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，themeantemperatureofJuly(notthehottestmonthintheyear)
atSaltenfiordinNorway，isashighas57。8degs。，andthisplaceisactually13degs。nearerthepolethanPortFamine！[8]Inhospitableasthisclimateappearstoourfeelingsevergreentreesflourishluxuriantlyunderit。Humming-birdsmaybeseensuckingtheflowers，andparrotsfeedingontheseedsoftheWinter’sBark，inlat。55degs。S。Ihavealreadyremarkedtowhatadegreetheseaswarmswithlivingcreatures；andtheshells(suchasthePatellae，Fissurellae，Chitons，andBarnacles)，accordingtoMr。
G。B。Sowerby，areofamuchlargersizeandofamorevigorousgrowth，thantheanalogousspeciesinthenorthernhemisphere。AlargeVolutaisabundantinsouthernTierradelFuegoandtheFalklandIslands。AtBahiaBlanca，inlat。39degs。S。，themostabundantshellswerethreespeciesofOliva(oneoflargesize)，oneortwoVolutas，andaTerebra。Now，theseareamongstthebestcharacterizedtropicalforms。ItisdoubtfulwhetherevenonesmallspeciesofOlivaexistsonthesouthernshoresofEurope，andtherearenospeciesofthetwoothergenera。Ifageologistweretofindinlat39degs。onthecoastofPortugalabedcontainingnumerousshellsbelongingtothreespeciesofOliva，toaVolutaandTerebra，hewouldprobablyassertthattheclimateattheperiodoftheirexistencemusthavebeentropical；butjudgingfromSouthAmerica，suchaninferencemightbeerroneous。
Theequable，humid，andwindyclimateofTierradelFuegoextends，withonlyasmallincreaseofheat，formanydegreesalongthewestcoastofthecontinent。Theforestsfor600milesnorthwardofCapeHorn，haveaverysimilaraspect。Asaproofoftheequableclimate，evenfor300or400milesstillfurthernorthward，ImaymentionthatinChiloe(correspondinginlatitudewiththenorthernpartsofSpain)thepeachseldomproducesfruit，whilststrawberriesandapplesthrivetoperfection。Eventhecropsofbarleyandwheat[9]areoftenbroughtintothehousestobedriedandripened。AtValdivia(inthesamelatitudeof40
degs。，withMadrid)grapesandfigsripen，butarenotcommon；olivesseldomripenevenpartially，andorangesnotatall。Thesefruits，incorrespondinglatitudesinEurope，arewellknowntosucceedtoperfection；andeveninthiscontinent，attheRioNegro，undernearlythesameparallelwithValdivia，sweetpotatoes(convolvulus)arecultivated；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’sLand(lat。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-lineontheCordillerabehindChiloe(withitshighestpointsrangingfromonly5600to7500feet)andincentralChile[11](adistanceofonly9degs。oflatitude)，istrulywonderful。ThelandfromthesouthwardofChiloetonearConcepcion(lat。37degs。)ishiddenbyonedenseforestdrippingwithmoisture。Theskyiscloudy，andwehaveseenhowbadlythefruitsofsouthernEuropesucceed。IncentralChile，ontheotherhand，alittlenorthwardofConcepcion，theskyisgenerallyclear，raindoesnotfallforthesevensummermonths，andsouthernEuropeanfruitssucceedadmirably；andeventhesugar-canehasbeencultivated。[12]Nodoubttheplaneofperpetualsnowundergoestheaboveremarkableflexureof9000feet，unparalleledinotherpartsoftheworld，notfarfromthelatitudeofConcepcion，wherethelandceasestobecoveredwithforest-trees；fortreesinSouthAmericaindicatearainyclimate，andrainacloudedskyandlittleheatinsummer。
Thedescentofglacierstotheseamust，Iconceive，mainlydepend(subject，ofcourse，toapropersupplyofsnowintheupperregion)onthelownessofthelineofperpetualsnowonsteepmountainsnearthecoast。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，wouldbetheeffectofasevereshock(andsuchoccurhere[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，and(lookingtothewestwardinthesamehemisphere)lessthan2degs。fromorchideousparasites，andwithinasingledegreeoftree-ferns！
