heroes of the telegraph-第29部分

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As　Professor　of　Vocal　Physiology　in　the　University　of　Boston；　he　was　engaged　in　training　teachers　in　the　art　of　instructing　deaf　mutes　how　to　speak；　and　experimented　with　the　Leon　Scott　phonautograph　in　recording　the　vibrations　of　speech。　　This　apparatus　consists　essentially　of　a　thin　membrane　vibrated　by　the　voice　and　carrying　a　light　stylus；　which　traces　an　undulatory　line　on　a　plate　of　smoked　glass。　　The　line　is　a　graphic　representation　of　the　vibrations　of　the　membrane　and　the　waves　of　sound　in　the　air。

On　the　suggestion　of　Dr。　Clarence　J。　Blake；　an　eminent　Boston　aurist；　Professor　Bell　abandoned　the　phonautograph　for　the　human　ear；　which　it　resembled；　and；　having　removed　the　stapes　bone；　moistened　the　drum　with　glycerine　and　water；　attached　a　stylus　of　hay　to　the　nicus　or　anvil；　and　obtained　a　beautiful　series　of　curves　in　imitation　of　the　vocal　sounds。　The　disproportion　between　the　slight　mass　of　the　drum　and　the　bones　it　actuated；　is　said　to　have　suggested　to　him　the　employment　of　goldbeater's　skin　as　membrane　in　his　speaking　telephone。　　Be　this　as　it　may；　he　devised　a　receiver；　consisting　of　a　stretched　diaphragm　or　drum　of　this　material　having　an　armature　of　magnetised　iron　attached　to　its　middle；　and　free　to　vibrate　in　front　of　the　pole　of　an　electro…magnet　in　circuit　with　the　line。

This　apparatus　was　completed　on　June　2；　1875；　and　the　same　day　he　succeeded　in　transmitting　SOUNDS　and　audible　signals　by　magneto…electric　currents　and　without　the　aid　of　a　battery。　　On　July　1；　1875；　he　instructed　his　assistant　to　make　a　second　membrane…receiver　which　could　be　used　with　the　first；　and　a　few　days　later　they　were　tried　together；　one　at　each　end　of　the　line；　which　ran　from　a　room　in　the　inventor's　house　at　Boston　to　the　cellar　underneath。　　Bell；　in　the　room；　held　one　instrument　in　his　hands；　while　Watson　in　the　cellar　listened　at　the　other。　　The　inventor　spoke　into　his　instrument；　'Do　you　understand　what　I　say？'　and　we　can　imagine　his　delight　when　Mr。　Watson　rushed　into　the　room；　under　the　influence　of　his　excitement；　and　answered；'Yes。'

A　finished　instrument　was　then　made；　having　a　transmitter　formed　of　a　double　electro…magnet；　in　front　of　which　a　membrane；　stretched　on　a　ring；　carried　an　oblong　piece　of　soft　iron　cemented　to　its　middle。　　A　mouthpiece　before　the　diaphragm　directed　the　sounds　upon　it；　and　as　it　vibrated　with　them；　the　soft　iron　'armature'　induced　corresponding　currents　in　the　cells　of　the　electro…magnet。　　These　currents　after　traversing　the　line　were　passed　through　the　receiver；　which　consisted　of　a　tubular　electro…magnet；　having　one　end　partially　closed　by　a　thin　circular　disc　of　soft　iron　fixed　at　one　point　to　the　end　of　the　tube。　This　receiver　bore　a　resemblance　to　a　cylindrical　metal　box　with　thick　sides；　having　a　thin　iron　lid　fastened　to　its　mouth　by　a　single　screw。　When　the　undulatory　current　passed　through　the　coil　of　this　magnet；　the　disc；　or　armature…lid；　was　put　into　vibration　and　the　sounds　evolved　from　it。

The　apparatus　was　exhibited　at　the　Centennial　Exhibition；　Philadelphia；　in　1876；　and　at　the　meeting　of　the　British　Association　in　Glasgow；　during　the　autumn　of　that　year；　Sir　William　Thomson　revealed　its　existence　to　the　European　public。　　In　describing　his　visit　to　the　Exhibition；　he　went　on　to　say：　　'In　the　Canadian　department　I　heard；　〃To　be　or　not　to　be　。　。　。　there's　the　rub；〃　through　an　electric　wire；　but；　scorning　monosyllables；　the　electric　articulation　rose　to　higher　flights；　and　gave　me　passages　taken　at　random　from　the　New　York　newspapers：　　〃s。s。　Cox　has　arrived〃　（I　failed　to　make　out　the　s。s。　Cox）；　〃The　City　of　New　York；〃　〃Senator　Morton；〃　〃The　Senate　has　resolved　to　print　a　thousand　extra　copies；〃　〃The　Americans　in　London　have　resolved　to　celebrate　the　coming　Fourth　of　July！〃　All　this　my　own　ears　heard　spoken　to　me　with　unmistakable　distinctness　by　the　then　circular　disc　armature　of　just　such　another　little　electro…magnet　as　this　I　hold　in　my　hand。'

To　hear　the　immortal　words　of　Shakespeare　uttered　by　the　small　inanimate　voice　which　had　been　given　to　the　world　must　indeed　have　been　a　rare　delight　to　the　ardent　soul　of　the　great　electrician。

The　surprise　created　among　the　public　at　large　by　this　unexpected　communication　will　be　readily　remembered。　　Except　one　or　two　inventors；　nobody　had　ever　dreamed　of　a　telegraph　that　could　actually　speak；　any　more　than　they　had　ever　fancied　one　that　could　see　or　feel；　and　imagination　grew　busy　in　picturing　the　outcome　of　it。　　Since　it　was　practically　equivalent　to　a　limitless　extension　of　the　vocal　powers；　the　ingenious　journalist　soon　conjured　up　an　infinity　of　uses　for　the　telephone；　and　hailed　the　approaching　time　when　ocean…parted　friends　would　be　able　to　whisper　to　one　another　under　the　roaring　billows　of　the　Atlantic。　　Curiosity；　however；　was　not　fully　satisfied　until　Professor　Bell；　the　inventor　of　the　instrument；　himself　showed　it　to　British　audiences；　and　received　the　enthusiastic　applause　of　his　admiring　countrymen。

The　primitive　telephone　has　been　greatly　improved；　the　double　electro…　magnet　being　replaced　by　a　single　bar　magnet　having　a　small　coil　or　bobbin　of　fine　wire　surrounding　one　pole；　in　front　of　which　a　thin　disc　of　ferrotype　is　fixed　in　a　circular　mouthpiece；　and　serves　as　a　combined　membrane　and　armature。　　On　speaking　into　the　mouthpiece；　the　iron　diaphragm　vibrates　with　the　voice　in　the　magnetic　field　of　the　pole；　and　thereby　excites　the　undulatory　currents　in　the　coil；　which；　after　travelling　through　the　wire　to　the　distant　place；　are　received　in　an　identical　apparatus。　　＇This　form　　was　patented　January　30；　1877。＇　　In　traversing　the　coil　of　the　latter　they　reinforce　or　weaken　the　magnetism　of　the　pole；　and　thus　make　the　disc　armature　　vibrate　so　as　to　give　out　a　mimesis　of　the　original　voice。　　The　sounds　are　small　and　elfin；　a　minim　of　speech；　and　only　to　be　heard　when　the　ear　is　close　to　the　mouthpiece；　but　they　are　remarkably　distinct；　and；　in　spite　of　a　disguising　twang；　due　to　the　fundamental　note　of　the　disc　itself；　it　is　easy　to　recognise　the　speaker。

This　later　form　was　publicly　exhibited　on　May　4；　1877　at　a　lecture　given　by　Professor　Bell　in　the　Boston　Music　Hall。　　'Going　to　the　small　telephone　box　with　its　slender　wire　attachments；'　says　a　report；　'Mr。　Bell　coolly　asked；　as　though　addressing　some　one　in　an　adjoining　room；　〃Mr。　Watson；　are　you　ready！〃　　Mr。　Watson；　five　miles　away　in　Somerville；　promptly　answered　in　the　affirmative；　and　soon　was　heard　a　voice　singing　〃America。〃。。。。Going　to　another　instrument；　connected　by　wire　with　Providence；　　forty…three　miles　distant；　Mr。　Bell　listened　a　moment；　and　said；　〃Signor　Brignolli；　who　is　assisting　at　a　concert　in　Providence　Music　Hall；　will　now　sing　for　us。〃　In　a　moment　the　cadence　of　the　tenor's　voice　rose　and　fell；　the　sound　being　faint；　sometimes　lost；　and　then　again　audible。　　Later；　a　cornet　solo　played　in　　Somerville　was　very　distinctly　heard。　　Still　later；　a　three…part　song　floated　over　the　wire　from　the　Somerville　terminus；　and　Mr。　Bell　amused　his　audience　exceedingly　　by　exclaiming；　〃I　will　switch　off　the　song　from　one　part　of　the　room　to　another；　so　that　all　can　hear。〃　At　a　subsequent　lecture　in　Salem；　Massachusetts；　communication　was　established　with　Boston；　eighteen　miles　distant；　and　Mr。　Watson　at　the　latter　place　sang　〃Auld　Lang　Syne；〃　the　National　Anthem；　and　〃Hail　Columbia；〃　while　the　audience　at　Salem　joined　in　the　chorus。'

Bell　had　overcome　the　difficulty　which　baffled　Reis；　and　succeeded　in　making　the　undulations　of　the　current　fit　the　vibrations　of　the　voice　as　a　glove　will　fit　the　hand。　　But　the　articulation；　though　distinct；　was　feeble；　and　it　remained　for　Edison；　by　inventing　the　carbon　transmitter；　and　Hughes；　by　discovering　the　microphone；　to　render　the　telephone　the　useful　and　widespread　apparatus　which　we　see　it　now。

Bell　patented　his　speaking　telephone　in　the　United　States　at　the　beginning　of　1876；　and　by　a　strange　coincidence；　　Mr。　Elisha　Gray　applied　on　the　same　day　for　another　patent　of　a　similar　kind。　　Gray's　transmitter　is　supposed　to　have　been　suggested　by　the　very　old　device　known　as　the　'lovers'　telephone；'　in　which　two　　diaphragms　are　joined　by　a　taut　string；　and　in　speaking　against　one　the　voice　is　conveyed　through　the　string；　solely　by　mechanical　vibration；　to　the　other。　　Gray　employed　electricity；　and　varied　the　strength　of　the　current　in　conformity　with　the　voice　by　causing　the　diaphragm　in　vibrating　to　dip　a　metal　probe　attached　to　its　centre　more　or　less　deep　into　a　well　of　conducting　liquid　in　circuit　with　the　line。　　As　the　current　passed　from　the　probe　through　the　liquid　to　the　line　a　greater　or　less　thickness　of　liquid　intervened　as　the　probe　vibrated　up　and　down；　and　thus　the　strength　of　the　current　was　regulated　by　the　resistance　offered　to　the　passage　of　the　current。　　His　receiver　was　an　electro…magnet　having　an　iron　plate　as　an　armature　capable　of　vibrating　under　the　attractions　of　the　varying　current。　　But　Gray　allowed　his　idea　to　slumber；　whereas　Bell　continued　to　perfect　his　apparatus。　　However；　when　Bell　achieved　an　unmistakable　success；　Gray　brought　a　suit　against　him；　which　resulted　in　a　compromise；　one　public　company　acquiring　both　patents。

Bell's　invention　has　been　contested　over　and　over　again；　and　more　than　one　claimant　for　the　honour　and　reward　of　being　the　original　inventor　of　the　telephone　have　appeared。　　The　most　interesting　case　was　that　of　Signor　Antonio　Meucci；　an　Italian　emigrant；　who　produced　a　mass　of　evidence　to　show　that　in　1849；　while　in　Havanna；　Cuba；　he　experimented　with　the　view　of　transmitting　speech　by　the　electric　current。　　He　continued　his　researches　in　1852…3；　and　subsequently　at　Staten　Island；　U。S。；　and　in　1860　deputed　a　friend　visiting　Europe　to　interest　people　in　his　invention。　　In　1871　he　filed　a　caveat　in　the　United　States　Patent　Office；　and　tried　to　get　Mr。　Grant；　President　of　the　New　York　District　Telegraph　Company；　to　give　the　apparatus　a　trial。　　Ill…health　and　poverty；　consequent　on　an　injury　due　to　an　explosion　on　board　the　Staten　Island　ferry　boat　Westfield；　retarded　his　experiments；　and　prevented　him　from　completing　his　patent。　　Meucci's　experimental　apparatus　was　exhibited　at　the　Philadelphia　Exhibition　of　1884；　and　attracted　much　attention。　　But　the　evidence　h