heroes of the telegraph-第48部分

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medical　studies；　and　resolved　to　apply　all　his　energies　to　the　introduction　of　the　telegraph。　Within　three　weeks　he　had　made；　partly　at　Heidelberg；　and　partly　at　Frankfort；　his　first　galvanometer；　or　needle　telegraph。　　It　consisted　of　three　magnetic　needles　surrounded　by　multiplying　　coils；　and　actuated　by　three　separate　circuits　of　six　wires。　　The　movements　of　the　needles　under　the　action　of　the　currents　produced　twenty…six　different　signals　corresponding　to　the　letters　of　the　alphabet。

'Whilst　completing　the　model　of　my　original　plan；'　he　wrote　to　his　mother　on　April　5；　'others　on　entirely　fresh　systems　suggested　themselves；　and　I　have　at　length　succeeded　in　combining　the　UTILE　of　each；　but　the　mechanism　requires　a　more　delicate　hand　than　mine　to　execute；　or　rather　instruments　which　I　do　not　possess。　　These　I　can　readily　have　made　for　me　in　London；　and　by　the　aid　of　a　lathe　I　shall　he　able　to　adapt　the　several　parts；　which　I　shall　have　made　by　different　mechanicians　for　secrecy's　sake。　　Should　I　succeed；　it　may　be　the　means　of　putting　some　hundreds　of　pounds　in　my　pocket。　　As　it　is　a　subject　on　which　I　was　profoundly　ignorant；　until　my　attention　was　casually　attracted　to　it　the　other　day；　I　do　not　know　what　others　may　have　done　in　the　same　way；　this　can　best　be　learned　in　London。'

The　'fresh　systems'　referred　to　was　his　'mechanical'　telegraph；　consisting　of　two　letter　dials；　working　synchronously；　and　on　which　particular　letters　of　the　message　were　indicated　by　means　of　an　electro…　magnet　and　detent。　　Before　the　end　of　March　he　invented　the　clock…work　alarm；　in　which　an　electro…magnet　attracted　an　armature　of　soft　iron；　and　thus　withdrew　a　detent；　allowing　the　works　to　strike　the　alarm。　This　idea　was　suggested　to　him　on　March　17；　1836；　while　reading　Mrs。　Mary　Somerville's　'Connexion　of　the　Physical　Sciences；'　in　travelling　from　Heidelberg　to　Frankfort。

Cooke　arrived　in　London　on　April　22；　and　wrote　a　pamphlet　setting　forth　his　plans　for　the　establishment　of　an　electric　telegraph；　but　it　was　never　published。　　According　to　his　own　account　he　also　gave　considerable　attention　to　the　escapement　principle；　or　step　by　step　movement；　afterwards　perfected　by　Wheatstone。　　While　busy　in　preparing　his　apparatus　for　exhibition；　part　of　which　was　made　by　a　clock…maker　in　Clerkenwell；　he　consulted　Faraday　about　the　construction　of　electro…　magnets；　The　philosopher　saw　his　apparatus　and　expressed　his　opinion　that　the　'principle　was　perfectly　correct；'　and　that　the　'instrument　appears　perfectly　adapted　to　its　intended　uses。'　Nevertheless　he　was　not　very　sanguine　of　making　it　a　commercial　success。　　'The　electro…magnetic　telegraph　shall　not　ruin　me；'　he　wrote　to　his　mother；　'but　will　hardly　make　my　fortune。'　He　was　desirous　of　taking　a　partner　in　the　work；　and　went　to　Liverpool　in　order　to　meet　some　gentleman　likely　to　forward　his　views；　and　endeavoured　to　get　his　instrument　adopted　on　the　incline　of　the　tunnel　at　Liverpool；　but　it　gave　sixty　signals；　and　was　deemed　too　complicated　by　the　directors。　　Soon　after　his　return　to　London；　by　the　end　of　April；　he　had　two　simpler　instruments　in　working　order。　　All　these　preparations　had　already　cost　him　nearly　four　hundred　pounds。

On　February　27；　Cooke；　being　dissatisfied　with　an　experiment　on　a　mile　of　wire；　consulted　Faraday　and　Dr。　Roget　as　to　the　action　of　a　current　on　an　electro…magnet　in　circuit　with　a　long　wire。　　Dr。　Roget　sent　him　to　Wheatstone；　where　to　his　dismay　he　learned　that　Wheatstone　had　been　employed　for　months　on　the　construction　of　a　telegraph　for　practical　purposes。　　The　end　of　their　conferences　was　that　a　partnership　in　the　undertaking　was　proposed　by　Cooke；　and　ultimately　accepted　by　Wheatstone。　　The　latter　had　given　Cooke　fresh　hopes　of　success　when　he　was　worn　and　　discouraged。　　'In　truth；'　he　wrote　in　a　letter；　after　his　first　interview　with　the　Professor；　'I　had　given　the　telegraph　up　since　Thursday　evening；　and　only　sought　proofs　of　my　being　right　to　do　so　ere　announcing　it　to　you。　　This　day's　enquiries　partly　revives　my　hopes；　but　I　am　far　from　sanguine。　　The　scientific　men　know　little　or　nothing　absolute　on　the　subject：　　Wheatstone　is　the　only　man　near　the　mark。'

It　would　appear　that　the　current；　reduced　in　strength　by　its　passage　through　a　long　wire；　had　failed　to　excite　his　electro…magnet；　and　he　was　ignorant　of　the　reason。　　Wheatstone　by　his　knowledge　of　Ohm's　law　and　the　electro…magnet　was　probably　able　to　enlighten　him。　　It　is　clear　that　Cooke　had　made　considerable　progress　with　his　inventions　before　he　met　Wheatstone；　he　possessed　a　needle　telegraph　like　Wheatstone；　an　alarm；　and　a　chronometric　dial　telegraph；　which　at　all　events　are　a　proof　that　he　himself　was　an　inventor；　and　that　he　doubtless　bore　a　part　in　the　production　of　the　Cooke　and　Wheatstone　apparatus。　　Contrary　to　a　statement　of　Wheatstone；　it　appears　from　a　letter　of　Cooke　dated　March　4；　1837；　that　Wheatstone　'handsomely　acknowledged　the　advantage'　of　Cooke's　apparatus　had　it　worked；'　his　（Wheatstone's）　are　ingenious；　but　not　practicable。'　But　these　conflicting　accounts　are　reconciled　by　the　fact　that　Cooke's　electro…magnetic　telegraph　would　not　work；　and　Wheatstone　told　him　so；　because　he　knew　the　magnet　was　not　strong　enough　when　the　current　had　to　traverse　a　long　circuit。

Wheatstone　subsequently　investigated　the　conditions　necessary　to　obtain　electro…magnetic　effects　at　a　long　distance。　　Had　he　studied　the　paper　of　Professor　Henry　in　SILLIMAN'S　JOURNAL　for　January　1831；　he　would　have　learned　that　in　a　long　circuit　the　electro…magnet　had　to　be　wound　with　a　long　and　fine　wire　in　order　to　be　effective。

As　the　Cooke　and　Wheatstone　apparatus　became　perfected；　Cooke　was　busy　with　schemes　for　its　introduction。　　Their　joint　patent　is　dated　June　12；　1837；　and　before　the　end　of　the　month　Cooke　was　introduced　to　Mr。　Robert　Stephenson；　and　by　his　address　and　energy　got　leave　to　try　the　invention　from　Euston　to　Camden　Town　along　the　line　of　the　London　and　Birmingham　Railway。　　Cooke　suspended　some　thirteen　miles　of　copper；　in　a　shed　at　the　Euston　terminus；　and　exhibited　his　needle　and　his　chronometric　telegraph　in　action　to　the　directors　one　morning。　　But　the　official　trial　took　place　as　we　have　already　described　in　the　life　of　Wheatstone。

The　telegraph　was　soon　adopted　on　the　Great　Western　Railway；　and　also　on　the　Blackwall　Railway　in　1841。　　Three　years　later　it　was　tried　on　a　Government　line　from　London　to　Portsmouth。　　In　1845；　the　Electric　Telegraph　Company；　the　pioneer　association　of　its　kind；　was　started；　and　Mr。　Cooke　became　a　director。　Wheatstone　and　he　obtained　a　considerable　sum　for　the　use　of　their　apparatus。　In　1866；　Her　Majesty　conferred　the　honour　of　knighthood　on　the　co…inventors；　and　in　1871；　Cooke　was　granted　a　Civil　List　pension　of　L100　a　year。　　His　latter　years　were　spent　in　seclusion；　and　he　died　at　Farnham　on　June　25th；　1879。　　Outside　of　telegraphic　circles　his　name　had　become　well…nigh　forgotten。



IV。　　ALEXANDER　BAIN。

Alexander　Bain　was　born　of　humble　parents　in　the　little　town　of　Thurso；　at　the　extreme　north　of　Scotland；　in　the　year　1811。　　At　the　age　of　twelve　he　went　to　hear　a　penny　lecture　on　science　which；　according　to　his　own　account；　set　him　thinking　and　influenced　his　whole　future。　Learning　the　art　of　clockmaking；　he　went　to　Edinburgh；　and　subsequently　removed　to　London；　where　he　obtained　work　in　Clerkenwell；　then　famed　for　its　clocks　and　watches。　　His　first　patent　is　dated　January　11th；　1841；　and　is　in　the　name　of　John　Barwise；　chronometer　maker；　and　Alexander　Bain；　mechanist；　Wigmore　Street。　　It　describes　his　electric　clock　in　which　there　is　an　electro…magnetic　pendulum；　and　the　electric　current　is　employed　to　keep　it　going　instead　of　springs　or　weights。　He　improved　on　this　idea　in　following　patents；　and　also　proposed　to　derive　the　motive　electricity　from　an　'earth　battery；'　by　burying　plates　of　zinc　and　copper　in　the　ground。　　Gauss　and　Steinheil　had　priority　in　this　device　which；　owing　to　'polarisation'　of　the　plates　and　to　drought；　is　not　reliable。　　Long　afterwards　Mr。　Jones　of　Chester　succeeded　in　regulating　timepieces　from　a　standard　astronomical　clock　by　an　improvement　on　the　method　of　Bain。　　On　December　21；　1841；　Bain；　in　conjunction　with　Lieut。　Thomas　Wright；　R。N。；　of　Percival　Street；　Clerkenwell；　patented　means　of　applying　electricity　to　control　railway　engines　by　turning　off　the　steam；　marking　time；　giving　signals；　and　printing　intelligence　at　different　places。　　He　also　proposed　to　utilise　'natural　bodies　of　water'　for　a　return　wire；　but　the　earlier　experimenters　had　done　so；　particularly　Steinheil　in　1838。　　The　most　important　idea　in　the　patent　is；　perhaps；　his　plan　for　inverting　the　needle　telegraph　of　Ampere；　Wheatstone　and　others；　and　instead　of　making　the　signals　by　the　movements　of　a　pivoted　magnetic　needle　under　the　influence　of　an　electrified　coil；　obtaining　them　by　suspending　a　movable　coil　traversed　by　the　current；　between　the　poles　of　a　fixed　magnet；　as　in　the　later　siphon　recorder　of　Sir　William　Thomson。　　Bain　also　proposed　to　make　the　coil　record　the　message　by　printing　it　in　type；　and　he　developed　the　idea　in　a　subsequent　patent。

Next　year；　on　December　31st；　1844；　he　projected　a　mode　of　measuring　the　speed　of　ships　by　vanes　revolving　in　th