,transcrib]'s ,note3 ,m9or typographical errors h be5 correct$ )\t note4 ,irregul>ities & inconsi/5cies 9 ! text h be5 reta9$ z pr9t$4 ,words pr9t$ 9 italics are m>k$ ) und]scores3 italics4 ,words pr9t$ 9 bold are m>k$ ) tildes3 bold4 ,a c>et 77 is us$ to indicate t ! foll[+ "* is pr9t$ z a sup]script4 ,illu/ration3 ,photograph & writt5 signature ( ,william ,rob9son ,,! ,,inv5tion ,,( ,,! ,,track ,,circuit ,,! ,,hi/ory ,,( ,,dr4 ,,william ,,rob9son',s ,,inv5tion ,,( ,,! ,,track ,,circuit ,,! ,,fundam5tal ,,unit ,,:i* ,,made ,,possible ,,our ,,pres5t ,,automatic ,,block ,,signal+ ,,& ,,int]lock+ ,,sy/ems ,,signal ,,section ,,am]ican ,,railway ,,association ,,new ,,york #aibb ,,preface ,believ+ t no m fitt+ memorial c be prep>$ 9 honor ( ,dr4 ,william ,rob9son ?an to reproduce ! sali5t po9ts relat+ to 8 great a*ievem5t z writt5 & publi%$ by himself 9 #aijf "u ! title ( ,hi/ory ( ,automatic ,electric & ,electrically ,controll$ ,fluid ,pressure ,signal ,sy/ems = ,railroads1 ! committee has accord+ly drawn l>gely f ?is pamphlet = ! mat]ial conta9$ 9 ,"p ,i4 ,"p ,,ii is devot$ to ,w4 ,a4 ,baldw91 =m]ly ,g5]al ,sup]9t5d5t ( ! ,p5nsylvania ,railroad1 :o 0 responsible = ! fir/ in/allations ( automatic block signals controll$ by track circuits4 ,z ?is memorial w\ld n be complete )\t a description ( ! track circuit1 its pr9ciple & op]ation "u pres5t day signal+ practices1 ,"p ,,iii is accord+ly devot$ to ?is subject4 ,,h]b]t ,s4 ,,balliet1 ,*airman2 ,,kei? ,e4 ,,kell5b]g]1 ,,h5ry ,m4 ,,sp]ry1 ,committee4 ,,cont5ts ,,resolution #a ,i ,,! ,,inv5tion ,,( ,,! ,,track ,,circuit #c ,rob9son's ,pat5t #db ,rob9son's ,description ( ,8 ,inv5tion #ej ,dr4 ,rob9son's ,record1 ,wesleyan ,univ]sity #ei ,dr4 ,rob9son's ,record1 ,a4,i4,e4,e4 #fj ,,ii ,,william ,a4 ,,baldw9 #fh ,,iii ,,! ,,track ,,circuit #gf ,its ,pr9ciple #gg ,its ,*>act]i/ics #he ,! ,ext5t ( its ,use #ih ,,iv ,,! ,,track ,,circuit ,,9 ,,great ,,brita9 ,,& ,,on ,,! ,,cont95t1 ,,by ,t4 ,s4 ,,lascelles #ajc ,"s ( ! ,fir/ ,in/allations #ajf ,track ,circuits on ! ,cont95t #aji ,,! ,,track ,,circuit#a ,p]haps no s+le inv5tion 9 ! hi/ory ( ! developm5t ( railway transportation has contribut$ m t[>d safety & despat* 9 t field ?an ! track circuit4 ,by ?is inv5tion1 simple 9 itself1 ! f\ndation 0 obta9$ = ! developm5t ( practically e "o ( ! intricate sy/ems ( railway block signal+ 9 use today :]e9 ! tra9 is1 "u all conditions1 cont9u\sly active 9 ma9ta9+ its own protection4 ,9 o!r words1 ! track circuit is today ! only m$ium recogniz$ z fundam5tally safe by exp]ts 9 railway signal+ :]eby a tra9 or any "p !re( may reta9 cont9u\s & direct control ( a block signal :ile occupy+ any portion ( ! track gu>d$ by ! signal4 #a ,f ! ,?ird ,annual ,report ( ,! ,block ,signal & ,tra9 ,control ,bo>d to ! ,int]/ate ,comm]ce ,commission4 ,dat$ ,nov4 #bb1 #aiaj4 ,resolution ,adopt$ at ,annual ,meet+ ( ,signal ,section1 ,a4,r4,a4 ,*icago1 ,june1 #aiba ,,:]eas1 ,almighty ,god1 9 ! ex]cise ( ,8 ,div9e w1 has remov$ f ?is _w our late honor>y memb]1 ,dr4 ,william ,rob9son1 &1 ,,:]eas1 ,dr4 ,rob9son1 well call$ ! fa!r ( automatic block signal+ because ( 8 basic inv5tion ( ! clos$ track circuit ,augu/ #bj1 #ahgb1 began ! developm5t ( an automatic signal sy/em 9 #ahfg & in/all$ ! s-call$ op5 circuit sy/em at ,k9zua1 ,pa41 on ! ,philadelphia ,erie1 n[ ! ,p5nsylvania ,railroad1 9 #ahgj1 &1 ,,:]eas1 he work$ on ! developm5t ( fib] = insulat$ rail jo9ts 9 #ahgf & also develop$ ! *annel p9 ab\t ! same "t1 &1 ,,:]eas1 "o ( ! fir/ signals controll$ by m ?an "o track circuit 0 in/all$ "u 8 direction at ! ,tehauntepec tunnel 9 ,cali=nia 9 #ahgg1 &1 ,,:]eas1 8 dea? at ,brooklyn1 ,n4,y41 on ,janu>y #b1 #aiba1 at ! age ( #hj1 is an irrep>able loss to ! ,association4 ,,!re=e1 we1 memb]s ( ! ,signal ,section1 ,am]ican ,railway ,association1 pay our la/ sad tribute to 8 memory & express our deep appreciation ( ! _m & la/+ obligations t our memb]s & fri5ds owe to him1 & by words & outw>d tok5 express our s9c]e sorr[ = ! irrep>able loss ! ,association has su/a9$4 ,,!re=e1 be x ,resolv$1 t a fitt+ memorial to ! memory ( ,dr4 ,william ,rob9son1 commemorat+ ! #ej? anniv]s>y ( 8 inv5tion ( ! clos$ track circuit1 be prep>$ & pres5t$ to ?is ,association at ! ,annual ,meet+ 9 #aibb4 ,resolv$1 t ^! resolutions be spread ^u ! records ( ! ,association4 ,,! ,,inv5tion ,,( ,,! ,,track ,,circuit ,ab\t #ahfg ,william ,rob9son1 !n a rec5t graduate f college1 ent]$ actively ^u ! developm5t ( an automatic signal sy/em = prev5t+ accid5ts ( v>i\s k9ds on railroads4 ,8 att5tion 0 call$ to ! subject by ! consid]ation ( c]ta9 railroad accid5ts :i* _h occurr$1 & = ! prev5tion ( :i* !re 7 no adequate means kn[n4 ,f ?is />t+ po9t he develop$ su* a sy/em1 & 9 #ahfi1 con/ruct$ an elaborate model illu/rat+ ! same1 :i* he exhibit$ at ! ,am]ican ,in/itute ,fair 9 ,new ,york ,city1 9 #ahgj4 ,?is sy/em 0 :at is n[ kn[n 9 ! art z a wire or op5 circuit sy/em2 t is1 !re 7 circuit-in/rum5ts 9 proximity to ! track :i* 7 actuat$ by ! :eels ( a c>4 ,! action ( ! :eels on a lev] at "o po9t clos$ ! circuit ?r\gh a relay1 ^: magnet 0 s arrang$ t ! in/ant x 0 magnetiz$ x attract$ its armature & kept its own circuit clos$4 ,! circuit ( ! magnet :i* directly actuat$ or controll$ ! signal 0 "u control ( ! relay1 :i* op]at$ to op5 & close ! signal circuit directly4 ,:5 ! tra9 or c> proce$$ to ! prop] po9t beyond1 x actuat$ a rev]s+ lev]1 ?us op5+ ! relay circuit & rev]s+ ! signal4 ,9 ! model describ$ ! rev]s+ lev] op]at$ to op5 ! relay circuit by cutt+ (f ! batt]y !refrom by %ort circuit+4 ,?is model 0 9 cont9u\s & p]fect op]ation ?r\gh\t ! duration ( ! fair4 ,at ! close ( ! fair ,mr4 ,rob9son _h "s ( 8 descriptive circul>s left ov]4 ,^! he imm$iately s5t out to railroad companies at r&om4 ,"o ( ^! circul>s1 at lea/1 0 z se$ s[n 9 good gr\nd4 ,x elicit$ an imm$iate response f ,mr4 ,william ,a4 ,baldw91 g5]al sup]9t5d5t ( ! ,philadelphia & ,erie railroad1 ) ! result t ,mr4 ,baldw91 :o 0 an old telegraph op]ator & a v able & progressive railroad man1 on look+ into ! sy/em 0 s impress$ ) its practicability & importance t he at once arrang$ ) ,mr4 ,rob9son to make an in/allation ( ! sy/em on 8 road4 ,?is 0 9 #ahgj4 ,at t "t ,mr4 ,!odore ,n4 ,ely1 n[ *ief ( motive p[] 7#aijf7 ( ! ,p5nsylvania railroad1 0 assi/ant sup]9t5d5t ( ! ,philadelphia ,erie1 &1 "u direction ( ,mr4 ,baldw91 furni%$ ,mr4 ,rob9son ) all ! facilities & mat]ial necess>y = prosecut+ ! "w ( in/allation4 ,?is in/allation 0 made at ,k9zua1 ,pa41 & aft] a little exp]im5t+ 0 soon 9 p]fect work+ ord]1 p]=m+ all claim$ = x1 & consid]$ satisfactory by ! railroad company4 ,?is 0 a normally op5-circuit wire sy/em1 h[ev]1 controll$ by track lev]s1 z above describ$1 9 connection ) ! model4 ,z soon z x 0 f\nd to be work+ p]fectly & accompli%+ all claim$ = x1 ,mr4 ,rob9son1 :o aim$ to be ! mo/ sev]e critic ( 8 own "w1 ent]$ sy/ematically into a deep] /udy ( ! sy/em f ! /&po9t ( a railroad man1 ) a view ( f9d+ ! weak po9ts 9 x1 if any exi/$4 ,he soon discov]$ ! foll[+ s]i\s defects1 :i* are inh]5t 9 all normally op5 circuit or wire sy/ems ( automatic signal+1 )\t exception4 ,su* sy/ems are extremely limit$ 9 _! functions1 & may1 "u c]ta9 circum/ances1 %[ a ,,safety signal :5 ! dang] actually exi/s :i* !y are design$ to av]t1 z 9 ! foll[+ cases3 ,fir/3 ,a tra9 ent]s regul>ly ^u ! section & sets ! signal at dang]2 ! tra9 breaks 9 two1 ! =w>d "p passes (f ! section1 rev]ses ! signal & %[s ,,all ,,cle> beh9d t portion ( ! tra9 rema9+ on ! section2 & a foll[+ tra91 lur$ on by ! false signal ,,all ,,cle>1 da%es into ! /all$ portion ( ! prec$+ tra9 left /&+ on ! section4 ,?is is extremely liable to happ5 on %>p curves & grades1 :]e breaks are n ( uncommon occurr5ce4 ,second3 ,a tra9 may ent] )9 ! section f ! opposite end or f a sid+1 ?us block+ ! track1 :ile ! signal1 n hav+ be5 affect$1 %[s ,,all ,,cle> z be=e1 a false signal aga94 ,?ird3 ,if a l9e wire break or o!r connection be int]f]$ ) accid5tally or malici\sly1 or ! batt]y fail f any cause1 ! signal w inv>iably %[ ,,all ,,cle>1 "u e tra9 pass+ ov] ! section1 a false signal aga94 ,mr4 ,rob9son at ?is e>ly date recogniz$ ! above s]i\s objections z insep>able f op5 circuit sy/em ( signal+1 app>5tly1 be=e ^! defects 7 recogniz$ by any "o else1 & at once ent]$ ^u ! solution ( ! problem pres5t$1 ( elim9at+ ^! objections by produc+ a signal sy/em :i* w\ld meet all ! requirem5ts ( safe & effici5t railroad+4 ,he reason$1 fir/1 t to accompli% ?is result e c> & e pair ( :eels 9 ! tra9 mu/ h controll+ p[] ov] ! signal ?r\gh\t e in* ( ! block section1 & second1 ! signal %\ld g to dang] by gravity1 ! electric curr5t be+ us$ to hold x at safety4 ,c\ld ^! two results be accompli%$8 ,c\ld ! rails be us$ 9 any way to c>ry ! prim>y curr5t 9 a reliable mann]8 ,manife/ly n by any op5 circuit means1 = ! reason t sections ( rails ( ev5 mod]ate l5g?1 on op5 circuit1 w\ld =m a good gr\nd1 especially 9 damp or wet wea!r1 ?us keep+ ! circuit clos$ cont9u\sly & prev5t+ any op]ation ( any k9d4 ,he at once ca/ aside ?is op5 rail circuit idea z fruitless1 & hav+ previ\sly1 9 #ahfi-gj1 us$ ! %ort circuit+ pr9ciple 9 8 model1 z above /at$1 he conclud$ t ?is pr9ciple pres5t$ ! only possible solution ( ! problem4 ,he !n made draw+s ( ! clos$ rail circuit sy/em sub/antially z x is us$ today1 & 9 #ahga appli$ = a pat5t !reon1 broadly cov]+ ! clos$ rail circuit sy/em4 ,9 #ahgb he made an exhibition ( ?is sy/em at ! ,/ate ,fair1 held at ,erie1 ,pa4 ,"h he plac$ a l>ge gong on ! end ( "o ( ! build+s1 on ! outside1 & inside he _h a track made 9 sections plac$ 9 a long wat] tank made = ! purpose4 ,! track 0 cov]$ sev]al in*es deep ) wat] & ! runn+ ge> ( ! c> model 0 simil>ly imm]s$4 ,! sy/em 0 connect$ on ! %ort circuit pr9ciple ?r\gh ! rails4 ,wires connect$ ! gong ) ! back contact ( ! track relay4 ,! wat] _h no p]ceptible effect on ! op]ation ( ! app>atus1 & :5 ! c> 0 run on ! signal section x %ort circuit$ ! curr5t f ! relay1 :i*1 releas+ its armature1 clos$ circuit ?r\gh its back contact & ?us ?r\gh ! magnet ( ! gong circuit1 ?us sett+ ! gong r++ l\d en\gh to be he>d all ov] ! gr\nds4 ,on runn+ ! c> (f ! section ! curr5t return$ to ! relay en]giz+ ! same & ?us op5+ ! gong circuit at ! back contact ( ! relay1 !reby caus+ ! gong to cease r++4 ,! :ole op]ation 0 p]fect1 demon/rat+ ! successful op]ation ( ! clos$ circuit sy/em1 & attract$ great cr[ds ( p z well z ! m>k$ att5tion ( practical railroad m54 ,x w be und]/ood1 ( c\rse1 t ! local circuit may be normally op5 z above describ$ & us$1 or normally clos$ z n[ commonly us$1 accord+ to ! exig5cies or requirem5ts1 or pref]5ces ( ! p>ties us+ ! same1 & :5 desir$1 a visual signal may be sub/itut$ = ! audible signal above describ$4 ,^! are all m9or details n involv+ sep>ate inv5tion4 ,mr4 ,rob9son _h previ\sly expla9$ ! new clos$ rail circuit sy/em to ,mr4 ,baldw91 :o 0 greatly int]e/$ & express$ 8 confid5ce 9 x & reque/$ ,mr4 ,rob9son to in/all ! sy/em at ,k9zua1 :]e he _h already in/all$ ! op5 circuit wire sy/em4 ,illu/ration3 ,fig4 #a4 ,rob9son's ,clos$ ,rail ,circuit ,sy/em4 ,philadelphia ,erie ,railroad1 #ahgb4 ,z all ! signal app>atus1 relays1 batt]ies1 (fice swit*es & ov]lapp+ devices 7 already 9 op]ation !re1 x took b a %ort "t to conv]t ?is op5 circuit sy/em into a clos$ rail circuit sy/em4 ,! fir/ exp]im5ts prov$ conclusively t ! sy/em w\ld "w4 ,! track1 h[ev]1 0 9 a fe>fully unsuitable condition = ! purpose4 ,! light rails 7 fi%$ toge!r by a f\r foot wood5 b> on ! outside1 & a twelve in* fi% plate on ! inside4 ,!re 7 two holes ?r\gh ! iron fi% plate1 all[+ "o bolt = ea* rail & f\r holes ?r\gh ! wood5 b>1 two = ea* rail4 ,h[ev]1 ) a little c>e he manag$ to get ! curr5t work+ ?r\gh ! :ole l5g? ( ! section ab\t a mile & a qu>t] 9 l5g?4 ,x 0 evid5t1 h[ev]1 t on su* a section z ?is a rail bond ( "s k9d w\ld be necess>y = reliable1 cont9u\s s]vice1 & "h1 at ?is "t1 9 #ahgb ,mr4 ,rob9son conceiv$ ! inv5tion ( ! bond wire me?od ( electrically connect+ ! rails1 n[ 9 univ]sal use1 or its equival5t1 on e electric railway ?r\gh\t ! _w us+ ! rails = a return4 ,z x _h be5 det]m9$ to lay new rails at ,k9zua1 ano!r in/allation ( ! clos$ rail circuit sy/em 0 ord]$ & imm$iately made at ,irv9eton1 ,pa4 ,?is signal is illu/rat$ 9 ,fig4 #a4 ,x w be obs]v$ t ! above in/allation1 l t at ,k9zua1 n only displays a visual block signal1 b also op]ates 9 connection !re) a l\d gong :i* has be5 easily he>d at a di/ance ( a half mile1 & 0 really he>d by pass5g]s 9 tra9s pass+1 ) clos$ w9d[s4 ,an eng9e] c\ld n possibly pass )\t he>+ x4 ,a wire is se5 at ! upp] "p ( ! signal box1 runn+ out to ! "r4 ,?is is an ov]lapp+ signal wire4 ,a tell-tale bell 0 also plac$ 9 ! /ation1 indicat+ ! actual position ( ! signal1 & also a manual swit*1 :]eby ! ag5t c\ld at any "t cut (f or %ort circuit ! track batt]y & expose ! dang] signal aga9/ a tra9 & in/antly receive a return signal :5 ! dang] signal 0 actually expos$4 ,! ,irv9eton in/allation work$ p]fectly f ! fir/ nev] fail+4 ,! locomotive eng9e]s 7 delight$ ) x & soon gave x ! "n ( ,! old reliable4 ,illu/ration3 ,,! ,,rob9son ,,clos$ ,,rail ,,circuit4 ,fig4 #b4 ,wm4 ,rob9son1 #ahga1 ,pat5t$ 9 ,france1 ,febru>y #bi1 #ahgb1 & ,unit$ ,/ates ,augu/ #bj1 #ahgb4 ,re-issu$ ,july #g1 #ahgd4 ,no4 #eieh4 ,! ,rob9son clos$ rail circuit1 :i* n[ =ms ! basis1 accord+ to ! be/ in=mation1 ( e effici5t automatic electric1 electro-pneumatic & electrically controll$ fluid pressure sy/em ?r\gh\t ! _w1 is illu/rat$ 9 its simple/ =m1 9 ,fig4 #b4 ,?is figure %[s ! railroad track divid$ into sections1 a mile m or less 9 l5g?1 ! section rails be+ insulat$ f adjac5t sections4 ,a light batt]y has its t]m9als connect$ to ! opposite rails at "o end ( ! section & at ! o!r end a relay magnet has its t]m9als connect$ to ! opposite rails4 ,?us ! curr5t passes ?r\gh ! :ole l5g? ( ! section1 keep+ ! relay on cont9u\sly clos$ circuit & magnetiz$ z its normal condition4 ,! relay ?us keeps ! second>y circuit1 :i* directly controls ! signal1 normally clos$1 :]eby ! signal is normally held 9 a position indicat+ safety4 ,:5 a tra9 ent]s ^u ! section1 ! :eels & axles1 connect+ ! opposite rails !re(1 %ort circuit ! curr5t f ! relay1 :i* in/antly releases its armature1 ?us op5+ ! signal circuit4 ,! signal is !n in/antly ?r[n to ! dang] position by means ( a c\nt]balance4 ,! signal may be ( ! enclos$ disk type1 electro-me*anical1 electro-pneumatic1 electrically controll$ gas1 or ( any o!r k9d4 ,! ,rob9son pat5t$ sy/em is broad1 basic & a g5]ic creation2 x is n limit$ to any specific con/ruction or arrangem5t ( signal b cov]s all k9ds4 ,9 exp\nd+ ! e>ly hi/ory ( ! art ( automatic signal+1 ! foll[+ photographic reproductions f "s ( ,rob9son's e>ly circul>s & pat5ts w be ( int]e/4 ,! foll[+ sections on ,,curve1 ,,tunnel1 ,,/ation1 ,,swit* & ,,draw-,,bridge ,,signals are a photographic reproduction f a circul> issu$ by ,mr4 ,rob9son 9 #ahgj3 ,,curve ,,& ,,tunnel ,,signals4 ,a tra9 approa*+ a curve w ?r[ up a r$ signal ar\nd ! curve z a w>n+ to tra9s f ! opposite direction1 & w also exhibit a signal 9 its re>4 ,?us1 collisions f front or re> are gu>d$ aga9/4 ,^! signals may be us$ ?r\gh\t ! :ole ext5t ( a road4 ,9 ent]+ a tunnel a tra9 w exhibit a signal at ! o!r end to indicate its entry1 & :5 x gets ?r\gh x w l[] ! signal & r+ a bell at ! opposite end to indicate its exit4 ,,/ation ,,signals4 ,a tra9 :5 x leaves a /ation1 & at v>i\s po9ts z x passes1 w indicate to ! /ations along ! l9e1 its ,location1 ,direction1 ,rapidity & ,l5g?4 ,?us all necess>y in=mation reg>d+ mov+ tra9s w be automatically ann\nc$ e few m9utes at ! /ations4 ,,swit* ,,& ,,draw-,,bridge ,,signals4 ,if a swit* or draw-bridge is misplac$ an approa*+ tra9 w set an al>m r++ at ! /ation & w also exhibit a r$ signal ahead ( ! tra9 z a w>n+ to ! eng9e] t ! swit* is misplac$4 ,! foll[+ head+ & sections are photographic reproductions ( p>ts ( a circul> issu$ by ,mr4 ,rob9son at ! "t ( its date1 ,septemb]1 #ahgb4 ,x w be obs]v$ t c]ta9 ( ^! sections are ! same z above reproduc$ f ! circul> ( #ahgj4 ,x w be not$ also t ! description ( ! sy/em begun aft] ! head+ is n "h complet$1 = ! reason t a full description is f\nd else:]e 9 ?is hi/ory4 ,,rob9son',s ,,improv$ ,,sy/ems ,,( ,,electric ,,railway ,,signals ,= ,swit*es1 ,draw-bridges1 ,cross+s1 ,curves1 ,cuts1 & ,tunnels2 also1 to indicate ! ,location1 ,direction1 ,rapidity1 & ,l5g? ( ,tra9s4 ,,important ,,improvem5ts4--,,electric ,,signal+ ,,)\t ,,track ,,in/rum5ts1 ,,or ,,l9e ,,wires4 ,,! ,,new ,,sy/em4 ,! op]ation ( ?is sy/em is z foll[s3 ,a railroad track is divid$ into sections ( any desir$ l5g?1 say "o mile1 m or less1 by sep>at+ ! abutt+ rails f metallic contact ) ! adjac5t sections1 b pres]v+ metallic cont9uity ?r\gh\t ! l5g? ( ! section4 ,! insulation ( ! abutt+ rails is accompli%$ ,,curve ,,& ,,tunnel ,,signals4 ,a tra9 approa*+ a curve ?r[s up a r$ signal ar\nd ! curve1 z a w>n+ to tra9s f ! opposite direction1 & also exhibits a signal 9 its re>4 ,?us1 collisions f front or re> are gu>d$ aga9/4 ,^! signals may be us$ ?r\gh\t ! :ole ext5t ( a road4 ,9 ent]+ a tunnel a tra9 exhibits a signal at ! o!r end to indicate its entry1 & :5 x gets ?r\gh x exhibits a signal at ! opposite end to indicate its exit4 ,,/ation ,,signals4 ,a tra9 :5 x leaves a /ation1 & at v>i\s po9ts z x passes1 indicates to ! /ations along ! l9e1 its ,location1 ,direction1 ,rapidity1 & ,l5g?4 ,?us all necess>y in=mation reg>d+ mov+ tra9s is automatically ann\nc$ e few m9utes at ! /ations4 ,! batt]ies = op]at+ ! signals w la/ = mon?s )\t att5tion1 & "o man c readily att5d to all ! signals & batt]ies ?r\gh\t ! :ole ext5t ( a road4 ,9 all cases1 :]e practicable1 ! signal wire %\ld be c>ri$ ?r\gh ! coils ( a bell-magnet 9 ! ne>e/ (fice4 ,by ?is means ! op]ator is in=m$ :5 ! batt]y p[] is decreas+1 & w>n$ t x requires r5ew+4 ,(fice connections c be made1 :5 desir$1 s t ! signals may be op]at$ by a telegraph key f ! (fice1 z well z by pass+ tra9s4 ,! signal wires may be tapp$ at int]vals all along ! l9e1 & l$ into small ca/ iron boxes plac$ conv5i5tly on ! telegraph poles4 ,conductors ( all tra9s1 furni%$ ) keys to ^! boxes1 c1 9 case ( special accid5t1 g to ! ne>e/ box1 t\* a key )9 ! same1 & ?us set dang] signals at "s di/ance 9 front & re> ( _! tra9s4 ,! telegraph keys 9 ^! boxes n only set ! dang] signals z describ$1 b !y also place ! said signals1 = ! "t be+1 entirely out ( control ( mov+ tra9s4 ,,! ,,clos$ ,,circuit4 ,! new sy/em1 z describ$1 ) clos$ circuit1 is ! be/ ev] devis$ = block-signal+1 s9ce ! failure ( ! batt]y ?r\gh neglect or o!rwise1 _c possibly be productive ( disa/r\s results to ! tra91 h[ev] implicitly ! signals may be reli$ on4 ,f ! ,fr5* ( ,feb4 #ahgb ,translation4 #hh? claim4 ,connect+ a batt]y ,b#e1 & a magnet ,m#e ) ! rails a#i1 b#i1 ( a section ( railroad track ,c#e 9 su* a mann] t :5 said rails are jo9$ by a metallic bridge1 ! electric curr5t w be div]t$ f ! magnet ,m#e1 b s t :5 said bridg+ device is remov$ f said section ,c#e ! electric curr5t w be free to pass ?r\gh & *>ge ! magnet ,m#e4 #ic;d4 ,a signal or signals audible or visual 9 comb9ation ) ! batt]y ,b#e & ! rails ( a railroad track1 ! :ole be+ arrang$ to actuate ! signal or signals1 sub/antially z describ$4 ,,william ,,rob9son4 ,,/4 ,,pet]sburg1 ,cl>ion ,c\nty1 ,pa41 ,septemb]1 #ahgb4 ,x w be obs]v$ t "s ( ! =ego+ sections ref] to ! op5 circuit sy/em1 "s specifically to ! clos$ circuit sy/em & "s are applicable to ei!r or bo?4 ,! foll[+ is a photographic reproduction ( a po/al c>d issu$ & di/ribut$ broadca/ by ,mr4 ,rob9son at ! "t ( its date1 ,may1 #ahgc4 ,x ne$s no comm5ts4 ,,rob9son',s ,,wireless ,,electric ,,signals1 ,,! ,,simple/1 ,,*eape/1 & ,only ,absolutely ,,safe ,electric ,signals 9 ,exi/5ce1 ,,n[ ,,9 ,,successful ,,op]ation ,,on ,,! ,,baltimore ,,& ,,ohio1 ,,phila41 ,,wilm+ton ,,baltimore1 ,,philadelphia ,,& ,,erie1 ,,& ,,o!r ,,rail ,,roads4 ,!y "w z ,,automatic ,,blocks ) tell-tale al>ms1 ,,(fice1 ,,/ation1 ,,road ,,cross+ & ,,swit* ,,signals1 & ,,brok5 ,,rail ,,detectors4 ,^! signals h work$ un9t]rupt$ly ?r\gh la/ w9t] reg>dless ( ra91 sn[1 slu% or sun%9e4 ,descriptive circul>s on application4 ,,may #ahgc4 ,,wm4 ,,rob9son1 ,/4 ,pet]sburg1 ,pa4 ,illu/ration3 ,fig4 #c4 ,illu/ration f ,rob9son's ,circul> ( ,janu>y1 #ahgd1 %[+ ! ,clos$ ,rail ,circuit1 ,relay & ,ov]lapp+ ,sy/em4 ,x is po9t$ out t ! above illu/ration ( ,janu>y1 #ahgd1 %[s ! ,rob9son clos$ track circuit1 z h]et(ore describ$1 ! relay ,r & ! track batt]y ,i =m+ a "p !re(1 ! signal actuat+ magnet ,e1 ! signal ,c op]at$ !reby1 ! circuit wires ( said magnet ,e connect$ to1 & controll$ by1 ! relay ,r1 & ! ov]lapp+ or di/ant signal ,l1 ) its circuit ,h controll$ absolutely by ! position ( ! signal ,c1 ! :ole %[+ a complete clos$ track circuit ov]lapp+ sy/em1 ) home & di/ant signals4 ,! foll[+ sections are f ?is circul> ( ,janu>y1 #ahgd3 ,:5 x is desir$ to op]ate a second>y signal ?r[n =w>d or back ( ! prim>y1 a l9e wire ,h is us$1 atta*$ to ! prim>y signal ,c 9 su* a way t ! second>y signal _c possibly op]ate unless ! prim>y signal ,c is fir/ expos$1 ?us clos+ circuit on ! wire ,h4 ,! prim>y signal batt]y ,k is us$ to op]ate ! second>y signal4 ,to set ! signal f an int]m$iate /ation a wire f ea* rail ( ! section ,a is run into ! /ation4 ,:5 ^! wires are connect$ by a key1 ! curr5t f ! batt]y ,i is plac$ on %ort circuit1 & ! signal expos$ z be=e4 7,see ,fig4 #g47 ,! foll[+ functions may be embrac$ 9 ! signals ( a s+le section4 ,,block ,,signal+1 bo? automatic & manipulat$1 ,,swit*1 ,,drawbridge1 ,,road-,,cross+1 & ,,/ation-,,approa* ,,signal+1 & ,,brok5 ,,rail ,,detect+4 ,9 ?is sy/em x w be obs]v$ t1 s9ce ! signal is expos$ me*anically1 any tamp]+ ) ! rails or connections1 or failure ( ! batt]y1 w inv>iably result 9 expos+ ! signal2 any error !re=e :i* may occur f any cause w be 9 behalf ( safety4 ,x is impossible to %[ safety :5 ! dang] exi/s :i* ! signal is design$ to av]t4 ,dur+ ! e>ly sev5ties ,mr4 ,rob9son made o!r clos$ rail circuit in/allations on ! ,philadelphia ,erie & o!r railroads 9 ,p5nsylvania & ,m>yl&4 ,visit ( ! ,p5nsylvania ,r4,r4 ,(ficials ,on ,octob] #bd1 #ahgc1 a special inspection tra9 ( ! ,p5nsylvania railroad pass$ ov] ! ,philadelphia ,erie railroad1 we/w>d4 ,! ,p5nsylvania ,r4,r4 (ficials abo>d 73 ,mr4 ,a4 ,j4 ,cassatt1 at t "t g5]al manag]2 ,mr4 ,g>dn]1 g5]al sup]9t5d5t2 ,mr4 ,lewis1 controll]2 ,mr4 ,rob]t ,pitcairn1 sup]9t5d5t we/]n division1 & ,mr4 ,frank ,?omson1 sup]9t5d5t motive p[]4 ,mr4 ,wm4 ,a4 ,baldw91 g5]al sup]9t5d5t ( ! ,p4 ,e4 road1 0 ( ! p>ty1 & ,mr4 ,rob9son jo9$ ! p>ty on ! latt] road1 & cont9u$ ) x ?r\gh to ,erie1 :i* 0 rea*$ 9 ! ev5+4 ,/ops 7 made at ,ridgway on ! ,middle division & at ,irv9eton on ! ,we/]n division to exam9e ! ,rob9son clos$ circuit rail sy/em ( signals1 :i* 7 9 full op]ation at ^? po9ts4 ,a ?or\gh exam9ation & v>i\s te/s 7 made1 to all ( :i* ! signals respond$ promptly & p]fectly4 ,! foll[+ is f a lett] by ,mr4 ,rob9son to 8 bro!r on ,octob] #be1 #ahgc3 ,mr4 ,baldw9 c\ld n say en\gh 9 favor ( ! signals4 99 99 99 ,( c\rse ,i rema9$ 9 ! backgr\nd1 except1 z to giv+ explanations4 ,aft] a :ile ,cassatt1 ,pitcairn & ,?omson got into a discussion ( ! batt]y & o!r po9ts1 & call$ me into ! r+ to ent] into ! discussion1 & x 0 q animat$ = "s "t4 ,pitcairn proce$$ to give 8 idea ( :at a signal %\ld be1 & ,mr4 ,baldw9 & ! re/ proce$$ to %[ him t ?is1 0 exactly 8 ideal4 ,mr4 ,g>dn]1 aft] le>n+ modus op]&i f diagrams c4 proce$$ to lay d[n ! law to ! re/1 demon/rat+ h[ !y w\ld h 'prev5t$ ^? accid5ts4' ,!y 7 all v mu* pleas$ ) ! signals b _! op]ation seem$ su* a surprise t ,i judge x w take !m sev]al days to ?9k ov] & realize ! actual op]ation & importance ( ! ?+4 ,rob9son's ,"w 9 ,new ,engl& ,9 ,decemb]1 #ahge1 ,mr4 ,rob9son w5t to ,bo/on & took up 8 resid5ce !re4 ,9 ,janu>y1 #ahgf1 he made an in/allation ( 8 clos$ rail circuit sy/em betwe5 ,elm /reet & ,nor? av5ue1 ,we/ ,som]ville1 on a bran* ( ! ,bo/on & ,l[ell railroad4 ,?is in/allation work$ p]fectly f ! beg9n+4 ,! ,emp]or ( ,brazil ,exam9es ! ,rob9son ,signal ,sy/em ,9 ,june1 #ahgf1 ,8 ,imp]ial ,maje/y1 ,dom ,p$ro ,,ii1 ,emp]or ( ,brazil1 be+ !n 9 ,bo/on1 graci\sly accept$ an invitation f ,mr4 ,rob9son to exam9e 8 ,wireless ,signal ,sy/em 9 op]ation on ! ,bo/on ,l[ell railroad4 ,accord+ly1 on ,june #ad1 !y proce$$ toge!r by special tra9 to ,we/ ,som]ville = ! purpose4 ,! foll[+ is an acc\nt ( ! visit1 f ! ,bo/on ,po/ ( ,june #ae1 #ahgf3 ,,dom ,,p$ro ,,ii4 ,,8 ,,maje/y ,,witnesses ,,! ,,op]ations ,,( ,,railroad ,,signals4 ,?\gh ! visit ( ,8 ,maje/y1 ! ,emp]or ( ,brazil1 to ?is city has be5 a brief "o1 yet x is n haz>d\s to say t no o!r cr[n$ head or repres5tative ( royalty :o has ev] appe>$ 9 ,bo/on has m closely inspect$ ! places :]e c5tre arts1 sci5ces & manufactur]s ?an he4 ,9 compliance ) an invitation1 ! ,dom proce$$ ye/]day morn+ to witness ! work+s ( ,rob9son's ,wireless ,signal ,sy/em1 n[ 9 op]ation on a portion ( ! ,l[ell railroad4 ,! ,emp]or & sev]al memb]s ( 8 suit took passage on bo>d a special tra9 on ! ,l[ell railroad soon aft] #h o'clock ye/]day morn+ & arriv$ at ! ,we/ ,som]ville /ation ab\t #h3cj1 :]e !y 7 met by ,pr(essor ,rob9son1 :o at once began to expla9 to ! royal p>ty 8 sy/em4 ,at ,elm /reet a l>ge visual signal is plac$ :i* is controll$ by ! curr5t f a s+le cell ( a batt]y connect$ ) ! rail sections at ,nor? av5ue1 no l9e wires :atev] be+ us$4 ,:ile ! ,emp]or wat*$ ! signal at ,elm /reet tra9s 7 run ov] ! :ole l5g? ( ! signal section 9 bo? directions4 ,z soon z ! tra9 ent]$ ^u ! section at ei!r end1 ! signal1 )\t a mom5t's delay1 %[$ ! track block$1 & :5 ! tra9 pass$ (f ! section x in/antly *ang$ ! signal to all cle>4 ,!n a rail 0 torn up1 & almo/ in/antly !reaft] ! signal d5ot$ dang] & rema9$ s until ! rail 0 re/or$ & prop]ly c\pl$ up1 :5 x z quickly *ang$ to all "r4 ,mr4 ,rob9son gave v>i\s o!r demon/rations illu/rat+ ! work+ ( ! sy/em4 ,to all ! te/s ! signal in/antly respond$4 ,8 ,maje/y 0 mu* int]e/$1 & ent]$ into a some:at l5g?y discussion ) ,pr(essor ,rob9son 9 reg>d to ! op]ations :i* he _h witness$4 ,! ,emp]or's que/ions display$ pr(\nd sci5tific k1 & he fully compreh5d$ ! sy/em4 ,at ! conclusion ( ! exp]im5t ,dom ,p$ro ?ank$ ,pr(essor ,rob9son = 8 k9dness 9 expla9+ & illu/rat+ 8 sy/em1 & invit$ him to communicate ) ! ,brazilian gov]nm5t ) a view to introduc+ ! sy/em 9 ,brazil4 ,on ! return ( ! p>ty to ! ,l[ell depot 9 ,bo/on1 ! ,emp]or 0 receiv$ ) great applause1 :i* he politely ackn[l$g$ by wav+ 8 hat4 ,x w be int]e/+ to note t on ,june #ad1 #ahgf1 ! day ! ,emp]or inspect$ ! ,rob9son ,signal ,sy/em at ,we/ ,som]ville1 ! batt]y _h be5 9 op]ation exactly #ahj days )\t any att5tion :atev] except t on two occasions a little wat] _h be5 add$ to make up = evaporation1 ! signal work+ p]fectly all t "t & ! batt]y ) full /r5g?4 ,illu/ration3 ,fig4 #d4 ,rob9son's ,electro-,me*anical ,signal 9 ,op]ation at ,we/ ,som]ville :5 ,inspect$ by ! ,emp]or ( ,brazil 9 #ahgf4 ,! foll[+ is f a report on ! above signal by ! /ation ag5t at ,elm /reet1 dat$ ,june #b1 #ahgg1 eighte5 mon?s aft] x _h be5 in/all$3 ,rob9son's ,electric ,signal at ?is place has be5 work+ un9t]rupt$ly s9ce x 0 fir/ put 9 op]ation4 99 99 99 ,! signal is entirely reliable4 ,! above signal cont9u$ to "w p]fectly = a numb] ( ye>s until ! signal po/1 :i* 0 ( wood1 rott$ d[n4 ,illu/ration3 ,fig4 #d;a4 ,! signal me*anism us$ on ! ,rob9son signal at ,elm /reet 0 ( ! electro-me*anical type4 ,figure #d is a half tone ( ! id5tical signal me*anism 9 op]ation !re :5 ! ,emp]or ( ,brazil exam9$ ! sy/em ) ,mr4 ,rob9son1 on ,june #ad1 #ahgf4 ,x is po9t$ out t ! above signal me*anism1 ,fig4 #d1 %[s a batt]y or pole *ang+ atta*m5t :i* is m cle>ly %[n 9 ,fig4 #d;a1 reproduc$ f ,rob9son's ,briti% pat5t ,no4 #cdgi ( ,augu/ #bi1 #ahgi4 ,9 ?is device ! movem5t ( ! cam i#b n only *anges ! batt]y b *anges ! pol>ity ?r\gh ! magnet ,m#b1 :i* may be plac$ any:]e & us$ = any purpose4 ,a special device = ! same purpose 0 us$ n only 9 connection ) ! relay on ! ,we/ ,som]ville signal1 b on _m o!rs in/all$ by ,mr4 ,rob9son4 ,?is batt]y & pole *ang+ device is m fully describ$ 9 ,rob9son's ,u4,s4 pat5t1 ,augu/ #be1 #ahgd1 ,no4 #aed1ebj1 ,automatic ,commutator2 ,application fil$ ,july #ah1 #ahgc4 ,! foll[+ extract !refrom1 & claim1 may be int]e/+3 ,x w be obs]v$ also1 t :ile ! actual *ange ( batt]y may be caus$ to take place :5 ! magnet attracts its armature1 yet ,i pref] to arrange x s t no *ange ( connections %all take place :5 ! armature is attract$1 ! actual *ange tak+ place only dur+ ! rev]se movem5t ( ! armature1 caus$ by ! retractile =ce ( ! spr+4 ,fur!rmore1 :5 desir$1 ! batt]ies may be s connect$ 9 circuit t rev]se curr5ts %all be pass$ ?r\gh ! magnets e "t ! batt]ies are *ang$4 ,,claim #b4 ,9 comb9ation ) ! electro-magnetic commutator hav+ ! describ$ circuit connections1 ! rail sections ,a',a991 ! "o clos+ ! circuit ?r\gh ! commutator1 & !reby det]m9+ ! batt]y to be connect$ to ! o!r rail section1 sub/antially z & = ! purpose set =?4 ,x mu/ be admitt$ t !re does n seem to be a v long /ep betwe5 ! disclosures ( ?is pat5t & ! pres5t me?od ( op]at+ a di/ant signal by rev]s+ curr5t ?r\gh a rail section4 ,x w be obs]v$ t 9 ?is pat5t "o rail is us$ z a return = a plurality ( batt]ies connect$ to indep5d5t opposite rail sections4 ,9 an autograph lett] address$ to ! au?or by ,pr(essor ,h5ry1 secret>y ( ! ,smi?sonian ,in/itution1 "u date ( ,octob] #ad1 #ahge1 ! ,pr(essor discusses ,rob9son's peculi> me?od ( us+ batt]ies 9 signal+ by :i* he obta9$ ! above wond]ful durability ( #ahj days or m )\t r5ewal1 & pron\nc$ ! results obta9$ v rem>kable4 ,8 discussion ( ! subject is some:at sugge/ive ( ! pr9ciples ( ! /orage batt]y4 ,swit*es ,9 #ahgf1 #g & #h1 ,mr4 ,rob9son made a numb] ( in/allations on ! ,bo/on & ,provid5ce1 ,old ,colony & ! ,bo/on1 ,l[ell & ,na%ua railroads4 ,on ! latt] road1 at ,wilm+ton ,junction1 he equipp$ two p>allel sections ( ! d\ble track1 includ+ six swit*es1 9 ?is %ort space1 five ( !m connect$ ) "o ( ! blocks4 ,^! sections 7 arrang$ z regul> clos$ circuit blocks1 op]ative "u ! mov+ tra9s4 ,! swit*es 7 also connect$ up 9 su* a way t e swit* _h to be clos$ & lock$ = ! ma9 l9e or ! dang] signal w\ld be expos$ aga9/ approa*+ tra9s4 ,?is in/allation 0 made 9 #ahgf4 ,! swit* connection appli$ to ^! swit*es is %[n 9 ,fig4 #e & a g5]al plan ( ! same is illu/rat$ 9 ,fig4 #f4 ,bo? ( ^! figures are reproductions f ,rob9son's a=esaid ,briti% pat5t ( #ahgi4 ,illu/ration3 ,fig4 #e4 ,illu/ration3 ,fig4 #f4 ,x w be obs]v$ t :5 ! swit* is on ! ma9 l9e ! wires #g1 #h are connect$ by ! plug #f on ! swit* connection1 ?us complet+ a work+ circuit ?r\gh ! rails & ar\nd ! swit*1 b :5 ! swit* is plac$ = a sid+ ! wires #g & #i are connect$ by ! plug #e1 ?us %ort circuit+ ! curr5t f ! magnet ,m1 ?us produc+ ! same effect z w\ld ! pres5ce ( a tra9 on ! section4 ,x is always bett] to %ort circuit ! curr5t ?an tru/ to ! m]e op5+ ( circuit s9ce %ort circuit+ is sure to produce in/antane\s results4 ,x w be obs]v$1 h[ev]1 t 9 ! above case ! movem5t ( ! swit* connection bo? op5s ! rail circuit & %ort circuits ! curr5t f ! relay4 ,x may be "h /at$ t ,mr4 ,rob9son equipp$ ?ree swit*es 9 "o clos$ circuit block1 9 ! mann] describ$ above1 on ! ,philadelphia & ,erie railroad 9 #ahgc4 ,illu/ration3 ,fig4 #g4 ,fig4 #g1 f ,rob9son's ,engli% pat5t ( #ahgi1 a=esaid1 %[s ! swit* ,g arrang$ to op]ate ! signal by h& f an (fice1 /ation or telegraph po/ by ! roadside1 z h]et(ore describ$4 ,drawbridges ,ab\t ! "t he made ! ,wilm+ton in/allations above describ$1 ,mr4 ,rob9son made an in/allation ( 8 sy/em also on ! ,old ,colony railroad1 9 :i* "o block signal section at ,som]set includ$ a drawbridge4 ,he includ$ ! track rails ( ! drawbridge 9 ! track circuit 9 su* a way t ! )draw+ or loos5+ ( any "o ( ! bridge lock-bolts w\ld display ! dang] signal1 :i* rema9$ expos$ until ! bridge & its lock-bolts 7 all re/or$ to _! normal condition insur+ safety4 ,tunnels ,long wet tunnels pres5t peculi> difficulties to ! reliable op]ation ( ! rail circuit2 & yet ^! difficulties are readily ov]come by includ+ "o or m additional relays 9 ! signal section1 z %[n 9 ,fig4 #h1 :i* illu/rates ! application ( ! ,rob9son track circuit sy/em z appli$ to ! ,tehauntepec tunnel 9 ,cali=nia4 ,mr4 ,rob9son =w>d$ ! signals & necess>y in/ructions1 & ! in/allation 0 made by ,mr4 ,/eph5 ,d4 ,field1 secret>y ( ! ,electrical ,con/ruction & ,ma9t5ance ,co4 ( ,san ,francisco4 ,illu/ration3 ,fig4 #h4 ,figure #h is f a sket* made by ,mr4 ,field 9 a lett] dat$ ,san ,francisco1 ,m>* #ba1 #ahgg1 address$ to ,mr4 ,rob9son4 ,9 ?is lett] ,mr4 ,field says3 ,i am j 9 ! receipt ( y\rs ( ! #ab?4 ,i _h anticipat$ y\r diagram & h ! signals arrang$ z y %[4 ,i use ! sy/em connect$ up z foll[s3 ,9 ! tunnel ! rails are buri$ 9 wet mud2 outside no moi/ure t\*es !m = six mon?s ( ! ye>4 ,x w be not$ t 9 ! above case ! signal section is two miles long1 ! tunnel be+ "o mile long1 ) its rails buri$ 9 wet mud1 & ! section ext5d+ "o-half mile at ei!r end ( ! tunnel4 ,an extra relay & batt]y are plac$ 9 ! c5t] ( ! section connect$ up z %[n4 ,?us1 :]e conditions require1 a signal section may be divid$ up into a numb] ( sub-sections4 ,lat] advices %[$ t ! above signals work$ p]fectly & gave entire satisfaction4 ,insulat$ ,jo9ts ,9 #ahgb & ! e>ly sev5ties ,mr4 ,rob9son insulat$ ! rail jo9ts to =m ! sections by wood5 b>s1 sub/antially z %[n 9 ,fig4 #i4 ,illu/ration3 ,fig4 #i4 ,illu/ration3 ,fig4 #aj4 ,9 #ahgf & lat] he usually insulat$ ! jo9ts z %[n 9 ,fig4 #aj1 us+ ! ,fi%] ,norris truss$ jo9t z a basis4 ,vulcaniz$ fib] is plac$ betwe5 ! bottom ( ! rail ends & ! base plate1 & fib] is plac$ betwe5 ! flanges ( ! rails & ! =elocks1 & fib]1 ! %ape ( ! rail section is plac$ betwe5 ! ends ( ! adjac5t rails1 all z %[n 9 ,fig4 #aj4 ,?is makes an excell5t insulat$ jo9t1 bo? me*anically & electrically4 ,rail ,bond+ ,dry ru/ =m+ betwe5 ! fi% plates & ! rails ( ! track1 at ! jo9ts1 makes a poor conductor1 & h5ce ! l[ curr5t1 f only "o or two cells ( batt]y us$ 9 ! rail circuit = signal+ is v liable to f9d suffici5t resi/ance at ! jo9ts f ?is cause to prev5t ! cont9u\s passage ( ! curr5t ?r\gh ! rails to ! relay4 ,mr4 ,rob9son discov]$ ?is difficulty 9 8 fir/ exp]im5ts 9 rail signal+ 9 #ahgb & ! necessity = mak+ a reliable electrical connection f rail to rail 9 ord] to insure ! reliability ( 8 clos$ circuit signal sy/em4 ,z h]et(ore /at$1 !re=e1 he at t "t conceiv$ ! inv5tion ( ! bond wire1 ,fig4 #aa1 = ?is purpose1 ! connection to be made by drill+ holes 9 ! adjac5t rails1 driv+ ! ends ( ! wires tightly into ^! holes1 & mak+ ! connection s close t !re w\ld be no room = moi/ure to p5etrate or ru/ to =m4 ,& z an alt]native =m he propos$ to secure ! ends ( ! wire1 or ( a plate1 to ! adjac5t rails by sold]+1 z %[n 9 ,fig4 #ab4 ,9 ^? e>ly days !re 7 s]i\s te*nical objections to bo? ( ^! me?ods4 ,fir/3 ,! difficulty & exp5se ( bor+ holes 9 all ! rails ( ! section & connect+ !m up1 & ! difficulty ( gett+ ! railroad company to cons5t to su* an innovation to te/ :at at t "t might be reg>d$ z an exp]im5t1 & ,second3 ,sold]+ seem$ impracticable on acc\nt ( ! difficulty ( heat+ up ! rail quickly en\gh at ! requir$ po9t4 ,mr4 ,rob9son1 !re=e1 po/pon$ ! application ( ! bond wire until he c\ld secure bett] facilities = apply+ & us+ x4 ,he1 meantime1 exp]im5t$ along o!r l9es1 h[ev]1 = ! purpose ( secur+ good electrical connection betwe5 adjac5t rails )\t bor+ holes !re94 ,"o ( ^! me?ods 0 v successful4 ,x consi/$ 9 ! use ( ela/ic split spr+s hav+ _! ends re/+ on ! flanges ( ! adjac5t rails1 & held 9 place by small blocks secur$ to ! ties4 ,! pass+ ( a tra9 depress+ ! rails slightly caus$ a slight frictional movem5t betwe5 ! rails & ! spr+s1 ?us pres]v+ good electrical contact4 ,9 ! ,we/ ,som]ville in/allation1 ne> ,bo/on1 made 9 ,janu>y1 #ahgf1 z h]et(ore describ$1 ,mr4 ,rob9son us$ ! bond wire %[n 9 ,fig4 #aa4 ,9 apply+ ?is1 holes 7 bor$ 9 ! rails & ! wire1 fitt+ ! holes z closely z possible1 7 =c$ 94 ,a semi-circul> pun* 0 !n c>efully us$ to set ! metal up close ar\nd ! wire4 ,!re has be5 no bett] bond wire devis$ s9ce !n except 9 me*anical con/ruction4 ,bonds ( v>i\s designs h be5 made heavi]1 & ) heavi] end plugs = me*anical connection to ! rails4 ,^! are good features z !y r5d] ! bond less liable to breakage1 &1 z is well kn[n1 = electric railroads !y %\ld be mu* heavi] ?an requir$ 9 signal+1 = ! sake ( conductivity4 ,a bond wire1 to get be/ results1 %\ld be homog5e\s1 made ( a s+le piece ( metal1 or if made ( sev]al pieces1 all ! pieces %\ld be weld$1 or at lea/1 sold]$ toge!r4 ,!y %\ld be ( suffici5t l5g? to insure flexibility )\t di/urb+ ! connection if ! rails %\ld move relatively to ea* o!r1 & ! :ole circumf]5tial surface ( ! plug end1 or its equival5t1 :5 possible1 %\ld be 9 ! close/ possible direct contact ) ! rail1 t is1 ! bond plug %\ld make connection ) ! rail z ne>ly z possible--homog5e\s4 ,weld+ w\ld be ! ideal connection b x is n always practicable4 ,! reason = ! above is obvi\s3 t !re %\ld be no room left betwe5 ! bond & rail = ru/ to =m4 ,x foll[s !n t a bond held 9 position by an indep5d5t plug :i* r5d]s x necess>y = ! curr5t to pass f ! bond to ! int]m$iate plug & f t plug to ! rail1 is n ! be/ =m ( bond1 = ! reason t x pres5ts a d\ble surface on :i* ru/ may =m4 ,figures #aa & #ab %[ ,rob9son's bond wires & /rips ( #ahgb1 ,fig4 #ab %[+ ! bond sold]$ to ! rail4 ,9 #ahgf1 #g & #h he us$ on v>i\s roads 9 ! vic9ity ( ,bo/on1 ! bond %[n 9 ,fig4 #aa4 ,9 #ahgf he us$ on ! ,bo/on & ,provid5ce road ! bond %[n 9 ,figs4 #aa1 #ac & #ad4 ,9 ! =m %[n 9 ,fig4 #ac1 holes are bor$ ?r\gh ! upp] ends ( ! plugs1 :i* 7 slightly tap]+4 ,! wire 0 =c$ ?r\gh ^! holes1 & ! wire & plugs 7 !n sold]$ toge!r ) h>d sold]4 ,! plugs be+ mat]ially l>g] ?an ! wire1 c\ld readily be driv5 home ) a good deal ( =ce1 ?us insur+ an excell5t electrical connection )\t endang]+ ! wire4 ,illu/ration3 ,fig4 #aa4 ,illu/ration3 ,fig4 #ab4 ,illu/ration3 ,fig4 #ac4 ,illu/ration3 ,fig4 #ad4 ,illu/ration3 ,fig4 #ae4 ,illu/ration3 ,fig4 #af4 ,9 ,rob9son's ,briti% pat5t ,no4 #cdgi1 ( ,augu/ #bi1 #ahgi1 a=esaid1 he illu/rat$ ! =m ( bond %[n 9 ,figs4 #ae & #af1 :i* is an equival5t ( t %[n 9 ,fig4 #ad1 us$ by him 9 #ahgf4 ,mr4 ,rob9son claim$ ! bond wire broadly 9 ?is ,briti% pat5t1 9 ! foll[+ claims3 #aj4 ,! wire ,a#c 9 comb9ation ) ! rails ,b#c1 ,b#c1 & securely fa/5$ !reto1 = ! purpose describ$4 #aa4 ,9 comb9ation ! wire ,a#c1 ! rails ,b#c1 ,b#c1 & ! rivets a#c1 a#c1 ! :ole arrang$ sub/antially z describ$ = ! purpose ( secur+ electrical cont9uity betwe5 said rails4 ,! above is believ$ to be ! fir/ disclosure ( means = electrically connect+ rails by a bond wire 9 any pat5t1 al?\gh ,rob9son _h disclos$ x to v>i\s p>ties1 & us$ x on in/allations ye>s be=e4 ,on ! subject ( rail bond+ ! foll[+ bit ( evid5ce may be ( int]e/3 ,9 a lett] dat$ ,baltimore1 ,octob] #bi1 #ahgd1 address$ to ,mr4 ,rob9son by ,mr4 ,j4 ,h4 ,c4 ,watts1 ( ,watts ,co41 manufactur]s ( ,rob9son's signal app>atus1 he says3 ,am afraid y\r idea ( sold]+ a /rip ( copp] to ! rails w prove v tr\blesome 9 c>ry+ out1 z x is a mo/ difficult matt] to heat s l>ge a body ( iron suffici5tly to make a sure jo9t su* z y require1 or t w /& ! j>r+ ( pass+ tra9s1 c41 to say no?+ ( sneak ?ieves :o ab\nd :]ev] copp] is ly+ ar\nd loose4 ,i "k h[ev] y sc(f at !ory s w 'dry up4' ,! electric dynamo ( today has remov$ ! above po9t$ out difficulty4 ,bond wires or /rips are n[ weld$ to ! adjac5t rails = ! purpose ( secur+ reliable electrical connection betwe5 !m4 ,weld+ is sold]+1 accord+ to ! def9ition ( ! t]m4 ,?us1 ! ,encyclop$ic diction>y gives ! def9ition3 ,sold]3 ,to unite or cem5t toge!r 9 any way4 99 99 99 ,9 autog5\s sold]+ ! two pieces are directly unit$ by ! p>tial fusion ( _! contigu\s surfaces4 ,?us1 m ?an ?irty ye>s ago ,rob9son propos$ to sold] bond wires or /rips to ! rails = ! purpose ( secur+ good electrical cont9uity betwe5 ! same4 ,b x became necess>y to wait "s tw5ty ye>s = ! developm5t ( a comm]cially practical process = accompli%+ ?is result4 ,?is is f\nd 9 ! mod]n electric weld+ process4 ,rob9son's object 0 to secure a p]fectly homog5e\s jo9t or connection betwe5 ! bond & ! rail4 ,8 inv5tion1 9 ?is connection1 consi/$ 9 a metallic bond arrang$ = electrically connect+ adjac5t rails ( ! track & means = =m+ a homog5e\s connection betwe5 ! bond & ! rails4 ,?is embraces any mode ( accompli%+ t result4 ,rob9son _h simply anticipat$ ! electric process by "s tw5ty ye>s1 b t process n[ accompli%es ! result 9 a simple mann] impossible ?irty ye>s ago4 ,! splice b>s n[ weld$ to opposite sides ( /reet rails 9 _m places are us$ prim>ily = ! purpose ( electrically bond+ ! rails2 incid5tally !y s]ve ! d\ble purpose ( also mak+ a good jo9t me*anically4 ,e electric railroad uses ! bond wire or plate 9 "s =m1 orig9ally inv5t$ & us$ by ,rob9son1 = electrically bond+ rails toge!r4 ,?us1 x is cle>1 ?is simple inv5tion ( ,rob9son made m ?an ?irty ye>s ago1 an outgr[? ( 8 orig9al creation ( ! clos$ rail circuit sy/em1 has made possible ! electric railroad+ ( today1 & ! me?od ( rail-bond+ is n[ us$ on e electric railway us+ a rail return1 ?r\gh\t ! _w4 ,illu/ration3 ,,rob9son',s ,,late/ ,,electric ,,signal+ ,,app>atus4 ,fig4 #ag4 ,r+s a ,bell on ! ,eng9e :5 ,track ahead is all ,cle>4 ,figure #ag is a reproduction f a po/al c>d dat$ ,septemb]1 #ahge1 & issu$ at t "t4 ,x illu/rates means = op]at+ a positive safety signal 9 ! cab ( a locomotive :5 ! track ahead is cle> & safe1 ! op]ative curr5t pass+ ?r\gh ! rails f ! di/ant end ( ! track section ^u :i* ! tra9 is ent]+4 ,?is sy/em is elaborat$ 9 ,rob9son's ,briti% pat5t ( ,augu/ #bi1 #ahgi1 :]e x is %[n op]atively appli$ to a s+le track 9 su* a mann] z to op]ate a signal on a locomotive approa*+ f ei!r direction1 ! op]ative curr5t com+ f ! opposite end ( ! section--no l9e wires be+ us$4 ,x is n ?\ght necess>y1 !re=e1 to m fully describe ! sy/em "h4 ,9 ,g5]al ,! scriptural injunction1 ,prove all ?+s1 hold fa/ t :i* is good1 is ! key note ( sci5tific progress4 ,he :o w\ld discov] tru? mu/ n accept any?+ because x is popul>ly accept$1 or reject any?+ because x is popul>ly reject$2 nor mu/ he reg>d any?+ z impossible because nev] h]et(ore accompli%$1 al?\gh p]haps attempt$ by ! mo/ able sci5ti/s4 ,:ile giv+ full weight to pr9ciples & laws demon/rat$ & v]ifi$ by orig9al inve/igations1 he mu/ be> 9 m9d t ^? pr9ciples & laws may be capable ( v>i\s comb9ations & int]pretations2 t ! popul> int]pretation may n be capable ( g5]al application1 & if n1 x mu/ be errone\s4 ,9 %ort1 he mu/ ent] ^u 8 inve/igations sy/ematically1 indep5d5tly & untrammel$ by prejudice4 ,^! rem>ks apply to electrical sci5ce ) great =ce at ! pres5t "t4 ,^? :o ent] ?is field to advantage %\ld be m5 ( culture1 ( !oretical k1 & em95tly practical4 ,^! facts are illu/rat$ by ! ef=ts h]et(ore put =? 9 ,europe & ! ,unit$ ,/ates to develop sy/ems ( rail signal+4 ,su* ef=ts1 9 ! e>ly days1 appe> to h be5 ex]t$ pr9cipally by !ori/s ^: propositions & complications prove !m to be n only ignorant ( "s ( ! fundam5tal pr9ciples ( electrical sci5ce1 b also1 "s ( !m1 extremely unpractical4 ,t ! ef=ts 9 ?is direction may be fairly und]/ood we w direct att5tion to a few ( ! sy/ems ( rail signal+ propos$1--^? :i* h elicit$ mo/ att5tion--giv+ outl9e illu/rations ( "s ( ! circuits :i* =m _! bases1 & po9t+ out _! defects & m]its4 ,e>ly ,rail ,sy/ems ,s f> z we h k1 ! idea ( us+ ! rails z conductors = electric signal+ purposes 0 fir/ sugge/$ 9 an ,engli% pat5t ( #ahdh4 ,?is 0 m]ely a sugge/ion1 h[ev]1 & no attempt 0 made to describe any specific me?od ( us+ ! rails = ! purpose4 ,9 #ahec1 h[ev]1 an ,engli% pat5t 0 grant$ to ,george ,dugmore & ,george ,millw>d1 9 :i* is describ$ a me?od propos$ = us+ ! rails z conductors4 ,! design ( ! inv5tion is to communicate betwe5 tra9s on ! same l9e1 & betwe5 tra9s & /ations1 = :i* purpose x is propos$ to use long sections ( rails4 ,! unpractical "p ( ?is sy/em is t to make x op]ate x is necess>y1 z ! inv5tors say1 to insulate ! opposite :eels ( all ! c>riages f ea* o!r1 9 ord] t electrical connection may n be e/abli%$ betwe5 ! opposite rail l9e by ! :eels & axle4 ,imag9e "o ( our gigantic locomotives hav+ its opposite driv]s electrically insulat$ f "o ano!r6 ,figure #ah repres5ts ! signal sy/em describ$ 9 ,william ,bull's ,engli% pat5t ( ,octob] #ca1 #ahfj4 ,9 ?is sy/em1 x w be obs]v$1 ! rail sections us$ are %ort1 tw5ty feet1 m or less1 & are ! t]m9als ( l9e wires :i* connect ) ! batt]y & magnet at ! /ation4 ,! signal at ! /ation is visual & consi/s ( an indicator op]at$ by :eel "w actuat$ or controll$ by ! electro-magnet ,m %[n 9 ! diagram4 ,! signal z describ$1 mov$ 9 "o direction only1 by a /ep-by-/ep movem5t4 ,9 ! foll[+ diagram ,m repres5ts magnet & ,b batt]y4 ,illu/ration3 ,fig4 #ah4 ,william ,bull's ,briti% ,pat5t1 ,octob] #ca1 #ahfj1 & ,frank ,l4 ,pope's ,exp]im5t at ,*>le/[n1 ,mass41 9 #ahga4 ,mr4 ,bull says3 ,at ! /ations at :i* x is requir$ t ! progress ( ! tra9 %all be indicat$1 a batt]y is fix$ & 9 connection !re) a dial or indicator1 bo? ( :i* are also connect$ ) ! l9e p]man5t way wire1 ! t]m9als ( :i* are ! pairs ( insulat$ rails1 z be=e describ$4 99 99 99 99 99 ,:5 ! tra9 arrives at ! contact po9ts on ! l9e1 ! electric circuit w\ld be complet$ by ! :eels ( ! eng9e connect+ ! two insulat$ rails1 :5 ! curr5t w\ld fl[ & actuate ! electro-magnetic armature1 c4 ,! mode ( insulat+ ! rails f ea* o!r is describ$ by ,bull z foll[s3--,betwe5 ! end ( ! rails1 & also betwe5 ! jo9t plates & rail ends1 ,i ins]t a ?9 piece ( lea!r1 mill-bo>d1 gutta p]*a1 or o!r suitable sub/ance1 suitable = cutt+ (f metallic contact1 & !reby insulate "o rail ( tw5ty feet1 m or less1 z may be necess>y4 ,9 ,pope1 9 a description ( 8 exp]im5t at ,*>le/[n1 9 a pap] read by him be=e ! ,new ,york ,society ( ,practical ,eng9e]s--( :i*1 by ! way1 ,mr4 ,rob9son 0 a *>t] memb]--& subsequ5tly publi%$1 admits t he did n use ! rail circuit at all 9 any prop] s5se ( ! t]m4 ,on ! contr>y1 he us$ l9e wires =m+ 8 ma9 circuit t]m9at+ 9 %ort sections ( rails1 =ty-two feet 9 l5g? accord+ to my recollection1 t is1 ! l5g? ( "o rail4 ,! tra9 pass+ ov] ! %ort rail section at "o po9t clos$ ! circuit ?r\gh ! l9e wires1 ?us expos+ ! signal1 :i* 0 held 9 place by a det5t4 ,! tra91 hav+ rea*$ a di/ant po9t1 pass$ ov] ano!r simil> %ort section ( rails1 clos+ circuit ?r\gh ano!r magnet :i* releas$ ! det5t & rev]s$ ! signal4 ,x w be obs]v$ t ! ess5tial features ( ! device us$ 9 ,pope's exp]im5t1 on :i* he laid great /ress1 & describ$ 9 ,bull's pat5t1 are id5tical1 t is1 ! circuit clos] consi/s1 9 ! "o case ( a section ( rails tw5ty feet long1 m or less1 on op5 circuit1 & ! o!r id5tically ! same1 b ) a rail section =ty-two feet long1 bo? us+ l9e wires4 ,pope & 8 fri5ds h]ald$ ?is exp]im5t--a revival ( ,bull's device--z demon/rat+ a wond]ful inv5tion on ! "p ( ,pope4 ,:at ,rob9son ,has ,done 9 ,automatic ,electric ,signal+ #a4 ,he has creat$ an epo* mak+ inv5tion ( incalculable value to ! human race 9 ! :olesale sav+ ( life & prop]ty on railroads1 an inv5tion ( increas+ importance & effici5cy z "t passes & its use is ext5d$4 ,x is an inv5tion s unique & pr(\ndly philosophical t ^? be/ skill$ 9 ! electrical art at ! "t x 0 made1 decl>$ t x 0 contr>y to all kn[n laws ( electrical action & c\ld n possibly "w4 #b4 ,rob9son's inv5tion 0 n an improvem5t on some?+ t prec$$ x4 ,x _h no prec$5t4 ,x 0 an entirely new creation involv+ pr9ciples & me?ods ( op]ation nev] be=e kn[n or us$ by anybody4 #c4 ,8 inv5tion 0 almo/ unique 9 ?is3 ,x 0 a basic inv5tion conceiv$1 te/$1 put 9 practical op]ation 9 _m in/allations1 & p]fect$1 z a sy/em1 9 all its details1 by its orig9al inv5tor4 ,he r$uc$ x to its l[e/ t]ms & its highe/ effici5cy1 a p]fection & effici5cy ( op]ation :i* h n be5 exce$$ s9ce x left 8 h&s _m ye>s ago4 #d4 ,8 inv5tion has made possible1 ) safety1 ! high spe$ railroad+ ( today4 #e4 ,z already /at$1 ! automatic signal sy/em us$ 9 & controll+ ! op]ation ( traffic ( ! ,new ,york subway is purely & exclusively a ,rob9son sy/em4 #f4 ,rob9son's automatic signal sy/em has increas$ ! traffic capacity ( ! ,new ,york subway at lea/ ?ree-fold1 & probably twice t4 ,)\t x ! subway equipm5t c\ld n transport ) safety1 "o-f\r? ! numb] ( pass5g]s n[ c>ri$4 #g4 ,?is inv5tion has creat$ a practically new indu/ry1 giv+ employm5t to _m ?\s&s ( m51 9 v>i\s capacities1 skill$ & unskill$4 #h4 ,x is enri*+ ! railroads by enabl+ !m to c>ry on twice ! traffic1 ) a giv5 equipm5t1 t !y c\ld ev] d be=e1 & also by sav+ _! equipm5t f de/ruction by collisions & o!r de/ructive means4 #i4 ,! ,rob9son automatic sy/em is admitt$ly ! only signal sy/em ev] produc$ t meets all ! requirem5ts ( safe & rapid railroad+4 #aj4 ,rob9son's subsidi>y inv5tion ( ! rail bond1 made m ?an fifty ye>s ago 9 connection ) 8 automatic sy/em ( signal+1 & n[ 9 univ]sal use on all electric roads us+ ! track return1 ?r\gh\t ! _w1 has made possible electric railroad+ z practic$ today4 ,)\t ?is ,rob9son bond or its equival5t ^? electric roads us+ ! track return c\ld n be op]at$4 #aa4 ,! ,rob9son automatic sy/em is a humanit>ian inv5tion ( ! v highe/ ord]1 to :i* ?\s&s ( travel]s by rail are indebt$ = ! pres]vation ( life & limb4 ,illu/ration3 ,w4 ,,rob9son4 ,improvem5t 9 ,electric ,signal+ ,app>atus = ,railroads4 ,no4 #acj1ffa4 ,pat5t$ ,aug #bj1 #ahgb4 ,,unit$ ,,/ates ,,pat5t ,,(fice ,,william ,,rob9son1 ,,( ,,brooklyn1 ,,new ,,york4 ,improvem5t 9 ,electric-,signal+ ,app>atus = ,railroads ,specifications =m+ "p ( ,lett]s ,pat5t ,no4 #acj1ffa1 dat$ ,augu/ #bj1 #ahgb4 ,be x kn[n t ,i1 ,,william ,,rob9son1 ( ,brooklyn1 9 ! c\nty ( ,k+s & ,/ate ( ,new ,york1 h inv5t$ a new & useful ,electric ,signal+ ,app>atus = ,railways1 ( :i* ! foll[+ is a full1 cle>1 & exact description1 ref]5ce be+ _h to ! accompany+ draw+ =m+ "p ( ?is specification4 ,! figure repres5ts a top view ( a d\ble-track railway1 ) suitable sections & wire connections1 toge!r ) an elevation ( ! signal-box ) its face remov$ to %[ ! signal )91 ! :ole be+ arrang$ to illu/rate my inv5tion4 ,! object ( ?is inv5tion is to op]ate electric signals1 audible or visible1 by means ( mov+ or /&+ vehicles or tra9s )\t ! use ( ord9>y track connections = clos+ or break+ circuits1 & )\t ! use or ) a limit$ use ( l9e-wires = conduct+ ! electric curr5t1 ! rails ( ! track be+ us$ = ! latt] purpose4 ,! inv5tion consi/s 9 an improv$ signal ( v simple con/ruction1 by :i* great ease ( action is secur$4 ,x also embraces c]ta9 peculi>ities 9 ! arrangem5t ( wires f ! signal & batt]y to ! track4 ,a 9 ! draw+ repres5ts a d\ble-track railroad4 ,c is a section ( track1 :i* may be a mile long1 m or less1 & hav+ its rails a b sep>at$ f metallic contact ) ! rails ( ! sections ,d & ,e1 z %[n at a' b'4 ,9 l mann] ! section ,c' ( ! o!r track has its rails sep>at$ f metallic contact ) ! rails ( ! sections ,d' & ,e'4 ,! rails a b c d %\ld ea* h metallic cont9uity ?r\gh\t ! l5g? ( its section4 ,! signal-box ,f is con/ruct$ ( any suitable mat]ial1 & is provid$ ) an orifice1 pref]ably 9 ! c5t]1 cov]$ ) glass w9d[s capable ( illum9ation1 ?r\gh :i* ! signal may be se5 :5 expos$1 day or night4 ,)9 ?is signal-box is plac$ ! signal ,g1 consi/+ ( a disk1 ,s1 atta*$ to ! lev] e1 :i*1 pivot$ at f1 turns on a horizontal axis4 ,to ! lev] e or its arbor is fix$ ! small projection or lev]1 pref]ably segm5tal1 g4 ,a cord1 l9k1 *a91 or delicate ela/ic spr+1 i1 is atta*$ to ! lev] g & to ! upp] "p ( ! long lev] ,l1 9 su* a mann] t :5 ! armature m1 :i* is atta*$ to ! lev] ,l1 is attract$ by its magnet ,m & ! upp] "p ( said lev] ,l sw+s 9 ! direction ( ! arr[ z1 ! upp] "p ( ! segm5tal lev] g moves =w>d & d[nw>d1 ?us p]mitt+ ! *a9 i to "w clos] to ! pivot f4 ,by ?is arrangem5t x w be se5 t ! greate/ lev]age-p[] is secur$ = mov+ ! signal :5 ! armature m is ! greate/ di/ance f its magnet & ! magnetic =ce is consequ5tly weake/1 ! lev]age-p[] dim9i%+ gradually z ! armature approa*es ! magnet4 ,! v]tical lev] ,l moves on a horizontal axis1 f'1 & is prev5t$ f sw++ too f> back f ! magnet by ! adju/able /op s1 :i* may be s adju/$ z to br+ ! armature m a great] or less di/ance f its magnet ,m1 z may be f\nd necess>y4 ,! lev]s ,l & e may be made ( any suitable mat]ial & 9 any mann]2 b are pref]ably con/ruct$ ( ?9 tubul> metal = ! purpose ( secur+ great /r5g? & rigidity ) m9imum weight & friction ( p>ts4 ,fur!rmore1 ! disk ,s is c\nt]balanc$ by an adju/able weight1 w1 & by mak+ t "p ( ! lev] e embrac$ betwe5 ! pivot f & ! disk ,s ( consid]able l5g?1 ! disk ,s is br\ght f a /ate ( concealm5t to a /ate ( exposure1 or ! rev]se1 by pass+ ?r\gh a comp>atively small angle1 & by arrang+ ! disk-lev] e1 z %[n 9 ! draw+1 9 su* a mann] t 9 br++ ! disk f a /ate ( concealm5t to a /ate ( exposure1 or ! rev]se1 said lev] e %all sw+ to & beyond a horizontal position1 ! greate/ uni=mity ( motion ) ! lea/ possible loss ( p[] are secur$4 ,hav+ ?us describ$ ! con/ruction ( ! visual signal ,g1 x w be se5 t :5 ! electro-magnet ,m is *>g$ x attracts ! armature m to itself1 ?us sw++ ! upp] end ( ! lev] ,l 9 ! direction ( ! arr[ z1 & c>ry+ ! upp] end ( ! lev] g =w>d1 at ! same "t turn+ ! same toge!r ) ! lev] e on ! axis f1 & c>ry+ ! disk ,s d[n into ! position indicat$ 9 dott$ outl9e4 ,n[ connect "o pole ( ! batt]y ,b ) ! rails a & c1 & ! o!r pole ) ! rails b & d ( ! sections ,c & ,c' by means ( ! wires k & k'1 respectively4 ,9 l mann] connect ! ends ( ! coils ( ! magnet ,m1 ! "o end ) ! rails a & c & ! o!r end ) ! rails b & d ( ! same sections ,c & ,c' by ! wires l & l'1 z %[n 9 ! draw+1 & ! app>atus is op]ative4 ,! wires f ! batt]y & ! signal to ! track are pref]ably insulat$4 ,be=e describ+ ! op]ation ( ! app>atus z a :ole1 x may be /at$ t ! electric curr5t w foll[ a nak$ metallic conductor if ( suffici5t surface1 ev5 :5 imm]s$ 9 a riv] or 9 ! mud at ! bottom ( a riv]1 because ! metal (f]s less resi/ance to its passage ?an ei!r wat] or mud4 ,mu* m w x foll[ ! rails ( a railroad track :5 !y are made a "p ( ! circuit1 s9ce ! rails pres5t a l>ge surface ( good conduct+ mat]ial1 :i* (f]s mu* less resi/ance to its passage ?an any surr\nd+ m$iums2 & x is well kn[n t :5 sev]al c\rses are pres5t$ ! electric curr5t w foll[ t c\rse :i* (f]s lea/ resi/ance to its passage4 ,! mode ( op]ation is z foll[s3 ,suppose ! sections ,c & ,c' to be entirely cle> ( c>s2 !n ! electric curr5t f ! positive pole ,p ( ! batt]y ,b w pass z indicat$ by ! arr[s x x1 ?r\gh ! wire k'1 rail b1 wire l'1 & magnet ,m1 *>g+ ! same1 & return ?r\gh ! wire l1 rail a1 & wire k1 z indicat$ by ! arr[s y' y1 to ! negative pole ,n ( ! batt]y4 ,! magnet ,m1 be+ ?us *>g$1 attracts its armature & sw+s ! signal-disk ,s into ! position ( concealm5t %[n 9 dott$ outl9e1 & holds x 9 t position z long z ! sections ,c ,c' are cle>4 ,n[ let a tra9 ent] ^u ,c or ,c'1 z indicat$ at ,h ,c'1 & ! :eels & axles ( ! same w bridge ov] ! rails c & d1 & ?us1 by (f]+ a l>ge conduct+-surface1 w pres5t to ! electric curr5t a complete circuit1 :i* (f]s mu* less resi/ance to its passage ?an t ?r\gh ! magnet ,m4 ,! electricity n[ takes ! c\rse ov] ! wire k'1 rail d1 :eels & axle ,h1 return+1 by ! rail c & wire k1 to ! batt]y1 z indicat$ by ! arr[s x x' y1 us+ ! rails c & d1 z w be se51 ) _! bridge1 & entirely avoid+ ! magnet ,m1 :i*1 be+ ?us demagnetiz$1 lets g its armature1 & ! c\nt]poise w1 :i* slightly ov]balances ! disk ,s1 c>ries ! same up 9 front ( ! orifice1 into a position ( exposure1 :]e x rema9s1 z %[n1 :ile a tra9 is on section ,c or ,c'4 ,:51 h[ev]1 ! tra9 has run (f1 leav+ sections ,c & ,c' cle>1 ! magnet ,m is in/antly *>g$ aga9 & ! signal-disk is remov$ & kept conceal$ until ! track is aga9 block$ by ! pres5ce ( ano!r tra91 :5 ! same process is repeat$4 ,:5 ! signal-disk is 9 a position ( exposure1 z %[n1 ! lev] l may s]ve to close an additional circuit ?r\gh ! batt]y ,b1 :i* may be us$ to op]ate an al>m1 ,i1 9 conjunction ) ! signal ,s1 or to actuate ano!r signal at a di/ant po9t4 ,fur!rmore1 ! concealm5t ( ! signal ,s may s]ve to close ano!r circuit = expos+ ano!r signal1 or ! rev]se4 ,in/ead ( us+ ! signal ,g1 con/ruct$ z h]e9 m9utely describ$1 a signal ( any suitable con/ruction may be us$ )\t affect+ ! _s ( ! inv5tion4 ,fur!rmore1 in/ead ( us+ ! magnet ,m to actuate ! signal directly1 x may be us$ z a relay1 op]at+1 :5 *>g$1 to keep ! circuit :i* directly actuates ! signal op5 or clos$1 z desir$4 ,x is evid5t t an al>m may be us$ ei!r 9 conjunction ) or indep5d5tly ( a visual signal4 ,! draw+ %[s an application p>ticul>ly adapt$ to road-cross+ signals on a d\ble track4 ,! signals may be us$1 also1 on a s+le track & be appli$ z block signals & = o!r purposes on s+le or d\ble tracks4 ,:5 us$ z a block-signal or = o!r purposes1 x may be desirable to indicate at a di/ant /ation :5 ! signal is op]ative4 ,to accompli% ?is object1 c>ry "o ( ! wires f ! magnet ,m to ! di/ant /ation4 ,"h let ! wire be pass$ ?r\gh ! coils ( a bell-magnet or o!r signal+ device1 & !nce be c>ri$ to ! track & atta*$ to ! same1 z already describ$4 ,! (fice signal w op]ate simultane\sly ) ! signal ,s4 ,?us any desir$ numb] ( signals may be op]at$ simultane\sly1 at diff]5t po9ts1 f a s+le section ( track4 ,by a slight modification ( ! plan describ$ an effici5t swit* & drawbridge signal may be op]at$1 ! rails be+ us$ z conductors4 ,?us half a mile1 m or less1 f a swit* may be plac$ a signal-box & signal1 sub/antially z describ$1 & connect$ ) ! rails1 z %[n4 ,ne> ?is po9t let ! rails be divid$1 tak+ c>e t ! signal & batt]y wire are connect$ to ! section t[>d ! swit*4 ,n[1 :ile ! swit* is on ! ma9 l9e1 ! b>s connect+ ! rails ( ! swit* w act z a bridge to div]t ! electricity f ! signal-magnet4 ,b :5 ! swit* is misplac$ ! metallic connection ( ! rails ( ! track w be int]rupt$4 ,! signal-magnet w ?us become *>g$ & ! position ( ! signal *ang$4 ,9 ?is case ! signal %\ld be expos$ :5 ! magnet ,m is *>g$4 ,9 l mann] a cross-b> may bridge ! rails on a draw-bridge4 ,! displac+ ( ! draw-bridge or )draw+ ( ! bolt or bolts :i* hold ! same 9 position w all[ ! signal-magnet to become *>g$ & ! signal to be *ang$1 sub/antially z describ$1 9 connection ) a swit*4 ,x is n necess>y 9 all cases t ! rails a & b1 section ,c1 %\ld bo? be sep>at$ f metallic contact ) ! sections ,d & ,e4 ,x may (t51 if n always1 be suffici5t to sep>ate only "o ( said rails f su* metallic contact ) ! adjac5t sections4 ,:at ,i "h claim z new1 & desire to secure by ,lett]s ,pat5t1 is-- #a4 ,! batt]y ,b & magnet ,m1 s connect$ ) ! rails ( a section ( railroad track t :5 said section is bridg$ by ! :eels & axle ( a c> ! electric circuit is *ang$ & ! signal op]at$ ?r\gh ! demagnetization ( ! magnet ,m1 sub/antially z specifi$4 #b4 ,a signal con/ruct$ p>tially ( tubul> mat]ial1 = ! purpose ( secur+ lightness comb9$ ) /r5g?1 9 ! mann] sub/antially z h]e9 set =?4 #c4 ,! arrangem5t ( ! pivotal be>+ ( ! lev] e at a po9t midway betwe5 ! horizontal l9es ( exposure & concealm5t ( ! signal-disk1 z %[n & describ$1 = ! purpose set =?4 #d4 ,! comb9ation ( ! ela/ic spr+ i1 or its equival5t1 ) ! lev]s ,l & e & signal-disk ,s1 sub/antially z set =?4 #e4 ,! batt]y ,b1 9 comb9ation ) ! wires k k'1 rails a b ( a railroad track1 wires l l'1 & magnet ,m1 sub/antially z & = ! purpose h]e9 describ$4 #f4 ,! additional or local circuit r1 9 comb9ation ) ! magnet ,m1 wires l l' k k'1 batt]y ,b1 & section ( rails ( a railroad track1 = op]ation1 ess5tially z describ$4 ,,william ,,rob9son4 ,witnesses3 ,,john ,,rooney1 ,,van ,,wyck ,,fo/]4 ,,dr4 ,,william ,,rob9son#b ,electrical & ,me*anical ,eng9e] ,fell[ ,am]ican ,in/itute ( ,electrical ,eng9e]s ,graduate ( ,wesleyan ,univ]sity ) ,degrees ( ,a4,b4 & ,a4,m4 ,po/ ,graduate ( ,bo/on ,univ]sity ) ,degree ( ,ph4,d4 #b ,repr9t$ f a circul> publi%$ by ,dr4 ,rob9son 9 #aiac4 ,data ,notes ,orig9ator & pat5tee 7basic pat5ts1 #ahgb7 ( ! ,clos$ ,track ,circuit ,sy/em ( ,automatic ,electric ,signal+1 ! basis ( practically e automatic electric block signal sy/em 9 use on railroads today4 ,! foll[+ brief description & comm5ts on ?is ,rob9son clos$ track circuit sy/em are f ! ,?ird ,annual ,report ( ! ,block ,signal & ,tra9 ,control ,bo>d to ! ,int]/ate ,comm]ce ,commission1 dat$ ,novemb] #bb1 #aiaj1 pages #agg et seq4 ,! ,track ,circuit ,p]haps no s+le inv5tion 9 ! hi/ory ( ! developm5t ( railway transportation has contribut$ m t[>d safety & despat* 9 t field ?an ! track circuit4 ,by ?is inv5tion1 simple 9 itself1 ! f\ndation 0 obta9$ = ! developm5t ( practically e "o ( ! intricate sy/ems ( railway block signal+ 9 use today :]e9 ! tra9 is1 "u all conditions1 cont9u\sly active 9 ma9ta9+ its own protection4 ,9 o!r words ! track circuit is today ! only m$ium recogniz$ z fundam5tally safe by exp]ts 9 railway signal+ :]eby a tra9 or any "p !re( may reta9 cont9u\s & direct control ( a block signal :ile occupy+ any portion ( ! track gu>d$ by ! signal4 ,inv5tion ( ! ,rail ,circuit ,to ,mr4 ,william ,rob9son ! ,pat5t ,(fice records conc$e ! honor ( hav+ devis$ ! fir/ practical track or 'rail circuit4' ,?is compris$ :at is t]m$ ! clos$ track circuit 9 di/9ction f ! op5 =m t prec$$ x4 99 99 99 ,clos$ track circuits are v reliable1 :olly safe 9 pr9ciple1 & simple ( application & ma9t5ance4 99 99 99 ,att5tion is !re=e direct$ to ! clos$ track circuit--! basis ( all mod]n automatic signal sy/ems t are entitl$ to recognition z embody+ ! highe/ atta9m5ts 9 ! matt] ( safety4 ,! ,clos$ ,track ,circuit ,! clos$ track circuit 9 its simple/ =m consi/s ( ! two rails ( a section act+ z prime conductors1 a g5]ator ma9ta9+ a diff]5ce ( pot5tial betwe5 !m :5 ! rails are unoccupi$1 & "o or m relays connect$ across ! rails4 99 99 99 ,! clos$ track circuit ma9ta9s ! relay1 normally1 9 an en]giz$ /ate1 & ! influ5ce ( ! tra9 ^u ! rails is to totally de-en]gize x by %unt+ or %ort-circuit+ ! g5]ator--a ?+ z effectively done by a s+le c> or locomotive z by a tra9 ( any l5g?1 = all practical purposes4 99 99 99 ,a failure ( ! g5]ator or a break 9 ! circuit1 :e!r 9 ! rails !mselves or 9 o!r p>ts ( ! circuit1 produces ! same effect ^u ! relay z t ( a tra9 ^u ! rails4 ,?is is 9 full con=mity ) ! accept$ pr9ciples ( safe signal+1 :i* give he$ n alone to ! action ( ! devices ( ! sy/em "u normal conditions1 b embrace also an equal reg>d = safe results foll[+ d]angem5ts ( !m4 ,hi/orical ,notes ,9 ?is connection a few hi/orical notes on ! orig9 & introduction ( ! clos$ rail circuit sy/em ( automatic electric block signal+ on railroads may prove ( int]e/4 ,9 #ahgj ,mr4 ,william ,rob9son exhibit$ at ! ,am]ican ,in/itute ,fair held 9 ,new ,york ,city1 an elaborate work+ model ( an automatic electric signal sy/em = railroads4 ,?is 0 a road cross+ signal op]at$ by tra9s approa*+ 9 ei!r direction4 ,:5 at a suitable di/ance ! tra9 set a gong r++ at ! road cross+ ahead1 :i* cont9u$ s\nd+ an al>m until ! tra9 _h pass$1 :5 x ceas$ r++4 ,9 ?is model ! relays 7 de-en]giz$ by %ort circuit+1 al?\gh ! signal 0 op]at$ on ! normally op5 circuit plan4 ,?is is believ$ to be ! fir/ case 9 :i* %ort-circuit+ _h be5 us$ 9 ! op]ation ( railway signals4 ,9 #ahga ,mr4 ,rob9son in/all$ ?is sy/em z an automatic block signal on a block ov] a mile 9 l5g?1 at ,k9zua1 ,pa41 on ! ,philadelphia & ,erie ,railroad4 ,?is in/allation embodi$ a relay1 a l>ge visual signal "u control ( ! relay1 a heavy electric gong op]at$ 9 conjunction ) ! visual signal1 all at ! signal /ation4 ,f ?is /ation an ov]lap ext5d$ to ! ag5t's /ation a mile ahead4 ,"h a signal bell 0 provid$ s t :5 ! visual signal 0 actually 9 ! dang] position x clos$ circuit on ! bell magnet 9 ! ag5t's /ation1 ! hamm] rema9+ aga9/ ! bell until ! rev]sal ( ! di/ant signal op5$ ! circuit ( ?is *eck signal4 ,?is sy/em work$ p]fectly1 p]=m+ all claim$ = x2 b x 0 a normally op5 circuit sy/em1 ! only pr9ciple ev] dream$ ( up to t "t = op]at+ an automatic electric railway signal4 ,imm$iately on ! completion ( ?is op5 circuit in/allation ,mr4 ,rob9son began to look = weak po9ts ab\t x1 & soon discov]$ sev]al n[ well kn[n z inh]5t 9 all normally op5 circuit sy/ems1 n ! lea/ ( :i* 0 t if ! circuit 7 brok5 or ! curr5t fail$ f any cause ! signal w\ld rema9 at safety1 ?us %[+ a false signal al?\gh dang] might be imm95t1 a radical error 9 pr9ciple fatal to ! reliability ( any normally op5 circuit sy/em ( signal+4 ,he !re=e1 aft] mu* /udy1 devis$ ! clos$ track circuit sy/em1 ! con/ruction & op]ation ( :i* are cle>ly describ$ above by ! ,int]/ate ,comm]ce ,commission4 ,9 devis+ ?is sy/em ,mr4 ,rob9son reason$ t to make an effici5t & reliable sy/em e pair ( :eels 9 ! tra9 mu/ control ! signal1 :]eby a s+le c> on ! block1 or a break 9 any "p ( ! circuit1 or loss ( curr5t f any cause affect+ ! relay1 w\ld keep ! signal at dang] z effectively z ! pres5ce ( a :ole tra9 on ! block4 ,^! consid]ations l$ him to ! inv5tion ( ! clos$ track circuit op]at+ z h]et(ore cle>ly describ$ by ! ,int]/ate ,comm]ce ,commission4 ,be=e mak+ te/s ( ! sy/em1 h[ev]1 he appli$ = & 0 all[$ basic pat5ts on ! clos$ track circuit sy/em 9 ! ,unit$ ,/ates & ,france1 ! ,unit$ ,/ates pat5t dat$ ,augu/ #bj1 #ahgb1 ,no4 #acj1ffa1 & ! ,fr5* pat5t ,febru>y #bi1 #ahgb1 ,no4 #id1cic4 ,hav+ all ! signal app>atus 9 op]ation at ,k9zua1 9 ! op5 circuit sy/em1 z above describ$1 x 0 a simple matt] = him to te/ ! clos$ circuit sy/em at ?is po9t4 ,he !re=e divid$ ! opposite rails ( ! track into sections insulat$ f ! adjac5t cont9u\s track rails & connect$ ! relay t]m9als to ^! sections at "o end & simil>ly connect$ a batt]y !reto at a suitable di/ance f ! relay1 ?us =m+ a clos$ track circuit4 ,?is be+ done1 ! fir/ tra9 t pass$ connect$ ! opposite rail l9es ?r\gh ! :eels & axles1 %ort circuit$ ! relay1 ?us op]at+ all ! signal circuits "u its control1 !reby practically demon/rat+ ! feasibility ( ! sy/em4 ,?is 0 9 #ahgb4 ,?is block 0 ext5d$ to ! ag5t's /ation ov] a mile f ! signal1 at :i* /ation ! track batt]y 0 plac$ & also a swit* = ! manual op]ation ( ! signal1 & also an ov]lapp+ telltale signal %[+ to ! ag5t :5 ! di/ant ma9 signal 0 actually expos$ at dang]4 ,! signal also indicat$ to ! ag5t ! approa* ( a tra9 :5 a mile away4 ,ano!r in/allation 0 imm$iately ord]$ to be made at ,irv9eton on ! same road4 ,?is 0 complet$ e>ly 9 #ahgc & work$ p]fectly f ! beg9n+1 p]=m+ all ! functions describ$ 9 connection ) ! in/allation at ,k9zua4 ,! locomotive eng9e]s 7 greatly int]e/$ & soon *ri/5$ ! ,irv9eton signal ,! ,old ,reliable4 ,?is 0 foll[$ by o!r in/allations on ?is road & 9 #ahgc ,mr4 ,rob9son _h made in/allations ( 8 clos$ rail circuit sy/em ( signal+ on f\r diff]5t railroads1 foll[$ by v>i\s in/allations on _m o!r railroads 9 ! foll[+ ye>s1 z he 0 ! sole own] ( ! sy/em = ab\t n9e ye>s1 t is1 until ab\t #ahhj or #ahha1 :5 ! ,we/+h\se p obta9$ control ( ! sy/em by ! pur*ase ( ,rob9son's int]e/s4 ,?is 0 promptly foll[$ by a reorganization "u ! "n ( ! ,union ,swit* & ,signal ,company1 ! t]ms ,union & ,signal repres5t+ ! ,rob9son int]e/s 9 ! reorganization4 ,?is company ?us became ! sole own] ( ! ,rob9son ,clos$ ,circuit ,sy/em ( signal+ until ! expiration ( 8 pat5ts1 :5 all o!r signal companies adopt$ ! ,rob9son sy/em z ! basis ( _! signal "w4 ,! orig9al "n ( ! ,rob9son ,company 0 ,! ,union ,electric ,signal ,company1 :i* ,rob9son organiz$ & own$ 9 #ahgh4 ,9 ! reorganization ! ^w ,electric 0 cancel$ f ?is title & ! words ,swit* & sub/itut$1 ?us =m+ ! pres5t title3 ,! ,union ,swit* & ,signal ,company4 ,rail ,bond+ ,exp]i5ce at ,k9zua ) a v poor track demon/rat$ ! necessity ( a rail bond to secure reliable electrical cont9uity ?r\gh\t ! rails con/itut+ ! block4 ,"h1 9 #ahgb1 ,mr4 ,rob9son conceiv$ ! inv5tion ( ! bond wire z us$ today4 ,9 an ef=t1 h[ev]1 to avoid ! h&icap ( hav+ to bore two holes 9 e rail ( long sections ( track1 he equipp$ a signal section 9 #ahgc ) ela/ic /eel plates be>+ on ! adjac5t rails at ! jo9ts4 ,?is did n prove z satisfactory1 h[ev]1 z ! bond wire4 ,he !re=e us$ bond wires made aft] 8 orig9al conception1 on e in/allation he made aft] #ahgc4 ,he made 8 bond wire 9 two =ms4 ,9 ! second =m he made /uds slightly tap]+1 bor$ holes ?r\gh !m1 ins]t$ ! ends ( ! wire 9 ^! holes1 braz$ !m toge!r & drove ^! /uds securely into holes bor$ 9 ! adjac5t rails4 ,an exam9ation ( ^! bonds aft] sev]al ye>s' s]vice %[$ t !y 7 app>5tly 9 z good condition me*anically & electrically z :5 fir/ put 9 place4 ,! ,rail ,bond is n[ an ess5tial basic feature ( practically e "o ( ! electric railway sy/ems n[ 9 op]ation1 s9ce !y all use ! track = a return1 & ! track rails mu/ be securely bond$ 9 ord] to insure indisp5sable electrical cont9uity ( ! circuit4 ,9 addition to 8 signal sy/em1 !re=e1 ,dr4 ,rob9son is cle>ly entitl$ to ! cr$it ( hav+ made1 be=e ! inception ( electric railroad+1 a simple basic inv5tion 9 8 bond wire1 :i* has made mod]n electric railroad+ possible1 an inv5tion indisp5sable to ! successful op]ation ( electric railroad+ z practic$ today4 ,?is inv5tion has sav$ ! electric roads untold millions ( doll>s & enabl$ !m to accompli% results 9 a simple mann] :i* c\ld n o!rwise be z well secur$ at any co/1 by ! only alt]native me?od1 ( runn+ return contact conductors 9 ! air4 ,,william ,,rob9son4 ,illu/ration3 ,,william ,,rob9son1 ,,ph4,d42 ,e4 ,m4,e4 ,orig9al inv5tor & pat5tee ( ! ,automatic ,electric ,signal ,sy/ems n[ 9 use on ! lead+ railroads 9 ! ,unit$ ,/ates & ,=eign ,c\ntries4 ,,dr4 ,,rob9son',s ,,record ,,f ,,wesleyan ,,univ]sity ,william ,rob9son1 ,b4,a41 #ahfe2 ,m4,a41 #ahfh1 ,alpha ,delta ,phi4 ,ph4,d4 ,bo/on ,univ]sity1 #aijg4 ,born ,novemb] #bb1 #ahdj1 9 ,irel&4 ,pr9cipal ( ,high ,s*ool1 ,ansonia1 ,conn41 #ahfe-ff4 ,9 ! oil region1 ,p5nsylvania1 #ahff4 ,taught 9 ,/am=d1 ,conn41 #ahfg4 ,pr9cipal ( ,spr+ ,valley ,academy1 ,n4,y41 #ahfg-fi4 ,engag$ 9 ! oil bus9ess 9 ,p5nsylvania1 #ahfi-gb4 ,presid5t & ,g5]al ,manag] ( ! ,rob9son ,electric ,railway ,signal ,company1 #ahgc4 ,engag$ 9 bus9ess 9 ,bo/on1 ,mass41 #ahge-ha4 ,organiz$ ! ,union ,electric ,signal ,company1 #ahgh4 ,travel$ 9 ,europe1 ,egypt & ,pale/9e = fifte5 mon?s1 #ahgi-hj4 ,inv5tor ( ! ,rob9son wireless electric railway signal sy/em1 ( ! ,rob9son radial c> truck1 ( ! coa/] brake us$ on bicycles1 ( roll] be>+ skates1 & ( a repeat+ telephone4 ,engag$ 9 develop+ & practis+ electric eng9e]+4 ,au?or3 ,hi/ory ( ,automatic ,electric & ,electrically ,controll$ ,fluid ,pressure ,signal ,sy/ems = ,railroads4 ,di$ ,janu>y #b1 #aiba1 ,brooklyn1 ,new ,york4 ,a4,i4,e4,e4 ,,record ,,( ,,dr4 ,,william ,,rob9son ,copy ( ,dr4 ,rob9son's record made f orig9al application ,no4 #abfe to ! ,am]ican ,in/itute ( ,electrical ,eng9e]s1 #cc ,we/ #ci? ,/reet1 ,new ,york ,city4 7,record fil$ ,july1 #aiji47 ,ref]5ces giv5 by ,dr4 ,rob9son3 ,william ,b4 ,pott]4 ,e4 ,w4 ,rice1 ,jr4 ,!odore ,/ebb9s1 ,dallas1 ,texas4 ,frank ,j4 ,sprague1 #afe ,broadway4 ,pr(4 ,*as4 ,a4 ,cross1 ,m4,i4,t4 ,pr(4 ,elihu ,?omson4 ,goss ,bryce1 ,me*4 ,eng41 #gf ,william ,/reet4 ,george ,l4 ,f[l]1 ,cons4 ,eng41 #ec ,broadway4 ,wm4 ,wallace ,:ite1 ,=eign ,pat5t ,solicitor & ,consul1 #cji ,broadway4 ,,william ,,rob9son 7,a4,m41 ,,ph4,d47 ,,electrical ,,& ,,me*anical ,,eng9e] ,born ,novemb] #bb1 #ahdj1 ,nor? ( ,irel&1 ( ,scot*-,iri% desc5t on pat]nal side & ,engli% on mat]nal side4 ,,eligible ,,= ,,transf]3 ,"u clauses 7a7 & 7c74 ,,education3 ,graduate ( ,wesleyan ,univ]sity1 full ,academic c\rse1 receiv+ ! degrees ( ,a4,b4 9 #ahfe & ,a4,m4 9 #ahfh4 ,po/-,graduate ( ,bo/on ,univ]sity 9 #aijg1 ) degree ( ,doctor ( ,philosophy2 c\rse includ+ ,electrical & ,me*anical ,eng9e]+4 ,,occupation ,,& ,,"w ,,done3 ,engag$ 9 develop+ & practis+ electrical eng9e]+ f prior to #ahgj up to ! pres5t "t 7#aiji74 ,orig9al inv5tor & pat5tee ( ! automatic electrical & electrically controll$ fluid pressure signal sy/ems = railroads n[ 9 univ]sal use on ! lead+ railroads 9 ! ,unit$ ,/ates & =eign c\ntries1 :]ev] & by :omsoev] in/all$1 ?r\gh\t ! _w4 #ahgj4 ,receiv$ f\r ,unit$ ,/ates pat5ts on ?is sy/em2 applications fil$ e>li]4 #ahgj4 ,exhibit$ an elaborate work+ model ( ! sy/em at ! ,am]ican ,in/itute 9 ,new ,york1 %[+ ! automatic signal sy/em 9 op]ation "u control ( pass+ c>s4 #ahga-b4 ,orig9al inv5tor & pat5tee ( ! clos$ track circuit sy/em ( signal+4 ,receiv$ basic ,unit$ ,/ates & ,fr5* pat5ts cov]+ same1 9 #ahgb4 ,applications fil$1 #ahga4 #ahgj-ga4 ,orig9al inv5tor & pat5tee ( ! automatic electro-pneumatic signal sy/ems = railroads 9 use = _m ye>s pa/4 ,receiv$ basic ,briti% pat5t cov]+ ?is sy/em 9 #ahga4 ,s f> z ,i h be5 able to asc]ta9 on c>eful inve/igation1 ?is pat5t appe>s to be ! fir/ ev] issu$ any:]e on ?is subject4 ,! foll[+ brief hi/orical exc]pt is tak5 f a ,unit$ ,/ates pat5t grant$ to me on ,octob] #bj1 #aijh1 ,no4 #ija1chc1 on an electric railway sy/em4 ,?is pat5t is "o ( a bun* ( eight tak5 out by me on ! same date1 on ! same subject4 ,! exc]pt relates to my "w 9 signal+4 ,! block signal sy/em h]e9 disclos$ is an embodim5t ( ! ,rob9son electro-pneumatic sy/em n[ 9 ext5sive op]ation on ! ,p5nsylvania railroad & _m o!r lead+ railroads 9 ?is & o!r c\ntries1 embody+ ! clos$ circuit rail sy/em = :i* a basic ,u4,s4 pat5t 0 grant$ to me on ,augu/ #bj1 #ahgb1 ,no4 #acj1ffa 7reissu$ ,july #g1 #ahgd71 ! electro-pneumatic signal sy/em disclos$ 9 my ,briti% pat5t ( ,augu/ #cj1 #ahga1 ,no4 #bbhj1 ! subject matt] ( bo? ( :i* pat5ts is disclos$ 9 my ,fr5* pat5t ( ,febru>y #bi1 #ahgb1 ,no4 #id1cic4 ,! electro-pneumatic signal sy/em disclos$ 9 ! above nam$ pat5ts is also disclos$ 9 my ,unit$ ,/ates pat5t dat$ ,novemb] #g1 #ahhb1 ,no4 #bfg1bei4 ,z above indicat$ ! block signal sy/em h]e9 describ$ comprises ! sy/em describ$ 9 my above nam$ pat5ts & n[ 9 g5]al use on lead+ /eam railroads1 b modifi$ & improv$ 9 a way adapt+ x = reliable & effici5t use 9 connection ) electric railroads ( ! sectional ?ird rail type4 ,! admission ( ! above brief hi/ory 9 ! above describ$1 & sub/antially 9 two o!r pat5ts ( ! same date1 is1 ( c\rse1 a complete v]ification ( its hi/orical accuracy by ! ,pat5t ,(fice4 #ahgb4 ,9 #ahgb ,i put ! clos$ track circuit sy/em ( signal+ 9 practical & successful op]ation at sev]al po9ts on diff]5t divisions ( ! ,philadelphia & ,erie railroad1 & on o!r roads4 #ahgb-gi4 ,9 #ahgb to '#gi ,i in/all$ ! clos$ circuit rail sy/em ( automatic signal+ on v>i\s railroads 9 ,p5nsylvania1 ,new ,engl& & else:]e4 ,i p]fect$ ! sy/em & put x 9 z p]fect & effici5t & durable op]ation at t "t z x is 9 today1 includ+ all its functions ( block1 swit*1 road-cross+1 ov]lapp+1 re> & front1 tell-tale & brok5 rail detector4 #ahgh4 ,organiz$ & own$ ! ,union ,electric ,signal ,company1 bas$ solely on my signal pat5ts1 at t "t n9e 9 numb]4 ,"s "t aft]w>ds ,george ,we/+h\se & 8 associates b\ght ! controll+ int]e/ 9 ! ,union ,electric ,signal ,company & reorganiz$ ! company "u ! "n ( ! ,union ,swit* & ,signal ,company4 ,?us1 ! automatic signal sy/em ( ! ,union ,swit* & ,signal ,co4 consi/s1 9 e ess5tial p>ticul>1 ( ! ,rob9son sy/em1 pure & simple4 ,x may be "h po9t$ out t all ! railway signal companies n[ 9 op]ation1 in/all+ automatic signals "u :atev] "n1 are us+ ! ,rob9son sy/em bodily1 & h be5 s9ce ! expiration ( ,rob9son's basic pat5ts4 ,!re is no o!r sy/em1 z a sy/em1 9 use4 ,,hi/ory3 ,sev]al ye>s ago ,i publi%$ a ,hi/ory ( ,automatic ,electric & ,electrically ,controll$ ,fluid ,pressure ,signal ,sy/ems = ,railroads1 ! only au!ntic hi/ory ev] publi%$ on ! subject4 ,?is 0 writt5 & publi%$ at ! in/ance ( eng9e]+ fri5ds1 9 ! int]e/ ( indisputable hi/orical accuracy4 ,telephone ,exp]im5ts #ahgf4 ,z a matt] ( m or less int]e/ ,i may "h /ate t ,i c>ri$ on a conv]sation by telephone1 9 #ahgf1 ?r\gh a railroad track1 ! circuit consi/+ ( ! two rail l9es con/itut+ a clos$ circuit signal block4 #ahgg-h4 ,deliv]$ num]\s illu/rat$ lectures on ! telephone1 & at ?is "t discov]$ ! pr9ciple ( ! wireless telephone & actually transmitt$ spee* cle>ly back & =? across an op5 space ( sev]al in*es to & f a telephone hav+ b "o t]m9al gr\nd$ & ! o!r free 9 ! air4 ,! free1 un9sulat$ wire 7except at supports7 ext5d$ sev]al hundr$ feet ?r\gh ! air4 ,! in/rum5ts us$ 7 l>ge magneto telephones ( my own special design+1 & made by me = ! special purpose ( illu/rat+ lectures4 ,no batt]y 0 us$4 ,electric ,railway ,sy/ems ,outside ( automatic signal+ ,i h done consid]able "w along orig9al electrical l9es4 ,9 addition to o!r "w ( importance ,i h = m ?an fifte5 ye>s devot$ mu* "t to develop+ a radically new dep>ture 9 electric railroad+4 ,on ?is sy/em ,i h appli$ = m ?an tw5ty pat5ts1 ext5d+ ov] a s]ies ( ye>s1 f\rte5 ( :i* pat5ts h already be5 issu$4 ,:at ,?is ,sy/em ,accompli%es #a4 ,! ?ird rail or contact conductor is made 9 sections or blocks ( any desir$ l5g?1 :i* sections are normally dead b become automatically alive :5 a tra9 ent]s !reupon1 & dead :5 ! tra9 leaves ! section4 #b4 ,:5 a tra9 ent]s ^u a section or block x prev5ts ! section back ( x f receiv+ work+ curr5t4 ,?us any numb] ( tra9s foll[+ ea* o!r w ea* be depriv$ ( work+ curr5t :5 ! l5g? ( a block back ( ! tra9 ahead ( x1 :e!r t tra9 be runn+ or /&+ /ill1 ?us prev5t+ collisions4 #c4 ,a tra9 approa*+ a swit* or drawbridge is automatically arre/$ ! l5g? ( a block away f ! block conta9+ ! swit* or draw be=e a bolt c be )drawn or a lock releas$ 9 ! latt]4 #d4 ,no possibility ( int]f]5ce betwe5 a possible w&]+ propulsion curr5t & ! functions ( any o!r curr5t4 #e4 ,all curr5ts us$ may be ( ! same or h any comb9ation ( diff]5t *>act]i/ics4 ,! sy/em is elaborate1 provid+ = safety on & (f ! tra9s1 economy ( curr5t1 simplicity & c]ta9ty 9 action1 disp5ses l>gely ) electrolytic action1 & :5 alt]nat+ propulsion curr5t is us$ ! return is conf9$ to ! l5g? ( ! block4 ,x is believ$ t ! sy/em w prev5t all dang] to pass5g]s & tra9s f ! direct action ( ! propulsion curr5t4 ,presid5t ,roosevelt call$ ! att5tion ( ! ,int]/ate ,comm]ce ,commission to my electrical & me*anical inv5tions = mak+ railroad+ safe4 ,me*anical ,eng9e]+ ,i h done consid]able orig9al "w 9 me*anical eng9e]+4 ,9 ?is connection ,i may m5tion ! well kn[n ,rob9son ,radial ,c> ,truck1 :i* is 9 q ext5sive op]ation on electric railways4 ,?is is ! only c> truck1 ,i believe1 ev] design$ & con/ruct$ on correct me*anical pr9ciples4 ,x is s con/ruct$ t e axle 9 ! c> or tra9 becomes exactly radial to any curve ar\nd :i* x passes1 all ! axles becom+ p>allel on /raight l9es only4 ,?is prev5ts we> & te> & gr9d+ & d]ailm5t on curves4 ,x also greatly economizes curr5t4 ,"o ( ^! radial c>s1 9 ,/4 ,l\is1 hav+ a #bh-;ft4 body1 exclusive ( plat=ms1 equipp$ ) a radial truck hav+ a #ae-;ft4 :eel-base & two motors1 /opp$ 9 ! middle ( a /reet corn] curve & />t$ ) ! same p[] z on a /raight l9e1 z %[n by c>eful te/s ) volt & ammet]s4 ,! te/ 0 made by (ficials ( ! company )\t my k at ! "t4 ,i believe ?is is ! com+ truck = electric locomotives4 7,i =w>d by same mail a catalogue ( ! ,rob9son ,radial ,c> ,truck1 fully illu/rat$1 = ! in=mation ( ! ,bo>d47 ,coa/] ,hub ,i am also ! inv5tor ( ! back p$al brak+ & coa/+ bicycle hub1 :i* has be5 9 g5]al use = _m ye>s4 ,my application = a basic pat5t cov]+ ?is hub has be5 p5d+ 9 ! ,pat5t ,(fice = twelve ye>s1 held back n9e ye>s by int]f]5ce litigation 9 ! ,pat5t ,(fice1 ow+ to an effete int]f]5ce sy/em :i* has no apology to (f] to ju/ify its exi/5ce4 ,turb9e ,eng9es ,9 turb9e eng9es ,i h made "s important improvem5ts4 ,9 "o ! eng9e is rev]sible by ! movem5t ( a s+le lev] 9 ei!r direction4 ,9 a second ! /eam is utiliz$ a second "t "u conditions d\bl+ ! orig9al effici5cy1 & balanc+ ! end ?ru/ p]fectly4 ,9 a ?ird improvem5t ! eng9e develops m ?an ?ree times z mu* p[] z any o!r turb9e ( its class occupy+ ! same floor space4 ,pat5ts all[$ b n yet issu$4 ,i figure t ocean /eam]s %\ld furni% a l>ge field = ^! ma*9es4 ,respectfully submitt$1 7,sign$7 ,,william ,,rob9son4 #bgf ,/uyvesant ,ave41 ,brooklyn1 ,n4,y4 ,"p ,,ii ,,william ,,a%bridge ,,baldw9 ,! progressive ideas ( ,william ,a%bridge ,baldw9 7 responsible = ! fir/ te/s ( ! clos$ track circuit "u actual op]at+ conditions4 ,x 0 ?r\gh 8 confid5ce 9 ?is inv5tion ( ,dr4 ,william ,rob9son t ! possibilities ( ! application ( ! clos$ track circuit to ! safety ( tra9 op]ation 0 prov$4 ,mr4 ,baldw91 at ! "t ! fir/ signal in/allations 7 made at ,k9zua1 ,pa41 & ,irv9eton1 0 g5]al sup]9t5d5t ( ! ,philadelphia & ,erie1 n[ "p ( ! ,nor!rn ,gr& division1 ,c5tral region1 ,p5nsylvania ,sy/em1 & because he made possible ! developm5t ( signal+ to its pres5t /&>d by 8 int]e/ & active co-op]ation 9 ! #gj's 9 mak+ tra9 movem5ts saf]1 x is b fitt+ t he %\ld be giv5 a place 9 ! memorial to ,dr4 ,william ,rob9son4 ,illu/ration3 ,tracks & ,location ( ,electric ,signals ,dr4 ,rob9son's ,pat5t ,k9zua ,pa4 #ahgb-ahgc4 ,illu/ration3 ,tracks & ,location ( ,electric ,signals ,dr4 ,rob9son's ,pat5t ,irv9eton #ahgb-ahgc4 ,be=e /at+ ,mr4 ,baldw9's railroad activities x w be well to describe briefly ! way 9 :i* he became int]e/$ 9 ,dr4 ,rob9son & 8 "w4 ,dr4 ,rob9son %ortly aft] be+ graduat$ f college began "w on a signal sy/em to prev5t tra9 accid5ts :i* 7 ( num]\s occurr5ce1 & made a model ( 8 op5 wire sy/em :i* 0 exhibit$ at ! fair held by ! ,am]ican ,in/itute ( ,electrical ,eng9e]s 9 ,new ,york 9 #ahgj4 ,at ! close ( ! fair1 he s5t out circul>s to (fic]s ( v>i\s railroad companies expla9+ 8 sy/em4 ,! "o receiv$ by ,mr4 ,baldw9 int]e/$ him to su* an ext5t t he arrang$ = ,dr4 ,rob9son to make an in/allation at ,k9zua1 ,pa41 9 #ahgj4 ,?is in/allation 0 ( ! normally op5 wire circuit controll$ by track lev]s4 ,aft] ! in/allation1 ,dr4 ,rob9son see+ t x _h _m s]i\s defects began /udy+ h[ to correct !m4 ,?is 0 accompli%$ by ! inv5tion ( ! clos$ track circuit4 ,he !n exhibit$ 8 clos$ track circuit sy/em ( signal+ at ! ,/ate ,fair held at ,erie1 ,pa41 9 #ahgb1 :]e he _h 8 track circuits op]at+ "u wat] 9 a long tank4 ,dr4 ,rob9son _h previ\sly expla9$ ! pr9ciples ( ! clos$ track circuit to ,mr4 ,baldw9 :o reque/$ him to make su* an in/allation at ,k9zua1 ,pa41 9 place ( ! op5 wire circuit4 ,aft] ?is 0 9 s]vice1 ,mr4 ,baldw9 ord]$ ano!r in/allation to be made at ,irv9eton1 ,pa41 & because ( ! good s]vice r5d]$1 ?is signal soon came to be call$ ! ,old ,reliable by ! locomotive eng9em54 7,a picture ( ?is signal appe>s 9 ,"p ,i47 ,old ,employees ,describe ,fir/ ,in/allations ,?r\gh ! c\rtesy ( ,a4 ,j4 ,:itney1 g5]al sup]9t5d5t1 ,nor!rn ,gr& division1 ,c5tral region1 ,p5nsylvania ,sy/em1 & ,a4 ,h4 ,rudd1 *ief signal eng9e] ( ! ,p5nsylvania ,sy/em1 ! foll[+ in=mation 0 develop$ f int]views ) ,wm4 ,metzg]1 #hh ye>s old1 ( ,irv9eton1 ,pa41 once an eng9e] on ! ,philadelphia ,erie2 ,associate ,judge ,j4 ,w4 ,hughes1 ( ,w>r51 ,pa41 =m]ly y>d ma/] at ,irv9eton2 ,john ,*ri/ie1 c> inspector at ,irv9eton1 & ,j4 ,c4 ,curtis1 =m]ly a tra9 dispat*] on ! ,r5ovo division4 ,ab\t #ahgb1 ,dr4 ,rob9son1 :o probably came f ,altoona1 erect$ a signal gov]n+ we/w>d movem5ts1 ne> ,irv9eton4 ,?is signal 0 locat$ j we/ ( ,irv9e ,run bridge1 on ! nor? side ( ! ma9 track 7?is track is n[ an ea/w>d track71 9 a small frame build+ adjac5t to ! track & 0 electrically op]at$ back ( a circul> op5+ ab\t two feet 9 diamet]1 by display ( a r$ flag dur+ ! day & a light 9 ! re> ( ! flag by night4 ,a bell 0 also locat$ 9 ! signal %anty & ano!r bell 9 ! telegraph (fice ( ! /ation1 locat$ at ! junction ( ! two railroads 7see sket*74 ,a trip device1 op]at$ by ! :eel flange1 =c$ contact ) wires c>ri$ on ! telegraph poles & op]at$ ! signal & bell 9 ! signal %anty z well z bell 9 ! telegraph (fice4 ,! signal 0 kn[n z ! ,old ,reliable & ! words ,dr4 ,rob9son's ,pat5t 7 pa9t$ ar\nd ! circul> op5+4 ,ano!r pair ( signals 0 in/all$ by ,dr4 ,rob9son at ,k9zua1 n[ ,ludl[1 = protection ( tra9s /opp+ at ,k9zua 7,ludl[7 /ation4 ,^! signals 7 op]at$ by ov]head wires z at ,irv9eton4 ,:5 a tra9 0 opposite "o ( ! signals1 x set bo? signals to r$ indication by op]at+ a r$ flag )9 a circul> op5+ 9 ! daytime & a light 9 ! re> ( ! flag at night4 ,a l\d gong 0 also in/all$ 9 ea* %anty :i* rang co9cid5t ) ! signal go+ to ! r$ indication4 ,:5 ! re> ( ! tra9 pass$ ! signal 9 advance bo? signals return$ to cle> & ! bells /opp$ r++4 ,?is sy/em 0 op]at$ ) batt]ies & 0 remov$ 9 less ?an a ye> on acc\nt ( ! difficulty ( ma9ta9+ ! batt]ies4 ,biographical ,sket* ( ,w4 ,a4 ,baldw9 ,! biographical sket* ( ,mr4 ,baldw91 z giv5 bel[ is tak5 f ! ,biographical ,directory ( ! ,railway ,(ficials ( ,am]ica--,edition ( #aijf4 ,,baldw91 ,,william ,,a%bridge1 presid5t1 ,clevel& ,m>ietta ,ry4 ,(fice1 ,pittsburgh1 ,pa4 ,born ,june #bh1 #ahce1 at ,philadelphia1 ,pa4 ,ent]$ railway s]vice ,novemb]1 #ahea1 z *a9man1 eng9e] corps1 ,coal ,run ,road1 9 ,s*uylkill c\nty1 ,p5nsylvania1 s9ce :i* he has be5 consecutively1 ,m>*1 #aheb to #ahed1 assi/ant eng9e] on ! same road2 #ahed to ,m>*1 #aheg1 level] & topograph]1 ,lackawanna ,bloomsburg ,road2 ,m>*1 #aheg1 to ,decemb]1 #aheh1 assi/ant eng9e]1 level] & topograph]1 ,honduras ,int]-,oceanic ,road1 at ,honduras1 ,c5tral ,am]ica2 ,decemb]1 #aheh1 to ,novemb]1 #ahei1 cl]k to sup]9t5d5t1 ,we/]n division1 ,p5nsylvania2 ,janu>y1 #ahfj1 to ,febru>y1 #ahfb1 assi/ant eng9e]1 ,p5nsylvania2 ,febru>y #g1 #ahfb1 to ,m>* #ac1 #ahfh1 sup]9t5d5t1 ,we/]n division1 ,philadelphia ,erie 7,p5nsylvania1 lessee72 ,m>* #ac1 #ahfh1 to ,may #g1 #ahgj1 assi/ant g5]al sup]9t5d5t1 same road2 ,may #g1 #ahgj1 to ,octob] #a1 #ahgc1 g5]al sup]9t5d5t1 ,philadelphia ,erie division1 ,p5nsylvania2 ,octob] #a1 #ahgc1 to ,septemb] #a1 #ahha1 g5]al sup]9t5d5t1 same division1 same road1 & ,s4 ,s4 divisions1 ,nor!rn ,c5tral ,ry42 ,septemb] #a1 #ahha1 to ,may #a1 #ahhb1 manag]1 ,p5nsylvania ,co41 & ,pittsburgh1 ,c9c9nati ,/4 ,l\is ,railway ,l9es2 ,may #a1 #ahhb1 to ,m>* #ca1 #ahhh1 manag]1 ,p5nsylvania ,co4's l9es2 ,april #a1 #ahhh1 to ,april1 #ahib1 vice-presid5t & g5]al manag]1 ,buffalo1 ,ro*e/] ,pittsburgh2 ,novemb]1 #ahic1 to date1 presid5t1 ,clevel& ,m>ietta ,ry42 ,novemb]1 #ahic1 to ,decemb] #ca1 #ahii1 also g5]al manag] same road4 ,retir$ f t road on ,april #cj1 #aijf1 at ! age ( #gj ye>s1 "u ! p5sion rules ( ! ,p5nsylvania ,l9es ,we/ ( ,pittsburgh1 ( :i* ! ,clevel& ,m>ietta 0 a "p4 ,mr4 ,baldw9 di$ on ,febru>y #ag1 #aiaa1 at ,sewickley1 ,pa41 at ! age ( #ge4 ,8 obitu>y1 z appe>+ 9 ! ,railway ,age = ,febru>y #bd1 #aiaa1 appe>s bel[4 ,,william ,,a%bridge ,,baldw91 =m] presid5t ( ! ,clevel& ,m>ietta1 :i* is n[ a "p ( ! ,p5nsylvania ,sy/em1 di$ 9 ,sewickley1 ,pa41 ,febru>y #ag4 ,mr4 ,baldw9 0 born on ,june #bh1 #ahce1 at ,philadelphia1 & began railway "w 9 ,novemb]1 #ahea1 ) a p>ty ( eng9e]s mak+ surveys 9 ,s*uylkill ,c\nty1 ,pa4 ,9 ,m>*1 #aheg1 he w5t to ,honduras1 ,c5tral ,am]ica1 z assi/ant eng9e]1 level] & topograph] on ! ,honduras ,int]-,oceanic ,railway4 ,9 ,decemb] ( ! foll[+ ye> he return$ to ?is c\ntry & ent]$ ! employ ( ! ,p5nsylvania ,railroad4 ,9 #ahfb he 0 appo9t$ sup]9t5d5t ( ! ,we/]n division ( ! ,philadelphia ,erie4 ,by ,may1 #ahgj1 he _h become g5]al sup]9t5d5t ( ! ,philadelphia ,erie division1 & 9 ,septemb]1 #ahha he 0 appo9t$ manag] ( ! ,p5nsylvania ,l9es ,we/ ( ,pittsburgh4 ,9 #ahhh he w5t to ,buffalo1 ,ro*e/] ,pittsburgh z vice-presid5t & g5]al manag]1 b five ye>s lat] he return$ to ! ,p5nsylvania ,sy/em & 0 made presid5t ( ! ,clevel& ,m>ietta4 ,"p ,,iii ,,! ,,track ,,circuit ,p]haps no s+le inv5tion 9 ! hi/ory ( ! developm5t ( railway transportation has contribut$ m t[>ds safety & despat* 9 t field ?an ! track circuit4 ,by ?is inv5tion1 simple 9 itself1 ! f\ndation 0 obta9$ = ! developm5t ( practically e "o ( ! intricate sy/ems ( railway block signal+ 9 use today :]e9 ! tra9 is1 "u all conditions1 cont9u\sly active 9 ma9ta9+ its own protection4 ,9 o!r words1 ! track circuit is today ! only m$ium recogniz$ z fundam5tally safe by exp]ts 9 railway signal+ :]eby a tra9 or any "p !re( may reta9 cont9u\s & direct control ( a block signal :ile occupy+ any portion ( ! track gu>d$ by ! signal4 ,to ,mr4 ,william ,rob9son ! ,pat5t ,(fice records conc$e ! honor ( hav+ devis$ ! fir/ practical track or ',rail circuit'4 ,?is compris$ :at is t]m$ ! clos$ track circuit4 99 99 99 ,clos$ track circuits are v reliable1 :olly safe 9 pr9ciple1 & simple ( application & ma9t5ance4 ,! above p>agraphs1 quot$ f ! ?ird annual report ( ! ,block ,signal & ,tra9 ,control ,bo>d to ! ,int]/ate ,comm]ce ,commission "u date ( ,novemb] #bb1 #aiaj1 ably express 9 a few words :at ! inv5tion ( ! track circuit has meant to ! railroads ( ?is & o!r c\ntries4 ,9 ord]1 h[ev]1 t ^? :o are n famili> ) ! pr9ciples ( ! track circuit may h "s g5]al k ( !m1 a simple1 non-te*nical description is giv51 z prep>$ "s ye>s ago by ,mr4 ,j4 ,p4 ,coleman1 ( ! ,union ,swit* ,signal ,company4 ,hi/orical in=mation on ! developm5t & use ( direct curr5t & alt]nat+ curr5t track circuits = roads us+ electricity = propulsion purposes & ^? us+ /eam w be f\nd 9 a report on ?is subject made by ,committee ,x to ! ,railway ,signal ,association 9 #aiaj4 ,! ,rail ,circuit ,pr9ciple ,by ,j4 ,p4 ,coleman4 ,assum+ t x is cle>ly und]/ood t ! curr5t is g5]at$ at ! batt]y2 t x fl[s f !nce ?r\gh ! conductors 7( :i* ! coils ( ! magnet =m "p7 & back aga9 to ! batt]y1 & t ! magnet is simply a device int]pos$ 9 ! circuit = ! purpose ( trans=m+ electrical en]gy into me*anical 7magnetic7 en]gy1 & t ! latt] c exi/ 9 an electro-magnet only ) ! pres5ce ( ! =m]1 we are n[ prep>$ to make cle> ! pr9ciple ( an electric track section4 ,to assi/ 9 ?is1 let u /ate an inv>iable law gov]n+ ! fl[ ( curr5ts3 ,if two or m pa?s be pres5t$ an electric curr5t1 x imm$iately becomes divid$1 & fl[s 9 ea* 9 quantities directly 9 proportion to ! conductivity ( ea*4 ,! unit ( electrical resi/ance1 :]eby ! comp>ative m]its ( v>i\s mat]ials & sizes ( mat]ials z conductors are designat$1 is call$ an ohm1 7j z ! unit ( l9eal measurem5t :]eby ! comp>ative l5g?s & sizes ( v>i\s objects are designat$1 is t]m$ a foot7 & we w !re=e use t t]m 9 ref]5ce to ! resi/ance ( a conductor4 ,illu/ration3 ,fig4 #a ,figure #a repres5ts an ord9>y gravity batt]y1 ! conductors f x1 & ! electro-magnet to :i* !y connect2 also ! armature z attract$ by ! magnet & ov]com+ ! spr+ :i* t5ds to )draw x f ! magnet4 ,n[1 z long z ! curr5t fl[s ?r\gh ! magnet1 ?is condition ( ?+s rema9s unalt]$2 b let a second pa? be pres5t$ to ! curr5t sev]al hundr$ times less 9 resi/ance ?an ! orig9al "o1 & ! result is t sev]al hundr$ p>ts ( ! curr5t w leave ! magnet = ! %ort circuit1 & consequ5tly leave s little rema9+ 9 ! orig9al "o t ! effect w be practically to demagnetize ! magnets4 ,illu/ration3 ,fig4 #b ,figure #b w r5d] ?is v app>5t if we w assume ! wire ( ! magnet ,r to possess a resi/ance ( #aj ohms1 & ! conductors !mselves a resi/ance s l[ z to be inappreciable & unwor?y ( consid]ation4 ,illu/ration3 ,fig4 #c ,illu/ration3 ,fig4 #d ,n[1 assume ! curr5t to be fl[+ & ! magnet to be *>g$1 & let u take a piece ( metal :i* has an electrical resi/ance ( #a_/ajj ( an ohm1 & lay x across ! conductors at any po9t betwe5 ! batt]y & ! magnet4 ,! result is1 t in/ead ( fl[+ ?r\gh #aj ohms resi/ance via ! magnet1 x foll[s ! inv>iable rule1 & takes t (f]+ b #a_/ajj ( an ohm2 or1 m to ! po9t1 if we assume ! conductors ref]r$ to to be "o mile ( /eel rails ea* 7,fig4 #c71 & aga9 leave _! resi/ance 7:i* w\ld be ab\t "o ohm ea*7 out ( consid]ation entirely1 leav+ t ( ! magnet z fir/ /at$1 & assume ! b> ( #a_/ajj ( an ohm to be an axle & pair ( :eels 7a7 ( a tra9 7,fig4 #d71 :i* possess ! same resi/ance1 we c readily see t ! result w\ld be exactly ! same1 i4e41 in/ead ( all ! curr5t pass+ ?r\gh ! magnets1 z :5 ! rails 7 unoccupi$1 ! pres5ce ( ! :eels ^u !m w\ld cause #iii_/ajjj ( ! curr5t to leave ! magnet & pass ?r\gh !m2 !y (f]+ b #iii_/ajjj ( ! resi/ance ( ! magnets1 & ?us leav+ b #a_/ajjj ( ! :ole curr5t pass+ ?r\gh !m1 :i* be+ s small a "p ( s feeble a curr5t is imp]ceptible & )\t suffici5t influ5ce to hold ! magnet *>g$4 ,!re=e1 x foll[s t ! in/ant t a pair ( :eels ent]s ^u a pair ( rails :i* ?us =m "p ( ! conductors ( an electrical curr5t hold+ *>g$ a magnet1 t magnet becomes practically demagnetiz$1 & consequ5tly loses all p[] to ov]come any oppos+ =ce 9 its armature4 ,:5 ! armature ( a magnet is arrang$ ^u a small lev]1 by motion ( :i* a second circuit is clos$ or op5$1 or two or m circuits are o!rwise controll$1 ! entire device is t]m$ a relay4 ,9 all =ms ( ?is in/rum5t1 z is ! case ) almo/ e o!r electrical in/rum5t1 ! armature is s arrang$ z to fall by gravity1 or by t5sion ( a small spr+ suitably arrang$1 away f ! cores ( ! magnets :5 !y become demagnetiz$4 ,illu/ration3 ,fig4 #e ,:5 swit*es are includ$ 9 a track section 7,fig4 #e71 x becomes necess>y = safety to h !m control ! track section 9 su* a way t unless !y are prop]ly set 7& lock$1 if desir$7 = ! ma9 track1 ! cont9uity ( ! rail circuit is int]rupt$ & ! signal is !reby held at dang]4 ,to r5d] m c]ta9 ?is result1 ! circuit controll] 7swit* box7 at ! swit* is arrang$ 9 su* a way t ! track circuit is n only int]rupt$ beyond ! swit*1 b is also %ort-circuit$ by x :5 ! swit* is n prop]ly set4 ,x is also necess>y = safety t ! side track f ! swit* po9ts back to ! f\l+ po9t 7,fig4 #e7 be includ$ 9 ! track section3 ?us insur+ t all tra9s on ^! tracks are out ( dang] ( collision ) ! ma9 track :5 a cle> signal is display$ on x4 ,9 divid+ tracks into di/9ct electrical sections1 x becomes necess>y to insulate ! rail ends at ! t]m9al ( ea*1 f ^? ( ! adjac5t sections4 ,if ?is 7 n done ! curr5t ( ea* section w\ld trav]se ! next1 & cont9ue on indef9itely1 influ5c+ ea* o!r s z to int]f]e ) or totally prev5t ! op]ation ( all4 ,9 ord] t we may fully compreh5d ! nature ( an insulation1 let u make cle> a few facts conc]n+ conductors 9 g5]al4 ,all mat]ials conduct electricity to a c]ta9 ext5t2 b "s ) mu* m fre$om ?an o!rs4 ,?us1 silv]1 copp]1 gold1 z9c1 plat9um1 iron1 /eel1 m]cury1 & o!r pure metals p]mit ! passage ( an electric curr5t ?r\gh !m ) b slight resi/ance1 7al?\gh all (f] a c]ta9 am\nt17 & are !re=e t]m$ conductors4 ,! foll[+ liquids are class$ z conductors3 conc5trat$ & dilut$ acids1 sal9e liquids & wat]1 al?\gh !y are mu* less effici5t z su* ?an ! metals4 ,to ?is li/ might be add$ ! e>? itself & ! v>i\s +r$i5ts =m+ x1 ! nature ( :i* +r$i5ts det]m9es v mu* its effici5cy z a conductor4 ,?us at po9ts ab\nd+ 9 m9]al deposits ! e>? w\ld be f> sup]ior z a conductor to ^? p>ts 9 :i* none exi/1 b at be/ %\ld be reg>d$ z a poor conductor4 ,next comes a class ( mat]ials :i* (f] a great resi/ance to ! curr5t1 & :i* f t reason are t]m$ non-conductors1 or insulators2 ( ?is class1 rubb]1 glass1 lea!r1 res91 wood1 brim/one & dry air are ! mo/ common4 ,wood be+ a non-conductor1 x is v evid5t t ! cross-ties "u ! /eel rails =m an insulation betwe5 !m & ! gr\nd2 also1 t if a piece ( ! same or simil> mat]ial be plac$ betwe5 ! rail ends1 & t if two o!r pieces ( suffici5t /r5g? be sub/itut$ = ! iron fi%-plates at t po9t1 a secure insulation w be =m$ betwe5 ! rails4 ,x is precisely 9 ?is way t ! insulation ( "o rail f ano!r is effect$ 7,fig4 #f7 & ! long1 practical use ( _m hundr$ jo9ts ( ?is sort1 has prov$ x to be a me?od bo? economical & ?or\ghly effici5t4 ,illu/ration3 ,fig4 #f ,a mu* m secure jo9t1 h[ev]1 is obta9$ by insulat+ ! exi/+ iron fi%-plates f ! rails by means ( heavy fib] plates1 & _! bolts f ! rails by fib] bu%+s 7,fig4 #g74 ,:ile ?is me?od is sup]ior to ! fir/ m5tion$ "o 9 t x makes a m secure rail jo9t1 x is no m effici5t z an insulation4 ,illu/ration3 ,fig4 #g ,"o w\ld naturally suppose t ow+ to ! l>ge surface ( contact exi/+ betwe5 ! rails & _! connect+ or fi%-plates1 & f ! app>5t security ( t contact obta9$ by ! bolts ?r\gh !m1 no tr\ble w\ld be exp]i5c$ by ! curr5t 9 pass+ f "o rail to ! o!r4 ,?is1 h[ev]1 is n ! case1 z ! bolts & ev5 ! plates !mselves frequ5tly become loose1 ev5 :5 provid$ ) ! be/ ( nut locks1 & ! ru/ & dirt settl+ betwe5 !m & ! rails (t5times increase ! resi/ance ( a track section to a s]i\s ext5t4 ,aga91 ev5 :5 tightly bolt$ & lock$1 ^! plates =m b an imp]fect contact1 ow+ to ! scale or ru/ ^u !m4 ,!re=e1 to insure t ! resi/ance ( a track section may be z l[ & z con/ant z possible1 we h f\nd x absolutely necess>y to connect ea* two adjac5t rail ends toge!r by means ( a %ort piece ( v /rong wire 7,fig4 #h74 ,illu/ration3 ,fig4 #h ,^! wires are t]m$ track wires 7bond wires7 & are provid$ ) a button-head rivet at ea* end1 :i* is securely sold]$ !reto1 = ! purpose ( secur+ !m to ! rails4 7,bond wires are n[ atta*$ to ! rails by *annel p9s or are weld$ on47 ,! connections f ! rails to ! batt]y & relay ( a track section are secur$ to ! rails 9 ! same mann]4 ,! batt]y is usually locat$ 9 a *ute or well sunk 9 ! gr\nd at ! t]m9al ( ea* section1 :i* is provid$ ) an elevator 9 :i* ! batt]y is plac$ & by :i* x may be rais$ & l[]$ at w4 ,all wires :5 plac$ und]gr\nd are run 9 groov$ lumb] 9 ord] t !y may be secure f injury4 ,ev5 9 v wet or sn[y wea!r a s+le j> ( gravity batt]y is g5]ally f\nd to furni% suffici5t curr5t to prop]ly "w ! relay at ! o!r end ( any section less ?an ?ree-qu>t]s ( a mile 9 l5g?2 al?\gh x frequ5tly happ5s on long] sections & occasionally on ^? ( ord9>y l5g? t two j>s are necess>y4 ,a great] numb] ( j>s is nev] advisable s9ce by increas+ ! int5sity ( ! curr5t1 ! liability ( its leak+ f "o rail to ! o!r dur+ wet wea!r is correspond+ly increas$1 & z ?is is att5d$ ) "s unc]ta9ty 9 ! work+ ( ! relay ( ! section--due to ! v>y+ int5sity ( ! curr5t--x %\ld be c>efully gu>d$ aga9/4 ,z two j>s ( gravity batt]y are n suffici5t to op]ate a signal1 lock1 bell or any simil> in/rum5t ) any degree ( c]ta9ty1 x becomes necess>y to h a second set ( batt]ies ( a great] numb] ( j>s = t purpose4 ,! armature ( ! magnet controll$ by ! track section is !re=e made to control a second circuit us+ a batt]y ( ?is sort 7,figs4 #c1 #d & #e7 & :i* includes ! magnet ( ! signal me*anism4 ,! use ( a relay on a track section is !re=e necess>y2 & :5 x becomes necess>y to control two or m devices1 ea* requir+ indep5d5t circuits1 by "o track1 ! use ( a relay is indisp5sable4 ,track ,circuit ,*>act]i/ics ,:ile ! fundam5tal pr9ciples ( ! track circuit are ! same today z !y 7 :5 x 0 orig9ally inv5t$ by ,dr4 ,rob9son 9 #ahgb1 x has be5 f\nd t x is n z simple a device z 0 =m]ly suppos$ to be ! case & _m problems h aris5 :i* h requir$ & is requir+ ! c>eful /udy ( ! signal eng9e]s4 ,accord+ly1 x is well to pres5t briefly "s ( ! track circuit *>act]i/ics z !y are kn[n today4 ,9 ! foll[+ pres5tation1 in=mation has be5 collect$ f _m diff]5t s\rces1 includ+ ab/racts f pap]s pres5t$ on ! track circuit by ,mr4 ,a4 ,r4 ,fug9a1 signal eng9e]1 & ,mr4 ,j4 ,b4 ,weigle1 signal inspector on ! ,l\isville ,na%ville4 ,!re are two g5]al classes ( track circuits1 direct curr5t & alt]nat+ curr5t1 :i* may be fur!r subdivid$ betwe5 s+le or d\ble rail circuits4 ,! ess5tial feature ( ! track circuit is ! insulation ( ea* section ( track f ! adjo9+ sections4 ,ea* rail 9 ! section is connect$ to ! "o adjo9+ by bond wires1 = ! purpose ( mak+ a cont9u\s conductor f "o end ( ! section to ! o!r4 ,rail ,bond+ ,"u ! pres5t me?ods ( bond+1 ! angle b> c>ries ! great] "p ( ! curr5t1 & bond wires frequ5tly c>ry z little z #bj p] c5t4 ( x & sometimes ev5 less4 ,! rail resi/ance is l[e/ ) new rails1 b x gradually gets high]1 due to ru/ & dirt =mations betwe5 ! angle b> & ! rail4 ,b ev5 ) new rail1 ! rail resi/ance v>ies greatly at diff]5t p]iods & ev5 at diff]5t times dur+ any tw5ty-f\r h\rs4 ,?is v>iation is entirely due to ! fact t ! angle b>s c>ry m ( ! curr5t ?an ! bond wires1 & t ! bond wires "u any condition are only l>ge en\gh to c>ry ! small] "p ( ! curr5t f ! batt]y4 ,! l[] ! resi/ance ( ! bonds ! less v>iable w be ! rail resi/ance4 ,! resi/ance ( ! angle b>s increases greatly z rail resi/ance increases1 z a result ( :i* ! angle b>s rapidly c>ry less ( ! curr5t4 ,x is n infrequ5t to f9d ! rail resi/ance to be z high z #j4bj ohms p] #a1jjj ft4 ( track1 & we h kn[n x to run z high z #j4bfd 9 new rail1 :]e especial att5tion _h be5 giv5 to obta9+ z good bond+ z possible4 ,"u su* conditions ! angle b> c>ries v little ( ! curr5t1 ! capacity ( ! bond is n suffici5t to c>ry ! curr5t1 & ! net result is a fail+ track circuit1 :i* is probably attribut$ to bad balla/1 z9c treat$ ties or o!r causes4 ,! pr9cipal defect 9 ! track circuit is t ( improp] bond+4 ,! only explanation z to :y ,no4 #h iron wires became /&>d = bond+ appe>s to be t ! bond wires 7 cut f ?is size iron telegraph wire :i* 0 9 g5]al use at ! "t rails began to be bond$4 ,x is important to obta9 bett] bond+ to obta9 a m9imum con/ant rail resi/ance4 ,x has be5 recomm5d$ t3 ,fir/--,! use ( galvaniz$ wire bonds %\ld be elim9at$4 ,second--,=ty p] c5t4 copp] clad bond wires %\ld be us$ z a tempor>y exp$i5t to replace galvaniz$ bond wires4 ,?ird--,except = !ft & cry/allization1 copp] bond wires w\ld be mu* m advisable4 ,f\r?--,l>g] bond wires %\ld be us$1 ^! bonds to be at lea/ equal 9 c>ry+ capacity to two #df-;94 ,no4 #f solid copp] or to two ,no4 #b1 #dj p] c5t4 copp] clad wires4 ,until rec5tly x has be5 ! g5]al op9ion ( all exp]ts on ! track circuit t ! rail resi/ance 0 r an unimportant factor & t1 z a g5]al rule1 ! *ange 9 rail resi/ance c\ld be disreg>d$ 9 mak+ track circuit inve/igations & calculations4 ,_m bad track circuit conditions h be5 laid to bad balla/ conditions1 z9c treat$ ties1 wet track1 etc41 :i*1 if c>efully analyz$1 w\ld h %[n ! tr\ble to be due to extremely high rail resi/ance4 ,^! faulty conclusions are be+ drawn ne>ly e day4 ,s+le rail track circuits1 s call$ f ! fact t b "o rail is insulat$1 are also us$4 ,in/allations ( ?is k9d are made to avoid ! exp5se ( two insulat$ jo9ts or :]e "o rail is ne$$ = ano!r circuit4 ,su* track circuits are m liable to failure ?an ^? hav+ bo? rails insulat$ = ! reason t ! break-d[n ( "o insulat$ jo9t w ext5d ! circuit beyond ! prop] limit & cause int]f]5ce ( neighbor+ circuits or ext5d$ %unt+ ( ! relay1 due to ! pres5ce ( a tra9 beyond ! insulat$ jo9t4 ,a track circuit may be made to p]=m two sep>ate functions 9 :i* ! direction or pol>ity z well z ! pres5ce ( curr5t is made use ( 9 ! relay1 provid$ ! fir/ or pr9cipal function actuat$ by ! pres5ce or abs5ce ( curr5t does n int]f]e ) ! second>y function1 actuat$ bo? by ! pres5ce ( curr5t & its pol>ity4 ,:]e swit*es occur 9 a track circuit1 special means mu/ be employ$ to prev5t %ort-circuit+ ?r\gh ! swit* rods & leakage ( curr5t to ! turn-out rail4 ,! usual me?od is ! use ( insulat$ swit* rods ) insulat$ jo9ts 9 ! leads ( ! turn\t & at ! f\l+ po9t ( ! turn\t4 ,! swit* po9ts are bond$ to ! /ock rails to insure %unt+ by a pair ( :eels on any "p ( ! track4 ,none ( ! me?ods employ$ 9 runn+ track circuits ?r\gh swit*es %[ any protection aga9/ an op5 swit*4 ,9 ord] to obta9 ?is protection a swit* in/rum5t or swit* box is us$4 ,?is consi/s ( a device ) electrical contacts1 ! :ole m\nt$ on a swit* timb] & connect$ to ! swit* po9t by means ( a rod s arrang$ t :5 a swit* slips op5 or is ?r[n op5 ! movem5t ( ! rod actuates contacts :i*1 on be+ clos$1 =m a clos$ pa? f "o rail to ! o!r ?r\gh wires connect+ ! rails to ! contacts1 ?us :5 ! contacts are clos$ by a swit* be+ op5$1 ! same effect is produc$ z if a tra9 0 on ! circuit1 %unt+ x out4 ,on electrically op]at$ roads :]e tracks are bond$ = ! return propulsion curr5t ) heavy copp] bonds1 no additional bond wires are necess>y4 ,! ,track ,batt]y ,! usual =m ( track circuit has a prim>y batt]y at "o end ( ! insulat$ track section1 ) ! positive t]m9al ( ! batt]y connect$ to "o rail & ! negative t]m9al to ! o!r1 :ile a relay at ! o!r end ( ! section is connect$ to ! rails 9 a simil> mann]4 ,curr5t fl[s f ! positive side ( ! batt]y ?r\gh ! "o rail1 ! relay & ! o!r rail back to ! batt]y1 ?us keep+ ! relay en]giz$4 ,= d4c4 track circuits1 f\r types ( cells h be5 us$ to a great] or less ext5t1 ! gravity cell2 ,lal&e 7soda7 cell2 /orage cell & dry cell4 ,! gravity cell has a voltage ( ab\t #j4h or #j4i volts1 ! resi/ance v>y+ ) ! mann] 9 :i* ! cell is ma9ta9$ & av]ag+ ab\t #c ohms4 ,x w rema9 active = long p]iods on clos$ circuits )\t appreciable pol>ization4 ,because ( ?is high int]nal resi/ance usually no ext]nal resi/ance is necess>y to be connect$ betwe5 x & ! rail ( ! track4 ,! e4m4f4 ( ! ,lal&e 7soda7 cell may v>y f ab\t #j4fg volts to #j4hh volts :ile ! int]nal resi/ance w range betwe5 #j4jai ohm to #j4d ohm4 ,because ( ! l[ int]nal resi/ance ( ^! cells x is necess>y to use an ext]nal resi/ance ( ! prop] value betwe5 ! cell & ! rail4 ,! /orage cell is made 9 v>i\s capacities & a fully *>g$ cell on op5 circuit has a voltage ( approximately #b4a volts :i*1 :5 plac$ on dis*>ge1 becomes approximately #b volts & drops to ab\t #a4h volts :5 completely dis*>g$4 ,! voltage 9 ?is type ( cell v>ies ) ! d5sity ( ! electrolyte & to a c]ta9 ext5t ) temp]ature4 ,x has practically a negligible int]nal resi/ance & x is also necess>y to use an ext]nal resi/ance 9 ! leads betwe5 ! cell & ! track to prev5t a fl[ ( excessive curr5t :5 a tra9 occupies ! track4 ,! dry cell is us$ only 9 em]g5cy cases or occasionally = op5 circuit track circuits ( #b or #c rail l5g?s1 :i* are sometimes us$ z annunciator />ts to ann\nce ! approa* ( a tra9 to a t[]-man4 ,x is design$ prim>ily = op5 circuit "w & w pol>ize :5 curr5t beyond a c]ta9 figure is drawn cont9u\sly f x4 ,! ,track ,relay ,! track relay is a developm5t ( ! in/rum5t ( ! same "n us$ 9 telegraph s]vice4 ,x consi/s ( an electro-magnet ( ! horse%oe type ) a pivot$ armature1 c>ry+ "o or m f+]s = mak+ or break+ electric circuits = ! control ( signal app>atus4 ,track relays ) resi/ances ( #b & #d ohms are usually employ$4 ,f exp]i5ce ) two-ohm relays on ! ,l4 ,n41 cov]+ a great _m ( !m on all k9ds ( circuits1 ! foll[+ conclusions are rea*$3 ,! two-ohm relay is m suitable = g5]al use on track circuits ?an ! f\r-ohm1 provid$ n less ?an ! ,r4,s4,a4 recomm5d$ limit+ resi/ance is us$ betwe5 ! batt]y & track4 ,! two-ohm relay w op]ate satisfactorily :]e ! f\r-ohm w n on bad track circuits1 & ) consid]ably less curr5t consumption4 ,! two-ohm relay w op]ate equally z well on good track circuits ( av]age l5g? z ! f\r-ohm1 !re be+ little diff]5ce 9 curr5t consumption on ?is class ( circuit4 ,"u ! same conditions long] track circuits may be op]at$ ) ! two-ohm relay4 ,! two-ohm relay is at lea/ z safe z ! f\r ohm4 ,x %\ld be ?or\ghly und]/ood t x is z important ) ! f\r-ohm relay z x is ) ! two-ohm relay to h n less ?an ! ,r4,s4,a4 recomm5d$ limit+ resi/ance betwe5 ! batt]y & track4 ,?is is important ) any k9d ( l[ int]nal resi/ance batt]y1 & "u c]ta9 conditions ) gravity batt]y also4 ,9 "o case assume a tra9 to be pass+ f ! relay end to ! batt]y end ( a track section & 9 ! o!r case f ! batt]y end to ! relay end4 ,! effect accompli%$ is ! same except t ! relay w n release s quickly :5 ! tra9 passes f ! batt]y end t[>ds ! relay end1 & ?is is 9 "p due to ! self-induction ( ! circuit ?r\gh ! relay coils1 ! rails & ! axles ( ! tra94 ,x is due m1 h[ev]1 to small curr5t leakage f ! adjac5t section & ! effects ( /ray curr5ts :i* are always pres5t to a great] or less degree4 ,a brok5 rail w also g5]ally op5 ! circuit & de-en]gize ! relay4 ,circuits = ! control ( ! v>i\s signal devices are brok5 ?r\gh ! contact po9ts ( ! track relay4 ,track ,circuit ,ma9t5ance ,cross ties h a relatively high resi/ance to ! passage ( electric curr5t1 b :5 a l>ge numb] connect ! rails _m multiple pa?s are introduc$ into ! circuit ?r\gh :i* ! curr5t may fl[ f "o rail to ! o!r1 &1 consid]+ !m z a :ole1 ! resi/ance !y (f] to ! passage ( ! curr5t rea*es a relatively l[ value4 ,consequ5tly !re is always a curr5t leakage f rail to rail ?r\gh ! cross ties & balla/4 ,e ef=t %\ld be made to secure & ma9ta9 ! be/ balla/ & dra9age possible on d4c4 z well z a4c4 track circuits4 ,c9d]s1 dirty s&1 s(t wat]-logg$ ties & balla/ n well clean$ away f ! base ( ! rail w produce track circuit tr\ble1 p>ticul>ly dur+ wet wea!r1 :ile good rock balla/1 s\nd ties & clean track give ! greate/ effici5cy4 ,! use ( ties fre%ly treat$ ) z9c *loride also r$uces ! balla/ resi/ance4 ,if too _m su* ties are us$ 9 a track circuit ! curr5t leakage betwe5 rails becomes s great t n en\gh curr5t rea*es ! relay to hold x clos$1 ! effect be+ ! same z if a tra9 is on ! track circuit %unt+ out ! relay4 ,= good results1 ! numb] ( z9c-treat$ ties in/all$ p] ye> 9 any track circuit %\ld n be great] ?an #ae p] c5t4 ( ! total numb] ( ties 9 t circuit4 ,track ,circuit ,tr\bles ,"s ( ! common track circuit ailm5ts are relay & track batt]y tr\bles1 defective track connections1 poor bond+ & brok5 rails1 %ort circuits or %unts1 excessive leakage & defective insulat$ jo9ts1 all ( :i* w cause ! signals to be set 9 ! dang] position1 :ile defective relays1 =eign curr5t & poor :eel contact may result 9 a false proce$ signal indication ) a tra9 9 ! block section4 ,x 0 ! q g5]al practice to op]ate bad track circuits by pil+ on gravity batt]y1 ei!r 9 multiple or multiple-s]ies arrangem5ts to obta9 op]at+ results )\t any reg>d to ! safety ( ! circuit &1 no d\bt1 _m false proce$ failures 7 caus$ !reby4 ,! effect ( temp]ature *anges on track circuit op]ation are ( consid]able importance4 ,! track relay1 :i* is g5]ally h\s$ 9 a ca/ or %eet iron box1 probably is affect$ m by *anges 9 temp]ature ?an any o!r "p ( ! track circuit4 ,! resi/ance ( a #b-ohm relay1 :i* is #b ohm at #gj degrees ,f41 w be #b4bb ohm at #abj degrees ,f41 & #a4fi ohm at #j degrees ,f41 a v>iation ( 4#ec ohm4 ,! pick up & release ( ! relay1 4#b & 4#a volt1 respectively1 at #gj degrees ,f41 w be 4#bb & 4#aa volt at #abj degrees ,f41 & 4#ag & 4#jhe volt at #j degrees ,f4 ,a relay1 ) a normal resi/ance ( #d ohm at #gj degrees ,f41 w be #d4de ohm at #abj degrees ,f4 & #c4ch ohm at #j degrees ,f41 a v>iation ( #a4jg ohm4 ,! pick up & release1 4#c & 4#ad volt1 respectively1 at #gj degrees ,f41 w be 4#cc & 4#af volt at #abj degrees ,f4 & 4#be & 4#ab volt at z]o4 ,! po9t :i* is int5d$ to be br\ght out by ^! figures is t :5 ! temp]ature ( ! relay increases1 a correspond+ly high] voltage is requir$ to pick up ! armature1 & :5 ! temp]ature decreases ! armature w hold up ) l[] voltage across ! coils4 ,?is indicates t a track relay is m liable to fail to release due to an imp]fect tra9 %unt 9 cold wea!r ?an at any o!r "t4 ,"s ( ! be/ prev5tatives t may be provid$ to gu>d aga9/ false proce$ signals due to track relays fail+ to release ) a tra9 9 ! circuit1 are3 #a4 ,use z mu* resi/ance z practicable betwe5 batt]y & track4 #b4 ,use l[ resi/ance bond wires1 & ma9ta9 bond+ 9 good %ape4 #c4 ,keep balla/ well cle>$ f contact ) rails4 #d4 ,ma9ta9 insulation 9 insulat$ track jo9ts 9 good condition4 ,aside f ^! simple rem$ies no def9ite rule c be giv5 to combat =eign curr5t4 ,if x is s tr\blesome t ^! me?ods d n ov]come x1 ! circuit affect$ mu/ be c>efully /udi$ to det]m9e ! s\rce ( ! =eign curr5t & its pa? to ! rails1 !n special means c usually be provid$ to ov]come x4 ,balla/ ,resi/ance & ,leakage ,! importance ( balla/ resi/ance has long be5 recogniz$1 & ?is always has be5 consid]$ ! great v>iable1 :]eas1 inve/igations %[ t ! balla/ resi/ance is at lea/ no m v>iable ?an ! rail resi/ance1 & t ( ! two x is m important to r$uce ! rail resi/ance to a m9imum1 & especially to e/abli% x z a con/ant4 ,:5 ! balla/ leakage problem 0 fir/ tak5 up 7on ! ,l4 ,n471 v>i\s k9ds ( balla/ 7 measur$ 9 bo? wet & dry wea!r1 ! int5tion be+ to det]m9e ! l[e/ possible resi/ance p] #ajjj ft4 = ea* k9d ( balla/4 ,x 0 propos$ 9 ?is way to e/abli% a /&>d m9imum resi/ance p] #ajjj ft4 = ea* k9d ( balla/4 ,= in/ance1 if a numb] ( measurem5ts 9 wet wea!r %[$ #h ohms p] #ajjj ft4 z a m9imum = track circuits ) cru%$ rock balla/1 x 0 ! int5tion to adopt #h ohms z ! /&>d m9imum balla/ resi/ance p] #ajjj ft4 = all track circuits :]e cru%$ rock balla/ 0 9 use4 ,if a numb] ( wet wea!r measurem5ts %[$ #d ohms p] #ajjj ft4 z a m9imum = c9d] balla/1 x 0 ! int5tion to adopt #d ohms z ! /&>d m9imum balla/ resi/ance p] #ajjj ft4 = all track circuits :]e c9d] balla/ 0 us$4 ,x 0 ! int5tion to foll[ out ! same process & e/abli% a /&>d = all k9ds ( balla/ 9 use4 ,?is 0 soon f\nd to be impracticable4 ,aft] mak+ _m balla/ resi/ance measurem5ts1 x 0 notic$ t ! v>iation ( ! resi/ance on any track circuit1 z betwe5 wet & dry wea!r1 g5]ally foll[$ q a def9ite rule4 ,= in/ance3 ,if ! resi/ance p] #ajjj ft4 ( dry balla/ 0 f\nd to be #bh ohms or m1 x w\ld be n less ?an #h ohms p] #ajjj ft4 :5 wet2 or if resi/ance ( dry balla/ 0 f\nd to be betwe5 #bb & #bh ohms p] #ajjj ft41 x w\ld be n less ?an #f ohms p] #ajjj ft4 :5 wet4 ,once a relay is pick$ up or en]giz$1 b a small am\nt ( curr5t is requir$ to ma9ta9 x 9 t condition4 ,?is is "o reason :y x is important to keep ! balla/ cle> ( ! rails & x is because ( ! condition :i* may cause a relay to rema9 en]giz$ t rules are 9 =ce requir+ ! signalm5 to disconnect a track relay :5 track =ces are *ang+ out rails4 ,comb9$ ,rail & ,bond ,wire ,resi/ance ,on circuits newly bond$ ) two #df-;94 galvaniz$ iron wires a jo9t1 ! comb9$ rail & bond wire resi/ance 0 f\nd 7on ! ,l4 ,n47 to v>y f 4#jb ohm p] #ajjj ft4 ( track on "s circuits to 4#bfe ohm on o!rs1 a diff]5ce ( ov] #acjj p] c5t4 ,?is 0 r puzzl+4 ,aft] a great _m measurem5ts _h be5 made on diff]5t circuits x 0 f\nd t no two measurem5ts gave ! same results1 not)/&+ ! fact t 9 _m circuits ! size ( rail1 l5g? ( bond wires1 & age ( bond+ 7 exactly ! same4 ,on acc\nt ( ! bond+ be+ new & ! *annel p9s well driv51 ! contact betwe5 ! bond wire & rail 0 above suspicion4 ,! only o!r "p ( a track circuit t c\ld possibly be ! cause ( ?is diff]5ce 0 9 ! contact betwe5 ! angle b>s & rails1 & ?is lat] prov$ to be ! case4 ,actual measurem5ts made 9 ! field prov$ t :5 ! rail is new & ! jo9t bolts tight1 ne>ly all ( ! curr5t fl[+ f rail to rail passes ?r\gh ! angle b>s1 :]eas :5 ! rails get old a coat+ ( ru/ & dirt =ms betwe5 ! rail & angle b>s1 =c+ practically all ( ! curr5t ?r\gh ! bond wires4 ,on mo/ ( ! circuits measur$ on ! ,l4 ,n4 ! comb9$ rail & bond wire resi/ance 0 f\nd to be less ?an 4#a ohm p] #ajjj ft4 ( track1 al?\gh _m 7 f\nd to be betwe5 4#aj & 4#cj ohm p] #ajjj ft4 ,x is int]e/+ to note t two circuits 7 f\nd bond$ ) two #eb-;94 iron wires1 = :i* ! comb9$ rail & bond wire resi/ance measur$ 4#daj ohm1 & t by add+ two #dj p] c5t4 copp] clad bond wires to ea* jo9t ! comb9$ resi/ance 0 r$uc$ to 4#add ohm4 ,! ,gr[? ( ! ,track ,circuit ,un=tunately !re exi/s little or no data reg>d+ ! mileage ( track circuits in/all$ f ! "t ! fir/ in/allation 0 made by ,dr4 ,rob9son at ,k9zua1 ,pa41 & ,irv9eton up to ab\t #aije4 ,dur+ ! p]iod betwe5 ,janu>y #a1 #aije1 & ,septemb] #cj1 #aijf1 ! total automatic block signal mileage in/all$ 0 #a1gaj4f1 :i* br\ght ! total up to #f1hbf4i = ! ,unit$ ,/ates4 ,betwe5 ,septemb] #cj1 #aijf1 & ,janu>y #a1 #aijh1 #c1igf4a miles ( automatic signals 7 in/all$1 :i* increas$ ! above total to #aj1hjc4j miles4 ,! ,block ,signal & ,tra9 ,control ,bo>d1 see+ ! ne$ = accurate data 9 ! signal field1 />t$ ! tabulation ( su* /ati/ics :5 x compil$ & issu$ ,block ,signal ,/ati/ics z ( ,janu>y #a1 #aijh4 ,aft] ?is bo>d w5t out ( exi/5ce1 ! ,bureau ( ,safety ( ! ,int]/ate ,comm]ce ,commission cont9u$ ! collection & publication ( ^! data ye>ly4 ,p]haps no bett] ^w picture c be giv5 ( :at ,dr4 ,rob9son's inv5tion has meant to ! railroads ?an to pres5t ! /ory 9 ! =m ( a table %[+ ! miles ( road & ! track equipp$ ) ! track circuit s9ce ,janu>y #a1 #aijh4 ,9 addition to ! table1 ! accompany+ *>t pres5ts ! in=mation 9 a graphical =m4 ,illu/ration3 ,progress ,*>t ( ,automatic ,signal ,in/allations ,s9ce ,janu>y #a1 #aijh4 ,track ,circuit ,mileage = ,automatic & ,controll$ ,manual ,signals 9 ! ,unit$ ,/ates z ,tak5 f ,i4,c4,c4 ,reports ---------------------------------------- ---------------------------- ,automatic ,controll$ ,manual ---------------------------------------- ---------------- ,miles ( ,road ,miles ( ,track ,miles ,miles ------------------------------------ ( ( ,track ,cont9u\s ,track ,cont9u\s ,road ,track ,circuits ,track ,circuits ,track at ,circuits at ,circuits ,/ation ,/ation ---------------------------------------- ------------------------ ,janu>y #a1 #aijh #aj1hai4c #ah1ecd4a #gbf4g #bab4j #baah4j #daj4h #aiji #ab1agd4c #bj1eij4i #djg4f #egb4b #igh4j #adac4j #aiaj #ad1bch4i #bc1gga4c #che4h #dia4e #iec4e #acga4c #aiaa #ag1gji4h #bi1aea4f #dhc4i #dci4d #aaai4c #gci4i #aiab #bj1cjj4j #cc1cdc4h #djb4j #bie4i #iee4f #dif4j #aiac #bb1aif4f #cf1hgc4j #cgj4b #bbh4c #hfh4i #chj4c #aiad #bf1efi4c #dd1dfa4b #bge4g #ahj4c #fbe4c #bha4f #aiae #bi1hfc4e #di1ddb4a #bej4e #ade4a #edi4c #ahe4g #aiaf #cj1idb4e #ea1aai4g #bee4a #abe4a #edi4f #agi4c #aiag #cb1ied4f #ec1gii4h #bcj4c #acb4j #ebd4h #aee4e #aiah #ce1aic4a #eg1jhc4f #bjh4a #aca4b #dea4f #aed4h #aiai #cf1ihi4d #ei1deh4b #bba4b #bef4i #dhc4h #dda4b #aibj #cg1ifh4h #fj1iib4c #aif4c #abi4b #dac4c #aea4d #aiba #ch1edc4i #fa1gdd4e #bjf4h #abe4g #dbb4f #aff4d ---------------------------------------- ------------------------ ,! fir/ ye>ly report ( ! ,bureau ( ,safety1 ,i4,c4,c41 on block signals to conta9 in=mation z to ! miles ( road & miles ( track on :i* alt]nat+ curr5t track circuits 7 in/all$1 0 t issu$ z ( ,janu>y #a1 #aiad4 ,data tak5 f t report up to ! la/ "o issu$ is pres5t$ 9 ! table bel[4 ,alt]nat+ ,curr5t ,track ,circuit ,mileage ---------------------------------------- ------- ,miles ( ,road ,miles ( ,track ---------------------------------------- ------- ,janu>y #a1 #aiad #c1bhi4b #d1add4f ,janu>y #a1 #aiae #b1gbh4b #e1had4i ,janu>y #a1 #aiaf #c1ahf4g #f1fgi4j ,janu>y #a1 #aiag #c1ccf4b #f1hbc4f ,janu>y #a1 #aiah #c1gdh4j #g1ecj4a ,janu>y #a1 #aiai #d1dif4f #h1fbj4b ,janu>y #a1 #aibj #d1fgf4e #i1jbf4j ,janu>y #a1 #aiba #d1ghf4a #i1abj4b ---------------------------------------- ------- ,alt]nat+ curr5t track circuits h c]ta9 advantages ov] direct curr5t track circuits1 p>ticul>ly 9 respect to _! immunity to ! dang]\s effects ( =eign direct curr5t to :i* d4c4 track circuits 9 "s communities are subject$4 ,! above table is !re=e ( int]e/ z x %[s ! application ( alt]nat+ curr5t z made to ,dr4 ,rob9son's inv5tion ( ! clos$ track circuit4 ,"p ,,iv ,,! ,,track ,,circuit ,,9 ,,great ,,brita9 ,,& ,,on ,,! ,,cont95t ,by ,t4 ,s4 ,lascelles ,no satisfactory records appe> to h be5 kept z to ! orig9 & developm5t ( track circuit+ outside ! ,unit$ ,/ates1 :i* r5d]s x v difficult to arrive at any conclusions t c\ld s]ve z a basis = a real hi/orical sket* ^u ?is int]e/+ subject4 ,9 view ( ! fact t ! ,signal ,section ( ! ,am]ican ,railway ,association proposes to publi% a memorial to ! late ,dr4 ,william ,rob9son1 g5]ally reg>d$ z ! inv5tor ( ! clos$ track circuit & c]ta9ly ! fir/ to utilize x 9 ! control ( an automatic block sy/em1 ! foll[+ brief rem>ks may prove ( int]e/ to ! writ]'s fell[ memb]s ( ! ,signal ,section4 ,x is n sugge/$ t !y are 9 any s5se complete1 z to make a complete survey w\ld require consid]able inve/igation4 ,!y really repres5t ! writ]'s pres5t g5]al und]/&+ ( ! subject & are op5 to su* criticism & correction z anyone may be able to (f] to !m1 9 ,engl& or else:]e4 ,!re is no d\bt b t track circuits 7 ?\ght ( & actually exp]im5t$ ) 9 ,engl& a great _m ye>s ago--probably z f> back z ! e>lie/ ,am]ican attempts--b ! want ( satisfactory records make x v difficult to decide on :at actually took place4 ,h[ev]1 x is c]ta9 t ! late ,w4 ,r4 ,sykes1 well-kn[n ?r\gh\t ! railway _w = 8 controll$ manual block & o!r inv5tions1 endeavor$ to use ! track circuit 9 ! sixties & t ,bull1 ! inv5tor ( ! bull-head$ rail employ$ 9 ,engl& = ! *air$ track univ]sally f\nd !re1 cle>ly _h ! idea ( a track circuit 9 8 m9d1 = he ref]s to x 9 a pat5t obta9$ 9 #ahfj4 ,x 0 app>5tly 9 ! e>ly "p ( ! sixties t ,w4 ,r4 ,sykes fix$ a track circuit exp]im5tally at ,briseton on ! old ,london1 ,*a?am & ,dov] ,railway1 & %ortly aft] also at ! ,cry/al ,palace ,/ation on ! same l9e4 ,! app>atus employ$ mu/ necess>ily h be5 r primitive4 ,9 ! sev5ties1 track circuit 0 in/all$ by him at ,/4 ,paul's /ation1 also on ! ,*a?am ,railway4 ,at t "t v little 0 kn[n ab\t ! track circuit !oretically & ! con/ruction ( ! relay 0 v diff]5t f our mod]n types4 ,sykes' relay complet$ ! control circuit by ! ins]tion ( a contact po9t into a m]cury tr\gh4 ,x 0 also1 ! writ] believes1 built on ! sol5oid pr9ciple4 ,s f> z is kn[n x 0 n sugge/$ at ?is "t & at all ev5ts n attempt$ to make an automatic block sy/em controll$ by track circuits1 su* s*emes = signal+ ( ?is type z 7 put =w>d be+ always bas$ on ! int]mitt5t or track in/rum5t control plan4 ,x mu/ be rememb]$ t ! conditions obta9+ 9 ,engl&1 widely diff]5t f ^? se5 9 ! ,unit$ ,/ates1 7 n su* z to give mu* enc\ragem5t to ! developm5t ( automatic signal+1 :ile ov] & above ?is1 ! ,engli% cons]vative nature always look$ askance at automaticity 9 railway app>atus4 ,automatic signals1 work$ on a track in/rum5t plan1 7 put into regul> "w on ! ,liv]pool ,ov]head ,railway 9 #ahic1 b x 0 n till #aijb t automatic signals controll$ by cont9u\s clos$ track circuits 7 to be se5 9 op]ation on an ,engli% ma9 l9e railway4 ,be=e ?is1 h[ev]1 track circuits _h made "s progress1 ?\gh n v mu*2 ! mo/ important in/ance ( its application 0 9 ! ,k+s ,cross tunnels1 j outside ! ,london t]m9al ( ! ,great ,nor!rn ,railway1 9 ! e>ly n9eties4 ,?is in/allation1 :i* 0 us$ "u none too favorable circum/ances f ! po9t ( view ( successful op]ation1 prov$ to ! ,engli% :at ! track circuit c\ld d & h]ald$ ! day :5 its place 9 ! safe work+ ( railways %\ld be bett] appreciat$4 ,by ?is "t 9 ! ,unit$ ,/ates1 l>gely "u ! influ5ce ( ! pione] "w ( ,dr4 ,rob9son1 automatic signal+ _h made q consid]able progress & ! pot5tialities ( ! track circuit _h be5 fairly realiz$4 ,x may occur to ,am]icans to ask :y x 0 t progress 9 ,engl& 0 s sl[ & ?is is a "q :i* _c be answ]$ by a s+le reason s9ce a comb9ation ( circum/ances 0 ! cause4 ,9 ! fir/ place ! old] type ( ,engli% signal (fic] 0 extraord9>ily cons]vative reg>d+ signal+ practice ( o!r c\ntries z he _h t peculi> type ( contempt :i* g5]ally comes f want ( k4 ,anyone :o1 l ! writ]1 li/5$ = in/ance to ! objections br\ght =w>d by "s ( ^! m5 to controll$ manual block1 w "k to :at absurd l5g?s !y c\ld g 9 resi/+ improvem5ts 9 work+4 ,al?\gh ?is _s1 :i* has m>k$ly dim9i%$ dur+ ! la/ #ae ye>s1 mu/ h acc\nt$ to "s ext5t = ! sl[ developm5t ( ! track circuit 9 ,engl&1 !re 7 yet "s reasons ( a m s5sible k9d :i* mu/ be borne 9 m9d4 ,! ,engli% light weight f\r-:eel$ freight c> )\t air brakes 0 & /ill is a bo!r to ! track circuit eng9e] because ( ! difficulty ( gett+ a satisfactorily l[ %unt "u all circum/ances4 ,!n aga9 ! ,mansell disc :eel made x necess>y to resort to bond+ betwe5 ! tire & ! hub be=e a vehicle w\ld %unt ! track circuit at all & ?is 0 an exp5se to :i* ! companies 7 loa? to g1 especially if !y _h or contemplat$ v few track circuits1 ?\gh ! use ( ev5 "o circuit really necessitat$ ! :ole ( ^! :eels be+ s treat$4 ,!re 0 no great dem& = automatic signal+1 z ! manual sy/em 0 giv+ good results & 0 also *eap at t "t1 ow+ to ! l[ wages paid to railway m54 ,?is & ! o!r reasons j giv5 comb9$ to r5d] ! progress 9 ,engl& extremely sl[4 ,"s ( ! ,fir/ ,in/allations ,nev]!less1 9 #aijb ! ,briti% ,pneumatic ,railway ,signal ,company1 :o _h 9 ! previ\s ye> in/all$ its fir/ l[ pressure pneumatic int]lock+ at ,grateley1 on ! ,london & ,s\? ,we/]n ,railway1 br\ght into use betwe5 t /ation & ,&ov] an automatic block sy/em controll$ by cont9u\s track circuits1 ! di/ance be+ ab\t six miles4 ,! signals 7 work$ by l[ pressure air4 ,! success ( ^! sy/ems l$ to ! adoption ( !m %ortly aft]w>ds on ! wid5$ f\r-track ma9 l9e betwe5 ,wok+ & ,bas+/oke on ! ,s\? ,we/]n1 a di/ance ( #bd miles4 ,! ,grateley-,&ov] in/allation has n[ be5 remov$1 n because x 0 at all unsatisfactory1 b because x 0 felt traffic & o!r circum/ances did n w>rant its fur!r employm5t4 ,9 #aije1 ,hall electro-gas automatic signals 7 br\ght into use on ! ,nor? ,ea/]n ma9 l9e betwe5 ,alne & ,?irsk1 a di/ance ( #aa miles4 ,9 #aijg1 semi-automatic signals 7 in/all$ betwe5 ,pangb\rne & ,gor+1 a di/ance ( #b-c_/d miles1 f\r track1 by ! ,great ,we/]n ,railway to divide up a long manual block section & a few simil> in/allations h be5 made on ! ,midl&1 ! ,great ,c5tral1 ! ,belfa/ & ,c\nty ,d[n & o!r roads4 ,by ?is ye>1 track circuit+ _h begun to be ext5sively us$ 9 ,engl&4 ,! ,briti% ,pneumatic ,signal ,company _h in/all$ a s]ies ( l[-pressure plants ne> ,man*e/] on ! ,great ,c5tral & track circuits 7 us$ ?r\gh\t :ile ! same ?+ _h be5 done at ,clapham ,junction on ! ,s\? ,we/]n4 ,! ,we/+h\se ,company _h suppli$ ! ,di/rict ,railway1 ,london1 ) automatic signals & 7 actively engag$ 9 fitt+ simil> app>atus to ! tube l9es2 !y soon aft]w>ds comm5c$ "w on ! ,metropolitan ,railway4 ,! ma9 /eam l9es began to apply track circuits at v>i\s places 9 conjunction ) ord9>y manual signal+ & ?is process receiv$ an add$ impetus f ! t]rible disa/] :i* befell ! ,midl& ,company's ,scot* ,express ne> a /ation call$ ,hawes ,junction1 :51 9 em]g+ f a tunnel x cra%$ into two light eng9es t _h be5 =gott5 & _h ent]$ ! block "u ! signals set = ! express4 ,sev]al o!r bad accid5ts1 notably "o at ,pontypridd1 on ! ,taff ,vale ,railway1 due to tra9s & eng9es be+ ov]look$ by signalm5 :ile /&+ at adv]se signals1 emphasiz$ ! necessity = pay+ s]i\s att5tion to ! "q ( track circuit+ & = und]tak+ a really e>ne/ /udy ( ! matt] to see :e!r ! difficulties due to ! light freight c>1 etc41 c\ld n be ov]come or at lea/ consid]ably m9imiz$4 ,consid]able progress _h be5 made by ! "t ! w> broke out & q a numb] ( track circuits _h come into exi/5ce on all ! pr9cipal roads1 al?\gh no ext5sion "w wor? notic+ 0 made to purely automatic block sy/ems on /eam roads1 ?is class ( "w be+ conf9$ to ! suburban electric l9es4 ,un=tunately1 9 ?is z 9 s _m ?+s ! w> _h a ret>d+ effect & caus$ ! po/ponem5t ( _m plans4 ,! increas$ price ( wages & mat]ials has hamp]$ progress a great deal & x w be "s "t yet be=e any great improvem5t is noticeable4 ,on ! o!r h&1 ! great increase 9 wages has caus$ a dem& on ! railways = a r$uction ( op]at+ co/s ) ! result t signal eng9e]s are endeavor+ to produce s*emes :i* w enable signal t[]s to be aboli%$ or clos$ at int]vals :]e !y 7 =m]ly kept cont9u\sly 9 s]vice & 9 ?is & o!r ways to disp5se ) unnecess>y /aff4 ,x is 9 ?is t ! track circuit w help v consid]ably4 ,its fur!r ext5sion on ,engli% l9es is a c]ta9ty & simply a "q ( "t & money4 ,s9ce ! inception ( ! ,in/itution ( ,railway ,signal ,eng9e]s a great am\nt ( "w has be5 done 9 discuss+ & /udy+ requisites & s on = track circuit "w1 bo? ( ! direct curr5t & alt]nat+ curr5t types4 ,all ?is has result$ 9 increas$ confid5ce on ! "p ( ! traffic (fic]s 9 track circuit & alli$ app>atus & caus$ !m to look m & m to ! signal eng9e] to help !m 9 _! "w & to accord him ! respect & cr$it he des]ves4 ,! writ] is aw>e t ^! l9es c only convey a v imp]fect idea ( ! actual /ate ( affairs1 b he pref]s to write !m n[ z a prelim9>y acc\nt1 n yet be+ 9 a position to furni% ! figures :i* ! ,signal ,section desires4 ,track ,circuits on ! ,cont95t ,turn+ to ! cont95t1 ! writ] mu/ necess>ily speak 9 v g5]al t]ms s9ce !re is less publi%$ on ?is subject by cont95tal j\rnals ?an by ,engli% &1 ( c\rse1 ! field is r a wide "o1 embrac+ s _m l&s & tongues4 ,! track circuit is1 ( c\rse1 kn[n !re fairly well1 b !re are no v great in/allations ( automatic block to be f\nd4 ,9 ! case ( ,france1 ! ,p>is1 ,lyons ,m$it]ranean _h1 be=e ! w>1 an in/allation betwe5 ,l>s*e & ,aup]re1 #bd miles1 & "s semi-automatic sections 9 v>i\s places4 ,! ,midi ,railway _h also ! ,hall disc sy/em f ,bordeaux to ,langon1 #bf miles1 & ! writ] believes ext5sions to ?is h s9ce be5 made4 ,! ,e/ ,railway began trials be=e ! w> & dur+ ! w>1 ow+ to %ortage ( /aff & hav+ greatness ( traffic to ! ea/]n milit>y area1 in/all$ automatic signal+ on ! ,p>is-,nug5t l9e4 ,! writ] has be5 told t x is "u consid]ation to equip ! :ole l9e to ,avric\rt1 :]e x connects ) ! ,alsace-,lorra9e sy/em4 ,! writ] is n aw>e :e!r ! o!r companies 9 ,france h any automatic blocks1 b he believes n4 ,!y all h1 h[ev]1 track circuits in/all$ at v>i\s places 9 connection ) ! ord9>y signal+4 ,ow+ to ! l[] /&>d ( liv+ & ! employm5t ( wom5 op]ators at _m po9ts1 !re is n s great an inc5tive to ! adoption ( automatic devices1 z 9 "s o!r c\ntries4 ,fr5* eng9e]s1 h[ev]1 "k :at ,am]icans h done 9 ?is way & "s v complete acc\nts ( ,am]ican sy/ems h appe>$ 9 ,la ,revue g5]ale des *em9s de f]4 ,! ,p>is ,metropolitan l9e is automatically signal$ by an int]mitt5t contact sy/em )\t track circuit4 ,9 ,g]many1 ! track circuit = /eam l9es is n look$ on ) mu* favor1 z ow+ to ! ext5sive employm5t ( ! ,siem5's controll$ manual & ! peculi> /ation ma/]s' sy/em ( control1 call$ ,/ation ,block1 always us$ 9 t c\ntry 7)1 x mu/ be admitt$1 a v high record = safety17 ! ,g]mans ?9k !y w\ld n ga9 mu* by any great use ( track circuit or automatic signals4 ,! writ] has j _h ?is view confirm$ by a fri5d return$ f visit+ ! important works ( ! ,g]man ,railway ,signal ,company at ,bru*sal1 ,bad54 ,automatic signal+ is us$ on c]ta9 important sections ( ! ,b]l9 ,elevat$ & ,und]gr\nd ,road1 in/all$ be=e ! w> by ! ,we/+h\se ,company1 ( ,london1 ) a4c4 d\ble rail track circuits & ?is w be ext5d$ ev5tually to cov] ! rema9+ sections /ill work$ by ! ,siem5's controll$ manual4 ,dr4 ,kemmann1 a memb] ( ! ,g5]al ,railway ,direction1 ,b]l91 publi%$ la/ ye> a v int]e/+ book describ+ 8 "w ) acc\nts also ( ! ,london ,und]gr\nd & ,new ,york ,subway in/allations1 %[+ t =eign sy/ems are /udi$ 9 ,g]many4 ,b = /eam roads ! writ] believes f :at he has /udi$ ( ,g]man me?ods & ideas on ! subject t ! manual sy/em w rema9 9 use & t ! track circuit w n be mu* adopt$4 ,! same rem>ks apply g5]ally to ,au/ria1 ,holl& & ,sc&9avia1 ?\gh 9 ! latt] case ,engli% ideas are m 9 evid5ce & x is probable t ! track circuit1 already 9 use to "s ext5t1 w be develop$ z "t goes on4 ,9 ,au/ria automatic signal+ 0 c]ta9ly tri$ on a small scale on ! ,s\!rn ,railway1 b ) :at results ! writ] _c say4 ,9 ,switz]l& ! ext5d$ use ( iron ties is aga9/ ! track circuit4 ,9 ,belgium ! ,hall sy/em 0 at "o "t 9 use betwe5 ,gh5t & ,wondelgem1 b z ! c\rse ( ! l9e 0 *ang$1 ^! signals 7 remov$4 ,! section 0 ab\t #c-a_/d miles long4 ,automatic signals d n exi/ !re n[ b ! track circuit is us$ at c]ta9 /ations1 notably ?r\gh\t ! all-electric p[] in/allation at & close to ,brussles ,nord4 ,! writ] does n believe x likely t automatic signal+ w be us$ on ! /eam roads 9 ,belgium1 at all ev5ts = "s "t yet4 ,) reg>d to ,italy1 ,spa9 & ,portugal1 ! writ] does n possess details1 b believes x likely t ! track circuit is only 9 use1 if at all1 at a few important /ations4 ,! new ,metropolitan l9e 9 ,madrid is equipp$ ) an int]mitt5t contact sy/em1 probably copi$ f ! ,p>is ,metropolitan4 ,al?\gh a little outside ! scope ( ^! notes1 ! writ] w\ld emphasize t 9 ! ,engli% colonies & 9 ,s\? ,am]ica 7especially1 h[ev]1 ! =m]7 ! track circuit is be+ mu* us$ & its value appreciat$4 ,automatic signal+ is 9 use 9 ,victoria1 ,que5sl&1 ,s\? ,au/ralia & ,new ,s\? ,wales4 ,! op]at+ conditions 9 ^! c\ntries no d\bt mu* resemble ,am]ican circum/ances & ! adoption ( automatic signals is a natural developm5t4 ,summ+ up1 ! writ] w\ld say1 t ! e>lie/ exp]im5ts ( ,w4 ,r4 ,sykes 9 ,engl& are probably z old z ^? ( ,dr4 ,rob9son1 b ow+ to ! diff]5t circum/ances 9 :i* ! =m] inv5tor 0 plac$1 he _h little enc\ragem5t to cont9ue !m & ?us ,am]ican developm5t at fir/ w5t on f> ahead ( ,engli%1 :ile ow+ to ! va/ness ( ! ,am]ican cont95t x mu/ always pres5t a l>g] field to ! signal eng9e]s' +5uity & activity4 ,9 lat] ye>s1 h[ev]1 ! ,engli% signalm5 awoke to ! importance ( ! "q & in/allations 7 con/ruct$ :i*1 if small]1 %[$ z great a degree ( te*nical p]fection z any 9 ,am]ica4 ,! future w d\btless see m su* in/allations4 ,x is n kn[n to ! writ] :e!r anyone on ! cont95t _h ! idea ( a track circuit z f> back z ,sykes' or ,rob9son's exp]im5ts or :5 ! fir/ attempts 7 made4 ,x w\ld require mu* inve/igation to f9d ?is out4 ,track circuit possibilities are n[ well kn[n !re & no d\bt its use w ext5d1 b 9 c]ta9 c\ntries1 notably ,g]many & ,switz]l&1 !re are local circum/ances :i* act r /rongly aga9/ x at pres5t4 ,! writ] _c give /ati/ics on ! subject n[4 ,!re are "s figures :i* he possesses1 b !y %\ld be v]ifi$ & amplifi$ be=e be+ us$ by ! ,signal ,section = publication4 ,! prec$+ notes are1 he is too fully aw>e1 v incomplete & g5]al1 b he hopes !y may be ( "s pres5t use4