heroes of the telegraph-第5部分

快捷操作: 按键盘上方向键 ← 或 → 可快速上下翻页 按键盘上的 Enter 键可回到本书目录页 按键盘上方向键 ↑ 可回到本页顶部! 如果本书没有阅读完，想下次继续接着阅读，可使用上方 "收藏到我的浏览器" 功能 和 "加入书签" 功能！

still　in　use。

In　1841　a　difference　arose　between　Cooke　and　Wheatstone　as　to　the　share　of　each　in　the　honour　of　inventing　the　telegraph。　　The　question　was　submitted　to　the　arbitration　of　the　famous　engineer；　Marc　Isambard　Brunel；　on　behalf　of　Cooke；　and　Professor　Daniell；　of　King's　College；　the　inventor　of　the　Daniell　battery；　on　the　part　of　Wheatstone。　　They　awarded　to　Cooke　the　credit　of　having　introduced　the　telegraph　as　a　useful　undertaking　which　promised　to　be　of　national　importance；　and　to　Wheatstone　that　of　having　by　his　researches　prepared　the　public　to　receive　it。　　They　concluded　with　the　words：　　'It　is　to　the　united　labours　of　two　gentlemen　so　well　qualified　for　mutual　assistance　that　we　must　attribute　the　rapid　progress　which　this　important　invention　has　made　during　five　years　since　they　have　been　associated。'　The　decision；　however　vague；　pronounces　the　needle　telegraph　a　joint　production。　　If　it　was　mainly　invented　by　Wheatstone；　it　was　chiefly　introduced　by　Cooke。　Their　respective　shares　in　the　undertaking　might　be　compared　to　that　of　an　author　and　his　publisher；　but　for　the　fact　that　Cooke　himself　had　a　share　in　the　actual　work　of　invention。

In　1840　Wheatstone　had　patented　an　alphabetical　telegraph；　or；　'Wheatstone　A　B　C　instrument；'　which　moved　with　a　step…by…step　motion；　and　showed　the　letters　of　the　message　upon　a　dial。　　The　same　principle　was　utilised　in　his　type…printing　telegraph；　patented　in　1841。　　This　was　the　first　apparatus　which　printed　a　telegram　in　type。　　It　was　worked　by　two　circuits；　and　as　the　type　revolved　a　hammer；　actuated　by　the　current；　pressed　the　required　letter　on　the　paper。　　in　1840　Wheatstone　also　brought　out　his　magneto…electrical　machine　for　generating　continuous　currents；　and　his　chronoscope；　for　measuring　minute　intervals　of　time；　which　was　used　in　determining　the　speed　of　a　bullet　or　the　passage　of　a　star。　　In　this　apparatus　an　electric　current　actuated　an　electro…magnet；　which　noted　the　instant　of　an　occurrence　by　means　of　a　pencil　on　a　moving　paper。　　It　is　said　to　have　been　capable　of　distinguishing　1/7300　part　of　a　second；　and　the　time　a　body　took　to　fall　from　a　height　of　one　inch。

The　same　year　he　was　awarded　the　Royal　Medal　of　the　Royal　Society　for　his　explanation　of　binocular　vision；　a　research　which　led　him　to　construct　the　stereoscope。　　He　showed　that　our　impression　of　solidity　is　gained　by　the　combination　in　the　mind　of　two　separate　pictures　of　an　object　taken　by　both　of　our　eyes　from　different　points　of　view。　　Thus；　in　the　stereoscope；　an　arrangement　of　lenses　and　mirrors；　two　photographs　of　the　same　object　taken　from　different　points　are　so　combined　as　to　make　the　object　stand　out　with　a　solid　aspect。　　Sir　David　Brewster　improved　the　stereoscope　by　dispensing　with　the　mirrors；　and　bringing　it　into　its　existing　form。

The　'pseudoscope'　（Wheatstone　was　partial　to　exotic　forms　of　speech）　was　introduced　by　its　professor　in　1850；　and　is　in　some　sort　the　reverse　of　the　stereoscope；　since　it　causes　a　solid　object　to　seem　hollow；　and　a　nearer　one　to　be　farther　off；　thus；　a　bust　appears　to　be　a　mask；　and　a　tree　growing　outside　of　a　window　looks　as　if　it　were　growing　inside　the　room。

On　November　26；　1840；　he　exhibited　his　electro…magnetic　clock　in　the　library　of　the　Royal　Society；　and　propounded　a　plan　for　distributing　the　correct　time　from　a　standard　clock　to　a　number　of　local　timepieces。　The　circuits　of　these　were　to　be　electrified　by　a　key　or　contact…maker　actuated　by　the　arbour　of　the　standard；　and　their　hands　corrected　by　electro…magnetism。　　The　following　January　Alexander　Bain　took　out　a　patent　for　an　electro…magnetic　clock；　and　he　subsequently　charged　Wheatstone　with　appropriating　his　ideas。　　It　appears　that　Bain　worked　as　a　mechanist　to　Wheatstone　from　August　to　December；　1840；　and　he　asserted　that　he　had　communicated　the　idea　of　an　electric　clock　to　Wheatstone　during　that　period；　but　Wheatstone　maintained　that　he　had　experimented　in　that　direction　during　May。　　Bain　further　accused　Wheatstone　of　stealing　his　idea　of　the　electro…magnetic　printing　telegraph；　but　Wheatstone　showed　that　the　instrument　was　only　a　modification　of　his　own　electro…magnetic　telegraph。

In　1843　Wheatstone　communicated　an　important　paper　to　the　Royal　Society；　entitled　'An　Account　of　Several　New　Processes　for　Determining　the　Constants　of　a　Voltaic　Circuit。'　It　contained　an　exposition　of　the　well…　known　balance　for　measuring　the　electrical　resistance　of　a　conductor；　which　still　goes　by　the　name　of　Wheatstone's　Bridge　or　balance；　although　it　was　first　devised　by　Mr。　S。　W。　Christie；　of　the　Royal　Military　Academy；　Woolwich；　who　published　it　in　the　PHILOSOPHICAL　TRANSACTIONS　for　1833。　　The　method　was　neglected　until　Wheatstone　brought　it　into　notice。　　His　paper　abounds　with　simple　and　practical　formula：　　for　the　calculation　of　currents　and　resistances　by　the　law　of　Ohm。　　He　introduced　a　unit　of　resistance；　namely；　a　foot　of　copper　wire　weighing　one　hundred　grains；　and　showed　how　it　might　be　applied　to　measure　the　length　of　wire　by　its　resistance。　　He　was　awarded　a　medal　for　his　paper　by　the　Society。　　The　same　year　he　invented　an　apparatus　which　enabled　the　reading　of　a　thermometer　or　a　barometer　to　be　registered　at　a　distance　by　means　of　an　electric　contact　made　by　the　mercury。　　A　sound　telegraph；　in　which　the　signals　were　given　by　the　strokes　of　a　bell；　was　also　patented　by　Cooke　and　Wheatstone　in　May　of　that　year。

The　introduction　of　the　telegraph　had　so　far　advanced　that；　on　September　2；　1845；　the　Electric　Telegraph　Company　was　registered；　and　Wheatstone；　by　his　deed　of　partnership　with　Cooke；　received　a　sum　of　L33；000　for　the　use　of　their　joint　inventions。

》From　1836…7　Wheatstone　had　thought　a　good　deal　about　submarine　telegraphs；　and　in　1840　he　gave　evidence　before　the　Railway　Committee　of　the　House　of　Commons　on　the　feasibility　of　the　proposed　line　from　Dover　to　Calais。　　He　had　even　designed　the　machinery　for　making　and　laying　the　cable。　　In　the　autumn　of　1844；　with　the　assistance　of　Mr。　J。　D。　Llewellyn；　he　submerged　a　length　of　insulated　wire　in　Swansea　Bay；　and　signalled　through　it　from　a　boat　to　the　Mumbles　Lighthouse。　Next　year　he　suggested　the　use　of　gutta…percha　for　the　coating　of　the　intended　wire　across　the　Channel。

Though　silent　and　reserved　in　public；　Wheatstone　was　a　clear　and　voluble　talker　in　private；　if　taken　on　his　favourite　studies；　and　his　small　but　active　person；　his　plain　but　intelligent　countenance；　was　full　of　animation。　　Sir　Henry　Taylor　tells　us　that　he　once　observed　Wheatstone　at　an　evening　party　in　Oxford　earnestly　holding　forth　to　Lord　Palmerston　on　the　capabilities　of　his　telegraph。　　'You　don't　say　so！'　exclaimed　the　statesman。　　'I　must　get　you　to　tell　that　to　the　Lord　Chancellor。'　And　so　saying；　he　fastened　the　electrician　on　Lord　Westbury；　and　effected　his　escape。　　A　reminiscence　of　this　interview　may　have　prompted　Palmerston　to　remark　that　a　time　was　coming　when　a　minister　might　be　asked　in　Parliament　if　war　had　broken　out　in　India；　and　would　reply；　'Wait　a　minute；　I'll　just　telegraph　to　the　Governor…General；　and　let　you　know。'

At　Christchurch；　Marylebone；　on　February　12；　1847；　Wheatstone　was　married。　　His　wife　was　the　daughter　of　a　Taunton　tradesman；　and　of　handsome　appearance。　　She　died　in　1866；　leaving　a　family　of　five　young　children　to　his　care。　　His　domestic　life　was　quiet　and　uneventful。

One　of　Wheatstone's　most　ingenious　devices　was　the　'Polar　clock；'　exhibited　at　the　meeting　of　the　British　Association　in　1848。　　It　is　based　on　the　fact　discovered　by　Sir　David　Brewster；　that　the　light　of　the　sky　is　polarised　in　a　plane　at　an　angle　of　ninety　degrees　from　the　position　of　the　sun。　　It　follows　that　by　discovering　that　plane　of　polarisation；　and　measuring　its　azimuth　with　respect　to　the　north；　the　position　of　the　sun；　although　beneath　the　horizon；　could　be　determined；　and　the　apparent　solar　time　obtained。　　The　clock　consisted　of　a　spy…　glass；　having　a　nichol　or　double…image　prism　for　an　eye…piece；　and　a　thin　plate　of　selenite　for　an　object…glass。　　When　the　tube　was　directed　to　the　North　Polethat　is；　parallel　to　the　earth's　axisand　the　prism　of　the　eye…piece　turned　until　no　colour　was　seen；　the　angle　of　turning；　as　shown　by　an　index　moving　with　the　prism　over　a　graduated　limb；　gave　the　hour　of　day。　　The　device　is　of　little　service　in　a　country　where　watches　are　reliable；　but　it　formed　part　of　the　equipment　of　the　North　Polar　expedition　commanded　by　Captain　Nares。　　Wheatstone's　remarkable　ingenuity　was　displayed　in　the　invention　of　cyphers　which　have　never　been　unravelled；　and　interpreting　cypher　manuscripts　in　the　British　Museum　which　had　defied　the　experts。　　He　devised　a　cryptograph　or　machine　for　turning　a　message　into　cypher　which　could　only　be　interpreted　by　putting　the　cypher　into　a　corresponding　machine　adjusted　to　reproduce　it。

The　rapid　development　of　the　telegraph　in　Europe　may　be　gathered　from　the　fact　that　in　1855；　the　death　of　the　Emperor　Nicholas　at　St。　Petersburg；　about　one　o'clock　in　the　afternoon；　was　announced　in　the　House　of　Lords　a　few　hours　later；　and　as　a　striking　proof　of　its　further　progress；　it　may　be　mentioned　that　the　result　of　the　Oaks　of　1890　was　received　in　New　York　fifteen　seconds　after　the　horses　passed　the　winning…post。