a journey in other worlds-第29节

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local　water…supply　would　cut　back　the　banks；　having　most　effect
where　they　were　steepest；　since　at　those　points　it　would　move
with　the　greatest　speed。　　Thus　the　majestic　canon　owes　its
existence　to　two　things：　the　length　of　time　the　river　has　been　at
work；　and　the　fact　that　the　water　flowing　through　it　comes　from
another　region　where；　of　course；　there　is　rain；　and　that　it　is
merely　in　transit；　and　so　affects　only　the　bed　on　which　it　moves。　
Granting　that　this　is　the　eastern　of　the　two　continents　we
observed；　it　evidently　corresponds　more　in　shape　to　the　Eastern
hemisphere　on　earth　than　to　the　New　World；　both　of　which　are　set
facing　one　another；　since　both　drain　towards　the　Atlantic　Ocean。　
But　the　analogy　here　holds　also；　for　the　past　outlines　of　the
Eastern　hemisphere　differed　radically　from　what　they　are　now。　
The　Mediterranean　Sea　was　formerly　of　far　greater　extent　than　we
see　it　to…day；　and　covered　nearly　the　whole　of　northern　Africa
and　the　old　upheaved　sea…bottom　that　we　see　in　the　Desert　of
Sahara。　　Much　of　this　great　desert；　as　we　know；　has　a
considerable　elevation；　though　part　of　it　is　still　below　the
level　of　the　Mediterranean。
　　　
〃Perhaps　a　more　striking　proof　of　this　than　are　the　remains　of
fishes　and　marine　life　that　are　found　there；　is　the　dearth　of
natural　harbours　and　indentations　in　Africa's　northern　coast；
while　just　opposite；　in　southern　Europe；　there　are　any　number；
which　shows　that　not　enough　time　has　elapsed　since　Africa's
upheaval　for　liquid　or　congealed　water　to　produce　them。　　Many　of
Europe's　best　harbours；　and　Boston's；　in　our　country；　have　been
dug　out　by　slow　ice…action　in　the　oft…recurring　Glacial　periods。　
The　Black　and　Caspian　Seas　were　larger　than　we　now　find　them；
while　the　Adriatic　extended　much　farther　into　the　continent；
covering　most　of　the　country　now　in　the　valley　of　the　Po。　　In
Europe　the　land　has；　of　course；　risen　also；　but　so　slowly　that
the　rivers　have　been　able　to　keep　their　channels　cut　down；　proof
of　their　ability　to　perform　which　feat　we　see　when　an　ancient
river　passes　through　a　ridge　of　hills　or　mountains。　　The　river
had　doubtless　been　there　long　before　the　mountains　began　to　rise；
but　their　elevation　was　so　gradual　that　the　rate　of　the　river's
cutting　down　equalled　or　exceeded　their　coming　up；　proof　of　which
we　have　in　the　patent　fact　that　the　ancient　river's　course
remains　unchanged；　and　is　at　right　angles　to　the　mountain　chain。　
From　all　of　which　we　see　that　the　Eastern　hemisphere's　crescent
hollowof　which；　I　take　it；　the　Mediterranean；　Black；　and
Caspian　Sea　depressions　are　the　remainshas　been　gradually
filled　in；　by　the　elevation　of　the　sea's　bottom；　and　the
extension　of　deltas　from　the　detrital　matter　brought　from　the
high　interior　of　the　continents　by　the　rivers；　or　by　the　combined
action　of　the　two。　　Now；　since　the　Gulf　of　Mexico　has　been
constantly　growing　smaller；　and　the　Mediterranean　is　being
invaded　by　the　land；　I　reason　that　similar　causes　will　produce
like　effects　here；　and　give　to　each　continent　an　area　far　greater
than　our　entire　globe。　　The　stormy　ocean　we　behold　in　the　west；
which　corresponds　to　our　Atlantic；　though　it　is　far　more　of　a
mare　clausum　in　the　geographical　sense；　is　also　destined　to
become　a　calm　and　placid　inland　sea。　　There　are；　of　course；
modifications　of　and　checks　to　the　laws　tending　to　increase　the
land　area。　　England　was　formerly　joined　to　the　continent；　the
land　connecting　the　two　having　been　rather　washed　away　by　the
waves　and　great　tides　than　by　any　sinking　of　the　English
Channel's　bottom；　the　whole　of　which　is　comparatively　shallow。　
Another　case　of　this　kind　is　seen　in　Cape　Cod　and　the　islands　of
Martha's　Vineyard　and　Nantucket；　all　of　which　are　washing　away　so
rapidly　that　they　would　probably　disappear　before　the　next
Glacial　period；　were　we　not　engaged　in　preventing　its　recurrence。　
These　detached　islands　and　sand…bars　once　formed　one　large
island；　which　at　a　still　earlier　time　undoubtedly　was　joined　to
the　mainland。　　The　sands　forming　the　detached　masses　are　in　a
great　processional　march　towards　the　equator；　but　it　is　the
result　simply　of　winds　and　waves；　there　being　no　indication　of
subsidence。　　Along　the　coast　of　New　Jersey　we　see　denudation　and
sinking　going　on　together；　the　well…known　SUNKEN　FOREST　being　an
instance　of　the　latter。　　The　border　of　the　continent　proper　also
extends　many　miles　under　the　ocean　before　reaching　the　edge　of
the　Atlantic　basin。　　Volcanic　eruptions　sometimes　demolish　parts
of　headlands　and　islands；　though　these　recompense　us　in　the
amount　of　material　brought　to　the　surface；　and　in　the　increased
distance　they　enable　water　to　penetrate　by　relieving　the　interior
of　part　of　its　heat；　for　any　land　they　may　destroy。〃



　　　　　　　　　　　　　　　　　　　　　　　　　　　CHAPTER　XI。

　　　　　　　　　　　　　　　　　　　　　　　　A　JOVIAN　NIAGARA。

Four　days　later；　after　crossing　a　ridge　of　mountains　that　the
pressure　on　the　aneroid　barometer　showed　to　be　about　thirty…two
thousand　feet　high；　and　a　stretch　of　flat　country　a　few　miles　in
width；　they　came　to　a　great　arm　of　the　sea。　　It　was　about　thirty
miles　wide　at　its　mouth；　which　was　narrowed　like　the　neck　of　a
bottle；　and　farther　inland　was　over　one　hundred　miles　across；　and
though　their　glasses；　the　clear　air；　and　the　planet's　size
enabled　them　to　see　nearly　five　hundred　miles；　they　could　not
find　its　end。　　In　the　shallow　water　along　　　　　　its　shores；　and　on
the　islands　rising　but　a　few　feet　　　　　above　the　waves；　they　saw
all　kinds　of　amphibians　and　sea…monsters。　　Many　of　these　were
almost　the　exact　reproduction　in　life　of　the　giant　plesiosaurs；
dinosaurs；　and　elasmosaurs；　whose　remains　are　preserved　in　the
museums　on　earth。　　The　reptilian　bodies　of　the　elasmosaurs；
seventy…five　feet　in　length；　with　the　forked　tongues；　distended
jaws　and　fangs　of　a　snake；　were　easily　taken　for　the　often
described　but　probably　mythical　sea…　serpent；　as　partially　coiled
they　occasionally　raised　their　heads　twelve　or　fifteen　feet。
　　　
〃Man　in　his　natural　state；〃　said　Cortlandt；　〃would　have　but　small
chance　of　surviving　long　among　such　neighbours。　　Buckland；　I
think；　once　indulged　in　the　jeu　d'esprit　of　supposing　an
ichthyosaur　lecturing　on　the　human　skull。　　'You　will　at　once
perceive；'　said　the　lecturer；　'that　the　skull　before　us　belonged
to　one　of　the　lower　order　of　animals。　　The　teeth　are　very
insignificant；　the　power　of　the　jaws　trifling；　and　altogether　it
seems　wonderful　how　the　creature　could　have　procured　food。'　
Armed　with　modern　weapons；　and　in　this　machine；　we　are；　of
course；　superior　to　the　most　powerful　monster；　but　it　is　not
likely　that；　had　man　been　so　surrounded　during　the　whole　of　his
evolution；　he　could　have　reached　his　present　plane。〃

Notwithstanding　the　striking　similarity　of　these　creatures　to
their　terrestrial　counterparts　that　existed　on　earth　during　its
corresponding　period；　there　were　some　interesting　modifications。　
The　organs　of　locomotion　in　the　amphibians　were　more　developed；
while　the　eyes　of　all　were　larger；　the　former　being　of　course
necessitated　by　the　power　of　gravity；　and　the　latter　by　the
greater　distance　from　the　sun。
　　　
〃The　adaptability　and　economy　of　Nature；〃　said　Cortlandt；　〃have
always　amazed　me。　　In　the　total　blackness　of　the　Kentucky　Mammoth
Cave；　where　eyes　would　be　of　no　use　to　the　fishes；　our　common
mother　has　given　them　none；　while　if　there　is　any　light；　though
not　as　much　as　we　are　accustomed　to；　she　may　be　depended　upon　to
rise　to　the　occasion　by　increasing　the　size　of　the　pupil　and　the
power　of　the　eye。　　In　the　development　of　the　ambulatory　muscles
we　again　see　her　handiwork；　probably　brought　about　through　the
'survival　of　the　fittest。'　　The　fishes　and　those　wholly　immersed
need　no　increase　in　power；　for；　though　they　weigh　more　than　they
would　on　earth；　the　weight　of　the　water　they　displace　is
increased　at　the　same　rate　also；　and　their　buoyancy　remains
unchanged。　　If　the　development　of　life　here　so　closely　follows
its　lines　on　earth；　with　the　exception　of　comparatively　slight
modifications；　which　are　exactly　what；　had　we　stopped　to　think；
we　should　have　expected　to　find；　may　we　not　reasonably　ask
whether　she　will　not　continue　on　these　lines；　and　in　time　produce
beings　like　ourselves；　but　with　more　powerful　muscles　and　eyes
capable　of　seeing　clearly　with　less　light？　　Reasoning　by　analogy；
we　can　come　to　no　other　conclusion；　unless　their　advent　is
anticipated　by　the　arrival　of　ready…made　colonists　from　the　more
advanced　earth；　like　ourselves。　　In　that　case　man；　by　pursuing
the　same　destructive　methods　that　he　has　pursued　in　regard　to
many　other　species；　may　exterminate　the　intervening　links；　and　so
arrest　evolution。〃
　　　
Before　leaving　Deepwaters　Bay　they　secured　a　pail　of　its　water；
which　they　found；　on　examination；　contained　a　far　larger
percentage　of　salt　and　solid　material　than　the　oceans　on　earth；
while　a　thermometer　that　they　immediately　immersed　in　it　soon
registered　eighty…five　degrees　Fahrenheit；　both　of　which
discoveries　confirmed　them　in　what　they　already　knew；　namely；
that　Jupiter　had　advanced　comparatively　little　from　the　condition
in　which　the　water　on　the　surface　is　hot；　in　which　state　the
earth　once　was。
　　　
They　were