〃Suppose　we　take　a　walk　all　round　on　the　beach；〃　proposed　the　Englishman；　〃there　is　no　telling　what　we　may　find；　we　may　run　on　something　that　has　drifted　ashore　from　some　wrecked　ship。〃
  Johnston　consented。　They　had　encompassed　the　entire　island；　which　was　oval　in　shape；　and　were　about　to　ascend　to　the　rock　to　put　fresh　fuel　on　the　fire　before　lying　down　to　sleep　for　the　night；　when　Thorndyke　noticed　a　road　that　had　evidently　been　worn　in　the　rock　by　human　footsteps。
  〃Made　by　feet；〃　he　said；　bending　down　and　looking　closely　at　the　rock　and　raking　up　a　handful　of　white　sand；　〃but　whether　the　feet　of　savage　or　civilized　mortal　I　can't　make　out。〃
  Johnston　was　a　few　yards　ahead　of　him　and　stooped　to　pick　up　something　glittering　in　the　moonlight。　It　was　a　tap　from　the　heel　of　a　shoe　and　was　of　solid　silver。
  〃Civilized；〃　he　said；　holding　it　out　to　his　companion；　〃and　of　the　very　highest　order　of　civilization。　Whoever　heard　of　people　rich　enough　to　wear　silver　heel…taps。〃
  〃Are　you　sure　it　is　silver？〃　asked　the　Englishman；　examining　it　closely。
  〃Pure　and　unalloyed；　see　how　the　stone　has　cut　into　it；　and　feel　its　weight。〃
  〃You　are　right；　I　believe；〃　returned　Thorndyke；　as　Johnston　put　the　strange　trophy　into　his　pocket…book；　and　the　two　adventurers　paused　a　moment　and　looked　mutely　into　each　other's　eyes。
  〃We　haven't　the　faintest　idea　of　where　we　are；〃　said　Johnston；　his　tone　showing　that　he　was　becoming　more　despondent。　〃We　don't　know　how　long　we　were　unconscious　in　the　balloon；　nor　where　we　were　taken　in　the　storm。　We　may　now　be　in　the　very　centre　of　the　North　Polar　seathis　knob　may　be　the　very　pivot　on　which　this　end　of　the　earth　revolves。〃
  The　Englishman　laughed。　〃No　danger；　the　sun　is　too　natural。　》From　the　poles　it　would　look　different。〃
  〃I　don't　mean　the　old　sun　that　you　read　so　much　about；　and　that　they　make　so　much　racket　over　at　home；　but　another　of　which　we　are　the　original　discoverera　sun　that　isn't　in　old　Sol's　beat　at　all；　but　one　that　revolves　round　the　earth　from　north　to　south　and　dips　in　once　a　day　at　the　north　and　the　south　poles。　See？〃
  The　Englishman　laughed　heartily　and　slapped　his　friend　on　the　shoulder。
  〃I　think　we　are　somewhere　in　the　Atlantic；　but　your　finding　that　heel…tap　does　puzzle　me。〃
  〃We　are　going　to　have　an　adventure；　beside　which　all　others　of　our　lives　will　pale　into　insignificance。　I　feel　it　in　my　bones。　See　how　evenly　this　road　has　been　worn　and　it　is　leading　toward　the　centre　of　the　island。〃
  In　a　few　minutes　the　two　adventurers　came　to　a　point　in　the　road　where　tall　cliffs　on　either　side　stood　up　perpendicularly。　It　was　dark　and　cold；　and　but　a　faint　light　from　the　moon　shone　down　to　them。
  〃I　don't　like　this；〃　said　Johnston；　who　was　behind　the　Englishman；　〃we　may　be　walking　into　the　ambush　of　an　enemy。〃
  〃Pshaw！〃　and　Thorndyke　plunged　on　into　the　gloomy　passage。　Presently　the　walls　began　to　widen　like　a　letter　〃Y〃　and　in　a　great　open　space　they　saw　a　placid　lake　on　the　bosom　of　which　the　moon　was　shining。　On　all　sides　the　towering　walls　rose　for　hundreds　of　feet。　Speechless　with　wonder　and　with　quickly…　beating　hearts　they　stumbled　forward　over　the　uneven　road　till　they　reached　the　shore　of　the　lake。　The　water　was　so　clear　and　still　that　the　moon　and　stars　were　reflected　in　it　as　if　in　a　great　mirror。
  〃Look　at　that！〃　exclaimed　Thorndyke；　pointing　down　into　the　depths；　〃what　can　that　be？〃
  Johnston　followed　Thorndyke's　finger　with　his　eyes。　At　first　he　thought　that　it　was　a　comet　moving　across　the　sky　and　reflected　in　the　water；　but；　on　glancing　above；　he　saw　his　mistake。　It　looked；　at　first；　like　a　great　ball　of　fire　rolling　along　the　bottom　of　the　lake　with　a　stream　of　flame　in　its　wake。
  Chapter　II。
  The　two　men　watched　it　for　several　minutes；　all　the　time　it　seemed　to　be　growing　larger　and　brighter　till；　after　a　while；　they　saw　that　the　light　came　from　something　shaped　like　a　ship；　sharp　at　both　ends；　and　covered　with　oval　glass。　As　it　slowly　rose　to　the　surface　they　saw　that　it　contained　five　or　six　men；　sitting　in　easy　chairs　and　reclining　on　luxurious　divans。　One　of　them　sat　at　a　sort　of　pilot…wheel　and　was　directing　the　course　of　the　strange　craft；　which　was　moving　as　gracefully　as　a　great　fish。
  Then　the　young　men　saw　the　man　at　the　pilot…wheel　raise　his　hand；　and　from　the　water　came　the　musical　notes　of　a　great　bell。　The　vessel　stopped；　and　one　of　the　men　sprang　up　and　raised　an　instrument　that　looked　like　a　telescope　to　his　eyes。　With　this　he　seemed　to　be　closely　searching　the　lake　shores；　for　he　did　not　move　for　several　minutes。　Then　he　lowered　the　instrument；　and　when　the　bell　had　rung　again；　the　vessel　rose　slowly　and　perpendicularly　to　the　surface　and　glided　to　the　shore　within　twenty　yards　of　where　the　adventurers　stood。
  〃Could　they　have　seen　us？〃　whispered　Thorndyke；　drawing　Johnston　nearer　the　side　of　the　cliff。
  〃I　think　so；　at　all　events；　they　are　between　us　and　the　outlet；　we　may　as　well　make　the　best　of　it。〃
  The　men；　all　except　the　pilot；　landed；　and　a　dazzling　electric　search…light　was　turned　on　the　spot　where　Thorndyke　and　Johnston　stood。　For　a　moment　they　were　so　blinded　that　they　could　not　see；　and　then　they　heard　footsteps；　and；　their　eyes　becoming　accustomed　to　the　light；　they　found　themselves　surrounded　by　several　men；　very　strangely　clad。　They　all　wore　long　cloaks　that　covered　them　from　head　to　foot　and　every　man　was　more　than　six　feet　in　height　and　finely　proportioned。　One　of　them；　who　seemed　to　be　an　officer　in　command；　bowed　politely。
  〃I　am　Captain　Tradmos；　gentlemen；　in　the　king's　service。　It　is　my　duty　to　make　you　my　prisoners。　I　must　escort　you　to　the　palace　of　the　king。〃
  〃That's　cool；〃　said　Johnston；　to　conceal　the　discomfiture　that　he　felt；　〃we　had　no　idea　that　you　had　a　kingdom。　We　have　tramped　all　over　this　island；　and　you　are　the　first　signs　of　humanity　we　have　met。〃
  He　would　have　recalled　his　words　before　he　had　finished　speaking；　if　he　could　have　done　so；　for　he　saw　by　the　manner　of　the　captain　that　he　had　been　over　bold。
  〃Follow　me；〃　answered　the　officer　curtly；　and　with　a　motion　of　his　hand　to　his　men　he　turned　toward　the　odd…looking　vessel。
  The　two　adventurers　obeyed；　and　the　cloaked　men　fell　in　behind　them。　Neither　Johnston　nor　Thorndyke　had　ever　seen　anything　like　the　peculiar　boat　that　was　moored　to　the　rocky　shore。　It　was　about　forty　feet　in　length；　had　a　hull　shaped　like　a　racing　yacht；　but　which　was　made　of　black　rubber　inflated　with　air。　It　was　covered　with　glass；　save　for　a　doorway　about　six　feet　high　and　three　feet　wide　in　the　side；　and　looked　like　a　great　oblong　bubble　floating　on　the　still　dark　water。　As　they　approached　the　searchlight　was　extinguished；　and　they　were　enabled　to　see　the　boat　to　a　better　advantage　by　the　aid　of　the　electric　lights　that　illuminated　the　interior。　It　was　with　feelings　of　awe　that　the　two　adventurers　followed　the　captain　across　the　gang…plank　into　the　vessel。
  The　electric　light　was　brilliantly　white；　and　in　various　places　pink；　red　and　light…blue　screens　mellowed　it　into　an　artistic　effect　that　was　very　soothing　to　the　eye。　The　ceiling　was　hung　with　festoons　of　prisms　as　brilliant　as　the　purest　diamonds；　and　in　them；　owing　to　the　gently　undulatory　movement　of　the　vessel；　colors　more　beautiful　than　those　of　a　rainbow　played　entrancingly。　Rare　pictures　in　frames　of　delicate　gold　were　interspersed　among　the　clusters　of　prisms；　and　the　floor　was　covered　with　carpets　that　felt　as　soft　beneath　the　foot　as　pillows　of　eider…down。
  As　he　entered　the　door　the　officer　threw　off　his　gray　cloak；　and　his　men　did　likewise；　disclosing　to　view　the　finest　uniforms　the　prisoners　had　ever　seen。　Captain　Tradmos's　legs　were　clothed　in　tights　of　light…blue　silk；　and　he　wore　a　blue　sack…coat　of　silk　plush　and　a　belt　of　pliant　gold；　the　buckles　of　which　were　ornamented　with　brilliant　gems。　His　eyes　were　dark　and　penetrating；　and　his　black　hair　lay　in　glossy　masses　on　his　shoulders。　He　had　the　head　of　an　Apollo　and　a　brow　indicative　of　the　highest　intellect。
  Leaving　his　men　in　the　first　room　that　they　entered；　he　gracefully　conducted　his　prisoners　through　another　room　to　a　small　cabin　in　the　stern　of　the　boat；　and　told　them　to　make　themselves　comfortable　on　the　luxurious　couches　that　lined　the　circular　glass　walls。
  〃Our　journey　will　be　of　considerable　length；〃　he　said；　〃and　as　you　are　no　doubt　fatigued；　you　had　better　take　all　the　rest　you　can　get。　I　see　that　you　need　food　and　have　ordered　a　repast　which　will　refresh　you。〃　As　he　concluded　he　touched　a　button　in　the　wall　and　instantly　a　table；　laden　with　substantial　food；　rare　delicacies　and　wines；　rose　through　a　trap…door　in　the　floor。　He　smiled　at　the　expressions　of　surprise　on　their　faces　and　touched　a　green　bottle　of　wine　with　his　white　tapering　hand。
  〃The　greater　part　of　our　journey　will　be　under　water；　and　our　wines　are　specially　prepared　to　render　us　capable　of　subsisting　on　a　rather　limited　quantity　of　air　during　the　voyage；　so　I　advise　you　to　partake　of　them　freely；　you　will　find　them　very　agreeable　to　the　taste。〃
  〃We　are　very　grateful；〃　bowed　Thorndyke；　from　his　seat　on　a　couch。　〃I　am　sure　no　prisoners　were　ever　more　graciously　or　royally　entertained。　To　be　your　prisoner　is　a　pleasure　to　be　re