voyage of the paper canoe-第11节

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ed。　　It　is　built　of　layers　of　well…seasoned　pine；　securely　fastened　together　to　form　one　solid　mass；　which；　after　having　been　laid　up　of　the　general　outline　required；　is　carefully　worked　off；　until　its　surface；　which　is　made　perfectly　smooth；　exactly　conforms　to　the　selected　lines；　and　its　beam；　depth；　and　length　are　those　of　the　given　boat。　　During　the　process　of　its　construction；　suitable　rabbets　are　cut　to　receive　the　lower　　keelson；　the　two　inwales；　and　the　bow　and　stern　deadwoods；　which；　being　put　in　position；　are　worked　off　so　that　their　surfaces　are　flush　with　that　of　the　model；　and　forming；　as　it　were；　an　integral　part　of　it。　　It　being　important　that　these　parts　should；　in　the　completed　boat；　be　firmly　attached　to　the　skin；　their　surface　is；　at　this　part　of　the　process；　covered　with　a　suitable　adhesive　preparation。

〃The　model　is　now　ready　to　be　covered　with　paper。　Two　kinds　are　used：　that　made　from　the　best　Manila；　and　that　prepared　from　pure　　unbleached　linen　stock；　the　sheets　being　the　full　length　of　the　model；　no　matter　what　that　may　be。　　If　Manila　paper　is　used；　the　first　sheet　is　dampened；　laid　smoothly　on　the　model；　and　securely　fastened　in　place　by　tacking　it　to　　certain　rough　strips　attached　to　its　upper　face。　Other　sheets　are　now　superposed　on　this　and　on　each　other；　and　suitably　cemented　together；　the　number　depending　upon　the　size　of　the　boat　and　the　stiffness　required。　　If　linen　paper　is　used；　but　one　sheet　is　employed；　of　such　weight　and　　dimensions　that；　when　dry；　it　will　give　just　the　thickness　of　skin　necessary。　　Should　the　surface　of　the　model　be　concave　in　parts；　as　in　the　run　of　boats　with　square　sterns　for　instance；　the　paper　is　made　to　conform　to　these　surfaces　by　suitable　convex　moulds；　which　also　hold　the　paper　in　place　until；　by　drying；　it　has　taken　and　will　　retain　the　desired　form。　　The　model；　with　its　enveloping　coat　of　paper；　is　now　removed　to　the　dry…room。　　As　the　paper　skin　dries；　all　wrinkles　disappear；　and　it　gradually　assumes　the　desired　shape。　　Finally；　when　all　moisture　has　been　evaporated；　it　is　taken　from　the　mould　an　exact　fac…simile　of　the　model　desired；　exceedingly　stiff；　perfectly　symmetrical；　and　seamless。

〃The　paper　is　now　subjected　to　the　water…proof　process；　and　the　skin；　with　its　keelson；　inwales；　and　dead…woods　attached；　is　then　placed　in　the　carpenter's　hands；　where　the　frame　is　completed　in　the　usual　manner；　as　described　for　wooden　boats。　　The　paper　decks　being　put　on；　it　is　then　ready　for　the　brass；　iron；　and　varnish　work。　　As　the　skins　of　these　boats　（racing…shells）　vary　from　one…sixteenth　of　an　inch　in　the　singles；　to　　one…twelfth　of　an　inch　in　the　six…oared　outriggers；　the　wooden　frame　becomes　necessary　to　support　and　keep　them　in　shape。　　In　applying　this　invention　to　gigs；　dingys；　canoes；　and　skiffs；　a　somewhat　different　method　is　adopted。　　Since　these　boats　are　subjected　to　much　hard　service；　and　must　be　so　constructed　as　to　permit　the　occupant　to　move　about　in　them　as　is　usual　in　such　craft；　a　light　and　strong　frame　of　wood　is　prepared；　composed　of　a　suitable　number　of　pairs　of　ribs；　with　stem　and　stern　pieces　cut　from　the　natural　crooks　of　hackmatack　roots。　　These　are　firmly　framed　to　two　gunwales　and　a　keelson；　extending　the　length　of　the　boat；　the　whole　forming　the　　skeleton　shape　of　the　desired　model。　　The　forms　for　these　boats　having　been　prepared；　as　already　described　for　the　racing…shells；　and　the　frame　being　let　into　this　form；　so　that　the　outer　surface　of　the　ribs；　stem　and　stern　pieces　will　conform　with　its　outer　surface；　the　paper　skin　is　next　laid　upon　it。　　The　skin；　manufactured　from　new；　　unbleached　linen　stock；　is　carefully　stretched　in　place；　and　when　perfectly　dry　is　from　one…tenth　to　three…sixteenths　of　an　inch　thick。　　Removed　from　the　model；　it　is　water…proofed；　the　frame　and　fittings　completed；　and　the　boat　varnished。　In　short；　in　this　class　of　boats；　the　shape；　style；　and　finish　are　precisely　that　of　wooden　ones；　of　corresponding　dimensions　and　class；　except　that　for　the　usual　wooden　sheathing　is　substituted　the　paper　skin　as　described。

〃The　advantages　possessed　by　these　boats　over　those　of　wood　are：

〃By　the　use　of　this　material　for　the　skins　of　racing…shells；　where　experience　has　demonstrated　the　smooth　bottom　to　be　the　best；　under…water　lines　of　any　degree　of　fineness　can　be　developed；　which　cannot　successfully　be　produced　in　those　of　wood；　even　where　the　streaks　are　so　reduced　in　thickness　that　strength；　stiffness；　and　　durability　are　either　wholly　sacrificed　or　greatly　　impaired。　　In　the　finer　varieties　of　'dug…outs'　equally　fine　lines　can　be　obtained；　but　so　delicate　are　such　boats；　if　the　sides　are　reduced　to　　three…sixteenths　of　an　inch　or　less　in　thickness；　that　it　is　found　practically　impossible　to　preserve　their　original　forms　for　any　length　of　time。　　Hence；　so　far　as　this　point　is　concerned；　it　only　remains　for　the　builder　to　select　those　models　which　science；　guided　by　experience；　points　out　as　the　best。

The　paper　skin；　after　being　water…proofed；　is　finished　with　hard　varnishes；　and　then　presents　a　solid；　perfectly　smooth；　and　horny　surface　to　the　action　of　the　water；　unbroken　by　joint；　lap；　or　seam。　　This　surface　admits　of　being　polished　as　smooth　as　a　coach…panel　or　a　mirror。　　Unlike　wood；　it　has　no　grain　to　be　cracked　or　split；　it　never　shrinks；　and；　paper　being　one　of　the　best　of　non…conductors；　no　ordinary　degree　of　heat　or　cold　affects　its　shape　or　hardness；　and　hence　these　boats　are　admirably　adapted　for　use　in　all　climates。　　　As　the　skin　absorbs　no　moisture；　these　boats　gain　no　weight　by　use；　and；　having　no　moisture　to　give　off　when　out　of　the　water；　they　do　not；　like　wooden　boats；　show　the　effect　of　exposure　to　the　air　by　leaking。　　They　are；　therefore；　in　this　respect　always　prepared　for　service。

The　strength　and　stiffness　of　the　paper　shells　are　most　remarkable。　　To　demonstrate　it；　a　　single　shell　of　twelve　inch　beam　and　twenty…eight　feet　long；　fitted　complete　with　its　outriggers；　the　hull　weighing　twenty…two　pounds；　was　placed　on　two　trestles　eight　feet　apart；　in　such　a　manner　that　the　trestles　were　each　the　same　distance　from　the　centre　of　the　cockpit；　which　was　thus　entirely　unsupported。　　A　man　　weighing　one　hundred　and　forty　pounds　then　seated　himself　in　it；　and　remained　in　this　position　three　minutes。　The　deflection　caused　by　this　strain；　being　accurately　measured；　was　found　to　be　　one…sixteenth　of　an　inch　at　a　point　midway　between　the　supports。　　If　this　load；　applied　under　such　abnormal　conditions；　produced　so　little　effect；　we　can　safely　assume　that；　when　thus　loaded　and　resting　on　the　water；　supported　throughout　her　whole　length；　and　the　load　far　more　equally　　distributed　over　the　whole　frame；　there　would　be　no　deflection　whatever。

〃Lightness；　when　combined　with　a　proper；　　stiffness　and　strength；　being　a　very　desirable　quality；　it　is　here　that　the　paper　boats　far　excel　their　　wooden　rivals。　　If　two　shells　are　selected；　the　one　of　wood　and　the　other　with　a　paper　skin　and　deck；　as　has　been　described；　of　the　same　dimensions　and　equally　stiff；　careful　experiment　proves　that　the　wooden　one　will　be　thirty　per　cent。　the　heaviest。　　If　those　of　the　same　dimensions　and　equal　weight　are　compared；　the　paper　one　will　be　found　to　exceed　the　wooden　one　in　stiffness　and　in　capacity　to　resist　torsional　strains　in　the　same　proportion。　　Frequent　boasts　are　made　that　wooden　shells　can　be　and　are　built　much　lighter　than　paper　ones；　and　if　the　quality　of　lightness　alone　is　considered；　this　is　true；　yet　when　the　practical　test　of　use　is　applied；　such　extremely　light　wooden　boats　have　always　proved；　and　will　continue　to　prove；　failures；　as　here　this　quality　is　only　one　of　a　number　which　combine　to　make　the　boat　serviceable。　　A　wooden　shell　whose　hull　weighs　twenty…two　pounds；　honest　weight；　is　a　very　fragile；　short…lived　affair。　　　A　paper　shell　of　the　same　dimensions；　and　of　the　same　weight；　will　last　as　long；　and　do　as　much　work；　as　a　wooden　one　whose　hull　turns　the　beam　at　thirty　pounds。

〃An　instance　of　their　remarkable　strength　is　shown　in　the　following　case。　In　the　summer　of　1870；　a　single　shell；　while　being　rowed　at　full　speed；　with　the　current；　on　one　of　our　　principal　rivers；　was　run　into　to　the　stone　abutment　of　a　bridge。　The　bow　struck　squarely　on　to　　obstacle；　and　such　was　the　momentum　of　the　mass　that　the　oarsman　was　thrown　directly　through　the　flaring　bow　of　the　cockpit　into　the　river。　　Witnesses　of　the　accident　who　were　familiar　with　wooden　shells　declared　that　the　boat　was　ruined；　but；　after　a　careful　examination；　only　the　bow…tip　was　found　to　be　twisted　in　a　spiral　form；　and　the　washboard　broken　at　the　point　by　the　oarsman　as　he　passed　between　the　sides。　　Two　dollars　covered　the　cost　of　repair。　　Had　it　been　a　wooden　shell　the　shock　would　have　crushed　its　stem　and　splintered　the　skin　from　the　bow　to　the　waist。〃

Old　and　cautious　seamen　tried　to　dissuade　me　from　contracting　with　the　Messrs。　Waters　for　the　building　of　a　stout　paper　canoe　for　my　journey。　Harvard　College　had　not　adopted　this　〃　newfangled　notion〃　at　that　time；　and　Cornell　had　only　begun　to　think　of　attempting　to　out…row　other　colleges　at　Saratoga　by　using　paper　boats。　The　Centennial　year　of　the　independence　of　the　United　States；　1876；　settled　all　d