10,  p.  164.  Solinus,  c.  37.  Salm.,  Exerc,  p.  531;  and 
the  passages  collected  by  Ukert,  in  his  Geogr.  der  Griechen  nnd  Romer, 
th.  ii.,  1,  s.  131,  note  14.)  On  the  improbability  that  meteoric  masses 
are  formed  from  metal-dissolving  gases,  which,  according  to  Fusiuieri, 
may  exist  in  the  highest  strata  of  our  atmosphere,  and,  previously  dif- 
fused through  an  almost  boundless  space,  may  suddenly  assume  a  solid 
condition,  and  on  the  penetration  and  misceability  of  gases,  see  my 
Relat.  Hist.,  t.  i.,  p.  525. 

*  Bessel,  in  Schum.,  Astr.  Nachr.,  1839,  No  380  und  381,  s.  222  iind 
346.  At  the  conclusion  of  the  Memoir  there  is  a  comparison  of  the 
Sun's  longitudes  with  the  epochs  of  the  November  phenomeuou,  from 
the  period  of  the  first  observations  in  Cumana  ia  1799. 


124  COS3IOS. 

sands.  The  latter,  which  are  compared  by  Arabian  authors 
to  swarms  of  locusts,  are  periodic  in  their  occurrence,  and 
move  in  streams,  generally  in  a  parallel  direction.  Among 
periodic  falls,  the  most  celebrated  are  that  known  as  the  No- 
vember phenomenon,  occurring  from  about  the  12th  to  the 
14th  of  November,  and  that  of  the  festival  of  St.  Lawrence 
(the  10th  of  August),  whose  *' fiery  tears"  were  noticed  in 
former  times  in  a  church  calendar  of  England,  no  less  than 
in  old  traditionary  legends,  as  a  meteorological  event  of  con- 
stant recurrence.*  Notwithstanding  the  great  quantity  of 
shooting  stars  and  fire-balls  of  the  most  various  dimensions, 
which,  according  to  Kloden,  were  seen  to  fall  at  Potsdam  on 
the  night  between  the  12th  and  13th  of  November,  1822, 
and  on  the  same  night  of  the  year  in  1832  throughout  the 
whole  of  Europe,  from  Portsmouth  to  Orenburg  on  the  Ural 
River,  and  even  in  the  southern  hemisphere,  as  in  the  Isle  of 
France,  no  attention  was  directed  to  the  periodicity  of  the 
phenomenon,  and  no  idea  seems  to  have  been  entertained  of 
the  connection  existing  between  the  fall  of  shooting  stars  and 
the  recurrence  of  certain  days,  until  the  prodigious  swarm  of 
shooting  stars  which  occurred  in  North  America  between  the 
12th  and  13th  of  November,  1833,  and  was  observed  by 
Olmsted  and  Palmer.  The  stars  fell,  on  this  occasion,  like 
flakes  of  snow,  and  it  was  calculated  that  at  least  240,000 
had  fallen  during  a  period  of  nine  hours.  Palmer,  of  New 
Haven,  Connecticut,  was  led,  in  consequence  of  this  splendid 
phenomenon,  to  the  recollection  of  the  fall  of  meteoric  stones 
in  1799,  first  described  by  EUicot  and  myself,!  and  which,  by 

*  Dr.  Thomas  Forster  {The  Pocket  Encyclopedia  of  Natural  Phe- 
nomena, 1827,  p.  17)  states  that  a  manuscript  is  preserved  in  the  libra- 
ry of  Chi-ist's  College,  Cambridge,^  written  in  the  tenth  century  by  a 
monk,  and  entitled  Ephemerides  Rerum  Naturalium,  in  which  the  nat- 
ural phenomena  for  each  day  of  the  year  are  inscribed,  as,  for  instance, 
the  first  flowering  of  plants,  the  arrival  of  birds,  &c. ;  the  10th  of  Au- 
gust is  distinguished  by  the  word  "  meteorodes."  It  was  this  indica- 
tion, and  the  tradition  of  the  fiery  tears  of  St.  Lawrence,  that  chiefly 
induced  Dr.  Forster  to  undertake  his  extremely  zealous  investigation 
of  the  August  phenomena.  (Quetelet,  Correspond.  Mathim.,  Serie  III., 
t.  i.,  1837,  p.  433.) 

+  Humb.,  Rel.  Hist.,  t.  i.,  p.  519-527.  Ellicot,  in  the  Transaction* 
of  the  American  Society,  1804,  vol.  vi.,  p.  29.  Arago  makes  the  follow- 
ing observations  in  reference  to  the  November  phenomena:  "  We  thus 
become  more  and  more  confirmed  in  the  belief  that  there  exists  a  zone 
composed  of  millions  of  small  bodies,  whose  orbits  cut  the  plane  of  the 

a  [No  such  manuscript  is  at  present  known  to  exist  in  the  Ubrary  of  that  college. 
For  this  information  I  am  indebted  to  the  inquiries  of  Mr.  Cory,  of  Pembroke  Col- 
lege, the  learned  editor  of  Hieroglyphics  of  Horapollo  Nilous,  Greek  and  English, 
1840.]— rr. 


AEROLITES.  125 

a  comparison  of  the  facts  I  had  adduced,  showed  that  the 
phenomenon  had  been  simultaneously  seen  in  the  New  Conti- 
n«it,  from  the  equator  to  New  Herrnhut  in  Greenland  (64^ 
14'  north  latitude),  and  between  46°  and  82°  longitude. 
The  identity  of  the  epochs  was  recognized  with  astonishment. 
The  stream,  which  had  been  seen  from  Jamaica  to  Boston 
(40°  21'  north  latitude)  to  traverse  the  whole  vault  of  heaven 
on  the  12th  and  13th  of  November,  1833,  was  again  observed 
in  the  United  States  in  1834,  on  the  night  between  the  13th 
and  14th  of  November,  although  on  this  latter  occasion  it 
showed  itself  with  somewhat  less  intensity.  In  Europe  the 
periodicity  of  the  phenomenon  has  since  been  manifested  with 
great  regularity. 

Another  and  a  like  regularly  recurring  phenomenon  is  that 
noticed  in  the  month  of  August,  the  meteoric  stream  of  St. 
Lawrence,  appearing  between  the  9th  and  14th  of  August. 
Muschenbroek,*  as  early  as  in  the  middle  of  the  last  century, 
drew  attention  to  the  frequency  of  meteors  in  the  month  of 
August ;  but  their  certain  periodic  return  about  the  time  of 
St.  Lawrence's  day  was  first  shown  by  Quetelet,  Olbers,  and 
Benzenberg.  We  shall,  no  doubt,  in  time,  discover  other  pe- 
riodically appearing  streams,!  probably  about  the  22d  to  the 

ecliptic  at  about  the  point  which  our  Eai-th  annually  occupies  between 
the  11th  and  13th  of  November.  It  is  a  new  planetary  world  begin- 
ning to  be  revealed  to  us."     (Annuaire,  1836,  p.  296.) 

*  Compare  Muschenbroek,  Introd.  ad  Phil.  Nat.,  1762,  t.  ii.,  p.  1061 ; 
Howard,  On  the  Climate  of  London,  vol.  ii.,  p.  23,  observations  of  the 
year  1806 ;  seven  years,  therefore,  after  the  earhest  observations  of 
Brandes  (Benzenberg,  ilber  Sternschnuppen,  s.  240-244)  ;  the  August 
observations  of  Thomas  Forster,  iu  Quetelet,  op.  cit.,  p.  438-453  ;  those 
of  Adolph  Erman,  Boguslawski,  and  Kreil,  in  Sebum.,  Jahrb.,  1838,  s. 
317-330.  Regarding  the  point  of  origin  in  Pei'seus,  on  the  10th  of  Au- 
gust, 1839,  see  the  accurate  measurements  of  Bessel  and  Erman  (Schum., 
Astr.  Nachr.,  No.  385  und  428) ;  but  on  the  10th  of  August,  1837,  the 
path  does  not  appear  to  have  been  retrograde ;  see  Arago,  in  Comptes 
Rendus,  1837,  t.  ii.,  p.  183. 

t  On  the  25th  of  April,  1095,  "  innumerable  eyes  in  France  saw  stars 
faUiug  from  heaven  as  thickly  as  hail"  {rit  grando,  nisi  lucerent,  pro  den- 
sitate  putaretur ;  Baldr.,  p.  88),  and  this  occurrence  was  regarded  by 
the  Council  of  Clermont  as  indicative  of  the  great  movement  in  Chris- 
tendom. (Wilken,  Gesch.  der  Kreuzzuge,  bd.  i.,  s.  75.)  On  the  25th 
of  April,  1800,  a  great  fall  of  stars  was  observed  in  Virginia  and  Mas 
sachusetts ;  it  v/as  "  a  fire  of  rockets  that  lasted  two  hours."  Arago 
was  the  first  to  call  attention  to  this  "  trainee  d'asteroTdes,"  as  a  recur- 
ring phenomenon.  {Annuaire,  1836,  p.  297.)  The  falls  of  aerolites  in 
the  beginning  of  the  mouth  of  December  are  also  deserving  of  notice. 
In  reference  to  their- periodic  recurrence  as  a  meteoric  stj-eam,  we  may 
mention  the  eai'ly  observation  of  Brandes  on  the  night  of  the  6th  and 
7th  of  December,  1798  (when  he  counted  2000  falling  stars),  and  very 


126  COSMOS. 

25tli  of  April,  between  the  Gth  and  12th  of  December-,  and, 
to  judge  by  the  number  of  true  falls  of  aerolites  enumerated 
by  Capocci,  also  between  the  27th  and  29th  of  November,  or 
about  the  1 7th  of  July. 

Although  the  phenomena  hitherto  observed  appear  to  have 
been  independent  of  the  distance  from  the  pole,  the  tempera- 
ture of  the  air,  and  other  climatic  relations,  there  is,  however, 
one  perhaps  accidentally  coincident  phenomenon  which  must 
not  be  wholly  disregarded.  The  Northern  Light,  the  Aurora 
Borealis,  was  unusually  brilliant  on  the  occurrence  of  the 
splendid  fall  of  meteors  of  the  12th  and  13th  November,  1833, 
described  by  Olmsted.  It  was  also  observed  at  Bremen  in 
1838,  where  the  periodic  meteoric  fall  was,  however,  less  re- 
markable than  at  Richmond,  near  London.  I  have  mentioned 
in  another  work  the  singular  fact  observed  by  Admiral  Wran- 
gel,  and  frequently  confirmed  to  me  by  himself,*'  that  when  he 

probably  the  enormous  fall  of  aSrolites  that  occurred  at  the  Rio  Assu, 
near  the  village  of  Macao,  in  the  !6razils,  on  the  11th  of  December,  1836. 
(Brandes,  Unterhalt.  fur  Freunde  der  Physik,  1825,  heft  i.,  s.  65,  and 
Comptes  Rendus,  t.  v.,  p.  211.)  Capocci,  in  the  interval  betvreen  1809 
and  1839,  a  space  of  thirty  years,  has  discovered  twelve  authenticated 
cases  of  aerolites  occurring  betw^een  the  27th  and  29th  of  November, 
besides  others  on  the  13th  of  November,  the  10th  of  August,  and  the 
17th  of  July.  (Comptes  Rendus,  t.  xi.,  p.  357.)  It  is  singular  that  in 
the  portion  of  the  Earth's  path  corresponding  vv^ith  the  months  of  Jan- 
uary and  February,  and  probably  also  with  March,  no  periodic  streams 
of  falling  stars  or  aerolites  have  as  yet  been  noticed ;  although,  when 
in  the  South  Sea  in  the  year  1803,  I  observed  on  the  15th  of  March  a 
remarkably  large  number  of  falling  stars,  and  they  were  seen  to  fall  as 
in  a  swarm  in  the  city  of  Quito,  shortly  before  the  terrible  earthquake 
of  Riobamba  on  the  4th  of  Februaiy,  1797.  From  the  phenomena  hith- 
erto observed,  the  following  epochs  seem  especially  worthy  of  remark : 

22d  to  the  25th  of  April. 

17th  of  July  (17th  to  the  26th  of  July  ?).    (Quet.,  Corr.,  1837,  p.  435.) 

10th  of  August. 

12th  to  the  14th  of  November. 

27th  to  the  29th  of  November. 

6th  to  the  12th  of  December. 

When  we  consider  that  the  regions  of  space  must  be  occupied  by 
myriads  of  comets,  we  are  led  by  analogy,  notwithstanding  the  differ- 
ences existing  between  isolated  comets  and  rings  filled  w^ith  asteroids, 
to  regard  the  frequency  of  these  meteoric  streams  with  less  astonish- 
ment than  the  first  consideration  of  the  phenomenon  would  be  likely 
to  excite. 

*  Ferd.  v.  Wrangle,  Reise  Idngs  der  Nordkuste  von  Sibirien  in  den 
Jahren,  1820-1824,  th.  ii.,  s.  259.  Regarding  the  recurrence  of  the 
denser  swarm  of  the  November  stream  after  an  interval  of  thirty-three 
years,  see  Olbers,  in  Jahrb.,  1837,  s.  280.  I  was  infonmed  in  Cumana 
that  shortly  before  the  fearful  earthquake  of  1766,  and  consequently 
thirty-three  years  (the  same  interval)  before  the  great  fall  of  stars  on 


AERULITKS.  1  il 

was  on  the  Siberian  coast  of  the  Polar  Sea,  he  observed,  during 
an  Aurora  BoreaHs,  certain  portions  of  the  vault  of  heaven, 
which  were  not  illuminated,  light  up  and  continue  luminous 
whenever  a  shooting  star  passed  over  them. 

The  different  meteoric  streams,  each  of  which  is  composed 
of  myriads  of  small  cosmical  bodies,  probably  intersect  our 
Earth's  orbit  in  the  same  manner  as  Biela's  comet.  Accord- 
ing to  this  hypothesis,  we  may  represent  to  ourselves  these 
asteroid-meteors  as  composing  a  closed  ring  or  zone,  within 
which  they  all  pursue  one  common  orbit.  The  smaller  plan- 
ets between  Mars  and  Jupiter  present  us,  if  we  except  Pallas, 
with  an  analogous  relation  in  their  constantly  intersecting 
orbits.  As  yet,  however,  we  have  no  certain  knowledge  as 
to  whether  changes  in  the  periods  at  which  the  stream  be- 
comes visible,  or  the  retardatio7is  of  the  phenomena  of  which 
I  hav^e  already  spoken,  indicate  a  regular  precession  or  oscilla.- 
tion  of  the  nodes — that  is  to  say,  of  the  points  of  intersection 
of  the  Earth's  orbit  and  of  that  of  the  ring  ;  or  whether  this 
rinsf  or  zone  attains  so  considerable  a  degree  of  breadth  from 
the  irregular  grouping  and  distances  apart  of  the  small  bodies, 
that  it  requires  several  days  for  the  Earth  to  traverse  it.  The 
system  of  Saturn's  satellites  shows  us  likewise  a  group  of  im- 
mense width,  composed  of  most  intimately-connected  cosmical 
bodies.  In  this  system,  the  orbit  of  the  outermost  (the  seventh) 
satellite  has  such  a  vast  diameter,  that  the  Earth,  in  her  rev- 
olution round  the  Sun,  requires  three  days  to  traverse  an  ex- 
tent of  space  equal  to  this  diameter.  If,  therefore,  in  one  of 
these  rings,  which  we  regard  as  the  orbit  of  a  periodical 
stream,  the  asteroids  should  be  so  irregularly  distributed  as  to 
consist  of  but  few  groups  sufficiently  dense  to  give  rise  to 
these  phenomena,  we  may  easily  understand  why  we  so  sel- 
dom witness  such  glorious  spectacles  as  those  exhibited  in  the 
November  months  of  1799  and  1833.  The  acute  mind  of 
Olbers  led  him  almost  to  predict  that  the  next  appearance 
of  the  phenomenon  of  shooting  stars  and  fire-balls  intermixed, 
falling  like  flakes  of  snow,  would  not  recur  until  between  the 
12th  and  14th  of  November,  1867. 

the  11th  and  12tli  of  November,  1799,  a  similar  fiery  mauif'estalioii  had 
been  observed  in  the  heavens.  But  it  was  on  the  21st  of  October,  1766, 
and  not  in  the  beginning  of  November,  that  the  earthquake  occurred. 
Possibly  some  traveler  in  Quito  may  yet  be  able  to  ascertain  the  day 
on  which  the  volcano  of  Cayambe,  which  is  situated  there,  was  for  the 
6j)ace  of  an  hour  enveloped  in  falling  slars,  so  tlmt  the  inhabitants  en- 
deavored to  appease  heaven  by  religious  processions.  {Eelat.  Hist., 
I'  \.,  ciiap.  i\'.,  p   .307  ;  chap,  x.,  j).  .520  and  527.) 


128  COSMOS. 

The  stream  of  the  November  asteroids  has  occasionally 
only  been  visible  in  a  small  section  of  the  Earth.  Thus,  for 
instance,  a  very  splendid  meteoric  shoiver  vi^as  seen  in  England 
in  the  year  1837,  w^hile  a  most  attentive  and  skillful  observer 
at  Braunsberg,  in  Prussia,  only  saw,  on  the  same  night,  which 
was  there  uninterruptedly  clear,  a  few  sporadic  shooting  stars 
fall  between  seven  o'clock  in  the  evening  and  sunrise  the  next 
morning.  Bessel*  concluded  from  this  "  that  a  dense  group 
of  the  bodies  composing  the  great  ring  may  have  reached  that 
part  of  the  Earth  in  which  England  is  situated,  while  the 
more  eastern  districts  of  the  Earth  might  be  passing  at  tht- 
time  through  a  part  of  the  meteoric  ring  proportionally  lesi- 
densely  studded  with  bodies."  If  the  hypothesis  of  a  regular 
progression  or  oscillation  of  the  nodes  should  acquire  greatei 
weight,  special  interest  will  be  attached  to  the  investigation 
0^  older  observations.  The  Chinese  annals,  in  which  great 
falls  of  shooting  stars,  as  well  as  the  phenomena  of  comets, 
are  recorded,  go  back  beyond  the  age  of  Tyrtseus,  or  the  sec- 
ond Messenian  war.  They  give  a  description  of  two  streams 
in  the  month  of  March,  one  of  which  is  687  years  anterior  to 
the  Christian  era.  Edward  Biot  has  observed  that,  among 
the  fifty -two  phenomena  which  he  has  collected  from  the 
Chinese  annals,  thosQ  that  were  of  most  frequent  recurrence 
are  recorded  at  periods  nearly  corresponding  with  the  20th 
and  22d  of  July,  O.S.,  and  might  consequently  be  identical 
with  the  stream  of  St.  Lawrence's  day,  taking  into  account 
that  it  has  advanced  since  the  epochsf  indicated.  If  the  fall 
of  shooting  stars  of  the  21st  of  October,  1366,  O.S.  (a  notice 
of  which  was  found  by  the  younger  Von  Boguslawski,  in 
Benessius  de  Horowic's  Ckronicon  Ecclesice  Pragensis),  be 
identical  with  our  November  phenomenon,  although  the  oc- 
currence in  the  fourteenth  century  was  seen  in  broad  day- 
light, we  find  by  the  precession  in  477  years  that  this  system 
of  meteors,  or,  rather,  its  common  center  of  gravity,  must  de- 

*  From  a  letter  to  myself,  dated  Jan.  24th,  1838.  The  enormous 
swarm  of  falling  stax's  in  November,  1799,  was  almost  exclusively  seen 
in  America,  where  it  was  witnessed  from  New  Herruhut  in  Greenland 
to  the  equator.  The  sw^ai'ms  of  1831  and  1832  were  visible  only  iu 
Europe,  and  those  of  1833  and  1834  only  in  the  United  States  of  North 
America. 

t  Lettre  de  M.  Edouard  Biot  a  M.  Quetelet,  sur  les  anciennes  appari- 
tions d'Etoiles  Filantes  en  Chine,  in  the  Bull,  de  V Acadimie  de  Brux' 
elles,  1843,  t.  x.,  No.  7,  p.  8.  On  the  notice  from  the  Ckronicon  Ec- 
clesice Pragensis,  see  the  younger  Boguslawski, in  Poggend.,  Annalert, 
bd.  xlviii.,  s.  612. 


AEROLITES.  ^  129 

Bcribe  a  retrograde  orbit  round  the  Sun.  It  also  follows,  from 
the  views  thus  developed,  that  the  non-appearance,  during 
certain  years,  in  any  portion  of  the  Earth,  of  the  two  streams 
hitherto  observed  in  November  and  about  the  time  of  St. 
Lawrence's  day,  must  be  ascribed  either  to  an  interruption  in 
the  meteoric  ring,  that  is  to  say,  to  intervals  occurring  be- 
tween the  asteroid  groups,  or,  according  to  Poisson,  to  the  ac- 
tion of  the  larger  planets*  on  the  form  and  position  of  thii 
annulus. 

The  solid  masses  which  are  observed  by  night  to  fall  to  the 
earth  from  fire-balls,  and  by  day,  generally  when  the  sky  is 
clear,  from  a  dark  small  cloud,  are  accompanied  by  much 
noise,  and  although  heated,  are  not  in  an  actual  state  of  in- 
candescence. They  undeniably  exhibit  a  great  degree  of  gen- 
eral identity  with  respect  to  their  external  form,  the  character 
of  their  crust,  and  the  chemical  composition  of  their  principal 
constituents.  These  characteristics  of  identity  have  been  ob- 
served at  all  the  different  epochs  and  in  the  most  various  parts 
of  the  earth  in  which  these  meteoric  stones  have  been  found. 
This  striking  and  early-observed  analogy  of  physiognomy  in 
the  denser  meteoric  masses  is,  however,  met  by  many  excep- 
tions regarding  individual  points.  What  differences,  for  in- 
stance, do  we  not  find  between  the  malleable  masses  of  iron 
of  Hradschina  in  the  district  of  Agram,  those  from  the  shores 
of  the  Sisim  in  the  government  of  Jeniseisk,  rendered  so  cele- 
brated by  Pallas,  or  those  which  I  brought  from  Mexico,t  all 
of  which  contain  96  per  cent,  of  iron,  from  the  aerolites  of 
Siena,  in  which  the  iron  scarcely  amounts  to  2  per  cent.,  or 
the  earthy  aerolite  of  Alais  (in  the  Department  du  Gard), 
which  broke  up  in  water,  or,  lastly,  from  those  of  Jonzac  and 
Juvenas,  which  contained  no  metallic  iron,  but  presented  a 

*  "  It  appears  that  an  apparently  inexhaustible  number  of  bodies,  too 
small  to  be  observed,  are  moving  in  the  regions  of  space,  either  around 
the  Sun  or  the  planets,  or  perhaps  even  around  their  satellites.  It  is 
supposed  that  when  these  bodies  come  in  contact  with  our  atmosphere, 
the  difference  between  their  velocity  and  that  of  our  planet  is  so  great, 
that  the  friction  which  they  experience  from  their  contact  with  the  air 
heats  them  to  incandescence,  and  sometimes  causes  their  explosion.  If 
the  group  of  falling  stars  form  an  annulus  around  the  Sun,  its  velocity 
of  circulation  may  be  very  different  from  that  of  our  Earth ;  and  the 
displacements  it  may  experience  in  space,  in  consequence  of  the  actions 
of  the  various  planets,  may  render  the  phenomenon  of  its  intersecting 
the  planes  of  the  ecliptic  possible  at  some  epochs,  and  altogether  im« 
possible  at  others." — Poisson,  Recherches  sur  la  Probability  des  Juge- 
vients,  p.  306,  307. 

t  Humboldt,  Essai  Politique  sur  la  Nmiv.  Espagne  (2de  edit.),  t.  iii. 
p.  310. 

F  2 


130  COSMOS. 

mixture  of  oryctognostically  distinct  crystalline  components  ! 
These  differences  have  led  mineralogists  to  separate  these  cos- 
mical  masses  into  two  classes,  namely,  those  containing  nick 
elliferous  meteoric  iron,  and  those  consisting  of  fine  or  coarse- 
ly-granular meteoric  dust.  The  crust  or  rind  of  aerolites  is 
peculiarly  characteristic  of  these  bodies,  being  only  a  few 
tenths  of  a  line  in  thickness,  often  glossy  and  pitch-like,  and 
occasionally  veined.*  There  is  only  one  instance  on  record, 
as  far  as  I  am  aware  (the  aerolite  of  Chantonnay,  in  La  Ven- 
dee), in  which  the  rind  was  absent,  and  this  meteor,  like  that 
of  Juvenas,  presented  likewise  the  peculiarity  of  having  pores 
and  vesicular  cavities.  In  all  other  cases  the  black  crust  is 
divided  from  the  inner  light-gray  mass  by  as  sharply-defined 
a  line  of  separation  as  is  the  black  leaden-colored  investment 
of  the  white  granite  blockst  which  I  brought  from  the  cata- 
racts of  the  Orinoco,  and  which  are  also  associated  with 
many  other  cataracts,  as,  for  instance,  those  of  the  Nile  and 
of  the  Congo  River.  The  greatest  heat  employed  in  our 
porcelain  ovens  would  be  insufficient  to  produce  any  thing 
similar  to  the  crust  of  meteoric  stones,  whose  interior  re- 
mains wholly  unchanged.  Here  and  there,  facts  have  been 
observed  which  would  seem  to  indicate  a  fusion  together  of 
the  meteoric  fragments  ;  but,  in  general,  the  character  of  the 
aggregate  mass,  the  absence  of  compression  by  the  fall,  and 
the  inconsiderable  degree  of  heat  possessed  by  these  bodies 
when  they  reach  the  earth,  are  all  opposed  to  the  hypothesis 
of  the  interior  being  in  a  state  of  fusion  during  their  short 
passage  from  the  boundary  of  the  atmosphere  to  our  Earth. 

The  chemical  elements  of  which  these  meteoric  masses 
consist,  and  on  which  Berzelius  has  thrown  so  much  light, 
are  the  same  as  those  distributed  throughout  the  earth's 
crust,  and  are  fifteen  in  number,  namely,  iron,  nickel,  cobalt, 
manganese,  chromium,  copper,  arsenic,  zinc,  potash,  soda,  sul- 
phur, phosphorus,  and  carbon,  constituting  altogether  nearly 
one  third  of  all  the  known  simple  bodies.  Notwithstanding 
this  similarity  with  the  primary  elements  into  which  inorganic 
bodies  are  chemically  reducible,  the  aspect  of  aerolites,  owing 
to  the  mode  in  which  their  constituent  parts  are  compounded, 
presents,  generally,  some  features  foreign  to  our  telluric  rocks 
and  minerals.     The  pure  native  iron,  which  is  almost  always 

*  The  peculiar  color  of  their  crust  was  observed  even  as'  early  as  ia 
the  time  of  Pliny  (ii.,  56  and  58):  "colore  adusto."  The  phrase  "lateri- 
bus  pluisse"  seems  also  to  refer  to  the  burned  outer  surface  of  aerolites. 

t  Humb.,  Rel.  Hist.,  t.  ii.,  chap,  xx.,  p.  299-302. 


AEROLITES.  131 

found  incorporated  with  aerolites,  imparts  to  them  a  pecul- 
iar, but  not,  consequently,  a  s,elenic  character  ;  for  in  other 
regions  of  space,  and  in  other  cosmical  hodies  besides  our  Moon, 
water  may  be  wholly  absent,  and  processes  of  oxydation  of 
rare  occurrence. 

Cosmical  gelatinous  vesicles,  similar  to  the  organic  nostoc 
(masses  which  have  been  supposed  since  the  Middle  Ages  to 
be  connected  with  shooting  stars),  and  those  pyrites  of  Sterli 
tamak,  west  of  the  Uralian  Mountains,  which  are  said  to  have 
constituted  the  interior  of  hailstones,*  must  both  be  classed 
among  the  mythical  fables  of  raeteorolog}^  Some  few  aero- 
lites, as  those  composed  of  a  finely  granular  tissue  of  olivine, 
augite,  and  labradorite  blended  together!  (as  the  meteoric  stone 
found  at  Juvenas,  in  the  Department  de  I'Ardeche,  which  re- 
sembled dolorite),  are  the  only  ones,  as  Gustav  Rose  has 
remarked,  which  have  a  more  familiar  aspect.  These  bodies 
contain,  for  instance,  crystalline  substances,  perfectly  similar 
to  those  of  our  earth's  crust  ;  and  in  the  Siberian  mass  of 
meteoric  iron  investigated  by  Pallas,  the  olivine  only  differs 
from  common  olivine  by  the  absence  of  nickel,  which  is  re- 
placed by  oxyd  of  tin.:t  As  meteoric  olivine,  like  our  basalt, 
contains  from  47b  to  49  per  cent,  of  magnesia,  constituting, 
according  to  Berzelius,  almost  the  half  of  the  earthy  compo- 
nents of  meteoric  stones,  we  can  not  be  surprised  at  the  great 
quantity  of  silicate  of  magnesia  found  in  these  cosmical  bodies. 
If  the  aerolite  of  Juvenas  contain  separable  crystals  of  augite 
and  labradorite,  the   numerical  relation  of  the   constituents 

*  Gustav  Rose,  Reise  nach  dem  Ural,  bd.  ii.,  s.  202. 

t  Gustav  Rose,  in  Poggend.,  Ann.,  1825,  bd.  iv.,  s.  173-192.  Ram- 
melsberg,  Erstes  Suppl.  zum  chem.  Handworterbuche  der  Mineralogie, 
1843,  s.  102.  "It  is,"  says  the  clear-minded  obsex-ver  Olbei's,  '"a  re- 
markable but  hitherto  uni-egarded  fact,  that  while  shells  are  found  in 
secondary  and  tertiaiy  formations,  no  fossil  meteoric  stones  have  as  yet 
been  discovered.  May  we  conclude  from  this  circumstance  that  pre- 
vious to  the  present  and  last  modification  of  the  earth's  surface  no  me- 
teoric stones  fell  on  it,  although  at  the  present  time  it  appears  probable, 
from  the  researches  of  Schreibers,  that  700  fall  annually?"  (Olbers, 
in  Schum.,  Jahrb.,  1838,  s.  329.)  Problematical  nickelliferous  masses 
of  native  iron  have  been  found  in  Northern  Asia  (at  the  gold-washing 
establishment  at  Petropawlowsk,  eighty  miles  southeast  of  Kusnezk), 
imbedded  thirty -one  feet  in  the  ground,  and  more  recently  in  the  West- 
ern Carpathians  (the  mountain  chain  of  Magura,  at  Szlanicz),  both  of 
which  are  remarkably  like  meteoric  stones.  Compare  Erman.  Arckiv 
fur  wissenschaftliche  Kundevon  Russland,  hd.  i.,  s.  315,  and  Haidhiger, 
Bericht  uher  Szlaniczer  Schurfe  in  Ungarn. 

X  Berzelins,  Jahresber.,  bd.  xv.,  s.  217  und  231.  Rammelsberg, 
Handtcdrterb.,  abth.  ii.,  s.  2.5-28. 


132  COSMOS. 

render  it  at  least  probable  tbat  the  meteoric  masses  of  Cha- 
teau-Ren ard  may  be  a  compound  of  diorite,  consisting  of  horn- 
blende and  albite,  and  those  of  Blansko  and  Chantonnay  com- 
pounds of  hornblende  and  labradorite.  The  proofs  of  the  tel- 
luric and  atmospheric  origin  of  aerolites,  which  it  is  attempt- 
ed to  base  upon  the  oryctognostic  analogies  presented  by  these 
bodies,  do  not  appear  to  me  to  possess  any  great  weight. 

Recallins:  to  mind  the  remarkable  interview  between  New- 
ton and  Conduit  at  Kensington,*  I  would  ask  why  the  ele- 
mentary substances  that  compose  one  group  of  cosmical  bodies, 
or  one  planetary  system,  may  not,  in  a  great  measure,  be  iden- 
tical ?  Why  should  we  not  adopt  this  view,  since  we  may 
conjecture  that  these  planetary  bodies,  like  all  the  larger  or 
smaller  agglomerated  masses  revolving  round  the  sun,  have 
been  thrown  ofi^  from  the  once  far  more  expanded  solar  at- 
mosphere, and  been  formed  from  vaporous  rings  describing 
their  orbits  round  the  central  body  ?  We  are  not,  it  appears 
to  me,  more  justified  in  applying  the  term  telluric  to  the  nickel 
and  iron,  the  olivine  and  pyroxene  (augite),  found  in  meteoric 
stones,  than  in  indicating  the  German  plants  Avhich  I  found 
beyond  the  Obi  as  European  species  of  the  flora  of  Northern 
Asia.  If  the  elementary  substances  composing  a  group  of 
cosmical  bodies  of  different  magnitudes  be  identical,  why 
should  they  not  likewise,  in  obeying  the  laws  of  mutual  at- 
traction, blend  together  under  definite  relations  of  mixture, 
composing  the  white  glittering  snow  and  ice  in  the  polar  zones 
of  the  planet  Mars,  or  constituting  in  the  smaller  cosmical 
masses  mineral  bodies  inclosing  crystals  of  olivine,  augite,  and 
labradorite  ?  Even  in  the  domain  of  pure  conjecture  we  should 
not  suffer  ourselves  to  be  led  away  by  unphilosophical  and  ar- 
bitrary views  devoid  of  the  support  of  inductive  reasoning. 

Remarkable  obscurations  of  the  sun's  disk,  during  whicli 
the  stars  have  been  seen  at  mid-day  (as,  for  instance,  in  the 
obscuration  of  1547,  which  continued  for  three  days,  and  oc- 
curred about^  the  time  of  the  eventful  battle  of  Miihlberg), 
can  not  be  explained  as  arising  from  volcanic  ashes  or  mists, 
and  were  regarded  by  Kepler  as  owing  either  to  a  materia 
cometica,  or  to  a  black  cloud  formed  by  the  sooty  exhalations 
of  the  solar  body.  The  shorter  obscurations  of  1090  and 
1203,  which  continued,  the  one  only  three,  and  the  other  six 

*  "  Sir  Isaac  Newton  said  he  took  all  the  planets  to  be  composed  of 
the  same  matter  with  the  Earth,  viz.,  earth,  water,  and  stone,  but  vari- 
ously concocted." — Turner,  Collections  for  the  History  of  Grantham^ 
eontainhig  authentic  Memoirs  of  Sir  Isaac  Newton,  p.  172. 


AEROLITES.  133 

hours,  were  supposed  by  Chiadni  and  Schnurrer  to  be  occa 
sioned  by  the  passage  of  meteoric  masses  before  the  sun's  disk. 
Since  the  period  that  streams  of  meteoric  shootmg  stars  were 
first  considered  with  reference  to  the  direction  of  their  orbit 
as  a  closed  ring,  the  epochs  of  these  mysterious  celestial  phe- 
nomena have  been  observed  to  present  a  remarkable  connec 
tion  with  the  regular  recurrence  of  swarms  of  shooting  stars 
Adolph  Erman  has  evinced  great  acuteness  of  mind  in  his  ac- 
curate investiofation  of  the  facts  hitherto  observed  on  this  sub- 
ject,  and  his  researches  have  enabled  him  to  discover  the  con- 
nection of  the  sun's  conjunction  with  the  August  asteroids  on 
the  7th  of  February,  and  with  the  November  asteroids  on  the 
12th  of  May,  the  latter  period  corresponding  with  the  days 
of  St.  Mamert  (May  11th),  St.  Pancras  (May  12th),  and  St. 
Servatius  (May  13th),  which,  according  to  popular  belief, 
were  accounted  "  cold  days."^ 

The  Greek  natural  philosophers,  who  were  but  little  dis 
posed  to  pursue  observations,  but  evinced  inexhaustible  fer 
tility  of  imagination  in  giving  the  most  various  interpretation 
of  half-perceived  facts,  have,  however,  left  some  hypotheses 
reofardinor  shooting  stars  and  meteoric  stones  which  strikingly 
accord  with  the  views  now  almost  universally  admitted  of 
the  cosmical  process  of  these  phenomena.  "  Falling  stars," 
says  Plutarch,  in  his  life  of  Lysander,t  "  are,   according  to 

*  Adolph  Erman,  in  Poggend.,  Annalen,  1839,  bd.  xlviii.,  s.  582- 
601.  Biot  had  preNaously  thrown  doubt  regarding  the  probability  of 
the  November  stream  reappearing  in  the  beginning  of  May  (Comptes 
Rendns,  1836,  t.  ii.,  p.  670).  Madler  has  examined  the  mean  depres- 
sion of  temperature  on  the  three  ill-named  days  of  May  by  Berlin  ob- 
servations for  eighty-six  years  (  Verhandl.  des  Vereins  zur  Befurd.  des 
Gartenbaues,  183"4,  s.  377),  and  found  a  retrogression  of  temperature 
amounting  to  20-2  Fahr.  from  the  11th  to  the  13th  of  May,  a  period  at 
wliich  nearly  the  most  rapid  advance  of  heat  takes  place.  It  is  much 
to  be  desired  that  this  phenomenon  of  depressed  temperature,  which 
some  have  felt  inclined  to  attribute  to  the  melting  of  the  ice  in  the 
northeast  of  Europe,  should  be  also  investigated  in  very  remote  spots, 
as  in  America,  or  i*i  the  southern  hemisphere.  (Comp.  Bull,  de  VAcad. 
Imp.  de  Si.  Petershourg,  1843,  t.  i..  No.  4.) 

t  Plut.,  Vitce  par.  in  Lysandro,  cap.  22.  The  statement  of  Dama- 
cho9  (Daimachos),  that  for  seventy  days  continuously  there  was  a  fiery 
cloud  seen  in  the  sky,  emitting  sparks  like  falling  stars,  and  which  then, 
sinkii^g  nearer  to  the  earth,  let  fall  the  stone  of  iEgos  Potamos,  "  which, 
however,  was  only  a  small  pai't  of  it,"  is  extremely  improbable,  since 
the  direction  and  velocity  of  the  fire-cloud  would  in  that  case  of  neces- 
sity have  to  remain  for  so  many  days  the  same  as  those  of  the  earth ; 
and  this,  in  the  fire-ball  of  the  19th  of  July,  1686,  described  by  Halley 
(  Trans.,  vol.  xxix.,  p.  163),  lasted  only  a  few  minutes.  It  is  not  alto- 
gether certain  whether  Daimachos,  the  writer,  -Kepi  evaef'ELag,  was  the 


134  coSiMos. 

k 
f 

the  opinion  of  some  physicists,  not  eruptions  of  the  ethereal 
fire  extinguished  in  the  air  immediately  after  its  ignition,  nor 
yet  an  inflammatory  combustion  of  the  air,  which  is  dissolved 
in  large  quantities  in  the  upper  regions  of  space,  but  these 
meteors  are  rather  a  fall  of  celestial  bodies,  which,  in  conse- 
quence of  a  certain  intermission  in  the  rotatory  force,  and  by 
the  impulse  of  some  irregular  movement,  have  been  hurled 
down  not  only  to  the  inhabited  portions  of  the  Earth,  but 
also  beyond  it  into  the  great  ocean,  where  we  can  not  find 
them."  Diogenes  of  Apollonia^  expresses  himself  still  more 
explicitly.  According  to  his  views,  "  Stars  that  are  invisible, 
and,  consequently,  have  no  name,  move  in  space  together  with 
those  that  are  visible.  These  invisible  stars  frequently  fall 
to  the  earth  and  are  extinguished,  as  the  stony  star  which  fell 
burning  at  -^gos  Potamos."  The  Apollonian,  who  held  all 
other  stellar  bodies,  when  luminous,  to  be  of  a  pumice-like 
nature,  probably  grounded  his  opinions  regarding  shooting 
stars  and  meteoric  masses  on  the  doctrine  of  Anaxagoras  the 
Clazomenian,  who  regarded  all  the  bodies  in  the  universe 
"  as  fragments  of  rocks,  which  the  fiery  ether,  in  the  force 
of  its  gyratory  motion,  had  torn  from  the  Earth  and  con- 
verted into  stars."  In  the  Ionian  school,  therefore,  according 
to  the  testimony  transmitted  to  us  in  the  views  of  Diogenes 
of  Apollonia,  aerolites  and  stars  were  ranged  in  one  and  the 
same  class  ;  both,  when  considered  with  reference  to  their 
primary  origin,  being  equally  telluric,  this  being  understood 
only  so  far  as  the  Earth  was  then  regarded  as  a  central  body,t 

same  person  as  Daimachos  of  Platjea,  who  was  sent  by  Seleucus  to 
India  to  the  sou  of  Androcottos,  and  who  was  charged  by  Strabo  with 
being  "  a  speaker  of  lies"  (p.  70,  Casaub.).  From  another  passage  of 
Plutarch  {Compar.  Solonis  c.  Cop.,  cap.  5)  we  should  almost  believe 
that  he  was.  At  all  events,  we  have  here  only  the  evidence  of  a  very 
late  author,  who  wrote  a  century  and  a  half  after  the  fall  of  aerolites 
occurred  in  Thrace,  and  whose  authenticity  is  also  doubted  by  Plutarch. 

■*  Stob.,  ed.  Heeren,  i.,  25,  p.  508 ;  Plut.,  de  plac.  Philos.,  ii.,  13. 

t  The  remarkable  passage  in  Plut.,  deplac.  Philos.,  ii.,  13,  runs  thus: 
''  Anaxagoras  teaches  that  the  surrounding  ether  is  a  fiery  substance, 
which,  by  the  power  of  its  rotation,  tears  rocks  from  the  earth,  inflames 
tliem,  and  converts  them  into  stars."  Applying  an  ancient  fable  to  il- 
lustrate a  physical  dogma,  the  Clazomenian  appears  to  have  ascribed 
the  fall  of  the  Nemtean  Lion  to  the  Peloponnesus  from  the  Moon  to 
such  a  rotatory  or  centrifugal  force,  (^lian.,  xii.,  7;  Pint.,  de  'Facie 
in  Orbe  Lunce,  c.  24;  Schol.  ex  Cod.  Paris.,  in  ApoU.  Argon.,  lib.  i., 
p.  498,  ed.  Schaef.,  t.  ii.,  p.  40;  Meineke,  Annal.  Alex.,  1843,  p.  85.) 
Here,  instead  of  stones  from  the  Moon,  we  have  an  niiimal  from  the 
Moon!  According  to  an  acute  remark  of  Bockh,  the  ancient  mythol- 
ogy of  the  Nerasean  lunar  lion  has  an  astronomical  origin,  tind  is  sym- 


AEROLITES.  135 

foiming  all  things  around  it  in  the  same  manner  as  we,  ac- 
cording to  our  present  views,  suppose  the  planets  of  our  sys- 
tem to  have  originated  in  the  expanded  atmosphere  of  anoth- 
er central  body,  the  Suri.  These  views  must  not,  therefore, 
be  confounded  with  what  is  commonly  termed  the  telluric  or 
atmospheric  origin  of  meteoric  stones,  nor  yet  with  the  singu- 
lar opinion  of  Aristotle,  which  supposed  the  enorn:v)us  mass 
of  iEgos  Potamos  to  have  been  raised  by  a  hurricane.  That 
arrogant  spirit  of  incredulity,  which  rejects  facts  without  at- 
tempting to  investigate  them,  is  in  some  cases  almost  more 
injurious  than  an  unquestioning  credulity.  Both  are  alike 
detrimental  to  the  force  of  investigfation.  Notwithstandinsr 
that  for  more  than  two  thousand  years  the  annals  of  different 
nations  had  recorded  falls  of  meteoric  stones,  many  of  which 
had  been  attested  beyond  all  doubt  by  the  evidence  of  irre- 
proachable eye-witnesses — notwithstanding  the  important  part 
enacted  by  the  Baetylia  in  the  meteor- worship  of  the  ancients 
— notwithstanding  the  fact  of  the  companions  of  Cortez  hav- 
ing seen  an  aerolite  at  Cholula  which  had  fallen  on  the  neigh- 
boring pyramid — notwithstanding  that  califs  and  Mongolian 
chiefs  had  caused  swords  to  be  forged  from  recently-fallen 
meteoric  stones — nay,  notwithstanding  that  several  persons 
had  been  struck  dead  by  stones  falling  from  heaven,  as,  for 
instance,  a  monk  at  Crema  on  the  4th  of  September,  1511, 
another  monk  at  Milan  in  1650,  and  two  Swedish  sailors  on 
board  ship  in  1674,  yet  this  great  cosmical  phenomenon  re- 
mained almost  wholly  unheeded,  and  its  intimate  connection 
with  other  planetary  systems  unknown,  until  attention  was 
drawn  to  the  subject  by  Chladni,  who  had  already  gained  im- 
mortal renown  by  his  discovery  of  the  sound-figures.  He  who 
is  penetrated  with  a  sense  of  this  mysterious  connection,  and 
whose  mind  is  open  to  deep  impressions  of  nature,  will  feel 
himself  moved  by  the  deepest  and  most  solemn  emotion  at 
the  sight  of  every  star  that  shoots  across  the  vault  of  heaven, 
no  less  than  at  the  glorious  spectacle  of  meteoric  swarms  in 
the  November  phenomenon  or  on  St.  Lawrence's  day.  Here 
motion  is  suddenly  revealed  in  the  midst  of  nocturnal  rest. 
The  still  radiance  of  the  vault  of  heaven  is  for  a  moment  an- 
imated with  life  and  movement.  In  the  mild  radiance  left 
on  the  track  of  the  shooting  star,  imagination  pictures  the 
lengthened  path  of  the  meteor  through  the  vault  of  heaven, 

bolically  connected  in  chronology  with  the  cycle  of  intercalation  of  the 
lunar  year,  with  the  moon- worship  at  Nemiea,  and  the  games  by  which 
it  was  acc(impanied. 


136  COSMOS. 

while,  every  where  around,  the  luminous  asteroids  proclaim 
the  existence  of  one  common  material  universe. 

If  we  compare  the  volume  of  the  innermost  of  Saturn's  sat- 
ellites, or  that  of  Ceres,  with  the  immense  volume  of  the  Sun, 
all  relations  of  magnitude  vanish  from  our  minds.  The  ex- 
tinction of  suddenly  resplendent  stars  in  Cassiopeia,  Cygnus, 
and  Serpentarius  have  already  led  to  the  assumption  of  other 
and  non-luminous  cosmical  bodies.  We  now  know  that  the 
meteoric  asteroids,  spherically  agglomerated  into  small  masses, 
revolve  round  the  Sun,  intersect,  like  comets,  the  orbits  of  the 
luminous  larger  planets,  and  become  ignited  either  in  the  vi- 
cinity of  our  atmosphere  or  in.  its  upper  strata. 

The  only  media  by  which  we  are  brought  in  connection 
with  other  planetary  bodies,  and  with  all  portions  of  the  uni- 
verse beyond  our  atmosphere,  are  light  and  heat  (the  latter 
of  which  can  scarcely  be  separated  from  the  former),*  and 
those  mysterious  powers  of  attraction  exercised  by  remote 
masses,  according  to  the  quantity  of  their  constituents,  upon 
our  globe,  the  ocean,  and  the  strata  of  our  atmosphere.  An- 
other and  different  kind  of  cosmical,  or,  rather,  material  mode 
of  contact  is,  however,  opened  to  us,  if  we  admit  falling  stars 
and  meteoric  stones  to  be  planetary  asteroids.  They  not  only 
act  upon  us  merely  from  a  distance  by  the  excitement  of  lumin- 
ous or  calorific  vibrations,  or  in  obedience  to  the  laws  of  mu- 
tual attraction,  but  they  acquire  an  actual  material  existence 
for  us,  reaching  our  atmosphere  from  the  remoter  regions  of 
universal  space,  and  remaining  on  the  earth  itself  Meteoric 
stones  are  the  only  means  by  which  we  can  be  brought  in  pos- 
sible contact  with  that  which  is  foreign  to  our  own  planet. 
Accustomed  to  gain  our  knowledge  of  what  is  not  telluric 
solely  through  measurement,  calculations,  and  the  deductions 
of  reason,  we  experience  a  sentiment  of  astonishment  at  find- 
ing that  we  may  examine,  weigh,  and  analyze  bodies  that  ap- 

*  The  following  remarkable  passage  on  the  radiation  of  heat  from 
the  fixed  stars,  and  on  their  low  combustion  arid  vitality — one  of  Kep- 
ler's many  aspirations — occurs  in  the  Paralipom.  in  Vitell.  Astron.  para 
Optica,  1604,  Propos.  xxxii.,  p.  25 :  "  Lucis  proprium  est  calor,  sydera 
omnia  calefaciunt.  De  syderum  luce  claritatis  ratio  testatur,  calorem 
universorum  in  minori  esse  proportione  ad  calorem  unius  solis,  quam 
ut  ab  homine,  cujus  est  certa  caloris  meusura,  uterquo  simul  percipi  et 
judicari  possit.  De  cincindularum  lucula  tenuissima  negare  non  potes, 
quin  cum  calore  sit.  Vivunt  enim  et  moventur,  hoc  autem  non  sine 
calefactione  perficitur.  Sic  neque  putrescentium  lignorum  lux  sno  ca« 
lore  destituitur ;  nam  ipsa  puetredo  quidam  lentus  ignis  est.  Inest  et 
stirpibus  suus  calor."  (Compare  Kepler,  Epit.  Astron.  Copernicance, 
1618,  t.  i.,  lib.  i.,  p.  35.) 


ZODIACAL    LIGHT.  137 

pertain  to  the  outer  world.  This  awakens,  by  the  power  of 
the  imagination,  a  meditative,  spiritual  train  of  thought,  where 
the  untutored  mind  perceives  only  scintillations  of  light  in  the 
firmament,  and  sees  in  the  blackened  stone  that  falls  from  the 
exploded  cloud  nothing  beyond  the  rough  product  of  a  power- 
ful natural  force. 

Although  the  asteroid-swarms,  on  which  we  have  been  led, 
from  special  predilection,  to  dwell  somewhat  at  length,  ap- 
proximate to  a  certain  degree,  in  their  inconsiderable  mass 
and  the  diversity  of  their  orbits,  to  comets,  they  present  this 
essential  difference  from  the  latter  bodies,  that  our  knowledge 
of  their  existence  is  almost  entirely  limited  to  the  moment  of 
their  destruction,  that  is,  to  the  period  when,  drawn  within 
the  sphere  of  the  Earth's  attraction,  they  become  luminous 
and  ignite. 

In  order  to  complete  our  view  of  all  that  we  have  learned 
to  consider  as  appertaining  to  our  solar  system,  which  now, 
since  the  discovery  of  the  small  planets,  of  the  interior  comets 
of  short  revolutions,  and  of  the  meteoric  asteroids,  is  so  rich 
and  complicated  in  its  form,  it  remains  for  us  to  speak  of  the 
ring  of  zodiacal  light,  to  which  we  have  already  alluded. 
Those  who  have  lived  for  many  years  in  the  zone  of  palms 
must  retain  a  pleasing  impression  of  the  mild  radiance  with 
which  the  zodiacal  light,  shooting  pyramidally  upward,  illu- 
mines a  part  of  the  uniform  length  of  tropical  nights.  I  have 
seen  it  shine  with  9.n  intensity  of  hglit  equal  to  the  milky  way 
in  Sagittarius,  and  that  not  only  in  the  rare  and  dry  atmos- 
phere of  the  summits  of  the  Andes,  at  an  elevation  of  from 
thirteen  to  fifteen  thousand  feet,  but  even  on  the  boundless 
grassy  plains,  the  llanos  of  Venezuela,  and  on  the  sea-shore, 
beneath  the  ever-clear  sky  of  Cumana.  This  phenomenon 
was  often  rendered  especially  beautiful  by  the  passage  of  light, 
fleecy  clouds,  which  stood  out  in  picturesque  and  bold  relief 
from  the  luminous  back-ground.  A  notice  of  this  aerial  spec- 
tacle is  contained  in  a  passage  in  my  journal,  while  I  was  on 
the  voyage  from  Lima  to  the  western  coasts  of  Mexico  :  "  For 
three  or  four  nights  (between  10^  a,nd  14°  north  latitude)  the 
zodiacal  light  has  appeared  in  greater  splendor  than  I  have 
ever  observed  it.  The  transparency  of  the  atmosphere  must 
be  remarkably  great  in  this  part  of  the  Southern  Ocean,  to 
judge  by  the  radiance  of  the  stars  and  nebulous  spots.  From 
the  14th  to  the  19th  of  March  a  regular  interval  of  three 
quarters  of  an  hour  occurred  between  the  disappearance  of  the 
sun's  disk  in  the  ocean  and  the  first  manifestation  of  the  zodi- 


138  COSMOS. 

acal  light,  although  the  night  was  already  perlectly  dark.  An 
hour  after  sunset  it  was  seen  in  great  brilUancy  between  Alde- 
baran  and  the  Pleiades  ;  and  on  the  18th  of  March  it  attained 
an  altitude  of  39^  5'.  Narrow  elongated  clouds  are  scattered 
over  the  beautiful  deep  azure  of  the  distant  horizon,  flitting 
past  the  zodiacal  light  as  before  a  golden  curtain.  Above 
these,  other  clouds  are  from  time  to  time  reflecting  the  most 
brightly  variegated  colors.  It  seems  a  second  sunset.  On 
this  side  of  the  vault  of  heaven  the  lightness  of  the  night  ap- 
pears to  increase  almost  as  much  as  at  the  first  quarter  of  the 
moon.  Toward  10  o'clock  the  zodiacal  light  generally  becomes 
very  faint  in  this  part  of  the  Southern  Ocean,  and  at  midnight 
I  have  scarcely  been  able  to  trace  a  vestige  of  it.  On  the  16th 
of  March,  when  most  strongly  luminous,  a  faint  reflection  was 
visible  in  the  east."  In  our  gloomy  so-called  "  temperate" 
northern  zone,  the  zodiacal  light  is  only  distinctly  visible  in 
the  beginning  of  Spring,  after  the  evening  twilight,  in  the 
western  part  of  the  sky,  and  at  the  close  of  Autumn,  before 
the  dawn  of  day,  above  the  eastern  horizon. 

It  is  difficult  to  understand  how  so  striking  a  natural  phe- 
nomenon should  have  failed  to  attract  the  attention  of  physi- 
cists and  astronomers  until  the  middle  of  the  seventeenth  cen- 
tury, or  how  it  could  have  escaped  the  observation  of  the  Ara- 
bian natural  philosophers  in  ancient  Bactria,  on  the  Euphra- 
tes, and  in  the  south  of  Spain.  Almost  equal  surprise  is  ex- 
cited by  th^  tardiness  of  observation  of  the  nebulous  spots  in 
Andromeda  and  Orion,  first  described  by  Simon  Marius  and 
Huygens.  The  earliest  explicit  description  of  the  zodiacal 
fight  occurs  in  Childrey's  Britannia  Baconica*  in  the  year 

*  "  There  is  another  thing  which  I  recommend  to  the  observation 
of  mathematical  men,  which  is,  that  in  February,  and  for  a  fittle  before 
and  a  Httle  after  that  month  (as  I  have  observed  several  years  together), 
about  six  in  the  evening,  when  the  twilight  hath  almost  deserted  the 
horizon,  you  shall  see  a  plainly  discernible  way  of  the  twilight  striking 
up  towai-d  the  Pleiades,  and  seeming  almost  to  touch  them.  It  is  so 
observed  any  clear  night,  but  it  is  best  iliac  nocte.  There  is  no  such 
way  to  be  observed  at  any  other  time  of  the  year  (that  I  can  perceive), 
nor  any  other  way  at  that  time  to  be  perceived  darting  up  elsewhere ; 
and  I  believe  it  hath  been,  and  will  be  constantly  visible  at  that  time 
S)f  the  year;  but  what  the  cause  of  it  in  nature  should  be,  I  can  not  yet 
imagine,  but  leave  it  to  future  inquiry."  (Childrey,  Britannia  Baco- 
nica, 1661,  p.  183.)  This  is  the  first  view  and  a  simple  description  of 
the  phenomenon.  (Cassini,  Dicouverte  de  la  Lumiere  Cileste  qui  pa- 
roit  dans  le  Zodiaque,  in  the  M&m.  de  VAcad.,  t.  viii.,  1730,  p.  276. 
Mairan,  TraiU  Phys.  de  V Aurore  Boriale,  1754,  p.  16.)  In  this  remark- 
able work  by  Childrey  there  are  to  be  found  (p.  9 1)  very  clear  accounts 
of  the  epochs  of  maxima  and  minima  diurnal  and  annual  temperatures. 

I 


zoiJiATAL   i.i(;in'.  139 

IGCl.  Tlie  first  observation  of  the  phenomenon  may  have 
been  made  two  or  three  years  prior  to  this  period  ;  but,  not- 
withstanding, the  merit  oi"  having  (in  the  spring  of  1683)  been 
the  first  to  investigate  the  phenomenon  in  all  its  relations  in 
space  is  incontestably  due  to  Dominicus  Cassini.  The  light 
whii^h  he  saw  at  Bologna  in  1668,  and  wliich  was  observed 
at  the  same  time  in  Persia  by  the  celebrated  traveler  Char- 
din  (the  court  astrologers  of  Ispahan  called  this  light,  which 
had  never  before  been  observed,  nijzek,  a  small  lance),  was 
not  the  zodiacal  light,  as  has  often  been  asserted,*  but  the 

and  of  the  retardation  of  the  extremes  of  the  effects  in  meteorological 
processes.  It  is,  howevei",  to  be  regretted  that  our  Baconian-philosophy- 
loving  author,  who  was  Lord  Henry  Somerset's  chaplain,  lell  into  the 
same  error  as  Bernardin  de  St.  Pierre,  and  regarded  the  Earth  as  elon- 
gated at  the  poles  (see  p.  148).  At  the  first,  he  believes  that  the  Earth 
was  spherical,  but  supposes  tliat  the  uninterrupted  and  inci'easing  addi- 
tion of  layers  of-ice  at  both  poles  has  changed  its  figure ;  and  that,  as  the 
ice  is  formed  from  water,  the  quantify  of  that  hquid  is  every  where 
diminishing. 

*  Dominicus  Cassini  {Man.  de  VAcad.,  t.  viii.,  1730,  p.  188),  and 
Mairaii  {Aurore  Bor.,  p.  16),  have  even  maintained  that  the  phenome- 
non observed  in  Persia  in  16G8  was  the  zodiacal  light.  Delambre 
{Hist,  de  V Astron.  Moderne,  t.  ii.,  p.  742),  in  very  decided  terms,  ascribes 
the  discovery  of  this  light  to  the  celebrated  traveler  Chardin  ;  but  in  the 
C our 07171  ement  de  Soliman,  and  in  several  passages  of  the  narrative  of  his 
travels  (ed.  de  Langles,  t.  iv.,  p.  326;  t.  x.,  p.  97),  he  only  applies  the 
term  niazouk  (nyzek),  or  "petite  lance,"  to  "  tiie  great  and  famous 
comet  which  appeared  over  neai'ly  the  whole  world  in  1668,  and  whose 
head  was  so  hidden  in  the  w^est  that  it  could  not  be  perceived  in  the 
horizon  of  Ispahan"  {Atlas  du  Voyage  de  Chardin,  Tab.  iv. ;  froin  the 
observations  at  Schiraz).  The  head  or  nucleus  of  the  comet  was,  how- 
ever, visible  in  the  Brazils  and  in  India  (Pingie,  Cometog7-.,  t.  ii.,  p.  22). 
Regardhig  the  conjectured  identity  of  the  last  great  comet  of  March, 
1843,  with  this,  which  Cassini  mistook  for  the  zodiacal  light,  see  Schuin., 
Astr.  Nachr.,  1843,  No.  476  and  480.  In  Persian,  the  term  "nizehi 
alteschin"  (fiery  spears  or  lances)  is  also  applied  to  the  rays  of  the  ris- 
ing or  setting  sun,  in  the  same  way  as  "  nayazik,"  according  to  Frey- 
tag's  Arabic  Lexicon,  signifies  "  Stella)  cadentes."  The  comparison  of 
comets  to  lances  and  swords  was,  however,  in  the  Middle  Ages,  ve;y 
common  in  all  languages.  The  great  comet  of  1500,  which  was  visible 
from  April  to  June^  was  always  termed  by  the  Italian  writers  of  tliat 
time  il  Signor  Astone  (see  my  Exa77ien  Critique  de  V Hist,  de  la  Geo- 
graphic, t.  v.,  p.  80).  All  the  hypotheses  that  have  been  advanced  to 
show  that  Descartes  (Cassini,  p.  230 ;  Mairan,  p.  16),  and  even  Kepler 
(Delambre,  t.  i.,  p.  601),  were  acquainted  with  the  zodiacal  light,  ap-. 
pear  to  me  altogether  untenable.  Descartes  {Principes,  iii.,  art.  136, 
137)  is  very  obscure  in  his  remarks  on  comets,  observing  that  their 
tails  are  formed  "  by  oblique  I'ays,  which,  falling  on  different  parts  of 
the  planetary  orbs,  strike  the  eye  laterally  by  extraordinaiy  refraction," 
and  that  they  might  be  seen  morning  and  evening,  "like  a  long  beam," 
when  the  Sun  is  between  the  comet  and  the  Earth.  This  passage  no 
more  refers  to  the  zodiacal  light  than  those  in  which  Kepler  {Epit.  As 


140  COSMOS. 

enormous  tail  of  a  comet,  whose  head  was  concealed  in  the 
vapory  mist  of  the  horizon,  and  which,  from  its  length  and 
appearance,  presented  much  similarity  to  the  great  comet  of 
1843.  We  may  conjecture,  with  much  probability,  that  the 
remarkable  light  on  the  elevated  plains  of  Mexico,  seen  for 
forty  nights  consecutively  in  1509,  and  observed  in  the  eastern 
horizon  rising  pyramidally  from  the  earth,  was  the  zodiacal 
light.  I  found  a  notice  of  this  phenomenon  in  an  ancient  Az- 
tec MS.,  the  Codex  Telleriano-Reinensis*  preserved  in  the 
Royal  Library  at  Paris. 

This  phenomenon,  whose  primordial  antiquity  can  scarcely 
be  doubted,  and  which  was  first  noticed  in  Europe  by  Childrey 
and  Dominicus  Cassini,  is  not  the  luminous  solar  atmosphere 
itself,  since  this  can  not,  in  accordance  with  mechanical  laws, 
be  more  compressed  than  in  the  relation  of  2  to  3,  and  conse- 
quently can  not  be  diffused  beyond  g^ths  of  Mercury's  helio- 
centric distance.  These  same  laws  teach  us  that  the  altitude 
of  the  extreme  boundaries  of  the  atmosphere  of  a  cosmical 

tron.  Copernicance,  t.  i.,  p.  57,  and  t.  ii.,  p.  893)  speaks  of  the  existence 
of  a  solar  atmosphere  (limbus  circa  solem,  coma  lucida),  which,  in 
eclipses  of  the  Sun,  prevents  it  ''from  being  quite  night;"  and  even 
more  uncertain,  or  indeed  erroneous,  is  the  assumption  that  the  "  trabes 
quas  6oKovg  vocant"  (Plin.,  ii.,  2G  and  27)  had  reference  to  the  tongue- 
shaped  rising  zodiacal  light,  as  Cassini  (p.  231,  art.  xxxi.)  and  Mairan 
(p.  15)  have  maintained.  Everywhere  among  the  ancients  the  trabes 
are  associated  with  the  bolides  (ardores  et  faces)  and  other  fiery  mete- 
ors, and  even  with  long-barbed  comets.  ( Regarding  doKog,  doKiag, 
doKLTijg,  see  Schafer,  Schol.  Par.  ad  Apoll.  Rhod.,  1813,  t.  ii.,  p.  206; 
Pseudo-Aristot.,  de  Mimdo,  2,  9  ;  Comment.  Alex.  Joh.  Philop.  et  Olymp. 
in  Aristot.  Meteor.,  lib.  i.,  cap.  vii.,  3,  p.  195,  Ideler;  Seneca,  Nat. 
Quf£st.,  i.,  1.) 

*  Humboldt,  Monumens  des  Peuples  Indighies  de  V Amirique,  t.  ii.. 
p.  301.  The  rare  manuscnpt  which  belonged  to  the  Archbishop  of 
Rheims,  Le  Tellier,  contains  various  kinds  of  extracts  from  an  Azt^ 
ritual,  an  astrological  calendar,  and  historical  annals,  extending  from 
1197  to  1549,  and  embx'aciug  a  notice  of  different  natural  phenomena, 
epochs  of  earthquakes  and  comets  (as,  for  instance,  those  of  1490  and 
1529),  and  of  (which  are  important  in  relation  to  Mexican  chronology) 
solar  eclipses.  In  Camargo's  manusci-ipt  Historia  de  Tlascala,  the  light 
rising  in  the  east  almost  to  the  zenith  is,  singularly  enough,  described 
as  "  sparkling,  and  as  if  sown  with  stars."  The  description  of  this 
phenomenon,  which  lasted  forty  days,  can  not  in  any  way  apply  to  vol- 
canic eruptions  of  Popocatepetl,  which  lies  very  near,  in  tlie  southeast- 
ern direction.  (Prescott,  History  of  the  Conquest  of  Mexico,  vol.  i.,  p. 
284.)  Later  commentators  have  confounded  this  phenomenon,  which 
Montezuma  regarded  as  a  warning  of  his  misfortunes,  with  the  "  estrella 
que  huraeava"  (literally,  which  spring  forth ;  Mexican  choloa,  to  leap  or 
spring  forth).  With  respect  to  the  connection  of  this  vapor  with  the 
star  Citlal  Choloha  (Venus)  and  with  "  the  mountain  of  the  star"  (Cit- 
laltepetl, the  volcano  of  Orizaba),  see  my  Monumens,  t.  ii.,  p.  303. 


ZODIACAL    LIGHT.  141 

body  above  its  equator,  that  is  to  say,  the  point  at  which 
gravity  and  centrifugal  force  are  in  equilibrium,  must  be  the 
same  as  the  altitude  at  which  a  sateUite  would  rotate  round 
the  central  body  simultaneously  with  the  diurnal  revolution 
of  the  latter.*  This  Umitation  of  the  solar  atmosphere  in  its 
present  concentrated  condition  is  especially  remarkable  when 
we  compare  the  central  body  of  our  system  with  the  nucleus 
of  other  nebulous  stars.  Herschel  has  discovered  several,  in 
which  the  radius  of  the  nebulous  matter  surrounding  the  star 
appeared  at  an  angle  of  150".  On  the  assumption  that  the 
parallax  is  not  fully  equal  to  1",  we  find  that  the  outermost 
nebulous  layer  of  such  a  star  must  be  150  times  further  from 
the  central  body  than  our  Earth  is  from  the  Sun.  If,  there- 
fore, the  nebulous  star  were  to  occupy  the  place  of  our  Sun, 
its  atmosphere  would  not  only  include  the  orbit  of  Uranus, 
but  even  extend  eight  times  beyond  it.t 

Considering  the  narrow  limitation  of  the  Sun's  atmosphere, 
which  we  have  just  described,  we  may  with  much  probability 
regard  the  existence  of  a  very  compressed  annulus  of  nebulous 
matter,|  revolving  freely  in  space  between  the  orbits  of  Venus 
and  Mars,  as  the  material  cause  of  the  zodiacal  light.     As 

*  Laplace,  Expos,  du  Syst.  du  Monde,  p.  270  ;  M6canique  C6leste, 
t.  ii.,  p.  169  and  171;  Schubert,  Astr.,hd.  iii.,  §  206. 

t  Arago,  in  tlie  Annuaire,  1842,  p.  408.  Compare  Sir  John  Her- 
schel's  considerations  on  the  volume  and  faintness  of  li^ht  of  planetary 
nebulae,  in  Mary  Somerville's  Connection  of  the  Physical  Sciences,  1835, 
p.  108.  The  opinion  that  the  Sun  is  a  nebulous  star,  whose  atmos- 
phere presents  the  phenomenon  of  zodiacal  liglit,  did  not  originate  with 
Dominicus  Cassini,  but  was  first  promulgated  by  Mairan  in  1730  (  Traits 
de  VAurore  Bor.,  p.  47  and  263 ;  Arago,  in  the  Annuaire,  1842,  p. 
412).     It  is  a  renewal  of  Kepler's  views. 

X  Dominicus  Cassini  was  the  first  to  assume,  as  did  subsequently 
Laplace,  Schubert,  and  Poisson,  the  hypothesis  of  a  separate  ring  to 
explain  the  form  of  the  zodiacal  light.  He  says  distinctly,  "  If  the 
orbits  of  Mercury  and  Venus  were  visible  (throughout  their  whole  ex- 
tent), we  should  invariably  observe  them  with  the  same  figure  and  in 
the  same  position  with  regard  to  the  Sun,  and  at  the  same  time  of  the 
year  with  the  zodiacal  light."  {Mim.  de  I' Acad.,  t.  viii.,  1730,  p.  218, 
and  Biot,  in  the  Comptes  Rendus,  1836,  t.  iii.,  p.  666.)  Cassini  be- 
lieved that  the  nebulous  ring  of  zodiacal  light  consisted  of  innumerable 
small  planetary  bodies  revolving  round  the  Sun.  He  even  went  so 
far  as  to  believe  that  the  fall  of  fire-balls  might  be  connected  with  the 
passage  of  the  Earth  through  the  zodiacal  nebulous  ring.  Olmsted, 
and  especially  Biot  (op.  cit.,  p.  673),  have  attempted  to  establish  its 
connection  with  the  November  phenomenon — a  connection  which  01 
bers  doubts.  (Schum.,  Jahrb.,  1837,  s.  281.)  Regarding  the  question 
whether  the  place  of  the  zodiacal  light  perfectly  coincides  with  that 
of  the  Sun's  equator,  see  Houzeau,  in  Schum.,  Astr.  Nachr.,  1843.  No 
492,  s.  190. 


142  COSMOS. 

yet  we  certainly  know  nothing  definite  regarding  its  actual 
material  dimensions  ;  its  augmentation*  by  emanations  from 
the  tails  of  myriads  of  comets  that  come  within  the  Sun's 
vicinity;  the  singular  changes  affecting  its  expansion,  since  it 
sometimes  does  not  appear  to  extend  beyond  our  Earth's  orbit ; 
or,  lastly,  regarding  its  conjectural  intimate  connection  with 
the  more  condensed  cosmical  vapor  in  the  vicinity  of  the  Sun. 
The  nebulous  particles  composing  this  ring,  and  revolving 
round  the  Sun  in  accordance  with  planetary  laws,  may  either 
be  self-luminous  or  receive  light  from  that  luminary.  Even 
in  the  case  of  a  terrestrial  mist  (and  this  fact  is  very  remark- 
able), which  occurred  at  the  time  of  the  new  moon  at  mid- 
night in  1743,  the  phosphorescence  was  so  intense  that  ob- 
jects could  be  distinctly  recognized  at  a  distance  of  more  than 
600  feet. 

I  have  occasionally  been  astonished,  in  the  tropical  climates 
of  South  America,  to  observe  the  variable  intensity  of  the 
zodiacal  light.  As  I  passed  the  nights,  during  many  months, 
in  the  open  air,  on  the  shores  of  rivers  and  on  llanos,  I  enjoy- 
ed ample  opportunities  of  carefully  examining  this  phenome- 
non. When  the  zodiacal  light  had  been  most  intense,  I  have 
observed  that  it  would  be  perceptibly  weakened  for  a  few 
minutes,  until  it  again  suddenly  shone  forth  in  full  brilliancy. 
In  some  few  instances  I  have  thought  that  I  could  perceive — 
not  exactly  a  reddish  coloration,  nor  the  lower  portion  darkened 
in  an  arc-like  form,  nor  even  a  scintillation,  as  Mairan  affirms 
he  has  observed — but  a  kind  of  flickering  and  wavering  of 
the  light.f  Must  we  suppose  that  changes  are  actually  in 
progress  in  the  nebulous  ring  ]  or  is  it  not  more  probable  that, 
although  I  could  not,  by  my  meteorological  instruments,  de- 
tect any  change  of  heat  or  moisture  near  the  ground,  and 
small  stars  of  the  fifth  and  sixth  magnitudes  appeared  to  shine 
with  equally  undiminished  intensity  of  light,  processes  of  con- 
densation may  be  going  on  in  the  uppermost  strata  of  the  air, 
by  means  of  which  the  transparency,  or,  rather,  the  reflection 
of  light,  may  be  modified  in  some  peculiar  and  unknown  man- 

*  Sir  John  Herschel,  Astron.,  ^  487. 

t  Arago,  in  the  Annuaire,  1832,  p.  246.  Several  physical  facts  ap 
pear  to  indicate  that,  in  a  mechanical  separation  of  matter  into  its  small- 
est particles,  if  the  mass  be  very  small  in  relation  to  the  surface,  the 
electrical  tension  may  increase  sufficiently  for  the  production  of  light 
and  heat.  Experiments  with  a  large  concave  miiTor  have  not  hitherto 
given  any  positive  evidence  of  the  presence  of  radiant  heat  in  the  zo- 
diacal light.  (Lettre  de  M.  Matthiessen  a  M.  Arago,  in  the  Comptes 
Rendus,  t.  xvi.,  1843,  Avril,  p.  687.) 


ZODIACAL    LIGHT.  143 

ner  ?  An  assumption  of  the  existence  of  such  meteorological 
causes  on  the  confines  of  our  atmosphere  is  strengthened  by 
the  "  sudden  flash  and  pulsation  of  light,"  which,  according 
to  the  acute  observations  of  Olbers,  vibrated  for  several  sec- 
onds through  the  tail  of  a  comet,  v/hich  appeared  during  the 
continuance  of  the  pulsations  of  light  to  be  lengthened  by  sev- 
eral  degrees,  and  then  again  contracted.*  As,  however,  the 
separate  particles  of  a  comet's  tail,  measuring  millions  of  miles, 

*  "What  you  tell  me  of  the  changes  of  light  in  the  zodiacal  light, 
and  of  the  causes  to  which  you  ascribe  such  changes  within  the  trop- 
ics, is  of  the  greater  interest  to  me,  since  I  have  been  for  a  long  time 
past  particularly  attentive,  every  spring,  to  this  phenomenon  in  our 
northern  latitudes.     I,  too,  have  always  believed  that  the  zodiacal  light 
I'otated ;  but  I  assumed  (contrary  to  Poisson's  opinion,  w^hich  you  have 
communicated  to  me)  that  it  completely  extended  to  the  Sun,  with 
considerably  augmenting  brightness.     The  light  circle  which,  in  total 
solar  eclipses,  is  seen  suiTOunding  the  darkened  Sun,  I  have  regarded 
as  the  brightest  portion  of  the  zodiacal  light.     I  have  convinced  my 
self  that  this  light  is  very  different  in  different  years,  often  for  several 
successive  years  being  very  bright  and  diffused,  while  in  other  years 
it  is  scarcely  perceptible.     I  think  that  I  find  the  first  trace  of  an  allu- 
sion to  the  zodiacal  light  in  a  letter  from  Rothmann  toTycho,  in  which 
he  mentions  that  in  spring  he  has  observed  the  twilight  did  not  close 
until  the  sun  was  24*^  below  the  horizon.     Rothmann  must  certainly 
have  confounded  the  disappeai'ance  of  the  setting  zodiacal  light  in  the 
vapors  of  the  western  horizon  with  the  actual  cessation  of  twilight.     I 
have  failed  to  observe  the  pulsations  of  the  light,  probably  on  account 
of  the  faintness  with  which  it  appears  in  these  countries.     You  are, 
however,  certainly  right  in  ascribing  those  rapid  vainalions  in  the  light 
of  the  heavenly  bodies,  which  you  have  perceived  in  tropical  climates, 
to  our  own  atmosphere,  and  especially  to  its  higher  regions.     This  is 
most  strikingly  seen  in  the  tails  of  large  comets.     We  often  observe, 
especially  in  tlie  clearest  weather,  that  these  tails  exhibit  pulsations, 
commencing  from  the  head,  as  being  the  lowest  part,  and  vibrating  in 
one  or  two  seconds  tln-ough  the  entire  tail,  which  thus  appears  rapidly 
to  become  some  degrees  longer,  but  again  as  rapidly  contracts.     That 
these   undulations,  which  were  formerly   noticed  with   attention  by 
Robert  Hooke,  and  in  more  recent  times  by  Schroter  and  Chladni,  do 
not  actnally  occur  in  the  tails  of  the  comets,  but  are  produced  by  our  at- 
mosphere, is  obvious  when  we  recollect  that  the  individual  parts  of 
those  tails  (which  ai'e  many  millions  of  miles  in  length)  lie  at  very  dif- 
ferent distances  from  us,  and  that  the  light  from  their  extreme  points 
can  only  reach  us  at  intervals  of  time  which  differ  several  minutes  from 
one  another.     Whether  what  you  saw  on  the  Orinoco,  not  at  intervals 
of  seconds,  but  of  minutes,  were  actual  coruscations  of  the  zodiacal 
light,  or  whether  they  belonged  exclusively  to  the  upper  strata  of  our 
atmosphere,  I  will  not  attempt  to  decide ;  neither  can  I  explain  the 
remarkable  lightness  of  whole  nights,  nor  the  anomalous  augmentation 
and  prolongation  of  the  twilight  in  the  year  1831,  particularly  if,  as  has 
been  remarked,  the  lightest  part  of  these  singular  twilights  did  not  coin- 
cide with  the  Sun's  place  below  the  horizon."     (From  a  letter  wr'tten 
by  Dr.  Olbers  to  myself,  and  dated  Bremen,  March  26th.  1833.) 


144  COSMOS. 

are  verj'  unequally  distant  from  the  earth,  it  is  not  possible, 
according  to  the  laws  of  the  velocity  and  transmission  of  light, 
that  we  should  be  able,  in  so  short  a  period  of  time,  to  per- 
ceive any  actual  changes  in.  a  cosmical  body  of  such  vast  ex- 
tent. These  considerations  in  no  way  exclude  the  reality  of 
the  change^  that  have  been  observed  in  the  emanations  from 
the  more  condensed  envelopes  around  the  nucleus  of  a  comet, 
nor  that  of  the  sudden  irradiation  of  the  zodiacal  light  from 
internal  molecular  motion,  nor  of  the  increased  or  diminished 
reflection  of  light  in  the  cosmical  vapor  of  the  luminous  ring, 
but  should  simply  be  the  means  of  drawing  our  attention  to 
the  differences  existing  between  that  which  appertains  to  the 
air  of  heaven  (the  realms  of  universal  space)  and  that  which 
belongs  to  the  strata  of  our  terrestrial  atmosphere.  It  is  not 
possible,  as  well-attested  facts  prove,  perfectly  to  explain  the 
operations  at  work  in  the  much-contested  upper  boundaries  of 
our  atmosphere.  The  extraordinary  lightness  of  whole  nights 
in  the  year  1831,  during  which  small  print  might  be  read  at 
midnight  in  the  latitudes  of  Italy  and  the  north  of  Germany, 
is  a  fact  directly  at  variance  with  all  that  we  know,  accord- 
ing to  the  most  recent  and  acute  researches  on  the  crepuscular 
theory,  and  of  the  height  of  the  atmosphere.^  The  phenom- 
ena of  light  depend  upon  conditions  still  less  understood,  and 
their  variability  at  twilight,  as  well  as  in  the  zodiacal  light, 
excite  our  astonishment. 

We  have  hitherto  considered  that  which  belongs  to  our  solar 
system — that  world  of  material  forms  governed  by  the  Sun — 
which  includes  the  primary  and  secondary  planets,  comets  of 
short  and  long  periods  of  revolution,  meteoric  asteroids,  which 
move  thronged  together  in  streams,  either  sporadically  or  in 
closed  rings,  and  finally  a  luminous  nebulous  ring,  that  re- 
volves round  the  Sun  in  the  vicinity  of  the  Earth,  and  for 
which,  owing  to  its  position,  we  may  retain  the  name  of  zo- 
diacal light.  Every  where  the  law  of  periodicity  governs  the 
motions  of  these  bodies,  however  different  may  be  the  amount 
of  tangential  velocity,  or  the  quantity  of  their  agglomerated 
material  parts  ;  the  meteoric  asteroids  which  enter  our  atmos- 
phere from  the  external  regions  of  universal  space  are  alone 
arrested  in  the  course  of  their  planetary  revolution,  and  re- 
tained within  the  sphere  of  a  larger  planet.  In  the  solar  sys- 
tem, whose  boundaries  determine  the  attractive  force  of  the 
central  body,  comets  are  made  to  revolve  in  their  elliptical 

*  Biot,  TraiU  d'Asiron.  Physique,  3eme  ed.,  1841,  t.  i.,  p.  171,  238. 
and  312. 


TRANSLATORY    MOTION    OF   THE    SOLAR    SYSTEM.     145 

orbits  at  a  distance  44  times  greater  than  that  of  Uranus ; 
nay,  in  those  comets  whose  nucleus  appears  to  us,  from  its 
inconsiderable  mass,  like  a  mere  passing  cosmical  cloud,  the 
Sun  exercises  its  attractive  force  on  the  outermost  parts  of  the 
emanations  radiating  from  the  tail  over  a  space  of  many  mill- 
ions of  miles.  Central  forces,  therefore,  at  once  constitute  and 
maintain  the  system. 

Our  Sun  may  be  considere'l  as  at  rest  when  compared  to  all 
the  large  and  small,  dense  and  almost  vaporous  cosmical  bodies 
that  appertain  to  and  revolve  around  it ;  but  it  actually  ro- 
tates round  the  common  center  of  gravity  of  the  whole  sys- 
tem, which  occasionally  falls  within  itself,  that  is  to  say,  re- 
mains within  the  material  circumference  of  the  Sun,  what- 
ever changes  may  be  assumed  by  the  positions  of  the  planets. 
A  very  different  phenomenon  is  that  presented  by  the  trans- 
latory  motion  of  the  Sun,  that  is,  the  progressive  motion  of 
the  center  of  gravity  of  the  whole  solar  system  in  universal 
space.  Its  velocity  is  such*  that,  according  to  Bessel,  the 
relative  motion  of  the  Sun,  and  that  of  6 1  Cygni,  is  not  less 
m  one  day  than  3,336,000  geographical  miles.  This  change 
of  the  entire  solar  system  would  remain  unknown  to  us,  if  the 
admirable  exactness  of  our  astronomical  instruments  of  meas- 
urement, and  the  advancement  recently  made  in  the  art  of 
observinff,  did  not  cause  our  advance  toward  remote  stars  to 
be  perceptible,  like  an  approximation  to  the  objects  of  a  dis- 
tant shore  in  apparent  motion.  The  proper  motion  of  the  star 
6 1  Cygni,  for  instance,  is  so  considerable,  that  it  has  amount- 
ed to  a  whole  degree  in  the  course  of  700  years. 

The  amount  or  quantity  of  these  alterations  in  the  fixed 
stars  (that  is  to  say,  the  changes  in  the  relative  position  of 
self-luminous  stars  toward  each  other),  can  be  determined 
with  a  greater  degree  of  certainty  than  we  are  able  to  attach 
to  the  genetic  explanation  of  the  phenomenon.  After  taking 
into  consideration  what  is  due  to  the  precession  of  the  equi- 
noxes, and  the  nutation  of  the  earth's  axis  produced  by  the 
action  of  the  Sun  and  Moon  on  the  spheroidal  figure  of  our 
globe,  and  what  may  be  ascribed  to  the  transmission  of  light, 
that  is  to  say,  to  its  aberration,  and  to  the  parallax  formed  by 
the  diametrically  opposite  position  of  the  Earth  in  its  course 
round  the  Sun,  we  still  find  that  there  is  a  residual  portion 

*  Bessel,  in  Schura.,  Jalirh.fur  1839,  s.  51;  probably  four  millions 
of  miles  daily,  iu  a  relative  velocity  of  at  the  least  3,336,000  miles,  or 
more  than  double  the  velocity  of  revolution  of  the  Earth  in  her  orbit 
round  the  Sun. 
Vol.  I.— G 


1  46  COd.MOS. 

of  the  annual  motion  of  the  fixed  stars  due  to  the  translatiou 
of  thy  whole  solar  system  in  universal  space,  and  to  the  true 
proper  motion  of  the  stars.  The  difficult  problem  of  numer- 
ically separating  these  two  elements,  the  true  and  the  appar- 
ent motion,  has  been  effected  by  the  careful  study  of  the  di- 
rection of  the  motion  of  certain  individual  stars,  and  by  the 
consideration  of  the  fact  that,  if  all  the  stars  were  in  a  state 
of  absolute  rest,  they  would  appear  perspectively  to  recede 
from  the  point  in  space  toward  which  the  Sun  was  directing 
its  course.  But  the  ultimate  result  of  this  investigation,  con- 
firmed by  the  calculus  of  probabilities,  is,  that  our  solar  sys- 
tem and  the  stars  both  change  their  places  in  space.  Accord- 
ing to  the  admirable  researches  of  Argelander  at  Abo,  who 
has  extended  and  more  perfectly  developed  the  work  begun  by 
William  Herschel  and  Prevost,  the  Sun  moves  in  the  direc- 
tion of  the  constellation  Hercules,  and  probably,  from  the 
combination  of  the  observations  made  of  537  stars,  toward  a 
point  lying  (at  the  equinox  of  1792-5)  at  257°  49'-7  R.A.,  and 
28°  49''7  N.D.  It  is  extremely  difficult,  in  investigations  of 
this  nature,  to  separate  the  absolute  from  the  relative  motion, 
and  to  determine  what  is  alone  owing  to  the  solar  system.* 

If  we  consider  the  proper,  and  not  the  perspective  motions 
of  the  stars,  we  shall  find  many  that  appear  to  be  distributed 
in  groups,  having  an  opposite  direction  ;  and  facts  hitherto 
observed  do  not,  at  any  rate,  render  it  a  necessary  assumption 
that  all  parts  of  our  starry  stratum,  or  the  whole  of  the  stellar 
islands  filling  space,  should  move  round  one  large  unknown 
luminous  or  non-luminous  central  body.  The  tendency  of  the 
human  mind  to  investigate  ultimate  and  highest  causes  cer- 
tainly inclines  the  intellectual  activity,  no  less  than  the  imag- 
ination of  mankind,  to  adopt  such  an  hypothesis.  Even  the 
Stagirite  proclaimed  that  "  every  thing  which  is  moved  must 
be  referable  to  a  motor,  and  that  there  would  be  no  end  to 


*  Regarding  the  motion  of  the  solar  system,  according  to  Bradley, 
Tobias  Mayer,  Lambert,  Lalaude,  and  William  Herschel,  see  Arago,iu 
the  Anmiaire,  1842,  p.  388-399;  Argelander,  in  Schum.,  Asfron.  Nachr., 
No.  363,  364,  398,  and  in  the  treatise  Voti  der  eigcnen  Bewegnng  des 
Soymensy stems  (On  the  proper  Motion  of  the  Solar  System),  1837,  s.  43, 
respecting  Perseus  as  the  central  body  of  the  whole  stellar  stratum, 
likewise  Otho  Struve,  in  the  Bull,  de  V Acad,  de  St.  Petersh.,  1842,  t.  x., 
No.  9,  p.  137-139.  The  last-named  astronomer  has  found,  by  a  more 
recent  combination,  261^  23'  R.A.4-37°  36'  Decl.  for  the  direction  of 
the  Sun's  motion;  and,  taking  the  mean  of  his  own  results  with  that  of 
Argelander,  we  have,  by  a  combination  of  797  stars,  the  formula  259" 
3'  R.A.  4-  34°  36'  Decl. 


TRANSLATORY    MOTION.  14T 

the  concatenation  of  causes  if  there  were  not  one  primordiai 
immovable  motor."* 

The  manifold  translatory  changes  of  the  stars,  not  those 
produced  by  the  parallaxes  at  which  they  are  seen  from  the 
changing  position  of  the  spectator,  but  the  true  changes  con- 
stantly going  on  in  the  regions  of  space,  afford  us  incontro- 
vertible evidence  of  the  dominion  of  the  laws  of  attraction  in 
the  remotest  regions  of  space,  beyond  the  limits  of  our  solar 
system.  The  existence  of  these  laws  is  revealed  to  us  by 
many  phenomena,  as,  for  instance,  by  the  motion  of  double 
stars,  and  by  the  amount  of  retarded  or  accelerated  motion  in 
different  parts  of  their  elliptic  orbits.  Human  inquiry  need 
no  longer  pursue  this  subject  in  the  domain  of  vague  conjec- 
ture, or  amid  the  undefined  analogies  of  the  ideal  world  ;  for 
even  here  the  progress  made  in  the  method  of  astronomical 
observations  and  calculations  has  enabled  astronomy  to  take 
up  its  position  on  a  firm  basis.  It  is  not  only  the  discovery 
of  the  astounding  numbers  of  double  and  multiple  stars  re- 
volving round  a  center  of  gravity  lying  ivitliout  their  system 
(2800  such  systems  having  been  discovered  up  to  1837),  but 
rather  the  extension  of  our  knowledge  regarding  the  funda- 
mental forces  of  the  whole  material  world,  and  the  proofs  we 
have  obtained  of  the  universal  empire  of  the  laws  of  attrac- 
tion, that  must  be  ranked  among  the  most  brilliant  discoveries 
of  the  age.  The  periods  of  revolution  of  colored  stars  present 
the  greatest  differences ;  thus,  in  some  instances,  the  period 
extends  to  43  years,  as  in  7\  of  Corona,  and  in  others  to  sev- 
eral thousands,  as  in  66  of  Cetus,  38  of  Gemini,  and  100  of 
Pisces.  Since  Herschel's  measurements  in  1782,  the  satellite 
of  the  nearest  star  in  the  triple  system  of  ^  of  Cancer  has  com- 
pleted more  than  one  entire  revolution.  By  a  skillful  com- 
bination of  the  altered  distances  and  angles  of  position,!  the 
elements  of  these  orbits  may  be  found,  conclusions  drawn  re- 
garding the  absolute  distance  of  the  double  stars  from  the 
Earth,  and  comparisons  made  between  their  mass  and  that 
of  the  Sun,  Whether,  however,  here  and  in  our  solar  sys- 
tem, quantity  of  matter  is  the  only  standard  of  the  amount 
of  attractive  force,  or  whether  specific  forces  of  attraction  pro- 
portionate to  the  mass  may  not  at  the  same  time  come  into 
operation,  as  Bessel  was  the  first  to  conjecture,  are  questions 

*  Aristot.,  de  Caelo,  iii.,  2,  p.  301,  Bekker ;  Phys.,  viii.,  5,  p.  256. 

t  Savary,  in  the  Connaissance  des  Terns,  1830,  p.  56  and  163.  Encke, 
Berl.  Jahrb..  1832,  s.  253,  &c.  Arago,  in  the  Annuaire,  1834,  p.  260 
295.    John  Herschel,  in  the  Memoirs  of  the  Astronom.  Soc,  vol.  v.,  p.  17 1 


148  COSMOS. 

whose  practical  solution  must  be  left  to  future  ages.*  When 
we  compare  our  Sun  with  the  other  fixed  stars,  that  is,  with  oth 
er  self-luminous  Suns  in  the  lenticular  starry  stratum  of  which 
our  system  forms  a  part,  we  find,  at  least  in  the  case  of  some, 
that  channels  are  opened  to  us,  which  may  lead,  at  all  events, 
to  an  approximate  and  limited  knowledge  of  their  relative 
distances,  volumes,  and  masses,  and  of  the  velocities  of  their 
translatory  motion.  If  we  assume  the  distance  of  Uranus 
from  the  Sun  to  be  nineteen  times  that  of  the  Earth,  that  is 
to  say,  nineteen  times  as  great  as  that  of  the  Sun  from  the 
Earth,  the  central  body  of  our  planetary  system  will  be  11, 900 
times  the  distance  of  Uranus  from  the  star  a  in  the  constella- 
tion Centaur,  almost  31,300  from  61  Cygni,  and  41,600  from 
Vega  in  the  constellation  Lyra.  The  comparison  of  the  vol- 
ume of  the  Sun  with  that  of  the  fixed  stars  of  the  first  mag- 
nitude  is  dependent  upon  the  apparent  diameter  of  the  latter 
bodies — an  extremely  uncertain  optical  element.  If  even  we 
assume,  with  Herschel,  that  the  apparent  diameter  of  Arctu- 
rus  is  only  a  tenth  part  of  a  second,  it  still  follows  that  the 
true  diameter  of  this  star  is  eleven  times  greater  than  that  of 
the  Sun.f  The  distance  of  the  star  61  Cygni,  made  known 
by  Bessel,  has  led  approximately  to  a  knowledge  of  the  quan- 
tity of  matter  contained  in  this  body  as  a  double  star.  Not- 
withstanding that,  since  Bradley's  observations,  the  portion 
of  the  apparent  orbit  traversed  by  this  star  is  not  sufficiently 
great  to  admit  of  our  arriving  with  perfect  exactness  at  the 
true  orbit  and  the  major  axis  of  this  star,  it  has  been  conjec- 
tured with  much  probability  by  the  great  Konigsberg  astron- 
omer,t  "  that  the  mass  of  this  double  star  can  not  be  very  con- 
siderably larger  or  smaller  than  half  of  the  mass  of  the  Sun." 
This  result  is  from  actual  measurement.  The  analogies  de- 
duced from  the  relatively  larger  mass  of  those  planets  in  our 
solar  system  that  are  attended  by  satellites,  and  from  the  fact 
that  Struve  has  discovered  six  times  more  double  stars  among 

*  Bessel,  Untersuchung.  des  Theils  der  planetaHschen  Storungen, 
welcke  aus  der  Betcegumg  der  Sonne  entsieken  (An  Investigation  of  the 
portion  of  the  Planetary  Disturbances  depending  on  the  Motion  of  the 
Sun)  in  Abh.  der  Berl.  Akad.  der  Wissensch.,  1824  (Mathem.  Classe), 
8.  2-6.  The  question  has  been  raised  by  John  Tobias  Mayer,  in  Com- 
ment. Soc.  Reg.  Gotting.,  1804-1808,  vol.  xvi.,  p.  31-68. 

t  Fkilos.  Trans,  for  1803,  p.  225.  Arago,  in  the  Annuaire,  1842,  p. 
375.  In  order  to  obtain  a  clearer  idea  of  the  distances  ascribed  in  a 
rather  earlier  part  of  the  text  to  the  fixed  stars,  let  us  assume  that  the 
Earth  is  a  distance  of  one  foot  from  the  Sun;  Uranus  is  then  19  feet, 
and  Vega  Lyrae  is  158  geographical  miles  from  it. 

X  Bessel,  in  Schum.,  Jahrb.,  1839,  s.  53. 


TRANSLATORY    MOTION.  l49 

the  brighter  than  among  the  telescopic  fixed  stars,  have  led 
other  astronomers  to  conjecture  that  the  average  mass  of  the 
larger  number  of  the  binary  stars  exceeds  the  mass  of  the 
Sun.*  We  are,  however,  far  from  having  arrived  at  general 
results  regarding  this  subject.  Our  Sun,  according  to  Arge- 
lander,  belongs,  with  reference  to  proper  motion  in  space,  to 
the  class  of  rapidly-moving  fixed  stars. 

The  aspect  of  the  starry  heavens,  the  relative  position  of 
stars  and  nebulse,  the  distribution  of  their  luminous  masses, 
the  picturesque  beauty,  if  I  may  so  express  myself,  of  the 
whole  firmament,  depend  in  the  course  of  ages  conjointly  upon 
the  proper  motion  of  the  stars  and  nebulse,  the  translation  of 
our  solar  system  in  space,  the  appearance  of  new  stars,  and 
the  disappearance  or  sudden  diminution  in  the  intensity  of  the 
light  of  others,  and,  lastly  and  specially,  on  the  changes  which 
the  Earth's  axis  experiences  from  the  attraction  of  the  Sun 
and  Moon.  The  beautiful  stars  in  the  constellation  of  the 
Centaur  and  the  Southern  Cross  will  at  some  future  time  be 
visible  in  our  northern  latitudes,  while  other  stars,  as  Sirius 
and  the  stars  in  the  Belt  of  Orion,  will  in  their  turn  disappear 
below  the  horizon.  The  places  of  the  North  Pole  will  suc- 
cessively be  indicated  by  the  stars  (3  and  a  Cephei,  and  6  Cygni, 
until  after  a  period  of  12,000  years,  Vega  in  Lyra  will  shine 
forth  as  the  brightest  of  all  possible  pole  stars.  These  data 
give  us  some  idea  of  the  extent  of  the  motions  which,  divided 
into  infinitely  small  portions  of-  time,  proceed  without  inter- 
mission in  the  great  chronometer  of  the  universe.  If  for  a 
moment  we  could  yield  to  the  power  of  fancy,  and  imagine 
the  acuteness  of  our  visual  organs  to  be  made  equal  with  the 
extremest  bounds  of  telescopic  vision,  and  bring  together  that 
which  is  now  divided  by  long  periods  of  time,  the  apparent 
rest  that  reigns  in  space  would  suddenly  disappear.  We 
should  see  the  countless  host  of  fixed  stars  movinor  in  throngfed 
groups  in  difierent  directions ;  nebulse  w^andering  through 
space,  and  becoming  condensed  and  dissolved  like  cosmical 
clouds  ;  the  vail  of  the  Milky  Way  separated  and  broken  up 
in  many  parts,  and  motion  ruling  supreme  in  every  portion  of 
the  vault  of  heaven,  even  as  on  the  Earth's  surface,  where  we 
see  it  unfolded  in  the  germ,  the  leaf,  and  the  blossom,  the  or 
ganisms  of  the  vegetable  world.  The  celebrated  Spanish  bot 
anist  Cavanilles  was  the  first  who  entertained  the  idea  of 
"  seeing  grass  grow,"  and  he  directed  the  horizontal  microme- 
ter threads  of  a  powerfully  magnifying  glass  at  one  time  to 
*  Madler,  Astron.,  s.  476;  also  in  Schum..  Jahrb.,  1839,  s.  9.5. 


150  COSMOS. 

the  apex  of  the  shoot  of  a  bambusa,  and  at  another  on  the 
rapidly-growing  stem  of  an  American  aloe  [Agave  Americmia), 
precisely  as  the  astronomer  places  his  cross  of  net- work  against 
a  culminating  star.  In  the  collective  life  of  physical  nature, 
in  the  organic  as  in  the  sidereal  world,  all  things  that  have 
been,  that  are,  and  will  be,  are  alike  dependent  on  motion. 

The  breaking  up  of  the  Milky  Way,  of  which  I  have  just 
spoken,  requires  special  notice.  William  Herschel,  our  safe 
and  admirable  guide  to  this  portion  of  the  regions  of  space, 
has  discovered  by  his  star-guagings  that  the  telescopic  breadth 
of  the  Miiky  Way  extends  from  six  to  seven  degrees  beyond 
what  is  indicated  by  our  astronomical  maps  and  by  the  extent 
of  the  sidereal  radiance  visible  to  the  naked  eye.*  The  two 
brilliant  nodes  in  which  the  branches  of  the  zone  unite,  in  the 
region  of  Cepheus  and  Cassiopeia,  and  in  the  vicinity  of  Scor- 
pio and  Sagittarius,  appear  to  exercise  a  powerful  attraction 
on  the  contiguous  stars  ;  in  the  most  brilliant  part,  however, 
between  /3  and  y  Cj^gni,  one  half  of  the  330,000  stars  that 
have  been  discovered  in  a  breadth  of  5^  are  directed  toward 
one  side,  and  the  remainder  to  the  other.  It  is  in  this  part 
that  Herschel  supposes  the  layer  to  be  broken  up.f  The  num- 
ber of  telescopic  stars  in  the  Milky  Way  uninterrupted  by  any 
nebulEe  is  estimated  at  18  millions.  In  order,  I  will  not  say, 
to  realize  the  greatness  of  this  number,  but,  at  any  rate,  to 
compare  it  with  something  analogous,  I  will  call  attention  to 
the  fact  that  there  are  not  in  the  whole  heavens  more  than 
about  8000  stars,  between  the  first  and  the  sixth  magnitudes, 
visible  to  the  naked  eye.  The  barren  astonishment  excited 
by  numbers  and  dimensions  in  space,  when  not  considered 
with  reference  to  applications  engaging  the  mental  and  per- 
ceptive powers  of  man,  is  awakened  in  both  extremes  of  the 
universe,  in  the  celestial  bodies  as  in  the  minutest  animal- 
cules.$  A  cubic  inch  of  the  polishing  slate  of  Bilin  contains, 
according  to  Ehrenberg,  40,000  millions  of  the  silicious  shells 
of  GalionellsB. 

The  stellar  Milky  Way,  in  the  region  of  which,  according  to 
Argelander's  admirable  observations,  the  brightest  stars  of  the 
firmament  appear  to  be  congregated,  is  almost  at  right  angles 

*  Sir  William  Herschel,  in  the  Pkilos.  Transact,  for  1817,  Part  ii. 
p.  328.  t  Arago,  in  the  Anmiaire,  1842,  p.  459. 

X  Sir  JoliQ  Herschel,  in  a  letter  from  Feldhuysen,  dated  Jan.  13th, 
1836.  Nicholl,  Architecture  of  the  Heavens,  1838,  p.  22.  (See,  also, 
some  separate  notices  by  Sir  William  Herschel  on  the  starless  space 
which  separates  us  by  a  great  distance  from  the  Milky  Way,  in  the 
Philos.  Transact,  for  1817,  Part  ii.,  p.  328.) 


THK    MII.lvV    WAV.  151 

with  another  Milky  Way,  composed  of  nebulai.  The  Ibrmer 
constitutes,  according  to  Sir  J  ohn  Herschel's  views,  an  annu- 
lus,  that  is  to  say,  an  independent  zone,  somewhat  remote  from 
our  lenticular-shaped  starry  stratum,  and  similar  to  Saturn's 
ring.  Our  planetary  system  lies  in  an  eccentric  direction, 
nearer  to  the  region  of  the  Cross  than  to  the  diametrically  op- 
posite point,  Cassiopeia.*  An  imperfectly  seen  nebulous  spot, 
discovered  by  Messier  in  1774,  appeared  to  present  a  remark- 
able similarity  to  the  form  of  our  starry  stratum  and  the  divided 
ring  of  our  Milky  Way.t  The  Milky  V/ay  composed  of  neb- 
ula; does  not  belong  to  our  starry  stratum,  but  surrounds  it  at 
a  great  distance  without  being  physically  connected  with  it, 
passing  ahiiost  in  the  form  of  a  large  cross  through  the  dense 
nebulae  of  Virgo,  especially  in  the  northern  wing,  through 
Comae  Berenicis,  Ursa  Major,  Andromeda's  girdle,  and  Pisces 
Boreales.  It  probably  intersects  the  stellar  Milky  Way  in 
Cassiopeia,  and  connects  its  dreary  poles  (rendered  starless  from 
the  attractive  forces  by  which  stellar  bodies  are  made  to  ag- 
glomerate into  groups)  in  the  least  dense  portion  of  the  starry 
stratum. 

We  see  from  these  considerations  that  our  starry  cluster, 
which  bears  traces  in  its  projecting  branches  of  having  been 
subject  in  the  course  of  time  to  various  metamorphoses,  and 
evinces  a  tendency  to  dissolve  and  separate,  owing  to  second- 
ary centers  of  attraction — is  surrounded  by  two  rings,  one  of 
which,  the  nebulous  zone,  is  very  remote,  while  the  other  is 
nearer,  and  composed  of  stars  alone.  The  latter,  which  wo 
generally  term  the  Milky  Way,  is  composed  of  nebulous  stars, 
avera^ino-  from  the  tenth  to  the  eleventh  degree  of  magni- 
tude,|  but  appearing,  when  considered  individually,  of  very 
difierent  magnitudes,  while  isolated  starry  clusters  (starry 
swarms)  almost  always  exhibit  throughout  a  character  of 
great  uniformity  in  magnitude  and  brilliancy. 

In  whatever  part  the  vault  of  heaven  has  been  pierced  by 
powerful  and  far-penetrating  telescopic  instruments,  stars  or 
luminous  nebulss  are  every  where  discoverable,  the  former,  in 

*  Sir  John  Herschel,  Astronom..,  §  624;  likewise  in  his  Obsei'vations 
■)n  Nebulceand  Clusters  of  Stars  {Phil.  Transact. ^  1833,  Part  ii.,p.  479, 
fig.  25) :  "  We  have  here  a  brother  system,  bearing  a  real  physical  re 
jemblauce  and  strong  analogy  of  structure  to  our  own." 

t  Sir  William  Herschel,  in  the  Phil.  Trans,  for  1785,  Part  i.,  p.  257. 
Sir  .John  Herschel,  Astron.,  $  61G.  ("  The  nebulous  region  of  the  heav- 
ens forms  a  nebulous  Milky  Way,  composed  of  distinct  uebulse,  as  the 
other  of  stars."  The  same  observation  was  made  in  a  letter  he  addressed 
to  mfi  in  March.  1829.)  t  Sir  John  Herschel,  Astron.,  $  585. 


152  COSMOS. 

Bome  cases,  not  exceeding  the  twentieth  or  twenty-fourth  de 
gree  of  telescopic  magnitude.  A  portion  of  the  nebulous  vapoi 
would  probably  be  found  resolvable  into  stars  by  more  power 
ful  optical  instruments.  As  the  retina  retains  a  less  vivid  im- 
pression of  separate  than  of  infinitely  near  luminous  points, 
less  strongly  marked  photometric  relations  are  excited  in  the 
latter  case,  as  Arago  has  recently  shown.*  The  definite  or 
amorphous  cosmical  vapor  so  universally  diffused,  and  which 
generates  heat  through  condensation,  probably  modifies  the 
transparency  of  the  universal  atmosphere,  and  diminishes  that 
uniform  intensity  of  light  which,  according  to  Halley  and  Gi- 
bers, should  arise,  if  every  point  throughout  the  depths  of  space 
were  filled  by  an  infinite  series  of  stars. f  The  assumption  of 
such  a  distribution  in  space  is,  however,  at  variance  with  ob- 
servation,  which  shows  us  large  starless  regions  of  space,  02:)en- 
ings  in  the  heavens,  as  William  Herschel  terms  them — one, 
four  degrees  in  width,  in  Scorpio,  and  another  in  Serpentari- 
us.  In  the  vicinity  of  both,  near  their  margin,  we  find  un- 
resolvable  nebulae,  of  which  that  on  the  western  edge  of  the 
opening  in  Scorpio  is  one  of  the  most  richly  thronged  of  the 
clusters  of  small  stars  by  which  the  firmament  is  adorned. 
Herschel  ascribes  these  openings  or  starless  regions  to  the  at- 
tractive and  agglomerative  forces  of  the  marginal  groups. $ 
"  They  are  parts  of  our  starry  stratum,"  says  he,  with  his 
usual  graceful  animation  of  style,  "  that  have  experienced 
great  devastation  from  time."  If  we  picture  to  ourselves  the 
telescopic  stars  lying  behind  one  another  as  a  starry  canopy 
spread,  over  the  vault  of  heaven,  these  starless  regions  in  Scor- 
pio and  Serpentarius  may,  I  think,  be  regarded  as  tubes 
through  which  we  may  look  into  the  remotest  depths  of  space. 
Other  stars  may  certainly  lie  in  those  parts  where  the  strata 
forming  the  canopy  are  interrupted,  but  these  are  unattainable 
by  our  instruments.  The  aspect  of  fiery  meteors  had  led  the 
ancients  likewise  to  the  idea  of  clefts  or  openings  [cJiasmata) 
in  the  vault  of  heaven.  These  openings  were,  however,  only 
regarded  as  transient,  while  the  reason  of  their  being  luminous 
and  fiery,  instead  of  obscure,  was  supposed  to  be  owing  to  the 

*  Arago,  iu  the  Annuaire,  1842,  p.  282-285,  409-411,  and  439-442. 

t  Olbers,  on  the  transparency  of  celestial  space,  in  Bode's  Jalirh., 
1826,  s.  110-121. 

X  "  An  opening  in  the  heavens,"  William  Hersche],in  the  Phil.  Trans. 
for  1785,  vol.  Ixxv.,  Part  i.,  p.  256.  Le  Fran9ais  Lalande,  in  the  Con- 
naiss.  des  Terns  pour  V An.  VIII.,  p.  383.  Arago,  in  the  Annuaire, 
1842,  p.  425. 


STARLESS    OPENINGS.  153 

translucent  illuminated  ether  which  lay  beyond  them.*  Der- 
ham,  and  even  Huygens,  did  not  appear  disinclined  to  explain 
in  a  similar  manner  the  mild  radiance  of  the  nebuleB.f 

When  we  compare  the  stars  of  the  first  magnitude,  which, 
on  an  average,  are  certainly  the  nearest  to  us,  with  the  non- 
nebulous  telescopic  stars,  and  further,  when  we  compare  the 
nebulous  stars  with  unresolvable  nebulae,  for  instance,  with 
the  nebula  in  Andromeda,  or  even  with  the  so-called  planetary 
nebulous  vapor,  a  fact  is  made  manifest  to  us  by  the  consider- 
ation of  the  varying  distances  and  the  boundlessness  of  space, 
which  shows  the  world  of  phenomena,  and  that  which  con- 
stitutes its  causal  reality,  to  be  dependent  upon  the  ])ropaga- 
tion  of  light.  The  velocity  of  this  propagation  is,  according 
to  Struve's  most  recent  investigations,  166,072  geographical 
miles  in  a  second,  consequently  almost  a  million  of  times 
greater  than  the  velocity  of  sound.  According  to  the  meas- 
urements of  Maclear,  Bessel,  and  Struve,  of  the  parallaxes 
and  distances  of  three  fixed  stars  of  very  unequal  magnitudes 
{a  Centauri,  16  Cygni,  and  a  Lyrse),  a  ray  of  light  requires 
respectively  3,  9^^.  and  12  years  to  reach  us  from  these  three 
bodies.  In  the  short  but  memorable  period  between  1572 
and  1604,  from  the  time  of  Cornelius  Gemma  and  Tycho 
Brahe  to  that  of  Kepler,  three  new  stars  suddenly  appeared 
in  Cassiopeia  and  Cygnus,  and  in  the  foot  of  Serpentarius. 
A  similar  phenomenon  exhibited  itself  at  intervals  in  1670,  in 
the  constellation  Vulpis.  In  recent  times,  even  since  1837, 
Sir  John  Herschel  has  observed,  at  the  Cape  of  Good  Hope, 
the  brilliant  star  r\  in  Argo  increase  in  splendor  from  the 
second  to  the  first  magnitude  4  These  events  in  the  universe 
belong,  however,  with  reference  to  their  historical  reality,  to 
other  periods  of  time  than  those  in  which  the  phenomena  of 
light  are  first  revealed  to  the  inhabitants  of  the  Earth  :  they 
reach  us  like  the  voices  of  the  past.  It  has  been  truly  said, 
that  with  our  large  and  powerful  telescopic  instruments  we 
penetrate  alike  through  the  boundaries  of  time  and  space  :  we 
measure  the  former  through  the  latter,  for  in  the  course  of  an 

*  Aristot.,  Meteor.,  ii.,  5,  1.  Seneca,  Natur.  Qucest.,  i.,  14,  2.  "  Cce- 
lum  discessisse,"  in  Gic,  de  Divin.,  i.,  43. 

t  Arago,  in  the  Annuaire,  1842,  p.  429. 

X  In  December,  1837,  Sir  John  Herschel  saw  the  star ;;  Argo,  which 
till  that  time  appeared  as  of  the  second  magnitude,  and  liable  to  no 
change,  rapidly  increase  till  it  became  of  the  first  magnitude.  In  Jan- 
uary, 1838,  the  intensity  of  its  light  was  equal  to  that  of  a  Centauri. 
According  to  our  latest  information,  Maclear,  in  March,  1843,  found  it 
as  bright  as  Canopus;  and  even  a  Crucis  looked  faint  by  rj  Argo. 

G2 


154  COSMOS. 

hour  a  ray  of  light  traverses  over  a  space  of  592  miHions  of 
miles.  While,  according  to  the  theogony  of  Hesiod,  the  di- 
mensions of  the  universe  were  supposed  to  be  expressed  by  the 
time  occupied  by  bodies  in  falling  to  the  ground  ("  the  brazen 
anvil  was  not  more  than  nine  days  and  nine  nights  in  falling 
from  heaven  to  earth"),  the  elder  Herschel  was  of  opinion* 
that  light  required  almost  two  millions  of  years  to  pass  to  the 
Earth  from  the  remotest  luminous  vapor  reached  by  his  forty- 
foot  reflector.  Much,  therefore,  has  vanished  long  before  it 
is  rendered  visible  to  us — much  that  we  see  was  once  differ- 
ently arranged  from  what  it  now  appears.  The  aspect  of  the 
starry  heavens  presents  us  with  the  spectacle  of  that  which 
is  only  apparently  simultaneous,  and  however  much  we  may 
endeavor,  by  the  aid  of  optical  instruments,  to  bring  the  mild- 
ly-radiant vapor  of  nebulous  masses  or  the  faintly-glimmering 
starry  clusters  nearer,  and  diminish  the  thousands  of  years 
interposed  between  us  and  them,  that  serve  as  a  criterion  of 
their  distance,  it  still  remains  more  than  probable,  from  the 
knowledge  we  possess  of  the  velocity  of  the  transmission  of 
luminous  rays,  that  the  light  of  remote  heavenly  bodies  pre- 
sents us  with  the  most  ancient  perceptible  evidence  of  the  ex- 
istence of  matter.  It  is  thus  that  the  reflective  mind  of  man 
is  led  from  simple  premises  to  rise  to  those  exalted  heights  of 
nature,  where,  in  the  light-illumined  realms  of  space,  "  myriads 
of  worlds  are  bursting  into  life  like  the  grass  of  the  night. "f 
From  the  regions  of  celestial  forms,  the  domain  of  Uranus, 
we  will  now  descend  to  the  more  contracted  sphere  of  terres- 
trial forces — to  the  interior  of  the  Earth  itself  A  mysterious 
chain  links  together  both  classes  of  phenomena.  According 
to  the  ancient  signification  of  the  Titanic  myth,$  the  powers 
of  organic  life,  that  is  to  say,  the  great  order  of  nature,  depend 
upon  the  combined  action  of  heaven  and  earth.  If  we  sup- 
pose that  the  Earth,  like  all  the  other  planets,  primordially 
belonged,  according  to  its  origin,  to  the  central  body,  the  Sun, 
and  to  the  solar  atmosphere  that  has  been  separated  into  neb- 

*  "  Hence  it  follows  that  the  rays  of  hght  of  the  remotest  nebulae 
must  have  been  almost  two  millions  of  years  on  their  way,  and  that 
consequently,  so  many  years  ago,  this  object  must  already  have  had 
an  existence  in  the  sidereal  heaven,  in  order  to  send  out  those  rays  by 
which  we  now  perceive  it."  William  Herschel,  in  the  Phil.  Trans. 
for  1802,  p.  498.  John  Herschel,  Astron.,  $  590.  Arago,  in  the  An- 
nuaire,  1842.  p.  334,  359,  and  382-385. 

t  From  my  brother's  beautiful  sonnet  "  Freiheitund  Gesetz."  (Wil- 
helm  von  Humboldt,  Gesammelte  Werhe,  bd.  iv.,  s.  358,  No.  25.) 

X  Otfried  MOUer,  Prolegomena,  s.  373. 


TERRESTRIAT.    PHENOMENA.  155 

ulous  rings,  the  same  connection  with  this  contiguous  Sun,  as 
well  as  with  all  the  remote  suns  that  shine  in  the  firmament, 
is  still  revealed  through  the  phenomena  of  light  and  radiating 
heat.  The  difference  in  the  degree  of  these  actions  must  not 
lead  the  physicist,  in  his  delineation  of  nature,  to  forget  the 
connection  and  the  common  empire  of  similar  forces  in  the 
universe.  A  small  fraction  of  telluric  heat  is  derived  from 
the-  regions  of  universal  space  in  which  our  planetary  system 
is  moving,  whose  temperature  (which,  according  to  Fourier, 
is  almost  equal  to  our  mean  icy  polar  heat)  is  the  result  of  the 
combined  radiation  of  all  the  stars.  The  causes  that  more  pow- 
erfully excite  the  light  of  the  Sun  in  the  atmosphere  and  in  the 
upper  strata  of  our  air,  that  give  rise  to  heat-engendering  elec- 
tric and  magnetic  currents,  and  awaken  and  genially  vivify 
the  vital  spark  in  organic  structures  on  the  earth's  surface, 
must  be  reserved  for  the  subject  of  our  future  consideration. 

As  we  purpose  for  the  present  to  confine  ourselves  exclusive- 
ly within  the  telluric  sphere  of  nature,  it  will  be  expedient  to 
cast  a  preliminary  glance  over  the  relations  in  space  of  solids 
and  fluids,  the  form  of  the  Earth,  its  mean  density,  and  the 
partial  distribution  of  this  density  in  the  interior  of  our  planet, 
its  temperature  and  its  electro-magnetic  tension.  From  the 
consideration  of  these  relations  in  space,  and  of  the  forces  in- 
herent in  matter,  we  shall  pass  to  the  reaction  of  the  interior 
on  the  exterior  of  our  globe  ;  and  to  the  special  consideration 
of  a  universally  distributed  natural  power — subterranean  heat ; 
to  the  phenomena  of  earthquakes,  exliibited  in  unequally  ex- 
panded circles  of  commotion,  which  are  not  referable  to  the 
action  of  dynamic  laws  alone  ;  to  the  springing  forth  of  hot 
wells ;  and,  lastly,  to  the  more  powerful  actions  of  volcanic 
processes.  The  crust  of  the  Earth,  which  may  scarcely  have 
been  perceptibly  elevated  by  the  sudden  and  repeated,  or  al- 
most uninterrupted  shocks  by  M^hich  it  has  been  moved  from 
below,  undergoes,  nevertheless,  great  changes  in  the  course  of 
centuries  in  the  relations  of  the  elevation  of  solid  portions, 
wdien  compared  with  the  surface  of  the  liquid  parts,  and  even 
in  the  form  of  the  bottom  of  the  sea.  In  this  manner  si- 
multaneous temporary  or  permanent  fissures  are  opened,  by 
which  the  interior  of  the  Earth  is  brought  in  contact  with 
the  external  atmosphere.  Molten  masses,  rising  from  an  un- 
known depth,  flow  in  narrow  streams  along  the  declivity  of" 
mountains,  rushing  impetuously  onward,  or  moving  slowly 
and  gently,  until  the  fiery  source  is  quenched  in  the  niidst  of 
exlialations,  and  the  lava  becomes  incrusted,  as  it  were,  by 


156  COSMOS. 

the  solidification  of  its  outer  surface.  New  masses  of  rocks 
are  thus  formed  before  our  eyes,  while  the  older  ones  are  in 
their  turn  converted  into  other  forms  by  the  greater  or  lesser 
agency  of  Plutonic  forces.  Even  where  no  disruption  takes 
place  the  crystalline  molecules  are  displaced,  combining  to 
Ibrm  bodies  of  denser  texture.  The  water  presents  structures 
of  a  totally  different  nature,  as,  for  instance,  concretions  of 
animal  and  vegetable  remains,  of  earthy,  calcareous,  or  alumin- 
ous precipitates,  agglomerations  of  finely-pulverized  mineral 
bodies,  covered  with  layers  of  the  silicious  shields  of  infusoria, 
and  with  transpwted  soils  containing  the  bones  of  fossil  ani- 
mal forms  of  a  more  ancient  world.  The  study  of  the  strata 
which  are  so  differently  formed  and  arranged  before  our  eyes, 
and  of  all  that  has  been  so  variously  dislocated,  contorted,  and 
upheaved,  by  mutual  compression  and  volcanic  force,  leads 
the  reflective  observer,  by  simple  analogies,  to  draw  a  com- 
parison between  the  present  and  an  age  that  has  long  passed. 
It  is  by  a  combination  of  actual  phenomena,  by  an  ideal  en- 
largement of  relations  in  space,  and  of  the  amount  of  active 
forces,  that  we  are  able  to  advance  into  the  long  sought  and 
indefinitely  anticipated  domain  of  geognosy,  which  has  only 
within  the  last  half  century  been  based  on  the  solid  founda- 
tion of  scientific  deduction. 

It  has  been  acutely  remarked,  "  that,  notwithstanding  our 
continual  employment  of  large  telescopes,  we  are  less  ac- 
quainted with  the  exterior  than  with  the  interior  of  other 
planets,  excepting,  perhaps,  our  own  satellite."  They  have 
been  weighed,  and  their  volume  measured  ;  and  their  mass 
and  density  are  becoming  known  with  constantly-increasing 
exactness ;  thanks  to  the  progress  made  in  astronomical  ob- 
servation and  calculation.  Their  physical  character  is,  how- 
ever, hidden  in  obscurity,  for  it  is  only  in  our  own  globe  that 
we  can  be  brought  in  immediate  contact  with  all  the  ele- 
ments of  organic  and  inorganic  creation.  The  diversity  of 
the  most  heterogeneous  substances,  their  admixtures  and  met- 
amorphoses, and  the  ever-changing  play  of  the  forces  called 
into  action,  afford  to  the  human  mind  both  nourishment  and 
enjoyment,  and  open  an  immeasurable  field  of  observation, 
from  which  the  intellectual  activity  of  man  derives  a  great 
portion  of  its  grandeur  and  power.  The  world  of  perceptive 
phenomena  is  reflected  in  the  depths  of  the  ideal  world,  and 
the  richness  of  nature  and  the  mass  of  all  that  admits  of  clas- 
sification gradually  become  the  objects  of  inductive  reasoning. 

I  would  here  allude  to  the  advantage,  of  which  I  have  al- 


TERRESTRIAL    PHENOMENA.  157 

ready  spoken,  possessed  by  that  portion  of  physical  science 
whose  origin  is  famihar  to  us,  and  is  connected  with  our  earth- 
ly existence.  The  physical  description  of  celestial  bodies,  from 
the  remotely-glimmering  nebulae  with  their  suns,  to  the  central 
body  of  our  own  system,  is  limited,  as  we  have  seen,  to  gen- 
eral conceptions  of  the  volume  and  quantity  of  matter.  No 
manifestation  of  vital  activity  is  there  presented  to  our  senses. 
It  is  only  from  analogies,  frequently  from  purely  ideal  com- 
binations, that  we  hazard  conjectures  on  the  specific  elements 
of  matter,  or  on  their  various  modifications  in  the  different 
planetary  bodies.  But  the  physical  knowledge  of  the  het- 
erogeneous nature  of  matter,  its  chemical  differences,  the  reg- 
ular farms  in  which  its  molecules  combine  together,  whether 
in  crystals  or  granules ;  its  relations  to  the  deflected  or  de- 
composed waves  of  Hght  by  which  it  is  penetrated ;  to  radi- 
ating, transmitted,  or  polarized  heat ;  and  to  the  brilHant  or 
invisible,  but  not,  on  that  account,  less  active  phenomena  of 
electro-magnetism — all  this  inexhaustible  treasure,  by  which 
the  enjoyment  of  the  contemplation  of  nature  is  so  much 
heightened,  is  dependent  on  the  surface  of  the  planet  which 
we  inhabit,  and  more  on  its  solid  than  on  its  liquid  parts.  I 
have  already  remarked  how  greatly  the  study  of  natural  ob- 
jects and  forces,  and  the  infinite  diversity  of  the  sources  they 
open  for  our  consideration,  strengthen  the  mental  activity,  and 
call  into  action  every  manifestation  of  intellectual  progress. 
These  relations  require,  however,  as  little  comment  as  that 
concatenation  of  causes  by  which  particular  nations  are  per- 
mitted to  enjoy  a  superiority  over  others  in  the  exercise  of  a 
material  power  derived  from  their  command  of  a  portion  of 
these  elementary  forces  of  nature. 

If,  on  the  one  hand,  it  were  necessary  to  indicate  the  dif- 
ference existing  between  the  nature  of  our  knowledge  of  the 
Earth  and  of  that  of  the  celestial  regions  and  their  contents, 
I  am  no  less  desirous,  on  the  other  hand,  to  draw  attention 
to  the  limited  boundaries  of  that  portion  of  space  from  which 
we  derive  all  our  knowledge  of  the  heterogeneous  character 
of  matter.  This  has  been  somewhat  inappropriately  termed 
the  Earth's  crust ;  it  includes  the  strata  most  contiguous  to 
the  upper  surface  of  our  planet,  and  which  have  been  laid 
open  before  us  by  deep  fissure-like  valleys,  or  by  the  labors  of 
man,  in  the  bores  and  shafts  formed  by  miners.    These  labors* 

*  In  speaking  of  the  greatest  depths  within  the  Earth  reached  by  hu 
man  labor,  we  must  recollect  that  there  is  a  ditference  between  the  (tb- 
solute  depth  (that  is  to  say,  the  depth  below  the  Earth's  surface  ut  tii;i. 


156  COSxMOS. 

do  not  extend  beyond  a  vertical  depth  of  somewhat  more  than 
2000  feet  (about  one  third  of  a  geographical  mile)  below  the 

point)  and  the  relative  depth  (or  that  beneath  the  level  of  the  sea).  The 
greatest  relative  depth  that  man  has  hitherto  reached  is  probably  the 
bore  at  the  new  salt- works  at  Minden,  in  Prussia:  in  June,  1844,  it 
was  exactly  1993  feet,  the  absolute  depth  being  2231  feet.  The  tern 
perature  of  the  water  at  the  bottom  was  91°  F.,  which,  assuming  the 
mean  temperature  o4'  the  air  at  49°-3,  gives  an  augmentation  of  tem- 
perature of  1°  for  every  54  feet.  The  absolute  depth  of  the  Artesian 
well  of  Grenelle,  near  Paris,  is  only  1795  feet.  According  to  the  ac- 
count of  the  missionary  Imbert,  the  fire-springs,  "  Ho-tsing,"  of  the  Chi- 
nese, which  are  sunk  to  obtain  [carbureted]  hydrogen  gas  for  salt-boil- 
ing, far  exceed  our  Artesian  springs  in  depth.  In  the  Chinese  province 
of  Szii-tschuan  these  fire-springs  are  very  commonly  of  the  depth  of 
more  than  2000  feet;  indeed,  at  Tseu-lieu-tsing  (the  place  of  continual 
flowj  there  is  a  Ho-tsing  which,  in  the  year  1812,  was  found  to  be  3197 
feet  deep.  (Humboldt,  Asie  Centrale,  t.  ii.,  p.  521  and  525.  Annales 
de  V Association  de  la  Propagation  de  la  Foi,  1829,  No.  16,  p.  369.) 

The  relative  depth  reached  at  Mount  Massi,  in  Tuscany,  south  of 
Vol  terra,  amounts,  according  to  Matteuci,  to  only  1253  feet.  The  bor- 
ing at  the  new  salt-works  near  Minden  is  probably  of  about  the  same 
relative  depth  as  the  coal-mine  at  Apendale,  near  Newcastle-under- 
Lyme,  in  Staifordshire,  where  men  work  725  yards  below  the  surface 
of  the  earth.  (Thomas  Smith,  Miner's  Guide,  1836,  p.  160.)  Unfortu- 
nately, I  do  not  know  the  exact  height  of  its  mouth  above  the  level 
of  the  sea.  The  relative  depth  of  the  Monk-wearmouth  mine,  near 
Newcastle,  is  only  1496  feet.  (Phillips,  in  the  Philas.  Mag.,  vol.  v., 
1834,  p.  446.)  That  of  the  Liege  coal-mine,  V Espirance,  at  Seraing, 
is  1355  feet,  according  to  M.  von  Dechen,  the  director ;  and  the  old 
mine  of  Marihaye,  near  Val-St.-Lambert,  in  the  valley  of  the  Maes, 
is,  according  to  M.  Gernaert,  Ingenieur  des  Mines,  1233  feet  in  depth. 
The  works  of  greatest  absolute  depth  that  have  ever  been  formed 
are  for  the  most  part  situated  in  such  elevated  plains  or  valleys  that 
they  either  do  not  descend  so  low  as  the  level  of  the  sea,  or  at  most 
reach  very  little  below  it.  Thus  the  Eselschacht,  at  Kuttenberg,  in  Bo- 
hemia, a  mine  which  can  not  now  be  worked,  had  the  enormous  abso- 
lute depth  of  3778  feet.  (Fr.  A.  Schmidt,  Berggesetze  der  oster  Mon., 
abth.  i.,  bd.  i.,  s.  xxxii.)  Also,  at  St.  Daniel  and  at  Geish,  on  the  Rorer- 
biihel,  in  the  Landgericht  (or  provincial  district)  of  Kitzbiihl,  there 
were,  in  the  sixteenth  century,  excavations  of  3107  feet.  The  plans 
of  the  works  of  the  Rorerbtihel  are  still  preserved.  (See  Joseph  von 
Sperges.  Tyroler  Bergwerksgeschichte,  s.  121.  Compare,  also,  Hum- 
boldt, Gutachten  uher  Herantreibung  des  Meissner  Stollens  in  die  Frei- 
berger  Erzrevier,  printed  in  Herder,  uber  den  jetz  bcgonnenen  Erbstol- 
len,  1838,  s.  cxxiv.)  We  may  presume  that  the  knowledge  of  the  ex- 
traordinary depth  of  the  Rorerbiihel  reached  England  at  an  early  period, 
for  I  find  it  remarked  in  Gilbert,  de  Magnete,  that  men  have  penetrated 
2400  or  even  3000  feet  into  the  crust  of  the  Earth.  ("  Exigua  videtur 
terrse  portio,  quae  unquam  hominibus  spectanda  emerget  aut  eruitur: 
cum  profundius  in  ejus  viscera,  ultra  ♦florescentis  extremitatis  coirupte- 
lam.  aut  propter  aquas  in  magnis  fodin  tanquam  per  venas  scaturientes 
aut  propter  aeris  salubrioris  ad  vitam  o  erariorum  sustinendani  neces- 
sarii  defectum,  aut  propter  ingentes  sumf  tus  ad  tautos  labures  exant- 
landos,  multasque  difficultates,  ad  profundi  n-es  terrte  partes  peuetrare 


TERRESTRIAL    PHENOMENA.  150 

level  of  the  sea,  and  consequently  only  about  g^VTr^^^  of  the 
Earth's  radius.  The  crystalUne  masses  that  have  been  erupt- 
ed from  active  volcanoes,  and  are  generally  similar  to  the 
rocks  on  the  upper  surface,  have  come  from  depths  which, 
although  not  accurately  determined,  must  certainly  be  sixty 
times  greater  than  those  to  which  human  labor  has  been  ena- 
bled  to  penetrate.  We  are  able  to  give  m  numbers  the  depth 
of  the  shaft  where  the  strata  of  coal,  after  penetrating  a  cer- 
tain way,  rise  again  at  a  distance  that  admits  of  being  accu- 
rately defined  by  measurements.  These  dips  show  that  the 
carboniferous  strata,  together  with  the  fossil  organic  remains 
which  they  contain,  must  lie,  as,  for  instance,  in  Belgium, 
more  than  five  or  six  thousand  feet*  below  the  present  level 

non  possumus;  adeo  ut  quadi-ingeutas  aut  [quod  rarissime]  quiugeiitas 
orgyas  iii  quibusdam  inetiillis  desceiidisse,  stupeudus  omnibus  videatur 
conatus."  —  Gulielmi  Gilbert!,  Colcestreusis,  de  Magnate  Physiologia 
nova.     Loud.,  1600,  p.  40.) 

Tiie  absolute  depth  of  the  mines  iu  the  Saxon  Erzgebirge,  near  Frei 
bure,  ai'e :  in  the  Tharmhofer  mines,  1944  feet;  in  the  Honeubirker 
mines,  1827  feet ;  the  i-elative  depths  are  only  677  and  277  feet,  if,  in 
order  to  calculate  the  elevation  of  the  mine's  mouth  above  the  level  of 
the  sea,  we  regard  the  elevation  of  Freiburg  as  determined  by  Reich^ 
recent  observations  to  be  1269  feet.  The  absolute  depth  of  the  cele- 
brated mine  of  Joachimsthal,  in  Bohemia  (Verkreuzung  des  Jung  Hauer 
Zechen-und  Andreasganges),  is  full  2120  feet ;  so  that,  as  Von  Dechen's 
measurements  show  that  its  surface  is  about  2388  feet  above  the  level 
of  the  sea,  it  follows  that  the  excavations  have  not  as  yet  reached  that 
point.  In  the  Harz,  the  Samson  mine  at  Andreasberg  has  an  absolute 
depth  of  2197  feet.  In  what  was  formerly  Spanish  America,  I  know 
of  no  mine  deeper  than  the  Valenciana,  near  Guanaxuato  (Mexico), 
where  I  found  the  absolute  depth  of  the  Planes  de  San  Bernardo  to  be 
1686  feet ;  but  these  planes  are  5960  feet  above  the  level  of  the  sea. 
If  we  compare  the  depth  of  the  old  Kuttenberger  mine  (a  depth  great- 
er than  the  height  of  our  Brockeu,  and  only  200  feet  less  than  that  of 
Vesuvius)  with  the  loftiest  structures  that  the  hands  of  man  have  erect- 
ed (with  the  Pyramid  of  Cheops  and  with  the  Cathedral  of  Strasburg), 
we  find  that  they  stand  in  the  ratio  of  eight  to  one.  In  this  note  I  have 
collected  all  the  certain  information  I  could  find  regarding  the  great- 
est absolute  and  relative  depths  of  mines  and  borings.  In  descending 
eastward  ft-om  Jerusalem  toward  the  Dead  Sea,  a  view  presents  itself 
to  the  eye,  which,  according  to  our  pi'esent  hypsometrical  knowledge 
of  the  surface  of  our  planet,  is  unrivaled  in  any  country ;  as  we  ap- 
proach the  open  ravine  through  which  the  Jordan  takes  its  course,  we 
tread,  with  the  open  sky  above  us,  on  rocks  which,  according  to  the  ba- 
rometric measurements  of  Berton  and  Russegger,  are  1385  feet  below  the 
level  of  the  Mediterranean.     (Humboldt,  Asie  Cenirale,  th.  ii.,  p.  323.) 

*  Basin-shaped  curved  strata,  which  dip  and  reappear  at  measurable 
distances,  although  their  deepest  portions  are  beyond  the  reach  of  the 
miner,  afford  sensible  evidence  of  the  nature  of  the  earth's  ciixst  at  great 
depths  below  its  surface.  Testimony  of  this  kind  possesses,  consequent- 
ly, a  great  geognostic  interest.     I  am  indebted  to  that  excellent  geog- 


160  COSMOS. 

Df  the  sea,  and  that  the  calcareous  and  the  curved  strata  of 
the  Devonian  basin  penetrate  twice  that  depth.  If  w^e  com- 
pare these  subterranean  basins  with  the  summits  ot"  mountains 
that  have  hitherto  been  considered  as  the  most  elevated  por- 
tions of  the  raised  crust  of  the  Earth,  we  obtain  a  distance  of 
37,000  feet  (about  seven  miles),  that  is,  about  the  j-jjth  of 
the  Earth's  radius.  These,  therefore,  would  be  the  limits  of 
vertical  depth  and  of  the  superposition  of  mineral  strata  to 
which  geognostical  inquiry  could  penetrate,  even  if  the  gener- 
al elevation  of  the  upper  surface  of  the  earth  were  equal  to 
the  height  of  the  Dhawalagiri  in  the  Himalaya,  or  of  the 
Sorata  in  Bolivia.  All  that  lies  at  a  greater  depth  below  the 
level  of  the  sea  than  the  shafts  or  the  basins  of  which  I  have 
spoken,  the  limits  to  which  man's  labors  have  penetrated,  or 
than  the  depths  to  which  the  sea  has  in  some  few  instances 
been  sounded  (Sir  James  Ross  was  unable  to  find  bottom  with 
27,600  feet  of  line),  is  as  much  unknown  to  us  as  the  interior 
of  the  other  planets  of  our  solar  system.  We  only  know  the 
mass  of  the  whole  Earth  and  its  mean  density  by  comparing 
it  with  the  open  strata,  which  alone  are  accessible  to  us.  In 
the  interior  of  the  Earth,  where  all  knowledge  of  its  chemical 
and  mineralogical  character  fails,  we  are  again  limited  to  as 
pure  conjecture,  as  in  the  remotest  bodies  that  revolve  round 
the  Sun.  We  can  determine  nothing  with  certainty  regard- 
ing the  depth  at  which  the  geological  strata  must  be  supposed 
to  be  in  state  of  softening  or  of  liquid  fusion,  of  the  cavities 
occupied  by  elastic  vapor,  of  the^  condition  of  fluids  when 
heated  under  an  enormous  pressure,  or  of  the  law  of  the  in- 

nosist,  Von  Dechen,  for  the  following  observations.  "■  The  depth  of 
the  coal  basin  of  Liege,  at  Mont  St.  Gilles,  which  I,  in  conjunction  with 
our  friend  Von  Oeynhausen,  have  ascertained  to  be  3890  feet  below 
the  surface,  extends  3464  feet  below  the  surface  of  the  sea,  for  the  ab- 
solute height  of  Mont  St.  Gilles  certainly  does  not  much  exceed  400 
feet ;  the  coal  basin  of  Mons  is  fully  1865  feet  deeper.  But  all  these 
depths  are  trifling  compared  with  those  w^hich  are  presented  by  the 
coal  strata  of  Saar-Revier  (SaarbiTJcken).  I  have  found,  after  repeated 
examinations,  that  the  lowest  coal  stratum  which  is  known  in  the  neigh- 
borhood of  Duttweiler,  near  Bettingen,  northeast  of  Saarlouis,  must  de- 
scend to  depths  of  20,682  and  22,015  feet  (or  3-6  geographical  miles) 
below  the  level  of  the  sea."  This  result  exceeds,  by  more  than  8000 
feet,  the  assumption  made  in  the  text  regarding  the  basin  of  the  De- 
vonian strata.  This  coal-field  is  therefore  sunk  as  far  below  the  sur- 
face of  the  sea  as  Chimborazo  is  elevated  above  it — at  a  depth  at  which 
the  Earth's  temperature  must  be  as  high  as  435°  F.  Hence,  from  tlie 
highest  pinnacles  of  the  Himalaya  to  the  lowest  basins  containing  the 
vegetation  of  an  earlier  world,  there  is  a  vertical  distance  of  about 
48,000  feet,  or  of  the  435th  part  of  the  Earth's  radiu.s. 


GEOGRAPHICAL    DISTRIBUTION.  161 

crease  of  density  from  the  upper  surface  to  tfcfi  center  of  the 
Earth. 

The  consideration  of  the  increase  of  heat  with  the  increase 
of  depth  toward  the  interior  of  our  planet,  and  of  the  reaction 
of  the  interior  on  the  external  crust,  leads  us  to  the  long  series 
of  volcanic  phenomena.  These  elastic  forces  are  manifested 
in  earthquakes,  eruptions  of  gas,  hot  wells,  mud  volcanoes  and 
lava  currents  from  craters  of  eruptions,  and  even  in  producing 
alterations  in  the  level  of  the  sea.*  Large  plains  and  vari- 
ously indented  continents  are  raised  or  sunk,  lands  are  sep 
arated  fi:om  seas,  and  the  ocean  itself,  which  is  permeated  by 
hot  and  cold  currents,  coagulates  at  both  poles,  converting 
water  into  dense  masses  of  rock,  which  are  either  stratified  and 
fixed,  or  broken  up  into  floating  banks.  The  boundaries  of 
sea  and  land,  of  fluids  and  solids,  are  thus  variously  and  fre- 
quently changed.  Plains  have  undergone  oscillatory  move- 
ments, being  alternately  elevated  and  depressed.  After  the 
elevation  of  continents,  mountain  chains  were  raised  upon  long 
fissures,  mostly  parallel,  and,  in  that  case,  probably  cotem- 
poraneous  ;  and  salt  lakes  and  inland  seas,  long  inhabited  by 
the  same  creatures,  were  forcibly  separated,  the  fossil  remains 
of  shells  and  zoophytes  still  giving  evidence  of  their  original 
connection.  Thus,  in  following  phenomena  in  their  mutual 
dependence,  we  are  led  from  the  consideration  of  the  forces 
acting  in  the  interior  of  the  Earth  to  those  which  cause  erup- 
tions on  its  surface,  and  by  the  pressure  of  elastic  vapors  give 
rise  to  burning  streams  of  lava  that  flow  from  open  fissures. 

The  same  powers  that  raised  the  chains  of  the  Andes  and 
the  Himalaya  to  the  regions  of  perpetual  snow,  have  occa- 
sioned new  compositions  and  new  textures  in  the  rocky  masses, 
and  have  altered  the  strata  which  had  been  previously  de- 
posited from  fluids  impregnated  with  organic  substances.  We 
here  trace  the  series  of  formations,  divided  and  superposed  ac- 
cording to  their  age,  and  depending  upon  the  changes  of  con- 
figuration of  the  surface,  the  dynamic  relations  of  upheaving 
forces,  and  the  chemical  action  of  vapors  issuing  from  the 
fissures. 

The  form  and  distribution  of  continents,  that  is  to  say,  of 
that  solid  portion  of  the  Earth's  surface  which  is  suited  to  the 
luxurious  development  of  vegetable  life,  are  associated  by  in- 
timate connection  and  reciprocal  action  with  the  encircling 

*  [See  Daubeney  On  Volcanoes,  2d  edit.,  1848,  p.  539,  &c.,  on  the  so- 
called  mui  volcanoes,  and  the  reasons  advanced  in  favor  of  adopting  the 
term  "salses"  to  designate  these  phenomena.] — Tr. 


162  uosmorj. 

sea,  in  which  organic  life  is  almost  entirely  limited  to  the  ani- 
mal world.  The  liquid  element  is  again  covered  by  the  at- 
mosphere, an  aerial  ocean  in  which  the  mountain  chains  and 
high  plains  of  the  dry  land  rise  like  shoals,  occasioning  a  va- 
riety of  currents  and  changes  of  temperature,  collecting  vapor 
from  the  region  of  clouds,  and  distributing  life  and  motion  by 
the  action  of  the  streams  of  water  which  flow  from  their  de- 
clivities. 

While  the  geography  of  plants  and  animals  depends  on 
these  intricate  relations  of  the  distribution  of  sea  and  land,  the 
configuration  of  the  surface,  and  the  direction  of  isothermal 
lines  (or  zones  of  equal  mean  annual  heat),  we  find  that  the 
case  is  totally  different  when  we  consider  the  human  race — 
the  last  and  noblest  subject  in  a  physical  description  of  the 
globe.  The  characteristic  differences  in  races,  and  their  rela- 
tive numerical  distribution  over  the  Earth's  surface,  are  con- 
ditions affected  not  by  natural  relations  alone,  but  at  the  same 
time  and  specially,  by  the  progress  of  civilization,  and  by  moral 
and  intellectual  cultivation,  on  Mdiich  depends  the  political 
superiority  that  distinguishes  national  progress.  Some  few 
races,  clinging,  as  it  were,  to  the  soil,  are  supplanted  and  ruined 
by  the  dangerous  vicinity  of  others  more  civilized  than  them- 
selves, until  scarce  a  trace  of  their  existence  remains.  Other 
races,  again,  not  the  strongest  in  numbers,  traverse  the  liquid 
element,  and  thus  become  the  first  to  acquire,  although  late, 
a  geographical  knowledge  of  at  least  the  maritime  lands  of  the 
whole  surface  of  our  globe,  from  pole  to  pole. 

I  have  thus,  before  we  enter  on  the  individual  characters 
of  that  portion  of  the  delineation  of  nature  which  includes  the 
sphere  of  telluric  phenomena,  shown  generally  in  what  man- 
ner the  consideration  of"  the  form  of  the  Earth  and  the  inces- 
sant action  of  electro-magnetism  and  subterranean  heat  may 
enable  us  to  embrace  in  one  view  the  relations  of  horizontal 
expansion  and  elevation  on  the  Earth's  surface,  the  geognostic 
type  of  formations,  the  domam  of  the  ocean  (of  the  liquid  por- 
tions of  the  Earth),  the  atmosphere  with  its  meteorological 
processes,  the  geographical  distribution  of  plants  and  animals, 
and,  finally,  the  physical  gradations  of  the  human  race,  which 
is,  exclusively  and  every  where,  susceptible  of  intellectual  cul- 
ture. This  unity  of  contemplation  presupposes  a  connection 
of  phenomena  according  to  their  internal  combination.  A 
mere  tabular  arrangement  of  these  facts  would  not  fulfill  the 
object  I  have  proposed  to  myself,  and  would  not  satisfy  that 
requiren\ent  for  cosraical  presentation  awakened  in  me  by  the ' 


I 


FKiUllK    OF    THE     EARTlf.  163 

aspect  of  nature  in  my  journeyings  by  sea  and  land,  by  the 
careful  study  of  forms  and  forces,  and  by  a  vivid  impression 
of  the  unity  of  nature  in  the  midst  of  the  most  varied  portions 
of  the  Earth.  In  the  rapid  advance  of  all  branches  of  physical 
science,  much  that  is  deficient  in  this  attempt  will,  perhaps, 
at  no  remote  period,  be  corrected,  and  rendered  more  perfect, 
for  it  belongs  to  the  history  of  the  development  of  knovt^ledge 
that  portions  which  have  long- stood  isolated  become  gradually 
connected,  and  subject  to  higher  laws.  I  only  indicate  the 
empirical  jiath  in  which  I  and  many  others  of  similar  pursuits 
with  myself  are  advancing,  full  of  expectation  that,  as  Plato 
tells  us  Socrates  once  desired,  "  Nature  may  be  interpreted  by 
reason  alone."* 

The  delineation  of  the  principal  characteristics  of  telluric 
phenomena  must  begin  with  the  form  of  our  planet  and  its 
relations  in  space.  Here,  too,  we  may  say  that  it  is  not  only 
the  mineralogical  character  of  rocks,  whether  they  are  crys- 
talline, granular,  or  densely  fossiliferous,  but  the  geometrical 
form  of  the  Earth  itself,  which  indicates  the  mode  of  its  origin, 
and  is,  in  fact,  its  history.  An  elliptical  spheroid  of  revolu- 
tion gives  evidence  of  having  once  been  a  soft  or  fluid  mass. 
Thus  the  Earth's  compression  constitutes  one  of  the  most  an- 
cient geognostic  events,  as  every  attentive  reader  of  the  book 
of  nature  can  easily  discern ;  and  an  analogous  fact  is  pre- 
sented in  the  case  of  the  Moon,  the  perpetual  direction  of  whose 
axes  toward  the  Earth,  that  is  to  say,  the  increased  accumula- 
tion of  matter  on  that  half  of  the  Moon  which  is  turned  to- 
ward us,  determines  the  relations  of  the  periods  of  rotation  and 
revolution,  and  is  probably  cotemporaneous  with  the  earliest 
epoch  in  the  formative  history  of  this  satellite.  The  mathe- 
matical figure  of  the  Earth  is  that  which  it  would  have  were 
its  surface  covered  entirely  by  water  in  a  state  of  rest ;  and  it 
is  this  assumed  form  to  which  all  geodesical  measurements  of 
decrees  refer.  This  mathematical  surface  is  difi'ereiit  from 
that  true  physical  surface  which  is  alTected  by  all  the  acci- 
dents and  inequalities  of  the  solid  parts. f  The  whole  figure 
of  the  Earth  is  determined  when  we  know  the  amount  of  the 

*  Plato,  Phccdo,  p.  97.  (Arist.,  Metaph.,  p.  985.)  Compare  Hegel, 
Philosophic  der  Geschichte,  1840,  s.  16. 

t  Bessel,  Allgemeine  Betrachtungen  uber  Gradmessungeri  nach  astro- 
nomisch-geoddtischen  Arbeiten,  at  the  conclusion  of  Bessel  and  Baeyer, 
Gradmessung  in  Ostpreussen,  s.  427.  Regarding  the  accumulation  ot" 
matter  on  the  side  of  the  Moon  turned  toward  us  (a  subject  noticed 
in  an  earlier  part  (jf  the  text),  see  Laplace,  Expos,  du  Syst.  du  Monde, 
p.  308. 


164  '  COSMOS. 

compression  at  the  poles  and  the  equatorial  diameter ;  m  or- 
der, however,  to  obtain  a  perfect  representation  of  its  form  it 
is  necessary  to  have  measurements  in  two  directions,  perpen- 
dicular to  one  another. 

Eleven  measurements  of  degrees  (or  determinations  of  the 
curvature  of  the  Earth's  surface  in  diflerent  parts),  of  which 
nine  only  belong  to  the  present  century,  have  made  us  ac- 
quainted with  the  size  of  our  globe,  which  Pliny  named  "  a 
point  in  the  immeasurable  universe."*  If  these  measurements 
do  not  always  accord  in  the  curvatures  of  different  meridians 
under  the  same  degree  of  latitude,  this  very  circumstance 
speaks  in  favor  of  the  exactness  of  the  instruments  and  the 
methods  employed,  and  of  the  accuracy  and  the  fidelity  to 
nature  of  these  partial  results.  The  conclusion  to  be  drawn 
from  the  increase  of  forces  of  attraction  (in  the  direction  from 
the  equator  to  the  poles)  with  respect  to  the  figure  of  a  planet 
is  dependent  on  the  distribution  of  density  in  its  interior. 
Newton,  from  theoretical  principles,  and  perhaps  likewise 
prompted  by  Cassini's  discovery,  previously  to  1666,  of  the 
compression  of  Jupiter,!  determined,  in  his  immortal  work, 
PhiLoso2:)hice  Naturalis  Principia,  that  the  compression  of  the 
Earth,  as  a  homogeneous  mass,  was  -^^-^Xh..     Actual  meas- 

*  Plin.,  ii.,  68.  Seneca,  Nat.  Qucest.,  Prcef.,  c.  ii.  "  El  mundo  as 
poco"  (the  Earth  is  small  and  narrow),  writes  Columbus  from  Jamaica 
to  Queen  Isabella  on  the  7th  of  July,  1503  ;  not  because  he  entertained 
the  philosophic  views  of  the  aforesaid  Romans,  but  because  it  appeared 
advantageous  to  him  to  maintain  that  the  journey  from  Spain  w^as  not 
long,  if,  as  he  observes,  "  we  seek  the  east  from  the  west."  Compare 
my  Examen  Crit.  de  VHist.  de  la  Geogr.  dn  15me  Siecle,  t.  i.,  p.  83,  and 
t.  ii.,  p.  327,  where  I  have  shown  that  the  opinion  maintained  by  De- 
lisle,  Fr6ret,  and  Gosselin,  that  the  excessive  differences  in  the  state- 
ments regarding  the  Earth's  circumference,  found  in  the  writings  of 
the  Greeks,  are  only  apparent,  and  dependent  on  different  values  being 
attached  to  the  stadia,  was  put  forward  as  early  as  1495  by  Jaime  Fer- 
rer, in  a  proposition  regai'ding  the  determination  of  the  line  of  demark- 
ation  of  the  papal  dominions. 

t  Brewster,  Life  of  Sir  Isaac  Newton,  1831,  p.  162.  "  The  discovery 
of  the  spheroidal  form  of  Jupiter  by  Cassini  had  probably  directed  the 
attention  of  Newton  to  the  determination  of  its  cause,  and,  consequent- 
ly, to  the  investigation  of  the  true  figure  of  the  Earth."  Although  Cas- 
sini did  not  announce  the  amount  of  the  compression  of  Jupiter  (—jth) 
till  1691  (Anciens  MSmoires  de  V Acad,  des  Sciences,  t.  ii.,  p.  108),  yet 
we  know  from  Lalande  (Astron.,  3me  ed.,  t.  iii.,  p.  335)  that  Moraldi 
possessed  some  printed  sheets  of  a  Latin  work,  "  On  the  Spots  of  the 
Planets,"  commenced  by  Cassini,  from  which  it  was  obvious  that  he 
was  aware  of  the  compression  of  Jupiter  before  the  year  1666,  and 
therefore  at  least  twenty-one  yeai's  before  the  publication  of  Newton's 
Principia. 


FIGURE    OF    THE    EARTH.  165 

urements,  made  by  the  aid  of  new  and  more  perfect  analysis, 
have,  however,  shown  that  the  compression  of  the  poles  of  the 
terrestrial  spheroid,  when  the  density  of  the  strata  is  regarded 
as  increasing  toward  the  center,  is  very  nearly  g^o^h. 

Three  methods  have  been  employed  to  investigate  the  curv- 
ature of  the  Earth's  surface,  viz.,  measurements  of  degrees, 
oscillations  of  the  pendulum,  and  observations  of  the  inequal- 
ities in  the  Moon's  orbit.  The  first  is  a  direct  geometrical 
and  astronomical  method,  while  in  the  other  two  we  determ- 
ine from  accurately  observed  movements  the  amount  of  the 
forces  which  occasion  those  naovements,  and  from  these  forces 
we  arrive  at  the  cause  from  whence  they  have  originated,  viz., 
the  compression  of  our  terrestrial  spheroid.  In  this  part  of 
my  delineation  of  nature,  contrary  to  my  usual  practice,  I 
have  instanced  methods  because  their  accuracy  affords  a  strik- 
ing illustration  of  the  intimate  connection  existing  among 
the  forms  and  forces  of  natural  phenomena,  and  also  because 
their  application  has  given  occasion  to  improvements  in  the 
exactness  of  instruments  (as  those  employed  in  the  measure- 
ments of  space)  in  optical  and  chronological  observations  ;  to 
greater  perfection  in  the  fundamental  branches  of  astronomy 
and  mechanics  in  respect  to  lunar  motion  and  to  the  resistance 
experienced  by  the  oscillations  of  the  pendulum  ;  and  to  the 
discovery  of  new  and  hitherto  untrodden  paths  of  analysis. 
With  the  exception  of  the  investigations  of  the  parallax  of 
stars,  which  led  to  the  discovery  of  aberration  and  nutation, 
the  history  of  science  presents  no  problem  in  which  the  ob- 
ject attained — the  knowledge  of  the  compression  and  of  the 
irregular  form  of  our  planet — is  so  far  exceeded  in  importance 
by  the  incidental  gain  which  has  accrued,  through  a  long  and 
weary  course  of  investigation,  in  the  general  furtherance  and 
improvement  of  the  mathematical  and  astronomical  sciences. 
The  comparison  of  eleven  measurements  of  degrees  (in  which 
are  included  three  extra-European,  namely,  the  old  Peruvian 
and  two  East  Indian)  gives,  according  to  the  most  strictly 
theoretical  requirements  allowed  for  by  Bessel,*"  a  compression 

*  According  to  Bessel's  examination  of  ten  measurements  of  degrees, 
in  which  the  error  discovered  by  Puissant  in  the  calculation  of  the 
French  measurements  is  taken  into  consideration  (Schumacher,  Astron. 
Nackr.,  1841,  No.  438,  s.  116),  the  semi-axis  major  of  the  elliptical 
spheroid  of  revolution  to  which  the  irregular  figure  of  the  Earth  most 
closely  approximates  is  3,272,077-14  toises,  or  20,924,774  feet;  the  semi- 
axis  minor,  3,261,159-83  toises,  or  20,854,821  feet;  and  the  amount  of 
compression  or  eccentricity  _^_^_-j.^d ;  the  length  of  a  mean  degree  of 
the  meridian,  57,013-109  tofses,  or  364,596  feet,  with  an  error  of  -\- 


166  coriiVios. 

of  -g-g-g-tli.  In  accordance  with  this,  the  polar  radius  is  1 0,938 
toises  (69,944  feet),  or  about  11|-  miles,  shorter  than  the  equa- 
torial radius  of  our  terrestrial  spheroid.  The  excess  at  the 
equator  in  consequence  of  the  curvature  of  the  upper  surface 
of  the  globe  amounts,  consequently,  in  the  direction  of  gravi- 
tation, to  somevv^hat  more  than  4^th  times  the  height  of 
Mont  Blanc,  or  only  21  times  the  probable  height  of  the 
summit  of  the  Dhawalagiri,  in  the  Himalaya  chain.  The 
lunar  inequalities  (perturbation  in  the  moon'^s  latitude  and 
longitude)  give,  according  to  the  last  investigations  of  Laplace, 
almost  the  same  result  for  the  eUipticity  as  the  measurements 
of  degrees,  viz.,  2-y¥^h.  The  results  yielded  by  the  oscillation 
of  the  pendulum  give,  on  the  whole,  a  much  greater  amount 
of  compression,  viz.,  •gjs'th.* 

2-8403  toises,  or  18-16  feet,  whence  the  leugtli  ofja  geographical  mile 
is  3807-23  toises,  or  6086-7  feet.  Previous  combinations  of  measure- 
ments of  degrees  varied  betvi^een  gl^d  and  g^^th;  thus  Walbeck  (Z>e 
Forma  et  Magnitudine  telluris  in  demensis  arcubus  Meridiani  definiendis, 
1819)  gives  3  Q^ij^th  :  Ed.  Schmidt  {Lekrhichder  Maikem.  und  Phi/s.  Geo- 
graphie,  1829,  s.  5)  gives -ggl^- 2d,  as  tlie  mean  of  seven  measures.  Re- 
specting the  influence  of  great  differences  of  longitude  on  the  polar 
compression,  see  Bibliotheqne  Universelle,  t.  xxxiii.,  p.  181,  and  t.  xxxv., 
p.  56 ;  likev^^ise  Connaissance  des  Term,  1829,  p.  290.  From  the  lunar 
inequalities  alone,  Laplace  {Expositioyi  du  Syst.  dn  Monde,  p.  229)  found 
it,  by  tiie  older  tables  of  Biirg,  to  be  «'y^th ;  and  subsequently,  from 
the  hmar  observations  of  Burckhardt  and  Bouvard,  he  fixed  it  at  ■,  g^.yth 
(M^canique  Cileste,  t.  v.,  p.  13  and  43). 

*  The  oscillations  of  the  pendulum  give  ^^^^th  as  the  general  result 
of  Sabine's  great  expedition  (1822  and  1823,  from  the  equator  to  80° 
north  latitude) ;  according  to  Freycinet,  g^^^.-^d,  exclusive  of  the  experi- 
ments instituted  at  the  Isle  of  France,  Guam,  aiad  Mowi  (Mawi);  ac- 
cording to  Forster,  ^^^th ;  according  to  Duperrey,  ^^^th ;  and  ac- 
cording to  Liitke  ('Partie  Nautique,  1836,  p.  232),  -o^gth,  calculated 
from  eleven  stations.  On  the  other  hand,  Mathieu  (  Connaiss.  des  Temps, 
1816,  p.  330)  fixed  the  amount  at  ^^_d,  from  observations  made  be- 
tween Formentera  and  Dunkirk;  and  Biot,  at  —yth,  from  observations 
between  Formentera  and  the  island  of  Unst.  Compare  Baily,  Report 
on  Pendulum  Experiments,  in  the  Memoirs  of  the  Royal  Astronomical 
Society,  vol.  vii.,  p.  96;  also  Borenius,  in  the  Bulletin  de  V Acad,  de  St. 
Pitersbourg,  1843,  t.  i.,  p.  2.5.  The  first  proposal  to  apply  the  length  of 
the  pendulum  as  a  standard  of  measure,  and  to  establish  the  third  part 
of  the  seconds  pendulum  (then  supposed  to  be  every  where  of  equal 
length)  as  a  pes  horarius,  or  general  measure,  that  might  be  recovered 
at  any  age  and  by  all  nations,  is  to  be  found  in  Huygens's  Horologium 
Oscillatorium,  1673,  Prop.  2.5.  A  similar  wish  was  afterward  publicly 
expressed,  in  1742,  on  a  monument  erected  at  the  equator  by  Bouguer, 
La  Condamine,  and  Godin.  On  the  beautiful  marble  tablet  which  ex- 
ists, as  yet  uninjured,  in  the  old  Jesuits'  College  at  Quito,  I  have  myself 
read  the  inscription,  Penduli  simplicis  (pquinoctialis  unius  minuti  secundt 


FIGURE    OF    THE    EARTH.  167 

Galileo,  who  first  observed  when  a  boy  (having,  probably, 
suffered  his  thoughts  to  wander  from  the  service)  that  the 
height  of  the  vaulted  roof  of  a  church  might  be  measured  by 
the  time  of  the  vibration  of  the  chandeliers  suspended  at  dif- 
ferent altitudes,  could  hardly  have  anticipated  that  the  pendu- 
lum would  one  day  be  carried  from  pole  to  pole,  in  ordof  to 
determine  the  form  of  the  Earth,  or,  rather,  that  the  unequal 
density  of  the  strata  of  the  Earth  affects  the  length  of  the  sec- 
onds pendulum  by  means  of  intricate  forces  of  local  attraction, 
which  are,  however,  almost  regular  in  large  tracts  of  land. 
These  geognostic  relations  of  an  instrument  intended  for  the 
measurement  of  time — this  property  of  the  pendulum,  by 
which,  like  a  sounding  line,  it  searches  unknown  depths,  and 
reveals  in  volcanic  islands,=^  or  in  the  declivity  of  elevated  con- 
tinental m.ountain  chains,!  dense  masses  of  basalt  and  mela- 

archetypus,  meyisurce  naturalis  exemplar,  niinam  universalis  !  From  an 
observation  made  by  La  Condamine,  in  his  Journal  du  Voyage  a  I'Equa- 
teur,  1751,  p.  163,  regarding  parts  of  the  inscription  that  were  not  tilled 
up.  and  a  slight  difference  between  Bougner  and  himself  respecting  the 
numbers,  I  was  led  to  expect  that  I  should  tind  considerable  discrepan- 
cies between  the  marble .  tablet  and  the  inscription  as  it  had  been  de- 
scribed in  Paris;  but,  after  a  careful  comparison,  I  mei'ely  found  two 
perfectly  unimportant  ditfereuces ;  "ex  arcu  graduum  Sj^"  instead  of 
"ex  arcu  graduum  plusquam  trium,"  and  the  date  of  1745  instead  of 
1742.  The  latter  circumstance  is  singular,  because  La  Condamine  re- 
turned to  Europe  in  November,  1744,  Bouguer  in  June  of  the  same  year, 
and  Godin  had  left  South  America  in  July,  1744.  The  most  necessary 
and  useful  amendment  to  the  numbers  on  this  inscription  would  have 
been  the  astronomical  longitude  of  Quito.  (Humboldt,  Ttecueil  d'Ob- 
serv.  Astroji.,  t.  ii.,  p.  319-354.)  Nonet's  latitudes,  engraved  on  Egyp- 
'  tian  monuments,  offer  a  more  recent  example  of  the  danger  presented 
by  the  grave  perpetuation  of  false  or  careless  results. 

*  Respecting  the  augmented  intensity  of  the  attraction  of  gravitation 
in  volcanic  islands  (St.  Helena,  Ualan,  Fernando  de  Noronha,  Isle  of 
France,  Guam,  Mowi,  and  Galapagos),  Rawak  (Liitke,  p.  240)  being 
an  exception,  probably  in  consequence  of  its  proximity  to  the  high 
land  of  New  Guinea,  see  Mathieu,  in  Delambre,  Hist,  de  VAstronomie,  au 
ISwe  Steele,  p.  701. 

t  Numerous  observations  also  show  great  irregularities  iu  the  length 
of  the  pendulum  in  the  midst  of  continents,  and  which  are  ascribed  to 
local  attractions.  (Delambre,  Mesure  de  la  Miridienne,  t.  iii.,  p.  548; 
Blot,  in  the  M6m.  de  V Acad6mie  des  Sciences,  t.  viii.,  1829,  p.  18  and 
23.)  In  passing  over  the  South  of  France  and  Lombardy  from  west  to 
east,  we  find  the  minimum  intensity  of  gravitation  at  Bordeaux ;  from 
thence  it  increases  rapidly  as  we  advance  eastward,  through  Figeac, 
Clermont-Ferrand,  Milan,  and  Padua;  and  in  the  last  town  we  find  that 
the  intensity  has  attained  its  maximum.  The  influence  of  the  southern 
declivities  of  the  Alps  is  not  merely  dependent  on  the  general  size  of 
their  mass,  but  (much  more),  in  the  opinion  of  Elie  de  Beaumont  (Reck, 
sitr  les  R6vol.  de  la  Surface  d>i  Globe,  1830,  p.  729).  on  the  rocks  of 
meJaphyie  and  serpentiue.  which  have  elttviited  the  cliain.      On  the 


168  COSMOS. 

phyre  instead  of  cavities,  render  it  difficult,  notwithstandmg 
the  admirable  simplicity  of  the  method,  to  arrive  at  any  great 
result  regarding  the  figure  of  the  Earth  from  observation  of 
the  oscillations  of  the  pendulum.  In  the  astronomical  part  of 
the  determination  of  degrees  of  latitude,  mountain  chains,  or 
the  denser  strata  of  the  Earth,  likewise  exercise,  although  in  a 
less  degree,  an  unfavorable  influence  on  the  measurement. 

As  the  form  of  the  Earth  exerts  a  powerful  influence  on  the 
motions  of  other  cosmical  bodies,  and  especially  on  that  of  its 
own  neighboring  satellite,  a  more  perfect  knowledge  of  the  mo- 
tion of  the  latter  will  enable  us  reciprocally  to  draw  an  infer- 
ence regarding  the  figure  of  the  Earth.  Thus,  as  Laplace  ably 
remarks,*  "An  astronomer,  without  leaving  his  observatory, 
may,  by  a  comparison  of  lunar  theory  with  true  observations, 
not  only  be  enabled  to  determine  the  form  and  size  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." 

declivity  of  Ararat,  which  with  Caucasus  may  be  said  to  lie  iii  the  cen- 
ter of  gravity  of  the  old  continent  formed  by  Europe,  Asia,  and  Africa, 
the  very  exact  pendulum  experiments  of  Fedorow  give  indications,  not 
of  subterranean  cavities,  but  of  dense  volcanic  masses.  (Parrot,  Reise 
zum  Ararat,  bd.  ii.,  s.  143.)  In  the  geodesic  operations  of  Carlini  and 
Plana,  in  Lombardy,  differences  ranging  from  20"  to  47"-8  have  been 
found  between  direct  observations  of  latitude  and  the  results  of  these 
operations.  (See  the  instances  of  Andrate  and  Mondovi,  and  those  of 
Milan  and  Padua,  in  the  Operations  Geodes.  et  Astron.  potir  la  Mesure 
d'un  Arc  du  Parallele  Moyen,  t.  ii.,  p.  347 ;  Effemeridi  Astron.  di  Mi- 
lano,  1842,  p.  57.)  The  latitude  of  Milan,  deduced  from  that  of  Berne,, 
according  to  the  French  triangulation,  is  45°  27'  52",  while,  according 
to  direct  astronomical  observations,  it  is  45°  27'  35".  As  the  perturba- 
tions extend  in  the  plain  of  Lombardy  to  Parma,  which  is  far  south  of 
thePo  (Plana,  Op6rat.  Geod.,  t.  ii.,  p.  847),  it  is  probable  that  there  are 
deflecting  causes  concealed  beneath  the  soil  of  the  plain  itself.  Struve 
has  made  similar  experiments  [  with  corresponding  results]  in  the  most 
level  parts  of  eastern  Europe.  (Schumacher,  Astron.  Nachrichten,  1830, 
No.  164,  s.  399.)  Regai'ding  the  influence  of  dense  masses  supposed  to 
lie  at  a  small  depth,  equal  to  the  mean  height  of  the  Alps,  see  the  ana- 
lytical expressions  given  by  Hossard  and  Rozet,  in  the  Comptes  Rendus, 
t.  xviii.,  1844,  p.  292,  and  compare  them  with  Poisson,  Traiti  dc  M6- 
caniqjie  (2me  ed.),  t.  i.,  p.  482.  The  earliest  observations  on  the  in- 
fluence which  dinerent.  kinds  of  I'ocks  exercise  on  the  vibration  of  ihe 
pendulum  are  those  of  Thomas  Young,  in  the  Philos.  Transactions  for 
1819,  p.  70-96.  In  drawing  conclusions  regarding  the  Earth's  curva- 
ture from  the  length  of  the  pendulum,  we  ought  not  to  overlook  the 
possibility  that  its  crust  may  have  undergone  a  process  of  hardening 
previously  to  metallic  and  dense  basaltic  masses  having  penetrated  froc3 
great  depths,  through  open  clefts,  and  approached  near  the  surface. 
*  Laplace,  Expos,  du  Syst.  du  Monde,  p.  231. 


DENSITY  OF  THE  EARTH.  169 

The  compression  which  may  be  inferred  from  lunar  inequali- 
ties affords  an  advantage  not  yielded  by  individual  measure- 
ments of  degrees  or  experiments  w^ith  the  pendulum,  since  it 
gives  a  mean  amount  which  is  referable  to  the  whole  planet. 
The  comparison  of  the  Earth's  compression  with  the  velocity 
of  rotation  .  shows,  further,  the  increase  of  density  from  the 
strata  from  the  surface  toward  the  center — an  increase  which 
a  comparison  of  the  ratios  of  the  axes  of  Jupiter  and  Saturn 
with  their  times  of  rotation  likewise  shows  to  exist  in  these 
two  large  planets.  Thus  the  knowledge  of  the  external  form 
of  planetary  bodies  leads  us  to  draw  conclusions  regarding  their 
internal  character. 

Th#  northern  and  southern  hemispheres  appear  to  present 
nearly  the  same  curvature  under  equal  degrees  of  latitude,  but, 
as  has  already  been  observed,  pendulum  experiments  and 
measurements  of  degrees  yield  such  different  results  for  indi- 
vidual portions  of  the  Earth's  surface  that  no  regular  figure 
can  be  given  which  would  reconcile  all  the  results  hitherto 
obtained  by  this  method.  The  true  figure  of  the  Earth  is  to 
a  regular  figure  as  the  uneven  surfaces  of  water  in  motion  are 
to  the  even  surface  of  water  at  rest. 

When  the  Earth  had  been  measured,  it  still  had  to  bo 
weighed.  The  oscillations  of  the  pendulum*  and  the  plum- 
met have  here  likewise  served  to  determine  the  mean  density 
of  the  Earth,  either  in  connection  with  astronomical  and  geo- 
detic operations,  with  the  view  of  finding  the  deflection  of  the 
plummet  from  a  vertical  line  in  the  vicinity  of  a  mountain,  or 
by  a  comparison  of  the  length  of  the  pendulum  in  a  plain  and 
on  the  summit  of  an  elevation,  or,  finally,  by  the  employment 
of  a  torsion  balance,  which  may  be  considered  as  a  horizon- 
tally vibrating  pendulum  for  the  measurement  of  the  relative 
density  of  neighboring  strata.     Of  these  three  methods!  the 

*  La  Caille's  pendulum  measurements  at  the  Cape  of  Good  Hope, 
which  have  been  calculated  with  much  care  by  Mathieu  (Delarabre, 
Hist,  de  VAstr-on.  an  ISme  Siecle,  p.  479),  give  a  compression  of  ^^j-.^^th; 
but,  from  several  comparisons  of  observations  made  in  equal  latitudes 
in  the  two  hemispheres  (New  HoUmid  and.  the  Malouines  (Falkland 
Islands),  compared  with  Barcelona,  New  York,  and  Dunkirk),  there  is 
»as  yet  no  reason  for  supposing  that  the  mean  compression  of  the  south- 
ern hemisphere  is  greater  than  that  oithe  northern.  (Blot,  in  the  M6in. 
de  VAcad.  des  Sciences,  t.  viii.,  1829,  p.  39-41.) 

t  The  three  methods  of  observation  give  the  ibllowing  results:  (1.)  by 
the  deflection  of  the  plumb-line  in  the  proximity  of  the  Shehallieu 
Mountain  (Gaelic,  Thichallin)  in  Perthshire,  4-713,  as  determined  by 
Maskelyne,  Kutton,  and  Playfair  (1774-1776  and  1810),  according  to  a 
method  that  had  been  proposed  by  Newton;  (2.)  by  pendulum  vibra 

Vol.  I  — H 


170  "  COSMOS. 

last  IS  the  most  certain,  since  it  is  independent  of  the  difficult 
determination  of  the  density  of  the  mineral  masses  of  which 
the  spherical  segment  of  the  mountain  consists  near  which  the 
observations  are  made.  According  to  the  most  recent  experi- 
ments of  Reich,  the  result  obtained  is  5'44  ;  that  is  to  say,  the 
mean  density  of  the  whole  Earth  is  5-44  times  gireater  than 
that  of  pure  water.  As,  according  to  the  nature  of  the  min- 
eralogical  strata  constituting  the  dry  continental  part  of  the 
Earth's  surface,  the  mean  density  of  this  portion  scarcely 
amounts  to  2*7,  and  the  density  of  the  dry  and  liquid  surface 
conjointly  to  scarcely  1*6,  it  follows  that  the  elliptical  un- 
equally compressed  layers  of  the  interior  must  greatly  increase 
m  density  toward  the  center,  either  through  pressure  or^owing 
to  the  heterogeneous  nature  of  the  substances.  Here  again 
we  see  that  the  vertical,  as  well  as  the  horizontally  vibrating 
pendulum,  may  justly  be  termed  a  geognostical  instrument. 

The  results  obtained  by  the  employment  of  an  instrument 
ol"  this  kind  have  led  celebrated  physicists,  according  to  the 
difference  of  the  hypothesis  from  which  they  started,  to  adopt 

tions  ou  niountaiiis,  4*837  (Carlini's  observations  on  Mount  Cenis  coni^ 
pared  with  Biot's  observations  at  Bordeaux,  Effemer.  Astron.  di  Milano, 
1824,  p.  184);  (3.)  by  the  torsion  balance  used  by  Cavendish,  with  an 
ap{)aratus  originally  devised  by  Mitchell,  5*48  (according  to  Hutton's 
revision  of  the  calculation,  5*32,  and  according  to  that  of  Eduai'd 
Schmidt,  5*52;  Lehrbitch  der  Math.  Geographic,  bd.  i.,  s.  487);  by  the 
torsion  balance,  according  to  Reich,  5-44,  In  the  calculation  of  these 
experiments  of  Professor  Reich,  which  have  been  made  with  masterly 
accuracy,  the  original  mean  result  was  5-43  (with  a  probable  error  of 
only  0  0233),  a  result  which,  being  increased  by  the  quantity  by  which 
the  Earth's  centrifugal  force  diminishes  the  force  of  gravity  for  the  lati- 
tude of  Freiberg  (50"^  55'),  becomes  changed  to  5*44.  The  employ- 
ment of  cast  iron  instead  of  lead  has  not  presented  any  sensible  differ- 
ence, or  none  exceeding  the  limits  of  errors  of  observation,  hence  dis- 
closing no  traces  of  magnetic  influences.  (Reich,  Versjiche  uberdie  mitt- 
lere  Dichtigheit  der  Erde,  1838,  s.  60,  62,  and  QQ.)  By  the  assumption 
of  too  slight  a  degree  of  ellipticity  of  the  Earth,  and  by  the  uncertainty 
of  the  estimations  regarding  the  density  of  rocks  on  its  surface,  the 
mean  density  of  the  Earth,  as  deduced  from  exiieriments  on  and  near 
mountains,  was  found  about  one  sixth  smaller  than  it  really  is,  name- 
ly, 4-761  (Laplace,  Mican.  CHesfe,  t.  v.,  p.  46),  or  4-783.  (Eduard 
Schmidt,  Lehrh.  der  Math.  Geogr.,  bd.  i.,  ^  387  uud  418.)'  On  Halley's 
hypothesis  of  the  Earth  being  a  hollow  sphere  (noticed  ia  page  171), 
which  was  the  germ  of  Franklin's  ideas  concerning  earthquakes,  see 
Philos.  Trans,  for  the  year  1693,  vol.  xvii.,  p.  563  {On  the  Structure  of 
the  laternal  Parts  of  the  Earth,  and  the  concave  habited  Arch  of  the 
Shell).  Halley  regarded  it  as  more  worthy  of  the  Creator  "  that  tlio 
Earth,  like  a  house  of  several  stories,  should  be  inhabited  both  without 
and  within.  For  light  in  the  hullovv  sphere  (p.  576)  provision  might  ii* 
Bome  manner  be  contrived." 


DENSITY  OF  THE  EARTH.  171 

entirely  opposite  views  regarding  the  nature  of  the  interior  of 
the  globe.  It  has  been  computed  at  what  depths  liquid  or 
even  gaseous  substances  would,  from  the  pressure  of  their 
own  superimposed  strata,  attain  a  density  exceeding  that  of 
platinum  or  even  iridium  ;  and  in  order  that  the  compression 
which  has  been  determined  within  such  narrow  limits  migh* 
be  brought  into  harmony  with  the  assumption  of  simple  and 
infinitely  compressible  matter,  Leslie  has  ingeniously  conceived 
the  nucleus  of  the  world  to  be  a  hollow  sphere,  filled  with  an 
assumed  "  imponderable  matter,  having  an  enormous  force  of 
expansion."  These  venturesome  and  arbitrary  conjectures 
have  given  rise,  in  wholly  unscientific  circles,  to  still  more 
fantastic  notions.  The  hollow  sphere  has  by  degrees  been 
peopled  with  plants  and  animals,  and  two  small  subterranean 
revolving  planets — Pluto  and  Proserpine — were  imaginatively 
supposed  to  shed  over  it  their  mild  light ;  as,  however,  it  was 
further  imagined  that  an  ever-uniform  temperature  reigned  in 
these  internal  regions,  the  air,  which  was  made  self-luminous 
by  compression,  might  well  render  the  planets  of  this  lower 
world  unnecessary.  Near  the  north  pole,  at  82°  latitude, 
whence  the  polar  light  emanates,  was  an  enormous  opening, 
through  which  a  descent  might  be  made  into  the  hollow 
sphere,  and  Sir  Humphrey  Davy  and  myself  were  even  pub- 
licly and  frequently  invited  by  Captain  Symmes  to  enter  upon 
this  subterranean  expedition  :  so  powerful  is  the  morbid  in- 
clination of  men  to  fill  unknown  spaces  with  shapes  of  won- 
der, totally  unmindful  of  the  counter  evidence  furnished  by 
well-attested  facts  and  universally  acknowledged  natural  laws. 
Even  the  celebrated  Halley,  at  the  end  of  the  seventeenth 
century,  hollowed  out  the  Earth  in  his  magnetic  speculations  I 
Men  were  invited  to  believe  that  a  subterranean  freely-ro- 
tating nucleus  occasions  by  its  position  the  diurnal  and  an- 
nual changes  of  magnetic  declination.  It  has  thus  been  at- 
tempted  in  our  own  day,  with  tedious  solemnity,  to  clothe  in 
a  scientific  garb  the  quaintly-devised  fiction  of  the  humorous 
Ilolberg.* 

*  [The  work  referred  to,  one  of  the  wittiest  prodnctions  of  tlie  learned 
Norwegian  satirist  and  dramatist  Holberg,  was  written  in  Latin,  and 
first  appeared  under  the  following  title  :  Nicolai  Klimii  Her  suhterra- 
neum  novum  tellvris  theonam  ac  historiam  qr/intce  monarchice  adhuc  «o- 
his  incogvAtce  exhibens  e  hibliotheca  b.  Abelini.  Hafniee  ct  Lipsice  snmt. 
Jac.  Prenss,  1741.  An  admirable  Danish  translation  of  this  learned 
but  severe  satire  on  the  institutions,  morals,  and  manners  of  the  inhab* 
itants  of  the  upper  Earth,  appeared  at  Copenhagen  in  1789,  and  was 
entitled  Niels  Klim^s  ujiderjordiske  reise  ved  Lndwig  Holberg,  oversat 


172  COSMOS. 

The  figure  of  the  Earth  and  the  amount  of  solidification 
(density)  w^hich  it  has  acquired  are  intimately  connected  with 
the  forces  by  which  it  is  animated,  in  so  far,  at  least,  as  they 
have  been  excited  or  awakened  from  without,  through  its 
planetary  position  with  reference  to  a  luminous  central  body. 
Compression,  when  considered  as  a  consequence  of  centrifugal 
force  acting  on  a  rotating  mass,  explains  the  earUer  condition 
of  fluidity  of  our  planet.  During  the  solidification  of  this 
fluid,  which  is  commonly  conjectured  to  have  been  gaseous 
and  primordially  heated  to  a  very  high  temperature,  an  enor- 
mous quantity  of  latent  heat  must  have  been  liberated.  If 
the  process  of  solidification  began,  as  Fourier  conjectures,  by 
radiation  from  the  cooling  surface  exposed  to  the  atmosphere, 
the  particles  near  the  center  would  have  continued  fluid  and 
hot.  As,  after  long  emanation  of  heat  from  the  center  toward 
the  exterior,  a  stable  condition  of  the  temperature  of  the 
Earth  would  at  length  be  established,  it  has  been  assumed 
that  with  increasing  depth  the  subterranean  heat  likewise 
uninterruptedly  increases.  The  heat  of  the  water  which 
flows  from  deep  borings  (Artesian  wells),  direct  experiments 
regarding  the  temperature  of  rocks  in  mines,  but,  above  all, 
the  volcanic  activity  of  the  Earth,  shown  by  the  flow  of  molt- 
en masses  from  open  fissures,  afibrd  unquestionable  evidence 
of  this  increase  for  very  considerable  depths  from  the  upper 
strata.  According  to  conclusions  based  certainly  upon  mere 
analogies,  this  increase  is  probably  much  greater  toward  the 
center. 

That  which  has  been  learned  by  an  ingenious  analytic  cal- 
culation, expressly  perfected  for  this  class  of  investigations,* 

efter  den  Latinske  original  af  Jens  Baggesen.  Holberg,  who  studied 
for  a  time  at  Oxford,  was  born  at  Bergen  in  1685,  and  died  in  1754  as 
Rector  of  the  University  of  Copenhagen.] — Tr. 

*  Here  we  must  notice  the  admirable  analytical  labors  of  Fourier, 
Biot,  Laplace;  Poisson,  Duhamel,  and  Lame.  In  his  Th6orie  Mathema- 
tique  de  la  Chaleur,  1835,  p.  3,  428-430,  436,  and  521-524  (see,  also, 
De  la  Rive's  abstract  in  the  Bibliotheque  Universelle  de  Geneve),  Pois- 
son has  developed  an  hypothesis  totally  different  from  Fourier's  view 
(  Theorie  Analytique  de  la  Chaleur.)  He  denies  the  present  fluid  state 
of  the  Earth's  center ;  he  believes  that  "  in  cooling  by  radiation  to  the 
medium  surrounding  the  Earth,  the  parts  which  were  first  solidified 
Bunk,  and  that  by  a  double  descending  and  ascending  current,  the  great 
inequality  was  lessened  which  would  have  taken  place  in  a  solid  body 
cooling  from  the  surface."  It  seems  more  probable  to  this  great  ge- 
ometer that  the  solidification  began  in  the  parts  lying  nearest  to  the 
center :  "  the  phenomenon  of  the  increase  of  heat  with  the  depth  does 
not  extend  to  the  whole  mass  of  the  Earth,  and  is  merely  a  consequence 
of  the  motion  of  our  planetary  system  in  space,  of  which  some  parts 


INTERNAL  HEAT  OF  THE  EARTH.         173 

reguiding  the  motion  of  heat  in  homogeneous  metallic  sphe- 
roids,  must  be  applied  with  much  caution  to  the  actual  char- 
acter of  our  planet,  considering  our  present  imperfect  knowl- 
edge of  the  substances  of  which  the  Earth  is  composed,  the 
difference  in  the  capacity  of  heat  and  in  the  conducting  power 
of  different  superimposed  masses,  and  the  chemical  changes 
experienced  by  solid  and  liquid  masses  from  any  enormous 
compression.  It  is  with  the  greatest  difficulty  that  our  pow- 
ers of  comprehension  can  conceive  the  boundary  line  which  di- 
vides the  fluid  mass  of  the  interior  from  the  hardened  mineral 
masses  of  the  external  surface,  or  the  gradual  increase  of  the 
solid  strata,  and  the  condition  of  semi-fluidity  of  the  earthy 
substances,  these  being  conditions  to  which  known  laws  of 
hydraulics  can  only  apply  under  considerable  modifications. 
The  Sun  and  Moon,  which  cause  the  sea  to  ebb  and  flow, 
fliost  probably  also  affect  these  subterranean  depths.  We 
may  suppose  that  the  periodic  elevations  and  depressions  of 
the  molten  mass  under  the  already  solidified  strata  must  have 
caused  inequalities  in  the  vaulted  surface  from  the  force  of 
pressure.  The  amount  and  action  of  such  oscillations  must, 
however,  be  small ;  and  if  the  relative  position  of  the  attract- 
ing cosmical  bodies  raiay  here  also  excite  "  spring  tides,"  it  is 
certainly  not  to  these,  but  to  more  powerful  internal  forces, 
that  we  must  ascribe  the  movements  that  shake  the  Earth's 
surface.  There  are  groups  of  phenomena  to  whose  existence 
it  is  necessary  to  draw  attention,  in  order  to  indicate  the 
universality  of  the  influence  of  the  attraction  of  the  Sun  and 
Moon  on  the  external  and  internal  conditions  of  the  Earth, 
however  little  we  may  be  able  to  determine  the  quantity  of 
this  influence. 

According  to  tolerably  accordant  experiments  in  Artesian 
wells,  it  ha?  been  shown  that  the  heat  increases  on  an  average 
about  1°  foi  every  54-5  feet.     If  this  increase  can  be  reduced 

are  of  a  very  different  temperature  from  others,  iu  consequence  of  stel- 
lar heat  (chaleur  stellah*e)."  Thus,  accoi'ding  to  Poisson,  the  warmth 
of  the  water  of  our  Artesian  wells  is  merely  that  which  has  penetrated 
into  the  Earth  from  without ;  and  the  Earth  itself  "  might  be  regarded 
as  in  the  same  circumstances  as  a  mass  of  rock  conveyed  from  the 
equator  to  the  pole  in  so  short  a  time  as  not  to  have  entirely  cooled. 
The  .ncrease  of  temperature  in  such  a  block  wtiiuld  not  extend  to  the 
central  strata."  The  physical  doubts  which  have  reasonably  been 
entertained  against  this  extraordinary  cosmical  view  (which  attributes 
to  the  regions  of  space  that  which  probably  is  more  dejieiident  on  the 
first  transition  of  matter  condensing  from  the  gaseo-fluid  into  the  solid 
state)  will  be  found  collected  in  Poggendorf 's  Annalen,  bd.  x.xxix,,  a. 
93-100. 


174  COSMOS. 

to  arithmetical  relations,  it  will  follow,  as  I  have  already  ob- 
served,* that  a  stratum  of  granite  would  be  in  a  state  of  fusion 
at  a  depth  of  nearly  twenty-one  geographical  miles,  or  between 
four  and  five  times  the  elevation  of  the  highest  summit  of  the 
Himalaya. 

We  must  distinguish  in  our  globe  three  different  modes  for 
the  transmission  of  heat.  The  first  is  periodic,  and  affects 
the  temperature  of  the  terrestrial  strata  according  as  the  heat 
penetrates  from  above  downward  or  from  below  upward,  being 
influenced  by  the  different  positions  of  the  Sun  and  the  sea- 
sons of  the  year.  The  second  is  likewise  an  efiect  of  the  Sun, 
although  extremely  slow  :  a  portion  of  the  heat  that  has  pene- 
trated into  the  equatorial  regions  moves  in  the  interior  of  the 
globe  toward  the  poles,  where  it  escapes  into  the  atmosphere 
and  the  remoter  regions  of  space.  The  third  mode  of  trans- 
mission is  the  slowest  of  all,  and  is  derived  from  the  seculaT 
cooling  of  the  globe,  and  from  the  small  portion  of  the  primi- 
tive heat  which  is  still  being  disengaged  from  the  surface. 

*  See  the  Introduction.    This  increase  of  temperature  has  been  found 

in  the  Puits  de  Greuelle,  at  Paris,  at  58'3  feet ;  in  the  boring  at  the  new 

salt-works  at  Minden,  almost  53*6  ;  at  Pregny,  near  Geneva,  according 

to  Auguste  de  la  Rive  and  Marcet,  notwithstanding  that  the  uiouth  oi 

the  boring  is  1609  feet  above  the  level  of  the  seaj  it  is  also  53-6  feet. 

This  coincidence  between  the  results  of  a  method  first  proposed  by 

Arago  in  the  year  1821  {Annuaire  du  Bureau  des  Longitudes,  1835,  p. 

234),  for  three  different  mines,  of  the  absolute  depths  of  1794,  2231, 

and  725  feet  respectively,  is  remarkable.    The  two  points  on  the  Earth, 

lying  at  a  small  vertical  distance  from  each  other,  whose  annual  mean 

temperatures  are  most  accurately  known,  are  probably  at  the  spot  on 

which  the  Paris  Observatory  stands,  and  the  Caves  de  I'Observatoire 

beneath  it:  the  mean  temperature  of  the  former  is  51'^"5,  and  of  the 

latter  53°-3,  the  ditference  being  lo-8  for  92  feet,  or  1°  for  51-77  feet. 

(Poisson,  Thiorie  Math,  de  la  Chaleur,  p.  415  and  462.)     In  the  course 

of  the  last  seventeen  years,  from  causes  not  yet  perfectly  understood, 

but  probably  not  connected  with  the  actual  temperature  of  the  caves, 

the  thermometer  standing  there  has  risen  very  nearly  0'-'*4.     Although 

in  Artesian  wells  there  are  sometimes  slight  errors  from  the  lateral 

permeation  of  water,  these  errors  are  less  injurious  to  the  accuracy  of 

conclusions  than  those  resulting  from  cuiTents  of  cold  air,  which  are 

almost  always  present  in  mines.     The  general  result  of  Reich's  great 

work  on  the  temperature  of  the  mines  in  the  Saxony  mining  districts 

gives  a  somewhat  slower  increase  of  the  terrestrial  heat,  or  1°  to  76*3 

feet.     (Reich,  Beob.  uber  die  Te^nperatur  des  Gesteins  in  verschieden  en 

Tiefen,  1834,  s.  134.)     Phillips,  however,  found  (Pogg.,  Annalen,  bd. 

xxxiv.,  s.   191),  in  a  shaft  of  the  coal-mine  of  Monk-wearmouth,  near 

Newcastle,  in  which,  as  I  have  already  remarked,  excavations  are  going 

on  at  a  depth  of  about  1500  feet  below  the  level  of  the  sea,  an  increase 

of  1°  to  59*06  feet,  a  result  almost  identical  with  that  found  by  Arago 

in  the  Puits  de  Grenell. 


MEAN  TEMPER A TURK  OF  THE  EARTH.       175 

This  loss  experienced  by  the  central  heat  must  have  been  very 
considerable  in  the  earliest  epochs  of  the  Earth's  revolutions, 
but  within,  historical  periods  it  has  hardly  been  appreciable 
by  our  instruments.  The  surface  of  the  Earth  is  therefore 
situated  between  the  glowing  heat  of  the  inferior  strata  and 
the  universal  regions  of  space,  whose  temperature  is  probably 
below  the  freezing-point  of  mercury. 

The   periodic  changes   of  temperature  which   have   been 
occasioned  on  the  Earth's  surface  by  the  Sun's  position  and 
by   meteorological    processes,    are    continued    in   its  interior, 
although  to  a  very  inconsiderable  depth.     The  slow  conduct- 
ing power  of  the  ground  diminishes  this  loss  of  heat  in  the 
winter,  and  is  very  favorable  to  deep-rooted   trees.     Points 
that  lie  at  very  different  depths  on  the  same  vertical  line 
attain  the  maximum  and  minimum  of  the  imparted  tempera- 
ture at  very  different  periods  of  time.     The  further  they  are 
removed  from  the  surface,  the  smaller  is  this  difference  be- 
tween the  extremes.     In  the  latitudes  of  our  temperate  zone 
(between  48^  and  52°),  the  stratum  of  invariable  temperature 
is  at  a  depth  of  from  59  to  64  feet,  and  at  half  that  depth 
the  oscillations  of  the  thermometer,  from  the  influence  of  the 
seasons,  scarcely  amount  to  half  a  degree.     In  tropical  cli- 
mates  this  invariable   stratum   is   only  one   foot  below  the 
surface,  and  this  fact  has  been  ingeniously  made  use  of  by 
Boussingault  to  obtain  a  convenient,  and,  as  he.  believes,  cer- 
tain determination  of  the  mean  temperature  of  the  air  of 
different  places.*     This  mean  temperature  of  the  air  at  a 
fixed  point,  or  at  a  group  of  contiguous  points  on  the  surface, 
is  to  a  certaiij  degree  the  fundamental  element  of  the  climato 
and  agricultural  relations  of  a  district ;  but  the  mean  tem- 
perature  of  the  whole  surface  is  very  different  from  that  of 
the  globe  itself.     The  questions  so  often  agitated,  whether  the 
mean  temperature  has  experienced  any  considerable  differences 
in  the  course  of  centuries,  whether  the  climate  of  a  country 
has  deteriorated,  and  whether  the  winters  have  not  become 
milder   and   the   summers  cooler,  can  only  be  answered  by 
means  of  the  thermometer  ;   this  instrument  has,  however, 
scarcely  been  invented  more  than  two  centuries  and  a  half, 
and  its  scientific   application  hardly  dates   back   120  years. 
The  nature  and  novelty  of  the  means  interpose,  therefore,  very 
narrow  limits  to  our  investigation  regarding  the  temperature 

*  Boussingault,  Su7-  la  Profondeur  a  laqnelle  se  trouve  la  Coiiche  de 
Temperature  invariable  entre  les  Tropiqv.es,  in  the  Annalcf  de.  Chimin 
et  de  Physique,  t.  liii.,  1833,  p.  225-247. 


176  COSMOS. 

of  the  air.  It  is  quite  otherwise,  however,  with  the  solution 
of  the  great  problem  of  the  internal  heat  of  the  whole  Earth. 
As  we  may  judge  of  uniformity  of  temperature  from  the  unal- 
tered time  of  vibration  of  a  pendulum,  so  we  may  also  learn, 
from  the  unaltered  rotatory  velocity  of  the  Earth,  the  amount 
of  stability  in  the  mean  temperature  of  our  globe.  This 
msight  into  the  relations  between  the  length  of  the  day  and 
the  heat  of  the  Earth  is  the  result  of  one  of  the  most  brilliant 
applications  of  the  knowledge  we  had  long  possessed  of  the 
movement  of  the  heavens  to  the  thermic  condition  of  our 
planet.  The  rotatory  velocity  of  the  Earth  depends  on  its 
volume  ;  and  since,  by  the  gTadual  cooling  of  the  mass  by 
radiation,  the  axis  of  rotation  would  become  shorter,  the  rota- 
tory velocity  would  necessarily  increase,  and  the  length  of  the 
day  diminish,  with  a  decrease  of  the  temperature.  From  the 
comparison  of  the  secular  inequalities  in  the  motions  of  the 
Moon  with  the  eclipses  observed  in  ancient  times,  it  follows 
that,  smc«  the  time  of  Hipparchus,  that  is,  for  full  2000 
years,  the  length  of  the  day  has  certainly  not  diminished  by 
the  hundredth  part  of  a  second.  The  decrease  of  the  mean 
heat  of  the  globe  during  a  period  of  2000  years  has  not,  there- 
fore, taking  the  extremest  limits,  diminished  as  much  as  a^gth 
of  a  degree  of  Fahrenheit.* 

This  invariability  of  form  presupposes  also  a  great  invaria- 
bility in  the  distribution  of  relations  of  density  in  the  interior 
of  the  globe.  The  translatory  movements,  which  occasion 
the  eruptions  of  our  present  volcanoes  and  of  ferruginous  lava, 
and  the  filling  up  of  previously  empty  fissures  and  cavities 
with  dense  masses  of  stone,  are  consequently  dnly  to  be  re- 
garded as  slight  superficial  phenomena  afiecting  merely  one 
portion  of  the  Earth's  crust,  which,  from  their  smallness 
when  compared  to  the  Earth's  radius,  become  wholly  insig- 
nificant. 

I  have  described  the  internal  heat  of  our  planet,  both  with 
reference  to  its  cause  and  distribution,  almost  solely  from  the 
results  of  Fourier's  admirable  investigations.  Poisson  doubts 
the  fact  of  the  uninterrupted  increase  of  the  Earth's  heat 

*  Laplace,  Exp.  dit,  Syst.  du  Monde,  p.  229  and  263  ;  Micaniqu6 
Celeste,  t.  v.,  p.  18  and  72.  It  should  be  remarked  that  the  fraction 
5^th  of  a  degree  of  Fahrenheit  of  the  mercurial  thermometer,  given  in 
the  text  as  the  limit  of  the  stability  of  the  Earth's  temperature  since 
the  days  of  Hipparchus,  rests  on  the  assumption  that  the  dilatation  of 
the  substances  of  which  the  Earth  is  composed  is  equal  to  that  of  glass. 
that  is  to  say,  y^.^o-oth  for  1°.  Regarding  this  hypothesis,  see  Arago 
in  the  Annuaire  for  1834,  p.  177-190. 


TERRESTRIAL  MAGNETISM.  177 

from  the  surface  to  the  center,  and  is  of  opinion  that  all  heat 
has  penetrated  from  without  inward,  and  that  the  tempera- 
ture of  the  globe  depends  upon  the  very  high  or  very  low 
temperature  of  the  regions  of  space  through- which  the  solar 
system  has  moved.  This  hypotiiesis,  imagined  by  one  of  the 
most  acute  mathematicians  of  our  time,  has  not  satisfied  phys- 
icists or  geologists,  or  scarcely,  indeed,  any  one  besides  its  au- 
thor. But,  whatever  mav  be  the  cause  of  the  internal  heat 
of  our  planet,  and  of  its  limited  or  unlimited  increase  in  deep 
strata,  it  leads  us,  in  this  general  sketch  of  nature,  through 
the  intimate  connection  of  all  primitive  phenomena  of  matter, 
and  through  the  common  bond  by  which  molecular  forces  are 
united,  into  the  mysterious  domain  of  magnetism.  Changes 
of  temperature  call  forth  magnetic  and  electric  currents.  Ter- 
restrial magnetism,  whose  main  character,  expressed  in  the 
three-fold  manifestation  of  its  forces,  is  incessant  periodic  va- 
riabihty,  is  ascribed  either  to  the  heated  mass  of  the  Earth 
itself,*  or  to  those  galvanic  currents  which  we  consider  as 
electricity  in  motion,  that  is,  electricity  moving  in  a  closed 
circuit.! 

The  mysterious  course  of  the  magnetic  needle  is  equally 
affected  by  time  and  space,  by  the  sun's  course,  and  by  changes 
of  place  on  the  Earth's  surface.  Between  the  tropics,  the 
hour  of  the  day  may  be  known  by  the  direction  of  the  needle 
as  well  as  by  the  oscillations  of  the  barometer.  It  is  affected 
instantly,  but  only  transiently,  by  the  distant  northern  light 
as  it  shoots  from  the  pole,  flashing  in  beams  of  colored  light 
across  the  heavens.  When  the  uniform  horary  motion  of  the 
needle  is  disturbed  by  a  magnetic  storm,  the  perturbation 
manifests  itself  simultaneously,  in  the  strictest  sense  of  the 
word,  over  hundreds  and  thousands  of  miles  of  sea  and  land, 
or  propagates  itself  by  degrees,  in  short  intervals  of  time,  in 

*  William  Gilbert,  of  Colchester,  whom  Galileo  pronounced  "  great 
to  a  degree  that  might  be  envied,"  said  "  magnus  magnes  ipse  est  globus 
terrestris."  He  ridicules  the  magnetic  mountains  of  Frascatori,  the  great 
cotemporary  of  Columbus,  as  being  magnetic  poles :  "  rejicienda  est 
vulgaris  opinio  de  montibus  magneticis,  aut  rupe  aliqua  magnetica,  aut 
polo  phantastico  a  polo  mundi  distante."  He  assumes  the  declination 
of  the  magnetic  needle  at  any  given  point  on  the  surface  of  the  Earth 
to  be  invariable  (variatio  uuiuscujusque  loci  constans  est),  and  refers 
the  curvatures  of  the  isogenic  lines  to  the  configuration  of  continents 
and  the  relative  positions  of  sea  basins,  wrhich  possess  a  weaker  mag- 
netic force  than  the  solid  masses  rising  above  the  ocean.  (Gilbert,  de 
Magnate,  ed.  1633,  p.  42,  98,  152,  and  155.) 

t  Gauss,  Allgemeine  Theorie  des  Erdmagnetismus,  in  the  Resultate  aut 
■  den  Beob.  des  Magnet.  Vereins,  1838,  s.  41,  p.  56. 

H  2 


17^  COSMOS. 

every  direction  over  the  Earth's  surface.*  In  the  former  case, 
the  simultaneous  manifestation  of  the  storm  may  servCj  with- 
in certain  hmitations.  Hke  Jupiter's  satelhtes,  fire-signals,  and 
well-observed  falls  of  shooting  stars,  for  the  geographical 
determination  of  degrees  of  longitude.  We  here  recognize 
with  astonishment  that  the  perturbations  of  two  small  mag- 
netic needles,  even  if  suspended  at  great  depths  below  the 
surface,  can  measure  the  distances  apart  at  which  they  are 
placed,  teaching  us,  for  instance,  how  far  Kasan  is  situated 
east  of  Gottingen  or  of  the  banks  of  the  Seine.  There  are 
also  districts  in  the  earth  where  the  mariner,  who  has  been 
enveloped  for  many  days  in  mist,  without  seeing  either  the 
sun  or  stars,  and  deprived  of  all  means  of  determining  the 
tirhe,  may  know  with  certainty,  from  the  variations  in  the 
inclination  of  the  magnetic  needle,  whether  he  is  at  the  north 
or  the  south  of  the  port  he  is  desirous  of  entering.! 

*  There  are  also  perturbations  which  are  of  a  local  character,  and 
do  not  extend  themselves  far,  and  are  probably  less  deep-seated.  Some 
years  ago  I  described  a  rare  instance  of  this  kind,  in  which  an  extraor- 
dinaiy  disturbance  was  felt  in  the  mines  at  Freiberg,  but  was  not  per- 
ceptible at  Berlin.  {Lettre  de  M.  de  Humboldt  a  Son  Altesse  Roy  ale  le 
Due  de  Sussex- sti7'  les  moyens  propres  a  perfectionner  la  Connaissance 
ill  Magn6tisme  Terrestre,  in  Becquerel's  TraiiS  Experimental  de  VElec- 
tricitS,  t.  vii.,  p.  442.)  Magnetic  storms,  which  were  simultaneously 
felt  from  Sicily  to  Upsala,  did  not  extend  from  Upsala  to  Alten.  (Gauss 
and  Weber,  Resultate  des  Magnet.  Vereins,  1839,  $  128;  Lloyd,  in  the 
Comptcs  Rendus  de  I' Acad,  des  Sciences,  t.  xiii.,  1843,  Sem.  ii.,  p.  725 
and  827.)  Among  the  numerous  examples  that  have  been  recently 
observed,  of  perturbations  occurring  simultaneously  and  extending  over 
wide  portions  of  the  Earth's  sm-face,  and  which  are  collected  in  Sabine's 
important  work  {Observ.  on  Days  of  unusual  Magnetic  Disturbance, 
1843),  one  of  the  most  i-emarkable  is  that  of  the  25th  of  September, 
1841,  which  was  observed  at  Toronto  in  Canada,  at  the  Cape  of  Good 
Hope,  at  Prague,  and  partially  in  Van  Diemen's  Land.  The  English 
Sunday,  on  which  it  is  deemed  sinful,  after  midnight  on  Saturday,  to 
register  an  observation,  and  to  follow  out  the  great  phenomena  of  crea- 
tion in  their  perfect  development,  interrupted  the  observatious  in  Van 
Diemen's  Land,  where,  in  consequence  of  the  difference  of  the  longi- 
tude, the  magnetic  storm  fell  on  the  Sunday.  {Observ.,  p.  xiv.,  78,  85, 
and  87.) 

t  I  have  described,  in  Lametherie's  Journal  de  Physique,  1804,  t. 
lix.,  p.  449,  the  application  (alluded  to  in  the  text)  of  the  jnagnetic  in- 
clination to  the  determination  of  latitude  along  a  coast  naming  north 
and  south,  and  which,  like  that  of  Chili  and  Peru,  is  for  a  part  of  the 
year  enveloped  in  mist  {gar7ia).  In  the  locality  I  have  just  mentioned, 
thi^  application  is  of  the  greater  importance,  because,  in  consequence 
of  the  strong  current  running  northward  as  far  as  to  Cape  Parena,  navi- 
gators incur  a  great  loss  of  time  if  they  approach  the  coast  to  the  north 
of  the  haven  they  are  seeking.  In  the  South  Sea,  from  Callao  de  Lima 
harbor  to  Truxillo,  which  differ  from  each  other  in  latitude  by  3°  57' 


TERRESTRIAL    MAHNETISM.  179 

When  the  needle,  by  its  sudden  disturbance  in  its  horary 
course,  indicates  the  presence  of  a  magnetic  storm,  we  are 
stiJl  unfortunately  ignorant  whether  the  seat  of  the  disturbing 
cause  is  to  be  sought  in  the  Earth  itself  or  in  the  upper  re- 
gions of  the  atmosphere.  If  we  regard  the  Earth  as  a  true 
magnet,  we  are  obliged,  according  to  the  views  entertained 
by  Friedrich  Gauss  (the  acute  propounder  of  a  general  theory 
of  terrestrial  magnetism),  to  ascribe  to  every  portion  of  the 
globe  measuring  one  eighth  of  a  cubic  meter  (or  Sy'^-ths  of  a 
French  cubic  foot)  in  volume,  an  average  amount  of  magnet- 
ism equal  to  that  contained  in  a  magnetic  rod  of  1  lb.  weight.* 
If  iron  and  nickel,  and  probably,  also,  cobalt  (but  not  chrome, 
as  has  long  been  believed),!  are  the  only  substances  which 
become  permanently  magnetic,  and  retain  polarity  from  a 
certain  coercive  force,  the  phenomena  of  Arago's  magnetism 
of  rotation  and  of  Faraday's  induced  currents  show,  on  the 
other  hand,  that  all  telluric  substances  may  possibly  be  made 
transitorily  magnetic.     According  to  the  experiments  of  the 

I  have  observed  a  variation  of  the  magnetic  inclination  amounting  to 
9°  (centesimal  division) ;  and  from  Callao  to  Guayaquil,  which  differ  in 
latitude  by  9°  50',  a  variation  of  23^-5.  (See  my  Relat.  Hist.,  t.  iii., 
p.  622.)  At  Guarmey  (10°  4'  south  lat.),  Huaura  (11°  3'  south  lat.), 
and  Chancay  (11°  32'  south  lat.),  the  incHnations  are  6°-80,  9°,  and 
10°-3.5  of  the  centesimal  division.  The  determination  of  position  by 
means  of  the  magnetic  inclination  has  this  remarkable  feature  connected 
with  it,  that  where  the  ship's  course  cuts  the  isoclinal  line  almost  per- 
pendicularly, it  is  the  only  one  that  is  independent  of  all  determination 
of  time,  and,  consequently,  of  observations  of  the  sun  Or  stars.  It  is 
only  lately  that  I  discovered,  for  the  first  time,  that  as  eaiiy  as  at  the 
close  of  the  sixteenth  century,  and  consequently  hardly  twenty  years 
after  Robert  Norman  had  invented  the  inclinatorium,  William  Gilbert, 
in  his  gi-eat  work  De  Magnete,  proposed  to  determine  the  latitude  by 
the  inclination  of  the  magnetic  needle.  Gilbert  {Physiologia  Nova  de 
Magneie,  lib.  v.,  cap.  8,  p.  200)  commends  the  method  as  applicable 
"  a^re  caliginoso."  Edward  Wright,  in  the  introduction  which  he 
added  to  his  master's  great  work,  describes  this  proposal  as  "  worth 
much  gold."  As  he  fell  into  the  same  error  with  Gilbert,  of  presum 
ing  that  the  isoclinal  lines  coincided  with  the  geographical  parallel 
circles,  and  that  the  magnetic  and  geographical  equators  were  identic- 
al, he  did  not  perceive  that  the  proposed  method  had  only  a  local  and 
very  limited  application. 

*  Gauss  and  Weber,  Resvltate  des  Magnet.  Vereins,  1838,  §  31,  s.  146. 

+  According  to  Faraday  (London  and  Edinburgh  Philosophical  Maga- 
zine, 1836,  vol.  viii.,  p.  178),  pure  cobalt  is  totally  devoid  of  magnetic 
power.  I  know,  however,  that  other  celebrated  chemists  (Heinrich 
Rose  and  Wohler)  do  not  admit  this  as  absolutely  certain.  If  out  of 
two  cai-efuUy-purified  masses  of  cobalt  totally  free  from  nickel,  one  ap- 
pears altogether  non-magnetic  (in  a  state  of  equilibrium),  I  think  it 
probable  that  the  other  owes  its  m;ignetic  property  to  a  want  of  purity ; 
and  this  opinion  coincides  with  Faraday's  view. 


180  COSMOS. 

h'rst-mentioned  of  these  great  physicists,  water,  ice,  glass,  and 
carbon  affect  the  vibrations  of  the  needle  entirely  in  the  same 
manner  as  mercury  in  the  rotation  experiments.*  Almost  all 
substances  show  themselves  to  be,  in  a  certain  degree,'  mag- 
netic when  they  are  conductors,  that  is  to  say,  when  a  current 
of  electricity  is  passing  through  them. 

Although  the  knowledge  of  the  attracting  poAver  of  native 
iron  magnets  or  loadstones  appears  to  be  of  very  ancient  date 
among  the  nations  of  the  West,  there  is  strong  historical  evi- 
dence in  proof  of  the  striking  fact  that  the  knowledge  of  the 
directive  power  of  a  magnetic  needle  and  of  its  relation  to 
terrestrial  magnetism  was  peculiar  to  the  Chinese,  a  people 
living  in  the  extremest  eastern  portions  of  Asia.  More  than 
a  thousand  years  before  our  era,  in  the  obscure  age  of  Codrus, 
and  about  the  time  of  the  return  of  the  Heraclidse  to  the  Pel- 
oponnesus, the  Chinese  had  already  magnetic  carriages,  on 
which  the  movable  arm  of  the  figure  of  a  man  continually 
pointed  to  the  south,  as  a  guide  by  which  to  find  the  way 
across  the  boundless  grass  plains  of  Tartary  ;  nay,  even  in  the 
third  century  of  our  era,  therefore  at  least  700  years  before 
the  use  of  the  mariner's  compass  in  European  seas,  Chinese 
vessels  navigated  the  Indian  Oceanf  under  the  direction  of 
magnetic  needles  pointing  to  the  south.  I  have  shown,  in 
another  work,  what  advantages  this  means  of  topographical  di- 
rection, and  the  early  knowledge  and  application  of  the  mag- 
netic needle  gave  the  Chinese  geographers  over  the  Greeks 
and  Romans,  to  whom,  for  instance,  even  the  true  direction 
of  the  Apennines  and  Pyrenees  always  remained  unknown. $ 

The  magnetic  power  of  our  globe  is  manifested  on  the  ter- 
restrial surface  in  three  classes  of  phenomena,  one  of  which 
exhibits  itself  in  the  varying  intensity  of  the  force,  and  the 
two  others  in  the  varying  direction  of  the  inclination,  and  in 

*  Arago,  in  the  Annales  de  Cliimie,  t.  xxxii.,  p.  214  ;  Brewster,  Treat- 
ise on  Magnetism,  1837,  p.  Ill;  Baumgartner,  in  the  Zeitschrift  fur 
Phys.  und  Mathem.,  bd.  ii.,  s.  419. 

t  Humboldt,  Examen  Critique  de  VHist.  de  la  Giographie,  t.  iii.,  p.  36. 

X  Asie  Centrale,  t.  i.,  Introduction,  p.  xxxviii.-xlii.  The  Western 
nations,  the  Greeks  and  the  Romans,  knew  that  magnetism  could  be 
communicated  to  iron,  and  that  that  metal  loould  retain  it  for  a  length  of 
time.  ("  Sola  hsec  materia  ferri  vires,  a  magnate  lapide  accipit,  retinet- 
que  longo  tempore."  Plin.,  xxxiv.,  14.)  The  great  discovery  of  the  ter- 
restrial directive  force  depended,  therefore,  alone  on  this,  that  no  one 
in  the  West  had  happened  to  observe  an  elongated  fragment  of  magnet- 
ic iron  stone,  or  a  magnetic  iron  rod,  floating,  by  the  aid  of  a  piece  of 
wood,  in  water,  or  suspended  in  the  air  by  a  tbreac],  in  such  a  position 
as  to  admit  of  free  motion. 


TERRESTRIAL   MAGNETISM.  181 

the  horizontal  deviation  from  the  terrestrial  meridian  of  the 
spot.  Their  combined  action  may  therefore  be  graphically 
represented  by  three  systems  of  lines,  the  isodynaniic,  isodinic, 
and  isogonic  (or  those  of  equal  force,  equal  inclination,  and 
equal  declination).  The  distances  apart,  and  the  relative  po- 
sitions of  these  moving,  oscillating,  and  advancing  curves,  do 
not  always  remain  the  same.  The  total  deviation  (variation 
or  declination  of  the  magnetic  needle)  has  not  at  all  changed, 
or,  at  any  rate,  not  in  any  appreciable  degree,  during  a  vv^hole 
century,  at  any  particular  point  on  the  Earth's  surface,*  as, 
for  instance,  the  western  part  of  the  Antilles,  or  Spitzbergen. 
In  like  manner,  we  observe  that  the  isogonic  curves,  when  they 
pass  in  their  secular  motion  from  the  surface  of  the  sea  to  a 
continent  or  an  island  of  considerable  extent,  continue  for  a  long 
time  in  the  same  position,  and  become  inflected  as  they  advance. 
These  gradual  changes  in  the  forms  assumed  by  the  lines 
in  their  translatory  motions,  and  which  so  unequally  modify 
the  amount  of  eastern  and  western  declination,  in  the  course 
of  time  render  it  difficult  to  trace  the  transitions  and  analogies 
of  forms  in  the  graphic  representations  belonging  to  different 
centuries.  Each  branch  of  a  curve  has  its  liistory,  but  this 
history  docs  not  reach  further  back  among  the  nations  of  the 
West  than  the  memorable  epoch  uf  the  13th  of  September, 
1492,  when  the  re-discoverer  of  the  New  World  found  a  line 
of  no  variation  3*^  west  of  the  meridian  of  the  island  ol'  Flores, 
one  of  the  Azores. t     The  whole  of  Europe,  excepting  a  small 

*  A  very  slow  secular  progression,  or  a  local  invariability  of  the  mag- 
netic declination,  prevents  the  confusion  which  might  arise  from  terres- 
trial influences  in  the  boundaries  of  land,  when,  with  an  utter  disregard 
for  the  coiTection  of  declination,  estates  are,  after  long  intervals,  meas- 
ured by  the  mere  application  of  the  compass.  "  The  whole  mass  of 
West  Indian  property,"  says  Sir  John  Herschel,  "  has  been  saved  from 
the  bottomless  pit  of  endless  litigation  by  the  invariability  of  the  mag- 
netic declination  in  Jamaica  and  the  surrounding  Archipelago  during 
the  whole  of  the  last  century,  all  surveys  of  property  there  having 
been  conducted  solely  by  the  compass."  See  Robertson,  in  the  Philo- 
sophical Transactions  for  1806,  Part  ii.,  p.  348,  On  the  Permanency  of 
the  Compass  in  Jamaica  since  1660.  In  the  mother  country  (England) 
the  magnetic  declination  has  varied  by  fully  14°  during  that  period. 

t  I  have  elsewhere  shown  that,  from  the  documents  which  have 
come  down  to  us  regarding  the  voyages  of  Columbus,  we  can,  with 
much  certainty,  fix  upon  three  places  in  the  Atlantic  line  of  no  declina- 
tion for  the  13th  of  September,  1492,  the  21st  of  May,  1496,  and  the 
16th  of  August,  1498.  The  Atlantic  line  of  no  declination  at  that  pe- 
riod ran  from  northeast  to  southwest.  It  then  touched  the  South 
American  continent  a  little  east  of  Cape  Codera,  while  it  is  now  ob- 
served to  reach  that  continent  on  the  northern  coast  of  the  Brazils. 
(Humboldt,  Examen  Critique  de  VHist.  de  la  Giogr.,  t.  iii.,  p.  44-48.) 


182  COSMOS. 

part  of  Russia,  has  now  a  western  declination,  while  at  the 
close  of  the  seventeenth  century  the  needle  first  pointed  due 
north,  in  London  in  1657,  and  in  Paris  in  1669,  there  being 
thus  a  difference  of  twelve  years,  notwithstanding  the  small 
distance  between  these  two  places.  In  Eastern  Russia,  to 
the  east  of  the  mouth  of  the  Volga,  of  Saratow,  Nischni-Now- 
gorod,  and  Archangel,  the  easterly  declination  of  Asia  is  ad- 
vancino-  toward  us.  Two  admirable  observers,  Hansteen  and 
Adolphus  Erman,  have  made  us  acquainted  with  the  remark- 
able double  curvature  of  the  lines  of  declination  in  the  vast 
region  of  Northern  Asia  ;  these  being  concave  toward  the 
pole  between  Obdorsk,  on  the  Oby,  and  Turuchansk,  and  con- 
vex between  the  Lake  of  Baikal  and  the  Gulf  of  Ochotsk.  In 
this  portion  of  the  earth,  in  northern  Asia,  between  the  mount- 
ains of  Werchojansk,  Jakutsk,  and  the  northern  Korea,  the 
isogenic  lines  form  a  remarkable  closed  system.  This  oval 
configuration^  recurs  regularly,  and  over  a  great  extent  of  the 
South  Sea,  almost  as  far  as  the  meridian  of  Pitcairn  and  the 
group  of  the  Marquesas  Islands,  between  20°  north  and  45° 

From  Gilbert's  Physiologia  Nova  de  Magnate,  we  see  plainly  (and  the 
fact  is  very  remarkable)  that  in  1600  the  declination  was  still  null  in 
the  region  of  the  Azoi'es,  just  as  it  had  been  in  the  time  of  Columbus 
(lib.  4,  cap.  1).  I  believe  that  in  my  Examen  Critique  (t.  iii.,  p.  54) 
I  have  proved  from  documents  that  the  celebrated  line  of  demarkation 
by  which  Pope  Alexander  VI.  divided  the  Western  hemisphere  between 
Portugal  and  Spain  was  not  drawn  through  the  most  western  point  of 
the  Azores,  because  Columbus  wished  to  convert  a  physical  into  a  po- 
litical division.  He  attached  great  importance  to  the  zone  (raya)  "  iu 
which  the  compass  shows  no  variation,  where  air  and  ocean,  the  latter 
covered  with  pastures  of  sea-weed,  exhibit  a  peculiar  constitution, 
where  cooling  winds  begin  to  blow,  and  where  [as  erroneous  observa- 
tions of  the  polar  star  led  him  to  imagine]  the  form  (sphericity)  of  the 
Earth  is  no  longer  the  same." 

*  To  determine  whether  the  two  oval  systems  of  isogouic  lines,  so 
singularly  included  each  within  itself,  will  continue  to  advance  for  cen- 
turies iu  the  same  inclosed  form,  or  will  unfold  and  expand  themselves, 
is  a  question  of  the  highest  interest  in  the  problem  of  the  physical 
causes  of  terrestrial  magnetism.  In  the  Eastern  Asiatic  nodes  the  dec- 
lination increases  from  without  inward,  while  in  the  node  or  oval  sys- 
tem of  the  South  Sea  the  opposite  holds  good ;  in  fact,  at  the  present 
time,  in  the  whole  South  Sea  to  the  east  of  the  meridian  of  Kamt- 
schatka,  there  is  no  line  where  the  dechnation  is  null,  or.  indeed,  in 
which  it  is  less  than  2°  (Erman.  in  Pogg.,  Annal.,  bd.  xxxi.,  §  129). 
Yet  Cornelius  Schouten,  on  Easter  Sunday^  1616.  appears  to  have  found 
the  declination  null  somewhere  to  the  southeast  of  Nnkahiva,  in  1.5 '^ 
south  lat.  and  132°  west  long.,  and  consequently  in  the  middle  of  tlie 
present  closed  isogonal  system.  (Hanstee'n,  Magnet,  der  Erde,  1819,  ^ 
28.)  It  must  not  be  forgotten,  in  the  midst  of  all  these  considerations. 
that  we  can  only  follow  the  direction  of  the  magnetic  lines  in  their 
progress  as  they  ai'e  projected  upon  the  surface  of  the  Earth. 


MAGNETISM.  183 

south  lat.  One  would  almost  be.  inclined  to  refjard  this  sin- 
gular config-uration  of  closed,  almost  concentric,  lines  of  decli- 
nation as  the  effect  of  a  local  character  of  that  portion  of  the 
globe  ;  but  if,  in  the  course  of  centuries,  these  apparently  iso- 
lated systems  should  also  advance,  we  must  suppose,  as  in  the 
case  ol"  all  great  natural  forces,  that  the  phenomenon  arises 
from  some  general  cause. 

The  horary  variations  of  the  declination,  which,  although 
dependent  upon  true  time,  are  apparently  governed  by  the 
Sun,  as  long  as  it  remains  above  the  horizon,  diminish  in  an- 
gular value  with  the  magnetic  latitude  of  place.  Near  the 
equator,  for  instance,  in  the  island  of  Rawak,  they  scarcely 
amount  to  three  or  four  minutes,  while  they  are  from  thirteen 
to  fourteen  minutes  in  the  middle  of  Europe.  As  in  the  whole 
northern  hemisphere  the  north  point  of  the  needle  moves  from 
east  to  west  on  an  average  from  8^  in  the  morning  until  1^  at 
mid-day,  while  in  the  southern  hemisphere  the  same  north 
point  moves  from  west  to  east,*  attention  has  recently  been 
drawn,  with  much  justice,  to  the  fact  that  there  must  be  a 
region  of  the  Earth  between  the  terrestrial  and  the  magnetic 
equator  where  no  horary  deviations  in  the  declination  are  to  be 
observed.  This  fourth  curve,  which  might  be  called  the  curve 
of  no  motio7i,  or,  rather,  the  line  of  no  variation  of  horary 
declination,  has  not  yet  been  discovered. 

The  term  magnetic  'poles  has  been  applied  to  those  points 
of  the  Earth's  surface  where  the  horizontal  power  disappears, 
and  more  importance  has  been  attached  to  these  points  than 
properly  appertains  to  them  ;t  and  in  like  manner,  the  curve, 
where  the  inclination  of  the  needle  is  null,  has  been  termed 
the  magnetic  equator.  The  position  of  this  line  and  its  secular 
change  of  configuration  have  been  made  an  object  of  careful 
investigation  in  modern  times.  According  to  the  admirable 
work  of  Duperrey,$  who  crossed  the  magnetic  equator  six  times 
between  1822  and  1825,  the  nodes  of  the  two  equators,  that 
is  to  say,  the  two  points  at  whicli  the  line  without  inclination 
intersects  the  terrestrial  equator,  and  consequently  passes  from 
one  hemisphere  into  the  other,  are  so  unequally  placed,  that 
in  1825  the  node  near  the  island  of  St.  Thomas,  on  the  west- 

*  Arago,  in  the  Annvaire,  1836,  p.  284,  and  1840,  p.  330-338. 

t  Gauss,  Allg'.  Theorie  des  Erdmagnet..  §  31. 

X  Duperrey,  De  la  Corifiguration  de  V Equateur  Magnitique,  in  the 
Annales  de  Chimie,  t.  xlv.,  p.  371  and  379.  (See,  also,  Morlet,  in  the 
M&moires  presentis  par  divers  Savans  a  V Acad.  Roy.  des  Sciences,  t.  iii., 
p.  132.) 


184  COSMOS. 

ern  coast  of  Africa,  was  1881°  distant  from  the  node  m  the 
South  Sea,  close  to  the  little  islands  of  Gilbert,  nearly  in  the 
meridian  of  the  Viti  group.  In  the  beginning  of  the  present 
century,  at  an  elevation  of  11,936  feet  above  the  level  of  the 
sea,  I  made  an  astronomical  determination  of  the  point  (7°  1' 
south  lat.,  48°  40'  west  long,  from  Paris),  where,  in  the  in- 
terior of  the  New  Continent,  the  chain  of  the  Andes  is  inter- 
sected by  the  magnetic  equator  between  Quito  and  Lima.  To 
the  west  of  this  point,  the  magnetic  equator  continues  to  trav- 
erse the  South  Sea  in  the  southern  hemisphere,  at  the  same 
time  slowly  drawing  near  the  terrestrial  equator.  It  first  pass- 
es into  the  northern  hemisphere  a  little  before  it  approaches 
the  Indian  Archipelago,  just  touches  the  southern  points  of 
Asia,  and  enters  the  African  continent  to  the  west  of  Socotora, 
almost  in  the  Straits  of  Bab-el-Mandeb,  where  it  is  most  dis- 
tant from  the  terrestrial  equator.  After  intersecting  the  un- 
known regions  of  the  interior  of  Africa  in  a  southwest  direc- 
tion, the  magnetic  equator  re-enters  the  south  tropical  zone  in 
the  Gulf  of  Guinea,  and  retreats  so  far  from  the  terrestrial 
equator  that  it  touches  the  Brazilian  coast  near  Os  Ilheos, 
north  of  Porto  Seguro,  in  15°  south  lat.  From  thence  to  the 
elevated  plateaux  of  the  Cordilleras,  between  the  silver  mines 
of  Micuipampa  and  Caxamarca,  the  ancient  seat  of  the  Incas, 
where  I  observed  the  inclination,  the  line  traverses  the  whole 
of  South  America,  which  in  these  latitudes  is  as  much  a  mag- 
netic terra  incognita  as  the  interior  of  Africa. 

The  recent  observations  of  Sabine*  have  shown  that  the 
node  near  the  island  of  St.  Thomas  has  moved  4°  from  east  to 
west  between  1825  and  1837.  It  would  be  extremely  im- 
portant to  know  whether  the  opposite  pole,  near  the  Gilbert 
Islands,  in  the  South  Sea,  has  approached  the  meridian  of  the 
Carolinas  in  a  westerly  direction.  These  general  remarks  will 
be  sufficient  to  connect  the  different  systems  of  isoclinic  non- 
parallel  lines  with  the  great  phenomenon  of  equilibrium  which 
is  manifested  in  the  magnetic  equator.  It  is  no  small  advant- 
age, in  the  exposition  of  the  laws  of  terrestrial  magnetism,  that 
the  magnetic  equator  (whose  oscillatory  change  of  form  and 
whose  nodal  motion  exercise  an  influence  on  the  inclination 
of  the  needle  in  the  remotest  districts  of  the  world,  in  conse- 
quence of  the  altered  magnetic  latitudes)!  should  traverse  the 

*  See  the  remarkable  chart  of  isocliuic  lines  in  the  Atlantic  Ocear 
for  the  years  1825  and  1837,  in  Sabine's  Contributions  to  Terrcstria- 
Magnetism,  1840,  p.  134. 

\  Huinljoldt,  Ucher  die  seciildre  Verdnderung  der  Magnetischea  In- 


MAGNETISM.  185 

ocean  throughout  its  whole  course,  excepting  ahout  one  fifth, 
and  consequently  be  made  so  much  more  accessible,  owing  to 
the  remarkable  relations  in  space  between  the  sea  and  land, 
and  to  the  means  of  which  we  are  now  possessed  for  determin- 
ing with  much  exactness  both  the  declination  and  the  inclina- 
tion at  sea. 

We  have  described  the  distribution  of  magnetism  on  the 
surface  of  our  planet  according  to  the  two  forms  of  declination 
and  iTiclination  ;  it  now,  tlierefore,  remains  for  us  to  speak  of 
the  intensity  of  the  force  which  is  graphically  expressed  by 
isodynamic  curves  (or  lines  of  equal  intensity).  The  investi- 
gation and  measurement  of  this  force  by  the  oscillations  of  a 
vertical  or  horizontal  needle  have  only  excited  a  general  and 
lively  interest  in  its  telluric  relations  since  the  beginning  of 
the  nineteenth  century.  The  application  of  delicate  optical 
and  chronometrical  instruments  has  rendered  the  measure- 
ment of  this  horizontal  power  susceptible  of  a  degree  of  accu- 
racy far  surpassing  that  attained  in  any  other  magnetic  de- 
terminations. The  isogenic  lines  are  the  more  important  in 
their  immediate  application  to  navigation,  while  we  find  from 
the  most  recent  views  that  isodynamic  lines,  especially  those 
which  indicate  the  horizontal  force,  are  the  most  valuable  ele- 
ments in  the  theorv  of  terrestrial  magnetism.*  One  of  the 
earliest  facts  yielded  by  observation  is,  that  the  intensity  of 
the  total  force  increases  from  the  equator  toward  the  pole.t 

clination  (On  the  secular  Change  in  the  Magnetic  Inclination),  in  Pogo-., 
Annal.,  bd.  xv.,  s.  322. 

*  Gauss,  Resultate  der  Beob.  des  Magn.  Vereins,  1838,  ^  21;  Sabine, 
Report  on  the  Variations  of  the  Magnetic  Intensity,  p.  63. 

t  The  following  is  the  histoiy  of  the  discovery  of  the  law  that  the 
intensity  of  the  force  increases  (in  general)  with  the  magnetic  latitude. 
When  I  was  anxious  to  attach  myself,  in  1798,  to  the  expedition  of 
Captain  Baudin,  who  intended  to  circumnavigate  the  globe,  I  was  re- 
quested by  Borda,  wrho  took  a  warm  interest  in  the  success  of  ray  proj- 
ect, to  examine  the  oscillations  of  a  vertical  needle  in  the  magnetic  me- 
ridian in  diflferent  latitudes  in  each  hemisphere,  in  order  to  determine 
whether  the  intensity  of  the  force  was  the  same,  or  whether  it  varied  in 
different  places.  During  my  travels  in  the  tropical  regions  of  America, 
I  paid  much  attention  to  this  subject.  I  observed  that  the  same  needle, 
which  in  tlie  space  often  minutes  made  245  oscillations  in  Paris,  246  in 
the  Havana,  and  242  in  Mexico,  performed  only  216  oscillations  during 
the  same  period  at  St.  Carlos  del  Rio  Negro  (1°  53'  north  lat.  and  80° 
40'  west  long.  Irom  Paris),  on  the  magnetic  equator,  i.  e.,  the  hne  in 
which  the  inclination  =0 ;  in  Peru  (7°  1'  south  lat.  and  80°  40'  west 
long,  from  Paris)  only  211 ;  while  at  Lima  (12°  2'  south  lat.)  the  num- 
ber rose  to  210.  I  found,  in  the  years  intervening  between  1799  and 
1803,  that  the  whole  force,  if  we  assume  it  at  1-0000  on  the, magnetic 
equator  in  the  Peruvian  Andes,  between  Micuipampa  and  Caxamarca. 


186  COSMOS. 

The  knowledge  which  we  possess  of  the  quantity  of"  this  in 
crease,  and  of"  all  the  numerical  relations  of  the  law  of  in- 

may  be  expressed  at  Paris  by  1-3482,  in  Mexico  by  1-3155,  in  San  Carlos 
del  Rio  Negro  by  1-0480,  and  in  Lima  by  1-0773.  When  I  developed 
this  law  of  the  variable  intensity  of  terrestrial  magnetic  force,  and  sup- 
ported it  by  the  numerical  value  of  observations  instituted  in  104  dif- 
ferent places,  in  a  Memoir  read  before  the  Paris  Institute  on  the  2Gth 
Frimaire,  An.  XIII.  (of  which  the  mathematical  portion  was  contributed 
by  M.  Biot),  the  facts  were  regarded  as  altogether  new.  It  was  only 
after  the  reading  of  the  paper,  as  Biot  expressly  states  (Lametherie, 
Journal  de  Physique,  t.  lix.,  p.  446,  note  2),  and  as  I  have  repeated  in 
the  Relation  Historique,  t.  i.,  p.  262,  note  1,  that  M.  de  Rossel  commu- 
nicated to  Biot  his  oscillation  experiments  made  six  years  earlier  (be- 
tween 1791  and  1794)  in  Van  Diemen's  Land,  in  Java,  and  in  Amboyna. 
These  experiments  gave  evidence  of  the  same  law  of  decreasing  force 
in  the  Indian  Archipelago.  It  must,  I  think,  be  supposed,  that  this  ex- 
cellent man,  when  he  wrote  his  work,  v^^as  not  awai'e  of  the  regularity 
of  the  augmentation  and  diminution  of  the  intensity,  as  before  the  read- 
ing of  my  paper  he  never  mentioned  this  (certainly  not  unimportant) 
physical  law  to  any  of  our  mutual  friends,  La  Place,  Delambre,  Prony, 
or  Biot.  It  was  not  till  1808,  four  years  after  my  retui-n  from  America, 
that  the  observations  made  by  M.  de  Rossel  were  published  in  the  Voy' 
age  de  V Entrecasteaux,  t.  ii.,  p.  287,  291,  321,  480,  and  644.  Up  to  the 
present  day  it  is  still  usual,  in  all  the  tables  of  magnetic  intensity  which 
have  been  published  iti  Germany  (Hausteen,  Magnet,  der  Erde,  1819, 
s.  71;  Gauss,  Beob.  des  Magnet.  Vereins,  1838,  s.  36-39  ;  Erman,  Phy- 
eikal.  Beoh.,  1841,  s.  529-579),  iu  England  (Sabine,  Report  on  Magnet. 
Intensity.  1838,  p.  43-62  ;  Contributions  to  Terrestrial  Magnetism,  1843), 
and  in  France  (Becquerel,  Traits  de  Electr.  et  de  3Iagnet.,  t.  vii.,  p. 
354-367),  to  reduce  the  oscillations  observed  in  any  part  of  the  Earth 
to  the  standard  of  force  which  I  found  on  the  magnetic  equator  iu 
Northern  Peru,  so  that,  according  to  the  unit  thus  arbitranly  assumed, 
the  intensity  of  the  magnetic  force  at  Paris  is  put  down  as  1*348.  Tht 
observations  made  by  Lamanoii  in  the  unfortunate  expedition  of  La 
Perouse,  during  the  stay  at  TenerifFe  (1785),  and  on  the  voiyage  to 
Macao  (1787),  are  still  older  than  those  of  Admiral  Rossel.  They  were 
sent  to  the  Academy  of  Sciences,  and  it  is  known  that  they  were  in  the 

Eossession  of  Condorcet  in  the  July  of  1787  (Becquerel,  t.  vii.,  p.  320)  ; 
ut,  notwithstanding  the  most  careful  search,  they  are  not  now  to  be 
found.  From  a  copy  of  a  very  important  letter  of  Lamanon,  now  in  the 
possession  of  Captain  Duperrey,  which  was  addressed  to  the  then  per- 
petual secretary  of  the  Academy  of  Sciences,  but  was  omitted  in  the 
narrative  of  the  Voyage  de  La  Pe^-ouse,  it  is  stated  "  that  the  attractive 
force  of  the  magnet  is  less  in  the  tropics  than  when  we  approach  the 
poles,  and  that  the  magnetic  intensity  deduced  from  the  number  of  os- 
cillations of  the  needle  of  the  inclination-compass  varies  and  increases 
with  the  latitude."  If  the  Academicians,  while  they  continued  to  ex- 
pect the  return  of  the  unfortunate  La  Perouse,  had  felt  themselves  justi- 
fied, in  the  course  of  1787,  in  publishing  a  truth  which  had  been  inde- 
pendently discovered  by  no  less  than  three  different  travelers,  the  theory 
of  terrestrial  magnetism  would  have  been  extended  by  the  knowledge 
of  a  new  class  of  observations,  dating  eighteen  years  earlier  than  they 
now  do.  This  simple  statement  of  facts  may  probably  justify  the  ol> 
Bervations  contained  in  the  third  volume  of  my  Relation  Historique  (p 


xMAGNETISM.  187 

tensity  affecting  the  whole  Earth,  is  especially  due,  since  1819. 
to  the  unwearied  activity  of  Edward  Sabine,  who,  after  hav- 
ing observed  the  oscillations  of  the  same  needles  at  the  Ameri- 
can north  pole,  in  Greenland,  at  Spitzbergen,  and  on  the  coasts 
of  Guinea  and  Brazil,  has  continued  to  collect  and  an'angc 
all  the  facts  capable  of  explaining  the  direction  of  the  isody- 
namic  lines.  I  have  myself  given  the  first  sketch  of  an  isody- 
namic  system  in  zones  for  a  small  part  of  South  America 
These  lines  are  not  parallel  to  lines  of  equal  incHnation  (iso- 
clinic  lines),  and  the  intensity  of  the  force  is  not  at  its  minimum 
at  the  magnetic  equator,  as  has  been  supposed,  nor  is  it  even 
equal  at  all  parts  of  it.  If  we  compare  Erman's  observations 
in  the  southern  part  of  the  Atlantic  Ocean,  where  a  faint  zone 
(0-706)  extends  from  Angola  over  the  island  of  St.  Helena  to 
the  Brazilian  coast,  with  the  most  recent  investigations  of  the 
celebrated  navigator  James  Clark  Ross,  we  shall  find  that 
on  the  surface  of  our  planet  the  force  increases  almost  in  the 
relation  of  1  :  3  toward  the  magnetic  south  pole,  where  Vic- 
toria Land  extends  from  Cape  Crozier  toward  the  volcano 
Erebus,  which  has  been  raised  to  an  elevation  of  12,600  ieet 
above  the  ice.*     If  the  intensity  near  the  magnetic  south  pole 

615):  "The  observations  on  the  variation  of  terresti'ial  magnetism,  to 
which  I  have  devoted  myself  for  thirty-two  years,  by  means  of  instru- 
ments which  admit  of  comparison  with  one  another,  in  America,  Europe, 
and  Asia,  embrace  an  area  extending  over  188  degrees  of  longitude, 
from  the  frontier  of  Chinese  Dzoungarie  to  the  west  of  the  South  Sea 
loathing  the  coasts  of  Mexico  and  Peru,  and  reaching  from  60°  north 
lat.  to  12°  south  lat.  I  regard  the  discovery  of  the  law  of  the  decre- 
ment of  magnetic  force  from  the  pole  to  tlie  equator  as  the  most  im- 
portant i-esult  of  my  American  voyage."  Although  Tiot  absolutely  cer- 
tain, it  is  very  probable  that  Condorcet  read  Lamanou's  letter  of  July, 
1787,  at  a  meeting  of  the  Paris  Academy  of  Sciences;  and  sucli  a  sim- 
ple reading  I  regard  as  a  sufficient  act  of  publication.  {Annvaire  dit 
Bureau  des  Longitudes,  1842,  p.  463.)  The  first  recognition  of  the  law 
belongs,  therefore,  beyond  all  question,  to  the  companion  of  La  Peiouse ; 
but,  long  disregarded  or  forgotten,  the  knowledge  of  the  law  that  the 
intensity  of  the  magnetic  force  of  the  Earth  varied  with  the  latitude, 
did  not,  I  conceive,  acquii^e  an  existence  in  science  until  the  [)ublica- 
tion  of  my  observations  from  1798  to  1804.  The  object  and  the  length 
of  this  note  will  not  be  indifferent  to  those  who  are  familiar  with  the 
recent  history  of  magnetism,  and  the  doubts  that  have  been  started  in 
connection  with  it,  and  who,  from  their  own  experience,  are  aware 
that  w^e  are  apt  to  attach  some  value  to  that  which  has  cost  us  the  un- 
interrupted labor  of  five  yeai's,  under  the  pressure  of  a  tropical  climate, 
and  of  perilous  mountain  expeditions. 

*  From  the  observations  hitherto  collected,  it  appears  that  the  max- 
imum of  intensity  for  the  wliole  surfoce  of  tlie  Earth  is  2*052,  and  the 
minimum  0.706.  Both  phenomena  occur  in  the  southern  hemisphere; 
^e  former  in  73°  47'  S.  lat.,  and  169°  30'  E.  long,  from  Paris,  ueai 


1H8  COSMOS. 

be  expressed  by  2-052  (the  unit  still  employed  being  the  in-* 
tensity  which  I  discovered  on  the  magnetic  equator  in  North- 
ern Peru),  Sabine  found  it  was  only  1-624  at  the  magnetic 
north  pole  near  Melville  Island  (74°  27'  north  lat.),  while  it 
is  1-803  at  New  York,  in  the  United  States,  which  has  al- 
most the  same  latitude  as  Naples. 

The  brilliant  discoveries  of  QErsted,  Arago,  and  Faraday 
have  established  a  more  intimate  connection  between  the  elec- 
tric tension  of  the  atmosphere  and  the  magnetic  tension  of  our 
terrestrial  globe.  While  CErsted  has  discovered  that  elec- 
tricity excites  magnetism  in  the  neighborhood  of  the  conduct- 
ing body,  Faraday's  experiments  have  elicited  electric  currents 
from  the  liberated  magnetism.  Magnetism  is  one  of  the  mani- 
fold forms  under  which  electricity  reveals  itself.  The  ancient 
vague  presentiment  of  the  identity  of  electric  and  magnetic 
attraction  has  been  verified  in  our  own  times.  "  When  elec- 
trum  (amber),"  says  Pliny,  in  the  spirit  of  the  Ionic  natural 
philosophy  of  Thales,*  "is  animated  by  friction  and  heat,  it 
will  attract  bark  and  dry  leaves  precisely  as  the  loadstone  at- 
tracts iron."  The  same  words  may  be  found  in  the  literature 
of  an  Asiatic  nation,  and  occur  in  a  eulogium  on  the  load- 
stone by  the  Chinese  physicist  Kuopho.f     I  observed  with  as- 

Mouut  Crozier,  west-northwest  of  the  south  magnetic  pole,  at  a  place 
where  Captain  .Tames  Ross  tbund  the  inclination  of  the  needle  to  be  87° 
11'  (Sabine,  Contributions  to  Terrestrial  Magnetisyn,  1843,  No.  5,  p. 
231);  the  latter,  observed  by  Erman,  at  19°  59'  S.  lat.,  and  37°  24'  W. 
long,  from  Paris,  320  miles  eastward  from  the  Brazilian  coast  of  Espiritu 
Santo  (Erman,  Phys.  Beoh.,  1841,  s.  570),  at  a  point  where  the  inclina- 
tion is  only  7°  55'.  The  actual  ratio  of  tlie  two  intensities  is  therefore 
as  1  to  2-906.  It  was  long  believed  that  the  greatest  intensity  of  the 
magnetic  force  was  only  two  and  a  half  times  as  great  as  the  weakest 
exhibited  on  the  Earth's  surface.  (Sabine,  Report  on  Magnetic  In- 
tensity, p.  82.) 

*  Of  amber  (succinum,  glessum)  Pliny  observes  (xxxvii.,  3),  "  Gen- 
era ejus  plura.  Attritu  digitorum  accepta  caloris  anima  trahunt  in  se 
paleas  ac  folia  arida  qute  levia  sunt,  ac  ut  magnes  lapis  ferri  ramenta 
quoque."  (Plato,  ira  Timceo,  p.  80.  Martin,  Etude  snr  le  Tim^e,  t.  ii., 
p.  343-346.  Strabo,  xv.,  p.  703,  Casaub. ;  Clemens  Alex.,  Strom.,  ii., 
p.  370,  where,  singularly  enough,  a  diffei'ence  is  made  between  to 
aovxiov  and  to  rjXsKTpov.)  When  Tlmles,  in  Aristot.,  de  Anima,  1,  2, 
and  Hippias,  in  Diog.  Laert.,  i.,  24,  describe  the  magnet  and  amber  as 
possessing  a  soul,  they  refer  only  to  a  moving  principle. 

t  "  The  magnet  attracts  iron  as  amber  does  the  smallest  grain  of  mus- 
tard seed.  It  is  like  a  breath  of  wind  which  mysteriously  penetrates 
through  both,  and  communicates  itself  with  the  rapidity  of  an  arrow." 
These  are  the  words  of  Kuopho,  a  Chinese  panegyrist  on  the  magnet, 
who  wrote  in  the  beginning  of  the  fourth  century.  (Klaproth.Lef^r.?  o 
M.  A.  de  Humboldt,  snr  V Inventio7i  de  la  Boussole,  1834,  p.  125.  ^ 


MiAGNETISM.  189 

tonishment,  on  the  wojdy  banks  of  the  Orinoco,  in  the  sports 
ol"  the  natives,  that  the  excitement  of  electricity  by  friction 
was  known  to  these  savage  races,  who  occupy  the  very  lowest 
place  in  the  scale  of  humanity.  Children  may  be  seen  to  rub 
the  dry,  flat,  and  shining  seeds  or  husks  of  a  traihng  plant 
(probably  a  Negretia)  until  they  are  able  to  attract  threads 
of  cotton  and  pieces  of  bamboo  cane.  That  which  thus  de- 
lights the  naked  copper-colored  Indian  is  calculated  to  awaken 
in  our  minds  a  deep  and  earnest  impression.  What  a  chasm 
divides  the  electric  pastime  of  these  savages  from  the  discov- 
ery of  a  metallic  conductor  discharging  its  electric  shocks,  or  a 
pile  composed  of  many  chemically-decomposing  substances,  or 
a  light-engendering  magnetic  apparatus  I  In  such  a  chasm 
lie  buried  thousands  of  years  that  compose  the  history  of  the 
intellectual  development  of  mankind  I 

The  incessant  change  or  oscillatory  motion  which  we  dis- 
cover in  all  magnetic  phenomena,  whether  in  those  of  the  in- 
clination, declination,  and  intensity  of  these  forces,  according 
to  the  hours  of  the  day  and  the  night,  and  the  seasons  and  the 
course  of  the  whole  year,  leads  us  to  conjecture  the  existence 
of  very  various  and  partial  systems  of  electric  currents  on  the 
surface  of  the  Earth.  Are  these  currents,  as  in  Seebeck's  ex- 
periments, thermo-magnetic,  and  excited  directly  from  unequal 
distribution  of  heat  ?  or  should  we  not  rather  regard  them  as 
induced  by  the  position  of  the  Sun  and  by  solar  heat  ?*  Have 
the  rotation  of  the  planets,  and  the  different  degrees  of  velocity 
which  the  individual  zones  acquire,  according  to  their  respect- 
ive distances  from  the  equator,  any  influence  on  the  distribii 
tion  of  magnetism  ?  Must  we  seek  the  seat  of  these  currents, 
that  is  to  say,  of  the  disturbed  electricity,  in  the  atmosphere, 
in  the  regions  of  planetary  space,  or  in  the  polarity  of  the  Sun 
and  Moon  ?  G^ilileo,  in  his  celebrated  Dialogo,  was  inclined 
to  ascribe  the  parallel  direction  of  the  axis  of  the  Earth  to  a 
magnetic  point  of  attraction  seated  in  universal  space. 

If  we  represent  to  ourselves  the  interior  of  the  Earth  as 
fused  and  undergoing  an  enormous  pressure,  and  at  a  degree 
of  temperature  the  amount  of  which  we  are  unable  to  assign, 

*  "  The  phenomena  of  periodical  variations  depend  manifestly  on  the 
action  of  solar  heat,  operating  probably  through  the  medium  of  thermo- 
electric currents  induced  on  the  Earth's  surface.  Beyond  this  rude 
guess,  however,  nothing  is  as  yet  known  of  their  physical  cause.  It  ia 
even  still  a  matter  of  speculation  v^diether  the  solar  influence  be  a  prin- 
cipal or  only  a  subordinate  cause  in  the  phenomena  of  terrestrial  mag 
netism."  (^Observations  to  he  made  in  the  Antarctic  Expedition,  1840. 
p.  35.) 


190  COSMOS. 

we  must  renounce  all  idea  of  a  magnetic  nucleus  of  the  Earth. 
All  magnetism  is  certainly  not  lost  until  we  arrive  at  a  white 
heat,*  and  it  is  manifested  when  iron  is  at  a  dark  red  heat , 
however  different,  therefore,  the  modifications  may  be  which 
are  excited  in  substances  in  their  molecular  state,  and  in  the 
coercive  force  depending  upon  that  condition  in  experiments 
of  this  nature,  there  will  still  remain  a  considerable  thickness 
of  the  terrestrial  stratum,  which, might  be  assumed  to  be  the 
seat  of  magnetic  currents.  The  old  explanation  of  the  horary 
variations  of  declination  by  the  progressive  warming  of  the 
Earth  in  the  apparent  revolution  of  the  Sun  from  east  to  west 
must  be  limited  to  the  uppermost  surface,  since  thermometers 
sunk  into  the  Earth,  which  are  now  being  accurately  observed 
at  so  many  different  places,  show  how  slowly  the  solar  heat 
penetrates  even  to  the  inconsiderable  depth  of  a  few  feet. 
Moreover,  the  thermic  condition  of  the  surface  of  water,  by 
which  two  thirds  of  our  planet  is  covered,  is  not  favorable  to 
such  modes  of  explanation,  when  we  have  reference  to  an  im- 
mediate action  and  not  to  an  effect  of  induction  in  the  aerial 
and  aqueous  investment  of  our  terrestrial  globe. 

In  the  present  condition  of  our  knowledge,  it  is  impossible 
to  aflbrd  a  satisfactory  reply  to  all  questions  regarding  the  ulti- 
mate physical  causes  of  these  phenomena.  It  is  only  with  ref- 
erence to  that  which  presents  itself  in  the  triple  manifestations 
of  the  terrestrial  force,  as  a  measurable  relation  of  space  and 
time,  and  as  a  stable  element  in  the  midst  of  change,  that 
science  has  recently  made  such  brilliant  advances  by  the  aid 
of  the  determination  of  mean  numerical  values.  From  To- 
ronto in  Upper  Canada  to  the  Cape  of  Good  Hope  and  Van  Die- 
men's  Land,  from  Paris  to  Pekin,  the  Earth  has  been  covered, 
since  1828,  with  magnetic  observatories,t  in  which  every  regu- 

*  Barlow,  in  the  Philos.  Trans,  for  1822,  Pt.  i.,  p.  117  ;  Sir  David 
Brewster,  Treatise  on  Magnetism,  p.  129.  Long  before  the  times  of 
Gilbert  and  Hooka,  it  was  taught  in  the  Chinese  work  Ow-thsa-tsou 
that  heat  diminished  the  directive  force  of  the  magnetic  needle.  (Kla- 
proth,  Leitre  a  M.  A.  de  Humholdl,  stir  V Invc7itio7i  de  la  Boussole,  p.  96.) 

t  As  the  first  demand  for  the  establishment  of  these  observatories  (a 
net-work  of  stations,  provided  with  similar  instruments)  proceeded 
from  me,  I  did  not  dare  to  cherish  the  hope  that  I  should  live  long 
enough  to  see  the  time  when  both  hemispheres  should  be  uniformly 
covered  with  magnetic  houses  under  the  associated  activity  of  able 
physicists  and  astronomers.  This  has,  however,  been  accomplished, 
and  chiefly  through  the  liberal  and  continued  support  of  the  Russian  and 
British  governments. 

In  the  yeai-s  1806  and  1807, 1  and  my  friend  and  fellow-laborer,  Herr 
Ollmanus,  while  at  Berlin,  observed  the  movements  of  the  needle,  espe- 


MAGNETISM.  191 

lar  or  in'egular  manifestation  of  the  terrestrial  force  is  detected' 
by  uninterrupted  and  simultaneous  observations,     A  variation 

daily  at  the  times  of  the  solstices  and  equinoxes,  frona  hour  to  hour, 
and  often  from  half  hour  to  half  hour,  for  five  or  six  days  and  nights 
uninterruptedly.  I  had  persuaded  myself  that  continuous  and  uninter- 
rupted observations  of  several  days  and  nights  (observatio  perpetua) 
were  preferable  to  the  single  observations  of  many  months.  The  ap- 
paratus, a  Prony's  magnetic  telescope,  suspended  in  a  glass  case  by  a 
thread  devoid  of  torsion,  allowed  angles  of  seven  or  eight  seconds  to  be 
read  off  on  a  finely-divided  scale,  placed  at  a  proper  distance,  and 
lighted  at  night  by  lamps.  Magnetic  perturbations  (storms),  which  oc- 
casionally recurred  at  the  same  hour  on  several  successive  nights,  led 
me  even  then  to  desire  extremely  that  similar  apparatus  should  be  used 
to  the  east  and  west  of  Berlin,  in  order  to  distinguish  general  terres- 
trial phenomena  from  those  which  are  mere  local  disturbances,  depend- 
ing on  the  inequality  of  heat  in  different  parts  of  the  Earth,  or  on  the 
cloudiness  of  the  atmosphere.  My  departure  to  Paris,  and  the  long 
period  of  political  distui'bance  that  involved  the  whole  of  the  west  of 
Europe,  prevented  my  wish  from  being  then  accomplished.  CErsted's 
great  discovery  (1820)  of  the  intimate  connection  between  electricity 
and  magnetism  again  excited  a  general  interest  (which  had  long  flag- 
ged) in  the  periodical  variations  of  the  electro-magnetic  tension  of  the 
Earth.  Arago,  who  many  years  previously  had  commenced  in  the  Ob- 
servatory at  Paris,  with  a  new  and  excellent  declination  instrument  by 
Gambey,  the  longest  uninterrupted  series  of  horaiy  observations  which 
we  possess  in  Europe,  showed,  by  a  comparison  with  simultaneous  ob- 
servations of  perturbation  made  at  Kasan,  what  advantages  might  be 
obtained  from  corresponding  measurements  of  declination.  When  I 
returned  to  Berlin,  after  an  eighteen  years'  residence  in  France,  I  had 
a  small  magnetic  house  erected  in  the  autumn  of  1828,  not  only  with 
the  view  of  carrying  on  the  woi-k  commenced  in  1806,  but  more  with 
the  object  that  simultaneous  observations  at  hours  previously  determ- 
ined might  be  made  at  Berlin,  Paris,  and  Freiburg,  at  a  depth  of  35 
fathoms  below  the  surface.  The  simultaneous  occurrence  of  the  per- 
turbations, and  the  parallelism  of  the  movements  for  October  and  De- 
cember, 1829,  were  then  graphically  represented.  (Pogg.,  Annalen, 
bd.  xix.,  s.  357,  taf.  i.-iii.)  An  expedition  into  Northern  Asia,  Under- 
taken in  1829,  by  command  of  the  Emperor  of  Russia,  soon  gave  me  an 
opportunity  of  working  out  my  plan  on  a  larger  scale.  This  plan  was 
laid  before  a  select  committee  of  one  of  the  Imperial  Academies  of 
Science,  and,  under  the  protection  of  the  Director  of  the  Mining  Depart- 
ment, Count  von  Cancrin,  and  the  excellent  superintendence  of  Pro- 
fessor Kupffer,  magnetic  stations  were  appointed  over  the  whole  of 
Northern  Asia,  from  Nicolajeff,  in  the  line  through  Catharinenburg,  Bar- 
naul, and  Nertschinsk,  to  Pekin. 

The  year  1832  {Gottinger  gelckrte  Anzeigen,  st.  206)  is  distinguished 
as  the  gi'eat  epoch  in  which  the  profound  author  of  a  general  theory  of 
teiTestrial  magnetism,  Friedrich  Gauss,  erected  apparatus,  constructed 
on  a  new  principle,  in  the  Gottingen  Observatoiy.  The  magnetic  ob- 
servatory was  finished  in  1834,  and  in  the  same  year  Gauss  distributed 
new  instruments,  with  instructions  for  their  use,  in  w^hich  the  celebrated 
physicist,  Wilhelm  Weber,  took  extreme  interest,  over  a  large  portion 
of  Germany  and  Swa^den,  and  the  whole  of  Italy.  {Rrsnltate  der  Beob. 
des  Magnetischcn  Verci/is  im  Jahr  1338,  s,  135,  and  i\)\i^c\n\.,  Annalen 


192  COSMOS. 

of  j^i-Q^th  of  the  magnetic  intensity  is  measured,  and,  at  cer- 
tain epochs,  observations  are  made  at  intervals  of  2i  minutes, 
and  continued  for  twenty-four  hours  consecutively.  A  great 
Eno-lisli  astronomer  and  physicist  has  calculated*  that  the 
mass  of  observations  w^hich  are  in  progress  will  accumulate  in 
the  course  of  three  years  to  1,958,000.  Never  before  has  so 
noble  and  cheerful  a  spirit  presided  over  the  inquiry  into  the 
quantitative  relations  of  the  laws  of  the  phenomena  of  nature. 
We  are,  therefore,  justified  in  hoping  that  these  laws,  when 
compared  with  those  which  govern  the  atmosphere  and  the 
remoter  regions  of  space,  may,  by  degrees,  lead  us  to  a  more 
intimate  acquaintance  with  the  genetic  conditions  of  magnetic 
phenomena.  As  yet  we  can  only  boast  of  having  opened  a 
greater-  number  of  paths  which  may  possibly  lead  to  an  ex- 
planation of  this  subject.     In  the  physical  science  of  terres- 

bd.  xxxiii.,  s.  426.)  In  the  magnetic  association  that  was  now  formed 
with  Gottingen  for  its  center,  simultaneous  observations  have  been  un- 
dertaken four  times  a^year  since  183G,  and  continued  uninterruptedly 
for  twenty-four  hours.  The  periods,  however,  db  not  coincide  with 
those  of  the  equinoxes  and  solstices,  which  I  had  proposed  and  followed 
out  in  1830.  Up  to  this  period,  Great  Britain,  in  possession  of  the  most 
extensive  commerce  and  the  largest  navy  in  the  world,  had  taken  no 
part  in  the  movement  which  since  1828  had  begun  to  yield  important 
results  for  the  more  fixed  ground- work  of  terrestrial  magnetism.  I  had 
the  good  fortune,  by  a  public  appeal  from  Berlin,  which  I  sent  in  April, 
1836,  to  the  Duke  of  Sussex,  at  that  time  President  of  the  Royal  So- 
ciety (Lettre  de  M.  de  Humboldt  a  S.A.R.  le  Due  de  Sussex,  sur  les 
moyens  propres  a  perfectionner  la  connaissance  du  magnetisme  terrestre 
par  I'etablissement  des  stations  magnetiques  et  d'observations  corre- 
spondantes),  to  excite  a  fiiendly  interest  in  the  undertaking  which  it 
had  so  long  been  the  chief  object  of  my  wish  to  cany  out.  In  my  let- 
ter to  the  Duke  of  Sussex  1  urged  the  establishment  of  permanent  sta- 
tions in  Canada,  St.  Helena,  the  Cape  of  Good  Hope,  the  Isle  of  France, 
Ceylon,  and  New  Holland,  which  five  years  previously  I  had  advanced 
as  good  positions.  The  Royal  Society  appointed  a  joint  physical  and 
meteorological  committee,  -which  not  only  proposed  to  the  government 
the  establishment  of  fixed  magnetic  observatories  in  both  hemispheres, 
but  also  the  equipment  of  a  naval  expedition  for  magnetic  observations 
in  the  Antarctic  Seas.  It  is  needless  to  proclaim  the  obligations  of 
science  in  this  matter  to  the  great  activity  of  Sir  John  Herschel,  Sabine, 
Airy,  and  Lloyd,  as  well  as  tlie  pov^^erful  support  that  was  afforded  by 
the  British  Association  for  the  Advancement  of  Science  at  their  meet- 
ing held  at  Newcastle  in  1838.  In  .Tune,  1839,  the  Antarctic  magnetic 
expedition,  under  the  command  of  Captain  James  Clark  Ross,  was  fully 
arranged ;  and  now,  since  its  successful  return,  we  reap  the  double 
fruits  of  highly  important  geographical  discoveries  around  the  south 
pole,  and  a  series  of  simultaneous  observations  at  eight  or  ten  magnetic 
stations. 

*  See  the  article  on  Terrestrial  Magnetism,  in  the  Quarterly  liemeio 
1840,  vol.  Ixvi.,  p.  271-312. 


AURORA    BOREALIS.  193 

trial  magnetism,  which  must  not  be  confounded  with'  the 
purely  mathematical  branch  of  the  study,  those  persons  only 
will  obtain  perfect  satisfaction  who,  as  in  the  science  oi  the 
meteorological  processes  of  the  atmosphere,  conveniently  turn 
aside  the  practical  bearing  of  all  phenomena  that  can  not  be 
explained  according  to  their  own  views. 

Terrestrial  magnetism,  and  the  electro-dynamic  forces  com- 
puted by  the  intellectual  Ampere,*  stand  in  simultaneous  and 
intimate  cormection  with  the  terrestrial  or  polar  light,  as  well 
as  with  the  internal  and  external  heat  of  our  planet,  whose 
nagnetic  poles  may  be  considered  as  the  poles  of  cold.f  The 
oold  conjecture  hazarded  one  hundred  and  twenty-eight  years 
since  by  Halley,|  that  the  Aurora  Borealis  was  a  magnetic 
phenomenon,  has  acquired  empirical  certainty  from  Faraday's 
brilliant  discovery  of  the  evolution  of  light  by  magnetic  forces. 
The  northern  light  is  preceded  by  premonitory  signs.  Thus, 
in  the  morning  before  the  occurrence  of  the  phenomenon,  the 
irregular  horary  course  of  the  magnetic  needle  generally  indi- 
cates a  disturbance  of  the  equilibrium  in  the  distribution  of 

*  Instead  of  ascribing  the  internal  heat  of  the  Earth  to  the  transition 
of  matter  from  a  vapor-like  fluid  to  a  solid  condition,  which  accom- 
panies the  formation  of  the  planets,  Ampere  has  propounded  the  idea, 
which  I  regard  as  highly  improbable,  that  the  Earth's  temperature  may 
be  the  consequence  of  the  continuous  chemical  action  of  a  nucleus  of 
the  metals  of  the  earths  and  alkalies  on  the  oxydizing  external  crust. 
"  It  can  not  be  doubted,"  he  observes  in  his  masterly  VMorie  des  Pheno- 
menes  Electro-dynaviiques,  1826,  p.  199,  "that  electro-magnetic  cur- 
rents exist  in  the  interior  of  the  globe,  and  that  tlie&s  cun-ents  are  the 
cause  of  its  temperature.  They  arise  from  the  action  of  a  central  me- 
tallic nucleus,  composed  of  the  metals  discovered  by  Sir  Humphrey 
Davy,  acting  on  the  surrounding  oxydized  layer." 

t  The  remai'kable  connection  between  the  curvature  of  the  magnetic 
lines  and  that  of  my  isothermal  lines  was  first  detected  by  Sir  David 
Brewster.  See  the  Transactions  of  the  Royal  Society  of  Edinburgh,  vol. 
ix.,  1821,  p.  318,  and  Treatise  on  Magnetism,  1837,  p.  42,  44,  47,  and 
268.  This  distinguished  physicist  admits  two  cold  poles  (poles  of  maxi- 
mum cold)  in  the  northern  hemisphere,  an  American  one  near  Cape 
Walker  (73°  lat.,  100°  W.  long.),  and  an  Asiatic  one  (73°  lat.,  80°  E. 
long.) ;  whence  arise,  according  to  him,  two  hot  and  two  cold  merid- 
ians, i.  c,  meridians  of  greatest  heat  and  cold.  Even  in  the  sixteenth 
century,  Acosta  {Historia  Nattiral  de  las  Indias,  1589,  lib.  i.,  cap.  17), 
grounding  his  opinion  on  the  observations  of  a  very  experienced  Portu- 
guese pilot,  taught  that  there  were  four  lines  without  declination.  It 
would  seem  from  the  controversy  of  Henry  Bond  (the  author  of  The 
Longitude  Found,  1676)  with  Beckborrow,  that  this  view  in  some  meas- 
ure influenced  Halley  in  his  theory  of  four  magnetic  poles.  See  my 
Examen  Critiqiie  dc  V Hist,  de  la  Oeographie,  t.  iii.,  p.  60. 

X  Halley,  in  the  Philosophical  Transactions,  vol.  xxix.  (for  1714-1716), 
No.  341. 

Vol.  T.— r 


194  COSMOS. 

terrestrial  inaffiietism.*    When  this  disturbance  attains  a  g^reat 
degree  of  intensity,  the  equilibrium  of  the  distribution  is  re- 
stored by  a  discharge   attended  by  a  development  of  light 
'  Tiie  Auroraf  itself  is,  therefore,  not  to  be  regarded  as  an  ex 
ternaily  manifested  cause  of  this  disturbance,  but  rather  as  v 
result  of  telluric  activity,  manifested  on  the  one  side  by  tht* 
appearance  of  the  light,  and  on  the  other  by  the  vibrations  of 
the  magnetic  needle."      The  splendid  appearance  of  colored 
polar  light  is  the  act  of  discharge,  the  termination  of  ^  mag 
netic  storm,  as  in  an  electrical  storm  a  development  of  light — 
the  flash  of  lightning — indicates  the  restoration  of  the  disturb- 
ed equilibrium  in  the  distribution  of  the  electricity.     An  elec- 
tric storm  is  generally  confined  to  a  small  space,  beyond  thc- 
limits  of  which  the  condition  of  -the  atmospheric  electricity 
remains  michanged.      A  magnetic  storm,  on  the  other  hand, 

*  [The  Aurora  Borealis  of  October  24tii,  1847,  Vvbich  was  one  of  the 
most  brilliant  ever  known  in  this  country,  was  preceded  by  great  mag- 
netic disturbance.  On  the  22d  of  October  the  maximum  of  the  west 
declination  was  23°  10' ;  on  the  23d  the  positiojj  of  the  magnet  was 
continually  changing,  and  the  extreme  west  declinations  were  between 
22°  44'  and  23°  37' ;  on  the  night  between  the  23d  and  24th  of  October, 
the  changes  of  position  were  very  largo  and  very  frequent,  the  magnet 
at  times  moving  across  the  field  so  rapidly  that  a  difficulty  was  experi- 
enced in  following  it.  During  the  day  of  the  24th  of  October  there  wa6 
a  constant  change  of  position,  but  after  midnight,  when  the  Aurora  be- 
i:au  perceptibly  to  decline  in  brightness,  the  disturbance  entirely  ceased. 
The  changes  of  position  of  the  horizontal-force  magnet  were  as  large  and 
;i8  frequent  as  those  of  the  declination  magnet,  but  the  vertical-force 
m:^iriiet  was  at  no  time  so  much  atfected  as  the  other  two  instruineuto. 
See  On  the  Aurora  Borealis,  as  it  was  seen  on  Sutidai/  evening,  October 
'lUk,  1847,  at  Blackheath,  by  James  Glaisher,  Esq..  of  the  Royal  Observa- 
tory, Greenwich,  iu  the  London,  Edinhirgh,  and  Dublin  Philos.  Mag. 
and  Journal  of  Science  for  Nov.,  1847.  See  further,  An  Account  of  the 
Aurora  Borealis  of  October  the  'Mth,  1847,  by  John  H.  Morgan,  Esq. 
We  must  not  omit  lo  mention  that  magnetic  disturbance  is  now  regis- 
tered by  a  photographic  process :  tlie  self-registering  photographic  ap- 
])aratus  used  for  this  purpose  in  the  Observatoiy  at  Greenwich  ^yas  de- 
signed by  Mr.  Brooke,.and  another  ingenious  instrument  of  this  kind 
has  been  invented  by  Mr.  F.  Konalds,  of  the  Richmond  Observatory.] — 

Tr. 

t  Dove,  iu  Poggend.,  Annalert,,  bd.  xx.,  s.  341  ;  bd.  xix.,  s.  ;388. 
"  The  declination  needle  acts  in  very  nearly  the  same  \A'ay  as  an  atmos- 
pheric electrometer,  whose  divergence  in  like  manner  shows  the  m- 
ci-eased  tension  of  the  electricity  before  this  has  become  so  great  as  to 
yield  a  spark."  See,  also,  the  excellent  observations  of  Professor  Kamtz, 
in  his  Lehrbvch  der  Meieorologie,  bd.  iii.,  s.  ^l\-:Ad,  and  Sir  Dim  i! 
Brewster,  in  his  Treatise  on  Magnetism,  p.  280.  Regarding  the  mau- 
iietic  properties  of  the  galvanic  flame,  or  luminous  arch  from  a  Buii- 
Hen'h  carbon  and  zinc  battery,  see  Casaelmann's  Bcobachiungen  (Mar- 
bur-.  1844).  s.  .56-(i2. 


I 

AURORA    BOREALIS.  l\)^ 

shows  its  influence  on  the  course  of  the  needle  over  large  por- 
tions of  continents,  and,  as  Arago  first  discovered,  far  from 
the  spot  where  the  evolution  of  light  was  visible.     It  is  not 
improbable  that,  as  heavily-charged  threatening  clouds,  owing 
to  frequent  transitions  of  the  atmospheric  electricity  to  an  op 
posite  condition,  are  not  always  discharged,  accompanied  b) 
lightning,  so  likewise  magnetic  storms  may  occasion  far-ex 
tending  disturbances  in  the  horary  course  of  the  needle,  with 
out  there  being  any  positive  necessity  that  the  equilibrium  of 
the  distribution  should  be  restored  by  explosion,  or  by  the 
passage  of  luminous  effusions  from  one  of  the  poles  to  the 
equator,  or  from  pole  to  pole. 

In  collecting  all  the  individual  features  of  the  phenomenon 
in  one  general  picture,  we  must  not  omit  to  describe  the  origin 
and  course  of  a  perfectly  developed  Aurora  Borealis.  Low 
down  in  the  distant  horizon,  about  the  part  of  the  heavens 
which  is  intersected  by  the  magnetic  meridian,  the  sky  which 
was  previously  clear  is  at  once  overcast.  A  dense  wall  or 
bank  of  cloud  seems  to  rise  gradually  higher  and  higher,  until 
it  attains  an  elevation  of  8  or  10  degrees.  The  color  of  the 
dark  segment  passes  into  brown  or  violet ;  and  stars  are  visi- 
ble through  the  cloudy  stratum,  as  when  a  dense  smoke  dark- 
ens the  sky.  A  broad,  brightly-luminous  arch,  first  white, 
then  yellow,  encircles  the  dark  segment ;  but  as  the  brilliant 
arch  appears  subsequently  to  the  smoky  gray  segment,  we  can 
not  agree  with  Argelander  in  ascribing  the  latter  to  the  efTect 
of  mere  contrast  with  the  bright  luminous  margin.*  The 
highest  point  of  the  arch  of  light  is,  according  to  accurate  ob- 
servations made  on  this  subject,!  not  generally  in  the  magnet- 
ic meridian  itself,  but  from  5^  to  18^  toward  the  direction  of 
the  magnetic  declination  of  the  place. $    In  northern  latitudes, 

*  Argelander,  in  the  important  observations  on  the  northern  light 
embodied  in  the  Vortrdgen  gehalten  in  der  physikalisch-okonomischen 
Gessellschaft  zu  Konigsberg,  bd.  i.,  1834,  s.  257-264. 

t  For  an  account  of  the  results  of  the  observations  of  Lottin,  Bravais, 
and  Siljerstrom,  who  spent  a  winter  at  Bosekop,  on  the  coast  of  Lap 
land  (70°  N.  lat.),  and  in  210  nights  saw  the  northern  lights  160  times, 
see  the  Comvtes  Rendus  de  V Acad,  des  Sciences,  t.  x.,  p.  289,  and  Mar- 
lins's M6teorologie,  1843,  p.  453.  See,  also,  Argelander,  in  the  Vdrtru' 
gen  geh.  in  der  Konigsberg  Gessellschaft,  bd.  i.,  s.  259. 

X  [Professor  Challis,  of  Cambridge,  states  that  in  the  Aurora  of  Oc- 
tober 24th,  1847,  the  streamers  all  converged  toward  a  single  point  of 
the  heavens,  situated  in  or  very  near  a  vertical  circle  passing  through 
the  magnetic  pole.  Around  this  point  a  corona  was  formed,  the  rays 
of  which  diverged  in  all  directions  from  the  center,  leaving  a  space  free 
from  light:  its  azimuth  was  18°  41'  from  soutli  to  east,  and  its  altitude 
69^  54'.     See  Professor  Challis,  in  the  Atkenceum,  Oct.  31,  1847.]— r>- 


196  COSMOS. 

in  the  immediate  vicinity  of  the  magnetic  pole,  the  smoke-like 
conical  segment  appears  less  dark,  and  sometimes  is  not  even 
seen.  Where  the  horizontal  force  is  the  M^eakest,  the  middle 
of  the  luminous  arch  deviates  the  most  from  the  magnetic 
meridian. 

The  luminous  arch  remains  sometimes  for  hours  together 
flashing  and  kindling  in  ever- varying  undulations,,  before  rays 
and  streamers  emanate  from  it,  and  shoot  up  to  the  zenith. 
The  more  intense  the  discharges  of  the  northern  light,  the 
more  bright  is  the  play  of  colors,  through  all  the  varying  gra- 
dations from  violet  and  bluish  white  to  green  and  crimson. 
Even  in  ordinary  electricity  excited  by  friction,  the  sparks  are 
only  colored  in  cases  where  the  explosion  is  very  violent  after 
great  tension.  The  magnetic  columns  of  flame  rise  either 
singly  from  the  luminous  arch,  blended  with  black  rays  simi- 
lar to  thick  smoke,  or  simultaneously  in  many  opposite  points 
of  the  horizon,  uniting  together  to  form  a  flickering  sea  of 
flame,  whose  brilliant  beauty  admits  of  no  adequate  descrip- 
tion, as  the  luminous  waves  are  every  moment  assuming  new 
and  varying  forms.  The  intensity  of  this  light  is  at  times  so 
great,  that  Lowenorn  (on  the  29th  of  June,  1786)  recognized 
the  coruscation  of  the  polar  light  in  bright  sunshine.  Motion 
renders  the  phenomenon  more  visible.  Round  the  point  in 
the  vault  of  heaven  which  corresponds  to  the  direction  of  the 
inclination  of  the  needle,  the  beams  unite  together  to  form  the 
so-called  corona,  the  crown  of  the  northern  light,  which  en- 
circles the  summit  of  the  heavenly  canopy  with  a  milder  ra- 
diance and  unflickering  emanations  of  light.  It  is  only  in 
rare  instances  that  a  perfect  crown  or  circle  is  formed,  but  on 
its  completion  the  phenomenon  has  invariably  reached  its 
maximum,  and  the  radiations  become  less  frequent,  shorter, 
and  more  colorless.  The  crown  and  the  luminous  arches 
break  up,  and  the  whole  vault  of  heaven  becomes  covered 
with  irregularly-scattered,  broad,  faint,  almost  ashy-gray  lu- 
minous immovable  patches,  which  in  their  turn  disappear, 
leaving  nothing  but  a  trace  of  the  dark,  smoke-like  segment 
on  the  horizon.  There  often  remains  nothing  of  the  whole 
spectacle  but  a  white,  delicate  cloud  with  feathery  edges,  or 
divided  at  equal  distances  into  small  roundish  groups  like  cir- 
ro-cumuli. 

This  connection  of  the  polar  light  with  the  most  delicate 

(irrous  clouds  deserves  special  attention,  because  it  shows  that 

he  electro-magnetic  evolution  of  light  is  a  part  of  a  meteoro- 

*-> .  cal  process.     Terrestrial  n^agnetism  here  manifests  its  in- 


AURORA    ROREALIS.  197 

fluence  on  the  atmosphere  and  on  the  condensation  of  aqueous 
vapor.  The  fleecy  clouds  seen  in  Iceland  by  Thienemann, 
and  which  he  considered  to  be  the  northern  light,  have  been 
seen  in  recent  times  by  Franklin  and  Richardson  near  the 
American  north  pole,  and  by  Admiral  Wrangel  on  the  Sibe- 
rian coast  of  the  Polar  Sea.  All  remarked  "  that  the  Aurora 
flashed  forth  in  the  most  vivid  beams  when  masses  of  cirrous 
strata  were  hovering  in  the  upper  regions  of  the  air,  and  when 
these  were  so  thin  that  their  presence  could  only  be  recognized 
by  the  formation  of  a  halo  round  the  moon."  These  clouds 
sometimes  range  themselves,  even  by  day,  in  a  similar  manner 
to  the  beams  of  the  Aurora,  and  then  disturb  the  course  of 
the  magnetic  needle  in  the  same  manner  as  the  latter.  On 
the  morning  after  every  distinct  nocturnal  Aurora,  the  same 
superimposed  strata  of  clouds  have  still  been  observed  that 
had  previously  been  luminous.*  The  apparently  converging 
polar  zones  (streaks  of  clouds  in  the  direction  of  the  magnetic 
meridian),  which  constantly  occupied  my  attention  during  my 
journeys  on  the  elevated  plateaux  of  Mexico  and  in  Northern 
Asia,  belong  probably  to  the  same  group  of  diurnal  phenom- 
ena.t 

*  John  Franklin,  Narrative  of  a  Journey  to  the  Shores  of  the  Polar 
Sea,  in  the  Years  1819-1822,  p.  552  and  597  ;  Thieuemanu,  in  the 
Edinburgh  Philosophical  Journal,  vol.  xx.,  p.  336  ;  Farquharson,  in  vol. 
vi.,  p.  392,  of  the  same  jouvnal ;  Wrangel,  Phys.  Beob.,  s.  59.  Parry 
even  saw  the  great  arch  of  the  northern  light  continue  throughout  the 
day.  {Journal  of  a  Second  Voyage,  performed  in  1821-1823,  p.  156.) 
Something  of  the  same  nature  was  seen  in  England  on  the  9th  of  Sep- 
tember, 1827.  A  luminous  arch,  20^  high,  with  columns  proceeding 
from  it,  was  seen  at  noon  in  a  part  of  the  sky  that  had  been  clear  after 
rain.  (^Journal  of  the  Royal  Institution  of  Great  Britain,  1828,  Jan., 
p.  429.) 

t  On  my  return  from  my  American  ti'avels,  I  described  the  delicate 
cirro-cumulus  cloud,  which  appears  uniformly  divided,  as  if  by  the 
action  of  I'epuUive  forces,  under  the  name  of  polar  bands  {bandes  ^w- 
laires),  because  their  perspective  point  of  convergence  is  mostly  at  first 
in  the  magnetic  pole,  so  that  the  parallel  rows  of  fleecy  clouds  follow 
the  magnetic  meridian.  One  peculiarity  of  this  mystei'ious  phenomenoL 
is  the  oscillation,  or  occasionally  the  gradually  progressive  motion,  of 
the  point  of  convergence.  It  is  usually  observed  that  the  bands  are 
only  fully  developed  in  one  region  of  the  heavens,  and  they  are  seeu 
to  move  first  from  south  to  north,  and  then  gradually  from  east  to  west. 
I  could  not  trace  any  connection  between  the  advancing  motion  of  the 
bands  and  alterations  of  the  currents  of  air  in  the  higher  regions  of  the 
atmosphere.  They  occur  when  tlie  air  is  extremely  calm  and  the 
heavens  are  quite  serene,  and  are  much  more  common  under  the 
tropics  than  in  the  temperate  and  frigid  zones.  I  have  seen  this  phe- 
nomenon on  the  Andes,  almost  under  the  equator,  at  an  elevation  of 
15.920  feet,  and  in  Northern  Asia,  \n.  the  plains  of  Krasnojarski,  south 


198  COSMOS. 

Southern  lights  have  often  been  seen  in  England  by  the  in- 
telligent and  indefatigable  observer  Dalton,  and  northern  lights 
have  been  observed  in  the  southern  hemisphere  as  far  as  45^ 
latitude  (as  on  the  14th  of  January,  1831).  On  occasions 
that  are  by  no  means  of  rare  occurrence,  the  equilibrium  at 
both  poles  has  been  simultaneously  disturbed.  I  have  discov- 
ered vi'ith  certainty  that  northern  polar  lights  have  been  seen 
within  the  tropics  in  Mexico  and  Peru.  We  must  distinguish 
between  the  sphere  of  simultaneous  visibility  of  the  phenom- 
enon and  the  zones  of  the  Earth  where  it  is  seen  almost  niofht- 
ly.  Every  observer  no  doubt  sees  a  separate  Aurora  of  his 
own,  as  he  sees  a  separate  rainbow.  A  great  portion  of  the 
Earth  simultaneously  engenders  these  phenomena  of  emana- 
tions of  light.  Many  nights  may  be  instanced  in  which  the 
phenomenon  has  been  simultaneously  observed  in  England 
and  in  Pennsylvania,  in  Pwome  and  in  Pekin.  When  it  is 
stated  that  Auroras  diminish  with  the  decrease  of  latitude, 
the  latitude  must  be  understood  to  be  magnetic,  and  as  meas- 
ured by  its  distance  from  the  magnetic  pole.  In  Iceland,  in 
Greenland,  Newfoundland,  on  the  shores  of  the  Slave  Lake, 
and  at  Fort  Enterprise  in  Northern  Canada,  these  lights  ap- 
pear almost  every  night  at  certain  seasons  of  the  year,  cele- 
brating with  their  flashing  beams,  according  to  the  mode  of 
expression  common  to  the  inhabitants  of  the  Shetland  Isles, 
"  a  merry  dance  in  heaven."*  While  the  Aurora  is  a  phe- 
nomenon of  rare  occurrence  in  Italy,  it  is  frequently  seen  in 
the  latitude  of  Philadelphia  (39°  57'),  owing  to  the  southern 
position  of  the  American  magnetic  pole.  In  the  districts 
which  are  remarkable,  in  the  New  Continent  and  the  Sibe- 
rian coasts,  for  the  frequent  occurrence  of  this  phenomenon, 
there  are  special  regions  or  zones  of  longitude  in  which  the 
polar  light  is  particularly  bright  and  brilliant. f     The  exist- 

of  Buchtarmiusk,  so  similarly  developed,  that  we  must  regard  the  in 
fluences  producing  it  as  very  widely  distributed,  and  as  depending  on 
general  natural  forces.  See  the  important  observations  of  Kamtz  (  Vor- 
lesungen  uber  Meteorologie,  1840,  s.  146),  and  the  more  recent  ones  of 
Martins  and  Bravais  {Mitiorologie,  1843,  p.  117).  In  south  polar  bauds, 
composed  of  veiy  delicate  clouds,  observed  by  Arago  at  Paris  on  the 
23d  of  June,  1844,  dark  rays  shot  upward  from  an  arch  running  east 
aud  west.  We  have  already  made  mention  of  black  rays,  resembling 
dark  smoke,  as  occurring  in  brilliant  nocturnal  northern  lights. 

*  The  northern  lights  are  called  by  the  Shetland  Islanders  "  the 
merry  dancers."  (Kendal,  in  the  Quarterly  Journal  of  Science,  new 
series,  vol.  iv.,  p.  395.) 

t  See  Muucke's  excellent  work  in  the  new  edition  of  Gehler'a  Physik 
Wdrterbvcli,  bd.  vii.,  i.,  s.  113-268,  and  especially  s.  158. 


AlKoRA     J'.tiKKALlS.  199 

ftnce  of  local  influences  can  not,  theretbre,  be  denied  in  theso 
oases.  Wrangel  saw  the  brilliancy  diminish  as  he  left  the 
shores  of  the  Polar  Sea,  about  Nischne-Kolymsk.  The  ob- 
servations made  in  the  North  Polar  expedition  appear  to  prove 
that  in  the  immediate  vicinity  of  the  magnetic  pole  the  de- 
velopment of  light  is  not  in  the  least  degree  more  intense  or 
frequent  than  at  some  distance  from  it. 

The  knowledge  which  we  at  present  possess  of  the  altitude 
of  the  polar  light  is  based  on  measurements  which,  from  their 
nature,  the  constant  oscillation  of  the  phenomenon  of  light, 
and  the  consequent  uncertainty  of  the  angle  of  parallax,  are 
not  deserving  of  much  confidence.  The  results  obtained,  set- 
ting aside  the  older  data,  fluctuate  between  several  miles  and 
an  elevation  of  3000  or  4000  feet;  and, -in  all  probability, 
the  northern  lights  at  different  times  occur  at  very  different 
elevations.*  The  most  recent  observers  are  disposed  to  place 
the  phenomenon  in  the  region  of  clouds,  and  not  on  the  con- 
fines of  the  atmosphere  ;  and  they  even  believe  that  the  rays 
of  the  Aurora  may  be  affected  by  winds  and  currents  of  air,  if 
the  phenomenon  of  light,  by  which  alone  the  existence  of  an 
electro-magnetic  current  is  appreciable,  be  actually  connected 
v/ith  material  groups  of  vesicles  of  vapor  in  motion,  or,  more 
correctly  speaking,  if  light  penetrate  them,  passing  from  one 
vesicle  to  another.  Franklin  saw  near  Great  Bear  Lake  a 
beaming  northern  light,  the  lower  side  of  which  he  thought 
illuminated  a  stratum  of  clouds,  wliile,  at  a  distance  of  only 
eighteen  geographical  miles,  Kendal,  who  was  on  watch 
throughout  the  whole  night,  and  never  lost  sight  of  the  sky, 
perceived  no  phenomenon  of  Hght.  The  assertion,  so  fre- 
quently maintained  of  late,  that  the  rays  of  the  Aurora  have 
been  seen  to  shoot  down  to  the  ground  between  the  spectator 
and  some  neighboring  hill,  is  open  to  the  charge  of  optical 
delusion,  as  ia  the  cases  of  strokes  of  lightning  or  of  the  fall 
of  fire-balls. 

Whether  the  magnetic  storms,  v/hose  local  character  we 
have  illustrated  by  such  remarkable  examples,  share  noise  as 
well  as  light  in  common  with  electric  storms,  is  a  question 

*  Farquharsou  ia  the  Edinburgh  Philos.  Jonrjial,  vol.  xvi.,  p.  304 ; 
PUlos.  Transact,  for  1829,  p.  113. 

[Tlie  height  of  the  bow  of  light  of  the  Aurora  seen  at  the  Canibridgo 
Observatory,  March  19,  1847,  was  determined  by  Professors  Challis,  of 
Cambridge,  and  Chevallier,  of  Durham,  to  be  177  miles  above  the  sur- 
fcice  of  the  Earth.  .See  tiie  notice  of  this  meteor  in  An  Account,  of  ih-^ 
Aurora  Borealis  of  Oct.  24,  1817,  bv  Jolin  H.  Morgan,  Esq.,  isfs.!— 
Tr. 


200  COSMOS. 

that  has  become  difficult  to  answer,  since  impHcit  confidenco 
is  no  longer  yielded  to  the  relations  of  Greenland  whale-fish- 
ers and  Siberian  fox-hunters.  Northern  lights  appear  to  have 
become  less  noisy  since  their  occurrences  have  been  more  ac- 
curately recorded.  Parry,  Franklin,  and  Richardson,  near 
the  north  polo  ;  Thienemann  in  Iceland  ;  Gieseke  in  Green- 
land ;  Lottn.  and  Bravais,  near  the  North  Cape  ;  Wrangel 
and  Anjou,  on  the  coast  of  the  Polar  Sea,  have  together  seen 
the  Aurora  thousands  of  times,  but  never  heard  any  sound 
attending  the  phenomenon.  If  this  negative  testimony  should 
not  be  deemed  equivalent  to  the  positive  counter-evidence  of 
Hearne  on  the  mouth  of  the  Copper  River  and  of  Henderson 
in  Iceland,  it  must  be  remembered  that,  although  Hood  heard 
a  noise  as  of  quickly-moved  musket-balls  and  a  slight  crack- 
ing sound  during  an  Aurora,  he  also  noticed  the  same  noise 
on  the  following  day,  when  there  was  no  northern  light  to  be 
seen  ;  and  it  must  not  be  forgotten  that  Wrangel  and  Gieseke 
were  fully  convinced  that  the  sound  they  had  heard  was  to 
be  ascribed  to  the  contraction  of  the  ice  and  the  crust  of  the 
snow  on  the  sudden  cooling  of  the  atmosphere.  The  belief 
in  a  crackling  sound  has  arisen,  not  among  the  people  gener- 
ally, but  rather  among  learned  travelers,  because  in  earlier 
times  the  northern  light  was  declared  to  be  an  efiect  of  atmos- 
pheric electricity,  on  account  of  the  luminous  manifestation 
of  the  electricity  in  rarefied  space,  and  the  observers  found  it 
easy  to  hear  what  they  wished  to  hear.  Recent  experiments 
with  very  sensitive  electrometers  have  hitherto,  contrary  to 
the  expectation  generally  entertained,  yielded  only  negative 
results.      The  condition  of  the  electricity  in  the  atmosphere.* 

*  [Mr.  James  Glaisher,  of  tlie  Royal  Observatory,  Greenwich,  iii  his 
interesting  Remarks  on  the  Weather  d7iring  the  Quarter  ending'  Decem- 
ber 31st,  1847,  says,  "  It  is  a  fact  well  worthy  of  notice,  that  from  the 
beginning  of  this  quarter  till  the  20th  of  December,  the  electricity  of 
the  atmosphere  was  almost  always  iu  a  neutral  state,  so  that  no  signs  of 
electi'icity  were  shown  for  several  days  together  by  any  of  the  electric- 
al instruments."  During  this  period  there  were  eight  exhibitions  of 
the  Aurora  Borealis,  of  which  one  was  the  peculiarly  bright  display  of 
the  meteor  on  the  24th  of  October.  These  frequent  exhibitions  of  brill- 
iant Aurone  seem  to  depend  upon  many  remarkable  meteorological  re- 
lations, for  we  find,  according  to  Mr.  Glaisher's  statement  in  the  paper 
to  which  we  have  already  alluded,  that  the  previous  fifty  years  afFoi'd 
nc  parallel  season  to  the  closing  one  of  1847.  The  mean  temperature 
of  evaporation  and  of  the  dew  point,  the  mean  elastic  force  of  vapor, 
the  mean  reading  of  the  barometer,  and  the  mean  daily  range  of  the 
readings  of  the  thermometers  iu  air,  were  all  greater  at  Greenwich 
during  that  season  of  1847  than  the  average  range  of  many  pi'ececliiig 
years.] — Tr. 


AURORA    BOREALIS..  201 

is  not  found  to  be  changed  during  the  most  intense  Aurora  ; 
but,  on  the  other  hand,  the  three  expressions  of  the  poAver  of 
terrestrial  magnetism,  decHnation,  inchnation,  and  intensity, 
are  all  affected  by  polar  light,  so  that  in  the  same  night,  and 
at  different  periods  of  the  magnetic  development,  the  same 
end  of  the  needle  is  both  attracted  and  repelled.  The  asser 
tion  made  by  Parry,  on  the  strength  of  the  data  yielded  by 
his  observations  in  the  neighborhood  of  the  magnetic  pole  at 
Melville  Island,  that  the  Aurora  did  not  disturb,  but  rathei 
exercised  a  calming  influence  on  the  magnetic  needle,  has  been 
satisfactorily  refuted  by  Parry's  own  more  exact  researches,* 
detailed  in  his  journal,  and  by  the  admirable  observations  of 
Richardson,  Hood,  and  Franklin  in  Northern  Canada,  and 
lastly  by  Bravais  and  Lottin  in  Lapland.  The  process  of  the 
Aurora  is,  as  has  already  been  observed,  the  restoration  of  a 
disturbed  condition  of  equilibrium.  The  effect  on  the  needle 
is  different  according  to  the  degree  of  intensity  of  the  explo- 
sion. It  was  only  unappreciable  at  the  gloomy  winter  station 
of  Bosekop  when  the  phenomenon  of  Hght  was  very  faint  and 
low  in  the  horizon.  The  shooting  cylinders  of  rays  have  been 
aptly  compared  to  the  flame  which  rises  in  the  closed  circuit 
of  a  voltaic  pile  between  two  points  of  carbon  at  a  considera- 
ble distance  apart,  or,  according  to  Fizeau,  to  the  flame  rising 
between  a  silver  and  a  carbon  point,  and  attracted  or  repelled 
by  the  magnet.  This  analogy  certainly  sets  aside  the  neces- 
sity of  assuming  the  existence  of  metallic  vapors  in  the  atmos- 
phere, which  some  celebrated  physicists  have  regarded  as  the 
substratum  of  the  northern  light. 

When  we  apply  the  indefinite  term  polar  light  to  the  lumin- 
ous phenomenon  which  we  ascribe  to  a  galvanic  current,  that 
is  to  say,  to  the  motion  of  electricity  in  a  closed  circuit,  we 
merely  indicate  the  local  direction  in  which  the  evolution  of 
light  is  most  freqilently,  although  by  no  means  invariably, 
seen.  This  phenomenon  derives  the  greater  part  of  its  im- 
portance from  the  fact  that  the  Earth  becomes  self-luminous, 
and  that  as  a  planet,  besides  the  light  which  it  receives  from 
the  central  body,  the  Sun,  it  shows  itself  capable  in  itself  of 
developing  light.  The  intensity  of  the  terrestrial  light,  or, 
rather,  the  luminosity  which  is  diffused,  exceeds,  in  cases  of 
the  brightest  colored  radiation  toward  the  zenith,  the  light 
of  the  Moon  in  its  first  quarter.  Occasionally,  as  on  the  7th 
of  January,  1831,  printed  characters  could  be  read  without 
difficulty.     This  almost  uninterrupted  development  of  light 

*  Kamtz,  Lehrbuch  der  Metecrologie,  bd.  iii.,  s.  498  und  501. 

I  2 


202  COSMOS. 

in  the  Earth  leads  us  by  analogy  to  the  remarkable  process 
exhibited  in  Venus.  The  portion  of  this  planet  which  is  not 
illumined  by  the  Sun  often  shines  with  a  phosphorescent  light 
of  its  own.  It  is  not  improbable  that  the  Moon,  Jupiter,  and 
the  comets  shine  with  an  independent  light,  besides  the  re- 
flected solar  light  visible  through  the  polariscope.  Without 
speaking  of  the  problematical  but  yet  ordinary  mode  in  which 
the  sky  is  illuminated,  when  a  low  cloud  may  be  seen  to  shine 
with  an  uninterrupted  flickering  light  for  many  minutes  to- 
gether, we  still  meet  with  other  instances  of  terrestrial  develop- 
ment of  light  in  our  atmosphere.  In  this  category  we  may 
reckon  the  celebrated  luminous  mists  seen  in  1783  and  1831  ; 
the  steady  luminous  appearance  exhibited  without  any  flick- 
ering in  great  clouds  observed  by  Rozier  and  Beccaria  ;  and 
lastly,  as  Arago*  well  remarks,  the  faint  difliised  light  which 
guides  the  steps  of  the  traveler  in  cloudy,  starless,  and  moon- 
less nights  in  autumn  and  winter,  even  when  there  is  no  snow 
on  the  ground.  As  in  polar  light  or  the  electro-magnetic 
storm,  a  current  of  brilliant  and  often  colored  light  streams 
through  the  atmosphere  in  high  latitudes,  so  also  in  the  torrid 
zones  between  the  tropics,  the  ocean  simultaneously  develops 
light  over  a  space  of  many  thousand  square  miles.  Here  the 
magical  effect  of  light  is  owing  to  the  forces  of  organic  nature. 
Foaming  with  light,  the  eddying  waves  flash  in  phosphores- 
cent sparks  over  the  wide  expanse  of  waters,  where  every  scin- 
tillation is  the  vital  manifestation  of  an  invisible  animal  world. 
So  varied  are  the  sources  of  terrestrial  light  I  Must  we  still 
suppose  this  light  to  be  latent,  and  combined  in  vapors,  in 
order  to  explain  Mose/s  images  2^Toduced  at  a  distance — a 
discovery  in  which  reality  has  hitherto  manifested  itself  like 
a  mere  phantom  of  the  imagination. 

As  the  internal  heat  of  our  planet  is  connected  on  the  one 
hand  with  the  generation  of  electro-magrietic  currents  and 
the  process  of  terrestrial  light  (a  consequence  of  the  magnetic 
storm),  it,  on  the  other  hand,  discloses  to  us  the  chief  source 
of  geognostic  phenomena.  We  shall  consider  these  in  their 
connection  with  and  their  transition  from  merely  dynamic  dis- 
turbances, from  the  elevation  of  whole  continents  and  mount- 
ain chains  to  the  development  and  effusion  of  gaseous  and 

*  Arago,  on  the  dry  fogs  of  1783  and  1831,  which  illuminated  the 
night,  in  the  Annuairedu  Bureau  des  Longitudes,  1832,  p.  246  and  250; 
and,  regarding  extraordinary  lumiuoas  appearances  in  clouds  without 
storms,  see  Notices  sur  la  Tonnerre.  in  the  Annuaire  pour  Van.  1838. 
p.  279-285. 


GK!)(;i\(»STI('     I'llKVOMKXA.  203 

liquid  tiuids,  of  hot  mud,  aud  of  those  heated  and  molten 
earths  which  become  sohdified  into  crystalline  mineral  masses. 
Modern  geognosy,  the  mineral  portion  of  terrestrial  physics, 
has  made  no  slio;ht  advance  in  having  investisfated  this  con 
nection  of  phenomena.  This  investigation  has  led  us  away 
from  the  delusive  hypothesis,  by  which  it  was  customary  for- 
merly to  endeavor  to  explain,  individually,  every  expression  of 
force  in  the  terrestrial  globe  :  it  shows  us  the  connection  of 
the  occurrence  of  heterogeneous  substances  with  that  which 
only  appertains  to  changes  in  space  (disturbances  or  eleva- 
tions), and  groups  together  phenomena  which  at  first  sight 
appeared  most  heterogeneous,  as  thermal  springs,  eilusion  of 
carbonic  acid  and  sulphurous  vapor,  innocuous  salses  (mud 
eruptions),  and  the  dreadful  devastations  of  volcanic  mount- 
ains.* In  a  general  view  of  nature,  all  these  phenomena  are 
fused  together  in  one  sole  idea  of  the  reaction  of  the  interior 
of  a  planet  on  its  external  surface.  We  thus  recognize  in  the 
depths  of  the  earth,  and  in  the  increase  of  temperature  with 
the  increase  of  depth  from  the  surface,  not  only  the  germ  of 
disturbing  movements,  but  also  of  the  gradual  elevation  of 
whole  continents  (as  mountain  chains  on  long  fissures),  of  vol- 
canic eruptions,  and  of  the  manifold  production  of  mountains 
and  mineral  masses.  The  influence  of  this  reaction  ot"  the 
interior  on  the  exterior  is  not,  however,  limited  to  inorganic 
nature  alone.  It  is  highly  probable  that,  in  an  earlier  world, 
more  powerful  emanations  of  carbonic  acid  gas,  blended  with 
the  atmosphere,  must  have  increased  the  assimilation  of  car- 
bon in  vegetables,  and  that  an  inexhaustible  supply  of  com- 
bustible matter  (lignites  and  carboniferous  formations)  must 
have  been  thus  buried  in  the  upper  strata  of  the  earth  by  the 
revolutions  attending  the  destruction  of  vast  tracts  of  forest. 
We  likewise  perceive  that  the  destiny  of  mankind  is  in  part 
dependent  on  the  formation  of  the  external  surface  of  the  earth, 
the  dfi-ection  of  mountain  tracts  and  high  lands,  and  on  the 
distribution  of  elevated  continents.  It  is  thus  granted  to  the 
inquiring  mind  to  pass  from  link  to  link  along  the  chain  of 
phenomena  until  it  reaches  the  period  when,  in  the  solidifying 
process  of  our  planet,  and  in  its  first  transition  from  the  gas- 
eous form  to  the  agglomeration  of  matter,  that  portion  of  the 
inner  heat  of  the  Earth  w^as  developed,  which  does  not  belong 
to  the  action  of  the  Sun. 

*  [See  Manteirs  Wonders  of  Geology,  1848,  vol.  i.,  p.  .34,  3(j,  10.5; 
also  Lyell's  Principcs  of  Geology,  vol.  ii.,  and  Daubeney  On  Volcanoes, 
^d  ed.,  1848.  Part  ii..  cli.  xxxii.,  xxxiii.] — 2r. 


204  coor.TOS. 

Tn  order  to  give  a  general  delineation  of  the  causal  con- 
nection of  geognostical  phenomena,  we  will  begin  with  those 
whose  chief  characteristic  is  dynamic,  consisting  in  motion 
and  in  change  in  space.  Earthquakes  manifest  themselves 
by  quick  and  successive  vertical,  or  horizontal,  or  rotatory  vi- 
brations.* In  the  very  considerable  number  of  earthquakes 
which  I  have  experienced  in  both  hemispheres,  alike  on  land 
and  at  sea,  the  two  first-named  kinds  of  motion  have  often  ap- 
peared to  me  to  occur  simultaneously.  The  mine-like  explo- 
sion— the  vertical  action  from  below  upward — was  most  strik- 
ingly manifested  in  the  overthrow  of  the  town  of  Riobamba 
in  1797,  when  tlie  bodies  of  many  of  the  inhabitants  were 
found  to  have  been  hurled  to  Cullca,  a  hill  several  hundred 
feet  in 'height,  and  on  the  opposite  side  of  the  River  Lican. 
The  propagation  is  most  generally  effected  by  undulations  in 
a  linear  direction,!  with  a  velocity  of  from  twenty  to  twenty- 
eight  miles  in  a  minute,  but  partly  in  circles  of  commotion  or 
large  ellipses,  in  which  the  vibrations  are  propagated  with 
decreasing  intensity  from  a  center  toward  the  circumference. 
There  are  districts  exposed  to  the  action  of  two  intersecting 
circles  of  commotion.  In  Northern  Asia,  where  the  Father 
of  History, t  and  subsequently  Theophylactus  Simocatta,§  de- 
scribed the  districts  of  Scythia  as  free  from  earthquakes,  I 
have  observed  the  metalliferous  portion  of  the  Altai  Mount- 
ains under  the  influence  of  a  two-fold  focus  of  commotion,  the 
Lake  of  Baikal,  and  the  volcano  of  the  Celestial  Mountain 
(Thianschan).ll  When  the  circles  of  commotion  intersect  one 
another — when,  for  instance,  an  elevated  plain  lies  between 
two  volcanoes  simultaneously  in  a  state  of  eruption,  several 
wave-systems  may  exist  together,  as  in  fluids,  and  not  mu- 
tually disturb  one  another.     We  may  even  suppose  interfer- 

*  [See  Daubeney  On  Volcanoes,  2d  ed.,  1848,  p.  509.]— Tr. 
t  [Ou  the  linear  direction  of  earthquakes,  see  Daubeney  Oit^Volca- 
noes,  p.  515.] — Tr. 

I  Herod,  iv.,  28.  The  prostration  of  the  colossal  statue  of  Memnou, 
which  has  been  again  restored  (Leti'onne,  La  Statue  Vocale  de  Memnon, 
1835,  p.  25,  26),  presents  a  fact  in  opposition  to  the  ancient  prejudice 
that  Egypt  is  free  from  earthquakes  (Pliny,  ii.,  80);  but  the  valley  of 
the  Nile  does  lie  external  to  the  circle  of  commotion  of  Byzantium,  the 
Archipelago,  and  Syria  (Ideler  ad  Aristot.,  Meteor.,  p.  584). 

§  Saint-Martin,  in  the  learned  notes  to  Lebeau,  Hist,  du  Bas  Empire, 
t.  Ix.,  p.  401. 

II  Humboldt,  Asie  Centrale,  t.  ii.,  p.  110-118.     In  regard  to  the  dif- 
ference between  agitation  of  the  surface  and  of  the  strata  lying  beneath 
it,  see  Gay-Lussac,  in  the  Annates  de  Chimie  et  de  Physique,  t.  xxii.,  p 
499. 


I  EARTHaUAKES.  205 

ence  to  exist  here,  as  in  the  intersecting  waves  of  sound.  The 
extent  of  the  propagated  waves  of  commotion  will  be  increased 
on  the  upper  surface  of  the  earth,  according  to  the  general  law 
of  mechanics,  by  which,  on  the  transmission  of  motion  in  elas- 
tic bodies,  the  stratum  lying  free  on  the  one  side  endeavors  to 
separate  itself  from  the  other  strata. 

Waves  of  commotion  have  been  investigated  by  means  of 
the  pendulum  and  the  seismometer*  with  tolerable  accuracy  in 
respect  to  their  direction  and  total  intensity,  but  by  no  means 
with  reference  to  the  internal  nature  of  their  alternations  and 
their  periodic  intumescence.  In  the  city  of  Quito,  which  lies 
at  the  foot  of  a  still  active  volcano  (the  Rucu  Pichincha), 
and  at  an  elevation  of  9540  feet  above  the  level  of  the  sea, 
which  has  beautiful  cupolas,  high  vaulted  churches,  and  mass- 
ive edifices  of  several  stories,  I  have  often  been  astonished 
that  the  violence  of  the  nocturnal  earthquakes  so  seldom 
causes  fissures  in  the  walls,  while  in  the  Peruvian  plains  os- 
cillations apparently  much  less  intense  injure  low  reed  cot- 
tages. The  natives,  who  have  experienced  many  hundred" 
earthquakes,  believe  that  the  difference  depends  less  upon  the 
length  or  shortness  of  the  waves,  and  the  slowness  or  rapidity 
of  the  horizontal  vibrations,!  than  on  the  uniformity  of  the 
motion  in  opposite  directions.  The  circling  rotatory  commo- 
tions are  the  most  uncommon,  but,  at  the  same  time,  the  most 
dangerous.  Walls  were  observed  to  be  twisted,  but  not  thrown 
down  ;  rows  of  trees  turned  from  their  previous  parallel  direc- 

*  [This  iustrument,  iu  its  simplest  form,  cousists  merely  of  a  basin 
filled  with  some  viscid  liquid,  which,  on  the  occurrence  of  a  shock  of 
an  earthquake  of  sufficient  force  to  disturb  the  equilibrium  of  the 
building  iu  which  it  is  placed,  is  tilted  on  one  side,  and  the  liquid  made 
to  rise  in  the  same  direction,  thus  showing  by  its  height  the  degree  of 
the  disturbance.  Professor  J.  Forbes  has  invented  an  instrument  of 
this  nature,  although  on  a  greatly  improved  plan.  It  consists  of  a  vert- 
ical metal  rod,  having  a  ball  of  lead  movable  upon  it.  It  is  supported 
upon  a  cylindrical  steel  wire,  which  may  be  compressed  at  pleasure  by 
means  of  a  screw.  A  lateral  movement,  such  as  that  of  an  earthquake, 
which  carries  forward  the  base  of  the  instrument,  can  only  act  upon  the 
ball  through  the  medium  of  the  elasticity  of  the  wire,  and  the  direction 
of  the  displacement  will  be  indicated  by  the  plane  of  vibration  of  the 

Eeudulum.     A  self-registering  apparatus  is  attached  to  the  machine, 
ee  Professor  J.  Forbes's  account  of  his  invention  in  Edinb.  Phil.  Trans., 
vol.  XV.,  Part  i.] — Tr. 

t  "  Tutissimum  est  cum  vibrat  crispante  aedificiorum  crepitu  ;  et  cum 
hitumescit  assurgens  alternoque  motu  residet,  iunoxium  et  cum  concur- 
rentia  tecta  contrario  ictu  arietant;  quoniam  alter  motus  alteri  renititur. 
Undantis  inclinatio  et  fluctus  more  quaidam  volutatio  infesta  est,  aut  cum 
in  unara  partem  totus  se  motus  impellit." — Plin.,  ii.,  8*2. 


206  coSxMos. 

tion  ;  and  fields  covered  with  different  kinds  of  plants  found 
to  be  displaced  in  the  great  earthquake  of  Riobamba,  in  the 
province  of  Quito,  on  the  4th  of  February,  1797,  and  in  that 
of  Calabria,  between  the  5th  of  February  and  the  28th  of 
March,  1783  The  phenomenon  of  the  inversion  or  displace- 
ment of  fields  and  pieces  of  land,  by  which  one  is  made  to  oc- 
cupy the  place  of  another,  is  connected  with  a  translatory  mo- 
tion or  penetration  of  separate  terrestrial  strata.  When  I 
made  the  plan  of  the  ruined  town  of  Riobamba,  one  particu- 
lar spot  was  pointed  out  to  me,  where  all  the  furniture  of  one 
house  had  been  found  under  the  ruins  of  another.  The  loose 
earth  had  evidently  moved  like  a  fluid  in  currents,  which  must 
be  assumed  to  have  been  directed  first  downward,  then  hori- 
zontally, and  lastly  upward.  It  was  found  necessary  to  ap- 
peal to  the  Audie7icia,  or  Council  of  Justice,  to  decide  upon 
the  contentions  that  arose  regarding  the  proprietorship  of  ob- 
jects that  had  been  removed  to  a  distance  of  many  hundred 
toises. 

In  countries  where  earthquakes  are  comparatively  of  much 
less  frequent  occurrence  (as,  for  instance,  in  Southern  Europe), 
a  very  general  belief  prevails,  although  unsupported  by  the 
authority  of  inductive  reasoning,*  that  a  calm,  an  oppressive 

*  Even  in  Italy  they  have  begun  to  observe  that  earthquakes  are  un- 
connected with  the  state  of  the  weather,  that  is  to  say,  with  the  appear- 
ance of  the  heavens  immediately  before  the  shock.  The  numerical  re- 
sults of  Friedrich  Hoffmann  {Hinterlassene  Werke,  bd.  ii.,  366-375)  ex- 
actly correspond  with  the  experience  of  the  Abbate  Sciua  of  Palermo. 
I  have  myself  several  times  observed  I'eddish  clouds  on  the  day  of  an 
earthquake,  and  shortly  before  it;  on  the  4th  of  November,  1799,  I  ex- 
perienced two  sharp  shocks  at  the  moment  of  a  loud  clap  of  thunder. 
{Relat.  Hist.,  liv.  iv.,  chap.  10.)  The  Turin  physicist,  Vassalli  Eandi, 
observed  Volta's  electrometer  to  be  strongly  agitated  during  the  pro- 
tracted earthquake  oT  Pignerol,  which  lasted  from  the  2(1  of  April  to 
the  17th  of  May,  1808;  Journal  de  Physique,  t.  Ixvii.,  p.  291.  But 
these  indications  presented  by  clouds,  by  modifications  of  atmospheric 
electricity,  or  by  calms,  can  not  be  regarded  as  generally  or  necessarily 
connected  with  earthquakes,  since  in  Quito,  Peru,  and  Chili,  as  well 
as  in  Canada  and  Italy,  many  earthquakes  are  observed  along  with  tlie 
purest  and  clearest  skies,  and  with  the  freshest  land  and  sea  breezes. 
But  if  no  meteorological  phenomenon  indicates  the  coming  earthqunke 
either  on  the  morning  of  the  shock  or  a  few  dnys  previously,  the  iuflii- 
ence  of  certain  periods  of  the  year  (the  vernal  and  autumnal  equinoxes), 
the  commencement  of  the  rainy  season  in  the  tropics  after  long  drought. 
and  the  change  of  the  monsoons  (according  to  general  belief),  can  not 
6e  overlooked,  even  though  the  genetic  connection  of  meteorological 
processes  with  those  going  on  in  the  interior  of  our  globe  is  still  envel- 
oped in  obscurity.  Numerical  inquiries  on  the  distribution  of  earth- 
quakes throughout  the  course  of  the  year,  such  as  tho.se  of  Von  Hoff, 
Peter  Merian,  and  Filedrich  Hoffmann,  bear  testimony  to  their  frequency 


EARTHQUAKErJ.  207 

leat,  and  a  misty  horizon,  are  always  the  forerunners  of  this 
phenomenon.  The  fallacy  of  this  popular  opinion  is  not  only 
refuted  by  my  own  experience,  but  likewise  by  the  observations 
of  all  those  who  have  lived  many  years  in  districts  where,  as 
in  Cumana,  Quito,  Peru,  and  Chili,  the  earth  is  frequently 
and  violently  agitated.  I  have  ielt  earthquakes  in  clear  air 
and  a  fresh  east  wind,  as  well  as  in  rain  and  thunder  storms. 
The  regularity  of  the  horary  changes  in  the  declination  of  the 
magnetic  needle  and  in  the  atmospheric  pressure  remained  un 
disturbed  between  the  tropics  on  the  days  when  earthquakes 
occurred.*  These  facts  agree  with  the  observations  made  bj' 
Adolph  Erman  (in  the  temperate  zone,  on  the  8th  of  March, 
1829)  on  the  occasion  of  an  earthquake  at  Irkutsk,  near  the 
Lake  of  Baikal.  During  the  violent  earthquake  of  Cumana, 
on  the  4th  of  November,  1799,  I  found  the  declination  and 
the  intensity  of  the  magnetic  force  alike  unchanged,  but,  to 
my  surprise,  the  inclination  of  the  needle  was  diminished  about 
48 '.t  There  was  no  ground  to  suspect  an  error  in  the  calcu- 
lation, and  yet,  in.  the  many  other  earthquakes  which  I  have 
experienced  on  the  elevated  plateaux  of  Quito  and  Lima,  the 
inclination  as  well  as  the  other  elements  of  terrestrial  mag- 
netism remained  always  unchanged.  Although,  in  general, 
the  processes  at  work  within  the  interior  of  the  earth  may  not 
be  announced  by  any  meteorological  phenomena  or  any  special 
appearance  of  the  sky,  it  is,  on  the  contrary,  not  improbable, 
as  we  shall  soon  see,  that  in  cases  of  violent  earthquakes  some 
eSect  may  be  imparted  to  the  atmosphere,  in  consequence  of 
which  they  can  not  always  act  in  a  purely  dynamic  manner. 

at  the  periods  of  the  equiuoxes.  It  is  singular  that  Pliny,  at  the  end  of 
his  fanciful  theory  of  earthquakes,  names  the  entire  frightful  phenom- 
enon a  subterranean  stoi'm  ;  not  so  much  in  consequence  of  the  rolling 
sound  which  frequently  accompanies  the  shock,  as  because  the  elastic 
forces,  concussive  by  their  tension,  accumulate  in  the  interior  of  the 
earth  when  they  are  absent  in  the  atmosphere  !  "  Ventos  in  causa  esse 
non  dubium  reor.  Neque  enim  unquara  intremiscunt  terrae,  nisi  sopito 
mari,  coeloque  adeo  tranquillo,  ut  volatus  avium  non  pendeant,  subtracto 
omni  spiritu  qui  vehit;  nee  unquam  nisi  post  ventos  conditos,  scilicet 
in  venas  et  cavernas  ejus  occulto  afflatu.  Neque  aliud  est  in  terra 
tremor,  quam  in  nube  tonitruum ;  nee  hiatus  aliud  quam  cum  fulmen 
erumpit,  incluso  spiritu  luctante  et  ad  libertatem  exire  nitente."  (Plin., 
ii.,  79.)  The  germs  of  almost  every  thing  that  has  been  observed  or 
imagined  on  the  causes  of  earthquakes,  up  to  the  present  day,  may  be 
found  in  Seneca,  Nat.  Qucest..  vi.,  4-31. 

*  I  have  given  proof  that  the  course  of  the  horaiy  variations  of  the 
Darometer  is  not  affected  before  or  after  earthquakes,  in  my  Relat.  Hist.. 
t.  i.,  p.  311  and  513. 

t  Humboldt,  Relat.  Hist.,  t.  i..  p.  51.5-517. 


208  COSMOS. 

• 

During-  the  long-continued  trembling  of  the  ground  in  the 
Piedmontese  valleys  of  Pelis  and  Clusson,  the  greatest  changes 
in  the  electric  tension  of  the  atmosphere  were  observed  while 
the  sky  was  cloudless.  The  intensity  of  the  hollow  noise  which 
generally  accompanies  an  earthquake  does  not  increase  in  the 
same  degree  as  the  force  of  the  oscillations.  I  have  ascertain- 
ed with  certainty  that  the  great  shock  of  the  earthquake  of 
Riobamba  (4th  Feb.,  1797) — one  of  the  most  fearful  phenom- 
ena recorded  in  the  physical  history  of  our  planet — was  not 
accompanied  by  any  noise  whatever.  The  tremendous  noise 
{el  gran  ruido)  which  was  heard  below  the  soil  of  the  cities 
of  Quito  and  Ibarra,  but  not  at  Tacunga  and  Hambato,  near- 
er the  center  of  the  motion,  occurred  between  eighteen  and 
twenty  minutes  after  the  actual  catastrophe.  In  the  cele- 
brated earthquake  of  Lima  and  Callao  (28th  of  October, 
1746),  a  noise  resembling  a  subterranean  thunder-clap  was 
heard  at  Truxillo  a  quarter  of  an  hour  after  the  shock,  and 
unaccompanied  by  any  trembling  of  the  ground.  In  like 
manner,  long  after  the  great  earthquake  in  New  Granada,  on 
the  16th  of  November,  1827,  described  by  Boussingault,  sub- 
terranean detonations  were  heard  in  the  whole  valley  of  Cauca 
during  twenty  or  thirty  seconds,  unattended  by  motion.  The 
nature  of  the  noise  varies  also  very  much,  being  either  rolling, 
or  rustling,  or  clanking  like  chains  when  moved,  or  like  near 
thunder,  as,  for  instance,  in  the  city  of  Quito  ;  or,  lastly,  clear 
and  ringing,  as  if  obsidian  or  some  other  vitrified  masses  were 
struck  in  subterranean  cavities.  As  solid  bodies  are  excellent 
conductors  of  sound,  which  is  propagated  in  burned  clay,  for 
instance,  ten  or  twelve  times  quicker  than  in  the  air,  the  sub- 
terranean noise  may  be  heard  at  a  great  distance  from  the 
place  where  it  has  originated.  In  Caraccas,  in  the  grassy 
plains  of  Calabozo,  and  on  the  banks  of  the  Rio  Apure,  which 
falls  into  the  Orinoco,  a  tremendously  loud  noise,  resembling 
thunder,  was  heard,  unaccompanied  by  an  earthquake,  over 
a  district  of  land  9200  square  miles  in  extent,  on  the  30th  of 
April,  1812,  while  at  a  distance  of  632  miles  to  the  north- 
east, the  volcano  of  St.  Vincent,  in  the  small  Antilles,  poured 
forth  a  copious  stream  of  lava.  With  respect  to  distance,  this 
was  as  if  an  eruption  of  Vesuvius  had  been  heard  in  the  north 
of  France.  In  the  year  1744,  on  the  great  eruption  of  the 
volcano  of  Cotopaxi,  subterranean  noises,  resembling  the  dis- 
charge oi'  cannon,  were  heard  in  Honda,  on  the  Magdalena 
River.  The  crater  of  Cotopaxi  lies  not  only  18,000  feet  high- 
er than.  Honda,  but  these  two  points  are  separated  by  the  co- 


«  EARTHaUAKES.  209 

iossal  mountain  chain  of  Quito,  Pasto,  and  Popayan,  no  less 
than  by  numerous  valleys  and  clefts,  and  they  are  436  miles 
apart.  The  sound  was  certainly  not  propagated  through  the 
air,  but  through  the  earth,  and  at  a  great  depth.  During  the 
violent  earthquake  of  New  Granada,  in  February,  1835,  sub- 
terranean thunder  was  heard  simultaneously  at  Popayan,  Bo- 
gota, Santa  Marta,  and  Caraccas  (where  it  continued  for  seven 
hours  without  any  movement  of  the  ground),  in  Haiti,  Jamai 
ca,  and  on  the  Lake  of  Nicaragua. 

These  phenomena  of  sound,  when  unattended  by  any  per- 
ceptible shocks,  produce  a  peculiarly  deep  impression  even  on 
persons  who  have  lived  in  countries  where  the  earth  has  been 
frequently  exposed  to  shocks.  A  striking  and  unparalleled  in- 
stance of  uninterrupted  subterranean  noise,  unaccompanied  by 
any  trace  of  an  earthquake,  is  the  phenomenon  known  in  the 
Mexican  elevated  plateaux  by  the  name  of  the  "roaring  and 
the  subterranean  thunder"  [bramidos  y  truenos  subterraneos) 
of  Guanaxuato.*  This  celebrated  and  rich  mountain  city 
lies  far  removed  from  any  active  volcano.  The  noise  began 
about  midnight  on  the  9th  of  January,  1784,  and  continued 
for  a  month.     I  have  been  enabled  to  give  a  circumstantial 


*  On  the  bramidos  of  Guanaxuato,  see  my  Essai  Polit.  sur  la  Noiiv. 
Espagne,  t.  i.,  p.  303.  The  subterranean  noise,  unaccompanied  with 
any  appreciable  shock,  in  the  deep  mines  and  on  the  surface  (the  town 
of  Guanaxuato  lies  G830  feet  above  the  level  of  the  sea),  was  not  heard 
in  the  neighboi'ing  elevated  plains,  but  only  in  the  mountainous  parts 
of  tile  Sierra,  from  the  Cuesta  de  los  Aguilares,  ueai'  Marfil,  to  the  north 
of  Santa  Rosa.  There  were  individual  parts  of  the  Sierra  24-28  miles 
northwest  of  Guanaxuato,  to  the  other  side  of  Chichi mequillo,  near  the 
boiling  spring  of  San  Jose  de  Comangillas,  to  which  the  waves  of  sound 
did  not  extend.  Extremely  stringent  measures  were  adopted  by  the 
magistrates  of  the  large  mountain  towns  on  the  14th  of  January,  1784, 
when  the  terror  produced  by  these  subterranean  thunders  was  at  its 
height.  "  The  flight  of  a  wealthy  family  shall  be  punished  with  a  fine 
of  1000  piasters,  and  that  of  a  poor  family  with  two  months'  imprison- 
ment. The  militia  shall  bring  back  the  fugitives."  One  of  the  most 
remarkable  points  about  the  whole  affair  is  the  opinion  which  the  mag- 
istrates (el  cabildo)  cherished  of  their  own  superior  knowledge.  In 
one  of  their  proclavias,  I  find  the  expression,  "  The  magistrates,  in  their 
wisdom  (en  su  sabiduria),  will  at  once  know  when  there  is  actual  dan- 
ger, and  will  give  orders  for  flight ;  for  the  present,  let  processions  be 
instituted."  The  terror  excited  by  the  tremor  gave  x'ise  to  a  famine, 
since  it  prevented  the  importation  of  com  from  the  table-lands,  where 
it  abounded.  The  ancients  were  also  aware  that  noises  sometimes  ex- 
isted without  earthquakes. — Aristot.,  Meteor.,  W.,  p.  802;  Plin.,  ii.,  80. 
Thf;  singular  noise  that  was  heard  from  March,  1822,  to  September, 
1824,  in  the  Dalmatian  island  Meleda  (sixteen  miles  from  Ragusa),  and 
on  which  Partsch  has  thrown  much  light,  was  occasionally  accompanied 
by  shocks. 


210  COSMOS. 

description  of  it  from  the  report  of  many  witnesses,  and  from 
the  documents  of  the  municipahty,  of  which  I  was  allowed  to 
make  use.  From  the  13th  to  the  IGth  of  January,  it  seemed 
to  the  inhabitants  as  if  heavy  clouds  lay  beneath  their  feet, 
from  which  issued  alternate  slow  rolling  sounds  and  short, 
quick  claps  of  thunder.  The  noise  abated  as  gradually  as  it 
had  begun.  It  was  limited  to  a  small  space,  and  was  not 
heard  in  a  l)asaltic  district  at  the  distance  of  a  few  miles. 
Almost  all  the  inhabitants,  in  terror,  left  the  city,  in  which 
large  masses  of  silver  ingots  were  stored  ;  but  the  most  cour- 
ageous, and  those  more  accustomed  to  subterranean  thunder, 
soon  returned,  in  order  to  drive  oft^  the  bands  of  robbers  who 
had  attempted  to  possess  themselves  of  the  treasures  of  the 
city.  Neither  on  the  surface  of  the  earth,  nor  in  mines  1600 
feet  in  depth,  was  the  slightest  shock  to  be  perceived.  No 
similar  noise  had  ever  before  been  heard  on  the  elevated  table- 
land of  Mexico,  nor  has  this  terrific  phenomenon  since  occurred 
there.  Thus  clefts  are  opened  or  closed  in  the  interior  of  the 
earth,  by  which  waves  of  sound  penetrate  to  us  or  are  impeded 
in  their  propagation. 

The  activity  of  an  igneous  mountain,  however  terrific  and 
picturesque  the  spectacle  may  be  which  it  presents  to  our  con- 
templation, is  ahvays  limited  to  a  very  small  space.  It  is  far 
otherwise  with  earthquakes,  which,  although  scarcely  per- 
ceptible to  the  eye,  nevertheless  simultaneously  propagate  their 
waves  to  a  distance  of  many  thousand  miles.  The  great 
earthquake  Vvdiich  destroyed  the  city  of  Lisbon  on  the  1st  of 
November,  1755,  and  whose  effects  were  so  admirably  investi- 
gated by  the  distinguished  philosopher  Emmanuel  Kant,  was 
felt  in  the  Alps,  on  the  coast  of  Sweden,  in  the  Antilles,  An- 
tigua, Barbadoes,  and  Martinique  ;  in  the  great  Canadian 
Lakes,  in  Thuringia,  in  the  fiat  country  of  Northern  Ger- 
many, and  in  the  small  inland  lakes  on  the  shores  of  the  Bal- 
tic."^ Remote  springs  were  interrupted  in  their  flow,  a  phe- 
nomenon attending  earthquakes  which  had  been  noticed  among 
the  ancients  by  Demetrius  the  Callatian.  The  hot  springs  of 
Toplitz  dried  up,  and  returned,  inundating  every  thing  around, 
and  having  their  waters  colored  with  iron  ocher.     In  Cadiz 

*  [It  has  been  computed  that  the  shock  of  this  earthquake  pervaded 
an  area  of  700,000  miles,  or  the  twelfth  part  of  the  circumference  of  the 
globe.  This  dreadful  shock  lasted  only  five  minutes:  it  happened  about 
nine  o'clock  in  the  morning  of  the  Feast  of  All  Saints,  when  almost  the 
whole  population  was  within  the  churches,  owing  to  which  circum- 
stance no  less  than  30,000  persons  perished  by  the  fall  of  these  edifices. 
See  Daubeney  0«  Volcanoes,  p.  .514-517.] — Tr 


EARTHaLTAKEf;.  2H 

die  sea  rose  to  an  elevation  of  sixty-four  feet,  while  in  the  An- 
tilles, where  the  tide  usually  rises  only  from  twenty-six  to 
twenty-eight  inches,  it  suddenly  rose  above  twenty  teet,  the 
water  being  of  an  inky  blackness.  It  has  been  computed  that 
on  the  1st  of  November,  1755,  a  portion  of  the  Earth's  sur- 
face, four  times  greater  than  that  of  Europe,  was  simultane- 
ously shaken.  As  yet  there  is  no  manifestation  offeree  known 
to  us,  includino-  even  the  murderous  inventions  of  our  own 
race,  by  which  a  greater  number  of  people  have  been  killed  in 
the  short  space  of  a  few  minutes  :  sixty  thousand  were  de- 
stroyed in  Sicily  in  1693,  from  thirty  to  forty  thousand  in  the 
earthquake  of  Riobamba  m  1797,  and  probably  five  times  as 
many  in  Asia  Minor  and  Syria,  under  Tiberius  and  Justinian 
the  elder,  about  the  years  19  and  526. 

There  are  instances  in  which  the  earth  has  been  shaken  for 
many  successive  days  in  the  chain  of  the  Andes  in  South 
America,  but  I  am  only  acquainted  with  the  following  cases 
in  which  shocks  that  have  been  felt  almost  every  hour  for 
months  together  have  occurred  far  from  any  volcano,  as,  for 
instance,  on  the  eastern  declivity  of  the  Alpine  chain  of  Mount 
Cenis,  at  Fenestrelles  and  Pignerol,  from  April,  1808  ;  be- 
tween New  ]Madrid  and  Little  Prairie, ^^  north  of  Cincinnati, 
in  the  United  States  of  America,  in  December,  1811,  as  well 
as  through  the  whole  winter  of  1812  ;  and  in  the  Pachalik  of 
Aleppo,  in  the  months  of  August  and  September,  1822.  As 
the  mass  of  the  people  are  seldom  able  to  rise  to  general  views, 
and  are  consequently  always  disposed  to  ascribe  great  phe- 
nomena to  local  telluric  and  atmospheric  processes,  wherever 
the  shaking  of  the  earth  is  continued  for  a  long  time,  fears  of 
the  eruption  of  a  new  volcano  arc  awakened.  In  some  few 
cases,  this  apprehension  has  certainly  proved  to  be  well  ground- 
ed, as,  for  instance,  in  the  sudden  elevation  of  volcanic  islands, 
and  as  we  see  in  the  elevation  of  the  volcano  of  Jorullo,  a 
mountain  elevated  1684  feet  above  the  ancient  level  of  the 
neighboring  plain,  on  the  29th  of  September,  1759,  after  mnety 
days  of  earthquake  and  subterranean  thunder. 

If  we  could  obtain  information  regarding  the  daily  condi- 
tion of  all  the  earth's  surface,  we  should  probably  discover  that 
the  earth  is  almost  always  undergoing  shocks  at  some  point 
of  its  superficies,  and  is  continually  influenced  by  the  reaction 

*  Drake,  Nat.  and  Statist.  View  of  Cincinnati,  p.  232-238:  Mitchell, 
m  the  Transactions  of  the  Lit.  and  Pliilos.  Soc.  of  New  York,  vol.  i.,  p. 
281-308.  In  llie  Piedmontese  county  of  Pignerol,  glasses  of  water,  fiUod 
to  thp  vei-\'  biini,  exhibited  for  hours  a  co!ilinuou.s  motion. 


212  COSMOS. 

of  the  interior  on  the  exterior.  The  frequency  and  general 
prevalence  of  a  phenomenon  which  is  probably  dependent  on 
the  raised  temperature  of  the  deepest  molten  strata  explain 
its  independence  of  the  nature  of  the  mineral  masses  in  which 
it  manifests  itself.  Earthquakes  have  even  been  felt  in  the 
loose  alluvial  strata  of  Holland,  as  in  the  neighborhood  of  Mid- 
dleburg  and  Vliessingen  on  the  23d  of  February,  1828.  Gran- 
ite and  mica  slate  are  shaken  as  well  as  limestone  and  sand- 
stone, or  as  trachyte  and  amygdaloid.  It  is  not,  therefore,  the 
chemical  nature  of  the  constituents,  but  rather  the  mechanical 
structure  of  the  rocks,  which  modifies  the  propagation  of  the 
motion,  the  wave  of  commotion.  Where  this  wave  proceeds 
along  a  coast,  or  at  the  foot  and  in  the  direction  of  a  mountain 
chain,  interruptions  at  certain  points  have  sometimes  been  re- 
marked, which  manifested  themselves  during  the  course  of 
many  centuries.  The  undulation  advances  in  the  depths  be- 
low, but  is  never  felt  at  the  same  points  on  the  surface.  The 
Peruvians^*  say  of  these  unmoved  upper  strata  that  "  they 
form  a  bridge."  As  the  mountain  chains  appear  to  be  raised 
on  fissures,  the  walls  of  the  cavities  may  perhaps  favor  the  di- 
rection of  undulations  parallel  to  them  ;  occasionally,  however, 
the  waves  of  commotion  intersect  several  chains  almost  per 
pendicularly.  Thus  we  see  them  simultaneously  breaking 
through  the  littoral  chain  of  Venezuela  and  the  Sierra  Parime. 
In  Asia,  shocks  of  earthquakes  have  been  propagated  from 
Lahore  and  from  the  foot  of  the  Himalaya  (22d  of  January, 
1832)  transversely  across  the  chain  of  the  Hindoo  Chou  to 
Badakschan,  the  upper  Oxus,  and  even  to  Bokhara. f  The 
circles  of  commotion  unfortunately  expand  occasionally  in  con- 
sequence of  a  single  and  unusually  violent  earthquake.  It  is 
only  since  the  destruction  of  Cumana,  on  the  14th  of  Decem- 
ber, 1797,  that  shocks  on  the  southern  coast  have  been  felt  in 
the  mica  slate  rocks  of  the  peninsula  of  Maniquarez,  situated 
opposite  to  the  chalk  hills  of  the  main  land.     The  advance 

*  In  Spanish  they  say,  rocas  qiie  hacen  puerde.  With  this  phenome- 
non of  non-propagation  through  superior  strata  is  connected  the  remark 
able  fact  that  in  the  beginning  of  this  century  shocks  were  felt  in  the 
deep  silver  mines  at  Marienberg,  in  the  Saxony  mining  district,  while 
not  the  slightest  trace  was  perceptiblo  at  the  surface.  The  miners 
ascended  in  a  state  of  alarm.  Couverijely,  the  workmen  ia  the  mines 
of  Falun  and  Persberg  felt  nothing  of  the  shocks  which  in  November, 
1823,  spread  dismay  among  the  inhabitants  above  ground. 

t  Sir  Alex.  Burnes,  Travels  in  Bokhara,  vol.  i.,  p.  18;  and  Wathen, 
Mem.  on  the  Ushek  State,  in  the  Journal  o J  the  Asiatic  Society  uf  Bengal, 
vol.  iii.,  p.  337. 


EARTHaUAKES.  213 

♦roni  south  to  north  "was  very  striking  in  the  almost  uninter- 
rupted undulations  of  the  soil  in  the  alluvial  valleys  of  the  Mis- 
sissippi, the  Arkansas,  and  the  Ohio,  from  1811  to  1813.  It 
seemed  here  as  if  subterranean  obstacles  were  gradually  over- 
come, and  that  the  way  being  once  opened,  the  undulatory 
movement  could  be  freely  propagated. 

Although  earthquakes  appear  at  first  sight  to  be  simply  dy- 
namic phenomena  of  motion,  we  yet  discover,  from  well-at- 
tested facts,  that  they  are  not  only  able  to  elevate  a  whole  dis- 
trict above  its  ancient  level  (as,  for  instance,  the  Ulla  Bund, 
after  the  earthquake  of  Cutch,  in  June,  1819,  east  of  the 
Delta  of  the  Indus,  or  the  coast  of  Chili,  in  November,  1822), 
but  we  also  find  that  various  substances  have  been  ejected  dur- 
ing the  earthquake,  as  hot  water  at  Catania  in  1818  ;  hot 
steam  at  New  Madrid,  in  the  Valley  of  the  Mississippi,  in 
1812  ;  irrespirable  gases,  Mofettes,  which  injured  the  flocks 
grazing  in  the  chain  of  the  Andes  ;  mud,  black  smoke,  and 
even  flames,  at  Messina  in  1781,  and  at  Cum  ana  on  the  14th 
of  November,  1797.  During  the  great  earthquake  of  Lisbon, 
on  the  1st  of  November,  1755,  flames  and  columns  of  smoke 
were  seen  to  rise  from  a  newly-formed  fissure  in  the  rock  of 
Alvidras,  near  the  city.  The  smoke  in  this  case  became  more 
dense  as  the  subterranean  noise  increased  in  intensity. =^  At 
the  destruction  of  Riobamba,  in  the  year  1797,  when  the 
shocks  were  not  attended  by  any  outbreak  of  the  neighboring 
volcano,  a  singular  mass  called  the  Moya  was  uplifted  from 
the  earth  in  numerous  continuous  conical  elevations,  the  whole 
being  composed  of  carbon,  crystals  of  augite,  and  the  silicious 
shields  of  infusoria.  The  eruption  of  carbonic  acid  gas  from 
fissures  in  the  Valley  of  the  Magdalene,  during  the  earthquake 
of  New  Granada,  on  the  16th  of  November,  1827,  sufibcated 
many  snakes,  rats,  and  other  animals.  Sudden  changes  of 
weather,  as  the  occurrence  of  the  rainy  season  in  the  tropics, 
at  an  unusual  period  of  the  year,  have  sometimes  succeeded 
violent  earthquakes  in  Quito  and  Peru.  Do  gaseous  fluids  rise 
from  the  interior  of  the  earth,  and  mix  with  the  atmosphere  % 
or  are  these  meteorological  processes  the  action  of  atmospheric 
electricity  disturbed  by  the  earthquake  ]  In  the  tropical  re- 
gions of  America,  where  sometimes  not  a  drop  of  rain  falls  for 
ten  months  together,  the  natives  consider  the  repeated  shocks 
of  earthquakes,  which  do  not  endanger  the  low  reed  huts,  as 
auspicious  harbingers  of  fruitfulness  and  abundant  rain. 

*  Philos.  Transact.,  vol.  xlix.,  p.  414. 


214  COSMOS. 

The  intimate  connection  of  the  phenomena  which  we  havt 
considered  is  still  hidden  in  obscurity.  Elastic  fluids  are  doubt 
lessly  the  cause  of  the  shght  and  perfectly  harmless  trembling 
of  the  earth's  surface,  which  has  often  continued  several  daya 
(as  in  1816,  at  Scaccia,  in  Sicily,  before  the  volcanic  eleva- 
tion of  the  island  of  Juha),  as  w^ell  as  of  the  terrific  explosions 
accompanied  by  loud  noise.  The  focus  of  this  destructive  agent, 
the  seat  of  the  moving  force,  lies  far  below  the  earth's  surface  ; 
but  we  know  as  little  of  the  extent  of  this  depth  as  we  know 
of  the  chemical  nature  of  these  vapors  that  are  so  highly  com- 
pressed. At  the  edges  of  two  craters,  Vesuvius,  and  the  tow- 
ering rock  which  projects  beyond  the  great  abyss  of  Pichin- 
cha,  near  Quito,  I  have  felt  periodic  and  very  regular  shocks  of 
earthquakes,  on  each  occasion  from  20  to  30  seconds  before 
the  burning  scoriae  or  gases  were  erupted.  The  intensity  of 
the  shocks  was  increased  in  proportion  to  the  time  interven- 
ing betw^een  them,  and,  consequently,  to  the  length  of  time 
in  which  the  vapors  were  accumulating.  This  simple  fact, 
which  has  been  attested  by  the  evidence  of  so  many  travelers, 
furnishes  us  with  a  general  solution  of  the  phenomenon,  in 
showing  that  active  volcanoes  are  to  be  considered  as  safety- 
valves  for  the  immediate  neighborhood.  The  danger  of  earth- 
quakes increases  when  the  openings  of  the  volcano  are  closed, 
and  deprived  of  free  communication  with  the  atmosphere  ;  but 
the  destruction  of  Lisbon,  of  Caraccas,  of  Lima,  of  Cashmir  in 
1554,*  and  of  so  many  cities  of  Calabria,  Syria,  and  Asia  Mi- 
nor, shows  us,  on  the  whole,  that  the  force  of  the  shock  is  not 
the  greatest  in  the  ^leighborhood  of  active  volcanoes. 

As  the  impeded  activity  of  the  volcano  acts  upon  the  shocks 
of  the  earth's  surface,  so  do  the  latter  react  on  the  volcanic 
phenomena.  Openings  of  fissures  favor  the  rising  of  cones  of 
eruption,  and  the  processes  which  take  place  in  these  cones, 
by  forming  a  free  communication  with  the  atmosphere.  A 
column  of  smoke,  which  had  been  observed  to  rise  for  months 
together  from  the  volcano  of  Paslo,  in  South  America,  sud- 
denly disappeared,  when,  on  the  4th  of  February,  1797,  the 
province  of  Quito,  situated  at  a  distance  of  192  miles  to  the 
south,  suffered  from  the  great  earthquake  of  Riobamba.  After 
the  earth  had  continued  to  tremble  for  some  time  through- 
out the  whole  of  Syria,  in  the  Cyclades,  and  in  Euboea,  the 
shocks  suddenly  ceased  on  the  eruption  of  a  stream  of  hot, mud 

*  On  the  frequency  of  earthquakes  in  Cashmir,  see  Troyer's  Geriiiai 
trauslation  of  the  ancient  Radjataringini,  vol.  ii.,  p.  297,  and  Car?  v' 
Hiigel,  Reisen,  bd.  ii.,  s.  184. 


earthuuakej?.  215 

on  the  Lelantine  plains  near  Chalcis.*  The  intelligent  geog-- 
rapher  of  Amasea,  to  whom  we  are  indebted  for  the  notice  of 
this  circumstance,  further  remarks  :  "  Since  the  craters  of  iEtna 
have  been  opened,  which  yield  a  passage  to  the  escape  of  fire, 
and  since  burning  masses  and  water  have  been  ejected,  the  coun- 
try near  the  sea-shore  has  not  been  so  much  shaken  as  at  the 
time  previous  to  the  separation  of  Sicily  from  Lower  Italy,  when 
all  communications  with  the  external  surface  were  closed." 

We  thus  recognize  in  earthquakes  the  existence  of  a  vol- 
canic force,  which,  although  every  where  manifested,  and  as 
generally  diffused  as  the  internal  heat  of  our  planet,  attains 
but  rarely,  and  then  only  at  separate  points,  sufficient  intensity 
to  exbibit  the  phenomenon  of  eruptions.  The  formation  of 
veins,  that  is  to  say,  the  filling  up  of  fissures  with  crystalline 
masses  bursting  forth  from  the  interior  (as  basalt,  melaphyre, 
and  greenstone),  gradually  disturbs  the  free  intercommunica- 
tion of  elastic  vapors.  This  tension  acts  in  three  different 
ways,  either  in  causing  disruptions,  or  sudden  and  retroversed 
elevations,  or,  finally,  as  v>^as  first  observed  in  a  great  part  of 
Sweden,  in  producing  changes  in  the  relative  level  of  the  sea 
and  land,  which,  although  continuous,  are  only  appreciable  at 
intervals  of  long  period. 

Before  we  leave  the  important  phenomena  which  we  have 
considered,  not  so  much  in  their  individual  characteristics  as 
in  their  general  physical  and  geognostical  relations,  I  would 
advert  to  the  deep  and  peculiar  impression  left  on  the  mind  by 
the  first  earthquake  which  we  experience,  even  where  it  is  not 
attended  by  any  subterranean  noise. f    This  impression  is  not, 

*  Strabo,  lib.  i.,  p.  100,  Casaub.  That  the  expression  7n]Xov  diaTTV- 
pov  Ttora/jLov  does  not  mean  erupted  mud,  but  lava,  is  obs'ious  from  a 
passage  in  Strabo,  lib.  vi.,  p.  412.  Compare  Walter,  in  his  Abnahme  der 
Vulkanischen  Thutigkeit  in  Historischen  Zeiten  (On  the  Decrease  of  Vol- 
canic Activity  during  Historical  Times),  1844,  s.  25. 

+  [Dr.  Tschudi,  in  his  interesting  work.  Travels  in  Peru,  translated 
from  the  German  by  Thomasina  Ross,  p.  170, 1847,  describes  striking- 
ly the  effect  of  an  earthquake  upon  the  native  and  upon  the  stranger. 
"  No  familiarity  with  the  phenomenon  can  blunt  this  feeling.  The  in- 
habitant of  Lima,  who  from  childhood  has  frequently  witnessed  these 
convulsions  of  nature,  is  roused  from  his  sleep  by  the  shock,  and  rushes 
from  his  apartment  with  the  cry  of  Miaericordia !  The  foreigner  from 
the  north  of  Europe,  who  knows  nothing  of  earthquakes  but  by  descrip 
tion,  waits  with  impatience  to  feel  the  movement  of  the  earth,  and  longs 
to  hear  with  his  own  ear  the  subterranean  sounds  which  he  has  hitherto 
considered  fabulous.  With  levity  he  treats  the  apprehension  of  a  com- 
ing convulsion,  and  laughs  at  the  fears  of  the  natives ;  but,  as  soon  as  his 
wish  is  gratified,  he  is  terror-stricken,  and  is  involur.tarily  prompted  to 
seek  s^ifety  in  flight."]— Tr. 


216  COSMOS. 

m  my  opinion,  the  result  of  a  recollection  of  those  fearful  pic- 
tures of  devastation  presented  to  our  imaginations  by  the  his- 
torical narratives  of  the  past,  but  is  rather  due  to  the  sudden 
revelation  of  the  delusive  nature  of  the  inherent  faith  by  "which 
we  had  clung  to  a  belief  in  the  immobility  of  the  solid  parts 
of  the  earth.  We  are  accustomed  from  early  childhood  to 
draw  a  contrast  between  the  mobility  of  water  an  i  the  im- 
mobility of  the  soil  on  which  we  tread  ;  and  this  feeling  is  con- 
firmed by  the  evidence  of  our  senses.  When,  therefore,  we 
suddenly  feel  the  ground  move  beneath  us,  a  mysterious  and 
natural  force,  with  which  we  are  previously  unacquainted,  is 
revealed  to  us  as  an  active  disturbance  of  stability.  A  moment 
destroys  the  illusion  of  a  whole  life  ;  our  deceptive  faith  in  the 
repose  of  nature  vanishes,  and  we  feel  transported,  as  it  were, 
into  a  realm  of  unknown  destructive  forces.  Every  sound — 
the  faintest  motion  in  the  air — arrests  our  attention,  and  we 
no  longer  trust  the  ground  on  whigh  we  stand.  Animals,  es- 
pecially dogs  and  swine,  participate  in  the  same  anxious  dis- 
quietude ;  and  even  the  crocodiles  of  the  Orinoco,  which  are 
at  other  times  as  dumb  as  our  little  lizards,  leave  the  trem- 
bling bed  of  the  river,  and  run  with  loud  cries  into  the  adjacent 
forests. 

To  man  the  earthquake  conveys  an  idea  of  some  universal 
and  unlimited  danger.  We  may  flee  from  the  crater  of  a  vol- 
cano in  active  eruption,  or  from  the  dwelling  whose  destruc- 
tion is  threatened  by  the  approach  of  the  lava  stream  ;  but  in 
an  earthquake,  direct  our  flight  whithersoever  we  will,  we  still 
feel  as  if  we  trod  upon  the  very  focus  of  destruction.  This  con- 
dition of  the  mind  is  not  of  long  duration,  although  it  takes  its 
origin  in  the  deepest  recesses  of  our  nature  ;  and  when  a  se- 
ries of  faint  shocks  succeed  one  another,  the  inhabitants  of  the 
country  soon  lose  every  trace  of  fear.  On  the  coasts  of  Peru, 
where  rain  and  hail  are  unknown,  no  Itss  than  the  rolling 
thunder  and  the  flashing  lightning,  these  luminous  explosions 
of  the  atmosphere  are  replaced  by  the  subterranean  noises 
which  accompany  earthquakes.*     Long  habit,  and  the  very 

*  ["  Along  the  whole  coast  of  Pefru  the  atmospheie  is  almost  uni- 
formly in  a  state  of  repose.  It  is  not  illtiminated  by  the  lightning's  flash, 
or  disturbed  by  the  roar  of  the  thunder;  no  deluges  of  rain,  uo  fierce 
hurricanes,  destroy  the  fruits  of  the  fields,  and  with  them  the  hopes  of 
the  husbandman.  But  the  mildness  of  the  elements  above  ground  ia 
frightfully  counterbalanced  by  their  subterranean  fury.  Lima  is  fre 
quently  visited  by  earthquakes,  and  several  times  the  city  has  been 
reduced  to  a  mass  of  ruins.  At  an  average,  forty-five  shocks  may  be 
counted  on  in  the  year.     Mo^  of  them  occur  in  the  latter  part  of  Octo- 


GASEOUS    EMANATIONS.  217 

pievalent  opinion  that  dangerous  shocks  are  only  to  be  appre- 
hended two  or  three  times  in  the  course  of  a  century,  cause 
faint  oscillations  of  the  soil  to  be  regarded  in  Lima  with  scarce- 
ly more  attention  than  a  hail  storm  in  the  temperate  zone. 

Having  thus  taken  a  general  view  of  the  activity — the 
inner  life,  as  it  were — of  the  Earth,  in  respect  to  its  internal 
heat,  its  electro-magnetic  tension,  its  emanation  of  light  at  the 
poles,  and  its  irregularly-recurring  phenomena  of  motion,  we 
will  now  proceed  to  the  consideration  of  the  material  products, 
the  chemical  changes  in  the  earth's  surface,  and  the  composi- 
tion of  the  atmosphere,  which  are  all  dependent  on  planetary 
vital  activity.  We  see  issue  from  the  ground  steam  and 
gaseous  carbonic  acid,  almost  always  free  from  the  admixture 
of  nitrogen  ;*  carbureted  hydrogen  gas,  which  has  been  used 
in  the  Chinese  province  Sse-tschuanf  for  several  thousand 
years,  and  receiitly  in  the  village  of  Fredonia,  in  the  State  of 
New  York,  United  States,  in  cooking  and  for  illumination ; 
sulphureted  hydrogen  gas  and  sulphurous  vapors  ;  and,  more 
rarely, $  sulphurous  and  hydrochloric  acids. §     Such  effusions 

ber,  in  November,  December,  Jamiaiy,  May,  and  June.  Experience 
gives  reason  to  expect  the  visitation  of  two  desolating  earthquakes  in  a 
century.  The  period  betv^-eeu  the  tv^ro  is  from  forty  to  sixty  years.  The 
most  considerable  catastrophes  experienced  in  Lima  since  Europeans 
have  visited  the  west  coast  of  South  America  happened  in  the  years 
1586,  1630, 1687,  1713,  1746, 1806.  There  is  reason  to  fear  that  in  the 
course  of  a  few  years  this  city  may  be  the  prey  of  another  such  visita- 
tion."—Tschudi,  op.  cit.]— -Tr. 

*  Bischof's  comprehensive  work,  Wdrmelehre  des  inneren  Erdkorpers. 

t  On  the  Artesian  tire-springs  (Ho-tsing)  in  China,  and  the  ancient 
use  of  portable  gas  (in  bamboo  canes)  in  the  city  of  Khiung-tsheu,  see 
Klaproth,  in  my  Asie  Centrale,  t.  iii.,  p.  519-530. 

X  Boussingault  (Annates  de  Chimie,  t.  Hi.,  p.  181)  observed  no  evolu- 
tion of  hydrochloric  acid  from  the  volcanoes  of  New^  Granada,  while 
Monticelli  found  it  in  euorijious  quantity  in  the  eruption  of  Vesuvius  in 
1813. 

$  [Of  the  gaseous  compounds  of  sulphur,  one,  sulphurous  acid,  ap- 
pears to  predominate  chiefly  in  volcanoes  possessing  a  certain  degree 
of  activity,  while  the  other,  sulphureted  hydrogen,  has  been  most  fre- 
quently perceived  among  those  in  a  dormant  condition.  The  occur- 
rence of  abundant  exhalations  of  sulphuric  acid,  which  have  been  hith 
erto  noticed  chiefly  in  extinct  volcanoes,  as,  for  instance,  in  a  stream 
issuing  from  that  of  Purace,  between  Bogota  and  Quito,  from  extinct 
volcanoes  in  Java,  is  satisfactorily  explained  in  a  recent  paper  by  M. 
Dumas,  Annales  de  Chimie,  Dec,  1846.  He  shows  that  when  sulphu- 
reted hydrogen,  at  a  temperature  above  100°  Fahr.,  and  still  better 
when  near  190°,  comes  in  contact  with  certain  porous  bodies,  a  cata- 
lytic action  is  set  up,  by  which  water,  sulphuric  acid,  and  sulphur  are 
produced.  Hence  probably  the  vast  deposits  of  sulphur,  associated 
with  sulphates  of  lime  and  strontiau,  which  are  met  with  in  the 
western  parts  of  Sicilv.] — Tr. 

Vol.  I— K. 


218  COSMOS. 

from  the  fissures  of  the  earth  not  only  occur  in  the  districts 
of  stiil  burning  or  long-extinguished  volcanoes,  but  they  may 
likewise  be  observed  occasionally  in  districts  where  neither 
trachyte  nor  any  other  volcanic  rocks  are  exposed  on  the 
earth's  surface.  In  the  chain  of  Quindiu  I  have  seen  sul- 
phur deposited  in  mica  slate  from  Avarm  sulphurous  vapor 
at  an  elevation  of  6832  feet^  above  the  level  of  the  sea, 
while  the  same  species  of  rock,  which  was  formerly  regarded 
as  primitive,  contains,  in  the  Cerro  Cuello,  near  Tiscan,  south 
of  Quito,  an  immense  deposit  of  sulphur  imbedded  in  pure 
quartz. 

Exhalations  of  carbonic  acid  (inofettes)  are  even  in  our  days 
to  be  considered  as  the  most  important  of  all  gaseous  emana- 
tions, with  respect  to  their  number  and  the  amount  of  their 
effusion.  We  see  in  Germany,  in  the  deep  valleys  of  the 
Eifel,  in  the  neighborhood  of  the  Lake  of  Laach,t  in  the 
crater-like  valley  of  the  Wehr  and  in  Western  Bohemia,  ex- 
halations of  carbonic  acid  gas  manifest  themselves  as  the  last 
etlbrts  of  volcanic  activity  in  or  near  the  foci  of  an  earlier 
world.  In  those  earlier  periods,  when  a  higher  terrestrial 
temperature  existed,  and  when  a  great  rmmber  of  fissures 
still  remained  unfilled,  the  processes  we  have  described  acted 
more  powerfully,  and  carbonic  acid  and  hot  steam  were  mixed 
in  larger  quantities  in  the  atmosphere,  from  whence  it  follows, 
as  Adolph  Brongniart  has  ingeniously  shown,|  that  the  primi- 
tive vegetable  world  must  have  exhibited  almost  every  where, 
and  independently  of  geographical  position,  the  most  luxurious 
abundance  and  the  fullest  development  of  organism.  In  these 
constantly  warm  and  damp  atmospheric  strata,  saturated  with 

."^  Hiiia'ooldt,  Recucil  cfObserv.  Asironomiques,  t.  i.,  p.  311  (Nivelle 
meat  Barometrique  de  la  Cordillere  des  Andes,  No.  206). 

t  [The  Lake  of  Laacb,  in  the  district  of  the  Eifel,  is  an  expanse  of 
water  two  miles  in  circumference.  The  thickness  of  the  vegetation  on 
the  sides  of  its  crater-like  basin  renders  it  difficult  to  discover  the  nature 
of  the  subjacent  rock,  but  it  is  probably  composed  of  black  cellular 
au<<itic  lava.  The  sides  of  the  crater  present  numerous  loose  masses, 
which  appear  to  have  been  ejected,  and  consist  of  glassy  feldspar,  ice- 
spar,  sodalite,  hauyne,  spinellane,  and  leucite.  The  resemblance  be- 
tween these  products  and  the  masses  formerly  ejected  from  Vesuvius  is 
most  remarkable.  (Uaubeney  On  Volcanoes,  p.  81.)  Dr.  Hibbert  re- 
gards the  Lake  of  Laach  as  formed  in  the  first  instance  by  a  crack 
caused  by  the  cooling  of  the  crust  of  the  earth,  which  was  widened 
afterward  into  a  circular  cavity  by  the  expansive  force  of  elastic  vapoi's. 
See  History  of  the  Extinct  Volcanoes  of  the  Basin  of  Neutoied,  1832.] 
—  Tr. 

t  Adolph  Brongniart,  in  the  AnnaJes  des  Sciences  Noturclles.  t.  xv., 
p.  225. 


GArfEOUS    EMANATIONS.  219 

carbonic  acid,  vegetation  must  have  attained  a  degree  of  vital 
activity,  and  derived  the  superabundance  of  nutrition  necessary 
to  furnish  materials  for  the  formation  of  the  beds  of  hgnite 
(coal),  constituting  the  inexhaustible  means  on  which  are  based 
the  physical  power  and  prosperity  of  nations.  Such  masses 
are  distributed  in  basins  over  certain  parts  of  Europe,  occur- 
ring in  large  quantities  in  the  British  Islands,  in  Belgium,  i,n 
France,  in  the  provinces  of  the  Lower  Rhine,  and  in  Upper 
Silesia.  At  the  same  primitive  period  of  universal  volcanic 
activity,  those  enormous  quantities  of  carbon  must  also  have 
escaped  from  the  earth  which  are  contained  in  limestone 
rocks,  and  which,  if  separated  from  oxygen  and  reduced  to  a 
solid  form,  would  constitute  about  the  eighth  part  of  the  abso- 
lute bulk  of  these  mountain  masses.*  That  portion  of  the 
carbon  which  was  not  taken  up  by  alkaline  earths,  but  re- 
mained mixed  with  the  atmosphere,  as  carbonic  acid,  was 
gradually  consumed  by  the  vegetation  of  the  earlier  stages  of 
the  world,  so  that  the  atmosphere,  after  being  purified  by  the 
processes  of  vegetable  life,  only  retained  the  small  quantity 
which  it  now  possesses,  and  which  is  not  injurious  to  the 
present  organization  of  animal  life.  Abundant  eruptions  of 
sulphurous  vapor  have  occasioned  the  destruction  of  the  spe- 
cies of  moUusca  and  fish  which  inhabited  the  inland  waters  of 
the  earlier  world,  and  have  given  rise  to  the  formation  of  the 
contorted  beds  of  gypsum,  which  have  doubtless  been  fre- 
quently affected  by  shocks  of  earthquakes. 

Gaseous  and  liquid  fluids,  mud,  and  molten  earths,  ejected 
from  the  craters  of  volcanoes,  which  are  themselves  only  a 
kind  of  "  intermittent  springs,^^  rise  from  the  earth  under  pre- 
cisely analogous  physical  relations.!  All  these  substances  owe 
their  temperature  and  their  chemical  character  to  the  place 
of  their  origin.  The  mean  temperature  of  aqueous  springs  is 
less  than  that  of  the  air  at  the  point  whence  they  emerge,  if 
the  water  flow  from  a  height ;  but  their  heat  increases  with 
the  depth  of  the  strata  with  which  they  are  in  contact  at  their 
origin.  We  have  already  spoken  of  the  numerical  law  regu- 
latinof  this  increase.  The  blendinjj  of  waters  that  have  come 
from  the  height  of  a  mountain  with  those  that  have  sprung 
from  the  depths  of  the  earth,  render  it  difficult  to  determine 
the  position  of  the  isogeothermal  li?iesX  (lines  of  equal  internal 

*  Bischof,  op.  cit.,  s.  324,  Anm.  2. 
t  Humboldt,  Asie  Centrale,  t.  i.,  p.  43. 

X  Ou  the  theory  of  isogeothermal  (chthonisothermal)  Imes,  consult  the 
ingenious  labors  of  Kupfter,  in  Pog^'.,  Atmalen,  bd   xv.,  s.  184,  and  bd 


220  COSMOS. 

terrestrial  temperature),  Avhen  this  determination  is  to  be 
made  from  the  temperature  of  flowing  springs.  Such,  at  any 
rate,  is  the  result  I  have  arrived  at  from  my  ov^n  observations 
and  those  of  my  fellow-travelers  in  Northern  Asia.  The 
temperature  of  springs,  which  has  become  the  subject  of  such 
continuous  physical  investigation  during  the  last  half  century, 
depends,  like  the  elevation  of  the  line  of  perpetual  snow,  on 
very  many  simultaneous  and  deeply- involved  causes.  It  is  a 
function  of  the  temperature  of  the  stratum  in  which  they  take 
their  rise,  of  the  specific  heat  of  the  soil,  and  of  the  quantity 
and  temperature  of  the  meteoric  water,*  which  is  itself  dif- 
ferent from  the  temperature  of  the  lower  strata  of  the  atmos- 
phere, according  to  the  different  modes  of  its  origin  in  rain, 
snow,  or  hail.f 

Cold  springs  can  only  indicate  the  mean  atmospheric  tem- 

xxxii.,  s.  270,  in  the  Voyage  dans  V Oural,  p.  382-398,  and  in  the 
Edinburgh  Journal  of  Science,  New  Series,  vol.  iv.,  p.  355.  See,  also, 
Kamtz,  Lehrb.  der  Meteor.,  bd.  ii.,  s.  217;  and,  on  the  ascent  of  the 
chthonisothermal  lines  in  mountainous  districts,  Bischof,  s.  174-198. 

*  Leop.  V.  Buch,  in  Pogg.,  Annalen,  bd.  xii.,  s.  405. 

t  On  the  temperature  of  the  drops  of  rain  in  Cumana,  which  fell  to 
72°,  when  the  temperature  of  the  air  shortly  before  had  been  86°  and 
88°,  and  during  the  i-ain  sank  to  74°,  see  my  Relat.  Hist.,  t.  ii.,  p.  22. 
The  rain-drops,  while  falling,  change  the  normal  temperature  they 
originally  possessed,  which  depends  on  the  height  of  the  clouds  from 
which  they  fell,  and  their  heating  on  their  upper  surface  by  the  solar 
rays.  The  rain-drops,  on  their  first  production,  have  a  higher  tempera- 
ture than  the  surrounding  medium  in  the  superior  strata  of  our  atmos- 
phei-e,  in  consequence  of  the  liberation  of  their  latent  heat ;  and  they 
continue  to  rise  in  temperature,  since,  in  falling  through  lower  and 
warmer  strata,  vapor  is  precipitated  on  them,  and  they  thus  increase  in 
size  (Bischof,  Wdrmelehre  des  imieren  Erdkorpers,  s.  73) ;  but  this  ad- 
ditional heating  is  compensated  for  by  evaporation.  The  cooling  of  the 
air  by  rain  (putting  out  of  the  question  what  probably  belongs  to  the 
electric  process  in  storms)  is  effected  by  the  drops,  which  are  them- 
selves of  lower  temperature,  in  consequence  of  the  cold  situation  in 
which  they  were  formed,  and  bring  down  w^ith  them  a  portion  of  the 
higher  colder  air,  and  which  finally,  by  moistening  the  ground,  give 
rise  to  evaporation.  These  are  the  ordinary  relations  of  the  phenome- 
non. When,  as  occasionally  happens,  the  rain-drops  are  warmer  than 
the  lower  strata  of  the  atmosphere  (Humboldt,  Rel.  Hist.,  t.  iii.,  p. 
513),  the  cause  must  probably  be  sought  in  higher  warmer  currents,  or 
in  a  higher  temperature  of  widely-extended  and  not  very  thick  clouds, 
from  the  action  of  the  sun's  rays.  How,  moreover,  the  phenomenon  of 
supplementary  rainbows,  which  are  explained  by  the  interference  of 
light,  is  connected  with  the  original  and  increasing  size  of  the  falling 
drops,  and  how  an  optical  phenomenon,  if  we  know  how  to  observe  it 
accurately,  may  enlighten  us  regarding  a  meteorological  process,  ac- 
cording to  diversity  of  zone,  has  been  shown,  with  much  talent  and  in 
genuity,  by  Arago,  in  the  Annuaire  for  1836,  p.  300- 


HOT    SPRINGS. 


221 


perature  when  they  are  unmixed  with  the  waters  rising  from 
great  depths,  or  descending  from  considerable  mountain  eleva- 
tions, and  when  they  have  passed  through  a  long  course  at  a 
depth  from  the  surface  of  the  earth  which  is  equal  in  our  lati- 
tudes to  40  or  60  feet,  and,  according  to  Boussingault,  to  about 
one  foot  in  the  equinoctial  regions  ;*  these  being  the  depths  at 
which  the  invariability  of  the  temperature  begins  in  th^  tem- 
perate and  torrid  zones,  that  is  to  say,  the  depths  at  which 
horary,  diurnal,  and  monthly  changes  of  heat  in  the  atmosphere 
cease  to  be  perceived. 

Hot  springs  issue  from  the  most  various  kinds  of  rocks.  The 
hottest  permanent  springs  that  have  hitherto  been  observed 
are,  as  my  own  researches  confirm,  at  a  distance  from  all  vol- 
canoes. I  will  here  advert  to  a  notice  in  my  journal  of  the 
Aguas  Calie7ites  de  las  Trincheras,  in  South  America,  between 
Porto  Cabello  and  Nueva  Valencia,  and  the  Aguas  de  Coman- 
gillas,  in  the  Mexican  territory,  near  Guanaxuato ;  the  for- 
mer of  these,  which  issued  from  granite,  had  a  temperature  of 
194°-5;  the  latter,  issuing  from  basalt,  205°-5.  The  depth 
)f  the  source  from  whence  the  water  flowed  with  this  temper- 
ature, judging  from  v/hat  we  know  of  the  law  of  the  increase 
of  heat  in  the  interior  of  the  earth,  was  probably  7140  feet, 
or  above  two  miles.  If  the  universally-difilised  terrestrial 
heat  be  the  cause  of  thermal  springs,  as  of  active  volcanoes, 
the  rocks  can  only  exert  an  influence  by  their  difTerent  capaci- 


"  The  profound  investigations  of  Boussingault  fully  convince  me,  that 
in  the  tropics,  tlie  temperature  of  the  ground,  at  a  very  slight  depth,  ex 
actly  corresponds  witli  the  mean  temperature  of  the  air.     The  follow 


ing  uistauces  are  sufficient  to  ilhistrate  this  fact : 


Stations  witbia  Tropical  Zones. 

Temperature  at  1  French 
foot  [l-00r>  of  the  Englisli 
foot]  below  the  earth's 
surface. 

Mean  Temper-       Height,  in  Enghsh 
ature  of  the          feet,    above    the 
air.                         level  of  the  sea. 

Guayaquil 

Anserma  Nuevo 

Zupia . 

78-8 
74-6 
70-7 
64-7 
59-9 

78-1         1               0 
74-8                 3444 
70-7                 4018 
65-6       "  !         5929 
59-9         '         9559 

Popayan 

Quito 

The  doubts  about  the  temperature  of  the  earth  within  the  tropics,  of 
wliich  I  am  probably,  in  some  degree,  the  cause,  by  my  observations 
oh  the  Cave  of  Caripe  (Cueva  del  Guacharo^),  Rel.  Hist.,  t.  ii:.,  p.  191- 
196),  are  resolved  by  the  consideration  that  I  compared  the  presumed 
mean  temperature  of  the  air  of  the  convent  of  Caripe,  G5°*3,  not  with 
the  temperature  of  the  air  of  the  cave,  G5°-G,  but  vs'ith  tlje  temperature 
of  the  subterranean  stream,  G2'^*3,  although  I  ob.served  {Rel.  Hist.,  t 
iii.,  p.  146  and  194)  that  mountain  water  from  a  gre.it  heigh 
probably  be  mixed  wilh  the  water  of  the  cave 


t  might 


222  COSMOS. 

ties  for  heat  and  by  tlieir  conducting  powers.  The  hottest  of 
all  permanent  springs  (between  203^  and  209°)  are  likewise, 
in  a  most  remarkable  degree,  the  purest,  and  such  as  hold  in 
solution  the  smallest  quantity  of  mineral  substances.  Their 
temperature  appears,  on  the  whole,  to  be  less  constant  than 
that  of  springs  between  122°  and  165°,  which  in  Europe,  at 
least,  "have  maintained,  in  a  most  remarkable  manner,  their 
hivariabilitif  of  heat  and  inineral  contents  during  the  last 
fifty  or  sixty  years,  a  period  ih  which  thermometrical  measure- 
ments and  chemical  analyses  have  been  applied  with  increas- 
ed exactness.  Boussingault  found  in  1823  that  the  thermal 
springs  of  Las  Trincheras  had  risen  12°  during  the  twenty- 
three  years  that  had  intervened  since  my  travels  in  1600.* 
This  calmly- flowing  spring  is  therefore  now  nearly  12°  hotter 
than  the  intermittent  fountains  of  the  Geyser  and  the  Strokr, 
whose  temperature  has  recently  been  most  carefully  determ- 
ined by  Krug  of  Nidda.  A  very  striking  proof  of  the  origin 
of  hot  springs  by  the  sinking  of  cold  meteoric  M'ater  into  the 
earth,  and  by  its  contact  with  a  volcanic  focus,  is  afibrded  by 
the  volcano  of  JoruUa  in  Mexico,  which  was  unknown  before 
my  American  journey.  When,  in  September,  1759,  Jorullo 
\was  suddeidy  elevated  into  a  mountain  1183  feet  above  the 
level  of  the  surrounding  plain,  two  small  rivers,  the  Rio  de 
Cuitimba  and  Rio  de  San  Pedro,  disappeared,  and  some 
time  afterward  burst  forth  ajjain,  durinjf  violent  shocks  of  an 
earthquake,  as  hot  springs,  whose  temperature  I  found  in  1803 
to  be  186°-4. 

The  springs  in  Greece  still  evidently  flow  at  the  same  places 
as  in  the  times  of  Hellenic  antiquity.  The  spring  of  Erasinos, 
two  hours'  journey  to  the  south  of  Argos,  on  the  declivity  of 
Chaon,  is  mentioned  by  Herodotus.  At  Delphi  we  still  see 
Cassotis  (now  the  springs  of  St.  Nicholas)  rising  south  of  the 
Lesche,  and  flowing  beneath  the  Temple  of  Apollo  ;  Castaiia, 
at  the  foot  of  PhsedriadiB  ;  Pirene,  near  Acro-Corinth  ;  and 
the  hot  baths  of  ^dipsus,  in  Euboea,  in  which  Sulla  bathed 
during  the  Mithridatic  war.f     I  advert  with  pleasure  to  these 

*  Boussingault,  in  the  Annales  de  Chimie,  t.  lii.,  p.  181.  The  spring 
of  Chaudes  Aigues,  in  Auvergne,  is  only  176°.  It  is  also  to  be  observ- 
ed, that  while  the  Aguas  Calieutes  de  las  Trincheras,  south  of  Porto 
Cabello  (Venezuela),  springing  from  granite  cleft  in  regular  beds,  and 
far  from  all  volcanoes,  have  a  temperature  of  fully  206°'6,  all  the  springs 
which  rise  in  the  vicinity  of  still  active  volcanoes  (Pasto,  Cotopaxi,  and 
Tunguragua)  have  a  temperature  of  only  97'~'-130°. 

t  Cassotis  (the  spring  of  St.  Nicholas)  and  Castaiia,  at  the  Phaedriad;e, 
mentioned  in  Pausanias,  x.,  24,  25,  and  x.,  8,  9  ;  Pirene  (Acro-Corinth), 


HOT    SPRINGS,  '223 

iacls,  as  they  show  us  that,  even  in  a  country  subject  to  fre- 
quent and  violent  shocks  of  earthquakes,  the  interior  of  our 
planet  has  retained  for  upward  of  2000  years  its  ancient  con- 
figuration in  reference  to  the  course  of  the  open  fissures  that 
yield  a  passage  to  these  waters.  The  Fontaine  jaillusante  of 
Lillers,  in  the  Department  des  Pas  de  Calais,  which  was  bored 
as  early  as  the  year  1126,  still  rises  to  the  same  height  and 
yields  the  same  quantity  of  water  ;  and,  as  another  instance,  I 
may  mention  that  the  admirable  geographer  of  the  Carama- 
nian  coast.  Captain  Beaufort,  sa\v  in  the  district  of  Phaselis  the 
same  flame  fed  by  emissions  of  inflammable  gas  which  was  de- 
scribed by  Pliny  as  the  flame  of  the  Lycian  Chimera.* 

The  observation  made  by  Arago  in  1821,  that  the  deepest 
Artesian  wells  are  the  warmest,!  threw  great  light  on  the  ori- 
gin of  thermal  springs,  and  on  the' establishment  of  the  law 
that  terrestrial  heat  increases  with  increasing  depth.  It  is  a 
remarkable  fact,  which  has  but  recently  been  noticed,  that  at 
the  close  of  the  third  century,  St.  Patricius,|  probably  Bishop 
of  Pertusa,  was  led  to  adopt  very  correct  views  regarding  the 
phenomenon  of  the  hot  springs  at  Carthage.  On  being  asked 
^yhat  was  the  cause  of  boiling  water  bursting  from  the  earth, 
he  replied,  "  Fiire  is  nourished  in  the  clouds  and  in  the  interior 

ill  Strabo,  p.  379  ;  the  spring  of  Erasinos,  at  Mount  Chaoii,  south  of  Ar- 
gos,  iu  Herod.,  vL,  67,  and  Fausanias,  ii.,  24,  7  ;  the  springs  of  iEdipsus 
in  Eubcea,  some  of  which  have  a  tempei'ature  of  88°,  while  in  others  it 
ranges  between  144°  and  167°,  in  Sli'abo,  p.  60  and  447,  and  Atheuaeu*, 
ii-,  3,  73  ;  the  hot  springs  of  Thermopyke,  at  the  foot  of  CEta,  with  a 
temperature  of  149°.  All  from  manuscript  notes  by  Professor  Curtius, 
the  learned  companion  of  Otfried  Mtiller. 

"^  Pliny,  ii.,  106;  Seneca,  Episf...  79,  §  3,  ed.  Ruhkopf  (Beaufort, /S«r. 
vcj/  of  the  Coast  of  Karamania,  1820,  art.  Yanar,  near  Deliktasch,  the 
ancient  Phasehs,  p.  24).  See,  also,  Ctesias,  Fragm.,  cap.  10  p.  250, 
ed-  Bahr;  Strabo,  lib.  xiv.,  p.  666,  Casaab. 

["  Not  far  from  the  Dehktae-h,  on  the  side  of  a  mountain,  is  tlie  per- 
petual fire  described  by  Captain  Beaufort.  The  travelers  found  it  as 
brilliant  as  ever,  and  even  somewhat  increased  ;  for,  besides  the  large 
flame  in  the  corner  of  the  ruins  described  by  Beaufort,  there  were  small 
jets  issuing  from  crevices  in  the  side  of  tlie  crater-like  cavity  five  or 
six  feet  deep.  At  the  bottom  was  a  shallow  pool  of  sulphureous  and 
turbid  water,  regarded  by  the  Turks  as  a  sovereign  remedy  for  all  skin 
complaints.  The  soot  deposited  from  the  flames  was  regarded  as  effi- 
cacious for  sore  eyelids,  and  valued  as  a  dye  for  the  eyebrows."  See 
the  highly  interesting  and  accurate  work,  Travels  in  Lycia,  by  Lieut. 
Sptatt  and  Professor  E.  Forbes.] — Tr. 

t  Arago,  in  the  Anmiaire  pour  183.5,  p.  234. 

X  Acta  S.  Patricii,  p.  55.5,  ed.  Ruinart,  t.  ii..  p.  385,  Mazochi.  Dn- 
reau  de  la  M.iUe  was  the  first  to  dr-nw  attention  to  this  remarkable  pas- 
sage iu  the  Recherches  s)ir  la  Top>graphic  de  Cnrthage,  18-?5.  p.  276. 
(See,  aUi),  Seneoi.  N-it-  Qmrsf..  iii..  24.) 


221  COSMOS. 

of  the  earth,  as  .^tna  and  other  mountains  near  Naples  may 
teach  you.  The  subterranean  waters  rise  as  if  through  si- 
phons. The  cause  of  hot  springs  is  this  :  waters  which  are 
more  remote  from  the  subterranean  fire  are  colder,  while  those 
which  rise  nearer  the  fire  are  heated  by  it,  and  bring  with 
them  to  the  surface  which  we  inhabit  an  insijpportable  degree 
of  heat." 

As  earthquakes  are  often  accompanied  by  eruptions  of  water 
and  vapors,  we  recognize  in  the  Salses,^  or  small  mud  vol- 
canoes, a  transition  from  the  changing  phenomena  presented 
by  these  eruptions  of  vapor  and  thermal  springs  to  the  more 
powerful  and  awful  activity  of  the  streams  of  lava  that  flow 
from  volcanic  mountains.  If  we  consider  these  mountains  as 
springs  of  molten  earths  producing  volcanic  rocks,  we  must  re- 
member that  thermal  waters,  when  impregnated  with  carbonic 
acid  and  sulphurous  gases,  are  continually  forming  horizon- 
tally ranged  strata  of  limestone  (travertine)  or  conical  eleva- 
tions, as  in  Northern  Africa  (in  Algeria),  and  in  the  Bancs 
of  Caxamarca,  on  the  western  declivity  of  the  Peruvian  Cor- 
dilleras. The  travertine  of  Van  Diemen's  Land  (near  Hobart 
Town)  contains,  according  to  Charles  Darwin,  remains  of  a 
vegetation  that  no  longer  exists.  Lava  and  travertine,  which 
are  constantly  forming  before  our  eyes,  present  us  with  the 
two  extremes  of  geognostic  relations. 

Salses  deserve  more  attention  than  they  have  hitherto  re- 
ceived from  geognosists.  Their  grandeur  has  been  overlooked 
because  of  the  two  conditions  to  which  they  are  subject ;  it  is 
only  the  more  peaceful  state,  in  which  they  may  continue  for 
centuries,  which  has  generally  been  described  :  their  origin  is, 
however,  accompanied  by  earthquakes,  subterranean  thunder, 
the  elevation  of  a  whole  district,  and  lofty  emissions  of  flame 
of  short  duration.  When  the  mud  volcano  of  Jokmali  began 
to  form  on  the  27th  of  November,  1827,  in  the  peninsula  of 
Abscheron,  on  the  Caspian  Sea,  east  of  Baku,  the  flames 
flashed  up  to  an  extraordinary  height  ibr  three  hours,  while 
during  the  next  twenty  hours  they  scarcely  rose  three  feet 
above  the  crater,  from  which  mud  was  ejected.  Near  the 
village  of  Baklichli,  west  of  Baku,  the  flames  rose  so  high  that 

*  [True  volcanoes,  as  we  have  seen,  generate  sulpbureted  hydrogen 
and  muriatic  acid,  upheave  tracts  of  land,  and  emit  streams  of  melted 
feldapathic  materials ;  salses,  on  the  contrary,  disengage  little  else  but 
carbm-eted  hydrogen,  together  with  bitumen  and  other  products  of  the 
distillation  of  coal,  and  pour  forth  no  other  torrents  except  of  mud,  oj 
argillaceous  materials  mixed  up  with  water.  Daubeney,  op  cit.,  p 
510.]— Tr. 


SALSES.  -  225 

they  could  be  seen  at  a  distance  of  twenty-four  miles.  Enor- 
mous masses  of  rock  were  torn  up  and  scattered  arounfl.  Sim- 
ilar masses  may  be  seen  round  the  now  inactive  mud  volcano 
of  Monte  Zibio,  near  Sassuolo,  in  Northern  Italy.  The  sec- 
ondary condition  of  repose  has  been  maintained  for  upward  of 
fifteen  centuries  in  the  mud  volcanoes  of  Girgenti,  the  Maca- 
lubi,  in  Sicily,  which  have  been  described  by  the  ancients. 
These  salses  consist  of  many  contiguous  conical  hills,  from 
eight  to  ten,  or  even  thirty  feet  in  height,  subject  to  variations 
of  elevation  as  well  as  of  form.  Streams  of  argillaceous  mud, 
attended  by  a  periodic  development  of  gas,  flow  from  the  small 
basins  at  the  summits,  which  are  filled  with  water ;  the  mud, 
although  usually  cold,  is  sometimes  at  a  high  temperature,  as 
at  Damak,  in  the  province  of  Samarang,  in  the  island  of  Java. 
The  gases  that  are  developed  with  loud  noise  differ  in  their 
nature,  consisting,  for  instance,  of  hydrogen  mixed  with  naph- 
tha, or  of  carbonic  acid,  or,  as  Parrot  and  myself  have  shown 
(in  the  peninsula  of  Taman,  and  in  the  Volcancitos  de  Tur- 
baco,  in  South  America),  of  almost  pure  nitrogen.* 

Mud  volcanoes,  after  the  first  violent  explosion  of  fire,  which 
is  not,  perhaps,  in  an  equal  degree  common  to  all,  present  to 
the  spectator  an  image  of  the  uninterrupted  but  weak  activity 
of  the  interior  of  our  planet.  The  communication  with  the 
deep  strata  in  which  a  high  temperature  prevails  is  soon  closed, 
and  the  coldness  of  the  mud  emissions  of  the  salses  seems  to  in- 
dicate that  the  seat  of  the  phenomenon  can  not  bo  far  re- 
moved from  the  surface  during  their  ordinary  condition.  The 
reaction  of  the  interior  of  the  earth  on  its  external  surface  is 
exhibited  with  totally  different  force  in  true  volcanoes  or  igne- 
ous mountains,  at  points  of  the  earth  in  which  a  permanent, 
or,  at  least,  continually-renewed  connection  with  the  volcanic 
force  is  manifested.  We  must  here  carefully  distinguish  be- 
tween the  more  or  less  intensely  developed  volcanic  phenom- 
ena, as,  for  instance,  between  earthquakes,  thermal,  aqueous, 
and  gaseous  springs,  mud  volcanoes,  and  the  appearance  of 
bell-formed  or  dome-shaped  trachytic  rocks  without  openings ; 
the  opening  of  these  rocks,  or  of  the  elevated  beds  of  basalt,  as 

*  Hamboldt,  Rel.  Hist.,  t.  iii.,  p.  562-567  ;  Asie  Centrale,  t.  i.,  p.  43 ; 
t.  ii.,  p.  505-515;  Vues  des  Cordilleres,  pi.  xli.  Regarding  the  Maca- 
lubi  (the  Arabic  Makhlub,  the  overthrown  or  inverted,  from  the  word 
Khalaba),  and  on  "  the  Earth  ejecting  fluid  earth,"  see  Solinus,  cap.  5: 
"idem  ager  Agrigentinus  eructat  limosas  scatm-igenes,  et  ut  venae  fon- 
tium  sufEciunt  rivis  subministrandis,  ita  in  hac  Siciliae  parte  solo  nun- 
Quam  deficiente,  aeterna  rejectatione  terrara  terra  evomit." 

K  2 


226  COSMOS. 

craters  of  elevation  ;  and,  lastly^the  elevation  of  a  permanent 
volcano  in  the  crater  of  elevation,  or  among  the  debris  of  its 
earlier  formation.  At  different  periods,  and  in  different  de- 
grees of  activity  and  force,  the  permanent  volcanoes  emit 
steam,  acids,  luminous  scorise,  or,  w^hen  the  resistance  can  be 
overcome,  narrow,  band-like  streams  of  molten  earths.  Elas- 
tic vapors  sometimes  elevate  either  separate  portions  of  the 
earth's  crust  into  dome-shaped  unopened  masses  of  feldspathic 
trachyte  and  dolerite  (as  in  Puy  de  Dome  and  Chimborazo), 
in  consequence  of  some  great  or  local  manifestation  offeree  in 
the  interior  of  our  planet,  or  the  upheaved  strata  are  broken 
through  and  curved  in  such  a  manner  as  to  form  a  steep  rocky 
ledge  on  the  opposite  inner  side,  vv^hich  then  constitutes  the  in- 
closure  of  a  crater  of  elevation.  If  this  rocky  ledge  has  been 
uplifted  from  the  bottom  of  the  sea,  which  is  by  no  means  al- 
ways the  case,  it  determines  the  whole  physiognomy  and  form 
of  the  island.  In  this  manner  has  arisen  the  circular  form  of 
Palma,  which  has  been  described  with  such  admirable  accu- 
racy by  Leopold  von  Buch,  and  that  of  Nisyros,*  in  the  /Egean 
Sea.  Sometimes  half  of  the  annular  ledge  has  been  destroy- 
ed, and  in  the  bay  formed  by  the  encroachment  of  the  sea  cor- 
allines have  built  their  cellular  habitations.  Even  on  conti- 
nents craters  of  elevation  are  often  filled  with  water,  and  em- 
bellish in  a  peculiar  manner  the  character  of  the  landscape. 
Their  origin  is  not  connected  with  any  determined  species  of 
rock  :  they  break  out  in  basalt,  trachyte,  leucitic  porphyry 
(somma),  or  in  doleritic  mixtures  of  augite  and  labradorite  ; 
and  hence  arise  the  different  nature  and  external  conformation 
of  these  inclosures  of  craters.  No  phenomena  of  eruptions  are 
manifested  in  such  craters,  as  they  open  no  permanent  channel 
of  communication  with  the  interior,  and  it  is  but  seldom  that 
we  meet  with  traces  of  volcanic  activity  either  in  the  neigh- 
borhood or  in  the  interior  of  these  craters.  The  force  which 
was  able  to  produce  so  important  an  action  must  have  been 
long  accumulating  in  the  interior  before  it  could  overpower  the 
resistance  of  the  mass  pressing  upon  it ;  it  sometimes,  for  in- 
stance, on  the  origin  of  new  islands,  will  raise  granular  rocks 
and  conglomerated  masses  (strata  of  tufa  filled  with  marine 
plants)  above  the  surface  of  the  sea.  The  compressed  vapors 
escape  through  the  crater  of  elevation,  but  a  large  mass  soon 
falls  back  and  closes  the  opening,  which  had  been  only  formed 
by  these  manifestations  of  force.     No  volcano  can,  therefore, 

*  See  the  interesting  little  map  of  the  island  of  Nit^yros,  in  Ross's 
Reisen  auf  den  Griechischen  Inseln,  bd.  ii.,  1843,  s.  69. 


VOLCANOES.  227 

be  produced.*  A  volcano,  properly  so  called,  exists  only  where 
a  permanent  connection  is  established  between  the  interior  of 
the  earth  and  the  atmosphere,  and  the  reaction  of  the  interior 
on  the  surface  then  continues  during  long  periods  of  time.  It 
may  be  interrupted  for  centuries,  as  in  the  case  of  Vesuvius, 
Fisove,t  and  then  manifest  itself  with  renewed  activity.  In 
the  time  of  Nero,  men  were  disposed  to  rank  ^tna  among 
the  volcanic  mountains  which  were  gradually  becoming  ex- 
tinct ,t  and  subsequently  ^lian^  even  maintained  that  mar- 
uiers  could  no  longer  see  the  sinking  summit  of  the  mountain 
from  so  great  a  distance  at  sea.  AVhere  these  evidences — 
these  old.  scaffoldings  of  eruption,  I  might  almost  say — still 
exist,  the  volcano  rises  from  a  crater  of  elevation,  while  a  high 
rocky  wall  surrounds,  like  an  amphitheater,  the  isolated  con- 
ical mount,  and  forms  around  it  a  kind  of  casing  of  highly  ele- 

*  Leopold  von  Buch,  Phys.  Besckreibung  der  Canarischen  Inselti,  s. 
326;  and  his  Memoir  uber  Erhebungscratere  und  Vulcane,  in  Poggend., 
AnnaL,  bd.  xxxvii.,  s.  169. 

In  his  remarks  on  the  separation  of  Sicily  from  Calabria,  Strabo  gives 
an  excellent  description  of  the  two  modes  in  which  islands  are  formed: 
"Some  islands,"  he  observes  (lib.  vi.,  p.  258,  ed.  Casaub.),  "are  frag- 
ments of  the  continent,  others  have  arisen  from  the  sea,  as  even  at  the 
present  time  is  known  to  happen ;  for  the  islands  of  the  great  ocean, 
lying  far  from  the  main  land,  have  probably  been  raised  from  its  depths, 
while,  on  the  other  hand,  those  near  promontories  appear  (according  to 
reason)  to  have  been  separated  from  the  continent." 

t  Ocre  Fisove  (Mons  Vesuvius)  in  the  Umbrian  language.  (Lassen, 
Deutung  der  Engubinischen  Tafeln  in  Rhein.  Museum,  1832,  s.  387.) 
The  w^ord  ochre  is  very  probably  genuine  Umbrian,  and  means,  accord- 
ing to  Yeslus,,  mountain,  ^tna  would  be  a  burning  and  shining  mount* 
ain,  if  Voss  is  coiTect  in  stating  that  klrvrj  is  an  Hellenic  sound,  and  is 
connected  with  aWu  and  aldLvog;  but  the  intelligent  writer  Parthey 
doubts  this  Hellenic  origin  on  etymological  grounds,  and  also  because 
^tua  was  by  no  means  regarded  as  a  luminous  beacon  for  ships  or 
wanderers,  in  the  same  manner  as  the  ever-travailing  Stroraboli  (Stron- 
gyle),  to  which  Homer  seems  to  refer  in  the  Odyssey  (xii.,  68,  202, 
and  219),  and  its  geographical  position  was  not  so  well  determined.  I 
suspect  that  ^tna  would  be  found  to  be  a  Sicilian  word,  if  we  had  any 
fragmentary  materials  to  refer  to.  According  to  Diodorus  (v.,  6),  the 
Sicani,  or  aborigines  preceding  the  Sicilians,  were  compelled  to  tiy  to 
the  western  part  of  the  island,  in  consequence  of  successive  erui)tion8 
extending  over  many  years.  The  most  ancient  eruption  of  INIouut  ^Etna 
on  record  is  that  mentioned  by  Pindar  and  ^Eschylus,  as  occurring  un- 
der Hiero,  in  the  second  year  of  the  75th  Olympiad.  It  is  probable 
that  Hesiod  was  aware  of  the  devastating  eruptions  of  iEtna  before  the 
period  of  Gree.k  immigration.  There  is.  however,  some  doubt  regard- 
ing the  word  AItvtj  in  the  text  of  Hesiod,  a  subject  into  which  I  have 
entered  at  some  length  in  another  place.  (Humboldt,  Examen  Crit. 
de  le  Geogr.,  t.  i.,  p.  1G8.) 

t  Seneca.  Epist.,  79.  $  .Lilian,  Var.  Hi^t..  yiii..  i  < 


22S  COSMOS. 

vated  strata.  Occasionally  not  a  trace  of  this  mclosure  is 
visible,  and  the  volcano,  which  is  not  always  conical;  rises 
immediately  from  the  neighboring  plateau  in  an  elongated 
form,  as  in  the  case  of  Piehincha,*  at  the  foot  of  which  lies 
the  city  of  Quito. 

As  the  nature  of  rocks,  or  the  mixture  (grouping)  of  simple 
minerals  into  granite,  gneiss,  and  mica  slate,  or  into  trachyte, 
basalt,  and  dolorite,  is  independent  of  existing  climates,  and  is 
the  same  under  the  most  varied  latitudes  of  the  earth,  so  also 
we  find  every  where  in  inorganic  nature  that  the  same  laws  of 
configuration  regulate  the  reciprocal  superposition  of  the  strata 
of  the  earth's  crust,  cause  them  to  penetrate  one  another  in 
the  form  of  veins,  and  elevate  them  by  the  agency  of  elastic 
forces.  This  constant  recurrence  of  the  same  phenomena  is 
most  strikingly  manifested  in  volcanoes.  When  the  mariner, 
amid  the  islands  of  some  distant  archipelago,  is  no  longer  guid- 
ed by  the  light  of  the  same  stars  with  which  he  had  been  fa- 
miliar in  his  native  latitude,  and  sees  himself  surrounded  by 
palms  and  other  forms  of  an  exotic  vegetation,  he  still  can 
trace,  reflected  in  the  individual  characteristics  of  the  land- 
scape, the  forms  of  Vesuvius,  of  the  dome-shaped  summits  of 
Auvergne,  the  craters  of  elevation  in  the  Canaries  and  Azores, 
or  the  fissures  of  eruption  in  Iceland.  A  glance  at  the  satel- 
lite of  our  planet  will  impart  a  wider  generalization  to  this  anal- 
ogy of  configuration.  By  means  of  the  charts  that  have  been 
drawn  in  accordance  with  the  observations  made  with  large 
telescopes,  we  may  recognize  in  the  moon,  where  water  and  air 
are  both  absent,  vast  craters  of  elevation  surrounding  or  sup- 
porting conical  mountains,  thus  affording  incontrovertible  evi- 
dence of  the  effects  produced  by  the  reaction  of  the  interior  on 
the  surface,  favored  by  the  influence  of  a  feebler  force  of  grav- 
itation. 

Although  volcanoes  are  justly  termed  in  many  languages 
"fire-emitting  mountains,"  mountains  of  this  kind  are  not 
formed  by  the  gradual  accumulation  of  ejected  currents  of 
lava,  but  their  origin  seems  rather  to  be  a  general  consequence 
of  the  sudden  elevation  of  soft  masses  of  trachyte  or  labrador- 
itic  augite.    The  amount  of  the  elevating  force  is  manifested 

*  [This  mountain  contains  two  funnel-shaped  craters,  apparently  re- 
sulting from  two  sets  of  eruptions:  the  western  nearly  circular,  ?nd 
having  in  its  center  a  cone  of  eruption,  from  the  summit  and  sides  of 
which  are  no  less  than  seventy  vents,  some  in  activity  and  others  ex- 
tinct. It  is  probable  that  the  larger  number  of  the  vents  were  })!'t) 
duced  at  periods  anterior  to  history,     Daubeney,  op.  cit.,  p.  488-] —  V'-- 


VOLCANOES.  229 

by  the  elevation  of  the  volcano,  which  varies  from  the  incon- 
siderable height  of  a  hill  (as  the  volcano  of  Cosima,  one  of  the 
Japanese  Kurile  islands)  to  that  of  a  cone  above  19,000  feet 
in  height.  It  has  appeared  to  nie  that  relations  of  height  have 
a  great  influence  on  the  occurrence  of  eruptions,  which  are 
more  frequent  in  low  than  in  elevated  volcanoes.  I  might  in- 
stance the  series  presented  by  the  following  mountains  :  Strom- 
boh,  2318  feet ;  Guacamayo,  in  the  province  of  Quixos,  from 
which  detonations  are  heard  almost  daily  (I  have  myself  often 
heard  them  at  Chillo,  near  Quito,  a  distance  of  eighty-eight 
miles);  Vesuvius,  3876  feet;  -^tna,  10,871  feet;  the  Peak 
of  Tenerifie,  12,175  feet;  and  Cotopaxi,  19,069  feet.  If  the 
focus  of  these  volcanoes  be  at  an  equal  depth  below  the  sur- 
face, a  greater  force  must  be  required  where  the  fused  masses 
have  to  be  raised  to  an  elevation  six  or  eight  times  greater 
than  that  of  the  lower  eminences.  While  the  volcano  Strom- 
boli  (Strongyle)  has  been  incessantly  active  since  the  Homeric 
ages,  and  has  served  as  a  beacon-light  to  guide  the  mariner  in 
the  Tyrrhenian  Sea,  loftier  volcanoes  have  been  characterized 
by  long  intervals  of  quiet.  Thus  we  see  that  a  whole  century 
often  intervenes  between  the  eruptions  of  most  of  the  colossi 
which  crown  the  summits  of  the  Cordilleras  of  the  Andes. 
Where  we  meet  with  exceptions  to  this  law,  to  which  I  long 
since  drew  attention,  they  mufet  depend  upon  the  circumstance 
that  the  connections  between  the  volcanic  foci  and  the  crater 
of  eruption  can  not  be  considered  as  equally  permanent  in  the 
case  of  all  volcanoes.  The  channel  of  communication  may  be 
closed  for  a  time  in  the  case  of  the  lower  ones,  so  that  they 
less  frequently  come  to  a  state  of  eruption,  although  they  do 
not,  on  that  account,  approach  more  nearly  to  their  final  ex- 
tinction. 

These  relations  between  the  absolute  height  and  the  fre- 
quency of  volcanic  eruptions,  as  far  as  they  are  externally  per 
ceptible,  are  intimately  connected  with  the  consideration  of 
the  local  conditions  under  which  lava  currents  are  erupted. 
Eruptions  from  the  crater  are  very  unusual  in  many  mount- 
ains, generally  occurring  from  lateral  fissures  (as  was  observed 
in  the  case  of  ^tna,  in  the  sixteenth  century,  by  the  cele- 
brated historian  Bembo,  when  a  youth^),  wherever  the  sides 

*  Petri  Bembi  Opuscula  {^tna  Dialogus),  Basil,  1556,  p.  63  :  "  Quic- 
quid  ill  iEtnae  matris  utero  coalescit,  nunqiiam  exit  ex  cratere  superiore, 
quod  vol  eo  iuscondere  gravis  materia  noii  queat,  vel,  quia  iuferius  alia 
Bpirameuta  sunt,  nou  fit  opus.  Despumant  flammis  urgeutibus  iguei  rivi 
pigro  fluxu  Iotas  delarabentes  plagas,  et  in  lapidem  indurescunt." 


230  COSMOS. 

of  the  upheaved  mountain  were  least  ahle,  from  their  configu- 
ration and  position,  to  offer  any  resistance.  Cones  of  eruption 
are  sometimes  uplifted  on  these  fissures  ;  the  .larger  ones,  which 
are  erroneously  termed  iieiv  volcmioes,  are  ranged  together  in  a 
line  marking  the  direction  of  a  fissure,  which  is  soon  reclosed, 
while  the  smaller  ones  are  grouped  together,  covering  a  whole 
district  with  their  dome-like  or  hive-shaped  forms.  To  the 
latter  belong  the  homitos  de  Jorullo,^  the  cone  of  Vesuvius 
erupted  in  October,  1822,  that  of  Awatscba,  according  to  Pos- 
tels,  and  those  of  the  lava-field  mentioned  by  Erman,  near  the 
Baidar  Mountains,  in  the  peninsula  of  Kamtschatka. 

When  volcanoes  are  not  isolated  in  a  plain,  but  surrounded, 
as  in  the  double  chain  of  the  Andes  of  Quito,  by  a  table-land 
having  an  elevation  from  nine  to  thirteen  thousand  feet,  this 
circumstance  may  probably  explain  the  cause  why  no  lava 
streams  are  formedf  during  the  most  dreadful  eruption  of  ig- 
nited scoriae  accompanied  by  detonations  heard  at  a  distance 
of  more  than  a  hundred  miles.  Such  are  the  volcanoes  of  Po- 
payan ,  those  of  the  elevated  plateau  of  Los  Pastes  and  of  the 
Andes  of  Quito,  with  the  exception,  perhaps,  in  the  case  of 
the  latter,  of  the  volcano  of  Antisana.  The  height  of  the  cone 
of  cinders,  and  the  size  and  form  of  the  crater,  are  elements 
of  configuration  which  yield  an  especial  and  individual  char- 
acter to  volcanoes,  although  the  cone  of  cinders  and  the  crater 
are  both  wholly  independent  of  the  dimensions  of  the  mount- 
ain. Vesuvius  is  more  than  three  times  lower  than  the  Peak 
of  Tenerifle  ;  its  cone  of  cinders  rises  to  one  third  of  the  height 
of  the  whole  mountain,  while  the  cone  of  cinders  of  the  Peak 
is  only  -^-^di  of  its  altitude. |  In  a  much  higher  volcano  than 
that  of  Teneriffe,  the  Rucu  Pichincha,  other  relations  occur 

*  See  my  drawing  of  the  volcano  of  .Torullo,  of  its  homitos,  and  of  the 
uplifted  malpays,  in  my  Viies  de  Cordilleres,  pi.  xliii.,  p.  239. 

[Burckhardt  states  that  during  the  twenty-four  years  that  have  inter- 
vened since  Baron  Humboldt's  visit  to  Jorullo,  the  homitos  have  either 
wholly  disappeared  or  completely  changed  their  forms.  See  Aufenthalt 
und  Reisen  in  Mexico  in  1825  und  1834.] — Tr. 

\  Humboldt,  £ssai  sur  la  Giogr.  desPtantes  et  Tableau  Phys.  des  R6- 
gions  Equinoxiales,  1807,  p.  130,  and  Essai  Geogn.  snr  le  Gisement  des 
Roches,  p.  321.  Most  of  the  volcanoes  in  Java  demonstrate  that  the 
cause  of  the  perfect  absence  of  lava  streams  in  volcanoes  of  incessant 
activity  is  not  alone  to  be  sought  for  in  their  form,  position,  and  height. 
Leop.  von  Buch,  Descr.  Phys.  des  lies  Canaries,  p.  419  ;  Reinwardt  and 
Hoffmann,  in  Poggend.,  Annalen.,  bd.  xii.,  s.  C07. 

\  [It  may  be  remarked  in  general,  although  the  rule  is  liable  to  ex- 
ceptions, that  the  dimensions  of  a  crater  are  in  an  inverse  ratio  to  the 
elevation  of  the  mountain.     Daubeuey,  op.  cit.,  p.  444.] — Tr. 


VOLCANOES.  231 

wliicli  approach  more  nearly  to  that  of  Vesuvius.  Among  all 
the  volcanoes  that  I  have  seen  iu  the  two  hemispheres,  the 
conical  form  of  Cotopaxi  is  the  most  beautifully  regular.  A 
sudclen  fusion  of  the  snow  at  its  cone  of  cinders  announces  the 
proximity  of  the  eruption.  Before  the  smoke  is  visible  in  the 
rarefied  strata  of  air  surrounding  the  summit  and  the  opening 
of  the  crater,  the  walls  of  the  cone  of  cinders  are  sometimes 
in  a  state  of  glowing  heat,  when  the  whole  mountain  presents 
an  appearance  of  the  most  fearful  and  portentous  blackness. 
The  crater,  which,  with  very  few  exceptions,  occupies  the 
summit  of  the  volcano,  forms  a  deep,  caldron-like  valley,  which 
is  often  accessible,  and  whose  bottom  is  subject  to  constant  al- 
terations. The  great  or  lesser  depth  of  the  crater  is  in  many 
volcanoes  likewise  a  sign  of  the  near  or  distant  occurrence  of 
an  eruption.  Long,  narrow  fissures,  from  which  vapors  issue 
forth,  or  small  rounding  hollows  filled  with  molten  masses,  al- 
ternately open  and  close  in  the  caldron-like  valley  ;  the  bottom 
rises  and  sinks,  eminences  of  scoriae  and  cones  of  eruption  are 
formed,  rising  sometimes  far  over  the  walls  of  the  crater,  and 
contin^jing  for  years  together  to  impart  to  the  volcano  a  pecul- 
iar character,  and  then  suddenly  fall  together  and  disappear 
during  a  new  eruption.  The  openings  of  these  cones  of  erup- 
tion, which  rise  from  the  bottom  of  the  crater,  must  not,  as  is 
too  often  done,  be  confounded  with  the  crater  which  incloses 
them.  If  this  be  maccessible  from  extreme  depth  and  from 
the  perpendicular  descent,  as  in  the  case  of  the  volcano  of 
Rucu  Pichincha,  wdiich  is  15,920  feet  in  height,  the  traveler 
may  look  from  the  edge  on  the  summit  of  the  mountains  which 
rise  in  the  sulphurous  atmosphere  of  the  valley  at  his  feet ; 
and  I  have  never  beheld  a  grander  or  more  remarkable  picture 
than  that  presented  by  this  volcano.  In  the  interval  between 
two  eruptions,  a  crater  may  either  present  no  luminous  ap- 
pearance, showing  merely  open  fissures  and  ascending  vapors, 
or  the  scarcely  heated  soil  may  be  covered  by  eminences  of 
scoria?,  that  admit  of  being  approached  without  danger,  and 
thus  present  to  the  geologist  the  spectacle  of  the  eruption  of 
burning  and  fused  masses,  which  fall  back  on  the  ledge  of  the 
cone  of  scoria3,  and  whose  appearance  is  regularly  announced 
by  small  wholly  local  earthquakes.  Lava  sometimes  streams 
forth  from  the  open  fissures  and  small  hollows,  without  break- 
ing through  or  escaping  beyond  the  sides  of  the  crater.  If, 
however,  it  does  break  through,  the  newly-opened  terrestrial 
stream  generally  flows  in  such  a  quiet  and  well-defined  course, 
that  the  deep  valley,  which  we  term  the  crater,  remains  acces- 


232  COSMOS. 

sible  even  during  periods  of  eruption.  It  is  impossible,  with- 
out an  exact  representation  of  the  configuration — the  normal 
type,  as  it  were,  of  fire-emitting  mountains,  to  form  a  just  idea 
of  those  phenomena  which,  owing  to  fantastic  descriptions  and 
an  undefined  phraseology,  have  long  been  comprised  under  the 
head  of  craters,  cones  of  eriqotioii,  and  volcanoes.  The  mar- 
ginal ledges  of  craters  vary  much  less  than  one  would  be  led 
to  suppose.  A  comparison  of  Saussure's  measurements  with 
my  own  yields  the  remarkable  result,  for  instance,  that  in  the 
course  of  forty-nine  years  (from  1773  to  1822),  the  elevation 
of  the  northwestern  margin  of  Mount  Vesuvius  [Rocca  del 
Palo)  may  be  considered  to  have  remained  unchanged.* 

Volcanoes  which,  like  the  chain  of  the  Andes,  lift  their  sum- 
mits high  above  the  boundaries  of  the  region  of  perpetual  snow, 
present  peculiar  phenomena.  The  masses  of  snow,  by  their 
sudden  fusion  during  eruptions,  occasion  not  only  the  most  fear- 
ful inundations  and  torrents  of  water,  in  which  smoking  scoriae 
are  borne  along  on  thick  masses  of"  ice,  but  they  likewise  ex- 
ercise a  constant  action,  while  the  volcano  is  in  a  state  of  per- 
fect repose,  by  infiltration  into  the  fissures  of  the  trachytie  rock. 
Cavities  which  are  either  on  the  declivity  or  at  the  foot  of  the 
mountain  are  gradually  converted  into  subterranean  reservoirs 
of  water,  which  communicate  by  numerous  narrow  openings 
with  mountain  streams,  as  we  see  exemplified  in  the  highlands 
of  Quito.  The  fishes  of  these  rivulets  multiply,  especially  in 
the  obscurity  of  the  hollows  ;  and  when  the  shocks  of  earth- 
quakes, which  precede  all  eruptions  in  the  Andes,  have  vio- 
lently shaken  the  whole  mass  of  the  volcano,  these  subterra- 
nean caverns  are  suddenly  opened,  and  water,  fishes,  and  tufa- 
ceous  mud  are  all  ejected  together.  It  is  through  this  singular 
phenomenont  that  the  inhabitants  of  the  highlands  of  Quito 
became  acquainted  with  the  existence  of  the  little  cyclopia 
fishes,  termed  by  them  the  prenadilla.  On  the  night  between 
the  19th  and  20th  of  June,  1698,  when  the  summit  of  Car- 
guairazo,  a  mountain  19,720  feet  in  height,  fell  in,  leaving 
only  two  huge  masses  of  rock  remaining  of  the  ledge  of  the 
crater,  a  space  of  nearly  thirty-two  square  miles  was  over- 
flowed and  devastated  by  streams  of  liquid  tufa  and  argilla- 
ceous mud  [lodazales),  containing  large  quantities  of  dead  fish. 

*  See  the  ground-work  of  my  measurements  compared  with  those  of 
Saussure  and  Lord  Minto,  in  the  Abhandlungen  der  Akademie  der  Wiss. 
zu  Berlin  for  the  years  1822  and  1823. 

t  Pimelodes  cyclopum.  See  Humboldt,  Recueil  d' Observations  dt 
Zoologie  et  d^Anatomie  Compar^e,  t.  i.,  p.  21-25. 


VOLCANOES.  233 

In  like  manner,  the  putrid  fever,  which  raged  seven  years  pre- 
viously in  the  mountain  town  of  Ibarra,  north  of  Quito,  was 
ascribed  to  the  ejection  of  fish  from  the  volcano  of  Imbaburu.* 

Water  and  mud,  which  flow  not  from  the  crater  itself,  but 
from  the  hollows  in  the  trachytic  mass  of  the  mountain,  can 
not,  strictly  speaking,  be  classed  among  volcanic  phenomena. 
They  are  only  indirectly  connected  with  the  volcanic  activity 
of  the  mountain,  resembling,  in  that  respect,  the  singular  me- 
teorological process  which  I  have  designated  in  my  earlier  writ- 
ings by  the  term  of  volcanic  storm.  The  hot  stream  which 
rises  from  the  crater  during  the  eruption,  and  spreads  itself  in 
the  atmosphere,  condenses  into  a  cloud,  and  surrounds  the  col- 
umn of  fire  and  cinders  which  rises  to  an  altitude  of  many 
thousand  feet.  The  sudden  condensation  of  the  vapors,  and, 
as  Gay-Lussac  has  shown,  the  formation  of  a  cloud  of  enor-  ^ 
mous  extent,  increase  the  electric  tension.  Forked  lightning 
flashes  from  the  column  of  cinders,  and  it  is  then  easy  to  dis- 
tinguish (as  at  the  close  of  the  eruption  of  Mount  Vesuvius,  in 
the  latter  end  of  October,  1822)  the  rolling  thunder  of  the  vol- 
canic storm  from  the  detonations  in  the  interior  of  the  mount- 
ain. The  flashes  of  lightning  that  darted  from  the  volcanic 
cloud  of  steam,  as  we  learn  from  Olafsen's  report,  killed  eleven 
horses  and  two  men,  on  the  eruption  of  the  volcano  of  Katla- 
gia,  in  Iceland,  on  the  17th  of  October,  1755. 

Having  thus  delineated  the  structure  and  dynamic  activity 
of  volcanoes,  it  now  remains  tor  us  to  throw  a  glance  at  the 
differences  existing  in  their  material  products.  The  subterra- 
nean forces  sever  old  combinations  of  matter  in  order  to  pro- 
duce new  ones,  and  they  also  continue  to  act  upon  matter  as 
long  as  it  is  in  a  state  of  liquefaction  from  heat,  and  capable 
of  being  displaced .  The  greater  or  less  pressure  under  which 
merely  softened  or  wholly  liquid  fluids  are  solidified,  appears  to 
constitute  the  main  diflerence  in  the  formation  of  Plutonic  and 
volcanic  rocks.  The  mineral  mass  which  flows  in  narrow, 
elongated  streams  from  a  volcanic  opening  (an  earth-spring), 
is  called  lava.  Where  many  such  currents  meet  and  are  ar- 
rested in  their  course,  they  expand  in  width,  filling  large  ba- 
sins, in  which  they  become  solidified  in  superimposed  strata. 
These  few  sentences  describe  the  general  character  of  the  prod- 
ucts of  volcanic  activity. 

*  [It  would  appear,  as  there  is  no  doubt  that  these  fishes  proceed  from 
the  mountain  itself,  that  there  must  be  large  lakes  in  the  interior,  which 
in  ordinaiy  seasons  are  out  of  the  immediate  influence  of  the  volcanio 
action      See  Daubeney,  op.  cit.,  p.  488,  497.] — Tr. 


234  COSMOS. 

Rocks  which  are  merely  broken  through  by  the  volcanic  ac- 
tion are  often  inclosed  in  the  igneous  products.  Thus  I  have 
ibund  angular  fragments  of  feldspathic  syenite  imbedded  in  the 
black  augitic  lava  of  the  volcano  of  .ToruUo,  in  Mexico  ;  but 
the  masses  of  dolomite  and  granular  limestone,  which  contain 
magnificent  clusters  of  crystalline  fossils  (vesuvian  and  garnets, 
covered  with  mejonite,  nepheline,  and  sodalite),  are  not  the 
ejected  products  of  Vesuvius,  these  belonging  rather  to  very 
generally  distributed  formations,  viz.,  strata  of  tufa,  which  are 
more  ancient  than  the  elevation  of  the  Somma  and  of  Vesu 
vius,  and  are  probably  the  products  of  a  deep-seated  and  con 
cealed  submarine  volcanic  action.*  We  find  five  metals  among 
the  products  of  existing  volcanoes,  iron,  copper,  lead,  arsenic, 
and  selenium,  discovered  by  Stromeyer  in  the  crater  of  Volca- 
no.! The  vapors  that  rise  from  the  fiwtarolles  cause  the  sub- 
limation of  the  chlorids  of  iron,  copper,  lead,  and  ammonium  ; 
iron  glancel  and  chlorid  of  sodium  (the  latter  often  in  large 
quantities)  fill  the  cavities  of  recent  lava  streams  and  the  fis- 
sures of  the  margin  of  the  crater. 

The  mineral  composition  of  lava  differs  according  to  the  na- 
ture of  the  crystalline  rock  of  which  the  volcano  is  formed,  the 
height  of  the  point  where  the  eruption  occurs,  whether  at  the 
foot  of  the  mountain  or  in  the  neighborhood  of  the  crater,  and 
the  condition  of  temperature  of  the  interior.  Vitreous  volcanic 
formations,  obsidian,  pearl-stone,  and  pumice,  are  entirely  want- 
ing in  some  volcanoes,  while  in  the  case  of  otliers  they  only 
proceed  from  the  crater,  or,  at  any  rate,  from  very  considera- 
ble heights.  These  important  and  involved  relations  can  only 
be  explained  by  very  accurate  crystallographic  and  chemical 
investigations.  My  fellow-traveler  in  Siberia,  Gustav  Rose, 
and  subsequently  Hermann  Abich,  have  already  been  able, 
by  their  fortunate  and  ingenious  researches,  to  throw  much 
light  on  the  structural  relations  of  the  various  kinds  of  vol- 
canic rocks. 

*  Leop.  vou  Buch,  in  Poggend.,  Annalen,  bd.  xxxvii.,  s.  179. 

t  [The  litde  island  of  Volcano  is  separated  from  Lipari  by  a  narrow 
channel.  It  appears  to  have  exhibited  strong  signs  of  volcanic  activ- 
ity long  before  \he  Christian  era,  and  still  emits  gaseous  exhalations. 
Stromeyer  detected  the  presence  of  selenium  in  a  mixture  of  sal  ammo- 
niac and  sulphur.  Another  product,  supposed  to  be  peculiar  to  this 
volcano,  is  boracic  acid,  wliich  lines  the  sides  of  the  cavities  in  beauti- 
ful white  silky  crystals.     Daubeney,  op.  cit.,  p.  257.] — Tr. 

t  Regarding  the  chemical  origin  of  iron  glance  in  volcanic  masses,  see 
Mitscherlich,  in  Poggend.,  Annalen,  bd.  xv.,  s.  630 ;  and  on  the  libera 
tion  of  hydrochloric  acid  in  the  crater,  see  Gay-Lussac,  in  the  Annal^ 
ic  Chimique  el  de  Physique,  t.  xxii.,  p.  423. 


VOLCANOES.  235 

Tlie  greater  part  of  the  ascending  vapor  is  mere  steam. 
When  condensed,  this  ibrms  springs,  as  in  Pantellaria,=^  where 
they  are  used  by  the  goatherds  of  the  island.  On  the  morn- 
mg  of  the  26th  of  October,  1822,  a  current  was  seen  to  flow 
from  a  lateral  fissure  of  the  crater  of  Vesuvius,  and  was  long 
supposed  to  have  been  boiling  water;  it  was,  however,  shown, 
by  Monticelh's  accurate  investigations,  to  consist  of  dry  ashes, 
which  fell  like  sand,  and  of  lava  pulverized  by  friction.  The 
ashes,  which  sometimes  darken  the  air  for  hours  and  days  to- 
gether, and  produce  great  injury  to  the  vineyards  and  olive 
groves  by  adhering  to  the  leaves,  indicate  by  their  columnar 
ascent,  impelled  by  vapors,  the  termination  of  every  great 
earthquake.  This  is  the  magnificent  phenomenon  which 
Pliny  the  younger,  in  his  celebrated  letter  to  Cornelius  Tacitus, 
compares,  in  the  ca.se  of  Vesuvius,  to  the  form  of  a  lofty  and 
thickly  branched  and  foliaceous  pine.  That  which  is  de- 
scribed as  flames  in  the  eruption  of  scoriee,  and  the  radiance 
of  the  glowing  red  clouds  that  hover  over  the  crater,  can  not 
be  ascribed  to  the  efi'ect  of  hydrogen  gas  in  a  state  of  combus- 
tion. They  are  rather  reflections  of  light  Avhich  issue  from 
molten  masses,  projected  high  in  the  air,  and  also  reflections 
from  the  burning  depths,  M^ience  the  gloAving  vapors  ascend. 
We  will  not,  however,  attempt  to  decide  the  nature  of  the 
flames,  which  are  occasionally  seen  now,  as  in  the  time  of 
Strabo,  to  rise  from  the  deep  sea  during  the  activity  of  littoral 
volcanoes,  or  shortly  before  the  elevration  of  a  volcanic  island. 

When  the  questions  are  asked,  what  is  it  that  burns  in  the 
volcano  ?  what  excites  the  heat,  fuses  together  earths  and 
metals,  and  imparts  to  lava  currents  of  thick  layers  a  degree 
of  heat  that  lasts  for  many  years?!  it  is  necessarily  in:iplied 
that  volcanoes  must  be  connected  with  the  existence  ot  sub- 
stances capable  of  maintaining  combustion,  like  the  beds  of 
coal  in  subterranean  fires.  According  to  the  diflerent  phase* 
of  chemical  science,  bitumen,  pyrites,  the  moist  admixture  of 
finely-pulverized  sulphur  and  iron,  pyrophoric  substances,  and 
the  metals  of  the  alkalies  and  earths,  have  in  turn  been  desig- 
nated as  the  cause  of  intensely  active  volcanic  phenomena. 
The  great  chemist,  Sir  Humphrey  Davy,  to  whom  we  are  in- 
debted for  the  knowledge  of  the  most  combustible  metallic 

*  [Steam  issues  from  many  parts  of  this  insular  mountain,  and  sev- 
eral hot  sj)rings  gush  forth  from  it,  which  form  together  a  lake  6000  feet 
in  circumference.     Daubeney,  op.  cit.] — Tr. 

t  See  the  beautiful  ex[)eriuieuts  on  the  cooling  of  masses  of  rock,  iu 
Bischof's  Wdrmtlehrc,  s.  :384,  443,  500-5 12. 


236  COSMOS. 

substances,  has  himself  renounced  his  bold  chemical  hypothesis 
in  his  last  work  {Consolatio7i  in  Travel,  and  last  Dai/s  of  a 
Philosopher) — a  work  which  can  not  fail  to  excite  in  the 
reader  a  feeling  of  the  deepest  melancholy.  The  great  mean 
density  of  the  earth  (5-44),  when  compared  with  the  specific 
weight  of  potassium  (0-865),  of  sodium  (0*972),  or  of  the 
metals  of  the  earths  (1'2),  and  the  absence  of  hydrogen  gas  in 
the  gaseous  emanations  from  the  fissures  of  craters,  and  from 
still  warm  streams  of  lava,  besides  many  chemical  considera- 
tions, stand  in  opposition  with  the  earlier  conjectures  of  Davy 
r,iid  Ampere.*  If  hydrogen  were  evolved  from  erupted  lava, 
how  great  must  be  the  quantity  of  the  gas  disengaged,  when, 
the  seat  of  the  volcanic  activity  being  very  low,  as  in  the  case 
of  the  remarkable  eruption  at  the  foot  of  the  Skaptar  Jokul  in 
Iceland  (from  the  11th  of  June  to  the  3d  of  August,  1783, 
described  by  Mackenzie  and  Soemund  Magnussen),  a  space  of 
many  square  miles  was  covered  by  streams  of  lava,  accumu- 
lated to  the  thickness  of  several  hundred  feet  I  Similar  diffi- 
cLilties  are  opposed  to  the  assumption  of  the  penetration  of  the 
atmospheric  air  into  the  crater,  or,  as  it  is  figuratively  ex- 
pressed, the  inhalation  of  the  earth,  when  we  have  regard  to 
the  small  quantity  of  nitrogen  emitted.  So  general,  deep- 
seated,  and  far-propagated  an  activity  as  that  of  volcanoes, 
can  not  assuredly  have  its  source  in  chemical  affinity,  or  in 
the  mere  contact  of  individual  or  merely  locally  distributed 
substances.  Modern  geognosyt  rather  seeks  the  cause  of  this 
activity  in  the  increased  temperature  with  the  increase  of 
depth  at  all  degrees  of  latitude,  in  that  powerful  internal  heat 
which  our  planet  owes  to  its  first  solidification,  its  formation 
in  the  regions  of  space,  and  to  the  spherical  contraction  of 

*  See  Berzelius  antlWohler,  in  Poirgend..  Annaleji,  bd.  i.,  s.  221,  and 
bJ.  xi.,  s.  146;  Gay-Lussac,  in  the  Annates  de  Ckimie,  t.  x.,  xii.,  p.  422  ; 
and  Bischof  s  Reasons  against  the  Chemical  Theory  of  Volcanoes,  iu  the 
Eaglisji  edition  of  liis  Wdrmelehre,  p.  297-309. 

t  [On  the  various  theoi'ies  that  have  been  advanced  iu  explanation  of 
volcanic  action,  see  Daubeney  On  Volcanoes,  a  woi'k  to  which  we  have 
made  continual  reference  during  the  preceding  pages,  as  it  constitutes 
the  most  recent  and  perfect  compendium  of  all  the  important  facts  re- 
lating to  this  subject,  and  is  peculiarly  adapted  to  serve  as  a  source  of 
reference  to  the  Cosmos,  since  the  learned  author  in  many  instances  en- 
ters into  a  full  exposition  of  the  views  advanced  by  Baron  Humboldt. 
The  appendix  contains  several  valuable  notes  with  reference  to  the 
most  recent  works  that  have  appeared  on  the  Continent,  on  subjects  re- 
lating to  volcanoes  ;  among  others,  an  interesting  notice  of  Professor 
Bischof's  views  "  on  the  origin  of  the  carbonic  acid  discharged  from 
volcanoes,"  as  enounced  in  his  recently  published  work,  Lehrbuch  der 
Chemischen  und  Physikalischen  Oeologie.'\ —  Tr. 


VOLCANOES.  237 

matter  revolving  elliptically  in  a  gaseous  condition.  We  have 
thus  mere  conjecture  and  supposition  side  by  side  with  cer- 
tain knowledge.  A  philosophical  study  of  nature  strives  ever 
to  elevate  itself  above  the  narrow  requirements  of  mere  natural 
description,  and  does  not  consist,  as  we  have  already  remark- 
ed, in  the  mere  accumulation  of  isolated  facts.  The  inquir- 
ing and  active  spirit  of  man  must  be  suffered  to  pass  from  the 
present  to  the  past,  to  conjecture  all  that  can  not  yet  be  knov^nti 
with  certainty,  and  still  to  dwell  with  pleasure  on  the  ancient 
myths  of  geognosy  which  are  presented  to  us  under  so  many 
various  forms.  If  we  consider  volcanoes  as  irregular  inter- 
mittent springs,  emitting  a  fluid  mixture  of  oxydized  metals, 
alkalies,  and  earths,  flowing  gently  and  calmy  wherever  they 
find  a  passage,  or  being  upheaved  by  the  powerful  expansive 
force  of  vapors,  we  are  involuntarily  led  to  remember  the  geog- 
nostic  visions  of  Plato,  according  to  which  hot  springs,  as  well 
as  all  volcanic  igneous  streams,  were  eruptions  that  might  be 
traced  back  to  one  generally  distributed  subterranean  cause, 
Pyriphlegetho7i .  * 

'^  According  to  Plato's  geognostic  views,  as  developed  in  the  Pkcedo, 
Pyriphlegelhon  plays  much  the  same  part  in  relation  to  the  activity  of 
volcanoes  that  we  now  ascribe  to  the  augmentation  of  heat  as  we  de- 
scend from  the  earth's  surface,  and  to  the  fused  condition  of  its  internal 
strata.     {Pheedo,  ed.  Ast,   p.  603  and  607;  Annot.,  p.  808  and  817.) 
"Within  the  earth,  and  all  around  it,  are  larger  and  smaller  caverns. 
Water  flows  there  in  abundance ;  also  much  tire  and  large  streams  of 
fire,  and  streams  of  moist  mud  (some  purer  and  others  more  filthy), 
like  those  in  Sicily,  consisting  of  mud  and  fire,  preceding  the  great  erup- 
tion.    These  streams  fill  all  places  that  fall  in  the  way  of  their  course. 
Pyriphlegethon  flows  forth  into  an  extensive  district  burning  with  a 
fierce  fire,  v^diere  it  forms  a  lake  larger  than  our  sea,  boiling  with  water 
and  mud.     From  thence  it  moves  in  circles  round  the  earth,  turbid  and 
muddy."     This  stream  of  molten  earth  and  mud  is  so  much  the  general 
cause  of  volcanic  phenomena,  that  Plato  expressly  adds,  "thus  is  Pyri- 
phlegethon constituted,  from  which  also  the  streams  of  fire  (ot  (ivaaeg), 
wherever  they  reach  the  earth  {oTzri  av  TVX(->cn-  ttjc  yijg),  inflate  such 
parts  (detached  fragments)."     Volcanic  scoriae  and  lava  streams  are 
therefore  portions  of  Pyriphlegethon  itself,  portions  of  the  subterranean 
molten  and  ever-undulating  mass.     That  ol  ^vaKEC  are  lava  streams,  and 
not,  as  Schneider,  Passow,  and  Schleiermacher  will  have  it,  "  fire-vom- 
iting mountains,"  is  clear  enough  from  many  passages,  some  of  which 
have  been  collected  by  Ukert  {Geogr.  der  Griechen  und  Romer,  th.  ii., 
s.  200)  ;  pva^  is  the  volcanic  phenomenon  in  reference  to  its  most  strik- 
ing characteristic,  the  lava  stream.     Hence  the  expression,  the  (yvaaeg 
of  iE.tna.      Aristot.,  Mirab.   Ausc,   t.   ii.,  p.  833  ;    sect.   38,  Bekker  ; 
Thucyd.,  iii.,  116;  Theophrast.,  De  Lap.,  22,  p.  427,  Schneider;  Diod., 
v.,  6,  and  xiv.,  59,  where  are  the   remarkable  words,  ''  Many  places 
near  the  sea,  in  the  neighborhood  of  iEtna,  were  leveled  to  the  ground, 
vmb  Tov  Ka7\.oviiEvov  pvuKog ;"    Strabo,  vi.,  p.  269 ;   xiii.,  p.  268,   and 


238  COSMOS. 

The  difiererit  volcanoes  over  the  earth's  surface,  when  they 
are  considered  independently  of  all  climatic  differences,  are 
acutely  and  characteristically  classified  as  central  and  linear 
volcanoes.  Under  the  first  name  are  comprised  those  which 
constitute  the  central  point  of  many  active  mouth's  of  erup- 
tion, distributed  almost  regularly  in  all  directions  ;  under  the 
second,  those  lying  at  some  little  distance  from  one  another, 
forming,  as  it  were,  chimneys  or  vents  along  an  extended 
fissure.  Linear  volcanoes  again  admit  of  further  subdivision, 
namely,  those  which  rise  like  separate  conical  islands  from  the 
bottom  of  the  sea,  being  generally  parallel  with  a  chain  of 
primitive  mountains,  Mdiose  foot  they  appear  to  indicate,  and 
those  volcanic  chains  which  are  elevated  on  the  highest  ridges 
of  these  mountain  chains,  of  which  they  form  the  summits.* 
The  Peak  of  Teneriffe,  for  instance,  is  a  central  volcano,  being 
the  central  point  of  the  volcanic  group  to  which  the  eruption 
of  Palma  and  Lancerote  may  be  referred.  The  long,  rampart- 
like chain  of  the  Andes,  which  is  sometimes  single,  and  some- 
times divided  into  two  or  three  parallel  branches,  connected 
by  various  transverse  ridges,  presents,  from  the  south  of  Chili 
to  the  northwest  coast  of  America,  one  of  the  grandest  in- 
stances of  a  continental  volcanic  chain.      The  proximity  of 

where  there  is  a  notice  of  the  celebrated  burning  mud  of  the  Lelantine 
plains,  in  Euboea,  i.,  p.  58,  Casaub.  ;  and  Appian,  De  Bello  Civili,  v., 
114.  The  blame  which  Aristotle  throws  on  the  geognostical  fantasies 
of  the  Phmdo  {Meteor.,  ii.,  2,  19)  is  especially  applied  to  the  sources  of 
the  rivers  flowing  over  the  earth's  surface.  The  distinct  statement  of 
Plato,  that  "  in  Sicily  eniptions  of  wet  mud  precede  the  glowing  (lava) 
stream,"  is  very  remarkable.  Observations  on  iEtna  could  not  have  led 
to  such  a  statement,  unless  pumice  and  ashes,  formed  into  a  mud-like 
mass  by  admixture  with  melted  snow  and  water,  during  the  volcano- 
electric  storm  in  the  crater  of  eruption,  were  mistaken  for  ejected  mud. 
It  is  more  probable  that  Plato's  streams  of  moist  mud  {vypov  nrjXov 
TTorauoL)  originated  in  a  faint  recollection  of  the  salses  (mud  volcanoes) 
of  Agrigentum,  which,  as  I  have  already  mentioned,  eject  argillaceous 
mud  w^ith  a  loud  noise.  It  is  much  to  be  regretted,  in  reference  to  this 
subject,  that  the  work  of  Theophrastus  Tvepi  pvaKoq  tov  ev  ^iKcTita,  On 
the  Volcanic  Stream  in  Sicily,  to  which  Diog.  Laert.,  v.,  49,  refers,  has 
not  come  down  to  us. 

*  Leopold  von  Buch,  Physikal.  Beschreib.  der  Canarischen  Inseln,  s. 
326-407.  I  doubt  if  we  can  agree  with  the  ingenious  Charles  Darwic 
{Geological  Observations  on  Volcanic  Islands,  1844,  p.  127)  in  regard- 
ing central  volcanoes  in  general  as  volcanic  chains  of  small  extent  on 
})arallel  fissures.  Friedrich  Hoffman  believes  that  in  the  group  of  the 
Lipari  Islands,  which  he  has  so  admirably  described,  and  in  which  two 
eruption  fissures  intersect  near  Panaria,  he  has  found  an  intermediate 
link  between  the  two  principal  modes  in  which  volcanoes  appear, 
namely,  the  central  volcanoes  and  volcanic  chains  of  Von  Buch  (Pog 
gendorf,  Annalen  der  Physik,  bd.  xxvi.,  s.  81-88). 


VOLCANOES.  239 

active  volcanoes  is  always  manifested  in  the  chain  of  the  An- 
des by  the  appearance  of  certain  rocks  (as  dolerite,  melaphyre, 
trachyte,  andesite,  and  dioritic  porphyry),  which  divide  the  so- 
called  primitive  rocks,  the  transition  slates  and  sandstones,  and 
the  stratified  formations.  The  constant  recurrence  of  this 
phenomenon  convinced  me  long  since  that  these  sporadic  rocks 
were  the  seat  of  volcanic  phenomena,  and  were  connected  with 
volcanic  eruptions.  At  the  foot  of  the  grand  Tunguragua, 
near  Penipe,  on  the  banks  of  the  Rio  Puela,  I  first  distinctly 
observed  mica  slate  resting  on  granite,  broken  through  by  a 
volcanic  rock. 

In  the  volcanic  chain  of  the  New  Continent,  the  separate 
volcanoes  are  occasionally,  when  near  together,  in  mutual  de- 
pendence upon  one  another  ;  and  it  is  even  seen  that  the  vol- 
canic activity  for  centuries  together  has  moved  on  in  one  and 
the  same  direction,  as,  for  instance,  from  north  to  south  in  the 
province  of  Quito.*  The  focus  of  the  volcanic  action  lies  be- 
low the  whole  of  the  highlands  of  this  province  ;  the  only 
channels  of  communication  with  the  atmosphere  are,  howev 
er,  those  mountains  which  we  designate  by  special  names,  as 
the  mountains  of  Pichincha,  Cotopaxi,  and  Tunguragua,  and 
which,  from  their  grouping,  elevation,  and  form,  constitute  the 
grandest  and  most  picturesque  spectacle  to  be  found  in  any 
volcanic  district  of  an  equally  limited  extent.  Experience 
shows  us,  in  many  instances,  that  the  extremities  of  such 
groups  of  volcanic  chains  are  connected  together  by  subterra- 
nean communications  ;  and  this  fact  reminds  us  of  the  ancient 
and  true  expression  made  use  of  by  Seneca,!  that  the  igneous 
mountain  is  only  the  issue  of  the  more  deeply-seated  volcanic 
forces.     In  the  Mexican  highlands  a  mutual  dependence  is 

*  Humboldt,  Geognost.  Beobach,  fiber  die  Vulkane  des  Hoclilandes  von 
Quito,  ill  Poggend.,  Annul,  der  Physik,  bd.  xliv.,  s.  194. 

t  Seneca,  while  he  speaks  veiy  clearly  regarding  the  problematical 
sinking  of  iEtna,  says  in  his  79th  letter,  "  Though  this  might  happen, 
not  because  the  mountain's  height  is  lowered,  but  because  the  fires  are 
weakened,  and  do  not  blaze  out  with  their  former  vehemence  ;  and  for 
which  reason  it  is  that  such  vast  clouds  of  smoke  ai'e  not  seen  in  the 
day-time.  Yet  neither  of  these  seem  incredible,  for  the  mountain  may 
possibly  be  consumed  by  being  daily  devoured,  and  the  fire  not  be  so 
large  as  formerly,  since  it  is  not  self-generated  here,  but  is  kindled  in 
the  distant  bowels  of  the  earth,  and  there  rages,  being  fed  with  con- 
tinual fuel,  not  with  that  of  the  mountain,  through  whicla  it  only  makes 
its  passage."  The  subterrauean  communication,  "by  galleries,"  be- 
tween the  volcanoes  of  Sicily,  Lipari,  Pithecusa  (Tschia),  and  Vesuvius, 
"of  the  last  of  which  we  may  conjecture  that  it  formerly  burned  and 
presented  a  fiery  circle,"  seems  fully  understood  by  Strabo  (lib.  i.,  p. 
247  and  248).     He  terms  the  whole  district  "  sub-igneous." 


240  COSMOS, 

also  observed  to  exist  among  the  volcanic  mountains  Oriza- 
ba, Popocatepetl,  Jorullo,  and  Colima ;  and  I  have  shown* 
that  they  all  lie  in  one  direction  between  18°  59'  and  19°  12' 
north  latitude,  and  are  situated  in  a  transverse  fissure  running 
from  sea  to  sea.  The  volcano  of  Jorullo  broke  forth  on  the 
29th  of  September,  1759,  exactly  in  this  direction,  and  over 
the  same  transverse  fissure,  being  elevated  to  a  height  of  1 604 
feet  above  the  level  of  the  surrounding  plain.  The  mountain 
only  once  emitted  an  eruption  of  lava,  in  the  same  manner  as 
is  recorded  of  Mount  Epomeo  in  Ischia,  in  the  year  1302 
But  although  Jorullo,  vt^hich  is  eighty  miles  from  any  active 
volcano,  is  in  the  strict  sense  of  the  word  a  new  mountain,  it 
must  not  be  compared  vrith  Monte  Nuovo,  near  Puzzuolo, 
which  first  appeared  on  the  19th  of  September,  1538,  and  is 
rather  to  be  classed  among  craters  of  elevation.  I  believe 
that  I  have  furnished  a  more  natural  explanation  of  the  erup- 
tion of  the  Mexican  volcano,  in  comparing  its  appearance  to 
the  elevation  of  the  Hill  of  Methone,  now  Methana,  in  the 
peninsula  of  Troezene.  The  description  given  by  Strabo  and 
Pausanias  of  this  elevation,  led  one  of  the  Roman  poets,  most 
celebrated  for  his  richness  of  fancy,  to  develop  views  which 
agree  in  a  remarkable  manner  with  the  theory  of  modern 
geognosy.  "  Near  Troezene  is  a  tumulus,  steep  and  devoid  of 
trees,  once  a  plain,  now  a  mountain.  The  vapors  inclosed  in 
dark  caverns  in  vain  seek  a  passage  by  which  they  may  escape. 
The  heaving  earth,  inflated  by  the  force  of  the  compressed 
vapors,  expands  like  a  bladder  filled  with  air,  or  like  a  goat- 
skin. The  ground  has  remained  thus  inflated,  and  the  high 
projecting  eminence  has  been  solidified  by  time  into  a  naked 
rock."  Thus  picturesquely,  and,  as  analogous  phenomena 
justify  us  in  beUeving,  thus  truly  has  Ovid  described  that 
great  natural  phenomenon  which  occurred  282  years  before 
our  era,  and,  consequently,  45  years  before  the  volcanic  sepa- 
ration of  Thera  (Santorino)  and  Therasia,  between  Troezene 
and  Epidaurus,  on  the  same  spot  where  Russegger  has  found 
veins  of  trachyte.f 

*  Humboldt,  Essai  Politique  sur  la  Now.  Espagne,  t.  ii.,  p.  173-175. 
t  Ovid's  description  of  the  eruptioa  of  Methone  (Meiam.,  xv.,  p.  296 
306) : 

"  Near  Troezene  stands  a  hill,  exposed  in  air 

To  winter  winds,  of  leafy  shadows  bare  : 

This  once  was  level  ground ;  but  (strange  to  tell) 

Th'  included  vapors,  that  in  caverns  dwell, 

Laboring  with  colic  pangs,  and  close  confined, 

In  vain  sought  issue  for  the  rumbhng  wind  : 

Yet  still  they  heaved  for  vent,  and  heaving  still, 

Enlarged  the  concave  and  shot  up  the  hill, 


VOLCANOES.  241 

Santorino  is  the  most  important  of  all  the  islands  of  erup 
timt  belonging  to  volcanic  chains.*     "  It  combines  within  it 


As  breath  extends  a  bladder,  or  the  skins 
Of  goats  are  blown  t'  inclose  the  hoarded  wines  ; 
The  mountain  yet  retains  a  mountain's  face, 
And  gathered  rubbish  heads  the  hollow  space." 

Dryden's  Translation, 

This  description  of  a  dome-shaped  elevation  on  the  continent  is  of 
^reat  importance  in  a  geognostical  point  of  view,  and  coincides  to  a  re- 
markable degree  with  Aristotle's  account  {Meteor.,  ii.,  8,  17-19)  of  the 
upheaval  of  islands  of  eruption :  "  The  heaving  of  the  earth  does  not 
cease  till  the  wind  (uvsfj.og)  which  occasions  the  shocks  has  made  its 
escape  into  the  crust  of  the  earth.  It  is  not  long  ago  since  this  actually 
happened  at  Heraclea  in  Pontus,  and  a  similar  event  formerly  occurred 
at  Hiera,  one  of  the  iEolian  Islands.  A  portion  of  the  earth  swelled  up. 
and  with  loud  noise  rose  into  the  form  of  a  hill,  till  the  mighty  urging 
blast  (TTvevfia)  found  an  outlet,  and  ejected  sparks  and  ashes  which 
covered  the  neighborhood  of  Lipari,  and  even  extended  to  several 
Italian  cities."  In  this  descx-iption,  the  vesicular  distension  of  the 
earth's  crust  (a  stage  at  which  many  trachytic  mountains  have  remained) 
is  very  well  distinguished  from  the  eruption  itself.  Strabo,  lib.  i.,  p. 
59  (Casaubon),  likewise  describes  the  phenomenon  as  it  occniTed  at 
Methone :  near  the  town,  in  the  Bay  of  Hermione,  there  arose  a  flaming 
eruption;  a  fiery  mountain,  seven  (?)  stadia  in  height,  was  then  thrown 
up,  which  daring  the  day  was  inaccessible  from  its  heat  and  sulphure- 
ous stench,  but  at  night  evolved  an  agreeable  odor  (?),  and  was  so  hot 
that  the  sea  boiled  for  a  distance  of  five  stadia,  and  was  turbid  for  full 
twenty  stadia,  and  also  was  filled  with  detached  masses  of  rock.  Re- 
gai'ding  the  present  miueralogical  character  of  the  peninsula  of  Methaua, 
see  Fiedler,  Reise  durck  Griechcn/and,  th.  i.,  s.  257-263. 

*  [I  am  indebted  to  the  kindness  of  Professor  E.  Forbes  for  the  fol- 
lowing interesting  account  of  the  island  of  Santorino,  and  the  adjacent 
islands  of  Neokaimeni  and  Microkaimeui.  ''  The  aspect  of  the  bay  is 
that  of  a  great  crater  filled  with  water,  Thei-a  and  Therasia  forming  its 
walls,  and  the  other  islands  being  after-productions  in  its  center.  We 
sounded  with  250  fathoms  of  line  in  the  middle  of  the  bay,  between 
Therasia  and  the  main  islands,  but  got  no  bottom.  Both  these  islands 
appear  to  be  similarly  formed  of  successive  strata  of  volcanic  ashes, 
which,  being  of  the  most  vivid  and  variegated  colors,  present  a  striking 
contrast  to  the  black  and  ciudery  aspect  of  the  central  isles.  Neokai- 
meni, the  last-formed  island,  is  a  great  heap  of  obsidian  and  scoriae. 
So,  also,  is  the  greater  mass,  Microkaimeni,  which  rises  up  in  a  conical 
form,  and  has  a  cavity  or  crater.  On  one  side  of  this  island,  however, 
a  section  is  exposed,  and  clifis  of  fine  pumiceous  ash  appear  stratified 
in  the  greater  islands.  In  the  main  island,  the  volcanic  strata  abut 
against  the  limestone  mass  of  Mount  St.  Elias  in  such  a  way  as  to  lead 
to  the  inference  that  they  were  deposited  in  a  sea  bottom  in  which  the 
present  mountain  rose  as  a  submarine  mass  of  rock.  The  people  at 
Santorino  assured  us  that  subterranean  noises  are  not  unfrequently 
heard,  especially  during  calms  and  south  winds,  when  they  say  the 
water  of  parts  of  the  bay  becomes  the  color  of  sulphur.  My  own  im- 
pression IS,  that  this  group  of  islands  constitutes  a  crater  of  elevation, 
of  which  the  outer  ones  are  the  remains  of  the  walls,  while  the  central 
gi-oup  are  of  later  origin,  and  consist  partly  of  upheaved  sea  bottom? 

Vol.  I.— L 


24"2  COSMOS. 

self  the  history  of  all  islands  of  elevation.  For  upward  of 
2000  years,  as  far  as  history  and  tiadition  certify,  it  would 
appear  as  if  nature  were  striving  to  form  a  volcano  in  the 
midst  of  the  crater  of  elevation."*  Similar  insular  eleva- 
tions, and  almost  always  at  regular  intervals  of  80  or  90 
years,!  have  been  manifested  in  the  island  of  St.  Michael,  in 
the  Azores  ;  but  in  this  case  the  bottom  of  the  sea  has  not 
been  elevated  at  exactly  the  same  parts. $  The  island  which 
Captain  Tillard  named  Sabrina,  appeared  unfortunately  at 
a  time  (the  30th  of  January,  1811)  when  the  political  rela- 
tions of  the  maritime  nations  of  Western  Europe  prevented 
that  attention  being  bestowed  upon  the  subject  by  scientific 
institutions  wdiich  was  afterward  directed  to  the  sudden  ap- 
pearance (the  2d  of  July,  1831),  and  the  speedy  destruction  of 
the  igneous  island  of  Ferdinandea  in  the  Sicilian  Sea,  between 
the  limestone  shores  of  Sciacca  and  the  purely  volcanic  island 
of  Pantellaria.§ 

aud  partly  of  erupted  matter — erupted,  liowever,  beneath  the  surface 
of  the  water."] — Tr. 

^•Leop.  von  Buch,  Physik.  Beschr.  der  Canar.  Inseln,  s.  356-358, 
and  particularly  tlie  French  ti'anslation  of  this  excellent  \vork,  p.  402  ; 
and  his  memoir  in  Poggendorf  s   Annalen,  bd.  xxxviii.,  s.  183.     A  sub- 
marine island  has  quite  recently  made  its  appearance  within  the  crater 
of  Santorino.     In  1810  it  was  still  fifteen  fatlioms  below  the  surface  of 
the  sea,  but  in  1830  it  had  risen  to  within  three  or  four.    It  rises  steeply 
like  a  great  cone,  from  the  bottom  of  the  sea,  and  the  continuous  ac 
tivity  of  the  submarine  crater  is  obvious  from  the  circumstance  that  sul 
phurous  acid  vapors  are  mixed  with  the  sea  water,  in  the  eastern  bay 
of  Neokaimeni,  in  the  same  manner  as  at  Vromolimni,  near  Methana. 
Coppered  ships  lie  at  anchor  in  the  bay  in  order  to  get  their  bottoms 
cleaned  and  polished  by  this  natural  (volcanic)  process.     (Virlet,  in  the 
Bulletin  de  la  Soci6t6  Giologiqnc  de  France,  t.  iii.,  p.  109,  and  Fiedler. 
Reise  ditrch  Griechenland,  th.  ii.,  s.  469  and  584.) 

t  Appaarance  of  a  new  island  near  St.  Miguel,  one  of  the  Azores,  11th 
of  June,  1638,  31st  of  December,  1719,  13th  of  June,  1811. 

X  [My  esteemed  finend,  Dr.  Webster,  professor  of  Chemistry  and 
Mineralogy  at  Harvard  College,  Cambridge,  Massachusetts,  U.  S.,  in 
his  Description  of  the  Island  of  St.  Michael,  SfC,  Boston,  1822,  gives  an 
interesting  account  of  the  sudden  appearance  of  the  island  named  Sa- 
brina,  which  was  about  a  inile  in  circumference,  and  two  or  three 
hundred  feet  above  the  level  of  the  ocean.  After  continuing  for  some 
weeks,  it  sank  into  the  sea.  Dr.  Webster  describes  the  whole  of  the 
island  of  St.  Michael  as  volcanic,  and  containing  a  number  of  conical 
hills  of  trachyte,  several  of  which  have  craters,  and  appear  at  some 
former  time  to  have  been  the  openings  of  volcanoes.  The  hot  spi-ings 
which  abound  in  the  island  are  impregnated  with  sulphureted  hydro- 
gen and  carbonic  acid  gases,  appearing  to  attest  tlje  existence  of  vol- 
canic action.] — Tr. 

§  Pi-evost,  in  the  Bulletin  de  la  Societe  Giologique,  t.  iii..  j>.  04 ;  Fried. 
rich  H-'-ft'inati,  Hlnierlassp.n>^   M^ptke.  bd.  ii..  >.  4'^l-4ifi. 


VOLCANOES.  24.3 

The  geographical  distribution  of  the  volcanoes  which  have 
been  in  a  state  of  activity  during  historical  times,  the  great 
number  of  insular  and  littoral  volcanic  mountains,  and  the  oc- 
casional, although  ephemeral,  eruptions  in  the  bottom  of  the 
sea,  early  led  to  the  belief  that  volcanic  activity  was  connect- 
ed with  the  neighborhood  of  the  sea,  and  was  dependent  upon 
it  for  its  continuance.  "  For  many  hundred  years,"  says  Jus- 
tinian, or  rather  Trogus  Pompeius,  whom  he  follows,*  "  ^tna 
and  the  ^olian  Islands  have  been  burning,  and  how  could 
this  have  continued  so  long  if  the  fire  had  not  been  fed  by  the 

■  *  "  Accedunt  viciiii  et  perpetiii  iEtnae  niontis  ignes  et  insularura 
./Eoliduin,  vekiti  ipsis  undis  alatnr  iiicendium ;  neque  euim  aliter  durare 
tot  seculis  tantus  ignis  potuisset,  nisi  humoris  uutrimentis  aleretur." 
(Justin,  Hist.  Philipp.,  iv.,  i.)  The  volcanic  theory  with  which  the 
physical  description  of  Sicily  here  begins  is  extremely  intricate.  Deep 
strata  of  sulphur  and  resin ;  a  very  thin  soil  full  of  cavities  and  easily 
fissured  ;  violent  motion  of  the  w^aves  of  the  sea,  which,  as  they  strike 
together,  draw  down  the  air  (the  wind)  for  the  maintenance  of  the  fire  : 
such  are  the  elements  of  the  theory  of  Trogus.  Since  he  seems  from 
Pliny  (xi.,  52)  to  have  been  a  physiognomist,  \ve  may  presume  that  his 
numerous  lost  works  were  not  confined  to  history  alone.  The  opinion 
that  air  is  forced  into  the  interior  of  the  earth,  there  to  act  on  the  vol- 
canic furnaces,  was  connected  by  the  ancients  ^vith  the  supposed  influ- 
ence of  winds  from  different  quarters  on  the  intensity  of  the  "fires  burn- 
ing in  iEtna,  Hiera,  and  Stromboli.  (See  the  remarkable  passage  in 
Strabo,  lib.  vi.,  p.  275  and  276.)  The  mountain  island  of  Stromboli 
(Strongyle)  was  regarded,  therefore,  as  the  dwelling-place  of  ^olus, 
"the  i-egulator  of  the  winds,"  in  consequence  of  the  sailors  foretelling 
the  weather  from  the  activity  of  the  volcanic  eruptions  of  this  island. 
The  connection  between  the  eruption  of  a  small  volcano  with  the  state 
of  the  barometer  and  the  direction  of  the  wind  is  still  generally  recog- 
nized (Leop.  von  Buch,  Descr.  Phys.  des  lies  Canaries,  p.  334  ;  Hoff- 
mann, in  Poggend.,  Annalen,  bd.  xxvi.,  s.  viii.),  although  our  present 
knowledge  of  volcanic  phenomena,  and  the  slight  changes  of  atmos- 
pheric pressure  accompanying  our  winds,  do  not  enable  us  to  offer  any 
satisfactoiy  explanation  of  the  fact.  Benibo,  who  during  his  youth  was 
brought  up  in  Sicily  by  Greek  refugees,  gave  an  agreeable  narrative  of 
his  wanderings,  and  in  his  j^tiia  Dialogus  (written  in  the  middle  of 
the  sixteenth  century)  advances  the  theory  of  the  penetration  of  sea 
water  to  the  very  center  of  the  volcanic  action,  and  of  the  necessity  of 
the  proximity  of  the  sea  to  active  volcanoes.  In  ascending  iEtna  the 
following  question  was  proposed :  "  Explana  potius  nobis  quie  petimus, 
ea  incendia  unde  oriantur  et  orta  quomodo  perdurent.  In  omni  tellure 
nuspiara  majores  fistulas  aut  meatus  ampliores  sunt  quam  in  locis,  quae 
vel  mari  vicina  sunt,  vel  a  man  protinus  alluuntur :  mare  erodi^  ilia 
facillime  pergitque  in  viscera  terras.  Itaque  cum  in  aliena  regna  sibi 
viam  faciat,  ventis  etiam  facit ;  ex  quo  fit,  ut  loca  qua^que  maritima 
maxime  terrae  motibus  subjecta  sint,  parum  mediterranea.  Habes 
quum  in  sulfuris  venas  venti  furentes  inciderint,  unde  incendia  oriantur 
iEtnffi  tUce.  Vides,  quse  mare  in  radicibus  habeat,  qu.e  sulfurea  sit, 
quae  cavernosa,  qua?  a  mari  aliquando  perforata  ventos  admiserit  restu- 
antes,  per  quos  idonea  flamm:e  materies  incenderetur." 


244  COSMOS. 

neighboring  sea  ?"*  In  order  to  explain  the  necessity  of  the 
vicinity  of  the  sea,  recourse  has  been  had,  even  in  modern 
times,  to  the  hypothesis  of  the  penetration  of  sea  water  into 
the  foci  of  volcanic  agency,  that  is  to  say,  into  deep-seated 
terrestrial  strata.  When  I  collect  together  all  the  facts  that 
may  be  derived  from  my  own  observation  and  the  laborious 
researches  of  others,  it  appears  to  me  that  every  thing  in  this 
involved  investigation  depends  upon  the  questions  whether  the 
great  quantity  of  aqueous  vapors,  which  are  unquestionably 
exhaled  from  volcanoes  even  when  in  a  state  of  -rest,  be  de- 
rived from  sea  water  impregnated  with  salt,  or  rather,  perhaps, 
with  fresh  meteoric  water ;  or  whether  the  expansive  force  of 
the  vapors  (which,  at  a  depth  of  nearly  94,000  feet,  is  equal 
to  2800  atmospheres)  would  be  able  at  different  depths  to 
counterbalance  the  hydrostatic  pressure  of  the  sea,  and  thus 
afford  them,  under  certain  conditions,  a  free  access  to  the 
focus  ;t  or  whether  the  formation  of  metallic  chlorids,  the 
presence  of  chlorid  of  sodium  in  the  fissures  of  the  crater,  and 
the  frequent  mixture  of  hydrochloric  acid  with  the  aqueous 
vapors,  necessarily  imply  access  of  sea  water  ;  or,  finally, 
whether  the  repose  of  volcanoes  (either  when  temporary,  or 
permanent  and  complete)  depends  upon  the  closure  of  the 
channels  by  which  the  sea  or  meteoric  water  was  conveyed, 
or  whether  the  absence  of  flames  and  of  exhalations  of  hydrogen 
(and  sulphureted  hydrogen  gas  seems  more  characteristic  of 
solfataras  than  of  active  volcanoes)  is  not  directly  at  variance 

*  [Although  extinct  volcanoes  seem  by  no  means  confined  to  the 
neighborhood  of  the  present  seas,  being  often  scattered  over  the  most 
inland  portions  of  our  existing  continents,  yet  it  will  appear  that-,  at  the 
time  at  which  tliey  were  in  an  active  state,  the  greater  part  were  in  the 
neighborhood  either  of  the  sea,  or  of  the  extensive  salt  or  fresh  water 
lakes,  which  existed  at  that  period  over  much  of  what  is  now  dry  land. 
This  may  be  seen  either  by  refemng  to  Dr.  Boue's  map  of  Europe,  or 
to  that  published  by  Mr.  Lyell  in  the  recent  edition  of  his  Principles  of 
Geology/  (1847),  from  both  of  which  it  will  become  apparent  that,  at  a 
comparatively  recent  epoch,  those  parts  of  France,  of  Germany,  of 
Hungary,  and  of  Italy,  which  afford  evidences  of  volcanic  action  now 
extinct,  were  covered  by  the  ocean.  Daubeney  On  Volcanoes,  p.  605.] 
—  Tr. 

t  Compare  Gay-Lussac,  Sur  les  Volcans,  in  the  Annales  de  Chimie, 
t.  xxii.,  p.  427,  and  Bischof,  Wdrmelehre,  s.  272.  The  eruptions  of 
smoke  and  steam  which  have  at  different  periods  been  seen  in  Lance 
rote,  Iceland,  and  the  Kurile  Islands,  during  the  ei-uption  of  the  neigh 
boring  volcanoes,  afford  indications  of  the  I'eaction  of  volcanic  foci 
through  tense  columns  of  water ;  that  is  to  say,  these  phenomena  oc 
cur  when  the  expansive  force  of  the  vapor  exceeds  the  hydrostatic 
pressure. 


VOLCANOES.  245 

with  the  hypothesis  of  the  decomposition  of  great  masses  of 
water  ?* 

The  discussion  of  these  important  physical  questions  does 
not  come  within  the  scope  of  a  work  of  this  nature  ;  but,  while 
we  are  considering  these  phenomena,  we  would  enter  somewhat 
more  into  the  question  of  the  geographical  distribution  of  still 
active  volcanoes.  We  find,  for  instance,  that  in  the  New  World, 
three,  viz.,  Jorullo,  Popocatepetl,  and  the  volcano  of  De  la 
Fragua,  are  situated  at  the  respective  distances  of  80,  132, 
and  196  miles  from  the  sea-coast,  while  in  Central  Asia,  as 
Abel  Remusatf  first  made  known  to  geognosists,  the  Thian- 
schan  (Celestial  Mountains),  in  which  are  situated  the  lava- 
emitting  mountain  of  Pe-schan,  the  solfatara  of  Urumtsi,  and 
the  still  active  igneous  mountain  (Ho-tscheu)  of  Turfan,  lie  at 
an  almost  equal  distance  (1480  to  1528  miles)  from  the  shores 
of  the  Polar  Sea  and  those  of  the  Indian  Ocean.  Pe-schan  is 
also  fully  1360  miles  distant  from  the  Caspian  Sea,$  and  172 
and  218  miles  from  the  seas  of  Issikul  and  Balkasch.  It  is 
a  fact  worthy  of  notice,  that  among  the  four  great  parallel 
mountain  chains  which  traverse  the  Asiatic  continent  from 
east  to  west,  the  Altai,  the  Thianschan,  the  Kuen-lun,  and 
the  Himalaya,  it  is  not  the  latter  chain,  which  is  nearest  to 
the  ocean,  but  the  two  inner  ranges,  the  Thianschan  and  the 
Kuen-lun,  at  the  distance  of  1600  and  720  miles  from  the  sea, 
which  have  fire-emitting  mountains  like  JEtna,  and  Vesuvius, 
and  generate  ammonia  like  the  volcano  of  Guatimala.  Chi- 
nese writers  undoubtedly  speak  of  lava  streams  v/hen  they  de- 
scribe the  emissions  of  smoke  and  flame,  which,  issuing  from 
Pe-schan,  devastated  a  space  measuring  ten  li^  in  the  first 
and  seventh  centuries  of  our  era.  Burning  masses  of  stone 
flowed,  according  to  their  description,  "  like  thin  melted  fat." 
The  facts  that  have  been  enumerated,  and  to  which  sufficient 
attention  has  not  been  bestowed,  render  it  probable  that  the 
vicinity  of  the  sea,  and  the  penetration  of  sea  water  to  the  foci 
of  volcanoes,  are  not  absolutely  necessary  to  the  eruption  of 

*  [See  Daubeney  On  Volcanoes,  Part  iii.,  ch.  xxxvi.,  xxxviii.,  xxxix.] 
—  Tr. 

t  Abel  Remusat,  Lettre  a  M.  Cordier,  in  the  Annales  de  Chimie,  t.  w. 
p.  137. 

t  Humboldt,  Asie  Centrale,  t.  ii.,  p.  30-33,  38-52,  70-80,  and  42G-428. 
The  existence  of  active  volcanoes  in  Kordofan,  540  miles  iVoni  the  Red 
Sea,  has  been  recently  contradicted  by  Rtippell,  Reisen  in  Nubien,  1829, 
«.  151. 

$  [A  li  is  a  Chinese  measurement,  equal  to  ab;:ut  one  thirtieth  of  a 
mile.]— Tr. 


246  COSMOS. 

subterranean  fire,  and  that  littoral  situations  only  favor  the 
eruption  by  forming  the  margin  of  a  deep  sea  basin,  which, 
covered  by  strata  of  water,  and  lying  many  thousand  feet  lower 
than  the  interior  continent,  can  offer  but  an  inconsiderable 
degree  of  resistance. 

The  present  active  volcanoes,  which  communicate  by  per- 
manent craters  simultaneously  with  the  interior  of  the  earth 
and  with  the  atmosphere,  must  have  been  formed  at  a  subse- 
quent period,  when  the  upper  chalk  strata  and  all  the  tertiary 
formations  were  already  present :  this  is  shown  to  be  the  fact 
by  the  trachytic  and  basaltic  eruptions  which  frequently  form 
the  walls  of  the  crater  of  elevation.  Melaphyres  extend  to  the 
middle  tertiary  formations,  but  are  found  already  in  the  Jura 
limestone,  where  they  break  through  the  variegated  sandstone.* 
We  must  not  confound  the  earlier  outpourings  of  granite,  quartz- 
ose  porphyry,  and  euphotide  from  temporary  fissures  in  the  old 
transition  rocks  with  the  present  active  volcanic  craters. 

The  extinction  of  volcanic  activity  is  either  only  partial — 
in  which  case  the  subterranean  fire  seeks  another  passage  of 
escape  in  the  same  mountain  chain — or  it  is  total,  as  in  Au- 
vergne.  More  recent  examples  are  recorded  in  historical  times, 
of  the  total  extinction  of  the  volcano  of  Mosychlos,t  on  the 
island  sacred  to  Hephsestos  (Vulcan),  whose  "  high  wdiirling 
flames"  were  known  to  Sophocles  ;  and  of  the  volcano  of  Me- 
dina, which,  according  to  Burckhardt,  still  continued  to  pour 
out  a  stream  of  lava  on  the  2d  of  November,  1276.  Every 
stage  of  volcanic  activity,  from  its  first  origin  to  its  extinction, 
is  characterized  by  peculiar  products  ;  first  by  ignited  scoriae, 
streams  of  lava  consisting  of  trachyte,  pyroxene,  and  obsidian, 
and  by  rapilli  and  tufaceous  ashes,  accompanied  by  the  devel- 

*  Dufreuoy  et  Elie  de  Beaumont,  Explication  de  la  Carte  GSologiqne 
de  la  France,  t.  i.,p.  89. 

t  Sophocl.,  Philoct.,  V.  971  and  972.  On  the  supposed  epoch  of  the 
extinction  of  the  Lemnian  fire  in  the  time  of  Alexander,  compare  Butt- 
mann,  in  the  Mnseiim  der  AHerthumswissenschaft,  bd.  i.,  1807,  s.  295  ; 
Dureau  de  la  Malle,  in  Malte-Brun,  Annates  des  Voyages,  t.  ix.,  1809, 
p.  5  ;  Ukert,  in  Bertuch,  Geogr.  Ephemeriden,  bd.  xxxix.,  1812,  s.  361; 
Rhode,  Res  Lemnicce,  1829,  p.  8 ;  and  Walter,  Veher  Ahnahme  der  Vul- 
han.  Thiitigkeit  in  Historischen  Zeiten,  1844,  s.  24.  The  chart  of  Lem- 
nos,  constructed  by  Choiseul,  makes  it  extremely  probable  that  the  ex- 
tinct crater  of  Mosychlos,  and  the  island  of  Chryse,  the  desert  habitation 
of  Philoctetes  (Otfried  Miiller,  Minyer,  s.  300),  have  been  long  swal- 
lowed up  by  the  sea.  Reefs  and  shoals,  to  the  northeast  of  Lemnos, 
still  indicate  the  spot  whei-e  the  ^Egean  Sea  once  possessed  an  active 
volcano  like  iF,tna,  Vesuvius,  Stromboli,  and  Volcano  (in  the  Lipaii 
Isles). 


ROCKS.  247 

opment  of  large  quantities  of  pure  aqueous  vapor  ;  subsequent- 
ly, when  the  volcano  becomes  a  solfatara,  by  aqueous  vapors 
mixed  with  sulphureted  hydrogen  and  carbonic  acid  gases  ; 
and,  finally,  when  it  is  completely  cooled,  by  exhalations  of 
carbonic  acid  alone.  There  is  a  remarkable  class  of  igneous 
mountains  which  do  not  eject  lava,  but  merely  devastating 
streams  of  hot  water,*  impregnated  with  burning  sulphur  and 
rocks  reduced  to  a  state  of  dust  (as,  for  instance,  the  Galun- 
gung  in  Java) ;  but  whether  these  mountains  present  a  normal 
condition,  or  only  a  certain  transitory  modification  of  the  vol- 
canic process,  must  remain  undecided  until  they  are  visited  by 
geologists  possessed  of  a  knowledge  of  chemistry  in  its  present 
condition. 

I  have  endeavored  in  the  above  remarks  to  furnish  a  gen- 
eral description  of  volcanoes — comprising  one  of  the  most  im- 
portant sections  of  the  history  of  terrestrial  activity — and  I 
have  based  my  statements  partly  on  my  own  observations,  but 
more  in  their  general  bearin,^  on  the  results  yielded  by  the  la- 
bors of  my  old  friend,  Leopold  von  Buch,  the  greatest  geogno- 
sist  of  our  own  age,  and  the  first  who  recognized  the  intimate 
connection  of  volcanic  phenomena,  and  their  mutual  depend- 
ence upon  one  another,  considered  with  reference  to  their  rela- 
tions in  space. 

Volcanic  action,  or  the  reaction  of  the  interior  of  a  planet  on 
its  external  crust  and  surface,  was  long  regarded  only  as  an 
isolated  phenomenon,  and  was  considered  solely  with  respect 
to  the  disturbing  action  of  the  subterranean  force  ;  and  it  is 
only  in  recent  times  that — greatly  to  the  advantage  of  geog- 
nostical  views  based  on  physical  analogies — volcanic  forces 
have  been  regarded  as  forming  7iew  rocks,  and  iranforining 
those  that  already  existed.  We  here  arrive  at  the  point  to 
which  I  have  already  alluded,  at  which  a  well-grounded  study 
of  the  activity  of  volcanoes,  whether  igneous  or  merely  such 
as  emit  gaseous  exhalations,  leads  us,  on  the  one  hand,  to  the 
mineralogical  branch  of  geognosy  (the  science  of  the  texture 
and  the  succession  of  terrestrial  strata),  and,  on  the  other,  to 
the  science  of  geographical  forms  and  outlines — the  configura- 
tion of  continents  and  insular  groups  elevated  above  the  level 

*  Compare  Reiuwardt  and  Hoflfmauu,  iu  Poggendorf 's  Annalen,  bd. 
xii.,  s.  607  ;  Leop.  von  Buch,  Descr.  des  lies  Canaries,  p.  424-426.  Tiie 
eruptions  of  argillaceous  mud  at  Carguairazo,  when  that  volcano  was 
destroyed  iu  1698,  the  Lodazales  of  Igualata,  and  the  Moya  of  Pelileo 
—all  on  the  table-land  of  Quit^ — arc  volcanic  phenomena  of  a  similar 
nature. 


248  COSMOS. 

of  the  sea.  This  extended  insight  into  the  cc^  action  of  nat 
ural  phenomena  is  the  result  of  the  philosop  lical  direction 
which  has  been  so  generally  assumed  by  the  more  earnest 
study  of  geognosy.  Increased  cultivation  of  science  and  en- 
largement of  political  views  alike  tend  to  unite  elements  that 
had  long  been  divided. 

If,  instead  of  classifying  rocks  according  to  their  varieties  of 
form  and  superposition  into  stratified  and  unstratified,  schistose 
and  compact,  normal  and  abnormal,  v/e  investigate  those  phe- 
nomena of  formation  and  transformation  which  are  still  going 
on  before  our  eyes,  we  shall  find  that  rgcks  admit  of  being  ar- 
ranged according  to  four  modes  of  origin. 

Rocks  of  eruption,  which  have  issued  from  the  interior  of 
the  earth  either  in  a  state  of  fusion  from  volcanic  action,  or 
in  a  more  or  less  soft,  viscous  condition,  from  Plutonic  action. 

Sedimentary  rocks,  which  have  been  precipitated  and  de- 
posited on  the  earth's  surface  from  a  fluid,  in  which  the  most 
minute  particles  were  either  dissolved  or  held  in  suspension 
constituting  the  greater  part  of  the  secondary  (or  flotz)  and 
tertiary  groups. 

Transformed  or  raetamorphic  rocks*  in  which  the  internal 
texture  and  the  mode  of  stratification  have  been  changed,  ei- 

*  [As  the  doctriue  of  mineral  metamurphism  is  nov/  eJccitiug  veiy 
general  attention,  we  subjoin  a  few  explanatory  observations  by  the 
celebrated  Swiss  philosopher.  Professor  Stoder,  taken  from  the  Edinh. 
New  Philos.  Journ.,  Jan.,  1848:  "In  its  widest  sense,  mineral  meta- 
morphism  means  every  change  of  aggregation,  structure,  or  chemical 
condition  which  rocks  have  undergone  subsequently  to  their  deposition 
and  stratification,  or  the  effects  which  have  been  produced  by  other 
forces  than  gravity  and  cohesion.  There  fall  under  this  definition,  the 
discoloration  of  the  surface  of  black  limestone  by  the  loss  of  carbon ; 
the  formation  of  brownish-red  crusts  on  rocks  of  limestone,  sandstone, 
many  slate  stones,  serpentine,  granite,  &c.,  by  the  decomposition  of  ir(ni 
pyrites,  or  magnetic  iron,  finely  disseminated  in  the  mass  of  the  rock  ; 
the  conversion  of  anhydrite  into  gypsum,  in  consequence  of  the  absorp- 
tion of  water ;  the  crumbling  of  many  granites  and  porphyries  into 
gravel,  occasioned  by  the  decomposition  of  the  mica  and  feldspar.  In 
'ts  more  limited  sense,  the  term  metamorphic  is  confined  to  those 
changes  of  the  rock  which  are  produced,  not  by  the  effect  of  the  at- 
mosphere or  of  water  on  the  exposed  surfaces,  but  which  are  produced, 
directly  or  indirectly,  by  agencies  seated  in  the  interior  of  the  earth. 
In  many  cases  the  mode  of  change  may  be  explained  by  our  physical 
or  chemical  theories,  and  may  be  viewed  as  the  effect  of  temperature 
or  of  electro-chemical  actions.  Adjoining  rocks,  or  connecting  com- 
Hiunications  with  the  interior  of  the  earth,  also  distinctly  point  out  the 
seat  from  which  the  change  proceeds.  In  many  other  cases  the  meta- 
morphic process  itself  remains  a  mystery,  and  from  the  nature  of  the 
products  alone  do  we  conclude  that  such  a  metamorphic  action  has 
taken  place."] — Tr. 


ROCKS.  249 

ther  by  contact  or  proximity  with  a  Plutonic  or  volcanic  en- 
dogenous rock  of  eruption,*  or,  what  is  more  frequently  the 
case,  by  a  gaseous  sublimation  of  substancest  which  accom- 
pany certain  masses  erupted  in  a  hot,  fluid  condition. 

Conglomerates ;  coarse  or  finely  granular  sandstones,  or 
breccias  composed  of  mechanically-divided  masses  of  the  three 
previous  species. 

These  four  modes  of  formation — ^by  the  emission  of  volcanic 
masses,  as  narrow  lava  streams  ;  by  the  action  of  these  masses 
on  rocks  previously  hardened ;  by  mechanical  separation  or 
chemical  precipitation  from  liquids  impregnated  v/ith  carbonic 
acid  ;  and,  finally,  by  the  cementation  of  disintegrated  rocks 
of  heterogeneous  nature — are  phenomena  and  formative  pro- 
cesses which  must  merely  be  regarded  as  a  faint  reflection  of 
that  more  energetic  activity  wliich  must  have  characterized 
the  chaotic  condition  of  the  earlier  world  under  wholly  difier- 
ent  conditions  of  pressure  and  at  a  higher  temperature,  not 
only  in  the  whole  crust  of  the  earth,  but  likewise  in  the  more 

*  lu  a  plan  of  the  neighborhood  of  Tezcuco,  Totouilco,  and  Moran 
(Atlas  Giographique  et  Physique,  pi.  vii.),  which  I  originally  (1803) 
intended  for  a  woi'k  which  I  never  published,  entitled  Pasigrafia  Geog- 
nostica  destinada  al  uso  de  los  Jovenes  del  Colegio  de  Mineria  de  Mexi- 
co, I  named  (in  1832)  the  Plutonic  and  volcanic  ex'uptive  rocks  endoge- 
nous (generated  in  the  interior),  and  the  sedimentary  and  flotz  rocks 
exogenous  (or  generated  externally  on  the  surface  of  the  earth).  Pasi- 
graphically,  the  former  w^ere  designated  by  an  arrow  directed  up- 
ward f ,  and  the  latter  by  the  same  symbol  directed  downward  |. 
These  signs  have  at  least  some  advantage  over  the  ascending  lines, 
which  in  the  older  systems  represent  arbitrarily  and  ungracefully  the 
horizontally  ranged  sedimentary  strata,  and  their  penetration  through 
masses  of  basalt,  porphyry,  and  syenite.  The  names  proposed  in  the 
pasigraphico-geognostic  plan  were  borrowed  from  De  Candolle's  nomen 
clature,  in  which  endogenous  is  synonymous  with  monocotyledonous, 
and  exogenotis  with  dicotyledonous  plants.  Mohl's  more  accurate  ex- 
amination of  vegetable  tissues  has,  however,  shown  that  the  growth  of 
monocotyledons  from  w^ithin,  and  dicotyledons  from  without,  is  not 
strictly  and  generally  true  for  vegetable  orga^iisms  (Link,  Elementa 
Philosophice  Botanicce,  t.  i.,  1837,  p.  287;  Endlicher  and  Unger,  Grund- 
zuge  der  Botanik,  1843,  s.  89 ;  and  Jussieu,  TraiU  de  Botanique,  t.  i., 
p.  85).  The  rocks  which  I  have  termed  endogenous  are  characteristic- 
ally distinguished  by  Lyell,  in  his  Principles  of  Geology,  1833,  vol.  iii., 
p.  374,  as  "  nether-formed"  or  "  hypogene  rocks." 

t  Compare  Leop.  von  Buch,  Ueber  Dolom.it  als  Gehirgsart,  !t823,  s. 
36  ;  and  his  remarks  on  the  degree  of  fluidity  tp  be  ascribed  to  Plutonic 
rocks  at  the  period  of  their  eruption,  as  well  as  on  the  formation  of 
gneiss  from  schist,  through  the  action  of  granite  and  of  the  substances 
upheaved  with  it,  to  be  found  in  the  Abhandl.  der  Akad.  der  Wissen- 
»ch.  zu  Berlin  for  the  year  1842,  s.  58  und  63,  and  in  the  Jahrhucli  fui 
Wissenschaftliche  Kritik,  1840,  s.  195. 

L  2 


250  COSMOS. 

extended  atmosphere,  overloaded  with  vapors.  The  vast  fis- 
sures which  were  formerly  open  in  the  solid  crust  of  the  eartli 
have  since  been  filled  up  or  closed  by  the  protrusion  of  eleva- 
ted mountain  chains,  or  by  the  penetration  of  veins  of  rocks  of 
eruption  (granite,  porphyry,  basalt,  and  melaphyre) ;  and  while, 
on  a  superficial  area  equal  to  that  of  Europe,  there  are  now 
scarcely  more  than  four  volcanoes  remaining  through  which 
fire  and  stones  are  erupted,  the  thinner,  more  fissured,  and  un- 
stable crust  of  the  earth  was  anciently  almost  every  where 
covered  by  channels  of  communication  between  the  fused  in- 
terior and  the  external  atmosphere.  Gaseous  emanations,  ris- 
ing from  very  unequal  depths,  and  therefore  conveying  sub- 
stances difiering  in  their  chemical  nature,  imparted  greater 
activity  to  the  Plutonic  processes  of  formation  and  transform- 
ation. The  sedimentary  formations,  the  deposits  of  liquid  fluids 
from  cold  and  hot  springs,  which  we  daily  see  producing  the 
travertine  strata  near  Rome,  and  near  Hobart  Town  in  Van 
Diemen's  Land,  afibrd  but  a  faint  idea  of  the  flotz  formation. 
In  our  seas,  small  banks  of  limestone,  almost  equal  in  hardness 
at  some  parts  to  Carrara  marble,*  are  in  the  course  of  forma- 
tion, by  gradual  precipitation,  accumulation,  and  cementation 
— processes  whose  mode  of  action  has  not  been  sufficiently 
well  hivestigated.  The  Sicilian  coast,  the  island  of  Ascension, 
and  King  George's  Sound  in  Australia,  are  instances  of  this 
mode  of  formation.  On  the  coasts  of  the  Antilles,  these 
formations  of  the  present  ocean  contain  articles  of  pottery, 
and  other  objects  of  human  industry,  and  in  Guadaloupe  even 
human  skeletons  of  the  Carib  tribes. t  The  negroes  of  the 
French  colonies  designate  these  formations  by  the  name  of 
Maconne-bo?i-Dieu.t  A  small  oolitic  bed,  formed  in  Lan- 
cerote,  one  of  the  Canary  Islands,  and  which,  notwithstand- 

*  Darwin,  Volcanic  Islands,  1844,  p.  49  and  154. 

t  [In  most  instances  the  bones  are  dispersed  ;  but  a  large.slab  of  rock, 
ui  which  a  considerable  portion  of  the  skeleton  of  a  female  is  imbedded, 
is  preserved  in  the  British  Museum.  The  presence  of  these  bones  has 
been  explained  by  the  circumstance  of  a  battle,  and  the  massacre  of  a 
tribe  of  Gallibis  by  the  Caribs,  v/hich  took  place  near  the  spot  in  which 
they  are  found,  about  120  years  ago ;  for,  as  the  bodies  of  the  slain 
were  i|^terred  on  the  sea-shore,  their  skeletons  may  have  been  subse- 
quently covered  by  sand-drift,  which  has  since  consolidated  into  lime- 
stone. Dr.  Moultrie,  of  the  Medical  College,  Charleston,  South  Caro- 
liua,  U.  S.,  is,  however,  of  opinion  that  these  bones  did  not  belong  to 
individuals  of  the  Carib  tribe,  but  of  the  Peruvian  race,  or  of  a  tribe 
possessing  a  similar  craniological development.] — Tr. 

t  Moreau  de  Jonnes,  Hisf.  Phys.  des  Antilles,  t.  i.,  p.  136,  138,  and 
543;  Humboldt,  Relation  Historique,  X.  iii.,  (>.  367. 


\ 


ROCKS.  251 

ino"  its  recent  formation,  bears  a  resemblance  to  Jura  lime- 
stone,  has  been  recognized  as  a  product  of  the  sea  and  of  tem- 
pests.* 

Composite  rocks  are  definite  associations  of  certain  oryctog-- 
uustic,  simple  mmerals,  as  feldspar,  mica,  solid  silex,  ausrite, 
and  nepheline.  Rocks  very  similar  to  these,  consisting  of  the 
same  elements,  but  grouped  differently,  are  still  formed  by 
volcanic  processes,  as  in  the  earlier  periods  of  the  world.  The 
character  of  rocks,  as  we  have  already  remarked,  is  so  inde- 
pendent of  geographical  relations  of  space,!  that  the  geologist 
recognizes  with  surprise,  alike  to  the  north  or  the  south  of 
the  equator,  in  the  remotest  and  most  dissimilar  zones,  the 
familiar  aspect,  and  the  repetition  of  even  the  most  minute 
characteristics  in  the  periodic  stratification  of  the  silurian 
strata,  and  in  the  effects  of  contact  with  augitic  masses  o^' 
eruption. 

We  will  now  enter  more  fully  into  the  consideration  of  the 
four  modes  in  which  rocks  are  formed — the  four  phases  ot" 
their  formative  processes  manifested  in  the  stratified  and  uu- 
stratified  portions  of  the  earth's  surface  ;  thus,  in  the  endog- 
enous or  erupted  rocks,  designated  by  modern  geognosists  as 
compact  and  abnormal  rocks,  we  may  enumerate  the  follow- 
ing principal  groups  as  immediate  products  of  terrestrial  ac- 
tivity : 

1 .  Granite  and  syenite  of  very  different  respective  ages  ; 
the  granite  is  frequently  the  more  recent,|  traversing  the  sy- 
enite in  veins,  and  being,  in  that  case,  the  active  upheaving 
agent.  "  Where  the  granite  occurs  in  large,  insulated  masses 
of  a  faintly-arched,  ellipsoidal  form,  it- is  covered  by  a  crust  or 
shell  cleft  into  blocks,  instances  of  which  are  met  with  alike 
in  the  Hartz  district,  in  Mysore,  and  in  Lower  Peru.  This 
sea  of  rocks  probably  owes  its  origin  to  a  contraction  of  the 
surface  of  the  granite,  owing  to  the  great  expansion  that  ac- 
companied its  first  upheaval. "§ 

Both  in  Northern  Asia,  II  on  the  charming  and  romantic 
shores  of  the  Lake  of  Kolivan,  on  the  northwest  declivity  of 

*  Near  Teguiza.     Leop.  von  Buch,  Canarische  Inseln,  s.  301. 

t  Leop.  von  Buch,  op.  cit.,  p.  9. 

t  Bernhard  Cotta,  Geognosie,  1839,  8.  273. 

§  Leop.  von  Buch,  Ueber  Granit  und  Gneiss,  in  the  Abhandl.  der  Berl. 
Akad.  for  the  year  1842,  s.  60. 

II  In  the  projecting  mural  masses  of  granite  of  Lake  Kolivan,  divided 
into  narrow  parallel  beds,  there  are  numerous  crystals  of  feldspar  and 
albite,  and  a  few  of  titanium  (Humboldt,  Asie  Centrale,  t.  i.,  p.  29.0, 
Qustav  Rose.  Reisc  nncli  dcm  Ural,  bd.  i.,  s.  524). 


252  COSMOS. 

the  Altai  Mountains,  and  at  Las  Trincheras,  on  the  slope  ol 
the  littoral  chain  of  Caraccas,*  I  have  seen  granite  divided 
into  ledges,  owing  probably  to  a  similar  contraction,  although 
the  divisions  appeared  to  penetrate  far  into  the  interior.  Fur- 
ther to  the  south  of  Lake  Kolivan,  toward  the  boundaries  of 
the  Chinese  province  Hi  (between  Buchtarminsk  and  the 
River  Narym),  the  formation  of  the  erupted  rock,  in  which 
there  is  no  gneiss,  is  more  remarkable  than  I  ever  observed  in 
any  other  part  of  the  earth.  The  granite,  which  is  always 
covered  with  scales  and  characterized  by  tabular  divisions, 
rises  in  the  steppes,  either  in  small  hemispherical  eminences, 
scarcely  six  or  eight  feet  in  height,  or  like  basalt,  in  mounds, 
terminating  on  either  side  of  their  bases  in  narrow  streams.! 
At  the  cataracts  of  the  Orinoco,  as  well  as  in  the  district 
of  the  Fichtelgebirge  (Seissen),  in  Galicia,  and  between  the 
Pacific  and  the  highlands  of  Mexico  (on  the  Papagallo),  I 
have  seen  granite  in  large,  flattened  spherical  masses,  which 
could  be  divided,  like  basalt,  into  concentric  layers.  In  the 
valley  of  Irtysch,  between  Buchtarminsk  and  Ustkamenogorsk, 
granite  covers  transition  slate  for  a  space  of  four  miles,!  pen- 
etrating into  it  from  above  in  narrow,  variously  ramified, 
wedge-like  veins.  I  have  only  instanced  these  peculiarities 
in  order  to  designate  the  individual  character  of  one  of  the 
most  generally  difiused  erupted  rocks.  As  granite  is  super- 
posed on  slate  in  Siberia  and  in  the  Departement  de  Finisterre 
(Isle  de  Mihau),  so  it  covers  the  Jura  limestone  in  the  mount- 
ains of  Oisons  (Ferments),  and  syenite,  and  indirectly  also 
chalk,  in  Saxony,  near  Weinbohla.§  Near  Mursinsk,  in  the 
Uralian  district,  granite  is  of  a  drusous  character,  and  here 
the  pores,  like  the  fissures  and  cavities  of  recent  volcanic  prod- 
ucts, inclose  many  kinds  of  magnificent  crystals,  especially 
beryls  and  topazes. 

2.  Quartzose  porphyry  is  often  found  in  the  relation  of 
veins  to  other  rocks.  The  base  is  generally  a  finely  granular 
mixture  of  the  same  elements  which  occur  in  the  larger  im- 

*  Humboldt,  Relation  Historique,  t.  ii.,  p.  99. 

t  See  the  sketch  of  Bu-i-tau,  which  I  took  from  the  south  side,  where 
the  Kirghis  tents  stood,  and  which  is  given  in  Rose's  Reise,  bd.  i.,  s.  584. 
On  spheres  of  granite  scaling  off  concentrically,  see  my  Relat.  Hist.,  t. 
ii-,  p.  497,  and  Essai  Giogn.  sur  les  Gisement  des  Roches,  p.  78. 

X  Humboldt,  Asie  Centrale,  t.  i.,  p.  299-311,  and  the  di-awings  in 
Rose's  i2ee«e,  bd.  i.,  s.  611,  in  which  we  see  the  curvature  in  the  layers 
of  granite  which  Leop.  von  Buch  has  pointed  out  as  characteristic. 

§  This  remarkable  superposition  was  first  described  by  Weiss  in 
Karsten's  Archiv  fur  Bergbau  mid  Huttemcesen,  bd.  xvi.,  1827,  s.  5. 


ROCKS.  253 

bedded  crystals.     In  granitic  porphyry  that  is  very  poor  in 
quartz,  the  feldspathic  base  is  ahnost  granular  and  laminated.* 

3.  Greenstones,  Diorite,  are  granular  mixtures  oi'  white 
albite  and  blackish-green  hornblende,  forming  dioritic  porphy- 
ry when  the  crystals  are  deposited  in  a  base  of  denser  tissue. 
The  greenstones,  either  pure,  or  inclosing  laminae  of  diallage 
(as  in  the  Fichtelgebirge),  and  passing  into  serpentine,  have 
sometimes  penetrated,  in  the  form  of  strata,  into  the  old  strat- 
ified fissures  of  green  argillaceous  slate,  but  they  more  fre- 
quently traverse  the  rocks  in  veins,  or  appear  as  globular 
masses  of  greenstone,  similar  to  domes  of  basalt  and  porphyry. t 

Hij'persthene  rock  is  a  granular  mixture  of  labradorite  and 
hypersthene. 

Euphotide  and  serpentine,  containing  sometimes  crystals 
of  augite  and  uralite  instead  of  diallage,  are  thus  nearly  allied 
to  another  more  frequent,  and,  I  might  almost  say,  more  en 
ergetic  eruptive  rock — augitic  porphyry. $ 

Melaphyre,  augitic,  uralitic,  and   oligoklastic  porphyries 
To  the  last-named  species  belongs  the  genuine  verd-antique^ 
so  celebrated  in  the  arts. 

Basalt,  containing  olivine  and  constituents  which  gelatin- 
ize in  acids ;  phonolithe  (porphyritic  slate),  trachyte,  and  dol- 
erite  ;  the  fi.rst  of  these  rocks  is  only  partially,  and  the  second 
always,  divided  into  thin  laminee,  which  give  them  an  ap- 
pearance of  stratification  when  extended  over  a  large  space. 
Mesotype  and  nepheline  constitute,  according  to  Girard,  an 
important  part  in  the  composition  and  internal  texture  of  ba- 
salt. The  nepheline  contained  in  basalt  reminds  the  geog- 
nosist  both  of  the  miascite  of  the  Ilmen  Mountains  in  the 
TJral,§  which  has  been  confounded  with  granite,  and  some- 
times contains  zirconium,  and  of  the  pyroxenic  nepheline  dis- 
covered by  Gumprecht  near  Lobau  and  Chemnitz. 

To  the  second  or  sedimentary  rocks  belong  the  greater  part 
of  the  formations  which  have  been  comprised  under  the  old 

*  Dufrenoy  et  Elie  de  Beaumont,  Giologie  de  la  France,  t.  i.,  p.  130. 

t  These  intercalated  beds  of  diorite  play  an  important  part  in  the 
mountain  district  of  Nailau,  near  Steben,  where  I  was  engaged  in 
mining  operations  in  the  last  century,  and  with  which  the  happiest  as- 
sociations of  my  early  life  are  connected.  Compare  Hoffmann,  in  Pog- 
gendorf 's   Annalen,  bd.  xvi.,  s.  558. 

X  In  the  southern  and  Bashkirian  portion  of  the  Ural.  Rose,  Reise, 
bd.  ii.,  s.  171. 

$  G.  Rose,  Reise  nach  dem  Ural,  bd.  ii.,  s.  47-52.  Respecting  the 
identity  of  eleolite  and  nepheline  (the  latter  containing  rather  the  more 
lime),  see  Scheerer,  in  Poggend.,  Annalen,  bd.  xlix.,  s.  359-381. 


254  COSMOS 

Bysteniatic,  but  not  very  correct  designation  of  transition,  Jl'utz 
or  secondary,  and  tertiary  formations.  If  the  erupted  rocks 
had  not  exercised  an  elevating,  and,  owing  to  the  simultane- 
ous shock  of  the  earth,  a  disturbing  influence  on  these  sedi- 
mentary formations,  the  surface  of  our  planet  would  have 
consisted  of  strata  arranged  in  a  uniformly  horizontal  direc- 
tion above  one  another.  Deprived  of  mountain  chains,  on 
whose  declivities  the  gradations  of  vegetable  forms  and  the 
scale  of  the  diminishing  heat  of  the  atmosphere  appear  to  be 
picturesquely  reflected — furrowed  only  here  and  there  by  val- 
leys of  erosion,  formed  by  the  force  of  fresh  water  moving  on 
in  gentle  undulations,  or  by  the  accumulation  of  detritus,  re- 
sulting from  the  action  of  currents  of  water — continents  would 
have  presented  no  other  appearance  from  pole  to  pole  than 
the  dreary  uniformity  of  the  llanos  of  South  America  or  the 
steppes  of  Northern  Asia.  The  vault  of  heaven  would  every 
where  have  appeared  to  rest  on  vast  plains,  and  the  stars  to 
rise  as  if  they  emerged  from  the  depths  of  ocean.  Such  a 
condition  of  things  could  not,  however,  have  generally  pre- 
vailed for  any  length  of  time  in  the  earlier  periods  of  the 
world,  since  subterranean  forces  must  have  striven  in  all  ep- 
ochs to  exert  a  counteracting  influence. 

Sedimentary  strata  have  been  either  precipitated  or  depos- 
ited from  liquids,  according  as  the  materials  entering  into 
their  composition  are  supposed,  whether  as  limestone  or  ar- 
gillaceous slate,  to  be  either  chemically  dissolved  or  suspend- 
ed and  commingled.  But  earths,  when  dissolved  in  fluids 
impregnated  with  carbonic  acid,  must  be  regarded  as  under- 
going a  mechanical  process  while  they  are  being  precipitated, 
deposited,  and  accumulated  into  strata.  This  viev/  is  of  some 
importance  with  respect  to  the  envelopment  of  organic  bodies 
in  petrifying  calcareous  beds.  The  most  ancient  sediments 
of  the  transition  and  secondary  formations  have  probably  been 
formed  from  water  at  a  more  or  less  high  temperature,  and 
at  a  time  when  the  heat  of  the  upper  surface  of  the  earth 
was  still  very  considerable.  Considered  in  this  point  of  view, 
a  Plutonic  action  seems  to  a  certain  extent  also  to  have  taken 
place  in  the  sedimentary  strata,  especially  the  more  ancient ; 
but  these  strata  appear  to  have  been  hardened  into  a  schistose 
structure,  and  under  great  pressure,  and  not  to  have  been 
solidified  by  cooling,  like  the  rocks  that  have  issued  from  the 
interior,  as,  for  instance,  granite,  porphyry,  and  basalt.  By 
degrees,  as  the  waters  lost  their  temperature,  and  were  able 
to  absorb  a  copious  supply  of  the  carbonic  acid  gas  with  w^hich 


ROCKS.  255 

the  atmosphere  was  overcharged,  they  became  fitted  to  hold 
m  solution  a  larger  quantity  ol'  lime. 

Tlte  sedimentary  strata,  setting  aside  all  other  exogenous, 
purely  mechanical  deposits  of  sand  or  detritus,  are  as  follows  : 

ScJiist,  of  the  lower  and  upper  transition  rock,  composing 
the  Silurian  and  devonian  formations  ;  from  the  lower  silurian 
strata,  which  were  once  termed  cambrian,  to  the  upper  strata 
of  the  old  red  sandstone  or  devonian  formation,  immediately 
in  contact  with  the  mountain  limestone. 

Carboniferous  deposits : 

Limestones  imbedded  in  the  transition  and  carboniferous 
formations ;  zechstein,  muschelkalk.  Jura  formation  and  chalk, 
also  that  portion  of  the  tertiary  formation  which  is  not  includ- 
ed in  sandstone  and  conglomerate. 

Travertine,  fresh-water  limestone,  and  silicious  concretions 
of  hot  springs,  formations  which  have  not  been  produced  un- 
der the  pressure  of  a  large  body  of  sea  water,  but  almost  in 
immediate  contact  with  the  atmosphere,  as  in  shallow  marsh- 
es and  streams. 

Infusorial  dejjosits  :  geognostical  phenomena,  whose  great 
importance  in  proving  the  influence  of  organic  activity  in  the 
formation  of  the  solid  part  of  the  earth's  crust  was  first  dis- 
covered at  a  recent  period  by  my  highly-gifted  friend  and  fel- 
low-traveler, Ehrenberg. 

If,  in  this  short  and  superficial  view  of  the  mineral  con- 
stituents of  the  earth's  crust,  I  do  not  place  immediately  after 
the  simple  sedimentary  rocks  the  conglomerates  and  sandstone 
formations  which  have  also  been  deposited  as  sedimentary 
strata  from  liquids,  and  which  have  been  imbedded  alternate- 
ly with  schist  and  limestone,  it  is  only  because  they  contain, 
together  with  the  detritus  of  eruptive  and  sedimentary  rocks, 
also  the  detritus  of  gneiss,  mica  slate,  and  other  metamorphic 
masses.  The  obscure  process  of  this  metamorphism,  and  the 
action  it  produces,  must  therefore  compose  the  third  class  of 
the  fundamental  forms  of  rock. 

Endogenous  or  erupted  rocks  (granite,  porphyry,  and  mela- 
phyre)  produce,  as  I  have  already  frequently  remarked,  not 
only  dynamical,  shaking,  upheaving  actions,  either  vertically 
or  laterally  displacing  the  strata,  but  they  also  occasion  chang- 
es in  their  chemical  composition  as  well  as  in  the  nature  of 
their  internal  structure  ;  new  rocks  being  thus  formed,  as 
gneiss,  mica  slate,  and  granular  limestone  (Carrara  and  Pa- 
rian marble).  The  old  silurian  or  devonian  transition  schists, 
the  belemnitic  limestone  of  Tarantaise,  and  the  dull  gray  cal 


256  COSMOS. 

careous  sandstone  (Macig7io),  which  contains  algsB  found  in 
the  northern  Apennines,  often  assume  a  new  and  more  brill- 
iant appearance  after  their  metamorphosis,  which  renders  il 
difficult  to  recognize  them.  The  theory  of  metamorphism 
was  not  established  until  the  individual  phases  of  the  change 
were  followed  step  by  step,  and  direct  chemical  experimenta 
on  the  difference  in  the  fusion  point,  in  the  pressure  and  time 
of  cooling,  were  brought  in  aid  of  mere  inductive  conclusions. 
Where  the  study  of  chemical  combinations  is  regulated  by 
leading  ideas,*  it  may  be  the  means  of  throwing  a  clear  light 
on  the  wide  field  of  geognosy,  and  over  the  vast  laboratory  of 
nature  in  which  rocks  are  continually  being  formed  and  mod- 
ified by  the  agency  of  subterranean  forces.  The  philosophical 
inquirer  will  escape  the  deception  of  apparent  analogies,  and 
the  danger  of  being  led  astray  by  a  narrow  view  of  natural 
phenomena,  if  he  constantly  bear  in  view  the  complicated 
conditions  which  may,  by  the  intensity  of  their  force,  have 
modified  the  counteracting  effect  of  those  individual  substan 
ces  whose  nature  is  better  known  to  us.  Simple  bodies  have, 
no  doubt,  at  all  periods,  obeyed  the  same  laws  of  attraction, 
and,  wherever  apparent  contradictions  present  themselves,  T 
am  confident  that  chemistry  will  in  most  cases  be  able  to 
trace  the  cause  to  some  corresponding  error  in  the  experiment. 
Observations  made  with  extreme  accuracy  over  large  tracts 
of  land,  show  that  erupted  rocks  have  not  been  produced  in  an 
irregular  and  unsystematic  manner.  In  parts  of  the  globe  most 
remote  from  one  another,  we  often  find  that  granite,  basalt,  and 
diorite  have  exercised  a  regular  arid  uniform  metamorphic  ac- 
tion, even  in  the  minutest  details,  on  the  strata  of  arjjillaceous 
slate,  dense  limestone,  and  the  grains  of  quartz  in  sandstones. 
As  the  same  endogenous  rock  manifests  almost  every  where  the 
same  degree  of  activity,  so,  on  the  contrary,  different  rocks  be- 
longing to  the  same  class,  whether  to  the  endogoiious  or  the 
erupted,  exhibit  great  differences  in  their  character.  Intense 
heat  has  undoubtedly  influenced  all  these  phenomena,  but  the 
degree  of  fluidity  (the  more  or  less  perfect  mobility  of  the  parti- 
cles— their  more  viscous  composition)  has  varied  very  consid- 
erably from  the  granite  to  the  basalt,  while  at  different  geo- 

*  See  the  admirable  researches  of  Mitscherlich,  in  the  Ahhandl.  dei 
Berl.  Akad.  for  the  years  1822  and  1823,  s.  25-41 ;  and  in  Poggend., 
Annalm,  bd.  x.,  s.  137-152;  bd.  xi.,  a.  323-332;  bd.  xli.,  s.  21^3-21^ 
(Gustav  Rose,  Ueher  Bildung  des  Kalkspaths  U7id  Aragonits,  iu  Pog- 
gend ,  Annalen,  bd.  xli.,  s,  353-366 ;  Huidinger,  in  the  Transactions 
tfthe  Royal  Society  of  Edinburgh,  1827,  p.  148.) 


ROCKS.  257 

iogical  periods  (or  metamorphic  phases  of  the  earth's  crust) 
other  substances  dissolved  in  vapors  have  issued  from  the  in- 
terior of  the  earth  simultaneously  with  the  eruption  of  granite, 
basalt,  greenstone  porphyry,  and  serpentine.  This  seems  a 
fitting  place  again  to  draw  attention  to  the  fact  that,  accord- 
ing to  the  admirable  views  of  modern  geognosy,  the  meta- 
morphism  of  rocks  is  not  a  mere  phenomenon  of  contact,  limit- 
ed to  the  effect  produced  by  the  apposition  of  two  rocks,  since 
it  comprehends  all  the  generic  phenomena  that  have  accom- 
panied the  appearance  of  a  particular  ei^pted  mass.  Even 
where  there  is  no  immediate  contact,  the  proximity  of  such  a 
mass  gives  rise  to  modifications  of  solidification,  cohesion,  gran- 
ulation, and  crystallization. 

All  eruptive  rocks  penetrate,  as  ramifying  veins,  either  into 
the  sedimentary  strata,  or  into  other  equally  endogenous  mass- 
es ;  but  there  is  a  special  importance  to  be  attached  to  the 
difference  manifested  between  Plutonic  rocks*  (granite,  por- 
ph}Ty,  and  serpentine)  and  those  termed  volcanic  in  the  strict 
sense  of  the  word  (as  trachyte,  basalt,  and  lava).  The  rocks 
produced  by  the  activity  of  our  present  volcanoes  appear  as 
band-like  streams,  but  by  the  confluence  of  several  of  them 
they  may  form  an  extended  basin.  Wherever  it  has  been 
possible  to  trace  basaltic  eruptions,  they  have  generally  been 
found  to  terminate  in  slender  threads.  Examples  of  these 
narrow  openings  may  be  found  in  three  places  in  Germany  : 
in  the  "  Pjlaster-kaute,''  at  Marksuhl,  eight  miles  from  Ei- 
senach ;  in  the  blue  "  Kuppe,''  near  Eschwege,  on  the  banks 
of  the  Werra  ;  and  in  the  Druidical  stone  on  the  Hollert  road 
(Siegen),  where  the  basalt  has  broken  through  the  variegated 
sandstone  and  gray  wacke  slate,  and  has  spread  itself  into  cup- 
like fungoid  enlargements,  which  are  either  grouped  together 
like  rows  of  columns,  or  are  sometimes  stratified  in  thin  1am- 
inse.  The  case  is  otherwise  with  granite,  syenite,  quartzose 
porphyry,  serpentine,  and  the  whole  series  of  unstratified  com- 
pact rocks,  to  which,  from  a  predilection  for  a  mythological 
nomenclature,  the  term  Plutonic  has  been  applied.  These, 
with  the  exception  of  occasional  veins,  were  probably  not 
erupted  in  a  state  of  fusion,  but  merely  in  a  softened  condi- 
tion ;  not  from  narrow  fissures,  but  from  long  and  widely-ex- 
tending gorges.  They  have  been  protruded,  but  have  not 
flowed  forth,  and  are  found,  not  in  streams  like  lava,  but  in 
extended  masses.!     Some  groups  of  dolerite  and  trachyte  in- 

*  [Lyell,  Principles  of  Geology,  vol.  i.i.,  p.  353  aud  359.] — Tr 

t  The  desciiptiou  here  given  of  the  relations  of  position  under  which 


'^58  COSMOS. 

dicate  a  certain  degree  of  basaltic  fluidity  ;  others,  which  iiavu 
been  expanded  into  vast  craterless  domes,  appear  to  have  been 
only  in  a  softened  condition  at  the  time  of  their  elevation. 
Other  trachytes,  like  those  of  the  Andes,  in  which  I  have  fre- 
quently perceived  a  striking  analogy  with  the  greenstones  and 
syenitic  porphyries  (which  are  argentiferous,  and  without 
quartz),  are  deposited  in  the  same  manner  as  granite  and 
quartzose  porphyry. 

Experiments  on  the  changes  which  the  texture  and  chem- 
ical constitution  of  rocks  experience  from  the  action  of  heat, 
have  shown  that  volcanic  masses*  (diorite,  augitic  porphyry, 
basalt,  and  the  lava  of  ^tna)  yield  different  products,  accord- 
ing to  the  difference  of  the  pressure  under  which  they  have 
been  fused,  and  the  length  of  time  occupied  during  their  cool- 
ing ;  thus,  where  the  cooling  was  rapid,  they  form  a  black 
glass,  having  a  homogeneous  fracture,  and  where  the  cooling 
was  slow,  a  stony  mass  of  granular  crystalline  structure.  In 
the  latter  case,  the  crystals  are  formed  partly  in  cavities  and 
partly  inclosed  in  the  matrix.  The  same  materials  yield  the 
most  dissimilar  products,  a  fact  that  is  of  the  greatest  import- 
ance in  reference  to  the  study  of  the  nature  of  erupted  rocks,  and 
of  the  metamorphic  action  which  they  occasion.  Carbonate  of 
lime,  when  fused  under  great  pressure,  does  not  lose  its  carbonic 
acid,  but  becomes,  when  cooled,  granular  limestone  ;  when 
the  crystallization  has  been  effected  by  the  dry  method,  sac- 
charoidal  marble  ;  while  by  the  humid  method,  calcareous 
spar  and  aragonite  are  produced,  the  former  under  a  lesser  de- 
gree of  temperature  than  the  latter. f  Differences  of  temper- 
granite  occurs,  expresses  the  geiieral  or  leading  character  of  the  whole 
fonnatiou.  But  its  aspect  at  some  places  leads  to  the  belief  that  it  was 
occasionally  more  fluid  at  the  period  of  its  eruption.  The  description 
given  by  Rose,  in  his  Reise  nach  dem  Ural,  bd.  i.,  s.  599,  of  part  of  the 
Narym  chain,  near  the  frontiers  of  the  Chinese  territories,  as  well  as  the 
evidence  afforded  by  trachyte,  as  described  by  Dufrenoy  and  Elie  de 
Beaumont,  in  their  Description  Giologique  de  la  France,  t.  i.,  p.  70. 
Having  already  spoken  in  the  text  of  the  narrow  apertures  through 
which  the  basalts  have  sometimes  been  effused,  I  will  here  notice  the 
large  fissures,  which  have  acted  as  conducting  passages  for  melaphyres, 
which  must  not  be  confounded  with  basalts.  See  Murchison's  inter- 
esting account  (  The  Silurian  System,  p.  126)  of  a  fissure  480  feet  wide, 
through  which  melaphyre  has  been  ejected,  at  the  coal-mine  at  Corn- 
brook,  Hoar  Edge. 

*  Sir  James  Hall,  in  the  Edin.  Trans.,  vol.  v.,  p.  43,  and  vol.  vi.,  p. 
71;  Gregory  Watt,  in  the  Phil.  Trans,  of  the  Roy.  Soc.  of  London  for 
1804,  Part  ii.,  p.  279  ;  Dartigues  and  Fleurieu  de  Bellevue,  in  the  Jour- 
nal de  Physique,  t.  Ix,,  p.  456;  Biscliof,  Wurmelchre,  s.  313  und  443. 

t  Gustav  R.)se,  in  ]';)u';-'-ij(l.,  Aannl'-n,  Ik!    xlii.,  i"   3o4, 


ROCKS.  259 

ftxure  likewise  modify  the  direction  in  which  the  diilerent  par- 
ticles arrange  themselves  in  the  act  of  crj'staliization,  and  also 
atlect  the  form  of  the  crystal.*  Even  when  a  body  is  not  in 
a  fluid  condition,  the  smallest  particles  may  undergo  certain 
relations  in  their  various  modes  of  arrangement,  which  are 
manifested  by  the  different  action  on  light. t  The  phenome- 
na presented  by  devitrification,  and  by  the  formation  of  steel 
by  cementation  and  casting — the  transition  of  the  fibrous  into 
the  granular  tissue  of  the  iron,  from  the  action  of  heat,$  and 
probably,  also,  by  regular  and  long-continued  concussions — 
likewise  throw  a  considerable  deo-ree  of  lisfht  on  the  gfcolooical 
process  of  metamorphism.  Heat  may  even  simultaneously  in- 
duce opposite  actions  in  crystalline  bodies  ;  for  the  admirable 
experiments  of  Mitscherlich  have  established  the  facts^  that 
calcareous  spar,  without  altering  its  condition  of  aggregation, 
expands  in  the  direction  of  one  of  its  axes  and  contracts  in 
the  other. 

If  we  pass  from  these  general  considerations  to  individual 
examples,  we  find  that  schist  is  converted,  by  the  vicinity  of 
Plutonic  erupted  rocks,  into  a  bluish-black,  glistening  roofing 
slate.  Here  the  planes  of  stratification  are  intersected  by  an- 
other system  of  divisional  stratification,  almost  at  right  ano'les 
with  the  former, ii  and  thus  indicating  an  action  subsequent  to 
the  alteration.  The  penetration  of  silica  causes  the  argilla- 
ceous schist  to  be  traversed  by  quartz,  transforming  it,  in  part, 
into  whetstone  and  silicious  schist ;  the  latter  sometimes  con- 
taining carbon,  and  being  then  capable  of  producing  galvanic 
effects  on  the  nerves.  The  highest  degree  of  silicification  of 
schist  is  that  observed  in  ribbon  jasper,  a  material  highly  val- 
uable in  the  arts, If  and  which  is  produced  in  the  Ourai  Mount- 

*  On  the  dimorphism  of  sulphur,  see  Mitscherhch,  Lehrhuch  der 
Chemie,  $  55-G3. 

t  On  gypsum  as  a  uniaxal  crystal,  and  on  the  sulphate  of  magnesia, 
and  the  oxyds  of  zinc  and  nickel,  see  Mitscherlich,  in  Poggend..  Anna- 
len,  bd.  xi.,  s.  328. 

X  Coste,  Versuche  am  Creusot  uber  das  hruchig  werden  des  Staheisens. 
Elie  de  Beaumont,  Mem.  Geol.,  t.  ii.,  p.  411. 

§  Mitscherlich,  Ueber  die  Ausdehniing  der  Krystallisirten  Kurper  durch 
die   Wdrmelehre,  in  Poggend.,  Annalen,  bd.  x.,  s.  151. 

II  On  the  double  system  of  divisional  planes,  see  Elie  de  Beauniijut, 
Geologic  de  la  France,  p.  41 ;  Credner,  Geognosie  Thuringens  und  dcs 
Harzes,  s.  40;  and  Ronier,  Das  Rheinische  Uehergangsgebirge.  1844, 
s.  5  nnd  9. 

^  The  t;ilica  is  not  merely  colored  by  peroxyd  of  iron,  but  is  accom- 
panied by  clay,  lime,  and  potash.  Ro.-^e,  Rcise,  bd.  ii..  s.  187.  On  llie 
lormalion  of  jasper  by  llic  acti.Mi  wf  dioriiic  porphyry,  angilo,  and  hy 


260  COSMOS. 

ains  by  the  contact  and  eruption  of  augitic  porphyry  (at  Orsk), 
of  dioritic  porphyry  (at  Aufschkul),  or  of  a  mass  of  hyper- 
sthenic rock  conglomerated  into  spherical  masses  (at  Bogos- 
lowsk).  At  Monte  Serrato,  in  the  island  of  Elba,  according 
to  Frederic  Hoffman,  and  in  Tuscany,  according  to  Alexander 
Brongniart,  it  is  formed  by  contact  with  euphotide  and  ser- 
pentine. 

The  contact  and  Plutonic  action  of  granite  have  sometimes 
made  argillaceous  schist  granular,  as  was  observed  by  Gustav 
Rose  and  myself  in  the  Altai  Mountains  (within  the  fortress 
of  Buchtarminsk),^  and  have  transformed  it  into  a  mass  re- 
sembling granite,  consisting  of  a  mixture  of  feldspar  and  mica, 
in  which  larger  laminae  of  the  latter  were  again  imbedded. ■'■ 
Most  geognosists  adhere,  with  Leopold  von  Buch,  to  the  well- 
known  hypothesis  "  that  all  the  gneiss  in  the  silnrian  strata  of 
the  transition  formation,  between  the  Icy  Sea  and  the  Gulf  of 
Finland,  has  been  produced  by  the  metamorphic  action  of 
granite.!  In  the  Alps,  at  St.  Gothard,  calcareous  marl  is 
likewise  changed  from  granite  into  mica  slate,  and  then  trans- 
formed into  gneiss."  Similar  phenomena  of  the  formation  of 
gneiss  and  mica  slate  through  granite  present  themselves  in 
the  oolitic  group  of  the  Tarantaise,§  in  which  belemnites  are 

perslliene  rock,  see  Rose,  bd.  ii.,  s.  IG9,  187,  uud  192.  See,  also,  bd. 
i.,  s.  427,  where  there  is  a  drawing  of  the  porphyry  spheres  between 
which  jasper  occurs,  in  the  calcareous  graywacke  of  Bogoslowsk,  being 
prodaced  by  the  Plutonic  influence  of  the  augitic  rock;  bd.  ii.,  s.  54-5; 
and  likewise  Humboldt,  Asie  Centrale,  t.  i.,  p.  486. 

*  Rose,  Reise  nacli  dem  Ural,  bd.  i.,  s.  580-588. 

t  In  respect  to  the  volcanic  origin  of  mica,  it  is  important  to  notice 
that  ciystals  of  mica  are  found  in  the  basalt  of  the  Bohemian  Mittelge- 
birge,  in  the  lava  that  in  1822  was  ejected  from  Vesuvius  (Monticelli, 
Storia  del  Vesuvio  negli  Anni  1821  e  1822,  §  99),  and  in  fragments  of 
argillaceous  slate  imbedded  in  scoriaceous  basalt  at  Hohenfels,  not  far 
from  Gerolstein,  in  the  Eifel  (see  Mitscherlich,  in  Leonhard,  Basali- 
Gehilde,  s.  244).  On  the  formation  of  feldspar  in  argillaceous  schist, 
through  contact  with  porphyiy,  occurring  between  Urval  and  Poi'et 
(Forez),  see  Dufreuoy,  in  6*1^0^.  de  la  France,  t.  i.,  p.  137.  It  is  proba- 
bly to  a  similar  contact  that  certain  schists  near  Paimpol,  in  Brittany, 
with  vi'hose  appearance  I  was  much  struck,  while  making  a  geological 
pedestrian  tour  through  that  interesting  country  with  Professor  Kunth, 
owe  their  amygdaloid  and  cellular  character,  t.  i.,  p.  234. 

X  Leopold  von  Buch,  in  the  Abhandlungen  der  Akad.  der  Wissen- 
schaft  zu  Berlin,  aus  dem  JaJir  1842,  s.  63,  and  in  the  JahrMichern  fur 
Wissenschaftliche  Krilik  Jahrg.  1840,  s.  196. 

$  Elie  de  Bea^lmont,  in  the  Annales  des  Sciences  Naiurelles,  t.  xv.,  p. 
362-372.  "  In  approaching  the  primitive  masses  of  Mont  Rosa,  and  the 
mountains  situated  to  the  west  of  Coni,  we  pei'ceive  that  the  secondary 
Btrata  gradually  lose  the  characters  inherent  in  their  mode  of  deposition. 
Frequently  assuming  a  character  apparently  arising  from  a  perfectly 


ROCKS.  201 

found  in  rocks,  which  have  some  claim  to  be  considered  as 
mica  slate,  and  in  the  schistose  group  in  the  western  part  of 
the  island  of  Elba,  near  the  promontory  of  Calamita,  and  the 
Fichtelgebirge  in  Baireuth,  between  Lomitz  and  Markleiten.* 
Jasper,  which,!  as  I  have  already  remarked,  is  a  production 
formed  by  the  volcanic  action  of  augitic  porphyry,  could  only 
be  obtained  in  small  quantities  by  the  ancients,  while  another 
material,  very  generally  and  efficiently  used  by  them  in  the 
arts,  was  granular  or  saccharoidal  marble,  which  is  likewise 
to  be  regarded  solely  as  a  sedimentary  stratum  altered  by  ter- 
restrial heat  and  by  proximity  with  erupted  rocks.  This  opin- 
ion is  corroborated  by  the  accurate  observations  on  the  phe- 
nomena of  contact,  by  the  remarkable  experiments  on  fusion 

distinct  cause,  but  not  losing  their  stratification,  tliey  somewhat  resem- 
ble in  their  physical  structure  a  biaud  of  half-consumed  wood,  in  which 
we  can  follow  the  traces  of  the  ligneous  fibers  beyond  the  spots  which 
continue  to  present  the  natural  characters  of  wood."  (See,  also,  the 
Annates  des  Sciences  Naturclles,  t.  xiv.,  p.  118-122,  and  von  Dechen, 
Geognosie,  s.  553.)  Among  the  most  striking  proofs  of  the  transforma- 
tion of  rocks  by  Plutonic  action,  we  must  place  the  belemnites  in  the 
Bchists  of  Nufibnen  (in  the  Alpine  valley  of  Eginen  and  in  the  Gries- 
glaciers),  ani^the  belemnites  found  by  M.  Charpentier  in  the  so-called 
primitive  limestone  on  the  western  descent  of  the  Col  de  la  Seigne,  be- 
tween the  Enclove  de  Monjovet  and  the  chdlet  of  La  Lanchette,  and 
which  he  showed  to  me  at  Bex  in  the  autumn  of  1822  {Annales  de 
Chimie,  t.  xxiii.,  p.  262). 

*  Hoffmann,  in  Poggend.,  AnnaJen,  bd.  xvi.,  s.  552,  "  Strata  of  tran 
sition  argillaceous  schist  in  the  Fichtelgebirge,  which  can  be  traced  for 
a  length  of  16  miles,  are  transformed  into  gneiss  only  at  the  two  ex- 
tremities, where  they  come  in  contact  with  granite.  We  can  there 
follow  the  gradual  formation  of  the  gneiss,  and  the  development  of  the 
mica  and  of  the  feldspathic  amygdaloids,  in  the  interior  of  the  argilla- 
ceous schist,  which  indeed  contains  in  itself  almost  all  the  elements  of 
these  substances." 

t  Among  the  works  of  art  which  have  come  down  to  us  from  the  an 
cient  Greeks  and  Romans,  we  observe  that  none  of  any  size — as  columns 
or  large  vases — are  formed  from  jasper;  and  even  at  the  present  day, 
this  substance,  in  large  masses,  is  only  obtained  from  the  Ural  Mountains. 
The  material  worked  as  jasper  from  the  Rhubarb  Mountain  (Raveniaga 
Sopka),  in  Altai,  is  a  beautiful  ribboned  poi-phyry.  The  word  jasper 
is  derived  from  the  Semitic  languages ;  and  from  the  confused  descrip- 
tions of  Theophrastus  (De  Lapidibus,  23  and  27)  and  PUuy  (xxxvii.,  8 
and  9),  who  rank  jasper  among  the  "  opaque  gems,"  the  name  appears 
to  have  been  given  to  fragments  of  jaspachat,  and  to  a  substance  which 
the  ancients  termed  jasponyx,  which  we  now  know  as  opal-jasper. 
Pliny  considers  a  piece  of  jasper  eleven  inches  in  length  so  rare  as  to 
require  his  mentioning  that  he  had  actually  seen  such  a  specimen : 
"  Magnitudinem  jaspidis  undecim  unciarum  vidimus,  formataiuque  iude 
effigiem  Neronis  thoracatam."  According  to  Theophrastus,  the  stone 
which  he  calls  emerald,  and  from  which  large  obelisks  were  cut,  must 
have  been  an  imperfect  jasper. 


262  COSMOS. 

made  by  Sir  James  Hall  more  than  half  a  century  ago,  and 
by  the  attentive  study  of  granitic  veins,  which  has  contributed 
so  largely  to  the  establishment  of  modern  geognosy.  Some- 
times the  erupted  rock  has  not  transformed  the  compact  into 
granular  limestone  to  any  great  depth  from  the  point  of  con- 
tact. Thus,  for  instance,  we  meet  with  a  slight  transforma- 
tion— a  penumbra — as  at  Belfast,  in  Ireland,  where  the  ba* 
saltic  veins  traverse  the  chalk,  and,  as  in  the  compact  cal- 
careous beds,  which  have  been  partially  inflected  by  the  con- 
tact of  syenitic  granite,  at  the  Bridge  of  Boscampo  and  the 
Cascade  of  Conzocoli,  in  the  Tyrol  (rendered  celebrated  by 
the  mention  made  of  it  by  Count  Mazari  Pcucati).*  Another 
mode  of  transformation  occurs  where  all  the  strata  of  the  com- 
pact limestone  have  been  changed  into  granular  hmestone  by 
the  action  of  granite,  and  syenitic  or  dioritic  porphyry. f 

I  would  here  wish  to  make  special  mention  of  Parian  and 
Carrara  marbles,  which  have  acquired  such,  celebrity  from  the 
noble  works  of  art  into  which  they  have  been  converted,  and 
which  have  too  long  been  considered  in  our  geognostic  collec- 
tions as  the  main  types  of  primitive  limestone.  The  action 
of  granite  has  been  manifested  sometimes  by  immediate  con- 
tact, as  in  the  Pyrenees,^  and  sometimes,  as  in  the  main  land 
of  Greece,  and  in  the  insular  groups  in  the  ^Egean  Sea,  through 
the  intermediate  layers  of  gneiss  or  mica  slate.  Both  cases 
presuppose  a  simultaneous  but  heterogeneous  process  of  trans 

*  Humboldt,  Leitre  a  M.  Brochant  de  Villiers,  in  the  Annales  dc 
Chimie  et  de  Physique,  t.  xxiii.,  p.  261 ;  Leop.  voii  Buch,  Geog.  Brief e 
iiber  das  sudliche  Tyrol,  s.  101,  105,  iind  273. 

t  On  the  transformation  of  compact  into  granular  limestone  by  the 
action  of  granite,  in  the  Pyrenees  at  the  Montagnes  de  Rancie,  see 
Dufrenoy,  in  the  M^moires  Gdologiques,  t.  ii.,  p.  440  ;  and  on  similai 
changes  in  the  Montagues  de  VOisans,  see  Elie  de  Beaumont,  in  ihe 
Mem.  G6olog.,  t.  ii.,  p.  379-415;  on  a  similar  effect  produced  by  the 
action  of  dioritic  and  pyroxenic  porphyry  (the  ophite  described  by  Elie 
de  Beaumont,  in  the  G6ologie  de  la  France,  t.  i.,  p.  72),  between  Tulosa 
and  St.  Sebastian,  see  Dufrenoy,  in  ihe  M6m.  Giolog.,  t.  ii.,  p.  130;  and 
by  syenite  in  the  Isle  of  Skye,  where  the  fossils  in  the  altered  limesloue 
may  still  be  distinguished,  see  Von  Dechen,  in  his  G6ognosie,  p.  573. 
In  the  transformation  of  chalk  by  contact  with  basalt,  the  transposition 
of  the  most  minute  particles  in  the  processes  of  crystallization  and 
granulation  is  the  more  remarkable,  because  the  excellent  microscopic 
investigations  of  Ehrenberg  have  shown  that  the  particles  of  chalk  pre- 
viously existed  in  the  form  of  closed  rings.  See  Poggend.,  Annalen  der 
Physik,  bd.  xxxix.,  s.  105;  and  on  the  rings  of  aragonite  deposiled 
from  solution,  see  Gustav  Rose  in  vol.  xlii.,  p.  354,  of  the  same  journal. 

X  Beds  of  granular  limestone  in  the  granite  at  Port  d'Oo  and  in  the 
Mont  de  Labourd.  See  Charpentier,  Constittition  Geologiqve  des  PyrA- 
nies,  p.  144,  ]  46. 


KOCKS.  263 

formation.  In  Attica,  in  the  island  of  Eubcea,  and  in  the 
Peloponnesus,  it  has  been  remarked,  "  that  the  limestone, 
when  superposed  on  mica  slate,  is  beautiful  and  crystalline  in 
proportion  to  the  purity  of  the  latter  substance  and  to  the 
smallness  of  its  argillaceous  contents  ;  and,  as  is  well  known, 
this  rock,  together  with  beds  of  gneiss,  appears  at  many  points, 
at  a  considerable  depth  below  the  surface,  in  the  islands  of 
Paros  and  Antiparos."*  We  may  here  infer  the  existence  of 
an  imperfectly  metamorphosed  flotz  formation,  if  faith  can  be 
yielded  to  the  testimony  of  Origen,  according  to  whom,  the 
ancient  Eleatic,  Xenophanes  of  Colophont  (who  supposed  the 
whole  earth's  crust  to  have  been  once  covered  by  the  sea),  de- 
clared that  marine  fossils  had  been  found  in  the  quarries  of 
Syracuse,  and  the  impression  of  a  fish  (a  sardine)  in  the  deepest 
rocks  of  Paros.  The  Carrara  or  Luna  marble  quarries,  which 
constituted  the  principal  source  from  which  statuary  marble 
was  derived  even  prior  to  the  time  of  Augustus,  and  which 
will  probably  continue  to  do  so  until  the  quarries  of  Paros 
shall  be  reopened,  are  beds  of  calcareous  sandstone — macigno 
— altered  by  Plutonic  action,  and  occurring  in  the  insulated 
mountain  of  Apuana,  between  gneiss-like  mica  and  talcose 
schist. I  Whether  at  some  points  granular  limestone  may 
not  have  been  formed  in  the  interior  of  the  earth,  and  been 
raised  by  gneiss  and  syenite  to  the  surface,  where  it  forms 
vein-like  fissures, §  is  a  question  on  which  I  can  not  hazard 
an  opinion,  owing  to  my  own  want  of  personal  knowledge  of 
the  subject. 

*  Leop.  vou  Biich,  Descr.  des  Canaries,  p.  394  ;  Fiedler,  Raise  durch 
das  Konigreich  Griechenland,  tb.  ii.,  s.,  181,  190,  und  516, 

t  I  have  previously  alluded  to  the  remarkable  passage  in  Origen's 
Philosophumena,  cap.  14  {Opera,  ed.  Delarue,  t.  i.,  p.  893).  From  the 
whole  context,  it  seems  very  improbable  that  Xenophanes  meant  an 
impression  of  a  laurel  {tvkov  (Ju^vff)  instead  of  an  impression  of  a  fish 
{tvtzov  u.(pVT]g).  Delame  is  wrong  in  blaming  the  correction  of  Jacob 
Gronovius  in  changing  the  laurel  into  a  sardel.  Tlie  petrifaction  of  a 
fish  is  also  much  more  probable  than  the  natural  picture  of  Silenus, 
which,  accoi'ding  to  Phny  (lib.  xxxvi.,  5),  the  quarry-men  are  stated  to 
have  met  with  in  Parian  marble  from  Mount  Marpessos.  Servius  ad 
Virg.,  ^n.,  \i..  All. 

X  On  the  geoguostic  relations  of  Carrara  (  The  City  of  the  Moon,  Strabo, 
lib.  v.,  p.  222),  see  Savi,  Osservazioni  sui  terreni  antichi  Toscani,  in 
the  Nnovo  Giornale  de'  Letterati  di  Pisa,  and  Hoffmann,  in  Karsten's 
Archiv  far  Mineralogie,  bd.  vi.,  s.  2.58-263,  as  well  as  in  his  Geogn. 
Reise  durch  Italien,  s.  244-265. 

^  According  to  the  assumption  of  an  excellent  and  very  experienced 
observer,  Karl  von  Leonhard.     See  his  Jahrbuch  fiir  Mineralogie,  1834 
e.  329,  aud  Bernhard  Cotta,  Geognosie,  s.  310. 


264  COSMOS. 

According  to  the  admirable  observations  of  Leopold  von 
Buch,  the  masses  of  dolomite  fomid  in  Southern  Tyrol,  and  on 
the  Italian  side  of  the  Alps,  present  the  most  remarkable  in- 
stance of  metamorphism  produced  by  massive  eruptive  rocks 
on  compact  calcareous  beds.  This  formation  of  the  hmestone 
seems  to  have  proceeded  from  the  fissures  which  traverse  it  in 
all  directions.  The  cavities  are  every  v/here  covered  w^ith 
rhomboidal  crj'^stals  of  magnesian  bitter  spar,  and  the  v^hole 
formation,  without  any  trace  of  stratification,  or  of  the  fossil 
remains  which  it  once  contained,  consists  only  of  a  granular 
aggregation  of  crystals  of  dolomite.  Talc  laminse  lie  scattered 
here  and  there  in  the  newly-formed  rock,  traversed  by  masses 
of  serpentine.  In  the  valley  of  the  Fassa,  dolomite  rises  per- 
pendicularly in  smooth  walls  of  dazzling  whiteness  to  a  height 
of  many  thousand  feet.  It  forms  sharply -pointed  conical 
mountains,  clustered  together  in  large  numbers,  but  yet  not  in 
contact  with  each  other.  The  contour  of  their  forms  recalls  to 
mind  the  beautiful  landscape  with  which  the  rich  imagination 
of  Leonardi  da  Vinci  has  embellished  the  back-ground  of  the 
portrait  of  Mona  Lisa. 

The  geognostic  phenomena  which  we  are  now  describing, 
and  which  excite  the  imagination  as  well  as  the  powers  of  the 
intellect,  are  the  result  of  the  action  of  augitic  porphyry  man- 
ifested in  its  elevating,  destroying,  and  transforming  force.* 
The  process  by  which  limestone  is  converted  into  dolomite  is 
not  regarded  by  the  illustrious  investigator  who  first  drew  at- 
tention to  the  phenomenon  as  the  consequence  of  the  talc  being 
derived  from  the  black  porphyry,  but  rather  as  a  transforma- 
tion simultaneous  with  the  appearance  of  this  erupted  stone 
through  wide  fissures  filled  with  vapors.  It  remains  for  future 
inquirers  to  determine  how  transformation  can  have  been  effect- 
ed without  contact  with  the  endogenous  stone,  where  strata 
of  dolomite  are  found  to  be  interspersed  in  limestone.  Where, 
in  this  case,  are  we  to  seek  the  concealed  channels  by  which 
the  Plutonic  action  is  conveyed  ?  Even  here  it  may  not,  how- 
ever, be  necessary,  in  conformity  with  the  old  Roman  adage, 
to  believe  "  that  much  that  is  alike  in  nature  may  have  been 
formed  in  wholly  difierent  ways."  When  we  find,  over  widely- 
extended  parts  of  the  earth,  that  two  phenomena  are  always 
associated  together,  as,  for  instance,  the  occurrence  of  mela- 

*  Leop.  von  Buch,  Geognostische  Briefe  an  Alex,  von  Humboldt,  1824, 
«.  86  and  82  ;  also  in  the  Annalen  de  Ckemie,  t.  xxiii.,  p.  276,  and  in  the 
Ahhandl.  der  Berliner  Akad.  avs  der  Jahren  1822  i(?id  1823,  s.  83-136  ; 
Von  Dechen,  Geognosie,  s.  574-576. 


ROCKS.  265 

phyre  and  the  transformation  of  compact  lii^iestone  into  a  crys- 
talline mass  differing  in  its  chemical  character,  we  are,  to  a 
certain  degree,  justified  in  believing,  where  the  second  phe- 
nomenon is  manifested  unattended  by  the  appearance  of  the 
first,  that  this  apparent  contradiction  is  owing  to  the  absence, 
in  certain  cases,  of  some  of  the  conditions  attendant  upon  the 
exciting  causes.  Who  would  call  in  question  the  volcanic  na- 
ture and  igneous  fluidity  of  basalt  merely  because  there  are 
some  rare  instances  in  which  basaltic  veins,  traversing  beds 
of  coal  or  strata  of  sandstone  and  chalk,  have  not  materially 
deprived  the  coal  of  its  carbon,  nor  broken  and  slacked  the 
sandstone,  nor  converted  the  chalk  into  granular  marble  1 
Wherever  we  have  obtained  even  a  faint  light  to  guide  us  in 
the  obscure  domain  of  mineral  formation,  we  ought  not  un- 
gratefully to  disregard  it,  because  there  may  be  much  that  is 
still  unexplained  in  the  history  of  the  relations  of  the  transi- 
tions, or  in  the  isolated  interposition  of  beds  of  unaltered  strata. 

After  having  spoken  of  the  alteration  of  compact  carbonate 
of  lime  into  granular  limestone  and  dolomite,  it  still  remains 
for  us  to  mention  a  third  mode  of  transformation  of  the  same 
mineral,  which  is  ascribed  to  the  emission,  in  the  ancient  pe- 
riods of  the  world,  of  the  vapors  of  sulphuric  acid.  This  trans- 
formation of  limestone  into  gypsum  is  analogous  to  the  pene- 
tration of  rock  salt  and  sulphur,  the  latter  being  deposited 
from  sulphureted  aqueous  vapor.  In  the  lofty  Cordilleras  of 
Quindiu,  far  from  all  volcanoes,  I  have  observed  deposits  of 
sulphur  in  fissures  in  gneiss,  while  in  Sicily  (at  Cattolica,  near 
Girgenti),  sulphur,  gypsum,  and  rock  salt  belong  to  the  most 
recent  secondary  strata,  the  chalk  formations.*"  I  have  also 
seen,  on  the  edge  of  the  crater  of  Vesuvius,  fissures  filled  with 
rock  salt,  which  occurred  in  such  considerable  masses  as  occa- 
sionally to  lead  to  its  being  disposed  of  by  contraband  trade. 
On  both  declivities  of  the  Pyrenees,  the  connection  of  diorit? 
and  pyroxene,  and  dolomite,  gypsum,  and  rock  salt,  can  not  be 
questioned  ;t  and  here,  as  in  the  other  phenomena  which  we 
have  been  considering,  every  thing  bears  evidence  of  the  ac- 
tion of  subterranean  forces  on  the  sedimentary  strata  of  the 
ancient  sea. 

There  is  much  difficulty  in  explaining  the  origin  of  the  beds 
of  pure  quartz,  which  occur  in  such  large  quantities  in  South 
America,  and  impart  so  peculiar  a  character  to  the  chain  of 

*  Hoffmau,  Geogn.  Reise,  edited  by  Von  Declieu,  s.  113-119,  and 
380-386;  Poggend.,  Annalen  der  Physik,  bd.  xxvi.,  s.  41. 

t  DiifVenoy,  in  the  Memoires  Geologiqnes.  t.  ii..  p.  145  and  179. 
Vol.  I.— M 


266  COSMOS. 

the  Andes.*  In  descending  toward  the  South  Sea,  fiom  Cax- 
amarca  toward  Guangamarca,  I  have  observed  vast  ra,asses 
of  quartz,  from  7000  to  8000  feet  in  height,  superposed  some- 
times on  porphyry  devoid  of  quartz,  and  sometimes  on  dioritc. 
Can  these  beds  have  been  transformed  from  sandstone,  as 
EHe  de  Beaumont  conjectures  in  the  case  of  the  quartz  strata 
on  the  Col  de  La  Poissonniere,  east  of  Brian^on  ?t  In  the 
Brazils,  in  the  diamond  district  of  Minas  Geraes  and  St.  Paul, 
which  has  recently  been  so  accurately  investigated  by  Clausen, 
Plutonic  action  has  developed  in  dioritic  veins  sometimes  ordi- 
nary mica,  and  sometimes  specular  iron  in  quartzose  itacol- 
umite.  The  diamonds  of  Grammagoa  are  imbedded  in  strata 
of  solid  silica,  and  are  occasionally  enveloped  in  lamiuje  of 
mica,  like  the  garnets  found  in  mica  slate.  The  diamonds 
that  occur  furthest  to  the  north,  as  those  discovered  in  1829 
at  58'^  lat.,  on  the  European  slope  of  the  Uralian  Mountains, 
bear  a  geognostic  relation  to  the  black  carboniferous  dolomite 
of  xldolfiskoit  and  to  augitic  porphyry,  although  more  accu- 
rate observations  are  required  in  order  fully  to  elucidate  this 
subject. 

Among  the  most  remarkable  phenomena  of  contact,  v/e 
must,  finally,  enumerate  the  formation  of  garnets  in  argilla- 
ceous schist  in  contact  with  basalt  and  dolerite  (as  in  Northum- 
berland and  the  island  of  Anglesea),  and  the  occurrence  of  a 
vast  number  of  beautiful  and  most  various  crystals,  as  garnets, 
vesuvian,  augite,  and  ceylanite,  on  the  surfaces  oi"  contact  be- 
tween the  erupted  and  sedimentary  rock,  as,  for  instance,  on 
the  junction  of  the  syenite  of  Monzon  with  dolomite  and  com- 
pact limestone. §  In  the  island  of  Elba,  masses  of  serpentine, 
which  perhaps  nowhere  more  clearly  indicate  the  character  of 
erupted  rocks,  have  occasioned  the  sublimation  of  iron  glance 
and  red  oxyd  of  iron  in  fissures  of  calcareous  sandstone.il  We 
still  daily  find  the  same  iron  glance  formed  by  sublimation 
from  the  vapors  and  the  walls  of  the  fissures  of  open  veins  on 
the  margin  of  the  crater,  and  in  the  fresh  lava  currents  of  the 
volcanoes  of  Stromboli,  Vesuvius,  and  -^tna.lF    The  veins  that 

*  Humboldt,  Essai  Oeogn.  sur  le  Gisement  des  Roches,  p.  93  ;  Asie 
Ccntrale,  t.  iii.,  p.  532. 

t  Elie  de  Beaumont,  in  the  Annales  des  Sciences  Naturelles,  t.  xv.,  ]) 
362 ;  Murchison,  Silurian  System,  p.  286. 

+  Rose,  Reise  nach  dem  Ural,  bd.  i.,  s.  364  und  367. 

<^  Leop.  vou  Bucb,  Briefe,  s.  109-129.  See,  also,  Elie  do  Beaumont, 
Oil  the  Contact  of  Granite  toith  the  Beds  of  the  Jura,  in  the  31^m.  GeoL, 
t.  ii.,  }).  408.  II    Hoifman,  Reise,  a.  30  niid  37. 

11  On  the  chemical  process  iu  the  f<jrmatioa  oi'  bpeculur  i:'oii,  s(.n^  Guy 


ROCKS.  267 

are  thus  formed  beneath  our  eyes  by  volcanic  forces,  where 
the  contiguous  rock  has  already  attained  a  certain  degree  of 
solidification,  show  us  how,  in  a  similar  manner,  mineral  and 
metallic  veins  may  have  been  every  where  formed  in  the  more 
ancient  periods  of  the  world,  where  the  solid  but  thinner  crust 
of  our  planet,  shaken  by  earthquakes,  and  rent  and  fissured 
by  the  change  of  volume  to  which  it  was  subjected  in  cooling, 
may  have  presented  many  communications  with  the  interior, 
and  many  passages  for  the  escape  of  vapors  impregnated  with 
earthy  and  metallic  substances.  The  arrangement  of  the  par- 
ticles in  layers  parallel  with  the  margins  of  the  veins,  the  regu- 
lar recurrence  of  analogous  layers  on  the  opposite  sides  of  the 
veins  (on  their  different  walls),  and,  finally,  the  elongated  cel- 
lular cavities  in  the  middle,  frequently  afford  direct  evidence 
of  the  Plutonic  process  of  sublimation  in  metalliferous  veins. 
As  the  traversing  rocks  must  be  of  more  recent  origin  than 
the  traversed,  we  learn  from  the  relations  of  stratification  ex- 
isting between  the  porphyry  and  the  argentiferous  ores  in  the 
Saxon  mines  (the  richest  and  most  important  in  Germany), 
that  these  formations  are  at  any  rate  more  recent  than  the 
vegetable  remains  found  in  carboniferous  strata  and  in  the  red 
sandstone.* 

All  the  facts  connected  with  our  geological  hypotheses  on 
the  formation  of  the  earth's  crust  and  the  metamorphism  of 
rocks  have  been  unexpectedly  elucidated  by  the  ingenious 
idea  which  led  to  a  comparison  of  the  slags  or  scoriae  of  our 
smelting  furnaces  with  natural  minerals,  and  to  the  attempt 
of  reproducing  the  latter  from  their  elements.!  In  all  these 
operations,  the  same  affinities  manifest  themselves  which  de- 
termine chemical  combinations  both  in  our  laboratories  and 
in  the  interior  of  the  earth.     The  most  considerable  part  of 

Lussac,  in  the  Annates  de  Chimie,  t.  xxii.,  p.  41.5,  and  Mitscherlich,  in 
Poggeud.,  Annalen,  bd.  xv.,  s.  630.  Moreover,  crystals  of  olivine  have 
been  formed  (probably  by  sublimation)  in  the  cavities  of  the  obsidian 
of  Cerro  del  Jacal,  whicla  I  brought  from  Mexico  (Gustav  Rose,  in 
Poggend.,  Annalen,  bd.  x.,  s.  323).  Hence  olivine  occurs  in  basalt, 
lava,  obsidian,  artificial  scoria?,  in  meteoric  stones,  in  the  syenite  of  Elf- 
dale,  and  (as  hyalosiderite)  in  the  wacke  of  the  Kaiserstahl. 

*  Constantin  von  Beust,  Ueber  die  Porphyrgebilde,  1835,  s.  89-96  ; 
also  his  Beleuchtung  der  Werner^ schen  Gangtheorie,  1840,  s.  6  ;  and  C 
von  Wissenbach,  Ahhildungen  merkwurdiger  Gangverhdltnisse,  1836,  fig. 
12.  The  ribbon-like  structure  of  the  veins  is,  how^ever,  no  more  to  bo 
regarded  of  general  occurrence  than  the  periodic  order  of  the  differen* 
members  of  these  masses. 

t  Mitscherlich.  Ueber  die  kunstliche  DarsteUnng  der  Mineralien,  m 
the  Abhandl.  der  Akademie  der  Wiss.  zu  Berlin,  1822-3,  s.  2.5-41 


268  COSMOS. 

the  simple  minerals  which  characterize  the  more  generally 
diffused  Plutonic  and  erupted  rocks,  as  well  as  those  on  which 
they  have  exercised  a  metamorphic  action,  have  been  produced 
in  a  crystalline  state,  and  with  perfect  identity,  in  artificial 
mineral  products.  We  must,  however,  distinguish  here  be- 
tween the  scoriae  accidentally  formed,  and  those  which  have 
been  designedly  produced  by  chemists.  To  the  former  belong 
feldspar,  mica,  augite,  olivine,  hornblende,  crystallized  oxyd 
of  iron,  magnetic  iron  in  octahedral  crystals,  and  metallic 
titanium  ;*  to  the  latter,  garnets,  idocrase,  rubies  (equal  in 
hardness  to  those  found  in  the  East),  olivine,  and  augite. t 
These  minerals  constitute  the  main  constituents  of  granite, 
gneiss,  and  mica  schist,  of  basalt,  dolerite,  and  many  porphy- 
ries. The  artificial  production  of  feldspar  and  mica  is  of  most 
especial  geognostic  importance  with  reference  to  the  theory  of 
the  formation  of  gneiss  by  the  metamorphic  agency  of  argilla- 
ceous schist,  which  contains  all  the  constituents  of  granite, 

*  In  scoriae,  crystals  of  feldspar  have  been  discovered  by  Heine  in 
the  refuse  of  a  furnace  for  copper  fusing,  near  Sangerhausen,  and  ana- 
lyzed by  Kersten  (Poggend.,  Annalcn,  bd.  xxxiii.,  s.  337);  crystals  of 
augite  in  scoriae,  at  Sahle  (Mitscherlich,  in  the  Abhandl.  der  Akad.  zu 
Berlin,  1822-23,  s.  40);  of  olivine  by  Seifstrom  (Leonhard,  Basalt-Ge- 
bilde,  bd.  ii.,  s.  495);  of  mica  in  old  scoriae  of  Schloss  Garpenberg 
(Mitscherlich,  in  Leonhard,  op.  cit.,  s.  506) ;  of  magnetic  iron  in  the 
scoriae  of  Chatillon  sur  Seine  (Leonhard,  s.  441)  ;  and  of  micaceous  iron 
in  potter's  clay  (Mitscherlich,  in  Leonhard,  op.  cit.,  s.  234). 

[See  Ebelmer's  papers  in  Ann.  de  Chimie  et  de  Physique,  1847  ;  also 
Report  on  the  Crystalline  Slags,  by  John  Percy,  M.D.,  F.R.S.,  and 
William  Hallows  Miller,  M.A.,  1847.  Dr.  Percy,  in  a  communication 
with  which  he  has  kindly  favored  me,  says  that  the  minerals  which  he 
has  found  artificially  produced  and  proved  by  analysis  are  Humboldtil- 
ite,  gehleuite,  olivine,  and  magnetic  oxyd  of  iron,  in  octahedral  crys- 
tals. He  suggests  that  the  circumstance  of  the  production  of  gehlenite 
at  a  high  temperature  in  an  iron  furnace  may  possibly  be  made  avail- 
able by  geologists  in  explaining  the  formation  of  the  rocks  in  which  the 
natural  mineral  occurs,  as  in  Fassathal  in  the  Tyrol.] — Tr. 

t  Of  minerals  purposely  produced,  we  may  mentioia  idocrase  and 
garnet  (Mitscherlich,  in  Poggend.,  Annalen  der  Physik,  bd.  xxxii.,  s. 
340);  ruby  (Gaudin,  in  the  Compies  Rendus  de  VAcademie  de  Science, 
t.  iv.,  Part  i.,  p.  999) ;  olivine  and  augite  (Mitscherlich  and  Berthier,  in 
the  Annales  de  Chimie  et  de  Physique,  t.  xxiv.,  p.  376).  Notwithstand- 
ing the  greatest  possible  similarity  in  crystalline  form,  and  perfect  iden- 
tity in  chemical  composition,  existing,  according  to  Gustav  Rose,  be- 
tween augite  and  hornblende,  hornblende  has  never  been  found  accom- 
panying augite  in  scoriae,  nor  have  chemists  ever  succeeded  in  artificial- 
ly producing  either  hornblende  or  feldspar  (Mitscherlich  in  Poggend., 
Annalen,  bd.  xxxiii.,  s.  340,  and  Rose,  Reise  nach  dem  Ural,  bcT.  ii.,  s. 
358  und  363).  See,  also,  Beudant,  in  the  Mem.  de  V Acad,  des  Sciences, 
t.  viii.,  p.  221,  and  Becquerel's  ingenious  experiments  in  his  Trait'  <it 
I  Electric'ti,  t.  i.,  p.  334  ;  t.  iii.,  p.  218;  and  t.  v.,  p.  148  and  185 


ROCKS.  269 

potash  not  excepted.*  It  would  not  b3  very  surprising,  there- 
fore, as  is  well  observed  by  the  distinguished  geognosist,  Von 
Dechen,  if  we  were  to  meet  with  a  fragment  of  gneiss  formed 
on  the  walls  of  a  smelting  furnace  which  was  built  of  argilla- 
ceous slate  and  graywacke. 

'  After  having  taken  this  general  view  of  the  three  classes 
of  erupted,  sedimentary,  and  metamorphic  rocks  of  the  earth's 
crust,  it  still  remains  for  us  to  consider  the  fourth  class,  com- 
prising conglomerates,  or  rocks  of  detritus.  The  very  term 
recalls  the  destruction  which  the  earth's  crust  has  suffered, 
and  likewise,  perhapw,  reminds  u?  of  the  process  of  cementation, 
which  has  connected  together,  by  means  of  oxyd  of  iron,  or  of 
some  argillaceous  and  calcareous  substances,  the  sometimes 
rounded  and  sometimes  angular  portions  of  fragments.  Con- 
glomerates and  rocks  of  detritus,  when  considered  in  the  widest 
sense  of  the  term,  manifest  characters  of  a  double  origin.  The 
substances  which  enter  into  their  mechanical  composition  have 
not  been  alone  accumulated  by  the  action  of  the  waves  of  the 
sea  or  currents  of  fresh  water,  for  there  are  some  of  these  rocks 
the  formation  of  which  can  not  be  attributed  to  the  action  of 
water.  "  When  basaltic  islands  and  trachytic  rocks  rise  on 
fissures,  friction  of  the  elevated  rock  against  the  walls  of  the 
fissures  causes  the  elevated  rock  to  be  inclosed  by  conglom- 
erates composed  of  its  own  matter.  The  granules  composing 
the  sandstones  of  many  formations  have  been  separated  rather 
by  friction  against  the  erupted  volcanic  or  Platonic  rock  than 
destroyed  by  the  erosive  force  of  a  neighboring  sea.  The  ex- 
istence of  these  friction  conglomerates,  which  are  met  with  in 
enormous  masses  in  both  hemispheres,  testifies  the  intensity 
ot"  the  force  with  which  the  erupted  rocks  have  been  propelled 
from  the  interior  through  the  earth's  crust.  This  detritus 
has  subsequently  been  taken  up  by  the  waters,  which  have 
then  deposited  it  in  the  strata  which  it  still  covers. "t  Sand- 
stone formations  are  found  imbedded  in  all  strata,  from  the 
lower  silurian  transition  stone  to  the  beds  of  the  tertiary  form- 
ations, supei-posed  on  the  chalk.  They  are  found  on  the 
margin  of  the  boundless  plains  of  the  New  Continent,  both 
within  and  without  the  tropics,  extending  like  breast-works 
along  the  ancient  shore,  against  which  the  sea  once  broke  in 
foaming  waves. 

*  D'Aubuisson,  in  the  Journal  de  Physique,  t.  Ixviii.,  p.  128. 

t  Leop.  von  Buch,  Gcognost.  Briefe,  s.  75-8"J.  w'uere  it  is  also  showi? 
why  the  new  red  saudstoue  (the  Todtliegende  of  the  Tlinringiaii  flota 
formatioii)  and  the  coal  measures  must  be  regarded  as  produ'-ed  b^ 
erupted  porpliyiy. 


270  COSMOS. 

If  we  cast  a  glance  on.  tlie  geographical  distribution  of 
rocks,  and  their  relations  in  space,  in  that  portion  of  the  earth's 
crust  which  is  accessible  to  us,  we  shall  find  that  the  most 
universally  distributed  chemical  substance  is  silicic  acid,  gen- 
erally in  a  variously-colored  and  opaque  form.  Next  to  solid 
silicic  acid  we  must  reckon  carbonate  of  lime,  and  then  the 
combinations  of  silicic  acid  with  alumina,  potash,  and  soda, 
with  lime,  magnesia,  and  oxyd  of  iron. 

The  substances  which  we  designate  as  rocks  are  determin- 
ate associations  of  a  small  number  of  minerals,  in  which  some 
combine  parasitically,  as  it  were,  with  others,  but  only  under 
definite  relations  ;  thus,  for  instance,  although  quartz  (silica), 
feldspar,  and  mica  are  the  principal  constituents  of  granite, 
these  minerals  also  occur,  either  individually  or  collectively, 
in  many  other  formations.  By  way  of"  illustrating  how  the 
quantitative  relations  of  one  feldspathic  rock  differ  from  anoth- 
er, richer  in  mica  than  the  former,  I  would  mention  that,  ac- 
cording to  Mitscherlich,  three  times  more  alumina  and  one 
third  more  silica  than  that  possessed  by  feldspar,  give  the  con- 
stituents that  enter  into  the  compositi(5n  of  mica.  Potash  is 
contained  in  both — a  substance  whose  existence  in  many  kinds 
of  rocks  is  probably  antecedent  to  the  dawn  of  vegetation  on 
the  earth's  surface. 

The  order  of  succession,  and  the  relative  age  of  the  difierent 
formations,  may  be  recognized  by  the  superposition  of  the  sed- 
imentary, metamorphic,  and  conglomerate  strata  ;  by  the  na- 
ture of  the  formations  traversed  by  the  erupted  mas.ses,  and 
— with  the  greatest  certainty — by  the  presence  of  organic  re- 
mains and  the  diflerences  of  their  structure.  The  application 
of  botanical  and  zoological  evidence  to  determine  the  relative 
age  of  rocks — this  chronometry  of  the  earth's  surface,  which 
was  already  present  to  the  lofiy  mind  of  Hooke — indicates  one 
of  the  most  glorious  epochs  of  modern  geognosy,  which  has 
finally,  on  the  Continent  at  least,  been  emancipated  from  the 
sway  of  Semitic  doctrines.  Palseontological  investigations 
have  imparted  a  vivifying  breath  of  grace  and  diversity  to  thb 
science  of  the  solid  structure  of  the  earth. 

The  fossiliferous  strata  contain,  entombed  within  them,  the 
floras  and  faunas  of  by-gone  ages.  We  ascend  the  stream  of 
time,  as  in  our  study  of  the  relations  of  superposition  we  de- 
scend deeper  and  deeper  through  the  different  strata,  in  which 
lies  revealed  before  us  a  past  world  of  animal  and  vegetable 
life.  Far-extending  disturbances,  the  elevation  of  great  mount- 
ain chains,  whose  relative  ages  we  are  able  to  define,  attest  the 


PALAEONTOLOGY.  271 

destruction  of  ancient  and  the  manifestation  of  recent  organ- 
isms. A  few  of  these  older  structures  have  remained  in  the 
midst  of  more  recent  species.  Owing  to  the  hmited  nature  of 
our  knowledge  of  existence,  and  from  the  figurative  terms  by 
which  we  seek  to  hide  our  ignorance,  we  apply  the  appellation 
recent  structure  to  the  historical  phenomena  ot"  transition  man- 
ifested in  the  organisms  as  well  as  in  the  forms  of  primitive 
seas  and  of  elevated  lands.  In  some  cases  these  organized 
structures  have  been  preserved  perfect  in  the  minutest  details 
of  tissues,  integument,  and  articulated  parts,  while  in  others, 
the  animal,  passing  over  soft  argillaceous  mud,  has  left  noth- 
ing but  the  traces  of  its  course, =^  or  the  remains  of  its  undi- 
gested food,  as  in  the  coprolites.f  In  the  lower  Jura  forma- 
tiolis  (the  lias  of  Lyme  Regis),  the  ink  bag  of  the  sepia  has 
been  so  wonderfully  preserved,  that  the  material,  which  myr- 

*  [III  certain  localities  of  the  new  red  sandstone,  in  the  Valley  of  the 
Connecticut,  numerous  tridactyl  marldngs  have  been  occasionally  ob- 
served on  the  surface  of  the  slabs  of  stone  vv^hen  split  asunder,  in  like 
manner  as  the  ripple-marks  appear  on  the  successive  layers  of  sandstone 
in  Tilgate  Forest.  Some  remarkably  distinct  impressions  of  this  kind, 
at  Turner's  Falls  (Massachusetts),  happening  to  attract  the  attention  of 
Dr.  James  Deane,  of  Greenfield,  that  sagacious  obsei'ver  was  struck 
with  their  resemblance  to  the  foot-marks  left  on  the  mud-banks  of  the 
adjacent  river  by  the  aquatic  birds  which  had  recently  frequented  the 
spot.  The  specimens  collected  were  submitted  to  Professor  G.  Hitch- 
cock, who  followed  up  the  inquiry  with  a  zeal  and  success  that  have 
led  to  the  most  interesting  results.  No  reasonable  doubt  now-  exists 
that  the  imprints  in  question  have  been  produced  by  the  tracks  of  bi- 
peds impressed  on  the  stone  when  in  a  soft  state.  The  announcement 
of  this  extraordinary  phenomenon  was  first  made  by  Professor  Hitc'i- 
cock,  in  the  American  Journal  of  Science  (January.  1836),  and  that 
eminent  geologist  has  since  published  full  descriptions  of  the  different 
species  of  imprints  which  he  has  detected,  in  his  splendid  work  on  the 
geology  of  Massachusetts. — iMantell's  Medals  of  Creation,  vol.  ii.,  p.  810. 
In  the  work  of  Dr.  Mantell  above  referred  to,  there  is,  in  vol.  ii.,  p.  815, 
an  admirable  diagram  of  a  sbb  from  Turner's  Falls,  covered  with  nu- 
merous foot-marks  of  birds,  indicating  the  track  of  ten  or  twelve  indi- 
viduals of  different  sizes.] — Tr. 

t  [From  the  examination  of  the  fossils  spoken  of  by  geologists  under 
the  name  of  Coprolites,  it  is  easy  to  determine  the  nature  of  the  food  of 
the  animals,  and  some  other  points;  and  when,  as  happened  occasion- 
ally, the  animal  was  killed  while  the  process  of  digestion  was  going  on, 
the  stomach  and  intestines  being  partly  filled  with  half-digested  I'ootl, 
and  exhibiting  the  coprolites  actually  in  situ,  we  can  make  out  wit!i 
certainty  not  only  the  true  nature  of  the  food,  but  the  proportionate  si/e 
of  the  stomach,  and  the  length  and  nature  of  the  intestinal  canal.  With 
in  the  cavity  of  the  nb  of  an  extinct  animal,  the  palaeontologist  \{iw* 
finds  recorded,  in  indelible  characters,  some  of  those  hiei'oglyplii<-.s  upon 
which  he  founds  his  hi.stoiT. —  The  Ancient  World,  by  D.  T.  An&ted 
1817,  p.  173.]  — Tr. 


272 .  COSMOS. 

iads  of  years  ago  might  have  served  the  animal  to  conceal  it- 
self from  its  enemies,  still  yields  the  color  with  which  its  image 
may  be  drawn.*"  In  other  strata,  again,  nothing  remains  bul 
the  faint  impression  of  a  muscle  shell ;  but  even  this,  if  it  be- 
long to  a  main  division  of  mol}usca,t  may  serve  to  show  the 
traveler,  in  some  distant  land,  the  nature  of  the  rock  in  which 
it  is  found,  and  the  organic  remains  with  which  it  is  associa* 
ted.  Its  discovery  gives  the  history  of  the  country  in  which  b 
occurs. 

The  analytic  study  of  primitive  animal  and  vegetable  lift 
has  taken  a  double  direction  :  the  one  is  purely  morpholog- 
ical, and  embraces,  especially,  the  natural  history  and  phys- 
iology of  organisms,  filling  up  the  chasms  in  the  series  of  stil) 
hving  species  by  the  fossil  structures  of  the  primitive  world. 
The  second  is  more  specially  geognostic,  considering  fossil  re- 
mains in  their  relations  to  the  superposition  and  relative  age 
of  the  sedimentary  formations.  The  former  has  long  predom- 
inated over  the  latter,  and  an  imperfect  and  superficial  com- 
parison of  fossil  remains  with  existing  species  has  led  to  errors, 
which  may  still  be  traced  in  the  extraordinary  names  applied 
to  certain  natural  bodies.  It  was  sought  to  identify  all  fossil 
species  with  those  still  extant  in  the  same  manner  as,  in  the 
sixteenth  century,  men  were  led  by  false  analogies  to  com- 
pare the  animals  of  the  New  Continent  with  those  of  the  Old. 
'Peter  Camper,  Soramering,  and  Blumenbach  had  the  merit 
of  being  the  first,  by  the  scientific  application  of  a  more  ac- 

*  A  discovery  made  by  Miss  Mary  Auniiig,  who  was  likewise  the 
discovei-er  of  the  coprolites  of  fish.  These  coprolites,  and  the  excre- 
ments of  the  Ichthyosauri,  have  been  found  in  such  abundance  in  Eu« 
gland  (as,  for  instance,  near  Lyme  Regis),  that,  according  to  Buckland's 
expression,  they  lie  like  potatoes  scattered  in  the  ground.  See  Buck- 
land,  Geology  considered  with  reference  to  Natural  Theology,  vol.  i.,  p. 
188-202  and  305.  With  I'espect  to  the  hope  expressed  by  Hooke  "  to 
raise  a  chronology"  from  the  mere  study  of  broken  and  fossilized  shells 
"  and  to  state  the  interval  of  time  wherein  such  or  such  catastrophes 
and  mutations  have  happened,"  see  his  Posthumous  Works,  Lecture, 
Feb.  29,  1688. 

[Still  more  wonderful  is  the  preservation  of  the  substance  of  the  an- 
imal of  certain  Cephalopodes  in  the  Oxford  clay.  In  some  specimens 
recently  obtained,  and  described  by  Professor  Owen,  not  only  the  ink 
bag,  but  the  muscular  mantle,  the  head,  and  its  crown  of  arms,  are  all 
preserved  in  connection  with  the  belemnite  shell,  while  one  specimen 
exhibits  the  large  eyes  and  the  funnel  of  the  animal,  and  the  remains  of 
two  fins,  in  addition  to  the  shell  and  the  ink  bag.  See  Ansted's  Ancient 
World,  p.  147.]— Tr. 

t  Leop.  von  Buch,  in  the  Abhandlungen  der  Akad.  der  Wiss.  zti  Ber 
lin  in  dcin  Jahr  1837,  s.  64. 


PALAEONTOLOGY.  273 

curate  comparative  anatomy,  to  throw  light  on  the  osteolog- 
ical  branch  of  pala3ontology — the  archaeology  of  organic  life  ; 
but  the  actual  geognostic  views  of  the  doctrine  of  fossil  re- 
mains, the  felicitous  combination  of  the  zoological  character 
with  the  order  of  succession,  and  the  relative  ages  of  strata,  are 
due  to  the  labors  of  George  Cuvier  and  Alexander  Brongniart. 

The  ancient  sedimentary  formations  and  those  of  transi- 
tion rocks  exhibit,  in  the  organic  remains  contained  within 
them,  a  mixture  of  structures  very  variously  situated  on  the 
scale  of  progressively-developed  organisms.  These  strata  con- 
tain but  few  plants,  as,  for  instance,  some  species  of  Fuci, 
Lycopodiacese  which  were  probably  arborescent,  Equisetacese, 
and  tropical  ferns  ;  they  present,  however,  a  singular  associa- 
tion of  animal  forms,  consisting  of  Crustacea  (trilobites  with 
reticulated  eyes,  and  Calymene),  Brachiopoda  {^Spirifer,  Or- 
this),  elegant  Sphseronites,  nearly  allied  to  the  Crinoidea,*  Or- 
thoceratites,  of  the  family  of  the  Cephalopoda,  corals,  and, 
blended  with  these  low  organisms,  fishes  of  the  most  singular 
forms,  imbedded  in  the  upper  silurian  formations.  The  fam- 
ily of  the  Cephalaspides,  whose  fragments  of  the  species 
Ptei-ichtys  were  long  held  to  be  trilobites,  belongs  exclusively 
to  the  devonian  period  (the  old  red),  manifesting,  according 
to  Agassiz,  as  peculiar  a  type  among  fishes  as  do  the  Ichthy- 
osauri and  Plesiosauri  among  reptiles. t  The  Goniatites,  of 
the  tribe  of  Ammonites,^  are  raianifested  in  the  transition 
chalk,  in  the  graywacke  of  the  devonian  periods,  and  even  in 
the  latest  silurian  formations. 

The  dependence  of  physiological  gradation  upon  the  age  of 
the  formations,  which  has  not  hitherto  been  shown  with  per- 
fect certainty  in  the  case  of  invertebrata,^  is  most  regularly 
manifested  in  vertebrated  animals.  The  most  ancient  of 
these,  as  we  have  already  seen,  are  fishes  ;  next  in  the  order 
of  succession  of  formation,  passing  from  the  lower  to  the  up- 
per, come  reptiles  and  mammalia.  The  first  reptile  (a  Sau- 
rian, the  Monitor  of  Cuvier),  which  excited  the  attention  of 
Leibnitz,  II  is  found  in  cuperiferous  schist  of  the  Zechstein  of 

*  Leop.  von  Buch,  Gebirgsformationenvon  Russland,  1840,  s.  24-40. 

t  Agassiz,  Monograpkie  des  Poissons  Fossiles  du  vieux  Gres  Rovge, 
p.  vi.  and  4. 

X  Leop.  von  Buch,  in  the  Abhandl.  der  Berl.  Akad.,  1838,  s.  149-168  ; 
Beyrich,  Beitr.  zur  Kenntniss  des  Rheinischen  Uebergangsgebirges,  1837, 
s.  45. 

$  Agassiz,  RecTierches  svr  les  Poissons  Fossiles,  t.  i.,  Introd.,  p.  xviii. ; 
Davy,  Consolation  in  Travel,  dial.  iii. 

li  A  Protosaurus,  according  to  Hermann  von  Meyer.     The  rib  o{  a 

M  2 


274  COSMOS. 

Thuringia ;  the  Palasosaurus  and  Thecodontosaurus  of  Bris- 
tol are,  according  to  Murchison,  of  the  same  age.  The  Sau- 
rians  are  found  in  large  numbers  in  the  muschelkalk,*  in  the 
keuper,  and  in  the  oolitic  formations,  where  they  are  the  most 
numerous.  At  the  period  of  these  formations  there  existed 
Plesiosauri,  having  long,  swan-like  necks  consisting  of  thirty 
vertebrae  ;  Megalosauri,  monsters  resembling  the  crocodile, 
forty-five  feet  in  length,  and  having  feet  whose  bones  were 
like  those  of  terrestrial  mammalia,  eight  species  of  large-eyed 
Ichthyosauri,  the  Geosaurus  or  Lacerta  gigantea  of  Som- 
mering,  and,  finally,  seven  remarkable  species  of  Pterodac- 
tyles,t  or  Saurians  furnished  with  membranous  wings.  In 
the  chalk  the  number  of  the  crocodilial  Saurians  diminishes, 
although  this  epoch  is  characterized  by  the  so-called  crocodile 
of  Maestricht  (the  JVIososaurus  of  Couybeare),  and  the  colos- 
sal, probably  graminivorous  Iguanodon.  Cuvier  has  found 
animals  belonging  to  the  existing  families  of  the  crocodile  in 
the  tertiary  formation,  and  Scheuchzer's  antediluvian  man 
{liomo  diluvii  testis),  a  large  salamander  allied  to  the  Ax- 
olotl,  which  I  brought  with  me  from  the  large  Mexican  lakes, 
belongs  to  the  most  recent  fresh-water  formations  of  CEnin- 

^^"•i  .       .  .  .  ■ 

The  determination  of  the  relative  ages  of  organisms  by  the 

superposition  of  the  strata  has  led  to  important  results  regard- 
ing the  relations  which  have  been  discovered  between  extinct 
families  and  species  (the  latter  being  but  few  in  number)  and 
those  which"  still  exist.  Ancient  and  modern  observations 
concur  in  showing  that  the  fossil  floras  and  faunas  differ  more 
from  the  present  vegetable  and  animal  forms  in  proportion  as 
they  belong  to  lower,  that  is,  more  ancient  sedimentary  for- 
mations.    The  numerical  relations  first  deduced  by  Cuvier 

Saurian  asserted  to  have  been  found  in  the  mountain  limestone  (car- 
bonate of  lime)  of  Northumberland  (Herm.  von  Meyer,  Palceologica,  s. 
299),  is  regarded  by  Lyell  {Geology,  1832,  vol.  i.,  p.  148)  as  very  doubt- 
ful. The  discoverer  himself  referred  it  to  the  alluvial  strata  which 
cover  the  mountain  limestone. 

*  F.  von  Alberti,  Monographie  des  Bunten  Sandsteins,  Musclielkalk» 
und  Keupers,  1834,  s.  119  und  314. 

t  See  Hermann  von  Meyer's  ingenious  considerations  regarding  the 
organization  of  the  flying  Saurians,  in  his  Palceologica,  s.  228-252.  In 
the  fossil  specimen  of  the  Pterodactylus  crassirostris,  which,  as  well  as 
the  longer  known  P.  longii'ostris  (Ornithocephalus  of  Sommering),  was 
found  at  Solenhofen,  ir  the  lithographic  slate  of  the  u[)per  Jura  forma- 
tion, Professor  Goldfass  has  even  discovered  traces  of  the  membranous 
wing,  "with  the  impressions  of  cui'ling  tufts  of  hair,  in  some  places  a 
full  inch  in  length."  t  [Ansted's  Ancient  World,  p.  .56.] — 7V. 


PALAEONTOLOGY.  21 J 

from  ihe  great  phenomena  of  the  metamorphism  of  organic 
life,*  have  led,  through  the  admirable  labors  of  Deshayes  and 
Lyell,  to  the  most  marked  results,  especially  with  reference  to 
the  difiereiit  groups  of  the  tertiary  formations,  which  contain 
a  considerable  number  of  accurately  investigated  structures. 
Agassiz,  who  has  examined  1700  species  of  Ibssil  fishes,  and 
who  estimates  the  number  of  living  species  which  have  either 
been  described  or  are  preserved  in  museums  at  8000,  expressly 
Bays,  in  his  masterly  work,  that,  "with  the  exception  of  a  few 
small  fossil  fishes  peculiar  to  the  argillaceous  geodes  of  Green- 
land, he  has  not  found  any  animal  of  this  class  in  all  the  tran 
sition,  secondary  or  tertiary  formations,  which  is  specificall) 
identical  with  any  still  extant  fish."  He  subjoins  the  im- 
portant observation  "  that  in  the  lower  tertiary  formations, 
for  instance,  in  the  coarse  granular  calcareous  beds,  and  in  the 
London  clay,t  one  third  of  the  fossil  fishes  belong  to  wholly 
extinct  families.  Not  a  single  species  of  a  still  extant  family 
is  to  be  found  under  the  chalk,  while  the  remarkable  family 
of  the  Sauroidi  (fishes  with  enameled  scales),  almost  allied 
to  reptiles,  and  which  are  found  from  the  coal  beds — in  which 
the  larger  species  lie — to  the  chalk,  where  they  occur  individ- 
ually, bear  the  same  relation  to  the  two  families  (the  Lepi- 
dosteus  and  Polyp terus)  which  inhabit  the  American  rivers 
and  the  Nile,  as  our  present  elephants  and  tapirs  do  to  the 
Mastodon  and  Anaplotheriun  of  the  primitive  world.  "$ 

The  beds  of  chalk  which  contain  two  of  these  sauroid  fishes 
and  gigantic  reptiles,  and  a  whole  extinct  world  of  corals  and 
muscles,  have  been  proved  by  Ehrenberg's  beautiful  discov- 
eries to  consist  of  microscopic  Polythalamia,  many  of  which 
still  exist  in  our  seas,  and  in  the  middle  latitudes  of  the  Nortli 
Sea  and  Baltic.  The  first  group  of  tertiary  formations  above 
the  chalk,  which  has  been  designated  as  belono^in^  to  the 
Eocene  Period,  does  not,  therefore,  merit  that  designation, 
since  "  the  daimi  of  the  ivorld  in  which  we  live  extends  mu  di 
further  back  in  the  history  of  the  past  than  we  have  hithe)  to 
supposed."  § 

As  we  have  already  seen,  fishes,  which  are  the  most  ancient 
of  all  vertebrata,  are  found  in  the  silurian  transition  strata, 

*  Cuvier,  Recherches  sur  les  Ossemens  Fossiles,  t.  i.,  p.  52-57.  See, 
also,  the  geological  scale  of  epochs  in  Phillips's  Geology,  1837,  p.  lG(i- 
185.  t  [See  Wonders  of  Geology,  yoi.  i.,  p.  230.]— Tr 

X  As;a.si\z,  Poissons  Fossiles,  t.  i.,  p.  30,  and  t.  iii.,  p.  1-5-2;  l)iifk- 
land.  Geology,  vol.  i.,  p.  273-277. 

§  Ehrenberg,  Ue'jer  noch  jetzt  lehende  Thierarten  der  KreUehiUhnig, 
in  the  Ahhandl.  der  Berliner  Aknd.,  1839,  8.  164. 


276  *  COSMOS. 

and  then  uninterruptedly  on  through  all  formations  to  the 
strata  of  the  tertiary  period,  while  Saurians  begin  with  the 
zechstone.  In  like  manner,  we  find  the  first  mammalia 
( Thylacotheriimi  Prevostii,  and  T.  Bucklandii,  which  are 
nearly  allied,  according  to  Valenciennes,*  with  marsupial  an- 
imals) in  the  oolitic  formations  (Stonesfield  schist),  and  the 
first  birds  in  the  most  ancient  6retaceous  strata. t  Such  are, 
according  to  the  present  state  of  our  knowledge,  the  lowest$ 
limits  of  fishes,  Saurians,  mammalia,  and  birds. 

Although  corals  and  Serpulidas  occur  in  the  most  ancient 
formations  simultaneously  with  highly-developed  Cephalopodes 
and  Crustaceans,  thus  exhibiting  the  most  various  orders 
grouped  together,  we  yet  discover  very  determinate  laws  in 
the  case  of  many  individual  groups  of  one  and  the  same  or- 
ders. A  single  species  of  fossil,  as  Goniatites,  Trilobites,  or 
Nummulites,  sometimes  constitutes  whole  mountains.  Where 
difierent  families  are  blended  together,  a  determinate  succes- 
sion of  organisms  has  not  only  been  observed  with  reference 
to  the  superposition  of  the  formations,  but  the  association  of 
certain  families  and  species  has  also  been  noticed  in  the  lower 
strata  of  the  same  formation.  By  his  acute  discovery  of  the 
arrangement  of  the  lobes  of  their  chamber-sutures,  Leopold 
von  Buch  has  been  enabled  to  divide  the  innumerable  quan- 
tity of  Ammonites  into  well-characterized  families,  and  to 
show  that  Ceratites  appertain  to  the  muschelkalk,  Arietes  to 
the  lias,  and  Goniatites  to  transition  limestone  and  graywacke.§ 
The  lower  limits  of  Belemnites  are,  in  the  keuper,  covered  by 
Jura  limestone,  and  their  upper  limits  in  the  chalk  forma- 
tions. ||  It  appears,  from  what  we  now  know  of  this  subject, 
that  the  waters  must  have  been  inhabited  at  the  same  epoch, 
and  in  the  most  widely-remote  districts  of  the-  world,  by  shell- 
fish, which  were,  at  any  rate,  in  part,  identical  with  the  fossil 
remains  found  in  England.  Leopold  von  Buch  has  discovered 
exogyra  and  trigonia  in  the  southern  hemisphere  (volcano  of 

*  Valenciennes,  in  the  Comptes  Rendus  de  V Acadimie  des  Sciences,  t. 
vii.,  1838,  Part  ii.,  p.  580. 

t  la  the  Weald  clay;  Beudant,  Giologie,  p.  173.  The  ornitholite* 
increase  in  number  in  the  gypsum  of  the  tertiary  formations.  Cuvier 
Ossemens  Fossiles,  t.  ii.,  p.  302-328. 

t  [Recent  collections  from  the  southern  hemisphere  show  that  this 
distribution  was  not  so  universal  during  the  earlier  epochs  as  has  gen- 
erally been  supposed.  See  papers  by  Darwin,  Sharpe,  Morris,  and 
M'Coy,  in  the  Geological  Journal.'] — Tr. 

$  Leop,  von  Buch,  in  the  Abhandl.  der  Berl.  Akad.,  1830,  s.  135-187 

II  Quenstedt,  Fldizgehirge  Wnrfemhergs,  1843,  s.  135. 


PALEONTOLOGY.  277 

Maypo  in  Chili),  and  D'Orbigny  lias  "described  Ammonites 
and  Gryphites  from  the  Himalaya  and  the  Indian  plains  of 
Cutch,  these  remains  being  identical  with  those  found  in  the 
old  Jurassic  sea  of  Germany  and  France. 

The  strata  which  are  distinguished  by  definite  kinds  of  pet- 
rifactions, or  by  the  fragments  contained  within  them,  form 
a  geognostic  horizon,  by  which  the  inquirer  may  guide  his 
steps,  and  arrive  at  certain  conclusions  regarding  the  identity 
or  relative  age  of  the  formations,  the  periodic  recurrence  of 
certain  strata,  their  parallelism,  or  their  total  suppression.  If 
we  classify  the  type  of  the  sedimentary  structures  in  the  sim- 
plest mode  of  generalization,  we  arrive  at  the  following  series 
in  proceeding  from  below  upward  : 

1.  The  so-called  tra7isitmn  rocks,  in  the  two  divisions  of 
upper  and  lower  graywacke  (silurian  and  devonian  systems), 
the  latter  being  formerly  designated  as  old  red  sandstone. 

2.  The  lower  trias*  comprising  mountain  limestone,  coal- 
measures,  together  with  the  lower  new  red  sandstone  (Todt- 
liegende  and  Zechstein).t 

3.  The  upper  trias,  including  variegated  sandstone, t  mu* 
chelkalk,  and  keuper. 

4.  Jura  limestone  (lias  and  oolite). 

5.  Green  sandstone,  the  quader  sanstein,  upper  and  lower 
chalk,  terminating  the  secondary  formations,  which  begin  with 
limestone. 

6.  Tertiary  forynations  in  three  divisions,  distinguished  as 
granular  limestone,  the  lignites,  and  the  sub-Apennine  gravei 
of  Italy. 

Then  follow,  in  the  alluvial  beds,  the  colossal  bones  of  the 
mammalia  of  the  primitive  world,  as  the  mastodon,  dinothe- 

*  Queustedt,  Flotzgebirge  Wurtembergs,  1843,  s.  13. 

t  IMurchison  makes  two  divisions  of  the  hunter  sandstone,  the  upper 
being  the  same  as  the  trias  of  Alberti,  while  of  the  lower  division,  to 
which  the  Vosges  sandstone  of  Elie  de  Beaumont  belongs — the  zeck' 
stein  and  the  todtliegende — he  forms  his  Permian  system.  He  makes 
the  secondary  formations  commence  with  the  upper  trias,  that  is  to  say, 
with  the  upper  division  of  our  (German)  bunter  sandstone,  w  hile  the 
Permian  system,  the  carboniferous  or  mountain  limestone,  and  the 
devonian  and  silurian  sti'ata,  constitute  his  palaeozoic  formations.  Ac- 
cording to  these  views,  the  chalk  and  Jura  constitute  the  upper,  and 
the  keuper,  the  muschelkalk,  and  the  hunter  sandstone  the  lower  sec- 
ondary formations,  while  the  Permian  system  and  the  carboniferous 
limestone  are  the  upper,  and  the  devonian  and  silurian  strata  are  the 
lower  palaeozoic  fonnation.  The  fundamental  principles  of  this  general 
classification  are  developed  in  the  great  work  in  which  this  indefaliga« 
ble  British  geologist  purposes  to  describe  the  geology  of  a  large  part  of 
Eastern  Europe. 


278  COSMOS. 

rium,  missniium,  and  the  megatlierides,  among  which  is 
Owen's  sloth-like  mylodon,  eleven  feet  in  length.*  Besides 
these  extinct  families,  we  find  the  fossil  remains  of  still  extant 
animals,  as  the  elephant,  rhinoceros,  ox,  horse,  and  stag.  The 
field  near  Bogota,  called  the  Ca^njoo  de  Gigantes.  which  is 
filled  with  the  hones  of  mastodons,  and  in  which  1  caused  ex- 
cavations to  be  made,  lies  8740  feet  above  the  level  of  the 
Bea,  while  the  osseous  remains,  found  in  the  elevated  plateaux 
of  Mexico,  belong  to  true  elephants  of  extinct  species. t  The 
projecting  spurs  of  the  Himalaya,  the  Sewalik  Hills,  which 
have  been  so  zealously  investigated  by  Captain  CautleyJ  and 
Dr.  Falconer,  and  the  Cordilleras,  whose  elevations  are,  prob- 
ably, of  very  different  epochs,  contain,  besides  numerous  mas- 
todons, the  sivatherium,  and  the  gigantic  land  tortoise  of  the 
primitive  world (Colossochelys),  which  is  twelve  feet  in  length 
and  six  in  height,  and  several  extant  families,  as  elephants, 
rhinoceroses,  and  giraffes ;  and  it  io  a  remarkable  fact,  that 
these  remains  are  found  in  a  zone  which  still  enjoys  the  same 
tropical  climate  which  must  be  supposed  to  have  prevailed  at 
the  period  of  the  mastodons.^ 

Having  thus  passed  in  review  both  the  inorganic  formations 
of  the  earth's  crust  and  the  animal  remains  which  are  con- 
tained within  it,  another  branch  of  the  history  of  organic  life 
still  remains  for  our  consideration,  viz.,  the  epoch  of  vegcta 
tion,  and  the  successive  floras  that  have  occurred  simul- 
taneously with  the  increasing  extent  of  the  dry  land  and  the 
modifications  of  the  atmosphere.  The  oldest  transition  strata, 
as  we  Jbave  already  observed,  contain  merely  cellular  marine 
plants,  and  it  is  only  in  the  devonian  system  that  a  few  cryp- 
togamic  forms  of  vascular  plants  (Calamites  and  Lycopodi- 
acese)  have  been  observed. II     Nothing  appears  to  corroborate 

*  [See  Mantell's  Wonders  of  Geology,  vol.  i.,  p.  168.]— Tr. 

t  Olivier,  Ossemens  Fossiles,  1821.  t.  i.,  p.  157,  261,  and  264.  See, 
also,  Humboldt,  Ueber  die  Hochebene  von  Bogota,  in  the  Devtschen 
Vierteljahrs-schrift,  1839,  bd.  i.,  s.  117. 

t  [The  fossil  fauna  of  the  Sewalik  range  of  hills,  skirting  the  south- 
ern base  of  the  Himalaya,  has  proved  more  abundant  in  genera  nnd 
species  of  mammalia  than  that  of  any  other  I'egioii  yet  explored.  As 
a  general  expression  of  the  leading  features,  it  may  be  stated,  that  it 
appears  to  have  been  composed  of  representative  forms  of  all  ages, 
from  the  oldest  of  the  tertiary  period  down  to  the  modern,  and  o{  all  tht 
geographical  divisions  of  the  Old  Continent  groupe<l  tofjether  into  Oiie 
comprehensive  fauna.  Fauna  Antiqita  Sivalicnsis,  by  Hu^h  Falconer. 
M.D.,  and  iMajor  P.  T.  Oautley.]— Tr. 

§  Journal  of  the  Asiatic  Society,  1844,  No.  15,  p.  109. 

II  Beyrich,  in  Karsten's  Archivfar  Mlneralogie,  1844.  bd.  xviii.,  s.  218 


PALAEONTOLOGY.  279 

the  theoretical  views  that  have  been  started  rejravdinjr  the 
simphcity  of  primitive  forms  of  organic  Hfe,  or  that  vegetable 
preceded  animal  lile,  and  that  the  former  was  necessarily  de- 
pendent upon  the  latter.  The  existence  of  races  of  men  in- 
habiting the  icy  regions  of  the  North  Polar  lands,  and  whose 
nutriment  is  solely  derived  from  lish  and  cetaceans,  shows  the 
possibility  of  maintaining  life  independently  of  vegetable  sub- 
stances. After  the  devonian  system  and  the  mountain  lime- 
stone, we  come  to  a  formation,  the  botanical  analysis  oi"  which 
has  made  such  brilliant  advances  in  modern  times.*  The 
coal  measures  contain  not  only  fern- like  cryptogamic  plants 
and  phanerogamic  monocotyledons  (grasses,  yucca-like  Lilia- 
cea3,  and  palms),  but  also  gymnospermic  dicotyledons  (Coniferte 
and  Cycadeas),  amounting  in  all  to  nearly  400  species,  as  char- 
acteristic of  the  coal  formations.  Of  these  we  will  onlv  enu- 
merate  arborescent  Calamites  and  Lycopodiacese,  scaly  Lepi- 
dodendra,  Sigillarise,  which  attain  a  height  of  sixty  feet,  and 
are  sometimes  found  standing  upright,  being  distinguished  by 
a  double  system  of  vascular  bundles,  cactus-like  Stigmarite,  a 
great  number  of  ferns,  in  some  cases  the  stems,  and  in  others 
the  fronds  alone  being  found,  indicating  by  their  abundance 
the  insular  form  of  the  dry  land,t  Cycadea3,$  especially  palms, 
although  fewer  in  number,^  Asterophyllites,  having  whorl-like 
leaves,  and  allied  to  the  Naiades,  with  araucaria-like  Coniferse,!! 
which  exhibit  faint  traces  of  annual  rings.  This  difference  of 
character  from  our  present  vegetation,  manifested  in  the  vege- 
tative forms  which  were  so  luxuriously  developed  on  the  drier 

*  By  the  important  labors  of  Couut  Sternberg,  Adolphe  Brougniart, 
Goppert,  and  Lindley. 

t  See  Robert  Brown's  Botany  of  Congo,  p.  42,  and  the  Memoir  of 
the  unfortunate  D'Urville,  De  la  Distribution  des  Fougeres  sur  la  Sur- 
face  du  Globe  Terrestre. 

X  Such  are  the  Cycadeae  discovered  by  Count  Sternberg  in  the  old 
carboniferous  formation  at  Radnitz,  in  Bohemia,  and  described  by 
Corda  (two  species  of  Cycatides  and  Zamites  Cordai.  See  Goppert, 
Fossile  Cycadeen  in  den  Arbeiten  der  Schles.  GeseUschaft,  fur  vaterl. 
Cultur  im  Jahr  1843,  s.  33,  37,  40,  and  50).  A  Cycadea  (Pterophyllum 
gonorrhachis,  Gopp.)  has  also  been  found  in  the  carboniferous  forma- 
tions in  Upper  Silesia,  at  Konigshtitte. 

$  Lindley,  Fossil  Flora,  No.  xv.,  p.  163. 

II  Fossil  Coniferce,  in  Buckland's  Geology,  p.  483-490.  Witham  has 
the  great  merit  of  having  first  recognized  the  existence  of  Coniferse  in 
the  early  vegetation  of  the  old  carboniferous  formation.  Almost  all  the 
trunks  of  trees  found  in  this  formation  were  previously  regarded  as 
palms.  The  species  of  the  genus  Arancaria  are,  however,  not  pecul- 
iar to  the  coal  formations  of  the  British  Islands;  they  likewise  occur  in 
Upper  Silesia. 


280  cu^.^iori. 

and  more  elevated  portions  of  the  old  red  sandstone,  was  main« 
tained  through  all  the  subsequent  epochs  to  the  most  recent 
chalk  formations  ;  amid  the  peculiar  characteristics  exhibited 
in  the  vejretable  forms  contained  in  the  coal  measures,  there 
is,  however,  a  strikingly-marked  prevalence  of  the  same  fami- 
lies, if  not  of  the  same  species,^  in  all  parts  of  the  earth  as  it 
then  existed,  as  in  New  Holland,  Canada,  Greenland,  and 
Melville  Island. 

The  vegetation  of  the  primitive  period  exhibits  forms  v/hich, 
from  their  simultaneous  affinity  w^ith  several  families  of  the 
present  world,  testify  that  many  intermediate  links  must  have 
become  extinct  in  the  scale  of  organic  development.  Thus, 
for  example,  to  mention  only  two  instances,  we  would  notice 
the  Lepidodendra,  which,  according  to  Lindley,  occupy  a  place 
between  the  Coniferse  and  the  Lycopodiaceee,!  and  the  Arau- 
carise  and  pines,  which  exhibit  some  peculiarities  in  the  union 
of  their  vascular  bundles.  Even  if  we  limit  our  consideration 
to  the  present  world  alone,  we  must  regard  as  highly  import- 
ant the  discovery  of  Cycadese  and  Conifera3  side  by  side  with 
SagenariaB  and  Lepidodendra  in  the  ancient  coal  measures. 
The  Coniferee  are  not  only  allied  to  Cupuliferaj  and  Betuliuce, 
with  which  we  find  them  associated  in  lignite  formations,  but 
also  with  Lycopodiacese.  The  family  of  the  sago-like  Cyca- 
dese approaches  most  nearly  to  palms  in  its  external  appear- 
ance, while  these  plants  are  specially  allied  to  Conifers  in  re- 
spect to  the  structure  of  their  blossoms  and  seed.J  Where 
many  beds  of  coal  are  superposed  over  one  another,  the  fami- 
lies and  species  are  not  always  blended,  being  most  frequently 
grouped  together  in  separate  genera  ;  Lycopodiacese  and  cer- 
tain ferns  being  alone  found  in  one  bed,  and  Stigmariae  and 
Sigillarise  in  another.  In  order  to  give  some  idea  of  the  lux- 
uriance of  the  vegetation  of  the  primitive  world,  and  of  the 
immense  masses  of  vegetable  matter  which  was  doubtlessly 
accumulated  in  currents  and  converted  in  a  moist  condition 
into  coal,§  I  would  instance  the  Saarbriicker  coal  measures, 

*  Adolphe  Brongniart,  Prodrome  d'vne  Hist,  des  VegUaux  Fossiles,  p. 
179  ;  Buckland,  Geology,  p.  479;  Eudlicher  and  Unger,  Grundzuge  der 
Boianik,  1843,  s.  455. 

t  "  By  means  of  Lepidodeudron,  a  better  passage  is  established  from 
flowering  to  flowerless  plants  than  by  either  Equisetum  or  Cycas,  or 
any  other  known  genus." — Lindley  and  Hiitton,  Fossil  Flora,  vol.  ii., 
p.  53. 

X  Kunth,  Anordnnng  der  Pflanzenfamilien,  in  his  Handb.  der  Bof.anik 
8.  307  und  314. 

§  That  coal  has  not  been  formed  froui  veii('tM])]r!  ii!)es  clianed  bv 


PALAEONTOLOGY.  281 

where  120  beds  are  superposed  on  one  another,  exchisive  of  a 
great  many  which  are  less  than  a  foot  in  thickness  ;  the  coal 
beds  at  Johnstone,  in  Scotland,  and  those  in  the  Creuzot,  in 
Burgundy,  are  some  of  them,  respectively,  thirty  and  fifty  feet 
in  thickness,^  while  in  the  forests  of  our  temperate  zones,  the 
carbon  contained  in  the  trees  growing  over  a  certain  area 
would  hardly  suffice,  in  the  space  of  a  hundred  years,  to  cover 
it  with  more  than  a  stratum  of  seven  French  lines  in  thick- 
ness.! Near  the  mouth  of  the  Mississippi,  and  in  the  "w^ood 
hills"  of  the  Siberian  Polar  Sea,  described  by  Admiral  Wran- 
gel,  the  vast  number  of  trunks  of  trees  accumulated  by  river 
and  sea  water  currents  affords  a  striking  instance  of  the 
enorm.ou3  quantities  of  drift-wood  which  must  have  favored 
the  formation  of  carboniferous  depositions  in  the  inland  waters 
and  insular  bays.  There  can  be  no  doubt  that  these  beds 
owe  a  considerable  portion  of  the  substances  of  which  they 
consist  to  grasses,  small  branching  shrubs,  and  cryptogamic 
plants. 

The  association  of  palms  and  Coniferee,  which  we  have  in- 
dicated as  being  characteristic  of  the  coal  formations,  is  dis- 
coverable throughout  almost  all  formations  to  the  tertiary 
period.     In  the  present  condition  of  the  world,  these  genera 

fire,  but  that  it  has  more  probably  been  produced  in  the  moist  way  by 
the  action  of  sulphuric  acid,  is  stnkingly  demonstrated  by  the  excellent 
observation  made  by  Goppert  (Karsteu,  Archiv  fur  Mineralogie,  bd. 
xviii.,  s.  530),  on  the  conversion  of  a  fragment  of  amber-tree  into  black 
coal.  The  coal  and  the  unaltered  amber  lay  side  by  side.  Regarding 
the  part  which  the  lower  forms  of  vegetation  may  have  had  in  the  for- 
mation of  coal  beds,  see  Link,  in  the  Abhandl.  der  Berliner  Akademie 
der  Wissenschaften,  f838,  s.  38. 

*  [The  actual  total  thickness  of  the  different  beds  in  Ensland  varies 
considerably  in  diiferent  districts,  but  appears  to  amount  in  the  Lanca- 
shire coal  field  to  as  much  as  150  feet. — Ansted's  Ancient  World,  p. 
78.  For  an  enumeration  of  the  thickness  of  coal  measures  in  America 
and  the  Old  Continent,  see  Mantell's  Wonders  of  Geology,  vol.  ii.,  p. 
69.]  — Tr. 

t  See  the  accurate  labors  of  Chevandier,  in  the  Comptes  Rendus  de 
VAcad^mie  des  Sciences,  1844,  t.  xviii.,  Part  i.,  p.  285.  In  comparing 
this  bed  of  carbon,  seven  lines  in  thickness,  with  beds  of  coal,  we  must 
not  omit  to  consider  the  enormous  pressure  to  which  the  latter  have 
been  subjected  from  superimposed  rock,  and  which  manifests  itself  in 
the  flattened  form  of  the  stems  of  the  trees  found  in  these  subterranean 
regions.  "  The  so-called  wood-hills  discovered  in  1806  by  Sirowatskoi, 
on  the  south  coast  of  the  island  of  New  Siberia,  consist,  according  to 
Hedenstrom,  of  horizontal  strata  of  sandstone,  alternating  with  bitu- 
minous trunks  of  ti'ees,  forming  a  mound  thirty  fathoms  in  height ;  at 
the  summit  the  stems  were  in  a  vertical  position.  The  bed  of  <lrift- 
wood  is  visible  at  five  wersts'  distance." — See  Wrangel,  Reise  Uin^a 
der  Nardkuste  von  Siberian,  in  den  Jahren  1820-24,  th.  i.,  s.  102. 


282  COSMOS. 

appear  to  exhibit  no  tendency  whatever  to  occur  associated 
lofrether.  We  have  so  accustomed  ourselves,  althouofh  erro- 
neously,  to  regard  Conifera3  as  a  northern  form,  that  I  experi- 
enced a  feehng  of  surprise  when,  in  ascending  from  the  shores 
of  the  South  Pacific  toward  Chilpansingo  and  the  elevated 
valleys  of  Mexico,  between  the  Venta  de  la  Moxonera  and  the 
Alto  de  los  Caxones,  4000  feet  above  the  level  of  the  sea,  I 
rode  a  whole  day  through  a  dense  wood  of  Pinus  occidentalis, 
where  I  observed  that  these  trees,  which  are  so  similar  to  the 
Weymouth  pine,  were  associated  with  fan  palms*  {Cori/pha 
dulcis),  swarming  v/ith  brightly-colored  parrots.  South  Amer- 
ica has  oaks,  but  not  a  single  species  of  pine  ;  and  the  first 
time  that  I  again  saw  the  familiar  form  of  a  fir-tree,  it  was 
thus  associated  with  the  strange  appearance  of  the  fan  palm.f 
Christopher  Columbus,  in  his  first  voyage  of  discovery,  saw 
Coniferaj  and  palms  growing  together  on  the  northeastern  ex- 
tremity of  the  island  of  Cuba,  likewise  within  the  tropics,  and 
scarcely  above  the  level  of  the  sea.  This  acute  observer, 
whom  nothing  escaped,  mentions  the  fact  in  his  journal  as  a 
remarkable  circumstance,  and  his  friend  Anghiera,  the  secre- 
tary of  Ferdinand  the  Catholic,  remarks  with  astonishment 
"  that  jKdmeta  and  inneta  are  found  associated  together  in 
the  newly-discovered  land."  It  is  a  matter  of  much  import- 
ance to  geology  to  compare  the  present  distribution  of  plants 
over  the  earth's  surface  w4th  that  exhibited  in  the  fossil  floras 
of  the  primitive  world.  The  temperate  zone  of  the  southern 
hemisphere,  which  is  so  rich  in  seas  and  islands,  and  v/here 

*  This  corypha  is  the  snyate  (in  Aztec,  zoyall')'o"  the  Palma  dulce  of 
the  natives.  See  Huiuboklt  auJ  Bonplaiid.  Synopt^ls  Plant,  ^^quinoct. 
Oihis  Novi,  t.  i.,  p.  302.  Professor  Buschmaiin,  who  is  profoundly  ac- 
quaiuted  with  the  American  languages,  remarks,  that  the  Palma  soy  ate 
is  so  named  in  Yepe's  Vocabulario  de  la  Lengua  Othomi,  and  that  the 
Aztec  word  zoyatl  (Molina,  Vocabulario  en  Lengua  Mexicana  y  Castel- 
lana,  p.  25)  recurs  in  uames  of  places,  such  as  Zoyatitlan  and  Zoya- 
pauco,  near  Chiapa. 

t  Near  Baracoa  and  Cayos  de  Moya.  See  the  Admiral's  journal  of 
the  2.5th  and  27th  of  November,  1492,  and  Humboldt,  Examen  Critique 
de  V Hist,  de  la  Giographie  du  Nouveau  Continent,  t.  ii.,  p.  252,  and  t. 
iii.,  p.  23.  Columbus,  who  invariably  paid  the  most  remarkable  atten- 
tion to  all  natural  objects,  v/as  the  first  to  observe  the  ditference  be- 
tween Podocarpus  and  Pinus.  "  I  find,"  said  he,  "  en  la  tierra  aspera 
del  Cibao  pinos  que  no  llevan  pinas  (fir  cones),  pero  portal  orden  com- 
puestos  por  naturaleza,  que  (los  frutos)  pareceu  azeytimas  del  Axarafe 
de  Sevilla."  The  great  botanist,  Richard,  when  he  published  his  ex- 
cellent Memoir  on  Cycade;Te  and  Conifene,  little  imagined  that  before 
the  time  of  L'Heritier,  and  even  before  the  end  of  the  fifteenth  cen- 
tury, a  navigator  had  separated  Podocarjyns  from  the  Abietineoe. 


PALiEONTOLOGY.  283 

tropical  forms  blend  so  remarkably  with  those  of  colder  parts 
of  the  earth,  presents,  according  to  Darwin's  beautiful  and 
animated  descriptions,*  the  most  instructive  materials  for  the 
study  of  the  present  and  the  past  geography  of  plants.  The 
history  of  the  primordial  ages  is,  in  the  strict  sense  of  the 
word,  a  part  of  the  history  of  plants. 

CycadesB,  which,  from  the  number  of  their  fossil  species,  must 
have  occupied  a  far  more  important  part  in  the  extinct  than 
in  the  present  vegetable  world,  are  associated  with  the  nearly 
allied  Coniferffi  from  the  coal  formations  upward.  They  are 
almost  wholly  absent  in  the  epoch  of  the  variegated  sandstone 
which  contains  Coniferse  of  rare  and  luxuriant  structure  (  Vol- 
tizia,  Ilaidingera,  Albertia) ;  the.  Cycadeae,  however,  occur 
most  frequently  in  the  keuper  and  lias  strata,  in  which  more 
than  twenty  diilerent  forms  appear.  In  the  chalk,  marine 
plants  and  naiades  predominate.  The  forests  of  Cycadeae  of 
the  Jura  formations  had,  therefore,  long  disappeared,  and  even 
in  the  more  ancient  tertiary  formations  they  are  quite  subor- 
dinate to  the  Coniferce  and  palms. t 

The  lignites,  or  beds  of  brown  coalt  which  are  present  in 
all  divisions  of  the  tertiary  period,  present,  among  the  most 
ancient  cryptogami  i  land  plants,  some  few  palms,  many  Co- 
nifera3  having  distinct  annual  rings,  and  foliaceous  shrubs  of  a 
more  or  less  tropical  character.  In  the  m^iddle  tertiary  period 
we  again  find  palms  and  Cycadese  fully  established,  and  final- 
ly a  great  similarity  with  our  existing  Hora,  manifested  in  the 
sudden  and  abundant  occurrence  of  our  pines  and  firs,  Cupu- 
lifei'ce,  maples,  and  poplars.  The  dicotyledonous  stems  found 
in  lisnite  are  occasionally  distinguished  bv  colossal  size  and 
great  age.  In  the  trunk  of  a  tree  found  at  Bonn,  Noggerath 
counted  792  annual  rings.  ^  In  the  north  of  France,  at  Yseux, 
near  Abbeville,  oaks  have  been  discovered  in  the  turf  moors 
of  the  Somme  which  measured  fourteen  feet  in  diameter,  a 
thickness  which  is  very  remarkable  in  the  Old  Continent  and 
without  the  tropics.  According  to  Goppert's  excellent  inves- 
tigations, which,  it  is  hoped,  may  soon  be  illustrated  by  plates^- 
it  would  appear  that  "  all  the  amber  of  the  Baltic  comes  from 

*  Charles  Darv/in,  Journal  of  the  Voyages  of  the  Adventure  and 
Beagle,  1839,  p.  271. 

t  GSppert  describes  three  other  Cycade.np  (species  of  Cycadites  and 
Plerophyllam),  tbuud  in  the  brown  carboniferous  schistose  clay  <>f  Alt- 
sattel  and  Coinniotuu,  in  Bohemia.  They  very  probably  belong  to  tho 
Eocene  Period.     Gopperf,  Fossile  Cycadecn,  .s.  fil, 

X  \_Medals  of  Creation,  vol.  i.,  cli.  v.,  &c.  Wonders  of  Geology,  vol.  i., 
p.  278,  392.] — YV.  $  Bnckland,  Geology,  p.  .^)09. 


284  COSMOS. 

a  coniferous  tree,  which,  to  judge  by  the  still  extant  remama 
of  the  wood  and  the  bark  at  different  ages,  approaches  very 
nearly  to  our  white  and  red  pines,  although  forming  a  distinct 
species.  The  amber-tree  of  the  ancient  world  {Pijzites  succi- 
fer)  abounded  in  resin  to  a  degree  far  surpassing  that  mani- 
lested  by  any  extant  coniferous  tree  ;  for  not  only  were  large 
masses  of  amber  deposited  in  and  upon  the  bark,  but  also  iu 
the  wood  itself,  following  the  course  of  the  medullary  rays, 
which,  together  with  ligneous  cells,  are  still  discernible  under 
the  microscope,  and  peripherally  between  the  rings,  being  some 
times  both  yellow  and  white." 

"  Among  the  vegetable  forms  inclosed  in  amber  are  male 
and  female  blossoms  of  our  native  needle-v/ood  trees  and  Cupu- 
liferjB,  while  fragments  which  are  recos^nized  as  belonoiuor  tc 
thuia,  cupressus,  ephedera,  and  castania  vesca,  blended  wdtk 
those  of  junipers  and  firs,  indicate  a  vegetation  difierent  fronr 
that  of  the  coasts  and  plains  of  the  Baltic. "=^ 

We  have  now  passed  through  the  whole  series  of  formationa 
comprised  in  the  geological  portidn  of  the  present  work,  pro- 
ceeding from  the  oldest  erupted  rock  and  the  most  ancient  sed- 
imentary formations  to  the  alluvial  land  on  which  are  scat- 
tered those  large  masses  of  rock,  the  causes  of  whose  general 
distribution  have  been  so  long  and  variously  discussed,  and 
which  are,  in  my  opinion,  to  be  ascribed  rather  to  the  pene- 
tration and  violent  outpouring  of  pent-up  waters  by  the  eleva- 
tion of  mountain  chains  than  to  the  motion  of  floating  blocks 
of  ice.f    The  most  ancient  structures  of  the  transition  forma- 

*  [The  forests  of  ambcr-piiie?,  Pinites  succifer,  were  iu  the  southeast- 
ei'n  part  of  what  is  now  the  bed  of  the  Baltic,  iu  about  .5.5°  N.  lat., 
and  37°  E.  long.  The  different  colors  of  amber  are  derived  from  local 
chemical  admixture.  The  amber  contains  fragments  of  vegetable  mat- 
ter, and  from  these  it  has  been  ascertained  that  the  amber-pine  forests 
contained  four  other  species  of  pine  (besides  the  Pinites  succifer),  sev- 
eral cypresses,  yews,  and  jiuiipers,  with  ouks,  poplars,  beeches,  &c. — 
altogether  forty-eight  species  of  trees  and  shrubs,  constituting  a  flora 
of  North  American  character.  There  are  also  some  ferns,  mosses,  fungi, 
and  liverworts.  See  Professor  Goppert,  Geo/.  Trans.,  I'Si^b.  Insects,  spi- 
ders, small  crustaceans,  leaves,  and  fragments  of  vegetable  tissue,  are 
imbedded  in  some  of  the  masses.  Upward  of  800  species  of  insects 
have  been  observed;  most  of  them  belong  to  species,  and  even  genera, 
that  appear  to  be  distinct  from  any  now  known,  but  others  are  nearly 
related  to  indigenous  species,  and  some  are  identical  with  existing  forms, 
that  inhabit  mjre  southern  climes. —  Wonders  of  Geology,  vol.  i.,  p.  242, 
&c.]— Tr. 

+  Leopold  von  Buch,  iu  the  Ahhandl.  der  Akad.  der  Wissensch .  zu 
Berlin,  1814-15,  s.  161  ;  and  in  Poggend.,  Annalen.  bd.  ix..  s.  57-'»  •  '''i** 
de  Pu'uumout,  in  the  Annales  des  Sciences  Nalnrelles,  t.  xi.\.,  p.  0^ 


.      GEOGNOSTIC    PERIODS.  285 

tion  with  which  we  are  acquainted  are  slate  and  gra^wacke, 
which  contain  some  remains  of  sea  weeds  from  the  silurian  or 
Cambrian  sea.  On  what  did  these  so-called  7?iost  ancie?U  for- 
mations rest,  if  gneiss  and  mica  schist  must  be  regarded  as 
changed  sedimentary  strata?  Dare  we  hazard  a  conjecture 
on  that  which  can  not  be  an  object  of  actual  geognostic  observ- 
ation ?  According  to  an  ancient  Indian  myth,  the  earth  is 
borne  up  by  an  elephant,  who  in  his  turn  is  supported  by  a 
gigantic  tortoise,  in  order  that  he  may  not  fall  ;  but  it  is  not 
permitted  to  the  credulous  Brahmins  to  inquire  on  what  the 
tortoise  rests.  We  venture  here  upon  a  somewhat  similar 
problem,  and  are  prepared  to  meet  with  opposition  in  our  en- 
deavors to  arrive  at  its  solution.  In  the  first  formation  of  the 
planets,  as  we  stated  in  the  astronomical  portion  of  this  work, 
it  is  probable  that  nebulous  rings  revolving  round  the  sun  were 
agglomerated  into  spheroids,  and  consolidated  by  a  gradual 
condensation  proceeding  from  the  exterior  toward  the  center. 
What  we  term  the  ancient  silurian  strata  are  thus  only  the 
upper  portions  of  the  sohd  crust  of  the  earth.  The  erupted 
rocks  which  have  broken  through  and  upheaved  these  strata 
have  been  elevated  from  depths  that  are  wholly  inaccessible 
to  our  research  ;  they  must,  therefore,  have  existed  under  the 
silurian  strata,  and  been  composed  of  the  same  association  of 
minerals  which  we  term  granite,  augite,  and  quartzose  por- 
phyry, when  they  are  made  known  to  us  by  eruption  through 
the  surface.  Basing  our  inquiries  on  analogy,  we  may  assume 
that  the  substances  which  fill  up  deep  fissures  and  traverse  the 
sedimentary  strata  are  merely  the  ramifications  of  a  lower  de- 
posit. The  foci  of  active  volcanoes  are  situated  at  enormous 
depths,  and,  judging  from  the  remarkable  fragments  which  I 
have  found  in  various  parts  of  the  earth  incrusted  in  lava  cur- 
rents, I  should  deem  it  more  than  probable  that  a  primordial 
granite  rock  forms  the  substratum  of  the  whole  stratified  edi- 
fice of  fossil  remains.*  Basalt  containing  olivine  first  shows 
itself  in  the  period  of  the  chalk,  trachyte  still  later,  while  erup- 
tions of  granite  belong,  as  we  learn  from  the  products  of  their 
metamorphic  action,  to  the  epoch  of  the  oldest  sedimentary 
strata  of  the  transition  formation.  Where  knowledge  can  not 
be  attained  from  immediate  perceptive  evidence,  we  may  be 
allowed  from  induction,  no  less  than  from  a  careful  comparison 
of  facts,  to  hazard  a  conjecture  by  which  granite  would  be  re- 

*  See  Elie  de  Beaumont,  Descr.  G^ol.  de  la  France,  t.  i.,  p.  6.5  ;  Beu 
dant,  Giologie,  1844,  p.  1(\d. 


286  COSMOS. 

stored  to  a  portion  of  its  Contested  right  and  title  tD  be  consid- 
ered as  a  iiriinnrdial  rock. 

The  recent  progress  of"  geognosy,  that  is  to  say,  the  more 
extended  knowledge  of  the  geognostic  epochs  characterized  by 
difference  of  mineral  formations,  by  the  peculiarities  and  suc- 
cession of  the  organisms  contained  within  them,  and  by  the 
position  of  the  strata,  whether  uplifted  or  inclined  horizontally 
leads  us,  by  means  of  the  causal  connection  existing  among  all 
natural  phenomena,  to  the  distribution  of  solids  and  fluids  into 
the  continents  and  seas  which  constitute  the  upper  crust  of  our 
planet.  We  here  touch  upon  a  point  of  contact  between  geo- 
logical and  geographical  geognosy  which  would  constitute  the 
complete  history  of  the  form  and  extent  of  continents.  The 
limitation  of  the  solid  by  the  fluid  parts  of  the  earth's  surface 
and  their  mutual  relations  of  area,  have  varied  very  consider- 
ably in  the  long  series  of  geognostic  epochs.  They  Avere  veiy 
different,  for  instance,  when  carboniferous  strata  were  horizon- 
tally deposited  on  the  inclined  beds  of  the  mountain  limestone 
and  old  red  sandstone  ;  when  lias  and  oolite  lay  on  a  substra- 
tum of  keuper  and  muschelkalk,  and  the  chalk  rested  on  the 
slopes  of  green  sandstone  and  Jura  limestone.  If,  with  Elie 
de  Beaumont,  we  term  the  waters  in  which  the  Jura  limestone 
and  chalk  formed  a  soft  deposit  the  Jui'assic  or  oolitic,  and  the 
creto.ceous,  seas,  the  outlines  of  these  formations  will  indicate, 
for  the  two  corresponding  epochs,  the  boundaries  between  the 
already  dried  land  and  the  ocean  in  which  these  rocks  were 
forming.  An  ingenious  attempt  has  been  made  to  draw  maps 
of  this  physical  portion  of  primitive  geography,  and  we  may 
consider  such  diagrams  as  more  correct  than  those  of  the  v\^an- 
derings  of  lo  or  the  Homeric  geography,  since  the  latter  are 
merely  graphic  representations  of  mythical  images,  while  the 
former  are  based  upon  positive  facts  deduced  from  the  science 
of  geology. 

The  results  of  the  investigations  made  regarding  the  areal 
relations  of  the  solid  portions  of  our  planet  are  as  follows  :  in 
the  most  ancient  times,  during  the  silurian  and  devonian  tran- 
sition epochs,  and  in  the  secondary  formations,  including  the 
trias,  the  continental  portions  of  the  earth  were  limited  to  in- 
sular groups  covered  with  vegetation  ;  these  islands  at  a  sub- 
sequent period  became  united,  giving  rise  to  numerous  lakes 
and  deeply-indented  bays  ;  and,  finally,  when  the  chains  of 
the  Pyrenees,  Apennines,  and  Carpathian  Mountains  were 
elevated  about  the  period  of  the  more  ancieiit  tertiary  forma- 
tions, large  contiueiits  appeared,  having  almost  their  prcscui 


PHYSICAL    GEOGRAPHY.  287 

size.*  Ill  the  silurian  epoch,  as  well  as  in  that  in  which  the  Cy- 
cadeee  flourished  in  such  abundance,  and  gigantic  saurians  were 
living,  the  dry  land,  from  pole  to  pole,  was  probably  less  than  it 
now  is  in  the  South  Pacific  and  the  Indian  Ocean.  We  shall 
see,  in  a  subsequent  part  of  this  work,  how  this  prepondera- 
ting quantity  of  water,  combined  with  other  causes,  must  have 
contributed  to  raise  the  temperature  and  induce  a  greater  uni- 
formity of  climate.  Here  we  would  only  remark,  in  consider- 
ing the  gradual  extension  of  the  dry  land,  that,  shortly  before 
the  disturbances  which  at  longer  or  shorter  intervals  caused 
the  sudden  destruction  of  so  great  a  number  of  colossal  verte- 
brata  in  the  diluvial  'period,  some  parts  of  the  present  conti- 
nental masses  must  have  been  completely  separated  from  one 
another.  There  is  a  great  similarity  in  South  America  and 
Australia  between  still  living  and  extinct  species  of  animals. 
In  New  Holland  fossil  remains  of  the  kangaroo  have  been 
found,  and  in  New  Zealand  the  semi-fossilized  bones  of  an  enor- 
mous bird,  resembling  the  ostrich,  the  dinornis  of  Owen, f  which 
is  nearly  allied  to  the  present  apteryx,  and  but  little  so  to  the  re- 
cently extinct  dronte  (dodo)  of  the  island  of  Rodriguez. 

The  form  of  the  continental  portions  of  the  earth  may,  per- 
haps, in  a  great  measure,  owe  their  elevation  above  the  sur- 
rounding level  of  the  water  to  the  eruption  of  quartzose  por- 
phyry, which  overthrew  with  violence  the  first  great  vegeta- 
tion from  which  the  material  of  our  present  coal  measures  was 
formed.  The  portions  of  the  earth's  surface  which  v»'e  term 
plains  are  nothing  more  than  the  broad  summits  of  hills  and 
mountains  whose  bases  rest  on  the  bottom  of  the  ocean.  Every 
plain  is,  therefore,  when  considered  according  to  its  submarine 
relations,  an  elevated  plateau,  whose  inequahties  have  been 
covered  over  by  horizontal  deposition  of  new  sedimentary  for- 
mations and  by  the  accumulation  of  alluvium. 

*  [These  movements,  described  in  so  few  words,  were  doubtless  go 
ing  on  tor  many  thousands  and  tens  of  thousands  of  revolutions  of  our 
planet.  They  were  accompanied,  also,  by  vast  but  slow  changes  of  other 
kinds.  The  expansive  force  employed  in  lifting  up,  by  mighty  move- 
ments, the  northern  portion  of  the  continent  of  Asia,  found  partial  vent ; 
and  from  partial  subaqueous  fissures  there  were  poured  out  the  tabular 
masses  of  basalt  occurring  in  Central  India,  while  an  extensive  area  of 
depression  in  the  Indian  Ocean,  marked  by  the  coral  islands  of  the  Lac- 
cadives,  the  Maldives,  the  great  Chagos  Bank,  and  some  others,  were 
in  the  course  of  depression  by  a  counteracting  movement. — Ansted'a 
Ancient  World,  p.  346,  &c.]— Tr. 

+  [See  American  Journal  of  Science,  vol.  xlv.,  j).  187  ;  nnd  Medals 
of  Creation,  vol.  ii.,  ]i.  817  ;  Trans.  Zoolog.  Society  of  London,  vol.  ii. : 
Wonders  of  Geolcry,  vol.  i.,  p.  rJ9.]— Tv. 


288  COSMOS. 

Among  the  general  subjects  of  contemplation  appertaining 
to  a  work  of  this  nature,  a  prominent  place  must  be  given,  first, 
to  the  consideration  of  the  qucmiity  of  the  land  raised  above 
the  level  of  the  sea,  and,  next,  to  the  individual  configuration 
of  each  part,  either  in  relation  to  horizontal  extension  (rela- 
tions of  form)  or  to  vertical  elevation  (hypsometrical  relations 
of  mountain-chains).  Our  planet  has  tv^^o  envelopes,  of  which 
one,  which  is  general — the  atmosphere — is  composed  of  an 
elastic  fluid,  and  the  other — the  sea — is  only  locally  distribu- 
ted, surrounding,  and  therefore  modifying,  the  form  of  the  land. 
These  two  envelopes  of  air  and  sea  constitute  a  natural  whole, 
on  which  depend  the  difference  of  climate  on  the  earth's  sur- 
face, according  to  the  relative  extension  of  the  aqueous  and 
solid  parts,  the  form  and  aspect  of  the  land,  and  the  direction 
and  elevation  of  mountain  chains.  A  knowledge  of  the  recip- 
rocal action  of  air,  sea,  and  land  teaches  us  that  great  me- 
teorological phenomena  can  not  be  comprehended  when  consid- 
ered independently  of  geognostic  relations.  Meteorology,  as 
well  as  the  geography  of  plants  and  animals,  has  only  begun 
to  make  actual  progress  since  the  mutual  dependence  of  the 
phenomena  to  be  investigated  has  been  fully  recognized.  The 
word  climate  has  certainly  special  reference  to  the  character 
of  the  atmosphere,  but  this  character  is  itself  dependent  on  the 
perpetually, concurrent  influences  of  the  ocean,  which  is  uni- 
versally and  deeply  agitated  by  currents  having  a  totally  oppo- 
site temperature,  and  of  radiation  from  the  dry  land,  which  va- 
ries greatly  in  form,  elevation,  color,  and  fertility,  whether  we 
consider  its  bare,  rocky  portions,  or  those  that  are  covered  with 
arborescent  or  herbaceous  vegetation. 

In  the  present  condition  of  the  surface  of  our  planet,  the  area 
of  the  solid  is  to  that  of  the  fluid  parts  as  1  :  2|ths  (accord- 
ing to  E-igaud,  as  100  :  270).'*  The  islands  form  scarcely  g-^d 
of  the  continental  masses,  which  are  so  unequally  divided  that 
they  consist  of  three  times  more  land  in  the  northern  than  in 
the  southern  hemisphere  ;  the  latter  being,  therefore,  pre-emi- 
nently oceanic.  From  40'-'  south  latitude  to  the  Antarctic 
pole  the  earth  is  almost  entirely  covered  with  water.  The 
fluid  element  predominates  in  like  manner  between  the  east- 
ern shores  of  the  Old  and  the  western  shores  of  the  New  Con- 
tinent, being  only  interspersed  with  some  few  insular  groups. 
The  learned  hydrographer  Fleurieu  has  very  justly  named  this 

*  See  Transactions  of  the  Cambridge  Philosopliical  Societ'j.  vrl.  vi  , 
Pai-t  ii.,  1837,  p.  297.     Other  writers  have  given  the  ratb  as  lOP  :  281. 


PHYSICAL    GEOGRAPHY.  289 

vast  oceanic  basin,  which,  under  the  tropics,  extends  over  145^ 
of  longitude,  the  Great  Ocean,  in  contradistinction  to  all  other 
seas.  The  southern  and  western  hemispheres  (reckoning  the 
latter  from  the  "meridian  of  Tenerifle)  are  therefore  more  rich 
iw.  water  than  any  other  region  of  the  whole  earth. 

These  are  the  main  points  involved  in  the  consideration  of 
the  relative  quantity  of  land  and  sea,  a  relation  which  exer- 
cises so  important  an  influence  on  the  distribution  of  temper- 
ature, the  variations  in  atmospheric  pressure,  the  direction 
of  the  winds,  and  the  quantity  of  moisture  contained  in  the 
air,  with  which  the  development  of  vegetation  is  so  essentially 
connected.  When  we  consider  that  nearly  three  fourths  ol 
the  upper  surface  of  our  planet  are  covered  with  water,*  we 
shall  be  less  surprised  at  the  imperfect  condition  of  meteorol- 
ogy before  the  beginning  of  the  present  century,  since  it  is  only 
during  the  subsequent  period  that  numerous  accurate  observa- 
tions on  the  temperature  of  the  sea  at  different  latitudes  and 
at  different  seasons  have  been  made  and  numerically  compared 
together. 

The  horizontal  configuration  of  continents  in  their  general 
relations  of  extension  was  already  made  a  subject  of  intellectual 
contemplation  by  the  ancient  Greeks.  Conjectures  were  ad- 
vanced regarding  the  maximum  of  the  extension  from  west  to 
east,  and  Dicsearchus  placed  it,  according  to  the  testimony  of 
Agathemerus,  in  the  latitude  of  Rhodes,  in  the  direction  of  a 
line  passing  from  the  Pillars  of  Hercules  to  Thine.  This  line, 
which  has  been  termed  the  'parallel  of  the  diaphragm  of  Di- 
ccEarchus,  is  laid  down  with  an  astronomical  accuracy  of  po- 
sition, which,  as  I  have  stated  in  another  work,  is  well  worthy 
of  exciting  surprise  and  admiration.!  Strabo,  who  was  proba- 
bly influenced  by  Eratosthenes,  appears  to  have  been  so  firmly 
convinced  that  this  parallel  of  36^  was  the  maximum  of  the 
extension  of  the  then  existing  world,  that  he  supposed  it  had 
some  intimate  connection  with  the  form  of  the  earth,  and 
therefore  places  under  this  line  the  continent  whose  existence 

*  lu  the  Middle  Ages,  the  opinion  prevailed  that  the  sea  covered  ^my 
one  seventh  of  the  surface  of  the  globe,  au  opinion  which  Cardinal  d'Ailly 
(Imago  Mundi,  cap.  8)  founded  on  the  fourth  apocrj'^phal  book  of  Esdras. 
Columbus,  wfho  derived  a  great  portion  of  his  cosmographical  knowledge 
from  the  cai"diaal's  work,  w^as  much  interested  in  upholding  this  idea 
of  the  smallness  of  the  sea,  to  which  the  misunderstood  expression  of 
"  the  ocean  stream"  contributed  not  a  httle.  See  Humboldt,  Examen 
CrUiquede  VHist.  de  la  Giograpkie,  t.  i.,  p.  186. 

t  Agathemerus,  in  Hudson,  Geographi  Minores,  t.  ii,,  p.  '1.  Seo 
Humboldt,  Asie  Cetdr.,  t    i..  p.  120-1-2.3, 

Vol.  I.— N 


290  coSiMos. 

he  divined  in  the  northern  hemisphere,  between  Theria  and 
the  coasts  of  Thine. =^ 

As  we  have  ah'eady  remarked,  one  hemisphere  of  the  earth 
(whether  we  divide  the  sphere  through  the  equator  or  through 
the  meridian  of  Teneriffe)  has  a  much  greater  expansion  of 
elevated  land  than  the  opposite  one  :  these  two  vast  ocean- 
girt  tracts  of  land,  which  we  term  the  eastern  and  western, 
or  the  Old  and  New  Continents,  present,  however,  conjointly 
with  the  most  striking  contrasts  of  configuration  and  position 
of  their  axes,  some  similarities  of  form,  especially  with  refer- 
ence to  the  mutual  relations  of  their  opposite  coasts.  In  the 
eastern  continent,  the  predominating  direction — the  position 
of  the  major  axis — inclines  from  east  to  west  (or,  more  cor- 
rectly speaking,  from  southwest  to  northeast),  while  in  the 
western  continent  it  inclines  from  south  to  north  (or,  rather, 
from  south-southeast  to  north-northwest).  Both  terminate  to 
the  north  at  a  parallel  coinciding  nearly  with  that  of  70^. 
while  they  extend  to  the  south  in  pyramidal  points,  having 
submarine  prolongations  of  islands  and  shoals.  Such,  for  in- 
stance, are  the  Archipelago  of  Tierra  del  Fuego,  the  Lagulias 
Bank  south  of  the  Cape  of  Good  Hope,  and  Van  Diemen's 
Land,  separated  from  New  Holland  by  Bass's  Straits.  North- 
ern Asia  extends  to  the  above  parallel  at  Cape  Taimura,  which, 
according  to  Krusenstern,  is  78°  16',  while  it  falls  below  it 
from  the  mouth  of  the  Great  Tschukotschja  River  eastward 
to  Behring's  Straits,  in  the  eastern  extremity  of  Asia — Cook's 
East  Cape — which,  according  to  Beechey,  is  only  66°  S'.f 
The  northern  shore  of  the  New  Continent  follows  with  toler- 
able exactness  the  parallel  of  70°,  since  the  lands  to  the  north 
and  south  of  Barrow's  Strait,  from  Boothia  Felix  and  Victoria 
Land,  are  merely  detached  islands. 

The  pyramidal  configuration  of  all  the  southern  extremities 
of  continents  belongs  to  the  similitudi7ies  pliydcce  in  configii- 
ratione  Qnundi,  to  which  Bacon  already  called  attention  in  his 
Novum  Organon,  and  with  which  Reinhold  Foster,  one  of 
Cook's  companions  in  his  second  voyage  of  circumnavigation, 
connected  some  ingenious  considerations.  On  looking  eastward 
from  the  meridian  of  Tenerifie,  we  perceive  that  the  southern 
extremities  of  the  three  continents,  viz.,  Africa  as  the  extreme 

*  Strabo,  lib.  i.,  p.  65,  Casaub.     See  Humboklt,  Examen  Crit.,  t.  i. 
p.  152. 

f  On  the  mean  latitude  of  the  Northern  Asiatic  shores,  and  the  true 
name  of  Cape  Taimura  (Cape  Siewero-Wostotschuoi),  and  C;ipe  North- 
east (Schalagskoi  Mys),  see  Humboldt,  Asie  Centrale.  t,  iii.,  p.  35.  37. 


PHYSICAL    GEOGRAPHY.  291 

of  the  Old  World,  Australia,  and  South  America,  successively 
approach  nearer  toward  the  south  pole.  New  Zealand,  whose 
length  extends  fully  12*^  of  latitude,  forms  an  intermediate 
link  between  Australia  and  South  America,  likewise  termina- 
ting in  an  island.  New  Leinster,  It  is  also  a  remarkable  cir- 
cumstance that  the  greatest  extension  toward  the  south  falls 
in  the  Old  Continent,  under  the  same  meridian  in  which  the 
extremest  projection  toward  the  north  pole  is  manifested.  This 
will  be  perceived  on  comparing  the  Cape  of  Good  Hope  and 
the  Lagullas  Bank  with  the  North  Cape  of  Europe,  and  the 
peninsula  of  Malacca  with  Cape  Taimura  in  Siberia.*  We 
know  not  whether  the  poles  of  the  earth  are  surrounded  by 
land  or  by  a  sea  of  ice.  Toward  the  north  pole  the  parallel 
of  82^  55'  has  been  reached,  but  toward  the  south  pole  only 
that  of  78^  10'. 

The  pyramidal  terminations  of  the  great  continents  are  vari- 
ously repeated  on  a  smaller  scale,  not  only  in  the  Indian  Ocean, 
and  in  the  peninsulas  of  Arabia,  Hindostan,  and  Malacca,  but 
also,  as  was  remarked  by  Eratosthenes  and  Polybius,  in  the 
Mediterranean,  where  these  writers  had  ingeniously  compared 
together  the  forms  of  the  Iberian,  Italian,  and  Hellenic  penin- 
sulas.! Europe,  whose  area  is  five  times  smaller  than  that 
of  Asia,  may  almost  be  regarded  as  a  multifariously  articulated 
western  peninsula  of  the  more  compact  mass  of  the  continent 
'  of  Asia,  the  climatic  relations  of  the  former  being  to  those  of 
the  latter  as  the  peninsula  of  Brittany  is  to  the  rest  of  France. t 
The  influence  exercised  by  the  articulation  and  higher  devel- 
opment of  the  form  of  a  continent  on  the  moral  and  intellect- 
ual condition  of  nations  was  remarked  by  Strabo,§  who  extols 

*  Humboldt,  Asie  Centrale,  t.  i.,  p.  198-200.  The  southern  point 
of  America,  and  the  Archipelago  which  we  call  Terra  del  Fuego,  lie  in 
the  meridian  of  the  northwestern  part  of  Baffin's  Bay,  and  of  the  great 
polar  land,  whose  limits  have  not  as  yet  been  ascertained,  and  which, 
perhaps,  belongs  to  West  Greenland. 

t  Strabo,  lib.  ii.,  p.  92,  108,  Casaub. 

X  Humboldt,  Asie  Centrale,  t.  iii.,  p.  25.  As  early  as  the  year  1817, 
in  my  work  De  distributione  Geographicd  Plantarum,  secundum  coeli 
temperiem,  et  altitndinem  Mojitium,  I  directed  attention  to  the  import 
ant  influence  of  compact  and  of  deeply-articulated  continents  on  climate 
and  human  civilization,  "  Regiones  vel  per  sinus  lunatos  in  longa  cornua 
porrecta^,  angulosis  littorum  recessibus  quasi  membratim  discerptaR,  vel 
spatia  patentia  in  immensum,  quorum  littora  uullis  incisa  angulis  ambit 
sine  anfractu  oceanus"  (p.  81,  182).  On  the  relations  of  the  extent  of 
coast  to  the  area  of  a  continent  (considered  in  some  degree  as  a  meas- 
ure of  the  accessibility  of  the  interior),  see  the  inquiries  in  Berghaus, 
Annalen  der  Erdkundc,  bd.  xii.,  183.5,  s.  430,  and  Physikal.  Atlas,  1839 
No.  iii  ,  8.  69.  $  Strabo.  lib.  ii.,  p.  92,  198,  Casaub. 


292  COSMOS. 

the  varied  form  of  our  small  continent  as  a  special  advantage. 
Africa*  and  South  America,  which  manifest  so  great  a  resem- 
blance in  their  configuration,  are  also  the  two  continents  that 
exhibit  the  simplest  littoral  outlines.  It  is  only  the  eastern 
shores  of  Asia,  w^hich,  broken  as  it  were  by  the  force  of  the 
currents  of  the  oceanf  [fractas  ex  cequore  terras),  exhibit  a 
richly-variegated  configuration,  peninsulas  and  contiguous  isl- 
ands alternating  from  the  equator  to  60°  north  latitude. 

Our  Atlantic  Ocean  presents  all  the  indications  of  a  valley. 
It  is  as  if  a  flow  of  eddying  waters  had  been  directed  first  to- 
ward the  northeast,  then  toward  the  northwest,  and  back 
again  to  the  northeast.  The  parallelism  of  the  coasts  north 
of  10°  south  latitude,  the  projecting  and  receding  angles,  the 
convexity  of  Brazil  opposite  to  the  Gulf  of  Guinea,  that  of 
Africa  under  the  same  parallel,  with  the  Gulf  of  the  Antilles, 
all  favor  this  apparently  speculative  view.|  In  this  Atlantic 
valley,  as  is  almost  every  where  the  case  in  the  configuration 
of  large  continental  masses,  coasts  deeply  indented,  and  rich 
in  islands,  are  situated  opposite  to  those  possessing  a  different 
character.  I  long  since  drew  attention  to  the  geognostic  im- 
portance of  entering  into  a  comparison  of  the  western  coast  of 
Africa  and  of  South  America  within  the  tropics.  The  deeply- 
curved  indentation  of  the  African  continent  at  Fernando  Po, 
4°  30'  north  latitude,  is  repeated  on  the  coast  of  the  Pacific 
at  18°  15'  south  latitude,  between  the  Valley  of  Arica  and 
the  Morro  de  Juan  Diaz,  w^here  the  Peruvian  coast  suddenly 
changes  the  direction  from  south  to  north  which  it  had  previ- 
ously followed,  and  inclines  to  the  northwest.     This  change 

*  Of  Africa,  Pliny  says  (v.  1),  "Nee  alia  pars  terrarum  pauciores  re- 
cipit  sinus."  The  small  Indian  peninsula  on  this  side  the  Ganges  pre- 
sents,  in  its  triangular  outline,  a  third  analogous  form.  In  ancient 
Greece  there  prevailed  an  opinion  of  the  regular  configuration  of  the 
dry  land.  There  were  four  gulfs  or  bays,  among  which  the  Persian 
Gulf  was  placed  in  opposition  to  the  Hyrcanian  or  Caspian  Sea  (Arrian, 
vii.,  16;  Plut.,  in  vita  Alexandri,  cap.  44;  Dionys.  Perieg.,  v.  48  and 
630,  p.  11,  38,  Bernh.).  These  four  bays  and  the  isthmuses  were,  ac- 
cording to  the  optical  fancies  of  Agesianax,  supposed  to  be  reflected  in 
the  moon  (Plut.,  de  Facie  in  Orbem  Lunce,  p.  921,  19).  Respecting  the 
terra  quadrijida,  or  four  divisions  of  the  dry  land,  of  which  two  lay 
north  and  two  south  of  the  equator,  see  Macrobius,  Comm.  in  Somnium 
Scipionis,  ii.,  9.  I  have  submitted  this  portion  of  the  geography  of  the 
ancients,  regarding  which  great  confusion  prevails,  to  a  new  and  care- 
ful examination,  in  my  Examen  Crit.  de  V Hist,  de  la  G^ogr.,  t.  i.,  p. 
119,  145,  180-185,  as  also  in  Asie  Centr.,  t.  ii.,  p.  172-178. 

+  Fleurieu,  in  Voyage  de  Marchand  autour  du  Monde,  t.  iv.,  p.  38-42. 

t  Humboldt,  in  the  Journal  de  Physiqve,  liii.,  1799,  p.  33;  and  Rel. 
Hist.,  t.  ii.,  p.  19;  t.  iii.,  p.  189,  198. 


PHYSICAL    GEOGRAPHY.  293 

of  direction  extends  in  like  manner  to  the  chain  of  the  Andes, 
which,  is  divided  into  two  parallel  branches,  affecting  not  only 
the  littoral  portions,*  but  even  the  eastern  Cordilleras.  In 
the  latter,  civilization  had  its  earliest  seat  in  the  South  Amer- 
ican plateaux,  where  the  small  Alpine  lake  of  Titicaca  bathes 
the  feet  of  the  colossal  mountains  of  Sorata  and  Illimani. 
Further  to  the  south,  from  Valdivia  and  Chiloe  (40°  to  42° 
south  latitude),  through  the  Archipelago  de  los  Cho?ios  to 
Tei'ra  del  Fuego,  we  find  repeated  that  singular  configuration 
of  fiords  (a  blending  of  narrow  and  deeply-indented  bays), 
which  in  the  Northern  hemisphere  characterizes  the  western 
shores  of  Norway  and  Scotland. 

These  are  the  most  general  considerations  suggested  by  the 
study  of  the  upper  surface  of  our  planet  with  reference  to  the 
form  of  continents,  and  their  expansion  in  a  horizontal  direc- 
tion. We  have  collected  facts  and  brought  forward  some 
analogies  of  configuration  in  distant  parts  of  the  earth,  but  we 
do  not  venture  to  regard  them  as  fixed  laws  of  form.  When 
the  traveler  on  the  declivity  of  an  active  volcano,  as,  for  in- 
stance, of  Vesuvius,  examines  the  frequent  partial  elevations 
by  which  portions  of  the  soil  are  often  permanently  upheaved 
several  feet  above  their  former  level,  either  immediately  pre- 
ceding or  during  the  continuance  of  an  eruption,  thus  forming 
roof-like  or  flattened  summits,  he  is  taught  how  accidental 
conditions  in  the  expression  of  the  force  of  subterranean  va- 
pors, and  in  the  resistance  to  be  overcome,  may  modify  the 
form  and  direction  of  the  elevated  portions.  In  this  manner, 
feeble  perturbations  in  the  equilibrium  of  the  internal  elastic 
forces  of  our  planet  may  have  inclined  them  more  to  its  north- 
ern than  to  its  southern  direction,  and  caused  the  continent 
in  the  eastern  part  of  the  globe  to  present  a  broad  mass,  whose 
major  axis  is  almost  parallel  with  the  equator,  while  in  the 
western  and  more  oceanic  part  the  southern  extremity  is  ex- 
tremely narrow. 

Very  little  can  be  empirically  determined  regarding  the 
causal  connection  of  the  phenomena  of  the  formation  of  con- 
tinents, or  of  the  analogies  and  contrasts  presented  by  their 

*  Humboldt,  iu  Pogijendorf's  Annalen  der  Physilc,  bd.  xl.,  s.  171. 
On  the  remarkable  fiord  formation  at  the  southeast  end  of  America,  see 
Darwin's  Journal  (^Narrative  of  the  Voyages  of  the  Adventure  and  Bea- 
gle, vol.  iii.),  1839,  p.  266.  The  parallelism  of  the  two  mountain  chains 
is  maintained  from  5°  south  to  5*^  north  latitude.  The  change  in  the 
direction  of  the  coast  at  Arica  appears  to  be  in  consequence  of  the  al- 
tered course  of  the  fissure,  above  which  the  Cordillera  of  the  Andes 
has  been  upheaved. 


294  COSMOS. 

* 

configuration.  All  that  we  know  regarding-  this  subject  re- 
solves itself  into  this  one  point,  that  the  active  cause  is  sub- 
terranean ;  that  continents  did  not  arise  at  once  in  the  form 
they  now  present,  but  were,  as  we  have  already  observed,  in- 
creased by  degrees  by  means  of  numerous  oscillatory  elevations 
and  depressions  of  the  soil,  or  were  formed  by  the  fusion  of 
separate  smaller  continental  masses.  Their  present  form  is, 
therefore,  the  result  of  two  causes,  which  have  exercised  a  con- 
secutive action  the  one  on  the  other  :  the  first  is  the  expression 
of  subterranean  force,  whose  direction  we  term  accidental, 
owing  to  our  inability  to  define  it,  from  its  removal  from  with- 
in the  sphere  of  our  comprehension,  while  the  second  is  derived 
from  forces  acting  on  the  surface,  among  which  volcanic  erup- 
tions, the  elevation  of  mountains,  and  currents  of  sea  water 
play  the  principal  parts.  How  totally  difTerent  would  be  the 
condition  of  the  temperature  of  the  earth,  and,  consequently, 
of  the  state  of  vegetation,  husbandry,  and  human  society,  if 
the  major  axis  of  the  New  Continent  had  the  same  direction 
as  that  of  the  Old  Continent ;  if,  for  instance,  the  Cordilleras, 
instead  of  having  a  southern  direction,  inclined  from  east  to 
west ;  if  there  had  been  no  radiating  tropical  continent,  like 
Africa,  to  the  south  of  Europe  ;  and  if  the  Mediterranean, 
which  was  once  connected  with  the  Caspian  and  Red  Seas, 
and  which  has  become  so  powerful  a  means  of  furthering  the 
intercommunication  of  nations,  had  never  existed,  or  if  it  had 
been  elevated  like  the  plains  of  Lombardy  and  Cyrene  1 

The  changes  of  the  reciprocal  relations  of  height  between 
the  fluid  and  solid  portions  of  the  earth's  surface  (changes 
which,  at  the  same  time,  determine  the  outlines  of  continents, 
and  the  greater  or  lesser  submersion  of  low  lands)  are  to  be 
ascribed  to  numerous  unequally  working  causes.  The  most 
powerful  have  incontestably  been  the  force  of  elastic  vapors 
inclosed  in  the  interior  of  the  earth,  the  sudden  change  of  tem- 
perature of  certain  dense  strata,*  the  unequal  secular  loss  of 

*  De  la  Beclie,  Sections  and  Views  illustrative  of  Geological  Phenome- 
na, 1830,  tab.  40 ;  Charles  Babbage,  Ohservations  on  the  Temple  of 
Serapis  at  Pozzuoli,  near  Naples,  and  on  certain  Causes  which  may 
produce  Geological  Cycles  of  great  Extent,  1834.  "  If  a  stratum  of  sand- 
stone five  miles  in  thickness  should  have  its  temperature  raised  about 
100°,  its  surface  would  rise  twenty-five  feet.  Heated  beds  of  clay 
would,  on  the  contrary,  occasion  a  sinking  of  the  ground  by  their  con- 
traction." See  Bischof,  Wdrmelehre  des  Innern  unseres  Erdkorpers,  s. 
303,  concerning  the  calculations  for  the  secular  elevation  of  Sweden,  on 
the  supposition  of  a  rise  by  so  small  a  quantity  as  7°  in  a  stratum  of 
about  155,000  feet  in  thickness,  and  heated  to  a  state  of  fusion. 


piiYS[('Ai.  <;i',u(;kaimiv.  295 

heat  experienced  by  the  crust  and  nucleus  ot"  the  earth,  occa- 
pioning  ridges  in  the  sohd  surface^  local  modifications  of  gravi- 
tation,* and,  as  a  consequence  of"  these  alterations,  in  the  curv- 
ature of  a  portion  of  the  liquid  element.  According  to  the 
views  generally  adopted  by  geognosists  in  the  present  day,  and 
w^hich  are  supported  by  the  observation  of  a  series  of  well- 
attested  facts,  no  less  than  by  analogy  with  the  most  import- 
ant volcanic  phenomena,  it  would  appear  that  the  elevation 
of  continents  is  actual,  and  not  merely  apparent  or  owing  to 
the  configuration  of  the  upper  surface  of  the  sea.  The  merit 
of  having  advanced  this  view  belongs  to  Leopold  von  Buch, 
who  first  made  his  opinions  known  to  the  scientific  world  in 
the  narrative  of  his  memorable  Travels  through  Norway  a?id 
Sweden  in  1806  and  I807.t  While  the  whole  coast  of 
Sweden  and  Finland,  from  Solvitzborg,  on  the  limits  of  North- 
ern Scania,  past  Gefle  to  Tornea,  and  from  Tornea  to  Abo, 
experiences  a  gradual  rise  of  four  feet  in  a  century,  the  south- 
ern part  of  Sweden  is,  according  to  Neilson,  undergoing  a 
simultaneous  depression.:}:     The  maximum  of  this  elevating 

*  The  opinion  so  iniplicitly  entertained  regarding  the  invariability  of 
the  force  of  gravity  at  any  given  point  of  the  earth's  surface,  has  in 
some  degree  been  controverted  by  the  gradual  rise  of  large  portions  of 
the  earth's  surface.  See  Bessel,  Ueber  Maas  mid  Gewicht,  in  Schu- 
macher's Jahrbuch  fur  1840,  s.  134. 

+  Th.  ii.  (1810),  s.  389.  See  Hallstroni,  in  Kongl.  Vetenskaps-Aca- 
demiens  Handlingar  (Stockh-),  1823,  p.  30;  Lyell,  in  the  Philos.  TraTis. 
for  1835  ;  Blom  (Anitmann  in  Budskerud),  Stat.  Besckr.  von  Noricegen, 
1843,  s.  89-116.  If  not  before  Von  Buck's  travels  through  Scandinavia, 
at  any  rate  before  their  publication,  Playfair,  in  1802,  in  his  illustrations 
of  the  Huttonian  theory,  §  393,  and,  according  to  Keilhau  {Om  Land- 
jordens  Stigning  in  Norge,  in  the  N^t  Magazine  fur  Naturvidenska- 
berne),  and  the  Dane  Jessen,  even  before  the  time  of  Playfair,  had  ex- 
pressed the  opinion  that  it  was  not  the  sea  which  was  sinking,  but  the 
solid  land  of  Sweden  which  was  rising.  Their  ideas,  however,  were 
wholly  unknown  to  our  great  geologist,  and  exerted  no  influence  on 
the  progi'ess  of  physical  geography.  Jessen,  in  his  work,  Kongeriget 
Norge  fremstillet  efter  dels  natui-lige  eg  borgerlige  Tilstand,  Kjobenh., 
1763,  sought  to  explain  the  causes  of  the  changes  in  the  relative  levels 
of  the  land  and  sea,  basing  his  views  on  the  early  calculations  of  Celsius, 
Kalm,  and  Dalin.  He  broaches  some  confused  ideas  regarding  the  pos- 
sibility of  an  internal  growth  of  rocks,  but  finally  declares  himself  in 
favor  of  an  upheaval  of  the  land  by  earthquakes,  "although,"  he  ob- 
serves, "  no"  such  rising  was  apparent  immediately  after  the  earthquake 
of  Egersund,  yet  the  earthquake  may  have  opened  the  way  for  other 
causes  producing  such  an  etfect." 

X  See   Berzelius,  Jakrsbericht  uber  die  Fortschritte  der  Physischcn 
Wiss.,  No.  18,  s.  686.     The  islands  of  Saltholm,  opposite   to  Copen 
hageu,  and  Bjornholm,  however,  rise  but  very  little — Bjornhohn  scarce- 
ly one  foot  in  a  century      See  Forchhammer,  in  Philos.  Magazine.  Zd 
Series,  vol,  ii.,  p    309 


296  COSMOS. 

force  appears  to  Lr  in  the  north  of  Lapland,  and  to  diminish 
gradually  to  the  south  toward  Calmar  and  Solvitzborg.  Lines 
marking  the  ancient  level  of  the  sea  in  pre-historic  times  are 
indicated  throughout  the  whole  of  Norway,*  from  Cape  Lin- 
desnaes  to  the  extremity  of  the  North  Cape,  by  banks  of  shells 
identical  with  those  of  the  present  seas,  and  which  have  late- 
ly been  most  accurately  examined  by  Bravais  during  his  long 
winter  sojourn  at  Bosekop.  These  banks  lie  nearly  650  feet 
above  the  present  mean  level  of  the  sea,  and  reappear,  accord- 
ing to  Keilhau  and  Eugene  Robert,  in  a  north-northwest  di- 
rection on  the  coasts  of  Spitzbergen,  opposite  the  North  Cape. 
Leopold  von  Buch,  who  was  the  first  to  draw  attention  to  the 
high  banks  of  shells  at  Tromsoe  (latitude  69^  40'),  has,  how- 
ever, shown  that  the  more  ancient  elevations  on  the  North 
Sea  appertain  to  a  different  class  of  phenomena,  from  the 
regular  and  gradual  retrogressive  elevations  of  the  Swedish 
shores  in  the  Gulf  of  Bothnia.  This  latter  phenomenon,  which 
is  well  attested  by  historical  evidence,  must  not  be  confound- 
ed with  the  changes  in  the  level  of  the  soil  occasioned  by 
earthquakes,  as  on  the  shores  of  Chili  and  of  Cutch,  and 
which  have  recently  given  occasion  to  similar  observations  in 
other  countries.  It  has  been  found  that  a  perceptible  sinking 
resulting  from  a  disturbance  of  the  strata  of  the  upper  surface 
sometimes  occurs,  corresponding  with  an  elevation  elsewhere, 
as,  for  instance,  in  West  Greenland,  accordins:  to  Pino-el  and 
Graah,  in  Dalmatia  and  in  Scania. 

Since  it  is  highly  probable  that  the  oscillatory  movements 
of  the  soil,  and  the  rising  and  sinking  of  the  upper  surface, 
were  more  strongly  marked  in  the  early  periods  of  our  planet 
than  at  present,  we  shall  be  less  surprised  to  find  in  the  inte- 
rior of  continents  some  few  portions  of  the  earth's  surface  ly- 
ing below  the  general  level  of  existing  seas.  Instances  of  this 
kind  occur  in  the  soda  lakes  described  by  General  Andreossy, 
the  small  bitter  lakes  in  the  narrow  Isthmus  of  Suez,  the 
Caspian  Sea,  the  Sea  of  Tiberias,  and  especially  the  Dead 
Sea.f     The  level  of  the  water  in  the  two  last-named  seas  is 

*  Keilhau,  in  Ni/t  Mag.  fur  Naturvid.,  1832,  bd.  i.,  p.  105-2.54;  bd. 
ii.,  p.  -57;  Bravais,  Sur  les  Lignes  d^ancien  Nweau  de  la  Mer,  1843,  p. 
15-40.  See,  also,  Darwin,  "on  the  Parallel  Roads  of  Glen-Roy  and 
Lochaber,"  in  Philos.  Trans,  for  1839,  p.  60. 

t  Humboldt,  Asie   Centrale,   t.  ii.,  p.  319-324;  t.  iii.,  p.  549-551 
The  depression  of  the  Dead  Sea  has  been  successively  determined  by 
the  barometrical  measurements  of  Count  Bertou,  by  the  more  careful 
ones  ot  Russegger,  and  by  the  trigonometrical  survey  of  Lieutenant  Sy- 
mond,  oi  the  Royal  Navy,  who  states  that  the  difTerence  of  level  be- 


PHYSICAL    GEOGRAPHY.  297 

666  and  1312  feet  below  the  level  of  the  Mediterranean.  If 
we  could  suddenly  remove  the  alluvial  soil  which  covers  the 
rocky  strata  in  many  parts  of  the  earth's  surface,  we  should 
discover  how  great  a  portion  of  the  rocky  crust  of  the  earth 
was  then  below  the  present  level  of  the  sea.  The  periodic, 
although  irregularly  alternating  rise  and  fall  of  the  water  of 
the  Caspian  Sea,  of  which  I  have  myself  observed  evident 
traces  in  the  northern  portions  of  its  basin,  appears  to  prove, ^ 
as  do  also  the  observations  of  Darwin  on  the  coral  seas,t  that 
without  earthquakes,  properly  so  called,  the  surface  of  the 
earth  is  capable  of  the  same  gentle  and  progressive  oscilla- 
tions as  those  which  must  have  prevailed  so  generally  in  the 
earliest  ages,  when  the  surface  of  the  hardening  crust  of  the 
earth  was  less  compact  than  at  present. 
•  The  phenomena  to  which  we  would  here  direct  attention 
remind  us  of  the  instability  of  the  present  order  of  things,  and 
of  the  changes  to  which  the  outlines  and  configuration  of  con- 
tinents are  probably  still  subject  at  long  intervals  of  time. 
That  which  may  scarcely  be  perceptible  in  one  generation, 
accumulates  during  periods  of  time,  whose  duration  is  revealed 
to  us  by  the  movement  of  remote  heavenly  bodies.  The  east- 
ern coast  of  the  Scandinavian  peninsula  has  probably  risen 

tween  the  surface  of  the  Dead  Sea  and  the  highest  houses  of  Jaffa  is 
about  160.5  feet.  Mr.  Alderson,  who  communicated  this  result  to  the 
Geographical  Society  of  London  in  a  letter,  of  the  contents  of  which  I 
was  informed  by  my  friend,  Captain  Washington,  was  of  opinion  (Nov. 
28,  1841)  that  the  Dead  Sea  lay  about  1400  feet  under  the  level  of  the 
Mediterranean.  A  more  recent  communication  of  Lieutenant  Symond 
(Jameson's  Edinburgh  New  Philosophical  Journal,  vol.  xxxiv.,  1843,  p, 
178)  gives  1312  feet  as  the  final  result  of  two  very  accordant  trigono- 
metrical operations. 

*  Sur  la  Mobility  du  fond  de  la  Mer  Caspienne,  in  my  Asie  Centr.,  t, 
ii.,  p.  283-294.  The  Imperial  Academy  of  Sciences  of  St.  Petersburgh. 
in  1830,  at  my  request,  charged  the  learned  physicist  Lenz  to  place 
marks  indicating  the  mean  level  of  the  sea,  for  definite  epochs,  in  dif- 
fei'ent  places  near  Baku,  in  the  peninsula  of  Abscheron.  In  the  same 
manner,  in  an  appendix  to  the  instructions  given  to  Captain  (now  Sir 
James  C.)  Ross  for  his  Antarctic  expedition,  I  m*ged  the  necessity  of 
causing  marks  to  be  cut  in  the  rocks  of  the  southern  hemisphere,  as 
had  already  been  done  in  Sweden  and  on  the  shores  of  the  Caspian 
Sea.  Had  this  measure  been  adopted  in  the  early  voyages  of  Bougain- 
ville and  Cook,  we  should  now  know  whether  the  secular  relative 
changes  in  the  level  of  the  seas  and  land  are  to  be  considered  as  a  gen- 
eral, or  merely  a  local  natural  phenomenon,  and  whether  a  law  of  di 
rection  can  be  recognized  in  the  points  which  have  simultaneous  ele- 
vation or  depression. 

t  On  the  elevation  and  depression  of  the  bottom  of  the  South  Sea, 
and  the  different  areas  of  alternate  movements,  see  Darwin's  Journal, 
p.  557,  5G 1-566. 

N2 


298  COSMOS. 

about  320  feet  in  the  space  of  8000  years;  and  in  12,000 
years,  if  the  movement  be  regular,  parts  of  the  bottom  of  the 
sea  which  He  nearest  the  shores,  and  are  in  the  present  day 
covered  by  nearly  fifty  fathoms  of  vv^ater,  will  come  to  the 
surface  and  constitute  dry  land.  But  what  are  such  intervals 
of  time  compared  to  the  length  of  the  geognostic  periods  re- 
vealed to  us  in  the  stratified  series  of  formations,  and  in  the 
world  of  extinct  and  varying  organisms  I  We  have  hitherto 
only  considered  the  phenomena  of  elevation  ;  but  the  analo- 
gies of  observed  facts  lead  us  with  equal  justice  to  assume  the 
possibility  of  the  depression  of  whole  tracts  of  land.  The 
mean  elevation  of  the  non-mountainous  parts  of  France 
amounts  to  less  than  480  feet.  It  would  not,  therefore,  re- 
quire any  long  period  of  time,  compared  with  the  old  geog- 
nostic periods,  in  which  such  great  changes  were  brought 
about  in  the  interior  of  the  earth,  to  effect  the  permanent 
submersion  of  the  northwestern  part  of  Europe,  and  induce 
essential  alterations  in  its  littoral  relations. 

The  depression  and  elevation  of  the  solid  or  fluid  parts  of 
the  earth — phenomena  which  are  so  opposite  in  their  action 
that  the  efiect  of  elevation  in  one  part  is  to  produce  an  appar- 
ent depression  in  another — are  the  causes  of  all  the  changes 
which  occur  in  the  configuration  of  continents.  In  a  work  of 
this  general  character,  and  in  an  impartial  exposition  of  the 
phenomena  of  nature,  we  must  not  overlook  the  possibility 
of  a  diminution  of  the  quantity  of  water,  and  a  constant  de- 
pression of  the  level  of  seas.  There  can  scarcely  be  a  doubt 
that,  at  the  period  when  the  temperature  of  the  surface  of  the 
earth  was  higher,  when  the  waters  were  inclosed  in  larger 
and  deeper  fissures,  and  when  the  atmosphere  possessed  a  to- 
tally different  character  from  what  it  does  at  present,  great 
changes  must  have  occurred  in  the  level  of  seas,  depending 
upon  the  increase  and  decrease  of  the  liquid  parts  of  the 
earth's  surface.  But  in  the  actual  condition  of  our  planet, 
there  is  no  direct  evidence  of  a  real  continuous  increase  or  de- 
crease of  the  sea,  and  we  have  no  proof  of  any  gradual  change 
in  its  level  at  certain  definite  points  of  "observation,  as  indi- 
cated by  the  mean  range  of  the  barometer.  According  to  ex- 
periments made  hy  Daussy  and  Antonio  Nobile,  an  increase 
in  the  height  of  the  barometer  would  in  itself  be  attended  by 
a  depression  in  the  level  of  the  sea.  But  as  the  mean  press- 
ure of  the  atmosphere  at  the  level  of  the  sea  is  not  the  same 
at  all  latitudes,  owing  to  meteorological  causes  depending  upon 
the  direction  of  the  wind  and  varying  degrees  of  moisture,  the 


PHYSICAL    GEOGRAniY.  299 

6arometer  alone  can  not  afford  a  certain  evidence  of  the  gen- 
2ral  change  of  level  in  the  ocean.  The  remarkable  fact  that 
«ome  of  the  ports  in  the  Mediterranean  were  repeatedly  left 
dry  during  several  hours  at  the  beginning  of  this  century,  ap- 
pears to  show  that  currents  may,  by  changes  occurring  in 
their  direction  and  force,  occasion  a  local  retreat  of  the  sea, 
and  a  permanent  drying  of  a  small  portion  of  the  shore,  with- 
out being  followed  by  any  actual  diminution  of  water,  or  any 
permanent  depression  of  the  ocean.  We  must,  however,  be 
very  cautious  in  applying  the  knowledge  which  we  have  late- 
ly arrived  at,  regarding  these  involved  phenomena,  since  we 
might  otherwise  be  led  to  ascribe  to  water,  as  the  elder  ele- 
ment, what  ought  to  be  referred  to  the  two  other  elements, 
earth  and  air. 

As  the  external  configuration  of  continents,  which  we  have 
already  described  in  their  horizontal  expansion,  exercises,  by 
their  variously-indented  littoral  outlines,  a  favorable  influence 
on  climate,  trade,  and  the  progress  of  civilization,  so  likewise 
does  their  internal  articulation,  or  the  vertical  elevation  of 
the  soil  (chains  of  mountains  and  elevated  plateaux),  give  rise 
to  equally  important  results.  Whatever  produces  a  poly- 
morphic diversity  of  forms  on  the  surface  of  our  planetary 
habitation  —  such  as  mountains,  lakes,  grassy  savannas,  or 
even  deserts  encircled  by  a  band  of  forests — impresses  some 
peculiar  character  on  the  social  condition  of  the  inhabitants. 
Ridges  of  high  land  covered  by  snow  impede  intercourse  ;  but 
a  blending  of  low,  discontinued  mountain  chains*  and  tracts 
of  valleys,  as  we  see  so  happily  presented  in  the  west  and 
south  of  Europe,  tends  to  the  multiplication  of  meteorological 
processes  and  the  products  of  vegetation,  and,  from  the  variety 
manifested  in  different  kinds  of  cultivation  in  each  district, 
even  under  the  same  degree  of  latitude,  gives  rise  to  wants 
that  stimulate  the  activity  of  the  inhabitants.  Thus  the  aw- 
ful revolutions,  during  which,  by  the  action  of  the  interior  on 
the  crust  of  the  earth,  great  mountain  chains  have  been  ele- 
vated by  the  sudden  upheaval  of  a  portion  of  the  oxydized 
exterior  of  our  planet,  have  served,  after  the  establishment 
of  repose,  and  on  the  revival  of  organic  life,  to  furnish  a  ricli- 
er  and  more  beautiful  variety  of  individual  forms,  and  iii  a 
great  measure  to  remove  from  the  earth  that  aspect  of  dreary 

*  Humboldt,  Rel.  Hist.,  t.  iii.,  p.  232-234.  See,  also,  the  able  re- 
marks on  the  configuratiou  of  the  earth,  and  the  position  of  its  Hues 
of  elevation,  in  Albrechts  von  Roon,  Grundzugen  der  Erd  Volker  und 
Staalenkvnde,  Abth.  i.,  1837,  s.  1.58,  270,  276. 


300  COSMOS. 

uniformity  wliich  exercises  so  impoverisliing  an  influence  on 
the  physical  and  intellectual  powers  of  mankind. 

x\ccording  to  the  grand  views  of  Elie  de  Beaumont,  we 
must  ascribe  a  relative  age  to  each  system  of  mountain  chains* 
on  the  supposition  that  their  elevation  must  necessarily  have 
occurred  between  the  period  of  the  deposition  of  the  vertical- 
ly elevated  strata  and  that  of  the  horizontally  inclined  strata 
running  at  the  base  of  the  mountains.  The  ridges  of  the 
Earth's  crust — elevations  of  strata  which  are  of  the  same  ge- 
ognostic  age — appear,  moreover,  to  follow  one  common  direc- 
tion. The  line  of  strike  of  the  horizontal  strata  is  not  always 
parallel  with  the  axis  of  the  chain,  but  intersects  it,  so  that, 
according  to  my  views,!  the  phenomenon  of  elevation  of  the 
strata,  which  is  even  found  to  be  repeated  in  the  neighboring 
plains,  must  be  more  ancient  than  the  elevation  of  the  chain. 
The  main  direction  of  the  whole  continent  of  Europe  (from 
southwest  to  northeast)  is  opposite  to  that  of  the  great  fissures 
which  pass  from  northwest  to  southeast,  from  the  mouths  of 
the  Rhine  and  Elbe,  through  the  Adriatic  and  Red  Seas,  and 
through  the  mountain  system  of  Putschi-Koh  in  Luristan,  to- 
ward the  Persian  Gulf  and  the  Indian  Ocean.  This  almost 
rectangular  intersection  of  geodesic  lines  exercises  an  import- 
ant influence  on  the  commercial  relations  of  Europe,  Asia, 
and  the  northwest  of  Africa,  and  on  the  progress  of  civilization 
on  the  formerly  more  flourishing  shores  of  the  Mediterranean  .J 

Since  grand  and  lofty  mountain  chains  so  strongly  excite 
our  imagination  by  the  evidence  they  aflbrd  of  great  terres- 
trial revolutions,  and  when  considered  as  the  boundaries  of 
climates,  as  lines  of  separation  for  waters,  or  as  the  site  of  a 
different  form  of  vegetation,  it  is  the  more  necessary  to  de- 
monstrate, by  a  correct  numerical  estimation  of  their  volume, 
how  small  is  the  quantity  of  their  elevated  mass  when  com- 
pared with  the  area  of  the  adjacent  continents.  The  mass 
of  the  Pyrenees,  for  instance,  the  mean  elevation  of  whose 
summits,  and  the  areal  quantity  of  whose  base  have  been  as- 
certained by  accurate  measurements,  would,  if  scattered  over 

*  Leop.  vou  Buch,  Ueber  die  Geognostischen  Systems  von  Deutschland, 
ia  his  Geogn.  Briefen  an  Alexander  von  Humboldt,  1824,  s.  2G5-271; 
Klie  de  Beaumont,  Recherches  sur  les  Revolutions  de  la  Swface  du  Globe, 
1829,  p.  297-307. 

t  Humboldt,  Asie  Centrale,  t.  i.,  p.  277-283.  See,  also,  my  Essai 
sur  le  Gisement  des  Roches,  1822,  p.  57,  and  Relat.  Hist.,  t.  iii.,  p. 
244-250. 

X  Asie  Centrale,  t.  i.,  p.  284,  286.  The  Adriatic  §ea  likewise  follows 
a  direction  from  S.E.  to  N.W. 


PHYSICAL    GEOGRAPHY.  301 

the  surface  of  France,  only  raise  its  mean  level  about  115 
feet.  The  mass  of  the  eastern  and  western  Alps  would  in 
like  manner  only  increase  the  height  of  Europe  about  21|^ 
feet  above  its  present  level.  I  have  found  by  a  laborious  in- 
vestigation,* which,  from  its  nature,  can  only  give  a  maximum 
limit,  that  the  center  of  gravity  of  the  volume  of  the  land 
raised  above  the  present  level  of  the  sea  in  Europe  and  North 
America  is  respectively  situated  at  an  elevation  of  671  and 
748  feet,  while  it  is  at  1132  and  1152  feet  in  Asia  and  South 
America.  These  numbers  show  the  low  level  of  northern 
regions.  In  Asia  the  vast  steppes  of  Siberia  are  compensated 
for  by  the  great  elevations  of  the  land  (between  the  Himalaya, 
the  North  Thibetian  chain  of  Kuen-lun,  and  the  Celestial 
Mountains),  from  28°  30'  to  40^  north  latitude.  We  may, 
to  a  certain  extent,  trace  in  these  numbers  the  portions  of  the 
Earth  in  which  the  Plutonic  forces  were  most  intensely  mani- 
fested in  the  interior  by  the  upheaval  of  continental  masses. 

There  are  no  reasons  why  these  Plutonic  forces  may  not, 
in  future  ages,  add  new  mountain  systems  to  those  which  Elie 
de  Beaumont  has  shown  to  be  of  such  different  ages,  and  in- 
clined in  such  difierent  directions.  Why  should  the  crust  of 
the  Earth  have  lost  its  property  of  being  elevated  in  ridges  ? 
The  recently-elevated  mountain  systems  of  the  xllps  and  the 
Cordilleras  exhibit  in  Mont  Blanc  and  Monte  Rosa,  in  Sorata, 
Illimani,  and  Chimborazo,  colossal  elevations  which  do  not 
favor  the  assumption  of  a  decrease  in  the  intensity  of  the  sub- 
terranean forces.  All  geognostic  phenomena  indicate  the 
periodic  alternation  of  activity  and  repose  ;t  but  the  quiet 
we  now  enjoy  is  only  apparent.  The  tremblings  which  still 
agitate  the  surface  under  all  latitudes,  and  in  every  species  of 
rock,  the  elevation  of  Sweden,  the  appearance  of  new  islands 
of  eruption,  are  all  conclusive  as  to  the  unquiet  condition  of 
our  planet. 

*  De  la  hauteur  Moyenne  des  Conlments,  in  my  Asie  Centrale,  t.  i.,  p. 
82-90,  165-189.  The  results  which  I  have  obtained  are  to  be  regard- 
ed as  the  extreme  value  {nombres-limites).  Laplace's  estinuile  of  the 
meau  height  of  continents  at  3280  feet  is  at  least  three  times  too  high. 
The  immortal  author  of  the  Mecanique  Celeste  (t.  v.,  p.  14)  \va.s  led  to 
this  conclusion  by  hypothetical  views  as  to  the  meau  depth  of  the  se:i. 
I  have  shown  (Asie  Centr.,  t.  i.,  p.  93)  that  the  old  Alexandii;iu  math- 
ematicians, on  the  testimony  of  Plutarch  {in  JEmilio  Paulo,  cap.  1.5), 
believed  this  depth  to  depend  on  the  height  of  the  mountains.  Tlie 
height  of  the  center  of  gravity  of  the  volume  of  the  continental  masses 
is  probably  subject  to  slight  variations  in  the  course  of  many  c.'!ntu:ie.s 

t  Zioeiier  Geologischer  Brief  von  Elie  de  Beaumont  an  Alexander  von 
Humboldt,  in  Poggendorf'.s   Annalen,  bd.  xxv.,  s.  1-58. 


302  COSMOS. 

The  two  envelopes  of  the  solid  suriace  of  our  planet — the 
liquid  and  the  aeriform — ^exhibit,  owing  to  the  mobility  of 
their  particles,  their  currents,  and  their  atmospheric  relations, 
many  analogies  combined  with  the  contrasts  which  arise  from 
the  great  difference  in  the  condition  of  their  aggregation  and 
elasticity.  The  depths  of  ocean  and  of  air  are  alike  unknown 
to  us.  At  some  few  places  under  the  tropics  no  bottom  has 
been  found  with  soundings  of  276,000  feet  (or  more  than  four 
miles),  while  in  the  air,  if,  according  to  Wollaston,  we  may 
assume  that  it  has  a  limit  from  which  waves  of  sound  may 
be  reverberated,  the  phenomenon  of  twilight  would  incline 
us  to  assume  a  height  at  least  nine  times  as  great.*  The 
aerial  ocean  rests  partly  on  the  solid  earth,  whose  mountain 
chains  and  elevated  plateaux  rise,  as  we  have  already  seen, 
like  green  wooded  shoals,  and  partly  on  the  sea,  whose  surface 
forms  a  moving  base,  on  which  rest  the  lower,  denser,  and 
more  saturated  strata  of  air. 

Proceeding:  unward  and  downward  from  the  common  limit  of 

Ox 

the  aerial  and  liquid  oceans,  we  fmd  that  the  strata  of  air 
and  water  are  subject  to  determinate  laws  of  decrease  oi"  tem- 
perature. This  decrease  is  much  less  rapid  in  the  air  than 
in  the  sea,  which  has  a  tendency  under  all  latitudes  to  main- 
tain its  temperature  in  the  strata  of  "water  most  contiguous  to 
the  atmosphere,  owing  to  the  sinking  of  the  heavier  and  more 
cooled  particles.  A  large  series  of  the  most  carefully  con- 
ducted observations  on  temperature  shows  us  that  in  the  or- 
dinary and  mean  condition  of  its  surface,  the  ocean  from  the 
equator  to  the  forty-eighth  degree  of  north  and  south  latitude 
is  somewhat  warmer  than  the  adjacent  strata  of  air.f  Owing 
to  this  decrease  of  temperature  at  increasing  depths,  fishes  and 
other  inhabitants  of  the  sea,  the  nature  of  whose  digestive  and 
respiratory  organs  fits  them  for  living  in  deep  water,  may  even, 
under  the  tropics,  find  the  low  degree  of  temperature  and  the 
coolness  of  climate  characteristic  of  more  temperate  and  more 
northern  latitudes.  This  circumstance,  which  is  analogous- 
to  the  prevalence  of  a  mild  and  even  cold  air  on  the  elevated 
plains  of  the  torrid  zone,  exercises  a  special  influence  on  the 
migration  and  geographical  distribution  of  many  marine  ani- 
mals. Moreover,  the  depths  at  wljich  fishes  live,  modify,  by 
the  increase  of  pressure,  their  cutaneous  respiration,  and  tlie 

*  [See  Wilson's  Paper,  Oa  Wollastoii's  Argument  from  the  Limitati.m 
of  the  Atmosphere  as  to  the  finite  Divisibility  of  Matter. —  Trans,  of  the. 
Royal  Society  of  Edinb.,  vol.  xvi.,  p.  1,  1845.] — Tr. 

t  Humboldt,  Relation  Hist.,  t.  iii.,  chup.  xxix.,  p.  514-530. 


PHYSICAL    GEOGRAPHY.  303 

oxygenous  and  nitrogenous  contents  of  their  swimming  blad- 
ders. 

As  fresh  and  salt  water  do  not  attain  the  maximum  of 
their  density  at  the  same  degree  of  temperature,  and  as  the 
saltness  of  the  sea  lowers  the  thermometrical  degree  corre- 
sponding to  this  point,  we  can  understand  how  the  watei 
drawn  from  great  depths  of  the  sea  during  the  voyages  of 
Kotzebue  and  Dupetit-Thouars  could  have  been  found  to  have 
only  the  temperature  of  37^  and  SG'^'O.  This  icy  temperature 
of  sea  water,  which  is  likewise  manifested  at  the  depths  of 
tropical  seas,  first  led  to  a  study  of  the  lower  polar  currents, 
which  move  from  both  poles  toward  the  equator.  Without 
these  submarine  currents,  the  tropical  seas  at  those  depths 
could  only  have  a  temperature  equal  to  the  local  maximum 
of  cold  possessed  by  the  falling  particles  of  water  at  the  radi- 
ating and  cooled  surface  of  the  tropical  sea.  In  the  Mediter- 
ranean, the  cause  of  the  absence  of  such  a  refrigeration  of  the 
lower  strata  is  ingeniously  explained  by  Arago,  on  the  as- 
sumption that  the  entrance  of  the  deeper  polar  currents  into 
the  Straits  of  Gibraltar,  where  the  water  at  the  surface  flows 
in  from  the  Atlantic  Ocean  from  west  to  east,  is  hindered  by 
the  submarine  counter-currents  which  move  from  east  to 
west,  from  the  Mediterranean  into  the  Atlantic. 

The  ocean,  which  acts  as  a  general  equalizer  and  moder- 
ator of  climates,  exhibits  a  most  remarkable  uniformity  and 
constancy  of  temperature,  especially  between  10°  north  and 
10°  south  latitude,*  over  spaces  of  many  thousands  of  square 
miles,  at  a  distance  from  land  where  it  is  not  penetrated  by 
currents  of  cold  and  heated  water.  It  has,  therefore,  been 
justly  observed,  that  an  exact  and  long-continued  investiga- 
tion of  these  thermic  relations  of  the  tropical  seas  might  most 
easily  afford  a  solution  to  the  great  and  much-contested  prob- 
lem of  the  permanence  of  climates  and  terrestrial  tempera 
tures.t     Great  changes  in  the  luminous  disk  of  the  sun  would, 

*  See  the  series  of  observations  made  by  me  in  the  South  Sea,  from 
0°  5'  to  13°  16'  N.  lat.,  in  my  Asie  Centrale,  t.  iii.,  p.  234. 

t  "  We  might  (by  means  of  the  temperature  of  the  ocean  under  the 
tropics)  enter  into  the  consideration  of  a  question  which  has  hitherto 
remained  unanswered,  namely,  that  of  the  constancy  of  terrestrial  tem 
peratures,  without  taking  into  account  the  very  cii'cumscribed  local 
influences  arising  from  the  diminution  of  wood  in  the  plains  and  on 
mountains,  and  the  drying  up  of  lakes  and  marshes.  Each  age  might 
easily  transmit  to  the  succeeding  one  some  few  data,  which  would  per- 
haps furnish  the  most  simple,  exact,  and  direct  means  of  deciding  whetn- 
er  the  sun,  which  is  almost  the  sole  and  exclusive  source  of  the  heat  of 


304  C03M03. 

if  they  were  of  long  duration,  be  reflected  with  more  certainty 
in  the  mean  temperature  of  the  sea  than  in  that  of  the  solid 
land. 

The  zones,  at  which  occur  the  maxima  of  the  oceanic  tem- 
perature and  of  the  density  (the  saline  contents)  of  its  waters, 
do  not  correspond  with  the  equator.  The  two  maxima  are 
separated  from  one  another,  and  the  waters  of  the  highest  tem- 
perature appear  to  form  two  nearly  parallel  lines  north  and 
south  of  the  geographical  equator,  Lenz,  in  his  voyage  of 
circumnavigation,  found  in  the  Pacific  the  maxima  of  density 
in  22°  north  and  17°  south  latitude,  while  its  minimum  was 
situated  a  few  degrees  to  the  south  of  the  equator.  In  the 
region  of  calms  the  solar  heat  can  exercise  but  little  influence 
on  evaporation,  because  the  stratum  of  air  impregnated  with 
saline  aqueous  vapor,  which  rests  on  the  surface  of  the  sea, 
remains  still  and  unchanged. 

The  surface  of  all  connected  seas  must  be  considered  as 
having  a  general  perfectly  equal  level  with  respect  to  their 
mean  elevation.  Local  causes  (probably  prevaihng  winds  and 
currents)  may,  however,  produce  permanent,  although  trifling 
changes  in  the  level  of  some  deeply-indented  bays,  as,  for  in- 
stance, the  Red  Sea.  The  highest  level  of  the  water  at  the 
Isthmus  of  Suez  is  at  different  hours  of  the  day  from  24  to 
30  feet  above  that  of  the  Mediterranean.  The  form  of  the 
Straits  of  Bab-el-Mandeb,  through  which  the  waters  appeal 
to  find  an  easier  ingress  than  egress,  seems  to  contribute  to 
this  remarkable  phenomenon,  which  was  known  to  the  an- 
cients.* The  admirable  geodetic  operations  of  Coraboeuf  and 
Delcrois  show  that  no  perceptible  difl^erence  of  level  exists  be- 
tween the  upper  surfaces  of  the  Atlantic  and  the  Mediterra- 
nean, along  the  chain  of  the  Pyrenees,  or  between  the  coasts 
of  northern  Holland  and  Marseilles. t 

our  planet,  changes  its  physical  constitution  and  splendor,  like  the  great 
er  number  of  the  stars,  or  whether,  on  the  contrary,  that  luminary  has 
attained  to  a  permanent  condition." — Arago,  in  the  Comptes  Rendua 
des  Siances  de  V Acad,  des  Sciences,  t.  xi.,  Part  ii.,  p.  309. 

*  Humboldt,  Asie  Centrale,  t.  ii.,  p.  321,  327. 

t  See  the  numerical  results  in  p.  328-333  of  the  volume  just  named 
From  the  geodesical  levelings  which,  at  my  request,  my  frieud  General 
Bolivar  caused  to  be  taken  by  Lloyd  and  Falmarc,  in  the  years  1828 
and  1829,  it  was  ascertained  that  the  level  of  the  Pacific  is  at  the  ut- 
most 3i  feet  higher  than  that  of  the  Caribbean  Sea;  and  even  that  at 
different  hours  of  the  day  each  of  the  seas  is  in  turn  the  higher,  accord- 
ing to  their  respective  hours  of  flood  and  ebb.  If  we  reflect  that  in  a 
distauce  of  64  miles,  comprising  933  stations  of  observation,  an  error  of 
three  feet  would  be  very  apt  to  occur,  we  may  say  that  in  these  new 


PHYSICAL    GEOGRAPHY.  305 

Disturbances  of  equilibrium  and  consequent  movements  cf( 
the  waters  are  partly  irregular  and  transitory,  dependent  upon 
winds,  and  producing  waves  which  sometimes,  at  a  distance 
from  the  shore  and  during  a  storm,  rise  to  a  height  of  more 
than  35  feet ;  partly  regular  and  periodic,  occasioned  by  the 
position  and  attraction  of  the  sun  and  moon,  as  the  ebb  and 
flow  of  the  tides ;  and  partly  permanent,  although  less  in- 
tense, occurring  as  oceanic  currents.  The  phenomena  of 
tides,  which  prevail  in  all  seas  (with  the  exception  of  the 
smaller  ones  that  are  completely  closed  in,  and  where  the  ebb- 
ing and  flowing  waves  are  scarcely  or  not  at  all  perceptible), 
have  been  perfectly  explained  by  the  Newtonian  doctrine, 
and  thus  brought  "  within  the  domain  of  necessary  facts." 
Each  of  these  periodically-recurring  oscillations  of  the  waters 
of  the  sea  has  a  duration  of  somewhat  more  than  half  a  day. 
Although  in  the  open  sea  they  scarcely  attain  an  elevation  of 
a  few  feet,  they  often  rise  considerably  higher  where  the  waves 
are  opposed  by  the  configuration  of  the  shores,  as,  for  instance, 
at  St.  Malo  and  in  Nova  Scotia,  where  they  reach  the  re- 
spective elevations  of  50  feet,  and  of  65  to  70  feet.  "  It  has 
been  shown  by  the  analysis  of  the  great  geometrician  La- 
place, that,  supposing  the  depth  to  be  wholly  inconsiderable 
when  compared  with  the  radius  of  the  earth,  the  stability  of 
the  equilibrium  of  the  sea  requires  that  the  density  of  its  fluid 
should  be  less  than  that  of  the  earth ;  and,  as  we  have  already 
seen,  the  earth's  density  is  in  fact  five  times  greater  than 
that  of  water.  The  elevated  parts  of  the  land  can  not  there- 
fore be  overflowed,  nor  can  the  remains  of  marine  animals 
found  on  the  summits  of  mountains  have  been  conveyed  to 
those  localities  by  any  previous  high  tides."*     It  is  no  slight 

operatious  we  have  further  confirmation  of  the  equilibrium  of  the  wa- 
ters which  communicate  round  Cape  Horn.  (Arago,  in  the  Annuaire 
du  Bureau  des  Longitudes  pour  1831,  p.  319.)  I  had  inferred,  from 
barometrical  observations  instituted  in  1799  and  1804,  tliat  if  there  were 
any  diflference  between  the  level  of  the  Pacific  and  the  Atlantic  (Ca- 
ribbean Sea),  it  could  not  exceed  three  meters  (nine  feet  three  inches). 
See  my  Relat.  Hist.,  t.  iii.,  p.  555-557,  and  Annales  de  Chimie,  t.  i., 
p.  55-64.  The  measurements,  which  appear  to  establish  an  excess  of 
height  for  the  waters  of  the  Gulf  of  Mexico,  and  for  those  of  the  nortli- 
ei'n  part  of  the  Adriatic  Sea,  obtained  by  combining  the  trigonometrical 
operations  of  Delcrois  and  Choppin  with  those  of  the  Swiss  and  Aus- 
trian engineers,  are  open  to  many  doubts.  Notwithstanding  tlie  form 
of  the  Adriatic,  it  is  improbable  that  the  level  of  its  waters  in  its  north- 
ern portion  should  be  28  feet  higher  than  that  of  the  Mediterranean  at 
Marseilles,  and  25  feet  higher  than  the  level  of  the  Atlantic  Ocean- 
See  my  Asie  Centrale,  t.  ii.,  p.  332. 
*  Bessel,  Ueber  Flnth  vnd  Ebbc,  in  Schamachev^ ejahrbuch,  1838,  s.  225 


806  COSMOS. 

evidence  of  the  importance  of  analysis,  which  is  too  often  re- 
garded with  contempt  among  the  unscientific,  that  Laplace's 
perfect  theory  of  tides  has  enabled  us,  in  our  astronomical 
ephemerides,  to  predict  the  height  of  spring-tides  at  the  peri- 
ods of  new  and  full  moon,  and  thus  put  the  inhabitants  of  the 
sea-shore  on  their  guard  against  the  increased  danger  attend- 
ing these  lunar  revolutions. 

Oceanic  currents,  which  exercise  so  important  an  influence 
on  the  intercourse  of  nations  and  on  the  climatic  relations  of 
adjacent  coasts,  depend  conjointly  upon  various  causes,  differ- 
ing alike  in  nature  and  importance.  Among  these  we  may 
reckon  the  periods  at  which  tides  occur  in  their  progress  round 
the  earth  ;  the  duration  and  intensity  of  prevailing  winds  ; 
the  modifications  of  density  and  specific  gravity  which  the  par- 
ticles of  water  undergo  in  consequence  of  differences  in  the 
temperature  and  in  the  relative  quantity  of  saline  contents  at 
different  latitudes  and  depths  ;*  and,  lastly,  the  horary  varia- 
tions of  the  atmospheric  pressure,  successively  propagated  from 
east  to  west,  and  occurring  with  such  regularity  in  the  trop- 
ics. These  currents  present  a  remarkable  spectacle ;  like  riv- 
ers of  uniform  breadth,  they  cross  the  sea  in  different  direc- 
tions, while  the  adjacent  strata  of  water,  which  remain  un- 
disturbed, form,  as  it  were,  the  banks  of  these  moving  streams. 
This  difference  between  the  moving  waters  and  those  at  rest 
is  most  strikingly  manifested  where  long  lines  of  sea- weed, 
borne  onward  by  the  current,  enable  us  to  estimate  its  veloc- 
ity. In  the  lower  strata  of  the  atmosphere,  we  may  some- 
times, during  a  storm,  observe  similar  phenomena  in  the  lim- 
ited aerial  current,  which  is  indicated  by  a  narrow  line  of 
trees,  which  are  often  found  to  be  overthrown  in  the  midst  of 
a  dense  wood. 

The  general  movement  of  the  sea  from  east  to  west  be- 

*  The  relative  density  of  the  pai'ticles  of  water  depends  simultane- 
ously on  the  temperature  and  on  the  amount  of  the  saline  contents — a 
circumstance  that  is  not  sufficiently  borne  in  mind  in  considering  the 
cause  of  cun-ents.  The  submarine  current,  which  brings  the  cold  po- 
lar water  to  the  equatorial  regions,  would  follow  an  exactly  opposite 
course,  that  is  to  say,  from  the  equator  toward  the  poles,  if  the  ditfer- 
ence  in  saline  contents  were  alone  concerned.  In  this  view,  the  geo- 
graphical distribution  of  temperature  and  of  density  in  the  water  of 
the  ocean,  under  the  different  zones  of  latitude  and  longitude,  is  of 
great  importance.  The  numerous  observations  of  Lenz  (Poggeudorf's 
Annalen,  bd.  xx.,  1830,  s.  129),  and  those  of  Captain  Beechey,  collect- 
ed in  his  Voyage  to  the  acijic,  vol.  ii.,  p.  727,  deserve  particular  at- 
tention. See  Humboldt,  Relat.  Hist.,  t.  i.,  p.  74,  and  Asia  Centrale, 
t.  iii.,  p.  356, 


PHYSICAL    GEOGRAPHy.  307 

tweeii  the  tropics  (termed  the  equatorial  or  rotation  current) 
is  considered  to  be  owing  to  the  propagation  ol'  tides  and  to 
the  trade  winds,  [ts  direction  is  changed  by  the  resistance 
it  experiences  from  the  prominent  eastern  shores  of  continents. 
The  results  recently  obtained  by  Daussy  regarding  the  veloc 
ity  of  this  current,  estimated  from  observations  made  on  the 
distances  traversed  by  bottles  that  had  purposely  been  thrown 
into  the  sea,  agree  within  one  eighteenth  with  the  velocity  of 
motion  (10  French  nautical  miles,  952  toises  each,  in  24  hours) 
which  I  had  found  from  a  comparison  Avith  earlier  experi- 
ments.*' Christopher  Columbus,  during  his  third  voyage, 
when  he  w-as  seeking  to  enter  the  tropics  in  the  meridian  of 
Tenerifie,  WTote  in  his  journal  as  follows  :t  "  I  regard  it  as 
proved  that  the  waters  of  the  sea  move  from  east  to  west,  as 
do  the  heavens  {las  aguas  van  con  los  cielos),  that  is  to  say, 
like  the  apparent  motion  of  the  sun,  moon,  and  stars." 

The  narrow  currents,  or  true  oceanic  rivers  which  traverse 
the  sea,  bring  warm  water  into  higher  and  cold  water  into 
lower  latitudes.  To  the  first  class  belongs  the  celebrated 
Gulf  Stream, t  which  Avas  known  to  Anghiera,§  and  more 
especially  to  Sir  Humphrey  Gilbert  in  the  sixteenth  century. 
Its  first  impulse  and  origin  is  to  be  sought  to  the  south  of 
the  Cape  of  Good  Hope  ;  after  a  long  circuit  it  pours  itself 
from  the  Caribbean  Sea  and  the  Mexican  Gulf  throuffh  the 
Straits  of  the  Bahamas,  and,  following  a  course  from  south- 
southwest  to  north-northeast,  continues  to  recede  from  the 
shores  of  the  United  States,  until,  further  deflected  to  the 
eastward  by  the  Banks  of  Newfoundland,  it  approaches  the 
European  coasts,  frequently  throwing  a  quantity  of  tropical 
seeds  {Mimosa  scandcns,  Guilaiidina  bonduc,  Dolichos  urens) 
on  the  shores  of  Ireland,  the  Hebrides,  and  Norway.  The 
northeastern  prolongation  tends  to  mitigate  the  cold  of  the 
ocean,  and  to  ameliorate  the  climate  on  the  most  northern  ex- 
tremity of  Scandinavia.    At  the  point  where  the  Gulf  Stream 

*  Humboldt,  Relat.  Hist.,  t.  i.,  p.  64  ;  Nouvelles  Annales  des  Voyages, 
1839,  p.  255. 

t  Humboldt,  Examen  Crit.  de  VHist.  de  la  Geogr.,  t.  iii.,  p.  100. 
Cohimbus  adds  shortly  after  (Navarrete,  Coleccio7i  de  los  Viages  y  De- 
scubrimientos  d-e  los  Espanoles,  t.  i.,  p.  SCO),  that  the  movement  i.s 
strongest  in  the  Caribbean  Sea.  In  i'act,  Rennell  terms  this  region, 
"  not  a  current,  but  a  sea  in  motion"  {Investigation  of  Currents,  p.  23). 

X  Humboldt,  Examen  Critique,  t.  ii.,  p.  250;  Relat.  Hist.,  t.  i.,  p. 
66-74. 

§  Petrtis  Martyr  de  Angliiera,  De  Rebus  Oceanicis  et  Orbe  Novo, 
Bas.,  I.r23,  Dec.  iii.,  lib.  vi.,  p.  57.  See  Humboldt,  Examen  Critique, 
t.  ii,,  p.  J  ) 4-257,  and  t,  iii..  p.  108. 


308  COSMOS. 

is  deflected  from  the  Banks  of  Newfoundland  toward  the  east, 
it  sends  oiF  branches  to  the  south  near  the  Azores.*  This  is 
the  situation  of  the  Sargasso  Sea,  or  that  great  bank  of  weeds 
which  so  vividly  occupied  the  imagination  of  Christopher  Co- 
lumbus, and  which  Oviedo  calls  the  sea- weed  meadows  [Pra- 
derias  de  yerva).  A  host  of  small  marine  animals  inhabits 
these  gently-moved  and  evergreen  masses  of  Fiicus  natans, 
one  of  the  most  generally  distributed  of  the  social  plants  of 
the  sea. 

The  counterpart  of  this  current  (which  in  the  Atlantic 
Ocean,  between  Africa,  America,  and  Europe,  belongs  almost 
exclusively  to  the  northern  hemisphere)  is  to  be  found  in  the 
South  Pacific,  where  a  current  prevails,  the  effect  of  whose  low 
temperature  on  the  climate  of  the  adjacent  shores  I  had  an 
opportunity  of  observing  in  the  autumn  of  1802.  It  brings 
the  cold  waters  of  the  high  southern  latitudes  to  the  coast  of 
Chili,  follows  the  shores  of  this  continent  and  of  Peru,  first  from 
south  to  north,  and  is  then  deflected  from  the  Bay  of  Arica  on- 
ward from  south-southeast  to  north-northwest.  At  certain 
seasons  of  the  year  the  temperature  of  this  cold  oceanic  cur- 
rent is,  in  the  tropics,  only  60°,  while  the  undisturbed  adjacent 
water  exhibits  a  temperature  of  810-5  and  SS*^-?.  On  that 
part  of  the  shore  of  South  America  south  of  Payta,  which  in- 
clines furthest  westward,  the  current  is  suddenly  deflected  in 
the  same  direction  from  the  shore,  turning  so  sharply  to  the 
west  that  a  ship  sailing  northward  passes  suddenly  from  cold 
into  warm  water. 

It  is  not  known  to  what  depth  cold  and  warm  oceanic  cur- 
rents propagate  their  motion  ;  but  the  deflection  experienced 
by  the  South  African  current,  from  the  Lagullas  Bank,  which 
is  fully  from  70  to  80  fathoms  deep,  would  seem  to  imply  the 
existence  of  a  far-extending  propagation.  Sand  banks  and 
shoals  lying  beyond  the  line  of  these  currents  may,  as  was  first 
discovered  by  the  admirable  Benjamin  Franklin,  be  recognized 
by  the  coldness  of  the  water  over  them.  This  depression  of 
the  temperature  appears  to  me  to  depend  upon  the  fact  that, 
by  the  propagation  of  the  motion  of  the  sea,  deep  waters  rise 
to  the  margin  of  the  banks  and  mix  with  the  upper  strata. 
My  lamented  friend.  Sir  Humphrey  Davy,  ascribed  this  phe- 
nomenon (the  knowledge  of  which  is  often  of  great  practical 
utility  in  securing  the  safety  of  the  navigator)  to  the  descent 
of  the  particles  of  water  that  had  been  cooled  by  nocturnal  ra- 

*  Humboldt,  Examen  Crit.,  t.  iii.,  p.  G4-109. 


PHYSICAL    GEOGRAPHY.  309 

diation,  and  which  remain  nearer  to  the  surface,  owing  to  the 
hinderance  placed  in  the  way  of  their  greater  descent  by  the 
intervention  of  sand-banks.  By  his  observations  Frankhn  may 
be  said  to  have  converted  the  thermometer  into  a  soundinjj 
line.  Mists  are  frequently  found  to  rest  over  these  depths,  ow- 
ing to  the  condensation  of  the  vapor  of  the  atmosphere  by  the 
cooled  waters.  I  have  seen  such  mists  in  the  south  of  Jamai- 
ca, and  also  in  the  Pacific,  defining  with  sharpness  and  clear- 
ness the  form  of  the  shoals  below  them,  appearing  to  the  eye 
as  the  aerial  reflection  of  the  bottom  of  the  sea.  A  still  more 
striking  eflect  of  the  cooling  produced  by  shoals  is  manifested 
in  the  higher  strata  of  air,  in  a  somewhat  analogous  manner 
to  that  observed  in  the  case  of  flat  coral  reefs,  or  sand  islands 
In  the  open  sea,  far  from  the  land,  and  when  the  air  is  calm, 
clouds  are  often  observed  to  rest  over  the  spots  where  shoals 
are  situated,  and  their  bearing  may  then  be  taken  by  the  com- 
pass in  the  same  manner  as  that  of  a  high  mountain  or  isola- 
ted peak. 

Although  the  surface  of  the  ocean  is  less  rich  in  livingf  forms 
than  that  of  continents,  it  is  not  improbable  that,  on  a  further 
investigation  of  its  depths,  its  interior  may  be  found  to  possess 
a  greater  richness  of  organic  life  than  any  other  portion  of  our 
planet.  Charles  Darwin,  in  the  agreeable  narrative  of  his  ex- 
tensive voyages,  justly  remarks  that  our  forests  do  not  conceal 
so  many  animals  as  the  low  woody  regions  of  the  ocean,  where 
the  sea- weed,  rooted  to  the  bottom  of  the  shoals,  and  the  sev- 
ered branches  of  fuci,  loosened  by  the  force  of  the  waves  and 
currents,  and  swimming  free,  imfbld  their  delicate  foliage,  up- 
borne by  air-cells.*  The  application  of  the  microscope  increas- 
es, in  the  most  striking  manner,  our  impression  of  the  rich  lux- 
uriance of  animal  life  in  the  oceaii,  and  reveals  to  the  aston- 
ished senses  a  consciousness  of  the  universality  of  life.  In  the 
oceanic  depths,  far  exceeding  the  height  of  our  loftiest  mount- 
ain chains,  every  stratum  of  water  is  animated  with  polygas- 
tric  sea- worms,  Cyclidise,  and  Ophrydinaj.  The  waters  swarm 
with  countless  hosts  of  small  luminiferous  animalcules,  Mam- 
maria(of  the  order  of  Acalephse),  Crustacea,  Peridinea,  and  cir- 
cling Nereides,  which,  when  attracted  to  the  surface  by  peculiar 
meteorological  conditions,  convert  every  v/ave  into  a  foaming 
band  of  flashing  light. 

*  [See  Structure  and  Distribution  of  Coral  Reefs,  hy  Charles  Darwiu, 
London,  1842.  Also,  Narrative  of  the  Surveying  Voyage  of  H.M.S. 
"  Fly^^  in  the  Eastern  Archipelago,  during  the  Years  1842-184G,  by  J. 
B.  Jukes,  Naturalist  to  the  expedition,  1847.] — Tr. 


310  COSMOS. 

The  abundance  of  these  marine  anhnalcules,  and  the  anima* 
matter  yielded  by  their  rapid  decomjjosition,  are  so  vast  that 
the  sea  water  itself  becomes  a  nutrient  fluid  to  many  of  tho 
larger  animals.  However  much  this  richness  in  animated 
forms,  and  this  multitude  of  the  most  various  and  highly-de- 
veloped microscopic  organisms  may  agreeably  excite  the  fancy, 
the  imagination  is  even  more  seriously,  and,  I  m^ight  say,  more 
solemnly  moved  by  the  impression  of  boundlessness  and  im- 
measurability, which  are  presented  to  the  mind  by  every  sea 
voyage.  All  who  possess  an  ordinary  degree  of  mental  activi- 
ty, and  delight  to  create  to  themselves  an  inner  world  of 
thought,  must  be  penetrated  with  the  sublime  image  of  the 
infinite  when  gazing  around  them  on  the  vast  and  boundless 
sea,  when  involuntarily  the  glance  is  attracted  to  the  distant 
horizon,  where  air  and  water  blend  together,  and  the  stars  con- 
tinually rise  and  set  before  the  eyes  of  the  mariner.  This  con- 
templation of  the  eternal  play  of  the  elements  is  clouded,  like 
every  human  joy,  by  a  touch  of  sadness  and  of  longing. 

A  peculiar  predilection  for  the  sea,  and  a  grateful  remem- 
brance of  the  impression  which  it  has  excited  in  my  mind,  when 
I  have  seen  it  in  the  tropics  in  the  calm  of  nocturnal  rest,  or 
in  the  fury  of  the  tempest,  have  alone  induced  me  to  speak  of 
the  individual  enjoyment  afibrded  by  its  aspect  before  I  en- 
tered upon  the  consideration  of  the  favorable  influence  which 
the  proximity  of  the  ocean  has  incontrovertibly  exercised  on 
the  cultivation  of  the  intellect  and  character  of  many  nations, 
by  the  multiplication  of  those  bands  which  ought  to  encircle 
the  whole  of  humanity,  by  affording  additional  means  of  arriv- 
ing at  a  knowledge  of  the  configuration  of  the  earth,  and  fur- 
thering the  advancement  of  astronomy,  and  of  all  other  math- 
ematical and  physical  sciences.  A  portion  of  this  influence 
was  at  first  limited  to  the  Mediterranean  and  the  shores  of 
southwestern  Africa,  but  from  the  sixteenth  century  it  has 
wddely  spread,  extending  to  nations  who  live  at  a  distance 
from  the  sea,  in  the  interior  of  continents.  Since  Columbus 
was  sent  to  "  unchain  the  ocean"*  (as  the  unknown  voice 
whispered  to  him  in  a  dream  when  he  lay  on  a  sick-bed  near 

*  The  voice  addressed  him  iu  these  words,  "  Maravillosamente  Dios 
liizo  sonar  tu  nombre  en  la  tieiTa  ;  de  los  atamientos  de  la  mar  Oceana, 
que  estaban  cerrados  con  cadenas  tan  tuertes,  te  dio  las  Haves" — "  God 
will  cause  thy  name  to  be  wonderfully  resounded  through  the  earth, 
and  give  thee  the  keys  of  the  gates  of  the  ocean,  which  are  closed  with 
strong  chains."  The  dream  of  Columbus  is  related  in  the  letter  to  the 
Catholic  monarchs  of  July  the  7th,  1503.  (Humboldt,  Exavien  CrUiqis.e, 
L  iii.  p.  234.) 


METEOROLOGY,  311 

the  River  Belem),  man  has  ever  boldly  ventured  onward  to- 
ward the  discovery  of  unknown  regions. 

The  second  external  and  general  covering  of  our  planet,  the 
aerial  ocean,  in  the  lower  strata,  and  on  the  shoals  of  which 
we  live,  presents  six  classes  of  natural  phenomena,  which  man- 
ifest the  most  intimate  connection  wTth  one  another.  They 
are  dependent  on  the  chemical  composition  of  the  atmosphere, 
the  variations  in  its  transparency,  polarization,  and  color,  its 
density  or  pressure,  its  temperature  and  humidity,  and  its  elec- 
tricity. The  air  contains  in  oxygen  the  first  element  of  phys-" 
ical  animal  life,  and,  besides  this  benefit,  it  possesses  another, 
which  may  be  said  to  be  of  a  nearly  equally  high  character, 
namely,  that  of  convejdng  sound  ;  a  faculty  by  which  it  like- 
wise becomes  the  conveyer  of  speech  and  the  means  of  com- 
municating thought,  and,  consequently,  of  maintaining  social 
intercourse.  If  the  Earth  were  deprived  of  an  atmosphere,  as 
we  suppose  our  moon  to  be,  it  would  present  itself  to  our  im- 
agination as  a  soundless  desert. 

The  relative  quantities  of  the  substances  composing  the 
strata  of  air  accessible  to  us  have,  since  the  beginning  of  the 
nineteenth  century,  become  the  object  of  investigations,  in 
which  Gay-Lussac  and  myself  have  taken  an  active  part ;  it 
is,  however,  only  very  recently  that  the  admirable  labors  of 
Dumas  and  Boussingault  have,  by  new  and  more  accurate 
methods,  brought  the  chemical  analysis  of  the  atmosphere  to 
a  high  degree  of  perfection.  According  to  this  analysis,  a 
volume  of  dry  air  contains  20  8  of  oxygen  and  79-2  of  nitro- 
gen, besides  from  two  to  five  thousandth  parts  of  carbonic 
acid  gas,  a  still  smaller  quantity  of  carbureted  hydrogen  gas,* 
and,  according  to  the  important  experiments  of  Saussure  and 
Liebig,  traces  of  ammoniacal  vapors,t  from  which  plants  de- 
rive their  nitrogenous  contents.  Some  observations  of  Lewy 
render  it  probable  that  the  quantity  of  oxygen  varies  percep- 

*  Boussingault,  Recherches  sur  la  Composition  de  V Atmosphere,  in  thd 
Annales  de  Chimie  et  de  Physique,  t.  Ivii.,  1834,  p.  171-173;  and  Ix.xi. 
1839,  p.  IIG.  According  to  Boussingault  and  Lewy,  the  pioportiun  of 
carbonic  acid  in  tlie  atmosphere  at  Audilly,  at  a  distance,  therefore,  from 
the  exhalations  of  a  city,  varied  only  between  000028  and  0-00031  hi 
vokime.  " 

+  Liebig,  lu  his  important  work,  entitled  Die  Organische  Chemie  in 
ihrer  Anwendung  auf  Agricultur  und  Physiologic,  1840,  s.  G2-7'2.  On 
the  influence  of  atmospheric  electricity  in  the  production  of  nitrut;-  of 
ammonia,  which,  coming  into  contact  with  carbonate  of  lime,  is  changed 
into  carbonate  of  ammonia,  see  Boussingault's  Economic  Rurale  con- 
sidiric  dans  ses  Rapports  avec  la  Chimie  et  la  M6t6orologie,  184  1,  t.  ii., 
p.  247,267,  and  t.  i.,  p.  84. 


312  COSMOS. 

tibly,  although  but  sHghtly,  over  the  sea  and  in  the  interior 
of  continents,  according  to  local  conditions  or  to  the  seasons  of 
the  year.  We  may  easily  conceive  that  changes  in  the  oxy- 
gen held  in  solution  in  the  sea,  produced  by  microscopic  an- 
imal organisms,  may  be.attended  by  alterations  in  the  strata 
of  air  in  immediate  contact  with  it.*  The  air  which  Martins 
collected  at  Faulhorn  at  an  elevation  of  8767  feet,  contained 
as  much  oxygen  as  the  air  at  Paris. f 

The  admixture  of  carbonate  of  ammonia  in  the  atmosphere 
may  probably  be  considered  as  older  than  the  existence  of  or- 
ganic beings  on  the  surface  of  the  earth.  The  sources  from 
which  carbonic  acid$  may  be  yielded  to  the  atmosphere  are 
most  numerous.  In  the  first  place  we  would  mention  the  res- 
piration of  animals,  who  receive  the  carbon  which  they  inhale 
from  vegetable  food,  while  vegetables  receive  it  from  the  at- 
mosphere ;  in  the  next  place,  carbon  is  supplied  from  the  in- 
terior of  the  earth  in  the  vicinity  of  exhausted  volcanoes  and 
thermal  springs,  from  the  decomposition  of  a  small  quantity  of 
carbureted  hydrogen  gas  in  the  atmosphere,  and  from  the  elec- 
tric discharges  of  clouds,  which  are  of  such  frequent  occurrence 
within  the  tropics.  Besides  these  substances,  which  we  have 
considered  as  appertaining  to  the  atmosphere  at  all  heights 
that  are  accessible  to  us,  there  are  others  accidentally  mixed 
with  them,  especially  near  the  ground,  which  sometimes,  in 
the  form  of  miasmatic  and  gaseous  contagia,  exercise  a  noxious 
influence  on  animal  organization.  Their  chemical  nature  has 
not  yet  been  ascertained  by  direct  analysis  ;  but,  from  the  con- 
sideration of  the  processes  of  decay  which  are  perpetually  go- 
ing on  in  the  animal  and  vegetable  substances  with  which  the 
surface  of  our  planet  is  covered,  and  judging  from  analogies 
deduced  from  the  domain  of  pathology,  we  are  led  to  infer  the 
existence  of  such  noxious  local  admixtures.  Ammoniacal  and 
other  nitrogenous  vapors,  sulphureted  hydrogen  gas,  and  com- 
pounds analogous  to  the  polybasic  ternary  and  quaternary  com- 
binations of  the  vegetable  kingdom,  may  produce  miasmata,^ 

*  Lewy,  in  the  Comptes  Rendus  de  VAcad.  des  Sciences,  t.  xvii.,  Part 
ii.,  p.  235-248. 

t  Dumas,  in  the  Annates  de  Chimie,  3e  Sirie,  t.  iii.,  1841,  p.  257. 

t  In  this  enumeration,  the  exhalation  of  carbonic  acid  by  plants  dur- 
ing the  night,  while  they  inhale  oxygen,  is  not  taken  into  account,  be- 
cause the  increase  of  carbonic  acid  from  this  source  is  amply  counter- 
balanced by  the  respiratory  process  of  plants  during  the  day.  See  Bous- 
singault's  Econ.  Rurale,  t.  i.,  p.  53-68,  and  Liebig's  Organische  Chemie, 
B.  16,  21. 

$  Gay-Lussac,  in  Annates  de  Chimie,  t.  liii.,  p.  120 ;  Payen,  M6m.  sut 


METEOROLOGY  313 

which,  under  various  forms,  may  generate  ague  and  typhus 
fever  (not  by  any  means  exclusively  on  wet,  marshy  ground, 
or  on  coasts  covered  by  putrescent  moUusca,  and  low  bushes 
of  Rhizo'phoTa  moMgle  and  Avicennia).  Fogs,  w^hich  have 
a  peculiar  smell  at  some  seasons  of  the  year,  remind  us  of 
these  accidental  admixtures  in  the  lower  strata  of  the  atmos- 
phere. Winds  and  currents  of  air  caused  by  the  heating  of 
the  ground  even  carry  up  to  a  considerable  elevation  solid 
substances  reduced  to  a  fine  powder.  The  dust  which  dark- 
ens the  air  for  an  extended  area,  and  falls  on  the  Cape  Verd 
Islands,  to  which  Darwin  has  drawn  attention,  contains,  ac- 
cording to  Ehrenberg's  discovery,  a  host  of  silicious-shelled  in 
fusoria. 

As  principal  features  of  a  general  descriptive  picture  of  the 
atmosphere,  we  may  enumerate  : 

1 .  Variations  of  atmospheric  pressure :  to  which  belong 
the  horary  oscillations,  occurring  with  such  regularity  in  the 
tropics,  \vhere  they  produce  a  kind  of  ebb  and  flow  in  the  at- 
mosphere, wdiich  can  not  be  ascribed  to  the  attraction  of  the 
moon,^  and  which  differs  so  considerably  according  to  geo- 
graphical latitude,  the  seasons  of  the  year,  and  the  elevation 
above  the  level  of  the  sea. 

2.  Climatic  distribution  of  heat,  which  depends  on  the 
relative  position  of  the  transparent  and  opaque  masses  (the 
fluid  and  solid  parts  of  the  surface  of  the  earth),  and  on  the 
hypsometrical  configuration  of  continents  ;  relations  which  de- 
termine the  geographical  position  and  curvature  of  the  iso- 
thermal lines  (or  curves  of  equal  mean  annual  temperature) 
both  in  a  horizontal  and  vertical  direction,  or  on  a  uniform 
plane,  or  in  difierent  superposed  strata  of  air. 

3.  The  distribution  of  the  humidity  of  the  atmosphere. 
The  quantitative  relations  of  the  humidity  depend  on  the  dif- 
ferences in  the  solid  and  oceanic  surfaces  ;  on  the  distance  from 
the  equator  and  the  level  of  the  sea  ;  on  the  form  in  which  the 

la  ComposUion  Chimi'que  des  Vegetaux,  p.  36,  42  ;   Liebig,  Org.  Cheinic. 
s.  229-3-15;   Boussiugaiilt,  Eco7i.  Rurale,  t.  i.,  p.  142-153. 

*  Boavard,  by  the  application  of  the  formula),  iu  1827,  whicli  La[)l:«ce 
had  deposited  with  the  Board  of  Longitude  shortly  before  his  death, 
found  that  the  portion  of  the  horary  oscillations  of  the  pressure  of  the 
atmosphere,  which  depends  on  the  attraction  of  the  moon,  can  not  raise 
the  mercury  in  the  barometer  at  Paris  more  than  the  0-018  of  a  milli- 
meter, while  eleven  years'  observations  at  the  same  place  show  the  nieau 
barometric  oscillation,  from  9  A.M.  to  3  P.M..  to  be  0756  millim.,  and 
from  3  P.M.  to  9  P.M.,  0-373  millim.  See  M6moires  de  VAcad.  des 
Sciences,  t.  vii.,  1827,  p.  267. 

Vol.  I.— O  • 


311  COSxMOS. 

aqueous  vapor  is  precipitated,  and  on  tlie  connection  existing 
between  these  deposits  and  the  chanijes  of  temperature,  and 
the  direction  and  succession  of  Avinds. 

4.  Tlie  electric  condition  of  the  atmosphere.  The  primary 
cause  of  this  condition,  when  the  heavens  are  serene,  is  still 
much  contested.  Under  this  head  we  must  consider  the  re- 
lation of  ascending-  vapors  to  the  electric  charge  and  the  form 
of  the  clouds,  according  to  the  different  periods  of  the  day  and 
year ;  the  difference  between  the  cold  and  warm  zones  of  the 
earth,  or  low  and  high  lands  ;  the  frequency  or  rarity  of  thun- 
der storms,  their  periodicity  and  formation  in  summer  and 
winter  ;  the  causal  connection  of  electricity,  with  the  infre- 
quent occurrence  of  hail  in  the  night,  and  with  the  phe- 
nomena of  water  and  sand  spouts,  so  ably  investigated  by 
Peltier. 

The  horary  oscillations  of  the  barometer,  which  in  the  trop- 
ics present  two  maxima  (viz.,  at  9  or  9J-  A.M.,  and  10^  or 
105  P.M.,  and  two  minima,  at  4  or  41  P.M.,  and"  4  A.M., 
occurring,  therefore,  in  almost  the  hottest  and  coldest  hours), 
have  long  been  the  object  of  my  most  careful  diurnal  and  noc- 
turnal observations.*  Their  regularity  is  so  great,  that,  in 
the  daytime  especially,  the  hour  may  be  ascertained  from  the 
height  of  the  mercurial  column  without  an  error,  on  the  av- 
erage, of  more  than  fifteen  or  seventeen  minutes.  In  the  tor- 
rid zones  of  the  New  Continent,  on  the  coasts  as  well  as  at 
elevations  of  nearly  13,000  feet  above  the  level  of  the  sea, 
where  the  mean  temperature  falls  to  44°-6,  I  have  found  the 
regularity  of  the  ebb  and  flow  of  the  aerial  ocean  undisturbed 
by  storms,  hurricanes,  rain,  and  earthquakes.  The  amount 
of  the  daily  oscillations  diminishes  from  1*32  to  0'18  French 
lines  from  the  equator  to  70^  north  latitude,  where  Bravais 
made  very  accurate  observations  at  Bosekop.f  The  supposi- 
tion that,  much  nearer  the  pole,  the  height  of  the  barometer 
is  really  less  at  10  A.M.  than  at  4  P.M.,  and,  consequently, 
that  the  maximum  and  minimum  influences  of  these  hours 

*  Observations  faites  four  conslater  la  Marche  des  Variations  Horaires 
dn  Barometre  sotis  les  Tropiques,  in  iny  Relation  Historique  die  Voyage, 
aux  Regions  Equinoxiales,  t.  iii.,  p.  270-31.3. 

t  Bravais,  in  Kaerntz  and  Martins,  Meleorologie,  p.  263.  A*^.  Halhi 
(ol*^  29'  N.  lat.),  the  oscillation  still  amounts  to  0-28  lines.  It  would 
seem  that  a  great  many  observations  will  be  required  in  oider  to  obfiiin 
re.sults  that  can  be  trusted  in  regard  to  the  hours  of  the  maximum  and 
minimum  on  mountains  in  the  temperate  zone.  See  the  nb^^ervationa 
of  horary  variations,  collected  on  the  Faulhurn  in  1832,  1841,  aiid  l?>\t 
(Martin?.  MHeorologie.  p.  25-i.) 


ATMOSPHERIC    PRESSURE.  315 

are  inverted,  is  not  confirmed  by  Parry's  observations  at  Port 
Bowen  (73°  14'). 

The  mean  height  of  the  barometer  is  somewhat  less  under 
the  equator  and  in  the  tropics,  ov\^ing  to  the  effect  of  the  rising 
current,*  than  in  the  temperate  zones,  and  it  appears  to  attain 
its  maximum  in  Western  Europe  between  the  parallels  of  40° 
and  45°.  If  with  Kilmtz  we  connect  together  by  isobaromet- 
ric  lines  those  places  which  present  the  same  mean  difference 
between  the  monthly  extremes  of  the  barometer,  we  shall  have 
curves  whose  geographical  position  and  inflections  yield  im- 
portant conclusions  regarding  the  influence  exercised  by  the 
form  of  the  land  and  the  distribution  of  seas  on  the  oscillations 
of  the  atmosphere.  Hindostan,  with  its  high  mountain  chains 
and  triangular  peninsulas,  and  the  eastern  coasts  of  the  New 
Continent,  where  the  warm  Gulf  Stream  turns  to  the  east  at 
the  Newfoundland  Banks,  exhibit  greater  isobarometric  oscil- 
lations than  do  the  group  of  the  Antilles  and  Western  Europe. 
The  prevailing  winds  exercise  a  principal  influence  on  the 
diminution  of  the  pressure  of  the  atmosphere,  and  this,  as  we 
have  already  mentioned,  is  accompanied,  according  to-Daussy, 
by  an  elevation  of  the  mean  level  of  the  sea.t 

As  the  most  important  fluctuations  of  the  pressure  of  the 
atmosphere,  whether  occurring  with  horary  or  annual  regu- 
larity, or  accidentally,  and  then  often  attended  by  violence  and 
danger,!  are,  like  all  the  other  phenomena  of  the  weather, 
mainly  owing  to  the  heating  force  of  the  sun's  rays,  it  has 
long  been  suggested  (partly  according  to  the  idea  of  Lambert) 
that  the  direction  of  the  wind  should  be  compared  with  the 
height  of  the  barometer,  alternations  of  temperature,  and  the 
increase  and  decrease  of  humidity.  Tables  of  atmospheric 
pressure  during  different  winds,  termed  barometric  ivi7idroses. 
afford  a  deeper  insight  into  the  connection  of  meteorological 
phenomena.^  Dove  has,  with  admirable  sagacity,  recognized, 
in  the  "  law  of  rotation"  in  both  hemispheres,  w^iich  he  him- 
self established,  the  cause  of  many  important  processes  in  the 
aerial  ocean. ||     The  difference  of  temperature  between  the 

*  Humboldt,  Essai  sur  la  Geographic  des  Planles,  1807,  p.  90;  .lud 
ia  ReL  Hist.,  t.  iii.,  p.  313  ;  and  on  the  diuiinutiou  of  atmospheric  press- 
ure ill  the  tropical  portions  of  the  Atlantic,  in  Poggeud..  Annalen  dcr 
Physik,  bd.  xxxvii.,  s.  245-258,  and  s.  468-486. 

t  Daussy,  in  the  Comptes  Rendits,  t.  iii.,  p.  136. 

X  Dove,  Ueber  die  Sturme,  in  Poggend.,  Aniialen,  bd.  Iii.,  s.  1. 

^  Leopold  von  Buch,  Baromelrische  Windrose,  in  Ahhandl.  dcr  AJcad. 
der  Wiss.  zu  Berlin  aus  den  Jahren  18 1 8- IS  19,  s.  187. 

il  See  Dove,   Meteorologische  Untersuchnngen.  1837,  s.  '""^313;  aiiJ 


316  COiMOS. 

equatorial  and  polar  regions  engenders  two  opposite  currents 
in  the  upper  strata  ol  the  atmosphere  and  on  the  Earth's  sur- 
face. Owing  to  the  difference  between  the  rotatory  velocity 
at  the  poles  and  at  the  equator,  the  polar  current  is  deflected 
eastward,  and  the  equatorial  current  westward.  The  great 
phenomena  of  atmospheric  pressure,  the  warming  and  cooling 
of  the  strata  of  air,  the  aqueous  deposits,  and  even,  as  Dove 
has  correctly  represented,  the  formation  and  appearance  of 
clouds,  alike  depend  on  the  opposition  of  these  two  currents, 
on  the  place  where  the  upper  one  descends,  and  on  the  dis- 
placement of  the  one  by  the  other.  Thus  the  figures  of  the 
clouds,  which  form  an  animated  part  of  the  charms  of  a  land- 
scape, announce  the  processes  at  work  in  the  upper  regions  of 
the  atmosphere,  and,  when  the  air  is  calm,  the  clouds  will 
often  present,  on  a  bright  summer  sky,  the  "  projected  image" 
of  the  radiating  soil  below. 

Where  this  influence  of  radiation  is  modified  by  the  relative 
position  of  large  continental  and  oceanic  surfaces,  as  between 
the  eastern  shore  of  Africa  and  the  western  part  of  the  Indian 
peninsula,  its  effects  are  manifested  in  the  Indian  monsoons, 
which  change  with  the  periodic  variations  in  the  sun's  decli- 
nation,* and  which  were  known  to  the  Greek  navigators  un- 
der the  name  of  Hipjoalos.  In  the  knowledge  of  the  mon- 
soons, which  undoubtedly  dates  back  thousands  of  years  among 
the  inhabitants  of  Hindostan  and  China,  of  the  eastern  parts 
of  the  Arabian  Gulf  and  of  the  western  shores  of  the  Malayan 

the  excellent  observations  of  Kamtz  on  the  descent  of  the  west  wind 
of  the  upper  current  in  high  latitudes,  and  the  general  phenomena  of 
the  direction  of  the  wind,  in  his  Vorlesungen  uber  Melerologie,  1840,  s. 
58-66,  196-200,  327-336,  353-364;  and  in  ^chnrndichev' s  Jahrhuch  fur 
1838,  s.  291-302.  A  very  satisfactory  and  vivid  representation  of  me- 
teorological phenomena  is  given  by  Dove,  in  his  small  work  entitled 
Witterungsveihdltnisse  von  Berlin,  1842.  On  the  knowledge  of  the 
earlier  navigators  of  the  rotation  of  the  wind,  see  Churruca,  Viage  al 
Magellanes,  1793,  p.  15 ;  and  on  a  remarkable  expression  of  Columbus, 
which  his  son  Don  Fernando  Colon  has  presented  to  us  in  his  Vida  del 
Almiranie,  cap.  55,  see  Humboldt,  Examen  Critique  de  V Hist,  de  G6- 
ographie,  t.  iv.,  p.  253. 

*  Monsun  (Malayan  musim,  the  hippalos  of  the  Greeks)  is  derived 
from  the  Arabic  word  mausim,  a  set  time  or  season  of  the  yeaj",  the  time 
of  the  assemblage  of  pilgrims  at  Mecca.  The  word  has  been  applied 
to  the  seasons  at  which  certain  winds  prevail,  which  are,  besides,  named 
from  places  lying  in  the  direction  from  whence  they  come ;  thus,  for 
instance,  there  is  the  mausim.  of  Aden,  of  Guzerat,  Malabar,  &c.  (Las- 
sen, Indische  Alterthumskunde,  bd.  i.,  1843,  s.  211).  On  the  contrasts 
between  the  solid  or  fluid  substrata  of  the  atmosphere,  see  Dove,  in  Der 
Abhandl.  der  Akad.  der  Wiss.  zu  Berlin  aus  dem  Jahr  1842,  s.  239 


CLIMATOLOGY.  317 

Sea,  and  in  the  still  more  ancient  and  more  general  acouaint- 
ance  with  land  and  sea  winds,  lies  concealed,  as  it  were,  the 
germ  of  that  meteorological  science  which  is  now  making  such 
rapid  progress.  The  long  chain  of  magnetic  stations  extend- 
ing from  Moscow  to  Pekin,  across  the  whole  of  Northern  Asia, 
will  prove  of  immense  importance  in  determining  the  law  of 
the  tvinds,  since  these  stations  have  also  for  their  object  the 
investigation  of  general  meteorological  relations.  The  com- 
parison of  observations  made  at  places  lying  so  many  hundred 
miles  apart,  will  decide,  for  instance,  whether  the  same  east 
wind  blows  from  the  elevated  desert  of  Gobi  to  the  interior  of 
Russia,  or  whether  the  direction  of  the  aerial  current  first  be- 
gan in  the  middle  of  the  series  of  the  stations,  by  the  descent 
of  the  air  from  the  higher  regions.  By  means  of  such  observ- 
ations, we  may  learn,  in  the  strictest  sense,  tche?ice  the  wind 
Cometh.  If  we  only  take  the  results  on  which  we  may  de- 
pend from  those  places  in  which  the  observations  on  the  direc- 
tion of  the  winds  have  been  continued  more  than  twenty  years, 
we  shall  liud  (from  the  most  recent  and  careful  calculations 
of  Wilhelm  Mahlmann)  that  in  the  middle  latitudes  of  the 
temperate  zone,  in  both  continents,  the  prevailing  aerial  cur- 
rent has  a  west-southwest  direction. 

Our  insight  into  the  distribution  of  heat  in  the  atm.osphere 
has  been  rendered  more  clear  since  the  attempt  has  been  made 
to  connect  together  by  lines  those  places  where  the  mean  an- 
nual summer  and  winter  temperatures  have  been  ascertained 
by  correct  observations.  The  system  of  isothermal,  isotheral^ 
and  isochimenal  lines,  which  I  first  brought  into  use  in  1817, 
may,  perhaps,  if  it  be  gradually  perfected  by  the  united  efforts 
of  investigators,  serve  as  one  of  the  main  foundations  o[  com- 
jMrative  climatology.  Terrestrial  magnetism  did  not  acquire 
a  right  to  be  regarded  as  a  science  until  partial  results  were 
graphically  connected  in  a  system  of  lines  of  equal  declina- 
tion, equal  inclination,  and  equcd  intensity. 

The  term  climate,  taken  in  its  most  general  sense,  indicalos 
all  the  changes  in  the  atmosphere  which  sensibly  aflect  our 
organs,  as  temperature,  humidity,  variations  iu  the  baromei- 
rical  pressure,  the  calm  state  of  the  air  or  the  action  ol'  oup-'- 
site  winds,  the  amount  of  electric  tension,  the  purity  ol'  tlic 
atmosphere  or  its  admixture  with  more  or  less  noxious  gase- 
ous exhalations,  and,  finally,  the  degree  of  ordinary  transpui-- 
ency  and  clearness  of  the  sky,  which  is  not  only  important 
with  respect  to  the  increased  radiation  from  tlu'  Earth,  the 
organic  development  of  plants,  and  the  ripening  of  fruits,  but 


318  COSMOS. 

also  with  reference  to  its  influence  on  the  feelings  and  mental 
condition  of  men. 

If  the  surface  of  the  Earth  consisted  of  one  and  the  same 
homogeneous  fluid  mass,  or  of  strata  of  rock  having  the  same 
color,  density,  smoothness,  and  power  of  absorbing  heat  from 
the  solar  ra3^s,  and  of  radiating  it  in  a  similar  manner  through 
the  atmosphere,  the  isothermal,  isotheral,  and  isochimenal 
lines  would  all  be  parallel  to  the  equator.  In  this  hypothet- 
ical condition  of  the  Earth's  surface,  the  power  of  absorbing 
and  emitting  light  and  heat  would  every  where  be  the  same 
under  the  same  latitudes.  The  mathematical  consideration 
of  climate,  which  does  not  exclude  the  supposition  of  the  ex- 
istence of  currents  of  heat  in  the  interior,  or  in  the  external 
crust  of  the  earth,  nor  of  the  propagation  of  heat  by  atmos- 
pheric currents,  proceeds  from  this  mean,  and,  as  it  were, 
primitive  condition.  Whatever  alters  the  capacity  for  ab- 
sorption and  radiation,  at  places  lying  under  the  same  parallel 
of  latitude,  gives  rise  to  inflections  in  the  isothermal  lines. 
The  nature  of  these  inflections,  the  angles  at  which  the  iso- 
thermal, isotheral,  or  isochimenal  lines  intersect  the  parallels 
of  latitude,  their  convexity  or  concavity  with  respect  to  the 
pole  of  the  same  hemisphere,  are  dependent  on  causes  which 
more  or  less  modify  the  temperature  under  difTerent  degrees 
of  longitude. 

The  progress  of  Climatology  has  been  remarkably  favored 
by  the  extension  of  European  civilization  to  two  opposite 
coasts,  by  its  transmission  from  our  western  shores  to  a  conti- 
nent which  is  bounded  on  the  east  by  the  Atlantic  Ocean. 
When,  after  the  ephemeral  colonization  from  Iceland  and 
Greenland,  the  British  laid  the  foundation  of  the  first  perma- 
nent settlements  on  the  shores  of  the  United  States  of  Amer- 
ica, the  emigrants  (whose  numbers  were  rapidly  increased  in 
consequence  either  of  religious  persecution,  fanaticism,  or  love 
of  freedom,  and  who  soon  spread  over  the  vast  extent  of  ter- 
ritory lying  between  the  Carolinas,  Virginia,  and  the  St.  Law- 
rence) were  astonished  to  find  themselves  exposed  to  an  intens- 
ity of  winter  cold  far  exceeding  that  which  prevailed  in  Ita- 
ly, France,  and  Scotland,  situated  in  corresponding  parallels 
of  latitude.  But,  however  much  a  consideration  of  these  cli- 
matic relations  may  have  awakened  attention,  it  was  not  at- 
tended by  any  practical  results  until  it  could  be  based  on  the 
numerical  data  of  mean  annual  temperature.  If,  between 
58^^  and  30*^  north  latitude,  we  compare  Nain,  on  the  coast 
of  Labrador,  with  Gottenburg  ;  Hahfax  with  Bordeaux  ;  New 


CIJMATOLOGY.  319 

V^ork  with  Naples  ;  St.  Augustine,  in  Florida,  with  Cairo,  we 
find  that,  under  the  same  degrees  of  latitude,  the  differences 
of  the  mean  annual  temperature  between  Eastern  America 
and  Western  Europe,  proceeding  from  north  to  south,  are  suc- 
cessively 20O-7,  130-9,  60-8,  and  almost  QO.  The  gradual 
decrease  of  the  differences  in  this  series  extending  over  28*^ 
of  latitude  is  very  striking.  Further  to  the  south,  under  the 
tropics,  the  isothermal  lines  are  every  where  parallel  to  the 
equator  in  both  hemispheres.  We  see,  from  the  above  exam- 
ples, that  the  questions  often  asked  in  society,  how  many  de- 
grees America  (without  distinguishing  between  the  eastern 
and  western  shores)  is  colder  than  Europe  ?  and  how  much 
the  mean  annual  temperature  of  Canada  and  the  United 
States  is  lower  than  that  of  corresponding  latitudes  in  Eu- 
rope ?  are,  when  thus  generally  exiiressed,  devoid  of  meaning. 
Tiiere  is  a  separate  difference  for  each  parallel  of  latitude,  and 
without  a  special  comparison  of  the  winter  and  summer  tem- 
peratures of  the  opposite  coasts,  it  will  be  impossible  to  arrive 
at  a  correct  idea  of  climatic  relations,  in  their  influence  on 
agriculture  and  other  industrial  pursuits,  or  on  the  individual 
comfort  or  discomfort  of  mankind  in  general. 

In  enumerating  the  causes  which  produce  disturbances  in 
the  form  of  the  isothermal  lines,  I  would  distinguish  between 
those  which  raue  and  those  which  lower  the  temperature. 
To  the  first  class  belong  the  proximity  of  a  western  coast  in 
the  temperate  zone  ;  the  divided  configuration  of  a  continent 
into  peninsulas,  with  deeply-indented  bays  and  inland  seas  ; 
the  aspect  or  the  position  of  a  portion  of  the  land  with  refer- 
ence either  to  a  sea  of  ice  spreading  far  into  the  polar  circle, 
or  to  a  mass  of  continental  land  of  considerable  extent.  Iving 
in  the  same  meridian,  either  under  the  equator,  or,  at  least, 
within  a  portion  of  the  tropical  zone  ;  the  prevalence  of  south- 
erly or  westerly  winds  on  the  western  shore  of  a  continent  in 
the  temperate  northern  zone  ;  chains  of  mountains  acting  as 
protecting  walls  against  winds  coming  from  colder  regions  ; 
the  iufrequeney  of  sM'^amps,  Avhich,  in  the  s])ring  and  begin- 
ning of  summer,  long  remain  covered  with  ice,  and  tJie  ab- 
sence of  woods  in  a  dry,  sandy  soil ;  finally,  the  cou.stant  se- 
renity of  the  sky  in  the  summer  months,  and  the  vicinity  of 
an  oceanic  current,  bringing  water  which  is  of  a  higher  tem- 
perature than  that  of  the  surrounding  sea. 

Among  the  causes  which  tend  to  lower  the  mean  ainiual 
temperature  I  include  the  following  ;  elevation  above  the  level 
of  the  sea,  when  not  forming  part  of  an  extended  jiiain  ;   the 


320  COSMOS. 

vicinity  of  an  eastern  coast  in  high  and  middle  latitudes ;  the 
compact  configuration  of  a  continent  having  no  littoral  curv- 
atures or  bays  ;  the  extension  of  land  toward  the  poles  into 
the  region  of  perpetual  ice,  without  the  intervention  of  a  sea 
remaining  open  in  the  winter  ;  a  geographical  position,  in 
which  the  equatorial  and  tropical  regions  are  occupied  by  the 
sea,  and,  consequently,  the  absence,  under  the  same  meridian, 
of  a  continental  tropical  land  having  a  strong  capacity  for  the 
absorption  and  radiation  of  heat ;  mountain  chains,  whose 
mural  form  and  direction  impede  the  access  of  warm  winds  , 
the  vicinity  of  isolated  peaks,  occasioning  the  descent  of  cold 
currents  of  air  down  their  declivities  ;  extensive  woods,  which 
hinder  the  insolation  of  the  soil  by  the  vital  activity  of  theii 
foliage,  which  produces  great  evaporation,  owing  to  the  ex- 
tension of  these  organs,  and  increases  the  surface  that  is  cool- 
ed by  radiation,  acting  consequently  in  a  three-fold  manner, 
by  shade,  evaporation,  and  radiation  ;  the  frequency  of  swamps 
or  marshes,  which  in  the  north  form  a  kind  of  subterranean 
glacier  in  the  plains,  lasting  till  the  middle  of  the  summer ;  a 
cloudy  summer  sky,  which  weakens  the  action  of  the  solar 
rays  ;  and,  finally,  a  very  clear  winter  sky,  favoring  the  radi- 
ation of  heat.* 

The  simultaneous  action  of  these  disturbing  causes,  wheth- 
er productive  of  an  increase  or  decrease  of  heat,  determines, 
as  the  total  effect,  the  inflection  of  the  isothermal  lines,  espe- 
cially with  relation  to  the  expansion  and  configuration  of  solid 
continental  masses,  as  compared  with  the  liquid  oceanic. 
These  perturbations  give  rise  to  convex  and  concave  summits 
of  the  isothermal  curves.  There  are,  however,  different  or- 
ders of  disturbing  causes,  and  each  one  must,  therefore,  be 
considered  separately,  in  order  that  their  total  effect  may  aft- 
erward be  investigated  with  reference  to  the  motion  (direc- 
tion, local  curvature)  of  the  isothermal  lines,  and  the  actions 
by  which  they  are  connected  together,  modified,  destroyed,  or 
increased  in  intensity,  as  manifested  in  the  contact  and  inter- 
section of  small  oscillatory  movements.  Such  is  the  method 
by  which,  I  hope,  it  may  some  day  be  possible  to  connect  to- 
gether, by  empirical  and  numerically  expressed  laws,  vast  se- 
ries of  apparently  isolated  facts,  and  to  exhibit  the  mutual  de- 
pendence which  must  necessarily  exist  among  them. 

The  trade  winds — easterly  winds  blowing  within  the  trop- 
ics— give  rise,  in  both  temperate  zones,  to  the  west,  or  west- 

*  HamLokit,  Recherches  sur  les  Causes  des  Inflexions  des  Lignes  Iso- 
thermes,  in  A.sie  Centr.,  t.  iii.,  p.  103-114,  118,  122,  188- 


CLIMATOLOGY.  321 

southwest  winds  which  prevail  in  those  regions,  and  which 
are  land  winds  to  eastern  coasts,  and  sea  winds  to  western 
coasts,  extending  over  a  space  which,  from  the  great  mass 
and  the  sinking  of  its  cooled  particles,  is  not  capable  of  any 
considerable  degree  of  cooling,  and  hence  it  follows  that  the 
east  winds  of  the  Continent  must  be  cooler  than  the  west 
winds,  where  their  temperature  is  not  aflected  by  the  occur- 
rence of  oceanic  currents  near  the  shore.  Cook's  young  com- 
panion on  his  second  voyage  of  circumnavigation,  the  intelli- 
gent George  Forster,  to  whom  I  am  indebted  for  the  lively 
interest  which  prompted  me  to  undertake  distant  travels,  was 
the  first  who  drew  attention,  in  a  definite  manner,  to  the  cli- 
matic difi^erences  of  temperature  existing  in  the  eastern  and 
western  coasts  of  both  continents,  and  to  the  similarity  of 
temperature  of  the  western  coast  of  North  America  in  the 
middle  latitudes,  with  that  of  Western  Europe.*  Even  in 
northern  latitudes  exact  observations  show  a  striking  differ- 
ence between  the  mean  aniiual  temperaUire  of  the  east  and 
w^est  coasts  of  America.  The  mean  annual  temperature  of 
Nain,  in  Labrador  (lat.  57*^  10'),  is  fully  60-8  below  the  freez- 
ing point,  while  on  the  northwest  coast,  at  New  Archangel, 
in  Russian  America  (lat.  57^  3'),  it  is  12*^-4  above  this  point. 
At  the  first-named  place,  the  mean  summer  temperature 
hardly  amounts  to  43°,  while  at  the  latter  place  it  is  57^. 
Pekin  (oQ*^  54'),  on  the  eastern  coast  of  Asia,  has  a  mean  an- 
nual temperature  of  52° -3,  which  is  9°  below  that  of  Naples, 
situated  somewhat  further  to  the  north.  The  mean  winter 
temperature  of  Pekin  is  at  least  5° "4  below  the  freezing  point, 
while  in  Western  Europe,  even  at  Paris  (48°  50'),  it  is  near- 
ly 6°  above  the  freezing  point.  Pekin  has  also  a  mean  win- 
ter cold  which  is  4° -5  lower  than  that  of  Copenhagen,  lying 
17°  further  to  the  north. 

We  have  already  seen  the  slowness  with  which  the  great 
mass  of  the  ocean  follows  the  variations  of  temperature  in  the 
atmosphere,  and  how  the  sea  acts  in  equalizing  temperatures, 
moderating  simultaneously  the  severity  of  winter  and  the  heat 
of  summer.  Hence  arises  a  second  more  important  contrast 
— that,  namely,  between  insular  and  littoral  climates  enjoyed 
by  all  articulated  continents  having  deeply-indented  bays  and 
peninsulas,  and  between  the  climate  of  the  interior  of  great 
masses  of  solid  land.     This  remarkable  contrast  has  been  fully 

*  George  Forster,  Kleine  Schriften,  th.  iii.,  1794,  s.  87  ;  Dove,  in 
Schumacher's  Jahrbuch  fur  1841,  s.  289;  Kamtz,  Meteorologie,  bd.  ii., 
8.  41.  43,  &7 ,  and  96 ;  Arago,  in  the  Comptes  Rendus,  t.  i.,  p.  268. 

02 


322  COSMOS. 

developed  by  Leopold  von  Buch  in  all  its  various  phenomena, 
both  with  respect  to  its  influence  on  vegetation  and  agricul- 
ture, on  the  transparency  of  the  atmosphere,  the  radiation  of 
the  soil,  and  the  elevation  of  the  line  of  perpetual  snow.  In 
the  interior  of  the  Asiatic  Continent,  Tobolsk,  Barnaul  on  the 
Oby,  and  Irkutsk,  have  the  same  mean  summer  heat  as  Ber- 
lin, Munster,  and  Cherbourg  in  Normandy,  the  thermometer 
sometimes  remaining  for  weeks  together  at  86°  or  88°,  while 
the  mean  winter  temperature  is,  during  the  coldest  month,  as 
low  as  — 0°*4  to  — 4°.  These  continental  climates  have 
therefore  justly  been  termed  excessive  by  the  great  mathema- 
tician and  physicist  Buffon  ;  and  the  inhabitants  who  live  in 
countries  having  such  excessive  climates  seem  almost  con- 
demned, as  Dante  expresses  himself, 

"  A  sofFerir  tormeuti  caldi  e  geli."* 

In  no  portion  of  the  earth,  neither  in  the  Canary  Islands, 
in  Spain,  nor  in  the  south  of  France,  have  I  ever  seen  more 
luxuriant  fruit,  especially  grapes,  than  in  Astrachan,  near  the 
shores  of  the  Caspian  Sea  (46°  21').  Although  the  mean 
annual  temperature  is  about  48°,  the  mean  summer  heat 
rises  to  70°,  as  at  Bordeaux,  while  not  only  there,  but  also 
further  to  the  south,  as  at  Kislar  on  the  mouth  of  the  Terek 
(in  the  latitude  of  Avignon  and  Rimini),  the  thermometer 
sinks  in  the  winter  to  — 13°  or  — 22°. 

Ireland,  Guernsey,  and  Jersey,  the  peninsula  of  Brittany, 
the  coasts  of  Normandy,  and  of  the  south  of  England,  present, 
by  the  mildness  of  their  winters,  and  by  the  low  temperature 
and  clouded  sky  of  their  summers,  the  most  striking  contrast 
to  the  continental  climate  of  the  interior  of  Eastern  Europe, 
In  the  northeast  of  Ireland  (54°  56'),  lying  under  the  same  par- 
allel of  latitude  as  Konigsberg  in  Prussia,  the  myrtle  blooms 
as  luxuriantly  as  in  Portugal.  The  mean  temperature  of  the 
month  of  August,  which  in  Hungary  rises  to  70^,  scarcely 
reaches  61°  at  Dublin,  which  is  situated  on  the  same  isother- 
mal line  of  49°  ;  the  mean  winter  temperature,  which  falls  to 
about  28°  at  Pesth,  is  40°  at  Dublin  (whose  mean  annual 
temperature  is  not  more  than  49°) ;  3°'6  higher  than  that  of 
Milan,  Pavia,  Padua,  and  the  whole  of  Lombardy,  where  the 
mean  annual  temperature  is  upward  of  55  '.  At  Stromness, 
in  the  Orkneys,  scarcely  half  a  degree  further  south  than  Stock- 
holm, the  winter  temperature  is  39°,  and  consequently  iiighei 
^han  that  of  Paris,  and  nearly  as  high  as  that  of  London. 

*  Dante,  Divina  Commedia.  Purgatorio,  cauto  iii. 


CLIMATOLOGY.  323 

Even  in  the  Faroe  Islands,  at  62"^  latitude,  the  inland  waters 
never  freeze,  owing  to  the  favoring  influence  of  the  west  winds 
and  of  the  sea.  On  the  charming  coasts  of  Devonshire,  near 
Salcombe  Bay,  which  has  been  termed,  on  account  of  the 
mildness  of  its  climate,  the  Moiitpelliej'  of  the  North,  the 
Agave  Mexicana  has  been  seen  to  blossom  in  the  open  air, 
while  orange-trees  trained  against  espaliers,  and  only  slightly 
protected  hy  matting,  are  found  to  bear  fruit.  There,  as  well 
as  at  Penzance  and  Gosport,  and  at  Cherbourg  on  the  coast 
of  Normandy,  the  mean  winter  temperature  exceeds  42^,  fall- 
ing short  by  only  2^*4  of  the  mean  winter  temperature  of 
Montpellier  and  Florence.*  These  observations  will  suffice 
to  show  the  important  influence  exercised  on  vegetation  and 
agriculture,  on  the  cultivation  of  fruit,  and  on  the  comfort  of 
mankind,  by  differences  in  the  distribution  of  the  same  mean 
annual  temperature,  through  the  different  seasons  of  the  year. 
The  lines  which  I  have  termed  isochimenal  and  isotheral 
(lines  of  equal  winter  and  equal  summer  temperature)  are  by 
no  means  parallel  with  the  isothermal  lines  (lines  of  equal 
annual  temperature).  If,  for  instance,  in  countries  where 
myrtles  grow  wild,  and  the  earth  does  not  remain  covered 
with  snow  in  the  winter,  the  temperature  of  the  summer  and 
autumn  is  barely  sufficient  to  bring  apples  to  perfect  ripeness, 
and  if,  again,  we  observe  that  the  grape  rarely  attains  the 
ripeness  necessary  to  convert  it  into  wine,  either  in  islands  or 
in  the  vicinity  of  the  sea,  even  when  cultivated  on  a  western 
coast,  the  reason  must  not  be  sought  only  in  the  low  degree 
of  summer  heat,  indicated,  in  littoral  situations,  by  the  ther- 
mometer when  suspended  in  the  shade,  but  likewise  in  another 
cause  that  has  not  hitherto  been  sufficiently  considered,  al- 
though it  exercises  an  active  influence  on  many  other  phe- 
nomena (as,  for  instance,  in  the  inflammation  of  a  mixture  of 
chlorine  and  hydrogen),  namely,  the  difTerence  between  direct 
and  diffused  light,  or  that  which  prevails  when  the  sky  is  clear 
and  when  it  is  overcast  by  mist.  I  long  since  endeavored  to 
attract  the  attention  of  physicists  and  physiologisisi  to  this 

*  Humboldt,  Sur  lesLignes  Isothermes,  iu  the  Memoircs  dc  Ph//siqiie 
n  de  Chimie  de  la  Societe  d'' Arcueil,  t.  iii.,  Paris,  1817,  [>.  1 1.3-1  ()•> ; 
Knight,  in  the  Transactions  of  the  HorticuUural  Society  of  London,  vol. 
,  p.  32  ;  Watson,  Remarks  on  the  Geographical  Distribution  of  British 
Plants,  1835,  p.  60;  Trevelyan,  in  Jamieson's  Edijihurgh  Nefo  Phil. 
Journal,  No.  18.  p.  154;  Mahlmann,  in  his  admirable  Gerni.iu  Tiaanila 
lion  of  my  Asia  Centrale,  th.  ii.,  s.  60. 

t  *'  HiKC  de  temperie  aei-is,  qui  terram  late  circumfundit,  ac  in  quo, 
longe  a  solo,  instniinenta  nostra  meteorologica  suspensa  habemus.     Sed 


324  COSMOS. 

difference,  and  to  the  %i7WieasuTed  heat  which  is  locally  devel- 
oped in  the  living  vegetable  cell  by  the  action  of  direct  light. 
If,  in  forming  a  thermic  scale  of  different  kinds  of  cultiva- 
tion,* we  begin  with  those  plants  which  require  the  hottest 
climate,  as  the  vanilla,  the  cacao,  banana,  and  cocoa-nut,  and 
proceed  to  pine-apples,  the  sugar-cane,  coffee,  frait-bearing 
date-trees,  the  cotton-tree,  citrons,  olives,  edible  chestnuts,  and 
vines  producing  potable  wine,  an  exact  geographical  consider- 
ation of  the  limits  of  cultivation,  both  on  plains  and  on  the 
declivities  of  mountains,  will  teach  us  that  other  climatic  re- 
lations besides  those  of  mean  annual  temperature  are  involved 
in  these  phenomena.  Taking  an  example,  for  instance,  from 
the  cultivation  of  the  vine,  we  find  that,  in  order  to  procure 
■potable  wine,t  it  is  requisite  that  the  mean  annual  heat  should 
exceed  49*^,  that  the  winter  temperature  should  be  upward  of 
33"^,  and  the  mean  summer  temperature  upward  of  64*^.  At 
Bordeaux,  in  the  valley  of  the  Garonne  (44°  50'  lat.),  the 
mean  annual,  winter,  summer,  and  autumn  temperatures  are 
respectively  57°,  43°,  71°,  and  58°.     In  the  plains  near  the 

alia  est  caloi'is  vis,  quem  radii  solis  nuUis  nubibus  velati,  in  foliis  ipsis 
et  fructibus  maturescentibus,  magis  miiiusve  coloratis,  gignunt,  quem- 
que,  ut  egregia  demonstrant  experimenta  amicissiraorum  Gay-Lussacii 
et  Thenardi  de  combustione  chlori  et  hydrogeuis,  ope  tbermometri  me- 
tiri  nequis.  Etenim  locis  planis  et  moutanis,  vento  libe  spirante,  cir- 
cumfusi  aeris  temperies  eadem  esse  potest  coelo  sudo  vel  nebuloso  ;  ide- 
uqu8  ex  observationibus  solis  therraometricis,  nullo  adhibito  Photome- 
tro,  baud,  cognosces,  quam  ob  causam  Gallise  septentrioualis  tractus 
Ai'moricanus  et  Nervicus,  versus  littora,  coelo  temperato  sed  sole  raro 
utentia,  Vitem  fere  non  tolerant.  Egent  enim  stirpes  non  solum  caloris 
fitimulo,  sed  et  lucis,  quae  magis  intensa  locis  excelsis  quam  planis,  du- 
plici  modo  plantas  raovet,  vi  sua  turn  propria,  tum  calorem  in  supei'ficie 
earum  excitante." — Humboldt,  De  Distributione  Geographica  Planta- 
riim,  1817,  p.  163-164. 

*  Humboldt,  op.  cit.,  p.  156-161;  Meyen,  in  his  Grtmdriss  der 
PfianzengeograpMe,  1836,  s.  379-467 ;  Boussingault,  Economic  Rurale, 
t.  ii.,  p.  675. 

t  The  following  table  illustrates  the  cultivation  of  the  vine  in  Europe, 
and  also  the  depreciation  of  its  produce  according  to  climatic  relations. 
See  ray  Asie  Centrale,  t.  iii.,  p.  159.  The  examples  quoted  in  the  text 
for  Bordeaux  and  Potsdam  are,  in  respect  of  numerical  relation,  alike 
applicable  to  the  countnes  of  the  Rhine  and.  Maine  (48^^  35'  to  50°  7' 
N.  lat.).  Cherbourg  in  Normandy,  and  Ireland,  show  in  the  most  re- 
mai'kable  manner  how,  with  thermal  relations  very  nearly  similar  to 
those  prevailing  in  the  interior  of  the  Continent  (as  estimated  by  tlie 
thermometer  in  the  shade),  the  results  are  nevertheless  extremely  dif- 
ferent as  regards  the  ripeness  or  the  unripeness  of  the  fruit  of  the  vine, 
this  difference  undoubtedly  depending  on  the  circumstance  whether 
the  vegetation  of  the  plant^proceeds  under  a  bright  sunny  sky,  o"  un 
<ler  a  sky  that  is  habitually  obscurer]  by  clnnds: 


I 


CLIMATOLOGY. 


325 


Baltic  (52^  30'  lat.),  where  a  wine  is  produced  that  can 
scarcely  be  considered  potable,  these  numbers  are  as  follows  : 
47'^0,  31°,  630-7,  and  47'^-o.  If  it  should  appear  strange 
that  the  great  differences  indicated  by  the  influence  of  climate 
on  the  production  of  wine  should  not  be  more  clearly  manifest- 
ed by  our  thermometers,  the  circumstance  will  appear  less 
singular  when  we  remember  that  a  thermometer  standing  in 
the  shade,  and  protected  from  the  effect  of  direct  insolation 
and  nocturnal  radiation  can  not,  at  all  seasons  of  the  year,  and 
during  all  periodic  changes  of  heat,  indicate  the  true  superficial 
temperature  of  the  ground  exposed  to  the  whole  effect  of  the 
sun's  rays. 

The  same  relations  which  exist  between  the  equable  littoral 
climate  of  the  peninsula  of  Brittany,  and  the  lower  winter  and 


Places. 

Latitude. 

Elevation. 

Mean 
of  the 
Year. 

Winter. 

Spring. 

Summer. 

Autumn. 

Number  of  the 
Years    of    the 
Observation. 

Bordeaux  .  .  . 

o       / 

44  50 

Ens-  ft. 

25-6 

Fahr. 

57-0 

43-0 

56-0 

71-0 

58-0 

10 

Strasbourg.  .  . 

48  35 

479-0 

49-6 

34-5 

50-0 

64-6 

50-0 

35 

Heidelberg.  . 

49  24 

333-5 

49-5 

34-0 

50-0 

64-3 

49-7 

20 

Mauheitn  .  .  . 

49  29 

300-5 

50-6 

34-6 

50-8 

67-1 

49-5 

12 

Wurzburg.  .  . 

49  48 

562-5 

50-2 

35-5 

50-5 

65-7 

49-4 

27 

Frankfort      on 

Maine .... 

50    7 

388-5 

49-5 

33-3 

50-0 

64-4 

49-4  I   19 

Berlin 

52  31 

102-3 

47-5 

31-0 

46-6 

63-6 

47-5      23 

Cherbourg  (no 

49  39 

.... 

52-1 

41-5 

50-8 

61-7 

54-3        3 

wine) 

Dublin  (ditto) 

53  23 

.... 

49-1 

40-2 

47-1 

59-6 

49-7      13 

The  great  accordance  in  the  distribution  of  the  annual  temperature 
through  the  different  seasons,  as  presented  by  the  results  obtained  for 
the  valleys  of  the  Rhine  and  Maine,  tends  to  confirm  the  accuracy  of 
these  meteorological  observations.    The  months  of  December,  January, 
and  February  are  reckoned  as  winter  months.     When  the  different 
qualities  of  the  wines  produced  in  Franconia,  and  in  the   countries 
around  the  Baltic,  are  compared  with  the  mean  summer  and  autumn 
temperature  of  Wilrzburg  and  Berlin,  we  are  almost  surprised  to  find 
a  difference  of  only  about  two  degrees.     The  difference  in  the  spring 
is  about  four  degrees.     The  influence  of  late  May  frosts  on  the  flower- 
ing season,  and  after  a  coi-respondingly  cold  winter,  is  almost  as  iiii 
portant  an  element  as  the  time  of  the  subsequent  ripening  of  the  grape, 
and  the  influence  of  direct,  not  diffused,  light  of  the  unclouded  sun 
The  difference  alluded  to  in  the  text  between  the  true  temperature  of 
the  surface  of  the  ground  and  the  indications  of  a  thermometer  sus 
pended  in  the  shade  and  protected  from  extraneous  influences,  is  in 
ierred  by  Dove  from  a  consideration  of  the  results  of  fifteen  years'  ob 
servations  made  at  the  Chiswick  Gardens.     See  Dove,  in  Bericht  i'lhe^ 
die  Verhandl.  der  Berl.  Akad.  der  Wisa.,  August,  1844,  s.  285. 


326  COSMOS. 

higher  summer  temperature  of  the  remainder  of  the  continent 
of  France,  are  Kkewise  manifested,  in  some  degree,  between 
Europe  and  the  great  continent  of  Asia,  of  which  the  former 
may  be  considered  to  constitute  the  western  peninsula.  Eu- 
rope owes  its  milder  climate,  in  the  first  place,  to  its  position 
with  respect  to  Africa,  whose  wide  extent  of  tropical  land  is 
favorable  to  the  ascending  current,  while  the  equatorial  region 
to  the  south  of  Asia  is  almost  wholly  oceanic ;  and  next  to  its 
deeply-articulated  configuration,  to  the  vicinity  of  the  ocean 
on  its  western  shores  ;  and,  lastly,  to  the  existence  of  an  open 
sea,  which  bounds  its  northern  confines.  Europe  would  there- 
fore become  colder*  if  Africa  were  to  be  overflowed  by  the 
ocean  ;  or  ii"  the  mythical  Atlantis  Avere  to  arise  and  connect 
Europe  with  North  America  ;  or  if  the  Gulf  Stream  were  no 
longer  to  diffuse  the  warming  influence  of  its  waters  into  the 
North  Sea  ;  or  if,  finally,  another  mass  of  solid  land  should  be 
upheaved  by  volcanic  action,  and  interposed  between  the 
Scandinavian  peninsula  and  Spitzbergen,  If  we  observe  that 
in  Europe  the  mean  annual  temperature  falls  as  we  proceed, 
from  west  to  east,  under  the  same  parallel  of  latitude,  from 
the  Atlantic  shores  of  France  through  Germany,  Poland,  and 
Russia,  toward  the  Uralian  Mountains,  the  main  cause  of  this 
phenomenon  of  increasing  cold  must  be  sought  in  the  form  of 
the  continent  (which  becomes  less  indented,  and  wider,  and 
more  compact  as  we  advance),  in  the  increasing  distance  from 
seas,  and  in  the  diminished  influence  of  westerly  winds.  Be- 
yond the  Uralian  Mountains  these  winds  are  converted  into 
cool  land-winds,  blowing  over  extended  tracts  covered  with 
ice  and  snow.  The  cold  of  western  Siberia  is  to  be  ascribed 
to  these  relations  of  configuration  and  atmospheric  currents, 
and  not — as  Hippocrates  and  Trogus  Pompeius,  and  even  cele- 
brated travelers  of  the  eighteenth  century  conjectured — to  the 
great  elevation  of  the  soil  above  the  level  of  the  sea.f 

If  we  pass  from  the  differences  of  temperature  manifested  in 
the  plains  to  the  inequalities  ol'  the  polyhedric  form  of  the  sur- 
Iftce  of  our  planet,  we  shall  have  to  consider  mountains  either 
in  relation  to  their  influence  on  the  climate  of  neighboring 

*  See  my  memoir,  Ueber  die  Haupt-Ursachen  der  Temperaturver- 
schiedenheii  auf  der  Erdoberjldche,  iu  the  Abhandl.  der  Akad.  der  Wis- 
sensch.  zu  Berlin  von  dem  Jahr  1827,  s.  311. 

t  The  general  level  of  Siberia,  from  Tobolsk,  Tomsk,  and  Barnaul, 
from  the  Altai  Mountains  to  the  Polar  Sea,  is  not  so  hiijh  as  tliat  of 
Manheim  and  Dresden ;  indeed,  Irkutsk,  far  to  the  east  of  the  Jenisei, 
is  only  1330  feet  above  the  level  of  the  sea,  or  about  one  third  lowei 
than  Munich. 


*.. 


CLIMATOLOGY.  327 


valleys,  or  according  to  the  effects  of  the  hypsometrical  rela- 
lioiis  on  their  own  summits,  which  often  spread  into  elevated 
p-.vU  M.-ix.  The  division  ol'  mountains  into  chains  separates 
iitc  earth's  surface  into  different  basins,  which  are  often  nar 
rov,-  iind  walled  in,  forming  caldron-like  valleys,  and  (as  in 
G  iv;cce  and  in  part  of  Asia  Minor)  constitute  an  individual 
local  climate  with  respect  to  heat,  moisture,  transparency  of 
atmosphere,  and  frequency  of  winds  and  storms.  These  cir- 
cumstances have  at  all  times  exercised  a  powerful  influence 
on  the  character  and  cultivation  of  natural  products,  and  on 
the  manners  and  institutions  of  neighboring  nations,  and  even 
on  the  feelings  with  which  they  regard  one  another.  This 
character  of  geographical  individuality  attains  its  maximum, 
if  we  may  be  allowed  so  to  speak,  in  countries  where  the  dif- 
ferences in  the  configuration  of  the  soil  are  the  greatest  possi- 
ble, either  in  a  vertical  or  horizontal  direction,  both  in  relief 
and  in  the  articulation  of  the  continent.  The  greatest  con- 
trast to  these  varieties  in  the  relations  of  the  surface  of  the 
earth  are  manifested  in  the  Steppes  of  Northern  Asia,  the 
grassy  plains  (savannahs,  llanos,  and  pampas)  of  the  New 
Continent,  the  heaths  {Ey'iceta)  of  Europe,  and  the  sandy  and 
stony  deserts  of  Africa. 

The  law  of  the  decrease  of  heat  with  the  increase  of  eleva- 
tion at  different  latitudes  is  one  of  the  most  important  subjects 
involved  in  the  study  of  meteorological  processes,  of  the  geog- 
raphy of  plants,  of  the  theory  of  terrestrial  refraction,  and  of 
the  various  hypotheses  that  relate  to  the  determination  of  the 
height  of  the  atmosphere.  In  the  many  mountain  journeys 
which  I  have  undertaken,  both  within  and  without  the  trop- 
ics, the  investigation  of  this  law  has  always  formed  a  special 
object  of  my  researches.* 

Since  we  have  acquired  a  more  accurate  knowledge  of  the 
true  relations  of  the  distribution  of  heat  on  the  surface  of  the 
earth,  that  is  to  say,  of  the  inflections  of  isothermal  and  isoth- 
eral  lines,  and  their  unequal  distance  apart  in  the  different 
eastern  and  western  systems  of  temperature  in  Asia,  Central 
Europe,  and  North  America,  we  can  no  longer  ask  the  gen- 
eral question,  what  fraction  of  the  mean  annual  or  summer 
temperature  corresponds  to  the  difference  of  one  degree  of 
geographical  latitude,  taken  in  the  same  meridian  ?  In  each 
system  of  isothermal  lines  of  equal  curvature  there  reigns  a 

*  Humboldt,  Recueil  d' Observations  Astronomiques,  t.  i.,  p.  126-140; 
Relation  Historiquc,  t.  i.,  p.  119,  141,  227;  Biot,  in  Connaissance  des 
Temps  pour  Van  1841,  p.  90-109. 


328  COSMOS. 

close  and  necessary  connection-between  three  elements,  name 
ly,  the  decrease  of  heat  in  a  vertical  direction  from  below  up 
ward,  the  difference  of  temperature  for  every  one  degree  of 
geographical  latitude,  and  the  uniformity  in  the  mean  tem- 
perature of  a  mountain  station,  and  the  latitude  of  a  point- 
situated  at  the  level  of  the  sea. 

In  the  system  of  Eastern  America,  the  mean  annual  temper- 
ature from  the  coast  of  Labrador  to  Boston  changes  l°-6  foi 
every  degree  of  latitude  ;  from  Boston  to  Charleston  about 
1°"7  ;  from  Charleston  to  the  tropic  of  Cancer,  in  Cuba,  the 
variation  is  less  rapid,  being  only  l°-2.  In  the  tropics  this 
diminution  is  so  much  greater,  that  from  the  Havana  to 
Cumana  the  variation  is  less  than  0°"4  lor  every  degree  of 
latitude. 

The  case  is  quite  different  in  the  isothermal  system  of  Cen- 
tral Europe.  Between  the  parallels  of  38°  and  71°  I  found 
that  the  decrease  of  temperature  was  very  regularly  0°-9  fbi 
every  degree  of  latitude.  But  as,  on  the  other  hand,  in  Cen- 
tral Europe  the  decrease  of  heat  is  1°;8  for  about  every  534 
feet  of  vertical  elevation,  it  follows  that  a  diilerence  of  eleva- 
tion of  about  267  feet  corresponds  to  the  diiTerence  of  one  de- 
gree of  latitude.  The  same  mean  annual  temperature  as  that 
occurring  at  the  Convent  of  St.  Bernard,  at  an  elevation  of 
8173  feet,  in  lat.  45°  50',  should  therefore  be  met  with  at  the 
level  of  the  sea  in  lat.  75°  50'. 

In  that  part  of  the  Cordilleras  which  falls  within  the  tropics, 
the  observations  I  made  at  various  heights,  at  an  elevation  of 
upward  of  19,000  feet,  gave  a  decrease  of  1°  for  every  341 
feet ;  and  my  friend  Boussingault  found,  thirty  years  after- 
ward, as  a  mean  result,  319  feet.  By  a  comparison  of  places 
in  the  Cordilleras,  lying  at  an  equal  elevation  above  the  level 
of  the  sea,  either  on  the  declivities  of  the  mountains  or  even 
on  extensive  elevated  plateaux,  I  observed  that  in  the  latter 
there  was  an  increase  in  the  animal  temperature  varying  from 
2°*7  to  4°*1.  This  difference  would  be  still  greater  if  it  were 
not  for  the  cooling  eftect  of  nocturnal  radiation.  As  the  dif- 
ferent climates  are  arranged  in  successive  strata,  the  one  above 
the  other,  from  the  cacao  woods  of  the  valleys  to  the  region 
of  perpetual  snow,  and  as  the  temperature  in  the  tropics  va- 
ries but  little  throughout  the  year,  we  may  form  to  ourselves 
a  tolerably  correct  representation  of  the  climatic  relations  to 
which  the  inhabitants  of  the  large  cities  in  the  Andes  are  sub- 
jected, by  comparing  these  climates  with  the  temperatures  of 
pavtioular  months  in  the  plains  of  France  and  Italy.      While 


THE  SNOW-LINE.  329 

the  heat  which  prevails  daily  on  the  woody  shores  of  the 
Orinoco  exceeds  hy  7^'2  that  of  the  month  of  August  at  Pa- 
lermo, we  find,  on  ascending  the  chain  of  the  Andes,  at  Po- 
payan,  at  an  elevation  of  582G  feet,  the  temperature  of  the 
three  summer  months  of  Marseilles ;  at  Quito,  at  an  eleva- 
tion of  9541  feet,  that  of  the  close  of  May  at  Paris ;  and  on 
the  Paramos,  at  a  height  of  11,510  feet,  where  only  stunted 
Alpine  shrubs  grow,  though  flowers  still  bloom  in  abund- 
ance, that  of  the  beginning  of  April  at  Paris.  The  intelligent 
observer,  Peter  Martyr  de  Anghiera,  one  of  the  friends  of 
Christopher  Columbus,  seems  to  have  been  the  first  who  rec- 
ognized (in  the  expedition  undertaken  by  Rodrigo  Enrique 
Colmenares,  in  October,  1510)  that  the  limit  of  perpetual 
snow  continues  to  ascend  as  we  approach  the  equator.  We 
read,  in  the  fine  work  De  Rebus  Oceanicis,^  "  the  River  Gaira 
comes  from  a  mountain  in  the  Sierra  Nevada  de  Santa  Marta,, 
which,  according  to  the  testimony  of  the  companions  of  Col- 
menares, is  higher  than  any  other  mountain  hitherto  discov- 
ered. It  must  undoubtedly  be  so  if  it  retain  S7ioiv  perpet- 
ually in  a  zone  which  is  not  more  than  10°  from  the  equi- 
noctial line."  The  lower  limit  of  perpetual  snow,  in  a  given 
latitude,  is  the  lowest  line  at  which  snow  continues  durino- 
summer,  or,  in  other  words,  it  is  the  maximum  of  height  to 
which  the  snow-line  recedes  in  the  course  of  the  year.  But 
this  elevation  must  be  distinguished  from  three  othey  phe- 
nomena, namely,  the  annual  fluctuation  of  the  snow-line,  the 
occurrence  of  sporadic  falls  of  snow,  and  the  existence  of  gla- 
ciers, which  appear  to  be  peculiar  to  the  temperate  and  cold 
zones.  This  last  phenomenon,  since  Saussure's  immortal 
work  on  the  Alps,  has  received  much  light,  in  recent  times, 
from  the  labors  of  Venetz,  Charpentier,  and  the  intrepid  and 
persevering  observer  Agassiz. 

We  know  only  the  lower,  and  not  the  upper  limit  of  per- 
petual snow  ;  for  the  mountains  of  the  earth  do  not  attain  to 
those  ethereal  regions  of  the  rarefied  and  dry  strata  of  air,  in 
which  we  may  suppose,  with  Bouguer,  that  the  vesicles  of 
aqueous  vapor  are  converted  into  crystals  of  ice,  and  thus  ren- 
dered perceptible  to  our  organs  of  sight.  The  lower  limit  of 
snow  is  not,  however,  a  mere  function  of  geographical  latitude 
or  of  mean  annual  temperature  ;  nor  is  it  at  the  equator,  or 

*  Anglerius,  Ve  Rebus  Oceanicis,  Dec.  xi.,  lib.  ii.,  p.  140  (ed.  Col., 
1574).  In  the  Sierra  de  Santa  Marta,  the  highest  point  of  which  ap- 
pears to  exceed  19,000  feet  (see  my  R€lat.  Hist.,  t.  ii.,  p.  214),  there  is 
a  peak  that  is  still  called  Fico  de  Gaira. 


330  COSMOS. 

even  in  the  region  of  the  tropics,  that  this  limit  attains  its 
greatest  elevation  above  the  level  of"  the  sea.  The  phenome- 
non ot"  which  we  are  treating  is  extremely  complicated,  de- 
pending on  the  general  relations  of  temperature  and  humidity, 
and  on  the  form  of  mountains.  On  submitting  these  relations 
to  the  test  of  special  analysis,  as  we  may  be  permitted  to  do 
from  the  number  of  determinations  that  have  recently  been 
made,*  we  shall  find  that  the  controlling  causes  are  the  dif- 
ferences in  the  temperature  of  different  seasons  of  the  year  ; 
the  direction  of  the  prevailing  winds  and  their  relations  to  the 
land  and  sea  ;  the  degree  of  dryness  or  humidity  in  the  upper 
strata  of  the  air  ;  the  absolute  thickness  of  the  accumulated 
masses  of  fallen  snow  ;  the  relation  of  the  snow-line  to  the  to- 
tal height  of  the  mountain  ;  the  relative  position  of  the  latter 
in  the  chain  to  which  it  belongs,  and  the  steepness  of  its  de- 
clivity ;  the  vicinity  of  other  summits  likewise  perpetually 
covered  with  snow  ;  the  expansion,  position,  and  elevation  of 
the  plains  from  which  the  snow-mountain  rises  as  an  isolated 
peak  or  as  a  portion  of  a  chain  ;  whether  this  plain  be  part 
of  the  sea-coast  or  of  the  interior  of  a  continent ;  whether  it 
be  covered  with  wood  or  waving  grass  ;  and  whether,  finally,  it 
consist  of  a  dry  and  rocky  soil,  or  of  a  wet  and  marshy  bottom. 
The  snow-line  which,  under  the  equator  in  South  Ameri- 
ca, attains  an  elevation  equal  to  that  of  the  summit  of  Mont 
Blanc  in  the  Alps,  and  descends,  according  to  recent  measure- 
ments, about  1023  feet  lower  toward  the  northern -tropic  in 
the  elevated  plateaux  of  Mexico  (in  19^  north  latitude),  rises, 
according  to  Pentland,  in  the  southern  tropical  zone  (14^  30' 
to  18"^  south  latitude),  being  more  than  2665  feet  higher  in 
the  maritime  and  western  branch  of  the  Cordilleras  of  Chili 
than  under  the  equator  near  Quito  on  Chimborazo,  Cotopaxi, 
and  Antisana.  Dr.  Gillies  even  asserts  that  much  further  to 
the  south,  on  the  declivity  of  the  volcano  of  Peuquenes  (lati- 
tude 33*^),  he  found  the  snow-line  at  an  elevation  of  between 
14,520  and  15,030  feet.  The  evaporation  of  the  snow  in  the 
extremely  dry  air  of  the  summer,  and  under  a  cloudless  sky, 
is  so  powerful,  that  the  volcano  of  Aconcagua,  northeast  of 
Valparaiso  (latitude  32*^  30'),  which  was  found  in  the  expe- 
dition of  the  Beagle  to  be  more  than  1400  feet  higher  than 
Chimborazo,  was  on  one  occasion  seen  free  from  snow.t     In 

*  See  my  table  of  the  height  of  the  line  of  perpetual  snow,  in  both 
hemispheres,  from  71°  15'  north  lat.  to  53°  54'  south  lat.,  in  my  Asii 
Centrale,  t.  iii.,  p.  360. 

t  Darwin,  Journal  of  the  Voyages  of  the  Adventure  and  Beagle,  p.  297 . 


THE    SNOW-LINE.  381 

an  almost  equal  northern  latitude  (from  30*^  45'  to  31*^),  the 
snow-line  on  the  southern  declivity  of  the  Himalaya  lies  at  an 
elevation  of  12,982  feet,  which  is  about  the  same  as  the  height 
which  we  might  have  assigned  to  it  from  a  comparison  with 
other  mountain  chains  ;  on  the  northern  declivity,  however, 
under  the  influence  of  the  high  lands  of  Thibet  (whose  mean 
elevation  appears  to  be  about  11,510  feet),  the  snow-line  is 
situated  at  a  height  of  16,G30  feet.  This  phenomenon,  Avhich 
has  long  been  contested  both,  in  Europe  and  in.  India,  and 
whose  causes  I  have  attempted  to  develop  in  various  works, 
published  since  1820,*  possesses  other  grounds  of  interest  than 

As  the  volcano  of  Aconcagua  was  not  at  that  time  in  a  state  of  eruption, 
we  must  not  ascribe  the  remarkable  phenomenon  of  the  absence  of 
snow  to  the  internal  heat  of  the  mountain  (to  the  escape  of  healed  air 
through  fissures),  as  is  sometimes  the  case  with  Cotopaxi.  Gillies,  in 
the  Journal  of  Natural  Science,  1830,  p.  316. 

*  t>ee  my  Second  Mernoire  sur  les  Montagues  de  I'lnde,  in  the  Annates 
de  Chimic  et  de  Physique,  t.  xiv.,  p.  5-55;  and  Asie  Centrale,  t.  id.,  p. 
^81-327.  While  the  most  learned  and  experienced  travelers  in  India, 
C(;lebr(ii)ke,  Webb,  and  Hodgson,  Victor  Jacquemont,  Forbes  Royle, 
Carl  von  Hiigel,  and  V^igne,  who  have  all  personally  examined  the 
Himalaya  range,  are  agreed  regarding  the  greater  elevation  of  the 
snuw-liue  on  the  Thibetian  side,  the  accuracy  of  this  statement  is  called 
in  question  by  John  Gerard,  by  the  geognosist  MacClelland,  the  editor 
of  the  Calcutta  Journal,  and  by  Captain  Thomas  Hutton,  assistant  sur- 
veyor of  the  Agra  Division.  The  appearance  of  my  work  on  Central 
Asia  gave  rise  to  a  redisciission  of  this  question.  A  recent  uumbei'  (vol. 
iv,,  January,  1844)  of  MacClelland  and  Griifith's  Calcutta  Journal  of 
Natural  History  contains,  however,  a  very  remarkable  and  decisive  no- 
tice of  the  determination  of  the  snow-line  in  the  Himalayas.  Mr.  Bat- 
ten, of  the  Bengal  service,  writes  as  follows  from  Camp  Semulka,  on  the 
Cosillah  Kiver,  Kuma')n :  "'In  the  .Tuly,  1843.  No.  14  of  your  valuable 
Journal  of  Natural  History,  which  I  have  only  Litcly  had  tl^e  o[!p.irtiiiii- 
ty  of  seeing,  I  read  Captain  Hutton's  paper  on  the  snow  of  the  Hima- 
layas, and  as  I  ditfered  almost  entirely  from  the  conclusions  s(j  confi- 
dently drawn  by  that  gentleman,  T  thought  it  right,  fur  the  iniercst 
of  scientitic  truth,  to  prepare  some  kind  of  answer ;  as,  however,  on  a 
more  attentive  perusal,  I  find  that  you  yourself  appear  implicitly  to 
adopt  Captain  Hutton's  views,  and  actually  use  these  words,  '  We  have 
long  been  conscions  of  the  error  here  so  well  pointed  out  by  Captain 
Hutton,  in  common  with  every  one  who  has  visited  the  Himalayas,^  I  ieel 
more  inclined  to  address  you,  in  the  fiist  instance,  and  to  ask  whether 
you  will  publish  a  short  reply  which  I  meditate;  and  whether  your 
note  to  Captain  Hutton's  paper  was  written  after  your  own  full  and 
careful  examination  of  the  subject,  or  merely  on  a  general  kind  of  ac- 
quiescence with  the  fact  and  opinions  of  your  able  contributor,  who  is 
so  well  known  and  esteemed  as  a  collector  of  scientific  data  ?  Now  I 
am  one  who  have  visited  the  Himalaya  on  the  w^estem  side ;  I  have 
cros.sed  the  Bi);endo  or  Booriu  Pass  into  the  Buspa  Valley,  in  Lower 
Kanawar,  returning  into  the  Revv'aien  Mountains  of  Ghurwal  by  the 
Koopiu  Pass;  I  have  visited  the  source  of  the  Jumna  at  Jumnootree  i 


332  cosM  ).s. 

those  of  a  purely  physical  nature,  since  it  exercises  no  incon- 
siderable desrree  of  influence  on  the  mode  of  life  of  numerous 
tribes — the  meteorological  processes  of  the  atmosphere  being 
the  controlling  causes  on  which  depend  the  agricultural  ol* 
pastoral  pursuits  of  the  inhabitants  of  extensive  tracts  of  con- 
tinents. 

As  the  quantity  of  moisture  in  the  atmosphere  increases 
with  the  temperature,  this  element,  which  is  so  important  for 
the  whole  organic  creation,  must  vary  with  the  hours  of  the 
day,  the  seasons  of  the  year,  and  the  differences  in  latitude 
and  elevation.  Our  knowledge  of  the  hygrometric  relations 
of  the  Earth's  surface  has  been  very  materially  augmented 
of  late  years  by  the  general  application  of  August's  psychrom- 
eter,  framed  in  accordance  with  the  views  of  Dalton  and 
Daniell,  lor  determining  the  relative  quantity  of  vapor,  or  the 

and,  moving  eastward,  the  sources  of  the  Kalee  or  Mundaknee  branch 
of  the  Ganges  at  Kadarnath;  of  the  Vishnoo  Gunga,  or  Ahiknunda,  at 
Buddrinath  and  Mana ;  of  the  Pindur  at  the  foot  of  the  Great  Peak 
Nundidevi;  of  the  Dhoulee  branch  of  the  Ganges,  beyond  Neetee,  cross- 
ing and  recross^ng  the  pass  of  that  name  into  Thibet;  of  the  Goree  or 
great  branch  of  the  Sardah,  or  Kalee,  near  Oonta  Dhonra,  beyond  Me- 
lum.  I  have  also,  in  my  official  capacity,  made  the  settlement  of  the 
Bhote  Mehals  of  this  province.  My  residence  of  more  than  six  years 
in  the  hills  has  thrown  me  constantly  in  the  way  of  European  and  na- 
tive ti'avelcrs,  nor  have  I  neglected  to  acquire  information  from  the  re- 
corded labors  of  others.  Yet,  with  all  this  experience,  I  am  prepared 
to  affirm  that  the  perpetual  snoic-line  is  at  a  higher  elevation  on  the  n(n'th- 
ern  slope  of  '  the  Himalaya'  than  on  the  southern  slope. 

"  The  facts  mentioned  by  Captain  Hutton  appear  to  me  only  to  refer 
to  the  northern  sides  of  all  mountains  in  these  regions,  and  not  to  affect, 
in  any  way,  the  reports  of  Captain  Webb  and  others,  on  which  Hum- 
boldt formed  his  theory.  Indeed,  how  can  any  facts  of  one  observer  itt 
one  place  falsify  the  facts  of  another  observer  in  another  place  ?  I  will- 
ingly allow  that  the  north  side  of  a  hill  retains  the  snow  longer  and 
deeper  than  the  south  side,  and  this  observation  applies  equally  to 
heights  in  Bhote  ;  but  Humboldt's  theory  is  on  the  question  of  the  per- 
petual snow-line,  and  Captain  Hulton's  references  to  Simla  and  Mus- 
sooree,  and  other  mountain  sites,  are  out  of  place  in  this  question,  or 
else  he  fights  against  a  shadow,  or  an  objection  of  his  own  creation. 
In  no  part  of  his  paper  does  he  quote  accurately  the  dictum  which  he 
wishes  to  oppose." 

If  the  mean  altitude  of  the  Thibetian  highlands  be  11,510  feet,  they 
admit  of  comparison  with  the  lovely  and  fruitful  plateau  of  Caxarnarca 
in  Peru.  But  at  this  estimate  they  would  still  be  1300  feet  lower  than 
the  plateau  of  Bolivia  at  the  Lake  of  Titicaca,  and  the  causeway  of  the 
town  of  Potosi.  Ladak,  as  appears  from  Vigne's  measurement,  by  de- 
termining the  boiling-point,  is  9994  feet  high.  This  is  probably  :ilso 
the  altitude  of  H'Lassa  (Yul-sung),  a  monastic  city,  which  Chine.'^f' 
writers  describe  as  the  realm  of  pleasure,  and  which  is  snrroundfd  by 
vineyards.     Must  not  these  lie  in  deep  valleys? 


HYGROMETRY.  •     333 

condition  of  moisture  of  the  atmosphere,  by  means  of  the  dif- 
ference of  the  deiv  j^oint  and  of  the  temperature  of  the  air. 
Temperature,  atmospheric  pressure,  and  the  direction  of  the 
wind,  are  all  intimately  connected  with  the  vivifying  action 
of  atmospheric  moisture.  This  influence  is  not,  however,  so 
much  a  consequence  of  the  quantity  of  moisture  held  in  solu- 
tion in  different  zones,  as  of  the  nature  and  frequency  of  the 
precipitation  which  moistens  the  ground,  whether  in  the  form 
of  dew,  mist,  rain,  or  snow.  According  to  the  exposition  made 
by  Dove  of  the  law  of  rotation,  and  to  the  general  views  of 
this  distinguished  physicist,*  it  would  appear  that,  in  our 
northern  zone,  "  the  elastic  force  of  the  vapor  is  greatest  with 
a  southwest,  and  least  with  a  northeast  wind.  On  the  west- 
ern side  of  the  windrose  this  elasticity  diminishes,  while  it  in- 
creases on  the  eastern  side  ;  on  the  former  side,  for  instance, 
the  cold,  dense,  and  dry  current  of  air  repels  the  warmer, 
lighter  current  containing  an  abundance  of  aqueous  vapor, 
while  on  the  eastern  side  it  is  the  former  current  which  is 
repulsed  by  the  latter.  The  southwest  is  the  equatorial  cur- 
rent, while  the  northeast  is  the  sole  prevailing  polar  current." 
The  agreeable  and  fresh  verdure  which  is  observed  in  many 
trees  in  districts  within  the  tropics,  where,  for  five  or  seven 
months  of  the  year,  not  a  cloud  is  seen  on  the  vault  of  heaven, 
and  where  no  perceptible  dew  or  rain  falls,  proves  that  the 
leaves  are  capable  of  extracting  water  from  the  atmosphere 
by  a  peculiar  vital  process  of  their  own,  which  perhaps  is  not 
alone  that  of  producing  cold  by  radiation.  The  absence  of 
rain  in  the  arid  plains  of  Cumana,  Coro,  and  Ceara  in  North 
Brazil,  forms  a  striking  contrast  to  the  quantity  of  rain  which 
falls  in  some  tropical  regions,  as,  for  instance,  in  the  Havana, 
where  it  would  appear,  from  the  average  of  six  years'  observ- 
ation by  Ramon  de  la  Sagra,  the  mean  annual  quantity  of 
rain  is  109  inches,  equal  to  four  or  five  times  that  which  falls 
at  Paris  or  at  Geneva. t     On  the  declivity  of  the  Cordilleras, 


it 


See  Dove,  Meteorologische  Vergleichnng  von  Nordamerika  vnd  Eu- 
ropa,  in  Schumacher's  Ja^r6McAy«r  1841,  s.  311 ;  and  his  Meteorologische 
Unfersuchungen,  s.  140. 

t  The  mean  annual  quantity  of  rain  that  fell  in  Paris  between  1805 
and  1822  was  found  by  Arago  to  be  20  inches;  in  London,  between 
1812  and  1827,  it  was  determined  by  Howard  at  25  inches;  while  at 
Geneva  the  mean  of  thirty-two  years'  observation  was  30*5  inches.  In 
Hindostan,  near  the  coast,  the  quantity  of  rain  is  from  115  to  128  indies-; 
and  in  the  island  of  Cuba,  fully  142  inches  fell  in  the  year  1821.  With 
regard  to  the  distribution  of  the  quantity  of  rain  in  Central  Europe,  at 
diSerent  periods  of  the  year,  see  the  admirable  researches  of  Ga3[)arin, 
Schouw,  and  Bravais,  in  the  Bibliotheque  Universelle,  t.  xxxviii.,  p.  54 


334    »  COSMOS. 

the  quantity  of  rain,  as  well  as  the  temperature,  diminishes 
with  the  increase  in  the  elevation.*  My  South  American 
fellow-traveler,  Caldas,  found  that,  at  Santa  Fe  de  Bogota, 
at  an  elevation  of  almost  8700  feet,  it  did  not  exceed  37 
inches,  heing  consequently  little  more  than  on  some  parts  of 
the  western  shore  of  Europe.  Boussingault  occasionally  ob- 
served at  Quito  that  Saussure's  hygrometer  receded  to  26° 
with  a  temperature  of  from  530-6  to  55°-4.  Gay-Lussac 
saw  the  same  hygrometer  standing  at  25° -3  in  his  great  aero- 
static ascent  in  a  stratum  of  air  7034  feet  high,  and  wath  a 
temperature  of  39°-2.  The  greatest  dryness  that  has  yet 
been  observed  on  the  surface  of  the  globe  in  low  lands  is 
probably  that  which  Gustav  Pwose,  Ehrenberg,  and  myself 
found  in  Northern  Asia,  between  the  valleys  of  the  Irtisch 
and  the  Oby.  In  the  Steppe  of  Platowskaja,  after  southwest 
winds  had  bloAvn  for  a  long  time  from  the  interior  of  the  Con- 
tinent, with  a  temperature  of  74°-7,  w^e  found  the  dew  point 
at  24°.  The  air  contained  only  yVo^^i^  ^f  aqueous  vapor. f 
The  accurate  observers  Kamtz,  Bravais,  and  Martins  have 
raised  doubts  during  the  last  few  years  regarding  the  greater 
dryness  of  the  mountain  air,  which  appeared  to  be  proved  by 
the  hygrometric  measurements  made  by  Saussure  and  my- 
self in  the  higher  regions  of  the  Alps  and  the  Cordilleras. 
The  strata  of  air  at  Zurich  and  on  the  Faulhorn,  which  can 
not  be  considered  as  an  elevated  mountain  when  compared 
with  non-European  elevations,  furnished  the  data  employed 
in  the  comparisons  made  by  these  observers. $  In  the  tropical 
region  of  the  Paramos  (near  the  region  where  snow  begins  to 
fall,  at  an  elevation  of  between  12,000  and  14,000  feet),  some 
species  of  large  flowering  myrtle-leaved  alpine  shrubs  are  al- 
most constantly  bathed  in  moisture ;  but  this  fact  does  not 
actually  prove  the  existence  of  any  great  and  absolute  quan- 
tity of  aqueous  vapor  at  such  an  elevation,  merely  afibrding 

and  264;  Tableau  du  Climat  de  V Italic,  p.  76;  and  Marlins's  notes  lo 
his  excellent  French  translation  of  Kamtz's  VorlesJtngeri  uber  MeUurol- 
ogie,  p.  142. 

*  According  to  Boussinganlt  {Economic  Rurale,  t.  ii.,  p.  603),  fht- 
mean  quantity  of  rain  that  fell  at  Marmato  (latitude  .5°  27',  altilu.ii; 
4675  feet,  and  mean  temperature  69°)  in  the  years  1833  and  1834  \v;is 
64  inches,  while  at  Santa  Fe  de  Bogota  (latitude  4°  36',  altitude  8083 
feet,  and  mean  temperature  58°)  it  only  amounted  to  39^  inches. 

t  For  the  particulars  of  this  observation,  see  my  Asic  Centrale,  t.  iii. 
p.  85-89  and  567 ;  and  regarding  the  amount  of  vapor  in  the  atnio> 
phere  in  the  lowlands  of  tropical  South  America,  consult  my  R6lal 
Hist.,  t.  i.,  p.  242-248;  t.  ii.,  p.  45,  164. 

\  Kamtz,  Vo.rlesungen  uber  Mcicorologie,  s.  117. 


ATMOSPHERIC    ELECTRICITY.  335 

ail  evidence  of  the  frequency  of  aqueous  precipitation,  in  like 
manner  as  do  the  frequent  mists  with  which  the  lovely  pla- 
teau of  Bogota  is  covered.  Mists  arise  and  disappear  several 
limes  in  the  course  of  an  hour  in  such  elevations  as  these,  and 
with  a  cahii  state  of  the  atmosphere.  These  rapid  alterna 
tions  characterize  the  Paramos  and  the  elevated  plains  of  the 
chain  of  the  Andes. 

The  electricity  of  the  atmosphere,  whether  considered  in 
the  lower  or  in  the  upper  strata  of  the  clouds,  in  its  silent 
prohlematical  diurnal  course,  or  in  the  explosion  of  the  light- 
ning and  thunder  of  the  tempest,  appears  to  stand  in  a  mani- 
fold relation  to  all  phenomena  of  the  distribution  of  heat,  of 
the  pressure  of  the  atmosphere  and  its  disturbances,  of  hydro- 
meteoric  exhibitions,  and  probably,  also,  of  the  magnetism  of 
the  external  crust  of  the  earth.  It  exercises  a  powerful  in- 
fluence on  the  whole  animal  and  vegetable  world ;  not  mere- 
ly by  meteorological  processes,  as  precipitations  of  aqueous  va- 
por, and  of  the  acids  and  ammoniacal  compounds  to  which  it 
gives  rise,  but  also  directly  as  an  electric  Ibrce  acting  on  the 
nerves,  and  promoting  the  circulation  of  the  organic  juices. 
This  is  not  a  place  in  which  to  renew  the  discussion  that  has 
been  started  regarding  the  actual  source  of  atmospheric  elec- 
tricity when  the  sky  is  clear,  a  phenomenon  that  has  altern 
ately  been  ascribed  to  the  evaporation  of  impure  fluids  im- 
pregnated with  earths  and  salts,*  to  the  growth  of  plants,!  or 
to  some  other  chemical  decompositions  on  the  surface  of  the 
earth,  to  the  unequal  distribution  of  heat  in  the  strata  of  the 
air,|  and,  finally,  according  to  Peltier's  intelligent  researches,^ 
to  the  agency  of  a  constant  charge  of  negative  electricity  in 
the  terrestrial  globe.  Limiting  itself  to  results  yielded  by 
electrometric  observations,  such,  for  instance,  as  are  furnished 
by  the  ingenious  electro-magnetic  apparatus  first  proposed  by 
CoJladon,  the  physical  description  of  the  universe  should 
merely  notice  the  incontestable  increase  of  intensity  in  the 
general  positive  electricity  of  the  atmosphere,  II  accompanying 
an  increase  of  altitude  and  the  absence  of  trees,  its  daily  va- 
riations (which,  according  to  Clark's  experiments  at  Dublin, 

*  Regarding  the  conditions  of  electricity  from  evaporation  at  higb 
temperatures,  see  Peltier,  in  the  Annales  de  Chimie,  t.  Ixxv.,  p.  3-30 

t  Pouillet,  in  the  Annales  de  Chimie,  t.  xxxv.,  p.  405. 

t  De  la  Rive,  in  his  admirable  Essai  Historique  snr  V ElcctriciU,  p. 
140. 

^  Peltier,  in  the  Compies  Rendus  de  V Acad,  des  Sciences,  t.  xii.,  p. 
307  ;  Becquerel,  Traile  de  VElec(ricit6  et  du  Magnetismc,  t.  iv.,  p.  10?" 

1]   Duprez,  Sur  V Electriciti  de  VAir  (BruxcUes,  181  i),  p.  5(5-61 


336  COSMOS. 

take  place  at  more  complicated  periods  than  those  found  by 
Saussure  and  myself),  and  its  variations  in  the  different 
seasons  of  the  year,  at  different  distances  from  the  equator, 
and  in  the  difierent  relations  of  continental  or  oceanic  sur- 
face. 

The  electric  equilibrium  is  less  frequently  disturbed  where 
the  aerial  ocean  rests  on  a  liquid  base  than  where  it  impends 
over  the  land  ;  and  it  is  very  striking  to  observe  how,  in  ex- 
tensive seas,  small  insular  groups  affect  the  condition  of  the 
atmosphere,  and  occasion  the  formation  of  storms.  In  fogs, 
and  in  the  commencement  of  falls  of  snov/,  I  have  seen,  in  a 
long  series  of  observations,  the  previously  permanent  positive 
electricity  rapidly  pass  into  the  negative  condition,  both  on 
the  plains  of  the  colder  zones,  and  in  the  Paramos  of  the  Cor- 
dilleras, at  elevations  varying  from  11,000  to  15,000  feet. 
The  alternate  transition  was  precisely  similar  to  that  indica- 
ted by  the  electrometer  shortly  before  and  during  a  storm.* 
When  the  vesicles  of  vapor  have  become  condensed  into  clouds, 
having  definite  outlines,  the  electric  tension  of  the  external 
surface  will  be  increased  m  proportion  to  the  amount  of  elec- 
tricity which  passes  over  to  it  from  the  separate  vesicles  of 
vapor.f  Slate-gray  clouds  are  charged,  according  to  Peltier's 
experiments  at  Paris,  with  negative,  and  white,  red,  and  or- 
ange-colored clouds  with  positive  electricity.  Thunder  clouds 
not  only  envelop  the  highest  summits  of  the  chain  of  the  An- 
des (I  have  myself  seen  the  electric  effect  of  lightning  on  one 
of  the  rocky  pinnacles  which  project  upward  of  15,000  feet 
above  the  crater  of"  the  volcano  of  Toluca),  but  they  have  also 
been  observed  at  a  vertical  height  of  26,650  feet  over  the  low 

*  Humboldt,  Relation  Historique,  t.  iii.,  p.  318.  I  here  only  refer 
to  those  of  my  experiments  in  which  the  three-foot  metallic  conductor 
of  Saussure's  electrometer  was  neither  moved  upward  nor  downward, 
nor,  according  to  Volta's  proposal,  armed  with  burning  sponge.  Those 
of  my  readers  who  are  well  acquainted  with  the  qufcaliones  vexatce  of 
atmospheric  electricity  will  understand  the  grounds  for  this  limitation. 
Respecting  the  formation  of  storms  in  the  tropics,  see  my  Ril.  Hist.,  t. 
ii.,  p.  45  and  202-209. 

t  Gay-Lussac,  in  the  Annales  de  Chimie  et  de  Physique,  t.  viii.,  p.  167. 
In  consequence  of  the  discordant  views  of  Lame,  Becquerel,  and  Pel- 
tier, it  is  difficult  to  come  to  a  conclusion  regarding  the  cause  of  the 
specific  distribution  of  electricity  in  clouds,  some  of  which  have  a  pos- 
itive, and  others  a  negative  tension.  The  negative  electricity  of  the 
air,  which  near  high  water-falls  is  caused  by  a  disintegration  of  the 
drops  of  water — a  fqct  originally  noticed  by  Tralles,  and  confirmed  by 
myself  in  various  latitudes — is  very  remarkable,  and  is  suflSciently  in- 
tense to  produce  an  appreciable  effect  on  a  delicate  electrometer  at  a 
diatance  of  300  or  400  feet. 


ATMOSPHERIC    ELECTRICITY.  337 

lands  in  the  temperate  zone.*  Sometimes,  however,  the 
stratum  of  cloud  from  which  the  thunder  proceeds  sinks  to  a 
distance  of  5000,  or,  indeed,  only  3000  feet  above  the  plain. 

According  to  Arago's  investigations — the  most  comprehen- 
sive that  we  possess  on  this  difficult  branch  of  meteorology — 
the  evolution  of  light  (lightning)  is  of  three  kinds — zigzag, 
and  sharply  defined  at  the  edges  ;  in  sheets  of  light,  illumin- 
ating a  whole  cloud,  which  seems  to  open  and  reveal  the  light 
within  it ;  and  in  the  form  of  fire-balls. t  The  duration  of  the 
two  first  kinds  scarcely  continues  the  thousandth  part  of  a 
second  ;  but  the  globular  lightning  moves  much  more  slowly 
remaining  visible  for  several  seconds.  Occasionally  (as  is 
proved  by  the  recent  observations,  which  have  confirmed  the 
description  given  by  Nicholson  and  Beccaria  of  this  phenom- 
enon), isolated  clouds,  standing  high  above  the  horizon,  con- 
tinue uninterruptedly  for  some  time  to  emit  a  luminous  ra- 
diance from  their  interior  and  from  their  margins,  although 
there  is  no  thmider  to  be  heard,  and  no  indication  of  a  storm  ; 
in  some  cases  even  hail-stones,  drops  of  rain,  and  flakes  of  snow 
have  been  seen  to  fall  in  a  luminous  condition,  when  the  phe- 
nomenon was  not  preceded  by  thunder.  In  the  geographical 
distribution  of  storms,  the  Peruvian  coast,  which  is  not  visited 
by  thunder  or  lightning,  presents  the  most  striking  contrast  to 
the  rest  of  the  tropical  zone,  in  which,  at  certain  seasons  of 
the  year,  thunder-storms  occur  almost  daily,  about  four  or  five 
hours  after  the  sun  has  reached  the  meridian.  According  to 
the  abundant  evidence  collected  by  Arago$  from  the  testimony 
of  navigators  (Scoresby,  Parry,  Ross,  and  Frankhn),  there  can 
be  no  doubt  that,  in  general,  electric  explosions  are  extremely 
rare  in  high  northern  regions  (between  70^^  and  75°  latitude). 

The  meteorological  portion  of  the  descriptive  history  of  na- 
ture which  we  are  now  concluding  shows  that  the  processes 
of  the  absorption  of  light,  the  liberation  of  heat,  and  the  va- 
riations in  the  elastic  and  electric  tension,  and  in  the  hygro- 
metric  condition  of  the  vast  aerial  ocean,  are  all  so  intimate- 
ly connected  together,  that  each  individual  meteorological 
process  is  modified  by  the  action  of  all  the  others.     The  com- 

*  Arago,  in  the  Annuaire  dn  Bureau  des  Longitudes  pour  1838,  p.  246. 
t  Arago,  op.  cit.,  p.  249-266.  (See,  also,  p.  268-279.) 
X  Arago,  op,  cit.,  p.  388-391.  The  learned  academician  Von  Baer, 
who  has  done  so  much  for  the  meteorology  of  Northern  Asia,  has  not 
taken  into  consideration  the  extreme  rarity  of  storms  in  Iceland  and 
Greenland ;  he  has  only  remarked  {Bulletin  de  V Academie  de  St.  Piters- 
bourg,  1839,  Mai)  that  in  Nova  Zembla  tmd  Spitzbergen  it  is  sometimes 
heard  to  thunder. 

Vol.  I.— P 


338  COSMOS. 

plicated  nature  of  these  disturbing  causes  (wliich  involuntarily 
remind  us  of  those  which  the  near  and  especially  the  smallest 
cosmical  bodies,  the  satellites,  comets,  and  shooting  stars,  are 
Bubjected  to  in  their  course)  increases  the  difficulty  of  giving  a 
full  explanation  of  these  involved  meteorological  phenomena, 
and  likewise  limits,  or  wholly  precludes,  the  possibility  of  that 
predetermination  of  atmospheric  changes  which  would  be  so 
important  for  horticulture,  agriculture,  and  navigation,  no  less 
than  for  the  comfort  and  enjoyment  of  life.  Those  who  place 
the  value  of  meteorology  in  this  problematic  species  of  predic- 
tion rather  than  in  the  knowledge  of  the  phenomena  them- 
selves, are  firmly  convinced  that  this  branch  of  science,  on  ac- 
count of  which  so  many  expeditions  to  distant  mountainous 
regions  have  been  undertaken,  has  not  made  any  very  consid- 
erable progress  for  centuries  past.  The  confidence  which  they 
refuse  to  the  physicist  they  yield  to  changes  of  the  moon,  and 
to  certain  days  marked  in  the  calendar  by  the  superstition  of 
a  by-gone  age. 

"  Great  local  deviations  from  the  distribution  of  the  mean 
temperature  are  of  rare  occurrence,  the  variations  being  in 
general  uniformly  distributed  over  extensive  tracts  of  land. 
The  deviation,  after  attaining  its  maximum  at  a  certain  point, 
gradually  decreases  to  its  limits  ;  when  these  are  passed,  how- 
ever, decided  deviations  are  observed  in  the  opjJodte  direction. 
Similar  relations  of  weather  extend  more  frequently  from  south 
to  north  than  from  west  to  east.  At  the  close  of  the  year  1829 
(when  I  had  just  completed  my  Siberian  journey),  the  maxi- 
mum of  cold  was  at  Berlin,  while  North  America  enjoyed  an 
mmsually  high  temperature.  It  is  an  entirely  arbitrary  as- 
sumption to  believe  that  a  hot  summer  succeeds  a  severe  win- 
ter, and  that  a  cool  summer  is  preceded  by  a  mild  winter." 
Opposite  relations  of  weather  in  contiguous  countries,  or  in 
two  corn-growing  continents,  give  rise  to  a  beneficent  equali- 
zation in  the  prices  of  the  products  of  the  vine,  and  of  agricul- 
tural and  horticultural  cultivation.  It  has  been  justly  re- 
marked, that  it  is  the  barometer  alone  which  indicates  to  us 
the  changes  that  occur  in  the  pressure  of  the  air  throughout 
all  the  aerial  strata  from  the  place  of  observation  to  the  ex- 
tremest  confines  of  the  atmosphere,  while*  the  thermometer 
and  psychrometer  only  acquaint  us  with  all  the  variations  oc- 
curring in  the  local  heat  and  moisture  of  the  lower  strata  of 

*  Kamtz,  ill  Schumacher's  Jahrhuch  fur  1838,  s.  285.  Regarding 
the  opposite  distribution  of  lieat  in  the  east  and  the  west  of  Europe  ;iiiil 
North  America,  see  Dove.  Repertorium  dcr  Physik,  bd.  iii..  s.  392-305. 


ORGANIC    LIFE,  339 

air  in  contact  with  the  ground.  The  simultaneous  thermic 
and  hygrometric  modifications  of  the  upper  regions  of  the  air 
can  only  be  learned  (when  direct  observations  on  mountain 
stations  or  aerostatic  ascents  are  impracticable)  from  hypo- 
thetical combinations,  by  making  the  barometer  serve  both  as 
a  thermometer  and  an  hygrometer.  Important  changes  of 
weather  are  not  owing  to  merely  local  causes,  situated  at  the 
place  of  observation,  but  are  the  consequence  of  a  disturbance 
in  the  equilibrium  of  the  aerial  currents  at  a  great  distance 
from  the  surface  of  the  Earth,  in  the  higher  strata  of  the  at- 
mosphere, bringing  cold  or  warm,  dry  or  moist  air,  rendering 
the  sky  cloudy  or  serene,  and  converting  the  accumulated 
masses  of  clouds  into  light  feathery  cirri.  As,  therefore,  the 
inaccessibility  of  the  phenomenon  is  added  to  the  manifold 
nature  and  complication  of  the  disturbances,  it  has  always 
appeared  to  me  that  meteorology  must  first  seek  its  founda- 
tion and  progress  in  the  torrid  zone,  where  the  variations  of 
the  atmospheric  pressure,  the  course  of  hydro-meteors,  and 
the  phenomena  of  electric  explosion,  are  all  of  periodic  occur- 
rence. 

As  we  have  now  passed  in  review  the  whole  sphere  of  in- 
organic terrestrial  life,  and  have  briefly  considered  our  planet 
with  reference  to  its  form,  its  internal  heat,  its  electro-mag- 
netic tension,  its  phenomena  of  polar  light,  the  volcanic  reac- 
tion of  its  interior  on  its  variously  composed  solid  crust,  and, 
lastly,  the  phenomena  of  its  two-fold  envelopes — the  aerial  and 
liquid  ocean — we  might,  in  accordance  with  the  older  method 
of  treating  physical  geography,  consider  that  we  had  com- 
pleted our  descriptive  history  of  the  globe.  But  the  nobler 
aim  I  have  proposed  to  myself,  of  raising  the  contemplation 
of  nature  to  a  more  elevated  point  of  view,  would  be  defeated, 
and  this  delineation  of  nature  would  appear  to  lose  its  most 
attractive  charm,  if  it  did  not  also  include  the  sphere  of  or- 
ganic life  in  the  many  stages  of  its  typical  development.  The 
idea  of  vitality  is  so  intimately  associated  with  the  idea  of  the 
existence  of  the  active,  ever-blending  natural  forces  which  an- 
imate the  terrestrial  sphere,  that  the  creation  of  plants  and 
animals  is  ascribed  in  the  most  ancient  mythical  representa- 
tions of  many  nations  to  these  forces,  while  the  condition  of 
the  surface  of  our  planet,  before  it  was  animated  by  vital 
forms,  is  regarded  as  coeval  with  the  epoch  of  a  chaotic 
conflict  of  the  struggling  elements.  But  the  empirical  do- 
main of  objective  contemplation,  and  the  delineation  of  our 
planet  in  its  present  condition,  do  not  include  a  consideration 


340  COSMOS. 

of  the  mysterious  and  insoluble  prolDlenis  of  origin  and  exist- 
ence. 

A  cosmical  history  of  the  universe,  resting  upon  facts  as  its 
basis,  has,  from  the  nature  and  limitations  of  its  sjDhere,  neces- 
sarily no  connection  with  the  obscure  domain  embraced  by  a 
history  of  organisms*  if  we  understand  the  word  history  in 
its  broadest  sense.  It  must,  however,  be  remembered,  that 
the  inorganic  crust  of  the  Earth  contains  within  it  the  same 
elements  that  enter  into  the  structure  of  animal  and  vegeta- 
ble organs.     A  physical  cosmography  would  therefore  be  in 

*  The  history  of  plants,  which  Eudlicher  and  Unger  have  described 
in  a  most  masterly  manner  {Grundzuge  der  Botanik,  1843,  s.  449-468), 
I  myself  separated  from  the  geography  of  plants  half  a  century  ago 
In  the  aphorisms  appended  to  my  Subterranean  Flora,  the  following 
passage  occurs  :  "  Geognosia  naturam  animantem  et  inanimam  vel,  ut 
vocabulo  minus  apto,  ex  antiquitate  saltem  hand  petito,  utar,  corpora 
orgauica  aeque  ac  inorganica  considerat.     Sunt  enim  tria  quibus  absol 
vitur  capita :  Geographia  oryctologica  quam  simpliciter  Geognosiam  vel 
Geologiam  dicunt,  virque  acutissimus  Wemerus  egregie  digessit ;  Geo- 
graphia zoologica,  cujus  doctrinse  fundamenta  Zimmermannus  et  Tre- 
virauus  jecerunt;  et  Geographia  plantarum  quam  sequales  nostri  diu  in- 
tactam  reliquerant.     Geographia  plantarum  vincula  et  cognationem 
tradit,  quibus  omnia  vegetabilia  inter  se  connexa  sint,  ten-ae  tractus 
quos  teueant,  in  aerem  atmosphasricum  qui3e  sit  eorum  vis  ostendit,  saxa 
atque  rupes  quibus  potissimum  algarum  primordiis  radicibusque  destru- 
antur  docet,  et  quo  pacto  in  telluris  superficie  humus  nascatur,  com- 
memorat.    Est  itaque  quod  dilFerat  inter  Geognosiam  et  Physiographiam, 
historia  naturalis  perperam  imncupatam  quum  Zoognosia,  Phytognosia, 
et  Oryctognosia,  quse  quidem  omnes  in  naturae  investigatione  versantur, 
non  nisi  singulorum  animalium,  plantarum,  rerum  metallicanim  vel 
(venia  sit  verbo)  fossilium  formas,  anatomen,  vires  scrutantur.    Historia 
Telluris,  Geognosiae  magis  quam  Physiographiae  affinis,  nemini  adhuc 
tentata,  plantarum  animaliumque  genera  orbem  inhabitantia  primaevum, 
migrationes  eorum  compluriumque  interitum,  ortum   quem   montes, 
valles,  saxorura  strata  et  venae  metalliferoe  ducunt,  aerem,  mutatis  tem- 
porum  vicibus,  modo  purum,  modo  vitiatum,  teiTas  superficiem  humo 
plantisque  paulatim  obtectam,  fluminum  inundantium  impetu  denuo 
nudatam,  iteruraque  siccatam  et  gramine  vestitam  commemorat.     Igi- 
tur  Historia  zoologica,  Historia  plantarum  et  Historia  oryctologica,  quaa 
non  nisi  pristinum  orbis  terrae  statum  indicant,  a  Geognosia  probe  dis- 
tinguendai." — Humboldt,  Flora  Friburgensis  Subterranea,  cui  accedunt 
Aphorismi  ex  Physiologia  Chemica  Plantarum,  1793,  p.  ix.-x.     Respect- 
ing the  "  spontaneous  motion,"  which  is  referred  to  in  a  subsequent 
part  of  the  text,  see  the  remarkable  passage  in  Aristotle,  De  Codo,  ii., 
2,  p.  284,  Bekker,  where  the  distinction  between  animate  and  inanimate 
bodies  is  made  to  depend  on  the  internal  or  external  position  of  the 
seat  of  the  determining  motion.     "  No  movement,"  says  the  Stagirite, 
"  proceeds  fi'om  the  vegetable  spirit,  because  plants  are  buried  in  a 
Btill  sleep,  from  which  nothing  can  arouse  them"  (Aristotle,  De  General. 
Animal.,  v.  i.,  p.  778,  Bekker);  and  again,  "because  plants  have  no 
desires  which  incite  them  to  spontaneous  motion."     (Arist.,  De  Sovino 
et  Vigil.,  cap.  i.,  p.  455,  Bekker.) 


MOTION    IN    PLANTS.  341 

complete  if  it  were  to  omit  a  consideration  of  these  forces,  and 
of  the  substances  which  enter  into  sohd  and  fluid  combina- 
tions in  organic  tissues,  under  conditions  which,  from  our  igno- 
rance of  their  actual  nature,  we  designate  by  the  vague  terra 
of  vital  forces,  and  group  into  various  systems,  in  accordance 
with  more  or  less  perfectly  conceived  analogies.  The  nat- 
ural tendency  of  the  human  mind  involuntarily  prompts  us 
to  follow  the  physical  phenomena  of  the  Earth,  through  all 
their  varied  series,  until  we  reach  the  final  stage  of  the  mor- 
phological evolution  of  vegetable  forms,  and  the  self-determin- 
ing powers  of  motion  in  animal  organisms.  And  it  is  by  these 
links  that  the  geography  of  wganic  beings — of  plants  and 
animals — is  connected  with  the  delineation  of  the  inorganic 
phenomena  of  our  terrestrial  globe. 

Without  entering  on  the  difficult  question  of  sjiontaneous 
motion,  or,  in  other  words,  on  the  difference  between  vegeta- 
ble and  animal  life,  we  would  remark,  that  if  nature  had  en- 
dowed us  with  microscopic  powers  of  vision,  and  the  integu- 
ments of  plants  had  been  rendered  perfectly  transparent  to 
our  eyes,  the  vegetable  world  would  present  a  very  different 
aspect  from  the  apparent  immobility  and  repose  in  which  it 
is  now  manifested  to  our  senses.  The  interior  portion  of  the 
cellular  structure  of  their  organs  is  incessantly  animated  by 
the  most  varied  currents,  either  rotating,  ascending  and  de- 
scending, ramifying,  and  ever  changing  their  direction,  as 
manifested  in  the  motion  of  the  granular  mucus  of  marine 
plants  (Naiades,  Characea3,  HydrocharidsB),  and  in  the  hairs  of 
phanerogamic  land  plants  ;  in  the  molecular  motion  first  dis- 
covered by  the  illustrious  botanist  Robert  Brown,  and  which 
may  be  traced  in  the  ultimate  portions  of  every  molecule  of 
matter,  even  when  separated  from  the  organ  ;  in  the  gyratorv 
currents  of  the  globules  of  cambium  {cyclosis)  circulating  in 
their  peculiar  vessels ;  and,  finally,  in  the  singularly  articula- 
ted self-unrolling  filamentous  vessels  in  the  antheridia  of  the 
chara,  and  in  the  reproductive  organs  of  liverworts  and  algae, 
in  the  structural  conditions  of  which  Meyen,  unhappily  too 
early  lost  to  science,  believed  that  he  recognized  an  analogy 
with  the  spermatozoa  of  the  animal  kingdom.*     If  to  these 

*  ["  la  certain  parts,  probably,  of  all  plants,  are  found  peculiar  spiral 
filaments,  having  a  striking  resemblance  to  the  spermatozoa  of  animals. 
They  have  been  long  known  in  the  organs  called  the  antheridia  of 
musses,  Hepaticn",  and  Characea?,  and  have  more  recently  been  dis- 
covered in  peculiar  cells  on  the  germinal  frond  of  ferns,  and  on  the 
very  young  leaves  of  the  buds  of^Phanerogamia.  They  are  found  in 
peculiar  cells,  and  when  these  are  placed  in  water  they  are  torn  by  the 


342  COSMOS. 

manifold  currents  and  gyratory  movements  we  add  the  phe- 
nomena of  endosmosis,  nutrition,  and  growth,  we  shall  have 
some  idea  of  those  forces  which  are  ever  active  amid  the  ap- 
parent repose  of  vegetable  life. 

Since  I  attempted  in  a  former  work,  Ansichten  der  Natur 
(Views  of  Nature),  to  delineate  the  universal  diffusion  of  life 
over  the  whole  surface  of  the  Earth,  in  the  distribution  of 
organic  forms,  both  with  respect  to  elevation  and  depth,  our 
knowledge  of  this  branch  of  science  has  been  most  remarkably 
increased  by  Ehrenberg's  brilliant  discovery  "  on  microscopic 
life  in  the  ocean,  and  in  the  ice  of  the  polar  regions" — a  dis- 
covery based,  not  on  deductive  conclusions,  but  on  direct  ob- 
servation. The  sphere  of  vitality,  we  might  almost  say,  the 
horizon  of  life,  has  been  expanded  before  our  eyes.  "  Not 
only  in  the  polar  regions  is  there  an  uninterrupted  develop- 
ment of  active  microscopic  life,  where  larger  animals  can  no 
longer  exist,  but  we  find  that  the  microscopic  animals  collect- 
ed in  the  Antarctic  expedition  of  Captain  James  Ross  exhibit 
a  remarkable  abundance  of  unknown  and  often  most  beautiful 
forms.  Even  in  the  residuum  obtained  from  the  melted  ice, 
swimming  about  in  round  fragments  in  the  latitude  of  70^  10', 
there  were  found  upward  of  fifty  species  of  silicious-shelled 
Polygastria  and  CoscinodiscsB  with  their  green  ovaries,  and 
therefore  living  and  able  to  resist  the  extreme  severity  of  the 
cold.  In  the  Gulf  of  Erebus,  sixty-eight  silicious-shelled  Poly- 
gastria and  Phytolitharia,  and  only  one  calcareous-shelled  Poly- 
thalamia,  were  brought  up  by  lead  sunk  to  a  depth  of  from 
1242  to  1620  feet." 

The  greater  number  of  the  oceanic  microscopic  forms  hith- 
*  rto  discovered  have  been  silicious-shelled,  although  the  anal- 
ysis of  sea  water  does  not  yield  silica  as  the  main  constituent, 
and  it  can  only  be  imagined  to  exist  in  it  in  a  state  of  suspen- 
sion. It  is  not  only  at  particular  points  in  inland  seas,  or  in 
the  vicinity  of  the  land,  that  the  ocean  is  densely  inhabited 
by  living  atoms,  invisible  to  the  naked  eye,  but  samples  of 

filament,  which  commences  an  active  spiral  motion.  The  signification 
of  these  organs  is  at  present  quite  unknown ;  they  appear,  from  the 
researches  of  Nageli,  to  resemble  the  cell  mucilage,  or  proto-plasma, 
in  composition,  and  are  developed  from  it.  Schleiden  regards  them  as 
mei'e  mucilaginous  deposits,  similar  to  those  connected  with  the  circu- 
lation in  cells,  and  he  contends  that  the  movement  of  these  bodies  in 
water  is  analogous  to  the  molecular  motion  of  small  particles  of  organic 
and  inorganic  substances,  and  depends  on  mechanical  causes." — Outlines 
of  Structural  and  Physiological  Botany,  by  A.  Henfrey,  F.L.S.,  &c., 
1846,  p.  23.]— Tr 


UNIVERSALITY    Ol'    ANIMAL    LIFE.  'MH 

water  taken  up  by  Schayer  on  his  return  from  Van  Diemen's 
Laud  (south  of  the  Cape  of  Good  Hope,  in  57°  latitude,  and 
under  the  trojoics  in  the  Atlantic)  show  that  the  ocean  in  its 
ordinary  condition,  without  any  apparent  discoloration,  con- 
tains numerous  microscopic  moving  organisms,  which  bear  no 
resemblance  to  the  swimming  fragmentary  silicious  filaments 
of  the  genus  Chaetoceros,  similar  to  the  Oscillatoria3  so  common 
in  our  fresh  waters.  Some  few  Polygastria,  which  have  been 
found  mixed  with  sand  and  excrements  of  penguins  in  Cock- 
burn  Island,  appear  to  be  spread  over  the  whole  earth,  while 
others  seem  to  be  peculiar  to  the  polar  regions. "^ 

We  thus  find  from  the  most  recent  observations  that  ani- 
mal life  predominates  amid  the  eternal  night  of  the  depths  of 
ocean,  while  vegetable  life,  which  is  so  dependent  on  the  pe- 
riodic action  of  the  solar  rays,  is  most  prevalent  on  continents. 
The  mass  of  vegetation  on  the  Earth  very  far  exceeds  that 
of  animal  organisms  ;  for  what  is  the  volume  of  all  the  large 
living  Cetacea  and  Pachydermata  when  compared  wdth  the 
thickly-crowded  colossal  trunks  of  trees,  of  from  eight  to  twelve 
feet  in  diameter,  which  fill  the  vast  forests  covering  the  trop- 
ical region  of  South  America,  between  the  Orinoco,  the  Ama- 
zon, and  the  Rio  da  Madeira  ?  And  although  the  character 
of  different  portions  of  the  earth  depends  on  the  combination 
of  external  phenomena,  as  the  outlines  of  mountains — the 
physiognomy  of  plants  and  animals — the  azure  of  the  sky — 
the  forms  of  the  clouds — and  the  transparency  of  the  atmos- 
phere— it  must  still  be  admitted  that  the  vegetable  mantle 
with  which  the  earth  is  decked  constitutes  the  main  feature 
of  the  picture.  Animal  forms  are  inferior  in  mass,  and  their 
powers  of  motion  often  withdraw  them  from  our  sight.     The 

*  See  Ehrenberg's  treatise  Ueber  das  kleinste  Leben  im  Ocean,  I'ead 
before  the  Academy  of  Science  at  Berlin  on  the  9th  of  May,  1844. 

[Dr.  J.  Hooker  found  Diatomace;c  in  countless  numbers  between  the 
parallels  of  60°  and  80°  south,  where  they  gave  a  color  to  the  sea,  and 
also  to  the  icebergs  floating  in  it.  The  death  of  these  bodies  in  the 
South  Arctic  Ocean  is  producing  a  submarine  deposit,  consisting  en- 
tirely of  the  silicious  particles  of  which  the  skeletons  of  these  vegeta- 
bles are  composed.  This  deposit  exists  on  the  shores  of  Victoria  Land 
and  at  the  base  of  the  volcanic  mountain  Erebus.  Dr.  Hooker  account- 
ed for  the  fact  that  the  skeletons  of  Diatoraaceae  had  been  found  in  the 
lava  of  volcanic  mountains,  by  referring  to  these  deposits  at  Mount 
Erebus,  which  lie  in  such  a  position  as  to  render  it  quite  possible  that 
the  skeletons  of  these  vegetables  should  pass  into  the  lower  fissures  of 
the  mountain,  and  then  passing  into  the  stream  of  lava,  be  thrown  out, 
unacted  upon  by  the  heat  to  which  they  have  been  exposed.  See  Dr. 
Hooker's  Pajier,  read  before  the  British  Association  at  Oxford,  July, 
1847.]— Tr. 


344  cosMoa. 

vegetable  kingdom,  on  the  contrary,  acts  upon  our  imagination 
by  its  continued  presence  and  by  the  magnitude  of  its  forms  ; 
for  the  size  of  a  tree  indicates  its  age,  and  here  alone  ag^e  is 
associated  with  the  expression  of  a  constantly  renewed  vigor.* 
In  the  animal  kingdom  (and  this  knowledge  is  also  the  result 
of  Ehrenberg's  discoveries),  the  forms  which  we  term  micro- 
scopic occupy  the  largest  space,  in  consequence  of  their  rapid 
propagation.!  The  minutest  of  the  Infusoria,  the  Monadidse, 
have  a  diameter  which  does  not  exceed  3  oVo^^  ^f  a  line,  and 
yet  these  silicious-shelled  organisms  form  in  humid  districts 
subterranean  strata  of  many  fathoms  in  depth. 

The  strong  and  beneficial  influence  exercised  on  the  feelings 
of  mankind  by  the  consideration  of  the  diffusion  of  life  through- 
out the  realms  of  nature  is  common  to  every  zone,  but  the  im- 
pression thus  produced  is  most  powerful  in  the  equatorial  re- 
gions,  in  the  land  of  palms,  bamboos,  and  arborescent  ferns, 
where  the  ground  rises  from  the  shore  of  seas  rich  in  mollusca 
and  corals  to  the  limits  of  perpetual  snov/.  The  local  distri- 
bution of  plants  embraces  almost  all  heights  and  all  depths. 
Organic  forms  not  only  descend  into  the  interior  of  the  earth, 
where  the  industry  of  the  miner  has  laid  open  extensive  ex- 
cavations and  sprung  deep  shafts,  but  I  have  also  found  snow- 
white  stalactitic  columns  encircled  by  the  delicate  web  of  an 
Usnea,  in  caves  where  meteoric  water  could  alone  penetrate 
through  fissures.  Podurellae  penetrate  into  the  icy  crevices  of^ 
the  glaciers  on  Mount  Rosa,  the  Grindelwald,  and  the  Upper 
Aar  ;  the  Chionsea  araneoides  described  by  Dalman,  and  the 
microscopic  Discerea  nivalis  (formerly  known  as  Protococ- 
cus),  exist  in  the  polar  snow  as  well  as  in  that  of  our  high 
mountains.  The  redness  assumed  by  the  snow  after  lying  on 
the  ground  for  some  time  was  known  to  Aristotle,  and  was 
probably  observed  by  him  on  the  mountains  of  Macedonia.! 

*  Humboldt,  Ansichten  der  Nairn-  (2te  Ausgabe,  1826),  bd.  ii.,  s.  21. 

t  On  multiplication  by  spontaneous  division  of  the  mother-corpuscle 
and  iutercalation  of  new  substance,  see  Ehrenberg,  Von  den  jetzt  leben- 
den  Thierarten  der  Kreidebildung,  in  the  Abkandl.  der  Berliner  Akad. 
der  Wiss.,  1839,  s.  94.  The  most  powerful  productive  faculty  in  na- 
ture is  that  manifested  in  the  Vorticellse.  Estimations  of  the  greatest 
possible  development  of  masses  will  be  found  in  Ehrenberg's  great 
work.  Die  Infus^ionsthierchen  als  vollkommne  Organismen,  1838,  s.  xiii., 
xix.,  and  244.  "  The  Milky  Way  of  these  organisms  comprises  the 
genera  Monas,  Vibrio,  Bacterium,  and  Bodo."  The  universality  of  life 
is  so  profusely  distributed  throughout  the  whole  of  nature,  that  the  small- 
er Infusoria  live  as  parasites  on  the  larger,  and  are  themselves  iii&abit- 
ed  by  others,  s.  194,  211,  and  512. 

t  Aristot..  Hist.  Animal.,  v.  xix.,  p.  552,  Bekk. 


UNIVERSALITY    OF    ANIMAL    LIFE.  345 

While,  on  the  loftiest  summits  of  the  Alps,  only  Lecidese, 
Parmeliae,  and  Umbilicariai  cast  their  colored  but  scanty 
covering  over  the  rocks,  exposed  by  the  melted  snow,  beauti- 
ful phanerogamic  plants,  as  the  Culcitiura  rufescens,  Sida 
pinchinchensis,  and  Saxifraga  Boussingaulti,  are  still  found 
to  flourish  in  the  tropical  region  of  the  chain  of  the  Andes,  at 
an  elevation  of  more  than  15,000  feet.  Thermal  springs  con- 
tain small  insects  (Hydroporus  thermalis),  Gallionellae,  Oscilla- 
toria,  and  Confervse,  while  their  waters  bathe  the  root-fibers  of 
phanerogamic  plants.  As  air  and  water  are  animated  at  dif- 
ferent temperatures  by  the  presence  of  vital  organisms,  so  like- 
wise is  the  interior  of  the  different  portions  of  animal  bodies. 
Animalcules  have  been  found  in  the  blood  of  the  frog  and  the 
salmon  ;  according  to  Nordmann,  the  fluids  in  the  eyes  of  fishes 
are  often  filled  with  a  worm  that  lives  by  suction  (Diplosto- 
mum),  while  in  the  gills  of  the  bleak  the  same  observer  has 
discovered  a  remarkable  double  animalcule  (Diplozoon  para- 
doxum),  having  a  cross-shaped  form  with  two  heads  and  two 
caudal  extremities. 

Although  the  existence  of  meteoric  Infusoria  is  more  than 
doubtful,  it  can  not  be  denied  that,  in  the  same  manner  as  the 
pollen  of  the  flowers  of  the  pine  is  observed  every  year  to  fall 
from  the  atmosphere,  minute  infusorial  animalcules  may  like- 
wise be  retained  for  a  time  in  the  strata  of  the  air,  after  hav- 
ing been  passively  borne  up  by  currents  of  aqueous  vapor.* 
This  circumstance  merits  serious  attention  in  reconsidering 
the  old  discussion  respecting  sjwntaneous  generation,!  and  the 

*  Ehrenberg,  op.  cit.,  s.  xiv.,  p.  122  and  493.  This  rapid  multiplica- 
tion of  microscopic  organisms  is,  in  the  case  of  some  (as,  for  instance, 
ia  wheat-eels,  wheel-animals,  and  water-bears  or  tardigrade  animal- 
cules), accompanied  by  a  remarkable  tenacity  of  life.  They  have  been 
seen  to  come  to  life  from  a  state  of  apparent  death  after  being  dried 
for  twenty-eight  days  in  a  vacuum  with  chloride  of  lime  and  sulphuric 
acid,  and  after  being  exposed  to  a  heat  of  248°.  See  the  beautiful  ex- 
periments of  Doyere,  in  M6jn.  sur  les  Tardigrades  et  sur  leur  propriety 
de  revenir  a  la  vie,  1842,  p.  119,  129,  131,  133.  Compare,  also,  Ehren 
berg,  s.  492-496,  on  the  revival  of  animalcules  that  had  been  dried 
during  a  space  of  many  years. 

t  On  the  supposed  ''primitive  transformation"  of  organized  or  uuor 
ganized  matter  into  plants  and  animals,  see  Ehrenberg,  in  Poggen- 
dorf's  Annalen  der  Physik.  bd.  xxiv.,  s.  1—48,  and  also  his  Infusions- 
thierchen,  s.  121,  525,  and  Joh.  Miiller,  Physiologic  des  Menschen  (4te 
Aufl.,  1844),  bd.  i.,  s.  8-17.  It  appears  to  me  worthy  of  notice  that  one 
of  the  early  fathers  of  the  Church,  St.  Augiistino.  in  treating  of  the 
question  how  islands  may  have  been  covered  with  new  animals  and 
plants  after  the  flood,  shows  himself  in  no  way  disinclined  to  adopt  the 
view  of  the  so-called  "  spontaneous  generation"  (generatio  cpquivoca, 

P  2 


346  COSMOS. 

more  so,  as  Ehrenberg,  as  I  have  already  remarked,  has  dis- 
covered that  the  nebulous  dust  or  sand  which  mariners  often 
encounter  in  the  vicinity  of  the  Cape  Verd  Islands,  and  even 
at  a  distance  of  380  geographical  miles  from  the  African  shore, 
contains  the  remains  of  eighteen  species  of  sihcious-shelled  pol- 
ygastric  animalcules. 

Vital  organisms,  whose  relations  in  space  are  compris^ed  un- 
der the  head  of  the  geography  of  plants  and  animals,  may  be 
considered  either  according  to  the  difference  and  relative  num- 
bers of  the  types  (their  arrangement  into  genera  and  species), 
or  according  to  the  number  of  individuals  of  each  species  on  a 
given  area.  In  the  mode  of  life  of  plants  as  in  that  of  ani- 
mals, an  important  difference  is  noticed  ;  they  either  exist  in 
an  isolated  state,  or  live  in  a  social  condition.  Those  species 
of  plants  which  I  have  termed  social*  uniformly  cover  vast 
extents  of  land.  Among  these  we  may  reckon  many  of  the 
marine  Algae — Cladoniae  and  mosses,  which  extend  over  the 
desert  steppes  of  Northern  Asia — grasses,  and  cacti  growing 

spontanea  aut  primaria).  "  If,"  says  he,  "  animals  liave  not  been 
brought  to  remote  islands  by  angels,  or  perhaps  by  inhabitants  of  con 
tinents  addicted  to  the  chase,  they  must  have  been  spontaneously  pro- 
duced upon  the  earth ;  although  here  the  question  certainly  arises,  to 
what  purpose,  then,  were  animals  of  all  kinds  assembled  in  the  ark?" 
"  Si  e  terra  exortas  sunt  (bestise)  secundum  originem  primam,  quando 
dixit  Deus:  Producat  terra  animam  vivam !  multo  clarius  apparet,  non 
tam  reparandorum  animalium  causa,  quam  figurandarum  variarum  gen- 
tium (?)  propter  ecclesiee  sacramentum  in  area  fuisse  omnia  genera,  si  in 
insulis  quo  trausire  non  possent,  multa  animalia  terra  pi'oduxit."  Augus- 
tinus,  De  Civitate  Dei,  lib.  xvi.,  cap.  7  ;  Opera,  ed.  Monach.  Ordinis  S. 
Benedicti,  t.  vii.,  Venet.,  1732,  p.  422.  Two  centuries  before  the  time  of 
the  Bishop  of  Hippo,  we  find,  by  extracts  from  Trogus  Pompeius,  that 
the  generatio  primaria  was  brought  foi'ward  in  connection  with  the 
earliest  drying  up  of  the  ancient  world,  and  of  the  high  table-land  oi 
Asia,  precisely  in  the  same  manner  as  the  terraces  of  Paradise,  in  the 
theory  of  the  great  Linna-us,  and  in  the  visionary  hypotheses  entertain- 
ed in  the  eighteenth  century  regarding  the  fabled  Atlantis:  "Quod  si 
omnes  quondam  terrae  submersae  profundo  fuerunt,  profecto  editissi- 
mam  quamque  partem  decurrentibus  aquis  primum  detectam ;  humil- 
limo  autem  solo  eandem  aquam  diutissime  immoratam,  et  quanto  prior 
quteque  pars  terrarum  siccata  sit,  tanto  prius  animalia  generare  coepisse. 
Porro  Scythiam  adeo  editiorem  omnibus  terris  esse  ut  cuncta  flumina 
ibi  nata  in  Maeotium,  turn  delude  in  Ponticum  et  iEgyptium  mare  de- 
currant." — Justinus,  lib.  ii.,  cap.  1.  The  erroneous  supposition  that  the 
land  of  Scythia  is  an  elevated  table-land,  is  so  ancient  that  we  meet 
with  it  most  clearly  expressed  in  Hippocrates,  De  yEre  et  Aquis,  cap. 
6,  $  96,  Coray.  •'  Scythia,"  says  he,  "  consists  of  high  and  naked 
plains,  which,  without  being  crowned  with  mountains,  ascend  higher 
and  higher  toward  the  north." 

*  Humboldt,  Aphorismi  ex  Physiologia  Chemica  Plantarum,  in  the 
Flora  Fribergensis  Suhterranea,  1793,  {).  178. 


GEOGRAPHY    OF    PLANTS.  347 

together  like  the  pipes  of  au  organ — Avicenniae  and  mangroves 
in  the  tropics — and  forests  of  Coniferse  and  of  birches  in  the 
plains  of  the  Baltic  and  in  Siberia.  This  mode  of  geographical 
distribution  determines,  together  with  the  individual  form  of 
the  vegetable  world,  the  size  and  type  of  leaves  and  flowers, 
in  fact,  the  principal  physiognomy  of  the  district  ;*  its  charac- 
ter being  but  little,  if  at  all,  influenced  by  the  ever-moving 
forms  of  animal  life,  which,  by  their  beauty  and  diversity,  so 
powerfully  affect  the  feeHngs  of  man,  whether  by  exciting  the 
sensations  of  admiration  or  horror.  Agricultural  nations  in- 
crease artificially  the  predominance  of  social  plants,  and  thus 
augment,  in  many  parts  of  the  temperate  and  northern  zones, 
the  natural  aspect  of  uniformity  ;  and  while  their  labors  tend 
to  the  extirpation  of  some  wild  plants,  they  likewise  lead  to 
the  cultivation  of  others,  which  follow  the  colonist  in  his  most 
distant  migration.  The  luxuriant  zone  of  the  tropics  oflers 
the  strongest  resistance  to  these  changes  in  the  natural  distri- 
bution  of  vegetable  forms. 

Observers  who  in  short  periods  of  time  have  passed  over 
vast  tracts  of  land,  and  ascended  lofty  mountains,  in  which 
climates  were  ranged,  as  it  were,  in  strata  one  above  another, 
must  have  been  early  impressed  by  the  regularity  with  which 
vegetable  forms  are  distributed.  The  results  yielded  by  their 
observations  furnished  the  rough  materials  for  a  science,  to 
which  no  name  had  as  yet  been  given.  The  same  zones  or 
regions  of  vegetation  which,  in  the  sixteenth  century,  Cardinal 
Bembo,  when  a  youth,!  described  on  the  declivity  of  yEtna, 
were  observed  on  Mount  Ararat  by  Tournefort.  He  ingen- 
iously compared  the  Alpine  flora  with  the  flora  of  plains  situ- 
ated in  different  latitudes,  and  was  the  first  to  observe  the  in- 
fluence exercised  in  mountainous  regions,  on  the  distribution 
of  plants  by  the  elevation  of  the  ground  above  the  level  of 
the  sea,  and  by  the  distance  from  the  poles  in  flat  countries. 
Menzel,  in  an  inedited  work  on  the  flora  of  Japan,  accidental- 
ly m.ade  use  of  the  term  geography  of  plants  ;  and  the  same 
expression  occurs  in  the  fanciful  but  graceful  work  of  Ber- 
nardin  de  St.  Pierre,  Etudes  de  la  Nature.  A  scientific  treat- 
ment of  the  subject  began,  however,  only  when  tlie  geography 
of  plants  was  intimately  associated  with  the  study  of  the  dis- 

*  On  the  pbysiognomy  of  plants,  see  Humboldt,  Ansichten  der  Natur, 
bd.  ii.,  s.  1-125. 

t  ^ina  Dialogus.  Opuscula,  Basil.,  1556,  p.  53,  54.  A  very  beauti- 
ful geography  of  the  plants  of  Mount  ^tna  has  recently  been  published 
by  Philippi.     See  Linncea,  1832.  s.  733. 


348  COSMOS. 

tribution  of  heat  over  the  surface  of  the  earth,  and  when  the 
arrangement  of  vegetable  forms  in  natural  families  admitted 
of  a  numerical  estimate  being  made  of  the  different  forms 
which  increase  or  decrease  as  we  recede  from  the  equator  to- 
M^ard  the  poles,  and  of  the  relations  in  which,  in  different  parts 
of  the  earth,  each  family  stood  with  reference  to  the  whole 
mass  of  phanerogamic  indigenous  plants  of  the  same  region. 
I  consider  it  a  happy  circumstance  that,  at  the  time  during 
which  I  devoted  my  attention  almost  exclusively  to  botanical 
pursuits,  I  was  led  by  the  aspect  of  the  grand  and  strongly 
characterized  features  of  tropical  scenery  to  direct  my  investi- 
gations tov/ard  these  subjects. 

The  study  of  the  geographical  distribution  of  animals,  re- 
garding which  Bulibn  hrst  advanced  general,  and,  in  most 
instances,  very  correct  views,  has  been  considerably  aided  in 
its  advance  by  the  progress  made  in  modern  times  in  the 
geography  of  plants.  The  curves  of  the  isothermal  lines,  and 
more  especially  those  of  the  isochimenal  lines,  correspond  with 
the  limits  which  are  seldom  passed  by  certain  species  of  plants, 
and  of  animals  which  do  not  wander  far  from  their  fixed  hab- 
itation, either  with  respect  to  elevation  or  latitude.*     The 

*  [The  following  valuable  remarks  by  Professor  Forbes,  on  the  cor- 
respondence existing  between  the  distribution  of  existing  faunas  and 
floras  of  the  Bi'itish  Islands,  and  the  geological  changes  that  have  affect- 
ed their  ai-ea,  will  be  read  with  much  intei-est;  they  have  been  copied, 
by  the  author's  permission,  from  the  Survey  Report,  p.  16 : 

"  If  the  view  I  have  put  forward  respecting  the  origin  of  the  flora  of 
the  British  mountains  be  true — and  every  geological  and  botanical  prob- 
ability, so  far  as  the  area  is  concerned,  favors  it — then  must  we  endeav- 
or to  find  some  more  plausible  cause  than  any  yet  shown  for  the  pres- 
ence of  numerous  species  of  jilants,  and  of  some  animals,  on  the  higher 
parts  of  Alpine  ranges  in  Europe  and  Asia,  specifically  identical  with 
animals  and  plants  indigenous  in  regions  very  far  north,  and  not  found 
in  the  intermediate  lowlands.  Tournefort  first  remarked,  and  Hum- 
boldt, the  great  organizer  of  the  science  of  natural  history  geography, 
demonstrated,  that  zones  of  elevation  on  mountains  correspond  to  par 
allels  of  latitude,  the  higher  with  the  more  northern  or  southern,  as  the 
case  might  be.  It  is  well  known  that  this  correspondence  is  recogniz- 
ed in  the  ^enevaX  fades  of  the  flora  and  fauna,  dependent  on  generic 
con'espondences,  specific  representatives,  and,  in  some  cases,  specific 
identities.  But  when  announcing  and  illustrating  the  law  that  climatal 
zones  of  animal  and  vegetable  life  are  mutually  repeated  or  represented 
by  elevation  and  latitude,  naturalists  have  not  hitherto  sufliiciently  (if 
at  all)  distinguished  between  the  evidence  of  that  law,  as  exhibited  by 
representative  species  and  by  identical.  In  reality,  the  former  essen- 
tially depend  on  the  law,  the  latter  being  an  accident  not  necessarily 
dependent  upon  it,  and  which  has  hitherto  not  been  accounted  for.  In 
the  case  of  the  Alpine  flora  of  Britain,  the  evidence  of  the  activity  of 
thp  lavg,  and  the  influence  of  the  accident,  are  inseparable,  the  law  ho- 


FLORAS    OF    DIFFERENT    COUNTRIES.  349 

elk,  for  instance,  lives  in  the  Scandinavian  peninsula,  almost 
ten  degrees  further  north  than  in  the  interior  of  Siberia,  where 
the  line  of  equal  winter  temperature  is  so  remarkably  concave, 
Plants  migrate  in  the  germ  ;  and,  in  the  case  of  many  species, 
the  seeds  are  furnished  with  organs  adapting  them  to  be  con- 
veyed to  a  distance  through  the  air.  When  once  they  have 
taken  root,  they  become  dependent  on  the  soil  and  on  the 
strata  of  air  surrounding  them.  Animals,  on  the  contrary,  can 
at  pleasure  migrate  from  the  equator  toward  the  poles  ;  and 
this  they  can  more  especially  do  where  the  isothermal  lines 
are  much  inflected,  and  where  hot  summers  succeed  a  great 
degree  of  winter  cold.  The  royal  tiger,  which  in  no  respect 
diiiers  from  the  Bengal  species,  penetrates  every  summer  into 

ing  maintained  by  a  transported  flora,  for  the  transmission  of  which  I 
have  shown  we  can  not  account  by  an  appeal  to  unquestionable  geo- 
logical events.  In  the  case  of  the  Alps  and  Carpathians,  and  some  other 
mountain  I'anges,  we  find  the  law  maintained  partly  by  a  representa- 
tive flora,  special  in  its  region,  i.  e.,  by  specific  centers  of  their  own, 
and  partly  by  an  assemblage  more  or  less  limited  in  the  several  ranges 
of  identical  species,  these  latter  iu  several  cases  so  numerous  that  or- 
dinary modes  of  transpoi'tation  now  in  action  can  no  more  account  for 
their  presence  than  they  can  for  the  presence  of  a  Norwegian  flora  on 
the  British  mountains.  Now  I  am  prepared  to  maintain  that  the  same 
means  which  introduced  a  sub- Arctic  (now  mountain)  flora  into  Britain, 
acting  at  the  same  epoch,  originated  the  identity,  as  far  as  it  goes,  of 
the  Alpine  floras  of  Middle  Europe  and  Central  Asia;  for,  now  that  we 
know  the  vast  area  swept  by  the  glacial  sea,  including  almost  the  whole 
of  Central  and  Northern  Europe,  and  belted  by  land,  since  greatly  up- 
lifted, which  then  presented  to  the  water's  edge  those  climatal  condi- 
tions for  which  a  sub-Arctic  flora — destined  to  become  Alpine — was 
specially  organized,  the  difficulty  of  deriving  such  a  flora  from  its  par- 
ent north,  and  of  difi'iising  it  over  the  snowy  hills  bounding  this  glacial 
ocean,  vanishes,  and  the  presence  of  identical  species  at  such  distant 
points  remain  no  longer  a  mystery.  Moreover,  when  we  consider  that 
the  greater  part  of  the  northern  hemisphere  was  under  such  climatal 
conditions  during  the  epoch  referred  to,  the  undoubted  evidences  of 
which  have  been  made  known  in  Europe  by  numerous  British  and 
Continental  observers,  on  the  bounds  of  Asia  by  Sir  Roderick  Murchi- 
sou,  in  America  by  Mr.  Lyell,  Mr.  Logan,  Captain  Bayfield,  and  oth- 
ei's,  and  that  the  botanical  (and  zoological  as  well)  region,  essentially 
northern  and  Alpine,  designated  by  Professor  Schouw  that  *  of  saxi- 
frages and  mosses,'  and  first  in  his  classification,  exists  now  only  on 
the  flanks  of  the  great  area  which  suflered  such  conditions ;  and  that, 
though  similar  conditions  reappear,  the  relationship  of  Alpine  and  Ai'ctic 
vegetation  in  the  southern  hemisphere,  with  that  iu  the  northern,  is 
entirely  maintained  by  representative,  and  not  by  identical  species  (the 
representative,  too,  being  iu  great  part  generic,  and  not  specific),  the 
general  truth  of  my  explanation  of  Alpine  floras,  including  identical 
species, becomes  so  strong,  that  the  view  proposed  acquires  fair  claims 
to  be  ranked  as  a  theory,  and  not  considered  merely  a  convenient  or 
bold  hypothesis."] — Tr. 


350  COSMOS. 

the  north  of  Asia  as  far  as  the  latitudes  of  BerHii  and  Ham- 
burg, a  fact  of  which  Ehrenberg  and  myself  have;  spoken  in 
other  works.* 

The  grouping  or  association  of  different  vegetable  species, 
to  which  we  are  accustomed  to  apply  the  term  Floras,  do  not 
appear  to  me,  from  what  I  have  observed  in  different  portions 
of  the  earth's  surface,  to  manifest  such  a  predominance  of  in- 
dividual families  as  to  j  ustify  us  in  marking  the  geographical 
distinctions  between  the  regions  of  the  Umbellatee,  of  the  So- 
lidaginse,  of  the  Labiatse,  or  the  Scitaminese.  With  reference 
to  this  subject,  my  views  differ  from  those  of  several  of  my 
friends,  who  rank  among  the  most  distinguished  of  the  bota- 
nists of  Germany.  The  character  of  the  floras  of  the  elevated 
plateaux  of  Mexico,  New  Granada,  and  Quito,  of  European 
Russia,  and  of  Northern  Asia,  consists,  in  my  opinion,  not  so 
much  in  the  relatively  larger  number  of  the  species  presented 
by  one  or  two  natural  families,  as  in  the  more  complicated 
relations  of  the  coexistence  of  many  families,  and  in  the  rela- 
tive numerical  value  of  their  species.  The  Graminese  and 
the  Cyperacese  undoubtedly  predominate  in  meadow  lands 
and  steppes,  as  do  Coniferee,  Cupuliferae,  and  BetulineaB  in  our 
northern  woods  ;  but  this  predominance  of  certain  forms  is 
only  apparent,  and  owing  to  the  aspect  imparted  by  the  social 
plants.  The  north  of  Europe,  and  that  portion  of  Siberia 
which  is  situated  to  the  north  of  the  Altai  Mountains,  have 
no  greater  right  to  the  appellation  of  a  region  of  GramineEe 
and  Coniferse  than  have  the  boundless  llanos  between  the 
Orinoco  and  the  mountain  chain  of  Caraccas,  or  the  pine  for- 
ests of  Mexico.  It  is  the  coexistence  of  forms  which  may  par- 
tially replace  each  other,  and  their  relative  numbers  and  as- 
sociation, which  give  rise  either  to  the  general  impression  of 
luxuriance  and  diversity,  or  of  poverty  and  uniformity  in  the 
contemplation  of  the  vegetable  world. 

In  this  fragmentary  sketch  of  the  phenomena  of  organiza- 
tion, I  have  ascended  from  the  simplest  cellf — the  first  mani- 
festation of  life — progressively  to  higher   structures.      "  The 

*  Ehrenberg,  in  the  Annales  des  Sciences  Naturelles,  t.  xxi.,  p.  387 
412;  Humboldt,  Asie  Centrale,  t.  i.,  p.  339-342,  and  t.  iii.,  p.  .96-101 

t  Schleiden,  Ueber  die  Enhvicklungsiceise  der  Pfianzenzellen,  in  Miil 
ler's  Archiv  fur  Anatomic  und  Physiologic,  1838,  s.  137-176;  also  his 
Grundzuge  der  wissenschnftlichen  Botanik,  th.  i.,  s.  191,  and  th.  ii.,  s 
11.     Schwann,  Mikroscopische   Untersnchungcn  ubcr  die   Uehereinstim- 
mting  in  der  Struktur  und  dem  Wachsthiim  der  Thiere  und  PJlanze?i, 
1839,  s.  45,  220.     Compare  also,  on  similar  propagation,  .Toh.  Miillei- 
Physiologic  des  Mcnschcn,  1840    th.  ii.,  s.  614. 


MAN.  351 

association  of  mucous  granules  constitutes  a  definitely-formed 
cytoblast,  around  which  a  vesicular  membrane  forms  a  closed 
cell,"  this  cell  being  either  produced  from  another  pre-existing 
cell,*  or  being  due  to  a  cellular  formation,  which,  as  in  the 
case  of  the  fermentation-fungus,  is  concealed  in  the  obscurity 
of  some  unknown  chemical  process.!  But  in  a  work  like  the 
present  w^e  can  venture  on  no  more  than  an  allusion  to  the 
mysteries  that  involve  the  question  of  modes  of  origin  ;  the 
geography  of  animal  and  vegetable  organisms  must  limit  itself 
to  the  consideration  of  germs  already  developed,  of  their  hab- 
itation and  transplantation,  either  by  voluntary  or  involuntary 
migrations,  their  numerical  relation,  and  their  distribution 
over  the  surface  of  the  earth. 

The  general  picture  of  nature  which  I  have  endeavored  to 
delineate  would  be  incomplete  if  I  did  not  venture  to  trace  a 
few  of  the  most  marked  features  of  the  human  race,  considered 
with  reference  to  physical  gradations — to  the  geographical 
distribution  of  cotemporaneous  types — to  the  influence  exer- 
cised upon  man  by  the  forces  of  nature,  and  the  reciprocal, 
although  weaker  action  which  he  in  his  turn  exercises  on 
these  natural  forces.  Dependent,  although  in  a  lesser  degree 
than  plants  and  animals,  on  the  soil,  and  on  the  meteorolog- 
ical processes  of  the  atmosphere  with  which  he  is  surrounded 
— escaping  more  readily  from  the  control  of  natural  forces,  by 
activity  of  mind  and  the  advance  of  intellectual  cultivation, 
no  less  than  by  his  wonderful  capacity  of  adapting  himself  to 
all  climates — man  every  where  becomes  most  essentially  asso- 
ciated with  terrestrial  life.  It  is  by  these  relations  that  the 
obscure  and  much-contested  problem  of  the  possibility  of  one 
common  descent  enters  into  the  sphere  embraced  by  a  general 
physical  cosmography.  The  investigation  of  this  problem  will 
impart  a  nobler,  and,  if  I  may  so  express  myself,  more  purely 
human  interest  to  the  closing  pages  of  this  section  of  my  work. 

The  vast  domain  of  language,  in  whose  varied  structure  we 
see  mysteriously  reflected  the  destinies  of  nations,  is  most  inti- 
mately associated  with  the  affinity  of  races  ;  and  what  even 
slight  differences  of  races  may  effect  is  strikingly  manifested 
in  the  history  of  the  Hellenic  nations  in  the  zenith  of  their 
intellectual  cultivation.  The  most  important  questions  of  the 
civilization  of  mankind  are  connected  with  the  ideas  of  races, 

*  Schleiden,  Grundzuge  der  wissenschafilicken  Botanik,  1842,  th.  i., 
6.  192-197. 

t  [Oil  cellular  formation,  see  Henfrey's  Outlines  of  Structural  and 
Physiological  Botany,  op.  cit.,  p.  16-22.] — Tr. 


352  COSMOS. 

community  of  language,  and  adherence  to  one  original  direc- 
tion of  the  intellectual  and  moral  faculties. 

As  long  as  attention  was  directed  solely  to  the  extremes  in 
varieties  of  color  and  of  form,  and  to  the  vividness  of  the  first 
impression  of  the  senses,  the  observer  was  naturally  disposed 
to  regard  races  rather  as  originally  different  species  than  as 
mere  varieties.  The  permanence  of  certain  types*  in  the  midst 
of  the  most  hostile  influences,  especially  of  climate,  appeared 
to  favor  such  a  view,  notwithstanding  the  shortness  of  the  in- 
terval of  time  from  which  the  historical  evidence  was  derived. 
In  my  opinion,  however,  more  powerful  reasons  can  be  ad- 
vanced in  support  of  the  theory  of  the  unity  of  the  human 
race,  as,  for  instance,  in  the  many  intermediate  gradations! 
in  the  color  of  the  skin  and  in  the  form  of  the  skull,  which 
have  been  made  known  to  us  in  recent  times  by  the  rapid  prog- 
ress of  geographical  knowledge — the  analogies  presented  by 
the  varieties  in  the  species  of  many  wild  and  domesticated  ani- 
mals— and  the  more  correct  observations  collected  regarding 
the  limits  of  fecundity  in  hybrids. |  The  greater  number  of 
the  contrasts  which  were  formerly  supposed  to  exist,  have  dis- 
appeared before  the  laborious  researches  of  Tiedemann  on  the 
brain  of  negroes  and  of  Europeans,  and  the  anatomical  iiives- 

*  Tacitus,  in  his  speculations  on  the  inhabitants  of  Britain  (Agricola, 
cap.  ii.),  distinguishes  with  much  judgment  between  that  which  may 
be  owing  to  the  local  climatic  relations,  and  that  which,  in  the  imrai- 
gi'ating  races,  may  be  owing  to  the  michangeable  influence  of  a  hered- 
itary and  transmitted  type.  "  Britanniam  qui  mortales  initio  colueiaint, 
indigenai  an  advecti,  ut  inter  barbaros,  parum  compertum.  Habitus 
corpons  varii,  atque  ex  eo  ai'gumeuta  ;  namque  rutilae  Caledoniam  hab- 
itantium  coma;,  magni  artus  Germanicam  originem  adseverant.  Silu 
rum  colorati  vultus  et  torti  plerumque  crines,  etposita  contra  Hispania, 
Iberos  veteres  trajecisse,  easque  cedes  occupasse  fidem  faciunt:  proxi- 
mi  Gallis,  et  similes  sunt:  seu  durante  originis  vi ;  seu  procurrentibus 
in  diversa  terris,  positio  coeli  corporibus  habitum  dedit."  Regarding 
the  persistency  of  types  of  conformation  in  the  hot  and  cold  regions  of 
the  earth,  and  in  the  mountainous  districts  of  the  New  Continent,  see 
my  Relation  Historique,  t.  i.,  p.  498,  503,  and  t.  ii,,  p.  572,  574. 

t  On  the  Amei'icau  races  generally,  see  the  magnificent  work  of 
Samuel  George  Morton,  entitled  Crania  Americana,  1839,  p.  6'2,  8G ; 
and  on  the  skulls  brought  by  Pentland  from  the  highlands  of  Titicaca, 
see  the  Dublin  Journal  of  Medical  and  Chemical  Science,  vol.  v.,  1834, 
p.  475  ;  also  Alcide  d'Orbigny,  Vhommc  AyiUricain  consid6r6  sous  ses 
rapports  Physiol,  et  Mor.,  1839,  p.  221 ;  and  the  work  by  Prince  Maxi- 
milian of  Wied,  which  is  well  worthy  of  notice  for  the  admirable  ethno 
graphical  remarks  in  which  it  abounds,  entitled  Reise  in  das  Innere  von 
Nordamerika  (1839). 

X  Rudolph  Wagner,  Ueher  Dlaidlinge  und  Bastarderzeugnng,  in  his 
notes  to  the  German  translation  of  Prichard's  Physical  History  of  Man- 
kind,  vol.  i.,  p.  138-150. 


RACES.  353 

tigalions  of  Vrolik  and  Weber  on  the  form  of  the  pelvis.  On 
comparing  the  dark-colored  African  nations,  on  whose  physical 
history  the  admirable  work  of  Prichard  has  thrown  so  much 
light,  with  the  races  inhabiting  the  islands  of  the  South-In- 
dian and  West- Australian  archipelago,  and  with  the  Papuas 
and  Alfourous  (Haroforas,  Endamenes),  we  see  that  a  black 
skin,  woolly  hair,  and  a  negro-like  cast  of  countenance  are  not 
necessarily  connected  together.*  So  long  as  only  a  small  por- 
tion of  the  earth  was  known  to  the  Western  nations,  partial 
views  necessarily  predominated,  and  tropical  heat  and  a  black 
skin  consequently  appeared  inseparable.  "  The  Ethiopians," 
said  the  ancient  tragic  poet  Theodectes  of  Phaselis,!  "  are 
colored  by  the  near  sun-god  in  his  course  with  a  sooty  luster, 
and  their  hair  is  dried  and  crisped  with  the  heat  of  his  rays." 
The  campaigns  of  Alexander,  which  gave  rise  to  so  many  new 
ideas  regarding  physical  geography,  likewise  first  excited  a  dis- 
cussion on  the  problematical  influence  of  climate  on  races. 
"  Families  of  animals  and  plants,"  writes  one  of  the  greatest 
anatomists  of  the  day,  Johannes  Miiller,  in  his  noble  and  com- 
prehensive work,  Physiologie  cles  Menschen,  "  undergo,  within 
certain  limitations  peculiar  to  the  different  races  and  species, 
various  modifications  in  their  distribution  over  the  surface  of 
the  earth,  propagating  these  variations  as  organic  types  of  spe- 
cies.$     The  present  races  of  animals  have  been  produced  by 

*  Prichard,  op.  cit.,  vol.  ii.,  p.  324. 

t  Onesicritus,  in  Strabo,  xv.,  p.  690,  695,  Casaub.  Welcker,  Grie- 
chische  Tragodien,  abth.  iii.,  s.  1078,  conjectures  that  the  vei'ses  of 
Theodectes,  cited  by  Strabo,  are  taken  from  a  lost  tragedy,  which  prob- 
ably bore  the  title  of  "  Memnon." 

X  [In  illustration  of  this,  the  conclusions  of  Professor  Edward  Forbes 
respecting  the  origin  and  diffusion  of  the  British  flora  may  be  cited. 
See  the  Survey  Memoir  already  quoted,  On  the  Connection  between  the 
Distribution  of  the  existing  Fauna  and  Flora  of  the  British  Islands,  &c., 
p.  65.  *'  1.  The  flora  and  fauna,  terrestrial  and  marine,  of  the  British 
islands  and  seas,  have  originated,  so  far  as  that  area  is  concerned,  since 
the  meioceue  epoch.  2.  The  assemblages  of  animals  and  plants  com- 
posing that  fauna  and  flora  did  not  appear  in  the  area  they  now  inhabit 
simultaneously,  but  at  several  distinct  points  in  time.  3.  Both  the  fauna 
and  flora  of  the  British  islands  and  seas  are  composed  partly  of  species 
which,  either  permanently  or  for  a  time,  appeared  in  that  area  before 
the  glacial  epoch  ;  partly  of  such  as  inhabited  it  during  that  epoch ;  and 
in  great  part  of  those  which  did  not  appear  there  until  afterward,  and 
whose  appearance  on  the  earth  was  coeval  with  the  elevation  of  the 
bed  of  the  glacial  sea  and  the  consequent  climatal  changes.  4.  The 
greater  part  of  the  terrestrial  animals  and  flowering  plants  now  inhab- 
iting the  Bx'itish  islands  are  members  of  specific  centers  beyond  their 
area,  and  have  migrated  to  it  over  continuous  land  before,  duriag,  or 
after  the  glacial  epoch.     5.  The  climatal  conditions  of  the  area  under 


354  COSMOS. 

the  combined  action  of  many  different  internal  as  well  as  ex- 
ternal conditions,  the  nature  of  which  can  not  in  all  cases  be 
defined,  the  most  striking  varieties  being  found  in  those  fami- 
lies which  are  capable  of  the  greatest  distribution  over  the  sur- 
face of  the  earth.  The  difierent  races  of  mankind  are  forms 
of  one  sole  species,  by  the  union  of  two  of  whose  members 
descendants  are  propagated.  They  are  not  different  species 
of  a  genus,  since  in  that  case  their  hybrid  descendants  would 
remain  unfruitful.  But  whether  the  human  races  have  de- 
scended from  several  primitive  races  of  men,  or  from  one  alone, 
is  a  question  that  can  not  be  determined  from  experience."* 

Geographical  investigations  regarding  the  ancient  seat,  the 
so-called  cradle  of  the  human  race,  are  not  devoid  of  a  myth- 

discussiou,  and  north,  east,  and  west  of  it,  were  severer  during  the  gla 
cial  epoch,  when  a  gi'eat  part  of  the  space  now  occupied  by  tlie  British 
isles  was  under  water,  than  they  ai'e  now  or  were  before ;  but  there  is 
good  reason  to  believe  that,  so  far  from  those  conditions  having  contin- 
ued severe,  or  having  gradually  diminished  in  severity  southward  of 
Britain,  the  cold  region  of  tlie  glacial  epoch  came  directly  into  contact 
with  a  region  of  more  southern  and  thermal  character  than  that  in  which 
the  most  southern  beds  of  glacial  drift  are  now  to  be  met  with.  6.  This 
state  of  things  did  not  materially  differ  from  that  now  existing,  under 
corresponding  latitudes,  in  the  North  American,  Atlantic,  and  Arctic 
seas,  and  on  their  bounding  shores.  7.  The  Alpine  floras  of  Europe 
and  Asia,  so  far  as  they  are  identical  with  the  flora  of  the  Arctic  and 
sub-Arctic  zones  of  the  Old  World,  are  fragments  of  a  flora  which  was 
diffused  from  the  north,  either  by  means  of  transport  not  now  in  action 
3n  the  temperate  coasts  of  Europe,  or  over  continuous  land  which  no 
^onger  exists.  The  deep  sea  fiiuna  is  in  like  manner  a  fragment  of  the 
general  glacial  fauna.  8.  The  floras  of  the  islands  of  the  Atlantic  re- 
gion, between  the  Gulf-weed  Bank  and  the  Old  World,  are  fragments 
of  the  great  Mediterranean  flora,  anciently  diffused  over  a  land  consti- 
tuted out  of  the  upheaved  and  never  again  submerged  bed  of  the  (shal- 
low) Meiocene  Sea.  This  great  flora,  in  the  epoch  anterior  to,  and 
probably,  in  part,  during  the  glacial  period,  had  a  greater  extension 
northward  than  it  now  presents.  9.  The  termination  of  the  glacial 
epoch  in  Europe  was  marked  by  a  recession  of  an  Arctic  fauna  and  flora 
northward,  and  of  a  fauna  and  flora  of  the  Mediterranean  type  south- 
ward ;  and  in  the  interspace  thus  produced  there  appeared  on  land  the 
Germanic  fauna  and  flora,  and  in  the  sea  that  fauna  termed  Celtic. 
10.  The  causes  which  thus  preceded  the  appearance  of  a  new  assem- 
blage of  organized  beings  were  the  destruction  of  many  species  of  ani- 
mals, and  probably  also  of  plants,  either  forms  of  extremely  local  dis- 
tribution, or  such  as  were  not  capable  of  enduring  many  changes  of  con- 
ditions— species,  in  short,  with  very  limited  capacity  for  horizontal  or 
vertical  diffusion.  11.  All  the  changes  before,  during,  and  after  the 
glacial  epoch  appear  to  have  been  gradual,  and  not  sudden,  so  that  no 
marked  line  of  demarkation  can  be  drawn  between  the  creatures  in- 
habiting the  same  element  and  the  same  locality  during  two  proximate 
periods."] — Tr. 

*  Job.  M\ji[\er,Physiologie  des  Mensehen,  bd.  ii.,  s.  768. 


RACES.  355 

ical  character,  '*  We  do  not  know,''  says  Wilhelm  von  Hum- 
boldt, in  an  unpublished  work  On  the  Varieties  of  Languages 
and  Nations,  "  either  from  history  or  from  authentic  tradition, 
any  period  of  time  in  which  the  human  race  has  not  been 
divided  into  social  groups.  Whether  the  gregarious  condition 
was  original,  or  of  subsequent  occurrence,  we  have  no  historic 
evidence  to  show.  The  separate  mythical  relations  found  to 
exist  independently  of  one  another  in  different  parts  of  the 
earth,  appear  to  refute  the  first  hypothesis,  and  concur  in 
ascribing  the  generation  of  the  whole  human  race  to  tlie  union 
of  one  pair.  The  general  prevalence  of  this  myth  has  caused 
it  to  be  regarded  as  a  traditionary  record  transmitted  from 
the  primitive  man  to  his  descendants.  But  this  very  circum- 
stance seems  rather  to  prove  that  it  has  no  historical  foiuida- 
tion,  but  has  simply  arisen  from  an  identity  in  the  mode  of 
intellectual  conception,  which  has  CA^ery  where  led  man  to 
adopt  the  same  conclusion  regarding  identical  phenomena  ;  in 
the  same  manner  as  many  myths  have  doubtlessly  arisen,  not 
from  any  historical  connection  existing  between  them,  but 
rather  from  an  identity  in  human  thought  and  imagination. 
Another  evidence  in  favor  of  the  purely  mythical  nature  of 
this  belief  is  afforded  by  the  fact  that  the  first  origin  of  man- 
kind— a  phenomenon  which  is  wholly  beyond  the  sphere  of 
experience — is  explained  in  perfect  conformity  with  existing 
views,  being  considered  on  the  principle  of  the  colonization  of 
some  desert  island  or  remote  mountainous  valley  at  a  period 
when  mankind  had  already  existed  for  thousands  of  years.  It 
is  in  vain  that  we  direct  our  thoughts  to  the  solution  of  the 
great  problem  of  the  first  origin,  since  man  is  too  intimately 
associated  with  his  own  race  and  with  the  relations  of  time 
to  conceive  of  the  existence  of  an  individual  independently  of 
a  preceding  generation  and  age.  A  solution  of  those  difficult 
questions,  which  can  not  be  determined  by  inductive  vea5:oning 
or  by  experience — whether  the  belief  in  this  presumed  tradi- 
tional condition  be  actually  based  on  historical  evidence,  or 
whether  mankind  inhabited  the  earth  in  gregarious  associa- 
tions from  the  origin  of  the  race — can  not,  therefore,  be  de- 
termined from  philological  data,  and  yet  its  elucidation  ought 
not  to  be  sought  from  other  sources." 

The  distribution  of  mankind  is  therefore  only  a  distribution 
into  varieties,  which  are  commonly  designated  by  the  some- 
what indefinite  term  races.  As  in  the  vegetable  kingdom, 
and  in  the  natural  history  of  birds  and  fishes,  a  classification 
into  many  small  families  is  based  on  a  surer  foundation  than 


356  (josMOS. 

where  large  sections  are  separated  into  a  few  but  large  divi- 
sions ;  so  it  also  appears  to  me,  that  in  the  determination  of 
races  a  preference  should  be  given  to  the  establishment  of 
small  families  of  nations.  Whether  we  adopt  the  old  classi- 
fication of  my  master,  Blumenbach,  and  a.dmit  Jive  races  (the 
Caucasian,  Mongolian,  American,  Ethiopian,  and  Malayan), 
or  that  of  Prichard,  into  seve7i  races*  (the  Iranian,  Turanian, 
American,  Hottentots  and  Bushmen,  Negroes,  Papuas,  and 
Alfourous),  we  fail  to  recognize  any  typical  sharpness  of  def- 
inition, ^or  any  general  or  well-established  principle  in  the  di- 
vision of  these  groups.  The  extremes  of  form  and  color  are 
certainly  separated,  but  without  regard  to  the  races,  which 
can  not  be  included  in  any  of  these  classes,  and  which  have 
been  alternately  termed  Scythian  and  Allophyllic.  Iranian  is 
certainl}*  a  less  objectionable  term  for  the  European  nations 
than  Caucasian ;  but  it  may  be  maintained  generally  that 
geographical  denominations  are  very  vague  when  used  to  ex- 
press the  points  of  departure  of  races,  more  especially  where 
the  country  which  has  given  its  name  to  the  race,  as,  for  in- 
stance, Turau  (Mawerannahr),  has  been  inhabited  at  differ- 
ent periods!  by  Indo-Germanic  and  Finnish,  and  not  by  Mon- 
golian tribes. 

*  Prichard,  op.  cit.,  vol.  i.,  p.  247. 

t  The  late  arrival  of  tlie  Turkish  and  Mongolian  tribes  on  the  Oxua 
and  on  the  Kirghis  Steppes  is  opposed  to  the  hypothesis  of  Niebuhr, 
accordhig  to  which  the  Scythians  of  Herodotus  and  Hippocrates  were 
Mongolians.  It  seems  far  more  probable  that  the  Scythians  (Scoloti) 
should  be  referred  to  the  Indo-Germanic  Massage t<e  (Alani).  The 
Mongolian,  true  Tartars  (the  latter  term  was  afterward  falsely  given  to 
purely  Turkish  tribes  in  Russia  and  Sibei'ia),  were  settled,  at  that  pe- 
riod, far  in  the  eastern  part  of  Asia.  See  my  Asie  Centrale,  t.  i.,  p.  239, 
400  ;  Examen  Critique  de  VHistoire  de  la  Giogr.,  th.  ii.,  p.  320.  A  dis- 
tinguished philologist,  Professor  Buschmann,  calls  attention  to  the  cir- 
cumstance that  the  poet  Firdousi,  in  his  half-mythical  prefatory  remarks 
in  \\ie  Schahnameh,  mentions  "a  fortress  of  the  Alani''  on  the  sea-shore, 
in  which  Selm  took  refuge,  this  prince  being  the  eldest  son  of  the 
King  Feriduu,  who  in  all  probability  lived  two  hundred  years  before 
Cyrus.  The  Kirghis  of  the  Scythian  steppe  were  originally  a  E'innish 
tribe  ;  their  three  hordes  probably  constitute  in  the  present  day  the 
most  numerous  nomadic  nation,  and  their  tribe  dwelt,  in  the  sixteenth 
century,  in  the  same  steppe  in  which  I  have  myself  seen  them.  The 
Byzantine  Menander  (p.  380-382,  ed.  Nieb.)  expressly  states  that  the 
Chacan  of  the  Turks  (Thu-Khiu),  in  5G9,  made  a  present  of  a  Kirghis 
slave  to  Zemarchus,  the  embassador  of  Justinian  II. ;  he  terms  her  a 
X^PXk )  tiiid.  we  find  in  Abulgasi  {Historia  MongoJorum  el  Tataroruni) 
that  the  Kirghis  are  called  Kirkiz.  Similarity  of  manners,  where  the 
nature  of  the  country  determines  the  i)rincipal  characteristics,  is  a  very 
uncertain  evidence  of  identity  of  race.  The  life  of  the  steppes  pro- 
duces among  the  Turks  (Ti  Tukiu),  the  Baschkirs  (Fins),  the  Kirghis, 


LANGUAGE.  357 

Larguages,  as  intellectual  creations  of  man,  and  as  closely- 
interwoven  with  the  development  of  mind,  are,  independently 
of  the  national  form  which  they  exhibit,  of  the  greatest  im- 
portance in  the  recognition  of  similarities  or  differences  in 
races.  This  importance  is  especially  owing  to  the  clew  which 
a  community  of  descent  affords  in  treading  that  mysterious 
^abyrinth  in  which  the  connection  of  physical  powers  and  in- 
tellectual forces  manifests  itself  in  a  thousand  different  forms. 
The  brilliant  progress  made  within  the  last  half  century,  in 
Germany,  in  philosophical  philology,  has  greatly  facilitated 
our  investigations  into  the  national  character*  of  languages 
and  the  influence  exercised  by  descent.  But  here,  as  in  all 
domams  of  ideal  speculation,  the  dangers  of  deception  are 
closely  linked  to  the  rich  and  certain  profit  to  be  derived. 

Positive  ethnographical  studies,  based  on  a  thorough  knowl- 
edge of  history,  teach  us  that  much  caution  should  be  applied 
in  entering  into  these  comparisons  of  nations,  and  of  the  lan- 
guages employed  by  them  at  certain  epochs.  Subjection, 
long  association,  the  influence  of  a  foreign  religion,  the  blend- 
ing of  races,  even  when  only  including  a  small  number  of  the 
more  influential  and  cultivated  of  the  immigrating  tribes, 
have  produced,  in  both  continents,  similarly  recurring  phenom- 
ena ;  as,  for  instance,  in  introducing  totally  different  families 
of  languages  among  one  and  the  same  race,  and  idioms,  having 
one  common  root,  among  nations  of  the  most  different  origin. 
Great  Asiatic  conquerors  have  exercised  the  most  powerful 
influence  on  phenomena  of  this  kind. 

But  language  is  a  part  and  parcel  of  the  history  of  the  de- 
velopment of  mind  ;  and,  however  happily  the  human  intel- 
lect, under  the  most  dissimilar  physical  conditions,  may  unfet- 
tered pursue  a  self-chosen  track,  and  strive  to  free  itself  from 
the  dominion  of  terrestrial  influences,  this  emancipation  is 
never  perfect.  There  ever  remains,  in  the  natural  capacities 
of  the  mind,  a  trace  of  something  that  has  been  derived  from 
the  influences  of  race  or  of  cUmate,  whether  they  be  associated 
with  a  land  gladdened  by  cloudless  azure  skies,  or  with  the 
vapory  atmosphere  of  an  insular  region.  As,  therefore,  rich- 
ness and  grace  of  language  are  unfolded  from  the  most  luxu- 

the  Torgodi  and  Dsungari  (Mongoliaus),  the  same  habits  of  nomadic 
Hfe,  and  the  same  use  of  felt  tents,  carried  on  wagons  and  pitched 
among  herds  of  cattle. 

*  Wilhelm  von  Humboldt,  Ueher  die  Verschiedenheit  der  menschlichen 
Sprachbaues,  in  his  great  work  Ueher  die  KawiSprache  auf  der  Insd 
Java,  bd.  i.,  s.  xxi.,  xlviii.,  and  ccxiv. 


Sbb  COSMOS. 

riant  depths  of  thought,  we  have  been  unwiUing  wholly  to 
disregard  the  bond  which  so  closely  links  together  the  physical 
world  with  the  sphere  of  intellect  and  of  the  feelings  by  de- 
priving this  general  picture  of  nature  of  those  brighter  lights 
and  tints  which  may  be  borrowed  from  considerations,  however 
slightly  indicated,  of  the  relations  existing  between  races  and 
languages. 

While  we  maintain  the  unity  of  the  human  species,  we  at 
the  same  time  repel  the  depressing  assumption  of  superior 
and  inferior  races  of  men.^  There  Tire  nations  more  sus- 
ceptible of  cultivation,  more  highly  civilized,  more  ennobled 
by  mental  cultivation  than  others,  but  none  in  themselves  no- 
bler than  others.  All  are  in  like  degree  designed  for  freedom  ; 
a  freedom  which,  in  the  ruder  conditions  of  society,  belongs 
only  to  the  individual,  but  which,  in  social  states  enjoying  po- 
litical institutions,  appertains  as  a  right  to  the  whole  body 
of  the  community.  "  If  we  would  indicate  an  idea  which, 
throughout  the  whole  course  of  history,  has  ever  more  and 
more  widely  extended  its  empire,  or  which,  more  than  any 
other,  testifies  to  the  much-contested  and  still  more  decidedly 
misunderstood  perfectibility  of  the  whole  human  race,  it  is 
that  of  establishing  our  common  humanity — of  striving  to  re- 
move the  barriers  which  prejudice  and  limited  views  of  every 
kind  have  erected  among  men,  and  to  treat  all  mankind,  with- 
out reference  to  religion,  nation,  or  color,  as  one  fraternity,  one 
great  community,  fitted  for  the  attainment  of  one  object,  the 
unrestrained  development  of  the  physical  powers.  This  is  the 
ultimate  and  highest  aim  of  society,  identical  with  the  direc- 
tion implanted  by  nature  in  the  mind  of  man  toward  the  in- 
definite extension  of  his  existence.  He  regards  the  earth  in 
all  its  limits,  and  the  heavens  as  far  as  his  eye  can  scan  their 
bright  and  starry  depths,  as  inwardly  his  own,  given  to  him 
as  the  objects  of  his  contemplation,  and  as  a  field  for  the  de- 
velopment of  his  energies.  Even  the  child  longs  to  pass  the 
hills  or  the  seas  which  inclose  his  narrow  home  ;  yet,  when 
his  eager  steps  have  borne  him  beyond  those  limits,  he  pines, 
like  the  plant,  for  his  native  soil  ;  and  it  is  by  this  touching 
and  beautiful  attribute  of  man — this  longing  for  that  which 
is  unknown,  and  this  fond  remembrance  of  that  which  is  lost 
— that  he  is  spared  from  an  exclusive  attachment  to  the  pres- 

*  The  very  cheerless,  and,  in  recent  times,  too  often  discussed  doc- 
trine of  the  unequal  rights  of  men  to  freedom,  and  of  slaveiy  as  an  in- 
stitution in  conformity  with  nature,  is  unhappily  found  most  systematic 
ally  developed  in  Aristotle's  Politica,  i.,  3,  5,  6. 


CONCLUSION    OF    THE    SUBJECT.  3? 

ent.  Thus  deeply  rooted  in  the  innermost  nature  of  man,  anu 
even  enjoined  upon  him  by  his  highest  tendencies,  the  recog- 
nition of  the  bond  of  humanity  becomes  one  of  the  noblest 
leading  principles  in  the  history  of  mankind. "=^ 

With  these  words,  which  draw  their  charm  from  the  depths 
of  feeling,  let  a  brother  be  permitted  to  close  this  general  de- 
scription of  the  natural  phenomena  of  the  universe.  From  the 
remotest  nebulse  and  from  the  revolving  double  stars,  we  have 
descended  to  the  minutest  organisms  of  animal  creation,  wheth- 
er manifested  in  the  depths  of  ocean  or  on  the  surface  of  our 
globe,  and  to  the  delicate  vegetable  germs  which  clothe  the 
naked  declivity  of  the  ice-crowned  mountain  summit  ;  and 
here  we  have  been  able  to  arrange  these  phenomena  accord- 
ing to  partially  known  laws  ;  but  other  laws  of  a  more  mys- 
terious nature  rule  the  higher  spheres  of  the  organic  world,  in 
which  is  comprised  the  human  species  in  all  its  varied  con- 
formation, its  creative  intellectual  power,  and  the  languages 
to  which  it  has  given  existence.  A  physical  delineation  of 
nature  terminates  at  the  point  where  the  sphere  of  intellect 
begins,  and  a  new  world  of  mind  is  opened  to  our  view.  It 
marks  the  limit,  but  does  not  pass  it. 

*  Wilhelm  vou  Humboldt,  Ueber  die  Kawi-Sprache,  bd.  iii.,  s.  426. 
I  subjoin  the  following  extract  from  this  work :  "  The  impetuous  con- 
quests of  Alexander,  the  more  politic  and  premeditated  extension  of 
territory  made  by  the  Romans,  the  wild  and  cruel  incursions  of  the 
Mexicans,  and  the  despotic  acquisitions  of  the  incas,  have  in  both  hemi- 
spheres contributed  to  put  an  end  to  the  separate  existence  of  many 
tribes  as  independent  nations,  and  tended  at  the  same  time  to  establish 
more  extended  international  amalgamation.     Men  of  great  and  strong 
minds,  as  well  as  w^hole  nations,  acted  under  the  influence  of  one  idea, 
the  purity  of  which  was,  however,  utterly  unknown  to  them.     It  was 
Christianity  which  first  promulgated  the  truth  of  its  exalted  charity, 
although  the  seed  sown  yielded  but  a  slow  and  scanty  harvest.     Before 
the  religion  of  Christ  manifested  its  form,  its  existence  was  only  re- 
vealed by  a  faint  foreshadowing  presentiment.     In  recent  times,  the 
idea  of  civilization  has  acquired  additional  intensity,  and  has  given  rise 
to  a  desire  of  extending  more  widely  the  relations  of  national  inter- 
course and  of  intellectual  cultivation ;  even  selfishness  begins  to  learn 
that  by  such  a  course  its  interests  will  be  better  served  than  by  violent 
and  forced  isolation.    Language,  more  than  any  other  attribute  of  man- 
kind, binds  together  the  whole  human  race.     By  its  idiomatic  proper 
\ie3  it  certainly  seems  to  separate  nations,  but  the  reciprocal  under 
itanding  of  foreign  languages  connects  men  together,  on  the  other  hand 
without  injuring  individual  national  characteristics." 


ADDITIONAL  NOTES 

TO    THE    PRESENT    EDITION.       MARCH,    1849. 


Gigantic  Birds  of  New  Zealand. — Vol.  i.,  p.  287. 

Au  extensive  and  highly  interesting  collection  of"  bones,  referrible  to 
several  species  of  the  Moa  (  Dinomis  of  Owen),  and  to  three  or  four  other 
genera  of  birds,  formed  by  Mr.  Walter  Mantell,  of  Wellington,  New  Zea- 
land, has  recently  arrived  in  England,  and  is  now  deposited  in  the  Brit- 
ish Museum.  This  series  consists  of  between  700  and  800  specimens, 
belonging  to  different  parts  of  the  skeletons  of  many  individuals  of 
various  sizes  and  ages.  Some  of  the  largest  vertebrae,  tibiae,  and  fem- 
ora equal  in  magnitude  the  most  gigantic  previously  knowni,  while  oth- 
ers are  not  larger  than  the  corresponding  bones  of  the  living  apteryx. 
Among  these  relics  are  the  skulls  and  mandibles  of  two  genera,  the  Di- 
nornis  and  Palapteryx ;  and  of  an  extinct  genus,  Notornis,  allied  to  the 
Rallidce ;  and  the  mandibles  of  a  species  of  Nestor,  a  genus  of  nocturu 
al  owl-like  parrots,  of  which  only  two  living  species  are  known.* 

These  osseous  remains  are  in  a  very  different  state  of  preservation 
from  any  pre\4ously  received  from  New  Zealand;  they  are  light  and 
porous,  and  of  a  light  fawn-color ;  the  most  delicate  processes  are  en 
tire,  and  the  articulating  surfaces  smooth  and  uninjured;  fragments  of 
egg-shells,  and  even  tlie  bony  i-ings  of  the  trachea  and  air  tubes,  are  pre- 
served. 

The  bones  were  dug  up  by  Mr.  Walter  Mantell  from  a  bed  of  marly 
sand,  containing  magnetic  iron,  crystals  of  hornblende  and  augite,  and 
the  detritus  of  augitic  rocks  and  earthy  volcanic  tuff.  This  sand  had 
filled  up  all  the  cavities  and  cancelli,  but  was  in  no  instance  consoli- 
dated or  aggregated  together;  it  was,  therefore,  easily  removed  by  a 
soft  brush,  and  the  bones  perfectly  cleared  without  injury. 

The  spot  whence  these  precious  relics  of  the  colossal  birds  that  once 
inhabited  the  islands  of  New  Zealand  were  obtained,  is  a  flat  tract  of 
land,  near  the  embouchure  of  a  river,  named  Waingongoro,  not  far  from 
Wanganui,  which  has  its  rise  in  the  volcanic  regions  of  Mount  Egmont. 
The  natives  atfirm  that  this  level  tract  was  one  of  the  places  first  dwelt 
upon  by  their  remote  ancestors ;  and  this  tradition  is  corroborated  by 
the  existence  of  numerous  heaps  and  pits  of  ashes  and  charred  bones, 
indicating  ancient  fires,  long  burning  on  the  same  spoL  In  these  fire- 
heaps  Mr.  Mantell  found  burned  bones  of  men,  moas,  and  dogs. 

The  fragments  of  egg-sliells,  imbedded  in  the  ossiferous  deposits,  had 
escaped  the  notice  of  all  previous  naturalists.  They  are,  unfortunately, 
very  small  portions,  the  lai'gest  being  only  four  inches  long,  but  they 
afford  a  chord  by  which  to  estimate  the  size  of  the  original.  Mr.  Man- 
tell observes  that  the  egg  of  the  Moa  must  have  been  so  large  that  a 
hat  would  form  a  good  egg-cup  for  it.  These  relics  evidently  belong 
to  two  or  moi-e  species,  perhaps  genera.     In  some  examples  the  ex- 

*  See  Professor  Owen's  Memoir  on  these  fossil  remains,  in  Zoological  TVansat^ 
tions.  1848 

Vol.  1.— Q 


S6ti  ADDITIONAL    IVOTES. 

tenml  siirlace  is  sujoutb :  iu  others  it  is  marked  with  short  intercepred 
linear  grooves,  resembhng  the  eggs  of  some  of  the  Struthionidie,  but 
distinct  from  all  known  recent  types.  In  this  valuable  collection  only 
one  boue.oFa  mammal  has  been  detected,  namely,  the  femur  of  a  dog. 
An  interesting  memoir  on  the  probable  geological  position  and  age 
of  the  ornithic  bone  deposits  of  New  Zealand,  by  Dr.  Mantell,  based 
on  the  observations  of  his  entei'prising  son,  is  published  in  the  Quarter- 
ly Journal  of  the  Geological  Society  of  London  ( 1848).  It  appears  that 
in  many  instances  the  bones  are  imbedded  iu  sand  and  clay,  which  lie 
beneath  a  thick  deposit  of  volcanic  detritus,  and  rest  on  an  argillaceous 
stratum  abounding  in  marine  shells.  The  specimens  found  in  the  rivers 
and  streams  have  been  washed  out  of  their  banks  by  the  currents  which 
now  flow  through  channels  from  ten  to  thirty  feet  deep,  formed  in  the 
more  ancient  alluvial  soil.  Dr.  Mantell  concludes  that  the  islands  of 
New  Zealand  wei'e  densely  peopled  at  a  period  geologically  recent, 
though  historically  remote,  by  tribes  of  gigantic  brevi-peunate  birds 
allied  to  the  ostrich  tribe,  all,  or  almost  all,  of  species  and  genera  now 
extinct;  and  that,  subsequently  to  the  formation  of  the  most  ancient 
ornithic  deposit,  the  sea-coast  has  been  elevated  from  fifty  to  one  hund- 
red feet  above  its  original  level ;  hence  the  terraces  of  shingle  and 
loam  which  now  skirt  the  maritime  districts.  The  existing  rivers  and 
mountain  torrents  flow  in  deep  gulleys  which  they  have  eroded  in  the 
course  of  centuries  in  these  pleistocene  strata,  in  like  manner  as  the 
river  couises  of  Auvergne,  in  Central  France,  are  excavated  in  the 
mammiferous  tertiary  deposits  of  that  country.  The  last  of  the  gigantic 
birds  were  probably  exterminated,  like  the  dodo,  by  human  agency; 
some  small  species  allied  to  the  apteryx  may  possibly  be  met  with  in 
the  unexplored  parts  of  the  middle  island. 

The  Dodo. — A  most  valuable  and  highly  interesting  history  of  the 
dodo  and  its  kindred*  has  recently  appeared,  in  which  the  history, 
affinities,  and  osteology  of  the  Dodo,  Solitaire,  and  other  extinct  birds 
of  the  islands  Mauritius,  Rodriguez,  and  Bourbon  are  admirably  eluci- 
dated by  H.  G.  Strickland  (of  Oxford),  and  Dr.  G.  A.  Melville.  The 
historical  part  is  by  the  former,  the  osteological  and  physiological  por- 
tion by  the  latter  eminent  anatomist.  We  would  earnestly  recommend 
the  reader  interested  in  the  most  perfect  history  that  has  ever  appear- 
ed, of  the  extinction  of  a  race  of  large  animals,  of  which  thousands  ex- 
isted but  three  centuries  ago,  to  refer  to  the  original  work.  We  have 
only  space  enough  to  state  that  the  authors  have  proved,  upon  the  most 
incontrovertible  evidence,  that  the  dodo  was  neither  a  vulture,  ostrich, 
nor  galline,  as  previous  anatomists  supposed,  but  a  frugiveroics  pigeon. 

*  T%e  Dodo  and  its  Kindred.  By  Messrs.  Strickland  and  Melville.  1  vol.  4to 
with  numerous  plates.    Reeves,  London,  1848. 


INDEX  TO  VOL.  I. 


ABicH,  Hermana,  structxiral  relations  of 
volcanic  rocks,  234. 

Acosta,  Joseph  de,  Historia  Natural  de  las 
Indias,  66,  193. 

Adams,  Mr.,  planet  Neptune.  See  note 
by  Translator,  90,  91. 

^gos  Potamos,  on  the  aerolite  of,  117, 
122. 

iElian  on  Mount  ^tna,  227. 

Aerolites  (shooting  stars,  meteors,  mete- 
oric stones,  fire-balls,  &.c.),  general  de- 
scription of,  111-137;  physical  charac- 
ter, 112-123 ;  dates  of  remarkable  falls, 
114,  115  ;  their  planetary  velocity,  116- 
120;  ideas  of  the  ancients  on,  115, 116; 
November  and  August  periodic  falls  of 
shooting  stars,  118-120,  124-126;  their 
direction  from  one  point  in  the  heav- 
ens, 120  ;  altitude,  120 ;  orbit,  127 ;  Chi- 
nese notices  of,  128  ;  media  of  commu- 
nication with  other  planetary  bodies, 
136 ;  their  essential  difierence  from 
comets,  137;  specific  weights,  116,  117; 
large  meteoric  stones  on  record,  117 ; 
chemical  elements,  117, 129-131 ;  crust, 
129,  130 ;  deaths  occasioned  by,  135. 

.a^schylus,  "  Prometheus  Delivered,"  115. 

JEtna,  Mount,  its  elevation,  28,  229 ;  sup- 
posed extinction  by  the  ancients,  227; 
its  eruptions  from  lateral  fissures,  229  ; 
similarity  of  its  zones  of  vegetation  to 
those  of  Ararat,  347. 

Agassiz,  Researches  on  Fossil  Fishes,  46, 
27.3-277. 

Alexander,  influence  of  his  campaigns  on 
physical  science,  353. 

Alps,  the,  elevation  of,  28,  29. 

Amber,  researches  on  its  vegetable  origin, 
284  ;  Goppert  on  the  ambor-tree  of  the 
ancient  world  (Pinites  succifer),  283. 

Ampere,  Andr6  Marie,  58,  193,  236. 

Anaxagoras  on  aerolites,  122  ;  on  the  sur- 
rounding ether,  134. 

Andes,  the,  their  altitude,  &c.  See  Cor- 
dilleras. 

Anghiera,  Peter  Martyr  de,  remarked  that 
the  palmeta  and  pineta  were  found  as- 
sociated together,  282,  283 ;  fii-st  recog- 
nized (1510)  that  the  limit  of  perpetual 
snow  continues  to  ascend  as  we  ap- 
proach the  equator,  329. 

Animal  life,  its  universality,  342-345;  as 
viewed  with  microscopic  powers  of  vis- 
ion, 341-346 ;  rapid  propagation  and  te- 
nacity of  life  in  animalcules,  344-346; 
geography  of,  341-346. 

Anning,  Miss  Mary,  discovery  of  the  ink 
bag  of  the  sepia,  and  of  coprolitee  of 


fish,  in  the  lias  of  Lyme  Regis,  871, 

272. 

Ansted's,  D.  T.,  "Ancient  World."  Sea 
notes  by  Translator,  271,  272,  274,  281 
287. 

Apian,  Peter,  on  comets,  101. 

Apollonius  Myndius,  described  the  patha 
of  comets,  103. 

Arago,  his  ocular  micrometer,  39  ;  chro- 
matic polarization,  52 ;  optical  consid- 
erations, 85 ;  on  comets,  99-106 ;  polar- 
ization experiments  on  the  light  of  com- 
ets, 105;  aerolites,  114;  on  the  Novem- 
ber fall  of  meteors,  124  ;  zodiacal  light, 
143;  raotion  of  the  solar  system,  146, 
147 ;  on  the  increase  of  heat  at  increas- 
ing depths,  173,  174  ;  magnetism  of  ro- 
tation, 179, 180 ,  horary  observations  of 
declination  at  Paris  compared  with  si- 
multaneous perturbations  at  Kasan, 
191 ;  discovery  of  the  influence  of  mag- 
netic storms  on  the  course  of  the  nee- 
dle, 194, 195 ;  on  south  polar  bands,  198 ; 
on  terrestrial  light,  202;  phenomenon 
of  supplementaiy  rainbows,  220 ;  ob- 
served the  deepest  Artesian  wells  to  be 
the  warmest,  223 ;  explanation  of  the 
absence  of  a  refrigeration  of  tempera- 
ture in  the  lower  strata  of  the  Mediter- 
ranean, 303 ;  observations  on  the  mean 
annual  quantity  of  rain  in  Paris,  333 ; 
his  investigations  on  the  evolution  of 
lightning,  337. 

Argelander  on  the  comet  of  1811, 109 ;  on 
the  motion  of  the  solar  system,  146, 149 ; 
on  the  hght  of  the  Aurora,  195,  196. 

Aristarchus  of  Samos,  the  pioneer  of  the 
Copernican  system,  65. 

Aristotle,  65 ;  his  definition  of  Cosmos,  69 ; 
use  of  the  terra  history,  75 ;  on  comets, 
103,  104 ;  on  the  Ligyan  field  of  stones, 
115;  aerolites,  122;  on  the  stone  of  ^Egos 
Potamos,  135  ;  aware  that  noises  some- 
times existed  without  earthquakes,  209 ; 
his  account  of  the  upheavals  of  islands 
of  eruption,  241 ;  "  spontaneous  mo- 
tion," 341 ;  noticed  the  redness  assum- 
ed by  long  fallen  snow,  344. 

Artesian  wells,  temperature  of,  174,  223. 

Astronomy,  results  of,  38-40 ;  phenomena 
of  physical  astronomy,  43,  44. 

Atmosphere,  the,  general  description  of, 
311,  316 ;  its  composition  and  admix- 
ture, 312;  variation  of  pressure,  31^ 
317;  climatic  distribution  of  heat,  313, 
317-328 ;  distribut  on  of  humidity,  313, 
328,  a34;  electric  condition,  314,  a'Cv 

3:}8. 


36i 


COSiMOS 


August,  his  pHychrometer,  332. 

Augustine,  St.,  his  views  on  spontaneous 
generation,  345,  346. 

\urora  Borealis.  general  description  of, 
193-202;  origin  and  course,  195,  196; 
altitude,  199 ;  brilliancy  coincident  with 
the  fall  of  shooting  stars,  126,  127; 
whether  attended  with  crackling  sound, 
199  200;  intensity  of  its  light,  201. 

Bacon,  Lord,  53,  58 ;  Novum  Organon, 
290. 

Baer,  Von,  337. 

Barometer,  the,  increase  of  its  height,  at- 
tended by  a  depression  of  the  level  of 
the  sea,  298 ;  horary  oscillations  of,  314, 
315. 

Batten,  Mr.,  letter,  on  the  snow-line  of  the 
two  sides  of  the  Himalayas,  331,  332. 

Beaufort.  Capt.,  observed  the  emissions 
of  inflammable  gas,  on  the  Caramanian 
coast,  as  described  by  Pliny,  223.  See, 
also,  note  by  Translator,  223, 

Beaumont,  Elie  de,  on  the  uplifting  of 
mountain  chains,  51,  300 ;  influence  of 
the  rocks  of  melaphyre  and  serpentine, 
in  the  southern  declivities  of  the  Alps, 
on  pendulum  experiments,  167 ;  con- 
jectures on  the  quartz  strata  of  the  Col 
de  la  Poissoniere,  266. 

Eeccaria,  observation  of  steady  luminous 
appearance  in  the  clouds,  202  ;  of  light- 
ning clouds,  unaccompanied  by  thun- 
der or  indications  of  storm,  337. 

Beechey,  Capt,  97 ;  observations  on  the 
temperature  and  density  of  the  water 
of  the  ocean  under  difterent  zones  of 
longitude  and  latitude,  306. 

Bembo,  Cardinal,  his  observations  on  the 
eruptions  of  Mount  JEtna,  229  ;  theory 
of  the  necessity  of  the  proximity  of  vol- 
canoes to  the  sea,  243;  vegetation  on 
the  declivity  of  jEtna,  347. 

Berard,  Capt,  shooting  stars,  119. 

Bertou,  Count,  his  barometrical  measure- 
ments of  the  Dead  Sea,  296. 

Berzelius  on  the  chemical  elements  of 
aerolites,  130,  131. 

Benzenberg  on  meteors  and  shooting 
stars,  119, 120 ;  their  periodic  return  in 
August,  125. 

Bessel's  theory  on  the  oscillations  of  the 
pendulum,  44 ;  pendulum  experiments, 
64  ;  on  the  parallax  of  61  Cygui,  88 ;  on 
Halley's  comet,  102, 103, 104 ;  on  the  as- 
cent of  shooting  stars,  123 ;  on  their  par- 
tial visibiUty,  128 ;  velocity  of  the  sun's 
translatory  motion,  145 ;  mass  of  the 
star  61  Cygni,  148 ;  parallaxes  and  dis- 
tances of  fixed  stars,  153 ;  comparison 
of  measurements  of  degrees,  165,  166. 
B  iot  on  the  phenomenon  of  twilight,  118 ; 
on  the  zodiacal  hght  141 ;  pendulum 
experiments  at  Bordeaux,  170. 
Biot,  Edward,  Chinese  observations  of 

comets,  101, 109 ;  of  aerolites,  128. 
FJischof  on  the  interior  heat  of  the  globe, 

^i.7,  219,  235,  244,  294. 
dluraenbach,  his  classification  of  the  races 
>t°  men,  35i5. 


Bockh,  origin  of  the  aLcient  myth  of  tb« 
Nemean  lunar  lion,  134,  135. 

Boguslawski,  falls  of  shooting  stars,  119 
128. 

Bonpland,  M.,  and  Humboldt,  on  the  pe- 
lagic shells  found  on  the  ridge  of  the 
Andes,  45. 

Bopp,  derivation  of  the  word  Cosmos, 
70. 

Boussingault,  on  the  depth  at  which  is 
found  the  mean  annual  temperature 
within  the  tropics,  175;  on  the  volca- 
noes of  New  Granada,  217  ;  on  the  tem- 
perature of  the  earth  in  the  tropics,  220. 
221 ;  temperature  of  the  thermal  springs 
of  Las  Trincheras,  222 ;  his  investiga- 
tions on  the  chemical  analysis  of  the  at- 
mosphere, 311,  312 ;  on  the  mean  an- 
nual quantity  of  rain  in  diflerent  parts 
of  South  America,  333,  334. 

Bouvard,  M.,  105 ;  his  observations  on  that 
portion  of  the  horary  oscillations  of  the 
pressure  of  the  atmosphere,  which  de 
pends  on  the  attraction  of  the  moon 
313. 

Bramidos  y  truenos  of  Guanaxuato,  209, 
210. 

Brandes,  tails  of  shooting  stars,  114,  1 16 
height  and  velocity  of  shooting  stars, 
120 ;  their  periodic  falls,  125,  126. 

Bravais,  on  the  Aurora,  201 ;  on  the  daily 
oscillations  of  the  barometer  in  70<3 
north  latitude,  314 ;  distribution  of  the 
quantity  of  rain  in  Central  Europe,  334 ; 
doubts  on  the  greater  dryness  of  mount- 
ain air,  334. 

Brewster,  Sir  David,  first  detected  the 
connection  between  the  curvature  of 
magnetic  lines  and  my  isothermal  lines, 
193. 

Brongniart,  Adolphe,  luxuriance  of  the 
primitive  vegetable  world,  218 ;  fossil 
flora  contained  in  coal  measures,  280. 

Brongniart,  Alexander,  formation  of  rib- 
bon jasper,  259 ;  one  of  the  founders  of 
the  archaeology  of  organic  life,  273. 

Brown,  Robert,  first  discoverer  f  »f  molec- 
ular motion,  341, 
Buch's,  Leopold  von,  theory  on  the  eleva- 
tion of  continents  and  mountain  chains, 
45;  on  the  craters  and  circular  form 
of  the  island  of  Palma,  226 ;  on  volca- 
noes, 234,  238,  242,  243,  247 ;  on  meta- 
morphic  rocks,  249-252,  260,  263,  264 ; 
on  the  origin  of  various  conglomerates 
and  rocks  of  detritus.  269 ;  classification 
of  ammonites,  276,  277;  physical  causes 
of  the  elevation  of  continents,  295  ;  on 
the  changes  in  height  of  the  Swedish 
coasts,  295. 
Buckland,  272 ;  on  the  fossil  flora  of  the 

coal  measures,  279. 
Buftbn,  his  views  on  the  geographical  dis- 
tribution of  animals,  348. 
Burckhardt,  on  the  volcano  of  Medina, 
246;   on  the  hornitos  de  JoruUo,  see 
note  by  Translator,  230. 
Burnes,  Sir  Alexander,  on  the  purity  of 
the  atmosphere  in  Bokhara,  li4ij  prop- 
agation of  shocks  of  earthquakes,  21  a 


INDEX. 


365 


Caille,  La,  pendulum  measurements  at 
the  Cape  of  Good  Hope,  169. 

Caldas,  quantity  of  rain  at  Santa  Fe  de 
Bogota,  334. 

Camargo's  MS.  Historia  de  Tlascala,  140. 

Capocci,  his  observations  on  periodic  falls 
of  aerolites,  126. 

Carlini,  geodesic  experiments  in  Lombar- 
dy,  168 ;  Mount  Cenis,  170. 

Carrara  marble,  262,  263. 

Carus,  his  definition  of  "  Nature,"  41. 

Caspian  Sea,  its  periodic  rise  and  fall,  297. 

Cassini,  Dominicus,  on  the  zodiacal  light, 
139,  140 ;  hypothesis  on,  141 ;  his  dis- 
covery of  the  spheroidal  form  of  Jupi- 
ter, 164. 

Cautley,  Capt,  and  Dr.  Falconer,  discov- 
ery of  gigantic  fossils  in  the  Himalayas, 
278.    See,  also,  note  by  Translator,  278. 

Cavanilles,  first  entertained  the  idea  of 
seeing  grass  grow,  149. 

Cavendish,  use  of  the  torsion  balance  to 
determine  the  mean  density  of  the 
Earth,  170. 

Challis,  Professor,  on  the  Aurora,  March 
19  and  Oct.  24th,  1847,  see  note  by 
Translator,  195,  199. 

Chardin,  noticed  in  Pei'sia  the  famous 
comet  of  1668,  called  "nyzek."  or  "pe- 
tite lance,"  139. 

Charpentier,  M.,  belemnites  found  in  the 
primitive  limestone  of  the  Col  de  la 
Seigne,  261 ;  glaciers,  329. 

Chemistry  as  distinguished  from  physics, 
62  ;  chemical  affinity,  63. 

Chevandier,  calculations  on  the  carbon 
contained  in  the  trees  of  the  forests  of 
our  temperate  zones,  281. 

Childrey  first  described  the  zodiacal  hght 
in  his  Britannia  Baconica,  138. 

Chinese  accounts  of  comets,  99,  100, 101 
shooting  stars,  128  ;  "  fire  springs,"  158 
knowledge  of  the  magnetic  needle,  180 
electro-magnetism,  188,  189. 

Chladni  on  meteoric  stones,  (fee,  118, 
135 ;  on  the  selenic  origin  of  aerolites, 
121 ;  on  the  supposed  phenomenon  of 
ascending  shooting  stars,  122 ;  on  the  ob- 
scuration of  the  Sun's  disk,  133 ;  sound- 
figures,  135;  pulsations  in  the  tails  of 
comets,  143. 

Choiseul,  his  chart  of  Lemnos,  246. 

Chromatic  polarization.  See  Polarization. 

Cirro-cumulus  cloud.     See  Clouds. 

Cirrous  strata.    See  Clouds. 

Clark,  his  experiments  on  the  variations 
of  atmospheric  electricity,  335,  336. 

Clarke,  J.  G.,  of  Maine,  U.  S.,  on  the  comet 
of  1843, 100. 

Climatic  distribution  of  heat,  313,  317- 
328  ;  of  humidity,  328,  333,  334. 

Chmatology,  317-329 ;  climate,  general 
sense  ot;  317,  318: 

Clouds,  their  electric  tension,  color,  and 
height,  336,  3.37 ;  connection  of  cirrous 
strata  with  the  Aurora  Borealis,  196 ; 
cirro-cumulus  cloud,  phenomena  of, 
197  ;  luminous,  202 ;  Dove  on  their  for- 
mation and  appearance,  315, 316 ;  often 
present  on  a  bright  summer  sity  the 


"projected  image"  of  the  soil  below, 
316;  volcanic,  233. 

Coal  formations,  ancient  vegetable  re 
mains  in,  280,  281. 

Ccal  mines,  depths  of,  158-160. 

Cclebrooke  on  the  snow-line  of  the  two 
sides  of  the  Himalayas,  31. 

CoUadon,  electro-magnetic  apparatus,  335. 

Columbus,  his  remark  that  "  the  Earth  is 
small  and  narrow,"  164;  found  the  com- 
pass showed  no  variation  in  the  Azores, 
181,  182 ;  of  lava  streams,  245 ;  noticed 
coniferae  and  palms  growing  together  in 
Cuba,  282 ;  remarks  in  his  journal  on 
the  equatorial  cuiTents,  307 ;  of  the  Sar- 
gasso Sea,  308 ;  his  dream,  310,  311. 

Comets,  general  description  of,  99-112 ; 
Biela's,  43,  86, 107, 108  ;  Blaupain's,  108 ; 
Clausen's,  108 ;  Encke's,  43,  64,  86, 106- 
108 ;  Faye's,  107,  108 ;  Halley's,  43, 100, 
102-109;  Lexell's  and  Burckhardt's, 
108,  110;  Messier's,108;  Olbers's,  109; 
Pons's,  109 ;  famous  one  of  1668,  seen 
in  Persia,  called  "nyzek,"  or  "petite 
lance,"  189  ;  comet  of  1843,  101 ;  their 
nucleus  and  tail,  87,  100;  small  mass, 
100 ;  diversity  of  form,  100-103 ;  light, 
104-106;  velocity,  109  ;  comets  of  short 
period,  107-109 ;  long  period,  109,  110; 
number,  99 ;  Chinese  observations  on, 
99-101 ;  value  of  a  knowledge  of  their 
orbits,  43  ;  possibility  of  collision  of  Bi- 
ela's and  Encke's  comets,  107,  108  ;  hy- 
pothesis of  a  resisting  medium  conjec- 
tured from  the  diminishing  period  of 
the  revolution  of  Encke's  comet,  100 ; 
apprehensions  of  their  collision  with 
the  Earth,  108,  110,  111 ;  their  popular 
supposed  influence  on  the  vintage,  111. 

Compass,  early  use  of  by  the  Chinese, 
180 ;  permanency  in  the  West  Indies, 
181. 

Condamine,  La,  inscription  on  a  marble 
tablet  at  the  Jesuit's  College,  Quito,  on 
the  use  of  the  pendulum  as  a  measure 
of  seconds,  166,  167. 

Cond6,  notice  of  a  heavy  shower  of  shoot- 
ing stars,  Oct.,  902,  119. 

Coraboeuf  and  Delcrois,  geodetic  opera- 
tions, 304. 

Cordilleras,  scenery  of,  26,  29,  33 ;  vege- 
tation, 34,  35 ;  intensity  of  the  zodiacal 
light,  137. 

Cosznography,  physical,  its  object  and  ul- 
timate aims,  57-60 ;  materials,  60. 

Cosmos,  the  author's  object,  38,  78  ;  prim- 
itive signification  and  precise  definition 
of  the  word,  69  ;  how  employed  by 
Greek  and  Roman  writers,  69,  60 ;  der- 
ivation, 70. 

Craters.     See  Volcanoes. 

Curtius,  Professor,  his  notes  on  the  tem-  • 
perature  of  various  springs  in  Greece. 
222,  223. 

Cuvier,  one  of  the  founders  of  the  archas 
ology  of  organic  life,  273  ;  discovery  ol 
fossil  crocodiles  in  the  tertiary  forma 
tion,  274. 

Daimachos  on  the  phenomena  attendlnj^ 


3G6 


COSMOri. 


the  fall  of  the  stone  of  iEgos  Potamos, 
133,  134. 

Dalinan  on  the  existence  of  Chionaea  ara- 
neoides  in  polar  snow,  344. 

Dalton,  observed  the  southern  lights  in 
England,  198. 

Dante,  quotation  from,  322. 

Darwin,  Charles,  fossil  vegetation  in  the 
travertine  of  Van  Diernen's  Land,  224  ; 
central  volcanoes  regarded  as  volcanic 
chains  of  small  extent  on  parallel  fis- 
sures, 2158 ;  instructive  materials  in  the 
temperate  zones  of  the  southern  hem- 
isphere for  the  study  of  the  present  and 
past  geography  of  plants,  282,  283  ;  on 
the  fiord  formation  at  the  southeast  end 
of  America,  293  ;  on  the  elevation  and 
depression  of  the  bottom  of  the  South 
Sea,  297 ;  rich  luxuriance  of  animal  life 
in  the  ocean,  309,  310 ;  on  the  volcano 
of  Aconcagua,  330. 

Daubeney  on  volcanoes.  See  Transla- 
tor's notes,  161,  203,  204,  210,  218,  224, 
228,  230,  233,  234,  235,  236,  244,  245. 

Daussy,  his  barometric  experiments,  298 ; 
observations  on  the  velocity  of  the  equa- 
torial current,  307; 

Davy,  Sir  Humphrey,  hypothesis  on  act- 
ive volcanic  phenomena,  235 ;  on  the 
low  temperature  of  water  on  shoals,  309. 

Dead  Sea,  its  depression  below  the  level 
of  the  Mediterranean,  296,  297. 

Dechen,  Von,  on  the  depth  of  the  coal- 
basin  of  Liege,  160. 

Delcrois.     See  Coraboeuf. 

Descartes,  his  fragments  of  a  contempla- 
ted work,  entitled  "  Monde,"  68  ;  on 
comets,  139. 

Deshayes  and  Lyell,  their  investigations 
on  the  numerical  relations  of  extinct 
and  existing  organic  life,  275. 

Dica;archus,  his  "parallel  of  the  dia- 
phram,"  289. 

Diogenes  Laertius,  on  the  aerolite  of 
Mgos  Potamos,  116,  122,  134. 

D'Orbigny,  fossil  remains  fi-om  the  Hima- 
laya and  the  Indian  plains  of  Cutch,  277. 

Dove  on  the  similar  action  of  the  declina- 
tion needle  to  the  atmospheric  electrom- 
eter, 194;  "law  of  rotation,"  315;  on  the 
formation  and  appearance  of  clouds, 
316  ;  on  the  difference  between  the 
true  temperature  of  the  surface  of  the 
ground  and  the  indications  of  a  ther- 
mometer suspended  in  the  shade,  325 ; 
hygrometric  windrose,  333. 

Doyere,  his  beautiful  experiments  on  the 
tenacity  of  life  in  animalcules,  345. 

Drake,  shaking  of  the  earth  for  successive 
days  in  the  United  States  (1811-12),  211. 

Dufrenoy  et  Elie  de  Beaumont,  Geologie 
de  la  France,  253,  258,  259,  260,  262,  266. 

Dumas,  results  of  his  chemical  analysis 
of  the  atmosphere,  311. 

Dunlop  on  the  comet  of  1825,  103. 

Duperrey  on  the  configuration  of  the  mag- 
netic equator,  183 ;  pendulum  oscilla- 
tions, 166. 

Duprez,  influence  of  trees  on  the  intensi- 
ty of  electricity  in  the  atmosphere,  335. 


Eandi,  Vassalli,  electric  perturbation  dur 
ing  the  protracted  earthquake  of  Pigne- 
rol,  206. 

Earth,  survey  of  its  crust,  72;  relative 
magnitude,  (fee,  in  the  solar  system, 
95-97 ;  genei-al  description  of  terrestri- 
al phenomena,  154-369;  geographical 
distribution,  161, 162;  its  mean  density, 
169-172 ;  internal  heat  and  temperature, 
172-176;  electro-magnetic  activity,  177- 
193  ;  conjectures  on  its  early  high  tem- 
perature, 172 ;  interior  increase  of  heat 
with  increasing  depth,  161  ;  greatest 
depths  reached  by  human  labor,  157- 
159 ;  methods  employed  to  investigate 
the  curvature  of  its  surface,  165-168 ; 
reaction  of  the  interior  on  the  external 
crust,  161,  202-247 ;  general  delineation 
of  its  reaction,  204-206 ;  fantastic  views 
on  its  interior,  171. 

Earthquakes,  general  account  of,  204-218 , 
their  manifestations,  204-206 ;  of  Ptio- 
bamba,  204,  206,  208,  213,  214 ;  Lisbon, 
210,  211,  213,  214  ;  Calabria,  206  ;  their 
propagation,  204,  212,  213;  waves  ot 
commotion,  205,  206,  212  ;  action  on 
gaseous  and  aqueous  springs,  210,  222, 
224  ;  salses  and  mud  volcanoes,  224- 
228 ;  erroneous  popular  belief  on,  206- 
208 ;  noise  accompanying  earthquakes, 
208-210 ;  their  vast  destruction  of  life, 
210,  211 ;  volcanic  force,  214,  215 ;  deep 
and  peculiar  impression  produced  on 
men  and  animals,  215,  216. 

Ehrenberg,  his  discovery  of  infusoria  in 
the  polishing  slate  of  Bilin,  150 ;  infuso- 
rial deposits,  255,  262  ;  brilliant  discov- 
ery of  microscopic  life  in  the  ocean  and 
in  the  ice  of  the  polar  regions,  342 ;  rap- 
id propagation  of  animalcules  and  their 
tenacity  of  life,  343-345  ;  transforma- 
tion of  chalk,  262. 

Electricity,  magnetic,   188-202  ;    conjec- 
tured electric  currents,  189,  190 ;  elec- 
tric   storms,   194  ;    atmospheric,   335 
337. 

Elevations,  comparative,  of  mountains  in 
the  two  hemispheres,  28,  29. 

Encke,  106  ;  his  computation  that  the 
showers  of  meteors,  in  1833,  proceeded 
from  the  same  point  of  space  in  the  di- 
rection in  which  the  Earth  was  moving 
at  the  time,  119,  120. 

Ennius,  71. 

Epicharmus,  writings  of,  71. 

Equator,  advantages  of  the  countries  boi 
dering  on,  33, 34  ;  their  organic  richness 
and  fertility,  34,  35 ;  magnetic  equator, 
183-185. 

Erman,  Adolph,  on  the  three  cold  days 
of  May  (llth-13th),  133 ;  lines  of  decli- 
nation in  Northern  Asia,  182 :  in  the 
southern  parts  of  the  Atlantic,  187  , 
observations  during  the  earthquake  at 
Irkutsk,  on  the  non-disturbance  of  the 
horary  changes  of  the  magnetic  needle, 
207. 

Eruptions  and  exhalations  (volcanic),  la- 
va, gaseous  and  liquid  fluids,  hot  mud, 
mud  mofettes,  &c.,  161,  210-270 


I\URX. 


307 


Ktlinographical  studies,  their  importance 

and  teaching,  357,  358. 
Kuripides,  his  Phaeton,  125. 

Falconer,  Dr.,  fossil  researches  in  the 
Himalayas,  278. 

Faraday,  radiating  heat,  electro-magnet- 
ism, (fcc,  49,  179,  188 ;  brilliant  discov- 
ery of  the  evolution  of  light  by  mag* 
netic  forces,  193. 

Farquharson  on  the  connection  of  cirrous 
clouds  with  the  Aurora,  197 ;  its  alti- 
tude, 199. 

Fedorow,  his  pendulum  experiments,  168. 

Feldt.on  the  ascent  of  shooting  stars,  123. 

Ferdinandea,  igneous  island  of,  242. 

Floras,  geographical  distribution  ol^  350. 

Forbes,  Professor  E.,  inference  to  his 
Travels  in  Lycia,  223  ;  account  of  the 
island  of  Santorino,  241,  242. 

Forbes,  Professor  J.,  his  improved  seis- 
mometer, 205 ;  on  the  correspondence 
existing  between  the  distribution  of  ex- 
isting floras  in  the  British  Islands,  348, 
349 ;  on  the  origin  and  ditfusiou  of  the 
British  flora,  353,  354. 

Forster,  George,  remarked  the  climatic 
diflerence  of  temperature  of  the  east- 
ern and  western  coasts  of  both  conti- 
nents, 321. 

Forster,  Dr.  Thomas,  monkish  notice  of 
'*  Meteorodes,"  ;23. 

Fossil  remains  of  tropical  plants  and  an- 
imals found  in  northern  regions,  46, 
270-284 ;  of  extinct  vegetation  in  the 
travertine  of  Van  Diemen's  Land,  224 ; 
fossil  human  remains,  250. 

Foster,  Reinhold,  pyramidal  configura- 
tion of  the  southern  extremities  of  con- 
tinents, 290,  291. 

Fourier,  temperature  of  our  planetary 
system,  155,  172,  176. 

Fracastoro  on  the  direction  of  the  tails  of 
comets  from  the  sun,  101. 

Fraelan,  fall  of  stars,  119. 

Franklin,  Benjamin,  existence  of  sand- 
banks indicated  by  the  coldness  of  the 
water  over  them,  308. 

Franklin,  Capt.,  on  the  Aurora,  197,  199, 
200,  201 ;  rarity  of  electric  explosions 
in  high  northern  regions,  337. 

Freycinet,  pendulum  oscillations,  166. 

Fusinieri  on  meteoric  masses,  123. 

Galileo,  104.  167. 

Galle,  Dr.,  91. 

Galvani,  Aloysio,  accidental  discovery  of 
galvanism,  52. 

Gaseous  emanations,  fluids,  mud,  and 
molten  earth,  217-220. 

Gasparin.  distribution  of  the  qcantity  of 
rain  in  Central  Europe,  333. 

Gauss,  Friedrich,  on  terrestrial  magnet- 
ism, 179 ;  his  erection,  in  1832,  of  a  mag- 
netic observatory  on  a  new  principle, 
191,  192. 

Gav-Lussac,  204,  233,  234,  266,  267,  311, 
.312,  334,  336. 

Geo^nostic  or  geological  description  of 
the  earth's  surf;i£o,  203-286. 


Geognosy  (the  study  of  the  textures  and 
position  of  the  earth's  surface),  its  prog- 
ress, 203. 

Geography,  physical,  288-311 ;  of  animal 
life,  341-34C;  of  plants,  346-351. 

Geographies,  Ritter's  (Carl),  "Geography 
in  relation  to  Nature  and  the  History 
of  Man,"  48,  67 ;  Varenius  (Bernhard), 
General  and  Comparative  Geography, 
66,  67. 

Gerard,  Capts.  A.  G.  and  J.  G.,  on  the 
snow-line  and  vegetation  of  the  Hima- 
layas, 31,  32,  331,  332. 

German  scientific  works,  their  defects, 
47. 

Geyser,  intermittent  fountains  of,  223. 

Gieseke  on  the  Aurora,  200. 

Gilbert,  Sir  Humphrey,  Gulf  Stream,  307. 

Gilbert,  William,  of  Colchester,  terres- 
ti-ial  magnetism,  158, 159, 177, 179, 182. 

Gillies,  Dr.,  on  the  snow-line  of  South 
America,  330,  331. 

Gioja,  crater  of,  98. 

Girard,  composition  and  textvtre  of  ba- 
salt, 253. 

Glaisher,  James,  on  the  Aurora  Borealis 
of  Oct.  24, 1847.  See  Translator's  notes, 
194,  200. 

Goldfuss,  Professor,  examination  of  fossil 
specimens  of  the  flying  saurians,  274. 

Goppert  on  the  conversion  of  a  fragment 
of  amber-tree  into  black  coal,  281 ;  cy- 
cadese,  283 ;  on  the  amber-tree  of  the 
Baltic,  283,  284. 

Gothe,  41,  47,  53. 

Greek  philosophers,  their  use  of  the  term 
Cosmos,  69,  70;  hypotheses  on  aero- 
lites, 122,  123,  134. 

Grimm,  Jacob,  graceful  symbolism  at- 
tached to  falling  stars  in  the  Lithuanian 
mythology,  112,  113. 

Gulf  Stream,  its  origin  and  course,  307. 

Gumprecht,  pyroxenic  nepheline,  253. 

Guanaxuato,  striking  subterranean  noise 
at,  209. 

Hall,  Sir  James,  his  experiments  on  min- 
eral fusion,  262. 

Halley,  comet,  43,  100,  102-109 ;  on  the 
meteor  of  1686,  118,  133 ;  on  the  light 
of  stars,  152 ;  hypothesis  of  the  earth 
being  a  hollow  sphere,  171 ;  his  bold 
conjecture  that  the  Aurora  Borealis  was 
a  magnetic  phenomenon,  193. 

Hansteen  on  magnetic  lines  of  declination 
in  Northern  Asia,  182. 

Hansen  on  the  material  contents  of  the 
moon,  96.  * 

Hedenstrom  on  the  so-called  "Wood 
Hills"  of  New  Siberia,  281. 

Hegel,  quotation  from  his  "  Philosophy 
of  History,"  76. 

Heine,  discovery  of  crystals  of  feldspar 
in  scoria?,  268.  - 

Hemmer,  falling  stai«,  119. 

Hencke,  plaaets  discovered  by.  See  note 
by  Translator,  90,  91. 

Henfrey,  A.,  extract  from  ins  Outlines  of 
Stnictnnil  and  Physiological  Botany 
See  »oti\«  by  Translator,  34 ),  342,  35i. 


368 


COSMOS 


Hensius  on  the  variations  of  form  in  the 
comet  of  1744,  102. 

Herodotus,  described  Scythia  as  free  from 
earthquakes,  204 ;  Scythian  saga  of  the 
sacred  gold,  which  fell  burning  from 
heaven,  115. 

Herschel,  Sir  William,  map  of  the  world, 
66 ;  inscription  on  his  monument  at  Up- 
ton, 87 ;  satellites  of  Saturn,  96 ;  diam- 
eters of  comets,  101 ;  on  the  comet  of 
1811,  103 ;  star  guagings,  150 ;  starless 
space,  150, 152 ;  time  required  for  light 
to  pass  to  the  earth  from  the  remotest 
luminous  vapor,  154. 

Herschel,  Sir  John,  letter  on  Magellanic 
clouds,  85 ;  satellites  of  Saturn,  96 ;  or- 
bits of  the  satellites  of  Uranus,  98 ;  di- 
ameter of  nebulous  stars,  141 ;  stellar 
Milky  Way,  150,  151 ;  light  of  isolated 
etarry  clusters,  151 ;  observed  at  the 
Cape,  the  star  rj  in  Argo  increase  in 
splendor,  153 ;  invariability  of  the  mag- 
netic declination  in  the  West  Indies,  181. 

Hesiod,  dimensions  of  the  universe,  154. 

Hevelius  on  the  comet  of  1618, 106. 

Hibbert,  Dr.,  on  the  Lake  of  Laach.  See 
note  by  Translator,  218. 

Himalayas,  the,  their  altitude,  28;  scen- 
ery and  vegetation,  29,  30;  tempera- 
ture, 30, 31 ;  variations  of  the  snow-line 
on  their  northern  and  southern  decliv- 
ities, 30-33,  331. 

Hind,  Mr.,  planets  discovered  by.  See 
Translator's  note,  90,  91. 

Hindoo  civilization,  its  primitive  seat,  35, 
36. 

Hippalos,  or  monsoons,  316. 

Hippocrates,  his  erroneous  supposition 
that  the  land  of  Scythia  is  an  elevated 
table-land,  346. 

Hoff,  numerical  inquiries  on  the  distri- 
bution of  earthquakes  throughout  the 
year,  207. 

Hoffman,  Friedrich,  observations  an  earth- 
quakes, 206,  207 ;  on  eruption  fissures 
in  the  Lipari  Islands,  238.- 

Holberg,  his  Satire,  "Travels  of  Nic.  Klim- 
ius,  in  the  world  under  groimd."  See 
Translators  note,  171,  172. 

Hood  on  the  Aurora,  200,  201. 

Hooke,  Robert,  pulsations  in  the  tails  of 
comets,  143 ;  his  anticipation  of  the  ap- 
plication of  botanical  and  zoological 
evidence  to  determine  the  relative  age 
of  rocks,  270-272. 

Ho-tsiugs,  Chinese  fire -springs,  their 
depth,  158 ;  chemical  composition,  217. 

Howard  on  the  climate  of  London,  125 ; 
mean  annual  quantity  of  rain  in  Lon- 
don, 333. 

Illigel,  Carl  von,  on  the  elevation  of  the 
valley  of  Kashmir,  32,  33 ;  on  the  snow- 
line of  the  Himalayas,  331. 

Humboldt,  Alexander  von,  works  by,  re- 
ferred to  in  various  notes : 

Annales  de  Chimie  et  de  Physique, 

31,  305. 
Annales  des  Sciences  Naturelles,  28. 
Ansichten  der  Natur,  342,  344,  347. 
Aflie  Centrale.  28,  31,  .33, 11.%  158, 159, 


180,  204,  217, 219,  225,  245,  251, 25^ 
260,  2891^290,  291,  ?92,  296,  300, 301. 
303-306,  320,  323,  324,  330,  331,  334, 
350,  356. 
Atlas  Geographique  et  Physique  du 

Nouveau  Continent,  33,  249. 
De  distributione  Geographica  Plan- 
tarum,  secundum  cojli  temperiem, 
*  et   altitudinem  Montium,  33,  291, 

324. 
Examen  Critique  de  I'Histoire  de  la 
Geographie,  58,  180,  181,  227,  289, 
292,  307,  308,  310,  316,  356. 
Essai  Geognostique  sur  le  Gisement 

des  Roches,  230,  252,  266,  300. 
Essai  Politique  sur  la  Nouvelle  Es- 

pagne,  129,  240. 
Essai  sur  la  Geographie  des  Plantes, 

33,  230,  315. 
Flora  Friburgensis  Subterranea,  340^ 

346. 
Journal  de  Physique,  178,  292. 
Letti'e  au  Due  de   Sussex,  sur  lea 
Moyens  propres  a  perfectionner  la 
connaissance  du  Magnitisme  Ter- 
restre,  178,  192. 
Moimmens  des  Peuples  Indigenes  de 

I'Amerique,  140. 
Nouvelles  Annales  des  Voyages,  307. 
Recueil    d'Observations    Astronom 

iques,  28, 167,  218,  327. 
Recueil  d'Observations  de  Zoologia 

et  d'Anatoraie  Comparee,  232. 
Relation  Historique  du  Voyage  axrx 
Regions  Equinoxiales,  113, 119, 123, 
127, 130,  186,  206,  207,  220,  221,  225, 
252,  292,  299,  300,  302,  305-307,  314, 
315,  327,  329,  334,  336. 
Tableau  Physique  des  Regions  Eqwi 

noxiales,  33,  230. 
Vues  des  Cordilleres,  225,  230. 
j  Humboldt,  Wilhehft  von,  on  the  primitive 
seat  of  Hindoo  civilization,  36  ;  sonnet, 
extract  from,  154 ;  on  the  gradual  rec- 
ognition by  the  human  race  of  the  bond 
of  humanity,  358,  359. 
Humidity,  313,  332-335. 
Hutton,  Capt.  Thomas,  his  paper  an  the 

snow-line  of  the  Himalayas,  331,  332. 
Huygens,  polarization  of  light,  52 ;  nebu- 
lous spots,  138. 
Hygrometry,  332, 333 ;  hygrometric  wind- 
rose,  333. 

Imagination,  abuse  of,  by  half-civilized  na- 
tions, 37. 
Imbert,   his   account  of   Chinese   "  fire- 
springs,"  158. 
Ionian  school  of  natural  philosophy,  65, 
i      77,  84,  134. 

Isogenic,  isoclinal,  isodynamic,  &c.     See 
i      Lines. 

Jacquemont,  Victor,  his  barometrical  ob- 
servations on  the  snow-line  of  the  Him- 
alayas, 32,  331. 

Jasper,  its  formation,  259-261. 

Jessen  on  the  gradual  rise  of  the  coast  oi 
Sweden,  295. 

JoriiUo,  hornitos  de,  230. 


INDEX. 


369 


Justinian,   conjectures   on   the   physical  ! 
causes  of  volcanic  eruptions,  243. 

Kamtz,  isobarometric  lines,  315;  doubts 
on  the  greater  dryness  of  mountain  air, 
334. 

Kant,  Emanuel,  "on  the  theory  and  struc- 
ture of  the  heavens,"  50,  65  ;  earth- 
quake at  Lisbon,  210. 

Keilhau  on  the  ancient  sea-line  of  the 
coast  of  Spitzbergen,  296. 

Kepler  on  the  distances  of  stars,  88;  on 
the  density  of  the  planets,  93 ;  law  of 
progression,  95  ;  on  the  number  of  com- 
ets, 99 ;  shooting  stars,  113  ;  on  the  ob- 
scuration of  the  sun's  disk,  132 ;  on  the 
radiations  of  heat  from  the  lixed  stars, 
136  ;  on  a  solar  atmosphere,  139. 

Kloden,  shooting  stars,  119,  124. 

Knowledge,  superficial,  evils  of,  43. 

Krug  of  Nidda,  temperature  of  the  Gey- 
ser and  the  Strokr  intermittent  fount- 
ains, 222. 

Krusenstem,  Admiral,  on  the  train  of  a 
fire-ball,  114. 

Kuopho,  a  Chinese  physicist,  on  the  at- 
traction of  the  magnet,  and  of  amber, 
188. 

Kupfl'er,  magnetic  stations  in  Northern 
Asia,  191. 

Lamanon,  187. 

Lambert,  suggestion  that  the  direction  of 
the  wind  be  compared  with  the  height 
of  the  barometer,  alterations  of  temper- 
ature, humidity,  &c.,  315. 

Lamont,  mass  of  Uranus,  93 ;  satellites  of 
Saturn,  96. 

Language  and  thought,  their  mutual  alli- 
ance, 56 ;  author's  praise  of  his  native 
language,  56. 

Languages,  importance  of  their  study, 
357,  359. 

Laplace,  his  "Systeme  du  Monde,"  48, 
62,  92,  141 ;  mass  of  the  comet  of  1770, 
107;  on  the  required  velocity  of  masses 
projected  from  the  Moon,  121,  122 ;  on 
the  altitude  of  the  boundaries  of  the  at- 
mosphere of  cosmical  bodies,  141 ;  zo- 
diacal Ught,  141 ;  lunar  inequalities,  166 ; 
the  Earth's  form  and  size  inferred  from 
lunar  inequalities,  168, 169 ;  his  estimate 
of  the  mean  height  of  mountains,  301 ; 
density  of  the  ocean  required  to  be  less 
than  the  earth's  for  the  stability  of  its 
equilibrium,  305  ;  results  of  his  perfect 
theory  of  tides,  306. 

Latin  writers,  their  use  of  the  term  "Mun- 
dus,"  70,  71. 

Latitudes,  Northern,  obstacles  they, pre- 
sent to  a  discovery  of  the  laws  of  Na-  i 
ture,  36 ;  earliest  acquaintance  with  the  ; 
governing  forces  of  the  physical  world,  I 
there  displayed,  36  ;  spread  from  thence 
of  the  germs  of  civiUzation,  36.  i 

Latitudes,  tropical,  their  advantages  for 
the  contemplation  of  nature,  33 ;  pow- 
erful  impressions,  from  their  organic 
richness  and  fertility,  34  ;  facilities  they 
present  for  a  knowledge  of  the  laws  of  | 

Q 


nature,  35 ;  brilliant  display  of  shooting 
stars,  113. 

Laugier.his  calculations  to  prove  Halley'a 
comet  identical  with  the  comet  of  1378, 
described  in  Chinese  tables,  109. 

Lava,  its  mineral  composition,  234. 

Lavoisier,  62. 

Lawrence  (St.),  fiery  tears,  124  ;  meteoric 
stream,  125. 

Leibnitz,  his  conjecture  that  the  planets 
increase  in  volume  in  proportion  to 
their  increase  of  distance  from  the 
Sun,  93. 

Lenz,  observationg  on  the  mean  level  of 
the  Caspian  Sea,  297 ;  maxima  of  dens- 
ity of  the  oceanic  temperature,  304  ; 
temperature  and  density  of  the  ocean 
under  difl'erent  zones  of  latitude  and 
longitude,  306. 

Leonhard,  Karl  von,  assumption  on  for- 
mations of  granular  limestone,  263. 

Leverrier,  planet  Neptune.  See  Trans- 
lator's note,  90,  91. 

Lewy,  observations  on  the  varying  quan- 
tity of  oxygen  in  the  atmosphere,  ac- 
cording to  local  conditions,  or  the  sea- 
sons, 311,  312. 

Lichtenberg,  on  meteoric  stones,  118. 

Liebig  on  traces  of  ammoniacal  vapors  in 
the  atmosphere,  311. 

Light,  chromatic  polarization  of,  52 ;  trans 
mission,  88  ;  of  comets,  104-106  ;  offix^ 
ed  stars,  105 ;  extraordinary  lightness 
instances  of,  142-144  ;  propagation  of, 
153 ;  speed  of  transit,  153, 154.  See  Au 
rora.  Zodiacal  Light,  &c. 

Lignites,  or  beds  of  brown  coal,  283,  284 

Lines,  isogonic  (magnetic  equal  devia 
tion),  177,  181-185;  isoclinal  (magnetic 
equal  inclination),  178,  179,  181-185 
isodynamic  (or  magnetic  equal  force) 
181, 185-194  ;  isogeothermal  (chthoniso 
thermal),  219  ;  isobarometric,  315  ;  iso 
thermal,  isotheral,  and  isochimenal,  317, 
327,  328,  348. 

Line  of  no  variation  of  horary  decUnation 
183 ;  lower  limit  of  perpetual  snow,  329- 
332;  phosphorescent,  113. 

Lisbon,  earthquake  of,  210,  211,  213,  214. 

Lord  on  the  limits  of  the  snow-line  on  the 
Himalayas,  32. 

Lottin,  his  observations  of  the  Aurora, 
with  Bravais  and  Siljerstrom,  on  the 
coast  of  Lapland,  195,  200,  201. 

Lowenorn,  recognized  the  coruscation  of 
the  polar  light  in  bright  sunshine,  196. 

Lyell,  Charles,  investigations  on  the  nu 
merical  relations  of  extinct  and  organ- 
ic life,  274,  275 ;  nether-formed  or  hyp- 
ogene  rocks,  249 ;  uniformity  of  the  pro- 
duction of  erupted  rocks,  257.  See  notes 
by  Translator,  203,  244,  257. 

Mackenzie,  description  of  a  remarkable 
eruption  in  Iceland,  23G. 

Maclear  on  a  Centauri,  88  ;  parallaxes 
and  distances  of  fixed  stars,  153 ;  in- 
crease in  brightness  of  rj  Argo,  153. 

Madler,  planetary  compression  of  Uranus, 
96 ;  distano*j  of  the  innermost  satellite 


370 


COSMOS. 


of  Saturn  from  the  center  of  that  planet, 
97  ;  material  contents  of  the  Moon,  96; 
its  libration,  98 ;  mean  depression  of 
temperature  on  the  three  cold  days  of 
May  (llth-13th),  133;    conjecture  that 
the  average  mass  of  the  larger  number 
of  binary  stars  exceeds  the  mass  of  the 
Sun,  149. 
Magellanic  clouds,  85. 
Magnetic  attraction,  188 ;  declination,  181- 
183  ;  horary  motion,  177-180 ;  horary 
variations,  183,  190 ;  magnetic  storms, 
177,  179,  195,  199 ;  their  intimate  con- 
nection with  the  Aurora,  193-201 ;  rep- 
resented by  three  systems  of  lines,  see 
Lines  ;  movement  of  oval  systems,  182; 
magnetic    equator,  183-185 ;    magnetic 
poles,  183,  184;  observatories,  190-192; 
magnetic  stations,  190,  191,  317. 
Magnetism,  terrestrial,  177-193, 201 ;  elec- 
tro, 177-191. 
Magnussen,  Soemund,  description  of  re- 
markable eruption  in  Iceland,  236. 
Mahlmann,  Wilhelm,  southwest  direction 
of  the  aerial  current  in  the  middle  lati- 
tudes of  the  temperate  zone,  317. 
Mairan  on  the  zodiacal  light,  138, 139, 142; 
his  opinion  that  the  Sun  is  a  nebulous 
star,  141. 
Malapert,  annular  mountain,  98. 
Malle,  Bureau  de  la,  223. 
Man,  general  view  of,  351-359 ;  proofs  of 
the  flexibility  of  his  nature,  27  ;  results 
of  his  intellectual  progress,  53,  54 ;  ge- 
ographical distribution  of  races,  351- 
356  ;    on  the  assumption  of  superior 
and  inferior  races,  351-358  ;  his  gradu- 
al recognition  of  the  bond  of  humanity, 
358,  359. 
Mantell,  Dr..  his  "  Wonders  of  Geology," 
see  notes  by  Translator,  45,  64,  203,  274, 
278,  281,  283,  284,  287;  "Medals  of  Cre- 
ation," 46,  271,  283,  287. 
Margarita     Philosophica     by     Gregory 

Reisch,  58. 
Marius,  Simon,  first  described  the  nebu- 
lous spots  in  Andromeda  and  Orion, 
138. 
Martins,  observations  on  polar  bands,  198 ; 
found  that  air  collected  at  Faulhorn  con- 
tained as  much  oxygen  as  the  air  of  Par- 
is, 312 ;  on  the  distribution  of  the  quan- 
tity of  rain  in  Central   Europe,  333  ; 
doubts  on  the  greater  dryness  of  mount- 
ain air,  334. 
Matthiessen,  letter  to  Arago  on  the  zodi- 
acal light,  142. 
Mathieu  on  the  augmented  intensity  of 
the  attraction  of  gravitation  in  volcanic 
islands,  167. 
Mayer,  Tobias,  on  the  motion  of  the  solar 

system,  146,  148. 
Mean  numerical  values,  their  necessity 

in  modern  physical  science,  81. 
Melloni,  his  discoveries  on  radiating  heat 

and  electro-magnetism,  49. 
Menzel,  unedited  work  by,  on  the  flora 

of  Japan,  347. 
Messier,  comet,  108  ;    nebulous  spot  re- 
eembhng  our  starry  stratum,  151. 


Metamorphic  Rocks.    See  Rocks. 

Meteorology,  311-339. 

Meteors,  see  Aerolites ;  meteoric  infuso 
ria,  345,  346. 

Methone,  Hill  of,  240. 

Meyen  on  forming  a  thermal  scale  of  cul- 
tivation, 324  ;  on  the  reproductive  or- 
gans of  liverworts  and  algte,  341. 

Meyer,  Hermann  von,  on  the  organization 
of  flying  saurians,  274. 

Milky  Way,  its  figure,  89  ;  views  of  Aris- 
totle on,  103 ;  vast  telescopic  breadth, 
150 ;  Milk^  Way  of  nebulous  spots  at 
right  angles  with  that  of  the  stars,  151. 

Minerals,  artificially  formed,  268,  269. 

Mines,  gi'eatest  depth  of,  157-159  ;  tem- 
perature, 158. 

Mist,  phosphorescent,  142. 

Mitchell,  protracted  earthquake  shocks  in 
North  America,  211. 

Mitscherlich  on  the  chemical  origin  of 
iron  glance  in  volcanic  masses,  234  ; 
chemical  combinations,  a  means  of 
throwing  a  clear  light  on  geognosy,  256 ; 
on  gypsum,  as  a  uniaxal  crystal,  259 ; 
experiments  on  the  simultaneously  op- 
posite actions  of  heat  on  crystalline 
bodies,  259 ;  formation  of  crystals  of 
mica,  260;  on  artificial  mineral  prod- 
ucts, 268,  271. 

Mofettes  (exhalations  of  carbonic  acid 
gas),  215-219. 

Monsoons  (Indian),  316,  317. 

Monticelli  on  the  current  of  hydrochloric 
acid  from  the  crater  of  Vesuvius,  235  ; 
crystals  of  mica  found  in  the  lava  of 
Vesuvius,  260. 

Moon,  the,  its  relative  magnitude,  96 ; 
density,  96  ;  distance  from  the  earth, 
97 ;  its  libration,  98,  163 ;  its  light  com- 
pared with  that  of  the  Aurora,  201,  202 ; 
volcanic  action  in,  228. 

Moons  or  satellites,  their  diameter,  dis- 
tances, rotation,  (fee,  95-99. 

Morgan,  John  H.,  "on  the  Aurora  Bore- 
alis  of  Oct.  24, 1847."  See  Translator's 
notes,  194,  199. 

Morton,  Samuel  George,  his  magnificent 
work  on  the  American  Races,  362. 

Moser's  images,  202. 

Mountains,  in  Asia,  America,  and  Europe, 
their  altitude,  scenery,  and  vegetation, 
27-30,  228,  347  ;  their  influence  on  cli- 
mate, natural  productions,  and  on  the 
human  race,  its  trade,  civilization,  and 
social  condition,  291,  292,  299,  300,  327 ; 
zones  of  vegetation  on  the  declivities 
of  29,  30,  327-329  ;  snow-lme  of,  30-33, 
330,  331. 

Mud  volcanoes.  See  Salses  and  Volca- 
noes. 

Miiller,  Johannes,  on  the  modifications 
of  plants  and  animals  within  certain 
limitations,  353. 

Muncke  on  the  appearance  of  Auroras  in 
certain  districts,  198. 

Murchison,  Sir  R.,  account  of  a  large  fis- 
sure through  which  melaphyre  had 
been  ejected,  258  ;  classification  of  fos- 
siliferous  strata,  277  ;  on  the  age  of  the 


INDEX. 


371 


Palseosaurus  and  Thecodontosaurus  of 
Bristol,  274. 

Muscheiibroek  on  the  frequency  of  mete- 
ors in  August,  125. 

Myndius,  Apollonius,  on  the  Pythagorean 
doctrine  of  comers,  103,  104. 

Vature,  result  of  a  rational  inquiry  into, 
25;  emotions  excited  by  her  contem- 
plation, 25;  striking  scenes,  26;  their 
sources  of  enjoyment,  26,  27 ;  magnifi- 
cence of  the  tropical  scenery,  33,  34,  35, 
344 ;  religious  impulses  from  a  com- 
munion with  nature,  37 ;  obstacles  to 
an  active  spirit  of  inquiry,  37 ;  mischief 
of  inaccurate  observations,  38  ;  higher 
enjoyments  of  her  study,  38 ;  narrow- 
minded  views  of  nature,  38  ;  lofty  im- 
pressions produced  on  the  minds  of  la- 
borious observers,  40  ;  nature  defined, 
41 ;  her  studies  inexhaustible,  41 ;  gen- 
eral observations,  their  great  advanta- 
ges, 42 ;  how  to  be  correctly  compre- 
hended, 72  ;  her  most  vivid  impressions 
earthly,  82. 

Nature,  philosophy  of,  24,  37;  physical 
description  of,  66,  67.  73. 

NebulcB,  84-86  ;  nebulous  Milky  Way  at 
right  angles  with  that  of  the  stars,  150- 
153  ;  nebulous  spots,  conjectures  on, 
83-86  ;  nebulous  stars  and  planetary 
nebulae,  85,  151,  152 ;  nebulous  vapor, 
83-86,  87,  152 ;  their  supposed  conden- 
sation in  conformity  with  the  laws  of 
attraction,  84. 

Neilson,  gradual  depression  of  the  south- 
ern part  of  Sweden,  295. 

Nericat,  Andrea  de,  popular  belief  in  Syr- 
ia on  the  fall  of  aerolites,  123. 

Newton,  discussed  the  question  on  the  dif- 
ference between  the  attraction  of  mass- 
es and  molecular  attraction,  63 ;  New- 
tonian axiom  confirmed  by  Bessel,  64  ; 
his  edition  of  the  Geography  of  Vareni- 
us,  66 ;  Principia  Mathematica,  67  ;  con- 
sidered the  planets  to  be  composed  of 
the  same  matter  with  the  Earth,  132 ; 
compression  of  the  Earth,  16.5. 

Nicholl,  J.  P.,  note  from  his  account  of  the 
planet  Neptune,  90,  91. 

Nicholson,  observations  of  lightning 
clouds,  unaccompanied  by  thunder  or 
indications  of  storm,  337. 

Nobile,  Antonio,  experiments  of  the  height 
of  the  barometer,  and  its  influence  on 
the  level  of  the  sea,  298. 

Noggerath  counted  792  annual  rings  in  the 
trunk  of  a  tree  at  Bonn,  283. 

Nordmann  on  the  existence  of  animal- 
cules in  the  fluids  of  the  eyes  of  fishes, 
345. 

Norman,  Robert,  iarented  the  inclinato- 
riura,  179. 

Observations,  scientific,  mischief  of  in- 
accurate, 38;  tendency  of  unconnect- 
ed, 40. 

Ocean,  general  view  of,  292-311 ;  its  ex- 
tent as  compared  with  the  dry  land,  288, 
289 ;  its  depth.  160,  302 ;  tides.  30.5. 306 ; 


decreasing  temperature  at  increased 
depths,  302 ;  uniformity  and  constancy 
of  temperature  in  the  same  spaces,  303; 
its  currents  and  their  various  causes, 
306-309  ;  its  phosphorescence  in  the 
torrid  zone,  202 :  its  action  on  climate, 
303,  319-329 ;  inifluence  on  the  mental 
and  social  condition  of  the  human  race, 
162,  291,  292,  294,  310;  richness  of  its 
organic  life,  309,  310;  oceanic  micro- 
scopic forms,  342,  343  ;  sentiments  ex- 
cited by  its  contemplation,  310. 

CErsted,  electromagnetic  discoveries, 
188,  191. 

Olbers,  comets,  104,  109;  aerolites,  114, 
118 ;  on  their  planetary  velocity,  121 ; 
on  the  supposed  phenomena  of  ascend- 
ing shooting  stars,  123 ;  their  periodic  re- 
turn in  August,  125;  November  stream, 
126;  prediction  of  a  brilliantfall  of  shoot- 
ing stars  in  Nov.,  1867, 127  ;  absence  of 
fossil  meteoric  stones  in  secondary  and 
tertiary  formations,  131 ;  zodiacal  light, 
its  vibration  through  the  tails  of  com- 
ets, 143 ;  on  the  transparency  of  celes- 
tial space,  152. 

Olmsted,  Denison,  of  New  Haven,  Con- 
necticut, observations  of  aerolites,  113, 
118,  119,  124. 

Oltmanns,  Herr,  observed  continuously 
with  Humboldt,  at  Berlin,  the  move- 
ments of  the  declination  needle,  190, 
191. 

Ovid,  his  description  of  the  volcanic  Hill 
of  Methone,  240. 

Oviedo  describes  the  weed  of  the  Gulf 
Stream  as  Praderias  de  yerva  (sea 
weed  meadows),  308. 

Palieontology,  270-284. 

Pallas,  meteoric  iron,  131 . 

Palmer,  New  Haven,  Connecticut,  on  the 
prodigious  swarm  of  shootirig  stars, 
Nov.  12  and  13,  1833,  124 ;  on  the  non- 
appearance in  certain  years  of  the  Au- 
gust and  November  fall  of  aerolites, 
129. 

Parallaxes  of  fixed  stars,  88,  89  ;  of  the  so- 
lar system,  145,  146. 

Parian  and  Carrara  marbles,  262,  263. 

Parry,  Capt.,  on  Auroras,  their  connection 
with  magnetic  perturbations,  197,  201 ; 
whether  atrended  with  any  sound,  200  ; 
seen  to  continue  throughout  the  day, 
197  ;  barometric  observation  at  Port 
Bowen,  314,  315  ;  rarity  of  electric  ex- 
plosions in  northern  regions,  337. 

Patricius,  St.,  his  accurate  conjectures  on 
the  hot  springs  of  Carthage,  223,  224. 

Peltier  on  the  actual  source  of  atmos- 
pheric electricity,  335,  336. 

Pendulum,  its  scientific  uses,  44  ;  experi- 
ments with,  64, 166, 169, 170  ;  employed 
to  investigate  the  curvature  of  the 
earth's  surl'ace.  165 ;  local  attraction,  its 
influence  on  the  pendulum,  and  geog- 
nostic  knowledge  deduced  from,  44, 45, 
167,  168 ;  experiments  of  Bessel,  64. 

Pentland,  his  measurements  of  the  Andisa 
28 


372 


COSMOS. 


Percy,  Dr.,  on  minerals  artificially  pro- 
duced.    See  note  by  Translator,  268. 

Permian  system  of  Murchison,  277. 

Perouse,  La,  expedition  of,  186. 

Persia,  great  comet  seen  in  (1668),  139, 
140. 

Pertz  on  the  large  aerolite  that  fell  in  the 
bed  of  the  River  Nami,  116. 

Peters,  Dr.,  velocity  of  stones  projected 
from  iEtna,  122. 

Peucati,  Count  Mazari,  partial  infection 
of  calcareous  beds  by  the  contact  of 
syenitic  granite  in  the  Tyrol,  262. 

Phillips  on  the  temperature  of  a  coal- 
mine at  increasing  depths,  174. 

Philolaiis,  his  astronomical  studies,  65; 
his  fragmentary  writings,  68-71. 

Philosophy  of  nature,  first  germ,  37. 

Phosphorescence  of  the  sea  in  the  torrid 
zones,  202. 

Physics,  their  limits,  50 ;  influence  of  phys- 
ical science  on  the  wealth  and  prosper- 
ity of  nations,  53 ;  province  of  physical 
science,  59  ;  distinction  between  the 
physical  history  and  physical  descrip- 
tion of  the  world,  71,  72 ;  physical  sci- 
ence, characteristics  of  its  modern  prog- 
ress, 81. 

Pindar,  227. 

Plana,  geodesic  experiments  in  Lombar- 
dy,  168. 

Planets,  89-99;  present  number  discov- 
ered, 90.  (See  note  by  Translator  on 
the  most  recent  discoveries,  90, 91) ;  Sir 
Isaac  Newton  on  their  composition,  132 ; 
limited  physical  knowledge  of,  156, 157  ; 
Ceres,  64-92;  Earth,  88-99;  Juno,  64, 
92-97,  106;  Jupiter.  64,  87,  92-98.  202; 
Mars,  87,  91-94,  132 ;  Mercury,  87,  92- 
94  ;  Pallas,  64,  92 ;  Saturn,  87,  92-94 ; 
Venus,  91-94,  202 ;  Uranus,  90-94 ;  plan- 
ets which  have  the  largest  number  of 
moons,  95,  96. 

Plants,  geographical  distribution  of,  346- 
350. 

Plato  on  the  heavenly  bodies,  &c.,  69 ;  in- 
terpretation of  nature,  163 ;  his  geog- 
nostic  views  on  hot  springs,  and  vol- 
canic igneous  streams,  237,  238. 

Pliny  the  elder,  his  Natural  History,  73  ; 
on  comets,  104  ;  aerohtes,  122,  123, 130; 
magnetism,  180;  attraction  of  amber, 
188 ;  on  earthquakes,  205,  207 ;  on  the 
flame  of  inflammable  gas,  in  the  district 
of  Phaselis,  223 ;  rarity  of  jasper,  261 ; 
on  the  configuration  of  Africa,  292. 

PUny  the  younger,  his  description  of  the 
great  eruption  of  Mount  Vesuvius,  and 
the  phenomenon  of  volcanic  ashes,  235. 

Plutarch,  truth  of  his  conjecture  that  fall- 
ing stars  are  celestial  bodies,  133,  134. 

Poisson  on  the  planet  Jupiter,  64 ;  conjec- 
ture on  the  spontaneous  ignition  of  me- 
teoric stones,  118 ;  zodiacal  light,  141 ; 
theorj'  on  the  earth's  temperature,  172, 
173,  174,  176,  177. 

Polarization,  chromatic,  results  of  its  dis- 
covery, 52 ;  experiments  on  the  light  of 
comets,  105,  106. 

Polybius,  291. 


Posidonius  on  the  Ligyan  field  of  stowea, 
115,  116. 

Pouillet  on  the  actual  source  of  atmos- 
pheric electricity,  335. 

Prejudices  against  science,  how  originat- 
ed, 38  ;  against  the  study  of  the  exact 
sciences,  why  fallacious,  40,  52. 

Prichard,  his  physical  history  of  Man- 
kind, 352. 

Pseudo-Plato,  54. 

Psychrometer,  332,338. 

Pythagoras,  first  employed  the  word  Cos 
mos  in  its  modern  sense,  69. 

Pythagoreans,  their  study  of  the  heavenly 
bodies,  65;  doctrine  on  comets,  103. 

Quarterly  Review,  article  on  Terrestrial 

Magnetism,  192. 
Quetelet  on  aerohtes,  114 ;  their  periodic 

return  in  August,  125. 

Races,  human,  their  geographical  distri 
bution,  and  unity,  351-359. 

Rain  drops,  temperature  of,  220 ;  mean  an- 
nual quantity  in  the  two  hemispheres, 
333,  334. 

Reich,  mean  density  of  the  earth,  as  as 
certained  by  the  torsion  balance,  170 ; 
temperature  of  the  mines  in  Saxony, 
174. 

Reisch,  Gregory,  his  "  Margarita  Philo 
sophica,"  58. 

Remusat,  Abel,  MongoUan  tradition  on  the 
fall  of  an  aerolite,  116 ;  active  volcanoes 
in  Central  Asia,  at  gi'eat  distances  from 
the  sea,  245. 

Richardson,  magnetic  phenomena  attend 
ing  the  Aurora,  197;  whether  accom 
panied  by  sound,  200 ;  influence  on  the 
magnetic  needle  of  the  Aurora,  201. 

Riobamba,  earthquake  at,  204,  206,  208, 
213,  214. 

Ritter,  Carl,  his  "  Geography  in  relation 
to  Nature  and  the  History  of  Man,"  48, 
67. 

Robert,  Eugene,  on  the  ancient  sea-line  o» 
the  coast  of  Spitzbergen,  296. 

Robertson  on  the  permanency  of  the  com- 
pass in  Jamaica,  181. 

Rocks,  their  nature  and  configuration, 
228 ;  geognostical  classification  into  four 
groups,  248-251 ;  i.  rocks  of  eruption, 
248, 251-253 ;  ii.  sedimentary  rocks,  248, 
254,  255  ;  iii.  transformed,  or  meta- 
morphic  rocks,  248,  249,  255,  256-269 ; 
i^'.  conglomerates,  or  rocks  of  detritus, 
269,  270 ;  their  changes  from  the  action 
of  heat,  258,  259  ;  phenomena  of  con- 
tact, 258-267 ;  effects  of  pressure  and 
the  rapidity  of  cooUng,  258,  267. 

Rose,  Gustav,  on  the  chemical  elements, 
(fee,  of  various  aerolites,  131 ;  on  the 
structural  relations  of  volcanic  rocks, 
234 ;  on  crystals  of  feldspar  and  albite 
found  in  granite,  251 ;  relations  of  posi- 
tion in  which  granite  occurs,  252-269  : 
chemical  process  in  the  formation  of 
various  minerals,  265-269. 

Ross,  Sir  James,  his  soundings  with  27.600 
feet  of  line,  160 ;  magnetic  observations 


INDEX. 


373 


at  the  South  Pole,  187;  important  re- 
sults of  the  Antarctic  magnetic  expedi- 
tion in  1839,  192  ;  rarity  of  electric  ex- 
plosions in  high  northern  regions.  337. 

Rossell,  M.  de,  his  magnetic  oscillation 
experiments,  and  their  date  of  pubU- 
cation,  186,  187. 

/tothmann,  confounded  the  setting  zodi- 
acal hght  with  the  cessation  of  twilight, 
143. 

JLozier,  observation  of  a  steady  luminous 
appearance  in  the  clouds,  202. 

Rijmker,  Encke's  comet,  106. 

iliippell  denies  the  existence  of  active 
volcanoes  in  Kordofan,  245. 

'■abine,  Edward,  observations  on  days  of 
unusual  magnetic  disturbance,  178 ;  re- 
cent magnetic  observations,  184,  185, 
187,  188. 
'agra,  Ramon  de  la,  observations  on  the 
mean  annual  quantity  of  rain  in  the 
Havana,  333. 

feint  Pierre,  Bernardin  de,  Paul  and  Vir- 
ginia, 26 ;  Studies  of  Nature,  347. 

lalses  or  mud  volcanoes,  224-228 ;  strik- 
ing phenomena  attending  their  origin, 
224,  225. 

^It- works,  depth  of,  158,  159  ;  tempera- 
ture, 174. 

lantorino,  the  most  important  of  the  isl- 
ands of  eruption,  241,  242;  description 
of.    See  note  by  Translator,  241. 

sargasso  Sea,  its  situation,  308. 

Satellites  revolving  round  the  primary 
planets,  their  diameter,  distance,  rota- 
tion, &c.,  94,  99 ;  Saturn's,  96-98,  127 ; 
Earth's,  see  Moon,  Jupiter's,  96,  97 ; 
Uranus,  96-98. 

Saurians,  flying,  fossil  remains  of,  274, 
275. 

Saussure,  measurements  of  the  marginal 
ledge  of  the  crater  of  Mount  Vesuvius, 
2.32 ;  traces  of  ammoniacal  vapors  in 
the  atmosphere,  311  ;  hygrometric 
measurements  with  Humboldt,  334-336. 

Schayer,  microscopic  organisms  in  the 
ocean,  342,  343. 

Scheerer  on  the  identity  of  eleolite  and 
nepheline,  253. 

Schelling  on  nature,  55 ;  quotation  from 
his  Giordino  Bruno,  77. 

Scheuchzner's  fossil  salamander,  conjec- 
tured to  be  an  antediluvian  man,  274. 

Schiller,  quotation  from,  36. 

Schnurrer  on  the  obscuration  of  the  sun's 
disk,  133. 

Schouten,  Cornelius,  in  1616  found  the 
declination  null  in  the  Pacific,  182. 

Schouw,  distribution  of  the  quantity  of 
rain  in  Central  Europe,  333. 

Schrieber  on  the  fragmentary  character 
of  meteoric  stones,  117. 

Scientific  researches,  their  frequent  re- 
sult, 50 ;  scientific  knowledge  a  require- 
ment of  the  present  age,  53,  54  ;  scien- 
tific terms,  their  vagueness  and  misap- 
plication, 58,  68. 

Scina,  Abbate,  earthquakes  unconnected 
with  the  state  of  the  weather,  206,  207. 


Scoresby,  rarity  3f  electric  explosions  in 
high  northern  regions,  337. 

Sea.     See  Ocean. 

Seismometer,  the,  205. 

Seleucus  of  Erythrea,  his  astronomical 
studies,  65. 

Seneca,  noticed  the  direction  of  the  tails 
of  comets,  102 ;  his  views  on  the  nature 
and  paths  of  comets,  103,  104 ;  omens 
drawn  from  their  sudden  appearance, 
111 ;  the  germs  of  later  observations  on 
earthquakes  found  in  his  writings,  207 ; 
problematical  extinction  and  sinking  of 
Mount  .(Etna,  227,  240. 

Shoals,  atmospheric  indications  of  their 
vicinity,  309. 

Sidereal  systems,  89,  90. 

Siljerstrom,  his  observations  on  the  Au- 
rora, with  Lottin  and  Bravais,  on  the 
coast  of  Lapland,  195. 

Sirowatskoi,  "  Wood  Hills"  in  New  Sibe- 
ria, 281. 

Snow-line  of  the  Himalayas,  30-33,  331, 
332 ;  of  the  Andes,  330 ;  redness  of  long- 
fallen  snow,  344. 

Solar  system,  general  description,  90-154 ; 
its  position  in  space,  89 ;  its  translatory 
motion,  145-150. 

Solinus  on  mud  volcanoes,  225. 

Sommering  on  the  fossil  remains  of  the 
large  vertebrata,  274. 

Somerville,  Mrs.,  on  the  volume  of  fire- 
balls and  shooting  stars,  116 ;  faintness 
of  light  of  planetary  nebulae,  141. 

Southern  celestial  hemisphere,  its  pictur- 
esque beauty,  85,  86. 

Spontaneous  generation,  345,  346. 

Springs,  hot  and  cold,  219-225  ;  intermit- 
tent, 219  ;  causes  of  their  temperature, 
220-222;  thermal,  222,  345;  deepest 
Artesian  wells  the  warmest,  observed 
by  Arago,  223 ;  salses,  224-226 ;  influ- 
ence of  earthquake  shocks  on  hot 
springs,  210,  222-224. 

Stars,  general  account  of,  85-90;  fixed, 
89.  90,  104;  double  and  multiple.  89, 
147;  nebulous,  85,  86.  151,  152;  their 
translatory  motion,  147-150 ;  parallaxes 
and  distances,  147-149 ;  computations 
of  Bessel  and  Herschel  on  their  diame- 
ter and  volume,  148 ;  immense  number 
in  the  Milky  Way,  150,  151 ;  star  dust, 
85 ;  star  gaugings,  150 ;  starless  spaces, 
150, 152 ;  telescopic  stars,  152 ;  velocity 
of  the  propagation  of  light  of,  153, 154 ; 
apparition  of  new  stars,  153. 

Storms,  magnetic  and  volcanic.  See 
Magnetism,  Volcanoes. 

Strabo,  observed  the  cessation  of  shocks 
of  earthquake  on  the  eruption  of  lava, 
215 ;  on  the  mode  in  which  islands  are 
formed,  227 ;  description  of  the  Hill  of 
Methone,  240;  volcanic  theory,  243; 
divined  the  existence  of  a  continent  in 
the  northern  hemisphere  between  The- 
ria  and  Thine,  289 ;  extolled  the  varied 
form  of  our  small  continent  as  favorable 
to  the  moral  and  intellectual  develop- 
ment of  its  people,  291,  292. 

Struve,  Qtho,  on  the  proper  motion  of  the 


374 


COSMOS. 


eolar  system,  146;  investigations  on  the 
propa2;ation  of  light,  153 ;  parallaxes 
and  distances  of  fixed  stars,  153 ;  ob- 
servations on  Halley's  comet,  105. 

Studer,  Professor,  on  mineral  metamorph- 
ism.     See  note  by  Translator,  248. 

Sun,  magnitude  of  its  volume  compared 
with  that  of  the  fixed  stars,  136 ;  obscu- 
ration of  its  disk,  132 ;  rotation  round 
the  center  of  gravity  of  the  whole  solar 
system,  145 ;  velocity  of  its  translatory 
motion,  145 ;  narrow  limitations  of  its 
atmosphere  as  compared  with  the  nu- 
cleus of  other  nebulous  stars,  141;  "sun 
stones"  of  the  ancients,  122 ;  views  of  the 
Greek  philosophers  on  the  sun,  122. 

Symond,  Lieut.,  his  trigonometrical  sur- 
vey of  the  Dead  Sea,  296,  297. 

Tacitus,  distinguished  local  climatic  rela- 
tions from  those  of  race,  352. 

Temperature  of  the  globe,  see  Earth  and 
Ocean  ;  remarkable  uniformity  over 
the  same  spaces  of  the  surface  of  the 
ocean,  303 ;  zones  at  which  occur  the 
maxima  of  the  oceanic  temperature, 
304 ;  causes  which  raise  the  tempera- 
ture, 319  ;  causes  which  lower  the  tem- 
perature, 319,  320 ;  temperature  of  va- 
rious places,  annual,  and  in  the  difler- 
ent  seasons,  322,323-328;  thermic  scale 
of  temperature,  324, 325 ;  of  continental 
climates  as  compared  with  insular  and 
littoral  climates,  321,  322 ;  law  of  de- 
crease with  increase  of  elevation,  327 ; 
depression  of,  by  shoals,  309  ;  refrigera- 
tion of  the  lower  strata  of  the  ocean,  303. 

Teneriffe,  Peak  of,  its  striking  scenery,  26. 

Theodectes  of  Phaselis  on  the  color  of  the 
Ethiopians,  353. 

Theon  of  Alexandria  described  comets  as 
"  wandering  light  clouds,"  100. 

Theophylactus  described  Scythia  as  free 
from  earthquakes,  204. 

Thermal  scales  of  cultivated  plants,  324. 
325. 

Thermal  springs,  their  temperature,  con- 
stancy, and  change,  221-224 ;  animal 
and  vegetable  life  in,  345. 

Thermometer,  338. 

Thibet,  habitability  of  its  elevated  pla- 
teaux, 331,  332. 

Thienemann  on  the  Aurora,  197,  200. 

Thought,  results  of  its  free  action,  53, 54 ; 
union  with  language,  56. 

Tiberias,  Sea  of,  its  depression  below  the 
level  of  the  Mediterranean,  296. 

Tides  of  the  ocean,  their  phenomena,  305, 
306. 

Tillard,  Capt,  on  the  sudden  appearance 
of  the  island  of  Sabrina,  242. 

Tournefort,  zones  of  vegetation  on  Mount 
Ararat,  347. 

Tralles,  his  notice  of  the  negative  electric- 
ity of  the  air  near  high  waterfalls,  336. 

Translator,  notes  by,  29  ;  on  the  increase 
of  the  earth's  internal  heat  with  increase 
of  depth,  45 ;  silicious  infusoria  and  an- 
imalculites,  46 .  chemical  analysis  of  an 
aerolite,  64  •  on  the  recent  discoveries 


of  planets,  90,  91 ;  observed  the  comet 
of  1843,  at  New  Bedford,  Massachusetts, 
in  bright  sunshine,  101 ;  on  meteoric 
stones,  111 ;  on  a  MS.,  said  to  be  in  the 
Hbrary  of  Christ's  College,  Cambridge, 
124  ;  on  the  term  "  salses,"  161 ;  on  Hol- 
berg's  satire,  "  Travels  in  the  World 
under  Ground,"  171 ;  on  the  Aurora  Bo- 
realis  of  Oct.  24,  1847,  194,  195,  199 ;  on 
the  electricity  of  the  atmosphere  dur- 
ing the  Aurora,  200 ;  on  volcanic  phe- 
nomena, 203,  204  ;  description  of  the 
seismometer,  205 ;  on  the  great  eai'th- 
quake  of  Lisbon,  210 ;  impression  made 
on  the  natives  and  foreigners  by  earth- 
quakes in  Peru,  215;  earthquakes  at 
Lima,  216,  217  ;  on  the  gaseous  com- 
pounds of  sulphur,  217,  218;  on  the 
Lake  of  Laach,  its  craters,  218  ;  on  the 
emissions  of  inflammable  gas  in  the  dis- 
trict of  Phaselis,  223  ;  on  true  volcanoes 
as  distinguished  from  salses,  224  ;  on 
the  volcano  of  Pichincha,  228 ;  on  the 
hornitos  de  Jorullo,  as  seen  by  Hum- 
boldt, 230  ;  general  rule  on  the  dimen- 
sions of  craters,  230 ;  on  the  ejection  of 
fish  from  the  volcano  of  Imbaburu,  233 ; 
on  the  little  isle  of  Volcano,  234 ;  vol- 
canic steam  of  Pantellaria,  235;  on  Dau- 
beney's  work  "On  Volcanoes,"  236  ;  ac- 
count of  the  island  of  Santorino,  241 ; 
of  the  island  named  Sabrina,  242 ;  on 
the  vicinitj^  of  extinct  volcanoes  to  the 
sea,  244  ;  meaning  of  the  Chinese  term 
"  li,"  245 ;  on  mineral  metamorphism, 
248 ;  on  fossil  human  remains  found  iu 
Guadaloupe,  250  ;  on  minerals  artificial- 
ly produced,  267,  268 ;  fossil  organic 
structures,  271, 272 ;  on  Coprolites,  271 ; 
geognostic  distribution  of  fossils,  276 ; 
fossil  fauna  of  the  Sewalik  Hills,  278 ; 
thickness  of  coal  measures,  281 ;  on  the 
amber  pine  forests  of  the  Baltic,  283, 
284  ;  elevation  of  mountain  chains,  286, 
287  ;  the  dinornis  of  Owen,  287 ;  depth 
of  the  atmosphere,  302 ;  richness  of  or- 
ganic lite  in  the  ocean,  309 ;  on  fila- 
ments of  plants  resembling  the  sperma- 
tozoa of  animals,  341 ;  on  the  Diatoma- 
ceee  found  in  the  South  Arctic  Ocean, 
343 ;  on  the  distribution  of  the  floras 
and  faunas  of  the  British  Isles,  348, 349  ; 
on  the  origin  and  dift'usion  of  the  Brit- 
ish flora,  353,  354. 

Translatory  motion  of  the  solar  system, 
145-150. 

Trogus,  Pompeius,  on  the  supposed  ne- 
cessity that  volcanoes  were  dependent 
on  their  vicinity  to  the  sea  for  their  con- 
tinuance, 243,  244  ;  views  of  the  an- 
cients on  spontaneous  generation,  346. 

Tropical  latitudes,  their  advantages  for 
the  contemplation  of  nature,  33  ;  pow- 
erful impressions  from  their  organic 
richness  and  fertihty,  34 ;  facilities  thej 
present  for  a  knowledge  of  the  laws  ot 
nature,  35 ;  transparency  of  the  atmos- 
phere, 114;  phosphorescence  of  the  sea. 
202. 

Tschudi,  Dr.,  extract  from  his  "  Travels 


I\DEX. 


375 


in  Teru."    See  Translator's  note,  215, 
216,  217. 
Turner,  note  on  Sir  Isaac  Newton,  132. 

Universality  of  animated  life,  342,  343. 

Valz  on  the  comet  of  1618,  106. 

Varenius,  Bernhard,  his  excellent  general 
and  comparative  Geography,  66,  67 ; 
edited  by  Newton,  66. 

Vegetable  world,  as  viewed  with  micro- 
scopic powers  of  vision,  341 ;  its  pre- 
dominance over  animal  life,  343. 

Vegetation,  its  varied  distribution  on  the 
earth's  surface,  29-31,  62 ;  richness  and 
fertility  in  the  tropics,  33-35 ;  zones  of 
vegetation  on  the  declivities  of  mount- 
ams,  29-32,  346-350.  See  ^tna,  Cor- 
dilleras, Himalayas,  Mountains. 

Vico,  satellites  of  Saturn,  96. 

Vigne,  measurement  of  Ladak,  332. 

Vine,  thermal  scale  of  its  cultivation,  324. 

Volcanoes,  28,  30,  35,  159,  161,  214,  215, 
224-248  ;  author's  application  of  the 
term  volcanic,  45;  active  volcanoes, 
safety-valves  for  their  immediate  neigh- 
borhood, 214  ;  volcanic  eruptions,  161, 
210-270 ;  mud  volcanoes  or  salses,  224- 
228 ;  traces  of  volcanic  action  on  the 
surface  of  the  earth  and  moon,  228 ;  in- 
fluence of  relations  of  height  on  the  oc- 
currence of  eruptions,  228-233 ;  vol- 
canic storm,  233  ;  volcanic  ashes,  233 ; 
classification  of  volcanoes  into  central 
and  linear,  238 ;  theory  of  the  necessity 
of  their  proximity  to  the  sea,  243-246 ; 
geographical  distribution  of  still  active 
volcanoes,  245-247 ;  metamorphic  ac- 
tion on  rocks,  247-249. 

Vrolik,  his  anatomical  investigations  on 
the  form  of  the  pelvis,  352,  353. 

Wagner,  Rudolph,  notes  on  the  races  of 
Africa,  352. 

Walter  on  the  decrease  of  volcanic  activ- 
ity. 215. 


Wartmann,  meteors,  113,  114. 

Weber,  his  anatomical  investigations  on 
the  form  of  the  pelvis,  353. 

Webster,  Dr.  (of  Harvard  College,  U.  S.), 
account  of  the  island  named  Sabrina. 
See  note  by  Translator,  242. 

Winds,  315-321 ;  monsoons,  316,  317 ; 
trade  winds,  320,  321 ;  law  of  rotation, 
importance  of  its  knowledge,  315-317. 

Wine,  on  the  temperature  required  for 
its  cultivation,  324 ;  thermic  table  of 
mean  annual  heat,  325. 

Wollastou  on  the  linaitation  of  the  atmos- 
phere, 302. 

Wrangel,  Admiral,  on  the  brilliancy  of  the 
Aurora  Borealis,  coincident  with  the 
fall  of  shooting  stars,  126,  127 ;  observa- 
tions of  the  Aurora,  197, 200 ;  wood  hills 
of  the  Siberian  Polar  Sea,  281. 

Xenophanes  of  Colophon,  described  com- 
ets as  wandering  light  clouds,  100 ;  ma- 
rine fossils  found  in  marble  quarries, 
263. 

Young,  Thomas,  earliest  observer  of  the 
influence  diflerent  kinds  of  rocks  exer- 
cise on  the  vibrations  of  the  pendulum, 
168. 

Yul-sung,  described  by  Chinese  writers  as 
"  the  realm  of  pleasure,"  332. 

Zimmerman,  Carl,  hypsometrical  le- 
marks  on  the  elevation  of  the  Hima- 
layas, 32. 

Zodiacal  light,  conjectures  on,  86-92  ; 
general  account  of,  137-144  ;  beautiful 
appearance,  137,  138  ;  first  described 
in  Childrey's  Britannia  Baconica,  138 ; 
probable  causes,  141 ;  intensity  in  trop- 
ical  climates,  142. 

Zones,  of  vegetation,  on  the  declivities  of 
mountains,  29-33 ;  of  latitude,  their  di 
versified  vegetation,  62 ;  of  the  south- 
em  heavens,  their  magnificence,  85, 86 ; 
polar,  197,  198. 


END    OF    VOL.   I, 


WILLIAMS  COLLEGE 


mil  mill!!!  II! 


3  0001  038243046 


SCHOW 
Q158  .H9 

V.   1 

Humboldt,  Alexander  von, 
1769-1859 


/ 


DATE  DUE 

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