a journey in other worlds-第18节

按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！


The　outer　one；　Deimos；　is　but　six　miles　in　diameter；　and　revolves
about　its　primary　in　thirty　hours　and　eighteen　minutes；　at　a
distance　of　fourteen　thousand　six　hundred　miles。　　As　it　takes　but
little　longer　to　complete　a　revolution　than　Mars　does　to　rotate
on　its　axis；　it　remains　in　the　Martial　sky　one　hundred　and
thirty…two　hours　between　rising　and　setting；　passing　through　all
the　phases　from　new　moon　to　full　and　back　again　four　times；　that
is；　it　swings　four　times　around　Mars　before　going　below　the
horizon。　　It　is　one　of　the　smallest　bodies　discovered　with　a
telescope。　　The　inner　one；　Phobos；　is　considerably　larger；　having
a　diameter　of　about　twenty　miles。　　It　is　but　twenty…seven　hundred
miles　from　Mars's　surface；　and　completes　its　revolution　in　seven
hours　and　thirty…eight　minutes；　which　is　shorter　than　any　other
known　period；　Jupiter's　nearest　moon　being　the　next；　with　eleven
hours　and　fifty…　nine　minutes。　　It　thus　revolves　in　less　than　a
third　of　the　time　Mars　takes　to　rotate；　and　must　consequently
rise　in　the　west　and　set　in　the　east；　as　it　is　continually
running　ahead　of　the　surface　of　the　planet；　though　the　sun　and
all　the　other　stars　rise　and　set　on　Mars　in　the　same　way　as　on
the　earth。〃
　　　
When　about　fifteen　thousand　miles　from　Mars；　they　sighted　Deimos
directly　ahead；　and　saw　that　they　should　pass　on　its　lefti。　e。；
behindfor　it　was　moving　across　them。　　The　sun　poured　directly
upon　it；　making　it　appear　full　and　showing　all　its　features。　
There　were　small　unevennesses　on　the　surface；　apparently　seventy
or　a　hundred　feet　high；　which　were　the　nearest　approach　to
mountains；　and　they　ran　in　ridges　or　chains。　　There　were　also
unmistakable　signs　of　volcanic　action；　the　craters　being　large
compared　with　the　size　of　the　planet；　but　shallow。　　They　saw　no
signs　of　water；　and　the　blackness　of　the　shadows　convinced　them
there　was　no　air。　　They　secured　two　instantaneous　photographs　of
the　little　satellite　as　the　Callisto　swept　by；　and　resumed　their
inspection　of　Mars。　　They　noticed　red　and　brownish　patches　on　the
peaks　that　had　that　morning　turned　white；　from　which　they
concluded　that　the　show　had　begun　to　melt　under　the　warm　spring
sun。　　This　strengthened　the　belief　they　had　already　formed；　that
on　account　of　its　twenty…seven　and　a　half　degrees　inclination　the
changes　in　temperature　on　Mars　must　be　great　and　sudden。　　So
interested　were　they　with　this；　that　they　did　not　at　first　see　a
large　and　bright　body　moving　rapidly　on　a　course　that　converged
with　theirs。
　　　
〃We　must　be　ready　to　repel　boarders；〃　said　Bearwarden；　observing
it　for　the　first　time　and　fixing　his　glass　upon　it。　　〃That　must
be　Phobos。〃
　　　
Not　ten　miles　off　they　beheld　Mars's　inner　moon；　and　though　their
own　speed　caused　them　to　overtake　and　rush　by　it　like　a
whirlwind；　the　satellite's　rapid　motion　in　its　orbit；　in　a　course
temporarily　almost　parallel　with　theirs；　served　to　give　them　a
chance　the　better　to　examine　it。　　Here　the　mountain　ranges　were
considerably　more　conspicuous　than　on　Deimos；　and　there　were
boulders　and　loose　stones　upon　their　slopes；　which　looked　as　if
there　might　at　some　time　have　been　frost　and　water　on　its
surface；　but　it　was　all　dry　now；　neither　was　there　any　air。　　The
evidences　of　volcanic　action　were　also　plainly　visible；　while　a
noticeable　flattening　at　the　poles　showed　that　the　little　body
had　once　rotated　rapidly　on　its　axis；　though　whether　it　did　so
still　they　had　not　time　to　ascertain。　　When　abreast　of　it　they
were　less　than　two　miles　distant；　and　they　secured　several
instantaneous　impressions；　which　they　put　aside　to　develop　later。　
As　the　radius　of　Phobos's　circle　was　far　shorter　than　that　of　the
parabolic　curve　they　were　making；　it　began　to　draw　away；　and　was
rapidly　left　behind。　　Applying　the　full　apergetic　force　to　Mars
and　the　larger　moon；　they　shot　away　like　an　arrow；　having　had
their　speed　increased　by　the　planet's　attraction　while
approaching　it；　and　subsequently　by　repulsion。
　　　
〃Either　of　those；〃　said　Bearwarden；　looking　back　at　the　little
satellites；　〃would　be　a　nice　yacht　for　a　man　to　explore　space　on。　
He　would　also；　of　course；　need　a　sun　to　warm　him；　if　he　wished　to
go　beyond　this　system；　but　that　would　not　have　to　be　a　large
affairin　fact；　it　might　be　smaller　than　the　planet；　and　could
revolve　about　it　like　a　moon。〃
　　　
〃Though　a　sun　of　that　size；〃　replied　Cortlandt；　〃might　retain　its
heat　for　the　time　you　wished　to　use　it；　the　planet　part　would　be
nothing　like　as　comfortable　as　what　we　have　here；　for　it　would　be
very　difficult　to　get　enough　air…pressure　to　breathe　on　so　small
a　body；　since；　with　its　slight　gravitation…pull；　to　secure
fifteen　pounds　to　the　square　inch；　or　anything　like　it；　the
atmosphere　would　have　to　extend　thousands　of　miles　into　space；　so
that　on　a　cloudy　day　you　would　be　in　darkness。　　It　would　be
better；　therefore；　to　have　such　a　sun　as　you　describe　and
accompany　it　in　a　yacht　or　private　car　like　this；　well　stocked
with　oxygen　and　provisions。　　When　passing　through　meteoric　swarms
or　masses　of　solid　matter；　collision　with　which　is　the　most
serious　risk　we　run；　the　car　could　follow　behind　its　sun　instead
of　revolving　around　it；　and　be　kept　from　falling　into　it　by
partially　reversing　the　attraction。　　As　the　gravitation　of　so
small　a　sun　would　be　slight；　counteracting　it　for　even　a
considerable　time　would　take　but　little　from　the　batteries。〃
　　　
〃There　are　known　to　be　several　unclaimed　masses；〃　added　Ayrault；
〃with　diameters　of　a　few　hundred　yards；　revolving　about　the　earth
inside　the　orbit　of　the　moon。　　If　in　some　way　two　of　these　could
be　brought　into　sufficiently　violent　collision；　they　would　become
luminous　and　answer　very　well；　the　increase　in　bulk　as　a　result
of　the　consolidation；　and　the　subsequent　heat；　about　serving　to
bring　them　to　the　required　size。　　Whenever　this　sun　showed　spots
and　indications　of　cooling；　it　could　be　made　to　collide　with　the
solid　head　of　some　comet；　or　small　asteroid；　till　its　temperature
was　again　right；　while　if；　as　a　result　of　these　accretions；　it
became　unwieldy；　it　could　be　caused　to　rotate　with　sufficient
rapidity　on　its　axis　to　split；　and　we　should　have　two　suns
instead　of　one。〃
　　　
〃Bravo！〃　said　Bearwarden。　　〃There　is　no　limit　to　what　can　be
done。　　The　idea　of　our　present　trip　would　have　seemed　more
chimerical　to　people　a　hundred　years　ago　than　this　new　scheme
appears　now。〃
　　　
Thus　they　sat　and　talked；　or　studied　maps　and　star…　charts；　or
the　stars　themselves；　while　the　hours　quickly　passed　and　they
shot　through　space。　　They　had　now　a　straight　stretch　of　over
three　hundred　million　miles；　and　had　to　cross　the　orbits　of
innumerable　asteroids　on　the　way。　　The　apparent　size　of　the　sun
had　by　this　time　considerably　decreased；　and　the　interior　of　the
Callisto　was　no　longer　uncomfortably　warm。　　They　divided　the　day
into　twenty…four　hours　from　force　of　habit；　and　drew　the　shades
tightly　during　what　they　considered　night；　while　Bearwarden
distinguished　himself　as　a　cook。



　　　　　　　　　　　　　　　　　　　　　　　　　　CHAPTER　III。

　　　　　　　　　　　　　　　　　　　　　　　　HEAVENLY　BODIES。

The　following　day；　while　in　their　observatory；　they　saw　something
not　many　miles　ahead。　　They　watched　it　for　hours；　and　in　fact　all
day；　but　notwithstanding　their　tremendous　speed　they　came　but
little　nearer。
　　　
〃They　say　a　stern　chase　is　a　long　one；〃　said　Bearwarden；　but　that
beats　anything　I　have　ever　seen。〃
　　　　
After　a　while；　however；　they　found　they　WERE　nearer；　the　time
taken　having　been　in　part　due　to　the　deceptive　distance；　which
was　greater　than　they　supposed。
　　　
〃A　comet！〃　exclaimed　Cortlandt　excitedly。　　〃We　shall　really　be
able　to　examine　it　near。〃
　　　
〃It's　going　in　our　direction；〃　said　Ayrault；　〃and　at　almost
exactly　our　speed。〃
　　　
While　the　sun　shone　full　upon　it　they　brought　their　camera　into
play；　and　again　succeeded　in　photographing　a　heavenly　body　at
close　range。　　The　nucleus　or　head　was　of　course　turned　towards
the　sun；　while　the　tail；　which　they　could　see　faintly；　preceded
it；　as　the　comet　was　receding　towards　the　cold　and　dark　depths　of
space。　　The　head　was　only　a　few　miles　in　diameter；　for　it　was　a
small　comet；　and　was　composed　of　grains　and　masses　of　stone　and
meteoric　iron。　　Many　of　the　grains　were　no　larger　than　peas　or
mustard…seeds；　no　mass　was　more　than　four　feet　in　diameter；　and
all　of　them　had　very　irregular　shapes。　　The　space　between　the
particles　was　never　less　than　one　hundred　times　their　masses。
　　　
〃We　can　move　about　within　it；〃　said　Ayrault；　as　the　Callisto
entered　the　aggregation　of　particles；　and　moved　slowly　forward
among　them。
　　　
The　windows　in　the　dome；　being　made　of　toughened　glass；　set
somewhat　slantingly　so　as　to　deflect　anything　touching　them；　and
having；　moreover；　the　pressure　of　the　inside　air　to　sustain　them；
were　fairly　safe；　while　the　windows　in　the　sides　and　base　were
but　little　exposed。　　Whenever　a　large　mass　seemed　dangerously
near　the　glass；　they　applied　an　apergetic　shock　to　it　and　sent　it
kiting　among　its　fellows。　　At　these　times　the　Callisto　recoiled
slightly　also；　the　resulting　motion　in　either　being　in　inverse
ratio　to　its　weight。　　There　was　constant　and　incessant　movement
among　the　individual　fragm