首页 >出版文学> THE VOYAGE OF THE BEAGLE>第42章
  June8th——WeweighedanchorearlyinthemorningandleftPortFamine。
  CaptainFitzRoydeterminedtoleavetheStraitofMagellanbytheMagdalenChannel,whichhadnotlongbeendiscovered。Ourcourselayduesouth,downthatgloomypassagewhichIhavebeforealludedtoasappearingtoleadtoanotherandworseworld。Thewindwasfair,buttheatmospherewasverythick;sothatwemissedmuchcuriousscenery。Thedarkraggedcloudswererapidlydrivenoverthemountains,fromtheirsummitsnearlydowntotheirbases。Theglimpseswhichwecaughtthroughtheduskymasswerehighlyinteresting;jaggedpoints,conesofsnow,blueglaciers,strongoutlines,markedonaluridsky,wereseenatdifferentdistancesandheights。
  InthemidstofsuchsceneryweanchoredatCapeTurn,closetoMountSarmiento,whichwasthenhiddenintheclouds。Atthebaseoftheloftyandalmostperpendicularsidesofourlittlecovetherewasonedesertedwigwam,anditaloneremindedusthatmansometimeswanderedintothesedesolateregions。
  Butitwouldbedifficulttoimagineascenewhereheseemedtohavefewerclaimsorlessauthority。Theinanimateworksofnature——rock,ice,snow,wind,andwater——allwarringwitheachother,yetcombinedagainstman——herereignedinabsolutesovereignty。
  June9th——InthemorningweweredelightedbyseeingtheveilofmistgraduallyrisefromSarmiento,anddisplayittoourview。Thismountain,whichisoneofthehighestinTierradelFuego,hasanaltitudeof6800
  feet。Itsbase,foraboutaneighthofitstotalheight,isclothedbyduskywoods,andabovethisafieldofsnowextendstothesummit。Thesevastpilesofsnow,whichnevermelt,andseemdestinedtolastaslongastheworldholdstogether,presentanobleandevensublimespectacle。
  Theoutlineofthemountainwasadmirablyclearanddefined。Owingtotheabundanceoflightreflectedfromthewhiteandglitteringsurface,noshadowswerecastonanypart;andthoselineswhichintersectedtheskycouldalonebedistinguished:hencethemassstoodoutintheboldestrelief。
  Severalglaciersdescendedinawindingcoursefromtheuppergreatexpanseofsnowtothesea-coast:theymaybelikenedtogreatfrozenNiagaras;
  andperhapsthesecataractsofblueicearefullasbeautifulasthemovingonesofwater。Bynightwereachedthewesternpartofthechannel;butthewaterwassodeepthatnoanchoragecouldbefound。Wewereinconsequenceobligedtostandoffandoninthisnarrowarmofthesea,duringapitch-darknightoffourteenhourslong。
  June10th——InthemorningwemadethebestofourwayintotheopenPacific。Thewesterncoastgenerallyconsistsoflow,rounded,quitebarrenhillsofgraniteandgreenstone。SirJ。NarboroughcalledonepartSouthDesolation,becauseitis“sodesolatealandtobehold:“andwellindeedmighthesayso。Outsidethemainislands,therearenumberlessscatteredrocksonwhichthelongswelloftheopenoceanincessantlyrages。WepassedoutbetweentheEastandWestFuries;andalittlefarthernorthwardtherearesomanybreakersthattheseaiscalledtheMilkyWay。Onesightofsuchacoastisenoughtomakealandsmandreamforaweekaboutshipwrecks,peril,anddeath;andwiththissightwebadefarewellforevertoTierradelFuego。
  Thefollowingdiscussionontheclimateofthesouthernpartsofthecontinentwithrelationtoitsproductions,onthesnow-line,ontheextraordinarilylowdescentoftheglaciers,andonthezoneofperpetualcongelationintheantarcticislands,maybepassedoverbyanyonenotinterestedinthesecurioussubjects,orthefinalrecapitulationalonemayberead。
  Ishall,however,heregiveonlyanabstract,andmustreferfordetailstotheThirteenthChapterandtheAppendixoftheformereditionofthiswork。
  OntheClimateandProductionsofTierradelFuegoandoftheSouth-westCoast——ThefollowingtablegivesthemeantemperatureofTierradelFuego,theFalklandIslands,and,forcomparison,thatofDublin:——SummerWinterMeanofSummerLatitudeTemp。Temp。andWinter
  Dublin5321’N。59。5439。249。37HenceweseethatthecentralpartofTierradelFuegoiscolderinwinter,andnolessthan9。5degs。lesshotinsummer,thanDublin。AccordingtovonBuch,themeantemperatureofJulynotthehottestmonthintheyear
  atSaltenfiordinNorway,isashighas57。8degs。,andthisplaceisactually13degs。nearerthepolethanPortFamine![8]Inhospitableasthisclimateappearstoourfeelingsevergreentreesflourishluxuriantlyunderit。Humming-birdsmaybeseensuckingtheflowers,andparrotsfeedingontheseedsoftheWinter’sBark,inlat。55degs。S。Ihavealreadyremarkedtowhatadegreetheseaswarmswithlivingcreatures;andtheshellssuchasthePatellae,Fissurellae,Chitons,andBarnacles,accordingtoMr。
  G。B。Sowerby,areofamuchlargersizeandofamorevigorousgrowth,thantheanalogousspeciesinthenorthernhemisphere。AlargeVolutaisabundantinsouthernTierradelFuegoandtheFalklandIslands。AtBahiaBlanca,inlat。39degs。S。,themostabundantshellswerethreespeciesofOlivaoneoflargesize,oneortwoVolutas,andaTerebra。Now,theseareamongstthebestcharacterizedtropicalforms。ItisdoubtfulwhetherevenonesmallspeciesofOlivaexistsonthesouthernshoresofEurope,andtherearenospeciesofthetwoothergenera。Ifageologistweretofindinlat39degs。onthecoastofPortugalabedcontainingnumerousshellsbelongingtothreespeciesofOliva,toaVolutaandTerebra,hewouldprobablyassertthattheclimateattheperiodoftheirexistencemusthavebeentropical;butjudgingfromSouthAmerica,suchaninferencemightbeerroneous。
  Theequable,humid,andwindyclimateofTierradelFuegoextends,withonlyasmallincreaseofheat,formanydegreesalongthewestcoastofthecontinent。Theforestsfor600milesnorthwardofCapeHorn,haveaverysimilaraspect。Asaproofoftheequableclimate,evenfor300or400milesstillfurthernorthward,ImaymentionthatinChiloecorrespondinginlatitudewiththenorthernpartsofSpainthepeachseldomproducesfruit,whilststrawberriesandapplesthrivetoperfection。Eventhecropsofbarleyandwheat[9]areoftenbroughtintothehousestobedriedandripened。AtValdiviainthesamelatitudeof40
  degs。,withMadridgrapesandfigsripen,butarenotcommon;olivesseldomripenevenpartially,andorangesnotatall。Thesefruits,incorrespondinglatitudesinEurope,arewellknowntosucceedtoperfection;andeveninthiscontinent,attheRioNegro,undernearlythesameparallelwithValdivia,sweetpotatoesconvolvulusarecultivated;andgrapes,figs,olives,oranges,waterandmuskmelons,produceabundantfruit。AlthoughthehumidandequableclimateofChiloe,andofthecoastnorthwardandsouthwardofit,issounfavourabletoourfruits,yetthenativeforests,fromlat。45to38degs。,almostrivalinluxuriancethoseoftheglowingintertropicalregions。Statelytreesofmanykinds,withsmoothandhighlycolouredbarks,areloadedbyparasiticalmonocotyledonousplants;largeandelegantfernsarenumerous,andarborescentgrassesentwinethetreesintooneentangledmasstotheheightofthirtyorfortyfeetabovetheground。Palm-treesgrowinlat37degs。;anarborescentgrass,verylikeabamboo,in40degs。;andanothercloselyalliedkind,ofgreatlength,butnoterect,flourishesevenasfarsouthas45degs。S。
  Anequableclimate,evidentlyduetothelargeareaofseacomparedwiththeland,seemstoextendoverthegreaterpartofthesouthernhemisphere;
  and,asaconsequence,thevegetationpartakesofasemi-tropicalcharacter。
  Tree-fernsthriveluxuriantlyinVanDiemen’sLandlat。45degs。,andImeasuredonetrunknolessthansixfeetincircumference。AnarborescentfernwasfoundbyForsterinNewZealandin46degs。,whereorchideousplantsareparasiticalonthetrees。IntheAucklandIslands,ferns,accordingtoDr。Dieffenbach[10]havetrunkssothickandhighthattheymaybealmostcalledtree-ferns;andintheseislands,andevenasfarsouthaslat。55degs。intheMacquarrieIslands,parrotsabound。
  OntheHeightoftheSnow-line,andontheDescentoftheGlaciersinSouthAmerica——Forthedetailedauthoritiesforthefollowingtable,Imustrefertotheformeredition:——HeightinfeetLatitudeofSnow-lineObserver
  CentralChile,lat。33degs。S。14,500-15,000Gillies,andtheAuthor。
  Chiloe,lat。41to43degs。S。6,000OfficersoftheBeagleandtheAuthor。
  TierradelFuego,54degs。S。3,500-4,000King。Astheheightoftheplaneofperpetualsnowseemschieflytobedeterminedbytheextremeheatofthesummer,ratherthanbythemeantemperatureoftheyear,weoughtnottobesurprisedatitsdescentintheStraitofMagellan,wherethesummerissocool,toonly3500or4000feetabovethelevelofthesea;althoughinNorway,wemusttraveltobetweenlat。
  67and70degs。N。,thatis,about14degs。nearerthepole,tomeetwithperpetualsnowatthislowlevel。Thedifferenceinheight,namely,about9000feet,betweenthesnow-lineontheCordillerabehindChiloewithitshighestpointsrangingfromonly5600to7500feetandincentralChile[11]adistanceofonly9degs。oflatitude,istrulywonderful。ThelandfromthesouthwardofChiloetonearConcepcionlat。37degs。ishiddenbyonedenseforestdrippingwithmoisture。Theskyiscloudy,andwehaveseenhowbadlythefruitsofsouthernEuropesucceed。IncentralChile,ontheotherhand,alittlenorthwardofConcepcion,theskyisgenerallyclear,raindoesnotfallforthesevensummermonths,andsouthernEuropeanfruitssucceedadmirably;andeventhesugar-canehasbeencultivated。[12]Nodoubttheplaneofperpetualsnowundergoestheaboveremarkableflexureof9000feet,unparalleledinotherpartsoftheworld,notfarfromthelatitudeofConcepcion,wherethelandceasestobecoveredwithforest-trees;fortreesinSouthAmericaindicatearainyclimate,andrainacloudedskyandlittleheatinsummer。
  Thedescentofglacierstotheseamust,Iconceive,mainlydependsubject,ofcourse,toapropersupplyofsnowintheupperregiononthelownessofthelineofperpetualsnowonsteepmountainsnearthecoast。Asthesnow-lineissolowinTierradelFuego,wemighthaveexpectedthatmanyoftheglacierswouldhavereachedthesea。Nevertheless,IwasastonishedwhenIfirstsawarange,onlyfrom3000to4000feetinheight,inthelatitudeofCumberland,witheveryvalleyfilledwithstreamsoficedescendingtothesea-coast。Almosteveryarmofthesea,whichpenetratestotheinteriorhigherchain,notonlyinTierradelFuego,butonthecoastfor650milesnorthwards,isterminatedby“tremendousandastonishingglaciers。”
  asdescribedbyoneoftheofficersonthesurvey。Greatmassesoficefrequentlyfallfromtheseicycliffs,andthecrashreverberateslikethebroadsideofaman-of-warthroughthelonelychannels。Thesefalls,asnoticedinthelastchapter,producegreatwaveswhichbreakontheadjoiningcoasts。Itisknownthatearthquakesfrequentlycausemassesofearthtofallfromsea-cliffs:howterrific,then,wouldbetheeffectofasevereshockandsuchoccurhere[13]onabodylikeaglacier,alreadyinmotion,andtraversedbyfissures!Icanreadilybelievethatthewaterwouldbefairlybeatenbackoutofthedeepestchannel,andthen,returningwithanoverwhelmingforce,wouldwhirlabouthugemassesofrocklikesomuchchaff。InEyre’sSound,inthelatitudeofParis,thereareimmenseglaciers,andyettheloftiestneighbouringmountainisonly6200feethigh。InthisSound,aboutfiftyicebergswereseenatonetimefloatingoutwards,andoneofthemmusthavebeenatleast168feetintotalheight。Someoftheicebergswereloadedwithblocksofnoinconsiderablesize,ofgraniteandotherrocks,differentfromtheclay-slateofthesurroundingmountains。Theglacierfurthestfromthepole,surveyedduringthevoyagesoftheAdventureandBeagle,isinlat。
  46degs。50’,intheGulfofPenas。Itis15mileslong,andinonepart7broadanddescendstothesea-coast。Butevenafewmilesnorthwardofthisglacier,inLagunadeSan[picture]
  Rafael,someSpanishmissionaries[14]encountered“manyicebergs,somegreat,somesmall,andothersmiddle-sized。”inanarrowarmofthesea,onthe22ndofthemonthcorrespondingwithourJune,andinalatitudecorrespondingwiththatoftheLakeofGeneva!
  InEurope,themostsouthernglacierwhichcomesdowntotheseaismetwith,accordingtoVonBuch,onthecoastofNorway,inlat。67degs。
  Now,thisismorethan20degs。oflatitude,or1230miles,nearerthepolethantheLagunadeSanRafael。ThepositionoftheglaciersatthisplaceandintheGulfofPenasmaybeputeveninamorestrikingpointofview,fortheydescendtothesea-coastwithin7。5degs。oflatitude,or450miles,ofaharbour,wherethreespeciesofOliva,aVoluta,andaTerebra,arethecommonestshells,withinlessthan9degs。fromwherepalmsgrow,within4。5degs。ofaregionwherethejaguarandpumarangeovertheplains,lessthan2。5degs。fromarborescentgrasses,andlookingtothewestwardinthesamehemispherelessthan2degs。fromorchideousparasites,andwithinasingledegreeoftree-ferns!