round the moon-第8章

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is　excessive；　penetrate　the　projectile　or　we　shall　be　frozen　to　death。〃

〃But　the　sun？〃

〃The　sun　warms　our　projectile；　which　absorbs　its　rays；　but　it
does　not　warm　the　vacuum　in　which　we　are　floating　at　this　moment。
Where　there　is　no　air；　there　is　no　more　heat　than　diffused　light；
and　the　same　with　darkness；　it　is　cold　where　the　sun's　rays　do　not
strike　direct。　　This　temperature　is　only　the　temperature　produced
by　the　radiation　of　the　stars；　that　is　to　say；　what　the
terrestrial　globe　would　undergo　if　the　sun　disappeared　one　day。〃

〃Which　is　not　to　be　feared；〃　replied　Nicholl。

〃Who　knows？〃　said　Michel　Ardan。　　〃But；　in　admitting　that　the　sun
does　not　go　out；　might　it　not　happen　that　the　earth　might　move
away　from　it？〃

〃There！〃　said　Barbicane；　〃there　is　Michel　with　his　ideas。〃

〃And；〃　continued　Michel；　〃do　we　not　know　that　in　1861　the　earth
passed　through　the　tail　of　a　comet？　　Or　let　us　suppose　a　comet
whose　power　of　attraction　is　greater　than　that　of　the　sun。
The　terrestrial　orbit　will　bend　toward　the　wandering　star；　and
the　earth；　becoming　its　satellite；　will　be　drawn　such　a　distance
that　the　rays　of　the　sun　will　have　no　action　on　its　surface。〃

〃That　_might_　happen；　indeed；〃　replied　Barbicane；　〃but　the
consequences　of　such　a　displacement　need　not　be　so　formidable　as
you　suppose。〃

〃And　why　not？〃

〃Because　the　heat　and　cold　would　be　equalized　on　our　globe。
It　has　been　calculated　that；　had　our　earth　been　carried　along　in
its　course　by　the　comet　of　1861；　at　its　perihelion；　that　is；　its
nearest　approach　to　the　sun；　it　would　have　undergone　a　heat
28；000　times　greater　than　that　of　summer。　　But　this　heat；　which
is　sufficient　to　evaporate　the　waters；　would　have　formed　a　thick
ring　of　cloud；　which　would　have　modified　that　excessive
temperature；　hence　the　compensation　between　the　cold　of　the
aphelion　and　the　heat　of　the　perihelion。〃

〃At　how　many　degrees；〃　asked　Nicholl；　〃is　the　temperature　of　the
planetary　spaces　estimated？〃

〃Formerly；〃　replied　Barbicane；　〃it　was　greatly　exagerated；　but
now；　after　the　calculations　of　Fourier；　of　the　French　Academy　of
Science；　it　is　not　supposed　to　exceed　60@　Centigrade　below　zero。〃

〃Pooh！〃　said　Michel；　〃that's　nothing！〃

〃It　is　very　much；〃　replied　Barbicane；　〃the　temperature　which　was
observed　in　the　polar　regions；　at　Melville　Island　and　Fort
Reliance；　that　is　76@　Fahrenheit　below　zero。〃

〃If　I　mistake　not；〃　said　Nicholl；　〃M。　Pouillet；　another　savant；
estimates　the　temperature　of　space　at　250@　Fahrenheit　below　zero。
We　shall；　however；　be　able　to　verify　these　calculations　for　ourselves。〃

〃Not　at　present；　because　the　solar　rays；　beating　directly
upon　our　thermometer；　would　give；　on　the　contrary；　a　very　high
temperature。　　But；　when　we　arrive　in　the　moon；　during　its
fifteen　days　of　night　at　either　face；　we　shall　have　leisure　to
make　the　experiment；　for　our　satellite　lies　in　a　vacuum。〃

〃What　do　you　mean　by　a　vacuum？〃　asked　Michel。　　〃Is　it　perfectly　such？〃

〃It　is　absolutely　void　of　air。〃

〃And　is　the　air　replaced　by　nothing　whatever？〃

〃By　the　ether　only；〃　replied　Barbicane。

〃And　pray　what　is　the　ether？〃

〃The　ether；　my　friend；　is　an　agglomeration　of　imponderable
atoms；　which；　relatively　to　their　dimensions；　are　as　far　removed
from　each　other　as　the　celestial　bodies　are　in　space。　　It　is
these　atoms　which；　by　their　vibratory　motion；　produce　both　light
and　heat　in　the　universe。〃

They　now　proceeded　to　the　burial　of　Satellite。　　They　had　merely
to　drop　him　into　space；　in　the　same　way　that　sailors　drop　a　body
into　the　sea；　but；　as　President　Barbicane　suggested；　they　must
act　quickly；　so　as　to　lose　as　little　as　possible　of　that　air
whose　elasticity　would　rapidly　have　spread　it　into　space。
The　bolts　of　the　right　scuttle；　the　opening　of　which　measured
about　twelve　inches　across；　were　carefully　drawn；　while　Michel；
quite　grieved；　prepared　to　launch　his　dog　into　space。　　The　glass；
raised　by　a　powerful　lever；　which　enabled　it　to　overcome　the
pressure　of　the　inside　air　on　the　walls　of　the　projectile；
turned　rapidly　on　its　hinges；　and　Satellite　was　thrown　out。
Scarcely　a　particle　of　air　could　have　escaped；　and　the　operation
was　so　successful　that　later　on　Barbicane　did　not　fear　to
dispose　of　the　rubbish　which　encumbered　the　car。





CHAPTER　VI


QUESTION　AND　ANSWER


On　the　4th　of　December；　when　the　travelers　awoke　after
fifty…four　hours'　journey；　the　chronometer　marked　five　o'clock
of　the　terrestrial　morning。　　In　time　it　was　just　over　five
hours　and　forty　minutes；　half　of　that　assigned　to　their　sojourn
in　the　projectile；　but　they　had　already　accomplished　nearly
seven…tenths　of　the　way。　　This　peculiarity　was　due　to　their
regularly　decreasing　speed。

Now　when　they　observed　the　earth　through　the　lower　window；
it　looked　like　nothing　more　than　a　dark　spot；　drowned　in　the
solar　rays。　　No　more　crescent；　no　more　cloudy　light！　　The　next
day；　at　midnight；　the　earth　would　be　_new_；　at　the　very　moment
when　the　moon　would　be　full。　　Above；　the　orb　of　night　was　nearing
the　line　followed　by　the　projectile；　so　as　to　meet　it　at　the
given　hour。　　All　around　the　black　vault　was　studded　with　brilliant
points；　which　seemed　to　move　slowly；　but；　at　the　great　distance
they　were　from　them；　their　relative　size　did　not　seem　to　change。
The　sun　and　stars　appeared　exactly　as　they　do　to　us　upon　earth。
As　to　the　moon；　she　was　considerably　larger；　but　the　travelers'
glasses；　not　very　powerful；　did　not　allow　them　as　yet　to　make
any　useful　observations　upon　her　surface；　or　reconnoiter　her
topographically　or　geologically。

Thus　the　time　passed　in　never…ending　conversations　all　about
the　moon。　　Each　one　brought　forward　his　own　contingent　of
particular　facts；　Barbicane　and　Nicholl　always　serious；　Michel
Ardan　always　enthusiastic。　　The　projectile；　its　situation；
its　direction；　incidents　which　might　happen；　the　precautions
necessitated　by　their　fall　on　to　the　moon；　were　inexhaustible
matters　of　conjecture。

As　they　were　breakfasting；　a　question　of　Michel's；　relating　to
the　projectile；　provoked　rather　a　curious　answer　from　Barbicane；
which　is　worth　repeating。　　Michel；　supposing　it　to　be　roughly
stopped；　while　still　under　its　formidable　initial　speed；　wished
to　know　what　the　consequences　of　the　stoppage　would　have　been。

〃But；〃　said　Barbicane；　〃I　do　not　see　how　it　could　have　been　stopped。〃

〃But　let　us　suppose　so；〃　said　Michel。

〃It　is　an　impossible　supposition；〃　said　the　practical　Barbicane；
〃unless　that　impulsive　force　had　failed；　but　even　then　its　speed
would　diminish　by　degrees；　and　it　would　not　have　stopped　suddenly。〃

〃Admit　that　it　had　struck　a　body　in　space。〃

〃What　body？〃

〃Why　that　enormous　meteor　which　we　met。〃

〃Then；〃　said　Nicholl；　〃the　projectile　would　have　been　broken
into　a　thousand　pieces；　and　we　with　it。〃

〃More　than　that；〃　replied　Barbicane；　〃we　should　have　been　burned
to　death。〃

〃Burned？〃　exclaimed　Michel；　〃by　Jove！　　I　am　sorry　it　did　not
happen；　‘just　to　see。'〃

〃And　you　would　have　seen；〃　replied　Barbicane。　　〃It　is　known　now
that　heat　is　only　a　modification　of　motion。　　When　water　is
warmed　that　is　to　say；　when　heat　is　added　to　itits　particles
are　set　in　motion。〃

〃Well；〃　said　michel；　〃that　is　an　ingenious　theory！〃

〃And　a　true　one；　my　worthy　friend；　for　it　explains　every
phenomenon　of　caloric。　　Heat　is　but　the　motion　of　atoms；　a
simple　oscillation　of　the　particles　of　a　body。　　When　they　apply
the　brake　to　a　train；　the　train　comes　to　a　stop；　but　what
becomes　of　the　motion　which　it　had　previously　possessed？　　It　is
transformed　into　heat；　and　the　brake　becomes　hot。　　Why　do　they
grease　the　axles　of　the　wheels？　　To　prevent　their　heating；
because　this　heat　would　be　generated　by　the　motion　which　is　thus
lost　by　transformation。〃

〃Yes；　I　understand；〃　replied　Michel；　〃perfectly。　　For　example；
when　I　have　run　a　long　time；　when　I　am　swimming；　when　I　am
perspiring　in　large　drops；　why　am　I　obliged　to　stop？
Simply　because　my　motion　is　changed　into　heat。〃

Barbicane　could　not　help　smiling　at　Michel's　reply；　then；
returning　to　his　theory；　said：

〃Thus；　in　case　of　a　shock；　it　would　have　been　with　our
projectile　as　with　a　ball　which　falls　in　a　burning　state　after
having　struck　the　metal　plate；　it　is　its　motion　which　is　turned
into　heat。　　Consequently　I　affirm　that；　if　our　projectile　had
struck　the　meteor；　its　speed　thus　suddenly　checked　would　have
raised　a　heat　great　enough　to　turn　it　into　vapor　instantaneously。〃

〃Then；〃　asked　Nicholl；　〃what　would　happen　if　the　earth's　motion
were　to　stop　suddenly？〃

〃Her　temperature　would　be　raised　to　such　a　pitch；〃　said
Barbicane；　〃that　she　would　be　at　once　reduced　to　vapor。〃

〃Well；〃　said　Michel；　〃that　is　a　way　of　ending　the　earth　which
will　greatly　simplify　things。〃

〃And　if　the　earth　fell　upon　the　sun？〃　asked　Nicholl。

〃According　to　calculation；〃　replied　Barbicane；　〃the　fall　would
develop　a　heat　equal　to　that　produced　by　16；000　globes　of　coal；
each　equal　in　bulk　to　our　terrestrial　globe。〃

〃Good　additional　heat　for　the　sun；〃　replied　Michel　Ardan；　〃of
which　the　inhabitants　of　Uranus　or　Neptune　would　doubtless　not
complain；　they　must　be　perished　with　cold　on　their　planets。〃

〃Thus；　my　friends；〃　said　Barbicane；　〃all　motion　suddenly　stopped
produces　heat。　　And　this　theory　allows　us　to　infer　that　the　heat
of　the　solar　disc　is　fed　by　a　hail　of　meteors　falling
incessantly　on　its　surface。　　They　have　even　calculated〃

〃Oh；　dear！〃　murmured　Michel；　〃the　figures　are　coming。〃

〃They　have　even　calculated；〃　continued　the　imperturbable　Barbicane；
〃that　the　shock　of　each　meteor　on　the　sun　ought　to　produce　a　heat
equal　to　that　of　4；000　masses　of　coal　of　an　equal　bulk。〃

〃And　what　is　the　solar　heat？〃　asked　Michel。

〃It　is　equal　to　that　produced　by　the　combustion　of　a　stratum　of
coal　surrounding　the　sun　to　a　depth　of　forty…seven　miles。〃

〃And　that　heat〃

〃Would　be　able　to　boil　two　billions　nine　hundred　millions　of
cubic　myriameters　＇2＇　of　water。〃

＇2＇　The　myriameter　is　equal　to　rather　more　than　10；936
cubic　yards　English。

〃And　it　does　not　roast　us！〃　exclaimed　Michel。

〃No；〃　replied　Barbicane；　〃because　the　terrestrial　atmosphere
absorbs　four…tenths　of　the　solar　heat；　besides；　the　quantity　of
heat　intercepted　by　the　earth　is　but　a　billionth　part　of　the
entire　radiation。〃

〃I　see　that　all　is　for　the　best；〃　said　Michel；　〃and　that　this
atmosphere　is　a　useful　invention；　for　it　not　only　allows　us　to
breathe；　but　it　prevents　us　from　roasting。〃

〃Yes！〃　said　Nicholl；　〃unfortunately；　it　will　not　be　the　same　in
the　moon。〃

〃Bah！〃　said　Michel；　always　hopeful。　　〃If　there　are　inhabitants；
they　must　breathe。　　If　there　are　no　longer　any；　they　must　have
left　enough　oxygen　for　three　people；　if　only　at　the　bottom　of
ravines；　where　its　own　weight　will　cause　it　to　accumulate；　and
we　will　not　climb　the　mountains；　that　is　all。〃　　And　Michel；
rising；　went　to　look　at　the　lunar　disc；　which　shone　with
intolerable　brilliancy。

〃By　Jove！〃　said　he；　〃it　must　be　hot　up　there！〃

〃Without　considering；〃　replied　Nicholl；　〃that　the　day　lasts　360　hours！〃

〃And　to　compensate　that；〃　said　Barbicane；　〃the　nights　have　the
same　length；　and　as　heat　is　restored　by　radiation；　their
temperature　can　only　be　that　of　the　planetary　space。