telegraph telegraph early electrical telegraph system dating 1830s invented english inventor english scientist telegraph system commercial service receiver consisted number moved electromagnetic point letters board feature liked early users unwilling learn codes employers want invest staff training later systems letter board code read directly movement came number reduced leading complex codes change motivated economic need reduce number telegraph wires related number change urgent early installations deteriorated causing original wires successful system eventually needle system continued service 1930s telegraph played murderer known boarded train london telegraph signal ahead terminus arrested novelty use telegraph crime fighting generated great deal publicity led increased acceptance use telegraph public telegraph arose collaboration best known eponymous bridge happy collaboration differing objectives men inventor entrepreneur wished patent commercially exploit hand academic interest commercial ventures intended publish results allow freely use difference outlook eventually led bitter dispute men claims priority invention differences taken arbitration acting acting eventually bought interest exchange royalties ideas building telegraph prior partnership consulted scientist expert advice scientific knowledge model actually practice came earlier ideas mechanical telegraph involving mechanism electromagnetic largely abandoned history january proposed design code telegraph directors liverpool manchester railway complicated purposes immediate need simple signal communication liverpool station rope engine house steep long tunnel outside station rope main stations common time avoid noise pollution case gradient steep locomotive ascend required simple signals indication engine house start hauling requested build simpler version fewer codes end april railway decided use instead telegraph equipped soon went partnership patented telegraph system number board moved point letters alphabet patent recommended needle system number depending number characters required code needle system installed london rail line constructed london birmingham successfully demonstrated july similar application liverpool project carriages detached town travelled gravity system needed signal engine house start hauling carriages waiting locomotive liverpool electric telegraph end rejected favour system commercial success telegraph installed great western railway miles station commercial telegraph world needle wire system cables originally installed underground steel cables soon began fail result deteriorating replaced wires poles interim measure needle system remaining working underground wires despite greater number codes line extended needle wire system installed point use electric telegraph started grow new railways built london rope hauled application equipped telegraph opened followed needle telegraph proved highly successful british railways sets use end nineteenth century remained service 1930s september formed company bought patents established telegraph business company murder suspect following use needle telegraph message january thought use telegraph catch murderer message murder gust committed salt hill london great coat reaches nearly feet compartment second class compartment system support lower case letters needle system omitted letters caused difficulty receiving operator repeatedly requested receiving assumed mistake continued small boy suggested sending operator allowed complete word understood arriving followed nearby coffee shop detective arrested newspaper coverage incident gave great deal publicity electric telegraph brought firmly public view widely publicised arrest events brought telegraph greater public attention led widespread use railway signalling event announcement telegraph birth second son queen_victoria news published times unprecedented speed minutes announcement operation telegraph consisted number magnetic turn short distance clockwise anti clockwise electromagnetic induction winding direction movement determined direction current telegraph wires board marked diamond shaped grid letter grid intersection arranged point specific letter number wires required system equal number number determines number characters patent recommends number early demonstration models number codes obtained respectively sending end rows buttons pair buttons row operator selected button row connected positive negative ends battery respectively ends connected telegraph wires end receiving station end receiving receive mode current flowed ends system pairs rotated opposite directions needle telegraph needle telegraph possible needle positions codes short able complete alphabet letters omitted great selling point telegraph simple use required little operator training code learn letter sent visibly displayed sending receiving operator telegraph originally wires needle system sixth wire provide common return operated independently giving possibility available codes codes required extensive operator training display read sight grid simple codes telegraph systems later use earth return avoid need return wire principle established time telegraph economic need reduce number wires end proved stronger incentive simplicity use led develop needle telegraph needle telegraph needle telegraph required wires needle common return somewhat different needle telegraph needed learned read display left right times quick succession single time directions quick succession needle moved gave total codes taken stop code letters omitted substituted respectively needle telegraph system developed replace failing multi wire telegraph line required wires complex code slower transmission speed needle system needed unit code movements represent letter needle system unit code codes entire alphabet like preceding needle system code units consisted rapid needle left right quick succession needle struck post moved causing ring different tones provided left right movements operator hear direction needle moved looking codes codes refined adapted added needle code achieved provision sixth wire common return making possible single needle original wires possible pairs opposite directions common wire provided codes theoretically possible common return signalling grid indication display worked marking edge diamond grid right pointed respectively left respectively additional buttons provided telegraph sets enable common return connected positive negative terminal battery according direction desired needle codes added needle code apparently codes marked plates later needle unit codes number shift letter shift numerous compound codes added operator controls wait repeat compounds similar found code characters run character gap needle number shift letter shift codes compounds reason written codes needle telegraph known equipment survived known letters assigned possible codes
Cooke and Wheatstone telegraph