heroes of the telegraph-第39部分

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；　thereby　varying　the　electric　current　and　deflecting　the　needle　of　the　galvanometer　to　one　side　or　the　other。　　The　instrument　was　said　to　indicate　a　change　of　temperature　equivalent　to　one…millionth　of　a　degree　Fahrenheit。　　It　was　tested　by　Edison　on　the　sun's　corona　during　the　eclipse　observations　of　July　29；　1875；　at　Rawlings；　in　the　territory　of　Wyoming。　　The　trial　was　not　satisfactory；　however；　for　the　apparatus　was　mounted　on　a　hen…house；　which　trembled　to　the　gale；　and　before　he　could　get　it　properly　adjusted　the　eclipse　was　over。

It　is　reported　that　on　another　trial　the　light　from　the　star　Arcturus；　when　focussed　on　the　vulcanite；　was　capable　of　deflecting　the　needle　of　the　galvanometer。　When　gelatine　is　substituted　for　vulcanite；　the　humidity　of　the　atmosphere　can　also　be　measured　in　the　same　way。

Edison's　crowning　discovery　at　Menlo　Park　was　the　celebrated　'phonograph；'　or　talking　machine。　　It　was　first　announced　by　one　of　his　assistants　in　the　pages　of　the　SCIENTIFIC　AMERICAN　for　1878。　　The　startling　news　created　a　general　feeling　of　astonishment；　mingled　with　incredulity　or　faith。　　People　had　indeed　heard　of　the　talking　heads　of　antiquity；　and　seen　the　articulating　machines　of　De　Kempelen　and　Faber；　with　their　artificial　vocal　organs　and　complicated　levers；　manipulated　by　an　operator。　　But　the　phonograph　　was　automatic；　and　returned　the　words　which　had　been　spoken　into　it　by　a　purely　mechanical　mimicry。　　It　captured　and　imprisoned　the　sounds　as　the　photograph　retained　the　images　of　light。　　The　colours　of　Nature　were　lost　in　the　photograph；　but　the　phonograph　was　said　to　preserve　the　qualities　even　of　the　human　voice。　Yet　this　wonderful　appliance　had　neither　tongue　nor　teeth；　larynx　nor　pharynx。　　It　appeared　as　simple　as　a　coffee…mill。　　A　vibrating　diaphragm　to　collect　the　sounds；　and　a　stylus　to　impress　them　on　a　sheet　of　tinfoil；　were　its　essential　parts。　　Looking　on　the　record　of　the　sound；　one　could　see　only　the　scoring　of　the　stylus　on　the　yielding　surface　of　the　metal；　like　the　track　of　an　Alpine　traveller　across　the　virgin　snow。　These　puzzling　scratches　were　the　foot…prints　of　the　voice。

Speech　is　the　most　perfect　utterance　of　man；　but　its　powers　are　limited　both　in　time　and　space。　　The　sounds　of　the　voice　are　fleeting；　and　do　not　carry　far；　hence　the　invention　of　letters　to　record　them；　and　of　signals　to　extend　their　range。　　These　twin　lines　of　invention；　continued　through　the　ages；　have　in　our　own　day　reached　their　consummation。　　The　smoke　of　the　savage；　the　semaphore；　and　the　telegraph　have　ended　in　the　telephone；　by　which　the　actual　voice　can　speak　to　a　distance；　and　now　at　length　the　clay　tablet　of　the　Assyrian；　the　wax　of　the　ancient　Greek；　the　papyrus　of　the　Egyptian；　and　the　modern　printing…press　have　culminated　in　the　phonograph；　by　which　the　living　words　can　be　preserved　into　the　future。　　In　the　light　of　a　new　discovery；　we　are　apt　to　wonder　why　our　fathers　were　so　blind　as　not　to　see　it。　　When　a　new　invention　has　been　made；　we　ask　ourselves；　Why　was　it　not　thought　of　before？　　The　discovery　seems　obvious；　and　the　invention　simple；　after　we　know　them。　Now　that　speech　itself　can　be　sent　a　thousand　miles　away；　or　heard　a　thousand　years　after；　we　discern　in　these　achievements　two　goals　toward　which　we　have　been　making；　and　at　which　we　should　arrive　some　day。　　We　marvel　that　we　had　no　prescience　of　these；　and　that　we　did　not　attain　to　them　sooner。　　Why　has　it　taken　so　many　generations　to　reach　a　foregone　conclusion？　　Alas！　they　neither　knew　the　conclusion　nor　the　means　of　attaining　to　it。　　Man　works　from　ignorance　towards　greater　knowledge　with　very　limited　powers。　　His　little　circle　of　light　is　surrounded　by　a　wall　of　darkness；　which　he　strives　to　penetrate　and　lighten；　now　groping　blindly　on　its　verge；　now　advancing　his　taper　light　and　peering　forward；　yet　unable　to　go　far；　and　even　afraid　to　venture；　in　case　he　should　be　lost。

To　the　Infinite　Intelligence　which　knows　all　that　is　hidden　in　that　darkness；　and　all　that　man　will　discover　therein；　how　poor　a　thing　is　the　telephone　or　phonograph；　　how　insignificant　are　all　his　'great　discoveries'！　　This　thought　should　imbue　a　man　of　science　with　humility　rather　than　with　pride。　　Seen　from　another　standpoint　than　his　own；　from　without　the　circle　of　his　labours；　not　from　within；　in　looking　back；　not　forward；　even　his　most　remarkable　discovery　is　but　the　testimony　of　his　own　littleness。　　The　veil　of　darkness　only　serves　to　keep　these　little　powers　at　work。　　Men　have　sometimes　a　foreshadowing　of　what　will　come　to　pass　without　distinctly　seeing　it。　　In　mechanical　affairs；　the　notion　of　a　telegraph　is　very　old；　and　probably　immemorial。　　Centuries　ago　the　poet　and　philosopher　entertained　the　idea　of　two　persons　far　apart　being　able　to　correspond　through　the　sympathetic　property　of　the　lodestone。　The　string　or　lovers'　telephone　was　known　to　the　Chinese；　and　even　the　electric　telephone　was　thought　about　some　years　before　it　was　invented。　Bourseul；　Reis；　and　others　preceded　Graham　Bell。

The　phonograph　was　more　of　a　surprise；　but　still　it　was　no　exception　to　the　rule。　　Naturally；　men　and　women　had　desired　to　preserve　the　accents　as　well　as　the　lineaments　of　some　beloved　friend　who　had　passed　away。　The　Chinese　have　a　legend　of　a　mother　whose　voice　was　so　beautiful　that　her　children　tried　to　store　it　in　a　bamboo　cane；　which　was　carefully　sealed　up。　Long　after　she　was　dead　the　cane　was　opened；　and　her　voice　came　out　in　all　its　sweetness；　but　was　never　heard　again。　　A　similar　idea　（which　reminds　us　of　Munchausen's　trumpet）　is　found　in　the　NATURAL　MAGICK　of　John　Baptista　Porta；　the　celebrated　　Neapolitan　philosopher；　and　published　at　London　in　1658。　He　proposes　to　confine　the　sound　of　the　voice　in　leaden　pipes；　such　as　are　used　for　speaking　through；　and　he　goes　on　to　say　that　'if　any　man；　as　the　words　are　spoken；　shall　stop　the　end　of　the　pipe；　and　he　that　is　at　the　other　end　shall　do　the　like；　the　voice　may　be　intercepted　in　the　middle；　and　be　shut　up　as　in　a　prison；　and　when　the　mouth　is　opened；　the　voice　will　come　forth　as　out　of　his　mouth　that　spake　it。　。　。　。　I　am　now　upon　trial　of　it。　　If　before　my　book　be　printed　the　business　take　effect；　I　will　set　it　down；　if　not；　if　God　please；　I　shall　write　of　it　elsewhere。'　Porta　also　refers　to　the　speaking　head　of　Albertus　Magnus；　whom；　however；　he　discredits。　　He　likewise　mentions　a　colossal　trumpeter　of　brass；　stated　to　have　been　erected　in　some　ancient　cities；　and　describes　a　plan　for　making　a　kind　of　megaphone；　'wherewith　we　may　hear　many　miles。'

In　the　VOYAGE　A　LA　LUNE　of　De　Cyrano　Bergerac；　published　at　Paris　in　1650；　and　subsequently　translated　into　English；　there　is　a　long　account　of　a　'mechanical　book'　which　spoke　its　contents　to　the　listener。　　'It　was　a　book；　indeed；'　says　Cyrano；　'but　a　strange　and　wonderful　book；　which　had　neither　leaves　nor　letters；'　and　which　instructed　the　Youth　in　their　walks；　so　that　they　knew　more　than　the　Greybeards　of　Cyrano's　country；　and　need　never　lack　the　company　of　all　the　great　men　living　or　dead　to　entertain　them　with　living　voices。　　Sir　David　Brewster　surmised　that　a　talking　machine　mould　be　invented　before　the　end　of　the　century。　Mary　Somerville；　in　her　CONNECTION　OF　THE　PHYSICAL　SCIENCES；　wrote　some　fifty　years　ago：　　'It　may　be　presumed　that　ultimately　the　utterances　or　pronunciation　of　modern　languages　will　be　conveyed；　not　only　to　the　eye；　but　also　to　the　ear　of　posterity。　　Had　the　ancients　possessed　the　means　of　transmitting　such　definite　sounds；　the　civilised　world　must　have　responded　in　sympathetic　notes　at　the　distance　of　many　ages。'　In　the　MEMOIRES　DU　GEANT　of　M。　Nadar；　published　in　1864；　the　author　says：　'These　last　fifteen　years　I　have　amused　myself　in　thinking　there　is　nothing　to　prevent　a　man　one　of　these　days　from　finding　a　way　to　give　us　a　daguerreotype　of　soundthe　phonograph　something　like　a　box　in　which　melodies　will　be　fixed　and　kept；　as　images　are　fixed　in　the　dark　chamber。'　It　is　also　on　record　that；　before　Edison　had　published　his　discovery　to　the　world；　M。　Charles　Cros　deposited　a　sealed　packet　at　the　Academie　des　Sciences；　Paris；　giving　an　account　of　an　invention　similar　to　the　phonograph。

Ignorance　of　the　true　nature　of　sound　had　prevented　the　introduction　of　such　an　instrument。　　But　modern　science；　and　in　particular　the　invention　of　the　telephone　with　its　vibrating　plate；　had　paved　the　way　for　it。　The　time　was　ripe；　and　Edison　was　the　first　to　do　it。

In　spite　of　the　unbridled　fancies　of　the　poets　and　the　hints　of　ingenious　writers；　the　announcement　that　a　means　of　hoarding　speech　had　been　devised　burst　like　a　thunderclap　upon　the　world。

＇In　seeing　his　mother's　picture　Byron　wished　that　he　might　hear　her　voice。　　Tennyson　exclaims；　'Oh　for　the　touch　of　a　vanished　hand；　and　the　sound　of　a　voice　that　is　still！'　Shelley；　in　the　WITCH　OF　ATLAS；　wrote：　'The　deep　recesses　of　her　odorous　dwelling　Were　stored　with　magic　treasuressounds　of　air；　Which　had　the　power　all　spirits　of　compelling；　Folded　in　cells　of　crystal　silence　there；　Such　as　we　hear　in　youth；　and　think　the　feeling　Will　never　dieyet　ere　we　are　aware；　The　feeling　and　the　sound　are　fled　and　gone；　And　the　regret　they　leave　remains　alone。'　Again；　in　his　SPIRIT　OF　SOLITUDE；　we　find：　'The　fire　of