,transcrib]'s ,note3 ,italics are enclos$ 9 und]scores4 ,additional notes w be f\nd ne> ! end ( ?is ebook4 ,,! ,,telephone1 ,,microphone1 ,,phonograph ,,! ,,telephone ,,! ,,microphone ,,! ,,phonograph ,,by ,,c\nt ,,du ,,moncel ,,membre ,,de ,l',,in/itut ,,au?oris$ ,,translation ,,) ,,additions ,,& ,,corrections ,,by ,,! ,,au?or ,,) #gj ,,illu/rations ,,on ,,wood ,,f\r? ,,edition ,,london ,,kegan ,,paul1 ,,tr5*1 ,,tr,,bn]1 ,,co4 ,,ltd4 ,,pat]no/] ,,h\se1 ,,*>+ ,,cross ,,road #ahib 7,! rights ( translation & ( reproduction are res]v$7 ,,cont5ts4 ,,page ,hi/ory ( ! telephone #a ,,musical ,,telephones4 ,reiss's telephone #aa ,wray's telephone #ae ,electric h>monica #ah ,gray's telephone #ba ,poll>d & ,g>ni]'s s++ cond5s] #bf ,,speak+ ,,telephones4 ,/r+ telephones #ca ,bell's electric telephone #ce ,gray's %>e 9 inv5tion ( telephone #fb ,,fundam5tal ,,pr9ciples ,,( ,,bell ,,telephone4 ,explanation ( pr9ciples #fg ,,ord9>y ,,arrangem5t ,,( ,,bell ,,telephone4 ,description & illu/rations #ga ,,batt]y ,,telephones4 ,edison's telephone #hc ,edison's *emical telephone #ij ,navez' telephone #ic ,poll>d & ,g>ni]'s telephone #ig ,helles5's telephone #ajj ,?omson & ,h\/on's telephone #aja ,telephones ) liquid s5d]s #ajc ,telephones ) voltaic arcs #ajg ,m]cury telephones #aaj ,friction telephones #aac ,,modification ,,( ,,bell ,,telephones4 ,telephones ) sev]al diaphragms #aad ,gray's sy/em #aah ,phelps's sy/em #aah ,cox ,walk]'s sy/em #aba ,tr\v's sy/em #aba ,demoget's sy/em #abd ,mac ,tighe's sy/em #abe ,modifications ( telephonic organs #abe ,righi's sy/em #abf ,ad]'s sy/em #abi ,jorg5son's sy/em #aca ,,exp]im5ts ,,) ,,! ,,telephone4 ,on ! effects ( voltaic & induc$ curr5ts #acb ,on ! effects ( diff]5t telephonic organs #aci ,edison's exp]im5ts #adj ,cane/relli's exp]im5ts #adb ,hughes's & ,roy's exp]im5ts #adc ,brguet's exp]im5ts #adi ,luv9i's exp]im5ts #adi ,w>wick's exp]im5ts #aea ,exp]im5ts on ! effects ( me*anical %ocks #aed ,des ,portes' exp]im5ts #aed ,?ompson's exp]im5ts #aeh ,!ory ( telephone #aei ,nature ( vibrations #afj ,action ( diaphragm #afc ,action ( magnet #afg ,action ( curr5ts #afi ,wies5dang]'s !rmophone #aga ,,o!r ,,exp]im5ts ,,) ,,! ,,telephone4 ,d',arsonval's exp]im5ts #agc ,eick's exp]im5ts #age ,demoget's exp]im5ts #agf ,s5sitiv5ess ( telephone #agi ,helles5's exp]im5ts #ahj ,zets*e's exp]im5ts #aha ,,! ,,microphone4 ,hi/ory ( microphone #ahb ,diff]5t sy/ems #ahg ,hughes's microphone #ahh ,gaiffe's sy/em #aij ,c>ette's sy/em #aia ,ducretet's sy/em #aib ,ducretet's speak] #aic ,b\det's speak] #aie ,gaiffe's !rmoscope #aig ,bly?'s sy/em #aii ,microphone z a speak+ in/rum5t #bjj ,hughes's sy/em #bjc ,o!r arrangem5ts ( microphones #bje ,v>cy's & ,tr\v's microphones #bjg ,lipp5s's microphone #bji ,hughes's exp]im5ts #baa ,hughes's !ory #bae ,microphone us$ z !rmoscope #bag ,edison's !rmoscope #bai ,exp]im5ts 9 ,london #bbj ,exp]im5t at ,bell9zona #bbc ,,applications ,,( ,,microphone4 ,its application to sci5tific rese>* #bbf ,application to telephonic relays #bbi ,application to surg]y #bcb ,v>i\s applications #bcf ,,ext]nal ,,influ5ce ,,on ,,telephonic ,,transmissions4 ,di/urb+ influ5ces #bci ,confusion ( circuits #bda ,induc$ reactions #bdc ,mr4 ,preece's sugge/ions #bde ,effects ( heat & moi/ure #bdi ,,e/abli%m5t ,,( ,,telephone ,,/ation4 ,poll>d & ,g>ni]'s sy/em #beb ,brguet & ,roosevelt's sy/em #bed ,edison's sy/em #beg ,,call-,,bells ,,& ,,al>ums4 ,we9hold's sy/em #bfb ,dut]tre & ,g\ault's sy/em #bfd ,puluj's sy/em #bff ,*iddey's sy/em #bfg ,,applications ,,( ,,telephone4 ,its application to simultane\s transmissions #bgj ,bell's sy/em #bgc ,lac\r's sy/em #bgf ,gray's sy/em #bhb ,,v>i\s ,,uses ,,( ,,! ,,telephone4 ,its use 9 (fices #bic ,its use 9 telegraphic s]vice #bid ,its application to milit>y purposes #big ,its application to indu/ry #cjb ,its application to sci5tific rese>* #cjc ,,! ,,phonograph4 ,edison's pat5t #cji ,description ( phonograph #cac ,sev]al sy/ems #cbb ,!ory ( phonograph #cbg ,,uses ,,( ,,phonograph4 ,acc\nt by ,edison #ccc ,la9brigot's sy/em #cci ,,fab]',s ,,speak+ ,,ma*9e #cda ,,app5dix4 ,p]rodon's sy/em ( telephonic al>um #cea ,v>ey's microphone speak] #ceb ,fit*'s microphone speak] #cec ,!ory ( telephone #cec ,poll>d's microphone #cef ,ad]'s electrophone #ceg ,g[]'s new telephone #ceh ,transmission ( spee* by telephones )\t diaphragm #cfj ,,! ,,telephone1 c4 ,,hi/ory ,,( ,,! ,,telephone4 ,/rictly speak+1 ! telephone is m]ely an in/rum5t adapt$ = ! transmission ( s\nd to a di/ance1 & ?is idea ( transmitt+ s\nd is z old z ! _w itself4 ,! ,greeks made use ( means :i* might effect x1 & !re is no d\bt t ^! means 7 sometimes us$ = ! pagan oracles4 ,b su* transmission ( s\nd 0 )9 some:at n>r[ limits1 & c]ta9ly did n exce$ ^? ( a speak+-tube4 ,mr4 ,preece consid]s t ! e>lie/ docum5t 9 :i* ?is transmission ( s\nd to a di/ance is di/9ctly =mulat$1 dates f #affg3 he ref]s to a pap] by "o ,rob]t ,hooke1 :o writes to ?is effect3 #8,x is n impossible to he> a :isp] at a furlong's di/ance1 x hav+ be5 already done2 & p]haps ! nature ( ! ?+ w\ld n make x m impossible1 ?\gh t furlong %\ld be t5 times multiply'd4 ,& ?\gh "s fam\s au?ors h affirm'd x impossible to he> ?r\gh ! ?9ne/ plate ( ,muscovy glass2 yet ,i "k a way1 by :i* 'tis easie en\gh to he> "o speak ?r\gh a wall a y>d ?ick4 ,x has n yet be5 ?or\ghly exam9'd h[ f> otac\/icons may be improv'd1 nor :at o!r wayes !re may be ( quickn+ our he>+1 or convey+ s\nd ?r\gh o!r bodies ?an ! air2 = t is n ! only m$ium ,i c assure ! read]1 t ,i h1 by ! help ( a di/5d$ wire1 propagat$ ! s\nd to a v consid]able di/ance 9 an in/ant1 or ) z seem+ly quick a motion z t ( light1 at lea/ incomp>ably quick] ?an t :i* at ! same "t 0 propagat$ ?r\gh ! air2 & ?is n only 9 a /raight l9e or direct1 b 9 "o b5d$ 9 _m angles4' ,?is plan = ! transmission ( s\nd is ! pr9ciple ( ! /r+ telephones :i* h attract$ att5tion = "s ye>s1 & x rema9$ 9 ! /age ( simple exp]im5t until #ahai1 :5 ,sir ,*>les ,:eat/one appli$ x to 8 magic lyre4 ,9 ?is in/rum5t1 s\nds 7 transmitt$ ?r\gh a long /rip ( deal1 ) "o end 9 connection ) a s\nd+ bo>d3 "o /ep m l$ to ! use ( ! membrane employ$ 9 /r+ telephones4 ,x w\ld be difficult to say ) :om ?is idea orig9at$1 s9ce x is claim$1 z if beyond dispute1 by sev]al telephone-mak]s4 ,if we may believe "s travell]s1 x has long be5 us$ 9 ,spa9 = ! correspond5ce ( lov]s4 ,h[ev] ?is may be1 x 0 n to be f\nd among ! sci5tific appliances ( "s ye>s ago1 & x 0 ev5 suppos$ by _m p]sons t ! cord consi/$ ( an ac\/ic tube ( sl5d] diamet]4 ,al?\gh ! in/rum5t has become a *ild's toy1 x has great sci5tific importance1 = x proves t vibrations capable ( reproduc+ spee* may be extremely m9ute1 s9ce !y c be me*anically transmitt$ m ?an a hundr$ y>ds4 ,f ! telegraphic po9t ( view1 h[ev]1 ! problem ( transmitt+ s\nds to a di/ance 0 f> f be+ solv$ 9 ?is way1 & ! idea ( apply+ electricity to ?is mode ( transmission naturally arose z soon z ! wond]ful effects ( electric telegraphy 7 obs]v$1 t is1 9 ! ye>s subsequ5t to #ahci4 ,a surpris+ discov]y made 9 ,am]ica by ,mr4 ,page1 9 #ahcg1 & aft]w>ds inve/igat$ by ,,mm4 ,w]!im1 ,de la ,rive1 & o!rs1 mu/ also h l$ up to x3 = x 0 obs]v$ t a magnetic b> c\ld emit s\nds :5 rapidly magnetis$ & demagnetis$1 & ^! s\nds correspond$ ) ! numb] ( curr5ts :i* produc$ !m4 ,aga91 ! electric vibrators devis$ by ,,mm4 ,macaulay1 ,wagn]1 ,neef1 etc41 & adapt$ to produce musical s\nds1 betwe5 #ahdg-aheb1 by ,,mm4 ,from5t & ,ptr9a1 %[$ t ! problem ( transmitt+ s\nds to a di/ance 0 n insoluble4 ,yet1 up to #ahed1 no "o _h v5tur$ to admit ! possibility ( transmitt+ spee* by electricity1 & :5 ,m4 ,*>les ,b\rseul publi%$ 9 t ye> a pap] on ! electric transmission ( spee*1 ! idea 0 reg>d$ z a fanciful dream4 ,i confess t ,i myself ?\ght x incr$ible1 & :5 ,i produc$ ! pap] 9 ! fir/ edition ( my acc\nt ( ! applications ( electricity1 publi%$ 9 #ahed1 ,i felt b\nd to add t ! s*eme seem$ m ?an d\btful4 ,yet1 z ! pap] 0 ?\ghtfully writt51 ,i _h no hesitation 9 publi%+ x1 affix+ ! signature ( ,,*4 ,b4 ,ev5ts ju/ifi$ ?is d>+ idea1 & al?\gh x did n include ! only pr9ciple :i* c\ld lead to ! reproduction ( articulate s\nds1 yet x 0 ! g]m ( ! f]tile inv5tion :i* has made ! names ( ,graham ,bell & ,eli%a ,gray fam\s4 ,= ?is reason ,i w aga9 quote ,m4 ,*>les ,b\rseul's pap]4 #8,aft] ! telegraphic m>vels :i* c reproduce at a di/ance h&-writ+s1 or ev5 m or less complicat$ draw+s1 x may appe> impossible to p5etrate fur!r into ! region ( ! m>vell\s4 ,yet we w try to advance a few /eps fur!r4 ,i h1 = example1 ask$ myself :e!r spee* itself may n be transmitt$ by electricity--9 a ^w1 if :at is spok5 9 ,vi5na may n be he>d 9 ,p>is4 ,! ?+ is practicable 9 ?is way3-- #8,we "k t s\nds are made by vibrations1 & are adapt$ to ! e> by ! same vibrations :i* are reproduc$ by ! int]v5+ m$ium4 ,b ! int5sity ( ! vibrations dim9i%es v rapidly ) ! di/ance3 s t x is1 ev5 ) ! aid ( speak+-tubes & trumpets1 impossible to exce$ some:at n>r[ limits4 ,suppose t a man speaks ne> a moveable disk1 suffici5tly flexible to lose none ( ! vibrations ( ! voice1 t ?is disk alt]nately makes & breaks ! curr5ts f a batt]y3 y may h at a di/ance ano!r disk1 :i* w simultane\sly execute ! same vibrations4 #8,x is true t ! int5sity ( ! s\nds produc$ w be v>iable at ! po9t ( dep>ture1 at :i* ! disk vibrates by means ( ! voice1 & con/ant at ! po9t ( arrival1 :]e x vibrates by means ( electricity2 b x has be5 %[n t ?is does n *ange ! s\nds4 ,x is1 moreov]1 evid5t t ! s\nds w be reproduc$ at ! same pit*4 #8,! pres5t /ate ( ac\/ic sci5ce does n p]mit u to decl>e priori if ?is w be precisely ! case ) syllables utt]$ by ! human voice4 ,! mode 9 :i* ^! syllables are produc$ has n yet be5 suffici5tly inve/igat$4 ,x is true t we "k t "s are utt]$ by ! tee?1 o!rs by ! lips1 & s on2 b ?is is all4 #8,h[ev] ?is may be1 obs]ve t ! syllables c only reproduce ^u ! s5se ( he>+ ! vibrations ( ! int]v5+ m$ium3 reproduce precisely ^! vibrations1 & y w reproduce precisely ^! syllables4 #8,x is1 at all ev5ts1 impossible 9 ! pres5t condition ( sci5ce to prove ! impossibility ( transmitt+ s\nd by electricity4 ,ev]y?+ t5ds to %[1 on ! contr>y1 t !re is su* a possibility4 ,:5 ! application ( electro-magnetism to ! transmission ( messages 0 fir/ discuss$1 a man ( great sci5tific atta9m5ts treat$ ! idea z utopian1 & yet !re is n[ direct communication betwe5 ,london & ,vi5na by means ( a simple wire4 ,m5 decl>$ x to be impossible1 b s x is4 #8,x ne$ n be said t num]\s applications ( ! highe/ importance w imm$iately arise f ! transmission ( spee* by electricity4 ,any "o :o is n deaf & dumb may use ?is mode ( transmission1 :i* w\ld require no app>atus1 except an electric batt]y1 two vibrat+ disks1 & a wire4 ,9 _m cases1 z = example 9 l>ge e/abli%m5ts1 ord]s might be transmitt$ 9 ?is way1 al?\gh transmission by electricity w n be us$ :ile x is necess>y to g f lett] to lett]1 & to make use ( telegraphs :i* require use & appr5tice%ip4 ,h[ev] ?is may be1 x is c]ta9 t 9 a m or less di/ant future1 spee* w be transmitt$ by electricity4 ,i h made "s exp]im5ts 9 ?is direction3 !y are delicate1 & dem& "t & pati5ce1 b ! approximations obta9$ promise a fav\rable result4' ,?is description is c]ta9ly n full en\gh to enable u to disc]n f x ! arrangem5t :i* w\ld lead to ! solution ( ! problem1 & if ! vibrations ( ! disk at ! receiv+ /ation 7 to foll[ f mak+ & break+ ! curr5t at ! s5d+-/ation1 "u ! influ5ce ( vibrations caus$ by ! voice1 !y w\ld only produce musical1 & n articulate s\nds4 ,yet ! idea 0 magnific5t1 z ,mr4 ,preece said1 ev5 :5 he ?\ght x impossible to realise x4 ,besides1 x is easy to see t ,m4 ,b\rseul himself 0 n deceiv$ z to ! difficulties ( ! problem1 z f> z articulate s\nds are conc]n$1 = he po9ts out1 z we h se51 ! diff]5ce exi/+ betwe5 ! simple vibrations :i* produce musical s\nds1 & ! complex vibrations :i* cause articulate s\nds2 b1 z he ju/ly said3 #8,reproduce at ! "o end ( ! l9e ! vibrations ( air caus$ at ! o!r1 & spee* w be transmitt$1 h[ev] complex ! me*anism may be by :i* x is effect$4' ,we %all pres5tly see h[ ! problem 0 solv$1 & x is probable t "s attempts _h already enabl$ ,m4 ,b\rseul to anticipate ! solution ( ! "q2 b !re is no?+ 9 8 pap] to %[ :at 7 ! means he propos$1 s t ! discov]y ( ! electric transmission ( spee* _c reasonably be ascrib$ to him1 & we d n und]/& :y we %\ld be reproa*$ = hav+ at t "t fail$ to appreciate ! importance ( a discov]y :i* seem$ to be !n only )9 ! range ( fancy4 ,x 0 n until #ahgf t ! problem ( ! electric transmission ( spee* 0 f9ally solv$1 & ! discov]y has lately giv5 rise to an int]e/+ controv]sy z to priority betwe5 ,mr4 ,eli%a ,gray1 ( ,*icago1 & ,mr4 ,graham ,bell1 on :i* we mu/ say a few words4 ,z e>ly z #ahgd ,mr4 ,eli%a ,gray 0 occupi$ ) a sy/em ( musical telephone1 :i* he wi%$ to apply to manifold telegraphic transmissions1 & ! inve/igations :i* he made1 9 ord] to e/abli% ?is sy/em "u ! be/ possible conditions1 gave him a glimpse ( ! possibility ( transmitt+ articulate words by electricity4 ,:ile c>ry+ on 8 exp]im5ts on ! telegraphic sy/em1 he arrang$ 9 fact1 ab\t ! #ae? ,janu>y1 #ahgf1 a sy/em ( speak+ telephone1 & he deposit$ ! specification & draw+s 9 ! ,am]ican ,pat5t ,(fice1 9 ! =m ( a caveat or provisional specification4 ,! deposit 0 made on ! #ad? ,febru>y1 #ahgf3 on ! v same day1 ,mr4 ,graham ,bell also deposit$1 9 ! ,am]ican ,pat5t ,(fice1 a reque/ = a pat5t 9 :i* he spoke ( an in/rum5t ( ! same k9d1 b ) special application to simultane\s telegraphic transmissions by means ( a telephonic app>atus2 & ! few words :i* c\ld1 9 ?is specification1 ref] to a telephone ) articulate s\nds1 appli$ to an in/rum5t :i*1 by ,mr4 ,bell's own admission1 _h n produc$ any satisfactory results4 ,9 ,mr4 ,gray's caveat1 on ! contr>y1 ! application ( ! in/rum5t to ! electric transmission ( spee* alone is indicat$1 ! description ( ! sy/em is complete1 & ! draw+s :i* accompany x are s exact1 t a telephone made f !m w\ld "w p]fectly3 ?is 0 prov$ by ,mr4 ,gray himself1 :51 "s "t aft]w>ds1 he f9i%$ 8 in/rum5ts1 :i* diff]$ 9 no respect f ! "o describ$ 9 ,mr4 ,bell's /atem5t z work$ by a batt]y4 ,on ^! gr\nds ,mr4 ,eli%a ,gray w\ld c]ta9ly h obta9$ ! pat5t1 if ! expiration ( 8 caveat _h n be5 ! result ( an omission ( =m 9 ! ,pat5t ,(fice1 :i*1 z we "k1 decides ! priority ( inv5tions 9 ,am]ica4 ,an action on ! gr\nd ( ?is omission has lately be5 br\ght aga9/ ,mr4 ,bell1 9 ! ,supreme ,c\rt ( ! ,am]ican ,pat5t ,(fice1 to set aside ! pat5t grant$ to him4 ,if ,mr4 ,gray did n appeal be=e1 x 0 because he 0 !n :olly occupi$ ) exp]im5ts on ! sy/em ( h>monic telephone1 appli$ to telegraphic communication1 & he _h no "t to att5d to ! matt]4 ,h[ev] ?is may be1 ,mr4 ,bell did n beg9 to give s]i\s att5tion to ! speak+ telephone until he _h obta9$ 8 pat5t1 & 8 ef=ts 7 soon cr[n$ ) success3 a few mon?s lat]1 he exhibit$ 8 speak+ telephone at ,philadelphia1 :i* has f t "t attract$ s mu* public att5tion1 & :i*1 :5 p]fect$ 9 a practical po9t ( view1 rea*$ ,europe 9 ! autumn ( #ahgg "u ! =m we "k4 ,to complete ?is summ>y acc\nt ( ! telephone1 we ought to say t s9ce its success a good _m claims ( priority h aris51 z if by en*antm5t4 ,mr4 ,john ,camack1 ( ,engli% orig91 has among o!rs claim$ ! inv5tion ( ! telephone1 n m]ely rely+ on ! description he gave ( ! in/rum5t 9 #ahfe1 b on ! draw+s he execut$2 he ev5 adds1 t if he _h n lack$ means = its con/ruction1 ?is w\ld h be5 ! date ( ! discov]y ( ! telephone4 ,a simil> pret5sion has be5 put =w>d by ,mr4 ,dolbe>1 a fell[ c\ntryman ( ,mr4 ,bell1 ( ^: claim we %all speak pres5tly4 ,signor ,manzetti1 ( ,ao/a1 says ! same ?+1 ass]t+ t 8 telephonic inv5tion 0 describ$ 9 sev]al newspap]s ( #ahfe1 among o!rs 9 #8,le ,petit ,j\rnal1' ( ,p>is1 on ! #bbnd ,novemb]1 #ahfe2 #8,il ,diritto' at ,rome1 #af? ,july1 #ahfe2 #8,l',e*o d',italia1' ,new ,york1 #i? ,augu/1 #ahfe2 #8,l',italia1' ,flor5ce1 #aj? ,augu/1 #ahfe2 #8,la ,comuna d',italia1' ,g5oa1 #a/ ,decemb]1 #ahfe2 #8,la ,v]it1' ,nov>a1 #d? ,janu>y1 #ahff2 #8,il ,comm]cio1' ,g5oa1 #f? ,janu>y1 #ahff4 ,x is true t no description ( ! sy/em 0 giv51 & t ! j\rnals 9 "q only ass]t$ t exp]im5ts _h be5 made1 :i* prov$ t ! practical solution ( ! problem ( transmitt+ spee* by electricity became possible by ?is sy/em4 ,at any rate ,m4 ,*>les ,b\rseul mu/ /ill h ! cr$it ( ! priority ( ! idea1 &1 9 our op9ion1 all claims made aft] ! fact only m]it slight consid]ation4 ,be=e consid]+ ,bell's telephone1 & ! diff]5t modifications :i* h be5 appli$ to x1 x seems wor? :ile1 9 ord] to make ! read] p]fectly famili> ) ^! k9ds ( in/rum5ts1 to /udy ! electro-musical telephones :i* prec$$ x1 & especially t ( ,m4 ,reiss1 :i* 0 made 9 #ahfj1 & became ! />t+ po9t ( all ! o!rs4 ,we %all f9d t ^! in/rum5ts h v important applications1 & t telegraphy w probably be "o day mu* advanc$ by _! use4 ,,musical ,,telephones4 ,telephone ( ,m4 ,reiss4--,?is telephone is1 z f> z ! reproduction ( s\nd is conc]n$1 bas$ ^u ,mr4 ,page's discov]ies 9 #ahcg1 &1 z reg>ds electric transmission1 x is bas$ on ! vibrat+ membrane ( :i* ,mr4 ,l4 ,scott made use 9 8 phonautograph1 9 #ahee4 ,?is in/rum5t is compos$1 l telegraphic sy/ems1 ( two di/9ct p>ts1 a s5d] & a receiv]1 z repres5t$ 9 fig4 #a4 ,illu/ration3 ,,fig4 #a4 ,! s5d] 0 virtually compos$ ( a s\nd+ box ,k1 hav+ on its upp] surface a l>ge circul> op5+1 across :i* a membrane 0 /ret*$1 & 9 its c5tre !re 0 fitt$ a ?9 disk ( plat9um o1 above :i* a metallic po9t c 0 fix$1 & ?is1 toge!r ) ! disk1 con/itut$ ! contact-break]4 ,on "o face ( ! s\nd+-box ,k1 !re 0 a sort ( speak+-tube1 = ! purpose ( collect+ ! s\nd1 & direct+ x to ! int]ior ( ! box1 9 ord] t x might !n react ^u ! membrane4 ,"p ( ! box ,k is brok5 away 9 ! plate1 9 ord] t ! diff]5t p>ts ( :i* x is made may be se54 ,! rods a1 c1 :i* support ! plat9um po9t b1 are 9 metallic contact ) a ,morse key t1 plac$ on ! side ( ! box ,k1 & ) an electro-magnet ,a1 :i* belongs to a telegraphic sy/em1 int5d$ to ex*ange ! signals requir$ to />t ! action ( ! two in/rum5ts at _! respective /ations4 ,! receiv] consi/s ( a s\nd+-box ,b1 on :i* re/ two supports d1 d1 be>+ an iron rod ( ! ?ickness ( a knitt+ ne$le4 ,an induction coil ( insulat$ wire g is w\nd r\nd ?is rod1 & ! :ole is enclos$ by ! lid ,d1 :i* conc5trates ! s\nd already increas$ by ! s\nd+-box3 = ?is purpose ! box is provid$ ) two op5+s bel[ ! coil4 ,! circuit is complet$ ?r\gh ! prim>y ( ?is coil by ! two t]m9als #c & #d1 & a ,morse key t is plac$ at ! side ( box ,b1 9 ord] to ex*ange signals4 ,9 ord] to "w ?is sy/em1 ! speak+ in/rum5t %\ld be plac$ be=e ! op5+ ,t1 & ?is in/rum5t may be a flute1 a viol91 or ev5 ! human voice4 ,! vibrations ( air occasion$ by ^! in/rum5ts cause ! telephonic membrane to vibrate 9 unison1 & ! latt]1 rapidly mov+ ! plat9um disk o to & f ! po9t b1 causes a s]ies ( breaks 9 ! curr5t1 :i* are repeat$ 9 ! iron wire d d1 & trans=m$ into metallic vibrations1 ( :i* ! numb] is equal to t ( ! s\nds successively produc$4 ,accord+ to ?is mode ( action1 ! possibility ( transmitt+ s\nds ) _! relative value becomes intelligible3 b x is equally cle> t s\nds ?us transmitt$ w n h ! timbre ( ^? :i* produce !m1 s9ce ! timbre is indep5d5t ( ! numb] ( vibrations1 & x mu/ be add$ t ! s\nds produc$ by ,m4 ,reiss's in/rum5t 7 z %rill z ^? ( a *ild's p5ny trumpet1 & by no means attractive4 ,! problem ( transmitt+ musical s\nds by electricity 01 h[ev]1 really solv$1 & x c be said ) tru? t an air or a melody c\ld be he>d at any giv5 di/ance4 ,! inv5tion ( ?is telephone dates1 z we h se51 f #ahfj1 & ,pr(essor ,heisl] speaks ( x 9 8 treatise ( te*nical physics1 publi%$ at ,vi5na 9 #ahff2 he ev5 ass]ts1 9 ! article :i* he devotes to ! subject1 t al?\gh ! in/rum5t 0 /ill 9 its infancy1 x 0 capable ( transmitt+ vocal melodies1 & n m]ely musical s\nds4 ,! sy/em 0 aft]w>ds p]fect$ by ,m4 ,van d] ,weyde1 :o1 aft] read+ ! acc\nt publi%$ by ,m4 ,heisl]1 s\ght to make ! box ( ! s5d] m sonor\s1 & to /r5g!n ! s\nds produc$ by ! receiv]4 ,he writes z foll[s 9 ! #8,am]ican ,sci5tific ,j\rnal3' #8,9 #ahfh1 ,i caus$ two telephones to be made1 simil> to ^? ,i h describ$1 & ,i exhibit$ !m at a meet+ ( ! ,polyte*nic ,club ( ! ,am]ican ,in/itute4 ,! transmitt$ s\nds 7 produc$ at ! f>!/ extremity ( ! ,coop] ,in/itute1 q outside ! hall 9 :i* ! audi5ce sat3 ! receiv] 0 plac$ on a table 9 ! hall itself4 ,! vocal airs 7 fai?fully reproduc$1 b ! s\nd 0 r weak & nasal4 ,i !n tri$ to improve ! in/rum5t1 & ,i fir/ obta9$ /rong] vibrations 9 ! box ,k by caus+ rev]b]ation f ! sides ( ! box1 by means ( holl[ p>titions4 ,i next int5sifi$ ! s\nds produc$ by ! receiv]1 by introduc+ sev]al iron wires into ! coil1 in/ead ( "o4 ,^! improvem5ts 7 submitt$ to ! meet+ ( ! ,am]ican ,association = ! ,advancem5t ( ,sci5ce1 :i* 0 held 9 #ahfi1 & x 0 consid]$ t ! inv5tion conta9$ ! g]m ( a new me?od ( telegraphic transmission :i* might lead to important results4' ,?is op9ion 0 soon aft]w>ds ju/ifi$ by ! discov]ies ( ,bell & ,eli%a ,gray4 ,messrs4 ,cecil & ,leon>d ,wray's ,telephone4--,?is sy/em1 repres5t$ 9 figs4 #b & #c1 is simply an improvem5t on t ( ,m4 ,reiss1 ) ! object ( int5sify+ ! effects produc$4 ,! s5d] is provid$ ) two membranes1 in/ead ( "o2 & its receiv]1 in/ead ( be+ =m$ ( a s+le iron wire cov]$ ) a magnetis+ coil1 is compos$ ( two di/9ct coils ,h1 ,h 7fig4 #b71 plac$ 9 ! same /raight l9e1 & )9 :i* are two iron rods4 ,^! rods are fa/5$ by "o ( _! ends to two copp] disks ,a1 ,b2 ^! disks are ma9ta9$ 9 a fix$ position by screws ,i1 ,i1 & ! two o!r extremities ( ! rods1 betwe5 ! coils1 are opposite ea* o!r1 n t\*+1 b divid$ by a v small int]val4 ,! in/rum5t is set ^u a s\nd+-box1 9 :i* !re is a hole ,t 9 ! space correspond+ to ! int]val betwe5 ! coils3 ^! coils communicate ) f\r t]m9als1 :i* are connect$ ) ! electric curr5t 9 su* a way t ! adjac5t poles ( ! two rods are ( opposite pol>ity1 ?us =m+ a s+le magnet1 divid$ 9 ! c5tre4 ,x seems t by ?is arrangem5t ! s\nd produc$ becomes mu* m di/9ct4 ,illu/ration3 ,,fig4 #b4 ,illu/ration3 ,,fig4 #c4 ,! =m ( ! s5d] also is some:at diff]5t f ! "o we h previ\sly describ$3 ! upp] "p1 in/ead ( be+ horizontal1 is r incl9$1 z x appe>s 9 fig4 #c1 & ! op5+ ,e ?r\gh :i* ! s\nd has to communicate ) ! vibrat+ membrane1 occupies a great "p ( ! upp] surface ( ! box1 :i* consequ5tly appe>s to be some:at oblique4 ,! second membrane ,g1 :i* is ( ca\t*\c1 =ms a sort ( p>tition :i* divides ! box 9 two1 />t+ f ! upp] end ( ! op5+3 ! inv5tor /ates t ?is w protect ! out] membrane ,d f ! brea? & o!r injuri\s effects1 :ile increas+ ! =ce ( ! vibrations produc$ on ! fir/ membrane1 z 9 a drum4 ,! contact-break] itself also diff]s f ! "o 9 ,m4 ,reiss's in/rum5t4 ,! plat9um disk b is only plac$ 9 circuit by means ( two sl5d] wires ( plat9um or /eel1 :i* are imm]s$ 9 two small cups1 fill$ ) m]cury1 & connect$ ) ! circuit4 ,9 ?is way1 ! movem5ts ( ! membrane ,d are free1 & its vibration is r5d]$ m easy4 ,! circuit is also brok5 by a little plat9um po9t re/+ on a lev] ) a spr+-jo9t1 ,k ,h1 :i* is above ! disk3 "o end ( ! lev]1 :i* is fix$ bel[ a k9d ( ,morse key ,m ,i1 makes x possible to close ! circuit ) ! h&1 s z to give ! signal = sett+ ! app>atus to "w4 ,electric ,h>monica4--,long be=e ,m4 ,reiss's inv5tion1 & consequ5tly /ill long] be=e t ( ,mr4 ,eli%a ,gray1 ,i m5tion$ a sort ( electric h>monica1 & describ$ x z foll[s 9 ! fir/ edition ( my #8,expos des applications de l',electricit1' publi%$ 9 #ahec3-- #8,! p[] possess$ by electricity to set metallic plates 9 motion & cause _! vibration has be5 us$ = ! production ( di/9ct s\nds1 :i* c be comb9$ & h>monis$2 b 9 addition to ?is purely physical application1 electro-magnetism has come to ! aid ( c]ta9 in/rum5ts1 su* z pianos1 organs1 c41 r5d]+ !m capable ( be+ play$ at a di/ance4 ,s t ?is extraord9>y =ce may be turn$ to acc\nt 9 arts :i* are app>5tly ! lea/ susceptible ( any application ( electricity4 #8,we h already spok5 ( ,m4 de la ,rive's contact-break]4 ,x is1 z we "k1 an iron disk1 sold]$ to a /eel spr+1 & ma9ta9$ 9 a fix$ position opposite to an electro-magnet by ano!r spr+ 9 connection ) "o bran* ( ! curr5t4 ,z ! o!r bran*1 aft] pass+ into ! wire ( ! electro-magnet1 t]m9ates 9 ! iron disk itself1 ! electro-magnet is only active at ! mom5t :5 ! disk t\*es ! t]m9al spr+2 at ! mom5t ( leav+ x1 ! magnetism ceases1 & ! iron disk returns to its normal position1 & !n leaves x aga94 ,9 ?is way a vibration is produc$1 rapid 9 proportion to ! small size ( ! vibrat+ disk1 & to ! greatness ( ! =ce produc$ by ! approa* ( ! disk to ! electro-magnet4 #8,9 ord] to increase ! acut5ess ( ! s\nds1 "o or o!r ( ^! exp$i5ts mu/ be employ$4 ,! simple/ way is to use a screw :i* c be tight5$ or relax$ at pleasure1 & :i* 9 ?is mann] removes ! vibrat+ disk to a great] or less di/ance f ! electro-magnet4 ,?is is ! case 9 ,m4 ,from5t's in/rum5t1 & by ?is means he has obta9$ s\nds ( extraord9>y acut5ess1 al?\gh n unpleasant to ! e>4 #8,m4 ,from5t has n appli$ ! app>atus to a musical in/rum5t1 b x is evid5t t x w\ld be easy to d s2 x w\ld only be necess>y to make ! notes ( a key-bo>d act on metallic lev]s1 ( a l5g? correspond+ to ! position requir$ by ! disk = ! vibration ( diff]5t tones4 ,^! diff]5t lev]s1 re/+ on ! disk1 w\ld act z a po9t ( contact1 b ! po9t w\ld v>y 9 position1 accord+ to ! t\*4 #8,if ! curr5t 7 con/ant1 su* an in/rum5t w\ld c]ta9ly h _m advantages ov] ! pipe in/rum5ts :i* are 9 use1 s9ce ! vibration might be prolong$ at w 9 ! case ( ea* note1 & ! s\nds w\ld be s(t]2 un=tunately ! irregul> action ( ! batt]y makes x difficult 9 practice4 ,^! k9ds ( in/rum5ts are !re=e only us$ z a means ( regulat+ by e> ! =ce ( ! batt]y1 a mu* m conv5i5t regulator ?an ! rheomet]s1 s9ce x is possible to e/imate by !m ! v>iations ( ! batt]y dur+ an exp]im5t )\t any di/raction ( ! m9d4' ,9 #ahef ,m4 ,ptr9a1 ( ,prague1 inv5t$ an analog\s arrangem5t1 to :i* he gave ! "n ( electric h>monica1 al?\gh1 /rictly speak+1 he _h n ?\ght ( x z a musical in/rum5t4 ,?is is :at ,i h said on ! subject 9 vol4 iv4 ( ! second edition ( my #8,expos des applications de l',electricit1' publi%$ 9 #ahei3-- #8,! pr9ciple ( ?is in/rum5t is simil> to t ( ,neef's rheotome1 9 :i* ! hamm] is replac$ by sl5d] rods1 ^: vibrations produce a s\nd4 ,f\r ( ^! rods are plac$ side by side1 & :5 mov$ by keys1 & arre/$ by lev]s1 produce comb9$ s\nds ( :i* ! orig9 may be easily %[n4' ,x is true t no?+ is said 9 ?is passage ( ! capability possess$ by ^! in/rum5ts ( be+ play$ at a di/ance2 b ?is idea 0 q legitimate1 & ,g]man p]iodicals ass]t t x 0 accompli%$ by ,m4 ,ptr9a ev5 be=e #ahef4 ,x 0 ! result ( :at ,i said at ! outset3 #8t electro-magnetism may come to ! aid ( c]ta9 in/rum5ts1 su* z pianos1 organs1 c41 9 ord] to enable !m to be play$ at a di/ance1' & ,i also po9t$ out ! exp$i5ts employ$ = ! purpose1 & ev5 = sett+ !m at "w1 "u ! influ5ce ( a small musical box4 ,i did n1 h[ev]1 ascribe importance to ! matt]1 & x is only by way ( hi/orical illu/ration t ,i speak ( ^! sy/ems4 ,telephone by ,mr4 ,eli%a ,gray1 ( ,*icago4--,?is sy/em1 inv5t$ 9 #ahgd1 is 9 reality only an in/rum5t ( ! nature ( ^? :i* prec$$ x1 b ) important modifications1 :i* made x possible to apply x usefully to telegraphy4 ,9 an e>ly model1 he made use ( an induction coil1 ) two helices1 "o ov] ! o!r3 ! contact-break]1 :i* 0 vibrat+1 0 multiple1 & s arrang$ z to produce vibrations num]\s en\gh to emit s\nds4 ,^! s\nds may1 z we h se51 be modifi$ by ?is arrangem5t1 accord+ to ! mode 9 :i* ! in/rum5t is adju/$1 & if !re are a c]ta9 numb] ( su* contact-break]s side by side1 ) vibrat+ disks s ord]$ z to produce ! diff]5t notes ( ! scale on sev]al octaves1 x becomes possible1 by a comb9ation ( c]ta9 notes1 to execute on ?is new k9d ( in/rum5t a piece ( music su* z may be produc$ by an h>monium1 an accordion1 or any o!r in/rum5t ) bl[]s4 ,! contact-break]s are set 9 motion by means ( ! prim>y curr5t ( ! induction coil1 z x circulates ?r\gh "o or o!r ( ! electro-magnets ( ^! contact-break]s1 actuat$ by ! l[]+ ( ! notes ( a key-bo>d connect$ ) !m1 & ! second>y curr5ts :i* arise 9 ! coil1 9 consequ5ce ( ! int]ruptions 9 ! prim>y curr5ts1 transmit ! correspond+ vibrations to a remote receiv]4 ,!re is an analogy betwe5 ?is in/rum5t & ! telephones ( :i* we h already spok5 by ,reiss & ,wray1 b ! effect is increas$ by ,mr4 ,gray's modifications4 ,we repres5t 9 fig4 #d ! arrangem5t ( ! fir/ sy/em4 ,! vibrators are ,a & ,a1 ! key-bo>d ,m & ,m1 ! induction coil ,b1 & ! receiv] ,c4 ,?is receiv] consi/s1 z we see1 ( a simple electro-magnet ,n ,n3 above its poles !re is a metal cyl9drical case ,c1 ( :i* ! bottom is made ( iron1 to s]ve z an armature4 ,?is box1 l a viol91 is pi]c$ ) two holes 9 ! =m ,s1 to s]ve z a s\nd+-bo>d2 & ,mr4 ,eli%a ,gray has asc]ta9$ t ! molecul> motion :i* takes place 9 ! magnetic core & its armature1 "u ! influ5ce ( alt]nate magnetisation & demagnetisation1 suffic$ to produce vibrations correspond+ to ! velocity ( ^! alt]nations1 & to emit s\nds :i* became audible :5 !y 7 magnifi$ by ! s\nd+-bo>d4 ,illu/ration3 ,,fig4 #d4 ,x is q intelligible t ! effect obta9$ 9 ?is sy/em might be reproduc$1 if1 in/ead ( contact-break]s or electric rheotomes1 me*anical contact-break]s 7 us$ at ! s5d+ /ation1 s arrang$ z to furni% ! requisite numb] ( breaks 9 ! curr5t :i* communicates ! vibrations ( ! diff]5t notes ( ! scale4 ,9 ?is way also x w\ld be possible to disp5se ) ! induction coil1 by caus+ ! curr5t :i* has be5 brok5 by ! me*anical contact-break] to react ^u ! receiv]4 ,mr4 ,eli%a ,gray has moreov] made a diff]5t arrangem5t ( ?is telephonic sy/em1 :i* he has appli$ to telegraphy = simultane\s electric transmissions1 ( :i* we %all speak pres5tly4 ,if we may believe ,mr4 ,eli%a ,gray1 ! vibrations transmitt$ by ! second>y curr5ts w\ld be capable1 by ! int]v5tion ( ! human body1 ( caus+ ! s\nds to be reproduc$ at a di/ance by conduct+ disks1 :i* vibrate readily1 & are plac$ on a s\nd+-box4 ,9 ?is way musical s\nds may be evok$ f copp] cyl9d]s plac$ ^u a table1 f a metallic disk fa/5$ to a k9d ( viol91 f a membrane /ret*$ on a drum1 or f any o!r resonant sub/ance1 by t\*+ any ( ^! objects ) "o h&1 :ile hold+ ! end ( ! l9e ) ! o!r4 ,^! s\nds1 ( :i* ! quality mu/ v>y ) ! sub/ance t\*$1 w\ld reproduce ! transmitt$ note ) ! precise numb] ( vibrations :i* belong to x4#a ,mr4 ,v>ley's ,telephone4--,?is is1 /rictly speak+1 m]ely a musical telephone ( ! same k9d z t ( ,mr4 ,gray1 b ! arrangem5t ( ! receiv] is orig9al & int]e/+4 ,?is "p ( ! in/rum5t ess5tially consi/s ( a drum ( l>ge size 7?ree or f\r feet 9 diamet]71 )9 :i* is a cond5s] =m$ ( f\r %eets ( t9foil1 divid$ by %eets ( "s insulat+ mat]ial1 & ) a surface ( ab\t half ! size ( ! drum4 ,! plates ( ! cond5s] are plac$ p>allel to ! membranes ( ! drum1 & v little remov$ f its surface4 ,if an electric *>ge is communicat$ to "o ( ! s]ies ( conduct+ plates ( ! cond5s]1 ^? :i* correspond to x are attract$1 & if !y 7 movable !y might communicate to ! int]v5+ /rata ( air a movem5t :i*1 on rea*+ ! membranes ( ! drum1 might1 by a s]ies ( *>ges 9 rapid succession1 cause ! membranes to vibrate1 & ?us produce s\nds3 ^! s\nds w\ld correspond to ! numb] ( *>ges & dis*>ges :i* _h occurr$4 ,s9ce ^! *>ges & dis*>ges are det]m9$ by ! contact ( ! two plates ( ! cond5s]1 at ! extremities ( ! second>y circuit ( an induction coil1 ( :i* ! prim>y circuit has be5 duly brok51 x becomes evid5t t1 9 ord] to cause ! drum to emit any giv5 s\nd1 x w be en\gh to produce ! numb] ( vibrations 9 ! contact-break] ( ! induction coil :i* are requir$ = ?is s\nd4 ,! means employ$ by ,mr4 ,v>ley to produce ^! int]ruptions are ! same :i* are 9 use 9 sev]al electrical in/rum5ts1 & especially 9 *ronographs--an electro-magnetic tun+-=k1 regulat$ s z to emit ! s\nd requir$4 ,?is tun+-=k may1 by act+ z contact-break]1 react on ! prim>y curr5t ( ! induction coil2 if ! numb] ( ! tun+-=ks equals t ( ! musical notes :i* are to be transmitt$1 & if ! electro-magnets :i* set !m 9 motion are connect$ ) ! key-bo>d ( a piano1 x w\ld be possible to transmit a melody to a di/ance by ?is sy/em1 z well z by t ( ,mr4 ,eli%a ,gray4 ,! peculi>ity ( ?is sy/em consi/s 9 ! reproduction ( s\nds by ! action ( a cond5s]1 & we %all pres5tly see t ?is idea1 adopt$ by ,messrs4 ,poll>d & ,gami]1 l$ to int]e/+ results4 ,s++ ,cond5s] ( ,,mm4 ,poll>d & ,g>ni]4--,?is in/rum5t1 :i* a/oni%es all :o he> x1 attract$ public att5tion 9 ,london "s "t ago4 ,x is difficult to say :y its fame 0 n great]1 s9ce mu* att5tion has be5 be/[$ on less curi\s in/rum5ts4 ,x is a fact t we h be5 able1 ?anks to ,,mm4 ,poll>d & ,g>ni]1 to he> songs issue f a sort ( copy-book1 s z to become audible ?r\gh\t ! room4 ,! songs ?us reproduc$ are c]ta9ly n always p]fectly true2 yet :5 ! p]son :o s+s into ! s5d] is a musician1 & und]/&s h[ to make use ( x1 ! cond5s] 9 "q w emit s\nds some:at resembl+ ^? ( ! violoncello or ! hautbois4 ,! s++ in/rum5t consi/s ( a cond5s] ,k1 =m$ ( ?irty %eets ( pap]1 laid "o ov] ! o!r1 f n9e to ?irte5 c5timtres 9 ?ickness3 betwe5 ^!1 tw5ty-eight %eets ( t9foil1 f six to twelve c5timtres ?ick1 are int]calat$1 s jo9$ z to =m ! two plates ( ! cond5s]4 ,= ?is purpose ! pair %eets are jo9$ toge!r at "o end ( ! copy-book1 & ! odd %eets at ! o!r end4 ,?is sy/em is fa/5$ to a /iff c>ton1 aft] tak+ c>e to b9d x ) a /rip ( pap]1 & ! %eets ( t9foil are jo9$ to ! two ends ( ! cond5s] by two copp] rims ,d1 ,d1 :i* are provid$ ) t]m9als = ! circuit wire1 & 9 ?is way ! s++ in/rum5t is con/ruct$4 ,a some:at heavy weight1 plac$ ^u ! cond5s] to compress ! %eets1 does n 9 any way prev5t x f work+2 & ?is vitiates ! !ory fir/ put =w>d to expla9 its effects1 t ! %eets 7 mov$ by attraction4 ,illu/ration3 ,,fig4 #e4 ,! s5d+ in/rum5t consi/s ( a sort ( telephone )\t a h&le1 ,e1 ( :i* ! vibrat+ disk is =m$ ( a v ?9 plate ( t94 ,a cyl9drical piece ( c>bon ,c is fa/5$ to its c5tre1 & is support$ by ano!r cyl9d] ( ! same mat]ial ,h4 ,?is re/s on a transv]se piece ( wood ,a ,b1 jo9t$ on ! side ,a1 on ! edge opposite to ! box1 by means ( a regulat+ screw ,v4 ,an ar*$ spr+ ,r 7! end ( a wat* spr+7 plac$ across ?is piece ( wood gives x a c]ta9 ela/icity b5ea? ! pressure1 & ?is ela/icity is necess>y 9 ord] t ! in/rum5t may act prop]ly1 & x ?us becomes a sort ( microphone ) a diaphragm4 ,! t9 plate is put into communication ) "o pole ( a batt]y ,p1 ( six ,leclan* cells1 & ! l[] c>bon cyl9d] ,h corresponds to ! prim>y helix ( an induction coil ,m1 previ\sly connect$ ) ! second pole ( ! batt]y3 ,f9ally1 ! two extremities ( ! second>y helix ( ! coil1 a & b1 are 9 imm$iate connection ) ! two plates ,d1 ,d1 ( ! cond5s]4 ,?is second>y helix %\ld consi/ ( tw5ty /r&s ( wire ,no4 #cb1 cov]$ ) silk1 & ! prim>y helix is made ( five /r&s ( wire ,no4 #af4 ,! l5g? ( ! coil %\ld n exce$ sev5 c5timtres & ! diamet] ( ! core ( f9e iron wire ought to be ab\t "o c5timtre4 ,9 ord] to produce song on ! cond5s]1 ! s5d] mu/ be s regulat$ t ! two c>bons ,c & ,h d n t\* ea* o!r 9 _! normal condition1 b !y %\ld be s close t 9 s++ ! vibrations ( ! disk ,l ,l may effect ! ne$ful contacts4 ,! adju/m5t c be easily made by ! t\*1 & by utt]+ ! same note until x is repeat$ by ! cond5s]4 ,if ?ree notes1 giv5 9 succession1 are fai?fully reproduc$1 ! in/rum5t may be assum$ to be prop]ly regulat$1 &1 9 ord] to make x "w1 x is en\gh to apply ! m\? to ! m\?piece z x is appli$ to a re$ pipe4 ,9 ord] to obta9 a satisfactory result1 ! disk ( ! in/rum5t mu/ be he>d to vibrate1 z 9 a flte l'oignon4 ,in/ead ( c>bons1 contacts ( plat9um may be us$2 b :5 arrang$ z we h describ$1 ! in/rum5t may be employ$ = sev]al purposes1 z we %all see pres5tly4 ,?is in/rum5t is made by ,,mm4 ,*>d9 & ,pray]4 ,m4 ,janss5s has made ! sy/em m portable by fa/5+ ! s5d]1 repres5t$ 9 fig4 #e1 to a h&le 9 :i* ! induction coil is plac$3 ! in/rum5t !n resembles an ord9>y telephone1 & ! vibration ( ! diaphragm is made m easy by pi]c+ two holes 9 x4 ,on ! side ( ! s5d+-box1 above & bel[ ! diaphragm1 !re are b9d+ screws 9 connection ) ! end ( ! h&le1 s9ce ! in/rum5t may be us$ z an ord9>y telephonic s5d]1 & ev5 z a telephonic receiv]4 ,,speak+ ,,telephones4 ,we h se5 t ! telephones j describ$ c only transmit musical s\nds1 s9ce !y c m]ely repeat simple vibrations1 9 great] or less numb]1 x is true1 b n 9 simultane\s comb9ations l ^? :i* reproduce articulate s\nds4 ,up to ! "t ( ,mr4 ,bell's inv5tion1 ! transmission ( spee* c\ld only take place ) ! aid ( ac\/ic tubes1 or ( ! /r+ telephones ( :i* we h spok54 ,al?\gh ^! in/rum5ts h no connection ) ! object ( our /udy 9 ?is "w1 we h ?\ght x necess>y to say a few words ab\t !m1 s9ce !y may sometimes be comb9$ ) electric telephones1 & also repres5t ! fir/ /age ( ! inv5tion4 ,/r+ ,telephones4--,^! in/rum5ts1 :i* h flood$ ! cities ( ,europe = sev]al ye>s1 s9ce ! date ( ! inv5tion 0 #ahfg1 are int]e/+ 9 !mselves1 & we are surpris$ t !y h n hi!rto tak5 a place 9 ! collections ( physical sci5ce4 ,!y are made ( two metal or c>dbo>d tubes1 9 ! =m ( a cyl9drical cone3 "o end is clos$ by a tightly /ret*$ membrane ( p>*m5t1 9 ! c5tre ( :i* ! cord or /r+ int5d$ to connect ! two cyl9d]s is fa/5$ by a knot4 ,:5 two su* tubes are connect$ 9 ?is way1 & ! cord is tightly /ret*$1 z 9 fig4 #f1 x is only necess>y to apply "o tube to ! e>1 :ile ano!r speaks into ! op5+ ( ! o!r tube3 ! words spok5 by ! latt] are in/antly transmitt$1 & x is ev5 possible to conv]se 9 q an und]tone4 ,"u ^! conditions ! vibrations ( ! membrane affect$ by ! voice are me*anically transmitt$ to ! o!r membrane by ! /r+1 :i*1 z ,rob]t ,hooke decl>$ 9 #affg1 is a bett] transmitt] ( s\nd ?an ! air4 ,9 ?is way x is possible to communicate at a di/ance ( #agj y>ds1 & ! size & nature ( ! cord h "s influ5ce4 ,! sell]s ( ^! in/rum5ts say t ! be/ results are obta9$ f silk5 cords1 & ! wor/ f ^? made ( hemp4 ,cords ( plait$ cotton are usually employ$ = ! sake ( *eapness4 ,illu/ration3 ,,fig4 #f4 ,9 "s patt]ns1 ! tubes are s arrang$ z to pres5t1 betwe5 ! membrane & ! m\?1 a diaphragm pi]c$ ) a hole1 & ! in/rum5t some:at resembles a bell ) its base bor$ & clos$ aga9 a little above ! p>*m5t membrane2 b ,i h n obs]v$ t ?is patt]n is decid$ly sup]ior to ! o!rs4 ,x has also be5 ass]t$ t horn-%ap$ tubes ( nickel silv] are to be pref]r$1 ( :i* ,i am equally d\btful4 ,at any rate1 ^! in/rum5ts h produc$ unexpect$ results2 & al?\gh _! practical use is v limit$1 !y are int]e/+ f a sci5tific po9t ( view1 & are in/ructive toys = *ildr54 ,mr4 ,mill>1 ( ,glasg[1 decl>es t ! effect produc$ by ^! telephones dep5ds v mu* on ! nature ( ! /r+1 ! way 9 :i* x is atta*$1 & ! way 9 :i* ! membrane is fa/5$ to ! m\?piece4 ,improvem5ts made 9 ! ,/r+ ,telephone4--,! amaz+ effects ( ! ,bell telephones h lately br\ght ! /r+ telephones1 :i* 7 only reg>d$ z *ildr5's toys1 aga9 into fa%ion4 ,s9ce !y h made x possible to transmit to sev]al p]sons ! words reproduc$ by an electric telephone1 means h be5 s\ght = comb9+ !m usefully ) ! latt]1 & ! be/ mode ( mak+ !m speak on a /r+ pres5t+ sev]al angles has be5 s\ght =3 x has be5 %[n t1 "u ! usual conditions1 ^! in/rum5ts only speak di/9ctly :5 ! /r+ is /ret*$ 9 a "r l9e4 ,to solve ?is problem1 x occurr$ to ,m4 ,a4 ,brguet to make use ( a sort ( tamb\r9e = ! supports1 ) ! /r+ pass$ ?r\gh _! c5tre2 ! s\nd convey$ by t "p ( ! /r+ :i* is 9 connection ) ! speak+-horn causes ! membrane ( ! tamb\r9e to vibrate1 :i* aga9 communicates ! vibration to ! next portion ( /r+4 ,9 ?is way ! angles may be multipli$ at w1 & ! /r+ may be support$ ?r\gh\t ! l5g? compatible ) ?is k9d ( telephone1 :i* does n exce$ #aab y>ds4 ,m4 ,a4 ,brguet has also inv5t$ a sy/em ( relays to accompli% ! same object4 ,he makes ! /r+s t]m9ate 9 two membranes :i* close ! two op5+s ( a brass cyl9d]4 ,! s\nds reproduc$ on "o ( ^! membranes react ^u ! o!r1 :i* vibrates "u its influ5ce1 z if x 7 affect$ by ! voice4 ,! cyl9d] !n acts z an ord9>y ac\/ic tube1 & its =m may be v>i$ at pleasure4 ,m4 ,a4 ,badet1 on ,febru>y #a1 #ahgh1 succe$$ 9 mak+ /r+ telephones 9 an analog\s way1 & he us$ p>*m5t /ret*$ ^u frames :i* act$ z resonant bo>ds4 ,! /r+ 0 fix$ 9 ! c5tre ( ! membrane1 & made ) x ! angle desir$4 ,sev]al sci5tific m51 among o!rs ,messrs4 ,:eat/one1 ,cornu1 & ,m]cadi]1 h long be5 occupi$ ab\t ^! ways ( transmission by wire1 & ,messrs4 ,mill>1 ,heaviside1 & ,nixon h lately made "s int]e/+ exp]im5ts1 on :i* we mu/ say a few words4 ,mr4 ,mill> asc]ta9$ t by means ( a telegraphic wire1 /ret*$ & connect$ by two copp] wires ) two vibrat+ disks1 musical s\nds might be convey$ to a di/ance exce$+ #afj y>ds1 & t by /ret*+ ^! wires ?r\gh a h\se1 & connect+ !m ) m\?-&-e> holes 9 diff]5t rooms1 communication betwe5 !m became p]fectly easy4 ,= ! vibrat+ disks he employ$ wood1 metal1 or gutta-p]*a1 9 ! =m ( a drum1 ) wires fix$ 9 ! c5tre4 ,! s\nd seems to become m int5se 9 proportion to ! ?ickness ( ! wire4 ,messrs4 ,heaviside & ,nixon1 9 _! exp]im5ts at ,newca/le-on-,tyne1 h asc]ta9$ t ! mo/ effective wire 0 ,no4 #d ( ! ,engli% gauge4 ,!y employ$ wood5 disks in* 9 ?ickness1 & ^! may be plac$ 9 any "p ( ! l5g? ( ! wire4 ,:5 ! wire 0 well /ret*$ & motionless1 x 0 possible to he> :at 0 said at a di/ance ( #bcj y>ds1 & x seems t ,mr4 ,huntley1 by us+ v ?9 iron diaphragms1 & by insulat+ ! l9e wire on glass supports1 0 able to transmit spee* = #b1dej feet1 9 spite ( ! zigzags made by ! l9e on its supports4 ,mr4 ,graham ,bell's ,electric ,telephone4--,telephonic in/rum5ts 7 at ?is /age :5 ,bell's telephone 0 %[n at ! ,philadelphia ,exhibition ( #ahgf4 ,sir ,william ,?ompson did n hesitate to call x #8! wond] ( wond]s1' & x in/antly attract$ univ]sal att5tion1 al?\gh !re 0 at fir/ mu* incr$ulity z to its g5u95ess4 ,?is telephone1 9 fact1 reproduc$ articulate words1 a result :i* surpass$ all ! conceptions ( physici/s4 ,9 ?is case x 0 no long] a conception1 to be treat$ z vision>y until !re 0 pro( to ! contr>y3 ! in/rum5t spoke1 & ev5 spoke s l\dly t x 0 n necess>y to apply ! e>4 ,sir ,william ,?ompson spoke to ?is effect on ! subject at ! meet+ ( ! ,briti% ,association at ,glasg[ 9 ,septemb] #ahgf3-- #8,9 ! dep>tm5t ( telegraphs 9 ! ,unit$ ,/ates ,i saw & he>d ,mr4 ,eli%a ,gray's electric telephone1 ( wond]ful con/ruction1 :i* c repeat f\r despat*es at ! same "t 9 ! ,morse code1 &1 ) "s improvem5ts 9 detail1 ?is in/rum5t is evid5tly capable ( a f\rfold deliv]y4 ,9 ! ,canadian dep>tm5t ,i he>d 8,to be or n to be8 ,!re's ! rub10 utt]$ ?r\gh a telegraphic wire1 & its pronunciation by electricity only made ! rally+ tone ( ! monosyllables m emphatic4 ,! wire also repeat$ "s extracts f ,new ,york pap]s4 ,) my own e>s ,i he>d all ?is1 di/9ctly articulat$ ?r\gh ! sl5d] circul> disk =m$ by ! armature ( an electro-magnet4 ,x 0 my fell[-juryman1 ,pr(essor ,watson1 :o1 at ! o!r extremity ( ! l9e1 utt]$ ^! words 9 a l\d & di/9ct voice1 :ile apply+ 8 m\? to a tightly /ret*$ membrane provid$ ) a small piece ( s(t iron1 :i* execut$ movem5ts correspond+ to ! s\nd vibrations ( ! air close to an electro-magnet introduc$ into ! circuit4 ,?is discov]y1 ! wond] ( wond]s 9 electric telegraphy1 is due to a "y fell[-c\ntryman ( our own1 ,mr4 ,graham ,bell1 a native ( ,ed9burgh & n[ naturalis$ 9 ,new ,york4 #8,x is impossible n to admire ! d>+ inv5tion by :i* we h be5 able to realise ) ^! simple exp$i5ts ! complex problem ( reproduc+ by electricity ! tones & delicate articulations ( voice & spee*2 & x 0 necess>y1 9 ord] to obta9 ?is result1 to f9d out ! means ( v>y+ ! int5sity ( ! curr5t 9 ! same proportion z ! inflections ( ! s\nd emitt$ by ! voice4' ,if we are to believe ,mr4 ,graham ,bell1 ! inv5tion ( ! telephone 0 n due to a spontane\s & =tunate conception3 x 0 ! result ( 8 long & pati5t /udies 9 ac\/ic sci5ce1 & ( ! lab\rs ( ! physici/s :o prec$$ him4#b ,8 fa!r1 ,mr4 ,alex&] ,melville ,bell1 ( ,ed9burgh1 _h /udi$ ?is sci5ce deeply1 & _h ev5 succe$$ 9 repres5t+ ) great +5uity ! adaptation ( ! vocal organs = ! emission ( s\nd4 ,x 0 natural t he %\ld in/il a ta/e = 8 fav\rite /udies into 8 son's m9d1 & !y made toge!r num]\s rese>*es 9 ord] to discov] ! relations :i* exi/ betwe5 ! diff]5t elem5ts ( spee* 9 diff]5t languages1 & ! musical relations ( v[els4 ,x is true t sev]al ( ^! rese>*es _h be5 made by ,m4 ,helmholtz1 & "u m fav\rable conditions2 b ^! /udies 7 ( great use to ,mr4 ,bell :5 he 0 aft]w>ds occupi$ ) ! telephone1 & ,helmholtz's exp]im5ts1 :i* he repeat$ ) "o ( 8 fri5ds1 ,mr4 ,hellis ( ,london1 conc]n+ ! artificial reproduction ( v[els by means ( electric tun+-=ks1 laun*$ him into ! /udy ( ! application ( electricity to ac\/ic in/rum5ts4 ,he fir/ inv5t$ a sy/em ( an electric h>monica ) a key-bo>d1 9 :i* ! diff]5t s\nds ( ! scale 7 reproduc$ by electric diapasons ( diff]5t =ms1 adapt$ to diff]5t notes1 & :i*1 :5 set 9 motion by ! successive l[]+ ( ! keys1 c\ld reproduce s\nds correspond+ to ! notes t\*$1 j z 9 an ord9>y piano4 ,he next1 z he tells u1 turn$ 8 att5tion to telegraphy1 & ?\ght ( mak+ ! ,morse telegraphs audible by caus+ ! electro-magnetic organ to react on s\nd+ contacts4 ,x is true t ?is result _h already be5 obta9$ 9 ! s\nd]s us$ 9 telegraphy1 b he ?\ght t by apply+ ?is sy/em to 8 electric h>monica1 & by employ+ su* an int5sify+ in/rum5t z ,helmholtz's resonator at ! receiv+ /ation1 x w\ld be possible to obta9 ?r\gh a s+le wire simultane\s transmissions :i* %\ld be due to ! action ( ! voice4 ,we %all see pres5tly t ?is idea 0 realis$ almo/ at ! same "t by sev]al inv5tors1 among o!rs by ,m4 ,paul ,lac\r1 ( ,cop5hag51 ,mr4 ,eli%a ,gray1 ( ,*icago1 & ,messrs4 ,edison & ,v>ley4 ,mr4 ,bell's /udy ( electric telephones really dates f ?is "t1 & he pass$ f complex to simple in/rum5ts1 mak+ a c>eful /udy ( ! diff]5t modes ( vibration :i* arise f diff]5t modes ( electric action4 ,! foll[+ is an ab/ract1 ) ! omission ( m te*nical details1 ( ! pap] read by ,mr4 ,bell to ! ,society ( ,telegraphic ,eng9e]s1 ,london1 ,octob] #ca1 #ahgg4 ,if ! int5sity ( an electric curr5t is repres5t$ by ! ord9ates ( a curve1 & ! duration ( breaks 9 ! curr5t by ! absciss1 ! giv5 curve may repres5t ! waves ( ! positive or negative curr5t respectively1 above & bel[ ! l9e ( ,x1 & ^! waves w be m or less acc5tuat$1 j z ! transmitt$ curr5ts are m or less in/antane\s4 ,if ! curr5ts :i* are int]rupt$ to produce a s\nd are q in/antane\s 9 _! manife/ation1 ! curve repres5ts a s]ies ( isolat$ ind5tations1 z we see 9 fig4 #g2 & if ! int]ruptions are s made z only to produce diff]5ces ( int5sity1 ! curve is pres5t$ "u ! =m ( fig4 #h4 ,f9ally1 if ! emissions ( curr5t are s ord]$ t _! int5sity alt]nately increases & dim9i%es1 ! curve takes ! =m repres5t$ 9 fig4 #i4 ,9 ! fir/ case1 ! curr5ts are int]mitt5t2 9 ! second1 pulsatory2 9 ! ?ird case1 !y are undulatory4 ,illu/ration3 ,,fig4 #g4 ,illu/ration3 ,,fig4 #h4 ,illu/ration3 ,,fig4 #i4 ,^! curr5ts are necess>ily positive or negative1 accord+ to _! position above or bel[ ! l9e x1 & if !y are alt]nately rev]s$1 ! curves pres5t ! =m giv5 9 fig4 #aj1 curves :i* ess5tially diff] f ! fir/1 n m]ely 9 ! diff]5t =m ( ! ind5tations1 b especially 9 ! suppression ( ! extra curr5t1 :i* is always f\nd 9 ! pulsatory & undulatory curr5ts4 ,illu/ration3 ,,fig4 #aj4 ,! two =m] sy/ems ( curr5ts h long be5 9 use = ! electric transmission ( musical s\nds1 ( :i* we h an int]e/+ example 9 ,reiss's telephone already describ$4 ,b ,mr4 ,bell claims to h be5 ! fir/ to employ ! undulatory curr5ts1 :i* made x possible to solve ! problem ( transmitt+ spee*4#c ,9 ord] to e/imate ! importance ( ?is discov]y1 x w be en\gh to analyse ! effects produc$ ) ^! diff]5t sy/ems ( curr5ts :5 sev]al notes ( v>y+ pit* are to be comb9$4 ,fig4 #g %[s a comb9ation 9 :i* ! /yles a1 a1 ( two s5d+ in/rum5ts cause ! int]ruption ( ! curr5t f ! same batt]y ,b1 s t ! giv5 vibrations %\ld be betwe5 !m 9 ! relation ( a ti]ce major1 t is 9 ! relation ( f\r to five4 ,"u su* conditions1 ! curr5ts are int]mitt5t1 & f\r contacts ( a are produc$ 9 ! same space ( "t z ! five contacts ( a1 & ! correspond+ electric int5sities w be repres5t$ by ! ind5tations we see 9 ,a#b & 9 ,b#b3 ! comb9ation ( ^! int5sities ,a#b ,b#b w produce ! ind5tations at unequal int]vals :i* may be obs]v$ on ! ?ird l9e4 ,x is evid5t t al?\gh ! curr5t ma9ta9s a uni=m int5sity1 !re is less "t = ! breaks :5 ! int]rupt+ /yles act toge!r ?an :5 !y act sep>ately1 s t :5 !re are a numb] ( contacts effect$ simultane\sly by /yles work+ at diff]5t degrees ( velocity1 ! effects produc$ w h ! effect ( a cont9u\s curr5t4 ,! maximum numb] ( di/9ct effects :i* c be produc$ 9 ?is way w1 h[ev]1 greatly dep5d on ! relation :i* exi/s betwe5 ! durations ( ! make & break ( ! curr5t4 ,! %ort] ! contacts are1 & ! long] ! breaks1 ! m num]\s w be ! effects transmitt$ )\t confusion1 & vice v]s4 ,by ! aid ( pulsatory curr5ts ! transmission ( musical s\nds is effect$ 9 ! way indicat$ 9 fig4 #h1 & x is se5 t :5 !y are produc$ simultane\sly1 ! result ,a#b ,b#b is analog\s to t :i* w\ld be produc$ by a cont9u\s curr5t ( m9imum int5sity4 ,9 ! case ( undulatory curr5ts ! result is diff]5t1 b 9 ord] to produce !m x is necess>y to h rec\rse to inductive effects1 & fig4 #i indicates ! mann] 9 :i* ! exp]im5t %\ld be made4 ,9 ?is case1 #8! curr5t f ! batt]y ,b is ?r[n into waves by ! inductive action ( iron or /eel re$s ,m1 ,m1 vibrat$ 9 front ( electro-magnets e1 e1 plac$ 9 circuit ) ! batt]y3 ,a#b & ,b#b repres5t ! undulations caus$ 9 ! curr5t by ! vibration ( ! magnetis$ bodies1 & x w be se5 t !re are f\r undulations ( ,b#b 9 ! same "t z five undulations ( ,a#b4 ,! resultant effect ^u ! ma9 l9e is express$ by ! curve ,a#b ,b#b1 :i* is ! algebraical sum ( ! s9usoidal curves ,a#b & ,b#b4 ,a simil> effect is produc$ :5 rev]s$ undulatory curr5ts are employ$1 z 9 fig4 #aj1 :]e ! curr5t is produc$ by ! vibration ( p]man5t magnets unit$ ^u a circuit1 )\t a voltaic batt]y4 #8,x w be und]/ood f figs4 #i & #aj t ! effect ( transmitt+ musical signals ( diff]5t pit*es simultane\sly along a s+le wire is n to oblit]ate ! vibratory "* ( ! curr5t1 z 9 ! case ( int]mitt5t & pulsatory curr5ts1 b to *ange ! %apes ( ! electrical undulations4 ,9 fact1 ! effect produc$ ^u ! curr5t is precisely analog\s to ! effect produc$ 9 ! air by ! vibration ( ! induc+ bodies ,m1 ,m4 ,h5ce x %\ld be possible to transmit z _m musical tones simultane\sly ?r\gh a telegraph wire z ?r\gh ! air4' ,illu/ration3 ,,fig4 #aa4 ,aft] apply+ ^! pr9ciples to ! con/ruction ( a telegraphic sy/em = multiple transmissions1 ,mr4 ,bell lo/ no "t 9 mak+ use ( 8 rese>*es to improve ! vocal tra9+ ( deaf mutes4 #8,x is well kn[n1' he said1 #8t deaf mutes are dumb m]ely because !y are deaf1 & t !re is no defect 9 _! vocal organs to incapacitate !m f utt]ance4 ,h5ce x 0 ?\ght t my fa!r's sy/em ( pictorial symbols1 popul>ly kn[n z visible spee*1 might prove a means :]eby we c\ld tea* ! deaf & dumb to use _! vocal organs & to speak4 ,! great success ( ^! exp]im5ts urg$ ^u me ! advisability ( devis+ me?ods ( exhibit+ ! vibrations ( s\nd optically1 = use 9 tea*+ ! deaf & dumb4 ,= "s "t ,i c>ri$ on exp]im5ts ) ! manometric capsule ( ,ko5ig1 & ) ! phonautograph ( ,lon ,scott4 ,! sci5tific app>atus 9 ! ,in/itute ( ,te*nology 9 ,bo/on 0 freely plac$ at my disposal = ^! exp]im5ts1 & x happ5$ t at t "t a /ud5t ( ! ,in/itute ( ,te*nology1 ,mr4 ,maurey1 _h inv5t$ an improvem5t ^u ! phonautograph4 ,he _h succe$$ 9 vibrat+ by ! voice a /ylus ( wood ab\t a foot 9 l5g? :i* 0 atta*$ to ! membrane ( ! phonautograph1 & 9 ?is way he _h be5 enabl$ to obta9 enl>g$ trac+s ^u a plane surface ( smok$ glass4 ,) ?is app>atus ,i succe$$ 9 produc+ v beautiful trac+s ( ! vibrations ( ! air = v[el s\nds4 ,"s ( ^! trac+s are %[n 9 fig4 #aa4 ,i 0 mu* /ruck ) ?is improv$ =m ( app>atus1 & x occurr$ to me t !re 0 a rem>kable lik5ess betwe5 ! mann] 9 :i* ?is piece ( wood 0 vibrat$ by ! membrane ( ! phonautograph & ! mann] 9 :i* ! ossicul ( ! human e> 7 mov$ by ! tympanic membrane4 ,i det]m9$ !re=e to con/ruct a phonautograph modell$ /ill m closely ^u ! me*anism ( ! human e>1 & = ?is purpose ,i s\ght ! assi/ance ( a di/+ui%$ auri/ 9 ,bo/on1 ,dr4 ,cl>5ce ,j4 ,blake4 ,he sugge/$ ! use ( ! human e> itself z a phonautograph1 in/ead ( mak+ an artificial imitation ( x4 ,! idea 0 novel1 & /ruck me accord+ly1 & ,i reque/$ my fri5d to prep>e a specim5 = me1 :i* he did4 ,! app>atus1 z f9ally con/ruct$1 is %[n 9 fig4 #ab4 ,! /apes 0 remov$1 & a /ylus ( hay ab\t an in* 9 l5g? 0 atta*$ to ! end ( ! incus4 ,^u moi/5+ ! membrana tympani & ! ossicul ) a mixture ( glyc]9e & wat]1 ! necess>y mobility ( ! p>ts 0 obta9$2 & ^u s++ into ! ext]nal artificial e> ! /ylus ( hay 0 ?r[n into vibration1 & trac+s 7 obta9$ ^u a plane surface ( smok$ glass pass$ rapidly und]nea?4 ,:ile engag$ 9 ^! exp]im5ts ,i 0 /ruck ) ! rem>kable disproportion 9 weight betwe5 ! membrane & ! bones t 7 vibrat$ by x4 ,x occurr$ to me t if a membrane z ?9 z tissue pap] c\ld control ! vibration ( bones t 71 comp>$ to x1 ( imm5se size & weight1 :y %\ld n a l>g] & ?ick] membrane be able to vibrate a piece ( iron 9 front ( an electro-magnet1 9 :i* case ! complication ( /eel rods %[n 9 my fir/ =m ( telephone1 c\ld be done away )1 & a simple piece ( iron atta*$ to a membrane be plac$ at ei!r end ( ! telegraphic circuit8 ,illu/ration3 ,,fig4 #ab4 #8,= ?is purpose ,i atta*$ ! re$ ,a 7fig4 #ac7 loosely by "o extremity to ! uncov]$ pole h ( ! magnet1 & fa/5$ ! o!r extremity to ! c5tre ( a /ret*$ membrane ( goldbeat]s' sk9 n4 ,i presum$ t ^u speak+ 9 ! neighb\rhood ( ! membrane n1 x w\ld be ?r[n into vibration & cause ! /eel re$ ,a to move 9 a simil> mann]1 occasion+ undulations 9 ! electrical curr5t t w\ld correspond to ! *anges 9 ! d5sity ( ! air dur+ ! production ( ! s\nd2 & ,i fur!r ?\ght t ! *ange ( ! int5sity ( ! curr5t at ! receiv+ end w\ld cause ! magnet !re to attract ! re$ ,a 9 su* a mann] t x %\ld copy ! motion ( ! re$ ,a1 9 :i* case its movem5ts w\ld occasion a s\nd f ! membrane n simil> 9 timbre to t :i* _h occasion$ ! orig9al vibration4 ,illu/ration3 ,,fig4 #ac4 ,illu/ration3 ,,fig4 #ad4 #8,! results1 h[ev]1 7 unsatisfactory & disc\rag+4 ,my fri5d ,mr4 ,?omas ,a4 ,watson1 :o assi/$ me 9 ?is fir/ exp]im5t1 decl>$ t he he>d a fa9t s\nd proce$ f ! telephone at 8 end ( ! circuit1 b ,i 0 unable to v]ify 8 ass]tion4 ,aft] _m exp]im5ts att5d$ by ! same only p>tially successful results1 ,i det]m9$ to r$uce ! size & weight ( ! spr+ z mu* z possible4 ,= ?is purpose ,i fa/5$ a piece ( clock spr+1 ab\t ! size & %ape ( my ?umbnail1 firmly to ! c5tre ( ! diaphragm1 & _h a simil> in/rum5t at ! o!r end 7fig4 #ad72 we 7 !n enabl$ to obta9 di/9ctly audible effects4 ,i rememb] an exp]im5t made ) ?is telephone1 :i* at ! "t gave me great satisfaction & delight4 ,"o ( ! telephones 0 plac$ 9 my lecture-room 9 ! ,bo/on ,univ]sity1 & ! o!r 9 ! basem5t ( ! adjo9+ build+4 ,"o ( my /ud5ts repair$ to ! di/ant telephone to obs]ve ! effects ( articulate spee*1 :ile ,i utt]$ ! s5t5ce1 8,d y und]/& :at ,i say80 into ! telephone plac$ 9 ! lecture-hall4 ,to my delight an answ] 0 return$ ?r\gh ! in/rum5t itself1 articulate s\nds proce$$ f ! /eel spr+ atta*$ to ! membrane1 & ,i he>d ! s5t5ce1 8,yes1 ,i und]/& y p]fectly40 ,x is a mi/ake1 h[ev]1 to suppose t ! articulation 0 by any means p]fect1 & expectancy no d\bt _h a great deal to d ) my recognition ( ! s5t5ce2 /ill1 ! articulation 0 !re1 & ,i recognis$ ! fact t ! indi/9ctness 0 entirely due to ! imp]fection ( ! in/rum5t4 ,i w n tr\ble y by detail+ ! v>i\s /ages ?r\gh :i* ! app>atus pass$1 b %all m]ely say t aft] a "t ,i produc$ ! =m ( in/rum5t %[n 9 fig4 #ae1 :i* s]v$ v well z a receiv+ telephone4 ,9 ?is condition my inv5tion 0 exhibit$ at ! ,c5t5nial ,exhibition 9 ,philadelphia4 ,! telephone %[n 9 fig4 #ad 0 us$ z a transmitt+ in/rum5t1 & t 9 fig4 #ae z a receiv]1 s t vocal communication 0 only e/abli%$ 9 "o direction4 ,illu/ration3 ,,fig4 #ae4 #8,! articulation produc$ f ! in/rum5t %[n 9 fig4 #ae 0 rem>kably di/9ct1 b its great defect consi/$ 9 ! fact t x c\ld n be us$ z a transmitt+ in/rum5t1 & ?us two telephones 7 requir$ at ea* /ation1 "o = transmitt+ & "o = receiv+ spok5 messages4 #8,x 0 det]m9$ to v>y ! con/ruction ( ! telephone1 & ,i s\ght by *ang+ ! size & t5sion ( ! membrane1 ! diamet] & ?ickness ( ! /eel spr+1 ! size & p[] ( ! magnet1 & ! coils ( insulat$ wire ar\nd _! poles1 to discov] empirically ! exact effect ( ea* elem5t ( ! comb9ation1 & ?us to d$uce a m p]fect =m ( app>atus4 ,x 0 f\nd t a m>k$ increase 9 ! l\dness ( ! s\nds result$ f %ort5+ ! l5g? ( ! coils ( wire1 & by enl>g+ ! iron diaphragm :i* 0 glu$ to ! membrane4 ,9 ! latt] case1 also1 ! di/9ctness ( ! articulation 0 improv$4 ,f9ally1 ! membrane ( goldbeat]s' sk9 0 disc>d$ entirely1 & a simple iron plate 0 us$ in/ead1 & at once intelligible articulation 0 obta9$4 ,! new =m ( in/rum5t is t %[n 9 fig4 #af1 &1 z _h be5 long anticipat$1 x 0 prov$ t ! only use ( ! batt]y 0 to magnetise ! iron core ( ! magnet1 = ! effects 7 equally audible :5 ! batt]y 0 omitt$ & a rod ( magnetis$ /eel sub/itut$ = ! iron core ( ! magnet4 #8,x 0 my orig9al int5tion1 & x 0 always claim$ by me1 t ! f9al =m ( telephone w\ld be op]at$ by p]man5t magnets 9 place ( batt]ies1 & num]\s exp]im5ts _h be5 c>ri$ on by ,mr4 ,watson & myself privately = ! purpose ( produc+ ?is effect4 ,illu/ration3 ,,fig4 #af4 #8,at ! "t ! in/rum5ts 7 fir/ exhibit$ 9 public ! results obta9$ ) p]man5t magnets 7 n ne>ly s /rik+ z :5 a voltaic batt]y 0 employ$1 :]e=e we ?\ght x be/ to exhibit only ! latt] =m ( in/rum5t4 #8,! int]e/ excit$ by ! fir/ publi%$ acc\nts ( ! op]ation ( ! telephone l$ _m p]sons to inve/igate ! subject1 & ,i d\bt n t numb]s ( exp]im5t]s h indep5d5tly discov]$ t p]man5t magnets might be employ$ in/ead ( voltaic batt]ies4 ,inde$ "o g5tleman1 ,pr(essor ,dolbe>1 ( ,tufts ,college1 n only claims to h discov]$ ! magneto-electric telephone1 b ,i und]/& *>ges me ) hav+ obta9$ ! idea f him ?r\gh ! m$ium ( a mutual fri5d4 ,illu/ration3 ,,fig4 #ag4 #8,a /ill m p[]ful =m ( app>atus 0 con/ruct$ by us+ a p[]ful comp\nd horse%oe magnet 9 place ( ! /raight rod :i* _h be5 previ\sly us$ 7see fig4 #ag74 ,inde$ ! s\nds produc$ by means ( ?is in/rum5t 7 ( suffici5t l\dness to be fa9tly audible to a l>ge audi5ce1 & 9 ?is condition ! in/rum5t 0 exhibit$ 9 ! ,essex ,in/itute1 9 ,salem1 ,massa*usetts1 on ,febru>y #ab1 #ahgg1 on :i* occasion a %ort spee* %\t$ into a simil> telephone 9 ,bo/on1 sixte5 miles away1 0 he>d by ! audi5ce 9 ,salem4 ,! tones ( ! speak]'s voice 7 di/9ctly audible to an audi5ce ( #fjj p1 b ! articulation 0 only di/9ct at a di/ance ( ab\t #f feet4 ,on ! same occasion1 also1 a report ( ! lecture 0 transmitt$ by ^w ( m\? f ,salem to ,bo/on1 & publi%$ 9 ! pap]s ! next morn+4 ,illu/ration3 ,,fig4 #ah4 #8,f ! =m ( telephone %[n 9 fig4 #af to ! pres5t =m ( ! in/rum5t 7fig4 #ah7 is b a /ep4 ,x is 9 fact ! arrangem5t ( fig4 #af 9 a portable =m1 ! magnet ,n ,s be+ plac$ inside ! h&le1 & a m conv5i5t =m ( m\?piece provid$4 #8,& "h ,i wi% to express my indebt$ness to sev]al sci5tific fri5ds 9 ,am]ica = _! co-op]ation & assi/ance4 ,i w\ld specially m5tion ,pr(essor ,peirce & ,pr(essor ,blake1 ( ,br[n ,univ]sity1 ,dr4 ,*ann+1 ,mr4 ,cl>ke1 & ,mr4 ,jones4 ,x 0 always my belief t a c]ta9 ratio w\ld be f\nd betwe5 ! sev]al p>ts ( a telephone1 & t ! size ( ! in/rum5t 0 immat]ial2 b ,pr(essor ,peirce 0 ! fir/ to demon/rate ! extreme smallness ( ! magnets :i* might be employ$4 ,! conv5i5t =m ( m\?piece %[n 9 fig4 #ag1 n[ adopt$ by me1 0 inv5t$ solely by my fri5d ,pr(essor ,peirce4' ,illu/ration3 ,,fig4 #ai4 ,ano!r =m ( transmitt+ telephone exhibit$ 9 ,philadelphia1 int5d$ = use ) ! receiv+ telephone 7fig4 #ae71 is repres5t$ by fig4 #ai4 ,a plat9um wire atta*$ to a /ret*$ membrane complet$ a voltaic circuit by dipp+ into wat]4 ,^u speak+ to ! membrane1 articulate s\nds proce$$ f ! telephone 9 ! di/ant room4 ,! s\nds produc$ by ! telephone became l\d] :5 dilute sulphuric acid1 or a saturat$ solution ( salt1 0 sub/itut$ = ! wat]4 ,audible effects 7 also produc$ by ! vibration ( plumbago 9 m]cury1 9 a solution ( bi*romate ( pota%1 9 salt & wat]1 9 dilute sulphuric acid1 & 9 pure wat]4 ,mr4 ,bell goes on to say3 #8,i h f\nd also t a musical tone proce$s f a piece ( plumbago or retort c>bon :5 an int]mitt5t curr5t ( electricity is pass$ ?r\gh x1 & ,i h obs]v$ ! mo/ curi\s audible effects produc$ by ! passage ( rev]s$ int]mitt5t curr5ts ?r\gh ! human body4 ,a rheotome 0 plac$ 9 circuit ) ! prim>y wires ( an induction coil1 & ! f9e wires 7 connect$ ) two /rips ( brass4 ,"o ( ^! /rips 0 held closely aga9/ ! e>1 & a l\d s\nd proce$$ f x :5ev] ! o!r slip 0 t\*$ ) ! o!r h&4 ,! /rips ( brass 7 next held "o 9 ea* h&4 ,! induc$ curr5ts occasion$ a muscul> tremor 9 ! f+]s4 ,^u plac+ my =ef+] to my e> a l\d crackl+ noise 0 audible1 seem+ly proce$+ f ! f+] itself4 ,a fri5d :o 0 pres5t plac$ my f+] to 8 e>1 b he>d no?+4 ,i reque/$ him to hold ! /rips himself4 ,he 0 !n di/9ctly consci\s ( a noise 7:i* ,i 0 unable to p]ceive7 proce$+ f 8 f+]4 ,9 ?is case a portion ( ! induc$ curr5ts pass$ ?r\gh ! head ( ! obs]v] :5 he plac$ 8 e> aga9/ 8 own f+]2 & x is possible t ! s\nd 0 occasion$ by a vibration ( ! surfaces ( ! e> & f+] 9 contact4 #8,:5 two p]sons receive a %ock f a ,ruhmkorff's coil by clasp+ h&s1 ea* tak+ hold ( "o wire ( ! coil ) ! free h&1 a s\nd proce$s f ! clasp$ h&s4 ,! effect is n produc$ :5 ! h&s are moi/4 ,:5 ei!r ( ! two t\*es ! body ( ! o!r1 a l\d s\nd comes f ! p>ts 9 contact4 ,:5 ! arm ( "o is plac$ aga9/ ! arm ( ! o!r1 ! noise produc$ c be he>d at a di/ance ( sev]al feet4 ,9 all ^! cases a slight %ock is exp]i5c$ s long z ! contact is pres]v$4 ,! introduction ( a piece ( pap] betwe5 ! p>ts 9 contact does n mat]ially int]f]e ) ! production ( ! s\nds1 b ! unpleasant effects ( ! %ock are avoid$4 #8,:5 an int]mitt5t curr5t f a ,ruhmkorff's coil is pass$ ?r\gh ! arms1 a musical note c be p]ceiv$ :5 ! e> is closely appli$ to ! arm ( ! p]son exp]im5t$ ^u4 ,! s\nd seems to proce$ f ! muscles ( ! =e-arm & f ! biceps muscle4 ,mr4 ,eli%a ,gray#d has also produc$ audible effects by ! passage ( electricity ?r\gh ! human body4 #8,an extremely l\d musical note is occasion$ by ! sp>k ( a ,ruhmkorff's coil :5 ! prim>y circuit is made & brok5 ) suffici5t rapidity2 :5 two rheotomes ( diff]5t pit* are caus$ simultane\sly to op5 & close ! prim>y circuit1 a d\ble tone proce$s f ! sp>k4 #8,a curi\s discov]y1 :i* may be ( int]e/ to y1 has be5 made by ,pr(essor ,blake4 ,he con/ruct$ a telephone 9 :i* a rod ( s(t iron1 ab\t six feet 9 l5g?1 0 us$ in/ead ( a p]man5t magnet4 ,a fri5d sang a cont9u\s musical tone into ! m\?piece ( a telephone1 l t %[n 9 fig4 #ag1 :i* 0 connect$ ) ! s(t iron in/rum5t allud$ to above4 ,x 0 f\nd t ! l\dness ( ! s\nd produc$ 9 ?is telephone v>i$ ) ! direction 9 :i* ! iron rod 0 held1 & t ! maximum effect 0 produc$ :5 ! rod 0 9 ! position ( ! dipp+-ne$le4 ,?is curi\s discov]y ( ,pr(essor ,blake has be5 v]ifi$ by myself4 #8,:5 a telephone is plac$ 9 circuit ) a telegraph l9e1 ! telephone is f\nd seem+ly to emit s\nds on its own acc\nt4 ,! mo/ extraord9>y noises are (t5 produc$1 ! causes ( :i* are at pres5t v obscure4 ,"o class ( s\nds is produc$ by ! inductive influ5ce ( neighb\r+ wires & by leakage f !m1 ! signals ( ! ,morse alphabet pass+ ov] neighb\r+ wires be+ audible 9 ! telephone1 & ano!r class c be trac$ to e>? curr5ts ^u ! wire1 a curi\s modification ( ?is s\nd reveal+ ! pres5ce ( defective jo9ts 9 ! wire4 #8,pr(essor ,blake in=ms me t he has be5 able to use ! railroad track = conv]sational purposes 9 place ( a telegraph-wire1 & he fur!r /ates t :5 only "o telephone 0 connect$ ) ! track ! s\nds ( ,morse op]at+ 7 di/9ctly audible 9 ! telephone1 al?\gh ! ne>e/ telegraph-wires 7 at lea/ =ty feet di/ant2 & ,pr(essor ,peirce has obs]v$ ! mo/ curi\s s\nds produc$ f a telephone 9 connection ) a telegraph-wire dur+ ! aurora borealis4' ,mr4 ,bell w5t on to describe in/ances 9 :i* airs sung or play$ ^u a musical in/rum5t are transmitt$ by a telephone1 :5 x is n kn[n :5ce !y come2 b ! /ronge/ pro( ( ! extraord9>y s5sibility ( ?is in/rum5t consi/s 9 its becom+ possible by its means to transmit spee* ?r\gh bodies :i* might be suppos$ to be non-conductors4 ,?us communication ) ! e>? ?r\gh ! human body c be made 9 spite ( ! int]v5tion ( %oes & /ock+s2 & x may ev5 be effect$ if1 in/ead ( /&+ on ! gr\nd1 ! p]son /&s on a brick wall4 ,only hewn /one & wood are a suffici5t h9drance to communication1 & if ! foot t\*es ! adjo9+ gr\nd1 or ev5 a blade ( grass1 x is en\gh to produce electric manife/ations4 ,mr4 ,bell says 9 conclusion3 #8,! "q w naturally arise1 ,?r\gh :at l5g? ( wire c ! telephone be us$8 ,9 reply to ?is1 ,i may say t ! maximum am\nt ( resi/ance ?r\gh :i* ! undulatory curr5t w pass1 & yet reta9 suffici5t =ce to produce an audible s\nd at ! di/ant end1 has yet to be det]m9$2 no difficulty has1 h[ev]1 be5 exp]i5c$ 9 laboratory exp]im5ts 9 conv]s+ ?r\gh a resi/ance ( #fj1jjj ohms1 :i* has be5 ! maximum at my disposal4 ,on "o occasion1 n hav+ a rheo/at at h&1 ,i may m5tion hav+ pass$ ! curr5t ?r\gh ! bodies ( sixte5 p]sons1 :o /ood h& 9 h&4 ,! longe/ l5g? ( real telegraph l9e ?r\gh :i* ,i h attempt$ to conv]se has be5 ab\t #bej miles4 ,on ?is occasion no difficulty 0 exp]i5c$ s long z p>allel l9es 7 n 9 op]ation4 ,sunday 0 *os5 z ! day on :i* x 0 probable o!r circuits w\ld be at re/4 ,conv]sation 0 c>ri$ on betwe5 myself 9 ,new ,york1 & ,mr4 ,?omas ,a4 ,watson 9 ,bo/on1 until ! op5+ ( bus9ess ^u ! o!r wires4 ,:5 ?is happ5$ ! vocal s\nds 7 v mu* dim9i%$1 b /ill audible4 ,x seem$1 inde$1 l talk+ ?r\gh a /orm4 ,conv]sation1 ?\gh possible1 c\ld be c>ri$ on ) difficulty1 ow+ to ! di/ract+ nature ( ! int]f]+ curr5ts4 #8,i am in=m$ by my fri5d ,mr4 ,preece t conv]sation has be5 successfully c>ri$ on ?r\gh a subm>9e cable1 sixty miles 9 l5g?1 ext5d+ f ,d>tm\? to ! ,isl& ( ,gu]nsey1 by means ( h& telephones4' ,illu/ration3 ,,fig4 #bj4 ,mr4 ,eli%a ,gray's ,%>e 9 ! ,inv5tion ( ! ,telephone4--,we h se5 t if ,mr4 ,bell 0 ! fir/ to con/ruct ! speak+ telephone 9 a practical =m1 ,mr4 ,gray _h at ! same "t conceiv$ ! idea ( an in/rum5t also capable ( reproduc+ spee*1 & ! description giv5 ( x 9 8 caveat 0 s precise t if x _h be5 made f 8 design1 x w\ld h act$ p]fectly4 ,?is 01 9 fact1 aft]w>ds prov$ by him4 ,9 ord] t our read]s may judge f _! own k ( ! %>e :i* %\ld be ascrib$ to ,mr4 ,eli%a ,gray 9 ! inv5tion ( ! telephone1 we reproduce 9 fig4 #bj ! draw+ :i* accompani$ ! caveat 9 "q4 ,! s5d]1 z we see1 is compos$ ( a sort ( tube1 clos$ at its l[] end by a membrane to :i* a plat9um wire is fix$2 ?is wire dips into a liquid ( mod]ate conduct+ p[]1 & an electrode made ( plat9um1 9 communication ) a batt]y1 is fix$ at ! bottom ( ! vessel conta9+ ! liquid4 ,! receiv] is compos$ ( an electro-magnet1 ( :i* ! armature is fix$ to ! c5tre ( a membrane1 /ret*$ on a k9d ( resonator or e>-trumpet :i* is held to ! e>1 & ! two in/rum5ts are unit$ by ! l9e wire z we see 9 ! plate4 ,"u ^! conditions1 ! undulatory curr5ts necess>y = ! reproduction ( spee* 7 obta9$ 9 a mode analog\s to t po9t$ out by ,mr4 ,bell 9 8 specification1 t is1 by ! v>iations ( resi/ance 9 ! liquid lay] int]pos$ betwe5 ! plat9um wires ( ! transmitt]2 & _! action1 ex]t$ on an electro-magnet1 ( :i* ! armature 0 fix$ on ! diaphragm ( ! resonator1 0 produc$ "u m fav\rable conditions ?an 9 ,mr4 ,bell's specification 7see fig4 #ac71 s9ce t g5tleman reg>ds ?is arrangem5t 7repres5t$ 9 fig4 #ad7 z an important improvem5t on 8 fir/ conception4 ,! :ole importance ( ! inv5tion re/s on ! int]v5tion ( undulatory curr5ts1 :i*1 z we h se51 are indisp5sable = ! reproduction ( spee*1 & x conc]ns u to "k :e!r x 0 ,mr4 ,bell or ,mr4 ,gray :o fir/ decl>$ _! importance2 = 9 bo? ! specifications deposit$ on ,febru>y #ad1 #ahgf1 ! use ( undulatory curr5ts 0 decl>$ to be indisp5sable4 ,mr4 ,gray ass]ts t he _h recognis$ _! importance = ! transmission ( comb9$ s\nds z e>ly z #ahgd2 b ,mr4 ,bell believes t ! undulatory curr5ts m5tion$ by ,mr4 ,gray at t "t 7 only curr5ts analog\s to ^? he _h designat$ "u ! "n ( pulsatory curr5ts1 :i* we h repres5t$ 9 fig4 #h4 ,we h se5 t s9ce ^! curr5ts only repres5t ! abrupt elevations & depressions ( int5sity1 !y are unfit = ! reproduction ( articulate s\nds1 :i*1 on ! contr>y1 dem& t ! v>iations ( int5sity %\ld result f successive ef=ts1 9 exact correspond5ce ) all ! inflections ( ! sonor\s vibrations effect$ by ! voice4 ,mr4 ,bell's claim to priority on ?is "q has be5 recognis$ by ! ,am]ican ,pat5t ,(fice1 s9ce he has be5 plac$ 9 possession ( ! pat5t4 ,h[ev] ?is may be1 ,mr4 ,gray's telephonic sy/em 0 complete1 & we see 9 x1 z we h already said1 ! orig9 ( ! batt]y telephones1 :i* h rec5tly produc$ su* important results4 ,let u n[ consid] ! relation :i* ?is sy/em be>s to ,mr4 ,bell's4 ,! ,bell sy/em1 z we h se51 al?\gh mak+ use ( a batt]y 9 ! fir/ in/ance1 only obta9$ ! dim9ution & increase ( electric =ce necess>y = ! articulation ( words by means ( induction curr5ts produc$ by ! movem5ts ( an armature ( s(t iron1 curr5ts ( :i* ! int5sity 0 consequ5tly due to ! range & inflections ( ^! movem5ts4 ,! batt]y only int]v5$ 9 ord] to communicate magnetic =ce to ! induc]4 ,?is use ( induc$ curr5ts 9 telephonic transmissions 0 already ( great importance1 s9ce v>i\s exp]im5ts subsequ5tly made h prov$ _! sup]iority to voltaic curr5ts = ?is purpose4 ,b exp]i5ce soon conv9c$ ,mr4 ,bell t a p[]ful inductive app>atus work$ by a batt]y 0 n only unnecess>y = ! action ( ?is app>atus1 b t a p]man5t magnet1 v small & weak1 w\ld provide suffici5t curr5ts4 ,?is discov]y1 9 :i*1 z we h se51 ,mr4 ,peirce _h "s %>e1 0 ( great importance1 s9ce x became possible to r$uce ! size ( ! in/rum5t consid]ably1 s z to make x portable & adapt$ = s5d+ & receiv+2 & x 0 %[n t ! telephone 0 ! mo/ s5sitive ( all in/rum5ts 9 reveal+ ! action ( curr5ts4 ,if1 !re=e1 ,mr4 ,bell 0 n ! fir/ to employ ! successful mode ( transmitt+ articulate words1 x mu/ be said t he s\ght1 l ,mr4 ,gray1 to solve ! problem by means ( undulatory curr5ts1 & t he obta9$ ^! curr5ts by ! effect ( induction1 a sy/em :i*1 z soon z x 0 p]fect$1 l$ to ! important results ) :i* we are all acqua9t$4 ,if he _h only giv5 to ! a/oni%$ _w an in/rum5t capable ( reproduc+ spee* telegraphically1 8 fame w\ld be great2 = ?is problem _h hi!rto be5 reg>d$ z insoluble4 ,mr4 ,gray's claims to ! inv5tion ( ! telephone are giv5 9 ! foll[+ summ>y f a v int]e/+ "w1 entitl$ #8,exp]im5tal ,rese>*es on ,electro-h>monic ,telegraphy & ,telephony3' #8#a4 ,i 0 ! fir/ to discov] ! means ( transmitt+ comp\nd s\nds & v>iable inflections ?r\gh a clos$ circuit by means ( two or m electric waves4 #8#b4 ,i ass]t t ,i 0 ! fir/ to discov] & utilise ! mode ( reproduc+ vibrations by ! use ( a magnet receiv] con/antly suppli$ ) electric action4 #8#c4 ,i also ass]t t ,i 0 ! fir/ to con/ruct an in/rum5t consi/+ ( a magnet ) a circul> diaphragm ( magnetic sub/ance1 support$ by its edge at a little di/ance f ! poles ( a magnet1 & capable ( be+ appli$ to ! transmission & reception ( articulate s\nds4' ,x is a curi\s fact1 wor? record+ "h1 t ,mr4 ,yates1 ( ,dubl91 9 #ahfe1 :5 try+ to improve ,reiss's telephone1 realis$ to a c]ta9 ext5t ,mr4 ,gray's conception ( ! liquid transmitt]2 = he introduc$ into ! plat9um contacts ( ,mr4 ,reiss's in/rum5t a drop ( wat] :i* adapt$ x = ! reproduction ( articulate s\nds4 ,h[ev]1 no notice 0 !n tak5 ( ?is result4 ,,exam9ation ,,into ,,! ,,fundam5tal ,,pr9ciples ,,on ,,:i* ,,bell',s ,,telephone ,,is ,,bas$4 ,al?\gh ! prec$+ acc\nt w\ld suffice to make ! pr9ciple ( ,bell's telephone intelligible to p]sons acqua9t$ ) electric sci5ce1 ?is w\ld n be ! case ) ! majority ( our read]s1 & we !re=e ?9k x necess>y to ent] into "s details z to ! s\rce ( ! electric curr5ts :i* are employ$ 9 telephonic transmissions4 ,^! details seem to u ! m necess>y1 s9ce _m p]sons /ill believe t ,bell's telephones are n electric1 because !y d n require a batt]y1 & !y are (t5 conf\nd$ ) /r+ telephones1 s t ! diff]5ce ( price betwe5 ,bell's in/rum5ts & ^? hawk$ 9 ! /reets seems a/oni%+4 ,)\t def9+ :at is meant by an electric curr5t1 :i* w\ld be too elem5t>y1 we may say t electric curr5ts c be produc$ by diff]5t causes1 & t1 9 addition to ^? :i* are due to batt]ies1 /rong curr5ts are also produc$ by ! =ce ex]t$ by magnets on a conduct+ circuit prop]ly arrang$4 ,su* curr5ts are call$ induction curr5ts1 & are us$ 9 ,bell's telephone4 ,9 ord] to und]/& h[ !y are develop$ "u ^! conditions1 x w be en\gh to exam9e :at takes place :5 ! pole ( a magnet is br\ght ne> to1 & )drawn f1 a clos$ circuit4 ,to d ?is1 let u suppose a copp] wire atta*$ to a galvanomet] 9 ! =m ( a circle1 & t "o pole ( a p]man5t magnet is direct$ t[>ds ! c5tre ( ! circle4 ,n[ obs]ve :at happ5s3 #a4 ,at ! mom5t :5 ! magnet approa*es an electric curr5t arises1 caus+ ! galvanomet] to deviate to "o side4 ,?is deviation w be great 9 proportion to ! ext5t ( ! movem5t1 & ! t5sion ( ! curr5t w be great 9 proportion to ! abruptness ( ! movem5t4 ,! curr5t w h[ev] be only in/antane\s4 #b4 ,at ! mom5t :5 ! magnet is )drawn1 a fre% curr5t ( ! same nature w arise1 b x w appe> 9 an opposite direction f ! =m]4 ,x w be :at is call$ a direct curr5t1 because x is 9 ! same direction z ! magnetic curr5t ( ! magnet :i* produces x1 :ile ! o!r curr5t is call$ inv]se4 #c4 ,if1 in/ead ( advanc+ or )draw+ ! magnet by means ( a s+le movem5t1 x is advanc$ 9 j]ks1 a succession ( curr5ts 9 ! same direction is produc$1 ( :i* ! exi/5ce c be asc]ta9$ by ! galvanomet] :5 !re is a suffici5t int]val betwe5 ! movem5ts1 b :5 ! int]vals are v slight ! curr5ts are int]fus$2 & s9ce inv]se effects take place :5 ! magnet is mov$ 9 a contr>y direction1 ! ne$le ( ! galvanomet] foll[s ! movem5ts ( ! magnet1 & to a c]ta9 ext5t /]eotypes !m4 #d4 ,if1 in/ead ( react+ on a simple clos$ circuit1 ! magnet ex]ts its =ce on a consid]able numb] ( circumvolutions ( ?is circuit1 t is1 on a bobb9 ( coil$ wire1 ! effects w be consid]ably increas$1 & !y w be /ill great] if !re be a magnetic core )9 ! bobb91 s9ce ! induc+ action w !n be m effectually ex]t$ ?r\gh\t ! bobb94 ,z ! magnetic core1 :5 x is magnetis$ & demagnetis$ "u ! influ5ce ( its approa* to or )drawal f ! induc+ magnet1 is subject to ! reaction f all ! fluctuations :i* occur 9 ! movem5ts ( ! magnet1 ! induc$ curr5ts :i* ensue are p]fectly def9$4 #e4 ,if1 in/ead ( a movable magnet1 we suppose x to be fix$ 9 ! c5tre ( ! coil1 ! induc$ curr5ts ( :i* we h spok5 may !n be det]m9$ by modify+ its =ce4 ,9 ord] to d s1 x is en\gh t an iron armature %\ld react ^u its poles4 ,:5 ?is armature is br\ght close to "o ( ! poles1 or to bo? at once1 x acquires =ce1 & produces an inv]se curr5t1 t is1 a curr5t 9 ! direction :i* w\ld h correspond$ to an approa* ( ! magnet to ! clos$ circuit4 ,on its )drawal ! inv]se effect is produc$2 b 9 bo? cases ! induc$ curr5ts correspond ) ! ext5t & direction ( ! movem5ts accompli%$ by ! armature1 & consequ5tly !y may reproduce its movem5ts by _! effects4 ,if ?is armature is an iron plate1 :i* vibrates "u ! influ5ce ( any s\nd 9 ?is disposition ( ! electro-magnetic sy/em1 ! alt]nate movem5ts ( ! plate w be trans=m$ into ! induc$ curr5ts1 & ^! w be /rong] or weak]1 m or less def9ite1 accord+ to ! range & complexity ( ! vibrations3 !y w1 h[ev]1 be undulatory1 s9ce !y w always result f successive & cont9u\s movem5ts1 & w consequ5tly be 9 ! conditions :i*1 z we h se51 are requir$ = ! transmission ( spee*4 ,z = ! action produc$ ^u ! receiv]1 t is1 on ! in/rum5t = reproduc+ spee*1 x is some:at complex1 & we %all h occasion to speak ( x pres5tly2 b we c get a g5]al impression ( x1 if we consid] t ! effects produc$ by ! induc$ curr5ts ( v>iable int5sity1 :i* trav]se ! coil ( ! electro-magnetic sy/em1 mu/ det]m9e1 by ! magnetisations & demagnetisations :i* ensue1 ! vibrations ( ! armature disk2 ^! vibrations1 m or less amplifi$ & def9$1 exactly repres5t ^? ( ! disk be=e :i* ! speak] /&s1 & c only be obta9$ f !m4 ,! effects are1 h[ev]1 9 reality m complex1 al?\gh !y are produc$ "u analog\s conditions1 & we %all h m to say ab\t !m :5 we come to speak ( ! exp]im5ts made ) ! telephone4 ,x mu/ mean:ile be obs]v$ t1 = ! reproduction ( spee*1 x is n necess>y t ! magnetic core %\ld be ( s(t iron1 s9ce ! vibratory effects may foll[ f diff]5tial z well z f direct magnetisation4 ,,ord9>y ,,arrangem5t ,,( ,,! ,,bell ,,telephone4 ,! arrangem5t mo/ g5]ally adopt$ = ! telephone is ! "o repres5t$ 9 fig4 #ba4 ,x consi/s ( a k9d ( circul> wood5 box1 fitt$ to ! extremity ( a h&le ,m1 :i* is also ( wood1 & conta9s ! magnetic b> ,n ,s4 ,?is b> is fix$ by means ( a screw t1 & is s arrang$ z to be mov$ =w>d & backw>d by tight5+ or loos5+ ! screw1 a condition necess>y 9 ord] to regulate ! in/rum5t4 ,at ! free extremity ( ! b> ! magnetic coil ,b is fix$2 ?is mu/1 accord+ to ,,mm4 ,poll>d & ,g>ni]1 be made ( wire ,no4 #db1 s z to pres5t a consid]able numb] ( spirals4 ,! ends ( ?is coil g5]ally t]m9ate at ! l[] end ( ! h&le 9 two copp] rods f1 f1 :i* trav]se its l5g?1 & are fa/5$ to two b9d+-screws ,i1 ,i1 :]e ! l9e wires ,c1 ,c are fix$4 ,9 ! in/rum5ts made by ,m4 ,brguet !re are1 h[ev]1 no b9d+-screws1 b a little twi/1 made ( two flexible wires cov]$ ) gutta-p]*a & silk1 is fa/5$ to ! two rods4 ,a wood5 cap is screw$ to ! end ( ! h&le1 & ! twi/ passes ?r\gh a hole made 9 ?is cap1 s t !re is no inconv5i5ce 9 work+ ! in/rum5t4 ,by lay+ hold ( ! ends ( ! wire twi/ ) pli]s x is possible to jo9 !m to ! circuit4 ,?is in/rum5t is repres5t$ 9 fig4 #bb4 ,illu/ration3 ,,fig4 #ba4 ,by ano!r arrangem5t1 ! wires ( ! coil end imm$iately 9 ! b9d+-screws :i* are plac$ bel[ ! wood5 box1 b ?is arrangem5t is inconv5i5t4 ,above ! pole ( ! magnetic b> is plac$ ! iron vibrat+ plate ,l ,l1 :i* is coat$ ei!r ) black or yell[ v>ni%1 ) t9 or blue oxide1 b :i* mu/ always be v ?94 ,?is plate is 9 ! =m ( a disk1 & by its rim1 re/+ on a ca\t*\c r+1 x is firmly fix$ to ! circul> edges ( ! wood5 box1 :i* is = ?is purpose made 9 two pieces4 ,^! pieces are adju/$ to ea* o!r1 ei!r by screws or by spirals cut 9 half ! ?ickness ( ! wood4 ,?is disk ought to be z ne> z possible to ! pol> end ( ! magnet1 yet n s ne> z to produce contact betwe5 ! two by ! vibrations ( ! voice4 ,f9ally1 ! m\?piece ,r ,r 7fig4 #ba71 :i* is 9 =m ( a wide funnel1 t]m9ates ! upp] "p ( ! box1 & %\ld be s arrang$ z to leave a c]ta9 space betwe5 ! disk & ! edges ( ! hole ,v1 :i* is op5 9 its c5tre4 ,! size ( ! box %\ld be s calculat$ z to p]mit ( its act+ z a s\nd+-box1 )\t h[ev] provok+ e*oes & a confusion ( s\nds4 ,illu/ration3 ,,fig4 #bb4 ,:5 ! in/rum5t is prop]ly made1 x w produce v m>k$ effects2 & ,m4 ,poll>d1 "o ( ! fir/ ,fr5*m5 to take up ! /udy ( telephones1 has writt5 z foll[s on ! subject3 #8,! in/rum5t :i* ,i h prep>$ gives results :i* are truly a/oni%+4 ,9 ! fir/ place1 :5 consid]+ ! resi/ance1 ! introduction into ! circuit ( five or six p]sons does n s5sibly dim9i% ! int5sity ( s\nds4 ,on putt+ an in/rum5t to ea* e>1 ! s5sation is precisely ! same z if ! correspond5t 7 speak+ "s y>ds beh9d4 ,! int5sity1 ! cle>ness1 ! purity ( tone are irreproa*able4 #8,i c speak to my colleague 9 q an und]tone1 sc>cely brea?+ z ,i may say1 & p]sons plac$ )9 two y>ds ( me w be unable to cat* a s+le ^w ( our conv]sation4 #8,on ! "p ( ! receiv]1 if anyone raises 8 voice to call me1 ,i he> ! call 9 all p>ts ( my (fice1 at lea/ :5 sil5ce prevails !re2 at any rate1 :5 ,i am seat$ at my table ) ! in/rum5t "s y>ds (f1 ,i c always he> ! call4 ,9 ord] to increase ! int5sity ( s\nd1 ,i fitt$ ! m\?piece ) a copp] horn ( conical %ape1 & "u ^! conditions words spok5 9 my bureau two or ?ree y>ds f ! m\?piece c be he>d at ! o!r end ( ! l9e2 f my /ation1 a little m ?an a y>d f ! tube1 ,i c he> & speak to my colleague )\t ef=t4' ,9 us+ ! ord9>y ,bell telephone1 x is necess>y to speak di/9ctly be=e ! m\?piece ( ! telephone :i* is h&l$1 :ile ! li/5] plac$ at ! correspond+ /ation keeps ! m\?piece ( ! receiv] to 8 e>4 ,^! two in/rum5ts =m a clos$ circuit ) ! two wires :i* connect !m1 b "o is en\gh to make ! transmission p]fect1 if c>e is tak5 to place bo? in/rum5ts 9 connection ) ! e>?1 :i* ?us takes ! place ( ! second wire4 ,m4 ,b\rb\ze ass]ts t ! int5sity ( s\nd 9 ! telephone is mu* increas$ by employ+ ?is exp$i5t1 b we believe t ?is increase dep5ds ^u ! conditions ( ! circuit1 al?\gh he ass]ts t ! fact c be prov$ 9 a circuit n exce$+ eighty y>ds4 ,= practical purposes x is necess>y to h two telephones at ea* /ation1 s z to hold "o to ! e> :ile speak+ ?r\gh ! o!r1 z 9 fig4 #bc4 ,x is also mu* m easy to he> ) a telephone appli$ to ea* e>1 9 :i* case !y are held z 9 fig4 #bd4 ,9 ord] n to fatigue ! arms1 an arrangem5t has be5 made by :i* !y are held be=e ! e>s by a /rap & spr+ :i* goes r\nd ! head4 ,illu/ration3 ,,fig4 #bc4 ,! s5d+ p[] ( ! telephone v>ies ) diff]5t voices4 ,mr4 ,preece ass]ts t %\t+ has no effect1 & t1 9 ord] to obta9 a fav\rable result1 ! intonation mu/ be cle>1 ! articulation di/9ct1 & ! s\nds emitt$ mu/ resemble musical s\nds z mu* z possible4 ,mr4 ,wilmot1 "o ( ! electricians employ$ by ! ,po/ ,(fice1 says t he has be5 able to make himself he>d on circuits ?r\gh :i* no o!r voices 7 audible4 ,! v[el s\nds are mo/ readily transmitt$1 & among o!r lett]s e1 g1 j1 k1 & q are always repeat$ m imp]fectly4 ,! e> requires practice1 & ! faculty ( he>+ v>ies 9 a surpris+ degree 9 diff]5t p4 ,s++ is v di/9ctly he>d1 z well z w9d in/rum5ts1 especially ! cornet--pi/on1 :i*1 :5 play$ 9 ,london1 0 he>d by ?\s&s ( p 9 ! ,corn ,ex*ange at ,bas+/oke4 ,illu/ration3 ,,fig4 #bd4 ,accord+ to ,mr4 ,rollo ,russell1 x is n necess>y to isolate ! circuit ( a telephone :5 ! di/ance is relatively slight2 ?us1 ) a circuit ( ab\t #dcj y>ds1 x is possible to use a simple copp] wire1 laid on ! grass1 )\t de/roy+ ! telephonic transmission f a small musical box1 z long z ! two wires d n t\* ea* o!r4 ,transmission took place1 ev5 :5 ! circuit 0 buri$ 9 moi/ e>? = a l5g? ( ?irty-five y>ds1 or imm]s$ 9 a well = a l5g? ( =ty-eight y>ds4 ,! words transmitt$ "u su* conditions did n diff] f ^? transmitt$ by an isolat$ circuit4 ,! telephone may be he>d at ! same mom5t by sev]al li/5]s1 ei!r by connect+ ! wires :i* unite ! telephones 9 correspond5ce 7ne> ! receiv+ telephone7 ) bran* wires ( o!r telephones1 :i* may be done up to ! numb] ( five or six1 9 %ort circuits2 or by means ( a little s\nd+-box clos$ by two ?9 membranes1 "o ( :i* is fix$ on ! vibrat+ disk4 ,:5 a c]ta9 numb] ( ac\/ic tubes are connect$ ) ! membrane1 ,mr4 ,m',k5drick ass]ts t sev]al p c he> di/9ctly4 ,telephones may also transmit spee* to diff]5t /ations simultane\sly1 by ins]t+ !m on ! same circuit1 & exp]im5ts made at ,new ,york %[$ t five in/rum5ts plac$ 9 diff]5t p>ts ( ! same telegraphic l9e c\ld be made to speak 9 ?is way4 ,9 ! telephonic exp]im5ts made on ! canal l9es 9 ! dep>tm5t ( ! ,yonne1 x 0 asc]ta9$ t on a wire sev5 miles & a half 9 l5g?1 on :i* sev]al telephones 7 plac$ at v>y+ di/ances1 ?ree or f\r p]sons 7 able to conv]se ) ea* o!r ?r\gh ! telephones1 & ea* c\ld he> :at ! o!r 0 say+4 ,! que/ions & answ]s c\ld be und]/ood1 ev5 9 cross+4 ,x 0 also possible1 by plac+ a telephone on a second wire1 a little ov] five miles 9 l5g?1 & half a y>d di/ant f ! o!r1 to he> ! conv]sation ex*ang$ on ! fir/ wire by foll[+ x to a di/ance n exce$+ a mile & a qu>t]4 ,ev5 ! diff]5t voices ( ! two speak]s c\ld be di/+ui%$4 ,s9ce ! telephone made its appe>ance 9 ,europe1 sev]al inv5tors h ass]t$ t !y are able to make a telephone speak s z to be audible 9 all p>ts ( a l>ge hall4 ,x has be5 %[n t ?is 0 accompli%$ by ,mr4 ,bell1 & 9 ?is respect we d n see t ^? :o h attempt$ to improve ! telephone h atta9$ results ( great] importance4 ,x is c]ta9 t ! ord9>y telephone c emit musical s\nds :i* become p]fectly audible 9 a tol]ably l>ge room1 :ile ! in/rum5t is /ill atta*$ to ! wall4 ,we %\ld also rememb] ! results obta9$ by ,,mm4 ,poll>d & ,g>ni] 9 ! exp]im5ts made at ,*]b\rg to connect ! mole ) ! ,prfecture ,m>itime4 ,! mole at ,*]b\rg is1 z we "k1 a k9d ( artificial isl& ?r[n up be=e ! t[n 9 ord] to make an an*orage4 ,! =ts :i* h be5 con/ruct$ on ! mole are connect$ by subm>9e cables ) ! milit>y port & ) ! ,prfecture ,m>itime4 ,on "o occasion1 aft] mak+ exp]im5ts 9 ! ,prfet's /udy on "o ( ! cables appli$ to a telephone1 sev]al p]sons 7 talk+ toge!r 9 ! room1 & 7 mu* surpris$ to he> ! bugle s\nd ! retreat1 ! s\nd appe>+ to come f "o "p ( ! room4 ,x 0 f\nd1 on exam9ation1 t ! telephone hung to ! wall 0 occupi$ ) ?is p]=mance4 ,on enquiry1 x appe>$ t "o ( ! manipulators on ! mole /ation _h amus$ himself by s\nd+ ! bugle be=e ! telephone on t /ation4 ,! mole is m ?an ?ree miles f ,*]b\rg1 & ! ,prfecture ,m>itime is 9 ! c5tre ( ! t[n4 ,yet ^! telephones _h be5 r\ghly made 9 ! docky>d work%ops2 & we h "h ano!r pro( ( ! small am\nt ( accuracy requir$ = ! successful work+ ( ^! in/rum5ts4 ,illu/ration3 ,,fig4 #be4 ,telephones ( v>i\s con/ruction on ! ,bell model are to be se5 at ,m4 ,c4 ,roosevelt's1 ,mr4 ,bell's ag5t 9 ,p>is1 #a1 ,rue de la ,b\rse4 ,!y are1 = ! mo/ "p1 con/ruct$ by ,m4 ,brguet1 & ! model 9 ! greate/ reque/1 exclusive ( ! "o we h describ$1 is ! great squ>e model1 ) a horse%oe magnet enclos$ 9 a flat box1 & a horn on its upp] side1 :i* s]ves z a m\?piece4 ,?is sy/em is repres5t$ 9 fig4 #be1 & x has be5 neatly con/ruct$ at ,bo/on "u ! be/ conditions4 ,9 ?is new model1 made by ,mr4 ,g[]1 ! magnet is compos$ ( sev]al plates t]m9at$ by magnetic cores ( iron1 to :i* ! coils are fix$1 & ! :ole is cov]$ ) a ?ick lay] ( p>aff94 ,! s\nds ?us reproduc$ are mu* /rong] & m di/9ct4 ,mr4 ,g[]1 :o is n[ ,mr4 ,roosevelt's p>tn]1 has made consid]able improvem5ts 9 ! diff]5t =ms ( ,mr4 ,bell's in/rum5t4 ,!re is "o model 9 ! =m ( a snuff-box1 9 :i* ! magnet is twi/$ into a spiral1 s z to ma9ta9 its l5g? 9 a circul> =m4 ,! pole1 :i* is 9 ! c5tre ( ! spiral1 is furni%$ ) an iron core1 to :i* ! induction coil is fa/5$1 & ! cov] ( ! snuff-box supports ! vibrat+ disk z well z ! m\?piece3 ?is model is repres5t$ 9 fig4 #bf4 ,9 ano!r model1 call$ ! mirror telephone1 ! prec$+ arrangem5t is fitt$ on to a h&le l ! glass ( a portable mirror1 & !re is a m\?piece on "o ( ! lat]al faces1 s t ! speak] uses ! in/rum5t z if he 7 speak+ be=e a *imney scre54 ,illu/ration3 ,,fig4 #bf4 ,mr4 ,bailey has diff]5t models ( telephones work$ by a batt]y or by ! ,edison c>bon ( :i* we %all speak pres5tly1 & ^!1 z well z ! telephones by ,messrs4 ,gray & ,phelps1 are m successful 9 convey+ s\nd on a long l9e ( wire4 ,,diff]5t ,,arrangem5ts ,,( ,,telephones4 ,! prodigi\s results atta9$ ) ! ,bell telephones1 :i* 7 at fir/ discr$it$ by _m sci5tific m51 necess>ily provok$1 z soon z _! au!nticity 0 prov$1 innum]able rese>*es on ! "p ( inv5tors1 & ev5 ( ^? :o 7 orig9ally ! mo/ incr$ul\s4 ,a ho/ ( improvem5ts & modifications h consequ5tly be5 sugge/$1 :i* are evid5tly n )\t int]e/1 & mu/ n[ be consid]$ by u4 ,,batt]y ,,telephones4 ,! ,edison ,telephone4--,"o ( ! e>lie/ & mo/ int]e/+ improvem5ts made 9 ! ,bell telephone is t introduc$ by ,mr4 ,edison 9 ! e>ly "p ( ! ye> #ahgf4 ,?is sy/em is inde$ m complicat$ ?an ! "o we h j consid]$1 s9ce x requires a batt]y1 & ! s5d+ in/rum5t diff]s f ! receiv+ in/rum5t2 b x is less apt to be affect$ by ext]nal causes1 & transmits s\nd to a great] di/ance4 ,! ,edison telephone1 l ,mr4 ,gray's1 :i* we h already _h occasion to m5tion1 is bas$ ^u ! action ( undulatory curr5ts1 det]m9$ by ! v>iations 9 ! resi/ance ( a conductor ( mod]ate conduct+ p[]1 :i* is ins]t$ 9 ! circuit1 & ! vibrations ( a diaphragm be=e :i* ! speak] /&s react ^u x4 ,only1 in/ead ( employ+ a liquid conductor1 :i* is practically useless1 ,mr4 ,edison has attempt$ to use semi-conduct+ solid bodies4 ,^? :i* 7 mo/ suitable f ?is po9t ( view 7 graphite & c>bon1 especially ! c>bon extract$ f compress$ lamp-black4 ,:5 ^! sub/ances are introduc$ into a circuit betwe5 two conduct+ plates1 "o ( :i* is moveable1 !y are capable ( modify+ ! resi/ance ( ! circuit almo/ 9 ! same proportion z ! pressure ex]t$ ^u !m by ! moveable plate1#e & x 0 se5 t1 9 ord] to obta9 ! undulatory curr5ts necess>y = ! production ( articulate s\nds1 x 0 en\gh to introduce a disk ( plumbago or ( lamp-black betwe5 ! vibrat+ plate ( a telephone & a plat9um plate plac$ 9 connection ) ! batt]y4 ,:5 ! telephone disk is plac$ 9 circuit1 its vibrations be=e ! disk ( c>bon produce a s]ies ( increas+ & decreas+ pressures1 ?us caus+ correspond+ effects 9 ! int5sity ( ! transmitt$ curr5t1 & ^! effects react 9 an analog\s mann] on ! undulatory curr5ts det]m9$ by induction 9 ! ,bell sy/em4 ,9 ord] to obta9 good results1 h[ev]1 sev]al accessory arrangem5ts 7 necess>y1 & we repres5t 9 fig4 #bg "o ( ! arrangem5ts made 9 ?is "p ( ,mr4 ,edison's telephonic sy/em4 ,illu/ration3 ,,fig4 #bg4 ,9 ?is figure a section ( ! in/rum5t is giv51 & its =m greatly resembles t ( ,bell4 ,l ,l is ! vibrat+ disk2 ,o ,o1 ! m\?piece2 ,m1 ! op5+ to ! m\?piece2 ,n ,n ,n1 ! case = ! in/rum5t1 :i* is1 l ! m\?piece1 made ( ebonite1 & bel[ ! disk x pres5ts a r l>ge cavity1 & a tubul> hole :i* is scoop$ 9 ! h&le4 ,9 its upp] "p ?is tube t]m9ates 9 a cyl9drical rim1 furni%$ ) a worm on :i* is screw$ a little rod ) a ridge on its inn] side1 & ! rheo/atic sy/em is plac$ )9 ?is tube4 ,! sy/em consi/s1 fir/1 ( a pi/on ,e1 fitt$ to ! end ( a long screw ,e ,f1 & ! turn+ ( ! button w move ! pi/on up or d[n )9 a c]ta9 limit4 ,above ?is pi/on !re is fitt$ a v ?9 plat9um plate ,a1 connect$ by a flexible *a9 & a wire ) a b9d+-screw ,p4 ,ano!r plate ,b1 exactly simil>1 is connect$ ) ! b9d+-screw ,p1 & ! c>bon disk ,c is plac$ betwe5 ^! two plates4 ,?is disk is compos$ ( compress$ lamp-black & petroleum1 & its resi/ance is "o ohm1 or #aaj y>ds1 ( telegraphic wire4 ,f9ally1 an ebonite disk is fa/5$ to ! upp] plat9um plate1 & an ela/ic pad1 compos$ ( a piece ( ca\t*\c tube ,g1 & ( a cork disk ,h1 is int]pos$ betwe5 ! vibrat+ plate ,l ,l & ! disk ,b1 9 ord] t ! vibrations ( ! plate may n be *eck$ by ! rigid ob/acle =m$ by ! :ole rheo/atic sy/em4 ,:5 ^! diff]5t p>ts are 9 position1 ! in/rum5t is regulat$ by ! screw ,f1 & ?is is easily done by screw+ or unscrew+ x until ! receiv+ telephone gives out its maximum ( s\nd4 ,illu/ration3 ,,fig4 #bh4 ,9 ano!r model1 repres5t$ 9 fig4 #bh1 :i* has produc$ ! be/ results 9 ! di/9ctness ) :i* s\nds are transmitt$1 ! vibrat+ plate ,l ,l is support$ on ! disks ( ! second>y c>bon conductor ,c by means ( a little iron cyl9d] ,a1 in/ead ( ! ca\t*\c pad1 & ! pressure is regulat$ by a screw plac$ bel[ e4 ,! m\?piece ,e ( ! in/rum5t is m prom95t1 & its op5+ is l>g]4 ,f9ally1 ! in/rum5t1 :i* is cas$ 9 nickel silv]1 is )\t a h&le4 ,! rigid disk b1 re/+ on ! fir/ plat9um plate p1 is ( alum9ium in/ead ( ebonite4 ,illu/ration3 ,,fig4 #bi4 ,! receiv+ telephone some:at resembles t ( ,mr4 ,bell1 yet x pres5ts "s diff]5ces :i* c be und]/ood f ! exam9ation ( fig4 #bi4 ,! magnet ,n ,s is horse%oe 9 =m1 & ! magnetis+ coil ,e only cov]s "o ( ! poles1 ,n3 ?is pole is precisely 9 ! c5tre ( ! vibrat+ plate ,l ,l1 :ile ! second pole is ne> ! edge ( ?is plate4 ,! size ( ! plate itself is consid]ably r$uc$3 its sup]ficies is ab\t ! same z t ( a five-franc piece1 & x is enclos$ 9 a k9d ( circul> groove1 :i* keeps x 9 a def9ite position4 ,9 consequ5ce ( ?is arrangem5t ! h&le ( ! in/rum5t is ( solid wood1 & ! vacant space = ! electro-magnetic sy/em is some:at l>g] ?an 9 ! ,bell model2 b an arrangem5t is made = subdu+ ! e*o1 & !re is a k9d ( s\nd+-box to magnify ! s\nd4 ,x is evid5t t ! relation :i* ! electro-magnetic sy/em be>s to ! vibrat+ disk mu/ increase ! s5sitiv5ess ( ! in/rum5t2 = z ! pole ,s is 9 close contact ) ! disk ,l ,l1 ! latt] is pol>is$1 & becomes m susceptible to ! magnetic influ5ce ( ! second pole ,n1 :i* is sep>at$ f x by an int]val n exce$+ ! ?ickness ( a %eet ( co>se pap]4 ,9 ,mr4 ,edison's two in/rum5ts1 ! receiv] & s5d]1 ! upp] "p ,c ,c1 correspond+ to ! vibrat+ disk1 in/ead ( be+ fix$ by screws to ! h&le1 is screw$ on to ! h&le itself1 :i* makes x mu* m easy to dism\nt ! in/rum5t4 ,mr4 ,edison has v>i$ ! =m ( 8 in/rum5ts 9 _m ways1 & _! cases h ( late be5 made ( metal ) a funnel-%ap$ m\?piece ( ebonite4 ,:5 ,mr4 ,edison _h asc]ta9$1 z inde$ ,mr4 ,eli%a ,gray _h done be=e him1 t induc$ curr5ts are m fav\rable to telephonic transmissions ?an voltaic curr5ts1 he trans=m$ ! curr5ts f ! batt]y :i* pass$ ?r\gh 8 s5d] into induc$ curr5ts by mak+ !m pass ?r\gh ! prim>y circuit ( a c>efully insulat$ induction coil2 ! l9e wire 0 !n put into communication ) ! second>y wire ( ! coil4 ,we %all aft]w>ds describe "s exp]im5ts :i* %[ ! advantages ( ?is comb9ation3 = ! pres5t we c only po9t out ! fact1 = x is n[ an integral quality ( almo/ all ! sy/ems ( batt]y telephones4 ,edison's ,*emical ,telephone4--,! curi\s & really useful effects produc$ by ,mr4 ,edison ) 8 electro-motograph prompt$1 ab\t ! beg9n+ ( ! ye> #ahgg1 8 idea ( apply+ ! pr9ciple ( ?is in/rum5t to ! telephone = ! reproduction ( transmitt$ s\nds2 & he obta9$ su* int]e/+ results t ! au?or ( an article on telephones1 publi%$ 9 ! #8,telegraphic ,j\rnal1' ,augu/ #ae1 #ahgg1 put =w>d ?is inv5tion z "o ( ! f9e/ ( ! n9ete5? c5tury4 ,x c]ta9ly appe>s to h giv5 bir? to ! phonograph1 :i* has lately become fam\s1 & has s mu* a/oni%$ m5 ( sci5ce4 ,to und]/& ! pr9ciple ( ?is telephone1 we mu/ give "s acc\nt ( ,mr4 ,edison's electro-motograph1 discov]$ 9 #ahgb4 ,?is in/rum5t is bas$ ^u ! pr9ciple t if a %eet ( pap]1 prep>$ ) a solution ( hydrate ( pota%1 is fa/5$ on a metallic plate :i* is unit$ to ! positive pole ( a batt]y1 & if a po9t ( lead or plat9um connect$ ) ! negative pole is mov$ ab\t ! pap]1 ! friction :i* ?is po9t enc\nt]s ceases aft] ! passage ( ! curr5t1 & x is !n able to slide z if ^u a mirror until ! curr5t is int]rupt$4 ,n[1 z ?is reaction may be effect$ in/antane\sly "u ! influ5ce ( extremely weak curr5ts1 ! me*anical effects produc$ by ^! alt]nations ( arre/ & motion may1 by a suitable arrangem5t ( ! in/rum5t1 det]m9e vibrations 9 correspond5ce ) ! int]ruptions ( curr5t produc$ by ! transmitt]4 ,9 ?is sy/em ! telephonic receiv] consi/s ( a resonator & a drum m\nt$ on an axis & turn$ by a w9*4 ,a pap] b&1 w\nd ^u a reel1 passes ov] ! drum1 ( :i* ! surface is r\gh1 & a po9t tipp$ ) plat9um1 & fitt$ to ! end ( a spr+ :i* is fix$ 9 ! c5tre ( ! resonator1 presses /rongly on ! pap]4 ,! curr5t f ! batt]y1 fir/ direct$ on ! spr+1 passes by ! plat9um po9t ?r\gh ! *emical pap]1 & returns by ! drum to ! batt]y4 ,on turn+ ! w9*1 ! pap] moves =w>d1 & ! normal friction :i* is produc$ betwe5 ! pap] & ! plat9um po9t pu%es ! po9t =w>d1 :ile produc+ by means ( ! spr+ a t5sion on "o side ( ! resonator2 b s9ce ! friction ceases at ea* passage ( ! curr5t ?r\gh ! pap]1 ! spr+ is no long] drawn out1 & ! resonator returns to its normal position4 ,s9ce ?is d\ble effect is produc$ by ea* vibration made 9 ! s5d]1 a s]ies ( vibrations takes place 9 ! resonator1 repeat+ ^? ( ! s5d]1 & consequ5tly ! musical s\nds :i* affect$ ! s5d] are reproduc$ to a c]ta9 ext5t4 ,accord+ to ! ,am]ican j\rnals1 ! results produc$ by ?is in/rum5t are a/oni%+3 ! weake/ curr5ts1 :i* w\ld h no effect on an electro-magnet1 become p]fectly efficaci\s 9 ?is way4 ,! in/rum5t c ev5 reproduce ) great int5sity ! highe/ notes ( ! human voice1 notes :i* c h>dly be di/+ui%$ by ! use ( electro-magnets4 ,! s5d] ne>ly resembles ! "o we h previ\sly describ$1 except t1 :5 x is us$ = musical s\nds1 a plat9um po9t is employ$ in/ead ( ! disk ( c>bon1 & x ought n to be 9 con/ant contact ) ! vibrat+ plate4 ,accord+ to ! #8,telegraphic ,j\rnal1' x consi/s simply ( a long tube1 two in*es 9 diamet]1 hav+ "o end cov]$ ) a diaphragm =m$ ( a ?9 %eet ( copp]1 & kept 9 its place by an ela/ic r+4 ,a small plat9um disk is rivet$ to ! c5tre ( ! copp] diaphragm1 & a po9t ( ! same metal1 fitt$ ) a firm support1 is adju/$ be=e ! disk4 ,:5 ! s+] /&s be=e ! diaphragm1 its vibration causes x to t\* ! plat9um po9t1 & produces ! numb] ( breaks 9 ! curr5t :i* corresponds to ! vibration ( ! notes utt]$4 ,! exp]im5ts lately made 9 ,am]ica1 9 ord] to decide on ! m]its ( v>i\s telephonic sy/ems1 %[ t ,mr4 ,edison's telephone gives ! be/ results4 ,! #8,telegraphic ,j\rnal1' ,may #a1 #ahgh1 /ates t on ,april #b ,mr4 ,edison's c>bon telephone 0 te/$ betwe5 ,new ,york & ,philadelphia on "o ( ! num]\s l9es ( ! ,we/ ,union4 ,! l5g? ( ! l9e 0 #ajf miles1 & ran p>allel to o!r wires almo/ ?r\gh\t its l5g?4 ,! effects ( induction caus$ by telegraphic transmissions ?r\gh ! adjac5t wires 7 en\gh to make spee* inaudible ?r\gh ! o!r telephones1 b !y _h no influ5ce on ,edison's telephone1 :i* 0 work$ ) a batt]y ( two cells & a small induction coil1 & ,messrs4 ,bat*elor1 ,phelps1 & ,edison 7 able to conv]se ) ease4 ,mr4 ,phelps' magnetic telephone1 :i* is consid]$ to be ! mo/ p[]ful ( its k9d1 did n af=d su* good results4 ,9 ! exp]im5ts made betwe5 ! ,p>is ,exhibition build+ & ,v]sailles1 ! jury commission 0 able to asc]ta9 t ! results 7 equally fav\rable4 ,telephones by ,colonel ,navez4--,colonel ,navez ( ! ,belgian ,artill]y1 inv5tor ( ! well-kn[n bali/ic *ronograph1 has endeav\r$ to improve ! ,edison telephone by employ+ sev]al disks ( c>bon in/ead ( "o4 ,he consid]s t ! v>iations ( electric resi/ance produc$ by c>bon disks "u ! influ5ce ( unequal pressure dep5d *iefly on _! surface ( contact1 & he consequ5tly believes t ! m ^! surfaces are multipli$1 ! great] ! diff]5ces 9 "q w be1 j z x happ5s :5 light is pol>is$ ?r\gh ice4 ,he adds t ^! disks act well by _! surfaces ( contact1 s9ce1 if !y are sep>at$ by copp] disks1 ! spee* reproduc$ ceases to be articulate4#f ,i am n surpris$ to le>n t ,colonel ,navez has f\nd a limit to ! numb] ( c>bon disks1 = ! reproduction ( spee* 9 ?is sy/em is due bo? to ! greatness ( ! diff]5ces ( resi/ance 9 ! circuit1 & to ! int5sity ( ! transmitt$ curr5t4 ,if !re=e ! in/rum5t's s5sitiv5ess to articulate s\nds is increas$ by increas+ ! numb] ( imp]fect contacts 9 ! circuit1 ! int5sity ( ! transmitt$ s\nds is dim9i%$1 & ?us s\nds lose _! p[]4 ,!re is consequ5tly a limit to be obs]v$ 9 ! numb] ( c>bon disks plac$ ^u ea* o!r2 & x dep5ds on ! nature ( ! imp]fect contacts :i* are employ$1 & on ! t5sion ( ! electric g5]ator4 ,9 ord] to /op ! unpleasant musical vibrations :i* accompany telephonic transmissions1 ,colonel ,navez employs = ! vibrat+ plate ( ! s5d] a silv]-plat$ copp] disk1 & = ! vibrat+ plate ( ! receiv] an iron disk l9$ ) brass & sold]$ toge!r4 ,he also employs ca\t*\c tubes ) m\?pieces & e>-tubes = ! transmission & reception ( s\nd1 & ^! in/rum5ts are plac$ level on a table4 ,= ?is purpose ! magnetis$ b> ( ! receiv+ telephone is replac$ by two horizontal magnets1 act+ ?r\gh a pole ( ! same nature on a little iron core :i* c>ries ! coil1 & :i* is plac$ v]tically betwe5 ! two magnets4 ,he necess>ily makes use ( a small ,ruhmkorff coil to trans=m ! electricity ( ! batt]y into induc$ electricity4 ,illu/ration3 ,,fig4 #cj4 ,illu/ration3 ,,fig4 #ca4 ,figs4 #cj & #ca repres5t ! two p>ts ( ?is telephonic sy/em4 ,! c>bon batt]y is 9 ,c 7fig4 #cj71 ! vibrat+ disk 9 ,l ,l1 & ! m\?piece ,e1 fitt$ to a ca\t*\c tube ,t ,e1 corresponds at ! l[] end to ! vibrat+ disk4 ,! c>bon batt]y is plac$ 9 metallic contact ) ! circuit by a plat9um rod ,e ,c1 & ! vibrat+ disk also communicates ) ! circuit ?r\gh a b9d+-screw4 ,9 ! receiv+ telephone 7fig4 #ca7 ! upp] "p is arrang$ mu* z 9 ! ord9>y telephones1 except t1 in/ead ( a m\?piece1 ! in/rum5t is fitt$ ) an e>-tube ,t ,o4 ,! two horse%oe magnets1 ,a1 ,a1 :i* communicate a uni=m pol>ity to ! iron core ,n1 support ! induction coil ,b4 ,! two t]m9als ( ?is receiv] are connect$ ) ! supplem5t>y wire ( ! induction coil1 & ! two t]m9als ( ! s5d] are connect$ ) ! two ends ( ! prim>y ( ?is coil1 & ) ! batt]y :i* is ins]t$ 9 ! circuit ne> ?is in/rum5t4 ,! ,poll>d & ,g>ni] ,telephones4--,! batt]y telephone made by ,,mm4 ,poll>d & ,g>ni] diff]s f ! =ego+ 9 ?is p>ticul>3 x simply employs two po9ts ( graphite1 m\nt$ 9 metallic porte-crayons1 & ^! po9ts are directly appli$ aga9/ ! vibrat+ plate ) a pressure :i* mu/ be regulat$4 ,fig4 #cb repres5ts ! arrangem5t adopt$1 :i*1 h[ev]1 may be inf9itely v>i$4 ,l ,l is ! vibrat+ t9 plate1 above :i* is ! m\?piece ,e1 & ,p1 ,p are ! two graphite po9ts ) _! porte-crayons4 ,!re is a screw on ! l[] "p ( ! porte-crayons :i* is fix$ 9 a hole pi]c$ 9 a metallic plate ,c ,c1 & by ?is means ! pressure ( ! p5cils aga9/ ! disk ,l ,l c be regulat$4 ,! metallic plate ,c ,c is made 9 two pieces1 plac$ side by side1 b insulat$ f ea* o!r1 s t !y may be plac$ 9 communication ) a cyl9drical commutator1 & by its means ! circuit c be arrang$ 9 diff]5t ways4 ,s9ce ! commutator consi/s ( five %eets1 ! transition f "o comb9ation to ano!r is in/antane\s1 & ^! comb9ations are z foll[s3 #a4 ,! curr5t ent]s by ! p5cil ,p1 passes into ! plate1 & s to l9e4 #b4 ,! curr5t ent]s by ! p5cil ,p1 passes into ! plate1 & s to l9e4 #c4 ,! curr5t comes simultane\sly by ! two p5cils ,p & ,p1 goes into ! plate1 & !nce to l9e4 #d4 ,! curr5t comes by ! p5cil ,p1 goes !nce to ! plate1 !n into ! p5cil ,p1 & s to l9e4 ,illu/ration3 ,,fig4 #cb4 ,by ?is means !re are two elem5ts ( comb9ation1 :i* may be employ$ sep>ately1 or by c\pl+ !m = t5sion or quantity4 ,:5 ! p5cils are prop]ly regulat$ & give a regul> transmission ( equal int5sity1 ! effects produc$ 9 ! transition f "o comb9ation to ano!r may be easily /udi$1 & x has be5 asc]ta9$3 fir/1 t 9 a %ort circuit !re is no appreciable *ange1 :atev] be ! comb9ation employ$2 secondly1 t :5 ! circuit is long1 or ( great resi/ance1 ! t5sion arrangem5t is ! be/1 & ?is 9 proportion to ! l5g? ( ! l9e4 ,?is telephonic sy/em1 l ! two prec$+ ones1 requires an induc+ ma*9e to trans=m voltaic into induc$ curr5ts3 we %all pres5tly speak ( ?is important accessory ( ^! in/rum5ts4 ,besides ?is arrangem5t1 ,,mm4 ,poll>d & ,g>ni] h employ$ ! "o we h repres5t$ 9 fig4 #e1 :i* has giv5 bett] results4 ,we %all see pres5tly t x c be us$ z ! receiv+ organ ( s\nds4 ,9 ea* case ! two c>bons mu/ be plac$ 9 contact1 & subject$ to a c]ta9 initial pressure1 :i* %\ld be regulat$ by ! screw fitt$ to ! support ( ! l[] c>bon4 ,z = ! receiv+ telephone1 ! arrangem5t adopt$ by ,,mm4 ,poll>d & ,g>ni] is ! same z ,bell's1 except t !y employ t9 plates & helices ( great] resi/ance4 ,?is resi/ance ranges 9 fact f #ajj to #abe miles4 #8,we h always held1' ^! g5tlem5 say1 #8t :atev] may be ! resi/ance ( ! out] circuit1 !re is an advantage 9 increas+ ! numb] ( spirals1 ev5 :5 us+ wire ,no4 #db1 :i* is ! "o we pref]4' ,illu/ration3 ,,fig4 #cc4 ,m4 ,helles5's ,reaction ,telephone4--,m4 ,helles5 believ$ t ! vibrations produc$ by ! voice on ! c>bon ( a telephonic s5d] w\ld be magnifi$ if ! moveable "p ( ! rheotome 7 subject$ to an electro-magnetic action result+ f ! vibrations !mselves1 & he has contriv$ a s5d]1 :i* is bas$ on ! pr9ciple %[n 9 fig4 #cc1 & :i* has ! m]it ( =m+ 9 itself ! induc+ app>atus int5d$ to trans=m ! voltaic curr5ts employ$4 ,?is in/rum5t is compos$ ( a v]tical iron tube1 support$ on a magnetic b> ,n ,s1 & surr\nd$ by a magnetis+ coil ,b ,b1 above :i* is fix$ an induc+ helix ( f9e wire ,i ,i1 communicat+ ) ! circuit4 ,)9 ! tube !re is a lead p5cil ,c1 held by a porte-crayon :i* c be rais$ or l[]$ by means ( a screw ,v fix$ bel[ ! magnetic b>4 ,f9ally1 above ?is p5cil1 !re is an iron vibrat+ plate ,l ,l1 ) a plat9um po9t 9 communication ) ! batt]y 9 its c5tre2 ! local circuit communicates ) ! p5cil by means ( ! magnetis+ helix ,b1 & = ?is purpose "o end is sold]$ to ! iron tube4 ,f ?is arrangem5t x foll[s t ! vibrations ( ! plate ,l ,l1 at ! mom5t :5 x comes ne>e/ to ! p5cil1 t5d to become great] 9 consequ5ce ( ! attractive =ce ex]t$ on ! plate1 & z ! pressure ( ! lead p5cil is increas$1 x increases ! diff]5ces ( resi/ance :i* result f x1 & consequ5tly causes great] v>iations 9 ! int5sity ( ! transmitt$ curr5ts4 ,reaction ,telephone ( ,messrs4 ,?omson & ,h\/on4--,! telephonic arrangem5t we h describ$ has lately be5 adopt$ by ,mr4 ,elihu ,?omson & ,mr4 ,edw9 ,j4 ,h\/on1 :o1 on ,june #ba1 #ahgh1 two mon?s aft] ,m4 ,helles5 expla9$ 8 sy/em to me1#g publi%$ an article 9 #8,! ,engli% ,me*anic & ,_w ( ,sci5ce' ab\t an in/rum5t v simil> to t ( ,m4 ,helles54 ,9 _! in/rum5t1 ! curr5t1 :i* passes ?r\gh a body ( mod]ately conduct+ capacity1 acts on an electro-magnet provid$ ) an induction coil1 & ?is electro-magnet reacts on ! diaphragm1 9 ord] to increase ! range ( its vibrations1 & to create at ! same mom5t two electric actions 9 ! same direction3 ! only diff]5ce lies 9 ! arrangem5t ( ! contact ( ?is indiff]5t conductor ) ! vibrat+ plate4 ,in/ead ( a simple contact effect$ by pressure betwe5 ?is plate & a c>bon p5cil1 a fragm5t ( ! same sub/ance ) a %>p5$ po9t is fix$ on ! vibrat+ plate1 & x dips into a drop ( m]cury :i* has be5 p\r$ into ! receptacle made = x at ! upp] end ( ! electro-magnet4 ,9 o!r respects1 ! arrangem5t ( ! in/rum5t is t ( an ord9>y telephone1 & ! iron rod ( ! electro-magnet repres5ts ! magnetis$ b> ( ! ,bell telephone4 ,! inv5tors ass]t t ?is in/rum5t c be us$ bo? z a s5d] & receiv]1 & x is 9 ! foll[+ mann] t x is work$ 9 ea* case4 ,:5 ! in/rum5t is transmitt+1 ! morsel ( c>bon dips m or less into ! m]cury1 & consequ5tly diff]5ces are produc$ 9 ! surfaces ( contact1 accord+ to ! range ( vibrations made by ! plate2 ! curr5t v>ies 9 int5sity 9 proportion to ?is range1 & induc$ curr5ts 9 ! induction coil result f ^! v>iations2 ! induc$ curr5ts react on ! receiv+ telephone1 z 9 ,bell's in/rum5t1 & are fur!r /r5g!n$ by ^? :i* are produc$ electrically by ! movem5t ( ! diaphragm be=e ! induction coil1 & ! iron ( ! electro-magnet4 ,:5 ! in/rum5t is us$ z a receiv]1 ! usual effects are display$1 = s9ce ! iron ( ! electro-magnet is magnetis$ by ! curr5t1 its conditions are precisely ^? ( ! ord9>y ,bell telephone1 & ! induc$ curr5ts rea* x 9 ! same mann]1 only ) great] int5sity4 ,messrs4 ,?omson & ,h\/on ass]t t _! sy/em has produc$ excell5t results1 & t by x ! s\nd ( ! voice is mu* less alt]$ ?an 9 o!r telephones4 ,telephones ) batt]ies & liquid s5d]s4--,we h se5 t 9 #ahfg ,mr4 ,gray conceiv$ ! idea ( a telephonic sy/em bas$ on ! diff]5ces ( resi/ance effect$ 9 a circuit complet$ by a liquid1 :5 ! lay] ( liquid int]pos$ betwe5 ! electrodes v>ies 9 ?ickness "u ! influ5ce ( ! vibrations ( ! telephonic plate :i* is 9 communication ) "o ( ^! electrodes4 ,?is sy/em has s9ce be5 ! subject ( /udy by sev]al inv5tors1 among o!rs by ,,mm4 ,ri*emond & ,salet2 & ,i give "s ( ! acc\nts :i* h be5 publi%$ respect+ _! rese>*es4 ,ano!r telephone = ! reproduction ( articulate s\nds1 :i* ,m4 ,ri*emond t]ms ! electro-hydro telephone1 has be5 rec5tly pat5t$ 9 ! ,unit$ ,/ates4 ,x resembles t ( ,mr4 ,edison 9 "s respects1 b in/ead ( mak+ use ( c>bon disks to modify ! resi/ance ( ! circuit1 wat] is employ$1 & ?is wat] is plac$ 9 communication ) ! circuit & batt]y by means ( two plat9um po9ts1 "o ( :i* is fix$ on ! metallic diaphragm :i* vibrates "u ! influ5ce ( ! voice4 ,z ! vibrations ( ! diaphragm transport ! po9t :i* is atta*$ to x to diff]5t p>ts ( ! int]pol> lay] ( liquid1 !y dim9i% or increase ! electric resi/ance ( ?is lay]1 & cause correspond+ v>iations 9 ! int5sity ( ! curr5t trav]s+ ! circuit4 ,! receiv+ telephone is ( ! usual k9d4 7,see #8,telegraphic ,j\rnal1' ,septemb] #ae1 #ahgg47 ,m4 ,salet writes3 #8,i ?\ght x w\ld be int]e/+ to con/ruct a telephone 9 :i* !re %\ld be absolute solid>ity 9 ! movem5ts ( ! two membranes1 & = ?is purpose ,i h avail$ myself ( ! great resi/ance ( liquids4 ,mr4 ,bell _h already obta9$ "s results by atta*+ to ! vibrat+ membrane a plat9um wire communicat+ ) a batt]y1 & dipp+ m or less into a metallic vessel1 itself connect$ by ! l9e ) ! receiv+ telephone & conta9+ "s acidulat$ wat]4 ,i h sub/itut$ = ! plat9um wire a small alum9ium lev] support+ a disk ( plat9um1 & at a v slight di/ance f x !re is a second disk 9 connection ) ! l9e4 ,! vibrations ( ! membrane1 tripl$ or quadrupl$ 9 _! range1 are n alt]$ 9 =m1 ?anks to ! small size & light weight ( ! lev]3 !y cause v>iations 9 ! ?ickness ( ! liquid lay] trav]s$ by ! curr5t1 & consequ5tly 9 its int5sity1 & ^! v>iations cause correspond+ diff]5ces 9 ! attractive =ce ( ! receiv+ electro-magnet4 ,"u its influ5ce ! receiv+ membrane executes movem5ts :i* are id5tical ) ^? ( ! s5d+ membrane4 ,! s\nd transmitt$ is v di/9ct1 & its timbre is p]fectly ma9ta9$1 a result :i* might h be5 anticipat$4 ,! consonants1 h[ev]1 are n s cle>ly pron\nc$ z ^? transmitt$ by ,mr4 ,bell's in/rum5t4 ,?is inconv5i5ce is mo/ app>5t :5 ! lev] is heavy1 & might easily be obviat$4 ,! electrolysis also produces a cont9ual murmur1 b ?is does n int]f]e ) ! di/9ctness ( ! s\nd4 #8,s9ce on ?is sy/em ! voice is n requir$ to produce1 b only to direct ! electric curr5t g5]at$ by a batt]y1 ! int5sity ( ! s\nd receiv$ might 9 !ory be increas$ at pleasure4 ,i h 9 fact be5 able to make ! receiv] emit v p[]ful s\nds1 & ,i ?9k t ?is advantage greatly c\nt]balances ! necessity ( employ+ a batt]y1 & a some:at delicate s5d+ in/rum5t4 ,un=tunately x c only be us$ = mod]ate di/ances4 ,assum+ t any displacem5t ( ! transmitt+ membrane increases ! resi/ance to a degree equival5t to five or six hundr$ y>ds ( wire3 if ! l9e is five hundr$ y>ds long1 ! int5sity ( ! curr5t w be r$uc$ by "o half1 & ! receiv+ membrane w take up a fre% position1 consid]ably diff]+ f ! fir/2 b if ! l9e is ?ree hundr$ miles 9 l5g?1 ! int5sity ( ! curr5t w only be modifi$ by a ?\s&? "p4 ,an imm5se batt]y mu/ !re=e be employ$ 9 ord] t ?is v>iation may be translat$ by a s5sible *ange 9 ! position ( ! receiv+ membrane4' 7,see #8,comptes ,r5dus de l',acadmie des ,sci5ces1' ,febru>y #ah1 #ahgh47 ,m4 ,j4 ,luv9i1 9 an article ins]t$ 9 #8,les ,mondes1' ,m>* #g1 #ahgh1 has sugge/$ a sy/em ( rheotome by means ( a curr5t1 = batt]y telephones1 :i*1 al?\gh complicat$1 possibly (f]s "s advantages1 s9ce x produces curr5ts alt]nately rev]s$4 ,9 ?is sy/em1 ! vibrat+ disk ( ! s5d]1 :i* %\ld be 9 a v]tical position1 reacts on a moveable horizontal wire1 turn$ back at a "r angle1 & support+ on ea* ( its bran*es two plat9um po9ts :i* dip into two bulbs1 fill$ ) a liquid ( mod]ate conduct+ capacity4 ,! two bran*es ( ?is wire1 insulat$ f ea* o!r1 are plac$ 9 communication ) ! two poles ( ! batt]y1 & ! f\r cups into :i* ! plat9um wire dips communicate inv]sely ) ! l9e & ! e>? by means ( plat9um wires immoveably fix$ 9 ! cups4 ,x foll[s f ?is arrangem5t1 t :5 ! di/ances are duly regulat$ betwe5 ! fix$ & moveable wires1 two equal curr5ts w be oppos$ to ea* o!r across ! l9e circuit :5 ! diaphragm is motionless2 b z soon z x vibrates1 ! respective di/ances ( ! wires w v>y1 & x foll[s f ?is t !re w be a diff]5tial curr5t1 ( :i* ! int5sity w correspond ) ! ext5t ( ! displacem5t ( ! sy/em1 or ) ! range ( vibrations1 & ! direction w v>y ) ! movem5ts above or bel[ ! l9e ( ! nodes ( vibration4 ,9 ?is way ! advantage ( ! induc$ curr5ts is obta9$4 ,telephones ) a batt]y & voltaic arcs4--,9 ord] to obta9 v>iations ( resi/ance ( /ill great] s5sitiv5ess ?an is ! case ) liquids or pulv]is$ sub/ances1 ! idea has be5 sugge/$ ( employ+ conductors ( heat$ gas1 & sev]al arrangem5ts ( batt]y telephones h be5 made 9 :i* ! circuit 0 complet$ by a /ratum ( air1 sep>at+ ! vibrat+ disk f a plat9um po9t1 :i* s]ves to excite an electric dis*>ge ( high t5sion4 ,"u ^! conditions1 ! /ratum ( air becomes ! conductor1 & ! int5sity ( ! curr5t :i* trav]ses x corresponds to its ?ickness4 ,?is problem has be5 solv$1 ei!r by means ( voltaic curr5ts ( high t5sion1 or by a ,ruhmkorff coil4 ,! =m] sy/em 0 arrang$ by ,m4 ,tr\v1 & he writes z foll[s on ! subject 9 ! j\rnal #8,la ,nature' ( ,april #f1 #ahgh3 #8,a metallic vibrat+ membrane =ms "o ( ! poles ( a high t5sion batt]y2 ! o!r pole is fa/5$ be=e ! disk by a micromet] screw :i* c be adju/$ s z to v>y ! di/ance f ! disk accord+ to ! t5sion ( ! batt]y1 b )\t ev] com+ 9 contact ) x4 ,! di/ance mu/ n 9 any case exce$ t to :i* ! dis*>ge ( ! batt]y c ext5d4 ,"u ^! conditions1 ! membrane :i* vibrates "u ! influ5ce ( ! waves ( s\nd has ! effect ( con/antly modify+ ! di/ance betwe5 ! two poles1 & ?us ( cont9ually v>y+ ! int5sity ( ! curr5t3 consequ5tly ! receiv+ in/rum5t 7a ,bell telephone1 or telephone ) an electro-magnet7 is subject$ to magnetic v>iations1 correspond+ to ! v>iations ( ! curr5t :i* affect x1 & ?is has ! effect ( mak+ ! receiv+ in/rum5t vibrate at ! same mom5t4 ,?is k9d ( telephonic in/rum5t relies1 !re=e1 on ! possibility ( v>y+ )9 wide limits ! resi/ance ( ! out] circuit ( a high-t5sion batt]y1 9 :i* ! poles are n 9 contact4 ,9 ord] to v>y ! conditions ( ?is resi/ance1 x is also possible to int]pose "s vap\r or o!r m$ium1 su* z air1 or gas ( great] or less r>ity4' ,m4 ,tr\v ?9ks t he 0 successful ) 8 batt]y ( small disks1 moi/5$ ) sulphate ( copp] & sulphate ( z9c1 arrang+ ^! elem5ts1 to ! numb] ( five or six hundr$1 9 glass tubes ( small diamet]4 ,x is well kn[n t x is unnecess>y = ! elem5ts to be ( l>ge size 9 ord] to obta9 t5sion curr5ts4 ,m4 de ,lalagade has sugge/$ an analog\s mode by employ+ = ! =mation ( ! arc a curr5t ( :i* ! t5sion is increas$ by ins]t+ a /rong electro-magnet into ! circuit4 ,?is electro-magnet acts on a ,hughes magnet 9 ord] to produce induction curr5ts capable ( mak+ ! receiv+ in/rum5t act4 ,m4 de ,lalagade says t a ,buns5 batt]y1 or "o ( six cells ) bi*romate ( pota%1 w be en\gh to produce a cont9u\s voltaic arc betwe5 ! vibrat+ plate ( a telephone & a plat9um po9t :i* is suffici5tly remote to avoid contact4 ,x is necess>y1 h[ev]1 to beg9 ) a contact1 9 ord] to produce ! =mation ( ?is arc4 ,9 ,m4 de ,lalagade's sy/em1 ! vibrat+ plate %\ld h 9 its c5tre a small plat9um plate1 9 ord] to obviate ! oxidis+ effects ( ! sp>k4 ,! inv5tor ass]ts t s\nds transmitt$ 9 ?is way1 & reproduc$ 9 a telephone ( :i* ! electro-magnetic sy/em is set ^u a s\nd+-box1 w h great] int5sity ?an ! s\nds transmitt$ by an ord9>y telephone1 & ! speak] w appe> to be close to ! e>4 ,m]cury ,telephones4--,^! sy/ems are bas$ on ! physical pr9ciple discov]$ by ,m4 ,lippmann1 t if a lay] ( acidulat$ wat] is plac$ above m]cury1 & connect$ ) x by an electrode & wire1 e me*anical action :i* ex]ts pressure on ! surface ( ! m]cury1 & alt]s ! =m ( its m5iscus1 w cause an electric reaction1 capable ( produc+ a curr5t ) a =ce :i* corresponds to ! me*anical action ex]t$4 ,conv]sely1 e electric action produc$ on ! circuit ( su* a sy/em w occasion a displacem5t ( ! m5iscus1 & consequ5tly its movem5t1 :i* w be m m>k$ 9 proportion to ! smallness ( ! tube 9 :i* ! m]cury is plac$1 & to ! greatness ( ! electric action4 ,?is electric action may result f a diff]5ce ( pot5tial 9 ! electric condition ( ! two extremities ( ! circuit1 :i* communicate ) ! electric s\rce employ$1 or ) "s electric g5]ator4#h ,illu/ration3 ,,fig4 #cd4 ,9 accordance ) ^! effects1 x is intelligible t if two tubes ,t ,t1 po9t$ at ! end1 & conta9+ m]cury1 are plung$ into two vessels ,v ,v 7fig4 #cd7 conta9+ acidulat$ wat] & m]cury1 & metallic wires1 ,p ,p1 ,q ,q1 are us$1 fir/ to connect ! columns ( m]cury 9 ! tubes1 & secondly ! lay]s ( m]cury at ! bottom ( ! two vessels1 ! tubes be+ a little remov$ f ! surface ( ! m]cury 9 ! vessels1 we %all !n h a metallic circuit1 complet$ by two electrolytes1 "o ( :i* w be subject$ to ! me*anical or electrical effects produc$ 9 ! o!r4 ,if two vibratory plates ,b ,b are plac$ above ! tubes1 & "o ( ^! is caus$ to vibrate1 ! o!r w reproduce ^! vibrations1 influ5c$ by ! vibratory movem5ts communicat$ by ! correspond+ column ( m]cury4 ,! vibrations !mselves w be 9 connection ) ! electrical dis*>ges result+ f ! movem5ts ( ! column ( m]cury 9 ! fir/ tube1 :i* are me*anically produc$4 ,if an electric g5]ator is introduc$ into ! circuit1 ! effect :i* we h j analys$ w be caus$ by modifications 9 ! pot5tial ( ?is g5]ator1 9 consequ5ce ( electro-capill>y effects4 ,b if no g5]ator is employ$1 ! action w result f electric curr5ts det]m9$ by ! electro-capill>y attraction itself4 ,9 ! latt] case1 h[ev]1 ! in/rum5t mu/ be m delicately made1 9 ord] to obta9 m s5sitive electric reaction1 & ,m4 ,a4 ,brguet describes 8 in/rum5t z foll[s4 #8,! in/rum5t consi/s ( a tube ( ?9 glass1 a few c5timtres 9 l5g?1 conta9+ alt]nate drops ( m]cury & acidulat$ wat]1 s z to con/itute s _m electro-capill>y elem5ts1 connect$ 9 t5sion4 ,! two ends ( ! tube are fus$ toge!r1 yet s z to all[ a plat9um wire to t\* ! ne>e/ drop ( m]cury on ea* side4 ,a small circle ( ?9 deal is fix$ at "r angles to ! tube by its c5tre1 ?us provid+ a surface ( "s ext5t1 :i* c be appli$ to ! e> :5 ! in/rum5t is a receiv]1 & to make ! tube m mobile "u ! influ5ce ( ! voice :5 ! in/rum5t is a s5d]4 ,! foll[+ are ! advantages (f]$ by in/rum5ts ( ?is con/ruction3-- #8#a4 ,!y d n involve ! use ( a batt]y4 #8#b4 ,! di/urb+ influ5ce ( ! resi/ance ( a long l9e is almo/ de/roy$ 9 ^! in/rum5ts1 al?\gh x is /ill appreciable 9 ! ,bell telephone4 #8#c4 ,two m]cury telephones1 c\pl$ toge!r z we describ$ above1 are absolutely correlative1 9 ?is s5se1 t ev5 diff]5t positions 9 ! equilibrium ( ! m]cury 9 "o ( !m produce diff]5t positions ( equilibrium 9 ! opposite in/rum5t4 ,x is !re=e possible to reproduce at a di/ance1 )\t a batt]y1 n m]ely fai?ful indications ( oscillatory movem5ts1 :i* is done by ! ,bell telephone1 b also ! exact image ( ! mo/ g5]al movem5ts4' ,friction ,telephones4--,mr4 ,e4 ,gray has q rec5tly appli$ ! pr9ciple ( produc+ s\nds by ! friction ( animal tissues to ! con/ruction ( a speak+ telephone :i* may be he>d ?r\gh a :ole room1 l ! s++ cond5s]4 ,he obta9s ?is result by means ( clockwork1 :i* causes ! rotation ( ! metallic disk ( :i* we h spok5 7p4 #bc71 & on :i* a piece ( sk9 is s arrang$ z to produce friction4 ,a c>bon or liquid telephone is plac$ at ! s5d+ /ation1 9 su* a way z to react on an induction coil1 z 9 ! sy/ems ( ,edison1 ,navez1 or ,poll>d1 & spee* is reproduc$ on ! rotat+ disk1 & is audible1 z we h said1 )\t ! necessity ( approa*+ ! e> to ! in/rum5t4 ,! be/ arrangem5t ( ! metallic disk on :i* ! animal tissue rubs is t ( a cyl9drical box1 ( :i* ! out] lid is made ( a ?9 %eet ( z9c ) a highly poli%$1 slightly oxidis$ surface2 = ! ag5t ( friction1 glove-lea!r slightly moi/5$ ) acidulat$ wat] may be us$1 or a s9ew ( an ox1 or sk9 tak5 f ! e> or tail ( a pig4 ,,modifications ,,introduc$ ,,9 ,,! ,,con/ruction ,,( ,,! ,,bell ,,telephones4 ,! modifications :i* we h be5 consid]+ relate to ! pr9ciple ( ! in/rum5t2 ^? :i* we h n[ to consid] are only modifications 9 ! =m & arrangem5t ( ! diff]5t organs :i* =m ! ,bell telephone itself1 & :i* h be5 design$ ) ! object ( increas+ ! int5sity & di/9ctness ( ! s\nds produc$4 ,telephones ) sev]al diaphragms4--,:5 we rememb] t ! induc$ curr5ts caus$ 9 a magnet result f ! vibratory movem5ts ( ! diaphragm1 & t ^! are produc$ by ! vibrations ( ! /ratum ( air int]pos$ betwe5 ?is diaphragm & ! vocal organ1 x necess>ily foll[s t if ^! vibrations ( ! air react on sev]al diaphragms1 ea* atta*$ to its electro-magnetic organ1 sev]al induc$ curr5ts might be caus$ simultane\sly1 & if ^! 7 prop]ly connect$1 _! effects on ! receiv] w\ld be s mu* ! m int5se1 s9ce ! s\nds produc$ w\ld result f ! comb9ation ( sev]al s\rces ( s\nd4 ,sev]al inv5tors1 />t+ f ?is argum5t1 h plann$ in/rum5ts ( v>y+ +5uity1 :i* we w n[ describe1 b )\t be+ able to decl>e :o 0 ! fir/ to realise ?is idea4 ,x is 9 fact s simple1 t x probably sugge/$ itself to ! m9ds ( sev]al inv5tors at ! same "t1 & we see t :ile ,m4 ,tr\v propos$ ?is improvem5t 9 ,france 9 ,novemb] #ahgg1 x 0 tri$ 9 ,am]ica & discuss$ 9 ,engl&1 :]e inde$ x 0 n expect$ to produce v fav\rable results4 ,mr4 ,preece wrote on ! subject 9 a pap] entitl$ #8,on "s ,physical ,po9ts connect$ ) ! ,telephone1' :i* 0 publi%$ 9 ,april #ahgh4 ,he obs]ves t all ! attempts to improve ! telephone h end$ 9 disappo9tm5t & failure4 ,"o ( ! fir/ attempts ( ! k9d 0 made by ,mr4 ,wilmot1 :o expect$ to obta9 fav\rable results by augm5t+ ! numb] ( diaphragms1 helices1 & magnets1 connect+ ! helices 9 a s]ies1 & caus+ !m to act simultane\sly1 s z to increase ! en]gy ( ! curr5ts develop$ by ! influ5ce ( ! voice2 b exp]i5ce %[$ t :5 ! in/rum5t act$ directly1 ! vibratory effect ( ea* ( ! diaphragms decreas$ 9 proportion to _! numb]1 & ! g5]al effect rema9$ ! same z ) a s+le diaphragm4 ,mr4 ,wilmot's in/rum5t 0 made 9 ! beg9n+ ( ,octob] #ahgg1 & t ( ,m4 ,tr\v 0 only an imitation ( x4 ,on ! o!r h&1 we see t if ! telephones ) sev]al membranes 7 n successful 9 ,engl&1 ?is 0 n ! case 9 ,am]ica1 = ! telephones :i* exp]i5ce has %[n to give ! be/ results 9 t c\ntry are ^? ( ,mr4 ,eli%a ,gray & ,mr4 ,phelps1 & ^! h sev]al diaphragms4 ,x is evid5t t !re are details ( con/ruction 9 ^! in/rum5ts :i* may appe> insignificant 9 !ory1 & :i* are not)/&+ v important f a practical po9t ( view1 & we believe t x is to ?is circum/ance t in/rum5ts ( ?is k9d owe _! success or failure4 ,?us1 = example1 x seems t ! vibrations ( air caus$ 9 ! m\?piece ought to be imm$iately direct$ on ! surface ( ! diaphragms by means ( di/9ct *annels2 x is necess>y t ! empty space r\nd ea* diaphragm %\ld be suffici5tly limit$ to prev5t e*oes & int]ruptions1 unless ! case is s l>ge t !re is no dang] ( su* effects4 ,above all1 x is necess>y t ! organs %\ld be fix$ 9 "s mat]ial unsusceptible ( rev]b]ation1 & = ?is reason a pref]5ce is giv5 to iron or ebonite4 ,x is c]ta9 t :5 ! in/rum5t is prop]ly made1 its effects are sup]ior to ^? ( ! ,bell telephones1 & x is ass]t$ 9 ! #8,telegraphic ,j\rnal' t exp]im5ts 7 made ) "o ( ^! in/rum5ts be=e ! ,royal ,society1 9 ,london1 ,may #a1 #ahgh1 & t ! int5sity ( s\nd 0 9 proportion to ! numb] ( diaphragms4 ,?is in/rum5t 0 design$ by ,mr4 ,cox ,walk]1 ( ,york1 & possess$ eight diaphragms4 ,he consid]s t ?is is ! arrangem5t :i* gives ! be/ results4 ,illu/ration3 ,,fig4 #ce4 ,mr4 ,eli%a ,gray's ,sy/em4--,mr4 ,eli%a ,gray's la/ sy/em1 :i* we repres5t 9 fig4 #ce1 is "o ( ^? :i* h giv5 ! be/ effects4 ,x is made1 z we see1 ( two telephones1 side by side1 to :i* correspond two tubes1 issu+ f a common m\?piece ,e4 ,"o ( ^! telephones is se5 9 section 9 ! plate1 ! o!r 9 elevation1 & !y correspond to ! two bran*es ( a nickel-plat$ horse%oe magnet ,n ,u ,s1 :i* may s]ve z a susp5sion r+4 ,9 t "p ( ! plate :i* repres5ts ! section1 ! induction coil is %[n 9 ,b1 & ! magnetic core1 ( s(t iron1 9 ,a1 :i* is screw$ to ! pol> end ( ! magnet ,s2 ! vibrat+ plate is 9 ,l ,l1 &1 z we see1 ! tube ( ! m\?piece t]m9ates on its surface4 ,9 ano!r model !re are f\r telephones side by side1 in/ead ( two1 & ! effects produc$ are /ill m m>k$4 ,mr4 ,phelps's ,sy/em4--,?is sy/em is only d$uc$ f ! la/1 b !re are two models ( x4 ,9 ! l>g] "o1 :i* makes x possible to he> z di/9ctly z if ! p]son ) :om conv]sation is held 7 speak+ 9 a l\d voice 9 ! same room1 ! two telephones are plac$ p>allel to ea* o!r1 & s z to pres5t _! diaphragms v]tically2 ! space betwe5 ^! two diaphragms is occupi$ by a v]tical tube1 t]m9at+ at its l[] end 9 a horizontal tube correspond+ to ! c5tres ( ! two diaphragms1 & on ?is tube ! m\?piece is fitt$1 :i* projects outside ! box 9 :i* ! in/rum5t is enclos$4 ,! induction coils1 & ! magnetic cores :i* trav]se !m1 foll[ ! axis ( ! sy/em1 & seem to con/itute ! axis ( a :eel :i* is pol>is$ by ! poles ( a horse%oe magnet1 ( :i* ! position ) ref]5ce to ! surface ( ! diaphragms c be regulat$ by moveable screws4 ,! appe>ance ( ! in/rum5t some:at resembles a gyroscope1 re/+ by a horizontal axis on two %afts :i* issue f a flatt5$ horse%oe magnet4 ,above ?is sy/em !re is ! electro-magnetic app>atus ( ! call-bell1 9 :i* !re is no?+ peculi>1 & :i* is l ! ,g]man al>ums ( :i* we %all speak at ! end ( ?is acc\nt4 ,?is in/rum5t is rem>kable = /r5g? & cle>ness ( s\nd1 & especially = its fre$om f ! ,pun* & ,judy voice s displeas+ 9 o!r telephones4 ,mr4 ,phelps's small model is 9 ! =m ( an oblong or elliptical snuff-box1 ( :i* ! two c5tres are occupi$ by two telephonic sy/ems1 influ5c$ by ! same magnet4 ,?is magnet is plac$ 9 a horizontal position bel[ ! snuff-box1 & its poles correspond to ! magnetic cores ( ! coils4 ,^! cores are made ( iron tubes1 split longitud9ally 9 ord] to de/roy irregul> induction reactions1 & ! iron diaphragms re/ on five spiral spr+s1 :i* raise !m above ! magnetic sy/em4 ,on _! o!r surface ! diaphragms are provid$ ) r+s ( "s semi-ela/ic sub/ance1 :i* prev5t ! c5tral vibrations ( ! disks f becom+ complicat$ by ^? ( _! edges4 ,! lid1 holl[$ out 9 v %all[ cavities1 is next plac$ ^u ! disks1 & !re are *annels ( communication 9 x to s]ve z a s\nd+-box4 ,! m\?piece corresponds to "o ( ^! cavities1 & ! o!r is clos$ by a small metallic /opp]1 :i* c be )drawn to regulate ! in/rum5t :5 necess>y4 ,s9ce ! vibrations ( air are transmitt$ by ! *annels to bo? cavities1 ! two telephones act toge!r1 al?\gh at fir/ sight only "o ( !m seems to be requir$ to produce ! effect4 ,mr4 ,phelps praises ! simultane\s effects produc$ on ! two in/rum5ts1 :i* he ascribes1 fir/1 to ! semi-ela/ic r+ surr\nd+ ! rim ( ea* disk1 & act+ z ! hamm] ( ! e>1 t is1 z a damp]2 !n1 to ! longitud9al splits ( ! magnetic core1 & la/ly to ! small size ( ! cavities left above ! vibrat+ disks4 ,! in/rum5t is made ( ebonite1 groov$ on ! surface 9 ord] to give a bett] grasp to ! h&4 ,mr4 ,phelps has a new model1 call$ ! cr[n telephone1 :i* is n[ 9 use 9 ,am]ica1 toge!r ) ,mr4 ,edison's c>bon s5d]4 ,9 x ea* ( ! two sy/ems ( ! l>ge model we h describ$ is work$ by six horse%oe magnets radiat+ r\nd ! magnetic core1 & s arrang$ t ! nor? poles correspond to ?is core1 & ! o!r poles to ! circul> rim ( ! diaphragm4 ,9 ?is way ! magnetic field is consid]ably enl>g$1 & ! s\nd mu* int5sifi$4 ,9 exp]im5ts rec5tly made at ,dr4 ,wells's *ur*1 ,new ,york1 an assembly ( ?ree hundr$ p 7 able to he> spee* & vocal or in/rum5tal music di/9ctly 9 diff]5t p>ts ( ! hall4 ,mr4 ,cox ,walk]'s ,sy/em4--,?is sy/em1 on :i* we h already said a few words1 has exactly ! arrangem5t ( t by ,mr4 ,eli%a ,gray4 ,! magnets :i* act ^u ! diaphragms are horse%oe1 & sep>ate pipes1 issu+ f a common m\?piece1 direct ! vibrations ( air on ! diaphragms4 ,^!1 inde$1 are only def9$ p>ts ( "o diaphragm1 b\nd$ 9 a circle by m\?pieces correspond+ to ! air-pipes1 & suffici5tly re/rict$ on _! edges to limit ! field ( vibration4 ,m4 ,tr\v's ,sy/em4--,m4 ,tr\v has simplifi$ ! arrangem5t ( telephones ) a d\ble diaphragm1 by design+ ! in/rum5t s z to make ,bell's b> magnet react by bo? poles at once on sev]al disks4 ,= ?is purpose1 he employs a tubul> magnet1 & w9ds a helix ?r\gh\t its :ole l5g?1 z we see 9 fig4 #cf4 ,?is magnet is ma9ta9$ 9 a fix$ position 9 ! c5tre ( a small cyl9drical box1 ( :i* ! base is slightly funnel-%ap$1 ?us act+ z a m\?piece & ac\/ic tube4 ,x is consequ5tly pi]c$ 9 ! c5tre ) a hole l>g] at a1 ! /ation = speak+1 ?an on ! opposite side b4 ,betwe5 ! base & ! poles ( ! magnet !re are two vibrat+ iron plates1 ,m1 ,m1 "o ( :i*1 ,m1 is pi]c$ ) a hole a ( ! same diamet] z ! holl[ "p ( ! magnet1 & consequ5tly small] ?an t ( ! m\?piece4 ,f9ally1 sev]al o!r plates n1 n1 n1 are rang$ 9 p>allel l9es betwe5 ^! two plates1 s t ! magnet & its helix may pass ?r\gh !m4 ,illu/ration3 ,,fig4 #cf4 ,:5 any?+ is said be=e ! m\?piece a1 ! waves ( s\nd enc\nt]+ ! edges ( ! plate ,m place x 9 vibration1 &1 cont9u+ _! passage inside ! tubul> magnet1 !y cause ! plate ,m to vibrate at ! same "t z ,m4 ,a d\ble induc+ action !re=e takes place on ! tubul> magnet1 & ?is is translat$ by ! induc$ curr5ts develop$ 9 ! helix1 :i* h great] en]gy s9ce ea* ( ! plates int5sifies ! magnetic effects produc$ at ! pole opposite to ! "o !y influ5ce1 :i* is always ! case ) b> magnets :5 ! inactive pole is provid$ ) an armature4 ,?is advantage may ev5 be obta9$ 9 ! case ( ord9>y telephones1 if ! screw :i* holds ! magnet is plac$ 9 contact ) a mass ( s(t iron4 ,9 ,m4 ,tr\v's arrangem5t1 ! induc$ curr5ts !re=e possess great] en]gy2 b he adds t ! s\nds reproduc$ w also be /r5g!n$ by ! multiplicity ( vibratory effects1 & by ! enl>gem5t ( ! magnetic effects1 :i* results f a bett] arrangem5t ( ! magnets4 #8,:5 ! e> is plac$ at a1' ,m4 ,tr\v writes1 #8x p]ceives imm$iately ! s\nds produc$ by ! fir/ plate ,m1 & ^? ( ! second plate rea* ! e> ?r\gh ! int]ior ( ! magnet4 ,?is new arrangem5t is well adapt$ = an exp]im5tal comp>ison ( ! results produc$ by a telephone ) a s+le membrane 7a ,bell telephone71 & ^? produc$ by a telephone ) sev]al membranes4 ,x is 9 fact en\gh to li/5 at ! two faces ( ! telephone alt]nately1 9 ord] to p]ceive at once ! diff]5ce ( int5sity 9 ! s\nds produc$4 ,^? collect$ at a1 on ! side ( ! pi]c$ iron plate1 appe> manife/ly d\bl$ 9 int5sity comp>$ ) ^? collect$ at b on ! side ( ! simple membrane :i* =ms ! ord9>y telephone4 #8,! diff]5ce is /ill m /rik+ if1 9 transmitt+ or receiv+ a s\nd ( inv>iable int5sity ?r\gh a multiple telephone1 ! unbrok5 membrane ,m is repeat$ly prev5t$ f vibrat+4' ,be=e mak+ ?is arrangem5t ,m4 ,tr\v _h plann$ ano!r1 :i* he pres5t$ to ! ,acadmie des ,sci5ces1 ,novemb] #bf1 #ahgg1 & :i* we h glanc$ at 9 ! beg9n+ ( ?is *apt]4 ,he describes x 9 ^! t]ms3-- #8,9 ord] to increase ! int5sity ( ! effects produc$ 9 ! ,bell telephone1 ,i h sub/itut$ = ! s+le membrane a cubic *amb]1 ( :i* ea* face is1 ) "o exception1 =m$ ( a vibrat+ membrane4 ,ea* ( ^! membranes1 put 9 vibration by ! same s\nd1 influ5ces a fix$ magnet1 :i* is also provid$ ) an electric circuit4 ,9 ?is way1 by connect+ all ! curr5ts g5]at$ by ! magnets1 a s+le int5sity is obta9$1 :i* increases 9 proportion to ! numb] ( magnets influ5c$4 ,! cube might be replac$ by a polyh$ron1 ( :i* ! faces might be =m$ ( an indef9ite numb] ( vibrat+ membranes1 s z to obta9 ! desir$ int5sity4' ,m4 ,demoget's ,sy/em4--,sev]al o!r sy/ems ( telephones ) multiple membranes h be5 propos$4 ,"o ( !m1 plann$ by ,m4 ,demoget1 consi/s 9 plac+ be=e ! vibrat+ disk ( ! ord9>y ,bell telephone1 sep>at$ by ! space ( a millimtre1 "o or two simil> vibrat+ disks1 tak+ c>e to pi]ce 9 ! c5tre ( ! fir/ a circul> hole ( ! same diamet] z t ( ! b> magnet1 & to pi]ce a l>g] hole 9 ! second membrane4 ,! inv5tor ass]ts t ! di/9ctness z well z ! int5sity ( s\nds is increas$ 9 ?is way4 #8,by ?is arrangem5t1' says ,m4 ,demoget1 #8s9ce ! vibrat+ magnetic mass is l>g] 9 proportion to ! magnet1 ! electro-motive =ce ( ! curr5ts g5]at$ is increas$1 & consequ5tly ! vibrations ( ! disks ( ! second telephone are m p]ceptible4' ,mr4 ,mc,tighe's ,telephone4--,9 ?is telephone1 :i* has sev]al diaphragms1 !re is a horse%oe magnet1 & in/ead ( plac+ ! coils ^u ! poles1 !re is a s+le coil fa/5$ to an iron core1 :i* is ins]t$ betwe5 wide pol> app5dices fitt$ to ! two poles ( ! magnet4 ,^! app5dices consi/ ( ?9 plates1 :i* act z vibrat+ plates4 ,modifications 9 ! arrangem5t ( ,telephonic ,organs4--,we see t ! =ms giv5 to ! ,bell telephone are v v>i$1 & ?is is /ill m ! case ) its con/itu5t organs1 )\t1 h[ev]1 produc+ any rem>kable improvem5ts4 ,mr4 ,preece obs]ves t little has be5 ga9$ by v>y+ ! size & /r5g? ( ! magnets1 & ! be/ effects h be5 obta9$ by us+ ! horse%oe magnets direct$ by ,mr4 ,bell himself4 ,! telephone 0 c]ta9ly introduc$ into ,europe ) ! arrangem5t :i* is !oretically ! be/1 al?\gh ,mr4 ,bell is /ill occupi$ 9 improv+ x4 ,?is is also ! op9ion ( ,m4 ,helles51 :o1 l ,mr4 ,preece1 has made _m exp]im5ts on ?is po9t2 b ?is has n det]r$ sev]al p f decl>+ t !y h discov]$ ! way ( mak+ a telephone speak s z to be audible to an assembly ( p4 ,( ! diff]5t in/rum5ts made ) ?is object1 t ( ,m4 ,righi seems to be ! mo/ important4 ,x 0 lately tri$ ) success at ! ,acadmie des ,sci5ces1 ! ,cons]vatoire des ,arts et ,mti]s1 & ! ,press pavilion ( ! ,exhibition4 ,illu/ration3 ,,fig4 #cg4 ,! receiv] is only a ,bell telephone ( l>ge size1 ) a diaphragm ( p>*m5t ,l ,l 7fig4 #cg71 9 ! c5tre ( :i* !re is a %eet-iron disk ,f4 ,?is membrane is /ret*$ on a l>ge funnel ,e1 :i* is fix$ on a box ,c ,c1 conta9+ ! electro-magnetic coil ,b3 & ! magnet ,n ,s1 mu* l>g] ?an 9 ! ord9>y in/rum5ts1 issues f ! box1 & s]ves z its support4 ,illu/ration3 ,,fig4 #ch4 ,! s5d] resembles ! "o repres5t$ 9 fig4 #ai1 except t1 in/ead ( liquid1 ,m4 ,righi employs plumbago mix$ ) p[d]$ silv]1 & ! plat9um ne$le is replac$ by a metallic disk ,d 7fig4 #ch74 ,! receiv] ,i1 :i* conta9s ! p[d]1 is support$ on a spr+ ,r1 :i* c be pu%$ up & d[n by a regulat+ screw ,v1 & ! :ole is fitt$ into a box ,c ,c1 & support$ on a foot ,p4 ,! speak] places himself above ! m\?piece ,e1 & ! vibrations transmitt$ to ! membrane ,l ,l cause ! v>iations ( resi/ance 9 ,i :i* are necess>y = ! transmission ( spee*1 z 9 ! ,edison sy/em4 ,two ,buns5 cells are en\gh to set ! in/rum5t at "w1 & x w make ! s\nd ( a trumpet or flute audible ?r\gh\t a room4 ,vocal music1 :i* is less int5se1 is necess>ily transmitt$ to a r less di/ance1 & words spok5 9 ! natural voice are he>d by ^? /&+ ab\t two y>ds & a half f ! in/rum5t4 ,! maximum di/ance at :i* ! in/rum5t has be5 work$ ) ! batt]y only is tw5ty-eight miles1 ! di/ance betwe5 ,bologna & ,f]r>a1 & = great] di/ances x is necess>y to h rec\rse to induction coils4 ,9 ?is case1 an induction coil is introduc$ into ! circuit at ea* /ation1 & its prim>y wire is trav]s$ by a curr5t f ! local batt]y1 & s also is ! s5d]1 :i* is else:]e connect$ ) ! receiv] by a commutator4 ,! second>y circuit ( ^! coils is complet$ ?r\gh ! e>? & l9e wire4 ,f ?is arrangem5t x foll[s t ! induc$ curr5t :i* influ5ces ! receiv] 9 correspond5ce1 only produces its effect aft] a second induction1 produc$ on ! prim>y wire ( ! local coil1 & x appe>s t ?is is a suffici5t effect2 b ! advantage ( ?is arrangem5t is1 t x is possible to receive & transmit s\nds )\t ! aid ( any?+ b ! commutator4 ,among o!r arrangem5ts :i* h be5 sugge/$1 we may m5tion "o 9 :i*1 in/ead ( ! b> magnet1 a horse%oe magnet is us$1 ) a vibrat+ plate plac$ betwe5 its poles4 ,= ?is purpose ! poles are tipp$ ) iron1 & "o ( !m is pi]c$ ) a hole :i* corresponds to ! m\?piece ( ! in/rum5t4 ,! two bran*es ( ! magnet are also furni%$ ) magnetis+ helices4 ,:5 any?+ is spok5 be=e ! hole1 ! vibrat+ plate causes induc$ curr5ts 9 ! two helices3 ^! curr5ts w\ld be ( opposite direction if ! poles 7 ( l nature1 b1 s9ce ! magnetic poles are ( contr>y nature1 !y are 9 ! same direction4 ,! vibrat+ plate !n acts l ! two plates ( ,m4 ,tr\v's in/rum5t1 :i* we h describ$ above4 ,9 ano!r arrangem5t1 lately made by ,ad]1 ! receiv] is only an ord9>y two-bran*$ magnet1 ( :i* ! armature is support$1 at ab\t two millimtres f its poles1 by a glass plate to :i* x is glu$1 & ! plate itself is fa/5$ to two rigid supports4 ,9 ord] to he> x is only necess>y to apply ! e> to ! plate4 ,! s5d] is a moveable rod ( iron or c>bon1 :i* re/s on a fix$ piece ( c>bon1 ) no pressure except its own weight1 & x supports a concave disk1 to :i* ! speak] applies 8 m\?4 ,^! two p>ts are s arrang$ z to move horizontally1 s t1 :5 ! in/rum5t is susp5d$1 ! circuit is =cibly disconnect$ by ! fact ( its position1 & is !re=e clos$ until anyone takes x up to speak4 ,spee* is well reproduc$ by ?is sy/em1 & may be transmitt$ to "s di/ance if x is made on a l>g] scale4 ,aga91 an anonym\s inv5tor1 9 a little note ins]t$ 9 #8,les ,mondes1' ,febru>y #g1 #ahgh1 writes z foll[s3 #8,s9ce ! int5sity ( ! curr5ts produc$ 9 ! telephone is 9 proportion to ! mass ( s(t iron :i* vibrates be=e ! pole ( ! magnet1 & s9ce1 on ! o!r h&1 ! plate is s5sitive 9 proportion to its t5uity1 ,i employ1 in/ead ( ! ord9>y plate1 "o r$uc$ by nitric acid to ! lea/ possible ?ickness1 & ,i fix x to a circle ( s(t iron1 :i* keeps x /ret*$ & =ms "p ( ! same sub/ance4 ,?is circle is plac$ 9 a circul> op5+ made inside ! comp>tm5t4 ,! int5sity ( a telephone is mu* increas$ :5 su* a sy/em replaces ! ord9>y plate1 ev5 at "o end ( ! l9e4' ,9 ord] to obta9 vibrat+ plates ( extreme t5uity1 ,m4 ,e4 ,du*em9 ?\ght ( employ+ v ?9 plates ( mica1 spr9kl$ ) pulv]is$ iron fix$ to ! plate by a lay] ( silicate ( pota%4 ,! inv5tor ass]ts t x is possible to correspond 9 a l[ voice ) ! aid ( ?is sy/em2 b x has ?is inconv5i5ce1 t ! plate w be brok5 by speak+ too l\d4 ,pr(essor ,jorg5son1 ( ,cop5hag51 has also made a ,bell telephone :i* produces v int5se s\nds1 & :i* has p]mitt$ him to obs]ve "s curi\s effects4 ,9 ?is in/rum5t1 ! magnet is made 9 a mode analog\s to ,nickls' tubul> magnets4 ,!re is fir/ a cyl9drical magnet ) a core ( s(t iron at its upp] end1 to :i* ! coil is fitt$2 next1 a magnetis$ tube1 =m$ ( a /eel r+1 :i* encloses ! fir/ magnetic sy/em1 & is connect$ ) x by an iron tube4 ,f9ally1 above ! pol> extremities ( ?is sy/em1 !re is ! vibrat+ disk1 ) ! same arrangem5t z t ( ord9>y telephones1 & ( :i* ! sup]ficies is l>ge4 ,if ?is plate is only a millimtre 9 ?ickness1 ! words spok5 c be he>d ?r\gh\t a room2 b ! s\nds lose _! cle>ness :5 ! e> is approa*$ to ! vibrat+ plate1 ! words are confus$1 & !re is ! rev]b]ation :i* is obs]v$ on speak+ 9 a place apt to produce e*oes3 ! li/5] is1 9 fact1 /unn$ by ! s\nds produc$4 ,on us+ a ?ick] plate--"o1 = example1 ( ?ree or f\r millimtres--! telephone only produces ! effect ( ! ord9>y in/rum5ts1 & x is necess>y to apply ! e> to x4 ,m4 ,m>9 ,maillet1 ( ,lyons1 has sugge/$ t ! s\nds reproduc$ by ! telephone might be increas$ by reflect+ !m ?r\gh a c]ta9 numb] ( reflectors1 :i*1 by conc5trat+ !m 9 a focus on a resonator1 w\ld consid]ably enl>ge !m4 ,s9ce ?is idea 0 n accompani$ by exp]im5ts1 x c h>dly be reg>d$ z s]i\s4 ,,telephonic ,,exp]im5ts4 ,s9ce ,mr4 ,bell's exp]im5ts ( :i* an acc\nt has be5 giv5 9 ! e>ly "p ( ?is "w1 mu* /udy has be5 giv5 by m5 ( sci5ce & inv5tors to ! effects produc$ 9 ?is curi\s in/rum5t1 s z to asc]ta9 its !ory & d$uce improvem5ts 9 its con/ruction4 ,we w take a glance at ^! rese>*es 9 succession4 ,exp]im5ts on ! ,effects produc$ by ,voltaic & ,induc$ ,curr5ts4--,! comp>ative /udy ( ! effects produc$ 9 ! telephone by voltaic & induc$ curr5ts 0 "o ( ! fir/ & mo/ important4 ,9 #ahgc1 z we h se51 ,mr4 ,eli%a ,gray conv]t$ ! voltaic curr5ts1 :i* he employ$ to cause ! vibrations ( 8 transmitt+ plate1 into induc$ curr5ts by means ( an induction coil1 su* z ,ruhmkorff's4 ,! voltaic curr5ts !n trav]s$ ! prim>y helix ( ! coil1 & ! induc$ curr5ts react$ on ! receiv+ in/rum5t1 produc+ on its electro-magnetic sy/em ! vibrations excit$ at ! s5d+ /ation4 ,:5 ,mr4 ,edison design$ 8 batt]y telephone1 he _h rec\rse to ! same means to "w 8 receiv+ telephone1 s9ce he _h asc]ta9$ t induc$ curr5ts 7 sup]ior to voltaic curr5ts4 ,b ?is peculi>ity ( ,mr4 ,edison's arrangem5t 0 n cle>ly und]/ood f ! descriptions :i* rea*$ ,europe1 s t sev]al p]sons believ$ t !y _h inv5t$ ?is arrangem5t--among o!rs1 ,colonel ,navez & ,,mm4 ,poll>d & ,g>ni]4 ,colonel ,navez1 9 an int]e/+ pap] on ! new telephonic sy/em1 pres5t$ to ! ,belgian ,royal ,academy1 ,febru>y #b1 #ahgh1 only sugge/s ?is arrangem5t z a mode ( reproduc+ spee* at a great di/ance2 b he quotes no exp]im5t :i* di/9ctly %[s ! advantages ( ?is comb9ation4 ,tw5ty days lat]1 ,,mm4 ,poll>d & ,g>ni]1 unacqua9t$ ) ,colonel ,navez's rese>*es1 s5t to me ! results !y _h obta9$ by simil> means1 & ^! results appe>$ to me s int]e/+ t ,i communicat$ !m to ! ,acadmie des ,sci5ces1 ,febru>y #be1 #ahgh4 ,9 ord] t ! importance ( ^! results may be cle>ly und]/ood1 ,i w repeat ! text ( ,m4 ,poll>d's lett]1 address$ to me on ,febru>y #bj1 #ahgh3 #8,) ! object ( increas+ ! v>iations ( electric int5sity 9 ! ,edison sy/em1 we induce a curr5t 9 ! circuit ( a small ,ruhmkorff coil1 & we fix ! receiv+ telephone to ! extremities ( ! induc$ wire4 ,! curr5t receiv$ has ! same int5sity z t ( ! induc+ curr5t1 & consequ5tly ! v>iations produc$ 9 ! curr5t :i* works ! telephone h a mu* wid] range4 ,! int5sity ( ! transmitt$ s\nds is /rongly increas$1 & ! value ( ?is increase dep5ds ^u ! relative numb] ( spirals 9 ! induc+ & induc$ circuits4 ,our attempts to det]m9e ! be/ proportions h be5 labori\s1 s9ce x is necess>y to make a coil = ea* exp]im5t2 we h hi!rto obta9$ excell5t results ) a small ,ruhmkorff coil r$uc$ to its simple/ =m1 t is1 )\t cond5s] or contact-break]4 ,! induc+ wire is ,no4 #af1 & is w\nd 9 five lay]s2 ! induc$ wire is ,no4 #cb1 & 9 tw5ty lay]s4 ,! l5g? ( ! coil is sev5 c5timtres4 #8,! foll[+ is ! mo/ rem>kable & in/ructive exp]im5t3 ,:5 sett+ ! s5d] to "w ) a s+le ,daniell cell1 !re is no appreciable effect at ! receiv+ /ation1 at lea/ 9 ! telephone :i* ,i h made1 :5 x is 9 imm$iate connection ) ! circuit2 aft] ins]t+ ! small induction coil1 s\nds become di/9ctly audible1 & _! int5sity equals t ( good ord9>y telephones4 ,s9ce ! batt]y curr5t is only mod]ately int5se1 ! po9ts ( plumbago are n worn d[n1 & ! regulat+ app>atus la/s = a long :ile4 ,:5 a /rong] batt]y is us$1 consi/+ ( six cells ( bi*romate ( pota% 79 t5sion7 or twelve ,leclan* cells1 suffici5t int5sity is obta9$ by ! direct action to make s\nds ne>ly z audible z 9 ord9>y telephones2 b :5 ! induction coil is ins]t$1 ! s\nds become mu* m int5se1 & may be he>d at a di/ance ( f fifty to sixty c5timtres f ! m\?piece4 ,songs may1 "u su* circum/ances1 be he>d at a di/ance ( sev]al y>ds2 b ! relative increase does n appe> to be s great z 9 ! case ( ! s+le ,daniell cell4' ,on ! o!r h&1 #8,les ,mondes1' ,m>* #g1 #ahgh1 conta9s an acc\nt ( a s]ies ( exp]im5ts made by ,signor ,luv9i1 ,pr(essor ( ,physics at ! ,milit>y ,academy ( ,tur91 :i* prov$ t ! introduction ( electro-magnets into ! circuit :i* connects ! two telephones s5sibly increases ! int5sity ( s\nd4 ,! maximum effect is produc$ by plac+ "o close to ! transmitt+1 & ! o!r close to ! receiv+ telephone1 & ! introduction ( o!r magnets is ( no use4 ,! induc+ wire ( a ,ruhmkorff coil1 :5 introduc$ into su* a circuit1 excit$ no s5sible effects ( induction 9 ! induc$ circuit1 & consequ5tly c\ld n set ! telephone 9 connection ) ?is circuit at "w4 ,b ! curr5t ( a ,cl>ke ma*9e produces s\nds resembl+ ! beats ( a drum1 :i* are deaf5+ :5 ! e> is appli$ to ! in/rum5t3 !y become v fa9t1 h[ev]1 at ! di/ance ( a mtre4 ,! curr5ts ( a ,ruhmkorff ma*9e are /ill m en]getic1 & ! s\nd fills a :ole room4 ,by modify+ ! position ( ! lev] ( ! coil1 ! s\nd passes ?r\gh diff]5t tones1 :i* are always 9 unison ) ! breaks ( ! curr5t1 at lea/ up to a c]ta9 pit*4 ,?is prop]ty ( curr5ts induc$ by ! ,ruhmkorff coil has enabl$ ,m4 ,gaiffe to obta9 by _! means a v simple mode ( regulat+ telephones1 s z to produce 9 !m ! maximum am\nt ( s5sibility4 ,= ?is purpose he places ! telephone he proposes to regulate 9 ! circuit ( an induction in/rum5t ) moveable helices & graduat$ int5sities4 ,! s\nds :i* result f ! vibrator are !n rev]b]at$ f ! telephone1 & are audible at a di/ance f ! in/rum5t2 by us+ a screw-driv]1 x is possible to adju/ ! screw to :i* ! free end ( ! b> magnet ( ! in/rum5t is fix$4 ,x c be tight5$ or loos5$1 s z to advance or )draw ! o!r end ( ! magnet f ! vibrat+ plate ( ! telephone1 & ! process is repeat$ until ! maximum int5sity ( s\nd is obta9$4 ,on ! o!r h&1 z ! s\nds giv5 out by ! two telephones 9 correspond5ce are int5se 9 proportion to ! degree ( unison 9 ! vibrations produc$ by !m1 x is necess>y to select ^? :i* emit ! same s\nds = ! same giv5 note2 & ! mode we h j describ$ may be employ$ ) advantage1 s9ce x w be en\gh to obs]ve :at in/rum5ts give ! same note 9 ! condition ( maximum s5sibility1 :5 regulat$ 9 ! same way by ! induction ma*9e4 ,x is v important t ! telephones 9 correspond5ce %\ld be well mat*$1 n only to ensure cle> transmissions1 b also ) ref]5ce to ! tone ( voice ( ^? :o are to use x4 ,! s\nd becomes m audible :5 ! tone ( voice corresponds to ! telephonic tone2 & = ?is reason "s telephones repeat ! voices ( wom5 & *ildr5 bett] ?an ^? ( m51 & ) o!rs ! rev]se takes place4 ,! telephonic vibrations v>y 9 diff]5t in/rum5ts1 & ^! v>iations may be not$ 9 ! way we h indicat$4 ,! advantages ( induc$ curr5ts 9 telephonic transmissions may be easily und]/ood1 if we consid] t ! v>iations ( resi/ance 9 ! circuit1 result+ f ! great] or less range 9 ! vibrations ( ! transmitt+ plate1 are ( con/ant value1 & c only manife/ _! effects di/9ctly 9 %ort circuits2 consequ5tly ! articulate s\nds :i* result f !m c only be really appreciable 9 circuits ( great resi/ance4 ,accord+ to ,mr4 ,w>r5 de la ,rue's exp]im5ts 7report$ 9 ! #8,telegraphic ,j\rnal1' ,m>* #a1 #ahgh71 ! curr5ts produc$ by ! vibrations ( ! voice 9 an ord9>y telephone repres5t 9 int5sity ^? ( a ,daniell cell trav]s+ #ajj megohms ( resi/ance 7or #aj1jjj1jjj kilomtres72 & x is pla9 t ! simple "q ( great] or less int5sity 9 ! curr5ts act+ on ! receiv+ telephone is n ! only ?+ we h to consid]4 ,) an en]getic batt]y1 x is evid5t1 9 fact1 t ! diff]5tial curr5ts w always be m int5se ?an ! induc$ curr5ts produc$ by ! action ( ! in/rum5t4 ,i myself am incl9$ to believe t induc$ curr5ts owe ! advantages !y possess to ! succession ( inv]se curr5ts & _! brief duration4 ,^! curr5ts1 ( :i* ,m4 ,blas]na consid]s t ! duration does n exce$ #a_/bjj ( a second1 are mu* m susceptible ?an voltaic curr5ts ( ! multipli$ vibrations :i* are *>act]i/ic ( phonetic vibrations1 & especially s9ce ! succession ( inv]se curr5ts :i* take place dis*>ge ! l9e1 rev]se ! magnetic effects1 & contribute to make ! action m di/9ct & rapid4 ,we _c !re=e be surpris$ t ! induc$ curr5ts ( ! induction coil1 :i* c be produc$ "u excell5t conditions at ! s5d+ /ation1 s9ce ! circuit ( ! voltaic curr5t is !n v %ort1 are able to furni% results1 n only m effective ?an ! voltaic curr5ts f :i* !y take _! orig91 b ev5 ?an ! induc$ curr5ts result+ f ! action ( ! ,bell telephone1 s9ce !y are inf9itely m en]getic4 ,z = ! effects produc$ by ! curr5ts ( ,bell telephones1 :i* are relatively great :5 we consid] _! size1 !y are easily expla9$ f ! fact t !y are produc$ "u ! influ5ce ( ! vibrations ( ! telephone plate1 s t _! v>iations ( int5sity always ma9ta9 ! same proportion1 :atev] may be ! resi/ance ( ! circuit1 & consequ5tly !y are n effac$ by ! di/ance :i* divides ! two telephones4 ,exp]im5ts on ! "p tak5 by ! diff]5t telephonic organs 9 ! transmission ( spee*4--,9 ord] to introduce all ! improvem5ts ( :i* a telephone is capable1 x is important to be q decid$ z to ! effects produc$ 9 ! sev]al p>ts ( :i* x is compos$1 & z to ! "p tak5 by ! sev]al organs :i* are at "w4 ,to atta9 ?is object sev]al m5 ( sci5ce & eng9e]s h und]tak5 a s]ies ( exp]im5ts :i* h produc$ v int]e/+ results4 ,"o ( ! po9ts on :i* x 0 mo/ important to ?r[ light 0 t ( asc]ta9+ :e!r ! vibrat+ plate us$ 9 _! telephone receiv]s by ,messrs4 ,bell & ,gray is ! only cause ( ! complex vibrations :i* reproduce spee*1 or if ! diff]5t p>ts ( ! electro-magnetic sy/em ( ! in/rum5t all conduce to ?is effect4 ,! exp]im5ts made by ,mr4 ,page 9 #ahcg on ! s\nds produc$ by ! resonant electro-magnetic rods1 & ! rese>*es pursu$ 9 #ahdf by ,messrs4 de la ,rive1 ,w]!im1 ,matteucci1 c41 on ?is curi\s ph5om5on1 all[ u to /ate ! "q1 :i* is c]ta9ly m complex ?an x at fir/ appe>s4 ,9 ord] to />t f a fix$ po9t1 x mu/ fir/ be asc]ta9$ :e!r a telephone c transmit spee* )\t a vibrat+ plate4 ,exp]im5ts made by ,mr4 ,edison#i 9 ,novemb] #ahgg1 ) telephones provid$ ) copp] diaphragms1 :i* produc$ s\nds1 make ! hypo!sis cr$ible2 & x receiv$ great] weight f ! exp]im5ts made by ,mr4 ,preece & ,mr4 ,bly?4 ,! fact 0 plac$ beyond a d\bt by ,mr4 ,spottiswoode 7see ! #8,telegraphic ,j\rnal' ( ,m>* #a1 #ahgh71 :o assures u t ! vibrat+ plate ( ! telephone may be entirely suppress$ )\t prev5t+ ! transmission ( spee*1 provid$ t ! pol> extremity ( ! magnet be plac$ q close to ! e>2 & x 0 aft] ?is t ,i pres5t$ to ! ,acadmie des ,sci5ces my pap] on ! !ory ( ! telephone1 :i* l$ to an int]e/+ discussion ( :i* ,i %all speak pres5tly4 ,at fir/ ! au!nticity ( ^! results 0 d5i$1 & !n an attempt 0 made to expla9 ! s\nds he>d by ,mr4 ,spottiswoode z a me*anical transmission ( ! vibrations1 effect$ aft] ! mann] ( /r+ telephones2 b ! num]\s exp]im5ts :i* h subsequ5tly be5 made by ,messrs4 ,w>wick1 ,rossetti1 ,hughes1 ,mill>1 ,lloyd1 ,bu*91 ,cane/relli1 ,wies5dang]1 ,v>ley1 & _m o!rs1 %[ t ?is is n ! case1 & t a telephone )\t a diaphragm c transmit spee* electrically4 ,colonel ,navez himself1 :o _h fir/ d5i$ ! fact1 n[ admits t a telephone )\t a diaphragm c emit s\nds1 & ev51 "u c]ta9 exceptional conditions1 c reproduce ! human voice2 b he /ill believes t x is impossible to di/+ui% articulate words4 ,?is unc]ta9ty z to ! results obta9$ by ! diff]5t physici/s :o h /udi$ ! matt] %[s t at any rate ! s\nds ?us reproduc$ are n cle>ly def9$1 & t 9 physical ph5om5a1 only appreciable to our s5ses1 ! appreciation ( an effect s undef9$ mu/ dep5d on ! p]fection ( our organs4 ,we %all pres5tly see t ?is v slight effect c be l>gely increas$ by ! arrangem5t adopt$ by ,messrs4 ,bell & ,gray1 & we %all also see t1 by a c]ta9 mode ( magnify+ ! vibrations1 x has be5 decisively prov$ t a telephone )\t a diaphragm c readily reproduce spee*4 ,i proce$ to give ! description ( su* a telephone1 :i* 0 %[n by ,mr4 ,mill> at ! meet+ ( ! ,briti% ,association at ,dubl9 9 ,augu/ #ahgh4 ,?is in/rum5t consi/s ( a small b> magnet1 ?ree in*es 9 l5g? & #e_/af ( an in* 9 wid? & ?ickness1 & a copp] helix 7,no4 #cj7 ( ab\t six mtres 9 l5g? is w\nd r\nd ! b>4 ,x is fix$ 9 a box ( r ?ick pa/ebo>d1 fitt$ above & bel[ ) two z9c plates1 :i* r5d] x v portable4 ,) a telephonic batt]y s5d] & a s+le ,leclan* cell1 spee* c be p]fectly transmitt$2 ! :i/l+ ( an air1 a song1 & ev5 ! act ( respiration become audible4 ,x seems also t ! in/rum5t c act )\t a magnet1 m]ely ) a piece ( iron surr\nd$ by ! helix2 b ! s\nds are !n mu* fa9t]4 ,signor ,ignace ,cane/relli obta9$ ! same results by mak+ "o ( ! c>bon telephonic s5d]s react on a telephone )\t a diaphragm1 by means ( an induction coil influ5c$ by two ,buns5 cells4 ,he writes z foll[s on ! subject3 #8,) ?is arrangem5t ,i 0 able to he> ! s\nd ( any musical in/rum5t on a telephone )\t a diaphragm3 s++1 speak+1 & :i/l+ 7 p]fectly audible4 ,:i/l+ c\ld be he>d1 ev5 :5 ! telephone )\t a diaphragm 0 plac$ at "s di/ance f ! e>4 ,9 "s cases1 dep5d+ on ! pit* ( ! voice1 on ! di/ance ( ! s5d+ /ation1 & on ! jo9t pressure ex]t$ by ! c>bons1 ,i c\ld ev5 di/+ui% words4 #8,i f9ally dis*>g$ ! curr5ts ( ! transmitt] into ! coils ( insulat$ copp] wire ) :i* ! two poles ( a magnet 7 provid$4 ,?is magnet 0 plac$ on a musical box1 made ( v ?9 slips ( wood1 & on plac+ ! e> at ! op5+ ( ! box ,i obta9$ ! same results z ) ! ord9>y telephones )\t a diaphragm4' ,m4 ,bu*91 aft] repeat+ exp]im5ts ( ! same k9d z ! above1 intimates t x is easy to he> ! s\nds produc$ by a telephone )\t a diaphragm1 by introduc+ into ! e> ! end ( an iron rod1 ( :i* ! o!r end is appli$ to ! active pole ( ! b> magnet ( ! telephone4 7,see #8,le ,j\rnal d',electricit1' ,octob] #e1 #ahgh47 ,i repeat f9ally ! acc\nt ( "s exp]im5ts made by ,mr4 ,hughes & ,m4 ,paul ,roy :i* are int]e/+ f our pres5t po9t ( view4 #a4 ,if an armature ( s(t iron is appli$ to ! poles ( an electro-magnet1 ) its two bran*es firmly fix$ on a bo>d1 & if pieces ( pap] are ins]t$ betwe5 ?is armature & ! magnetic poles1 s z to obviate ! effects ( cond5s$ magnetism2 if1 f9ally1 ?is electro-magnet is connect$ ) a speak+ microphone1 ( ! =m giv5 9 fig4 #ci1 x is possible to he> ! words spok5 9 ! microphone on ! bo>d :i* supports ! electro-magnet4 #b4 ,if two electro-magnets are plac$ 9 communication ) a microphone1 ) _! poles ( contr>y signs opposite to ea* o!r1 & if _! poles are sep>at$ by pieces ( pap]1 spee* w be di/9ctly reproduc$1 )\t employ+ armature or diaphragm4 ,^! exp]im5ts are1 h[ev]1 delicate1 & dem& a practis$ e>4 #c4 ,if1 in/ead ( caus+ ! curr5t produc$ by a microphone to pass ?r\gh ! helix ( a receiv+ telephone1 x is s5t directly into ! b> magnet ( ?is telephone 9 ! direction ( its axis--t is1 f "o pole to ano!r--! words pron\nc$ 9 ! microphone may be di/9ctly he>d4 ,?is exp]im5t by ,m4 ,paul ,roy indicates1 if x is exact1 t ! electric pulsations :i* trav]se a magnet longitud9ally w modify its magnetic int5sity4 ,! exp]im5t1 h[ev]1 dem&s v]ification4 ,ano!r po9t 0 obscure4 ,x 0 important to "k :e!r ! diaphragm ( a telephone really vibrates1 or at lea/ if its vibrations c\ld involve its displacem5t1 su* z occurs 9 an electric vibrator1 or 9 w9d in/rum5ts :i* vibrate ) a curr5t ( air4 ,m4 ,anto9e ,brguet has made "s int]e/+ exp]im5ts on ! subject1 :i* %[ t su* a movem5t _c take place1 s9ce spee* 0 reproduc$ ) great di/9ctness f telephones ) vibrat+ plates ( v>i\s degrees ( ?ickness1 & he c>ri$ ! exp]im5t s f> z to employ plates fifte5 c5timtres 9 ?ickness4#aj ,:5 pieces ( wood1 ca\t*\c1 & o!r sub/ances 7 laid ^u ^! ?ick plates1 ! results 7 ! same4 ,9 ?is case x _c be suppos$ t ! plates 7 mov$ to & fro4 ,i h moreov] asc]ta9$1 by plac+ a lay] ( wat] or ( m]cury on ^! plates1 & ev5 on ?9 diaphragms1 t no s5sible movem5t took place1 at lea/ :5 ! induc$ curr5ts produc$ by ! action ( speak+ 7 us$ z ! electric s\rce4 ,no ripples c\ld be se5 on ! surface ( ! liquid1 ev5 :5 lum9\s reflectors 7 employ$ to detect !m4 ,& inde$ x c h>dly be admitt$ t a curr5t n m int5se ?an t ( a ,daniell elem5t1 :i* has trav]s$ #aj1jjj1jjj kilomtres ( telegraphic wire--a curr5t :i* c only %[ deviation on a ,?omson galvanomet]--%\ld be p[]ful en\gh to make an iron plate z tightly /ret*$ z t ( a telephone vibrate by attraction1 ev5 if we grant t ! curr5t 0 produc$ by lay+ a f+] on ! diaphragm4 ,v nice photographic exp]im5ts d1 h[ev]1 %[ t vibrations are produc$ on ! diaphragm ( ! receiv+ telephone2 !y are inde$ excessively slight1 b ,mr4 ,blake ass]ts t !y are en\gh to cause a v light index1 re/+ on ! diaphragm1 to make slight inflections on a l9e :i* x describes on a regi/]4 ,yet ?is small vibration ( ! diaphragm does n %[ t x is due to ! effect ( attraction1 = x may result f ! act ( magnetisation itself 9 ! c5tre ( ! diaphragm4#aa ,an int]e/+ exp]im5t by ,mr4 ,hughes1 repeat$ "u diff]5t conditions by ,mr4 ,mill>1 confirms ?is op9ion4 ,if ! magnet ( a receiv+ telephone consi/s ( two magnetis$ b>s1 p]fectly equal1 sep>at$ f ea* o!r by a magnetic insulator1 & !y are s plac$ 9 ! coil z to br+ alt]nately ! poles ( ! same & ( contr>y signs opposite to ! diaphragm1 x is kn[n t ! telephone w reproduce spee* bett] 9 ! latt] case ?an 9 ! =m]4 ,n[1 if ! effects 7 due to attraction1 ?is w\ld n be ! case2 = ! actions are 9 disagreem5t :5 ! poles ( contr>y signs are subject$ to ! same electric influ5ce1 :ile !y are 9 agreem5t :5 ^! poles are ( l signs4 ,on ! o!r h&1 x is kn[n t if sev]al iron plates are put toge!r 9 ord] to =m ! diaphragm ( ! receiv]1 ! transmission ( s\nds is mu* /rong] ?an ) a simple diaphragm2 & yet ! attraction1 if x has any?+ to d ) x1 c\ld only be ex]t$ on "o ( ! diaphragms4 ,x fur!r appe>s t x is n m]ely ! magnetic core :i* emits s\nds1 b t !y are also produc$ ) "s di/9ctness by ! helices4 ,signor ,rossetti _h already asc]ta9$ ?is fact1 & _h ev5 rem>k$ t !y c\ld be animat$ by a slight oscillatory movem5t along ! b> magnet1 :5 !y 7 n fix$ ^u x4 ,sev]al obs]v]s1 among o!rs ,m4 ,paul ,roy1 ,h]r ,wies5dang]1 & ,signor ,cane/relli1 h s9ce m5tion$ simil> facts1 :i* are really int]e/+4 #8,if1' writes ,m4 ,paul ,roy1 #8a coil ( f9e wire1 :i* is at ! extremity ( ! b> magnet ( a ,bell telephone1 receives ! pulsatory curr5ts transmitt$ by a c>bon telephone1 x is only necess>y to br+ ! coil close to ! e> 9 ord] to he> ! s\nds4 #8,! s\nds receiv$ 9 ?is way are v fa9t1 b become mu* /rong] if a piece ( iron is introduc$ into ! circuit coil4 ,a magnet acts ) /ill great] =ce1 ev5 :5 x consi/s ( a simple magnetis$ ne$le4 ,f9ally1 ! s\nd assumes its maximum int5sity :5 an iron disk is ins]t$ betwe5 ! e> & ! coil4 #8,by plac+ ! end ( ! coil to ! e>1 & s5d+ a curr5t ?r\gh x f ! b> magnet1 x is asc]ta9$ t ! s\nd is at its m9imum :5 ! neutral l9e ( ! magnet is enclos$ by ! coil1 & t x increases until atta9+ its maximum1 :5 ! magnet is mov$ until "o ( its poles corresponds to ! coil4 #8,?is fact ( ! reproduction ( s\nds by a helix is univ]sal4 ,e induction coil & e electro-magnet are capable ( reproduc+ s\nd :5 ! curr5ts ( ! s5d] are ( suffici5t int5sity4' ,signor ,cane/relli writes z foll[s3 #8,) ! comb9ation ( a c>bon telephone & "o )\t diaphragm or magnet--t is1 ) only a simple coil--,i 0 able to he> :i/l+ ?r\gh ! coil1 plac$ close to ! e>4 ,?is coil 0 ( v f9e copp] wire1 & ! curr5ts 7 produc$ ?r\gh an induction coil by two ,buns5 elem5ts4 ,! contacts ( ! telephone 7 9 c>bon1 & x 0 ins]t$ 9 ! prim>y circuit4 #8,i fa/5$ ! coil to ! middle ( a tightly /ret*$ membrane :i* s]v$ z ! base ( a %ort metal cyl9d]4 ,:5 a magnet 0 plac$ ne> ?is "p ( ! coil1 ! s\nds 7 int5sifi$1 & :5 ,i fix$ ! magnet 9 ?is position1 ,i c\ld he> :at 0 said4 #8,i aft]w>ds sub/itut$ = ! magnet a second coil1 fa/5$ to a wood5 b>1 & on caus+ ! induc$ curr5ts to pass into bo? coils at once ,i 0 able to he> articulate spee*1 al?\gh n )\t difficulty4 #8,"u ^! latt] conditions ,i f\nd x possible to con/ruct a telephone )\t a magnet1 b x requir$ a /rong curr5t1 & x 0 necess>y to speak into ! s5d] 9 a special mann]1 s z to produce /rong & conc5trat$ s\nds4' ,ano!r v int]e/+ exp]im5t by ,m4 ,a4 ,brguet %[s t all ! con/itu5t p>ts ( ! telephone--! h&le1 ! copp] rims1 & ! case1 z well z ! diaphragm & ! electro-magnet--c transmit s\nds4 ,m4 ,brguet asc]ta9$ ?is fact by ! use ( /r+ telephones1 :i* he atta*$ to diff]5t p>ts ( ! telephone on :i* ! exp]im5t 0 made4 ,9 ?is way he 0 n only able to e/abli% a correspond5ce betwe5 ! p]son :o work$ ! electric telephone & ! "o :o 0 li/5+ ?r\gh ! /r+ telephone1 b he also made sev]al /r+ telephones act1 :i* 7 atta*$ to diff]5t p>ts ( ! electric telephone4 ,^! two s]ies ( exp]im5ts %[ t s\nds may be obta9$ f diff]5t p>ts ( ! telephone )\t any v appreciable vibratory movem5ts4 ,b ,signor ,luv9i wi%$ = a fur!r assurance ( ! fact1 by asc]ta9+ :e!r ! magnetisation ( any magnetic sub/ance1 foll[$ by its demagnetisation1 w\ld involve a v>iation 9 ! =m & dim5sions ( ?is sub/ance4 ,he consequ5tly caus$ a l>ge tubul> electro-magnet to be made1 :i* he fill$ ) a quantity ( wat]1 s t1 :5 its two ends 7 cork$1 ! liquid %\ld rise 9 a capill>y tube fitt$ to "o ( ! corks4 ,9 ?is way ! slighte/ v>iations 9 ! capacity ( ! holl[ "p ( ! electro-magnet 7 reveal$ by ! asc5t or desc5t ( ! liquid column4 ,he next s5t an electric curr5t ( v>y+ int5sity ?r\gh ! electro-magnet1 b he 0 nev] able to detect any *ange 9 ! level ( ! wat] 9 ! tube2 al?\gh by ?is arrangem5t he c\ld measure a *ange ( volume ( #a_/cj ( a cubic millimtre4 ,x appe>s f ?is exp]im5t t ! vibrations produc$ 9 a magnetic sub/ance "u ! influ5ce ( successive magnetisations & demagnetisations1 are :olly molecul>4 ,yet o!r exp]im5ts made by ,m4 ,cane/relli seem to %[ t ^! vibrations are s f> s5sible z to produce s\nds :i* c be detect$ by ! microphone4 ,he writes z foll[s on ! subject3 #8,:5 ! brok5 curr5ts ( an induction coil are dis*>g$ into a coil plac$ on a s\nd+-box1 x is possible to he> at a little di/ance ! s\nds produc$ by ! induc$ curr5ts ?us g5]at$4 ,on approa*+ ! magnet to ! op5+ ( ! coil1 ^! s\nds are int5sifi$1 & ! vibrations ( ! magnet become s5sible to ! t\*2 ?is vibration might ev5 be made visible by susp5d+ ! magnet ins]t$ into ! coil to a metallic wire1 :i* is fitt$ to a membrane /ret*$ on a drum1 & ! latt] w !n reproduce s\nds4 ,:5 ! same magnet is susp5d$ to a microphone1 x is possible1 ) ! aid ( a telephone1 to asc]ta9 ! same effects1 :i* are !n increas$4' ,we %all pres5tly consid] h[ ^! diff]5t d$uctions are to be int]pret$1 s z to r5d] ! true !ory ( ! telephone intelligible2 b1 be=e do+ s1 we w m5tion "s o!r exp]im5ts :i* are n )\t int]e/4 ,we h se5 t ! exp]im5ts ( ,messrs4 ,edison1 ,bly?1 & ,preece1 %[ t s\nds may be reproduc$ by a telephone ) a diaphragm made ( "s unmagnetic sub/ance1 & !y also %[1 :i* is /ill m curi\s1 t ^! s\nds may be transmitt$ "u ! influ5ce ( induc$ curr5ts produc$ by ^! diaphragms :5 !y are plac$ 9 vibration be=e ! magnet4 ,messrs4 ,edison & ,bly? _h already adduc$ ?is fact1 :i* 0 receiv$ ) incr$ulity1 b x has be5 confirm$ by ,mr4 ,w>wick 9 an article publi%$ 9 ! #8,engli% ,me*anic4' ,he writes t 9 ord] to act ^u ! magnet1 s z to produce induc$ curr5ts1 some?+ possess$ ( great] en]gy ?an gas mu/ fir/ be made to vibrate4 ,x is n1 h[ev]1 necess>y t ?is sub/ance %\ld be magnetic1 = diamagnetic sub/ances act p]fectly4#ab ,mr4 ,preece s\ght = ! cause 9 ! induc$ curr5ts develop$ 9 any conduct+ body :5 a magnet is mov$ be=e x1 curr5ts :i* give rise to ! ph5om5on discov]$ by ,arago & kn[n by ! "n ( magnetism by rotation4 ,yet ^! facts d n appe> to u to be suffici5tly well e/abli%$ to make ! !ory wor?y ( s]i\s consid]ation1 & x is possible t ! effects obs]v$ result$ f simple me*anical transmissions4 ,to conclude ! acc\nt ( ^! exp]im5ts1 we w add t ,mr4 ,w4 ,f4 ,b>rett ?9ks x some:at difficult to def9e ! mode ( vibration ( ! diaphragm1 s9ce1 :ile a c]ta9 am\nt ( compression ex]t$ on ! iron de/roys ! s\nds result+ f ! peculi> effects ( magnetisation1 a /ill /rong] compression causes !m to reappe>4 ,x is c]ta9 t ! "q is full ( obscurity1 & dem&s great rese>*3 x is en\gh to h %[n t ! !ory hi!rto held is insuffici5t4 ,on ! o!r h&1 ,colonel ,navez consid]s t ! int5sity ( s\nd reproduc$ 9 a telephone dep5ds n only on ! range ( vibrations1 b also on ! vibrat+ surface & ! effect x produces on ! /ratum ( air :i* transmits ! s\nd4 7,see pap] by ,colonel ,navez 9 ! #8,bullet9 de l',acadmie de ,belgique1' ,july #g1 #ahgh47 ,exp]im5ts on ! ,effects :i* result f ,me*anical ,%ocks communicat$ to diff]5t p>ts ( a ,telephone4--,if a piece ( iron is appli$ to ! screw :i* holds ! magnet ( ! ord9>y telephone1 x is obs]v$ t ! transmitt$ s\nds are m di/9ct1 ow+ to ! =ce suppli$ to ! active pole ( ! magnet2 b at ! mom5t :5 ! piece ( iron is appli$ to ! screw a di/9ct noise is he>d1 :i* seems to be due to ! me*anical vibrations caus$ 9 ! magnet at ! mom5t ( ! %ock4 ,m4 des ,portes1 a lieut5ant 9 ! ,fr5* navy1 has lately made "s int]e/+ exp]im5ts on ?is class ( ph5om5a4 ,he has obs]v$ t if1 9 a telephonic circuit ( #ij y>ds complet$ by ! e>?1 ! s5d+ telephone is r$uc$ to a simple magnet1 provid$ ) ! coil :i* con/itutes its electro-magnetic organ1 & if ?is magnet is susp5d$ v]tically by a silk5 ?read1 ) ! coil above x1 a bl[ /ruck ^u ! magnet1 ei!r by a copp] rod or a piece ( wood1 w cause di/9ct s\nds to be produc$ 9 ! receiv+ telephone--s\nds :i* w increase 9 int5sity :5 ! bl[ is /ruck close to ! coil1 & :i* w become /ill /rong]1 b less cle>1 if a vibrat+ plate ( s(t iron is plac$ 9 contact ) ! upp] pole ( ! magnet4 ,:5 ! /rik+ in/rum5t is made ( iron1 ! s\nds 9 "q are m /rongly m>k$ ?an if x is ( wood1 & :5 ! magnet has a vibrat+ disk appli$ to its active pole1 a vibration ( ! disk takes place at ! mom5t :5 ! %ock is he>d4 ,if ! /rik+ body is a magnet1 ! s\nds produc$ resemble ^? obta9$ :5 x is ( iron1 if ! effect is produc$ betwe5 poles ( ! same nature2 b if ! poles are ( contr>y natures1 a second noise is he>d aft] ea* bl[1 :i* is produc$ by draw+ away ! magnet1 & :i* appe>s to be a bl[ /ruck ) mu* less =ce4 ,! s\nd is ( c\rse increas$ if ! magnet is provid$ ) its vibrat+ disk4 ,if words are utt]$ on ! vibrat+ disk ( ! s5d+ telephone1 :5 x is appli$ to ! pole ( ! magnet1 v>i\s s\nds are he>d on ! receiv+ telephone1 some:at simil> to ^? produc$ by vibrat+ "o ( ! /r+s ( a viol91 & ! s\nd made 9 )draw+ ! disk f contact ) ! magnet is di/9ctly he>d 9 ! receiv]4 ,! p]son :o applies 8 e> to ! vibrat+ disk ( ! s5d] :5 x is arrang$ z above1 may he> ! voice ( anyone :o speaks into ! receiv]1 b _c di/+ui% ! words1 ow+1 no d\bt1 to ! cond5s$ magnetism at ! po9t ( contact betwe5 ! magnet & ! vibrat+ disk1 :i* slack5s ! magnetic v>iations & makes x m difficult = !m to take place4 ,a coil is n necess>y 9 ord] to p]ceive ! bl[s /ruck ^u ! magnet ) a rod ( s(t iron4 ,x is en\gh to w9d ?ree turns ( nak$ conduct+ wire1 :i* acts z l9e wire1 r\nd "o end ( ! magnet1 & ! s\nds p]ceiv$ cease1 z 9 o!r exp]im5ts1 :5 ! circuit is brok51 pla9ly %[+ t !y are n due to me*anical transmission4 ,x is a /ill m curi\s fact t if ! magnet is plac$ 9 ! circuit1 s z to =m an integral "p ( x1 & if ! two ends ( ! conduct+ wire are w\nd r\nd ! ends ( ! magnet1 ! bl[s /ruck ^u ! latt] ) ! s(t iron rod are p]ceiv$ 9 ! telephone z soon z "o pole ( ! magnet is provid$ ) a vibrat+ disk4 ,i h myself repeat$ ,m4 des ,portes' exp]im5ts by simply /rik+ on ! screw :i*1 9 ord9>y telephones1 fa/5s ! magnet to ! in/rum5t1 & ,i h asc]ta9$ t1 :5ev] ! circuit 0 complete1 ! bl[s /ruck ) an ivory knife 7 repeat$ by ! telephone3 !y 71 x is true1 v fa9t :5 ! vibrat+ disk 0 remov$1 b v m>k$ :5 ! disk 0 9 its place4 ,on ! o!r h&1 no s\nd 0 p]ceiv$ :5 ! circuit 0 brok54 ,^! s\nds 7 l\d] :5 ! bl[s 7 /ruck ^u ! screw ?an :5 !y 7 /ruck on ! pole ( ! magnet itself above ! coil3 = ?is reason1 t 9 ! fir/ case ! magnet c\ld vibrate freely1 :ile 9 ! second ! vibrations 7 /ifl$ by ! fix$ position ( ! b> magnet4 ,^! effects may be to "s ext5t expla9$ by say+ t ! vibrations caus$ 9 ! magnet by ! %ock produce undulatory displacem5ts ( ! magnetis$ p>ticles 9 ! :ole l5g? ( ! b>1 & t induc$ curr5ts w\ld1 accord+ to ,l5z's law1 result 9 ! helix f ^! displacem5ts--curr5ts ( :i* ! =ce w\ld increase :5 ! p[] ( ! magnet 0 fur!r excit$ by ! reaction ( ! diaphragm1 :i* acts z an armature1 & also by t ( ! /rik+ in/rum5t :5 x also is magnetic4 ,yet x is m difficult to expla9 ,m4 des ,portes' lat] exp]im5ts1 & ! effect may be produc$ by some?+ m ?an ! ord9>y induc$ curr5ts4 ,^! are n ! only exp]im5ts :i* %[ ! effects produc$ "u ! influ5ce ( molecul> di/urbance ( v>i\s k9ds4 ,mr4 ,?ompson1 ( ,bri/ol1 has obs]v$ t if a piece ( iron & a t9 rod plac$ p]p5dicul>ly on ! iron are introduc$ into ! circuit ( an ord9>y telephone1 x is en\gh to /rike ! t9 rod 9 ord] to produce a l\d s\nd 9 ! telephone4 ,he has also %[n t if ! two ends ( a b> magnet are enclos$ by two induction coils :i* are plac$ 9 connection ) ! circuit ( a telephone1 & if ! flame ( a _s lamp is mov$ bel[ ! magnet 9 ! space divid+ ! two coils1 a di/9ct s\nd is he>d z soon z ! flame ex]ts its influ5ce on ! b> magnet4 ,?is effect is und\bt$ly due to ! weak5+ ( ! magnetic =ce ( ! b> :i* is produc$ by ! action ( heat4 ,i h myself obs]v$ t a scrat*+ s\nd on "o ( ! wires :i* connect ! telephones is he>d 9 bo? ( !m1 at :atev] po9t 9 ! circuit ! scrat* is made4 ,! s\nds produc$ are inde$ v fa9t1 b !y c be di/9ctly he>d1 & !y become m int5se :5 ! scrat* is made on ! b9d+-screws ( ! telephone wires4 ,^! s\nds _c result f ! me*anical transmission ( vibrations1 s9ce !y are imp]ceptible :5 ! circuit is brok54 ,f ^! exp]im5ts x appe>s t "s s\nds :i* h be5 obs]v$ 9 telephones tri$ on telegraph /ations may arise f ! friction ( ! wires on _! supports--a friction :i* produces ^? v int5se s\nds :i* are sometimes he>d on telegraphic wires4 ,!ory ( ! ,telephone4--,x appe>s f ! sev]al exp]im5ts ( :i* we h spok5 t ! explanation g5]ally giv5 ( ! effects produc$ 9 ! telephone is v imp]fect1 & t ! transmission ( spee*1 in/ead ( result+ f ! repetition by ! membrane ( ! receiv+ telephone 7influ5c$ by electro-magnetism7 ( vibrations caus$ by ! voice on ! membrane ( ! transmitt+ membrane1 is due to molecul> vibrations produc$ 9 ! :ole electro-magnetic sy/em1 & especially on ! magnetic core conta9$ 9 ! helix4 ,^! vibrations mu/ be ( ! same nature z ^? :i* h be5 obs]v$ 9 resonant electro-magnetic rods by ,,mm4 ,page1 de la ,rive1 ,w]!im1 ,matteucci1 c41 & ^! h be5 employ$ 9 telephones by ,reiss1 by ,cecil & ,leon>d ,wray1 & by ,v&]weyde4 ,accord+ to ?is hypo!sis1 ! pr9cipal (fice ( ! vibrat+ plate consi/s 9 its reaction1 9 ord] to produce ! induc$ curr5ts :5 ! voice has plac$ x 9 vibration1 & by ?is reaction on ! pol> extremity ( ! b> magnet x /r5g!ns ! magnetic effects caus$ 9 ! c5tre ( ! b> :5 x vibrates "u ! electro-magnetic influ5ce1 or at lea/ :5 x is affect$ by ! magnet4 ,s9ce ! range ( ^! vibrations = a s+le note is great 9 proportion to ! flexibility ( ! note1 & s9ce1 on ! o!r h&1 ! v>iations 9 ! magnetic condition ( ! plate are rapid 9 proportion to ! smallness ( its mass1 ! advantage ( employ+1 z ,mr4 ,edison has done1 v ?9 & relatively small plates is readily und]/ood4 ,9 ! case ( transmission1 ! wid] range ( vibration increases ! int5sity ( ! induc$ curr5ts transmitt$4 ,9 ! case ( reception ! v>iations 9 ! magnetis+ =ce :i* produces ! s\nds are r5d]$ cle>] & m di/9ct1 bo? 9 ! armature membrane & 9 ! b> magnet3 some?+ is ga9$1 !re=e1 9 ea* case4 ,?is hypo!sis by no means excludes ! phonetic effects ( ! me*anical & physical vibrations :i* may be produc$ 9 ! armature plate "u ! influ5ce ( magnetisation & demagnetisation to :i* x is subject$1 & ^! jo9 _! influ5ce to t ( ! magnetic core4 ,:at is ! nature ( ! vibrations s5t into ! receiv+ telephone8 ,?is "q is /ill obscure1 & ^? :o h /udi$ x are f> f be+ 9 agreem5t3 z e>ly z #ahdf x 0 ! subject ( an int]e/+ discussion betwe5 ,,mm4 ,w]!im & de la ,rive1 & ! new discov]ies r5d] x /ill m complex4 ,m4 ,w]!im consid]s t ^! vibrations are at once longitud9al & transv]se1 & arise f attractions ex*ang$ betwe5 ! spirals ( ! magnetis+ helix & ! magnetic p>ticles ( ! core4 ,m4 de la ,rive holds t 9 ! case we are consid]+ ! vibrations are simply longitud9al1 & result f molecul> contractions & expansions produc$ by ! diff]5t comb9ations assum$ by ! magnetic molecules "u ! influ5ce ( magnetisation & demagnetisation4 ,?is appe>s to u to be ! mo/ natural explanation1 & x seems to be confirm$ by ! exp]im5t made by ,m4 ,guillem9 9 #ahdf4 ,m4 ,guillem9 asc]ta9$ t if a flexible iron rod1 surr\nd$ by a magnetis+ helix1 is kept 9 position by a vice at "o end1 & b5t back by a weight at ! o!r1 x c be made to return in/antly to its normal position by s5d+ a curr5t ?r\gh ! magnetis+ helix4 ,?is recov]y c 9 su* a case be due to no?+ b ! contraction caus$ by ! magnetic molecules1 :i*1 "u ! influ5ce ( _! magnetisation1 t5d to produce int]molecul> attractions1 & to modify ! ela/ic conditions ( ! metal4 ,x is kn[n t :5 iron is ?us magnetis$ x becomes z h>d z /eel1 & a file makes no impression on its surface4 ,x is at any rate impossible to dispute t s\nds are produc$ 9 ! magnetic core1 z well z 9 ! armature1 "u ! influ5ce ( int]mitt5t electric action4 ,^! s\nds may be musical or articulate2 = z soon z ! s5d] has produc$ ! electric action requir$1 !re is no reason :y vibrations :i* are effect$ 9 a transv]se or longitud9al direction %\ld transmit ! "o m ?an ! o!r4 ,^! vibrations may1 z we h se51 be t]m$ microscopic4 ,signor ,luv9i1 :o %>es our op9ion ( ! =ego+ !ory1 does n1 h[ev]1 ?9k x :olly satisfactory1 unless acc\nt is tak5 ( ! reaction caus$ by ! b> magnet on ! helix :i* surr\nds x4 #8,!re _c1' he says1 #8be action )\t reaction1 & consequ5tly ! molecul> action produc$ 9 ! magnet ought to cause correspond+ v>iations 9 ! helix1 & ^! two effects ought to contribute to ! production ( s\nds4' ,he supports ?is rem>k by a ref]5ce to ,pr(essor ,rossetti's exp]im5t1 ( :i* we h spok5 above4 ,we believe1 h[ev]1 t ?is d\ble reaction ( :i* ,signor ,luv9i speaks is n indisp5sable1 = we h se5 t insulat$ helices c produce s\nds2 x is true t ! spirals1 react+ on ea* o!r1 may be ! cause ( ?is4 ,! difficulty ( expla9+ ! production ( s\nds 9 an electro-magnetic organ de/itute ( armature caus$ ! au!nticity ( ! exp]im5ts we h describ$ to be at fir/ d5i$1 & ,colonel ,navez />t$ a controv]sy ) u :i* is n likely to be soon t]m9at$2 yet "o result ( ?is controv]sy is t ,colonel ,navez 0 oblig$ to admit t ! s\nd ( ! human voice may be reproduc$ by a telephonic receiv] )\t a disk4 ,b he /ill believes t ?is reproduction is s fa9t t x is n possible to recognise articulate words1 & he ma9ta9s t ! transv]se vibrations ( ! disk1 :i* are due to effects ( attraction1 are ! only ones to reproduce articulate spee* ) su* int5sity z to be ( any use4 ,x is c]ta9 t ! articulation ( spee* requires a some:at int5se vibration :i* _c easily be produc$ 9 a telephone )\t a diaphragm2 = x mu/ be rememb]$ t 9 an in/rum5t s arrang$1 ! magnetic effects are r$uc$ 9 a consid]able ratio1 :i* is t ( ! magnetic =ce develop$ 9 ! magnet1 multipli$ by itself1 & t s fa9t an action z t effect$ 9 a telephone becomes almo/ null :51 9 consequ5ce ( ! suppression ( ! armature1 x is only repres5t$ by ! squ>e root ( ! =ce :i* produc$ x4 ,x is !re=e possible t ! s\nds :i* are h>dly p]ceptible 9 a telephone )\t a diaphragm become audible :5 ! cause :i* provokes !m is multipli$ by itself1 & :5 !re are 9 addition ! vibrations produc$ 9 ! he>t ( ! armature itself1 influ5c$ by ! magnetisations & demagnetisations to :i* x is subject$4 ,9 ord] to %[ t ! action ( ! diaphragm is less indisp5sable ?an ,colonel ,navez seems to imag9e1 & t its vibrations are n due to electro-magnetic attractions1 x w be en\gh to ref] to ,mr4 ,hughes's exp]im5ts1 :i* we h m5tion$ above4 ,x is c]ta9 t if ?is 7 ! effect produc$1 we %\ld he> bett] :5 ! two b> magnets pres5t _! poles ( ! same nature be=e ! diaphragm1 ?an :5 !y pres5t ! poles ( contr>y natures1 s9ce ! :ole action w\ld !n conv]ge 9 ! same direction4 ,aga91 ! m m>k$ effects obta9$ ) multiple diaphragms 9 juxtaposition completely exclude ?is hypo!sis4 ,x is1 h[ev]1 possible t 9 electro-magnetic telephones ! iron diaphragm1 9 virtue ( ! rapid v>iations ( its magnetic condition1 may contribute to r5d] ! s\nds cle>] & m di/9ct2 x may react 9 ! way ! tongue does2 b we believe t ! great] or less di/9ctness ( ! articulate s\nds mu/ be *iefly due to ! range ( vibrations4 ,?us ,mr4 ,hughes has %[n t ! c>bons ( metallis$ wood employ$ 9 8 microphonic speak]s 7 to be pref]r$ to retort c>bons = ! transmission ( spee*1 = ! v reason t !y _h less conductivity1 s t ! diff]5ces ( resi/ance :i* result f diff]5ces ( pressure are m m>k$1 & consequ5tly x is easi] to seize ! diff]5t degrees ( vocal s\nds :i* con/itute articulate spee*4 ,x mu/ be cle>ly und]/ood t :at we h j said only applies to ! ,bell telephone1 t is1 to a telephone 9 :i* ! electric curr5ts h su* a fa9t int5sity t x _c be suppos$ !re is any ext]nal attractive effect4 ,:5 ^! curr5ts are s en]getic z to produce su* an effect1 a transv]se electro-magnetic vibration c]ta9ly takes place1 :i* is add$ to ! molecul> vibration1 & helps to increase ! s\nds produc$4 ,b x is no less true t ?is transv]se vibration by attraction or by movem5t ( ! diaphragm is n necess>y = ! reproduction ( s\nds1 :e!r musical or articulate4 ,we are n n[ conc]n$ ) ! discussion ( magnetic effects2 !re has be5 an advance 9 sci5ce s9ce ,colonel ,navez />t$ ! controv]sy1 & we mu/ ask h[ 8 !ory ( ! movem5ts ( ! telephone diaphragm by attraction w expla9 ! reproduction ( spee* by a receiv+ microphone de/itute ( any electro-magnetic organ1 & ,i c ass]t t my exp]im5ts %[ t !re c be no me*anical transmission ( vibrations1 s9ce no s\nd is he>d :5 ! circuit is brok5 or depriv$ ( its batt]y4 ,colonel ,navez mu/ !re=e accept ! molecul> vibrations4 ,?is c]ta9ly gives u a new field = /udy2 b x is because ,european m5 ( sci5ce p]si/ 9 rema9+ b\nd by incomplete !ories t we h all[$ ! ,am]icans :o despise !m to reap ! glory ( ! great discov]ies by :i* we h lately be5 a/oni%$4 ,! exp]im5ts quot$ above %[ t s\nds may be reproduc$ n only by simple helices )\t an electro-magnetic organ1 b also by ! plates ( a cond5s]1 9 spite ( ! pressure ex]t$ ^u !m2 & :5 we add to ?is ! effects ,i h j po9t$ out1 x may be suppos$ t vibrations ( s\nd mu/ result f e reaction betwe5 two bodies :i* has ! effect ( produc+ abruptly & at close int]vals modifications 9 ! condition ( _! electric or magnetic equilibrium4 ,x is kn[n t ! pres5ce ( pond]able matt] is necess>y = ! production ( electric effects1 & x is possible t ! molecul> vibrations ( :i* ,i h spok5 may be ! result ( molecul> movem5ts1 due to ! v>iations ( ! electric =ce :i* holds ! molecules 9 a special condition ( reciprocal equilibrium4 ,9 conclusion1 ! !ory ( ! telephone & microphone1 consid]$ z reproductive organs ( spee*1 is /ill f> f be+ p]fectly cle>1 & x w\ld be imprud5t to be too positive on que/ions ( su* rec5t orig94 ,! !ory ( ! electric transmission ( s\nds 9 electro-magnetic telephones is some:at complex4 ,x has be5 se5 t !y c be obta9$ f diaphragms ( non-magnetic sub/ance1 & ev5 f simple me*anical vibrations produc$ by %ocks4 ,are we to ascribe !m 9 ! fir/ case to ! inductive reaction ( ! magnet on ! vibrat+ plate1 & 9 ! second case to ! movem5ts ( magnetic p>ticles be=e ! spirals ( ! helix8 ,! matt] is /ill v obscure2 yet x is conceivable t ! modifications ( ! induc+ action ( ! magnet on ! vibrat+ diaphragm may involve v>iations 9 ! magnetic int5sity1 j z we c admit an effect ( ! same k9d due to ! approa* & )drawal ( ! magnetic p>ticles ( ! spirals ( ! helix2 ,m4 ,trve1 h[ev]1 believes t !re is 9 ! latt] case a special action1 :i* he has already _h occasion to /udy "u o!r circum/ances1 & he sees 9 ! curr5t ?us caus$ ! effect ( ! trans=mation ( ! me*anical lab\r produc$ amid/ ! magnetic molecules4 ,! "q is complicat$ by ! fact t ^! effects are (t5 produc$ by purely me*anical transmissions4 ,!re is ano!r po9t to consid]1 on :i* ,colonel ,navez has made "s int]e/+ rem>ks2 t is1 :e!r ! effects 9 ! receiv] are /rong] ) p]man5t ?an ) tempor>y magnets4 ,9 ! fir/ model ( ! telephone1 exhibit$ by ,mr4 ,bell at ,philadelphia1 ! receiv] 01 z ,i h said1 made ( a tubul> electro-magnet1 furni%$ ) a vibrat+ disk at its cyl9drical pole2 b ?is arrangem5t 0 ab&on$ by ,mr4 ,bell1 ) ! object1 z he /ates 9 8 pap]1 ( r5d]+ 8 in/rum5t bo? a receiv] & a s5d]4#ac ,yet ,colonel ,navez ma9ta9s t ! magnet plays an important "p1 & is ev5 indisp5sable "u ! pres5t conditions ( its =m4 #8,x is possible1' he says1 #8"u c]ta9 circum/ances1 & by mak+ ! in/rum5t 9 a special way1 to make a ,bell receiv] speak )\t a p]man5t magnet1 yet ) an in/rum5t ( ! usual con/ruction ! s\nd ceases :5 ! magnet is )drawn & replac$ by a cyl9d] ( s(t iron4 ,9 ord] to re/ore ! voice ( ! telephone1 x is en\gh to approa* ! pole ( a p]man5t magnet to ! cyl9d] ( s(t iron4 ,x foll[s f ^! exp]im5ts t a ,bell telephone _c act prop]ly unless ! disk is subject$ to an initial magnetic t5sion obta9$ by means ( a p]man5t magnet4 ,x is easy to d$uce ?is ass]tion f a consid]ation ( ! !ory4' ,! ass]tion may be true 9 ! case ( ,bell telephones1 :i* are work$ by extremely weak curr5ts1 b :5 ^! curr5ts are relatively /rong1 all electro-magnets w reproduce spee* p]fectly1 & we h se5 t ,m4 ,ad] made a telephone ) ! ord9>y electro-magnet :i* act$ p]fectly4 ,! action ( ! curr5ts s5t ?r\gh ! helix ( a telephone c be easily expla9$4 ,:atev] may be ! magnetic conditions ( ! b>1 ! induc$ curr5ts ( diff]5t int5sity :i* act ^u x produce modifications 9 its magnetic /ate1 & h5ce ! molecul> vibrations foll[ f contraction & expansion4 ,^! vibrations are likewise produc$ 9 ! armature "u ! influ5ce ( ! magnetisations & demagnetisations :i* are produc$ by ! magnetic action ( ! core1 & !y contribute to ! vibrations ( ! core itself1 :ile at ! same "t ! modifications 9 ! magnetic condition ( ! sy/em are increas$ by ! reaction ( ! two magnetic p>ts ^u ea* o!r4 ,:5 ! b> is made ( s(t iron1 ! induc$ curr5ts act by creat+ magnetisations ( great] or less en]gy1 foll[$ by demagnetisations :i* are ! m prompt s9ce inv]se curr5ts always succe$ to ^? :i* h be5 active1 & ?is causes ! alt]nations ( magnetisation & demagnetisation to be m di/9ct & rapid4 ,:5 ! b> is magnetis$1 ! action is diff]5tial1 & may be ex]t$ 9 ei!r direction1 accord+ z ! induc$ curr5ts correspond+ to ! vibrations :i* are effect$ pass ?r\gh ! receiv+ coil 9 ! same or opposite direction z ! magnetic curr5t ( ! b>4 ,if ^! curr5ts are 9 ! same direction1 ! action is /r5g!n+1 & ! modifications are effect$ z if a magnetisation _h tak5 place4 ,if ^! curr5ts are ( opposite direction1 ! inv]se effect is produc$2 b1 :atev] ! effects may be1 ! molecul> vibrations ma9ta9 ! same reciprocal relations & ! same height 9 ! scale ( musical s\nds4 ,if ! "q is consid]$ f ! ma!matical po9t ( view1 we f9d ! pres5ce ( a con/ant1 correspond+ ) ! int5sity ( ! curr5t1 :i* does n exi/ 9 me*anical vibrations1 & :i* may possibly be ! cause ( ! peculi> tone ( spee* reproduc$ by ! telephone1 a tone :i* has be5 comp>$ to ! voice ( ,pun*4 ,m4 ,dubois ,raymond has publi%$ an int]e/+ pap] on ?is !ory1 :i* appe>$ 9 #8,les ,mondes1' ,febru>y #ba1 #ahgh1 b we d n reproduce x "h1 s9ce 8 rem>ks are too sci5tific = ! read]s = :om ?is "w is int5d$4 ,we w only add t ,mr4 ,c4 ,w4 ,cunn+ham ass]ts t ! vibrations produc$ 9 a telephone _c be manife/$ "u precisely ! same conditions z ^? :i* affect ! tympanum ( ! e>1 because ! latt] has a peculi> funnel-%ap$ =m1 :i* excludes e fundam5tal note1 specially adapt$ to x1 & ?is is n ! case ) ! b>s & magnetic plates :i* possess fundam5tal notes capable ( greatly alt]+ ! half-tones ( ! voice4 ,he consid]s ! alt]ation ( ! voice obs]v$ 9 ! telephone mu/ be ascrib$ to ^! fundam5tal notes4 ,m4 ,wies5dang]'s ,!rmophone4--,m4 ,wies5dang]1 9 an article ins]t$ 9 ! #8,engli% ,me*anic & ,_w ( ,sci5ce1' ,septemb] #ac1 #ahgh1 ascribes ! reproduction ( spee* 9 c]ta9 telephones to vibratory movem5ts result+ f molecul> expansions & contractions produc$ by v>iations ( temp]ature1 & ^! v>iations w\ld foll[ f ! curr5ts ( v>y+ int5sity :i* are transmitt$ ?r\gh ! telephonic circuits4 ,he 0 consci\s ( "o objection to ?is !ory1 namely1 t ! movem5ts ( expansion & contraction due to heat are sl[ly produc$1 & consequ5tly are n capable ( sub/antial action1 rapid en\gh to produce vibrations2 b he consid]s t molecul> effects ne$ n take place "u ! same conditions z ^? :i* are display$ 9 ! case ( mat]ial sub/ances4 ,m4 ,wies5dang] believes t ?is hypo!sis w expla9 ! reproduction ( spee* 9 ! receiv+ microphones ( ,mr4 ,hughes1 & t x may ev5 be appli$ to ! !ory ( ! electro-magnetic telephone1 if we consid] t a magnetis+ helix1 z well z a magnetic core1 r\nd :i* an electric curr5t circulates1 is m or less heat$1 accord+ to ! int5sity ( ! curr5t :i* trav]ses x1 especially :5 ! wire ( ! helix & ! core are bad conductors ( electricity & ( magnetism4 ,pursu+ ?is idea1 ,m4 ,wies5dang] has s\ght to con/ruct telephones 9 :i* calorific effects are m fully develop$1 & ) ?is object he us$ v f9e wire ( ,g]man silv] & plat9um to make ! coils4 ,he asc]ta9$ t ^! coils c\ld produce s\nds !mselves1 &1 to increase _! int5sity1 he put !m betwe5 disks ( iron1 or on t9 tubes1 plac$ on resonant surfaces close to ! disks4 ,9 ?is way he says t he 0 able to make a good receiv+ telephone )\t employ+ magnets4 ,he aft]w>ds arrang$ ! in/rum5t 9 diff]5t ways1 ( :i* ! two foll[+ are ! mo/ notewor?y4 ,9 ! fir/1 ! electro-magnetic sy/em 0 simply =m$ by a magnetic disk ) a helix w\nd r\nd x1 ( :i* ! wire 0 9 connection ) ! circuit ( a microphone1 & :i* 0 fa/5$ to ! c5tre ( ! p>*m5t membrane ( an ord9>y /r+ telephone2 ! disk consi/$ ( two iron plates sep>at$ by a c>bon disk ( small] diamet]1 & ! :ole 0 s compress$ z to =m a solid mass4 ,9 ! second1 ! helix 0 w\nd on a t9 tube1 six in*es long & five-eigh?s ( an in* 9 diamet]1 :i* 0 sold]$ by m]ely a po9t to ! c5tre ( ! diaphragm ( an ord9>y telephone4 ,! inv5tor ass]ts t ! tube & diaphragm only act z resonators1 & t ! s\nds produc$ by ?is in/rum5t are ne>ly ! same z ^? obta9$ f ! ord9>y /r+ telephone3 ! tunes ( a musical box 7 he>d1 & ! reproduction ( spee* 0 p]fect1 bo? 9 int5sity & 9 di/9ctness ( s\nd2 x ev5 appe>$ t telephonic s\nds 7 audible ) ! t9 tube alone1 surr\nd$ by ! helix4 ,m4 ,wies5dang] says t #8^! diff]5t receiv+ telephones %[ cle>ly t ! diaphragm & magnet are n ess5tial1 b m]ely accessory1 p>ts ( a telephone4' ,,v>i\s ,,exp]im5ts ,,made ,,) ,,! ,,telephone4 ,we mu/ n[ consid] a s]ies ( exp]im5ts :i* demon/rate ! wond]ful prop]ties ( ! telephone1 & :i* may also give "s indication ( ! importance ( ! influ5ces by :i* x is liable to be affect$4 ,exp]im5ts by ,m4 d',arsonval4--,we h se5 t ! telephone is an extremely s5sitive in/rum5t1 b its s5sitiv5ess c\ld sc>cely be appreciat$ by ord9>y means4 ,9 ord] to gauge x1 ,m4 d',arsonval has comp>$ x to ! n]ve ( a frog1 :i* has hi!rto be5 reg>d$ z ! mo/ p]fect ( all galvanoscopes1 & x appe>s f 8 exp]im5ts t ! s5sitiv5ess ( ! telephone is two hundr$ times great] ?an t ( ! frog's n]ve4 ,m4 d',arsonval has giv5 ! foll[+ acc\nt ( 8 rese>*es 9 ! records ( ! ,acadmie des ,sci5ces1 ,april #a1 #ahgh3 #8,i prep>$ a frog 9 ,galvani's mann]4 ,i took ,siem5s' in/rum5t ( induction1 us$ 9 physiology "u ! "n ( ! *>iot in/rum5t4 ,i excit$ ) ! ord9>y p9c]s ! sciatic n]ve1 & ,i )drew ! induc$ coil until ! n]ve no long] respond$ to ! electric excitem5t4 ,i !n sub/itut$ ! telephone = ! n]ve1 & ! induc$ curr5t1 :i* _h ceas$ to excite ! latt]1 made ! in/rum5t vibrate /rongly4 ,i )drew ! induc$ coil1 & ! telephone cont9u$ to vibrate4 #8,9 ! /illness ( night ,i c\ld he> ! vibration ( ! telephone :5 ! induc$ coil 0 at a di/ance fifte5 times great] ?an ! m9imum at :i* ! excitem5t ( ! n]ve took place2 consequ5tly1 if ! same law ( inv]se squ>es applies to induction & to di/ance1 x is evid5t t ! s5sitiv5ess ( ! telephone is two hundr$ times great] ?an t ( ! n]ve4 #8,! s5sitiv5ess ( ! telephone is inde$ exquisite4 ,we see h[ mu* x exce$s t ( ! galvanoscopic frog's leg1 & ,i h ?\ght ( employ+ x z a galvanoscope4 ,x is v difficult to /udy ! muscul> & n]v\s curr5ts ) a galvanomet] ( #cj1jjj turns1 because ! in/rum5t is defici5t 9 in/antane\s action1 & ! ne$le1 on acc\nt ( its in]tia1 _c display ! rapid succession ( electric v>iations1 su* z are effect$1 = example1 9 a muscle ?r[n into electric convulsion4 ,! telephone is free f ?is inconv5i5ce1 & x responds by vibration to ea* electric *ange1 h[ev] rapid x may be4 ,! in/rum5t is !re=e well adapt$ = ! /udy ( electric tetanus 9 ! muscle4 ,x is c]ta9 t ! muscul> curr5t w excite ! telephone1 s9ce ?is curr5t excites ! n]ve1 :i* is less s5sitive ?an ! telephone4 ,b = ?is purpose "s special arrangem5t ( ! in/rum5t is requir$4 #8,x is true t ! telephone c only reveal ! v>iations ( an electric curr5t1 h[ev] fa9t !y may be2 b ,i h be5 able1 by ! use ( a v simple exp$i5t1 to reveal by its means ! pres5ce ( a cont9u\s curr5t1 also ( extreme fa9tness4 ,i s5d ! curr5t 9 "q into ! telephone1 &1 to obta9 its v>iations1 ,i break ?is curr5t me*anically ) a tun+-=k4 ,if no curr5t is trav]s+ ! telephone1 x rema9s sil5t4 ,if1 on ! o!r h&1 ! fa9te/ curr5t exi/s1 ! telephone vibrates 9 unison ) ! tun+-=k4' ,pr(essor ,eick1 ( ,wurzburg1 has also us$ ! telephone = physiological rese>*es1 b 9 a direction precisely opposite to t explor$ by ,m4 d',arsonval4 ,he asc]ta9$ t :5 ! n]ves ( a frog 7 plac$ 9 connection ) a telephone1 !y 7 =cibly contract$ :5 anyone 0 speak+ into ! in/rum5t1 & ! =ce ( ! contractions *iefly dep5d$ on ! words pron\nc$4 ,= in/ance1 ! v[els a1 e1 i produc$ h>dly any effect1 :ile o & especially u caus$ a v /rong contraction4 ,! words ,liege /ill1 pron\nc$ 9 a l\d voice1 only produc$ a fa9t movem5t1 :ile ! ^w ,tuck]1 ev5 :5 spok5 9 a l[ voice1 /rongly agitat$ ! frog4 ,^! exp]im5ts1 rem9d+ u ( ^? by ,galvani1 7 necess>ily bas$ on ! effects produc$ by ! induc$ curr5ts develop$ 9 ! telephone1 & !y %[ t if ?is in/rum5t is a m s5sitive galvanoscope ?an ! n]ve ( a frog1 ! latt] is m susceptible ?an ! mo/ p]fect galvanomet]4 ,exp]im5ts by ,m4 ,demoget4--,9 ord] t he might comp>e ! int5sity ( ! s\nds transmitt$ by ! telephone ) ! int5sity ( orig9al s\nds1 ,m4 ,demoget plac$ two telephones 9 an op5 space4 ,he held ! fir/ to 8 e>1 :ile 8 assi/ant )drew to a di/ance1 con/antly repeat+ ! same syllable ) ! same int5sity ( tone 9 ! second in/rum5t4 ,he fir/ he>d ! s\nd transmitt$ by ! telephone1 & !n ! s\nd :i* rea*$ him directly1 s t comp>ison 0 easy1 & he obta9$ ! foll[+ results4 ,at a di/ance ( #ic y>ds ! orig9al & ! transmitt$ s\nds 7 receiv$ ) equal int5sity1 :ile ! vibrat+ disk 0 ab\t #e c5timtres f ! e>4 ,at ?is mom5t1 !re=e1 ! relative int5sity 0 z #be to #ha1jjj1jjj4 ,9 o!r words1 ! s\nd transmitt$ by ! telephone 0 only #a_/cjjjjjj ( ! emitt$ s\nd4 #8,b1' said ,m4 ,demoget1 #8s9ce ! /ations at :i* we work$ c\ld n be reg>d$ z two po9ts freely vibrat+ 9 space1 ! ratio may be r$uc$ by "o half on acc\nt ( ! influ5ce ( ! e>?1 & ! s\nd transmitt$ by ! telephone may be suppos$ to be #a1ejj1jjj times weak] ?an t emitt$ by ! voice4 #8,aga91 s9ce we "k t ! int5sity ( ! two s\nds is 9 proportion to ! squ>e ( ! range ( vibrations1 x may be conclud$ t ! vibrations ( ! two telephone disks 7 9 direct proportion to ! di/ance1 t is1 z #e to #i1jjj1 or t ! vibrations ( ! s5d+ telephone 7 eighte5 hundr$ times great] ?an ^? ( ! receiv+ telephone4 ,^! latt] may !re=e be comp>$ to molecul> vibrations1 s9ce ! range ( ^? ( ! s5d+ telephone 0 extremely small4 #8,)\t 9 any degree detract+ f ! m]it ( ,bell's rem>kable inv5tion1' cont9ues ,m4 ,demoget1 #8x foll[s f :at ,i h said above t ! telephone1 consid]$ z a s5d+ in/rum5t1 leaves mu* to be desir$1 s9ce x only transmits ! #ah_/ajj "p ( ! orig9al p[]2 & if x has produc$ su* unexpect$ results1 ?is is due to ! p]fection ( ! organ ( he>+1 r ?an to ! p]fection ( ! in/rum5t itself4' ,m4 ,demoget consid]s ?is loss ( p[] :i* takes place 9 ! telephone to be *iefly ow+ to ! eight trans=mations 9 succession to :i* s\nd is subject$ be=e rea*+ ! e>1 sett+ aside ! loss due to ! electric resi/ance ( ! l9e1 :i* might 9 itself suffice to absorb ! :ole =ce4 ,9 ord] to e/imate ! =ce ( ! induc$ curr5ts :i* act ^u a telephone1 ,m4 ,demoget has attempt$ to comp>e !m ) curr5ts ( :i* ! int5sity is kn[n1 & :i* produce vibrations ( l nature & =ce3 = ?is purpose he has made use ( two telephones1 ,a & ,b1 communicat+ ?r\gh a l9e #bb y>ds 9 l5g?4 ,he plac$ a small file 9 slight contact ) ! vibrat+ disk ( ! telephone ,a1 & caus$ friction betwe5 ! file & a metallic plate3 ! s\nd ?us produc$ 0 necess>ily transmitt$ by ! telephone ,b1 ) an int5sity :i* c\ld be e/imat$4 ,he !n sub/itut$ a batt]y = ! telephone ,a1 & ! file 0 introduc$ into ! circuit by connect+ x ) "o ( ! poles4 ,! curr5t c\ld only be clos$ by ! friction ( ! file ) ! plate1 :i* _h a spr+1 & 0 9 communication ) ! o!r end ( ! circuit4 ,9 ?is way brok5 curr5ts 7 obta9$1 :i* caus$ vibration 9 ! telephone ,b1 & produc$ a s\nd ( :i* ! int5sity v>i$ ) ! /r5g? ( ! batt]y curr5t4 ,9 ?is way ,m4 ,demoget endeav\r$ to f9d ! electric int5sity capable ( produc+ a s\nd simil> to t ( ! telephone ,a1 & he asc]ta9$ t x correspond$ 9 int5sity to t produc$ 9 a small !rmo-electric batt]y =m$ ( an iron & a copp] wire1 two millimtres 9 diamet]1 flatt5$ at ! end1 & sold]$ to ! t93 ! fa9t curr5t produc$ by ?is batt]y only caus$ a %ort wire galvanomet] to deviate two degrees4 ,?is e/imate does n appe> to u to unite s _m conditions ( accuracy z to enable u to d$uce f x ! degree ( s5sitiv5ess possess$ by a telephone1 a s5sitiv5ess :i* ! exp]im5ts ( ,messrs4 ,w>r5 de la ,rue1 ,br\gh1 & ,peirce %[ to be mu* great]4 ,mr4 ,w>r5 de la ,rue1 z we h se51 us$ ,?omson's galvanomet]1 & comp>$ ! deviation produc$ on ! scale ( ?is galvanomet] ) t caus$ by a ,daniell cell trav]s+ a circle complet$ by a rheo/at3 he asc]ta9$ t ! curr5ts dis*>g$ by an ord9>y ,bell telephone are equival5t to ^? ( a ,daniell cell trav]s+ #ajj megohms ( resi/ance1 t is1 #f1bjj1jjj miles ( telegraphic wire4 ,mr4 ,br\gh1 ! ,director ( ,indian ,telegraphs1 consid]s t ! /ronge/ curr5t :i* at any giv5 mom5t causes a ,bell telephone to "w does n exce$ #a_/ajjjjjj ( ! unit ( curr5t1 t is1 "o ,web]1 & ! curr5t transmitt$ to ! /ations on ! ,indian telegraphic l9e is #djj1jjj times z /rong4 ,f9ally1 ,pr(essor ,peirce1 ( ,bo/on1 comp>es ! effects ( ! telephonic curr5t ) ^? :i* w\ld be produc$ by an electric s\rce ( :i* ! electro-motive =ce %\ld be #a_/bjjjjj "p ( a volt1 or "o ,daniell cell4 ,mr4 ,peirce ju/ly rem>ks t x is difficult to e/imate ! real value ( ^! k9ds ( curr5ts at any precise sum1 s9ce x ess5tially v>ies accord+ to ! int5sity ( ! s\nds produc$ on ! transmitt+ telephone2 b x may be affirm$ t x is less ?an ! #a_/ajjjjjj "p ( ! curr5t usually employ$ to "w ! in/rum5ts on telegraphic l9es4 ,signor ,galileo ,f]r>is1 :o has rec5tly publi%$ an int]e/+ treatise on ?is "q 9 ! #8,atti della ,reale ,accademia delle ,sci5ze di ,tor9o' 7,june #ac1 #ahgh71 /ates t ! int5sity ( ! curr5ts produc$ by ! ord9>y ,bell telephone v>ies ) ! pit* ( ! s\nd emitt$4 ,exp]im5ts by ,m4 ,helles51 ( ,cop5hag54--,9 ord] to e/imate ! reciprocal effects ( diff]5t p>ts ( a telephone1 ,m4 ,helles5 has made telephones ( ! same size ) ?ree diff]5t arrangem5ts :i* act inv]sely to ea* o!r4 ,! fir/ 0 ( ! ord9>y =m1 ! second l t ( ,bell's fir/ sy/em1 t is1 ) a membrane support+ a small iron armature on its c5tre1 in/ead ( a vibrat+ disk1 & ! ?ird telephone consi/$ ( a holl[ cyl9drical magnet1 ) ! vibrat+ disk fix$ to "o ( its poles1 & ! disk 0 adapt$ to move be=e a flat1 snail-%ap$ spiral1 ( :i* ! numb] ( spirals equall$ ^? ( ! two o!r helices4 ,9 ?is la/ arrangem5t1 ! induc$ curr5ts result+ f ! vibrations ( ! voice might be assimilat$ to ^? :i* foll[ f ! approximation & )drawal ( ! two p>allel spirals1 "o ( :i* %\ld be trav]s$ by a curr5t4 ,x is ?is la/ arrangem5t :i* ,mr4 ,bell has adopt$ z produc+ ! be/ effects1 & x is r>e 9 ! hi/ory ( discov]ies t an inv5tor hits at once on ! be/ arrangem5t ( 8 in/rum5t4 ,exp]im5ts by ,m4 ,zets*e4--,!re are always a few p]v]se m9ds1 impell$ by a _s ( contradiction to d5y evid5ce1 & ?us !y attempt to depreciate a discov]y ( :i* ! glory irritates !m4 ,! telephone & ! phonograph h be5 ! objects ( su* unwor?y criticism4 ,x has be5 said t electric action _h no?+ to d ) ! effects produc$ 9 ! telephone1 & t x only act$ "u ! influ5ce ( me*anical vibrations transmitt$ by ! conduct+ wire1 j z 9 a /r+ telephone4 ,x 0 9 va9 to demon/rate to ^! ob/9ate m9ds t no s\nd is produc$ :5 ! circuit is brok51 & 9 ord] to conv9ce !m ,m4 ,zets*e has made "s exp]im5ts to %[1 f ! mode 9 :i* s\nd is propagat$1 t x is absurd to ascribe ! s\nd produc$ 9 a telephone to me*anical vibration4 ,he wrote to ?is effect 9 an article ins]t$ 9 ! #8,j\rnal ,tlgraphique1' ,b]ne1 ,janu>y #be1 #ahgh3 #8,! correspond5ce by telephone betwe5 ,leipzig & ,dresd5 af=ds ano!r pro( t ! s\nds :i* reproduce words at ! receiv+ /ation are due to electric curr5ts1 & n to me*anical vibrations4 ,! velocity ) :i* s\nd is transmitt$ by vibrations on ! wire1 9 ! case ( longitud9al undulations1 may be e/imat$ at ?ree miles "o furlong a second1 s t ! s\nd ought to trav]se ! di/ance f ,leipzig to ,dresd5 9 #be seconds4 ,! same "t ought to elapse be=e receiv+ ! answ]4 ,consequ5tly !re %\ld be an int]val ( m ?an ?ree-qu>t]s ( a m9ute all[$ = ea* ex*ange ( communication1 :i* is by no means ! case4' ,exp]im5ts :i* may be made by anyone4--,we w conclude ?is *apt]1 devot$ to ! acc\nt ( ! diff]5t exp]im5ts made ) ! telephone1 by ! m5tion ( a s+ul> exp]im5t1 :i*1 al?\gh easily p]=m$1 has only be5 sugge/$ a few mon?s ago by a ,p5nsylvanian newspap]4 ,x consi/s 9 ! transmission ( spee* by a telephone simply laid on "s "p ( ! human body adjac5t to ! *e/4 ,x has be5 ass]t$ t any "p ( ! body w produce ?is effect1 b accord+ to my exp]i5ce1 ,i c\ld only succe$ :5 ! telephone 0 firmly appli$ to my *e/4 ,"u su* conditions1 & ev5 ?r\gh my clo!s1 ,i c\ld make myself he>d :5 speak+ 9 a v l\d voice1 f :i* x appe>s t ! :ole ( ! human body takes "p 9 ! vibrations produc$ by ! voice4 ,9 ?is case1 ! vibrations are me*anically transmitt$ to ! diaphragm ( ! s5d+ telephone1 n by ! air1 b by ! body itself act+ on ! outside ( ! telephone4 ,,! ,,microphone4 ,! microphone is 9 fact only ! s5d] ( a batt]y telephone1 b ) su* di/9ctive *>act]i/ics t x may be reg>d$ z an orig9al inv5tion :i* is entitl$ to a special "n4 ,! inv5tion has lately giv5 rise to an un=tunate controv]sy betwe5 its inv5tor1 ,mr4 ,hughes1 & ,mr4 ,edison1 ! inv5tor ( ! c>bon telephone & ! phonograph--a controv]sy :i* has be5 embitt]$ by ! newspap]s1 & = :i* !re 7 no gr\nds4 ,= al?\gh ! sci5tific pr9ciple ( ! microphone may appe> to be ! same z t ( ,mr4 ,edison's c>bon s5d]1 its arrangem5t is totally diff]5t1 its mode ( action is n ! same1 & ! effect requir$ ( x is ( q ano!r k9d4 ,less ?an ?is is ne$$ to con/itute a new inv5tion4 ,besides1 a ?or\gh exam9ation ( ! v pr9ciple ( ! in/rum5t mu/ make u wond] at ,mr4 ,edison's claim to priority4 ,he _c 9 fact reg>d z 8 exclusive possession ! discov]y ( ! prop]ty possess$ by "s sub/ances ( mod]ate conductivity ( hav+ ?is p[] modifi$ by pressure4 ,9 #ahef1 & (t5 subsequ5tly1 z = example 9 #ahfd1 #ahgb1 #ahgd1 & #ahge1 ,i made num]\s exp]im5ts on ?is po9t1 :i* are describ$ 9 ! fir/ volume ( ! second edition ( my #8,expos des applications de l',electricit1' & also 9 sev]al pap]s pres5t$ to ! ,acadmie des ,sci5ces1 & ins]t$ 9 _! ,comptes r5dus4 ,m4 ,cl>ac aga91 9 #ahfe1 employ$ a tube made ( plumbago1 & provid$ ) a moveable electrode1 to produce v>iable resi/ances 9 a telegraphic circuit4 ,besides1 9 ,mr4 ,edison's telephonic s5d]1 ! c>bon disk1 z we h se51 mu/ be subject$ to a c]ta9 initial pressure1 9 ord] t ! curr5t may n be brok5 by ! vibrations ( ! plate on :i* x re/s1 & consequ5tly ! modifications ( resi/ance 9 ! circuit :i* produce articulate s\nds are only caus$ by great] or less increase & dim9ution ( pressure1 t is1 by diff]5tial actions4 ,we %all pres5tly see t ?is is n ! case ) ! microphone4 ,9 ! fir/ place1 ! c>bon contact is effect$ 9 ! latt] in/rum5t on o!r c>bons & n ) plat9um disks1 & ^! contacts are multiple4 ,9 ! second place1 ! pressure ex]t$ on all ! po9ts ( contact is excessively slight1 s t ! resi/ances c be v>i$ 9 an inf9itely great] ratio ?an 9 ,mr4 ,edison's sy/em2 & = ?is v reason x is possible to magnify ! s\nds4 ,9 ! ?ird place1 a microphone c be made ( o!r sub/ances besides c>bon4 ,f9ally1 no vibrat+ disk is ne$$ to make ! microphone act2 ! simple m$ium ( air is en\gh1 s t x is possible to "w ! in/rum5t f "s little di/ance4 ,we d n !re=e see ! gr\nds = ,mr4 ,edison's ass]tions1 & especially = ! way 9 :i* he has spok5 ( ,messrs4 ,hughes & ,preece1 :o are well kn[n 9 sci5ce & are 9 all respects hon\rable m54 ,i repeat my regret t ,mr4 ,edison %\ld h made ?is ill-judg$ attack on !m1 s9ce x mu/ injure himself1 & is unwor?y ( an inv5tor ( su* di/9ction4 ,if we look at ! "q f ano!r po9t ( view1 we mu/ ask ,mr4 ,edison :y1 if he inv5t$ ! microphone1 he did n make u acqua9t$ ) its prop]ties & results4 ,^! results are inde$ />tl+1 s9ce ! microphone has 9 s %ort a "t attract$ g5]al att5tion2 & x is evid5t t ! cle>-sight$ g5ius ( ?is celebrat$ ,am]ican inv5tor w\ld h made ! mo/ ( ! discov]y if x 7 really 84 ,! only ju/ification = ,mr4 ,edison's claim consi/s 9 8 ignorance ( ! purely sci5tific discov]ies made 9 ,europe1 s t he suppos$ ! inv5tion ( ! microphone to be :olly involv$ 9 ! pr9ciple :i* he reg>ds z 8 peculi> discov]y4 ,9 ,mr4 ,hughes's in/rum5t :i* we are n[ consid]+1 ! s\nds1 in/ead ( rea*+ ! receiv+ /ations mu* dim9i%$1 :i* is ! case ) ord9>y telephones1 & ev5 ) t ( ,mr4 ,edison1 are (t5 rem>kably increas$1 & x is = ?is reason t ,mr4 ,hughes has giv5 to ?is telephonic sy/em ! "n ( ,microphone1 s9ce x c be employ$ to discov] v fa9t s\nds4 ,yet we mu/ add t ?is increase really takes place only :5 ! s\nds result f me*anical vibrations transmitt$ by solid sub/ances to ! s5d+ in/rum5t4 ,! s\nds propagat$ ?r\gh ! air are und\bt$ly a little m int5se ?an 9 ! ord9>y sy/em1 b !y lose "s ( _! =ce1 & !re=e x _c be said t 9 ?is case ! microphone has ! same effect ^u s\nds z ! microscope has on objects on :i* light is ?r[n4 ,x is true t ) ?is sy/em x is possible to speak at a di/ance f ! in/rum5t1 & ,i h ev5 be5 able to transmit conv]sation 9 a l\d voice1 :5 /&+ at a di/ance ( n9e y>ds f ! microphone4 ,:5 close to ! in/rum5t1 ,i 0 also p]fectly able to make myself he>d at ! receiv+ /ation :ile speak+ 9 a l[ voice1 & ev5 to s5d ! s\nds to a di/ance ( t5 or fifte5 c5timtres f ! m\?piece ( ! receiv+ telephone by rais+ ! voice a little2 b ! increase ( s\nd is n really v evid5t unless x is produc$ by a me*anical action transmitt$ to ! /&>d ( ! in/rum5t4 ,?us ! /eps ( a fly walk+ on ! /& are cle>ly he>d1 & give ! s5sation ( a horse's tread2 & ev5 a fly's scream1 especially at ! mom5t ( dea?1 is said by ,mr4 ,hughes to be audible4 ,! ru/l+ ( a fea!r or ( a piece ( /uff on ! bo>d ( ! in/rum5t1 s\nds completely inaudible 9 ord9>y circum/ances1 are di/9ctly he>d 9 ! microphone4 ,x is ! same ) ! tick+ ( a wat* plac$ ^u ! /&1 :i* may be he>d at t5 or fifte5 c5timtres f ! receiv]4 ,a small musical box plac$ ^u ! in/rum5t gives out s mu* s\nd1 9 consequ5ce ( its vibratory movem5ts1 t x is impossible to di/+ui% ! notes1 & 9 ord] to d s x is necess>y to place ! box close to ! in/rum5t1 )\t all[+ x to come 9 contact ) any ( its con/itu5t p>ts4 ,x !re=e appe>s t ! in/rum5t is affect$ by ! vibrations ( air1 & ! transmitt$ s\nds are fa9t] ?an ^? he>d close to ! box4 ,on ! o!r h&1 ! vibrations produc$ by ! p5dulum ( a clock1 :5 plac$ 9 communication ) ! /&>d ( ! in/rum5t by means ( a metallic rod1 are he>d p]fectly1 & may ev5 be di/+ui%$ :5 ! connection is made by ! int]v5tion ( a copp] wire4 ,a curr5t ( air project$ on ! sy/em gives ! s5sation ( a trickle ( wat] he>d 9 ! di/ance4 ,f9ally1 ! rumbl+ ( a c>riage outside ! h\se is trans=m$ into a v int5se crackl+ noise1 :i* may comb9e ) ! tick+ ( a wat*1 & w (t5 ov]p[] x4 ,diff]5t ,sy/ems ( ,microphones4--,! microphone has be5 made 9 sev]al ways1 b ! "o repres5t$ 9 fig4 #ci is ! arrangem5t :i* r5d]s x ! mo/ s5sitive4 ,9 ?is sy/em1 two small c>bon cubes1 ,a1 ,b1 are plac$ "o above ! o!r on a v]tical wood5 prism2 two holes are pi]c$ 9 ! cubes to s]ve z sockets = a sp9dle-%ap$ c>bon p5cil1 t is1 ) ! po9ts f9$ (f at ! two ends1 & ab\t f\r c5timtres long3 if ( a l>ge size1 ! in]tia w be too great4 ,"o end ( ?is p5cil is 9 ! cavity ( ! l[] c>bon1 & ! o!r mu/ move freely 9 ! upp] cavity :i* ma9ta9s x 9 a position approa*+ to t ( in/able equilibrium1 t is1 9 a v]tical position4 ,mr4 ,hughes /ates t ! c>bons become m effective if !y are /eep$ 9 a ba? ( m]cury at r$ heat1 b !y w act well )\t und]go+ ?is process4 ,! two c>bon cubes are also provid$ ) metallic contacts :i* admit ( _! be+ plac$ 9 connection ) ! circuit ( an ord9>y telephone 9 :i* a ,leclan* batt]y has be5 plac$1 or "o1 two1 or ?ree ,daniell cells1 ) an additional resi/ance introduc$ into ! circuit4 ,illu/ration3 ,,fig4 #ci4 ,9 ord] to use ?is in/rum5t1 x is plac$ on a table1 ) ! bo>d :i* s]ves to support x1 tak+ c>e to dead5 any extrane\s vibrations by int]pos+ betwe5 ?is bo>d & ! table sev]al folds ( /uff s arrang$ z to =m a cu%ion1 or1 :i* is bett]1 a belt ( wadd+1 or two ca\t*\c tubes3 :at is said by a p]son /&+ be=e ?is sy/em is imm$iately reproduc$ 9 ! telephone1 & if a wat* is plac$ on ! /&1 or a box ) a fly enclos$ 9 x1 all its movem5ts are he>d4 ,! in/rum5t is s s5sitive t words said 9 a l[ voice are mo/ easily he>d1 & x is possible1 z ,i h already said1 to he> ! speak] :5 he is /&+ n9e y>ds f ! microphone4 ,yet "s precautions are necess>y 9 ord] to obta9 good results ) ?is sy/em1 & besides ! cu%ions plac$ b5ea? ! in/rum5t to gu>d x f ! extrane\s vibrations :i* might ensue f any movem5ts communicat$ to ! table1 x is also necess>y to regulate ! position ( ! c>bon p5cil4 ,x mu/ always re/ on "s po9t ( ! rim ( ! upp] cavity2 b z ! contact may be m or less satisfactory1 exp]i5ce alone w %[ :5 x is 9 ! be/ position1 & x is a good plan to make use ( a wat* to asc]ta9 ?is4 ,! e> is !n appli$ to ! telephone1 & ! p5cil is plac$ 9 diff]5t positions until ! maximum effect is obta9$4 ,to avoid ! necessity ( regulat+ ! in/rum5t 9 ?is way1 :i* mu/ be done repeat$ly by ?is arrangem5t1 ,,mm4 ,*>d9 & ,b]jot1 :o are +5i\s 9 ! con/ruction ( telephones on ?is patt]n1 h add$ to x a small spr+-plate1 ( :i* ! pressure c be regulat$1 & :i* re/s aga9/ ! c>bon p5cil itself4 ,?is sy/em works well4 ,illu/ration3 ,,fig4 #dj4 ,m4 ,gaiffe1 by con/ruct+ x l a sci5tific in/rum5t1 has giv5 ! in/rum5t a m elegant =m4 ,fig4 #dj repres5ts "o ( 8 two models4 ,9 ?is case1 ! cubes or c>bon dice are support$ by metallic hold]s1 & ! upp] "o ,e is made to move up & d[n a copp] column ,g1 s z to be plac$ 9 ! "r position by tight5+ ! screw ,v4 ,9 ?is way ! c>bon p5cil c be made to incl9e m or less1 & its pressure on ! upp] c>bon c be alt]$ at pleasure4 ,:5 ! p5cil is 9 a v]tical position1 ! in/rum5t transmits articulate s\nds ) difficulty1 on acc\nt ( ! in/ability ( ! po9ts ( contact1 & ru/l+ s\nds are he>d4 ,:5 ! incl9ation ( ! p5cil is too great1 ! s\nds are pur] & m di/9ct1 b ! in/rum5t is less s5sitive4 ,! exact degree ( incl9ation %\ld be asc]ta9$1 :i* is easily done by exp]im5t4 ,9 ano!r model ,m4 ,gaiffe sub/itutes = ! c>bon p5cil a v ?9 squ>e plate ( ! same mat]ial1 bevell$ on its l[] & upp] surfaces1 & revolv+ 9 a groove cut 9 ! l[] c>bon4 ,?is plate mu/ be only slightly incl9$ 9 ord] to t\* ! upp] c>bon1 & "u ^! conditions x transmits spee* m l\dly & di/9ctly4 ,i mu/ also m5tion ano!r arrangem5t1 devis$ by ,capta9 ,c>ette ( ! ,fr5* ,eng9e]s1 :i* is v successful 9 transmitt+ in>ticulate s\nds4 ,9 ?is case ! v]tical c>bon is pe>-%ap$1 & its l>g] end re/s 9 a hole made 9 ! l[] c>bon2 its upp] & po9t$ end goes into a small hole made 9 ! upp] c>bon1 b s z h>dly to t\* x1 & !re is a screw to regulate ! di/ance betwe5 ! two c>bons4 ,"u su* conditions1 ! contacts are s un/able t almo/ any?+ w put an end to !m1 & consequ5tly ! v>iations 9 ! int5sity ( ! transmitt$ curr5t are s /rong t ! s\nds produc$ by ! telephone may be he>d at ! di/ance ( sev]al y>ds4 ,illu/ration3 ,,fig4 #da4 ,fig4 #da repres5ts ano!r arrangem5t1 devis$ by ,m4 ,ducretet4 ,! two c>bon blocks are at ,d ,d1 ! moveable c>bon p5cil is at ,c1 ! telephone at ,t1 & ! b9d+ screws at ,b ,b4 ,an enl>g$ figure ( ! arrangem5t ( ! c>bons is giv5 on ! left4 ,! arm :i* holds ! upp] c>bon ,d is fa/5$ to a rod1 be>+ a plate ,p1 ( :i* ! surface is r\gh1 & a little cage ,c1 made ( wire nett+1 c be plac$ ^u ! plate1 s z to enable u to /udy ! movem5ts ( liv+ insects4 ,:5 spee* is to be transmitt$ ) a =ce :i* c make ! telephone audible 9 a l>ge room1 ! microphone mu/ h a special arrangem5t1 & fig4 #db repres5ts ! "o :i* ,mr4 ,hughes consid]s ! mo/ successful1 to :i* he has giv5 ! "n ( speak]4 ,illu/ration3 ,,fig4 #db4 ,9 ?is new =m1 ! moveable c>bon :i* is requir$ to produce ! v>iable contacts is at ,c1 at ! end ( a horizontal b> ,b ,a1 prop]ly balanc$ s z to move up & d[n on its c5tral po9t4 ,! support on :i* ! b> oscillates is fa/5$ to ! end ( a spr+ plate 9 ord] t x may vibrate m easily1 & ! l[] c>bon is plac$ at ,d bel[ ! fir/4 ,x consi/s ( two pieces laid ^u ea* o!r1 s z to increase ! s5sitiv5ess ( ! in/rum5t1 & we repres5t ! upp] piece at ,e1 :i* is rais$ s z to %[ t :5 x is desir$ only "o ( ^! c>bons ne$ be us$4 ,= ?is purpose ! c>bon ,e is fa/5$ to a morsel ( pap]1 :i* is fix$ to ! little bo>d & contributes to ! articulation4 ,a spr+ ,r1 ( :i* ! t5sion c be regulat$ by ! screw t1 s]ves to regulate ! pressure ( ! two c>bons4 ,mr4 ,hughes recomm5ds ! use ( metallis$ *>coal prep>$ f deal4#ad ,! :ole is !n enclos$ 9 a semi-cyl9drical case ,h ,i ,g1 made ( v ?9 pieces ( deal1 & ! sy/em is fix$1 toge!r ) ano!r simil> sy/em1 9 a flat box1 ,m ,j ,l ,i1 :i*1 on ! side ,m ,i1 pres5ts an op5+ be=e :i* ! speak] /&s1 tak+ c>e to keep 8 l[] lip at a di/ance ( two c5timtres f ! bottom ( ! box4 ,if ! two telephones are connect$ = /r5g?1 & if ! batt]y employ$ consi/s ( two cells ( bi*romate ( pota%1 x is possible to act s /rongly on ! curr5t1 t1 aft] trav]s+ an induction coil only six c5timtres long1 a telephone ( ,bell's squ>e model c be made to speak1 s z to be he>d f all p>ts ( a room2 a speak+ tube1 ab\t a y>d long1 mu/ inde$ be appli$ to x4 ,mr4 ,hughes ass]ts t ! s\nds produc$ by x are ne>ly z l\d z ^? ( ! phonograph1 & ?is is confirm$ by ,mr4 ,?omson4 ,m4 ,b\det de ,p>is has lately inv5t$ a microphone speak] ( ! same k9d1 ) :i* x is possible to make a small telephone utt] a l\d s\nd4 ,an induction coil1 influ5c$ by a s+le ,leclan* cell1 mu/ be employ$4 ,suppose t a v small c>bon rod ) po9t$ ends is plac$ at ! bottom ( a box1 ( ab\t ! size ( a wat*4 ,"o end ( ! rod re/s aga9/ a morsel ( c>bon1 :i* is fa/5$ to a v ?9 /eel diaphragm1 plac$ be=e a m\?piece :i* acts z a lid to ! box1 & is screw$ above x4 ,next suppose t a small piece ( pap]1 fold$ 9 two1 9 ! %ape ( ! lett] ,v1 is fix$ above t "p ( ! c>bon 9 contact ) ! c>bon ( ! diaphragm4 ,?is con/itutes ! in/rum5t1 & 9 ord] to "w x1 x mu/ be held 9 a v]tical position be=e ! m\?1 at a di/ance ( ab\t ?ree c5timtres1 & x is necess>y to speak 9 ! ord9>y tone4 ,if ! telephone is plac$ 9 direct communication ) ?is in/rum5t1 x w s5d ! voice to a di/ance4 ,)\t employ+ a ,leclan* cell1 ! voice may be he>d at ! di/ance ( t5 y>ds1 if "o ( ! c>bons us$ = ! phonograph is plac$ be=e ! m\?piece ( ! telephone4 ,9 ?is sy/em1 ! s5sitiv5ess ( ! in/rum5t is entirely due to ! slightness ( ! contact betwe5 ! two c>bons1 & ! slight ela/icity ( ! fold$ pap] con/itutes ! contact4 ,p]haps ! pap] itself has "s influ5ce2 at any rate ! mo/ delicate spiral spr+ is incapable ( produc+ ! same effect1 & x is necess>y to susp5d ! in/rum5t v]tically1 9 ord] t ! weight ( ! moveable c>bon may n affect x4 ,x c be regulat$ by depress+ or elevat+ t "p ( ! pap] :i* re/s on ! c>bon rod4 ,al?\gh x is possible to "w all telephones ) ?is in/rum5t1 "s are m effective ?an o!rs4 ,! m\?piece mu/ be concave1 & ! diaphragm mu/ be close to its rim1 & mu/ be made ( a p>ticul> k9d ( t94 ,! ord9>y diaphragm does n act well1 & ,m4 ,b\det de ,p>is has tri$ sev]al1 s z to obta9 ! maximum effect4 ,x is c]ta9 t :5 ! in/rum5ts are z well regulat$ z ^? :i* ! inv5tor has deposit$ ) me1 _! results are really surpris+4 ,x is ev5 possible1 by us+ sev]al microphones at ! s5d+ /ation1 to obta9 ! reproduction ( duets1 & ev5 ( trios1 ) rem>kable effect4 ,) ?is k9d ( microphone speak] ,m4 ,b\det de ,p>is is able to transmit spee* into a snuff-box telephone1 m]ely consi/+ ( a flat helix ( wire1 plac$ be=e a slightly magnetis$ /eel plate1 & )\t ins]tion ( a magnetic core4 ,a s+le ,leclan* cell 0 en\gh4 ,an exp]im5t ( ! same nature 0 tri$ 9 ,engl&1 b x 0 f\nd necess>y to use six ,leclan* cells4 ,illu/ration3 ,,fig4 #dc ,illu/ration3 ,,fig4 #dd4 ,! microphone may also be made ( morsels ( c>bon press$ into a box betwe5 two metallic electrodes1 or enclos$ 9 a tube ) two electrodes repres5t$ by two elongat$ fragm5ts ( c>bon4 ,9 ! latt] case ! c>bons ought to be z cyl9drical z possible1 & ^? made by ,m4 ,c>r = ! ,jablo*k(f c&les are v suitable4 ,fig4 #dc repres5ts an in/rum5t ( ?is k9d :i* ,m4 ,gaiffe arrang$ = me1 & :i*1 z we %all see1 s]ves z a !rmoscope 7fig4 #dd74 ,x is compos$ ( a quill fill$ ) morsels ( c>bon1 & ^? at ! two ends are tipp$ ) metal4 ,"o ( ^! metal tips ends 9 a l>ge-head$ screw :i*1 by means ( its supports ,a ,b1 is able to press m or less on ! morsels ( c>bon 9 ! tube1 & consequ5tly to e/abli% a m or less intimate contact betwe5 !m4 ,:5 ! in/rum5t is prop]ly regulat$1 spee* c be reproduc$ by speak+ above ! tube4 ,x is !re=e a microphone z well z a !rmoscope4 ,mr4 ,hughes has rem>k$ "o curi\s fact1 namely1 t if ! diff]5t lett]s ( ! alphabet are pron\nc$ sep>ately be=e ?is sort ( microphone1 "s ( !m are mu* m di/9ctly he>d ?an o!rs1 & x is precisely ^? :i* correspond to ! brea?+s ( ! voice4 ,a microphone ( ?is k9d may be made by sub/itut+ = ! c>bon p[d]s ( m or less conductivity1 or ev5 metal fil+s4 ,i h %[n 9 my pap] on ! action ( sub/ances ( mod]ate conductivity1 t su* p[] v>ies consid]ably ) ! pressure & ! temp]ature2 & z ! microphone is bas$ on ! diff]5ces ( conduct+ p[] :i* result f diff]5ces ( pressure1 we c und]/& t ^! p[d]s may be us$ z a means ( telephonic transmission4 ,9 a rec5t arrangem5t ( ?is sy/em ,mr4 ,hughes has made ! p[d] adh]e toge!r ) a sort ( gum1 & has ?us made a cyl9drical p5cil :i*1 :5 connect$ ) two electrodes :i* are good conductors1 c produce effects analog\s to ^? we h j describ$4 ,z ,i h said1 x is possible to use metal fil+s1 b ,mr4 ,hughes pref]s p[d]$ *>coal4 ,mr4 ,bly? /ates t a flat box1 ab\t #ae in*es by #i1 fill$ ) coke1 & ) two t9 electrodes fix$ to ! two ends1 is "o ( ! be/ arrangem5ts = a microphone4 ,he says t ?ree ( ^! in/rum5ts1 hung l pictures aga9/ ! wall ( a room1 w\ld suffice1 :5 influ5c$ by a s+le ,leclan* cell1 to make all ! s\nds produc$ 9 a telephone audible1 & especially vocal airs4 ,mr4 ,bly? ev5 ass]ts t a microphone capable ( transmitt+ spee* c be made ) a simple piece ( coke1 connect$ ) ! circuit by its two ends1 b x mu/ be coke3 a retort c>bon1 ) electrodes1 w n act4 ,x is a rem>kable prop]ty ( ^! k9ds ( microphones t !y c act )\t a batt]y1 at lea/ :5 !y are s arrang$ z to =m a voltaic elem5t = !mselves1 & ?is c be done by ?r[+ wat] on ! c>bons4 ,mr4 ,bly?1 :o 0 ! fir/ to speak ( ?is sy/em1 does n di/9ctly indicate its arrangem5t1 & we may assume t 8 in/rum5t did n diff] f ! "o we h already describ$1 to :i* wat] mu/ h be5 add$4 ,9 ?is way1 inde$1 ,i h be5 able to transmit n only ! tick+ ( a wat* & ! s\nds ( a musical box1 b spee* itself1 :i* 0 (t5 m di/9ctly express$ ?an 9 an ord9>y microphone1 s9ce x 0 free f ! sputt]+ s\nd :i* is apt to accompany ! latt]4 ,mr4 ,bly? also ass]ts t s\nds may be transmitt$ )\t ! addition ( wat]1 b 9 ?is case he consid]s t ! result is due to ! moi/ure ( ! brea?4 ,c]ta9ly mu* moi/ure is n requir$ to set a voltaic c\ple 9 action1 especially :5 a telephone is ! in/rum5t ( manife/ation4 ,! ord9>y microphone may be us$ )\t a batt]y1 if ! circuit 9 :i* x is ins]t$ is 9 communication ) ! e>? by means ( e>!n cakes2 ! curr5ts :i* !n trav]se ! circuit w suffice to make ! tick+s ( a wat* plac$ ^u ! microphone p]fectly audible4 ,m4 ,caud]ay1 ( ,lausanne1 9 a pap] s5t to ! ,acadmie des ,sci5ces1 ,july #h1 #ahgh1 in=ms u t he made ?is exp]im5t on a telegraphic wire :i* unites ! ,htel des ,alpes at ,montreux ) a *let on ! hill--a di/ance ( ab\t #eej y>ds4 ,! ,microphone us$ z a ,speak+ ,in/rum5t4--,! microphone c n only transmit spee*1 b x c also "u c]ta9 conditions reproduce x1 & consequ5tly supply ! place ( ! receiv+ telephone4 ,?is seems difficult to und]/&1 s9ce a cause = ! vibratory motion produc$ 9 "p ( ! circuit itself c only be s\ght 9 ! v>iations 9 int5sity ( ! curr5t1 & ! effects ( attraction & magnetisation h no?+ to d ) x4 ,c ! action be ref]r$ to ! repulsions reciprocally ex]t$ by ! contigu\s elem5ts ( ! same curr5t8 ,or are we to consid] x to be ( ! same nature z t :i* causes ! emission ( s\nds f a wire :5 a brok5 curr5t passes ?r\gh x1 s t an electric curr5t is itself a vibratory curr5t1 z ,mr4 ,hughes believes8 ,x is difficult to reply to ^! que/ions 9 ! pres5t /ate ( sci5ce2 we c only /ate ! fact1 :i* has be5 publi%$ by ,messrs4 ,hughes1 ,bly?1 ,rob]t ,c\rt5ay1 & ev5 by ,mr4 ,edison himself4 ,i h be5 able to v]ify ! fact myself "u ! exp]im5tal conditions indicat$ by ,mr4 ,hughes1 b ,i 0 n s successful 9 ! attempt to repeat ,mr4 ,bly?'s exp]im5ts4 ,?is g5tleman /at$ t 9 ord] to he> spee* 9 a microphone x w\ld be en\gh to use ! model made f fragm5ts ( c>bon1 z we h describ$1 to jo9 to x a second microphone ( ! same k9d1 & to introduce into ! circuit a batt]y consi/+ ( two ,grove elem5ts4 ,if anyone !n speaks above ! c>bons ( "o ( ! microphones1 :at is said %\ld be di/9ctly he>d by ! p]son :o puts 8 e> to ! o!r1 & ! importance ( ! s\nds ?us produc$ w correspond ) ! int5sity ( ! electric s\rce employ$4 ,z ,i h said1 ,i 0 unable by foll[+ ?is me?od to he> any s\nd1 /ill less articulate spee*2 & if o!r exp]im5ts _h n conv9c$ me1 ,i %\ld h d\bt$ ! correctness ( ! /atem5t4 ,b ?is negative exp]im5t does n 9 fact prove any?+1 s9ce x is possible t my conditions 7 wrong1 & t ! c9d]s :i* ,i employ$ 7 n subject to ! same conditions z ,mr4 ,bly?'s fragm5ts ( coke4 ,illu/ration3 ,,fig4 #de4 ,) respect to ,mr4 ,hughes's exp]im5ts1 ,i h repeat$ !m ) ! microphone made by ,,mm4 ,*>d9 & ,b]jot1 us+ t by ,m4 ,gaiffe z ! s5d]1 & ,i asc]ta9$ t ) a batt]y ( only f\r ,leclan* cells1 a scrat* made on ! s5d]1 & ev5 ! tremul\s motion & ! airs play$ 9 a little musical box plac$ on ! s5d]1 7 reproduc$--v fa9tly1 x is true--9 ! second microphone2 9 ord] to p]ceive !m1 x 0 en\gh to apply ! e> to ! v]tical bo>d ( ! in/rum5t4 ,x is true t spee* 0 n reproduc$1 b ( ?is ,mr4 ,hughes _h w>n$ me2 x 0 evid5t t ) ?is arrangem5t ! in/rum5t 0 n suffici5tly s5sitive4 ,a diff]5t arrangem5t ( ! microphone is requir$ = ! transmission & ! reproduction ( spee* by ?is sy/em1 & a section ( ! "o :i* ,mr4 ,hughes f\nd mo/ successful is giv5 9 fig4 #de4 ,x some:at resembles ,mr4 ,hughes's microphone speak]1 plac$ 9 a v]tical position1 & ! fix$ c>bon is fa/5$ to ! c5tre ( ! /ret*$ membrane ( a /r+ telephone4 ,! e> or m\? tube is at ,a1 ! membrane at ,d ,d1 ! c>bon j m5tion$ at ,c3 ?is c>bon is ( metallis$ *>coal prep>$ f deal1 & s also is ! d\ble c>bon ,e1 :i* is 9 contact ) x & is fa/5$ to ! upp] end ( ! little b> ,g ,i4 ,! :ole is enclos$ 9 a small box1 & ! pressure ex]t$ on ! contact ( ! two c>bons is regulat$ by a spr+ ,r & a screw ,h4 ,! tube ( ! telephone s]ves z an ac\/ic tube = ! li/5]1 & ,mr4 ,hughes's speak]1 describ$ above1 acts z s5d]4 ,x is h>dly necess>y to say t ! two in/rum5ts are plac$ at ea* end ( ! circuit1 t ! c>bons are connect$ ) ! two poles ( a batt]y ( "o or two cells ( bi*romate ( pota%1 or two ,buns5 or six ,leclan* cells1 & ! two in/rum5ts are connect$ by ! l9e wire4 ,"u su* conditions1 conv]sation may be ex*ang$1 b ! s\nds are always mu* less di/9ct ?an !y are 9 a telephone4 ,i 0 able to asc]ta9 ?is fact ) a r\ghly made in/rum5t br\ght f ,engl& by ,mr4 ,hughes4 ,,mm4 ,b]jot1 ,*>d91 & de ,mrit5s1 :o 7 also pres5t at ! exp]im5ts1 7 able ) me to he> spee* p]fectly1 & ,i h s9ce successfully repeat$ ! exp]im5t alone1 b x does n always succe$1 & "u its pres5t conditions ! in/rum5t has no importance 9 a sci5tific po9t ( view4 ,x is evid5t t ! in/rum5t c disp5se ) any support1 & ! little box !n =ms ! h&le ( ! in/rum5t2 9 ?is case ! two b9d+ screws are plac$ at ! end ( ?is h&le1 z 9 a telephone4 ,! microphone speak] ) a disk1 repres5t$ 9 fig4 #e1 :i* acts z s5d] to ! s++ cond5s]1 c be us$1 :5 prop]ly regulat$1 z a receiv+ microphone4 ,m4 ,b]jot has obta9$ good results f a little in/rum5t ( ! same k9d z t 9 fig4 #de1 b ) a metal diaphragm1 & ! microphonic sy/em consi/s ( a cyl9drical piece ( c>bon re/+ on a small disk ( ! same sub/ance1 :i* is galvanis$ & sold]$ to ! diaphragm4 ,! :ole is enclos$ 9 a small r\nd box1 ) its upp] "p cut 9 ! =m ( a m\?piece4 ,x seems t all microphone s5d]s ) disks c reproduce spee* m or less p]fectly2 x is a "q ( adju/+ & ref9+ ! c>bon po9ts ( contact4 ,a weak batt]y1 consi/+ ( a s+le ,leclan* cell1 is bett] = ^! in/rum5ts ?an a /rong batt]y1 precisely because ( ! effects ( oxidation & pol>isation1 :i* are s en]getically produc$ at ^! po9ts ( contact :5 ! batt]y is /rong4 ,! effects ( ! microphone receiv] expla9 ! s\nds1 (t5 v int5se1 produc$ by ! ,jablo*k(f c&les :5 !y are influ5c$ by electro-magnetic ma*9es4 ,^! s\nds always vibrate 9 unison ) ^? emitt$ by ! ma*9e itself1 & !y result1 z ,i h already %[n1 f ! rapid magnetisations & demagnetisations :i* are effect$ by ! ma*9e4 ,^! effects1 obs]v$ by ,m4 ,m>cel ,deprez1 7 p>ticul>ly m>k$ 9 ,m4 de ,mrit5s' fir/ ma*9es4 ,o!r ,arrangem5ts ( ,microphones4--,an arrangem5t su* z we h j describ$ has be5 employ$ by ,m4 ,c>ette to =m an extremely p[]ful microphone speak]4 ,! only diff]5ce is t ! /ret*$ membrane is replac$ by a ?9 metallic disk3 he fa/5s "o ( ! c>bons to ! c5tre ( ?is disk1 & applies to x ! o!r c>bon1 :i* is po9t$1 & held by a porte-c>bon ) a regulat+ screw1 s t ! pressure :i* takes place betwe5 ! two c>bons may be regulat$ at pleasure4 ,by ?is arrangem5t spee* may be he>d at a di/ance f ! telephone4 ,9 o!r respects x resembles ! telephone s5d] repres5t$ 9 fig4 #e4 ,m4 de ,mrit5s has execut$ ! sy/em repres5t$1 fig4 #de1 on a l>ge scale1 =m+ ! tube ,a ,b ( a z9c funnel a y>d 9 l5g?1 & 9 ?is way he has be5 able to magnify ! s\nds1 s t a conv]sation held 9 a l[ voice1 ?ree or f\r y>ds f ! in/rum5t1 has be5 produc$ 9 a telephone ) m sonor\s di/9ctness4 ,! in/rum5t 0 plac$ on ! floor ( ! ap>tm5t1 ) ! op5+ ( ! funnel above1 & ! telephone 0 9 ! cell>s ( ! h\se4 ,! =m ( ! microphone has be5 v>i$ 9 a ?\s& ways1 to suit ! purposes to :i* x 0 to be appli$4 ,9 ! #8,engli% ,me*anic & ,_w ( ,sci5ce1' ,june #bh1 #ahgh1 we see ! draw+s ( sev]al arrangem5ts1 "o ( :i* is specially adapt$ = he>+ ! /eps ( a fly4 ,x is a box1 ) a %eet ( /raw pap] /ret*$ on its upp] "p2 two c>bons1 sep>at$ by a morsel ( wood1 & connect$ ) ! two circuit wires1 are fa/5$ to x1 & a c>bon p5cil1 plac$ crosswise betwe5 ! two1 is kept 9 ?is position by a groove made 9 ! latt]4 ,a v weak batt]y w be en\gh to set ! in/rum5t at "w1 & :5 ! fly walks ov] ! %eet ( pap] x produces vibrations /rong en\gh to react en]getically on an ord9>y telephone4 ,! in/rum5t mu/ be cov]$ ) a glass globe4 ,:5 a wat* is plac$ on ! membrane1 ) its h&le appli$ to ! morsel ( wood :i* divides ! two c>bons1 ! noise ( its tick+ may be he>d ?r\gh a :ole room4 ,two c>bon cubes plac$ side by side1 & only divid$ by a play+-c>d1 may also be us$ in/ead ( ! arrangem5t ( c>bons describ$ above4 ,a semicircul> cavity1 made 9 ! upp] "p ( ! two c>bons1 9 :i* are plac$ "s little c>bon balls1 small] ?an a pea & l>g] ?an a mu/>d se$1 w make x possible to obta9 multiple contacts :i* are v mobile & peculi>ly fit = telephonic transmissions4 ,?is arrangem5t has be5 made by ,mr4 ,t4 ,cuttriss4 ,sev]al o!r arrangem5ts ( microphones h be5 devis$ by diff]5t mak]s & inv5tors1 su* z ^? ( ,messrs4 ,v>ey1 ,tr\v1 ,v]ek]1 de ,combettes1 ,loiseau1 ,lipp5s1 de ,c\rtois1 ,poll>d1 ,vois91 ,dumont1 ,jackson1 ,pat]son1 ,taylor1 c41 & !y are m or less satisfactory4 ,! in/rum5ts ( ,,mm4 ,v>ey1 ,tr\v1 ,lipp5s1 & de ,c\rtois are ! mo/ int]e/+1 & we w describe !m4 ,m4 ,v>ey's microphone consi/s ( a s\nd+ box ( deal1 m\nt$ 9 a v]tical position on a /&1 & two microphones are arrang$ on ei!r side ( x1 ) v]tical c>bons unit$ = t5sion4 ,a small ,gaiffe cell ( *loride ( silv]1 )\t liquid1 is appli$ to ! /&>d ( ! in/rum5t1 & is en\gh to make x "w p]fectly4 ,?is sy/em is extremely s5sitive4 ,m4 ,tr\v's microphones1 repres5t$ 9 figs4 #df1 #dg1 #dh1 are extremely simple1 s t he is able to sell !m at a v mod]ate price4 ,!y g5]ally consi/ ( a small v]tical cyl9drical box1 z we see 9 ! figure1 ) disks ( c>bon at its two ends1 :i* are unit$ by a c>bon rod1 or by a metallic tube tipp$ ) c>bon4 ,?is rod or tube turns freely 9 two cavities made 9 ! c>bons1 & ! box1 :ile act+ z a s\nd+ box1 becomes at ! same "t a prison = ! insects ^: movem5ts & noises are ! objects ( /udy4 ,illu/ration3 ,,fig4 #df4 ,^! boxes may be susp5d$ on a cross-b> 7fig4 #dg7 by ! two communicat+ wires1 s z to be completely insulat$4 ,9 ?is case ! tick+ ( a wat* plac$ ^u ! bo>d1 friction1 & ext]nal %ocks are h>dly he>d1 b on ! o!r h& ! s\nd vibrations ( ! air alone are transmitt$1 & !y acquire great di/9ctness4 ,we h (t5 repeat$ ^! exp]im5ts1 & h always f\nd t ! tones ( ! voice 7 p]fectly pres]v$4 ,! model repres5t$ fig4 #dh is /ill m simple1 & appe>s to be ! late/ developm5t ( ?is k9d ( in/rum5t4 ,x consi/s ( a /& & a disk unit$ by a c5tral rod4 ,! upp] disk moves r\nd ! c5tral rod1 & p]mits ! v]tical c>bon to assume any incl9ation :i* is desir$4 ,x is evid5t t ! in/rum5t w become less s5sitive :5 ! c>bon is m oblique4 ,illu/ration3 ,,fig4 #dg4 ,we mu/ also m5tion a v successful microphone devis$ by ,m4 ,lipp5s4 ,x is a slightly made box1 l t ( ,m4 ,v>ey1 & on its opposite faces !re are appli$1 on two frames left empty = ! purpose1 two ?9 plates ( h>d5$ ca\t*\c1 9 ! c5tre ( :i* inside ! box1 two c>bons are fa/5$1 & on _! out] surface a half-sph]e is holl[$4 ,illu/ration3 ,,fig4 #dh4 ,! int]val betwe5 ! two c>bons h>dly am\nts to two millimtres1 & a c>bon ball is ins]t$ into ! two cavities :i* =m its sph]ical case4 ,?is ball is support$ by a spiral spr+ :i* c be ext5d$ m or less by means ( a wire w\nd on a w9dlass :i* is fix$ above ! in/rum5t1 l ! spr+ ( an electric telegraph in/rum5t4 ,by means ( ?is spr+1 ! pressure ( ! c>bon ball aga9/ ! sides ( ! cavity :i* conta9s x c be regulat$ at pleasure1 & ! s5sitiv5ess ( ! in/rum5t & its capacity = transmitt+ spee* c be adju/$4 ,"u ^! conditions1 ! vibrations ( ! ca\t*\c plates directly affect ! microphone1 & ! curr5ts ( air h no influ5ce on x1 s t ! effects are m di/9ct4 ,x is s s5sitive t x is be/ = ! speak] to place himself at ! di/ance ( at lea/ #ej c5timtres f ! in/rum5t4 ,m4 ,lipp5s' in/rum5t is a pretty "o1 m\nt$ on a wood5 /&1 :i* is neatly turn$4 ,9 ord] to put an end to ! sputt]+ usual 9 microphones1 x occurr$ to ,m4 de ,c\rtois to prev5t any cessation ( contact betwe5 ! c>bons by keep+ !m close toge!r1 & to effect ! v>iations ( resi/ance necess>y = articulate s\nds by mak+ !m slide ov] ea* o!r1 s z to ins]t a %ort] or long] portion ( ! c>bon 9 ! circuit4 ,= ?is purpose a vibrat+ disk is plac$ 9 a v]tical position 9 a rigid frame1 & a small conduct+ rod1 t]m9at$ by a po9t$ c>bon1 is appli$ to x1 ) ?is c>bon po9t re/+ on ano!r flat piece ( c>bon plac$ bel[ x4 ,influ5c$ by ! vibrations ( ! disk1 ! c>bon po9t moves to & fro1 effect+ m or less ext5sive contacts ) ! l[] c>bon1 & ?us produc+ v>iations ( resi/ance :i* almo/ correspond to ! range ( vibrations on ! disk4 ,exp]im5ts made ) ! ,microphone4--,i mu/ n[ m5tion ! int]e/+ exp]im5ts :i* l$ ,mr4 ,hughes to ! inv5tion ( ! rem>kable in/rum5t ( :i* we h spok51 z well z ^? und]tak5 by o!r sci5tific m51 ei!r f a sci5tific or a practical po9t ( view4 ,believ+ t light & heat c modify ! conductivity ( bodies1 ,mr4 ,hughes w5t on to consid] :e!r s\nd vibrations1 transmitt$ to a conductor trav]s$ by a curr5t1 w\ld n also modify ?is conductivity by provok+ ! contraction & expansion ( ! conduct+ molecules1 :i* w\ld be equival5t to ! %ort5+ or l5g!n+ ( ! conductor ?us affect$4 ,if su* a prop]ty exi/$1 x w\ld make x possible to transmit s\nds to a di/ance1 s9ce v>iations 9 ! conductivity w\ld result f v>iations correspond+ to ! int5sity ( ! curr5t act+ on ! telephone4 ,! exp]im5t :i* he made on a /ret*$ metal wire did n1 h[ev]1 fulfil 8 expectation1 & x 0 only :5 ! wire vibrat$ s /rongly z to break1 t he he>d a s\nd at ! mom5t ( its fracture4 ,:5 he aga9 jo9$ ! two ends ( ! wire1 ano!r s\nd 0 produc$1 & he soon p]ceiv$ t imp]fect contact betwe5 ! two brok5 ends ( wire w\ld enable him to obta9 a s\nd4 ,mr4 ,hughes 0 !n conv9c$ t ! effects he wi%$ to produce c\ld only be obta9$ ) a divid$ conductor1 & by means ( imp]fect contacts4 ,he !n s\ght to discov] ! degree ( pressure :i* x 0 mo/ exp$i5t to ex]t betwe5 ! two adjac5t ends ( ! wire1 & = ?is purpose he effect$ ! pressure by means ( weights4 ,he asc]ta9$ t :5 ! pressure did n exce$ ! weight ( an ounce on ! squ>e in* at ! po9t ( connection1 ! s\nds 7 reproduc$ ) di/9ctness1 b some:at imp]fectly4 ,he next modifi$ ! conditions ( ! exp]im5t1 & satisfi$ himself t x 0 unnecess>y to jo9 ! wires end to end 9 ord] to obta9 ?is result4 ,!y might be plac$ side by side on a bo>d1 or ev5 sep>at$ 7) a conductor plac$ crosswise betwe5 !m71 provid$ t ! conductors 7 ( iron1 & t !y 7 kept 9 metallic connection by a slight & con/ant pressure4 ,! exp]im5t 0 made ) ?ree ,p>is po9ts1 & arrang$ z x appe>s 9 fig4 #di1 & x has s9ce be5 repeat$ "u v fav\rable conditions by ,mr4 ,will\ghby ,smi? ) ?ree ( ! s-call$ rat-tail files1 :i* made x possible to transmit ev5 ! fa9t s\nd ( ! act ( respiration4#ae ,illu/ration3 ,,fig4 #di4 ,he aft]w>ds tri$ diff]5t comb9ations ( ! same nature1 :i* (f]$ sev]al solutions ( cont9uity1 & a /eel *a9 produc$ fairly good results1 b slight inflections1 l ^? caus$ by ! timbre ( ! voice1 7 n reproduc$1 & he tri$ o!r arrangem5ts4 ,he fir/ s\ght to apply metallic p[d]s to ! po9ts ( contact2 p[d]$ z9c & t91 kn[n 9 comm]ce "u ! "n ( :ite bronze1 greatly increas$ ! effects obta9$2 b !y 7 un/able1 on acc\nt ( ! oxidation ( ! contacts2 & x 0 9 seek+ to solve ?is difficulty1 z well z to discov] ! mo/ simple means ( obta9+ a slight & con/ant pressure on ! contacts1 t ,mr4 ,hughes 0 l$ to ! arrangem5t1 previ\sly describ$1 ( c>bons impregnat$ ) m]cury1 & he ?us obta9$ ! maximum effect4#af ,mr4 ,hughes consid]s t ! successful effects ( ! microphone dep5d on ! numb] & p]fection ( ! contacts1 & ?is is d\btless ! reason :y "s arrangem5ts ( ! c>bon p5cil 9 ! in/rum5t describ$ above 7 m fav\rable ?an o!rs4 ,9 ord] to reconcile ^! exp]im5ts ) 8 preconceiv$ ideas1 ,mr4 ,hughes ?\ght t1 s9ce ! diff]5ces ( resi/ance proce$+ f ! vibrations ( ! conductor 7 only produc$ :5 x 0 brok51 ! molecul> movem5ts 7 arre/$ by ! lat]al resi/ances :i* 7 equal & opposite1 b t if "o ( ^! resi/ances 7 de/roy$1 ! molecul> movem5t c\ld be freely develop$4 ,he consid]s t an imp]fect contact is equival5t to ! suppression ( "o ( ^! resi/ances1 & z soon z ?is movem5t c take place1 ! molecul> expansions & contractions :i* result f ! vibrations mu/ correspond to ! increase or dim9ution ( resi/ance 9 ! circuit4 ,we ne$ n pursue ,mr4 ,hughes's !ory fur!r1 s9ce x w\ld take too long to develope x1 & we mu/ cont9ue our exam9ation ( ! diff]5t prop]ties ( ! microphone4#ag ,c>bon1 z we h said1 is n ! only sub/ance :i* c be employ$ to =m ! s5sitive organ ( ?is sy/em ( transmission4 ,mr4 ,hughes has tri$ o!r sub/ances1 includ+ ^? :i* are good conductors1 su* z metals4 ,iron af=d$ r good results1 & ! effect produc$ by surfaces ( plat9um :5 x 0 greatly subdivid$ 0 equal1 if n sup]ior1 to t furni%$ by ! m]curis$ c>bon4 ,yet s9ce ! difficulty ( mak+ in/rum5ts ) ?is metal is great]1 he pref]s ! c>bon1 :i* resembles x 9 be+ incapable ( oxidation4 ,we h already said t ! microphone may be us$ z a !rmoscope1 9 :i* case x mu/ h ! special arrangem5t repres5t$ 9 fig4 #dc4 ,"u ^! conditions1 heat1 react+ on ! conductivity ( ^! contacts1 may cause su* v>iations 9 ! resi/ance ( ! circuit t ! curr5t ( ?ree ,daniell cells w be annull$ by approa*+ ! h& to ! tube4 ,9 ord] to e/imate ! relative int5sity ( ! diff]5t s\rces ( heat1 x w be en\gh to introduce into ! circuit ( ! two electrodes ,a & ,b1 fig4 #dc1 a batt]y ,p1 ( "o or two ,daniell cells1 & a mod]ately s5sitive galvanomet] ,g4 ,= ?is purpose "o ( #abj turns w suffice4 ,:5 ! deviation decreases1 x %[s t ! s\rce ( heat is sup]ior to ! surr\nd+ atmosph]e2 & conv]sely1 t x is inf]ior :5 ! deviation increases4 ,mr4 ,hughes says t ! effects result+ f ! int]v5tion ( sun%9e & %ad[ are %[n on ! in/rum5t by consid]able v>iations 9 ! deviations ( ! galvanomet]4 ,inde$ x is s s5sitive to ! slighte/ v>iations ( temp]ature t x is impossible to ma9ta9 x 9 repose4 ,i h repeat$ ,mr4 ,hughes's exp]im5ts ) a s+le ,leclan* cell1 & = ?is purpose ,i employ$ a quill1 fill$ ) five fragm5ts ( c>bon1 tak5 f ! cyl9drical c>bons ( small diamet] :i* are made by ,m4 ,c>r = ! electric light4 ,i h obta9$ ! results :i* are m5tion$ by ,mr4 ,hughes1 b ,i ought to say t ! exp]im5t is a delicate "o4 ,:5 ! pressure ( ! fragm5ts ( c>bon aga9/ ea* o!r is too great1 ! curr5t trav]ses !m ) too mu* =ce to all[ ! calorific effects to v>y ! deviation ( ! galvanomet]1 & :5 ! pressure is too slight1 ! curr5t w n pass ?r\gh !m4 ,a m$ium degree ( pressure mu/ !re=e be effect$ to ensure ! success ( ! exp]im5t1 & :5 x is obta9$1 x is obs]v$ t on ! approa* ( ! h& to ! tube1 a deviation ( #ij w1 aft] a few seconds1 dim9i%1 s t x seems to correspond ) ! approa* or )drawal ( ! h&4 ,b brea?+ produces ! mo/ m>k$ effects1 & ,i am dispos$ to believe t ! great] or less deviations produc$ by ! emission ( articulate s\nds :5 ! diff]5t lett]s ( ! alphabet are pron\nc$ sep>ately1 are due to m or less direct emissions ( heat$ gas f ! *e/4 ,x is c]ta9 t ! lett]s :i* require ! mo/ /rongly m>k$ s\nds1 su* z ,a1 ,f1 ,h1 ,i1 ,k1 ,l1 ,m1 ,n1 ,o1 ,p1 ,r1 ,s1 ,w1 ,y1 ,z1 produce ! greate/ deviations ( ! galvanometric ne$le4 ,9 my pap] on ! conductivity ( su* bodies z are mod]ately good conductors1 ,i _h already po9t$ out ?is effect ( heat ^u divid$ sub/ances1 & ,i also %[$ t aft] a retrograde movem5t1 :i* is always produc$ at once1 a movem5t takes place 9 an inv]se direction to ! index ( ! galvanomet] :5 heat has be5 appli$ = "s in/ants1 & ?is deviation is mu* great] ?an ! "o :i* is fir/ indicat$4 ,9 a pap] publi%$ 9 ! #8,am]ican ,sci5tific ,j\rnal1' ,june #bh1 #ahgh1 ,mr4 ,edison gives "s int]e/+ details on ! application ( 8 sy/em ( a telephonic s5d] to measur+ pressures1 expansions1 & o!r =ces capable ( v>y+ ! resi/ance ( ! c>bon disk by means ( great] or less compression4 ,s9ce 8 exp]im5ts on ?is subject date f ,decemb] #ahgg1 he aga9 claims priority 9 ! inv5tion ( us+ ! microphone z a !rmoscope2 b we mu/ obs]ve t accord+ to ,mr4 ,hughes's arrangem5t ( 8 in/rum5t1 ! effect produc$ by heat is precisely ! rev]se ( ! effect describ$ by ,mr4 ,edison4 ,9 fact1 9 ! arrangem5t adopt$ by ! latt]1 heat acts by increas+ ! conductivity acquir$ by ! c>bon "u ! increas$ pressure produc$ by ! expansion ( a body s5sitive to heat3 9 ,mr4 ,hughes's sy/em1 ! effect produc$ by heat is precisely ! contr>y1 s9ce x !n acts only on ! contacts1 & n by means ( pressure4 ,!re=e ! resi/ance ( ! microphone-!rmoscope is increas$ "u ! influ5ce ( heat1 in/ead ( be+ dim9i%$4 ,?is contr>y effect is due to ! division ( "s sub/ance :i* is only a mod]ate conductor1 & ,i h %[n t "u su* conditions ^! bodies1 :5 only slightly heat$1 always dim9i% ! int5sity ( ! curr5t :i* !y transmit4 ,i believe t ,mr4 ,edison's arrangem5t is ! be/ = ! !rmoscopic in/rum5t1 & makes x possible to measure mu* less int5se s\rces ( heat4 ,inde$ he ass]ts t by its aid ! heat ( ! lum9\s rays ( ! />s1 moon1 & sun may be measur$1 & also ! v>iations ( moi/ure 9 ! air1 & b>ometric pressure4 ,?is in/rum5t1 :i* we give fig4 #ej1 ) its sev]al details1 & ) ! rheo/atic arrangem5t employ$ = measur+1 consi/s ( a metallic piece ,a fix$ on a small bo>d ,c1 & on "o ( its sides !re is ! sy/em ( plat9um disks & c>bons %[n 9 fig4 #bh4 ,a rigid piece ,g1 furni%$ ) a socket1 s]ves z ! ext]nal support ( ! sy/em1 & into ?is socket is introduc$ ! tap]+ end ( "s sub/ance :i* is readily affect$ by heat1 moi/ure1 or b>ometric pressure4 ,! o!r extremity is support$ by ano!r socket ,i1 fitt$ to a screw-nut ,h1 :i* may be m or less tight5$ by a regulat+ screw4 ,if ?is sy/em is introduc$ into a galvanometric circuit a1 b1 c1 i1 g1 provid$ ) all ! in/rum5ts ( ! electric scale ( measure1 ! v>iations 9 l5g? ( ! sub/ance ins]t$ are translat$ by great] or less deviations ( ! galvanometric ne$le1 :i* foll[ f ! diff]5ces ( pressure result+ f ! l5g!n+ or %ort5+ ( ! surface capable ( expansion :i* is ins]t$ 9 ! circuit4 ,illu/ration3 ,,fig4 #ej4 ,! exp]im5ts on ! microphone made 9 ,london at ! meet+ ( ! ,society ( ,telegraphic ,eng9e]s on ,may #be1 #ahgh1 7 wond]fully successful1 & !y 7 ! subject ( an int]e/+ article 9 ! #8,eng9e]' ( ,may #ca1 :i* ass]ts t ! :ole assembly he>d ! microphone speak1 & t its voice 0 v l t ( ! phonograph4 ,:5 ! meet+ 0 in=m$ t ^! words _h be5 utt]$ at "s di/ance f ! microphone1 ! ,duke ( ,argyll1 :o 0 pres5t1 :ile admir+ ! important discov]y1 c\ld n help exclaim+ t ?is inv5tion might h t]rible consequ5ces1 s9ce1 = in/ance1 if "o ( ,pr(essor ,hughes's in/rum5ts 7 plac$ 9 ! room 9 ,d[n+ ,/reet1 9 :i* ,h] ,maje/y's m9i/]s hold _! cab9et c\ncil1 _! secrets might be he>d 9 ! room 9 :i* ! pres5t meet+ took place4 ,he add$ t if "o ( ^! little in/rum5ts 7 9 ! pocket ( ,c\nt ,s*\val(f1 or ( ,"l ,salisbury1 we %\ld at once be 9 possession ( ! secrets = :i* all ,europe 0 anxi\sly wait+4 ,if ^! in/rum5ts 7 able to repeat all ! conv]sations held 9 ! room 9 :i* !y /ood1 !y might be really dang]\s1 & ! ,duke ?\ght t ,pr(essor ,hughes1 :o _h inv5t$ su* a spl5did yet p]il\s in/rum5t1 ought next to seek an antidote = 8 discov]y4 ,dr4 ,lyon ,playfair1 aga91 ?\ght t ! microphone ought to be appli$ to ! arophone1 s t by plac+ ^! in/rum5ts 9 ! two ,h\ses ( ,p>liam5t1 ! spee*es ( great orators might be he>d by ! :ole population )9 five or six squ>e miles4 ,! exp]im5ts lately made ) ! microphone at ,halifax %[ t ! ,duke ( ,argyll's pr$ictions 7 fully ju/ifi$4 ,x seems t a microphone 0 plac$ on a pulpit-desk 9 a *ur* 9 ,halifax1 & connect$ by a wire ab\t two miles long ) a telephone plac$ close to ! b$ ( a sick p]son1 :o 0 able to he> ! pray]s1 ! *ant+1 & ! s]mon4 ,?is fact 0 communicat$ to me by ,mr4 ,hughes1 :o he>d x f a tru/wor?y s\rce1 & x is said t sev5 pati5ts h subscrib$ = ! exp5se ( an arrangem5t by :i* !y may he> ! *ur* s]vices at ,halifax )\t fatigue4 ,! microphone has also lately be5 appli$ to ! transmission ( a :ole op]a1 z we le>n f ! foll[+ acc\nt 9 ! #8,j\rnal ,tlgraphique1' ,b]ne1 ,july #be1 #ahgh3-- #8,a curi\s micro-telephonic exp]im5t took place on ,june #ai at ,bell9zona1 ,switz]l&4 ,a travell+ company ( ,italian s+]s 0 to p]=m ,donizetti's op]a1 8,don ,pasquale10 at ! !atre ( t t[n4 ,m4 ,patoc*i1 a telegraphic eng9e]1 took ! opportunity ( mak+ exp]im5ts on ! comb9$ effects ( ,hughes's c>bon microphone z ! s5d+ in/rum5t1 & ,bell's telephone z ! receiv]4 ,) ?is object he plac$ a ,hughes microphone 9 a box on ! fir/ ti]1 close to ! /age1 & connect$ x by two wires1 f "o to half a millimtre 9 ?ickness1 to f\r ,bell receiv]s1 :i* 7 plac$ 9 a billi>d-room above ! ve/ibule ( ! !atre1 & inaccessible to s\nds )9 ! !atre itself4 ,a small batt]y ( two cells1 ( ! ord9>y type us$ 9 ! ,swiss telegraphic s]vice1 0 ins]t$ 9 ! circuit1 close to ! ,hughes microphone4 #8,! result 0 completely successful4 ,! telephones exactly reproduc$1 ) wond]ful purity & di/9ctness1 ! in/rum5tal music ( ! or*e/ra1 z well z ! voices ( ! s+]s4 ,sev]al p decl>$ t !y did n lose a note ( ei!r1 t ! words 7 he>d p]fectly2 ! airs 7 reproduc$ 9 a natural key1 ) e v>iation1 :e!r piano or =te1 & sev]al amateurs assur$ ,m4 ,patoc*i t by li/5+ to ! telephone !y 7 able to e/imate ! musical beauty1 ! quality ( ! s+]s' voices1 & ! g5]al effect ( ! piece1 z completely z if !y _h be5 among ! audi5ce )9 ! !atre4 #8,! result 0 ! same :5 resi/ances equival5t to #aj kilomtres 7 introduc$ into ! circuit1 )\t increas+ ! numb] ( cells 9 ! batt]y4 ,we believe t ?is is ! fir/ exp]im5t ( ! k9d :i* has be5 made 9 ,europe1 at lea/ 9 a !atre1 & ) a complete op]a2 & ^? :o are acqua9t$ ) ! delicacy & grace ( ! airs 9 8,don ,pasquale0 w be able to appreciate ! s5sitiv5ess ( ! comb9$ in/rum5ts inv5t$ by ,hughes & ,bell1 :i* d n suff] ! mo/ delicate t\*es ( ?is music to be lo/4' ,al?\gh exp]im5ts ) ! microphone are ( su* rec5t date1 !y h be5 v v>i\s1 & among o!r curi\s exp]im5ts we le>n f ! ,engli% newspap]s t ! attempt has be5 made to con/ruct an in/rum5t on ! same pr9ciple z ! telephone1 :i* %all be s5sitive to ! v>iations ( light4 ,x is kn[n t "s sub/ances1 & p>ticul>ly sel5ium1 are electrically affect$ by light1 t is1 t _! conductivity v>ies consid]ably ) ! great] or less am\nt ( light :i* is %$ ^u !m4 ,if1 !re=e1 a circuit 9 :i* a sub/ance ( ?is nature is ins]t$1 is abruptly subject$ to a some:at int5se light1 ! increase ( resi/ance :i* results f x ought to produce a p[]ful s\nd 9 a telephone ins]t$ 9 ! circuit4 ,?is fact has be5 v]ifi$ by exp]im5t1 & ,mr4 ,will\ghby ,smi? inf]s f x1 z we h already sugge/$1 t ! effects produc$ 9 ! microphone are due to v>iations ( resi/ance 9 ! circuit1 :i* are produc$ by m or less close contacts betwe5 imp]fect conductors4 ,9 ord] to obta9 ?is effect "u ! mo/ fav\rable conditions1 ,mr4 ,siem5s employs two electrodes1 consi/+ ( network ( v f9e plat9um wire1 fitt+ into ea* o!r l two =ks1 ( :i* ! prongs are int]lac$4 ,^! electrodes are ins]t$ betwe5 two glass plates1 & a drop ( sel5ium1 dropp$ 9 ! c5tre ( ! two pieces ( network1 connects !m on a circul> surface l>ge en\gh to e/abli% suffici5t conductivity 9 ! circuit4 ,x is on ?is flatt5$ drop t ! ray ( light mu/ be project$4 ,,applications ,,( ,,! ,,microphone4 ,! applications ( ! microphone increase 9 numb] e day1 & 9 addition to ^? ( :i* we h j spok51 !re are o!rs ( really sci5tific & ev5 ( practical int]e/4 ,among ! numb] is ! use :i* c be made ( x z a sy/em ( relays = telegraphy1 9 sci5ce = ! /udy ( vibrations imp]ceptible to our s5ses1 9 m$ic9e & surg]y1 & ev5 9 manufactures4 ,its application to ,sci5tific ,rese>*4--,we h se5 t sev]al physici/s1 includ+ ,messrs4 ,spottiswoode1 ,w>wick1 ,rossetti1 ,cane/relli1 ,wies5dang]1 ,lloyd1 ,mill>1 ,bu*91 & ,bly?1 h be5 able to he> :at is said 9 a telephone :i* has no iron diaphragm1 b x 0 s difficult to e/abli% ! fact t x has be5 (t5 disput$4 ,m c]ta9 evid5ce 0 desirable1 & ! microphone is an opportune ag5t = af=d+ x4 ,! #8,telegraphic ,j\rnal' ( ,septemb] #a1 #ahgh1 obs]ves t ,m4 du ,moncel1 9 ord] to claim ! victory 9 8 controv]sy ) ,colonel ,navez1 _h /ill to %[ t ! s\nds :i* appe>$ to be in>ticulate 9 telephones )\t a diaphragm might become intelligible if !y 7 int5sifi$4 ,?is has be5 done = him by ! use ( ,mr4 ,hughes's microphone1 & ! foll[+ exp]im5ts 7 made = ! purpose4 #a4 ,if a magnetis+ coil1 surr\nd+ a b> ( s(t iron1 is ins]t$ 9 ! circuit ( a microphone1 ) a batt]y ( ?ree cells1 ! tick+ ( a wat* & o!r s\nds ( ! same k9d may be he>d on approa*+ ! e> to ! electro-magnet :i* has be5 ?us con/itut$4 ,x is true t ^! s\nds are v fa9t :5 !y are n amplifi$1 b if ! electro-magnet is fa/5$ to a bo>d1 & a second microphone is fix$ to ! same bo>d1 ! s\nds produc$ by ! electro-magnet are magnifi$1 & become di/9ctly audible 9 ! telephone :i* is plac$ 9 connection ) ?is second microphone4 #b4 ,^! s\nds may be fur!r amplifi$ by re/+ "o ( ! extremities ( ! core ( ! electro-magnet on "o ( ! poles ( a p]man5t magnet1 :i* is fix$ ^u ! bo>d4 ,articulate spee* may !n be he>d 9 ! telephone :i* is plac$ 9 connection ) ! microphone re/+ on ! bo>d1 & ! po9t at issue betwe5 ,,mm4 ,navez & ,du ,moncel is completely decid$ 9 ?is way3 = ! auxili>y microphone c only propagate & amplify ! vibration ( articulate s\nds1 :i* are communicat$ by ! b> magnet ( ! coil to ! bo>d on :i* ! two in/rum5ts are plac$4 ,9 ?is way x w\ld be possible to r5d] articulate s\nds p]ceptible to ,m4 ,navez1 :5 transmitt$ by ! b> magnet ( a telephone )\t a diaphragm4 #c4 ,:5 a second b> magnet re/s on ! free pole ( ! electro-magnet1 s z to pres5t to x a pole ( ! same nature z ! "o ) :i* x is already 9 communication--9 a ^w1 if a b> is plac$ betwe5 ! two poles ( a horse%oe electro-magnet1 ! effects are /ill m m>k$1 & h5ce x may be assum$ t ! b> reacts z an armature1 by conc5trat+ ! l9es ( magnetic =ce 9 ! vic9ity ( ! helix4 #d4 ,:5 ! two poles ( a horse%oe magnet are ins]t$ toge!r inside a coil1 _! effects are equally en]getic1 al?\gh by ?is arrangem5t "o ( ! poles might be expect$ to neutralise ! effect ( ! o!r3 b ! mo/ important effects h be5 obta9$ by plac+ an armature ( s(t iron across ! poles ( ! magnet :i* has be5 already ins]t$ 9 ! coil4 ,"u ^! conditions articulate s\nds are di/9ctly he>d4 ,^! exp]im5ts 7 confirm$ by ,mr4 ,f4 ,v>ley1 9 a lett] publi%$ 9 ! #8,telegraphic ,j\rnal' ( ,septemb] #ae1 #ahgh1 & among ! fre% exp]im5ts m5tion$ by him1 we w quote ^? :i* he made ) an iron tube ins]t$ 9 a helix1 9 :i* ! two opposite poles ( two b> magnets are introduc$4 ,^! poles are only sep>at$ f ea* o!r by ! int]val ( an in*1 s t ! c5tre ( ! iron tube may be /rongly magnetis$4 ,mr4 ,v>ley says t ?is la/ arrangem5t reproduces ! articulate s\nds :i* issue f a s5d+ microphone1 & ?is exp]im5t is m decisive ?an t ( ,pr(essor ,hughes1 9 :i* case x might be suppos$ t ! b> magnet1 re/+ on ! pol> end ( an electro-magnetic b>1 0 only a modification ( ! disk 9 ! ,bell telephone1 set 9 vibration by ! alt]nate curr5ts pass+ ?r\gh ! helix1 & t ^! vibrations 7 communicat$ to ! bo>d1 & became s5sible :5 enl>g$ by ! microphone4 ,b su* an objection _c be alleg$ 9 ! case ( ! arrangem5t describ$ above1 = s9ce ! s\nd is produc$ betwe5 ! curr5t pass+ into ! helix & ! magnetic curr5t ( ! b>1 x c only be ! result ( a vibration produc$ by a di/urbance ( ! reciprocal relations subsi/+ betwe5 ^! two elem5ts4 ,mr4 ,v>ley adds t ^! exp]im5ts confirm ,m4 du ,moncel's rese>*es1 :i* h ?r[n consid]able light ^u ! causes :i* are at "w 9 ! action ( ! speak+ telephone1 & ) :i* we h hi!rto be5 imp]fectly acqua9t$4 ,its application to ,telephonic ,relays4--,9 ,febru>y #ahgh1 ,i fir/ began to consid] ! mode ( =m+ telephonic relays1 b ,i 0 *eck$ by ! discov]y t !re 0 no vibration 9 ! receiv+ telephone1 & ,i made ! foll[+ communication on ! subject to ! ,acadmie des ,sci5ces on ,febru>y #be3--#8;,if ! vibrations ( ! disk 9 ! receiv+ telephone 7 ! same z ^? ( ! s5d+ telephone1 x is easy to see t if a telephone ) a local batt]y1 act+ bo? z s5d] & receiv]1 7 sub/itut$ = ! receiv+ telephone1 x might1 by ! int]v5tion ( ! induction coil1 act z a relay1 & might !re=e n only amplify ! s\nd1 b also transmit x to any di/ance4 ,x is1 h[ev]1 d\btful :e!r ! vibrations ( ! two correspond+ disks are ( ! same nature1 & if ! s\nd be due to molecul> contractions & expansions1 ! solution ( ! problem becomes mu* m difficult4 ,"h is !re=e a field = exp]im5ts4' ,^! exp]im5ts h be5 successfully made by ,mr4 ,hughes1 :o acqua9t$ me ) !m e>ly 9 ,june #ahgh1 & !y l$ to ! discov]y ( a mo/ int]e/+ sy/em ( microphonic relays4 ,on a wood5 bo>d ( mod]ate size1 su* z a draw+ bo>d1 he plac$ a microphone ) a c>bon br\ght to a f9e po9t at ea* end1 & fix$ 9 a v]tical position4 ,"o or m telephones 7 plac$ 9 ! circuit1 ) _! membranes fac+ ! bo>d1 & a cont9u\s s\nd 0 he>d1 sometimes resembl+ a musical note1 sometimes ! s++ ( boil+ wat] 9 an ov52 & ! s\nd1 :i* c\ld be he>d at a di/ance1 w5t on indef9itely1 z long z ! electric =ce 0 ex]t$4 ,mr4 ,hughes expla9s ?is ph5om5on 9 ! foll[+ way4 ,! slighte/ %ock :i* affects ! microphone has ! effect ( s5d+ curr5ts1 m or less brok51 ?r\gh ! telephones1 :i* trans=m !m into s\nd vibrations1 & s9ce ^! are me*anically transmitt$ by ! bo>d to ! microphone1 !y ma9ta9 & ev5 amplify its action1 & produce fre% vibrations on ! telephones4 ,?us a fre% action is ex]t$ on ! microphone1 & s on indef9itely4 ,aga91 if a second microphone1 9 connection ) ano!r telephonic circuit1 be plac$ ^u ! same bo>d1 we h an in/rum5t :i* acts z a telephonic relay1 t is1 x transmits to a di/ance ! s\nds communicat$ to ! bo>d1 & ^! s\nds may s]ve ei!r z a call1 or z ! elem5ts ( a message 9 ! ,morse code1 if a ,morse manipulator is plac$ 9 ! circuit ( ! fir/ microphone4 ,mr4 ,hughes adds t he has made sev]al v successful exp]im5ts ) ?is sy/em ( in/rum5ts1 al?\gh he only employ$ a ,daniell batt]y ( six cells )\t any induction coil4 ,by fa/5+ a pa/ebo>d tube1 #dj c5timtres 9 l5g?1 to ! receiv+ telephone1 he 0 able to he> 9 all p>ts ( a l>ge room ! cont9u\s s\nd ( ! relay1 ! tick+ ( a wat*1 & ! scrat*+ ( a p5 ^u pap]4 ,he did n try to transmit spee*1 s9ce x w\ld n h be5 reproduc$ ) suffici5t di/9ctness "u su* conditions4 ,s9ce ?is fir/ attempt1 ,mr4 ,hughes has arrang$ ano!r & /ill m curi\s sy/em ( microphonic relays1 = :i* two microphones ) v]tical c>bons are requir$4 ,he places two microphones ( ?is description on a bo>d1 & connects "o ( !m ) a ?ird microphone1 :i* acts z a s5d]1 :ile ! second is 9 communication ) a telephone & a second batt]y3 9 ?is way ! words utt]$ be=e ! s5d] are he>d 9 ! telephone1 )\t employ+ any electro-magnetic organ = ! telephonic relay4 ,9 ,augu/ #ahgh1 ,messrs4 ,h\/on & ,?omson likewise arrang$ a sy/em ( telephonic relays :i* only diff]s f t ( ,mr4 ,hughes 9 ! p>ticul> ( hav+ ! microphone fix$ on ! diaphragm ( ! telephone1 & n on ! bo>d beside x4 ,! sy/em consi/s ( ?ree v]tical microphones1 :i* c be comb9$ = t5sion or quantity1 accord+ to ! conditions = :i* !y are requir$4 ,! model ( ?is in/rum5t 0 repres5t$ 9 ! #8,telegraphic ,j\rnal' ( ,augu/ #ae1 #ahgh1 to :i* we mu/ ref] our read]s1 if !y wi% = fur!r in=mation on ! subject4 ,its application to ,m$ic9e & ,surg]y4--,! extreme s5sitiv5ess ( ! microphone sugge/$ its use = ! obs]vation ( s\nds produc$ )9 ! human body1 s t x might s]ve z a /e?oscope = li/5+ to ! action ( ! lungs & he>t4 ,dr4 ,ri*>dson & ,mr4 ,hughes are n[ busy 9 ! attempt to c>ry out ?is idea1 b s f> ! result is n v satisfactory1 al?\gh !y /ill hope to succe$4 ,mean:ile1 ,m4 ,ducretet has made a v s5sitive /e?oscopic microphone1 :i* we repres5t 9 fig4 #ea4 ,x consi/s ( a c>bon microphone ,c ,p1 ) a simple contact1 ( :i* ! l[] c>bon ,p is fitt$ to "o ( ,m4 ,m>ais' tamb\r9es ) a vibrat+ membrane ,t4 ,?is tamb\r9e is connect$ ) ano!r ,t1 by a ca\t*\c tube1 :i* is to be appli$ to ! diff]5t p>ts ( ! body :i* dem& auscultation1 & :i* is !re=e t]m$ ! tamb\r explorateur4 ,! s5sitiv5ess ( ! in/rum5t is regulat$ by means ( a c\nt]poise ,p ,o1 :i* is screw$ ^u ! arm ( a b5t lev]1 & to ?is ! second c>bon ,c is fix$4 ,! extreme s5sitiv5ess ( ,m4 ,m>ais' tamb\r9es 9 transmitt+ vibrations is well kn[n1 & s9ce _! s5sitiv5ess is fur!r increas$ by ! microphone1 ! in/rum5t becomes almo/ too impressionable1 s9ce x reveals all sorts ( s\nds1 :i* x is difficult to di/+ui% f ea* o!r4 ,su* an in/rum5t c only be ( use :5 entru/$ to exp]i5c$ h&s1 & a special education ( ! organ ( he>+ is ne$ful1 9 ord] to turn x to acc\nt4 ,illu/ration3 ,,fig4 #ea4 ,9 a "w lately publi%$ by ,m4 ,gib\x on ! application ( ! microphone to m$ic9e1 ?is /e?oscopic sy/em is r sev]ely criticis$1 & n )\t reason if1 z ,m4 ,gib\x ass]ts1 x is only s5sitive to ! movem5ts :i* take place on ! surface ( ! body1 & ^? :i* are int]nal are ei!r lo/ or altoge!r *ang$ 9 "*4 ,b )\t pron\nc+ on ! improvem5ts :i* may ultimately be made 9 ! in/rum5t1 ,m4 ,gib\x ?9ks t its mo/ important use 9 m$ical practice consi/s 9 its all[+ a c]ta9 numb] ( /ud5ts to obs]ve ) ! pr(essor ! diff]5t s\nds ( ! body1 to /udy !m ) him 9 _! diff]5t phases1 & ?us to pr(it m readily by 8 tea*+4 ,a microphonic circuit might bifurcate betwe5 sev]al telephones1 s t ea* p]son might he> = himself :at is he>d by o!rs4 ,! mo/ important application ( ! in/rum5t to surgical purposes has lately be5 made by ,sir ,h5ry ,?ompson1 aid$ by ,mr4 ,hughes1 = ! exam9ation ( ! bladd] 9 cases ( /one4 ,x enables him to asc]ta9 ! pres5ce & precise position ( calculi1 h[ev] small !y may be4 ,= ! purpose ( rese>*1 he uses a s\nd1 made ( a ,maille*ort rod1 a little b5t at ! end1 & plac$ 9 communication ) a s5sitive c>bon microphone4 ,:5 ! s\nd is mov$ ab\t 9 ! bladd]1 ! rod comes 9 contact ) /ony p>ticles1 ev5 if !y are no l>g] ?an a p9's head1 & friction ensues1 produc+ 9 ! telephone vibrations :i* c be easily di/+ui%$ f ^? caus$ by ! simple friction ( ! rod on ! s(t tissues ( ! sides ( ! bladd]4 ,! arrangem5t ( ! in/rum5t is %[n 9 fig4 #eb4 ,! microphone is plac$ 9 ! h&le :i* conta9s ! s\nd1 & is ! same z t giv5 9 fig4 #db1 b ( small] size1 & ! two conduct+ wires e :i* lead to ! telephone1 issue f ! h&le by ! end a opposite to t bb to :i* ! s\nd dd is screw$4 ,z ?is in/rum5t is n int5d$ to reproduce spee*1 retort c>bons in/ead ( wood c>bons may be us$4 ,illu/ration3 ,,fig4 #eb4 ,"s deaf p1 ^: s5se ( he>+ is n completely de/roy$1 h be5 able to he> by an exp$i5t bas$ ^u ! pr9ciple ( ! microphone4 ,= ?is purpose two telephones1 connect$ by a metallic cr[n1 :i* is plac$ on ! temples1 are appli$ to ! e>s ( ! deaf p]son1 & ! telephones are plac$ 9 communication ) a batt]y microphone1 :i* hangs to ! end ( a d\ble conduct+ wire4 ,! deaf man keeps ! microphone 9 8 pocket1 & pres5ts x z an ac\/ic tube to ! p]son :o wi%es to conv]se ) him4 ,mr4 ,hughes's speak]1 repres5t$ fig4 #db1 is ! "o us$4 ,v>i\s ,applications4--,! microphone may be us$ 9 _m o!r ways1 "s ( :i* are sugge/$ 9 ! #8,engli% ,me*anic' ( ,june #ba1 #ahgh4 ,! article /ates t by means ( ?is in/rum5t1 eng9e]s w be able to e/imate ! effects ( ! vibrations caus$ on old & new build+s by ! passage ( heavy loads2 a soldi] w be able to discov] ! enemy's approa* :5 he is sev]al miles (f1 & may ev5 asc]ta9 :e!r he has to d ) artill]y or cavalry2 ! approa* ( %ips to ! neighb\rhood ( torp$oes may be automatically h]ald$ on ! coa/ by ?is means1 s t an explosion may be produc$ at ! "r mom5t4 ,x has also be5 propos$ to use ! microphone to give notice ( an escape ( gas 9 coal-m9es4 ,! gas1 9 escap+ f betwe5 ! seams ( coal1 makes a :i/l+ noise1 :i* might1 ) ! aid ( ! microphone & telephone1 be he>d at ! top ( ! %aft4 ,aga91 x has be5 sugge/$ t ! microphone might be us$ z a seismograph to reveal ! subt]ranean noises :i* g5]ally prec$e e>?quakes & volcanic eruptions1 & :i* w\ld be mu* int5sifi$ by ?is in/rum5t4 ,x might ev5 be ( use to ,signor ,palmi]i = 8 obs]vations 9 ! ,vesuvius ,obs]vatory4 ,! microphone has also be5 us$ by ,mr4 ,*&l] ,rob]ts to r5d] ! diffusion ( gase\s molecules ?r\gh a por\s membrane s5sible to ! e>4 ,z might h be5 expect$1 ! acclamation ) :i* ,mr4 ,hughes's inv5tion 0 receiv$ l$ to ! ass]tion ( o!r claims to priority1 & 9 addition to t ( ,mr4 ,edison1 on :i* we h already giv5 our op9ion1 !re are sev]al o!rs1 %[+ t if "s microphonic effects 7 discov]$ at diff]5t times be=e ! date ( ,mr4 ,hughes's discov]y1 !y c\ld n h be5 consid]$ important1 s9ce !y 7 n ev5 ann\nc$4 ,among ! numb] 0 t ( ,mr4 ,w5twor? ,lascelles ,scott1 specifi$ 9 ! #8,electrician' ( ,may #be1 #ahgh1 & t ( ,m4 ,weyh]1 pres5t$ to ! ,socit de ,physique1 ,p>is1 9 ,june #ahgh4 ,ano!r1 made by ,m4 ,dut]tre1 is ( some:at great] importance1 = 8 exp]im5ts 7 report$ 9 ! ,r\5 pap]s 9 ,febru>y ( ! same ye>3 yet !re is no j gr\nd = su* claims1 s9ce ! e>lie/ date ( 8 exp]im5ts is subsequ5t to ! exp]im5ts fir/ made by ,mr4 ,hughes4 ,^! began e>ly 9 ,decemb] #ahgg1 & 9 ,janu>y #ahgh !y 7 exhibit$ to (ficials ( ! ,subm>9e ,telegraph ,company1 z ,mr4 ,preece decl>$ 9 a lett] address$ to ! sev]al sci5tific m54 ,,ext]nal ,,influ5ce ,,on ,,telephonic ,,transmissions4 ,! ob/acles :i* occur 9 telephonic transmissions proce$ f ?ree causes3 #a4 ,! int5sity ( s\nd is dim9i%$ by ! loss ( curr5t 9 transmission--a loss :i* is mu* great] 9 ! case ( induc$ curr5ts ?an 9 ^? receiv$ f a batt]y4 #b4 ,confusion is caus$ by ! influ5ce ( adjac5t curr5ts4 #c4 ,! induction f "o wire to ano!r4 ,?is la/ influ5ce is mu* great] ?an is usually suppos$4 ,if two p]fectly insulat$ wires are plac$ side by side1 "o 9 communication ) ! circuit ( an electric bell1 & ! o!r ) ! circuit ( a telephone1 ! latt] w repeat ! s\nds ( ! bell ) an int5sity (t5 great en\gh to act z a call )\t apply+ ! in/rum5t to ! e>4 ,,mm4 ,poll>d & ,g>ni]1 9 _! int]e/+ exp]im5ts ) ! induc$ curr5ts ( ! ,ruhmkorff coil1 h asc]ta9$ t 9 ?is way n m]ely s\nds may be obta9$ :i* correspond ) ! induc$ curr5ts result+ f ! action ( ! prim>y curr5t1 b also ^? :i* result f ! action ( ! second>y curr5t on o!r helices1 :i* are t]m$ curr5ts ( ! second ord]4 ,^! diff]5t reactions frequ5tly cause ! telephonic transmissions made on telegraphic l9es to be di/urb$ by irregul> s\nds1 aris+ f ! electric transmissions on adjo9+ l9es2 b x does n appe> t ^! influ5ces altoge!r neutralise ea* o!r1 s t conv]sation held 9 ! ord9>y way & a message s5t 9 ! ,morse code may be he>d simultane\sly4 ,at ! ,artill]y ,s*ool1 ,cl]mont1 a telephonic communication has be5 e/abli%$1 = ! sake ( exp]im5ts1 betwe5 ! s*ool & ! butts1 :i* are at a di/ance ( ab\t eight miles4 ,ano!r communication ( ! same k9d has be5 e/abli%$ betwe5 ! ,cl]mont ,obs]vatory & ! "o at ,puy-de-,dme1 :i* is ne>ly n9e miles f ! =m]4 ,^! two l9es are c>ri$ on ! same po/s = a c\rse ( six miles1 toge!r ) an ord9>y telegraphic wire1 & = a di/ance ( #ccj y>ds !re are sev5 o!r su* wires4 ,! two telephonic wires are sep>at$ f ea* o!r by a space ( #he c5timtres4 ,! foll[+ facts h be5 obs]v$ "u ^! conditions4 #a4 ,! s*ool telephone is p]fectly able to read (f f _! s\nd ! ,morse messages :i* pass ?r\gh ! two adjac5t telegraph wires1 & ! tick+ ( ! in/rum5t does n at all int]f]e ) ! vocal communication ( ! telephone1 nor r5d] x inaudible4 #b4 ,! two adjac5t telegraphic l9es1 al?\gh n 9 contact1 confuse _! messages toge!r1 & x has sometimes be5 possible to he> messages f ,puy-de-,dme at ! s*ool ?r\gh ! wire :i* runs to ! butts1 al?\gh ! di/ance betwe5 ! two l9es is n[h]e less ?an #he c5timtres4 ,^! inconv5i5ces h be5 9 "s degree rem$i$ by ins]t+ /rong resi/ances 9 ! circuit1 or by putt+ ! curr5t to e>? at "s di/ance f ! telephonic /ations4 ,m4 ,iz>n1 ,pr(essor ( ,physics at ! ,lyce1 ,cl]mont1 holds t telephonic electric curr5ts may readily be turn$ aside by ! e>?1 especially if 9 ! c\rse ( _! passage !y enc\nt] metallic conductors1 su* z gas or wat] pipes4 ,he writes z foll[s on ! subject1 9 a pap] address$ to ! ,acadmie des ,sci5ces1 on ,may #ac1 #ahgh3--#8;,i set up a telephone 9 ! ,cl]mont ,lyce ) a s+le wire1 m ?an #ej y>ds 9 l5g?1 :i* crosses ! c\rt-y>d ( ! ,lyce1 & goes f ! laboratory1 :]e x is susp5d$ to a gas-burn]1 to a room ne> ! port]'s lodge1 :]e x is susp5d$ to ano!r gas-burn]4 ,:5 ,i appli$ my e> to ! telephone1 ,i c\ld di/9ctly he> ! telegraphic signals1 ,morse or o!rwise1 :i* came ei!r f ! telegraph (fice at ,cl]mont1 or f ! telephone (fice :i* 0 at "w betwe5 ! ,s*ool ( ,artill]y & ! butts bel[ ,puy-de-,dme1 a di/ance ( eight miles4 ,i c\ld ov]he> words1 & especially ! milit>y ord]s issu$ at ! butts = ! purpose ( be+ he>d at ! s*ool4 ,yet my wire is p]fectly indep5d5t ( ^? us$ = signall+1 & is ev5 v remote f !m2 b z ! wires ( ! telegraph (fice & ( ! ,s*ool ( ,artill]y g to e>? at a little di/ance f ! gas-pipes1 x is probable t ?is ph5om5on is caus$ by a div]sion ( ! curr5t produc$ 9 my wire1 by means ( ! e>? & ! network ( metal pipes4' ,mr4 ,preece made ! same rem>k 9 8 notice ( #8"s physical po9ts connect$ ) ! telephone4' ,aga91 we read 9 ! #8,telegraphic ,j\rnal' ( ,june #ae1 #ahgh1 t 9 a telephonic conc]t transmitt$ f ,buffalo to ,new ,york1 ! s+]s at ,buffalo 7 he>d 9 an (fice plac$ outside ! telegraphic circuit 9 :i* ! transmission 0 effect$4 ,on enquiry1 x 0 asc]ta9$ t ! wire ?r\gh :i* ! telephonic transmission took place1 0 at "o po9t 9 its c\rse close to ! "o :i* directly transmitt$ ! musical s\nds1 b ! di/ance betwe5 ! two wires 0 n less ?an t5 feet4 ,:5 ! circuits are altoge!r metallic1 !re is mu* less risk ( confusion1 & ,m4 ,zetz*e decl>es t s\nds proce$+ f o!r wires are 9 ?is case little he>d1 & !n only mom5t>ily1 s t x is mu* m easy to he> ) ?is arrangem5t ?an ) ! "o 9 ord9>y use4 #8,x is n1' he says1 #8! resi/ances ( ! wire1 b r ! div]sions ( ! curr5t ne> ! po/s1 :i* int]f]e ) telephonic correspond5ce on long l9es above gr\nd4 ,?is 0 prov$ by ! foll[+ exp]im5ts3--,i connect$ ! telegraphic l9e f ,dresd5 to ,*emnitz ) a l9e f ,*emnitz to ,leipzig 7#ed miles71 :i* made a circuit ( #ajc miles1 go+ to e>? at its two extremities4 ,!re 0 no communication betwe5 ,dresd5 & ,leipzig1 b ,leipzig & ,dresd5 c\ld communicate ) ease1 9 spite ( ! great] ext5t ( l9e4 ,i broke ! connection ) e>?1 fir/ at ,leipzig1 !n simultane\sly at ,leipzig & ,dresd51 & ,i obs]v$ ! foll[+ effects4 ,:5 insulation took place at ,leipzig only1 ! telephone c\ld be he>d at ! /ations ( ,dresd51 ,riesa1 & ,wurz52 :5 ! l9e 0 insulat$ at bo? ends1 ! communication 0 good betwe5 ! two latt] /ations1 b x 0 obs]v$ t at ! int]m$iate /ation ! words spok5 at ,wurz5 7 m di/9ctly he>d ?an ! words spok5 at ,riesa 7 he>d at ,wurz54 ,s9ce ! di/ance f ,wurz5 to ,leipzig is little m ?an half t f ,riesa to ,dresd51 !re are consequ5tly ne>ly twice z _m po/s on ! latt] l9e1 :i* c>ry ! curr5ts to e>?1 & h5ce ,i conclude t ^! div]sions ( curr5t expla9 ! possibility ( conv]s+ on an insulat$ l9e1 & also :y s\nds are m di/9ctly he>d at ! ,riesa /ation 9 consequ5ce ( ! great] int5sity ( curr5t /ill rema9+ on ! l9e4' ,"s vibrations also result f ! action ( curr5ts ( air on telegraphic wires1 :i* produce ! humm+ s\nd s well kn[n on "s l9es1 & ^! may also react on ! telephone2 b !y are 9 ?is case g5]ally me*anically transmitt$1 & !y may be di/+ui%$ f ! o!rs1 if ! s\nds :i* ensue are he>d aft] ! telephone is exclud$ f ! circuit by a break ) a %ort circuit & aft] ! communication to e>? e/abli%$ beh9d ! telephone has be5 brok54 ,! induc$ reactions caus$ by ! l9e wires on ea* o!r are n ! only ones :i* may be obs]v$ on a telephonic circuit3 e manife/ation ( electricity ne> a telephone may produce s\nds ( great] or less =ce4 ,( ?is we h already giv5 a pro( 9 ,m4 d',arsonval's exp]im5ts1 & o!rs by ,m4 ,demoget demon/rate ! fact /ill m cle>ly4 ,9 fact1 if a small b> magnet provid$ ) a vibrator be plac$ be=e "o ( ! telephones ( a telephonic circuit1 & ! vibrat+ plate ( ! telephone be remov$1 9 ord] to draw away ! s\nd produc$ by ! vibrator1 its humm+ noise may be di/9ctly he>d on ! second telephone ( ! circuit2 a noise :i* atta9s its maximum :5 ! two extremities ( ! electro-magnet are at _! ne>e/ po9t to ! telephone )\t a diaphragm1 & x is at its m9imum :5 ?is electro-magnet is pres5t$ to x along its neutral l9e4 ,m4 ,demoget supposes t ! action :i* is ex]t$ 9 ?is in/ance is t ( a magnet ex]t+ two induc+ actions :i* are opposite & symmetrical1 ) a field limit$ by a d\ble p>aboloid & ) an axis1 accord+ to 8 exp]im5ts1 :i* ext5d$ #ee c5timtres beyond ! magnetic core1 & a v]tical diamet] ( #fj c5timtres4 ,he believes t 9 ?is way x w\ld be easy to telegraph on ! ,morse sy/em1 & t1 9 ord] to d s1 x w\ld only be necess>y to apply a key to ! induc+ electro-magnet4 ,mr4 ,preece po9ts out ?ree ways ( ov]com+ ! difficulty pres5t$ by ! induc$ reactions caus$ by ! wires on ea* o!r4 #a4 ,by increas+ ! int5sity ( ! transmitt$ curr5ts1 s z to make !m decid$ly /rong] ?an ! induc$ curr5ts1 & to r$uce ! s5sitiv5ess ( ! receiv+ telephone4 #b4 ,to place ! telephonic wire beyond ! range ( induction4 #c4 ,to neutralise ! effects ( induction4 ,! fir/ mode may be effect$ by ,edison's batt]y sy/em1 & we h se5 t x is v successful4 ,9 ord] to put ! second mode 9 practice1 ,mr4 ,preece says t x w\ld be necess>y to /udy ! two k9ds ( induction :i* are develop$ on telegraphic l9es3 electro-/atic induction1 analog\s to t produc$ on subm>9e cables1 & electro-dynamic induction1 result+ f electricity 9 motion4 ,9 ! =m] case1 ,mr4 ,preece proposes to int]pose betwe5 ! telephone wire & ! o!r wires a conduct+ body 9 communication ) ! e>?1 capable ( becom+ a scre5 to ! induction by itself absorb+ ! electro-/atic effects4 ,he says t ?is might be accompli%$ by surr\nd+ ! telegraphic wires adjac5t to ! telephonic wire ) a metallic envelope1 & !n plung+ !m 9 wat]4 ,he adds t ! effects ( /atic induction are n completely de/roy$ 9 ?is way1 s9ce ! sub/ance us$ is a bad conductor1 b !y are consid]ably r$uc$1 z he has prov$ by exp]im5ts betwe5 ,dubl91 ,holyhead1 ,man*e/]1 & ,liv]pool4 ,9 ! second case1 ,mr4 ,preece admits t an iron envelope might p>alyse ! electro-dynamic effects produc$ by absorb+ !m1 s t if insulat$ wires 7 employ$1 cov]$ ) an iron case1 & communicat+ ) ! e>?1 ! two induc$ reactions w\ld be annull$4 ,we w n foll[ ,mr4 ,preece 9 8 !ory z to ^! effects--a !ory :i* seems to u op5 to "q1 b we cont5t ourselves ) po9t+ out 8 propos$ mode ( att5uation4 ,9 ord] to c>ry out ! ?ird exp$i5t1 x might be ?\ght t x w\ld be en\gh to employ a return wire in/ead ( go+ to e>?1 = "u su* conditions ! curr5ts induc$ on "o ( ! wires w\ld be neutralis$ by ^? result+ f ! same induction on ! second wire1 :i* w\ld !n act 9 an opposite direction2 b ?is mode w\ld only be successful :5 !re is a v small int]val betwe5 ! two telephone wires1 & !y are at a consid]able di/ance f ! o!r wires4 ,:5 ?is is n ! case1 & !y are all close toge!r1 z 9 subm>9e or subt]ranean cables1 consi/+ ( sev]al wires1 ?is mode is q ineffici5t4 ,a small cable1 includ+ two conductors1 insulat$ ) gutta-p]*a1 may be successfully c>ri$ ?r\gh ! air4 ,! use ( two conductors has ! fur!r advantage ( avoid+ ! inconv5i5ce ( /ray curr5ts on ! l9e & ?r\gh ! e>?1 :i*1 :5 ! communications to e>? are imp]fect1 p]mit ! l9e curr5t to pass m or less easily into ! telephonic l9e4 ,9 addition to ! di/urb+ causes 9 telephonic transmission we h j m5tion$1 !re are o!rs :i* are also v appreciable1 & among !m are ! accid5tal curr5ts :i* are cont9ually produc$ on telegraphic l9es4 ,^! curr5ts may proce$ f sev]al causes1 at "o "t f atmosph]ic electricity1 at ano!r f t]re/rial magnetism1 at ano!r f !rmo-electric effects produc$ ^u ! l9es1 at ano!r f ! hydro-electric reactions produc$ on ! wires & disks 9 communication ) ! e>?4 ,^! curr5ts are always v un/able1 & consequ5tly !y are likely1 by react+ on ! transmitt$ curr5ts1 to modify !m s z to produce s\nds ^u ! telephone4 ,mr4 ,preece ass]ts t ! s\nd proce$+ f e>? curr5ts some:at resembles t ( fall+ wat]4 ,! dis*>ges ( atmosph]ic electricity1 ev5 :5 ! /orm is remote1 produce a s\nd :i* v>ies ) ! nature ( ! dis*>ge4 ,:5 x is diffus$ & ! clap takes place ne> at h&1 ,dr4 ,*ann+1 ( ,provid5ce1 ,u4,s41 says t ! s\nd resembles t produc$ by a drop ( fus$ metal :5 x falls into wat]1 or1 /ill m1 t ( a rocket dis*>g$ at a di/ance3 9 ?is case x might seem t ! s\nd w\ld be he>d be=e ! appe>ance ( ! fla%1 :i* cle>ly %[s t ! electric dis*>ges ( ! atmosph]e only take place 9 consequ5ce ( an electric di/urbance 9 ! air4 ,mr4 ,preece adds t a wail+ s\nd is sometimes he>d1 :i* has be5 comp>$ to t ( a "y bird1 & :i* mu/ proce$ f ! induc$ curr5ts :i* t]re/rial magnetism produces 9 ! metallic wires :5 plac$ 9 vibration by curr5ts ( air4 ,m4 ,gressi]1 9 a communication made to ! ,acadmie des ,sci5ces on ,may #f1 #ahgh1 has spok5 ( "s ( ^! s\nds1 b he is totally mi/ak5 9 ! s\rce to :i* he ascribes !m4 #8,9 addition to ! crackl+ s\nd caus$ by ! work+ ( telegraph in/rum5ts on ! adjac5t l9es1 a confus$ murmur takes place 9 ! telephone1 a friction s int5se t x might sometimes be ?\ght t ! vibrat+ disk 0 splitt+4 ,?is murmur is he>d m by night ?an by day1 & is sometimes intol]able1 s9ce x becomes impossible to und]/& ! telephone1 al?\gh no?+ is go+ on 9 ! (fice to di/urb ! s\nd4 ,! same noise is he>d :5 only "o telephone is us$4 ,a good galvanomet] ins]t$ 9 ! circuit reveals ! pres5ce ( s5sible curr5ts1 sometimes 9 "o direction1 sometimes 9 ano!r4' ,i /udi$ ^! curr5ts = a long "t ) ! galvanomet]1 & made !m ! subject ( f\r pap]s :i* 7 laid be=e ! ,acadmie des ,sci5ces 9 #ahgb1 & ,i am conv9c$ t !y h 9 g5]al no?+ to d ) atmosph]ic electricity1 b result ei!r f !rmo-electric or hydro-electric influ5ce4 ,!y take place con/antly & 9 all wea!rs on telegraph l9es1 :e!r ^! l9es are insulat$ at "o end1 or 9 contact ) ! e>? at bo? ends4 ,9 ! fir/ case1 ! pol> electrodes ( ! c\ple are =m$ by ! telegraph wire & ! e>? plate1 g5]ally ( ! same nature1 & ! int]m$iate conduct+ m$ium is repres5t$ by ! po/s :i* support ! wire & ! e>? :i* completes ! circuit4 ,9 ! second case1 ! c\ple is =m$ 9 almo/ ! same way1 b ! diff]5ce 9 ! *emical composition ( ! gr\nd at ! two po9ts :]e ! e>? plates are buri$1 & sometimes _! diff]5t temp]ature1 ex]t a /rong influ5ce4 ,if only ! fir/ case be consid]$1 x g5]ally happ5s t on f9e summ] days ! curr5ts produc$ dur+ ! day are inv]se to ^? :i* are produc$ by night1 & v>y ) ! surr\nd+ temp]ature 9 "o or ! o!r direction4 ,! pres5ce or abs5ce ( ! sun1 ! passage ( cl\ds1 ! curr5ts ( air involve abrupt & /rongly m>k$ v>iations1 :i* may be easily foll[$ on ! galvanomet]1 & :i* cause m or less di/9ct s\nds 9 ! telephone4 ,dur+ ! day1 ! curr5ts are direct$ f ! telegraph l9e to ! e>? plate1 because ! heat ( ! wire is great] ?an t ( ! plate1 & ^! curr5ts are !n !rmo-electric4 ,dur+ ! night1 on ! o!r h&1 ! wire is cool$ by ! dew1 :i* causes a great] oxidation on ! wire ?an t :i* takes place on ! plate1 & ! curr5ts !n become hydro-electric4 ,i say m ab\t ^! curr5ts because1 9 consequ5ce ( a mi/ak5 belief z to _! orig91 x has be5 suppos$ t ! telephone might s]ve = ! /udy ( ! v>iations ( ! atmosph]ic electricity g5]ally diffus$ ?r\gh ! air4 ,su* an application ( ! telephone w\ld1 "u ^! conditions1 be n only useless1 b also mislead+1 by induc+ ! /udy ( v complex ph5om5a1 :i* c\ld lead to no?+ m ?an ,i h already /at$ 9 my diff]5t pap]s on ! subject4 ,c]ta9 local influ5ces w also produce s\nds 9 ! telephone4 ,?us ! di/5sion ( ! diaphragm by ! moi/ heat ( ! brea?1 :5 ! in/rum5t is held be=e ! m\? 9 speak+1 causes a p]ceptible murmur4 ,f ! electro-/atic reactions1 s /rongly produc$ on ! subm>9e cables1 9 consequ5ce ( electric transmissions1 x might be suppos$ t x w\ld n be easy to hold telephonic correspond5ce ?r\gh ?is k9d ( conductor1 &1 to asc]ta9 ! fact1 an exp]im5t 0 made on ! cable betwe5 ,gu]nsey & ,d>tm\?1 a di/ance ( sixty miles4 ,articulate spee*1 only a little indi/9ct1 01 h[ev]1 p]fectly transmitt$4 ,o!r exp]im5ts1 made by ,messrs4 ,preece & ,wilmot1 on an artificial subm>9e cable1 plac$ 9 conditions analog\s to ^? ( ! ,atlantic cable1 %[$ t a telephonic correspond5ce might be kept up at a di/ance ( a hundr$ miles1 al?\gh ! effects ( induction 7 app>5t4 ,at ! di/ance ( #aej miles1 x 0 some:at difficult to he>1 & ! s\nds 7 v fa9t1 z if "s "o 7 speak+ ?r\gh a ?ick p>tition4 ,! s\nd dim9i%$ rapidly until ! di/ance ( #bjj miles 0 rea*$1 & aft] t x became p]fectly indi/9ct1 al?\gh s++ c\ld /ill be he>d4 ,x 0 ev5 possible to he> ?r\gh ! :ole l5g? ( ! cable1 t is1 = #c1jjj miles1 b ,mr4 ,preece believ$ ?is to be due to ! induction ( ! cond5s] on itself3 he holds1 h[ev]1 t s++ may be he>d at a mu* great] di/ance ?an spee*1 ow+ to ! m regul> succession ( electric waves4 ,mr4 ,preece also made exp]im5ts on ! subt]ranean telegraphs betwe5 ,man*e/] & ,liv]pool1 a di/ance ( #cj miles1 & f\nd no difficulty 9 ex*ang+ correspond5ce2 & x 0 ! same ) ! cable f ,dubl9 to ,holyhead1 a di/ance ( #fg miles4 ,?is cable _h sev5 conduct+ wires1 & :5 ! telephone 0 connect$ ) "o ( !m1 ! s\nd 0 repeat$ ?r\gh all ! o!rs1 b 9 a fa9t] degree4 ,:5 ! curr5ts ( ! telegraphic in/rum5ts pass$ ?r\gh ! wires1 ! induction 0 app>5t1 b n s great z to prev5t telephonic communication4 ,,e/abli%m5t ,,( ,a ,,telephonic ,,/ation4 ,al?\gh ! telephonic sy/em ( telegraphy is v simple1 yet c]ta9 accessory arrangem5ts are indisp5sable = its use4 ,?us1 = example1 an al>um call is necess>y1 9 ord] to "k :5 ! ex*ange ( correspond5ce is to take place1 & in=mation t ! call has be5 he>d is likewise necess>y4 ,an electric bell is !re=e an indisp5sable addition to ! telephone1 & s9ce ! same circuit may be employ$ = bo? sy/ems1 if a commutator is us$1 x 0 necess>y to f9d a mode ( mak+ ! commutator act automatically1 s z to ma9ta9 ! simple action ( ! sy/em :i* con/itutes its pr9cipal m]it4 ,,mm4 ,poll>d & ,g>ni]'s ,sy/em4--,) ?is object1 ,,mm4 ,poll>d & ,g>ni] devis$ a v successful arrangem5t la/ ,m>*1 :i* employs ! weight ( ! in/rum5t to act ^u ! commutator4 ,= ?is purpose1 !y susp5d$ ! in/rum5t to ! end ( a spr+ plate1 fa/5$ betwe5 ! two contacts ( ! commutator4 ,! circuit wire corresponds ) ?is plate1 & ! two contacts correspond1 ! "o ) ! telephone1 ! o!r ) ! bell4 ,:5 ! telephone hangs bel[ ! spr+-support1 t is1 :5 x is n at "w1 its weight l[]s ! spr+ plate on ! l[] contact1 & ! communication ( ! l9e ) ! bell is e/abli%$3 :51 on ! o!r h&1 ! telephone is rais$ = use1 ! spr+ plate t\*es ! high] contact1 & communication is e/abli%$ betwe5 ! l9e & telephone4 ,9 ord] to make ! bell s\nd1 x is only necess>y to e/abli%1 on ! wire :i* connects ! l9e ) ! bell contact ( ! commutator1 a break] :i* c bo? jo9 & break ! curr5t1 & :i* communicates on "o side ) ! contact ( ! bell1 & on ! o!r ) its batt]y4 ,! ord9>y pu% ( an electric bell w be suffici5t1 if x is suppli$ ) a second contact1 b ,,mm4 ,poll>d & ,g>ni] wi%$ to make ?is action also automatic1 & consequ5tly !y devis$ ! arrangem5t repres5t$ 9 fig4 #ec4 ,illu/ration3 ,,fig4 #ec4 ,9 ?is sy/em1 z well z 9 ^? :i* h s9ce be5 devis$1 two telephones are employ$1 "o ( :i* is con/antly appli$ to ! e>1 & ! o!r to ! m\?1 s z to make x possible to speak :ile li/5+4 ,! telephones are support$ by ?ree wires1 two ( :i* conta9 flexible conductors1 :ile ! ?ird only acts z a support4 ,two ( ! f\r wires ( ! two telephones are connect$ ) ea* o!r1 & ! o!r two are connect$ ) ! two b9d+ screws ( ! commutator t1 t3 ! wires )\t conductors are susp5d$ to ! extremities ( ! two flexible plates l1 l1 :i* correspond ) e>? & l9e4 ,:5 at re/1 ! weight ( ! telephones presses ! two plates l1 l1 on ! l[] contacts ,s1 ,s1 b :5 ! in/rum5ts are tak5 up ^! plates press aga9/ ! high] contacts4 ,! two bell wires t]m9ate on ! l[] contacts1 ^? ( ! telephones on ! high] contacts1 & "o ( ! poles ( ! batt]y is connect$ ) ! l[] contact on ! left ,s1 ! o!r ) ! high] contact on ! "r ,t4 ,:5 at re/1 ! sy/em is appli$ to ! electric bell1 & ! curr5t s5t f ! opposite /ation w foll[ ! circuit ,l l ,s ,s ,s l ,t1 s t ! call w be made4 ,on tak+ up ! two telephones1 ! circuit ( ! bell sy/em is brok51 & t ( ! telephones is e/abli%$1 s t ! curr5t foll[s ! c\rse ,l l ,t t t ,t l ,t4 ,if only "o telephone is held at a "t1 ! curr5t is s5t into ! bell sy/em ( ! opposite /ation1 & foll[s ! r\te ,p ,s l ,l ,t l ,t t ,p --4 ,9 ?is way ! ?ree actions necess>y = call+1 correspond+1 & enabl+ ! correspond+ in/rum5t to give a call1 are almo/ involunt>ily made4 ,sy/em by ,,mm4 ,brguet & ,roosevelt4--,9 ! sy/em e/abli%$ by ! ,p>is ag5ts ( ! ,bell company1 ! arrangem5t resembles ! "o j describ$1 except t !re is only "o spr+ commutator1 & ! call is made ) ! pu% ( an ord9>y electric bell4 ,a mahogany bo>d is susp5d$ f ! wall1 & on x are arrang$1 fir/1 ! ord9>y electric bell sy/em1 ) a s5d+ pu% fix$ bel[ x2 second1 two =ks support+ two telephones1 "o ( :i* is fa/5$ to ! b> ( a commutator1 arrang$ z a ,morse key4 ,! two telephones are connect$ by two conduct+ wires1 s arrang$ z to be capable ( ext5sion1 & two ( _! f\r b9d+ screws are 9 imm$iate connection ) ea* o!r1 & ! o!r two ) ! e>?1 l9e1 & batt]y1 by means ( ! commutator1 ! s5d+ pu%1 & ! bell sy/em4 ,! arrangem5t is %[n 9 fig4 #ed4 ,illu/ration3 ,,fig4 #ed4 ,! commutator ,a consi/s ( a metallic b> a c1 be>+ ! susp5sion =k ( "o ( ! telephones ,f bel[ its po9t ( articulation3 x ends 9 two p9s a & c1 bel[ :i* ! two contacts ( ! commutator are fix$1 & a spr+ compresses ! l[] arm ( ! b>1 s z to cause ! o!r arm to re/ con/antly on ! high] contact4 ,= great] security a /eel tongue a b is fa/5$ to ! l[] end ( ! b>1 & rubs aga9/ ! small %aft b1 :i* is provid$ ) two insulat$ contacts1 correspond+ to ^? ( ! bo>d4 ,! b> is 9 communication ) ! l9e wire by means ( ! call-pu%1 & ! upp] ( ! two contacts we h j describ$ corresponds ) "o ( ! telephone wires :i* is ins]t$ 9 ! same circuit1 :ile ! o!r corresponds ) ! bell sy/em ,s1 :i* is 9 communication ) e>?4 ,x foll[s f ?is arrangem5t1 t :5 ! "r telephone presses its :ole weight on ! support1 ! b> ( ! commutator is incl9$ on ! l[] contact1 & consequ5tly ! l9e is 9 direct communication ) ! bell1 s t ! call c be made4 ,:51 on ! o!r h&1 ! telephone is remov$ f its support1 ! b> re/s on ! high] contact1 & ! telephones are connect$ ) ! l9e4 ,pressure on ! s5d+ pu% s]ves to call ! correspond+ /ation3 ! connection ( ! l9e ) ! telephones is !n brok51 & x is e/abli%$ ) ! batt]y ( ! s5d+ /ation1 :i* s5ds its curr5t ?r\gh ! bell ( ! correspond+ /ation4 ,9 ord] to obta9 ?is d\ble effect1 ! contact spr+ ( ! s5d+ pu% g5]ally re/s ^u a contact fa/5$ to a piece ( wood %ap$ l a jo9]'s rule1 :i* cov]s x 9 front1 & bel[ ?is spr+ !re is a second contact1 :i* communicates ) ! positive pole ( ! /ation batt]y4 ,! o!r contact corresponds ) ! l9e wire1 & a connection takes place betwe5 ! e>? wire & ! negative pole ( ! /ation batt]y1 s t ! e>? wire is common to ?ree circuits3 #a/4 ,to ! telephone circuit4 #bnd4 ,to t ( ! bell sy/em4 #crd4 ,to t ( ! local batt]y4 ,! second =k1 :i* supports ! telephone on ! "r1 is fix$ to ! bo>d1 & is indep5d5t ( any electric curr5t4 ,x is cle> t ?is arrangem5t may be v>i$ 9 a ?\s& ways1 b ! model we h j describ$ is ! mo/ practical4 ,edison's ,sy/em4--,! problem becomes m complex 9 ! case ( batt]y telephones1 s9ce ! batt]y mu/ be common to bo? sy/ems1 & ! induction coil mu/ be ins]t$ 9 two di/9ct circuits4 ,fig4 #ee repres5ts ! model adopt$ 9 ,mr4 ,edison's telephone4 ,illu/ration3 ,,fig4 #ee4 ,9 ?is arrangem5t1 !re is a small /& ,c on ! mahogany bo>d on :i* ! bases ( ! two telephones re/4 ,! bell sy/em ,s is work$ by an electro-magnetic speak] ,p1 :i* s]ves1 :5 a ,morse key is add$ to ! sy/em1 = ex*ange ( correspond5ce 9 ! ,morse code1 if !re %\ld be any defect 9 ! telephones1 or to put !m 9 work+ ord]4 ,above ! speak] !re is a commutator ) a /opp] ,d to adapt ! l9e = s5d+ or receiv+1 ) or )\t ! bell2 & bel[ ! /& ,c ! induction coil1 de/9$ to trans=m ! voltaic curr5ts into induc$ curr5ts1 is arrang$ 9 a small clos$ box ,e4 ,:5 ! commutator is at reception1 ! l9e is 9 imm$iate correspond5ce ei!r ) ! speak] or ) ! receiv+ telephone1 accord+ to ! hole 9 :i* ! /opp] is ins]t$2 :51 on ! o!r h&1 x is at s5d+1 ! l9e corresponds to ! second>y circuit ( ! induction coil4 ,"u ^! conditions ! action is no long] automatic2 b s9ce ?is k9d ( telephone c only be usefully employ$ = telegraphy1 9 :i* case ^? :o "w x are acqua9t$ ) electric app>atus1 !re is no inconv5i5ce 9 ?is complication4 ,,call-,,bells ,,& ,,al>ums4 ,! call-bells appli$ to telegraphic s]vice h be5 arrang$ 9 diff]5t ways4 ,:5 ! vibrat+ bells are 9 use1 l ^? ( :i* we h j spok51 x is necess>y to use a batt]y1 & ! advantages (f]$ by telephones ) induc$ curr5ts are ?us s5sibly dim9i%$4 ,9 ord] to disp5se ) ! batt]y1 ! use ( ! electro-magnetic bell has be5 sugge/$4 ,9 ?is case !re are usually two bells1 ) a hamm] oscillat+ betwe5 !m1 & a support =m$ ( ! pol>is$ armature ( an electro-magnet4 ,! electro-magnetic in/rum5t is plac$ bel[ ?is sy/em2 x is turn$ by a w9*1 & s5ds ! curr5ts1 alt]nately rev]s$1 :i* are necess>y to communicate ! vibratory movem5t to ! hamm]1 & ?is movem5t is en\gh to make ! two bells t9kle4 ,bel[ ! w9* ( ?is electro-magnetic in/rum5t !re is a commutator ) two contacts1 :i* adapts ! in/rum5t = s5d+ or receiv+4 ,m4 ,m&r\x has simplifi$ ?is sy/em1 & has r$uc$ x to small dim5sions by ! foll[+ arrangem5t4 ,he fixes two magnetic cores1 furni%$ ) coils1 on ea* ( ! two poles ( a horse%oe magnet1 compos$ ( two b>s connect$ by an iron c\pl]1 & betwe5 ! poles exp&$ by ^! f\r cores he ins]ts an armature1 )9 :i* !re is a /eel spr+ fa/5$ to "o ( ^! poles4 ,9 ?is way ! armature is pol>is$1 & oscillates "u ! influ5ce ( ! rev]s$ curr5ts transmitt$ by an in/rum5t ( ! same k9d provid$ ) an induction sy/em4 ,^! oscillations may h ! effect ( produc+ ! s\nd ( a call-bell1 & ! induction sy/em may consi/ ( a manipulat+ key1 fa/5$ to a duplex sy/em ( armature1 regul>ly appli$ to ! magnetic cores1 tak5 9 pairs4 ,on communicat+ a s]ies ( movem5ts to ?is manipulator1 a s]ies ( induc$ curr5ts 9 an inv]se direction are produc$1 :i* cause ! armature ( ! correspond+ /ation to act z we h already se51 & :i* may ev51 :5 necess>y1 furni% a s]ies ( ,morse signals = a suitable manipulation4 ,on acc\nt ( ! small size ( ?is sy/em1 x might be appli$ to ! telephonic s]vice ( ! army4 ,! ,bell ,telephone ,company 9 ,p>is has arrang$ ano!r little call-sy/em :i* is q satisfactory & has ! advantage ( act+ z a telephone at ! same "t4 ,! model resembles ! "o we h t]m$ a snuff-box telephone1 & x has a button commutator by means ( :i* ! in/rum5t is plac$ 9 communication ) ! electro-magnetic sy/em ( ! in/rum5t1 or ) a batt]y :i* is able to make ! telephone vibrate ) "s =ce4 ,to make a call1 ! button mu/ be press$1 & ! batt]y curr5t is communicat$ to ! correspond+ in/rum5t1 :i* beg9s to vibrate :5 ! call is made2 & :5 notice is giv5 ( ! receipt ( ! signal1 ! pressure on ! button is remov$1 & x becomes possible to speak & receive z 9 ord9>y telephones4 ,illu/ration3 ,,fig4 #ef4 ,m4 de ,we9hold's ,sy/em4--,m4 ,zetz*e speaks highly ( an al>um devis$ by ,pr(essor ,a4 de ,we9hold1 :i* resembles t by ,m4 ,lor5z1 repres5t$ 9 fig4 #ef4 ,its organ ( s\nd consi/s ( a /eel bell ,t1 f #ac to #ad c5timtres 9 diamet]1 & ton$ to give ab\t #dbj d\ble vibrations 9 a second4 #8,its diamet] & tone1' he says1 #8are important1 & any great dep>ture f ! rule laid d[n dim9i%es ! effect4 ,! op5+ ( ! bell is bel[1 & x is fix$ on a /& by its c5tre4 ,a slightly curv$ b> magnet1 provid$ at its two ends ) iron app5dices enclos$ 9 a coil1 trav]ses ! /&4 ,! b> magnet ( ! telephone also t]m9ates 9 an iron app5dix enclos$ 9 a coil4 ,9 bo? cases ! *anges produc$ 9 ! magnetic condition appe> to be m int5se ?an !y are 9 magnets )\t app5dices4 ,! b> magnet is plac$ )9 ! bell 9 ! direction ( "o ( its diamet]s1 s t ! app5dices almo/ t\* its sides4 #8,:5 ! bell is /ruck on a spot ab\t #ij f ?is diamet] ) a wood5 clapp] ,m1 :i* acts ) a spr+1 & is )drawn by /ret*+ ! spr+ & !n lett+ x g1 z 9 a bell = ! d9n]-table1 ! vibrations imp>t$ to x s5d curr5ts into ! coils1 & ^! curr5ts produce id5tical vibrations on ! iron disk ( ! telephone1 :i* are int5sifi$ by a conical resonator fitt$ to ! telephone1 s z to be easily he>d "s paces (f4 ,= ord9>y use1 ! bell coil is brok5 into a %ort circuit by means ( a metallic spr+ ,r1 & consequ5tly1 :5 ! bell is /ruck1 ! spr+ mu/ be op5$ s z n to break ! circuit4 ,an in/rum5t ( ! same k9d has also be5 devis$ by ,h]r ,w4 ,e4 ,fe9 at ,/uttg>dt4' ,illu/ration3 ,,fig4 #eg4 ,illu/ration3 ,,fig4 #eh4 ,,mm4 ,dut]tre & ,g\ault's ,sy/em4--,"o ( ! mo/ +5i\s solutions ( ! problem ( mak+ ! telephone call has rec5tly be5 propos$ by ,,mm4 ,dut]tre & ,g\ault4 ,figs4 #eg & #eh repres5t ! opposite faces ( ! in/rum5t4 ,x consi/s ( a k9d ( snuff-box telephone1 l ! "o %[n 9 fig4 #bf1 & x is s arrang$ z to s5d or receive ! call1 accord+ to ! way 9 :i* x is plac$ on its /&1 :i* is only an ord9>y bracket fa/5$ to ! wall4 ,:5 x is plac$ on ! bracket s z to h ! telephone m\?piece on ! outside1 x is adapt$ = receiv+1 & c !n give ! call4 ,:51 on ! o!r h&1 its position on ! bracket is rev]s$1 x p]mits ! o!r /ation to make ! call1 by produc+ vibrations on a vibrator "u ! influ5ce ( a batt]y1 & ^! vibrations rev]b]ate 9 ! correspond+ in/rum5t ) suffici5t =ce to produce ! call4 ,if ! in/rum5t is tak5 up1 & ! f+] is plac$ on a small spr+ button1 x may !n be us$ z an ord9>y telephone4 ,9 ?is in/rum5t1 ! magnet ,n ,s 7fig4 #eg7 is snail-%ap$1 l o!rs we h m5tion$1 b ! core ( s(t iron ,s1 to :i* ! coil ,e is fa/5$1 c produce two diff]5t effects on its two extremities4 ,on ! "o side1 x reacts on a small armature :i* is fa/5$ to ! end ( a vibrat+ disk ,c1 fig4 #eh2 ! armature is plac$ aga9/ a contact fa/5$ to ! bridge ,b1 & con/itutes an electro-magnetic vibrator4 ,= ?is purpose ! bridge is 9 metallic communication ) ! coil wire1 ( :i* ! o!r end corresponds ) ! l9e wire1 & ! spr+ ,c is m\nt$ on an upright ,a1 :i* also supports ano!r spr+ ,d ,g act+ on two contacts1 "o plac$ at ,g1 & correspond+ to ! e>? wire1 ! o!r at ,h1 & connect$ ) ! positive pole ( ! batt]y4 ,a small moveable button1 :i* passes ?r\gh a hole 9 ! lid ( ! box1 & projects beyond x1 is fix$ at ,g1 & all ?is "p ( ! in/rum5t faces ! bottom ( ! box4 ,! upp] "p consi/s ( ! vibrat+ disk & ! m\?piece1 s t ! me*anism we h describ$ is all m\nt$ on an inn] p>tition =m+ a false bottom to ! box4 ,:5 ! box re/s ^u its base1 on ! side %[n 9 fig4 #eh1 ! button at ,g presses on ! spr+ ,d ,g1 & raises x s z to break ! connection ) ! batt]y2 ! coil ( ! in/rum5t is !n unit$ to ! circuit1 & consequ5tly receives ! transmitt$ curr5ts1 :i* foll[ ?is r\te3 l9e wire1 coil ,e1 bridge ,b1 spr+ ,c1 spr+ ,d ,g1 e>? contact4 ,if ^! curr5ts are transmitt$ by a vibrator1 !y are /rong en\gh to produce a noise :i* c be he>d 9 all p>ts ( a room1 & consequ5tly ! call may be giv5 9 ?is way4 ,if ! curr5ts are due to telephonic transmission1 ! in/rum5t is appli$ to ! e>1 c>e be+ tak5 to put ! f+] on ! button ,g1 & ! ex*ange ( correspond5ce takes place z 9 ord9>y in/rum5ts2 b x is simpl] & m manageable to ins]t a second telephone 9 ! circuit = ?is purpose4 ,:5 ! box is inv]t$ on its m\?piece1 & ! button ,g ceases to press on ! spr+ ,d ,g1 ! batt]y curr5t reacts on ! vibrator ( ! in/rum5t1 & s5ds ! call to ! correspond+ /ation1 foll[+ ?is r\te3 ,i ,d ,a ,c ,b ,e1 l9e1 e>? & batt]y2 & ! call goes on until ! correspond5t breaks ! curr5t by tak+ up 8 in/rum5t1 ?us w>n+ ! o!r t he is ready to li/54 ,sy/em ( ,m4 ,puluj4--,!re is yet ano!r call sy/em1 devis$ by ,m4 ,puluj4 ,x consi/s ( two telephones )\t m\?pieces1 connect$ toge!r1 & ) coils plac$ opposite ! bran*es ( two tun+-=ks1 tun$ z ne>ly z possible to ! same tone4 ,a small metal bell is fix$ betwe5 ! opposite faces ( ! tun+-=ks1 & a wire /ret*$ ne> !m is provid$ ) a small ball 9 contact ) _! bran*es4 ,:5 ! tun+-=k at ! s5d+ /ation is put 9 vibration by /rik+ x ) an iron hamm] cov]$ ) sk91 ! tun+ =k at ! o!r /ation vibrates also1 & its ball /rikes ^u ! bell4 ,z soon z ! signal is return$ by ! second /ation1 m\?pieces ) iron diaphragms are fa/5$ to ! telephones1 & ! correspond5ce beg9s4 ,x seems t1 by ! use ( a resonator1 ! s\nd :i* rea*es ! receiv+ /ation may be s int5sifi$ z to become audible 9 a l>ge hall1 & ! bell signal may be he>d 9 an adjo9+ room1 ev5 ?r\gh a clos$ door4 ,mr4 ,alfr$ ,*iddey's ,sy/em4--,?is arrangem5t consi/s ( a sl5d] copp] tube1 eight in*es long1 & ) an orifice ( #a_/cj ( an in*1 ( :i* ! l[] end is sold]$ to ! diaphragm ( a telephone4 ,a bran* jo9t1 to :i* an india-rubb] tube is fitt$1 connects x ) a gas jet1 :i* is light$ & surr\nd$ ) a lamp %ade1 9 su* a way z to make x produce1 "u giv5 conditions1 s\nds resembl+ ^? ( ! s++ flames4 ,a p]fectly simil> sy/em is arrang$ at ! o!r end ( ! l9e1 9 su* a way t ! s\nds emitt$ 9 ea* case %all be precisely 9 unison4 ,if ! two sy/ems are s regulat$ z n to emit s\nds 9 _! normal condition1 !y c be made to s+ by caus+ a tun+-=k 9 ! vic9ity ( "o or ! o!r to vibrate ! same note1 & !n ! correspond+ flame w beg9 to s+1 produc+ a vibration 9 ! diaphragm ( ! telephone ) :i* x is 9 correspond5ce1 & h5ce w foll[ ! vibration ( ! diaphragm ( ! o!r telephone1 & consequ5tly ! vibration ( ! flame ( ! call+ in/rum5t4 ,9 ?is way ! call signal may be made )\t ! int]v5tion ( any batt]y4 ,,applications ,,( ,,! ,,telephone4 ,! applications ( ! telephone are mu* m num]\s ?an might be suppos$ at ! fir/ glance4 ,z f> z ! telegraphic s]vice is conc]n$1 its use mu/ evid5tly be r limit$1 s9ce x _c regi/] ! messages s5t1 & ! spe$ ( transmission is inf]ior to t ( ! improv$ sy/em ( telegraphs2 yet 9 _m cases x w\ld be v valuable1 ev5 = a telegraphic sy/em1 s9ce x is possible to "w x )\t any special telegraphic tra9+4 ,! fir/ com] may s5d & receive ) ! telephone1 & ?is is c]ta9ly n ! case ev5 ) ! simple/ =ms ( telegraphic in/rum5ts4 ,?is sy/em is !re=e already 9 use 9 public (fices & factories1 = communication 9 m9es1 = subm>9e works1 = ! navy1 especially :5 sev]al vessels manuvre 9 ! same wat]s1 "s t[$ by o!rs2 f9ally1 = milit>y purposes1 ei!r to transmit ord]s to diff]5t corps1 or to communicate ) s*ools ( artill]y & rifle practice4 ,9 ,am]ica ! municipal telegraphic s]vice & t ( telegraphs limit$ to ! area ( t[ns are conduct$ 9 ?is way1 & x is probable t ?is sy/em w soon be adopt$ 9 ,europe4 ,inde$1 a s]vice ( ?is k9d 0 e/abli%$ 9 ,g]many la/ autumn at ! telegraph (fices ( "s t[ns1 & ! ,london ,po/ ,(fice is n[ ?9k+ ( e/abli%+ x 9 ,engl&4 ,b1 besides its use = ! purposes ( correspond5ce1 ! telephone c be useful to ! telegraphic s]vice itself by af=d+ "o ( ! simple/ means ( obta9+ a numb] ( simultane\s transmissions ?r\gh ! same wire1 & ev5 ( be+ comb9$ 9 duplex ) ! ,morse telegraphs4 ,its applications 9 ! microphonic =m are incalculable1 & ! prov]b :i* decl>es t #8walls h e>s' may 9 ?is way be lit]ally true4 ,x is al>m+ to ?9k ( ! consequ5ces ( su* an indiscreet organ4 ,diplomati/s mu/ c]ta9ly r$\ble _! res]ve1 & t5d] confid5ces w no long] be made ) ! same frankness4 ,on ?is po9t we _c ?9k t mu* w be ga9$1 b on ! o!r h& ! physician w probably soon make use ( ?is inv5tion to asc]ta9 m readily ! processes go+ on )9 ! human body4 ,,application ,,( ,,! ,,telephone ,,to ,,simultane\s ,,telegraphic ,,transmissions4 ,! simultane\s transmission ( sev]al messages ?r\gh ! same wire is "o ( ! mo/ curi\s & important applications ( ! telephone to telegraphic in/rum5ts :i* c be made1 & we h se5 t x 0 ?is application :i* l$ ,messrs4 ,gray & ,bell to ! inv5tion ( speak+ telephones4 ,! admiration :i* ^! in/rum5ts h excit$ has ?r[n ! orig9al idea into ! backgr\nd1 al?\gh x has p]haps a m practical importance4 ,we w n[ consid] ^! sy/ems4 ,an articulat+ telephone is n necess>y 9 ord] to obta9 simultane\s transmission3 ! musical telephones devis$ by ,,mm4 ,petr9a1 ,gray1 ,from5t1 c41 are q suffici5t1 & a brief explanation ( _! pr9ciple w make ?is intelligible4 ,suppose t !re are sev5 electro-magnetic vibrators at ! two correspond+ /ations1 :i* are tun$ ) ! same tun+-=k on ! diff]5t notes ( ! scale1 & suppose t a key-bo>d1 resembl+ ! ,morse telegraph key1 is arrang$ s t1 by l[]+ ! keys1 electric reaction takes place on ea* vibrator3 x is easy to see t ^! vibrators may be made to react 9 ! same way on ! correspond+ vibrators ( ! opposite /ation2 b !y mu/ be tun$ on ! same note1 & ! s\nds emitt$ w cont9ue :ile ! keys are l[]$4 ,by keep+ !m d[n = a %ort] or long] "t1 ! long or %ort s\nds :i* con/itute ! elem5ts ( telegraphic language 9 ! ,morse sy/em may be obta9$1 & consequ5tly an audible transmission becomes possible4 ,let u n[ suppose t a telegraphi/ accu/om$ to ?is mode ( transmission is plac$ be=e ea* ( ! vibrators1 & t !y transmit diff]5t messages at ! same mom5t 9 ?is way3 ! telegraphic wire w be in/antane\sly trav]s$ by sev5 curr5ts1 brok5 & mass$ ^u ea* o!r1 & !y might be expect$ to produce a m$ley ( confus$ s\nds on ! vibrators at ! receiv+ /ation2 b s9ce !y ea* h>monise ) ! correspond+ vibrator1 !y h no s5sible influ5ce except on ^? = :i* !y are int5d$4 ,! dom9ant s\nd may be made /ill m di/9ct by apply+ a ,helmholtz resonator to ea* vibrator1#ah t is1 an ac\/ic in/rum5t :i* w only vibrate "u ! influ5ce ( ! note to :i* x is tun$4 ,9 ?is way x is possible to select ! transmitt$ s\nds1 & only to all[ ea* employ to he> t :i* is int5d$ = him4 ,consequ5tly1 h[ev] confus$ ! s\nds may be on ! receiv+ vibrators1 ! p]son to :om d is assign$ w only receive d s\nds1 ! p]son to :om sol is assign$ w only receive sol s\nds1 s t correspond5ce may be c>ri$ on z well z if !y _h ea* a special wire4 ,9 ! mode we h describ$1 ?is telegraphic sy/em only admits ( audible transmissions1 & consequ5tly _c regi/] messages4 ,to supply ?is defect1 x has be5 sugge/$ to make ! receiv+ vibrators react on regi/]s1 s arrang+ ! latt] t _! electric organ may pres5t su* magnetic in]tia1 t1 :5 x is influ5c$ by ! vibrations ( s\nd1 its effect may be ma9ta9$ ?r\gh\t ! "t ( vibration4 ,exp]im5ts %[ t a ,morse receiv]1 work$ by ! curr5t ( a local batt]y1 w be en\gh = ?is purpose2 s t if ! musical vibrator is made to react z a relay1 t is1 on a contact 9 connection ) ! local batt]y & ! receiv]1 ! dots & da%es may be obta9$ on x :i* are ! con/itu5t elem5ts ( ! ,morse code4 ,on ^! pr9ciples1 & consid]+ t ! musical spaces sep>at+ ! diff]5t notes ( ! scale are su* z may be easily di/+ui%$ by ! resonator1 sev5 simultane\s transmissions may be obta9$ on ! same wire2 b exp]i5ce %[s t x is necess>y to be cont5t ) a mu* small] numb]4 ,yet ?is numb] may easily be d\bl$ by apply+ ! mode ( transmission 9 an opposite direction to ! sy/em4 ,mr4 ,bell /ates t ! idea ( apply+ ! telephone to multiple electric transmissions occurr$ simultane\sly to ,m4 ,paul ,lac\r ( ,cop5hag51 to ,mr4 ,eli%a ,gray ( ,*icago1 to ,mr4 ,v>ley ( ,london1 & to ,mr4 ,edison ( ,new ,york2 b !re is "s confusion "h1 = we h already se51 f ref]5ce to ! pat5ts1 t ,mr4 ,v>ley's sy/em dates f #ahgj1 t ( ,m4 ,paul ,lac\r f ,septemb] #ahgd1 t ( ,mr4 ,eli%a ,gray f ,febru>y #ahge1 & ^? ( ,messrs4 ,bell & ,edison 7 /ill lat]4 ,yet x appe>s f ,mr4 ,gray's specification t he 0 ! fir/ to conceive & execute in/rum5ts ( ! k9d4 ,9 fact1 9 a specification drawn up on ,augu/ #f1 #ahgd1 he di/9ctly put =w>d ! sy/em we h describ$1 & :i* is ! basis ( ^? ( :i* we h /ill to speak4 ,?is specification 0 only an addition to two o!rs made out 9 ,april & ,june #ahgd4 ,mr4 ,v>ley's sy/em has only an indirect relation to ! "o we h describ$4 ,x appe>s f :at ,mr4 ,bell said on ! subject 9 a pap] address$ to ! ,society ( ,telegraphic ,eng9e]s 9 ,london1 t he himself only atta*es a second>y int]e/ to ?is inv5tion4 ,he said t he _h be5 /ruck ) ! idea t ! great] or less duration ( a musical s\nd might repres5t ! dot & da% ( ! telegraphic alphabet1 & x occurr$ to him t simultane\s telegraphic transmissions1 ( :i* ! numb] %\ld only be limit$ by ! delicacy ( ! s5se ( he>+1 might be obta9$ by suitable comb9ations ( long & %ort s\nds1 & t ^! %\ld be effect$ by a keybo>d ( tun+-=ks appli$ to "o end ( a telegraphic l9e1 & s arrang$ z to react electrically on electro-magnetic in/rum5ts /rik+ on ! /r+s ( a piano4 ,= ?is purpose x w\ld be necess>y to assign an employ to ea* ( ! keys = ! s]vice ( transmission1 & to arrange t 8 correspond5t %\ld only di/+ui% 8 peculi> note among all ^? transmitt$4 ,x 0 ?is idea1 ,mr4 ,bell adds1 :i* l$ to 8 rese>*es 9 telephony4 ,= sev]al ye>s he s\ght = ! be/ mode ( reproduc+ musical s\nds at a di/ance by means ( vibrat+ rheotomes3 ! be/ results 7 giv5 by a /eel plate vibrat+ betwe5 two contacts1 ( :i* ! vibrations 7 electrically produc$ & ma9ta9$ by an electro-magnet & a local batt]y4 ,9 consequ5ce ( its vibration1 ! two contacts 7 t\*$ alt]nately1 & ! two circuits 7 alt]nately brok52 ! local circuit :i* kept ! plate 9 vibration1 & ! o!r :i* 0 connect$ ) ! l9e1 & react$ on ! di/ant receiv]1 s z to effect simultane\s vibrations 9 x4 ,a ,morse key 0 plac$ 9 ! latt] circuit ne> ! s5d+ in/rum5t1 & :5 x 0 l[]$1 vibrations 7 s5t ?r\gh ! l9e2 :5 x 0 rais$1 ^! vibrations ceas$1 & x is easy to see t1 by l[]+ ! key = a long] or %ort] "t1 ! %ort & long s\nds necess>y = ! diff]5t comb9ations ( telegraphic language c\ld be obta9$4 ,moreov]1 if ! vibrat+ plate ( ! receiv+ in/rum5t 7 s regulat$ z to vibrate 9 unison ) ! s5d+ in/rum5t 9 correspond5ce1 x w\ld vibrate bett] ) ?is s5d] ?an ) ano!r ^: plate 0 n s adju/$4 ,x is evid5t t diff]5t s\nds might be simultane\sly transmitt$ ) sev]al plates by ?is arrangem5t ( contact break]1 & t at ! receiv+ /ation ! s\nds might be di/+ui%$ by ea* employ1 s9ce ! "o :i* corresponds to ! fundam5tal note ( ea* vibrat+ plate is reproduc$ by t plate4 ,consequ5tly1 ! s\nds produc$ by ! vibrat+ plate ( d1 = example1 w only be audible at ! receiv+ /ation on ! plate tun$ to d1 & ! same w be ! case ) ! o!r plates2 s t ! s\nds w rea* _! de/9ation1 if n )\t confusion1 yet ) suffici5t cle>ness to be di/+ui%$ by ! employs4 ,mr4 ,bell sums up ! defects /ill exi/+ 9 8 sy/em z foll[s3--#a/4 ,! receiv] ( ! messages mu/ h a good musical e>1 9 ord] to di/+ui% ! value ( s\nds4 #bnd4 ,s9ce ! signals c only take place :5 ! transmitt$ curr5ts are 9 ! same direction1 two wires mu/ be employ$ 9 ord] to ex*ange messages on ea* side4 ,he surm\nt$ ! fir/ difficulty by provid+ ! receiv] ) an in/rum5t :i* he call$ ! vibrat+ contact break]1 & :i* regi/]$ automatically ! s\nds produc$4 ,?is contact break] 0 plac$ 9 ! circuit ( a local batt]y1 :i* c\ld "w a ,morse in/rum5t "u c]ta9 conditions4 ,:5 ! s\nds emitt$ by ! in/rum5t did n correspond ) ^? = :i* x _h be5 tun$1 ! contact break] _h no effect on ! telegraphic in/rum5t3 x only act$ :5 ! s\nds 7 ^? :i* 7 to be int]pret$1 & its action necess>ily correspond$ to ! l5g? ( ! s\nds4 ,mr4 ,bell adds t he appli$ ! sy/em to electro-*emical telegraphs2 b we ne$ n dwell on ?is "p ( ! inv5tion1 s9ce1 z we h said1 x is no long] 8 special /udy4 ,sy/em ( ,m4 ,lac\r ( ,cop5hag54--,m4 ,lac\r's sy/em 0 pat5t$ on ! #bnd ,septemb]1 #ahgd1 b 8 exp]im5ts 7 comm5c$ on ! #e? ,june ( ! same ye>4 ,s9ce ,m4 ,lac\r believ$ t ! vibrations w\ld be imp]ceptible on long l9es1 8 fir/ attempts 7 made on a some:at %ort l9e2 b 9 ,novemb] #ahgd fre% exp]im5ts 7 made betwe5 ,fr$]icia & ,cop5hag5 on a l9e #bbe miles 9 l5g?1 & x 0 asc]ta9$ t vibratory effects c\ld be easily transmitt$1 ev5 "u ! influ5ce ( a r weak batt]y4 ,illu/ration3 ,,fig4 #ei4 ,9 ,m4 ,lac\r's sy/em1 ! s5d+ in/rum5t is a simple tun+-=k1 plac$ 9 a horizontal position1 & "o ( its arms reacts on a contact break]1 :i* c produce precisely ! same numb] ( dis*>ges ( curr5ts z !re are vibrations ( ! tun+-=k4 ,if a ,morse manipulator is ins]t$ 9 ! circuit1 x is evid5t t if x is work$ s z to produce ! dots & da%es ( ! ,morse alphabet1 ! same signals w be reproduc$ at ! opposite /ation1 & ! signals w be manife/$ by long & %ort s\nds1 if an electro-magnetic receiv] is connect$ ) ! circuit4 ,?is s5d] is %[n fig4 #ei4 ,fig4 #fj repres5ts ,m4 ,lac\r's receiv]4 ,x consi/s ( a tun+-=k ,f made ( s(t iron1 n ( /eel l ! s5d+ tun+-=k1 & ea* ( its bran*es is ins]t$ 9 ! bobb9 ( an electro-magnetic coil ,c ,c2 two di/9ct electro-magnets ,m ,m react close to ! extremities ( ! =k1 9 su* a way t ! pol>ities develop$ on ! two bran*es ( ! =k "u ! influ5ce ( ! coils ,c ,c %\ld be ( contr>y signs to ^? ( ! electro-magnets ,m ,m4 ,illu/ration3 ,,fig4 #fj4 ,if ?is d\ble electro-magnetic sy/em is ins]t$ 9 a l9e circuit1 x foll[s t1 = ea* dis*>ge ( ! transmitt$ curr5t1 a correspond+ attraction ( ! bran*es ( ! tun+-=k w take place1 & consequ5tly !re w be a vibration1 produc+ a s\nd1 if ! dis*>ges are num]\s4 ,?is s\nd w naturally be %ort or long 9 proportion to ! duration ( ! s5d]'s action1 & x w be ! same z t ( ! tun+-=k 9 t in/rum5t4 ,aga91 if "o bran* ( ! tun+-=k reacts on a contact ,p ins]t$ 9 ! circuit ( ! local batt]y communicat+ ) a ,morse receiv]1 traces w be produc$ on ?is receiv] ( l5g? v>y+ ) ! duration ( ! s\nds1 = ! ,morse electro-magnet w be s quickly affect$ by ! successive breaks 9 ! curr5t t its armature w rema9 /ation>y ?r\gh\t ea* vibration4 #8,i h n yet be5 able1' said ,m4 ,lac\r 9 an address deliv]$ be=e ! ,dani% ,academy ( ,sci5ce 9 #ahge1 #8to calculate ! "t necess>y = ! production ( def9ite vibrations 9 ! tun+-=k4 ,diff]5t factors h to be consid]$1 b exp]im5t has %[n t ! "t :i* elapses be=e ! local circuit is brok5 is su* a small fraction ( a second z to be almo/ inappreciable1 ev5 :5 ! curr5t is v weak4 #8,s9ce int]mitt5t curr5ts only affect a tun+-=k on condition t x vibrates 9 unison ) ! "o :i* produces !m1 x foll[s t if a s]ies ( s5d+ tun+-=ks1 tun$ to ! diff]5t notes ( ! scale1 is plac$ at "o end ( a circuit1 & if a simil> s]ies ( electro-magnetic tun+-=ks1 9 exact accordance ) ! fir/1 is plac$ at ! o!r end ( ! circuit1 ! int]mitt5t curr5ts transmitt$ by ! s5d+ tun+-=ks w be add$ to ea* o!r )\t becom+ confus$1 & ea* ( ! receiv+ tun+-=ks w only be affect$ by ! curr5ts emitt$ by ! tun+-=k 9 unison ) x4 ,9 ?is way ! comb9ations ( elem5t>y signals repres5t+ a ^w may be telegraph$ simultane\sly4' ,m4 ,lac\r enum]ates ! ways 9 :i* ?is sy/em may be appli$ z foll[s3 #8,if ! keys 9 connection ) ! s5d+ tun+-=ks are plac$ side by side1 & are l[]$ 9 succession1 or two or ?ree toge!r1 x w be en\gh to play on ! keys z on a musical in/rum5t1 9 ord] t ! air may be he>d at ! receiv+ /ation1 or ! signals transmitt$ simultane\sly may ea* belong to a diff]5t message4 ,?is sy/em w !re=e all[ ! fur!/ /ation on a l9e to communicate ) "o or sev]al int]m$iate /ations1 & vice v]sa1 )\t di/urb+ ! communication at o!r /ations4 ,9 ?is way two /ations c ex*ange signals1 unp]ceiv$ by ! re/4 ,! p[] ( s5d+ _m signals at once af=ds a good means ( improv+ ! autographic telegraph4 ,9 ! in/rum5ts n[ 9 use1 su* z ^? ( ,caselli & ,d',arl9c\rt1 !re is only "o trac+ /ylus1 & ?is /ylus mu/ pass ov] ! :ole surface ( ! telegram 9 ord] to obta9 a copy ( x1 b ) ! telephone a c]ta9 numb] ( /yli may be plac$ side by side 9 ! =m ( a comb1 & ?is comb ne$ only be drawn 9 a c]ta9 direction to pass ov] ! surface ( ! telegram4 ,9 ?is way a m fai?ful copy w be obta9$ 9 a %ort] "t4' ,m4 ,lac\r also obs]ves t 8 sy/em possesses a m]it already po9t$ out by ,mr4 ,v>ley1 namely1 t ! in/rum5ts p]mit ! passage ( ord9>y curr5ts )\t reveal+ _! pres5ce1 :5ce x foll[s t ! accid5tal curr5ts :i* (t5 di/urb telegraphic transmissions w h no effect on ^! sy/ems4 ,m4 ,lac\r began )\t apply+ an electro-magnetic sy/em to 8 in/rum5t 9 ord] to ma9ta9 ! movem5t ( ! tun+-=k1 b he soon saw t ?is accessory 0 indisp5sable1 & he made ! tun+-=ks !mselves electro-magnetic4 ,x also occurr$ to him to conv]t ! transmitt$ curr5ts into pulsatory curr5ts by ins]t+ an induction coil 9 ! circuit1 :i* 0 also done by ,mr4 ,eli%a ,gray4 ,f9ally1 9 ord] to obta9 ! imm$iate action ( ! tun+-=ks & ! imm$iate cessation ( _! action1 he con/ruct$ !m s z to r$uce _! in]tia z mu* z possible4 ,?is 0 effect$ by ins]t+ ! two bran*es ( ! tun+-=k 9 ! same coil & by l5g!n+ its h&le1 & turn+ x back s t x might pass ?r\gh a second coil1 divid+ into two bran*es & embrac+ ! two vibrat+ bran*es1 b )\t t\*+ !m4 ,:5 a curr5t trav]ses bo? coils1 x produces1 9 ! k9d ( horse%oe magnet =m$ by ! two sy/ems1 opposite pol>ities :i* provoke a d\ble reaction 9 ! vibrat+ bran*es--a reaction by repulsion ex]t$ by ! two bran*es 9 virtue ( ! same pol>ity1 & a reaction by attraction by ! o!r two bran*es 9 virtue ( _! opposite pol>ities2 & ?is d\ble action is repeat$ by ! movem5ts ( a contact break] appli$ to "o ( ! vibrat+ bran*es ( ! tun+-=k4 ,illu/ration3 ,,fig4 #fa4 ,mr4 ,eli%a ,gray's ,sy/em4--,accord+ to ! sy/em orig9ally pat5t$1 ea* s5d]1 repres5t$ fig4 #fa1 consi/s ( an electro-magnet ,m ,m re/+ bel[ a small copp] tablet ,b ,s1 9 su* a way t its poles pass ?r\gh ?is tablet & are on a level ) its upp] surface4 ,a /eel plate ,a ,s is fix$ above ^! poles2 its t5sion c be regulat$ by means ( a screw ,s2 & ano!r screw c is plac$ on ! plate1 & is 9 electric communication ) a local batt]y ,r by means ( a ,morse key4 ,bel[ ! plate ,a ,s !re is a contact d connect$ ) ! l9e wire ,l2 ?is contact is met by ! plate at ! mom5t ( its attraction by ! electro-magnet1 & breaks ! curr5t ( a l9e batt]y ,p1 :i* acts on ! receiv] ( ! opposite /ation4 ,f9ally1 ! electric communication e/abli%$ betwe5 ! local batt]y ,r & ! electro-magnet1 z may be se5 9 ! figure1 produces vibrations 9 ! /eel plate ,a ,s at ea* l[]+ ( ! key1 z 9 ! case ( ord9>y vibrations--vibrations :i*1 ) a suitable t5sion ( ! plate & a giv5 int5sity ( ! batt]y ,r1 c produce a def9ite musical note4 ,moreov]1 s9ce at ea* vibration ! plate ,a ,s meets ! contact1 dis*>ges ( ! l9e curr5t take place ?r\gh ! l9e ,l1 & react on ! receiv+ in/rum5t1 caus+ x to reproduce exactly ! same vibrations z ^? ( ! s5d+ in/rum5t4 ,illu/ration3 ,,fig4 #fb4 ,! receiv+ in/rum5t repres5t$ fig4 #fb exactly resembles ! "o we h j describ$1 except t !re is no contact d bel[ ! vibrat+ plate ,a ,s1 & ! contact c1 in/ead ( communicat+ ) ! l9e wire1 is 9 electric connection ) a regi/] ,e & a local batt]y ,p4 ,x foll[s f ?is arrangem5t t :5 ! plate ,a ,s vibrates "u ! influ5ce ( ! brok5 curr5ts pass+ ?r\gh ! electro-magnet ,m ,m1 simil> vibrations are s5t ?r\gh ! regi/]2 b if ! electro-magnetic organ ( ?is regi/] is prop]ly regulat$1 ^! vibrations c only produce ! effect ( a cont9u\s curr5t1 & h5ce ! l5g? ( ! traces left on ! in/rum5t w v>y ) ! duration ( ! s\nds produc$4 ,9 ?is way ! regi/ration ( ! da%es & dots :i* con/itute ! signs ( ! ,morse vocabul>y w be effect$4 ,if x is rememb]$ t ! plate ,a ,s vibrates "u ! influ5ce ( electro-magnetic attractions m readily 9 proportion to _! approximation 9 numb] to ! vibrations correspond+ to ! fundam5tal s\nd x c emit1 x becomes cle> t if ?is plate is tun$ to ! same note z t ( ! correspond+ in/rum5t1 x w be r5d]$ peculi>ly s5sitive to ! vibrations transmitt$ by ! s5d]1 & ! o!r vibrations :i* may affect x w only act fa9tly4 ,moreov]1 a resonator plac$ above ! plate w greatly increase ?is pr$isposition2 s t if sev]al sy/ems ( ?is k9d1 tun$ to diff]5t notes1 produce simultane\s transmissions1 ! s\nds correspond+ to ! diff]5t vibrations w be 9 a c]ta9 s5se select$ & di/ribut$1 9 spite ( _! comb9ation1 into ! receiv]s = :i* !y are specially adapt$1 & ea* ( !m may reta9 ! traces ( ! s\nds emitt$ by add+ ! regi/]1 :i* may be s arrang$ z to act z an ord9>y ,morse receiv]4 ,mr4 ,gray /ates t ! numb] ( s5d+ in/rum5ts & indep5d5t local circuits may be equal to t ( ! tones & semitones ( two or m octaves1 provid$ t ea* vibrat+ plate be tun$ to a diff]5t note ( ! scale4 ,! in/rum5ts may be plac$ side by side1 & _! respective local keys1 arrang$ l ! keys ( a piano1 w make x easy to play an air comb9+ notes & *ords2 !re may also be an int]val betwe5 ! in/rum5ts1 :i* may be suffici5tly f> f ea* o!r to all[ ! employs to "w )\t be+ di/ract$ by s\nds n int5d$ = !m4 ,9 a new arrangem5t1 exhibit$ at ! ,p>is ,exhibition1 #ahgh1 ,mr4 ,gray consid]ably modifi$ ! way ( work+ ! v>i\s electro-magnetic organs :i* we h j describ$4 ,9 ?is case1 ! plates consi/ ( tun+-=ks ) "o bran* kept 9 cont9ual vibration at bo? /ations1 & ! signals only become p]ceptible by int5sify+ ! s\nds produc$4 ,?is arrangem5t foll[s f ! necessity ( keep+ ! l9e circuit always clos$ = multiple transmissions ( ?is nature1 s z to react ) pulsatory curr5ts1 :i* are alone able1 z we h already se51 to reta9 ! individual "* ( sev]al s\nds simultane\sly transmitt$4 ,illu/ration3 ,,fig4 #fc4 ,"u ^! conditions1 ! s5d] consi/s1 z we see 7fig4 #fc71 ( a b> tun+-=k1 a1 :i* is groov$ = ! passage ( a runn]1 heavy en\gh to tune ! =k to ! desir$ note1 & x oscillates betwe5 two electro-magnets e & f & two contacts ,i & ,g4 ,! diff]5ce ( resi/ance 9 ! electro-magnets is v great3 9 ! "o f ! resi/ance is equal to #b miles ( telegraphic wire1 9 ! o!r x does n exce$ #ddj y>ds4 ,:5 electric communication is e/abli%$ z we see 9 ! figure1 ! foll[+ effect takes place4 ,s9ce ! curr5t ( ! local batt]y ?r\gh ! two electro-magnets is brok5 by ! re/-contact ( ! ,morse key ,h1 ! plate a is subject to two contr>y actions2 b s9ce ! electro-magnet f has m turns ?an ! electro-magnet e1 its action is prepond]ant1 & ! plate is attract$ t[>ds f1 & produces a contact ) ! spr+ ,g1 :i* op5s a way ( less resi/ance = ! curr5t4 ,s9ce ! curr5t !n passes almo/ :olly ?r\gh ,g1 b1 #a1 #b1 ,b1 ! electro-magnet is n[ able to act2 ! plate a is !n attract$ t[>ds e1 &1 by produc+ a contact on ! spr+ ,i1 x s5ds ! curr5t ( ! l9e ,b ,p ?r\gh ! telegraphic l9e1 if ! key ,h is at ! same "t l[]$ on ! s5d+ contact3 if n1 !re w be no effect 9 ?is direction1 b s9ce ! plate a has left ! spr+ ,g1 ! fir/ effect ( attraction by ! electro-magnet f w be repeat$1 & ?is t5ds to draw ! plate aga9 t[>ds f4 ,?is /ate ( ?+s is repeat$ indef9itely s z to ma9ta9 ! vibration ( ! plate1 & to s5d out signals correspond+ ) ^! vibrations :5ev] ! key ,h is l[]$4 ,! ela/ic nature ( ! plate makes ^! vibrations m easy1 & x ought also to be put 9 me*anical vibration at ! outset4 ,! receiv]1 repres5t$ fig4 #fd1 consi/s ( an electro-magnet ,m1 m\nt$ on a s\nd+-box ,c1 & hav+ an armature =m$ by a tun+-=k ,l ,l firmly buttress$ on ! box by a cross b> ,t4 ,!re is a runn] ,p on ! armature1 slid+ 9 a groove1 :i* makes x possible to tune ! vibrations ( ! tun+-=k to ! fundam5tal note ( ! s\nd+-box ,c1 :i* is s arrang$ z to vibrate 9 unison ) x4 ,"u ^! conditions1 ! box z well z ! tun+-=k w act z an analys] ( ! vibrations transmitt$ by ! curr5ts1 & may set ! regi/] at "w by itself react+ on a break] ( ! local curr5t4 ,to obta9 ?is result1 a membrane ( gold-beat]'s sk9 or p>*m5t mu/ be /ret*$ be=e ! op5+ ( ! box1 & a plat9um contact mu/ be appli$ to x1 s arrang$ z to meet a metallic spr+ connect$ ) any k9d ( regi/] or a ,morse in/rum5t1 :5 ! membrane vibrates4 ,z1 h[ev]1 9 ,am]ica ! messages are g5]ally receiv$ by s\nd1 ?is addition to ! sy/em is n 9 use4 ,illu/ration3 ,,fig4 #fd4 ,! in/rum5t is n only regulat$ by ! runn] ,p1 b also by a regulat+ screw ,v :i* all[s ! electro-magnet ,m to be prop]ly adju/$4 ,! regulat+ sy/em is made m exact by ! small screw ,v1 & ! in/rum5t is connect$ ) ! l9e by ! b9d+ screw ,b4 ,( c\rse ?is d\ble arrangem5t is necess>y = ea* ( ! s5d+ sy/ems4 ,z ,i h already said1 sev5 diff]5t messages might !oretically be s5t at once 9 ?is way1 b ,mr4 ,gray has only adapt$ 8 in/rum5t = f\r2 he has1 h[ev]1 made use ( ! duplex sy/em1 :i* all[s him to d\ble ! numb] ( transmissions1 s t eight messages may be s5t at ! same "t1 f\r 9 "o direction1 & f\r 9 ano!r4 ,mr4 ,hosk9s ass]ts t ?is sy/em has be5 work$ ) complete success on ! l9es ( ! ,we/]n ,union ,telegraph ,company1 f ,bo/on to ,new ,york1 & f ,*icago to ,milwaukee4 ,s9ce ^! exp]im5ts 7 made1 fre% improvem5ts h r5d]$ x possible to s5d a mu* l>g] numb] ( messages4 ,mr4 ,gray has also1 aid$ by ,mr4 ,hosk9s1 devis$ a sy/em by :i* telephonic messages may be s5t on a wire previ\sly us$ = ,morse in/rum5ts4 ,mr4 ,v>ley _h already solv$ ?is problem1 b ,mr4 ,gray's sy/em seems to h produc$ important results1 & has !re=e a claim to our att5tion4 ,we d n1 h[ev]1 describe x "h1 s9ce x is n )9 ! l9es m>k$ out = u1 & ^? :o are int]e/$ 9 ! subject w f9d all ! necess>y details 9 a pap] ins]t$ 9 ! #8,j\rnal ( ! ,society ( ,telegraphic ,eng9e]s1 ,london1' vol4 vi4 ,mr4 ,v>ley's ,sy/em4--,?is sy/em is evid5tly ! e>lie/ 9 date1 s9ce x 0 pat5t$ 9 #ahgj1 & ! pat5t describes ! pr9ciple ( mo/ ( ! arrangem5ts :i* h s9ce be5 adopt$ by ,messrs4 ,lac\r1 ,gray1 & ,bell4 ,x is bas$ ^u ! use ( 8 own musical telephone1 :i* we h already describ$1 b ) "s v>iations 9 its arrangem5t1 :i* make x some:at l ! ,reiss sy/em4 ,x 0 ,mr4 ,v>ley's aim to make 8 telephone "w 9 conjunction ) in/rum5ts ) ord9>y curr5ts1 by ! addition ( rapid electric waves1 incapable ( mak+ any practical *ange 9 ! me*anical or *emical capacity ( ! curr5ts :i* s]ve = ! ord9>y signals1 yet able to make di/9ct signals1 p]ceptible to ! e> & ev5 to ! eye4 ,he says3 #8,an electro-magnet (f]s at fir/ a great resi/ance to ! passage ( an electric curr5t1 & may consequ5tly be reg>d$ z a p>tially opaque body ) respect to ! transmission ( v rapid inv]se curr5ts or ( electric waves4 ,!re=e1 if a tun+-=k1 or an in/rum5t ) a vibrat+ plate1 tun$ to a giv5 note1 be plac$ at ! s5d+ /ation1 & s arrang$ z to be kept 9 con/ant vibration by magnetic influ5ce1 ! curr5t :i* acts ^u x mu/ be pass$ into two helices plac$ "o above ! o!r s z to con/itute ! prim>y helix ( an induction coil3 9 ?is way x w be possible to obta9 9 two di/9ct circuits two s]ies ( rapidly brok5 curr5ts1 :i* w correspond to ! two directions ( ! vibrations ( ! tun+-=k1 & we %all also h ! induc$ curr5ts produc$ 9 ! second>y helix by ^! curr5ts1 :i* may act on a ?ird circuit4 ,?is ?ird circuit may be plac$ 9 connection ) a telegraphic l9e previ\sly us$ by an ord9>y telegraphic sy/em1 if a cond5s] is appli$ to x1 & 9 ?is way two diff]5t transmissions may be obta9$ simultane\sly4' ,illu/ration3 ,,fig4 #fe4 ,fig4 #fe repres5ts ! arrangem5t ( ?is sy/em4 ,d is ! vibrat+ plate ( ! tun+-=k design$ to produce ! electric contacts necess>y to ma9ta9 x 9 motion4 ,^! contacts are at ,s & ,s1 & ! electro-magnets :i* affect x are at ,m & ,m4 ,! induction coil is at ,i1 & ! ?ree helices ( :i* x is compos$ are indicat$ by ! circul> l9es :i* surr\nd x4 ,!re is a ,morse manipulator at ,a1 ano!r at ,a1 & ! two batt]ies :i* "w ! sy/em are at ,p & ,p4 ,! cond5s] is at ,c1 & ! telephone is at ! end ( ! l9e ,l4 ,:5 ! vibration ( ! plate ,d t5ds to ! "r1 & ! electric contact takes place at ,s1 ! curr5t ( ! batt]y ,p1 aft] trav]s+ ! prim>y helix1 rea*es ! electro-magnets ,m ,m1 :i* give x an impulse 9 ! contr>y direction4 ,:51 on ! o!r h&1 x t5ds to ! left1 ! curr5t is s5t ?r\gh ! second prim>y circuit1 :i* w be balanc$ by ! fir/4 ,consequ5tly !re w be a s]ies ( rev]s$ curr5ts 9 ! induc$ circuit correspond+ to ! key ,a1 :i* w alt]nately *>ge & dis*>ge ! cond5s] ,c1 ?us s5d+ into ! l9e a correspond+ s]ies ( electric undulations :i* w react on ! telephone plac$ at ! end ( ! l9e2 & z ! duration ( ! transmitt$ curr5ts w v>y ) ! "t t ! key ,a is l[]$1 a correspond5ce 9 ! ,morse code may be obta9$ 9 ! telephone1 :ile ano!r correspond5ce is ex*ang$ ) ! key ,a & ! ord9>y ,morse receiv]s4 ,9 ord] to r5d] ! vibratory signals visible1 ,mr4 ,v>ley proposes to use a f9e /eel wire1 /ret*$ ?r\gh a helix & fac+ a n>r[ slit1 to reproduce ! vibrations4 ,a light1 :i* is int]cept$ by ! wire1 is plac$ beh9d ! slit4 ,z soon z a curr5t passes1 ! wire vibrates & ! light appe>s4 ,a l5s is plac$ s z to magnify ! image ( ! lum9\s slit1 & project x on a :ite scre5 :ile ! wire is 9 vibration4 ,,v>i\s ,,uses ,,( ,,! ,,telephone4 ,its dome/ic application4--,we h se5 t telephones may be us$ ) advantage 9 public & private (fices3 !y c be set up at a mu* less exp5se ?an ac\/ic tubes1 & 9 cases :]e ! latt] w\ld nev] be employ$4 ,) ! aid ( ! calls we h describ$1 !y (f] ! same advantages1 & ! connection betwe5 ! in/rum5ts is m easily conceal$4 ,! diff]5ce ( price 9 e/abli%+ !m is 9 ! ratio ( "o to sev54 ,= ?is purpose electro-magnetic telephones are evid5tly ! be/1 s9ce !y require no batt]y & are always ready to "w4 ,!y are already 9 use 9 _m ,gov]nm5t (fices1 & x is probable t !y w soon be comb9$ ) electric bells = ! s]vice ( hotels & ( l>ge public & private e/abli%m5ts3 !y may ev5 be us$ 9 private h\ses = giv+ ord]s to s]vants & port]s1 :o may ?us save visitors f ! fatigue ( a useless asc5t ( sev]al /oreys4 ,9 factories1 telephones w c]ta9ly soon replace ! telegraphic communication :i* has already become g5]al4 ,!y may n only be us$ = ord9>y messages1 b to call = help 9 case ( fire1 & !y w become an integral "p ( sev]al sy/ems already e/abli%$ = ?is purpose4 ,9 c\ntries :i* h free telegraphic communication1 ! telephone has already replac$ 9 great measure ! private telegraph in/rum5ts :i* h hi!rto be5 9 use2 & if ! same privilege is ext5d$ to ,france1 no o!r mode ( correspond5ce w be us$4 ,its application to telegraphic s]vice4--,! advantage to be d]iv$ by ! telegraphic s]vice f ! telephone is r limit$1 s9ce1 z f> z ! spe$ ( transmission is conc]n$1 x is ( less value ?an _m ( ! telegraphic in/rum5ts n[ 9 use1 & ! messages :i* x produces _c be regi/]$4 ,yet 9 municipal (fices n ov]burd5$ ) messages !y (f] ! advantage ( n requir+ a tra9$ s]vice4 ,on long] l9es _! use w\ld be ( little value4 ,! #8,b]ne ,telegraphic ,j\rnal' has publi%$ "s int]e/+ rem>ks on ?is subject1 ( :i* ! foll[+ is a summ>y4 #a/4 ,9 ord] to s5d a message ) ! special advantages ( ! sy/em1 ! s5d] ought to be able to address 8 correspond5t )\t ! int]v5tion ( an (ficial4 ,^? :o are acqua9t$ ) ! network ( wires "k ?is to be impossible4 ,int]m$iate (fices = receiv+ messages are ess5tial1 & ! public _c be admitt$ to ^? set ap>t = s5d+ & receiv+2 consequ5tly ! s5d] mu/ deliv] a writt5 message4 #bnd4 ,if ! message is writt51 ! *ief advantage ( ! in/rum5t is lo/1 s9ce x mu/ be read & utt]$ al\d1 :i* c\ld n be done if express$ 9 a language ) :i* ! employs 7 unacqua9t$4 #crd4 ,! in/rum5ts n[ 9 use at ! telegraph (fices c transmit messages m quickly ?an if !y 7 spok54 ,9 ,g]many1 h[ev]1 a telephone s]vice has be5 e/abli%$ 9 sev]al telegraph (fices1 & its possible advantages are enum]at$ z foll[s 9 ! (ficial circul> :i* creat$ x3 #8,! (fices :i* w be op5$ to ! public = ! s]vice ( telephonic messages 9 ,g]many w be reg>d$ z indep5d5t e/abli%m5ts2 yet !y w be 9 connection ) ! ord9>y telegraph (fices1 :i* w und]take to s5d telephonic messages ?r\gh _! wires4 #8,! transmission w take place z foll[s3 ,! s5d+ (fice w reque/ ! receiv+ (fice to prep>e ! in/rum5t2 z soon z ! tubes are adju/$1 ! s5d+ (fice w give ! signal = despat*+ ! v]bal message4 #8,! s5d] mu/ speak sl[ly & cle>ly1 )\t rais+ 8 voice2 ea* syllable mu/ be di/9ctly pron\nc$2 ! f9al syllables especially mu/ be well articulat$1 & !re mu/ be a pause aft] ea* ^w1 9 ord] to give ! receiv] "t to write x d[n4 #8,:5 ! telegram has be5 receiv$1 ! employ at ! receiv+ (fice mu/ v]ify ! numb] ( words2 !n he mu/ repeat ?r\gh ! telephone ! :ole message )\t paus+1 s z to make sure t !re is no mi/ake4 #8,9 ord] to ensure secrecy1 ! telephones are plac$ ap>t1 :]e p]sons unconnect$ ) ! s]vice _c he> ! v]bal message1 & ! employs are =bidd5 to reveal to anyone ! names ( ! correspond5ts4 #8,! *>ge = telephonic messages1 z = ! ord9>y telegraphic s]vices1 is at ! rate ( s mu* a ^w4' ,! use ( ! telephone has also be5 sugge/$ = v]ify+ ! p]fect junction ( telegraphic wires4 ,x is c]ta9 t1 if ! junction is complete1 no abnormal s\nds w be he>d1 or only ^? :i* result f accid5tal curr5ts2 b if ! junction is bad1 ! imp]fect contacts :i* take place produce v>iations 9 electric int5sity :i* are translat$ into ! m or less m>k$ s\nds obs]v$ 9 ! telephone4 ,m4 ,mauborgne1 ! electrician atta*$ to ! ,nor!rn ,railway ( ,france1 has lately us$ ! telephone in/ead ( ! galvanomet] to asc]ta9 ! condition ( ! circuits 9 correspond5ce ) ! in/rum5ts 9 use = electric signals4 ,! reactions produc$ on ! galvanomet] ne$le by ! pieces ( iron :i* are plac$ at ! sides ( ! railway (t5 make its indications unc]ta91 & a /rong w9d produces irregul> movem5ts 9 ! in/rum5t :i* int]f]e ) obs]vations4 ,x 0 also necess>y to place ! galvanomet] ) due reg>d to ! po9ts ( ! compass1 & to wait = ! ne$le to settle1 :i* involv$ loss ( "t4 ,! op]ation is easily accompli%$ ) ! telephone1 s9ce ! /rokes ( ! call-bell are di/9ctly reproduc$2 x is made to r+ by work+ ! contacts :i* ne$ v]ification1 & 9 ! same way ! condition ( ! batt]y c be asc]ta9$4 ,application to milit>y purposes4--,s9ce ! telephone 0 inv5t$1 num]\s exp]im5ts h be5 made 9 diff]5t c\ntries to asc]ta9 :e!r x w\ld be ( use 9 milit>y op]ations4 ,^! exp]im5ts h hi!rto be5 only mod]ately satisfactory1 on acc\nt ( ! noise insep>able f an army1 :i* g5]ally makes x impossible to he> ! telephone1 & e means ( int5sify+ its s\nds has be5 eag]ly s\ght4 ,x 0 at fir/ suppos$ t ! discov]y ( ! microphone _h solv$ ! problem1 & ,i receiv$ _m enquiries f milit>y s*ools on ! subject1 b ,i h n be5 able to see t any?+ has be5 ga9$ f ?is po9t ( view4 ,! telephone is1 h[ev]1 ( great use 9 s*ools ( artill]y & rifle practice4 ,n[ t fire>ms c>ry s f>1 x has become necess>y to be in=m$ by telegraph ( ! po9ts hit on ! t>get1 9 ord] to judge ( ! accuracy ( aim1 & = ?is purpose telegraphic t>gets 7 sugge/$2 b telephones are mu* to be pref]r$1 & !y are n[ us$ ) good effect4 ,if ! telephone is unsuit$ = ! s]vice ( ! fly+ telegraph 9 ! field1 x may be ( great use 9 ! def5ce ( t[ns1 to transmit ! ord]s ( ! comm&ant to diff]5t batt]ies1 & ev5 = ! ex*ange ( correspond5ce ) captive balloons s5t to hov] ov] fields ( battle4 ,9 spite ( ! difficulties att5d+ its use1 ! exp]im5t 0 made by ! ,russians 9 ! late w>3 ! cable wire ( communication 0 #ejj or #fjj y>ds long1 & s light t x c\ld be laid by "o man4 ,! #8,telegraphic ,j\rnal' ( ,m>* #ae1 #ahgh1 /ates t ! bad wea!r did n int]f]e ) ! work+ ( ! in/rum5ts2 b ! noise made x difficult to he>1 & x 0 necess>y to cov] ! head ) a hood to int]cept ext]nal s\nds4 ,?is _c be consid]$ a satisfactory result1 yet ! telephone may be ( great s]vice to an army by int]cept+ ! enemy's messages3 a bold man1 provid$ ) a pocket telephone1 :o plac$ himself 9 a retir$ spot1 might div]t ! curr5t ( ! enemy's telegraphic wire into 8 telephone1 & get possession ( all 8 despat*es1 z we saw 0 ! case at ,cl]mont4 ,he might ev5 d ?is by div]t+ ! curr5t to e>? or to a rail ( ! railway l9e4 ,^! are sugge/ions = future rese>*1 & x is probable t !y may "s day be turn$ to practical acc\nt4 ,its application to ! navy4--,! telephone may be ( ! greate/ use 9 naval matt]s1 = ! s]vice ( electro-semaphores1 = isl& =ts & %ips at an*or4 ,m4 ,poll>d says t #8exp]im5ts made betwe5 ! ,prfecture ,m>itime at ,*]b\rg1 ! semaphores & ! =ts on ! mole1 demon/rate ! advantage !re w\ld be 9 e/abli%+ telephones at ^! /ations1 s9ce !y w\ld ensure an easy communication betwe5 ! vessels ( a squadron & ! l& !y are approa*+4 ,by s9k+ small cables :i* come to ! surface ( ! wat] along moor+ *a9s1 & t]m9ate 9 buoys or cases :i* rema9 p]man5tly 9 ! h>b\r1 ! %ips ( w> may 9 ?is way place !mselves 9 communication ) ! ,prfecture ,m>itime z !y ca/ an*or1 &1 by tempor>ily connect+ ! vessels toge!r ) light cables1 ! admiral may communicate freely ) ! :ole squadron4' ,! telephone has be5 tri$ on bo>d %ip = transmitt+ ord]s1 b )\t success1 on acc\nt ( ! noise always go+ on 9 a vessel4 ,! telephone may be usefully appli$ to ! s]vice ( subm>9e torp$oes4 ,we h already se5 h[ x may be appli$ 9 connection ) ! microphone1 b x may also be us$ 9 fir+ ! torp$oes aft] ! exact position ( ! enemy's %ip has be5 asc]ta9$ f two reconnaissances tak5 f diff]5t p>ts ( ! coa/4 ,! telephone1 aga91 makes x possible to v]ify ! condition ( torp$oes1 & to asc]ta9 if !re is any fault 9 ! circuit )9 ! explosives4 ,= ?is purpose a v weak curr5t has be5 us$1 & a galvanomet] is n always able to indicate ! fault1 :ile ! extreme s5sitiv5ess ( ! telephone w d s 9 ! simple/ way4 ,capta9 ,m',evoy1 ( ! ,am]ican ,army1 sugge/$ a way ( asc]ta9+1 :ile on %ore1 ! condition ( torp$oes "u wat]1 by connect+ ! buoys :i* support !m ) ! l& by means ( a telephonic l9e4 ,by ins]t+1 9 ! buoy :i* supports ! torp$o1 metallic disks1 s arrang$ z to vibrate ) e movem5t caus$ by ! waves ^u ! buoy1 a cont9u\s noise w be he>d 9 ! telephone1 aft] ! circuit has be5 complet$ by ! metallic disks2 & ! noise w g on z long z ! disks cont9ue to oscillate1 & w cease z soon z ! buoy is completely cov]$ by ! wat]4 ,:5 x ceases1 !re=e1 if n affect$ by "s accid5tal cause1 x may be suppos$ t ! enemy's %ip is pass+ ov] ! buoy4 ,m4 ,trve1 aga91 has %[n t ! telephone might be us$ ) advantage = ! telegraphic communication betwe5 vessels 9 t[1 & ,m4 des ,portes has appli$ x ) good effect to div+ op]ations4 ,9 ?is in/ance1 "o ( ! glass panes 9 ! helmet is replac$ by a copp] plate 9 :i* ! telephone is fram$1 s t ! div] ne$ only make a slight movem5t ( 8 head 9 ord] to receive or address communications to ^? 9 *>ge ( ! app>atus4 ,) ?is sy/em ! keels ( vessels may be exam9$1 & an acc\nt giv5 ( _! condition1 )\t br++ up ! div]s1 :i* has hi!rto be5 necess>y4 ,m4 de ,p>ville1 ! able & le>n$ editor ( ! ,j\rnal ,sci5tifique & ! sci5ce dep>tm5t ( ! ,j\rnal des ,dbats1 has sugge/$ a new & int]e/+ application ( ! telephone4 ,x conc]ns ! possibility ( mak+ use ( x to det]m9e ! precise position ( ! magnetic m]idian1 t is1 ! true direction ( ! magnetis$ ne$le4 ,= ?is purpose a ,bell telephone is necess>y1 ( :i* ! magnetic core is =m$ ( an iron rod a mtre 9 l5g?1 kept1 by a suitable susp5sion1 at ne>ly ! same angle ( incl9ation z a dipp+-ne$le4 ,?is rod w be magnetis$ "u ! influ5ce ( t]re/rial magnetism1 & ! telephone w be able to transmit ! s\nds produc$ by "s sort ( vibrator plac$ ne> its m\?piece4 ,^! s\nds w be /rong 9 proportion to ! degree ( magnetisation ( ! b>2 & if ! telephone is turn$ r\nd ! horizon1 keep+ ! b> at ! same angle ( incl9ation1 ! s\nds transmitt$ to ! receiv+ telephone w be greate/ :5 ! axis ( ! b> is 9 ! plane ( ! magnetic m]idian1 & lea/ :5 x is at #ij4 ,x w !re=e be possible to asc]ta9 f ! direction ( ! axis at ! mom5t :5 ! s\nds are no long] he>d1 ! exact incl9ation ( ! magnetic ne$le f nor? to s\?1 = x w be giv5 by ! p]p5dicul> to ! l9e :i* is foll[$ by ! axis ( ! iron b> at t mom5t4 ,x is possible t1 ) ?is sy/em1 ! di/urb+ influ5ce on ! magnetic ne$le ( ! mass ( iron 9 iron-plat$ vessels might be almo/ de/roy$1 & a m exact ori5tation ?an t ( ! compass might be obta9$4 ,! same process may make x possible to e/imate & measure ! v>iations ( t]re/rial magnetism4 ,m4 de ,p>ville has n himself tri$ to apply ?is sy/em2 b ,mr4 ,blake's exp]im5ts1 ( :i* we spoke 9 an e>ly "p ( ?is "w1 make x probable t x might be done ) advantage4 ,application to indu/ry4--,"o ( ! e>lie/ & mo/ important applications ( ! telephone is t :i* 0 fir/ made to ! s]vice ( m9es 9 ,engl& & ,am]ica 9 ! autumn ( #ahgg4 ,! great l5g? ( ! gall]ies is well kn[n1 & _h already involv$ ! use ( ! electric telegraph = transmitt+ ord]s2 b ! m9]s did n und]/& h[ to "w ^! in/rum5ts1 & ! s]vice 0 ill p]=m$4 ,?anks to ! telephone1 ?r\gh :i* ! fir/ corn] c s5d & receive a message1 !re is no long] any difficulty 9 ! communication betwe5 ! gall]ies & ! surface ( ! m9e4 ,! v5tilation ( m9es c also be regulat$ by ! aid ( telephones4 ,if "o ( ^! in/rum5ts is plac$ ne> a :eel kept 9 motion by ! air :i* passes ?r\gh ! v5tilat+ %aft1 & ano!r is plac$ 9 ! inspector's (fice he c asc]ta9 by ! s\nd if ! v5tilation is duly c>ri$ on1 & if ! ma*9e works regul>ly4 ,application to sci5tific rese>*4--,m4 d',arsonval's exp]im5ts1 :i* we h already m5tion$1 %[ t ! telephone c be us$ z an extremely s5sitive galvanoscope2 b s9ce x c only produce s\nds "u ! influ5ce ( brok5 curr5ts1 ! circuit on :i* ! exp]im5t is made mu/ be divid$ at r close int]vals4 ,x has be5 se5 t x is n ev5 necess>y to ins]t ! telephone 9 ! circuit3 x may be influ5c$1 :5 at a di/ance1 ei!r imm$iately or by ! induction ( ! brok5 curr5t on a circuit plac$ p>allel to ! fir/1 & ! =ce ( ^! effects may be increas$ by ! reaction ( a core ( iron1 r\nd :i* ! induc+ circuit is w\nd4 ,! drawback to ?is sy/em is t ! direction ( ! curr5t is n asc]ta9$1 s t x _c be us$ z a measur+ in/rum5t2 b1 on ! o!r h&1 x is s s5sitive1 s easy to arrange1 & s inexp5sive1 t x might be ( ! greate/ use z a galvanoscope4 ,mr4 ,w>r5 de ,la ,rue has also made use ( ! telephone 9 8 rese>*es into ! electric dis*>ges ( high-t5sion batt]ies1 9 ord] to foll[ ! diff]5t phases ( ! dis*>ge dur+ ! lum9\s ph5om5a :i* x produces4 ,9 ?is way he asc]ta9$ t :5 a cond5s] is plac$ 9 connection ) a batt]y =m$ ( a consid]able numb] ( insulat$ elem5ts1 & is gradually dis*>g$ ?r\gh a ,geissl] tube1 a dull & fa9t s\nd is he>d 9 ! telephone1 z long z ! /ratifications ( light appe> to be p]fectly /able2 b ! s\nd becomes consid]ably /rong]1 & sometimes ev5 pi]c+1 9 proportion to ! diffusion ( ^! /ratifications1 & to _! approa* to ! po9t ( ext9ction3 :5ce x is %[n t ! dis*>ge ( a batt]y into tubes 9 :i* a vacuum has be5 made is int]mitt5t4 ,mr4 ,spottiswoode has repeat$ ! same exp]im5ts ) ! dis*>ges ( ,holtz ma*9es1 & ) l>ge cond5s]s1 & he f\nd t ! mo/ pi]c+ s\nds produc$ by ! telephone co9cid$ ) ! greate/ developm5t ( ! /ratifications4 ,^! s\nds1 h[ev]1 sometimes ceas$ = a mom5t4 ,x 0 ev5 possible to asc]ta91 f ! int5sity ( ! s\nds produc$1 ! diff]5ces ( t5sion :i* might be manife/$ 9 ! *>ge ( ! cond5s] & ! slack5+ ( ! ma*9e's motion1 & ! diff]5ces ( int5sity 9 ^! s\nds might 9 "s cases exce$ an octave4 ,! fall 9 ! scale g5]ally appe>$ 9 half-tones in/ead ( gradually1 & ! introduction ( resi/ances into ! circuit modifi$ ! s\nds v mu*3 !y might ev5 be int5sifi$ by approa*+ ! f+] to ! dis*>g+ tube4 ,f exp]im5ts made ) ! telephone betwe5 ,calais & ,b\logne1 x appe>s t ?is in/rum5t might be appli$ ) advantage to ! sci5ce ( projectiles4 ,9 fact1 9 "s artill]y practice :i* took place on ! %ore at ,b\logne1 a telephone 0 plac$ close to ! gun1 & ! explosion 0 he>d at a di/ance ( ne>ly two miles1 :]e ! projectile fell4 ,x 0 possible to e/imate its velocity by measur+ ! lapse ( "t betwe5 ! mom5t :5 ! projectile left ! gun1 & its fall4 ,?is calculation is usually made by obs]v+ ! fla% f ! cannon's m\?2 b 9 "s cases1 z 9 a fog or 9 practice at long ranges1 ! telephone may be usefully sub/itut$ = ocul> obs]vation4 ,on ! field ( battle1 an obs]v]1 provid$ ) a telephone & plac$ on a hill1 might rectify f a di/ance ! aim ( 8 batt]y1 :i* is g5]ally e/abli%$ 9 a %elt]$ & less elevat$ place4 ,,! ,,phonograph4 ,mr4 ,edison's ,phonograph1 :i* has = ! la/ ye> attract$ s mu* att5tion1 is an in/rum5t :i* n only regi/]s ! diff]5t vibrations produc$ by spee* on a vibrat+ plate1 b reproduces ! same words 9 correspond5ce ) ! traces regi/]$4 ,! fir/ function ( ?is in/rum5t is n ! result ( a new discov]y4 ,physici/s h long s\ght to solve ! problem ( regi/]+ spee*1 & 9 #ahef ,mr4 ,leo ,scott inv5t$ an in/rum5t well kn[n to physici/s "u ! "n ( ,phonautograph1 :i* completely solv$ ! difficulty3 ?is in/rum5t is describ$ 9 all ! m detail$ treatises on physics4 ,b ! second function ( ! ,edison in/rum5t 0 n realis$ nor ev5 m5tion$ by ,mr4 ,scott1 & we are surpris$ t ?is able inv5tor %\ld h reg>d$ ,mr4 ,edison's inv5tion z an injuri\s act ( spoliation4 ,we regret on 8 own acc\nt1 s9ce no "o has wi%$ to deprive him ( ! cr$it he des]ves1 t he %\ld h publi%$ a pamphlet on ! subject1 c\*$ 9 t]ms ( su* asp]ity1 :i* proves no?+1 & only /ates facts :i* 7 well kn[n to all physici/s4 ,if any o!r p]son c\ld claim ! inv5tion ( ! phonograph1 at lea/ 9 its mo/ curi\s prop]ty ( reproduc+ spee*1 x w\ld c]ta9ly be ,m4 ,*>les ,cros2 = 9 a seal$ pap] deposit$ at ! ,acadmie des ,sci5ces1 ,april #cj1 #ahgg1 he po9t$ out ! pr9ciple ( an in/rum5t by means ( :i* spee* might be reproduc$ 9 accordance ) ! m>ks trac$ on a regi/] l t ( ! phonautograph4#ai ,mr4 ,edison's pat5t1 9 :i* ! pr9ciple ( ! phonograph is fir/ indicat$1 is dat$ ,july #ca1 #ahgg1 & he 0 /ill only occupi$ ) ! repetition ( ! ,morse signals4 ,9 ?is pat5t ,mr4 ,edison describ$ a mode ( regi/]+ ^! signals by means ( ind5tations trac$ ) a /ylus on a %eet ( pap] w\nd r\nd a cyl9d]1 & ?is cyl9d] _h a spiral groove cut on its surface4 ,! trac+s ?us produc$ 7 to be us$ = ! automatic transmission ( ! same message1 by pass+ x aga9 "u a /ylus :i* %\ld react on a curr5t break]4 ,9 ?is pat5t1 !re=e1 no?+ is said ( ! regi/ration ( spee* or ( its reproduction2 b1 z ! #8,telegraphic ,j\rnal' ( ,may #a1 #ahgh1 obs]ves1 ! =ego+ inv5tion gave him ! means ( solv+ ?is d\ble problem z soon z x 0 sugge/$ to him4 ,if we may believe ! ,am]ican j\rnals1 ?is sugge/ion soon came1 & x 0 ! result ( an accid5t4 ,9 ! c\rse ( "s exp]im5ts ,mr4 ,edison 0 mak+ ) ! telephone1 a /ylus atta*$ to ! diaphragm pi]c$ 8 f+] at ! mom5t :5 ! diaphragm began to vibrate "u ! influ5ce ( ! voice1 & ! prick 0 en\gh to draw blood4 ,x !n occurr$ to him t if ! vibrations ( ! diaphragm enabl$ ! /ylus to pi]ce ! sk91 !y might produce on a flexible surface su* di/9ct outl9es z to repres5t all ! undulations produc$ by ! voice1 & ev5 t ! same outl9es might me*anically reproduce ! vibrations :i* _h caus$ !m1 by react+ on a plate capable ( vibrat+ 9 ! same way z t :i* he _h already us$ = ! reproduction ( ! ,morse signals4 ,f t mom5t ! phonograph 0 discov]$1 s9ce !re 0 only a /ep betwe5 ! idea & its realisation1 & 9 less ?an two days ! in/rum5t 0 made & tri$4 ,?is is an +5i\s /ory1 yet we w\ld r believe t ! discov]y 0 made 9 a m s]i\s _s4 ,9 fact1 su* an inv5tor z ,mr4 ,edison1 :o _h discov]$ ! electro-motograph1 & _h appli$ x to ! telephone1 0 already on ! way to discov] ! phonograph1 & we ?9k too well ( 8 p[]s to atta* mu* cr$it to ?is ,am]ican romance4 ,besides1 ,mr4 ,edison 0 well acqua9t$ ) ,mr4 ,scott's phonautograph4 ,mr4 ,edison's phonograph 0 only pat5t$ 9 ,janu>y #ahgg4 ,consequ5tly1 :5 we look at ! pr9ciple ( ! inv5tion1 ,m4 ,cros und\bt$ly may claim priority2 b x is a "q :e!r ! sy/em describ$ 9 8 seal$ pap]1 & publi%$ 9 ! ,sema9e du ,cl]g1 ,octob] #h1 #ahgg1 w\ld h be5 capable ( reproduc+ spee*4 ,our d\bt seems ju/ifi$ by ! unsuccessful attempts ( ! ,abb ,leblanc to c>ry out ,m4 ,cros' idea4 ,:5 we h to d ) su* undulat+ & complex vibrations z ^? involv$ 9 ! reproduction ( articulate words1 x is necess>y t ! /]eotyp+ %\ld 9 "s s5se be effect$ by ! words !mselves1 & _! artificial reproduction w necess>ily fail to m>k ! slight diff]5ces :i* di/+ui% ! delicate comb9ations ( spee*4 ,besides1 ! movem5ts p]=m$ by a po9t conf9$ to a groove t foll[s a s9usoidal curve _c be effect$ ) all ! fre$om necess>y = ! developm5t ( s\nds1 & ! friction ex]t$ on ! two edges ( ! groove w (t5 be ( a nature to /ifle !m4 ,a di/+ui%$ memb] ( ! ,socit de ,physique1 :5 ,i exhibit$ ! phonograph to t society1 ju/ly said t ,mr4 ,edison's :ole inv5tion consi/$ 9 ! ?9 metallic %eet on :i* ! vibrations are inscrib$2 ?is %eet p]mits ! movem5ts ( ! vibrat+ plate to be directly /]eotyp$1 & !reby ! problem is solv$4 ,x 0 necess>y to f9d su* an exp$i5t1 & x 0 done by ,mr4 ,edison1 :o is !re=e ! inv5tor ( ! phonograph4 ,aft] ,m4 ,cros1 & be=e ,mr4 ,edison1 ,,mm4 ,napoli & ,m>cel ,deprez attempt$ to make a phonograph1 b ) s little success t !y believ$ at "o "t ! problem to be insoluble1 & ?rew d\bts on ,mr4 ,edison's inv5tion :5 x 0 ann\nc$ to ! ,socit de ,physique4 ,!y subsequ5tly resum$ _! lab\rs1 & lead u to hope t !y may ev5tually produce a phonograph ( m p]fect con/ruction ?an t ( ,mr4 ,edison4 ,we %all h m to say on ?is subject4 ,9 conclusion1 ! me*anical reproduction ( spee* 0 fir/ effect$ by ,mr4 ,edison1 & 9 s do+ he has accompli%$ "o ( ! mo/ curi\s & important discov]ies ( our "t1 s9ce x has %[n t ?is reproduction 0 mu* less complicat$ ?an _h be5 suppos$4 ,yet ! !oretical consequ5ces ( ! discov]y mu/ n be exagg]at$1 s9ce ,i d n consid] x by any means prov$ t our !ories on ! voice are incorrect4 ,!re is 9 fact a great diff]5ce betwe5 ! reproduction ( a s\nd :i* has be5 utt]$1 & ! mode 9 :i* ! same s\nd 0 produc$4 ,! reproduction may be easily effect$1 z ,m4 ,b\rseul has rem>k$1 z soon z a mode has be5 discov]$ ( transmitt+ ! vibrations ( air1 h[ev] complex !y may be2 b 9 ord] to produce ! complex vibrations ( spee* by ! voice1 sev]al special organs mu/ be ex]cis$--fir/1 ! muscles ( ! ?roat2 secondly1 ! tongue1 ! lips1 & ev5 ! tee?--& = ?is reason an articulat+ ma*9e is necess>ily v complex4 ,surprise 0 express$ t ! speak+ ma*9e1 :i* 0 br\ght f ,am]ica two ye>s ago1 & exhibit$ at ! ,gr& ,htel1 ,p>is1 0 s extremely complicat$1 s9ce ! phonograph solv$ ! problem 9 su* a simple way4 ,?is is because ! latt] in/rum5t only reproduces spee*1 :ile ! =m] utt]s x1 & ! inv5tor ( ! speak+ ma*9e _h to employ 9 8 me*anism all ! organs :i* are necess>y 9 our organism = ! reproduction ( spee*4 ,! problem 0 inf9itely m complex1 & ?is inv5tion has n attract$ all ! att5tion x des]v$4 ,we %all speak ( x pres5tly4 ,we mu/ n[ describe ! phonograph & ! diff]5t applications :i* h be51 or :i* may be1 made ( x4 ,description ( ,phonograph1 & mode ( us+ x4--,! fir/ & be/ kn[n model ( ?is in/rum5t1 :i* we repres5t 9 fig4 #ff1 simply consi/s ( a regi/]+ cyl9d] ,r1 set 9 motion ) ! h& by a w9* ,m1 be=e :i* a vibrat+ plate is plac$1 furni%$ on its face ) a telephone m\?piece ,e1 & on ! rev]se side ) a trac+ po9t4 ,?is trac+ po9t1 :i* is se5 at s 9 ! section ( ! in/rum5t giv5 9 fig4 #fh1 is n fix$ directly on ! plate2 x re/s on a spr+ r1 & a ca\t*\c pad c is plac$ betwe5 x & ! vibrat+ disk4 ,?is pad is =m$ ( ! end ( a tube :i* is design$ to s5d ! vibrations ( ! plate to ! po9t s )\t /ifl+ !m4 ,ano!r pad a1 plac$ betwe5 ! plate ,l ,l & ! rigid support ( ! po9t1 mod]ates 9 "s degree ^! vibrations1 :i*1 )\t ?is precaution1 w\ld g5]ally be too p[]ful4 ,illu/ration3 ,,fig4 #ff4 ,! cyl9d]1 ( :i* ! axis ,a ,a 7fig4 #ff7 is cut at "o end l a screw1 to enable x to make a lat]al progressive movem5t simultane\sly ) ! rotatory movem5t effect$ on itself1 has on its surface a n>r[ screw-?read co9cid+ ) t ( ! axis1 & :5 ! trac+ po9t is ins]t$1 x is able to pass along x = a di/ance correspond+ to ! "t occupi$ 9 turn+ ! cyl9d]4 ,a %eet ( t9foil or ( v ?9 copp] is c>efully appli$ to ! surface ( ! cyl9d]1 & x %\ld be slightly press$ d[n ^u x1 s z to %[ a fa9t trac+ ( ! groove1 & to all[ ! po9t ( ! vibrat+ disk to be plac$ 9 a prop] position4 ,! po9t re/s on ! foil "u a pressure :i* mu/ be regulat$1 & = ?is purpose1 z well z to deta* ! cyl9d] :5 x is desir$ to place or take away ! t9foil1 !re is ! articulat$ sy/em ,s ,n :i* su/a9s ! support ,s ( ! vibrat+ disk4 ,?is sy/em consi/s ( a jo9t$ lev] 9 :i* !re is a nut screw = ! screw ,r4 ,! h&le ,n at ! end ( ! lev] all[s ! trac+ sy/em to be turn$ aside :5 ! screw ,r is loos5$4 ,9 ord] to regulate ! pressure ( ! trac+ po9t on ! %eet ( t9foil1 x is en\gh to turn ! screw ,r loosely 9 its socket1 & to tight5 x z soon z ! "r degree ( pressure is obta9$4 ,?is is ! simple sy/em by :i* spee* c engrave itself on a plate 9 durable *>act]s1 & x works 9 ! foll[+ mann]4 ,illu/ration3 ,,fig4 #fg4 ,! speak] /&s be=e ! m\?piece ,e1 z be=e a telephone or an ac\/ic tube1 & speaks 9 a /rong1 emphatic voice1 ) 8 lips press$ aga9/ ! walls ( ! m\?piece1 z we see 9 fig4 #fg2 at ! same mom5t he turns ! h&le ( ! cyl9d]1 :i* is provid$ ) a heavy fly-:eel 9 ord] t ! movem5t may be regul>4 ,influ5c$ by ! voice1 ! plate ,l ,l beg9s to vibrate1 & sets ! trac+ po9t at "w1 :i* presses on ! t9foil at ea* vibration1 & produces a furr[ ^: dep? v>ies along its c\rse 9 correspond5ce ) ! unequal vibrations ( ! disk4 ,! cyl9d] :i* moves at ! same "t pres5ts ! diff]5t p>ts ( ! groove ( :i* we h spok5 to ! trac+ po9t 9 succession2 s t :5 ! spok5 s5t5ce comes to an end1 ! design :i* has be5 prick$ out1 consi/+ ( a succession ( reliefs & depressions1 repres5ts ! regi/ration ( ! s5t5ce itself4 ,! fir/ "p ( ! op]ation is !re=e accompli%$1 & by deta*+ ! %eet f ! in/rum5t ! words may be put away 9 a portfolio4 ,we h n[ to see h[ ! in/rum5t is able to reproduce :at has be5 s easily inscrib$4 ,= ?is purpose x is only necess>y to repeat ! process1 & ! id5tical effect w be reproduc$ 9 an inv]se s5se4 ,! trac+ /ylus is replac$ at ! end ( ! groove x has already trav]s$1 & ! cyl9d] is aga9 set 9 motion4 ,:5 ! engrav$ track passes aga9 "u ! po9t1 x has a t5d5cy to raise x & to imp>t to x movem5ts :i* mu/ necess>ily be ! repetition ( ^? :i* fir/ produc$ ! trac+4 ,! vibrat+ plate is ob$i5t to ^! movem5ts1 & beg9s to vibrate1 ?us produc+ ! same s\nds1 & consequ5tly ! same words2 yet s9ce !re is necess>ily a loss ( p[] 9 ?is d\ble trans=mation ( me*anical effects1 ! speak+ tube ,c is atta*$ to ! m\?piece ,e 9 ord] to int5sify ! effects4 ,"u ^! conditions ! words reproduc$ by ! in/rum5t may be he>d 9 all p>ts ( a hall1 & x is />tl+ to he> ?is voice--some:at %rill1 x mu/ be admitt$--:i* seems to utt] its s5t5ces f beyond ! grave4 ,if ?is inv5tion _h tak5 place 9 ! middle ages1 x w\ld c]ta9ly h be5 appli$ to gho/ly app>itions1 & x w\ld h be5 invaluable to miracle-mong]s4 ,illu/ration3 ,,fig4 #fh4 ,z ! height ( ! notes ( ! musical scale dep5ds on ! numb] ( vibrations effect$ by a vibrat+ sub/ance 9 a giv5 "t1 speak+ w be reproduc$ 9 a tone ( :i* ! pit* w dep5d on ! velocity ( rotation giv5 to ! cyl9d] on :i* ! t9foil is w\nd4 ,if ! velocity is ! same z t :i* 0 us$ 9 regi/ration1 ! tone ( ! words reproduc$ is ! same z t 9 :i* !y 7 utt]$4 ,if ! velocity is great]1 ! tone is high]2 if less1 ! tone is l[]2 b ! acc5t ( ! speak] may always be recognis$4 ,ow+ to ?is peculi>ity ! reproduction ( songs is ne>ly always defective 9 in/rum5ts turn$ by ! h&2 !y s+ out ( tune4 ,?is is n ! case :5 ! in/rum5t is mov$ by a well-regulat$ sy/em ( clockwork1 & 9 ?is way a satisfactory reproduction ( a duet has be5 obta9$4 ,! words regi/]$ on t9foil c be (t5 reproduc$2 b ! s\nds become fa9t] & m indi/9ct at ea* repetition1 s9ce ! trac+s 9 relief are gradually effac$4 ,! reproduction on copp] is m successful1 b if int5d$ to be p]man5t ! %eets mu/ be /]eotyp$1 & 9 ?is case ! in/rum5t mu/ be diff]5tly arrang$4 ,an attempt has be5 made to obta9 spee* f ! phonograph by tak+ ! words regi/]$ inv]sely to _! true direction4 ,9 ?is way ! s\nds obta9$ 7 necess>ily q unlike ! words utt]$2 yet ,messrs4 ,fleem+ ,j5k9 & ,ew+ h obs]v$ t n only are ! v[els un*ang$ by ?is inv]se action1 b consonants1 syllables1 & ev5 :ole words may be reproduc$ ) ! acc5t !y w\ld h if spok5 backw>ds4 ,! s\nds produc$ by ! phonograph1 al?\gh fa9t] ?an ^? ( ! voice :i* produc$ ! regi/]$ trac+1 are /rong en\gh to react on ! ord9>y /r+ telephone1 & ev5 on a ,bell telephone2 & z 9 ?is case ! s\nds d n g beyond ! in/rum5t1 & c only be he>d by ! p]son :o is us+ x1 x is easy to asc]ta9 t ! s\nd has n be5 produc$ by trick]y4 ,mr4 ,edison pres5t$ 8 phonograph to ! ,acadmie des ,sci5ces ?r\gh me1 ,m>* #aa1 #ahgh1 & :5 8 ag5t1 ,m4 ,puskas1 caus$ ! wond]ful in/rum5t to speak1 a murmur ( admiration 0 he>d f all p>ts ( ! hall--a murmur succe$$ by repeat$ applause4 ,a lett] appe>$ 9 ! newspap]s f "o ( ! p]sons pres5t1 9 :i* he said t #8! le>n$ ,academy1 g5]ally s cold1 _h nev] be=e ab&on$ itself to su* en?usiasm4 ,yet "s memb]s ( a sceptical turn ( m9d1 in/ead ( exam9+ ! physical fact1 ascrib$ x to moral causes1 & a report soon ran ?r\gh ! room :i* seem$ to accuse ! ,academy ( hav+ be5 my/ifi$ by a clev] v5triloqui/4 ,c]ta9ly ! _s ( anci5t ,gaul is /ill to be f\nd among ! ,fr5*1 & ev5 9 ! ,academy4 ,"o said t ! s\nds emitt$ by ! in/rum5t 7 precisely ^? ( a v5triloqui/4 ,ano!r ask$ if ! movem5ts ( ,m4 ,puskas' face & lips z he turn$ ! in/rum5t did n resemble ! grimaces ( a v5triloqui/4 ,a ?ird admitt$ t ! phonograph might emit s\nds1 b believ$ t x 0 mu* help$ by ! manipulator4 ,f9ally1 ! ,academy reque/$ ,m4 du ,moncel to try ! exp]im5t1 & z he 0 n accu/om$ to speak into ! in/rum5t1 x 0 unsuccessful1 to ! great joy ( ! incr$ul\s4 ,"s memb]s ( ! ,academy1 h[ev]1 desir+ to asc]ta9 ! real nature ( ! effects1 begg$ ,m4 ,puskas to repeat ! exp]im5ts be=e !m 9 ! secret>y's (fice "u su* conditions z !y %\ld lay d[n4 ,m4 ,puskas compli$ ) ?is reque/1 & !y 7 absolutely satisfi$ ) ! result4 ,yet o!rs rema9$ incr$ul\s1 & x 0 necess>y t !y %\ld make ! exp]im5t = !mselves be=e !y accept$ ! fact t spee* c\ld be reproduc$ 9 s simple a way4' ,! anecdote ,i h j relat$ _c be int]pret$ to ! discr$it ( ! ,acadmie des ,sci5ces1 s9ce x is especially b\nd to pres]ve ! true pr9ciples ( sci5ce intact1 & only to accept />tl+ facts aft] a c>eful exam9ation4 ,ow+ to ?is attitude1 all :i* emanates f ! ,academy c be receiv$ ) complete confid5ce2 & we _c approve too highly ( res]ve :i* does n give way to ! fir/ impulse ( en?usiasm & admiration4 ,! failure ( my exp]im5t at ! ,academy 0 simply due to ! fact t ,i spoke at too great a di/ance f ! vibrat+ disk1 & t my lips did n t\* ! sides ( ! m\?piece4 ,"s days lat]1 at ! reque/ ( sev]al ( my colleagues1 ,i made repeat$ trials ( ! in/rum5t1 & ,i soon succe$$ 9 mak+ x speak z well z ! suppos$ v5triloqui/2 b ,i le>n$ at ! same "t t practice is necess>y to ensure success4 ,"s words are reproduc$ m readily ?an o!rs2 ^? :i* include _m v[els & _m r's come out bett] ?an ^? :i* ab\nd 9 consonants1 & especially 9 s's4 ,x is !re=e n surpris+ t1 ev5 9 ! case ( an exp]i5c$ manipulator l ,mr4 ,edison's ag5t1 "s ( ! s5t5ces utt]$ by him are m audible ?an o!rs4 ,! simultane\s repetition ( sev]al s5t5ces 9 diff]5t languages by regi/]+ "o ov] ! o!r is "o ( ! mo/ surpris+ effects ( ! phonograph4 ,z _m z ?ree diff]5t s5t5ces h be5 obta9$2 b 9 ord] to di/+ui% !m ?r\gh ! confus$ s\nds :i* result f plac+ "o ov] ! o!r1 x is necess>y t diff]5t p]sons1 giv+ special att5tion to a p>ticul> s5t5ce1 %\ld ?us sep>ate !m & und]/& _! s5se4 ,vocal airs may1 9 ! same way1 be regi/]$ ov] ! ^w trac+s1 & 9 ?is case x is m easy to di/+ui% !m4 ,!re are sev]al models ( phonographs4 ,! "o repres5t$ 9 fig4 #ff has be5 *iefly us$ = public exp]im5ts1 b !re is a small model1 g5]ally sold to ! public1 9 :i* ! cyl9d] is mu* long]1 & s]ves at once = regi/] & fly-:eel4 ,?is in/rum5t gives good results1 b c only be us$ = %ort s5t5ces4 ,9 ?is model1 z inde$ 9 ! o!r1 ! words are m easily regi/]$ by fa/5+ a small tube 9 ! =m ( a prolong$ speak+-trumpet to ! m\?piece2 ! vibrations ( ! air are ?us conc5trat$ on ! vibrat+ disk1 & act ) great] en]gy4 ,! t5uity ( ! vibrat+ disk adds to ! effici5cy ( ! in/rum5t1 & ! trac+ po9t may be fitt$ directly to ?is disk4 ,illu/ration3 ,,fig4 #fi4 ,i ne$ n describe p>ticul>ly ! phonograph :i* acts by clockwork4 ,! in/rum5t resembles ! "o repres5t$ fig4 #ff1 except t x is m\nt$ on a r high table1 to give room = ! desc5t ( ! weight :i* moves ! clockwork2 ! me*anism is appli$ directly to ! axis ( ! cyl9d]1 supply+ ! place ( ! w9*1 & is regulat$ by a small fly-:eel4 ,! :eel us$ 9 an ,engli% sy/em has be5 adopt$1 b we pref] t ( ,m4 ,vill>ceau1 :i* has small w+s4 ,s9ce x is always difficult to fit ! t9foil to ! cyl9d]1 ,mr4 ,edison has tri$1 ) good success1 to obta9 ! trac+ on a plane surface ( t9foil1 by means ( ! arrangem5t repres5t$ fig4 #fi4 ,9 ?is new model1 ! plate on :i* ! t9 or copp] %eet is to be appli$ has a spiral groov+1 ( :i* "o end corresponds to ! c5tre ( ! plate1 & ! o!r to its out] edges4 ,! plate is set 9 motion by a p[]ful sy/em ( clockwork1 ( :i* ! velocity is regulat$ ) ref]5ce to ! l5g? ( ! turns ( ! spiral4 ,! vibrat+ disk is arrang$ z 9 ! =m] in/rum5t1 & is plac$ above ?is plate2 ! trac+ po9t may1 by means ( a movem5t ( progression imp>t$ to ! sy/em1 foll[ ! spiral groove f ! c5tre ( ! plate to its circumf]5ce4 ,x mu/ n be suppos$ t all ! t9foil us$ = phonographic regi/ration is equally good4 ,! foil mu/ be ( a def9ite ?ickness1 & comb9$ ) a def9ite am\nt ( lead4 ,t :i* is us$ = wrapp+ *ocolate1 & inde$ all foil ( ,fr5* manufacture1 is too ?9 & too exclusively made ( t9 to produce good results1 & ,m4 ,puskas 0 oblig$ to import "s f ,am]ica to cont9ue 8 exp]im5ts4 ,! relative proportion ( lead & t9 has n yet be5 def9$1 & ! selection ( foil has be5 made empirically2 b z ! use ( ! phonograph becomes m g5]al1 ?is proportion mu/ be asc]ta9$1 & x may easily be done by analys+ ! composition ( ! foil :i* gives ! be/ results4 ,illu/ration3 ,,fig4 #gj4 ,! arrangem5t ( ! trac+ po9t is also ( mu* importance = ! successful action ( ! phonograph4 ,x mu/ be v sl5d] & v %ort 7n exce$+ a millimtre 9 l5g?71 s z to regi/] di/9ctly ! smalle/ vibrations ( ! vibrat+ disk )\t deviat+ f ! normal direction ( ! cyl9d]1 :i* might be ! case1 if x 7 long1 on acc\nt ( ! unequal friction ex]t$ on ! t9foil4 ,x mu/ also be made ( a metal :i* has no t5d5cy to te> ! metallic %eet4 ,iron appe>s to comb9e mo/ ( ! conditions dem&$4 ,! phonograph is /ill 9 its infancy1 & x is probable t x may soon be enabl$ to regi/] spee* )\t ! necessity ( speak+ into a m\?piece4 ,accord+ to ! newspap]s1 ,mr4 ,edison has already discov]$ a way ( collect+1 )\t ! aid ( an ac\/ic tube1 ! s\nds utt]$ at a di/ance ( ?ree or f\r feet f ! in/rum5t1 & ( pr9t+ !m on a metallic %eet4 ,f ?is !re is only a /ep to ! p[] ( inscrib+ a spee* utt]$ 9 a l>ge hall at any di/ance f ! phonograph2 & if ?is /ep is tak51 phonography may be sub/itut$ ) advantage = %or?&4 ,we add 9 a note ! in/ructions giv5 by ,m4 ,roosevelt to ! pur*as]s ( phonographs1 s z to enable !m to "w ! in/rum5t4#bj ,consid]ations on ! !ory4--,al?\gh ! explanation we h giv5 w make ! effects ( ! phonograph intelligible1 x leads to a curi\s "q :i* has greatly int]e/$ physici/s--namely1 h[ x is t ! trac+ made on s yield+ a surface z t9 c1 :5 retrac$ by ! /ylus1 ( :i* ! rigidity is relatively great1 produce a vibratory movem5t )\t be+ completely de/roy$4 ,to ?is we reply t ! retrac+ is effect$ ) su* extreme rapidity t ! effects ( active =ce :i* are develop$ only manife/ !mselves locally1 & t "u ^! conditions ! me*anical effects ex]t$ are z en]getic 9 s(t z 9 h>d sub/ances4 ,! curi\s exp]im5t1 relat$ 9 s _m books on physics1 mu/ be rememb]$1 ( a plank pi]c$ :5 a c&le s]ves z ! projectile ( a gun4 ,! v>i\s accid5ts caus$ by ! dis*>ge ( pap] wadd+s mu/ also be rememb]$4 ,"u su* conditions ! motion imp>t$ to ! molecules :i* receive ! %ock has n "t to be transmitt$ to ! :ole mass ( ! sub/ance to :i* !y belong1 & ^! molecules are compell$ to sep>ate f x1 or at any rate to produce1 :5 ! sub/ance is capable ( vibration1 a c5tre ( vibration :i* diffuses waves ?r\gh\t its surface1 & produces s\nds4 ,sev]al sci5tific m51 among o!rs ,messrs4 ,preece & ,may]1 h c>efully /udi$ ! =m ( ! trac+ left by ! voice on ! t9foil ( ! phonograph1 & !y obs]ve t x greatly resembles ! outl9e ( ! s++ flames s well %[n by ,h]r ,ko5ig's in/rum5ts4 ,mr4 ,may] wrote on ?is subject 9 ! #8,popul> ,sci5ce ,mon?ly ,review' ( ,april #ahgh4 ,he said t he _h be5 successful 9 reproduc+ a spl5did trac+ on smok$ glass1 :i* gave 9 pr(ile ! outl9e ( ! vibrations ( s\nd regi/]$ on ! t9foil ) _! v>y+ curves4 ,= ?is purpose he fa/5$ to ! spr+ support ( ! trac+ po9t ( ! phonograph a sl5d] rod1 t]m9at+ 9 a po9t1 :i* press$ obliquely aga9/ ! plate ( smok$ glass1 &1 s9ce ! latt] 0 9 a v]tical position1 a movem5t imp>t$ to ! rod enabl$ x to produce a s9usoidal trac+4 ,by ?is arrangem5t1 :5 ! phonograph 0 at "w1 two sy/ems ( trac+s 7 produc$ at ! same mom5t1 ( :i* "o 0 ! pr(ile ( ! o!r4 ,mr4 ,may] _h n1 at ! "t he wrote1 be5 long en\gh 9 possession ( ! in/rum5t to make _m exp]im5ts ) x1 b f a /udy ( "s ( its curves x appe>$ to him t ! regi/]$ outl9es bore a /rong resemblance to ^? ( ,ko5ig's s++ flames4 ,illu/ration3 ,,fig4 #ga4 ,fig4 #ga repres5ts ! trac+ :i* corresponds to ! lett] a :5 pron\nc$ z 9 bat1 9 ! ?ree sy/ems ( regi/ration4 ,t correspond+ to l9e ,a is an enl>g$ reproduction ( ! trac+ left on ! t9foil2 t correspond+ to l9e ,b repres5ts its pr(ile on ! %eet ( smok$ glass4 ,f9ally1 l9e ,c %[s ! outl9e ( ,ko5ig's s++ flames1 :5 ! same s\nd is produc$ q close to ! membrane ( ! regi/]4 ,x mu/ be q close1 s9ce ! =m ( ! trac+ produc$ by a po9t] atta*$ to a vibrat+ membrane1 :5 influ5c$ by composite s\nds1 dep5ds on ! di/ance int]v5+ betwe5 ! membrane & ! s\rce ( s\nd1 & an inf9ite v>iety 9 ! =m ( ! trac+ may be obta9$ by modify+ ! di/ance4 ,9 fact1 :5 ?is di/ance is increas$1 ! waves ( s\nd :i* result f composite s\nds react on ! membrane at diff]5t mom5ts ( _! emission4 ,= example1 if ! composite s\nd is =m$ ( six h>monics1 ! displacem5t ( ! s\rce ( vibration f ! fir/ h>monic by ! l5g? ( a wave w respectively remove ! second1 ?ird1 f\r?1 fif?1 & six? h>monics 1 1 #a1 #a1 #a ! l5g? ( a wave1 & consequ5tly ! outl9e result+ f ! comb9ation ( waves w no long] be ! same z x 0 be=e ! displacem5t ( ! s\rce ( s\nd1 al?\gh ! p]ception ( ! s\nds rema9s ! same 9 bo? cases4 ,?is pr9ciple is cle>ly demon/rat$ by ,ko5ig's in/rum5t1 by l5g!n+ & %ort5+ an ext5sible tube1 ins]t$ betwe5 ! resonator & ! vibrat+ membrane1 :i* is plac$ close to ! flame2 & ?is expla9s ! disagreem5t ( physici/s z to ! composition ( vocal s\nds :i* !y h analys$ by means ( ! s++ flames4 ,mr4 ,may] adds t ^! facts fur!r %[ t we _c hope to read ! impressions & trac+s ( ! phonograph1 :i* n only v>y ) ! nature ( ! voice1 b also ) ! diff]5t mom5ts at :i* ! h>monics ( ! voice are emitt$1 & ) ! relative diff]5ces 9 ! int5sities ( ^! h>monics4 ,not)/&+ ?is ass]tion1 we reproduce 7fig4 #gb7 an extremely curi\s trac+ s5t to u by ,mr4 ,blake1 :i* repres5ts ! vibrations produc$ by ! words #8,br[n1 ,univ]sity3 h[ d y d8' ,!y 7 photograph$ by means ( an index fa/5$ to a vibrat+ disk on :i* a ray ( light 0 ?r[n4 ,! ^w #8h[' is p>ticul>ly rem>kable = ! comb9$ =ms ( ! inflections ( ! vibrations4 ,rec5t exp]im5ts seem to %[ t ! m ! vibrat+ membrane ( ! phonograph resembles ! human e> 9 its con/ruction1 ! bett] x repeats & regi/]s ! s\nd vibrations3 x %\ld be /ret*$1 z f> z possible1 9 ! same way z ! tympanum is /ret*$ by ! hamm] ( ! e>1 & moreov] x %\ld h ! same =m1 s9ce ! vibrations ( air are 9 ?is case mu* m effective4 ,illu/ration3 ,,fig4 #gb4 ,mr4 ,edison consid]s t ! size ( ! op5+ ( ! m\?piece has consid]able influ5ce on ! di/9ct articulation ( spee*4 ,:5 ! s\nds are pron\nc$ be=e ! :ole surface ( ! diaphragm1 "s hiss+ s\nds are lo/4 ,!y are1 on ! contr>y1 int5sifi$ :5 ^! s\nds rea* ! diaphragm ?r\gh a n>r[ orifice ) %>p rims4 ,if ! op5+ is too!d on its flatt5$ rims1 ! hiss+ consonants are deliv]$ m cle>ly4 ,spee* is reproduc$ m p]fectly :5 ! m\?piece has a cov]+ ( "s ?ickness1 s arrang$ z to dead5 ! s\nds aris+ f ! friction ( ! trac+ po9t on ! t94 ,mr4 ,h>dy has r5d]$ ! regi/ration ( phonographic trac+s m easy by add+ a small ebonite tube1 resembl+ ! m\?piece ( a w9d in/rum5t1 to ! m\?piece ( ! phonograph4 ,,uses ,,( ,,! ,,phonograph ,,& ,,its ,,future4 ,mr4 ,edison has lately publi%$ 9 ! #8,nor? ,am]ican ,review' ( ,may-,june #ahgh an article on ! future ( ! phonograph1 9 :i* he himself discusses ! diff]5t applications :i* may be made ( ?is in/rum5t4 ,)\t %>+ all 8 anticipations1 :i* appe> to u to be v premature1 we ?9k t "s extracts f 8 pap] may be int]e/+4 #8,9 ord] to furni% a basis on :i* ! read] may take 8 /& 444 a few categorical que/ions & answ]s are giv5 ^u ! ess5tial features ( ! pr9ciple involv$4 #8#a4 ,is a vibrat+ plate or disk capable ( receiv+ a complex motion :i* %all correctly repres5t ! peculi> prop]ty ( ea* & all ! multif>i\s vocal & o!r s\nd waves8 #8,! telephone answ]s affirmatively4 #8#b4 ,c su* complex movem5t be transmitt$ f su* plate by means ( a s+le emboss+ po9t atta*$ !reto1 to effect a record ^u a pla/ic mat]ial1 by ind5tation1 ) su* fidelity z to give to su* ind5tations ! same v>i$ & complex =m8 ,& if s1 w ?is emboss+ po9t1 ^u be+ pass$ ov] ! record ?us made1 foll[ x ) su* fidelity z to transmit to ! disk ! same v>iety ( movem5t1 & ?us effect a re/oration or reproduction ( ! vocal or o!r s\nd waves1 )\t loss ( any prop]ty ess5tial to produc+ on ! e> ! same s5sation z if com+ direct f ! orig9al s\rce8 #8,! answ] to ?is may be summ$ up 9 a /atem5t ( ! fact t 444 ! writ] has at v>i\s times dur+ ! pa/ weeks reproduc$ ^! waves ) su* degree ( accuracy 9 ea* & e detail z to enable 8 assi/ants to read1 )\t ! loss ( a ^w1 "o or m columns ( a newspap] article unfamili> to !m1 & :i* 7 spok5 into ! app>atus :5 !y 7 n pres5t4 ,! only p]ceptible loss 0 f\nd to be 9 ! quality ( ! utt]ance1 a non-ess5tial 9 ! practical application ( ! in/rum5t4 ,inde$1 ! articulation ( "s individuals has be5 p]ceptibly improv$ by passage ?r\gh ! phonograph1 ! orig9al utt]ance be+ mutilat$ by "s imp]fection ( lip & m\? =mation1 & ^! mutilations correct$ or elim9at$ by ! me*anism ( ! phonograph4#ba #8#c4 ,c a record be remov$ f ! app>atus on :i* x 0 made1 & replac$ ^u a second )\t mutilation or loss ( effective p[] to vibrate ! second plate8 #8,?is is a m]e me*anical detail1 pres5t+ no great] ob/acle ?an hav+ prop] reg>d = ! p]fect int]*angeabl5ess ( ! v>i\s work+ p>ts ( ! app>atus--n s nice a problem z ! manufacture ( ! ,am]ican wat*4 #8#d4 ,:at z to ! facility ( plac+ & remov+ ! second %eet1 & z to its transportation by mail8 #8,b t5 or fifte5 seconds suffice = su* plac+ or remov+4 ,a special envelope w probably be requir$1 ! weight & =m ( :i*1 h[ev]1 w b slightly increase ! co/ ( po/age4 #8#e4 ,:at z to durability8 #8,repeat$ exp]im5ts h prov$ t ! ind5tations possess wond]ful endur+ p[]1 ev5 :5 ! reproduction has be5 effect$ by ! comp>atively rigid plate us$ = _! production4 ,x is propos$1 h[ev]1 to use a m flexible plate = reproduc+1 :i*1 ) a p]fectly smoo? /one po9t--diamond or sapphire--w r5d] ! record capable ( f fifty to "o hundr$ repetitions1 en\gh = all practical purposes4 #8#f4 ,:at z to duplication ( a record & its p]man5ce8 #8,_m exp]im5ts h be5 made1 ) m or less success1 9 ! ef=t to obta9 electrotypes ( a record1 & ! writ] is in=m$ t x has v rec5tly be5 successfully accompli%$4 ,he c c]ta9ly see no great practical ob/acle 9 ! way4 ,?is1 ( c\rse1 p]mits ( an indef9ite multiplication ( a record1 & its pres]vation = all "t4 #8#g4 ,:at is ! requisite =ce ( wave imp++ ^u ! diaphragm1 & ! proximity ( ! m\? to ! diaphragm1 to effect a record8 #8,^! dep5d 9 great measure ^u ! volume ( s\nd desir$ 9 ! reproduction4 ,if ! reproduction is to be made audible to an assembly1 consid]able =ce is requisite 9 ! orig9al utt]ance2 if = ! individual e>1 only ! ord9>y conv]sational tone 7ev5 a :isp] has be5 reproduc$74 ,9 bo? cases ! orig9al utt]ances are deliv]$ directly 9 ! m\?piece ( ! in/rum5t4 ,an audible reproduction may1 h[ev]1 be _h by speak+ at ! in/rum5t f a di/ance ( f two to ?ree feet 9 l\d tone4 ,! application ( a fl>+ tube or funnel to collect ! s\nd waves1 & ! con/ruction ( an especially delicate diaphragm & emboss+ po9t1 c41 are ! simple means :i* sugge/ !mselves to effect ?is4444 #8,! =ego+ pres5tm5t ( ! /age ( developm5t rea*$ by ! sev]al ess5tial features ( ! phonograph demon/rates ! foll[+ faits accomplis3 #8#a4 ,! captivity ( all mann] ( s\nd waves1 hi!rto designat$ z 8fugitive10 & _! ret5tion4 #8#b4 ,_! reproduction ) all _! orig9al *>act]i/ics1 )\t ! pres5ce or cons5t ( ! orig9al s\rce1 & aft] ! lapse ( any p]iod ( "t4 #8#c4 ,! transmission ( su* captive s\nds ?r\gh ! ord9>y *annels ( comm]cial int]c\rse & trade 9 a mat]ial =m1 = purposes ( communication4 #8#d4 ,indef9ite multiplication & pres]vation ( su* s\nds1 )\t reg>d to ! exi/5ce or non-exi/5ce ( ! orig9al s\rce4 #8#e4 ,! captivation ( s\nds1 ) or )\t ! k or cons5t ( ! s\rce ( _! orig9444 #8,! app>atus n[ be+ p]fect$ 9 me*anical details w be ! /&>d phonograph1 & may be us$ = all purposes1 except su* z require special =m ( matrix1 su* z toys1 clocks1 c41 = an indef9ite repetition ( ! same ?+4 ,! ma9 utility ( ! phonograph be+1 h[ev]1 = ! purposes ( lett]-writ+ & o!r =ms ( dictation1 ! design is made ) a view to its utility = t purpose4 #8,! g5]al pr9ciples ( con/ruction are1 a flat plate or disk1 ) spiral groove on ! face1 work$ by clockwork und]nea? ! plate2 ! grooves are cut v closely toge!r1 s z to give a great total l5g? to ea* l5g? ( surface--a close calculation gives z ! capacity ( ea* %eet ( foil ne>ly #dj1jjj words4 ,! %eets be+ b t5 in*es squ>e1 ! co/ is s trifl+ t b a hundr$ words might be put on a s+le %eet economically4444 #8,! practical application ( ?is =m ( phonograph is v simple4 ,a %eet ( foil is plac$ 9 ! phonograph1 ! clockwork set 9 motion1 & ! matt] dictat$ into ! m\?piece )\t o!r ef=t ?an :5 dictat+ to a /5ograph]4 ,x is !n remov$1 plac$ 9 suitable =m ( envelope1 & s5t ?r\gh ! ord9>y *annels to ! correspond5t = :om x is design$4 ,he1 plac+ x ^u 8 phonograph1 />ts 8 clockwork1 & li/5s to :at 8 correspond5t has to say4' ,s9ce ?is pap] by ,mr4 ,edison appe>$ 9 ,june #ahgh1 he has appli$ ! phonograph to sev]al o!r purposes1 among :i* we may m5tion t ( regi/]+ ! =ce ( s\nds on railways1 & especially on ! metropolitan atmosph]ic railway 9 ,new ,york4 ,! in/rum5t :i* he has made = ?is purpose resembles t by ,mr4 ,leo ,scott1 & be>s ! same "n4 ,x is describ$ & repres5t$ 9 ! #8,daily ,graphic' ( ,july #ai1 #ahgh1 z well z ! a]ophone1 ! megaphone1 & ! microtasimet]1 :i* is adapt$ = a/ronomical obs]vations4 ,we %\ld exce$ ! limits laid d[n = ?is volume1 if we 7 to give a m detail$ acc\nt ( ^! inv5tions4 ,m4 ,lambrigot1 "o ( ! (ficials on ! telegraphic l9es 9 ,france1 & ! au?or ( v>i\s improvem5ts 9 ! ,caselli telegraph1 has %[n me a phonographic sy/em ( 8 own inv5tion 9 :i* x is r$uc$ to its simple/ =m4 ,he s5t me ! foll[+ description ( 8 sy/em4 #8,! in/rum5t consi/s ( a wood5 slab plac$ v]tically on a /& & firmly fix$ ^u x4 ,!re is a r\nd op5+ 9 ! middle ( ! slab1 cov]$ by a tightly /ret*$ %eet ( p>*m5t be>+ a /eel knife1 :i*1 l ! trac+ po9t ( ! phonograph1 is int5d$ to trace ! vibrations4 ,a solid block rises f ! /& to ! middle ( ! slab1 & supports a slide on :i* a runn] c move 9 front ( ! slab4 ,!re is a /rip ( glass on ?is runn]1 ( :i* "o side is cov]$ ) /e>9e4 ,:5 ! runn] is mov$ to & fro1 ! /e>9e comes 9 contact ) ! knife & takes ! m\ld ( its =m1 :i* is curv$ ?r\gh\t4 #8,a s\nd places ! %eet ( p>*m5t 9 vibration1 & imp>ts its movem5t to ! knife1 :i* traces v>i\s l9es on ! surface ( ! /e>9e4 #8,! reproduction ?us obta9$ on ! /rip ( glass is subject$ to ! ord9>y processes ( metallisation4 ,by galvanism a deposit ( copp] is obta9$ :i* reproduces ! l9es 9 an inv]se way4 ,9 ord] to make ! metallic plate speak1 x is necess>y to pass a po9t ( ivory1 wood1 or horn lightly ov] ! signs1 &1 by mov+ x m or less quickly1 ! diff]5t tones c be he>d1 j z !y 7 spok54 #8,s9ce copp] is relatively h>d] ?an lead1 ! copp] plate on :i* ! vibrations are trac$ w af=d an unlimit$ numb] ( reproductions4 ,to obta9 ?is result1 a lead wire mu/ be appli$ to ! plate1 & due pressure mu/ be ex]t$ on x4 ,! wire is flatt5$ & takes ! impression ( all ! traces :i* !n appe> 9 relief4 ,if ! edge ( a c>d is pass$ ?r\gh ?is impress$ trac+1 ! same s\nds are produc$ z ^? :i* are obta9$ f ! copp] plate4' ,m4 ,lambrigot sugge/s t ! speak+ plates might be useful 9 _m ways3 = example1 !y might make x easy to le>n ! correct pronunciation ( =eign languages1 s9ce a suffici5t numb] might be collect$ to make a sort ( vocabul>y :i* w\ld give ! acc5t ( ! words mo/ 9 use 9 a giv5 language4 ,by ?is simple process ,m4 ,lambrigot has be5 able to obta9 a /rong impression1 )9 a copp] groove1 ( ! vibrations caus$ by ! voice1 & !y are s di/9ctly engrav$ t :ole s5t5ces may be he>d1 if !y are retrac$ by ! %>p5$ po9t ( a mat*4 ,x is true t ! reproduction is imp]fect1 & t ^? words are only to be di/+ui%$ :i* 7 previ\sly kn[n2 b x is possible t bett] results w be obta9$ f improvem5ts 9 ! sy/em1 & at any rate ! di/9ct impression ( ! vibrations ( ! voice on a h>d metal is a really int]e/+ discov]y4 ,i h made "o some:at important obs]vation 9 ! work+ ( ! phonograph--namely1 t if spee* is regi/]$ on ! in/rum5t 9 a v hot room1 & x is !n c>ri$ to a cold] room1 ! reproduction ( spee* is imp]fect 9 proportion to ! diff]5ce ( temp]ature4 ,?is is probably ow+ to consid]able modifications 9 ! ela/icity ( ! ca\t*\c pad :i* is ins]t$ betwe5 ! trac+ po9t & ! vibrat+ disk3 p]haps diff]5ces ( expansion 9 ! t9foil h also "s effect4 ,,fab]',s ,,am]ican ,,speak+ ,,ma*9e4 ,ab\t two ye>s ago ! newspap]s ann\nc$ ) "s pomp t a speak+ ma*9e _h rea*$ ,p>is1 :i* f> surpass$ ,vaucanson's duck1 & :i* w\ld attract g5]al att5tion4 ,un=tunately ! inv5tion 0 n 9 ! fir/ in/ance br\ght =w>d ) any sci5tific au?ority1 & 0 soon relegat$ to take a place among ! curiosities exhibit$ by conjurors4 ,9 a c\ntry s ess5tially critical & sceptical z ,france1 !re are always ^? :o pr(ess incr$ulity1 & :o w ev5 resi/ evid5ce1 & x 0 ass]t$ t ! ma*9e only spoke because its exhibitor 0 an able v5triloqui/4 ,?is is an old ass]tion :i* has lately be5 made ) ref]5ce to ! phonograph4 ,"s sci5tific pap]s e*o$ ! absurdity1 & ! speak+ ma*9e 0 s discr$it$ t x is n[ unnotic$1 al?\gh x is a mo/ +5i\s & int]e/+ conception4 ,:5 w our c\ntry be cur$ ( ! error ( d5y+ ev]y?+ )\t due exam9ation8 ,s9ce we ourselves only judge ( ?+s aft] hav+ s]i\sly consid]$ !m1 we ?9k x j to v9dicate ! tru? z to ,mr4 ,fab]'s ma*9e1 & ?is c only be done by an exact description ( x4 ,z ,i said 9 ! la/ *apt]1 !re is a great diff]5ce betwe5 ! production & ! reproduction ( a s\nd1 & a ma*9e l ! phonograph1 adapt$ = ! reproduction ( s\nd1 may diff] ess5tially f a ma*9e :i* really speaks4 ,9 fact1 ! reproduction ev5 ( articulate s\nds may be v simple1 z soon z we possess ! means ( /]eotyp+ ! vibrations ( air necess>y to transmit ^! s\nds2 b 9 ord] to produce !m1 & especially to emit ! complex vibrations :i* con/itute spee*1 x is necess>y to set 9 motion a numb] ( special organs1 fulfill+ m or less exactly ! functions ( ! l>ynx1 ! m\?1 ! tongue1 ! lips1 & ev5 ! nose4 ,= ?is reason1 a speak+ ma*9e is necess>ily v complicat$1 & ?is is precisely ! case ) ! ma*9e we are n[ consid]+4 ,su* a ma*9e is n n[ made = ! fir/ "t1 & ! ,academy has lately be5 rem9d$ ( a speak+ head :i* 0 9 ! possession ( ! philosoph] ,alb]tus ,magnus 9 ! ?irte5? c5tury1 & :i* 0 de/roy$ by ,/4 ,?omas ,aqu9as z a diabolical inv5tion4 ,mr4 ,fab]'s speak+ ma*9e 0 exhibit$ two ye>s ago at ! ,gr& ,htel1 & may n[ be se5 9 ! room adjo9+ ,m4 ,rob]t ,h\d9's !atre1 ! same room 9 :i* ,mr4 ,giff>d exhibit$ ! telephone4 ,x consi/s ( ?ree di/9ct p>ts3 #a/1 ( a l>ge bell[s work$ by a p$al1 :i* produces ! curr5ts ( air necess>y = ! production ( s\nds1 & to "s ext5t acts z ! lungs2 #bnd1 a vocal in/rum5t1 consi/+ ( a l>ynx accompani$ by diaphragms ( v>i\s =ms to modify ! s\nds1 ( a m\? ) ca\t*\c lips & tongue1 & ( a tube ) an outlet some:at resembl+ ! nasal cavities2 #crd1 ( a sy/em ( jo9t$ lev]s & ( p$als1 t]m9at+ 9 keys l ^? ( a piano4 ,! mo/ int]e/+ "p ( ! ma*9]y1 ( :i* we repres5t ! pr9ciple fig4 #gc1 is ! vocal app>atus1 :i* involv$ ! sev]e/ /udy ( physics 9 ord] to succe$ 9 ! production ( articulate s\nds4 ,x consi/s1 fir/1 ( a r ?ick ca\t*\c tube1 )9 :i* !re is a k9d ( :i/le ,l1 z 9 a cl>ionet4 ,! :i/le consi/s ( a small ca\t*\c cyl9d] ) a longitud9al slit1 & be=e ?is is plac$ a v ?9 ivory plate l9$ ) ca\t*\c4 ,?is plate is fix$ at "o end to ! cyl9d]1 & deviates slightly f x at its free end1 s z to p]mit ! curr5t ( air project$ f ! bell[s ,s to p5etrate betwe5 ! two p>ts1 & to cause ! vibrations 9 ! ivory plate necess>y = ! production ( a s\nd4 ,! extremity ( ! ca\t*\c cyl9d] is clos$ on ?is side1 & is fitt$ to an iron rod t :i* comes out ( ! pipe1 & is connect$ ) a sy/em ( b>s1 correspond+ to ! keybo>d ( a piano1 by :i* ! =ce ( s\nds c be regulat$4 ,?is =ce dep5ds on ! wid? ( ! op5+ betwe5 ! tongue & ! cyl9d]4 ,illu/ration3 ,,fig4 #gc4 ,! :i/le1 :i* plays ! "p ( ! l>ynx1 is necess>ily plac$ opposite ! op5+ ( ! bell[s1 & a sort ( t\rniquet ,m is fa/5$ to ! op5+ itself1 :i* is able to move on c]ta9 conditions1 s t x may produce ! roll+ s\nd ( r4 ,?is is done by fa/5+ be=e ! op5+ a diaphragm 9 :i* !re is a some:at wide & long slit1 & ?is slit c be almo/ clos$ by a little b> ( ! same size ,m1 revolv+ on a transv]se axis :i* supports x by its c5tre4 ,9 its normal condition1 ?is little b> is kept 9 a slant+ position by cords atta*$ to ! keybo>d1 & ! air eject$ by ! bell[s readily trav]ses ! slit 9 ord] to rea* ! l>ynx2 b two damp]s are fa/5$ to ! rods :i* transmit movem5t1 ) :i* ! cords j m5tion$ are also connect$4 ,on l[]+ ! notes ( ! key-bo>d1 ! passage ( air is contract$1 & ! little plate beg9s to oscillate & to press aga9/ a b& ( lea!r1 produc+ by its vibration an action simil> to t produc$ by ! cricket4 ,?is little t\rniquet only beg9s to act :5 ! damp]s are l[]$ by a p$al work$ by ! h&2 & ?is is also ! case ) ! iron rod t1 :i* modifies ! acut5ess ( ! s\nds pass+ ?r\gh ! l>ynx4#bb ,bel[ ! l>ynx tube1 :i* is only five c5timtres 9 l5g?1 !re is ano!r pipe ,g1 also ( ca\t*\c1 :i* t]m9ates 9 a sph]ical cavity connect$ ) ! out] air by a ca\t*\c tube ,i1 slightly rais$1 & clos$ by a valve1 ( :i* ! movem5ts are regulat$ by a p$al work$ by ! keybo>d4 ,:5 ! valve is op51 ! s\nds emitt$ ?r\gh ! l>ynx are some:at nasal4#bc ,! l>ynx communicates ) ! m\? ?r\gh a squ>e funnel-%ap$ pipe1 to :i* six metallic diaphragms ,d are fa/5$2 ! diaphragms are plac$ 9 a v]tical position beh9d ea* o!r1 & h ind5tations on _! l[] end1 :i* are int5d$ to dim9i% m or less ! orifice = ! curr5t ( air1 & to imp$e its passage ) great] or less =ce4 ,! diaphragms1 :i* we repres5t sep>ately fig4 #gd1 are connect$ ) ! keybo>d by jo9t$ iron rods t1 &1 = ! emission ( mo/ articulate s\nds1 sev]al ( ! diaphragms are mov$ at ! same mom5t & at diff]5t heights4 ,we %all return to ?is subject4 ,illu/ration3 ,,fig4 #gd4 ,! m\? consi/s ( a ca\t*\c cavity ,o1 some:at resembl+ ! human m\?1 & =m+ a cont9uation to ! *annel we h j describ$4 ,! tongue ,c1 likewise modell$ on ! human tongue1 is plac$ )9 ! m\?1 & connect$ ) two jo9t$ rods t1 t1 fa/5$ to its two opposite ends1 s z to enable ! tongue to raise its tip1 or t\* ! palate1 9 ob$i5ce to ! notes ( ! keybo>d4 ,! l[] ca\t*\c lip ,a c also be m or less clos$1 accord+ to ! action ( ! keybo>d on its special rod4 ,f9ally1 a circul> metallic piece ,e1 foll[+ ! %ape ( ! m\?1 is plac$ above ! upp] lip1 ) a small op5+ 9 x to admit ( ! pronunciation ( ! lett] f4 ,! keybo>d has f\rte5 notes1 ( diff]5t l5g?s1 produc+ ! foll[+ lett]s :5 l[]$1 a1 o1 u1 i1 e1 l1 r1 v1 f1 s1 *1 b1 d1 g4 ,! longe/ corresponds to g1 & ! %orte/ to a4 ,!re are two p$als bel[ ! g note & ^? ( b & d1 correspond+ ) ! op5+ ( ! tube :i* produces nasal s\nds1 & to ! rod :i* regulates ! op5+ ( ! l>ynx1 & ?is makes x possible to obta9 p1 t1 & k f ! notes b1 d1 g4 ,! me*anical effects produc$ by l[]+ ! diff]5t notes 9 succession are z foll[s3-- #a4 ,! a note moves ! fir/ five diaphragms4 #b4 o also moves ^! five diaphragms1 b v>ies ! pit*1 & closes ! m\? a little4 #c4 u does ! same1 only fur!r clos+ ! m\?4 #d4 t moves a s+le diaphragm1 raises ! tip ( ! tongue1 & op5s ! m\? m widely4 #e4 e moves six diaphragms1 ?r[s ! tongue fur!r back1 & op5s ! m\? /ill m4 #f4 l moves five diaphragms1 s5ds ! tongue aga9/ ! palate1 & fur!r op5s ! m\?4 #g4 r moves six diaphragms & ! t\rniquet1 l[]s ! tongue1 & some:at closes ! m\?4 #h4 v moves five diaphragms1 almo/ closes ! m\?1 & keeps ! tongue d[n4 #i4 f l[]s ! circul> app5dix ( ! upp] lip1 & almo/ entirely closes ! m\?4 #aj4 s moves ?ree diaphragms1 half closes ! m\?1 & half raises ! tongue4 #aa4 * moves ?ree diaphragms1 keeps ! m\? half clos$1 & fur!r l[]s ! tongue4 #ab4 b moves five diaphragms1 closes ! m\?1 & keeps ! tongue completely d[n4 #ac4 d moves six diaphragms1 keeps ! m\? ?ree p>ts clos$1 & raises ! tongue a little4 #ad4 g moves five diaphragms1 keeps ! m\? ?ree p>ts clos$1 & ! tongue completely d[n4 m is produc$ by l[]+ note b & op5+ ! valve ( ! pipe :i* gives nasal s\nds4 n is obta9$ by l[]+ note d & op5+ ! same valve4 h is obta9$ f note s by l[]+ ! p$al :i* acts ^u ! l>ynx1 & half clos+ x4 ,s9ce ! o!r lett]s ( ! alphabet are comp\nd s\nds1 !y c be produc$ by comb9ations ( ! prec$+ lett]s4 ,al?\gh ! words pron\nc$ by ?is ma*9e are di/9ct1 !y are spok5 9 a uni=m1 drawl+ tone1 :i* might1 ,i %\ld h ?\ght1 h exclud$ ! idea ( imposition4 ,"s ( !m are inde$ f> f di/9ct1 yet ! results are n less rem>kable2 & :5 we consid] ! am\nt ( /udy & exp]i5ce :i* mu/ h be5 appli$ to ! comb9ation ( all ^! arrangem5ts1 x seems surpris+ t physici/s h n giv5 m att5tion to su* an int]e/+ ma*9e4 ,z = ! me*anical execution1 x is impossible to admire too highly ! simple & +5i\s mann] 9 :i* all ! complicat$ movem5ts ( ! diff]5t vocal organs h be5 connect$ ) ! keybo>d1 ( :i* ! me*anism has be5 s calculat$ z only to produce ! precise action ( ! organ :i* is requir$ = any giv5 effect4 ,= ?is purpose1 ! notes ( ! keybo>d regul>ly increase 9 l5g?1 s z to produce at a s+le t\* diff]5t me*anical effects on ! rods :i* act ^u ! me*anism2 & s9ce mo/ ( ! notes are requir$ to react simultane\sly on ! :ole me*anism1 ! rods :i* transmit ! movem5t are fa/5$ to a s]ies ( jo9t$ lev]s :i* cross ! notes ( ! keybo>d at "r angles4 ,pegs ( diff]5t l5g? are fa/5$ to ! notes at ?is junction1 s z to produce ! simultane\s action ( ! diff]5t organs ( ! ma*9e4 ,! public w believe t ! ass]tions ( v5triloquism are unf\nd$ :5 ,i add t ,i myself h made ! ma*9e speak4 ,,app5dix4 ,! ,p]rodon ,sy/em ( ,telephonic ,al>um4--,capta9 ,p]rodon1 ( ! ,fr5* ,artill]y1 has lately improv$ ! sy/em inv5t$ by ,,mm4 ,dut]tre & ,g\ault1 by a self-act+ call4 ,= ?is purpose he has fa/5$ a spr+ contact be=e ! diaphragm1 comb9$ ) ! diaphragm & ! electro-magnetic sy/em s z to =m a vibrator4 ,! vibrations ?us produc$ are /rong en\gh to res\nd 9 an ord9>y telephone1 s z to make ! call audible 9 spite ( ext]nal noises4 ,! sy/em has be5 arrang$ 9 diff]5t ways4 ,9 "o arrangem5t1 a small plate ( t9foil is glu$ to ! out] surface ( ! diaphragm1 & ! end ( ! telephone coil wire is connect$1 bel[ ! inn] surface ( ! m\?piece1 ) a silv] wire sold]$ to a spr+ plate1 :i* con/itutes ! contact ( ! vibrator4 ,?is spr+ plate1 slightly curv$1 is fix$ bel[ "o ( ! b9d+-screws ( ! telephone1 & t]m9ates at its free end 9 a regulat+ screw by :i* ! int]val betwe5 ! contacts c be regulat$1 & ! in/rum5t c be arrang$ z a telephonic organ4 ,to d ?is1 ! screw c be )drawn1 & ins]t$ 9 a nut :i* e/abli%es direct connection betwe5 ! l9e & ! telephone coil4 ,x is easy to adapt an ord9>y telephone to ?is sy/em4 ,9 ano!r arrangem5t ,m4 ,c\rtot's mirror telephone has be5 employ$1 & a sort ( spr+ p$al is ins]t$ 9 ! wood ( ! m\?piece1 :i* t]m9ates 9 a b5t silv] wire1 support+ an index adapt$ to make a contact ) a squ>e plate sold]$ to ! diaphragm4 ,! batt]y is plac$ 9 connection ) ! spr+ ( ! p$al1 & "o end ( ! telephone coil-wire communicates z be=e ) ! diaphragm4 ,:5 a call is to be made1 ! p$al mu/ be press$1 & ! batt]y imm$iately communicates ) ! silv] wire :i*1 ) ! diaphragm1 con/itutes ! vibrator1 & an electric vibration is s5t ?r\gh ! circuit1 & produces ! call4 ,= receiv+1 ! p$al is all[$ to rev]t to its normal position1 & ! index ( ! p$al1 t\*+ ! contact 9 connection ) ! diaphragm1 e/abli%es direct communication betwe5 ! two telephones1 :ile break+ ! contact ( ! silv] wire ) ! diaphragm1 s t ! batt]y _c act4 ,x appe>s t exp]im5ts made at ! musketry s*ool at ,orleans = a di/ance ( #cgj miles h be5 v successful4 ,m4 ,v>ey's ,microphone ,speak]4--,m4 ,v>ey has rec5tly arrang$ a successful microphonic speak]1 9 :i* ! pr9ciple ( ! microphone repres5t$ 9 fig4 #ci is ma9ta9$4 ,! sy/em ( ?ree v]tical c>bons is arrang$ inside a sort ( snuff-box1 ( :i* ! lid is made ( a ?9 plate ( mica1 horn1 or ebonite4 ,! snuff-box is provid$ ) two h+$ arms1 s t x may be plac$ 9 ! mo/ conv5i5t position = speak+1 & at ! same "t ! s5sitiv5ess ( ! in/rum5t c be regulat$4 ,a small batt]y1 consi/+ ( two ,gaiffe cells ( *loride ( silv]1 is plac$ 9 ! p$e/al on :i* ! in/rum5t /&s1 & sets ! microphone at "w )\t fur!r tr\ble4 ,9 ?is way ! speak] c be us$ l an ord9>y telephone1 & is n affect$ by vibrations ( air4 ,only vibrations ( s\nd react ^u x4 ,microphonic ,speak] by ,fit*4--,mr4 ,pope /ates t ?is speak] has produc$ excell5t results 9 ,am]ica4 ,x is m]ely ,edison's c>bon telephone r$uc$ to its simple/ =m4 ,x consi/s ( a small cyl9drical box1 :i* has a m\?piece l ! "o repres5t$ fig4 #bh4 ,! box conta9s two c>bon disks ( ! same diamet] z itself1 & is l9$ ) a k9d ( felt4 ,metal wires1 inlaid 9 a groove scoop$ on ! circumf]5ce ( ! c>bons1 place !m 9 communication ) ! circuit & batt]y1 & transmission takes place by means ( ! vibrations ( ! upp] c>bon1 :i* is directly influ5c$ by ! voice )\t ! int]v5tion ( any diaphragm4 ,^! vibrations1 :i* c be freely develop$ 9 consequ5ce ( ! ela/icity ( ! felt pad :i* supports ! l[] c>bon1 produce on ! surface ( contact ( ! two c>bons ! modifications ( int5sity ( curr5t necess>y = ! reproduction ( spee*1 9 ! same way z o!r microphones4 ,an induction coil is necess>ily employ$ = a long circuit1 & ! effects ( induction 9 ! adjac5t wires are modifi$ by two rheo/ats introduc$ into ! circuit at its two extremities4 ,fur!r rem>ks on ! !ory ( ! ,telephone4--,foll[+ ! example ( a c]ta9 sceptic 9 ! ,acadmie des ,sci5ces1 ,colonel ,navez cont9ues to ma9ta9 ! !ory fir/ =m$ z to ! mode 9 :i* ! telephone acts1 9 spite ( ! cle>e/ pro(s ( its insuffici5cy2 b mo/ sci5tific m5 :o consid] ! "q h come r\nd to our op9ion1 & admit ! concurr5ce ( sev]al causes 9 ! reproduction ( spee* by ?is rem>kable in/rum5t4 ,mr4 ,fleem+ ,j5k9 writes to ?is effect 9 ! new edition ( a treatise on ,electricity & ,magnetism4 ,he obs]ves t a s+ul> fact has be5 discov]$ by sev]al p]sons1 :o h asc]ta9$ t n m]ely non-magnetic & non-conduct+ bodies c be sub/itut$ = ! diaphragms ( receiv+ telephones1 b t !y w act )\t a diaphragm at all4 ,9 ?is case x is evid5t t we h to d ) ! s\nds discov]$ by ,page1 & t !y are produc$ by ! magnet itself1 9 :i* ea* molecul> movem5t con/itutes ! s\rce ( ! s\nd produc$4 ,?is s\nd becomes articulate z soon z its increase & decrease c foll[ ! increas+ or decreas+ action ( ! voice :i* produces x at ! s5d+ /ation4 ,x is c]ta9 t :5 ! transmitt$ curr5ts are due to ! action ( ! ,bell diaphragm1 ! s\nds due to ! ,page effects ought to correspond ) ^? :i* w\ld be giv5 by iron diaphragms adapt$ to ! receiv+ in/rum5ts2 s t1 :5 a telephone has an iron diaphragm1 !re are 9 fact two voices1 t ( ! diaphragm1 :i* is /rong1 & t ( ! magnet1 :i* is weak4 ,:5 a disk ( wood is sub/itut$ = "o ( iron1 x acts z a s\nd+ bo>d = ! ,page effect1 & :5 ! disk is ( metal1 induction is develop$ by ! magnetic modifications1 & t5ds to produce vibration1 ?us develop+ a ?ird s\rce ( s\nd1 :i* may be call$ ! ,ampre effect4 ,f9ally1 a f\r? s\rce ( s\nd may result f ! induc$ effects produc$ 9 ! wire itself 9 consequ5ce ( *anges 9 ! int5sity ( curr5t4 ,^! s\nds1 fir/ obs]v$ by ,m4 de la ,rive1 h s9ce be5 /udi$ by ,mr4 ,f]gusson ( ,ed9burgh 7vide #8,telegraphic ,j\rnal' ( ,novemb] #a1 #ahgh74 ,mr4 ,fleem+ ,j5k9's op9ion only diff]s f m9e 9 8 ascrib+ ! en]gy ( s\nd acquir$ by a telephone ) an iron diaphragm to ! prepond]ance ( s\nds 9 ! latt]1 :]eas ,i consid] x to be *iefly due to ! increase ( en]gy 9 ! :ole magnetic sy/em produc$ by ! reaction ( ! two magnetic p>ts on ea* o!r4 ,if ! two effects c\ld be tak5 s+ly1 x is probable t ! s\nds produc$ by ea* ( !m sep>ately w\ld be simil>1 s9ce 9 magnetic effects ! reaction & action are equal4 ,b z !y are comb9$1 x becomes difficult to assign to ea* ! %>e :i* belongs to x 9 ! g5]al effect obs]v$4 ,besides1 x is q possible t ! s\nds ( ! diaphragm may appe> to be /rong] & m di/9ct because x is ne>] to ! e> ?an ! magnet1 & because ! effects ( magnetisation & demagnetisation are !n m easily produc$ 9 consequ5ce ( ! mass ( ! magnetic body be+ small]4 ,mr4 ,fleem+ ,j5k9 goes on to say t ! "q ( ! displacem5t ( surface 9 ! diaphragm & magnet is v complex1 b t he ?9ks x impossible to d5y ! exi/5ce ( su* displacem5t1 s9ce ! air :i* acts z ! vehicle ( s\nd betwe5 ! e> & ! s\rce ( s\nd is plac$ 9 vibration2 yet ?is displacem5t maybe effect$ q o!rwise ?an by flexion4 ,suppose t ! magnetic molecules ( ^! bodies are drawn toge!r by magnetisation1 :i* t5ds to dim9i% ! int]molecul> space :i* sep>ates !m1 ! po9ts ( surface ( ! sub/ance correspond+ to ^! int]vals w be elevat$ 9 a mann] equival5t to a displacem5t ( surface1 & ! effect ( ?is w be ! same z a flexion movem5t4 ,at ! mom5t ( demagnetisation a depression in/ead ( an elevation w take place1 & ! vibratory movem5ts w ?us be produc$ )\t any electro-magnetic attraction1 & x is precisely ^! vibrations :i* ,mr4 ,fleem+ ,j5k9 t]ms molecul> vibrations4 ,he evid5tly does n mean t su* attractions _c take place3 !y may react1 toge!r ) ! molecul> vibrations1 :5 ! electric =ce is capable ( produc+ !m4 ,he adds t ! reproduction ( s\nds by a cond5s]1 by simple coils1 & by a c>bon microphone1 has conv9c$ him t ! action j analys$ requires g5]alisation4 ,we h rec5tly se5 an article by ,mr4 ,hughes 9 ! #8,telegraphic ,j\rnal1' ,nov4 #ae1 #ahgh1 9 :i*1 to our surprise1 he n only opposes all ! !ories he has hi!rto held1 b cites exp]im5ts :i* are q inconclusive1 s9ce !y 7 p]=m$ "u conditions 9 :i* electro-magnetic effects mu/ necess>ily be display$4 ,he made use ( voltaic curr5ts produc$ by a batt]y ( ?ree ,daniell cells4 ,9 ord] to e/imate ! transv]se effects result+ 9 su* a case f attraction1 ! exp]im5ts he m5tions are :olly unnecess>y3 !y may be felt ) ! h&4 ,on ! o!r h&1 he has evid5tly =gott5 t ! curr5ts employ$ 9 a ,bell telephone h no influ5ce on a v s5sitive galvanomet]4 ,m4 ,poll>d's ,microphone4--,?is microphone1 :i* has be5 arrang$ 9 sev]al ways1 ess5tially consi/s ( a c>bon rod kept 9 a horizontal position by a wire1 & re/+ on two o!r v]tical c>bons4 ,! upright ( ! arm :i* holds ! wire c revolve toge!r ) ?is arm1 & is ?us able to regulate ! pressure ( ! horizontal c>bon on ! two v]tical c>bons4 ,x appe>s t ?is in/rum5t is extremely s5sitive1 & t ! regulation effect$ on ! two contacts is bett] ?an :5 x is effect$ on "o only4 ,x is fair to add t ,m4 ,vois9 previ\sly s5t me ! sket* ( a some:at simil> arrangem5t4 ,m4 ,dut]tre has also made use ( su* an arrangem5t 9 :at he calls ! ,dolm5 microphone4 ,?ree pieces ( coke 9 ! =m ( a dolm51 t is1 two uprights1 support+ a ?ird & horizontal c>bon1 are plac$ 9 circuit4 ,m4 ,g\ault has in=m$ me t spee* 0 well transmitt$ by ?is in/rum5t1 & x is1 l t ( ,mr4 ,bly?1 :i* succe$$ x1 ( wond]ful simplicity4 ,?is microphone1 z well z "o compos$ ( two pieces ( lead-p5cil plac$ 9 a wat*-case1 & connect$ by a piece ( money1 7 exhibit$ to ! ,indu/rial ,society at ,r\51 ,febru>y #a1 #ahgh1 ( :i* an acc\nt 0 publi%$ 9 ! ,bullet9 ( t society4 ,m4 ,ad]'s ,electrophone4--,m4 ,ad] has rec5tly con/ruct$ a rem>kable telephonic in/rum5t1 :i* reproduces spee* & song 9 a q exceptional & simple way4 ,x consi/s ( a drum #ae c5timtres 9 diamet]1 cov]$ ) p>*m5t at "o end only4 ,six small t9 armatures1 "o c5timtre 9 l5g? & two millimtres 9 wid?1 are fix$ 9 ! c5tre ( ! p>*m5t 9 a circle six c5timtres 9 diamet]4 ,six microscopic electro-magnets1 ^: di/ance f ! armatures c be regulat$ by a screw1 are plac$ opposite ! armatures )9 a wood5 circle4 ,! magnets are horse%oe1 ) bran*es #ab millimtres long & #d millimtres 9 diamet]1 includ+ ! coils1 & ! magnetic core is #a millimtre ?ick4 ,!y are all 9 connection1 & act simultane\sly "u ! sole influ5ce ( ! batt]y curr5t4 ,! s5d] is ! same z t ( ,m4 ,ad] describ$ be=e4 ,) ?is in/rum5t spee* may be he>d at a di/ance ( six or sev5 y>ds1 & songs are mu* m di/9ctly he>d ?an 9 ! s++ cond5s]4 ,ow+ to ! simplicity ( ! arrangem5t1 ! in/rum5t is n co/ly4 ,! extraord9>y effects ( ?is telephone are due to ! small size ( ! electro-magnets1 :i*1 z we believe1 produce mu* m rapid magnetic effects ?an ^? ( l>g] size4 ,m4 ,ad] has also made a small ord9>y telephone bas$ on ?is pr9ciple1 ( :i* ! s\nds are mu* /rong] ?an 9 o!rs4 ,modification ( ,bell ,telephone4--,mr4 ,g[] has rec5tly made a new sy/em ( telephone )\t a batt]y1 :i* n only reproduces spee* l\dly en\gh to be he>d at ! di/ance ( eight or n9e y>ds f ! in/rum5t1 b w also transmit x :5 ! speak] is at a mod]ate di/ance f ! s5d+ in/rum5t4 ,9 ?is latt] case1 inde$1 ! receiv+ telephone mu/ be br\ght close to ! e>4 ,al?\gh ?is d\ble problem _h already be5 solv$ by ! use ( telephones ) microphonic s5d]s1 ! results furni%$ by ! in/rum5ts 9 "q are /ill m curi\s1 s9ce !y are obta9$ )\t batt]ies1 & are ev5 m di/9ct4 ,9 ?is new sy/em1 :i* is only an improvem5t on ,bell's squ>e model1 ! horse%oe magnet is ( a peculi> =m1 :i* r5d]s x m p[]ful4 ,x is =m$ ( a k9d ( half-circle ( magnetis$ /eel1 ) its two ends turn$ back1 s z to =m a diamet] ( ! circle1 only ?is diamet] is divid$ 9 ! c5tre3 s t ! two poles ( ! magnet are plac$ "o be=e ! o!r1 z 9 ,f>aday's electro-magnet4 ,! poles are tipp$ ) iron1 t]m9at+ 9 front 9 two ?9 iron plates1 on :i* are plac$ ! electro-magnetic coils1 :i* are oblong1 & con/itute ! magnetic core4 ,! diaphragm1 ?ick] ?an ! ord9>y diaphragms1 is ( t91 & is fix$ firmly to ! edges ( ! circul> box :i* encloses ! :ole1 & :i* =ms a k9d ( s\nd+-box4 ,! box is made ( copp]1 & ! diaphragm is s firmly fa/5$ to x z to become homog5e\s ) x1 & to give out a s\nd :5 ! box is t\*$1 :i* is n ! case 9 ord9>y telephones4 ,?is is "o ( ! conditions :i* make ! in/rum5t a bett] conductor ( s\nd4 ,! magnet is also mu* m p[]ful4 ,x is magnetis$ by a curr5t f a p[]ful ,gramme ma*9e1 :i* acts ^u x = almo/ tw5ty m9utes4 ,! in/rum5t has1 /rictly speak+1 no m\?piece3 ! lid ( ! box :i* supports ! diaphragm1 & is sep>at$ f x by a space ( two millimtres1 has m]ely a hole bor$ 9 x above ! c5tre ( ! diaphragm1 & into ?is hole ei!r a t9 trumpet1 #ej c5timtres 9 l5g?1 is screw$1 :5 ! in/rum5t is requir$ to reproduce or transmit spee* to a di/ance1 or an ac\/ic tube :5 x is to be us$ l an ord9>y telephone4 ,! rem>kable "p ( ! sy/em is t ! in/rum5t c itself give a v l\d call by only brea?+ into x in/ead ( speak+4 ,= ?is purpose a small oblong op5+ is made 9 ! diaphragm at a half diamet] f its c5tre1 & beh9d ?is ! re$ ( an h>monium is appli$ to a squ>e copp] plate fix$ on ! diaphragm itself4 ,on us+ ! bell[s ! expell$ air passes ?r\gh ?is little hole1 &1 on rea*+ ! re$1 sets x 9 vibration1 & produces a s\nd ( :i* ! acut5ess dep5ds on ! conditions ( ! vibrat+ plate4 ,?is addition to ! diaphragm 9 no way alt]s its prop]ties 9 ! reproduction ( spee*1 s t1 aft] us+ ! bell[s1 conv]sation may beg91 & ! receiv+ telephone repeats :at is said aft] emitt+ a s\nd some:at resembl+ ! note ( a bugle4 ,! in/rum5t is !n provid$ ) ! speak+ tube ( :i* we h spok54 ,no?+ c be m rem>kable ?an ?is p[] ( li/5+ to conv]sation :ile seat$ 9 an arm*air six or sev5 y>ds f ! in/rum5t1 nor is x necess>y to move 9 ord] to reply4 ,! correspond5t1 inde$1 mu/ be close to ! ac\/ic tube 9 ord] to speak & li/51 & he mu/ speak r l\d 9 ord] to be he>d at any di/ance f ! o!r /ation4 ,b ! li/5] receives ! s\nds s amplifi$ t x might be suppos$ t a giant 0 speak+1 & conv]sation held 9 a l[ tone may ev5 be di/+ui%$4 ,^! results are really extraord9>y1 & ev5 to ^? famili> ) su* effects ?is incessant progress is surpris+4 ,^! results may be ascrib$ to ! foll[+ causes3-- #a4 ,fir/1 t ! conditions ( ! magnet are bett] ?an ^? ( ord9>y in/rum5ts4 #b4 ,t ! diaphragm is also ?ick]1 l>g]1 & bett] /ret*$4 #c4 ,t ! box is ( metal1 & calculat$ to act z a s\nd+-box4 #d4 ,! speak+ trumpet magnifies ! s\nds4 #e4 ,! ac\/ic tubes conc5trate ! s\nd waves on ! c5tre ( ! diaphragm4 ,note on "s fre% ,exp]im5ts ) ,telephones )\t any ,diaphragm4 ,9 a pap] publi%$ ,m>* #d1 #ahgh1 ,i made "s sugge/ions on ! !ory ( ! s\nds produc$ 9 ! telephone1 & on ! contradictory ass]tions ( physici/s z to ! transmission ( spee* by ord9>y telephones :5 devoid ( diaphragm4 ,^! rem>ks induc$ ,m4 ,ad] to und]take "s exp]im5ts :i* n only demon/rate ! tru? ( my op9ion1 b br+ to light "s fre% facts :i* may be ( great importance to ac\/ic sci5ce4 ,m4 ,ad] has 9 fact n only succe$$ 9 mak+ a telephone )\t a diaphragm speak1 b he has made x speak m l\dly & ) less alt]ation ( ! voice ?an we f9d to be ! case ) a small model ( ! ord9>y telephone4 ,no "o1 !re=e1 c n[ ma9ta9 t ! s\nds produc$ by ! magnetic cores are s fa9t t !y _c be tak5 into acc\nt among ! effects produc$1 & t x is at any rate impossible = !m to reproduce articulate s\nds4 ,to obta9 ?is result1 ,m4 ,ad] r$uc$ ! size ( ! magnetic core to t ( a simple iron wire1 "o millimtre 9 diamet]1 & he fa/5$ x by "o ( its ends to a small wood5 bo>d4 ,"u ^! conditions1 x 0 en\gh to fa/5 a small helix ( f9e wire on ?is iron wire1 & to apply ! bo>d to ! e> 9 ord] to he> spee* di/9ctly1 ) ! aid ( a microphonic speak] actuat$ by a voltaic curr5t4 ,b ! range ( s\nd 0 consid]ably increas$ if a mass ( metal 0 appli$ to ! free end ( ! iron wire3 9 ?is case x 0 possible to he> :5 ! wood5 bo>d 0 remov$ to a di/ance ( t5 or fifte5 c5timtres f ! e>4 ,if ! wire is 9 contact ) masses ( metal at ea* end1 ! effect is fur!r increas$2 b ! two masses mu/ n be 9 metallic communication ) ea* o!r1 & mu/ be to "s ext5t insulat$ by a m or less ela/ic m$ium4 ,if ! metallic masses are sold]$ to ! wire1 ! effects are /ill great]4 ,m4 ,ad] 0 also able to reproduce spee* by us+ a simple coil )\t a magnetic core1 b 9 ?is case ! spirals mu/ be op51 & n press$ toge!r4 ,if !y are /eep$ 9 gum1 no s\nd is he>d1 b spee* w become in/antly audible if a wire or a magnetis$ ne$le is ins]t$ 9 ! coil1 or ev5 if a second metallic helix is plac$ 9 ! circuit3 always provid$ t "o ( ! ends ( ^! magnetic organs re/s ^u1 or is fa/5$ to1 ! bo>d on :i* ! coil is fix$4 ,m4 ,ad] has likewise obta9$ a v di/9ct reproduction ( spee* at a di/ance ( two or ?ree y>ds f ! in/rum5t by ins]t+ betwe5 ! two /ret*$ membranes ( two tamb\r9es a b5t wire :i* acts z a spr+ & passes ?r\gh an electro-magnetic coil4 ,"u ^! conditions1 magnetisation ( ! wire 9 a great] or less degree affects its ela/icity & causes vibrations :i* are magnifi$ by ! membranes1 & transmitt$ s\nds are reproduc$ ) int5sity4 ,un=tunately articulate spee* is less di/9ct ) ?is sy/em ?an ) ! "o ,i describ$ be=e4 ,m4 ,ad] has (t5 _h occasion to make "o curi\s rem>k1 namely1 t ! timbre ( ! voice & its high or l[ key v>ies ) ! degree ( t5sion giv5 to ! wire2 b if ! fundam5tal note ( ! wire is dead5$ by press+ x betwe5 ! f+]s1 ! s\nds reproduc$ !n become dull & monoton\s4 ,!y are also some:at fa9t]4 ,signor ,c>lo ,resio has also obs]v$ t 9 a telephone s5d] ! v>iations ( int5sity 9 ! curr5t correspond ) ! vibrations caus$ by spee*1 & ^! are reproduc$ by correspond+ v>iations 9 a liquid column1 :i* may ?us act z a telephone receiv]1 & consequ5tly may reproduce spee* )\t any electro-magnetic organ1 z 9 a microphone speak]4 ,"u ^! conditions1 h[ev]1 a lay] ( wat] is ins]t$ betwe5 ! plat9um electrodes & ! surr\nd+ air1 & consequ5tly ?is liquid lay] mu/ be put 9 vibration "u ! influ5ce ( v>y+ int5sities ( curr5t4 ,mr4 ,edison has also n[ made a practical application ( ! *emical telephone we h m5tion$ be=e4 ,! trials made ) x h be5 v satisfactory1 %[+ t s\nds transmitt$ 9 ?is way c be he>d 9 a l>ge room4 ,,pr9t$ ,,by ,,spottiswoode ,,& ,,co41 ,,new-,,/reet ,,squ>e ,,london ,,footnotes #a ,mr4 ,gray1 9 an article ins]t$ 9 ! ,telegraph] ( ,octob] #g1 #ahgf1 ent]s into full details ( ?is mode ( transmitt+ s\nds by ! tissues ( ! human body1 & he gives ! foll[+ z ! conditions 9 :i* x mu/ be plac$ to obta9 a fav\rable result3 #a4 ,! electricity mu/ be ( a high t5sion1 9 ord] to h an effect p]ceptible to ! e>4 #b4 ,! sub/ance employ$ to t\* ! metallic plate mu/ be s(t1 flexible1 & a good conductor1 up to ! po9t ( contact3 x mu/ !n int]pose a slight resi/ance1 nei!r too great nor too small4 #c4 ,! disk & ! h&1 or any o!r tissue1 mu/ n only be 9 contact1 b ! contact mu/ result f rubb+ or glid+ ov] ! surface4 #d4 ,! p>ts 9 contact mu/ be dry1 s z to ma9ta9 ! requir$ degree ( resi/ance4 #b ,he cites ! foll[+ names 9 8 acc\nt ( electric telephony3--,page1 ,m>rian1 ,beatson1 ,gassiot1 ,de la ,rive1 ,matteucci1 ,guillem91 ,w]!im1 ,w>tmann1 ,janni>1 ,j\le1 ,laborde1 ,legat1 ,reiss1 ,pogg5dorf1 ,du ,moncel1 ,delez5ne1 ,gore1 c4 ,vide ,mr4 ,bell's pap]1 9 ! ,j\rnal ( ! ,society ( ,telegraphic ,eng9e]s 9 ,london1 vol4 vi4 pp4 #cij1 #cia4 #c ,?is /atem5t is disput$ by ,mr4 ,eli%a ,gray1 ow+1 z we %all see1 to a misund]/&+ z to ! ^w undulatory curr5t4 #d ,eli%a ,gray4 ,eng4 ,pat4 ,spec4 ,no4 #bfdf1 ,aug4 #ahgd4 #e ,?is prop]ty has long be5 kn[n1 b n appli$4 ,9 #ahef1 9 ! second edition ( my ,expos des applications d',electricit1 ,i po9t$ !m out 9 speak+ ( ! contact-break]s4 ,i also spoke ( !m 9 a pap] on electro-magnets 7publi%$ 9 ! ,annales tlgraphiques1 #ahfe71 & 9 sev]al articles laid be=e ! ,acadmie des ,sci5ces 9 #ahgb & #ahge on ! conductivity ( fil+s & conduct+ p[d]s4 ,m4 ,clrac1 9 #ahfe1 also us$ !m to obta9 v>iable resi/ances4 #f ,9 #ahfe ,i 0 able to v]ify ?is obs]vation :5 tight5+ ! spirals ( an electro-magnet on a nak$ wire4 ,! great] ! numb] ( spirals "u pressure1 ! m def9ite 7 ! diff]5ces ( resi/ance 9 ! magnetis+ helix4 #g ,m4 ,helles5 communicat$ ! plan ( 8 in/rum5t to me on ,may #c1 #ahgh1 & 8 exp]im5ts 7 made 9 ,cop5hag5 ?ree weeks e>li]4 #h ,m4 ,m4 ,j4 ,page _h already notic$ t if a telephone is plac$ 9 ! circuit ( ! prim>y helix ( an induction coil1 :ile ! second>y helix ( ?is in/rum5t is plac$ 9 ! circuit ( "o ( ,m4 ,lippmann's capill>y electromet]s1 a movem5t ( ! m]curial column ( ! electromet] takes place at ea* ^w1 & ?is movem5t is effect$ t[>ds ! capill>y end ( ! tube1 9 :atev] direction ! curr5t is s5t by ! telephone4 ,?is is because ! m]cury always t5ds to move m rapidly at its capill>y end ?an at ! o!r extremity4 #i ,mr4 ,edison1 9 a lett] writt5 ,novemb] #be1 #ahgg1 writes t he has made two telephones :i* act ) copp] diaphragms1 bas$ on ,arago's effects ( magnetism by rotation4 ,he asc]ta9$ t a copp] diaphragm might replace ! iron plate1 if its ?ickness did n exce$ #a_/cb ( an in*4 ,! effect produc$ is slight :5 ! copp] diaphragm is plac$ betwe5 two correspond+ in/rum5ts2 b :5 ! s5d] only is furni%$ ) ! copp] diaphragm1 & ! receiv] is arrang$ z usual1 communication becomes easy4 ,mr4 ,preece repeat$ ^! exp]im5ts1 b he only obta9$ v slight & indi/9ct effects3 he consequ5tly believes t !y are ( no practical use1 al?\gh v int]e/+ 9 !ory4 #aj ,mr4 ,bell _h previ\sly made a l exp]im5t1 :i* sugge/$ to him t molecul> vibrations _h z mu* to d ) ! action ( ! telephone z me*anical vibrations4 #aa ,m4 ,boss*a1 :o has publi%$ 9 ! ,ar*ives nerl&aises an int]e/+ pap] on ! int5sity ( electric curr5ts 9 ! telephone1 says t ! m9imum int5sity ( curr5ts necess>y to produce a s\nd 9 a telephone by ! vibration ( its diaphragm may be less ?an #ajj_/ajjj ( a ,daniell elem5t1 & ! displacem5t ( ! c5tre ( ! diaphragm w\ld !n be invisible4 ,he 0 unable to measure exactly ! range ( movem5ts produc$ 9 ! diaphragm by ! influ5ce ( ! voice1 b he believes x to be less ?an ! ?\s&? "p ( a millimtre2 & f ?is x foll[s t1 = a s\nd ( #hhj vibrations1 ! int5sity ( ! induc$ curr5ts develop$ w\ld be #jjjjjgib ( ! unit ( electro-magnetic int5sity4 #ab ,mr4 ,w>wick describes 8 exp]im5ts z foll[s3 #8,! magnets employ$ 7 ne>ly ( ! usual size1 #a in* 9 diamet]1 & ne>ly eight times z long4 ,at fir/ ,i employ$ iron disks1 b ,i f\nd !m to be unnecess>y4 ,:5 ,i _h disc>d$ !m1 ,i tri$ sev]al sub/ances3 fir/ a ?9 disk ( iron1 :i* answ]$ p]fectly bo? = s5d] & receiv]4 ,a disk ( %eet iron1 ab\t ( an in* 9 ?ickness1 did n act s well1 b all t 0 said 0 q und]/ood4 ,9 mak+ exp]im5ts ) ! disks1 ,i simply plac$ !m above ! in/rum5t1 )\t fix+ !m 9 any way3 ! wood5 cov] & ! conical cavity 7 also laid aside1 because ! transmission & reception c\ld be effect$ z well )\t !m4 ,?is "p ( ! in/rum5t seems to be sup]flu\s1 s9ce1 :5 ! disk is simply plac$ level to ! e>1 ! s\nd seems to be increas$ by be+ br\ght ne>]4 ,al?\gh iron acts bett] ?an any?+1 x appe>s t iron disks are n absolutely necess>y1 & t diamagnetic sub/ances also act p]fectly4 ,i wi%$ t my assi/ant1 :o 0 at "s di/ance1 & c\ld n he> any direct s\nd1 %\ld cont9ue 8 calculations4 ,i took away ! iron disk & plac$ across ! in/rum5t a wide iron b>1 an in* ?ick4 ,on apply+ my e> to x1 ,i c\ld he> e s\nd di/9ctly1 b some:at m fa9tly4 ,a piece ( copp]1 ?ree in*es squ>e1 0 sub/itut$ = x3 al?\gh ! s\nd 0 /ill di/9ct1 x 0 fa9t] ?an be=e4 ,?ick pieces ( lead1 z9c1 & /eel 7 alt]nately tri$4 ,! /eel act$ 9 almo/ ! same way z ! iron1 &1 z 9 ! o!r cases1 ea* ^w 0 he>d fa9tly b di/9ctly4 ,"s ( ^! metals are diamagnetic1 & yet ! action took place4 ,"s non-metallic sub/ances 7 next tri$2 fir/ a piece ( w9d[-glass1 :i* act$ v well4 ,! action 0 fa9t ) a piece ( a wood5 mat*-box2 b on us+ pieces ( gradually increas+ ?ickness ! s\nd 0 s5sibly increas$1 & ) a piece ( solid wood1 #a in* 9 ?ickness1 ! s\nd 0 p]fectly di/9ct4 ,i next replac$ x by an empty wood5 box1 :i* act$ v well4 ,a piece ( cork1 in* ?ick1 act$1 b some:at fa9tly4 ,a block ( razor-/one1 #b in*es ?ick1 0 plac$ ^u ! in/rum5t2 &1 on apply+ ! e> to x1 x 0 q easy to foll[ ! speak]4 ,i !n tri$ to he> )\t ! ins]tion ( any sub/ance1 &1 on apply+ my e> q close to ! coil & magnet1 ,i he>d a fa9t s\nd1 & on li/5+ att5tively ,i und]/ood all t 0 said4 ,9 all ^! exp]im5ts ! s\nds 7 p]ceiv$1 b ! s\nds transmitt$ or attempt$ did n act precisely alike4 ,! s\nd ( a tun+-=k1 plac$ on ! iron disk itself or on ! case ( ! in/rum5t1 0 cle>ly he>d3 ?9 iron disks 7 m effective = articulate spee*4 ,) o!r sub/ances1 /one1 solid wood1 glass1 z9c1 c41 ! s\nd ( ! tun+-=k 0 he>d1 :e!r x re/$ ^u !m1 or ! vibrat+ =k 0 held above !m4 ,^! sub/ances 7 n adapt$ = transmitt+ ! s\nd ( ! voice4 ,^! 7 all laid aside1 & ! s\nd+ in/rum5t 0 held directly above ! pole ( ! magnet3 ! s\nd 0 cle>ly he>d1 al?\gh !re 0 no?+ b air betwe5 ! end ( ! magnet & ! tun+-=k4 ,! s\nd 0 p]haps less int5se :5 ! tun+-=k 0 held directly above ! pole1 ?an :5 x 0 at ! end ( ! magnet4 ,i next tri$ if my voice c\ld be he>d ) ?is arrangem5t4 ,! result 0 r d\btful1 b ,i ?9k t "s action mu/ h tak5 place1 = ! tun+-=k 0 he>d :5 x 0 simply vibrat$ ne> ! pole4 ,! effect ( ! voice c only h diff]$ 9 ! degree ( int5sity3 x 0 too fa9t to be he>d at ! o!r extremity4 ,i repeat$ ^! effects2 ,i assur$ myself ( !m1 & ,i succe$$ 9 transmitt+ s\nds di/9ctly on ! pole )\t a disk1 &1 on ! o!r h&1 by apply+ my e> to ! in/rum5t1 ,i 0 able to he> di/9ctly all t 0 said1 al?\gh !re 0 no disk4' #ac ,^! are 8 own words3 #8,! articulation produc$ f ! in/rum5t 0 rem>kably cle>1 b its great defect consi/$ 9 ! fact t x c\ld n be us$ z a s5d+ in/rum5t1 & ?us two telephones 7 requir$ at ea* /ation1 "o = transmitt+ & "o = receiv+ spok5 messages4' #ad ,^! c>bons are made by heat+1 9 a temp]ature gradually rais$ to :ite heat1 fragm5ts ( deal ( a close fibre1 :i* is enclos$ 9 an iron tube or box h]metically seal$4 #ae ,mr4 ,will\ghby ,smi? v>i$ ?is exp]im5t by plac+ a packet ( silk ?reads coat$ ) copp] on ! disconnect$ ends ( ! circuit1 :i* 7 arrang$ at "r angles ) ea* o!r4 ,"u ^! conditions ! in/rum5t became s s5sitive1 t ! curr5t ( air produc$ by a lamp plac$ above ! sy/em1 caus$ a decid$ crackl+ noise 9 ! telephone4 #af ,mr4 ,hughes obs]ves on ?is subject t c>bon is a valuable mat]ial = su* purposes1 s9ce x does n oxidise1 & its effects are great] :5 comb9$ ) m]cury4 ,he takes ! prep>$ *>coal us$ by arti/s1 br+s x to a :ite heat1 & sudd5ly plunges x 9 a ba? ( m]cury1 ( :i* ! globules in/antly p5etrate ! pores ( *>coal1 & may be said to metallise x4 ,he also tri$ *>coal coat$ ) a deposit ( plat9um1 or impregnat$ ) *loride ( plat9um1 b ?is 0 n m successful ?an ! =m] me?od4 ,if ! *>coal ( fir-wood is br\ght to a :ite heat 9 an iron tube1 conta9+ t9 & z9c1 or any o!r metal :i* readily evaporates1 x is metallis$1 & is adapt$ = use if ! metal is subdivid$ 9 ! pores ( *>coal & n comb9$ ) x4 ,:5 iron is introduc$ into c>bon 9 ?is way x is "o ( ! mo/ effective metals4 ,! *>coal ( fir-wood1 9 itself a bad conductor1 may ?us acquire great conduct+ p[]4 #ag ,mr4 ,hughes rem>ks t ! vibrations :i* affect ! microphone1 ev5 9 speak+ at a di/ance f ! in/rum5t1 d n proce$ f ! direct action ( ! s\nd waves on ! contacts ( ! microphone1 b f ! molecul> vibrations produc$ by x on ! bo>d :i* s]ves to support ! in/rum5t2 he %[s1 9 fact1 t ! int5sity ( s\nds produc$ by ! microphone is 9 proportion to ! size ( ! surface ( ?is bo>d1 & :5 ! s5d+ microphone is enclos$ 9 a cyl9drical case1 its s5sitiv5ess is n mu* dim9i%$ if ! surface ( ! box enclos+ ! :ole is suffici5tly l>ge4 ,f ?is po9t ( view he has s\ght to increase ! s5sitiv5ess ( 8 in/rum5ts by fix+ ! frame on :i* ! moveable p>ts ( ! s5d] & receiv] revolve on a spr+ plate4 #ah ,helmholtz's resonator is bas$ ^u ! pr9ciple t a volume ( air conta9$ 9 an op5 vase emits a c]ta9 note :5 plac$ 9 vibration1 & t ! height ( ! note dep5ds on ! size ( ! vase & ( its op5+4 ,helmholtz makes use ( a globe ) a l>ge op5+ on "o side & a small "o on ! o!r1 & ! small "o is appli$ to ! e>4 ,if a s]ies ( musical notes take place 9 ! air1 ! "o :i* is 9 h>mony ) ! fundam5tal note ( ! globe is int5sifi$1 & c be di/+ui%$ f ! re/4 ,! same effect takes place :51 on s++ to a piano accompanim5t1 "s /r+s are he>d to vibrate m /rongly ?an o!rs1 namely1 ^? :i* vibrate 9 unison ) ! s\nds emitt$4 ,! resonators are made 9 v>i\s ways2 ^? mo/ g5]ally us$ are cases ( diff]5t l5g?s :i* also s]ve z s\nd+-boxes4 #ai ,i give ! text ( ,m4 ,cros' seal$ pap]1 op5$ by 8 reque/1 at ! ,acadmie des ,sci5ces1 ,decemb] #c1 #ahgg3--#8,speak+ g5]ally1 my process consi/s 9 obta9+ traces ( ! movem5t to & fro ( a vibrat+ membrane1 & 9 us+ ?is trac+ to reproduce ! same movem5ts1 ) _! intr9sic relations ( duration & int5sity1 ei!r on ! same membrane or on "o adapt$ to give out ! s\nds :i* result f ?is s]ies ( movem5ts4 #8,x is !re=e necess>y t an extremely delicate trac+1 su* z may be obta9$ by pass+ a ne$le ov] a surface black5$ by fire1 %\ld be trans=m$ into a trac+1 capable ( suffici5t resi/ance to guide an index :i* w transmit its movem5ts to ! membrane ( s\nd4 #8,a light index is fa/5$ to ! c5tre ( a vibrat+ membrane2 x t]m9ates 9 a po9t 7a metallic wire or tip ( a fea!r7 :i* re/s on a surface :i* has be5 black5$ by fire4 ,?is surface =ms "p ( a disk1 to :i* ! d\ble action ( rotation & rectil9e> progression has be5 giv54 ,if ! membrane is at re/1 ! po9t w trace a simple spiral2 if ! membrane vibrates1 !re w be undulations 9 ! spiral1 & ^! undulations w repres5t ! precise movem5ts ( ! membrane 9 _! duration & int5sity4 #8,by a well-kn[n photographic process a transp>5t trac+ ( ! undulations ( ! spiral c be repres5t$ by a l9e ( simil> dim5sions on "s resi/+ sub/ance1 temp]$ /eel = example4 #8,:5 ?is is done1 ?is resi/+ surface is plac$ 9 a turn+ ma*9e :i* causes x to revolve & advance ) a velocity & motion simil> to ^? by :i* ! regi/]+ surface 0 actuat$4 ,a metallic po9t if ! trac+ is concave1 or a groov$ index if x is 9 relief1 is kept ^u ! trac+ by a spr+1 & ! index :i* supports ?is po9t is connect$ ) ! c5tre ( ! membrane :i* produces ! s\nds4 ,"u ^! conditions1 ! membrane w be actuat$ n by ! vibrat+ air1 b by ! trac+ :i* guides ! index1 & ! impulses w be precisely simil> 9 duration & int5sity to ^? to :i* ! regi/]+ membrane 0 subject$4 #8,! spiral trac+ repres5ts equal successions ( "t by increas+ or decreas+ l5g?s4 ,!re is no inconv5i5ce 9 ?is1 s9ce ! turns ( ! spiral are v close toge!r1 if only ! circumf]5ce ( ! turn+ circle is us$2 b !n ! c5tral surface is lo/4 #8,9 all cases ! trac+ ( ! helix on a cyl9d] is mu* m satisfactory1 & ,i am n[ try+ to make ?is idea practicable4' #bj ,nev] make a contact betwe5 ! /ylus & ! cyl9d] until ! latt] is cov]$ ) ! t9foil4 ,d n beg9 to turn ! cyl9d] until assur$ t ev]y?+ is 9 its place4 ,take c>e1 :5 ! /ylus returns to ! po9t ( dep>ture1 to br+ ! m\?piece =w>d4 ,always leave a m>g9 ( f five to t5 millimtres on ! left & at ! beg9n+ ( ! %eet ( t9foil2 = if ! /ylus describes ! curve on ! extreme edge ( ! cyl9d]1 x may te> ! %eet or come out ( ! groove4 ,be c>eful n to deta* ! spr+ ( ! ca\t*\c pad4 ,to fix ! t9foil1 apply v>ni% to ! end ) a pa9t-bru%2 take ?is end betwe5 ! f+] & ?umb ( ! left h&1 ) ! /icky "p t[>ds ! cyl9d]2 raise x ) ! "r h& & apply x q smoo?ly to ! cyl9d]2 br+ r\nd ! /icky end1 & jo9 !m firmly4 ,to adju/ ! /ylus & place x 9 ! c5tre ( ! groove1 br+ ! cyl9d] to ! "r1 s z to place ! /ylus opposite ! left extremity ( ! t9foil2 br+ =w>d ! cyl9d] g5tly & by degrees1 until ! /ylus t\*es ! t9foil ) =ce en\gh to impr9t a m>k4 ,obs]ve if ?is m>k is q 9 ! c5tre ( ! groove 79 ord] to d ?is1 make a m>k ) ! nail across ! cyl9d]71 & if x is n1 adju/ ! /ylus to ! "r or left by means ( ! little screw plac$ above ! m\?piece4 ,! dep? ( ! impression made by ! /ylus %\ld be millimtre1 j en\gh = x to leave a slight trac+1 :atev] ! range ( vibrations may be4 ,to reproduce ! words1 ! w9* mu/ be turn$ ) ! same velocity z :5 !y 7 inscrib$4 ,! av]age velocity %\ld be ab\t eighty turns a m9ute4 ,9 speak+1 ! lips mu/ t\* ! m\?piece1 & deep guttural s\nds are bett] he>d ?an ^? :i* are %rill4 ,9 reproduc+1 ! tight5+ screw mu/ be loos5$ & br\ght 9 front ( ! m\?piece1 ! cyl9d] mu/ be br\ght back to its po9t ( dep>ture1 ! contact betwe5 ! /ylus & ! foil mu/ be r5ew$1 & ! cyl9d] mu/ aga9 be turn$ 9 ! same direction z :5 ! s5t5ce 0 spok54 ,to increase ! volume ( reproduc$ s\nd1 a tube ( c>dbo>d1 wood1 or horn may be appli$ to ! m\?piece2 x mu/ be ( a conical =m1 & its l[] end %\ld be r l>g] ?an ! op5+ ( ! m\?piece4 ,! /ylus consi/s ( a ,no4 #i ne$le1 some:at flatt5$ on its two sides by friction on an oil$ /one4 ,! ca\t*\c pad :i* connects ! plate ) ! disk s]ves to weak5 ! vibrations ( ! plate4 ,if ?is pad %\ld come (f1 heat ! head ( a small nail1 apply x to ! wax :i* fa/5s ! pad to ! plate or to ! spr+1 s z to s(t5 x2 !n press ! ca\t*\c lightly1 until x adh]es to ! place f :i* x 0 deta*$4 ,! pads mu/ be r5ew$ f "t to "t1 z !y lose _! ela/icity4 ,c>e mu/ be tak5 9 replac+ !m n to injure ! vibrat+ plate1 ei!r by too /rong a pressure or by graz+ x ) ! in/rum5t employ$ to fix ! pad4 ,! fir/ exp]im5ts %\ld be ) s+le words or v %ort s5t5ces1 :i* c be ext5d$ z ! e> becomes accu/om$ to ! in/rum5t's peculi> tone4 ,! tone is v>i$ by accel]at+ or slack5+ ! rotatory movem5t ( ! cyl9d]4 ,! cries ( animals may be imitat$4 ,in/rum5tal music may be reproduc$ by plac+ a c>dbo>d tube be=e ! m\?piece4 ,! airs %\ld be play$ 9 rapid "t1 s9ce1 :5 !re is no sy/em ( clockwork1 !y w be m p]fectly reproduc$ ?an ^? :i* are play$ sl[ly4 #ba ,we confess t we f9d x difficult to believe 9 ?is prop]ty ( ! phonograph1 f :i* we h only he>d ! h>% & unpleasant voice ( ,pun*4 #bb ,! action ( ?is p$al is effect$ by two little rock]s1 s connect$ t ! upp] damp] is l[]$ a little be=e ! l[] damp] is rais$--a condition necess>y to produce ! quiv]+ motion ( ! plate :i* furni%es ! roll+ r4 #bc ,! arrangem5t ( ?is "p ( ! in/rum5t is rem>kable 9 ?is p>ticul>1 t 9 ! case ( c]ta9 lett]s ! air is eject$ ) m or less =ce ?r\gh ! pipe ,i1 :ile 9 ! case ( o!r lett]s ! air is drawn into ! same tube4 ,s9ce ,i 0 unable to see ! int]nal arrangem5t ( ^! cavities1 ,i c only give an imp]fect acc\nt ( ! me*anism at "w4 ,transcrib]'s ,notes ,punctuation1 hyph5ation1 & spell+ 7 made consi/5t :5 a pr$om9ant pref]5ce 0 f\nd 9 ! orig9al book2 o!rwise !y 7 n *ang$4 ,simple typographical errors 7 correct$2 unbalanc$ quotation m>ks 7 rem$i$ :5 ! *ange 0 obvi\s1 & o!rwise left unbalanc$4 ,illu/rations 9 ?is e,book h be5 position$ betwe5 p>agraphs & outside quotations4 ,footnotes1 orig9ally at ! bottoms ( ! pages t ref]5c$ !m1 h be5 collect$1 sequ5tially r5umb]$1 & plac$ ne> ! end ( ! book4 ,! ,table ( ,cont5ts is n well-coord9at$ ) ! actual text4 ,! ,transcrib] has n add$ miss+ entries1 b has attempt$ to correct page numb] discrepancies4 ,sev]al diagrams use labels ) prime m>ks1 b ! accompany+ explanations d n always include ! prime m>ks4