They　stumbled　on　over　the　rocky　surface　in　silence。　At　times；　the　roof　of　the　cavern　sank　so　low　that　they　had　to　stoop　to　pass　under　it；　and　again　it　rose　sharply　like　the　roof　of　a　cathedral；　and　the　rays　of　the　far…away；　but　ever…increasing　light；　shone　upon　glistening　stalactites　that　hung　from　the　darkness　above　them　like　daggers　of　diamonds　set　in　ebony。
  〃It　is　not　so　near　as　I　supposed；〃　said　the　Alphian　wearily。　〃And　the　light　seemed　to　me　to　be　shining　on　a　cliff　over　which　water　is　pouring　in　places。　Yes；　you　can　see　that　it　is　water　by　the　ripples　in　the　light。〃
  〃Yes；　but　where　can　the　light　itself　be？〃
  〃I　cannot　yet　tell；　wait　till　we　get　nearer。〃
  In　about　an　hour　they　came　to　a　wide　chasm　on　the　other　side　of　which　towered　a　vast　cliff　of　white　crystal。　It　was　on　this　that　the　trembling　light　was　playing。
  〃Not　a　waterfall　after　all；〃　said　Branasko；　〃see；　there　is　the　source　of　the　reflection；〃　and　he　pointed　to　the　left　through　a　series　of　dark　chambers　of　the　cavern　to　a　dazzling　light。　〃Come；　let's　go　nearer　it。〃　He　moved　a　few　steps　forward　and　then　happening　to　look　over　his　shoulder　he　stopped　abruptly；　and　uttered　an　exclamation　of　surprise。
  〃What　is　it？〃　And　Johnston　followed　the　eyes　of　the　Alphian。
  〃Our　shadows　on　the　crystal　cliff；〃　said　Branasko　in　an　awed　tone；　〃only　the　light　from　the　changing　sun　could　make　them　so。〃
  Johnston　shuddered　superstitiously　at　the　tone　of　Branasko's　quivering　voice；　and　their　giant　shadows　which　stood　out　on　the　smooth　crystal　like　silhouettes。　So　clear…cut　were　they；　that；　in　his　own　shadow；　the　American　could　see　his　breast　heaving　and　in　Branasko's　the　quivering　of　the　Alphian's　huge　body　and　limbs。
  〃If　we　have　happened　upon　the　home　of　the　sun；　only　the　spirit　of　the　dead　kings　could　tell　what　will　become　of　us；〃　said　Branasko。
  〃Puh！　you　are　blindly　superstitious；〃　said　Johnston；　〃what　if　we　do　come　upon　the　sun？　Let's　go　down　there　and　look　into　the　mystery。〃
  Branasko　fell　into　the　rear　and　the　American　stoutly　pushed　ahead　toward　the　light　which　was　every　moment　increasing。　As　they　advanced　the　cave　got　larger　until　it　opened　out　into　a　larger　plain　over　which　hung　fathomless　darkness；　and　out　of　the　plain　a　great　dazzling　globe　of　light　was　slowly　rising。
  〃It　is　the　sun　itself；〃　exclaimed　Branasko；　and　he　sank　to　the　earth　and　covered　his　face　with　his　hands。　〃I　have　not　thought　ever　to　see　it　out　of　the　sky。〃
  The　American　was　deeply　thrilled　by　the　grand　sight。　He　sat　down　by　Branasko　and　together　they　watched　the　vast　ball　of　light　emerge　from　the　black　earth　and　gradually　disappear　in　a　great　hole　in　the　roof　of　the　cavern。　It　left　a　broad　stream　of　light　behind　it；　and；　now　that　the　sun　it…　self　was　out　of　view；　the　silent　spectators　could　see　the　great　square　hole　from　which　it　had　risen。
  As　if　by　mutual　consent；　they　rose　and　made　their　way　over　the　rocks　to　the　verge　of　the　hole；　which　seemed　several　thousand　feet　square。　At　first；　owing　to　the　brightness　of　the　sun　overhead；　they　could　see　nothing；　but；　as　the　great　orb　gradually　disappeared；　they　began　to　see　lights　and　the　figures　of　men　moving　about　below。　Later　they　observed　the　polished　parts　of　stupendous　machinerymachinery　that　moved　almost　noiselessly。
  Johnston　caught　sight　of　a　great　net…work　of　moving　cables　reaching　from　the　machinery　up　through　the　hole　above　and　exclaimed　enthusiastically：〃A　mechanical　sun！　electric　daylight！　What　genius！　A　world　in　a　great　cave！　Hundreds　of　square　miles　and　thousands　of　well　organized　people　living　under　the　light　of　an　artificial　sun！〃
  The　Alphian　looked　at　him　astonished。　〃Is　it　not　so　in　your　country？〃　he　asked。
  Johnston　smiled。　〃The　great　sun　that　lights　the　outer　world　is　as　much　greater　than　that　ball　of　light　as　Alpha　is　greater　than　a　grain　of　sand。　But　this　surely　is　the　greatest　achievement　of　man。　But　while　I　now　understand　how　your　sun　goes　over　the　whole　of　Alpha；　I　cannot　see　how　it　returns。〃
  〃Then　you　have　not　heard　of　the　great　tunnel　of　the　Sun；〃　replied　the　Alphian。
  〃No；what　is　it？〃
  〃It　runs　beneath　Alpha　and　connects　the　rising　and　setting　points　of　the　sun。　There　is　a　point　beneath　the　king's　palace　where；　by　a　staircase；　the　king　and　his　officers　may　go　down　and　inspect　the　sun　as　it　is　on　its　way　back　to　the　east　during　the　day。〃
  〃Wonderful！〃
  〃And　once　a　year　a　royal　party　goes　in　the　sun　over　its　entire　course。　It　is　said　that　it　is　sumptuously　furnished　inside；　and　not　too　warm；　the　lights　being　only　innumerable　small　ones　on　the　outside。〃
  The　two　men　were　silent　for　a　moment　then　Johnston　said：
  〃Perhaps　we　might　be　able　to　get　into　it　unobserved　and　be　thus　carried　over　to　the　other　side；　or　reach　the　palace　through　the　tunnel。〃
  Branasko　started　convulsively；　and　then；　as　he　looked　into　the　earnest　eyes　of　the　American；　he　said　despondently：
  〃We　have　got　to　die；　anyway；　it　may　be　well　for　us　to　think　of　it；　but　on　the　other　side；　in　the　Barrens；　there　is　no　more　chance　for　escape　than　here。　But　the　adventure　would　at　least　give　us　something　to　think　about；　let's　try　it。〃
  〃All　right；　but　how　can　we　get　down　there　where　the　sun　starts　to　rise？〃　asked　the　American；　peering　cautiously　over　the　edge　of　the　hole。
  〃There　must　be　some　way；〃　answered　Branasko。　〃Ah；　see！　further　to　the　left　there　are　some　ledges；　let's　see　what　can　be　done　that　way。〃
  〃I　am　with　you。〃
  The　rays　of　the　departing　sun　were　almost　gone；　and　the　electric　lights　down　among　the　machinery　seemed　afar　off　like　stars　reflected　in　deep　water。　With　great　difficulty　the　two　men　lowered　themselves　from　one　sharp　ledge　to　another　till　they　had　gone　half　down　to　the　bottom。
  〃It　is　no　use；〃　said　Branasko；　peering　over　the　lowest　ledge。　〃There　are　no　more　ledges　and　this　one　juts　out　so　far　that　even　if　there　were　smaller　ones　beneath　we　could　not　get　to　them。〃
  〃That　is　true；〃　agreed　the　American；　〃but　look；　is　not　that　a　lake　beneath？　I　think　it　must　be；　for　the　lights　are　reflected　on　its　surface。〃
  〃You　are　right；〃　answered　Branasko；　〃and　I　now　see　a　chance　for　us　to　get　down　safely。〃
  〃How？〃
  〃The　workers　are　too　far　from　the　lake　to　see　us；　we　can　drop　into　the　water　and　swim　ashore。〃
  〃Would　they　not　hear　the　splashing　of　our　bodies？〃
  〃I　think　not；　but　first　let's　experiment　with　a　big　stone。〃
  Suiting　the　action　to　the　word；　they　secured　a　stone　weighing　about　seventy…five　pounds　and　brought　it　to　the　ledge。　Carefully　poising　it　in　mid…air；　they　let　it　go。　Down　it　went；　cutting　the　air　with　a　sharp　whizzing　sound。　They　listened　breathlessly；　but　heard　no　sound　as　the　rock　struck　the　water；　and　the　men　among　the　machinery　seemed　undisturbed。　Only　the　widening　circles　of　rings　on　the　lake's　surface　indicated　where　the　stone　had　fallen。
  〃Good；〃　ejaculated　the　Alphian；　〃are　you　equal　to　such　a　plunge？　The　water　must　be　deep；　and　we　won't　be　hurt　at　all　if　only　we　can　keep　our　feet　downward　and　hold　our　breath　long　enough。　Our　clothing　will　soon　dry　down　there；　for　feel　the　warmth　that　comes　from　below。〃
  The　Alphian　slowly　crawled　out　on　the　sharpest　projection　of　the　ledge。　〃Are　you　willing　to　try　it？〃　he　asked；　over　his　shoulder。
  〃Yes。〃
  〃Well；　wait　till　you　see　me　swim　ashore；　and　then　follow。〃
  Johnston　shuddered　as　the　strong　fellow　swung　himself　over　the　ledge　and　hung　downward。
  〃Adieu；〃　said　Branasko；　and　he　let　go。　Down　he　fell；　as　straight　as　an　arrow；　into　the　shadows　below。　For　an　instant　Johnston　heard　the　fluttering　of　the　fellow's　clothing　as　he　fell　through　the　darkness；　and　then　there　was　no　sound　except　the　low　whirr　of　the　cables　and　the　monotonous　hum　of　the　great　wheels　beneath。　Then　the　smooth　surface　of　the　lake　was　broken　in　a　white　foaming　spot；　and；　later；　he　saw　something　small　and　dark　slowly　swimming　shoreward。　It　was　Branasko；　and　the　men　to　the　right　had　not　heard　or　seen　him。
  Johnston　saw　him　reach　the　shore；　then　he　crawled　out　to　the　point　of　the　projecting　rock　and　tremblingly　lowered　himself　till　he　hung　downward　as　Branasko　had　done。　He　had　just　drawn　a　deep　breath　preparatory　to　letting　go　his　hold；　when；　chancing　to　look　down；　he　saw　a　long　narrow　barge　slowly　emerging　from　the　cliff　directly　under　him。　For　an　instant　he　was　so　much　startled　that　he　almost　lost　his　grip　on　the　rock。　He　tried　to　climb　back　on　the　ledge；　but　his　strength　was　gone。　He　felt　that　he　could　not　hold　out　till　the　boat　had　passed。　Death　was　before　him；　and　a　horrible　one。　The　boat　seemed　to　crawl。　Everything　was　a　blur　before　his　eyes。　His　fingers　began　to　relax；　and　with　a　low　cry　he　fell。
  Chapter　X。
  To　Thorndyke　the　dark　corridor　seemed　endless。　The　king's　last　words　had　now　a　sinister　meaning；　and　Bernardino's　whispered　warning　filled　him　with　dread。　〃Keep　your　presence　of　mind；〃　she　urged；　was　it　then；　some　frightful　mental　ordeal　he　was　about　to　pass　through？
  Presently　they　came　to　a　door。　Thorn…　dyke　heard　his　guide　feeling　for　the　bolt　and　key…hole。　The　rattling　of　the　keys　sounded　like　a　ghostly　threat　in　the　empty　corridors。　The　air　was　as　damp　as　a　fog；　and　the　stones　were　cold　and　slimy。　After　a　moment　the　guard　succeeded　in　unlocking　the　door　and　roughly　pushed　the　Englishman　forward。　The　door　closed　with　a　little　puff；　and　Thor