heroes of the telegraph-第2部分

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ozolus；　a　Jesuit　lecturer　of　Rome；　in　1767；　by　Odier；　a　Geneva　physicist；　in　1773；　who　states　in　a　letter　to　a　lady；　that　he　conceived　the　idea　on　hearing　a　casual　remark；　while　dining　at　Sir　John　Pringle's；　with　Franklin；　Priestley；　and　other　great　geniuses。　　'I　shall　amuse　you；　perhaps；　in　telling　you；'　he　says；'that　I　have　in　my　head　certain　experiments　by　which　to　enter　into　conversation　with　the　Emperor　of　Mogol　or　of　China；　the　English；　the　French；　or　any　other　people　of　Europe　。。。　You　may　intercommunicate　all　that　you　wish　at　a　distance　of　four　or　five　thousands　leagues　in　less　than　half　an　hour。　Will　that　suffice　you　for　glory？'

George　Louis　Lesage；　in　1782；　proposed　a　plan　similar　to　'C。　M。's；'　using　underground　wires。　　An　anonymous　correspondent　of　the　JOURNAL　DE　PARIS　for　May　30；　1782；　suggested　an　alarm　bell　to　call　attention　to　the　message。　　Lomond；　of　Paris；　devised　a　telegraph　with　only　one　wire；　the　signals　to　be　read　by　the　peculiar　movements　of　an　attracted　pith…ball；　and　Arthur　Young　witnessed　his　plan　in　action；　as　recorded　in　his　diary。　M。　Chappe；　the　inventor　of　the　semaphore；　tried　about　the　year　1790　to　introduce　a　synchronous　electric　telegraph；　and　failed。

Don　Francisco　Salva　y　Campillo；　of　Barcelona；　in　1795；　proposed　to　make　a　telegraph　between　Barcelona　and　Mataro；　either　overhead　or　underground；　and　he　remarks　of　the　wires；　'at　the　bottom　of　the　sea　their　bed　would　be　ready　made；　and　it　would　be　an　extraordinary　casualty　that　should　disturb　them。'　　In　Salva's　telegraph；　the　signals　were　to　be　made　by　illuminating　letters　of　tinfoil　with　the　spark。　　Volta's　great　invention　of　the　pile　in　1800　furnished　a　new　source　of　electricity；　better　adapted　for　the　telegraph；　and　Salva　was　apparently　the　first　to　recognise　this；　for；　in　the　same　year；　he　proposed　to　use　it　and　interpret　the　signals　by　the　twitching　of　a　frog's　limb；　or　the　decomposition　of　water。

In　1802；　Jean　Alexandre；　a　reputed　natural　son　of　Jean　Jacques　Rousseau；　brought　out　a　TELEGRAPHE　INTIME；　or　secret　telegraph；　which　appears　to　have　been　a　step…by…step　apparatus。　　The　inventor　concealed　its　mode　of　working；　but　it　was　believed　to　be　electrical；　and　there　was　a　needle　which　stopped　at　various　points　on　a　dial。　　Alexandre　stated　that　he　had　found　out　a　strange　matter　or　power　which　was；　perhaps　generally　diffused；　and　formed　in　some　sort　the　soul　of　the　universe。　　He　endeavoured　to　bring　his　invention　under　the　eye　of　the　First　Consul；　but　Napoleon　referred　the　matter　to　Delambre；　and　would　not　see　it。　Alexandre　was　born　at　Paris；　and　served　as　a　carver　and　gilder　at　Poictiers；　then　sang　in　the　churches　till　the　Revolution　suppressed　this　means　of　livelihood。　　He　rose　to　influence　as　a　Commissary…general；　then　retired　from　the　army　and　became　an　inventor。　　His　name　is　associated　with　a　method　of　steering　balloons；　and　a　filter　for　supplying　Bordeaux　with　water　from　the　Garonne。　　But　neither　of　these　plans　appear　to　have　been　put　in　practice；　and　he　died　at　Angouleme；　leaving　his　widow　in　extreme　poverty。

Sommering；　a　distinguished　Prussian　anatomist；　in　1809　brought　out　a　telegraph　worked　by　a　voltaic　battery；　and　making　signals　by　decomposing　water。　　Two　years　later　it　was　greatly　simplified　by　Schweigger；　of　Halle；　and　there　is　reason　to　believe　that　but　for　the　discovery　of　electro…magnetism　by　Oersted；　in　1824　the　chemical　telegraph　would　have　come　into　practical　use。

In　1806；　Ralph　Wedgwood　submitted　a　telegraph　based　on　frictional　electricity　to　the　Admiralty；　but　was　told　that　the　semaphore　was　sufficient　for　the　country。　　In　a　pamphlet　he　suggested　the　establishment　of　a　telegraph　system　with　public　offices　in　different　centres。　　Francis　Ronalds；　in　1816；　brought　a　similar　telegraph　of　his　invention　to　the　notice　of　the　Admiralty；　and　was　politely　informed　that　'telegraphs　of　any　kind　are　now　wholly　unnecessary。'

In　1826…7；　Harrison　Gray　Dyar；　of　New　York；　devised　a　telegraph　in　which　the　spark　was　made　to　stain　the　signals　on　moist　litmus　paper　by　decomposing　nitric　acid；　but　he　had　to　abandon　his　experiments　in　Long　Island　and　fly　the　country；　because　of　a　writ　which　charged　him　with　a　conspiracy　for　carrying　on　secret　communication。　　In　1830　Hubert　Recy　published　an　account　of　a　system　of　Teletatodydaxie；　by　which　the　electric　spark　was　to　ignite　alcohol　and　indicate　the　signals　of　a　code。

But　spark　or　frictional　electric　telegraphs　were　destined　to　give　way　to　those　actuated　by　the　voltaic　current；　as　the　chemical　mode　of　signalling　was　superseded　by　the　electro…magnet。　　In　1820　the　separate　courses　of　electric　and　magnetic　science　were　united　by　the　connecting　discovery　of　Oersted；　who　found　that　a　wire　conveying　a　current　had　the　power　of　moving　a　compass…needle　to　one　side　or　the　other　according　to　the　direction　of　the　current。

La　Place；　the　illustrious　mathematician；　at　once　saw　that　this　fact　could　be　utilised　as　a　telegraph；　and　Ampere；　acting　on　his　suggestion；　published　a　feasible　plan。　　Before　the　year　was　out；　Schweigger；　of　Halle；　multiplied　the　influence　of　the　current　on　the　needle　by　coiling　the　wire　about　it。　　Ten　years　later；　Ritchie　improved　on　Ampere's　method；　and　exhibited　a　model　at　the　Royal　Institution；　London。　　About　the　same　time；　Baron　Pawel　Schilling；　a　Russian　nobleman；　still　further　modified　it；　and　the　Emperor　Nicholas　decreed　the　erection　of　a　line　from　Cronstadt　to　St。　Petersburg；　with　a　cable　in　the　Gulf　of　Finland　but　Schilling　died　in　1837；　and　the　project　was　never　realised。

In　1833…5　Professors　Gauss　and　Weber　constructed　a　telegraph　between　the　physical　cabinet　and　the　Observatory　of　the　University　of　Gottingen。　At　first　they　used　the　voltaic　pile；　but　abandoned　it　in　favour　of　Faraday's　recent　discovery　that　electricity　could　be　generated　in　a　wire　by　the　motion　of　a　magnet。　　The　magnetic　key　with　which　the　message　was　sent　Produced　by　its　action　an　electric　current　which；　after　traversing　the　line；　passed　through　a　coil　and　deflected　a　suspended　magnet　to　the　right　or　left；　according　to　the　direction　of　the　current。　　A　mirror　attached　to　the　suspension　magnified　the　movement　of　the　needle；　and　indicated　the　signals　after　the　manner　of　the　Thomson　mirror　galvanometer。　　This　telegraph；　which　was　large　and　clumsy；　was　nevertheless　used　not　only　for　scientific；　but　for　general　correspondence。　　Steinheil；　of　Munich；　simplified　it；　and　added　an　alarm　in　the　form　of　a　bell。

In　1836；　Steinheil　also　devised　a　recording　telegraph；　in　which　the　movable　needles　indicated　the　message　by　marking　dots　and　dashes　with　printer's　ink　on　a　ribbon　of　travelling　paper；　according　to　an　artificial　code　in　which　the　fewest　signs　were　given　to　the　commonest　letters　in　the　German　language。　　With　this　apparatus　the　message　was　registered　at　the　rate　of　six　words　a　minute。　　The　early　experimenters；　as　we　have　seen；　especially　Salva；　had　utilised　the　ground　as　the　return　part　of　the　circuit；　and　Salva　had　proposed　to　use　it　on　his　telegraph；　but　Steinheil　was　the　first　to　demonstrate　its　practical　value。　　In　trying；　on　the　suggestion　of　Gauss；　to　employ　the　rails　of　the　Nurenberg　to　Furth　railway　as　the　conducting　line　for　a　telegraph　in　the　year　1838；　he　found　they　would　not　serve；　but　the　failure　led　him　to　employ　the　earth　as　the　return　half　of　the　circuit。

In　1837；　Professor　Stratingh；　of　Groninque；　Holland；　devised　a　telegraph　in　which　the　signals　were　made　by　electro…magnets　actuating　the　hammers　of　two　gongs　or　bells　of　different　tone；　and　M。　Amyot　invented　an　automatic　sending　key　in　the　nature　of　a　musical　box。　　From　1837…8；　Edward　Davy；　a　Devonshire　surgeon；　exhibited　a　needle　telegraph　in　London；　and　proposed　one　based　on　the　discovery　of　Arago；　that　a　piece　of　soft　iron　is　temporarily　magnetised　by　the　passage　of　an　electric　current　through　a　coil　surrounding　it。　　This　principle　was　further　applied　by　Morse　in　his　electro…magnetic　printing　telegraph。　Davy　was　a　prolific　inventor；　and　also　sketched　out　a　telegraph　in　which　the　gases　evolved　from　water　which　was　decomposed　by　the　current　actuated　a　recording　pen。　　But　his　most　valuable　discovery　was　the　'relay；'　that　is　to　say；　an　auxiliary　device　by　which　a　current　too　feeble　to　indicate　the　signals　could　call　into　play　a　local　battery　strong　enough　to　make　them。　　Davy　was　in　a　fair　way　of　becoming　one　of　the　fathers　of　the　working　telegraph；　when　his　private　affairs　obliged　him　to　emigrate　to　Australia；　and　leave　the　course　open　to　Cooke　and　Wheatstone。



CHAPTER　II。

CHARLES　WHEATSTONE。

The　electric　telegraph；　like　the　steam…engine　and　the　railway；　was　a　gradual　development　due　to　the　experiments　and　devices　of　a　long　train　of　thinkers。　　In　such　a　case　he　who　crowns　the　work；　making　it　serviceable　to　his　fellow…men；　not　only　wins　the　pecuniary　prize；　but　is　likely　to　be　hailed　and　celebrated　as　the　chief；　if　not　the　sole　inventor；　although　in　a　scientific　sense　the　improvement　he　has　made　is　perhaps　less　than　that　of　some　ingenious　and　forgotten　forerunner。　　He　who　advances　the　work　from　the　phase　of　a　promising　idea；　to　that　of　a　common　boon；　is　entitled　to　our　gratitude。　　But　in　honouring　the　keystone　of　the　arch；　as　it　were；　let　us　acknowledge　the　substructure　on　which　it　rests；　and　keep　in　mind　the　entire　bridge。　　Justice　at　least　is　due　to　those　who　have　laboured　without　reward。

Sir　William　Fothergill　Cooke　and　Sir　Charles　Wheatstone　were　the　first　to　bring　the　electric　telegraph　into　daily　use。　　But　we　have　selected　Wheatstone　as　our　hero；　because　he　was　eminent　as　a　man　of　science；　and　chiefly　instrumental　in　perfecting　the　apparatus。　　As　James　Watt　is　identified　with　the　steam…engine；　and　George　Stephenson　with　the　railway；　so　is　Wheatstone　with　the　telegraph。

Charles　Wheatstone　was　born　near　Gloucester；　in　February；　1802。　　His　father　was　a　music…seller　in　the　town；　who；　four　years　later；　removed　to　128；　Pall　Mall；　London；　and　became　a　teacher　of　the　flute。　　He　used　to　say；　with　not　a　little　pride；　that　he　had　been　engaged　in　assisting　at　the　musical　education　of　the　Princess　Charlotte。　　Charles；　the　second　son；　went　to　a　village　school；　near　Gloucester；　and　afterwards　to　several　institutions　in　London。　　One　of　them　was　in　Kennington；　and　kept　by　a　Mrs。　Castlemaine；　who　was　astonished　at　his　rapid　progress。　　Fr