and　lived　in　luxury　and　comfort　in　the　midst　of　a　land　of
  perpetual　ice。　　Their　cities　were　veritable　hothouses；　and　when　I
  had　come　within　this　one　my　respect　and　admiration　for　the
  scientific　and　engineering　skill　of　this　buried　nation　was　unbounded。
  The　moment　we　entered　the　city　Talu　threw　off　his　outer　garments
  of　fur；　as　did　we；　and　I　saw　that　his　apparel　differed　but　little
  from　that　of　the　red　races　of　Barsoom。　　Except　for　his　leathern
  harness；　covered　thick　with　jewels　and　metal；　he　was　naked；
  nor　could　one　have　comfortably　worn　apparel　in　that　warm　and
  humid　atmosphere。
  For　three　days　we　remained　the　guests　of　Prince　Talu；　and
  during　that　time　he　showered　upon　us　every　attention　and　courtesy
  within　his　power。　　He　showed　us　all　that　was　of　interest　in　his
  great　city。
  The　Marentina　atmosphere　plant　will　maintain　life　indefinitely
  in　the　cities　of　the　north　pole　after　all　life　upon　the　balance　of
  dying　Mars　is　extinct　through　the　failure　of　the　air　supply；　should
  the　great　central　plant　again　cease　functioning　as　it　did　upon　that
  memorable　occasion　that　gave　me　the　opportunity　of　restoring　life
  and　happiness　to　the　strange　world　that　I　had　already　learned　to
  love　so　well。
  He　showed　us　the　heating　system　that　stores　the　sun's　rays　in
  great　reservoirs　beneath　the　city；　and　how　little　is　necessary　to
  maintain　the　perpetual　summer　heat　of　the　glorious　garden　spot
  within　this　arctic　paradise。
  Broad　avenues　of　sod　sewn　with　the　seed　of　the　ocher　vegetation
  of　the　dead　sea　bottoms　carried　the　noiseless　traffic　of　light
  and　airy　ground　fliers　that　are　the　only　form　of　artificial
  transportation　used　north　of　the　gigantic　ice…barrier。
  The　broad　tires　of　these　unique　fliers　are　but　rubber…like　gas
  bags　filled　with　the　eighth　Barsoomian　ray；　or　ray　of　propulsion
  that　remarkable　discovery　of　the　Martians　that　has　made　possible
  the　great　fleets　of　mighty　airships　that　render　the　red　man　of　the
  outer　world　supreme。　　It　is　this　ray　which　propels　the　inherent　or
  reflected　light　of　the　planet　off　into　space；　and　when　confined
  gives　to　the　Martian　craft　their　airy　buoyancy。
  The　ground　fliers　of　Marentina　contain　just　sufficient　buoyancy
  in　their　automobile…like　wheels　to　give　the　cars　traction　for
  steering　purposes；　and　though　the　hind　wheels　are　geared　to　the
  engine；　and　aid　in　driving　the　machine；　the　bulk　of　this　work　is
  carried　by　a　small　propeller　at　the　stern。
  I　know　of　no　more　delightful　sensation　than　that　of　riding　in
  one　of　these　luxuriously　appointed　cars　which　skim；　light　and　airy
  as　feathers；　along　the　soft；　mossy　avenues　of　Marentina。　　They　move
  with　absolute　noiselessness　between　borders　of　crimson　sward　and
  beneath　arching　trees　gorgeous　with　the　wondrous　blooms　that　mark
  so　many　of　the　highly　cultivated　varieties　of　Barsoomian　vegetation。
  By　the　end　of　the　third　day　the　court　barberI　can　think　of　no
  other　earthly　appellation　by　which　to　describe　himhad　wrought
  so　remarkable　a　transformation　in　both　Thuvan　Dihn　and　myself　that
  our　own　wives　would　never　have　known　us。　　Our　skins　were　of　the
  same　lemon　color　as　his　own；　and　great；　black　beards　and　mustaches
  had　been　deftly　affixed　to　our　smooth　faces。　　The　trappings　of
  warriors　of　Okar　aided　in　the　deception；　and　for　wear　beyond　the
  hothouse　cities　we　each　had　suits　of　the　black…　and　yellow…striped　orluk。
  Talu　gave　us　careful　directions　for　the　journey　to　Kadabra；　the
  capital　city　of　the　Okar　nation；　which　is　the　racial　name　of　the
  yellow　men。　　This　good　friend　even　accompanied　us　part　way；　and　then；
  promising　to　aid　us　in　any　way　that　he　found　possible；　bade　us　adieu。
  On　parting　he　slipped　upon　my　finger　a　curiously　wrought　ring　set　with
  a　dead…black；　lusterless　stone；　which　appeared　more　like　a　bit　of
  bituminous　coal　than　the　priceless　Barsoomian　gem　which　in　reality　it　is。
  〃There　had　been　but　three　others　cut　from　the　mother　stone；〃
  he　said；　〃which　is　in　my　possession。　　These　three　are　worn　by
  nobles　high　in　my　confidence；　all　of　whom　have　been　sent　on　secret
  missions　to　the　court　of　Salensus　Oll。
  〃Should　you　come　within　fifty　feet　of　any　of　these　three　you　will
  feel　a　rapid；　pricking　sensation　in　the　finger　upon　which　you
  wear　this　ring。　　He　who　wears　one　of　its　mates　will　experience　the
  same　feeling；　it　is　caused　by　an　electrical　action　that　takes　place
  the　moment　two　of　these　gems　cut　from　the　same　mother　stone　come
  within　the　radius　of　each　other's　power。　　By　it　you　will　know　that
  a　friend　is　at　hand　upon　whom　you　may　depend　for　assistance
  in　time　of　need。
  〃Should　another　wearer　of　one　of　these　gems　call　upon　you　for　aid
  do　not　deny　him；　and　should　death　threaten　you　swallow　the　ring
  rather　than　let　it　fall　into　the　hands　of　enemies。　　Guard　it　with
  your　life；　John　Carter；　for　some　day　it　may　mean　more　than　life　to　you。〃
  With　this　parting　admonition　our　good　friend　turned　back
  toward　Marentina；　and　we　set　our　faces　in　the　direction　of　the
  city　of　Kadabra　and　the　court　of　Salensus　Oll；　Jeddak　of　Jeddaks。
  That　very　evening　we　came　within　sight　of　the　walled　and　glass…roofed
  city　of　Kadabra。　　It　lies　in　a　low　depression　near　the　pole；　surrounded
  by　rocky；　snow…clad　hills。　　From　the　pass　through　which　we　entered
  the　valley　we　had　a　splendid　view　of　this　great　city　of　the　north。
  Its　crystal　domes　sparkled　in　the　brilliant　sunlight　gleaming　above
  the　frost…covered　outer　wall　that　circles　the　entire　one　hundred　miles
  of　its　circumference。
  At　regular　intervals　great　gates　give　entrance　to　the　city；
  but　even　at　the　distance　from　which　we　looked　upon　the　massive　pile
  we　could　see　that　all　were　closed；　and；　in　accordance　with　Talu's
  suggestion；　we　deferred　attempting　to　enter　the　city　until　the
  following　morning。
  As　he　had　said；　we　found　numerous　caves　in　the　hillsides　about　us；
  and　into　one　of　these　we　crept　for　the　night。　　Our　warm　orluk
  skins　kept　us　perfectly　comfortable；　and　it　was　only　after　a　most
  refreshing　sleep　that　we　awoke　shortly　after　daylight　on　the
  following　morning。
  Already　the　city　was　astir；　and　from　several　of　the　gates　we　saw
  parties　of　yellow　men　emerging。　　Following　closely　each　detail
  of　the　instructions　given　us　by　our　good　friend　of　Marentina；　we
  remained　concealed　for　several　hours　until　one　party　of　some　half
  dozen　warriors　had　passed　along　the　trail　below　our　hiding　place
  and　entered　the　hills　by　way　of　the　pass　along　which　we　had　come
  the　previous　evening。
  After　giving　them　time　to　get　well　out　of　sight　of　our　cave；
  Thuvan　Dihn　and　I　crept　out　and　followed　them；　overtaking　them
  when　they　were　well　into　the　hills。
  When　we　had　come　almost　to　them　I　called　aloud　to　their　leader；
  when　the　whole　party　halted　and　turned　toward　us。
  The　crucial　test　had　come。　　Could　we　but　deceive　these　men
  the　rest　would　be　comparatively　easy。
  〃Kaor！〃　I　cried　as　I　came　closer　to　them。
  〃Kaor！〃　responded　the　officer　in　charge　of　the　party。
  〃We　be　from　Illall；〃　I　continued；　giving　the　name　of　the　most　remote
  city　of　Okar；　which　has　little　or　no　intercourse　with　Kadabra。
  〃Only　yesterday　we　arrived；　and　this　morning　the　captain　of
  the　gate　told　us　that　you　were　setting　out　to　hunt　orluks；
  which　is　a　sport　we　do　not　find　in　our　own　neighborhood。　　We　have
  hastened　after　you　to　pray　that　you　allow　us　to　accompany　you。〃
  The　officer　was　entirely　deceived；　and　graciously　permitted　us
  to　go　with　them　for　the　day。　　The　chance　guess　that　they　were　bound
  upon　an　orluk　hunt　proved　correct；　and　Talu　had　said　that　the
  chances　were　ten　to　one　that　such　would　be　the　mission　of　any　party
  leaving　Kadabra　by　the　pass　through　which　we　entered　the　valley；
  since　that　way　leads　directly　to　the　vast　plains　frequented　by　this
  elephantine　beast　of　prey。
  In　so　far　as　the　hunt　was　concerned；　the　day　was　a　failure；
  for　we　did　not　see　a　single　orluk；　but　this　proved　more　than
  fortunate　for　us；　since　the　yellow　men　were　so　chagrined　by　their
  misfortune　that　they　would　not　enter　the　city　by　the　same　gate　by
  which　they　had　left　it　in　the　morning；　as　it　seemed　that　they　had
  made　great　boasts　to　the　captain　of　that　gate　about　their　skill　at
  this　dangerous　sport。
  We；　therefore；　approached　Kadabra　at　a　point　several　miles
  from　that　at　which　the　party　had　quitted　it　in　the　morning；
  and　so　were　relieved　of　the　danger　of　embarrassing　questions
  and　explanations　on　the　part　of　the　gate　captain；　whom　we　had
  said　had　directed　us　to　this　particular　hunting　party。
  We　had　come　quite　close　to　the　city　when　my　attention　was
  attracted　toward　a　tall；　black　shaft　that　reared　its　head　several
  hundred　feet　into　the　air　from　what　appeared　to　be　a　tangled　mass
  of　junk　or　wreckage；　now　partially　snow…covered。
  I　did　not　dare　venture　an　inquiry　for　fear　of　arousing　suspicion
  by　evident　ignorance　of　something　which　as　a　yellow　man　I　should
  have　known；　but　before　we　reached　the