,transcrib]'s ,notes ,all app>5t pr9t]'s errors & v>iations 9 spell+ h be5 reta9$1 !re are also "s inconsi/5cies 9 ! hyph5ation ( words4 ,all ^! h be5 detail$ at ! end ( ! text4 ,!re are a numb] ( ma!matical equations 9 ! text1 ^! h be5 r5d]$ into a text repres5tation t attempts to make !m z cle> z possible :ile mat*+ ! text z closely z possible4 ,multi-l9e fractions h be5 r5d]$ on "o l9e ) ! addition ( extra brackets if requir$ to ensure cl>ity4 ,sup]scripts are d5ot$ ) foll[$ by ! sup]script$ t]m 9 4 ,subscripts are d5ot$ by ) ! subscript$ t]m 9 4 ,squ>e roots are d5ot$ by sq foll[$ by ! root$ t]m 9 4 ,"s equations h foll[+ punctuation1 bo? commas or full /ops1 9 ! orig9al text z ?\gh ! equation is "p ( ! s5t5ce4 ,! middle dot has be5 us$ 9 ! orig9al text1 bo? z a multiplication symbol & z a decimal po9t4 ,^! h be5 kept b ! middle dot z a multiplication symbol 9 =mulae is surr\nd$ by s+le spaces4 ,italicis$ text 9 ! orig9al text is repres5t$ by text1 bold text is repres5t$ by bold4 99 99 99 99 99 ,,h]tzian ,,wave ,,wireless ,,telegraphy4 ,,by ,,dr4 ,j4 ,a4 ,,flem+1 ,f4,r4,s4 ,f ! ,,popul> ,,sci5ce ,,mon?ly1 ,june-,decemb]1 #aijc4 99 99 99 99 99 ,f ! ,popul> ,sci5ce ,mon?ly1 ,june1 #aijc4 ,,h]tzian ,,wave ,,wireless ,,telegraphy4#a ,,by ,,dr4 ,j4 ,a4 ,,flem+1 ,f4,r4,s41 ,,pr(essor ,,( ,,electrical ,,eng9e]+1 ,,univ]sity ,,college1 ,,london4 ,! imm5se public int]e/ :i* has be5 ar\s$ ( late ye>s 9 ! subject ( telegraphy )\t connect+ wires has und\bt$ly be5 /imulat$ by ! a*ievem5ts ( ,mr4 ,m>coni 9 effect+ communication ov] great di/ances by means ( ,h]tzian waves4 ,! p]iodicals & daily j\rnals1 :i* are ! *ief av5ues ?r\gh :i* in=mation rea*es ! public1 :il/ eag] to describe 9 a s5sational mann] ^! wond]ful applications ( electrical pr9ciples1 h done little to convey an intelligible explanation ( !m4 ,h5ce x appe>$ probable t a s]vice w\ld be r5d]$ by an endeav\r to pres5t an acc\nt ( ! pres5t condition ( electric wave telegraphy 9 a mann] acceptable to ^? unv]s$ 9 ! advanc$ te*nicalities ( ! subject1 b acqua9t$ at lea/ ) ! elem5ts ( electrical sci5ce4 ,x is ! purpose ( ^! articles to attempt ?is task4 ,we %all1 h[ev]1 limit ! discussion to an acc\nt ( ! sci5tific pr9ciples und]ly+ ! op]ation ( ?is p>ticul> =m ( wireless telegraphy1 omitt+1 z f> z possible1 ref]5ces to m]e que/ions ( priority & developm5t4 ,! practical problem ( electric wave wireless telegraphy1 :i* has be5 v>i\sly call$ ,h]tzian wave telegraphy1 ,m>coni telegraphy1 or sp>k telegraphy 7,funk5telegraphie71 is t ( ! production ( an effect call$ an electric wave or tra9 ( electric waves1 :i* c be s5t out f "o place1 controll$1 detect$ at ano!r place1 & int]pret$ into an alphabetic code4 ,up to ! pres5t "t1 ! *ief "p ( t int]communication has be5 effect$ by means ( ! ,morse code1 9 :i* a gr\p ( long & %ort signs =m ! lett] or symbol4 ,"s attempts h be5 made ) m or less success to "w pr9t+ telegraphs & ev5 writ+ or draw+ telegraphs by ,h]tzian waves1 b h n pass$ beyond ! exp]im5tal /age1 :il/ wireless telephony by ?is means is /ill a dream ( ! future4 ,we %all1 9 ! fir/ place1 consid] ! transmitt+ arrangem5ts &1 incid5tally1 ! nature ( ! effect or wave transmitt$2 9 ! second place1 ! receiv+ appliances2 &1 f9ally1 discuss ! problem ( ! isolation or secrecy ( ! intellig5ce convey$ betwe5 any two places4 ,! transmitt] us$ 9 ,h]tzian wave telegraphy consi/s ess5tially ( a device = produc+ electric waves ( a type :i* w travel ov] ! surface ( ! l& or sea )\t spe$y dissipation1 & ! important elem5t 9 ?is arrangem5t is ! radiator1 by :i* ^! waves are s5t out4 ,x w be an advantage to beg9 by expla9+ ! electrical action ( ! radiator1 & !n proce$ to discuss ! details ( ! transmitt+ appliances4 ,x w probably assi/ ! read] to arrive mo/ easily at a g5]al idea ( ! functions ( ! v>i\s portions ( ! transmitt+ arrangem5ts1 & 9 p>ticul> ( ! radiator1 if we take z our />t+ po9t an analogy :i* exi/s betwe5 electric wave g5]ation = telegraphic purposes & air wave g5]ation = s\nd signal purposes4 ,mo/ p]sons h visit$ "s ( ! l>ge ligh?\ses :i* exi/ ar\nd our coa/s & h !re se5 a /eam or air sir51 z us$ = ! production ( s\nd signals dur+ fogs4 ,if !y h exam9$ ?is appliance1 !y w "k t x consi/s1 9 ! fir/ place1 ( a long metal tube1 g5]ally ) a trumpet-%ap$ m\?piece4 ,at ! bottom ( ?is tube !re is a fix$ plate ) holes 9 x1 aga9/ :i* revolves ano!r simil>ly p]=at$ plate4 ,^! two plates sep>ate a back *amb] or w9d *e/ f ! tube1 & ! w9d *e/ communicates ) a res]voir ( compress$ air or a high-pressure /eam boil]4 ,9 ! communication pipe !re is a valve :i* c be sudd5ly op5$ = a long] or %ort] "t4 ,:5 ! movable plate revolves1 ! co9cid5ce or non-co9cid5ce ( ! holes 9 ! two plates op5s or %uts ! air passage way v rapidly4 ,h5ce :5 ! bla/ ( air or /eam is turn$ on1 ! fl[ is cut up by ! revolv+ plates into a s]ies ( puffs :i* inflict bl[s ^u ! /ation>y air 9 ! sir5 tube4 ,if ^! bl[s come at ! rate1 say1 ( a hundr$ a second1 !y give rise to a]ial oscillations 9 ! tube1 :i* impress ! e> z a deep1 musical note or ro>2 & ?is cont9u\s s\nd c be cut up by clos+ ! valve int]mitt5tly into long & %ort p]iods1 & s caus$ to signal a lett] accord+ to ! ,morse code1 d5ot+ ! "n ( ! ligh?\se4 ,9 ?is case ! object is to produce3 fir/1 a]ial vibrations 9 ! tube1 giv+ rise to a tra9 ( p[]ful air waves2 secondly1 to int]mit ?is wave-tra9 s z to produce an intelligible signal2 & ?irdly1 to transmit ?is wave z f> z possible ?r\gh space4 ,! production ( a s\nd or air wave c only be a*iev$ by adm9i/]+ a v sudd5 bl[ to ! g5]al mass ( ! air 9 ! tube4 ,?is impulse mu/ be suffici5t to call into op]ation ! in]tia & ela/ic qualities ( ! air4 ,x is f\nd1 moreov]1 t ! amplitude ( ! result+ wave1 or ! l\dness ( ! s\nd1 is increas$ by suitably proportion+ ! l5g? ( ! sir5 pipe & ! frequ5cy ( ! air puffs2 :il/ ! di/ance at :i* x is he>d dep5ds also 9 "s degree ^u ! =m ( ! m\?piece4 ,inside ! sir5 tube1 :5 x is 9 op]ation1 ! air molecules are 9 rapid vibratory motion 9 ! direction ( ! l5g? ( ! tube4 ,if we c\ld at any "o in/ant exam9e ! di/ribution & *anges ( air pressure 9 ! tube1 we %\ld f9d t at "s places !re are l>ge1 & at o!rs small1 v>iations 9 air pressure4 ,^! latt] places are call$ ! nodes ( pressure4 ,at ! pressure nodes1 h[ev]1 we %\ld f9d l>ge v>iations 9 ! velocity ( ! air p>ticles1 & ^! po9ts are call$ ! ant9odes ( velocity4 ,9 ^? places at :i* ! pressure v>iation is greate/1 ! velocity *anges are lea/1 & vice v]sa4 ,outside ! tube1 z a result ( ^! air motions 9 x1 we h a hemisph]ical air wave produc$1 :i* travels out f ! m\?piece z a c5tre2 & if we c\ld exam9e ! di/ribution ( air pressure & velocity ?r\gh all ext]nal space1 we %\ld f9d a di/ribution :i* is p]iodic 9 space z well z "t1 con/itut+ ! famili> ph5om5on ( an air wave4 ,turn+ !n to consid] ! production ( an electric1 in/ead ( an air wave1 we notice 9 ! fir/ place t ! m$ium ) :i* we are conc]n$ is ! e!r fill+ all space4 ,?is e!r p]mits ! production ( physical *anges 9 x :i* are analog\s to1 b n id5tical 9 nature )1 ! pressures & movem5ts :i* con/itute a s\nd wave4 ,! ,h]tzian radiator is an appliance = act+ on ! e!r z ! sir5 acts on ! air4 ,x produces a wave 9 x1 & x c be %[n t all ! p>ts ( ! above describ$ sir5 app>atus h _! electrical equival5ts 9 ! transmitt] employ$ 9 ,h]tzian wave wireless telegraphy4 ,to und]/& ! nature ( an electric wave we mu/ consid]1 9 ! fir/ place1 "s prop]ties ( ! e!r4 ,9 ?is m$ium we c at any place produce a /ate call$ electric displacem5t or e!r /ra9 z we c produce compression or r>efaction 9 air2 &1 j z ! latt] *anges are said to be creat$ by me*anical =ce1 s ! =m] is said to be due to electric =ce4 ,we c n def9e m cle>ly ! nature ( ?is e!r /ra9 or displacem5t until we "k mu* m ab\t ! /ructure ( ! e!r ?an we d at pres5t4 ,we c picture to ourselves ! op]ation ( compress+ air z an approximation ( ! air molecules1 b ! difficulty ( compreh5d+ ! nature ( an electric wave arises f ! fact t we _c yet def9itely resolve ! notion ( electric /ra9 into any simpl] or m famili> ideas4 ,we h to be cont5t1 !re=e1 to disguise our pres5t ignorance by ! use ( "s descriptive t]m1 su* z electric /ra91 electro/atic /ra9 or e!r /ra91 to describe ! direct$ condition ( ! space ar\nd a body 9 a /ate ( electrification :i* is produc$ by electric =ce4 ,?is electric /ra9 is c]ta9ly n ( ! nature ( a compression 9 ! e!r1 b mu* m ak9 to a twi/ or rotational /ra9 9 a solid body4 ,= our pres5t purpose x is n s necess>y to po/ulate any p>ticul> !ory ( ! e!r z x is to possess "s consi/5t hypo!sis1 9 t]ms ( :i* we c describe ! ph5om5a :i* w conc]n u4 ,^! effects are1 z we %all see1 p>tly /ates ( electrification on ! surface or di/ributions ( electric curr5t 9 wires or rods1 & p>tly conditions 9 ! space outside !m1 :i* we are l$ to recognise z di/ributions ( electric /ra9 & ( an associat$ effect call$ magnetic flux4 ,we f9d su* a !ory at h& at ! pres5t "t 9 ! electronic !ory ( electricity1 :i* has n[ be5 suffici5tly develop$ & popul>is$ to make x useful z a descriptive hypo!sis4#b ,?is !ory has ! great recomm5dation t x (f]s a means ( aboli%+ ! p]plex+ dualism ( e!r & pond]able matt]1 & gives a def9ite &1 9 a s5se1 objective mean+ to ! ^w electricity4 ,9 ?is physical speculation1 ! *ief subject ( contemplation is ! electron1 or ultimate p>ticle ( negative electricity1 :i*1 :5 associat$ 9 great] or less numb] ) a matrix ( "s description1 =ms ! atom ( pond]able matt]4 ,to avoid fur!r hypo!sis1 ?is matrix may be call$ ! co-electron2 & we %all adopt ! view t a s+le *emical atom is a union ( a co-electron ) a surr\nd+ envelope or gr\p ( electrons1 "o or m ( ! latt] be+ deta*able4 ,we ne$ n /op to speculate on ! /ructure ( ! atomic core or co-electron1 :e!r x is compos$ ( positive & negative electrons or ( some?+ entirely diff]5t4 ,! s+le electron is ! indivisible unit or atomic elem5t ( s-call$ negative electricity1 & ! neutral *emical atom depriv$ ( "o electron is ! unit ( positive electricity4 ,on ?is hypo!sis1 ! *emical atom is to be reg>d$ z a microcosm1 a sort ( a sol> sy/em 9 m9iature1 ! compon5t electrons be+ capable ( vibration relatively to ! atomic c5tre ( mass4 ,fur!rmore1 f ?is po9t ( view x is ! electron :i* is ! effective cause ( radiation4 ,x alone has a grip on ! e!r :]eby x is able to e/abli% wave motion 9 ! latt]4 ,dr4 ,l>mor has develop$ 9 consid]able detail an hypo!sis ( ! nature ( an electron :i* makes x ! c5tre or conv]g5ce-po9t ( l9es ( a self-lock$ e!r /ra9 ( a torsional type4 ,! notion ( an atom m]ely z a c5tre ( =ce 0 "o famili> to ,f>aday & mu* support$ by ,boscovi* & o!rs4 ,! fatal objection to ! validity ( ?is notion z orig9ally /at$ 0 t x (f]s no possibility ( expla9+ ! in]tia ( matt]4 ,on ! electronic hypo!sis1 ! s\rce ( all in]tia is ! in]tia ( ! e!r1 & until we are able to dissect ?is la/ quality into any?+ simpl] ?an ! "t-elem5t involv$ 9 ! production ( an e!r /ra9 or displacem5t1 we mu/ accept x z an ultimate fact1 n m elucidat$ because we speak ( x z ! inductance ( ! electron4 ,we po/ulate1 !re=e1 ! foll[+ ideas3 ,we h to ?9k ( ! e!r z a homog5e\s m$ium 9 :i* a /ra9 ( "s k9d1 mo/ probably ( a rotational type1 is possible4 ,?is /ra9 appe>s only "u ! influ5ce ( an appropriate /ress call$ ! electric =ce1 & disappe>s :5 ! =ce is remov$4 ,h5ce to create ?is /ra9 necessitates ! exp5diture ( en]gy4 ,an electron is a c5tre or conv]g5ce-po9t ( l9es ( p]man5t e!r /ra9 ( su* nature t x _c release itself4 ,to obta9 "s idea ( ! nature ( su* a /ructure1 let u imag9e a flat /eel b& =m$ into a r+ by weld+ ! ends toge!r4 ,!re is !n no torsional /ra94 ,if1 h[ev]1 we suppose ! b& cut 9 "o place1 "o end !n giv5 half a turn & ! cut ends aga9 weld$1 we %all h on ! b& a self-lock$ twi/1 :i* c be displac$ on ! b&1 b :i* c n release itself or be releas$ except by cutt+ ! r+4 ,h5ce we see t to make an electron 9 an e!r possess+ torsional ela/icity w\ld require creative en]gy1 & :5 made1 ! electron _c de/roy itself except by occupy+ simultane\sly ! same place z an electron ( opposite type4 ,e electron ext5ds1 !re=e1 z ,f>aday said ( ! atom1 ?r\gh\t ! univ]se1 & ! prop]ties t we f9d 9 ! electron are only !re because !y are fir/ 9 ! univ]sal m$ium1 ! e!r4 ,e l9e ( e!r or electric /ra9 mu/1 !re=e1 be a self-clos$ l9e1 or else x mu/ t]m9ate on an electron & a co-electron4 ,s f> we h only consid]$ ! electron at re/4 ,if1 h[ev]1 x moves1 x c be ma!matically demon/rat$ t x mu/ give rise to a second =m ( e!r /ra9 :i* is relat$ to ! electric /ra9 z a twi/ is relat$ to a ?ru/ or a vortex r+ to a squirt 9 liquid or a rotation to a l9e> progression4 ,! e!r /ra9 :i* results f ! lat]al movem5t ( l9es ( electric /ra9 is call$ ! magnetic flux1 & x c be ma!matically %[n t ! movem5t ( an electron1 consi/+ :5 a re/ ( a radial conv]g5ce ( l9es ( electric /ra91 mu/ be accompani$ by ! production ( self-clos$ l9es ( magnetic flux1 di/ribut$ 9 conc5tric circles or r+s r\nd x1 ! planes ( ^! circles be+ p]p5dicul> to ! direction ( motion ( ! electron4 ,?is electronic hypo!sis1 !re=e1 af=ds a basis on :i* we c build up a !ory af=d+ an explanation ( ! nature ( ! intimate connection kn[n to exi/ betwe5 e!r1 matt] & electricity4 ,! electron is ! connect+ l9k betwe5 !m all1 = x is 9 itself a c5tre ( conv]g5t e!r /ra92 isolat$1 x pres5ts itself z electricity ( ! negative or res9\s k9d2 &1 9 comb9ation ) co-electrons & o!r electrons1 x =ms ! atoms ( pond]able matt]4 ,at re/ ! electron or ! co-electron con/itutes an electric *>ge1 & :5 9 motion x is an electric curr5t4 ,a /eady flux or drift ( electrons 9 "o direction & co-electrons 9 ! opposite direction is a cont9u\s electric curr5t1 :il/ _! m]e oscillation ab\t a mean position is an alt]nat+ curr5t4 ,fur!rmore1 ! vibration ( an electron1 if suffici5tly rapid1 enables x to e/abli% :at are call$ electric waves 9 ! e!r1 b :i* are really deta*$ & self-clos$ l9es ( e!r /ra9 di/ribut$ 9 a p]iodic mann] ?r\gh space4 ,we h1 !re=e1 to />t )1 ?ree conceptions conc]n+ ! electron1 viz43 ,its condition :5 at re/2 its /ate :5 9 uni=m motion2 & its op]ations :5 9 vibration or rapid oscillation4 ,9 ! fir/ case1 by our fundam5tal supposition1 x consi/s ( l9es ( e!r /ra9 ( a type call$ ! electric /ra91 radiat+ uni=mly 9 all directions4 ,:5 9 uni=m motion1 x c be %[n t ^! l9es ( electric /ra9 t5d to gr\p !mselves 9 a plane p]p5dicul> to ! l9e ( motion drawn ?r\gh ! electron1 & _! lat]al motion g5]ates ano!r class ( /ra9 call$ ! magnetic /ra91 dispos$ 9 conc5tric circles describ$ r\nd ! electron & ly+ 9 ?is equatorial plane4 ,! pro( ( ! above propositions _c be giv5 v]bally1 b requires ! aid ( ma!matical analysis ( an advanc$ k9d4 ,! read] mu/ be ref]r$ = ! complete demon/ration to ! writ+s ( ,pr(essor ,j4 ,j4 ,?omson#c & ,mr4 ,oliv] ,heaviside4#d ,9 ! ?ird case1 :5 ! electron vibrates1 we h a /ate 9 :i* self-clos$ l9es ( electric /ra9 & magnetic flux are ?r[n (f & move away ?r\gh ! e!r con/itut+ electric radiation1 ,! mann] 9 :i* ?is happ5s 0 fir/ describ$ by ,h]tz 9 a ,pap] on ,electric ,oscillations treat$ accord+ to ! ,me?od ( ,maxwell4#e ,z ?is ph5om5on lies at ! v root ( ,h]tzian wave wireless telegraphy1 we mu/ sp5d a mom5t or two 9 its c>eful exam9ation4 ,let u imag9e two metal rods plac$ 9 l9e & con/itut+ :at is call$ a l9e> oscillator4 ,let ^! rods h adjac5t ends sep>at$ by a v small air space1 & let "o rod be *>g$ ) positive & ! o!r ) negative electricity4 ,on ! electronic !ory ?is is expla9$ by /at+ t !re is an accumulation ( electrons 9 "o & ( co-electrons 9 ! o!r4 ,^! *>ges create a di/ribution ( electric /ra9 ?r\gh\t _! neighb\rhood1 :i* foll[s approximately ! same law ( di/ribution z ! l9es ( magnetic =ce ( a b> magnet1 & may be r\ghly repres5t$ z 9 ,fig4 #a4 ,suppose !n t ! air gap is de/roy$1 ^! *>ges move t[>ds ea* o!r & disappe> by unit+1 ! l9es ( electric /ra9 !n collapse1 & z !y %r9k 9 give rise to circul> l9es ( magnetic flux embrac+ ! rods4 ,?is ext]nal di/ribution ( magnetism con/itutes an electric curr5t 9 ! rods produc$ by ! movem5t ( ! two opposite electric *>ges4 ,at ?is /age x may be expla9$ t ! electrons or atoms ( electricity c 9 "s cases make _! way freely betwe5 ! atoms ( pond]able matt]4 ,! =m] are incomp>ably small] ?an ! latt]1 & 9 ^? cases 9 :i* ?is electronic movem5t c take place easily1 we call ! mat]ial a good conductor4 ,illu/ration3 ,,fig4 #a4--,,l9es ,,( ,,electric ,,/ra9 ,,betwe5 ,a ,,positive ,,& ,,negative ,,electron ,,at ,,re/4 ,suppose !n ! electric *>ges reappe> 9 rev]s$ positions & g ?r\gh an oscillatory motion4 ,! result 9 ! ext]nal space w\ld be ! alt]nate production ( l9es ( electric /ra9 & magnetic flux1 ! direction ( ^! l9es be+ rev]s$ ea* half cycle4 ,inside ! rods we h a movem5t ( electrons & co-electrons to & fro1 electric *>ges at ! ends ( ! rods alt]nat+ ) electric curr5ts 9 ! rods1 ! *>ges be+ at a maximum :5 ! curr5t is z]o1 & ! curr5t at a maximum :5 ! *>ges h = ! mom5t disappe>$4 ,outside ! rods we h a correspond+ set ( *>ges1 l9es ( electric /ra9 /ret*+ f end to end ( ! rod1 alt]nat+ ) r+s ( magnetic flux embrac+ ! rod4 ,s f> we h suppos$ ! oscillation to be relatively a sl[ "o4 ,illu/ration3 ,,fig4 #b4--,,successive ,,/ages ,,9 ,,! ,,de=mation ,,( ,a ,,l9e ,,( ,,/ra9 ,,betwe5 ,,positive ,,& ,,negative ,,electrons ,,9 ,,rapid ,,oscillation1 ,,%[+ ,,clos$ ,,loop ,,( ,,electric ,,/ra9 ,,?r[n ,,(f4 ,imag9e next t ! to & fro movem5t ( ! electrons or *>ges is suffici5tly rapid to br+ into play ! in]tia quality ( ! m$ium4 ,we !n h a diff]5t /ate ( affairs4 ,! l9es ( /ra9 9 ! ext]nal m$ium _c contract or collapse quickly en\gh to keep up ) ! c\rse ( ev5ts1 or movem5ts ( ! electrons 9 ! rods1 & h5ce _! regul> contraction & absorption is *ang$ into a process ( a diff]5t k9d4 ,z ! electrons & co-electrons1 i4e41 ! electric *>ges1 vibrate to & fro1 ! l9es ( electric /ra9 connect+ !m are nipp$ 9 & ?r[n (f z completely indep5d5t & clos$ l9es ( electric /ra91 & at ea* successive alt]nation1 gr\ps or bat*es ( ^! loops ( /ra9 are deta*$ f ! rod1 &1 s to speak1 take on an indep5d5t exi/5ce4 ,! :ole process ( ! =mation ( ^! self-clos$ l9es ( electric /ra9 is be/ und]/ood by exam9+ a s]ies ( diagrams :i* r\ghly repres5t ! v>i\s /ages ( ! process4 ,9 ,fig4 #b we h a diagram 7a7 ! curv$ l9e 9 :i* del9eates approximately ! =m ( "o l9e ( electric /ra9 r\nd a l9e> oscillator1 ) sp>k gap 9 ! c5tre1 "o half be+ *>g$ positively & ! o!r negatively4 ,let u !n suppose t ! insulation ( ! sp>k gap is de/roy$1 s t ! opposite electric *>ges ru% toge!r & oscillate to & fro4 ,! /ra9 l9es at ea* oscillation are !n cross$ or decussate1 & ! result1 z %[n 9 ,fig4 #b1 d1 is t a portion ( ! en]gy ( ! field is ?r[n (f 9 ! =m ( self-clos$ l9es ( /ra9 7see ,fig4 #b1 e74 ,at ea* oscillation ( ! *>ges ! direction ( ! l9es ( /ra9 spr++ f end to end ( ! radiator is rev]s$4 ,x is a g5]al prop]ty ( l9es ( /ra9 :e!r electric or magnetic1 t !re is a t5sion along ! l9e & a pressure at "r angles4 ,9 o!r words1 ^! l9es ( electric /ra9 are l ela/ic ?reads1 !y t5d to contract 9 ! direction ( _! l5g? & press sideways on ea* o!r :5 9 ! same direction4 ,h5ce x is n difficult to see t z ea* bat* ( self-clos$ l9es ( /ra9 is ?r[n (f1 ! direction ( ! /ra9 r\nd ea* loop is alt]nately 9 "o direction & 9 ! o!r4 ,h5ce ^! loops ( electric /ra9 press ea* o!r out1 & ea* "o t is =m$ squeezes ! already =m$ loops fur!r & fur!r f ! radiator4 ,! loops1 !re=e1 m>* away into space 7see ,fig4 #b1 f74 ,if we imag9e ourselves /&+ at a little di/ance at a po9t on ! equatorial l9e & able to see ^! loops ( /ra9 z !y pass1 we %\ld recognise a procession ( loops1 consi/+ ( alt]nately direct$ /ra9 l9es m>*+ pa/4 ,?is movem5t ?r\gh ! e!r ( self-clos$ l9es ( electric /ra9 con/itutes :at is call$ electric radiation4 ,h5ce along a l9e drawn p]p5dicul> to ! radiator ?r\gh its c5tre1 !re is a di/ribution ( electric /ra9 normal to t l9e1 :i* is p]iodic 9 space & 9 "t4 ,moreov]1 9 addition to ^! l9es ( electric /ra91 !re are at "r angles to !m ano!r set ( self-clos$ l9es ( magnetic flux4 ,alt]nat$ betwe5 ! in/ants :5 ! electric *>ges at ! ends ( ! radiator are at _! maximum1 we h in/ants :5 ! radiator rod is ! seat ( an electric curr5t1 & h5ce ! field r\nd x is fill$ ) circul> l9es ( magnetic flux coaxial ) ! radiator4 ,z ! curr5t alt]nates 9 direction ea* half p]iod1 ^! r+s ( magnetic flux alt]nate 9 direction z reg>ds ! flux1 & h5ce we mu/ complete our m5tal picture ( ! space r\nd ! radiator rods :5 ! *>ges are oscillat+ by suppos+ x fill$ ) conc5tric r+s ( magnetic flux :i* are p]iodically rev]s$ 9 direction1 & h _! maximum values at ^? in/ants & places :]e ! l9es ( electric /ra9 h _! z]o values4 ,accord+ly1 along ! equatorial l9e we h two sets ( /ra9s 9 ! e!r1 di/ribut$ p]iodically 9 space & 9 "t4 ,fir/1 ! l9es ( electric /ra9 9 ! plane ( ! radiator1 &1 secondly1 ! l9es ( magnetic flux at "r angles to ^!4 ,at any "o po9t 9 space ^! two *anges1 ! /ra9 & ! flux1 succe$ ea* o!r p]iodically1 be+1 h[ev]1 at "r angles 9 direction4 ,at any "o mom5t ^! two effects are di/ribut$ p]iodically or cyclically ?r\gh space1 & ^! *anges 9 "t & space con/itute an electric wave or electromagnetic wave4 ,we may !n summ>ise ! above /atem5ts by say+ t ! mo/ rec5t hypo!sis z to ! nature ( electrical action & ( electricity itself is briefly compris$ 9 ! foll[+ /atem5ts3 ,! univ]sally diffus$ m$ium call$ ! e!r has _h creat$ 9 x c]ta9 c5tres ( /ra9 or radiat+ po9ts f :i* proce$ l9es ( /ra91 & ^! c5tres ( =ce are call$ electrons4 ,electrons mu/1 !re=e1 be ( two k9ds1 positive & negative1 accord+ to ! direction ( ! /ra9 radiat+ f ! c5tre4 ,^! electrons 9 _! free condition con/itute :at we call electricity1 & ! electrons !mselves are ! atoms ( electricity :i*1 9 "o s5se1 is1 !re=e1 z mu* mat]ial z t :i* we call ord9>y gross or pond]able matt]4 ,collocations ( ^! electrons con/itute ! atoms ( gross matt]1 & we mu/ consid] t ! individuality ( any atom is n det]m9$ m]ely by ! id5tity ( ! electrons compos+ x1 b by ! p]man5ce ( _! arrangem5t or =m4 ,9 any mass ( mat]ial sub/ance !re is probably a cont9ual ex*ange ( electrons f "o atom to ano!r1 & h5ce at any "o giv5 mom5t1 :il/ a numb] ( ! electrons are an association =m+ mat]ial atoms1 !re w be a fur!r numb] ( isolat$ b int]m+l$ electrons1 :i* are call$ ! free electrons4 ,9 sub/ances :i* we call good conductors1 we mu/ imag9e t ! free electrons h ! p[] ( mov+ freely ?r\gh or betwe5 ! mat]ial atoms1 & ?is movem5t ( ! electrons con/itutes a curr5t ( electricity2 :il/ a sup]fluity ( electrons ( ei!r type 9 any "o mass ( matt] con/itutes :at we call a *>ge ( electricity4 ,h5ce an electrical oscillation1 :i* is m]ely a v rapid alt]nat+ curr5t tak+ place 9 a conductor1 is on ?is hypo!sis assum$ to consi/ 9 a rapid movem5t to & fro ( ! free electrons4 ,we may picture to ourselves1 !re=e1 a rod ( metal 9 :i* electrical oscillations are tak+ place1 z simil> to an organ-pipe or sir5 tube 9 :i* movem5ts ( ! air p>ticles are tak+ place to & fro1 ! free electrons correspond+ ) ! air p>ticles4 ,ow+ to ! nature ( ! /ructure ( an electron1 x foll[s1 h[ev]1 t e movem5t ( an electron is accompani$ by *anges 9 ! di/ribution ( ! electric /ra9 or e!r /ra9 tak+ place ?r\gh\t all surr\nd+ space1 &1 z already expla9$1 c]ta9 v rapid movem5ts ( ! electrons h ! effect ( deta*+ clos$ l9es ( /ra9 9 ! e!r :i* move (f ?r\gh space1 =m+1 :5 cyclically di/ribut$1 an electric wave4 ,illu/ration3 ,,fig4 #c4--,,simple ,,m>coni ,,radiator4 ,b1 batt]y2 ,i1 induction coil2 ,k1 signall+ key2 ,s1 sp>k gap2 ,a1 a]ial wire2 ,e1 e>? plate4 ,we may next proce$ to apply ^! pr9ciples to ! explanation ( ! action ( ! simple/ =m ( ,h]tzian wave telegraphic radiator1 viz41 ! ,m>coni a]ial wire4 ,9 its orig9al =m ?is consi/s ( a long v]tical insulat$ wire1 ,a1 ! l[] end ( :i* is atta*$ to "o ( ! sp>k balls ,s ( an induction coil1 ,i1 ! o!r sp>k ball be+ connect$ to e>? ,e1 & ! two sp>k balls be+ plac$ a few millimetres ap>t 7see ,fig4 #c74 ,:5 ! coil is set 9 action oscillatory or ,h]tzian sp>ks pass betwe5 ! balls1 electric oscillations are set up 9 ! wire & electric waves are radiat$ f x4 ,def]r+ = ! mom5t a m detail$ exam9ation ( ! op]ations ( ! coil & at ! sp>k gap1 we may "h say t ! action :i* takes place 9 ! a]ial wire is z foll[s3 ,! wire is fir/ *>g$ to a high pot5tial1 let u suppose1 ) negative electricity4 ,we may imag9e ?is process to consi/ 9 =c+ additional electrons into x1 ! induction coil act+ z an electron pump4 ,up to a c]ta9 pressure ! sp>k gap is a p]fect insulator1 b at a critical pressure1 :i* = sp>k gap l5g?s ( f\r or five millimetres & balls ab\t "o c5timetre 9 diamet] approximates to ?ree ?\s& volts p] millmetre1 ! insulation ( ! air gives way1 & ! *>ge 9 ! wire ru%es into ! e>?4 ,9 consequ5ce1 h[ev]1 ( ! in]tia ( ! m$ium or ( ! electrons1 ! *>ge1 s to speak1 ov]%oots ! m>k1 & ! wire is !n left ) a *>ge ( opposite sign4 ,?is aga9 9 turn reb\nds1 & s ! wire is dis*>g$ by a s]ies ( electrical oscillations1 consi/+ ( alt]nations ( /atic *>ge & electric dis*>ge4 ,we may fa/5 our att5tion ei!r on ! ev5ts tak+ place 9 ! v]tical wire or 9 ! m$ium outside1 b ! two sets ( ph5om5a are insep>ably connect$ & g on toge!r4 ,:5 ! a]ial wire is /atically *>g$1 we may describe x by say+ t !re is an accumulation ( electrons or co-electrons 9 x4 ,outside ! wire !re is1 h[ev]1 a di/ribution ( electric /ra9 ! /ra9 l9es proce$+ f ! wire to ! e>? 7see ,fig4 #d74 ,illu/ration3 ,,fig4 #d4--,,l9es ,,( ,,electric ,,/ra9 7,,dott$ ,,l9es7 ,,ext5d+ ,,betwe5 ,a ,,m>coni ,,a]ial1 ,a1 ,,& ,,! ,,e>? ee ,,be=e ,,dis*>ge4 ,! wire has capacity ) respect to ! e>?1 & x acts l ! inn] coat+ ( a ,leyd5 j>1 ( :i* ! dielectric is ! air & e!r ar\nd x1 & ! out] coat+ is ! e>?'s surface4 ,:5 ! dis*>ge takes place1 we may consid] t electrons ru% out ( ! wire & !n ru% back aga9 into x4 ,at ! mom5t :5 ! electrons ru% out ( or into ! a]ial wire1 we say !re is an electric curr5t fl[+ into or out ( ! wire1 & ?is electron movem5t1 !re=e1 creates ! magnetic flux :i* is di/ribut$ 9 conc5tric circles r\nd ! wire4 ,?is curr5t1 &1 !re=e1 motion ( electrons1 c be prov$ to exi/ by its heat+ effect ^u a f9e wire ins]t$ 9 s]ies ) ! a]ial1 & 9 ! case ( l>ge a]ials x may h a mean value ( _m amp]es & a maximum value ( hundr$s ( amp]es4 ,inside ! a]ial wire we h1 !re=e1 alt]nations ( electric pot5tial or *>ge & electric curr5t1 or we may call x electron-pressure & electron-movem5t4 ,!re is1 !re=e1 an oscillation ( electrons 9 ! a]ial wire1 j z 9 ! case ( an organ-pipe !re is an oscillation ( air molecules 9 ! pipe4 ,outside ! a]ial we h v>iations & di/ributions ( electric /ra9 & magnetic flux4 ,! resemblance betwe5 ! clos$ organ-pipe & ! simple ,m>coni a]ial is1 9 fact1 v complete4 ,9 ! case ( ! clos$ organ-pipe1 we h a longitud9al oscillation ( air molecules 9 ! pipe4 ,at ! op5 end or m\?piece1 :]e we h air mov+ 9 & out1 ! air movem5t is alt]nat+ & consid]able1 b !re is little or no v>iation ( air pressure4 ,at ! upp] or clos$ end ( ! pipe we h great v>iation ( air pressure1 b little or no air movem5t 7see ,fig4 #e74 ,comp>e ?is n[ ) ! electrical ph5om5a ( ! a]ial4 ,at ! sp>k ball or l[] end we h little or no v>iation ( pot5tial or electron pressure1 b we h electrons ru%+ into & out ( ! a]ial at ea* half oscillation1 =m+ ! electric dis*>ge or curr5t4 ,at ! upp] or insulat$ end we h little or no curr5t1 b great v>iations ( pot5tial or electron pressure4 ,suppos+ we c\ld exam9e ! wire in* by in*1 all ! way up f ! sp>k balls at ! bottom to ! top1 we %\ld f9d at ea* /age ( our j\rney t ! range ( v>iation & maximum value ( ! curr5t 9 ! wire became less & ^? ( ! pot5tial became great]4 ,at ! bottom we h ne>ly z]o pot5tial or no electric pressure1 b l>ge curr5t1 & at ! top end1 no curr5t1 b great v>iation ( pot5tial4 ,illu/ration3 ,,fig4 #e4--;,,amplitude ,,( ,,pressure ,,v>iation ,,9 ,a ,,clos$ ,,organ ,,pipe1 ,,indicat$ ,,by ,,! ,,ord9ates ,,( ,,! ,,dott$ ,,l9e xy4 ,we c repres5t ! amplitude ( ! curr5t & pot5tial values along ! a]ial by ! ord9ates ( a dott$ l9e s drawn t its di/ance f ! a]ial repres5ts ! pot5tial oscillation or curr5t oscillation at t po9t 7see ,fig4 #f74 ,?is di/ribution ( pot5tial & curr5t along ! wire does n necess>ily imply t any "o electron moves f> f its normal position4 ,! actual movem5t ( any p>ticul> air molecule 9 ! case ( a s\nd wave is probably v small1 & reckon$ 9 million?s ( an in*4 ,s also we mu/ suppose t any "o electron may h a small individual amplitude ( movem5t1 b ! displacem5t is transf]r$ f "o to ano!r4 ,conduction 9 a solid may be effect$ by ! movem5t ( free electrons int]m+l$ ) ! *emical atoms1 b any "o electron may be cont9ually pass+ f a condition ( fre$om to "o ( comb9ation4 ,illu/ration3 ,,fig4 #f4--7;a7 ,,di/ribution ,,( ,,electric ,,pressure ,,9 ,a ,,m>coni ,,a]ial1 ,a1 7b7 ,,di/ribution ,,( ,,electric ,,curr5t ,,9 ,a ,,m>coni ,,a]ial1 ,,z ,,%[n ,,by ,,! ,,ord9ates ,,( ,,! ,,dott$ ,,l9e xy4 ,s mu* = ! ev5ts inside ! wire1 b n[ outside ! wire its electric *>ge is repres5t$ by l9es ( electric /ra9 spr++ f ! a]ial to ! e>?4 ,x mu/ be rememb]$ t e l9e ( /ra9 t]m9ates on an electron or a co-electron4 ,h5ce1 :5 ! dis*>ge or sp>k takes place betwe5 ! sp>k balls1 ! rapid movem5t ( ! electrons 9 ! wire is accompani$ by a r$i/ribution & movem5t ( ! l9es ( /ra9 outside4 ,z ! negative *>ge fl[s out ( ! a]ial ! ends ( ! /ra9 l9es abutt+ on to x run d[n ! wire & are transf]r$ to ! e>?1 & at ! next in/ant ?is semi-loop ( electric or e!r /ra91 ) its ends on ! e>?1 is pu%$ out sideways f ! wire by ! gr[? ( a new set ( l9es ( e!r /ra9 9 an opposite direction4 ,! process is be/ und]/ood by consult+ a s]ies ( diagrams :i* repres5t ! di/ribution & approximate =m ( a few ( ! /ra9 l9es at successive in/ants 7see ,fig4 #g74 ,9 betwe5 ! l9es ( =mation ( ! successive /ra9 l9es betwe5 ! a]ial & ! e>?1 correspond+ to ! successive alt]nate electric *>ges ( ! a]ial ) opposite sign1 !re are a set ( conc5tric r+s ( magnetic flux =m$ r\nd x :i* are alt]nately 9 opposite directions1 & ^! exp& out1 keep+ /ep ) ! progress ( ! deta*$ /ra9 loops & hav+ _! planes at "r angles to ! latt]4 ,z ! semi-loops ( electric /ra9 m>* outw>ds ) _! feet on ! gr\nd1 ^! /ra9 l9es mu/ always be suppos$ to t]m9ate on electrons1 b n cont9ually on ! same electrons4 ,s9ce ! e>? is a conductor1 we mu/ suppose t !re is a cont9ual migration ( ! electrons =m+ ! atoms ( ! e>?1 & t :5 "o electron ent]s an atom1 ano!r leaves x4 ,h5ce1 correspond+ to ! electric wave 9 ! space above1 !re are electrical *anges 9 ! gr\nd b5ea?4 ,?is view is confirm$ by ! well-kn[n fact t ! a*ievem5t ( ,h]tzian wave telegraphy is mu* dep5d5t on ! nature ( ! surface ov] :i* x is conduct$1 & c be c>ri$ on m easily ov] good conduct+ mat]ial1 l sea wat]1 ?an ov] badly conduct+ dry l&4 ,illu/ration3 ,,fig4 #g4--,,successive ,,/ages ,,9 ,,! ,,production ,,( ,a ,,semi-,,loop ,,( ,,electric ,,/ra9 ,,by ,a ,,m>coni ,,a]ial ,,radiator4 ,! matt] may be view$1 h[ev]1 f ano!r /&po9t4 ,good conductors are opaque to ,h]tzian waves2 9 o!r words1 are non-absorptive4 ,! en]gy ( ! electric wave is n s rapidly absorb$ :5 x glides ov] a sea surface z :5 x is pass+ ov] a surface :i* is an indiff]5t conductor1 l dry l&4 ,9 fact1 x is possible by ! improvem5t ( ! signals to detect a heavy fall ( ra9 9 ! space betwe5 two /ations sep>at$ only by dry l&4 ,x is1 h[ev]1 cle> t on ! electronic !ory ! progression ( ! l9es ( electric /ra9 c only take place if ! surface ov] :i* !y move is a fairly good conductor1 unless ^! l9es ( /ra9 =m completely clos$ loops4 ,h5ce we may sum up by say+ t !re are ?ree set ( ph5om5a to :i* we mu/ pay att5tion 9 =mulat+ any complete !ory ( ! a]ial4 ,! fir/ is ! op]ation tak+ place 9 ! v]tical wire1 :i* is describ$ by say+ t electrical oscillations or vibratory movem5ts ( electrons are tak+ place 9 x1 &1 on our adopt$ !ory1 x may be said to consi/ 9 a longitud9al vibration ( electrons ( su* a nature t we may appropriately call ! a]ial an e!r organ-pipe4 ,!n 9 ! next place1 we h ! di/ribution & movem5t ( ! l9es ( electric /ra9 & magnetic flux 9 ! space outside ! wire1 con/itut+ ! electric wave2 & la/ly1 !re are ! electrical *anges 9 ! conductor ov] :i* ! wave travels1 :i* is ! e>? or wat] surr\nd+ ! a]ial4 ,9 subsequ5tly deal+ ) ! details ( transmitt+ arrangem5ts1 att5tion w be direct$ to ! necessity = :at telegraphi/s call a good e>? 9 connection ) ,h]tzian wave telegraphy4 ,?is only means t !re mu/ be a p]fectly free egress & +ress = ! electrons leav+ or ent]+ ! a]ial1 s t no?+ h9d]s _! access to ! conduct+ surface ov] :i* ! wave travels4 ,!re mu/ be no?+ to /op or ?rottle ! ru% ( electrons into or out ( ! a]ial wire1 or else ! l9es ( /ra9 _c be deta*$ & & travel away4 ,we may next consid] m p>ticul>ly ! en]gy :i* is available = radiation & :i* is radiat$4 ,9 ! orig9al =m ( simple ,m>coni a]ial1 ! a]ial itself :5 insulat$ =ms "o coat+ or surface ( a cond5s]1 ! dielectric be+ ! air & e!r ar\nd x1 & ! o!r conductor be+ ! e>?4 ,! electric en]gy /or$ up 9 x j be=e dis*>ge takes place is num]ically equal to ! product ( ! capacity ( ! a]ial & half ! squ>e ( ! pot5tial to :i* x is *>g$4 ,if we call ,c ! capacity ( ! a]ial 9 micr(>ads1 & ,v ! pot5tial 9 volts to :i* x is rais$ be=e dis*>ge1 !n ! en]gy /orage 9 j\les ,e is giv5 by ! equation1 ,e 7,,cv#b7 _/ 7#b 4 #ajf74 ,s9ce "o j\le is ne>ly equal to ?ree-qu>t]s ( a foot-p\nd1 ! en]gy /orage 9 foot-p\nds ,f is r\ghly giv5 by ! rule ,f 7#c_/h7;,,cv#b_/ajf4 ,= sp>k l5g?s ( ! ord] ( five to fifte5 millimetres1 ! disruptive voltage 9 air ( ord9>y pressure is at ! rate ( #c1jjj volts p] millimetre4 ,h5ce1 if ,s /&s = ! sp>k l5g? 9 millimetres1 & ,c = ! a]ial capacity 9 micr(>ads1 x is easy to see t ! en]gy /orage 9 foot-p\nd is ,f 7#bg;,,cs#b7 _/ #h4 ,if ! a]ial consi/s ( a /r&$ wire =m$ ( #g_/bb & has a l5g? ( #aej feet1 & is insulat$ & held v]tically ) its l[] end ne> ! e>?1 x w\ld h a capacity ( ab\t "o ?ree t5-?\s&?s ( a micr(>ad or #j4jjjc mfd4#f ,h5ce1 if x is us$ z a ,m>coni a]ial & op]at$ ) a sp>k gap ( "o c5timetre 9 l5g?1 ! en]gy /or$ up 9 ! wire be=e ea* dis*>ge w\ld be only "o-t5? 7#j4a7 ( a foot-p\nd4 ,by no means c all ( ?is en]gy be radiat$ z ,h]tzian waves2 "p ( x is dissipat$ z heat & light 9 ! sp>k1 & yet su* an a]ial c1 ) a s5sitive receiv] su* z t devis$ by ,mr4 ,m>coni1 make itself felt = a hundr$ miles ov] sea 9 e direction4 ,?is fact gives u an idea ( ! extremely small en]gy :i*1 :5 prop]ly imp>t$ to ! e!r1 c effect wireless telegraphy ov] imm5se di/ances4 ,( c\rse1 ! m9imum telegraphic signal1 say ! ,morse dot1 may involve a good _m1 p]haps half-a-doz51 dis*>ges ( ! wire1 b ev5 !n ! am\nt ( en]gy conc]n$ 9 affect+ ! receiv] at ! di/ant place is exce$+ly small4 ,! problem1 !re=e1 ( long-di/ance telegraphy by ,h]tzian waves is l>gely1 ?\gh n entirely1 a matt] ( associat+ suffici5t en]gy ) ! a]ial wire or radiator4 ,!re are obvi\sly two ?+s :i* may be done2 fir/1 we may increase ! capacity ( ! a]ial1 & secondly1 we may increase ! *>g+ voltage or1 9 o!r words1 l5g!n ! sp>k gap4 ,!re is1 h[ev]1 a well-def9$ limit to ?is la/ a*ievem5t4 ,if we l5g!n ! sp>k gap too mu*1 its resi/ance becomes too great & ! sp>k ceases to be oscillatory4 ,we c make a dis*>ge1 b we obta9 no radiation4 ,:5 us+ an induction coil1 ab\t a c5timetre1 or at mo/ a c5timetre & a half1 is ! limit+ l5g? ( oscillatory sp>ks2 9 o!r words1 our available pot5tial diff]5ce is re/rict$ to #cj1jjj or #dj1jjj volts4 ,by o!r appliances we c1 h[ev]1 obta9 oscillatory sp>ks hav+ a voltage ( #ajj1jjj or #bjj1jjj volts1 & s obta9 :at ,h]tz call$ active sp>ks five or six c5timetres 9 l5g?4 ,turn+ !n to ! "q ( capacity1 we may enquire 9 ! next place h[ ! capacity ( an a]ial wire c be increas$4 ,?is has g5]ally be5 done by putt+ up two or m a]ial wires 9 contiguity & jo9+ !m toge!r1 & s mak+ arrangem5ts call$ 9 ! admitt$ slang ( ! subject multiple a]ials4 ,! measurem5t ( ! capacity ( insulat$ wires c be easily c>ri$ out by means ( an appliance devis$ by ! au?or & ,mr4 ,w4 ,c4 ,cl9ton1 consi/+ ( a rotat+ commutator :i* alt]nately *>ges ! insulat$ wire at a s\rce ( kn[n electromotive =ce & !n dis*>ges x ?r\gh a galvanomet]4 ,if ?is galvanomet] is subsequ5tly /&>dis$1 s t ! amp]e value ( its deflection is kn[n1 we c det]m9e easily ! capacity ,c ( ! a]ial or insulat$ conductor1 reckon$ 9 micr(>ads1 :5 x is *>g$ to a pot5tial ( ,v volts1 & dis*>g$ n times a second ?r\gh a galvanomet]4 ,! s]ies ( dis*>ges are equival5t to a curr5t1 ( :i* ! value 9 amp]es ,a is giv5 by ! equation ,a 7n,v,c7 _/ 7#ajf71 & h5ce1 if ! value ( ! curr5t result+ is kn[n1 we h ! capacity ( ! a]ial or conductor express$ 9 micr(>ads1 giv5 by ! =mula ,c 7,a#ajf7 _/ 7n,v74 ,a s]ies ( exp]im5ts made on ?is plan h reveal$ ! fact t if a numb] ( v]tical insulat$ wires are hung up 9 ! air & r ne> toge!r1 ! electrical capacity ( ! :ole ( ! wires 9 p>allel is n ne>ly equal to ! sum ( _! individual capacities4 ,if a numb] ( p>allel insulat$ wires are sep>at$ by a di/ance equal to ab\t #c p] c5t4 ( _! l5g?1 ! capacity ( ! :ole lot toge!r v>ies r\ghly z ! squ>e root ( _! numb]4 ,?us1 if we call ! capacity ( "o v]tical wire 9 free space unity1 !n ! capacity ( f\r wires plac$ r ne> toge!r w only be ab\t twice t ( "o wire1 & t ( tw5ty-five wires w only be ab\t five times "o wire4 ,?is approximate rule has be5 confirm$ by exp]im5ts made ) long wires "o hundr$ or two hundr$ feet 9 l5g? 9 ! op5 air4 ,h5ce x po9ts to ! fact t ! ord9>y plan ( endeav\r+ to obta9 a l>ge capacity by putt+ sev]al wires 9 p>allel & n v f> ap>t is v uneconomical 9 mat]ial4 ,! diagrams 9 ,fig4 #h %[ ! v>i\s me?ods :i* h be5 employ$ by ,mr4 ,m>coni & o!rs 9 ! con/ruction ( su* multiple wire a]ials4 ,if1 = in/ance1 we put f\r insulat$ /r&$ #g_/bb wires ea* #ajj feet long1 ab\t six feet ap>t1 all be+ held 9 a v]tical position1 ! capacity ( ! f\r toge!r is n mu* m ?an twice t ( a s+le wire4 ,9 ! same mann]1 if we arrange #aej simil> wires1 ea* #ajj feet long1 9 ! =m ( a conical a]ial1 ! wires be+ di/ribut$ at ! top r\nd a circle #ajj feet 9 diamet]1 ! :ole gr\p w n h mu* m ?an twelve times ! capacity ( "o s+le wire1 al?\gh x weighs #aej times z mu*4 ,illu/ration3 ,,fig4 #h4--,,v>i\s ,,=ms ,,( ,,a]ial ,,radiator4 a1 s+le wire2 b1 multiple wire2 c1 fan %ape2 d1 cyl9drical2 g1 ,conical4 ,! au?or has design$ an a]ial 9 :i* ! wires1 all ( equal l5g?1 are arrang$ suffici5tly f> ap>t n to r$uce ea* o!r's capacity4 ,z a r\gh guide 9 practice1 x may be borne 9 m9d t a wire ab\t "o t5? ( an in* 9 diamet] & "o hundr$ feet long1 held v]tical & insulat$1 ) its bottom end ab\t six feet f ! gr\nd1 has a capacity ( #j4jjjb ( a micr(>ad1 if no o!r e>!d v]tical conductors are v ne> x4 ,! moral ( all ?is is t ! am\nt ( electric en]gy :i* c be /or$ up 9 a simple ,m>coni a]ial is v limit$1 & is n mu* m ?an "o-t5? ( a j\le or "o-f\rte5? ( a foot-p\nd1 p] hundr$ feet ( #g_/bb wire4 ,! a/oni%+ ?+ is t ) s little /orage ( en]gy x %\ld be possible to transmit intellig5ce to a di/ance ( a hundr$ miles )\t connect+ wires4 ,"o consequ5ce1 h[ev]1 ( ! small am\nt ( en]gy :i* c be accumulat$ 9 a simple ,m>coni a]ial is t ?is en]gy is almo/ entirely radiat$ 9 "o oscillation or wave4 ,h5ce1 /rictly speak+1 a simple a]ial ( ?is type does n create a tra9 ( waves 9 ! e!r1 b probably at mo/ a s+le impulse or two4 ,illu/ration3 ,,fig4 #i4--,,m>coni-,,braun ,,sy/em ,,( ,,induc+ ,,electromotive ,,=ce ,,9 ,,an ,,a]ial1 ,a4 ,b1 batt]y2 ,k1 key2 ,i1 induction coil2 ,s1 sp>k gap2 ,c1 ,leyd5 j>2 ,e1 e>? plate2 ps1 oscillation trans=m]4 ,we %all lat] on consid] "s consequ5ces :i* foll[ f ?is fact4 ,mean:ile1 x may be expla9$ t !re are me?ods by :i* n only a mu* l>g] am\nt ( en]gy c be accumulat$ 9 connection ) an a]ial1 b m su/a9$ oscillations creat$ ?an by ! orig9al ,m>coni me?od4 ,"o ( ^! me?ods orig9at$ ) ,pr(essor ,braun1 ( ,/rasburg1 & a modification 0 fir/ describ$ by ,mr4 ,m>coni 9 a lecture be=e ! ,society ( ,arts ( ,london4#g ,9 ?is me?od ! *>ge 9 ! a]ial is n creat$ by ! direct application to x ( ! second>y electromotive =ce ( an induction coil1 b by means ( an induc$ electromotive =ce creat$ 9 ! a]ial by an oscillation trans=m]4 ,! me?od due to ,pr(essor ,braun is z foll[s3 ,a cond5s] or ,leyd5 j> has "o t]m9al1 say1 its inside1 connect$ to "o sp>k ball ( an induction coil4 ,! o!r sp>k ball is connect$ to ! outside ( ! ,leyd5 j> or cond5s] ?r\gh ! prim>y coil ( a trans=m] ( a p>ticul> k9d1 call$ an oscillation trans=m] 7see ,fig4 #i74 ,! sp>k balls are br\ght )9 a few millimetres ( ea* o!r4 ,:5 ! coil is set 9 op]ation1 ! j> is *>g$ & dis*>g$ ?r\gh ! sp>k gap1 & electrical oscillations are set up 9 ! circuit consi/+ ( ! dielectric ( ! j>1 ! prim>y coil ( ! oscillation trans=m] & ! sp>k gap4 ,! second>y circuit ( ?is oscillation trans=m] is connect$ 9 betwe5 ! e>? & ! insulat$ a]ial wire2 h5ce1 :5 ! oscillations take place 9 ! prim>y circuit1 !y induce o!r oscillations 9 ! a]ial circuit4 ,b ! arrangem5t is n v effective unless1 z is %[n by ,mr4 ,m>coni1 ! two circuits ( ! oscillation trans=m] are tun$ toge!r4 ,we %all return pres5tly to ! consid]ation ( ?is =m ( transmitt]2 mean:ile we may notice t by means ( su* an arrangem5t x is possible to create 9 ! a]ial a f> great] *>g+ electromotive =ce ?an w\ld be ! case if ! a]ial 7 connect$ directly to "o t]m9al ( ! second>y circuit ( ! induction coil1 ! o!r t]m9al be+ to e>?1 & ! two t]m9als connect$ z usual by sp>k balls4 ,by ! inductive arrangem5t x is possible to create 9 an a]ial electromotive =ces :i* are equival5t to a sp>k ( a foot 9 l5g?1 & :5 ! l5g? ( ! a]ial is also prop]ly proportion$ ! pot5tial along x w increase all ! way up1 until at ! top or insulat$ end ( ! a]ial x may rea* an am\nt capable ( giv+ sp>ks sev]al feet 9 l5g?4 ,f ! rem>ks already made on ! analogy betwe5 ! clos$ organ-pipe & ! ,m>coni a]ial wire1 x w be se5 t ! wave :i* is radiat$ f ! a]ial mu/ h a wave l5g? f\r times t ( ! a]ial if ! a]ial is vibrat+ 9 its fundam5tal mann]4 ,x is also possible to create electrical oscillations 9 a v]tical wire :i* are ! h>monics ( ! fundam5tal4 ,all musicians are aw>e t 9 ! case ( an organ-pipe if ! pipe is bl[n g5tly x s\nds a note :i* is call$ ! fundam5tal ( ! pipe4 ,! celebrat$ ma!matician1 ,daniel ,b]n\illi1 discov]$ t an organ-pipe c be made to yield a succession ( musical notes by prop]ly v>y+ ! pressure ( ! curr5t ( air bl[n into x4 ,if ! pipe is an op5 pipe1 & if we call ! frequ5cy ( ! prim>y note obta9$ :5 ! pipe is g5tly bl[n1 unity1 !n :5 we bl[ m /rongly ! pipe yields notes :i* are ! h>monics ( ! fundam5tal "o2 t is to say1 notes :i* h frequ5cies repres5t$ by ! numb]s #b1 #c1 #d1 #e1 c4 ,if1 h[ev]1 ! pipe is clos$ at ! top1 !n ov]-bl[+ ! pipe makes x yield ! odd h>monics or ! tones :i* are relat$ to ! prim>y tone 9 ! ratio ( #c1 #e1 #g1 c41 to unity4 ,accord+ly1 if a /opp$ pipe gives z its fundam5tal ! note ,c1 its fir/ ov]tone w be ! fif? above ! octave or ,g'4 ,illu/ration3 ,,fig4 #aj4--,,seibt',s ,,app>atus ,,= ,,%[+ ,,/ation>y ,,waves ,,9 ,,long ,,sol5oid ,a4 ,i1 induction coil2 ,s1 sp>k gap2 ,l1 inductance coil2 ,c#a;,c#b1 ,leyd5 j>s2 ,e1 e>? wire4 ,z already rem>k$1 ! a]ial wire or radiator z us$ 9 ,m>coni telegraphy may be look$ ^u z a k9d ( e!r organ-pipe or sir5 tube1 & its electrical ph5om5a are 9 e respect simil> to ! ac\/ic ph5om5a ( ! ord9>y clos$ organ-pipe4 ,:5 ! a]ial is s\nd+ its fundam5tal e!r note1 ! conditions :i* p]ta9 are t !re is a curr5t fl[+ into ! a]ial at ! l[] end1 b at t po9t ! v>iation 9 pot5tial is v small1 :]eas at ! upp] end !re is no curr5t1 b ! v>iations ( pot5tial are v l>ge4 ,accord+ly1 we say t at ! upp] end ( ! a]ial !re is an ant9ode ( pot5tial & a node ( curr5t1 & at ! bottom an ant9ode ( curr5t & a node ( pot5tial4 ,by alt]+ ! frequ5cy ( ! electrical impulses we c create 9 ! a]ial an arrangem5t ( nodes ( curr5t or pot5tial correspond+ to ! ov]tones ( a clos$ organ-pipe4 ,b :atev] may be ! arrangem5t ! conditions mu/ always hold t !re is a node ( curr5t at ! upp] end & an antidote ( curr5t at ! l[] end4 ,9 o!r words1 !re are l>ge v>iations ( curr5t at ! place :]e ! a]ial t]m9ates on ! sp>k-gap & no curr5t at ! upp] end4 ,! fir/ h>monic is =m$ :]e !re is a node ( pot5tial at "o-?ird ( ! l5g? ( ! a]ial f ! top4 ,9 ?is case we h a node ( pot5tial n only at ! l[] end ( ! wire1 b at two-?irds ( ! way up4 ,9 ! same way we c create 9 ! clos$ organ-pipe1 by prop]ly ov]bl[+ ! pipe1 a region ab\t two-?irds ( ! way up ! pipe1 :]e ! pressure *anges 9 ! air are practically no great] ?an !y are at ! m\?piece4 ,we c make evid5t visually 9 a beautiful mann] ! exi/5ce ( simil> /ation>y electrical waves 9 an a]ial by means ( an +5i\s arrangem5t devis$ by ,dr4 ,georg ,seibt1 ( ,b]l94 ,x consi/s ( a v long silk-cov]$ copp] wire1 ,a 7see ,fig4 #aj71 w\nd 9 a close spiral ( s+le lay] r\nd a wood5 rod six feet long & ab\t two in*es 9 diamet]4 ,?is rod is insulat$1 & at ! l[] end ! wire is connect$ to a ,leyd5 j> circuit1 consi/+ ( a ,leyd5 j> or j>s & an inductance coil1 ,l1 ! inductance ( :i* c be v>i$4 ,oscillations are set up 9 ?is j> circuit by means ( an induction-coil dis*>ge1 & ! l[] end ( ! long spiral wire is atta*$ to "o po9t on ! j> circuit4 ,9 ?is mann] we c communicate to ! bottom end ( ! long spiral wire a s]ies ( electric impulses1 ! "t p]iod ( :i* dep5ds ^u ! capacity ( ! j> & ! inductance ( ! dis*>ge circuit4 ,we c1 moreov]1 v>y ?is frequ5cy ov] wide limits4 ,p>allel to ! long spiral wire is susp5d$ ano!r copp] wire1 ,e 7see ,fig4 #aj71 & betwe5 ?is wire & ! silk-cov]$ copp] wire dis*>ges take place due to ! pot5tial diff]5ce betwe5 ea* "p ( ! wire & ?is long a]ial wire4 ,if we arrange matt]s s t ! impulses communicat$ to ! bottom end ( ! long spiral wire correspond to its fundam5tal note or p]iodic "t1 !n 9 a d>k5$ room we %all see a lum9\s gl[ or dis*>ge betwe5 ! v]tical wire & ! spiral wire1 :i* increases 9 int5sity all ! way up to ! top ( ! spiral wire4 ,! lum9osity ( ?is bru% dis*>ge at any po9t is evid5ce ( ! pot5tial ( ! spiral wire at t po9t1 & its di/ribution cle>ly demon/rates t ! diff]5ce ( pot5tial betwe5 ! spiral wire & ! a]ial increases all ! way up f ! bottom to ! top ( ! spiral wire4 ,9 ! next place1 by mak+ a little adju/m5t & by v>y+ ! inductance ( ! j> circuit1 we c increase ! frequ5cy ( ! impulses :i* are fall+ ^u ! spiral wire2 & !n x w be notic$ t ! di/ribution ( ! bru% dis*>ge or lum9osity is alt]$1 & t !re is a maximum n[ at ab\t "o-?ird ( ! height ( ! spiral wire1 & a d>k place at ab\t two-?irds ( ! height1 & ano!r bright place at ! top1 ?us %[+ t we h a node ( pot5tial at ab\t two-?irds ! way up ! wire 7see ,fig4 #aa71 & we h !re=e set up 9 ! spiral wire electrical oscillations correspond+ to ! fir/ ov]tone4 ,x is possible to %[ 9 ! same way ! exi/5ce ( ! second h>monic 9 ! coil1 b ! lum9osity !n becomes too fa9t to be se5 at a di/ance4 ,illu/ration3 ,,fig4 #aa4--;,,h>monic ,,oscillations ,,9 ,,long ,,sol5oid ,,%[n ,,) ,,seibt',s ,,app>atus4 ,an int]e/+ =m ( a]ial devis$ by ,pr(essor ,slaby1 ( ,b]l91 dep5ds = its action entirely on ! fact t ! electrical oscillations set up 9 x :i* radiate are h>monics ( ! fundam5tal tone4 ,illu/ration3 ,,fig4 #ab4--,,non-,,radiative ,,clos$ ,,loop ,,a]ial4 ,illu/ration3 ,,fig4 #ac4--,,slaby',s ,,loop ,,radiator4 ,a clos$ v]tical loop1 ,a#a;,a#b 7see ,fig4 #ab71 is =m$ by erect+ two p>allel insulat$ wires v]tically a few feet ap>t & jo9+ !m toge!r at ! top4 ,at ! bottom ^! wires are connect$1 ) ! second>y t]m9als ( an induction coil1 a cond5s]1 ,c1 or ,leyd5 j>1 be+ bridg$ across ! t]m9als & a pair ( sp>k balls1 ,s1 ins]t$ 9 "o side ( ! loop4 ,x w readily be se5 t on sett+ ! coil 9 action1 oscillations w take place 9 ^! v]tical wires1 b t if ! oscillations are simply ! fundam5tal note ( ! sy/em1 !n at any mom5t correspond+ to a curr5t go+ up "o side ( ! loop ( wire !re mu/ be a curr5t com+ d[n ! o!r4 ,accord+ly1 an arrangem5t ( ?is k9d1 =m+ :at is call$ a clos$ circuit1 w n radiate or radiates b v feebly4 ,pr(essor ,slaby f\nd1 h[ev]1 t x might be conv]t$ into a p[]ful radiator if we give ! two sides ( ! loop unequal capacity or inductance & at ! same "t e>? "o ( ! l[] ends ( ! loop1 z %[n 9 ,fig4 #ac4 ,by ?is means x is possible to set up 9 ! loop electrical ov]tones or h>monics ( ! fundam5tal oscillation1 & if we cause ! sy/em to vibrate s z to produce its fir/ odd h>monic1 !re is a pot5tial node at ! l[] end ( bo? v]tical sides ( ! loop1 a pot5tial node on bo? v]tical sides at two-?irds ( ! way up1 & a pot5tial ant9ode at ! summit ( ! loop2 !n1 "u ^! circum/ances1 ! clos$ loop ( wire is 9 ! same electrical condition z if two simple ,m>coni a]ials1 bo? emitt+ _! fir/ odd h>monic oscillation1 7 plac$ side by side & jo9$ toge!r at ! top4 ,x is a little difficult )\t ! employm5t ( ma!matical analysis to expla9 precisely ! mann] 9 :i* e>?+ "o side ( ! loop or mak+ ! loop unsymmetrical z reg>ds inductance has ! effect ( creat+ ov]tones 9 x4 ,! foll[+ r\gh illu/ration may1 h[ev]1 be ( "s assi/ance4 ,imag9e a long spiral metallic spr+ support$ horizontally by ?reads4 ,let ?is repres5t a conductor1 & let any movem5t to or fro ( a "p ( ! spr+ repres5t a curr5t 9 t conductor4 ,suppose we take hold ( ! spr+ at "o end1 we c move x bodily to & fro z a :ole4 ,9 ?is case1 e "p ( ! spr+ is mov+ "o way or ! o!r 9 ! same mann] at ! same "t4 ,?is corresponds ) ! case 9 :i* ! dis*>ge ( ! cond5s] ?r\gh ! uni=m loop conductor is a fl[ ( electricity1 all 9 "o direction "o way or ! o!r4 ,! curr5t is 9 ! same direction 9 all p>ts ( ! loop at ! same "t1 &1 !re=e1 if ! curr5t is go+ up "o side ( ! loop x is at ! same "t com+ d[n ! o!r side4 ,h5ce ! two sides ( ! loop are always 9 exact opposition z reg>ds ! effect ( ! curr5t 9 !m on ! ext]nal space1 & ! loop does n radiate4 ,return+ aga9 to ! case ( ! spr+4 ,suppos+ t we add a weight to "o end ( ! spr+ by atta*+ to x a metal ball1 & !n move ! o!r end to & fro ) c]ta9 p]iodic motion1 x w be f\nd q easy to set up 9 ! spr+ a pulsatory motion resembl+ ! movem5t ( ! air 9 an op5 organ-pipe4 ,"u ^! circum/ances bo? ends ( ! spr+ w be mov+ inw>ds or outw>ds at ! same "t1 & ! c5tral portions ( ! spr+1 al?\gh be+ press$ & exp&$ slightly1 are mov+ to & fro v little4 ,?is corresponds 9 ! case ( ! loop$ a]ial ) a curr5t fl[+ up or d[n bo? sides at ! same "t2 9 o!r words1 :5 ?is mode ( electrical oscillation is e/abli%$ 9 ! loop1 its electrical condition is j t ( two simple ,m>coni a]ials jo9$ toge!r at ! top & vibrat+ 9 _! fundam5tal mann]4 ,accord+ly1 if "o side ( ! d\ble loop is e>!d1 we !n h an arrangem5t :i* radiates waves4 ,pr(essor ,slaby f\nd t by giv+ "o side ( ! loop less inductance ?an ! o!r1 & at ! same "t e>?+ ! side hav+ great] inductance at ! bottom1 he 0 able to make an arrangem5t :i* radiat$1 n 9 virtue ( ! normal oscillations ( ! cond5s]1 b 9 virtue ( ! h>monic oscillations set up 9 ! conductor itself4 ,! ma!matical !ory ( ?is radiator has be5 v fully develop$ by ,dr4 ,georg ,seibt4 ,x w be se51 !re=e1 t !re are sev]al ways 9 :i* we may />t into exi/5ce oscillations 9 an a]ial4 ,fir/1 ! a]ial may be insulat$1 & we may *>ge x to a high pot5tial & all[ ?is *>ge sudd5ly to ru% out4 ,al?\gh ?is process gives rise to a di/urbance 9 ! e!r1 z already expla9$1 x is analog\s to a pop or explosion 9 ! air1 r ?an to a su/a9$ musical note4 ,! exact ac\/ic analogue w\ld be obta9$ if we imag9e a long pipe pump$ full ( air & !n sudd5ly op5$ at "o end4 ,! air w\ld ru% out1 &1 communicat+ a bl[ to ! out] air1 w\ld create an atmosph]ic di/urbance appreciat$ z a noise or small explosion4 ,?is is :at happ5s :5 we cut ! /r+ & let ! cork fly out f a bottle ( *ampagne4 ,at ! same "t1 ! in]tia ( ! air ru%+ out ( ! tube w\ld cause x to ov]%oot ! m>k1 & a %ort "t aft] op5+ ! valve ! tube1 s f> f conta9+ compress$ air1 w\ld conta9 air slightly r>efi$ ne> its m\?1 & ?is r>efication w\ld travel back up ! tube 9 ! =m ( wave motion1 &1 be+ reflect$ z cond5sation at ! clos$ end1 travel d[n aga92 & s aft] be+ reflect$ once or twice at ! op5 or clos$ end1 become damp$ out v rapidly 9 virtue ( bo? air friction & ! radiation ( ! en]gy4 ,9 ! case1 h[ev]1 ( ! ord9>y organ-pipe1 we d n dep5d m]ely ^u a /ore ( compress$ air put into ! pipe1 b we h a /ore ( en]gy to draw ^u 9 ! =m ( ! l>ge am\nt ( compress$ air conta9$ 9 a w9d *e/1 :i* is be+ cont9ually suppli$ by ! bell[s4 ,?is /ore ( compress$ air is f$ into ! organ-pipe1 ) ! result t we obta9 a cont9u\s radiation ( s\nd waves4 ,! fir/ case1 9 :i* ! only /ore ( en]gy is ! compress$ air orig9ally conta9$ 9 ! pipe1 illu/rates ! op]ation ( ! simple ,m>coni a]ial4 ,! second case1 9 :i* !re is a l>g] /ore ( en]gy to draw ^u1 ! organ-pipe be+ connect$ to a w9d *e/1 illu/rates ! ,m>coni-,braun me?od1 9 :i* an a]ial is employ$ to radiate a /ore ( electric en]gy conta9$ 9 a cond5s]1 gradually lib]at$ by ! a]ial 9 ! =m ( a s]ies ( electrical oscillations & waves4 ,9 ?is arrangem5t ! cond5s] corresponds to ! w9d *e/1 & x is cont9ually kept full ( electrical en]gy by means ( ! induction coil or trans=m]1 :i* answ]s to ! bell[s ( ! organ4 ,f ! cond5s]1 electrical en]gy is dis*>g$ ea* "t ! sp>k dis*>ge passes at a sp>k gap 9 ! =m ( electrical oscillations set up 9 ! prim>y circuit ( an oscillation trans=m]4 ,! second>y circuit ( ?is trans=m] is connect$ 9 betwe5 ! e>? & ! a]ial1 & !re=e may be consid]$ z "p ( x1 &1 accord+ly1 ! en]gy :i* is radiat$ f ! a]ial is n simply t :i* is /or$ up 9 x 9 virtue ( its own small capacity1 b t :i* is /or$ up 9 ! mu* l>g] capacity repres5t$ by ! prim>y cond5s] or1 z x may be call$1 ! electrical w9d *e/4 ,by ! second arrangem5t we h !re=e ! means ( radiat+ m or less cont9u\s tra9s ( electric waves1 correspond+ ) ea* sp>k dis*>ge4 ,to create p[]ful oscillations 9 ! a]ial1 "o condition ( success is t !re %all be an id5tity 9 "t-p]iod betwe5 ! circuit ( ! a]ial & t ( ! prim>y cond5s]4 ,! a]ial is an op5 circuit :i* has capacity ) respect to ! e>?1 & x has also inductance1 p>tly due to ! wire ( ! a]ial & p>tly due to ! second>y circuit ( ! oscillation trans=m] 9 s]ies ) x4 ,! prim>y circuit or sp>k circuit has capacity--viz41 ! capacity ( ! en]gy-/or+ cond5s]--& x has also inductance--viz41 ! inductance ( ! prim>y circuit ( ! oscillation trans=m]4 ,we %all consid] at a lat] /age m p>ticul>ly ! details ( syntonis+ arrangem5ts1 b mean:ile x may be said t "o condition = sett+ up p[]ful waves by means ( ! above arrangem5t is t ! electrical "t-p]iod ( bo? ! two circuits m5tion$ %all be ! same4 ,?is involves adju/+ ! inductance & capacity s t ! product ( conductance & capacity = ea* ( ^! two circuits is num]ically ! same4 ,in/ead ( employ+ an oscillation trans=m] betwe5 ! cond5s] circuit & ! a]ial1 ! a]ial may be connect$ directly to "s po9t on ! cond5s] circuit at :i* ! pot5tial oscillations are l>ge1 & we h !n ano!r arrangem5t devis$ by ,pr(essor ,braun 7see ,fig4 #ad74 ,9 ?is case1 9 ord] to accumulate l>ge pot5tial oscillations at ! top ( ! a]ial1 x is1 z we h se51 necess>y t ! l5g? ( ! a]ial %all be "o qu>t] ! l5g? ( ! wave4 ,if1 !re=e1 ! electrical oscillations 9 ! cond5s] circuit are at ! rate ( ,n p] second1 9 o!r words1 h a frequ5cy ,n1 ! wave-l5g? correpond+ to ?is frequ5cy is giv5 by ! expression1 #cx#ajaj_/,n cms4 ,! numb] #cx#ajaj is ! value 9 c5timetres p] second ( ! velocity ( ! electromagnetic wave1 & is id5tical ) t ( light4 ,! correspond+ resonant l5g? ( ! a]ial is !re=e "o-f\r? ( ?is wave-l5g?1 or #cx#ajaj_/d,n4 ,g5]ally speak+1 h[ev]1 x w be f\nd t ) any l5g? ( a]ial :i* is practicable1 say1 #bjj feet or #f1jjj cms41 ?is proportion necessitates r a high frequ5cy 9 ! prim>y oscillation circuit4 ,9 ! case consid]$--viz41 = an a]ial #bjj feet 9 height--! oscillations 9 ! prim>y circuit mu/ h a frequ5cy ( "o & a qu>t] million4 ,?is high frequ5cy c only be obta9$ ei!r by greatly r$uc+ ! inductance ( ! prim>y dis*>ge circuit1 or r$uc+ ! capacity4 ,if we r$uce ! capacity1 we !reby greatly r$uce ! /orage ( en]gy1 & x is n practicable to r$uce ! inductance bel[ a c]ta9 am\nt4 ,illu/ration3 ,,fig4 #ad4--;,,braun',s ,,radiator4 ,b1 batt]y2 ,i1 induction coil2 ,k1 key2 ,s1 sp>k-gap2 ,l1 inductance coil2 ,c1 cond5s]2 ,a1 a]ial4 ,summ+ up1 x may be said t !re are ?ree1 &1 z f> z ! writ] is aw>e1 at pres5t only ?ree1 modes ( excit+ ! electrical oscillations 9 an a]ial wire4 ,fir/1 ! a]ial may itself be us$ z an electrical res]voir & *>g$ to a high pot5tial & sudd5ly dis*>g$ to ! e>?4 ,?is is ! orig9al ,m>coni me?od4 ,! second me?od1 due to ,braun1 consi/ ( atta*+ ! a]ial to "s po9t on an oscillation circuit consi/+ ( a cond5s]1 an inductance coil & a sp>k gap1 9 s]ies ) "o ano!r1 & *>g+ & dis*>g+ ! cond5s] across ! sp>k gap s z to create alt]ations ( pot5tial at "s po9t on ! oscillation circuit4 ,! l5g? ( ! a]ial mu/ !n be s proportion$ z above describ$ t x is resonant to ?is frequ5cy4 ,?irdly1 we may employ ! arrangem5t involv+ an oscillation trans=m]1 9 :i* ! oscillations 9 ! prim>y cond5s] circuit are made to induce o!rs 9 ! a]ial circuit1 ! "t-p]iod ( ! two circuits be+ ! same4 ,?is me?od may be call$ ! ,braun-,m>coni me?od4 ,pr(essor ,slaby has comb9$ toge!r 9 a c]ta9 way ! orig9al ,m>coni simple a]ial ) ! resonant qu>t]-wave-l5g? wire ( ,braun4 ,he con/ructs :at he calls a multiplicator1 :i* is really a wire w\nd into a loose spiral connect$ at "o po9t to an oscillation circuit consi/+ ( a cond5s] inductance1 ! l5g? ( ?is wire be+ proportion$ s t !re is a great resonance or multiplication ( t5sion or pot5tial at its free end4 ,?is free end is !n atta*$ to ! l[] end ( an ord9>y ,m>coni a]ial1 & s]ves to *>ge x ) a high] pot5tial ?an c\ld be obta9$ by ! use ( ! induction coil directly atta*$ to x4 99 99 99 99 99 ,we h next to consid] ! appliances = creat+ ! necess>y *>g+ electromotive =ce1 & = /or+ & releas+ ?is *>ge at pleasure1 s z to g5]ate ! requir$ electrical oscillations 9 ! a]ial4 ,x is ess5tial t ?is g5]ator %\ld be able to create n only l>ge pot5tial diff]5ce1 b also a c]ta9 m9imum electric curr5t4 ,accord+ly1 we are limit$ at ! pres5t mom5t to "o ( two appliances--viz41 ! induction coil or ! alt]nat+ curr5t trans=m]4 ,x w n be necess>y to ent] into an explanation ( ! action ( ! induction coil4 ,! coil g5]ally employ$ = wireless telegraphy is te*nically kn[n z a t5-in* coil--i4e41 a coil :i* is capable ( giv+ a t5-in* sp>k betwe5 po9t$ conductors 9 air at ord9>y pressure4 ,! con/ruction ( a l>ge coil ( ?is description is a matt] requir+ great te*nical skill1 & is n to be attempt$ )\t consid]able previ\s exp]i5ce 9 ! manufacture ( small] coils4 ,! second>y circuit ( a t5-in* coil is =m$ ( d\ble silk-cov]$ copp] wire2 g5]ally speak+1 ! gauge call$ ,no4 #cf1 or else ,no4 #cd ,s4,w4,g4 is us$1 & a l5g? ( t5 to sev5te5 miles ( wire is employ$ on ! second>y circuit1 accord+ to ! gauge ( wire select$4 ,= ! precautions necess>y 9 con/ruct+ ! second>y coil1 practical manuals mu/ be consult$4#h ,v great c>e is requir$ 9 ! insulation ( ! second>y circuit ( an induction coil to be us$ 9 ,h]tzian wave telegraphy1 because ! second>y circuit is !n subject$ to impulsive electromotive =ces la/+ = a %ort "t1 hav+ a mu* high] electromotive =ce ?an t :i* ! coil itself normally produces4 ,! prim>y circuit ( a t5-in* coil g5]ally consi/s ( a l5g? ( #cjj or #djj feet ( ?ick insulat$ copp] wire4 ,9 su* a coil ! second>y circuit w\ld require ab\t t5 miles ( ,no4 #cd ,h4,c4 copp] wire1 mak+ #ej1jjj turns r\nd ! core4 ,x w\ld h a resi/ance at ord9>y temp]atures ( #f1fjj ohms1 & an inductance ( #dfj h5rys4 ,! prim>y circuit1 if =m$ ( #cfj turns ( ,no4 #ab ,h4,c4 copp] wire1 w\ld h a resi/ance ( #j4cf ( an ohm1 & an inductance ( #j4jb ( a h5ry4 ,an important matt] 9 connection ) an induction coil to be us$ = wireless telegraphy is ! resi/ance ( ! second>y circuit4 ,! purpose = :i* we employ ! coil is to *>ge a cond5s] ( "s k9d4 ,if a con/ant electromotive =ce 7,v7 is appli$ to ! t]m9als ( a cond5s] hav+ a capacity ,c1 !n ! diff]5ce ( pot5tial 7v7 ( ! t]m9als ( ! cond5s] at any "t t ! contact is made is giv5 by ! expression3 v ,v7#a - e-t_/,,rc74 ,9 ! above equation1 ! lett] e /&s = ! numb] #b4gahbh1 ! base ( ! ,napi]ian log>i?ms1 & ,r is ! resi/ance 9 s]ies ) ! cond5s]1 ( :i* ! capacity is ,c1 to :i* ! electromotive =ce is appli$4 ,?is equation c easily be d$uc$ f fir/ pr9ciples1#i & x %[s t ! pot5tial diff]5ce v ( ! t]m9als ( ! cond5s] does n in/antly atta9 a value equal to ! impress$ electromotive =ce ,v1 b rises up gradually4 ,?us1 = in/ance1 suppose t a cond5s] ( "o micr(>ad is be+ *>g$ ?r\gh a resi/ance ( "o megohm by an impress$ voltage ( #ajj volts1 ! equation %[s t at ! end ( ! fir/ second aft] contact1 ! t]m9al pot5tial diff]5ce ( ! cond5s] w be only #fc volts1 at ! end ( ! second second1 #hf volts1 & s on4 ,s9ce e-#aj is an exce$+ly small numb]1 x foll[s t 9 #aj seconds ! cond5s] w\ld be practically *>g$ ) a voltage equal to #ajj volts4 ,! product ,,cr 9 ! above equation is call$ ! "t-con/ant ( ! cond5s]1 & we may say t ! cond5s] is practically *>g$ aft] an int]val ( "t equal to t5 times ! "t-con/ant1 c\nt+ f ! mom5t ( fir/ contact betwe5 ! cond5s] & ! s\rce ( con/ant voltage4 ,! "t-con/ant is to be reckon$ z ! product ( ! capacity 7,c7 9 micr(>ads1 by ! resi/ance ( ! *>g+ circuit 7,r7 9 megohms4 ,to take ano!r illu/ration4 ,suppos+ we are *>g+ a cond5s] hav+ a capacity ( "o-hundre? ( a micr(>ad1 ?r\gh a resi/ance ( t5 ?\s& ohms4 ,s9ce t5 ?\s& ohms is equal to "o-hundr$? ( a megohm1 ! "t-con/ant w\ld be equal to "o-t5-?\s&? ( a second1 & t5 times ?is "t-con/ant w\ld be equal to a ?\s&? ( a second4 ,h5ce1 9 ord] to *>ge ! above capacity ?r\gh ! above resi/ance1 x is necess>y t ! contact betwe5 ! s\rce ( voltage & ! cond5s] %\ld be ma9ta9$ = at lea/ "o-?\s&? "p ( a second4 ,9 discuss+ ! me?ods ( int]rupt+ ! circuit1 we %all return to ?is matt]1 b1 mean:ile1 x may be said t 9 ord] to secure a small "t-con/ant = ! *>g+ circuit1 x is desirable t ! second>y circuit ( ! induction coil %\ld h z l[ a resi/ance z possible4 ,?is1 ( c\rse1 involves w9d+ ! second>y circuit ) a r ?ick wire4 ,if1 h[ev]1 we employ a wire l>g] 9 size ?an ,no4 #cd1 or at ! mo/ ,no4 #cb1 ! bulk & ! co/ ( ! induction coil began to rise v rapidly4 ,h5ce1 z 9 all o!r dep>tm5ts ( electrical con/ruction1 ! details ( ! design are m or less a matt] ( compromise4 ,g5]ally speak+1 h[ev]1 x may be said t ! l>g] ! capacity :i* is to be *>g$1 ! l[] %\ld be ! resi/ance ( ! second>y circuit ( ! induction coil4 ,9 ! practical con/ruction ( induction coils = wireless telegraphy1 manufactur]s h dep>t$ f ! /ock designs4 ,we are all famili> ) ! appe>ance ( ! in/rum5t mak]'s induction coil2 its poli%$ mahogany base1 its lacqu]$ brass fitt+s1 & its second>y bobb9 con/ruct$ ( & cov]$ ) ebonite4 ,b su* a coil1 al?\gh x may look v pretty on ! lecture table1 is yet v unsuit$ to positions 9 :i* x may be us$ 9 connection ) ,h]tzian wave telegraphy4 ,?ree important adjuncts ( ! induction coil are ! prim>y cond5s]1 ! int]rupt] & ! prim>y key4 ,! int]rupt] is ! arrangem5t = int]mitt+ ! prim>y curr5t4 ,we h 9 "s way or o!r to rapidly int]rupt ! prim>y curr5t1 & ! torr5t ( sp>ks t !n appe>s betwe5 ! second>y t]m9als ( ! coil is due to ! electromotive =ce set up 9 ! second>y circuit at ea* break or int]ruption ( ! prim>y circuit4 ,we may divide int]rupt]s into five classes4 ,we h fir/ ! well-kn[n hamm] int]rupt] :i* ,cont95tal writ]s g5]ally attribute to ,neef or ,wagn]4#aj ,9 ?is int]rupt]1 ! magnetisation ( ! iron core ( ! coil is caus$ to attract a s(t-iron block fix$ at ! top ( a brass spr+1 & by s do+ to int]rupt ! prim>y circuit betwe5 two plat9um contacts4 ,mr4 ,apps1 ( ,london1 add$ an arrangem5t = press+ back ! spr+ aga9/ ! back contact1 & ! =m ( hamm] t is n[ g5]ally employ$ is !re=e call$ an ,apps break4 ,z ! t5-in* coil takes a prim>y curr5t ( t5 amp]es at sixte5 volts :5 9 op]ation1 x requires v sub/antial plat9um contacts to )/& ! int]ruption ( ?is curr5t cont9u\sly )\t damage4 ,! small plat9um contacts t are g5]ally put on ^! coils by in/rum5t mak]s are v soon worn out 9 practical wireless telegraph "w4 ,if a hamm] break is us$ at all1 x is ess5tial to make ! contacts ( v /\t pieces ( plat9um1 & f "t to "t1 z !y get burnt away or r\gh5$1 !y mu/ be smoo!d up ) a f9e file4 ,x does n require mu* skill to keep ! hamm] contacts 9 good ord] & prev5t !m f /ick+ toge!r & becom+ damag$ by ! break sp>k4 ,by regulat+ ! pressure ( ! spr+ aga9/ ! back contact1 by means ( an adju/+ screw1 ! rate at :i* ! break vibrates c be regulat$1 b z a rule x is n possible1 ) a hamm] break1 to obta9 m ?an ab\t #hjj int]ruptions p] m9ute1 or1 say1 twelve a second4 ,! hamm] break is usually op]at$ by ! magnetism ( ! iron core ( ! coil1 b = "s reasons x is bett] to sep>ate ! break f ! coil altoge!r1 & to "w x by an indep5d5t electromagnet1 :i*1 h[ev]1 may be excit$ by a curr5t f ! same batt]y supply+ ! induction coil4 ,= coils up to ! t5-in* size ! hamm] break c be us$ :5 v rapid int]ruptions are n requir$4 ,x is n 9 g5]al practicable to "w coils l>g] ?an ! t5-in* size ) a plat9um contact hamm] break1 z su* a butt contact becomes ov]heat$ & /icks if m ?an t5 amp]es is pass$ ?r\gh x4 ,9 ! case ( l>g] coils1 we h to employ "s =m ( int]rupt] 9 :i* m]cury or a conduct+ liquid =ms "o ( ! contact surfaces4 ,! next class ( int]rupt] is ! vibrat+ or h&-work$ m]cury break1 9 :i* a plat9um or /eel p9 is made to vibrate 9 & out ( m]cury4 ,?is movem5t may be effect$ by ! attraction ( an iron armature by an electromagnet1 or by ! v>y+ magnetism ( ! core ( ! coil1 or x may be effect$ m sl[ly by h&4 ,! m]cury surface mu/ be cov]$ ) wat]1 alcohol1 p>aff9 or creosote oil to prev5t oxidation & to ext+ui% ! break sp>k4 ,! int]ruption ( ! prim>y curr5t obta9$ by ! m]cury break is m sudd5 ?an t obta9$ by ! plat9um contact 9 air1 9 consequ5ce ( ! m rapid ext9ction ( ! sp>k2 h5ce ! sp>ks obta9$ f coils fitt$ ) m]cury int]rupt]s are g5]ally f tw5ty to ?irty p] c5t4 long] ?an ^? obta9$ f ! same coil "u ! same conditions1 ) plat9um contact int]rupt]s4 ,! m]cury breaks w n1 h[ev]1 "w well unless clean$ at regul> int]vals by empty+ (f ! oil & r9s+ well ) clean wat]1 & h5ce !y require r m att5tion ?an plat9um int]rupt]s4 ,x is n g5]ally possible to obta9 s _m int]ruptions p] m9ute ) ! simple vibrat+ m]cury int]rupt] z ) ! ord9>y hamm] int]rupt]4 ,! m]cury int]rupt] has1 h[ev]1 ! advantage t ! contact "t dur+ :i* ! circuit is kept clos$ may be made long] ?an is ! case ) ! hamm] break4 ,also1 if fre% wat] is all[$ to fl[ cont9u\sly ov] ! m]cury surface1 x c be kept clean1 & ! break w !n op]ate = consid]able p]iods ( "t )\t att5tion4 ,! m]cury int]rupt] may be work$ by a sep>ate electromagnet or by ! magnetism ( ! core ( ! induction coil4 ,! ?ird class ( int]rupt] may be call$ ! motor int]rupt]1 ( :i* a l>ge numb] h be5 inv5t$ 9 rec5t ye>s4 ,9 ?is int]rupt] "s =m ( a cont9u\sly-rotat+ electromotor is employ$ to make & break a m]cury or o!r liquid contact4 ,9 "o simple =m ! motor %aft c>ries an ecc5tric1 :i* simply dips a plat9um po9t into m]cury1 or else a plat9um horse%oe into two m]cury surfaces1 mak+ 9 ?is mann] an int]ruption ( ! prim>y circuit at "o or two places4 ,z a small motor c easily be run at twelve hundr$ revolutions p] m9ute1 or tw5ty p] second1 x is possible to secure easily 9 ?is mann] a uni=m rate ( int]ruption ( ! prim>y curr5t at ! rate ( ab\t tw5ty p] second4 ,if1 h[ev]1 mu* high] spe$s are employ$1 !n ! "t ( contact becomes abbreviat$1 & ! ability ( ! coil to *>ge a capacity is dim9i%$4 ,pr(essor ,j4 ,tr[bridge has describ$ an effective =m ( motor break = l>ge coils1 9 :i* ! int]ruption is caus$ by )draw+ a /\t plat9um wire f a dilute solution ( sulphuric acid1 & by ?is means he increas$ ! sp>k giv5 by a coil provid$ ) hamm] break & cond5s] f fifte5 in*es to ?irty in*es :5 us+ ! liquid break & no cond5s]4#aa ,a good =m ( motor-int]rupt]1 due to ,dr4 ,mack5zie ,davidson1 consi/s ( a slate disc be>+ p9 contacts fix$ on ! prolong$ /eel axle ( a motor plac$ 9 an incl9$ position2 ! disc & ! l[] "p ( ! axle lie 9 a vessel fill$ "o-?ird ) m]cury & two-?irds ) p>aff9 oil4 ,! circuit is made & brok5 by ! revolution ( ! disc caus+ ! p9s to ent] & leave ! m]cury4 ,! spe$ ( ! motor c be regulat$ by a small resi/ance1 & c be adapt$ to ! electromotive =ce us$ 9 ! prim>y circuit4 ,:5 ! motor is runn+ sl[ly ! int]rupt] c be us$ ) a l[ electromotive =ce1 t is to say1 some?+ betwe5 twelve & tw5ty volts1 b ) a high] spe$ a l>ge electromotive =ce c be us$ )\t dang] ( ov]heat+ ! prim>y coil1 & ) an electromotive =ce ( ab\t fifty volts1 ! int]ruptions may be s rapid t an unbrok5 arc ( flame1 resembl+ an alt]nat+-curr5t arc1 spr+s betwe5 ! second>y t]m9als ( ! coil4 ,mr4 ,tesla has devis$ num]\s =ms ( rotat+ m]cury break4 ,9 "o1 a />-%ap$ metal disc revolves 9 a box s t its po9ts dip into m]cury cov]$ ) oil1 & make & break contact4 ,9 ano!r =m1 a jet ( m]cury plays aga9/ a simil> %ap$ rotat+ :eel4 ,= details1 ! read] mu/ consult ! full] descriptions 9 ,! ,electrical ,_w ( ,new ,york1 ,vol4 ,,xxxii41 p4 #aaa1 #ahih2 also ,vol4 ,,xxxiii41 p4 #bdg2 or ,sci5ce ,ab/racts1 ,vol4 ,,ii41 pp4 #df & #dg1 #ahih4 ,! f\r? class ( int]rupt] is call$ a turb9e int]rupt]4 ,9 ?is appliance1 a jet ( m]cury is =c$ out ( a small ap]ture by means ( a c5trifugal pump1 & is made to squirt aga9/ a metal plate1 & int]rupt$ int]mitt5tly by a too!d :eel made ( insulat+ mat]ial rotat$ by ! motor :i* drives ! pump4 ,! curr5t supply+ ! coil passes ?r\gh or along ?is jet ( m]cury1 & is !re=e r5d]$ int]mitt5t :5 ! :eel revolves4 ,9 ! case ( ?is int]rupt]1 ! duration ( ! contacts1 z well z ! numb] ( int]ruptions p] second1 is "u control1 & = ?is reason bett] results are probably obta9$ ) x ?an ) any o!r =m ( break4 ,a description ( a turb9e m]cury break devis$ by ,m4 ,max ,levy 0 giv5 9 ! ,elektrote*nis*e ,zeits*rift1 ,vol4 ,,xx41 p4 #gag1 ,octob] #ab1 #ahii 7see also ,sci5ce ,ab/racts1 ,vol4 ,,iii41 p4 #fc1 ab/ract ,no4 #afe7 z foll[s3-- ,a too!d :eel made ( insulat+ mat]ial c>ries f #f to #bd tee?1 & c be made to rotate f #cjj to #a1jjj times p] m9ute1 ! int]ruptions be+ ?us regulat$ betwe5 #e & #djj p] second4 ,by rais+ or l[]+ ! position ( ! jet ( m]cury & t ( ! plate aga9/ :i* x /rikes1 ! duration ( ! contact c be v>i$1 s t x is possible to regulate ?is p]iod )\t di/urb+ ! numb] ( int]ruptions p] second4 ,! sp>ks obta9$ f a coil work$ ) a turb9e int]rupt] h m quantity ?an ! sp>ks obta9$ ) any o!r int]rupt] "u simil> conditions1 & ! coil c be work$ ) a f> high] voltage ?an is possible :5 us+ ! hamm] break4 ,9 ?is mann]1 ! appe>ance ( ! second>y sp>ks c be v>i$ f ! ?9 snappy sp>ks giv5 by ! hamm] break to ! ?ick flame-l arc sp>ks giv5 by ! electrolytic break4 ,?is break c be adapt$ = any voltage f twelve to two hundr$ & fifty volts1 & ! prim>y circuit _c be clos$ be=e ! int]rupt] is act+4 ,! m]cury 9 ! break is g5]ally cov]$ ) alcohol or p>aff9 oil to r$uce oxidation1 & ! appliance is ne>ly noiseless :5 9 op]ation4 ,! m]cury has to be clean$ at int]vals1 if ! int]rupt] is mu* us$4 ,if alcohol is us$ to cov] ! m]cury1 ! clean+ is v simple2 ! break requires only to be r9s$ "u a wat] tap4 ,:5 p>aff9 oil is us$1 ! clean+ is g5]ally effect$ ) ! help ( a few ounces ( sulphuric acid 9 a v few m9utes4 ,x is be/1 h[ev]1 to clean ! m]cury cont9u\sly by all[+ ! wat] to fl[ ov] x4 ,! motor driv+ ! c5trifugal pump & ! fan c be w\nd = any voltage1 & x is be/ to h x s arrang$ t ?is motor works on ! same batt]y :i* supplies ! prim>y circuit ( ! coil1 ! two circuits work+ p>allel toge!r4 ,a rheo/at c be add$ to ! motor circuit to regulate ! spe$4 ,! turb9e break driv5 by an indep5d5t motor1 :i* is kept always runn+1 has ano!r advantage ov] ! hamm] break 9 practical wireless telegraphy1 viz41 t a useful second>y sp>k c be secur$ ) a %ort] "t ( closure ( ! prim>y circuit1 s9ce !re is no in]tia to ov]come z 9 ! case ( ! hamm] break4 ,?is latt] =m has only cont9u$ 9 use because ( its simplicity & ease ( managem5t by ord9>y op]ators4 ,! m]cury turb9e int]rupt] has be5 ext5sively adopt$ bo? 9 ! ,g]man & ,briti% navies 9 connection ) induction coils us$ = wireless telegraphy4 ,la/ly we h ! electrolytic int]rupt]s1 ! fir/ ( :i* 0 introduc$ by ,dr4 ,wehnelt1 ( ,*>lott5burg1 9 ! ye> #ahii1 & modifi$ by subsequ5t inv5tors4 ,9 its orig9al =m1 a glass vessel fill$ ) dilute sulphuric acid 7"o ( acid to five or else t5 p>ts ( wat]7 conta9s two electrodes ( v diff]5t sizes2 "o is a l>ge lead electrode =m$ ( a piece ( %eet lead laid r\nd ! int]ior ( ! vessel1 & ! o!r is a %ort piece ( plat9um wire project+ f ! end ( a glass or porcela9 tube4 ,! small] ( ^! electrodes is made ! positive1 & ! l>ge "o ! negative4 ,if ?is electrolytic cell is connect$ 9 s]ies ) ! prim>y circuit ( ! induction coil 7! cond5s] be+ cut out7 & suppli$ ) an electromotive =ce f =ty to eighty volts1 an electrolytic action takes place :i* int]rupts ! curr5t p]iodically4#ab ,an enorm\s numb] ( int]ruptions c1 by suitable adju/m5t1 be produc$ p] second1 & ! appe>ance ( a dis*>ge f ! second>y t]m9als ( ! coil1 :ile us+ ! ,wehnelt break1 m resembles an alt]nate-curr5t arc ?an ! usual disruptive sp>k4 ,at ! "t :5 ! ,wehnelt break 0 fir/ introduc$1 great int]e/ 0 excit$ 9 x1 & ! te*nical j\rnals 9 #ahii 7 full ( discussions z to ! !ory ( its op]ation4#ac ,! g5]al facts conc]n+ ! ,wehnelt break are t ! electrolyte mu/ be dilute sulphuric acid 9 ! proportion ( "o ( acid to five or t5 ( wat]4 ,! l>ge lead plate mu/ be ! ca?ode or negative pole1 & ! anode or positive pole mu/ be a plat9um wire1 ab\t a millimetre 9 diamet]1 & project+ "o or two millimetres f ! po9t$ end ( a porcela91 glass or o!r acid-pro( insulat+ tube4 ,! ap]ture ?r\gh :i* ! plat9um wire works mu/ be s tight t acid _c ent]1 yet x is desirable t ! plat9um wire %\ld be capable ( be+ project$ m or less f ! ap]ture by means ( an adju/+ screw4 ,! glass vessel :i* conta9s ^! two electrodes %\ld be ( consid]able size1 hold+1 say1 a qu>t ( fluid1 & x is bett] to include ?is vessel 9 a l>g] "o 9 :i* wat] c be plac$ to cool ! electrolyte1 z ! latt] gets v w>m :5 ! break is us$ cont9u\sly4 ,if su* an electrolytic cell has a cont9u\s electromotive =ce appli$ to x t5d+ to =ce a curr5t ?r\gh ! electrolyte f ! plat9um wire to ! lead plate1 we c di/+ui% ?ree /ages 9 its op]ation1 :i* are det]m9$ by ! electromotive =ce & ! inductance 9 ! circuit4 ,fir/1 if ! electromotive =ce is bel[ sixte5 or tw5ty volts1 !n ord9>y & sil5t electrolysis ( ! liquid proce$s1 bubbles ( oxyg5 be+ lib]at$ f ! plat9um wire & hydrog5 set free aga9/ ! lead plate4 ,if ! electromotive =ce is rais$ above tw5ty-five volts1 !n if !re is no inductance 9 ! circuit1 ! cont9u\s fl[ ( curr5t proce$s1 b if ! circuit ( ! electrolyte possesses a c]ta9 m9imum inductance1 ! "* ( ! curr5t fl[ *anges1 & x becomes int]mitt5t1 & ! cell acts z an int]rupt]1 ! curr5t be+ int]rupt$ f #ajj to #b1jjj times p] second1 accord+ to ! electromotive =ce & ! inductance ( ! circuit4 ,"u ^! conditions1 ! cell produces a rattl+ noise & a lum9\s gl[ appe>s r\nd ! tip ( ! plat9um wire4 ,?us1 9 a p>ticul> case1 ) an inductance ( #j4jjd millih5ry 9 ! circuit ( a ,wehnelt break1 no int]ruption ( ! circuit took place1 b ) "o millih5ry ( inductance 9 ! circuit1 & ) an electromotive =ce ( #dh volts1 ! curr5t became int]mitt5t at ! rate ( #icj p] second1 & by increas+ ! voltage to #abj volts1 ! int]mitt5cy rose to #a1hej a second4 ,! ,wehnelt break acts be/ z an int]rupt] ) an electromotive =ce f #dj to #hj volts4 ,at high] voltages a ?ird /age sets 93 ! lum9\s gl[ r\nd ! plat9um wire disappe>s1 & x becomes surr\nd$ ) a lay] ( vap\r1 z obs]v$ by ,,mm4 ,violle & ,*assagny2 ! int]ruptions ( curr5t cease1 & ! plat9um wire becomes r$ hot4 ,if !re is no inductance 9 ! circuit1 ! int]rupt] /age nev] sets 9 at all1 b ! fir/ /age passes directly into ! ?ird /age4 ,9 ! fir/ /age bubbles ( oxyg5 rise /eadily f ! plat9um wire1 & 9 ! int]rupt$ /age !y rise at long] int]vals1 b regul>ly4 ,! cell w n1 h[ev]1 act z a break at all unless "s inductance exi/s 9 ! circuit4 ,9 apply+ ! ,wehnelt break to an induction coil1 ! cond5s] is disc>d$ & also ! ord9>y hamm] break1 & ! ,wehnelt break is plac$ 9 circuit ) ! prim>y coil4 ,9 "s cases1 ! inductance ( ! prim>y coil alone is suffici5t to />t ! break 9 op]ation1 b ) voltages above #ej or #fj1 x is g5]ally necess>y to supplem5t ! inductance ( ! prim>y coil by ano!r inductive coil4 ,! be/ =m ( ,wehnelt break = op]at+ induction coils is ! "o ) multiple anodes 7see ,dr4 ,m>*ant1 ,! ,electrician1 ,vol4 ,,xlii41 p4 #hda1 #ahii71 & :5 x has to be us$ = long p]iods1 ! ca?ode may advantage\sly be =m$ ( a spiral ( lead pipe1 ?r\gh :i* cold wat] is made to circulate4 ,ano!r =m ( electrolytic break 0 introduc$ by ,mr4 ,caldwell4 ,9 ?is1 a vessel conta9+ dilute sulphuric acid is divid$ into two p>ts4 ,9 ! p>tition is a small hole1 & 9 ! two comp>tm5ts are electrodes ( %eet lead4 ,! small hole causes an int]mitt5cy 9 ! curr5t :i* conv]ts ! arrangem5t into a break4 ,mr4 ,campbell ,sw9ton modifi$ ! above arrangem5t by mak+ ! p>tition to consi/ ( a sort ( porcela9 te/-tube ) a hole 9 ! bottom4 ,?is hole c be m or less plugg$ up by a glass rod drawn out to a po9t1 & ?is is us$ to m or less close ! hole4 ,?is porcela9 vessel conta9s dilute acid & /&s 9 a l>g] vessel ( acid1 & lead electrodes are plac$ 9 bo? comp>tm5ts4 ,! curr5t & int]mitt5cy c be regulat$ by m or less clos+ ! ap]ture betwe5 ! two regions4 ,:5 ! ,wehnelt break is appli$ to an ord9>y t5-in* induction coil1 & ! inductance ( ! prim>y circuit & ! electromotive =ce v>i$ until ! break int]rupts ! curr5t regul>ly & ) ! frequ5cy ( "s hundr$ a second1 ! "* ( ! second>y dis*>ge is entirely diff]5t f its appe>ance ) ! ord9>y hamm] break4 ,! ?9 blue lightn+-l sp>ks are !n replac$ by a ?ick] mobile flam+ dis*>ge1 :i* resembles an alt]nat+-curr5t arc1 &1 :5 c>efully exam9$ or photograph$1 is f\nd to consi/ ( a numb] ( sep>ate dis*>ges sup]impos$ ^u "o ano!r 9 slightly diff]5t positions4 ,_m !ories h be5 adopt$ z to ! action ( ! break1 b "t w n p]mit u to exam9e ^!4 ,pr(essor ,s4 ,p4 ,?ompson & ,dr4 ,m>*ant h sugge/$ a !ory ( resonance4#ad ,"o difficulty 9 expla9+ ! action ( ! break is creat$ by ! fact t x w n "w if ! plat9um wire is made a ca?ode4 ,al?\gh ! ,wehnelt break has "s advantages 9 connection ) ! use ( ! induction coil = ,ro5tg5 ray "w1 its utility z f> z reg>ds ,h]tzian wave telegraphy is n by any means s m>k$4 ,x has already be5 expla9$ t1 9 ord] to *>ge a cond5s] ( a giv5 capacity at a con/ant voltage1 ! electromotive =ce mu/ be appli$ = a c]ta9 m9imum "t1 :i* is det]m9$ by ! value ( ! capacity & ! resi/ance ( ! second>y circuit ( ! induction coil4 ,if ! coil is a t5-in* coil & has a second>y resi/ance (1 say1 #f1jjj ohms1 & if ! capacity to be *>g$ has a value1 say1 ( "o-?irtie? ( a micr(>ad1 !n ! "t-con/ant ( ! circuit is #a_/e1jjj ( a second4 ,!re=e1 ! contact ) ! cond5s] mu/ be ma9ta9$ = at lea/ #a_/ejj ( a second1 dur+ ! "t t ! second>y electromotive =ce ( ! coil is at its maximum1 s t ! cond5s] may become *>g$ to a voltage :i* ! coil is !n capable ( produc+4 ,9 ! induction coil1 ! electromotive =ce g5]at$ 9 ! second>y coil at ! break ( ! prim>y curr5t is high] ?an t at ! make1 & ?is electromotive =ce1 o!r ?+s be+ equal1 dep5ds ^u ! rate at :i* ! magnetism ( ! iron core dies away1 & its duration is %ort] 9 proportion z ! :ole "t occupi$ 9 ! disappe>ance ( ! magnetism is less4 ,! ,wehnelt break does n increase ! actual second>y electromotive =ce1 nor app>5tly its duration1 b x greatly increases ! numb] ( times p] second ?is electromotive =ce makes x appe>ance4 ,h5ce ?is break increases ! curr5t1 b n ! electromotive =ce 9 ! second>y coil4 ,x1 !re=e1 does n assi/ u 9 ! direction requir$--viz41 9 prolong+ ! duration ( ! second>y electromotive =ce to enable l>g] capacities to be *>g$4 ,! important po9t 9 connection ) ! work+ ( a coil us$ = *>g+ a cond5s] is n ! l5g? ( sp>k :i* ! coil c give alone1 b ! l5g? ( sp>k :i* c be obta9$ betwe5 small balls atta*$ to ! second>y t]m9als1 :5 ^! t]m9als are also connect$ to ! two surfaces ( ! cond5s]4 ,?us1 a coil may give a t5-in* sp>k if work$ alone1 b on a capacity ( "o-?irtie? ( a micr(>ad x may n be able to give m ?an a five-millimetre sp>k4 ,h5ce1 9 describ+ ! value ( a coil = wireless telegraph purposes1 x is n ! lea/ use to /ate ! l5g? ( sp>k :i* ! coil w give betwe5 ! po9t$ conductors 9 air1 b we mu/ "k ! sp>k l5g? :i* x w give betwe5 brass balls1 say1 #a c5timetre 9 diamet]1 connect$ to ! second>y t]m9als1 :5 ^! t]m9als are also %ort-circuit$ by a /at$ capacity1 ! sp>k n exce$+ t l5g? at :i* x becomes non-oscillatory4 ,a good way ( describ+ ! value ( an induction coil = wireless telegraph purposes is to /ate ! l5g? ( oscillatory sp>k :i* c be produc$ betwe5 balls "o c5timetre 9 diamet] connect$ to ! second>y t]m9als1 :5 ^! balls are %ort-circuit$ by a cond5s] hav+ a capacity1 say1 ( "o-hundr$? ( a micr(>ad1 & also "o-t5? ( a micr(>ad4 ,if a hamm] or motor int]rupt] is employ$ ) ! coil1 !n a prim>y cond5s] mu/ be connect$ across ! po9ts betwe5 :i* ! prim>y circuit is brok54 ,?is cond5s] g5]ally consi/s ( %eets ( t9foil alt]nat$ ) %eets ( p>aff9 pap]1 & = a t5-in* coil may h a capacity ( ab\t #j4d or #j4e ( a micr(>ad4#ae ,"l ,rayleigh discov]$ t if ! int]ruption ( ! prim>y circuit is suffici5tly sudd5 & complete1 z :5 ! prim>y circuit is sev]$ by a bullet f a gun1 ! prim>y cond5s] c be remov$ & yet ! sp>ks obta9$ f ! second>y circuit are actually long] ?an ^? obta9$ ) ! cond5s] & ! ord9>y break4#af ,9 ! use1 h[ev]1 ( ! coil = ,h]tzian wave telegraphy1 ) all int]rupt]s except ! ,wehnelt break a cond5s] ( suitable capacity mu/ be jo9$ across ! break po9ts4 ,turn+ 9 ! next place to ! prim>y key1 or signall+ int]rupt]1 x is necess>y to be able to control ! torr5t ( sp>ks betwe5 ! second>y t]m9als ( ! coil1 & to cut !m up into long & %ort p]iods 9 accordance ) ! lett]s ( ! ,morse alphabet4 ,?is is done by means ( ! prim>y key4 ,! prim>y key g5]ally consi/s ( an ord9>y massive s+le contact key ) heavy plat9um contacts4 ,z ! curr5t to be int]rupt$ am\nts to ab\t t5 amp]es & is fl[+ 9 a highly inductive circuit1 ! sp>k at break is consid]able4 ,if ! attempt is made to ext+ui% ?is sp>k by mak+ ! contacts move rapidly away f "o ano!r ?r\gh a long di/ance1 9 o!r words1 by us+ a key ) a wide movem5t1 !n ! spe$ at :i* ! signals c be set is greatly dim9i%$4 ,! spe$ ( s5d+ greatly dep5ds ^u ! "t tak5 to move ! key up & d[n betwe5 s5d+ two dots1 & h5ce a %ort range key s5ds quick] ?an a long range key4 ,if x is desir$ to use a %ort range key1 !n "s me?od mu/ be employ$ to ext+ui% ! sp>k at ! contacts4 ,?is is done 9 "o ( ?ree ways3 ,ei!r by us+ a high resi/ance coil to %ort-circuit ^! contacts1 or by a cond5s]1 or by a magnetic bl[-out1 z 9 ! case ( an electric tramc> circuit controll]4 ,( ^!1 ! magnetic bl[-out is probably ! be/4 ,mr4 ,m>coni has design$ a signall+ key :i* p]=ms ! function n only ( int]rupt+ ! prim>y circuit1 b at ! same "t breaks connection betwe5 ! receiv+ appliance & ! a]ial4 ,! au?or has design$ = signall+ purposes a multiple contact key :i* int]rupts ! circuit simultane\sly 9 t5 or twelve diff]5t places4 ,! p>ticul> po9t ab\t ?is break is ! means :i* are tak5 to make ! twelve int]ruptions absolutely simultane\s4 ,if ^! int]ruptions are n simultane\s1 ! sp>k always takes place at ! contact :i* is brok5 fir/1 b if ! circuit is int]rupt$ 9 a doz5 places q simultane\sly1 !n ! sp>k is cut up into a doz5 diff]5t portions1 & ! sp>k at ea* contact is v mu* dim9i%$4 ,by ?is break1 voltages up to two ?\s& volts may be q easily dealt )4 ,v>i\s =ms ( break h be5 devis$ 9 :i* ! circuit is brok5 "u oil or insulat+ fluids1 b1 g5]ally speak+1 ^! devices are n v portable1 & a dry contact betwe5 plat9um surfaces ) appropriate means = cutt+ up ! sp>k & bl[+ x out s t ! me*anical movem5t ( ! swit* may be small is ! be/ ?+ to use4 ,! signall+ key is really a v important "p ( ! transmitt+ arrangem5t1 because :atev] may be ! improvem5ts 9 receiv+ in/rum5ts1 x is n possible to receive fa/] ?an we c s5d4 ,a great _m /atem5ts h appe>$ 9 ! daily pap]s z to ! possibility ( receiv+ hundr$s ( words a m9ute by ,h]tzian wave telegraphy1 b ! fact rema9s t :atev] may be ! s5sibility ( ! receiv+ appliance1 ! rate at :i* telegraphy ( any k9d c be conduct$ is ess5tially dep5d5t ^u ! rate at :i* ! signals c be s5t1 & ?is 9 turn is l>gely dep5d5t ^u ! me*anical movem5t :i* ! key has to make to int]rupt ! prim>y circuit1 & s int]rupt ! second>y dis*>ge4 ,9 ord] to make ! sep>ation ( ! contact po9ts ( ! swit* z small z possible1 & yet prev5t an arc be+ e/abli%$1 v>i\s bl[-out devices h be5 employ$4 ,! simple/ arrangem5t = ?is purpose is a p[]ful p]man5t magnet s plac$ t its int]-pol> field embraces ! contact po9ts & is at "r angles to !m4 ,z already expla9$1 ! applicability ( ! induction coil 9 wireless telegraphy is limit$ by ! fact ( ! high resi/ance ( ! second>y circuit & ! small curr5t t c be suppli$ f x4 ,data are yet want+ to %[ :at is ! precise effici5cy ( ! induction coil1 z us$ 9 ,h]tzian wave telegraphy1 b !re are reasons = believ+ t x does n exce$ #ej or #fj p] c5t4 ,:]e l>ge cond5s]s h to be *>g$--9 o!r words1 :]e we h to deal ) l>g] p[]s--we are oblig$ to disc>d ! induction coil & to employ ! alt]nat+-curr5t trans=m]4 ,b ?is introduces u to a new class ( difficulties4 ,if an alt]nat+-curr5t trans=m] w\nd = a second>y voltage1 say1 ( #bj1jjj or #cj1jjj volts1 has its prim>y circuit connect$ to an alt]nator1 !n if ! second>y t]m9als1 to :i* are connect$ two sp>k balls1 are gradually br\ght )9 /rik+ di/ance ( "o ano!r1 ! mom5t we d ?is an alt]nat+-curr5t arc />ts betwe5 ^! balls4 ,if ! trans=m] is a small "o1 !re is no difficulty 9 ext+ui%+ ?is arc by )draw+ ! second>y t]m9als1 b if ! trans=m] is a l>ge "o1 say1 ( t5 or tw5ty kil[atts1 dang]\s effects are apt to ensue :5 su* an exp]im5t is tri$4 ,! %ort circuit+ ( ! second>y circuit almo/ entirely annuls ! inductance ( ! prim>y circuit4 ,!re is1 !re=e1 a ru% ( curr5t into ! trans=m]1 & if x is connect$ to an alt]nator ( l[ armature resi/ance ! fuses are g5]ally bl[n & o!r damage done4 ,let u supppse1 !n1 t ! second>y t]m9als ( ! trans=m] are also connect$ to a cond5s]4 ,on br++ toge!r ! sp>k balls connect$ ) ! second>y t]m9als we may h "o or m oscillatory dis*>ges1 b ! process w n be cont9u\s1 because ! mom5t t ! alt]nat+-curr5t arc />ts betwe5 ! sp>k balls x r$uces _! diff]5ce ( pot5tial to a comp>atively l[ value1 & h5ce ! *>ge tak5 by ! cond5s] is v small1 &1 moreov]1 ! circuit is n int]rupt$ p]iodically s z to re-/>t a tra9 ( oscillations4 ,:51 !re=e1 we desire to employ an alt]nat+-curr5t trans=m] z a s\rce ( electromotive =ce1 al?\gh x may h ! advantage t ! resi/ance ( ! second>y circuit ( ! trans=m] is g5]ally small comp>$ ) t ( ! second>y circuit ( an induction coil1 yet1 nev]!less1 we are confront$ ) two practical difficulties3 7#a7 ,h[ to control ! prim>y curr5t fl[+ into ! trans=m]1 & 7#b7 h[ to de/roy ! alt]nat+-curr5t arc betwe5 ! sp>k balls & r$uce ! dis*>ge entirely to ! disruptive or oscillatory dis*>ge ( ! cond5s]4 ,! control ov] ! curr5t c be obta9$1 9 accordance ) a plan sugge/$ by ! au?or1 by ins]t+ 9 ! prim>y circuit ( ! trans=m] two v>iable *ok+ coils4 ,! =m 9 :i* x is pref]r$ to con/ruct ^! is t ( a cyl9drical bobb9 /&+ ^u a lam9at$ cross-piece ( iron4 ,^! bobb9s c h let d[n into !m an ,e-%ap$ piece ( lam9at$ iron1 s z to complete ! magnetic circuit1 & ?us raise ! inductance ( ! bobb94 ,by plac+ two ( ^! v>iable *ok+ coils 9 s]ies ) ! prim>y circuit1 ! curr5t is "u p]fect control4 ,we c fix a m9imum value bel[ :i* ! curr5t %all n fall1 by adju/+ ! position ( ! cores ( ^! two *ok+ coils1 & we c !n cause t curr5t to be increas$ up to a c]ta9 limit :i* x _c exce$1 by %ort-circuit+ "o ( ^! *ok+ coils by an appropriate swit*4 ,sev]al ways h be5 sugge/$ = ext+ui%+ ! alt]nat+ curr5t arc :i* =ms betwe5 ! sp>k balls connect$ to ! second>y t]m9als :5 ^! are br\ght )9 a c]ta9 di/ance ( "o ano!r4 ,"o ( ^! is due to ,mr4 ,tesla4 ,he places a /rong electromagnet s t its l9es ( magnetic flux pass transv]sely betwe5 ! sp>k balls4 ,:5 ! dis*>ge takes place ! electric arc is bl[n out1 b if ! balls are %ort-circuit$ by a cond5s] ! oscillatory dis*>ge ( ! cond5s] /ill takes place across ! sp>k gap4 ,pr(essor ,elihu ,?omson a*ieves ! same result by employ+ a bla/ ( air ?r[n on ! sp>k gap4 ,?is has ! effect ( de/roy+ ! alt]nat+-curr5t arc1 b /ill leaves ! oscillat+ dis*>ge ( ! cond5s]4 ,! action is some:at t$i\s to expla9 9 words1 b x c easily be und]/ood t ! bla/ ( air1 by cont9ually break+ d[n ! alt]nat+-curr5t arc :i* t5ds to =m1 all[s ! cond5s] connect$ to ! sp>k balls to become *>g$ ) ! pot5tial ( ! second>y circuit ( ! trans=m]1 & t ?is cond5s] !n dis*>ges across ! sp>k gap1 produc+ an oscillatory dis*>ge 9 ! usual mann]4 ,! au?or has f\nd t1 )\t ! use ( any air bla/ or electromagnet1 simple adju/m5t ( ! d\ble *ok+ coil 9 ! prim>y circuit ( ! trans=m]1 z above describ$1 is suffici5t to br+ ab\t ! desir$ result1 :5 ! capacity ( ! cond5s] is adju/$ to be 9 resonance4 ,ano!r me?od1 :i* has be5 adopt$ by ,m4 d',arsonval1 is to cause ! sp>k to pass betwe5 two balls plac$ at ! extremities ( metal rods1 :i* are 9 rapid rotation l ! spokes ( a :eel4 ,9 ?is case1 ! draught ( air produc$ by ! passage ( ! sp>k balls bl[s out ! arc & p]=ms ! same function z ! bla/ ( air 9 ,pr(essor ,elihu ,?omson's me?od4 ,:5 ^! adju/m5ts are prop]ly made1 x is possible1 by means ( a cond5s] & an alt]nat+-curr5t trans=m] suppli$ ) curr5t f an alt]nator1 to create a rapidly int]mitt5t oscillatory dis*>ge1 ! sp>ks ( :i* succe$ "o ano!r s quickly t x appe>s almo/ cont9u\s4 ,:5 us+ a l>ge trans=m] & cond5s]1 ! noise & brilliancy ( ^! sp>ks are almo/ unbe>able1 & ! eyes may be injur$ by look+ at ?is sp>k = m ?an a mom5t4 ,9 ! con/ruction ( trans=m]s int5d$ to be us$ 9 ?is mann]1 v special precautions h to be tak5 9 ! insulation ( ! prim>y & second>y circuits1 & ! insulation ( ^! f ! core4 ,x may be rem>k$ 9 pass+ t exp]im5t+ ) l>ge high-t5sion trans=m]s c\pl$ to cond5s]s ( l>ge capacity is exce$+ly dang]\s "w1 & ! greate/ precautions are necess>y to avoid accid5t4 ,9 ! light1 h[ev]1 ( suffici5t exp]i5ce !re is no difficulty 9 employ+ high-t5sion trans=m]s 9 ! above-describ$ mann]1 & 9 obta9+ electromotive =ces ( upw>ds ( a hundr$ ?\s& volts suppli$ ?r\gh trans=m]s capable ( yield+ any requir$ am\nt ( curr5t4 ,on occasions :]e cont9u\s curr5t alone is available1 a motor g5]ator has to be employ$ conv]t+ ! cont9u\s curr5t into an alt]nat+ curr5t4 ,?is is be/ a*iev$ by ! employm5t ( a small alt]nator directly c\pl$ to a cont9u\s-curr5t motor2 or by provid+ ! %aft ( a cont9u\s-curr5t motor ) two r+s connect$ to two opposite portions ( its armature1 s t :5 cont9u\s curr5t is suppli$ to ! bru%es press+ aga9/ ! commutator1 an alt]nat+ curr5t c be drawn (f f two o!r bru%es t\*+ ! above-m5tion$ insulat$ r+s4 ,! next elem5t ( importance 9 ! transmitt+ arrangem5t is ! sp>k gap4 ,9 ! case ( ^? transmitt]s employ+ an ord9>y induction coil1 ! second>y sp>k1 or ! dis*>ge ( any cond5s] connect$ to ! second>y t]m9als c be tak5 betwe5 ! brass balls ab\t half an in* or "o in* 9 diamet]1 ) :i* ! t]m9als ( ! second>y coil are usually furni%$2 & x is g5]ally ! cu/om to all[ ?is sp>k dis*>ge to take place 9 air at ord9>y pressure4 ,9 ! v e>ly days ( 8 "w ,mr4 ,m>coni adopt$ ! dis*>g] devis$ by ,pr(essor ,rhigi1 9 :i* ! sp>k takes place betwe5 two brass balls plac$ 9 vasel9e or o!r highly insulat+ oil4#ag ,b :atev] advantage may accrue f us+ oil z ! dielectric 9 :i* ! sp>k dis*>ge takes place1 :5 c>ry+ out simple laboratory exp]im5ts on ,h]tzian waves1 !re is no advantage 9 ! case ( wireless telegraphy4 ,! ,rhigi dis*>g] 01 !re=e1 soon disc>d$4 ,if dis*>ges hav+ l>ge quantity are pass$ ?r\gh oil1 x is rapidly decompos$ or *>r$1 & ceases to reta9 ! special insulat+ & self-re/or+ "* :i* is necess>y 9 ! m$ium 9 :i* an oscillat+ sp>k is =m$4 ,! conditions :5 ! dis*>ges ( l>ge cond5s]s are pass$ betwe5 sp>k balls are entirely diff]5t f ^? :5 ! quantity ( ! sp>k1 or to put x 9 m exact language1 ! curr5t pass+1 is v small4 ,9 ! case ( ,h]tzian exp]im5ts x is necess>y1 z %[n by ,h]tz1 to ma9ta9 a high /ate ( poli% on ! sp>k balls :5 !y are employ$ = ! production ( %ort waves ( small en]gy1 b :5 we are deal+ ) l>ge quantities ( en]gy at ea* dis*>ge1 ^? me?ods :i* succe$ = laboratory exp]im5ts are p]fectly impracticable4 ,! conditions necess>y to be fulfill$ by a dis*>g] = use 9 ,h]tzian wave telegraphy are t ! surfaces %all ma9ta9 a con/ant condition & n be fus$ or eat5 away by ! sp>k1 &1 next1 t ! m$ium 9 :i* ! dis*>ge takes place %all n be decompos$ by ! passage ( ! sp>k1 b %all ma9ta9 ! prop]ty ( giv+ way sudd5ly :5 a c]ta9 critical pressure is rea*$1 & pass+ in/antly f a condition 9 :i* x is a v p]fect insulator to "o 9 :i* x is a v good conductor2 &1 ?irdly1 t on ! cessation ( ! dis*>ge1 ! m$ium %all imm$iately re/ore itself to its orig9al condition4 ,:5 us+ ! ord9>y t5-in* induction coil1 & :5 ! capacity *>g$ by x does n exce$ a small fraction ( a micr(>ad1 x is q suffici5t to employ brass or /eel balls sep>at$ by a c]ta9 di/ance 9 air1 at ! ord9>y pressure1 z ! arrangem5t ( ! dis*>g]4 ,:51 h[ev]1 we come to deal ) ! dis*>ges ( v l>ge cond5s]s1 at high electromotive =ces1 !n x is necess>y to h special arrangem5ts to prev5t ! de/ruction ( ! surfaces betwe5 :i* ! sp>k passes1 or _! cont9ual alt]ation1 & _m devices h be5 inv5t$ = ?is purpose4 ,! au?or has devis$ an arrangem5t :i* fulfils ! above conditions v p]fectly = use 9 l>ge p[] /ations1 b ! details ( ?is _c be made public at ! pres5t "t4 99 99 99 99 99 ,we h to consid] 9 connection ) ?is "p ( ! subject ! dielectric /r5g? ( air "u diff]5t pressures & = diff]5t ?icknesses4 ,x 0 %[n by ,"l ,kelv91 9 #ahfj1 t ! dielectric /r5g? ( v ?9 lay]s ( air is great] ?an t ( ?ick lay]s4#ah ,! electric =ce1 reckon$ 9 volts p] c5timetre1 requir$ to pi]ce a ?ickness ( air f two to t5 millimetres 9 ?ickness1 at atmosph]ic pressure1 may be tak5 at #cj1jjj volts p] c5timetre4 ,! same =ce 9 electro/atic units is repres5t$ by ! numb] #ajj1 s9ce a gradi5t ( #cjj volts p] c5timetre corresponds to a =ce ( "o electro/atic unit4 ,x appe>s also t = air & o!r gases !re is a c]ta9 m9imum voltage 7approximately #djj volts7 bel[ :i* no dis*>ge takes place1 h[ev] ne> ! conduct+ surfaces may be approximat$4 ,9 ?is p>ticul> practical application1 h[ev]1 we are only conc]n$ ) sp>k l5g?s :i* are measur$ 9 millimetres or c5timetres1 ly+1 say1 betwe5 "o or two millimetres & five or six c5timetres4 ,ov] ?is range ( sp>k l5g? we %all n g5]ally be wrong 9 reckon+ ! voltage requir$ to produce a sp>k betwe5 metal balls 9 air at ! ord9>y pressure to be giv5 by ! rule3 ,disruptive voltage #c1jjj x sp>k-gap l5g? 9 millimetres4 ,if1 h[ev]1 ! air pressure is increas$ above ! normal by includ+ ! sp>k balls 9 a vessel 9 :i* air c be compress$1 !n ! sp>k l5g?1 correspond+ to a giv5 pot5tial diff]5ce1 v rapidly decreases4 ,mr4 ,f4 ,j4 ,j]vis-,smi?#ai f\nd t by increas+ ! air pressure f "o atmosph]e to two atmosph]es r\nd a pair ( sp>k balls he r$uc$ ! sp>k l5g? giv5 by a c]ta9 voltage f #b4e to #j4ge c5timetre4 ,pr(essor ,r4 ,a4 ,fess5d5 has also made "s int]e/+ obs]vations on ! effect ( us+ compress$ air r\nd sp>k gaps4 ,he f\nd t if a c]ta9 voltage betwe5 metal surfaces w\ld yield a sp>k f\r in*es 9 l5g?1 at ! ord9>y pressure ( ! air1 if ! sp>k balls 7 enclos$ 9 a cyl9d]1 ! air r\nd !m compress$ at #ejlb4 p] squ>e in*1 ! sp>k l5g? = ! same pot5tial diff]5ce ( ! balls 0 only "o qu>t] ( an in*1 or "o-sixte5? ( its =m] value4 ,! writ] has also made exp]im5ts ) an app>atus design$ to /udy ! effect ( compress$ air r\nd ! sp>k gap4 ,! exp]im5tal arrangem5ts are z foll[s3 ,a t5-in* induction coil has "o ( its t]m9als connect$ to ! int]nal coat+ ( a batt]y ( ,leyd5 j>s4 ,! ext]nal coat+ is connect$ ?r\gh ! prim>y coil ( an oscillation trans=m] ) ! o!r second>y t]m9al ( ! coil1 & ^! second>y t]m9als are also connect$ to a sp>k gap consi/+ ( two brass balls enclos$ 9 a glass vessel into :i* air c be =c$ by a pump1 ! air pressure be+ measur$ by a gauge4 ,! balls 9 ! glass vessel are set at a di/ance ( ab\t ?ree millimetres ap>t4 ,! second>y circuit ( ! oscillation trans=m] is connect$ to ano!r pair ( sp>k balls1 ! di/ance ( :i* c be v>i$4 ,suppose we beg9 ) ! air 9 ! glass vessel conta9+ ! balls connect$ to ! second>y t]m9als ( ! induction coil1 :i* may be call$ ! second>y balls1 at atmosph]ic pressure1 & create oscillatory dis*>ges 9 ! prim>y coil ( ! oscillation trans=m]1 we h a sp>k betwe5 ! balls1 :i* may be call$ ! t]ti>y balls1 connect$ to ! second>y t]m9als ( ! oscillation trans=m]4 ,if ! second>y balls are plac$1 say1 ?ree millimetres ap>t1 ! air 9 ! glass vessel enclos+ !m be+ at ! ord9>y atmosph]ic pressure1 !n ) "o p>ticul> arrangem5t ( j>s us$1 a sp>k tw5ty-five or tw5ty-six millimetres long betwe5 ! t]ti>y balls w take place4 ,suppose1 !n1 we increase ! pressure ( ! air r\nd ! second>y balls1 pump+ x by degrees to #aj1 #bj1 #cj1 #dj & #ejlb4 p] squ>e in* above ! atmosph]ic pressure4 ,we f9d t ! sp>k betwe5 ! t]ti>y balls w gradually leap a great] & great] di/ance1 & :5 ! pressure ( ! air is #ejlb4 p] squ>e in*1 we c obta9 a fifty-millimetre sp>k betwe5 ! t]ti>y balls1 :]eas :5 ! air 9 ! glass vessel is at atmosph]ic pressure1 we c only obta9 a sp>k betwe5 ! t]ti>y balls ( half t l5g?4 ,?is exp]im5t demon/rates t ! effect ( compress+ ! air r\nd ! second>y t]m9als ( ! induction coil is to greatly increase ! diff]5ce ( pot5tial betwe5 ^! balls be=e ! sp>k passes4 ,9 fact1 x requires ab\t d\ble ! voltage to =ce a sp>k ( ! same l5g? ?r\gh air compress$ at #ejlb4 on ! squ>e in* t x does to make a sp>k ( id5tical l5g? betwe5 ! same balls 9 air at normal pressure4 ,?is %[s t !re is a v great advantage 9 tak+ ! dis*>ge sp>k 9 compress$ air4 ,a bett] effect c be produc$ by sub/itut+ dry gase\s hydro*loric acid = air at ord9>y pressures4 ,"o o!r incid5tal advantage is t ! noise ( ! sp>k is v mu* r$uc$4 ,! cont9ual crackle1 ( ! dis*>ge sp>k ( ! induction coil 9 connection ) wireless telegraphy is v annoy+ to s5sitive e>s1 b 9 ?is mann] we c r5d] x p]fectly sil5t4 ,pr(essor ,fess5d5 also /ates t :5 ! sp>k balls are surr\nd$ by compress$ air1 & if "o ( ! balls is connect$ ) a radiator1 ! compression ( ! air1 al?\gh x %ort5s ! sp>k-gap correspond+ to a giv5 voltage1 does n 9 any way increase ! radiation4 ,:51 h[ev]1 ! air 9 ! sp>k-ball vessel is compress$ to #fjlb4 9 ! squ>e in*1 !re is a m>k$ increase 9 ! effective radiation1 & at #hjlb4 p] squ>e in* ! en]gy emitt$ 9 ! =m ( waves is ne>ly ?ree & a-half times great] ?an at #ejlb41 ! pot5tial diff]5ce betwe5 ! balls rema9+ ! same4 ,?is effect is no d\bt connect$ ) ! fact t ! production ( a wave1 :e!r 9 e!r or 9 any o!r mat]ial1 is n s mu* dep5d5t ^u ! absolute =ce appli$ z ^u ! sudd5ness ( its application4 ,to translate x into ! language ( ! electronic !ory1 we may say t ! electron radiates only :il/ x is be+ accel]at$1 & t its radiat+ p[]1 !re=e1 dep5ds n s mu* ^u its motion z ^u ! rate at :i* its motion is *ang+4 ,! advantage 9 us+ compress$ air r\nd ! sp>k gap is t we c increase ! effective pot5tial diff]5ce betwe5 ! balls )\t r5d]+ ! sp>k non-oscillatory4 ,9 air ( ! ord9>y pressure !re is a c]ta9 well-def9$ limit ( sp>k l5g? = ea* voltage1 beyond :i* ! dis*>ge becomes non-oscillatory1 b by ! employm5t ( sp>k balls 9 compress$ air1 we c increase ! pot5tial diff]5ce betwe5 ! balls correspond+ to a giv5 di/ance ap>t be=e a dis*>ge takes place1 or employ high] pot5tials ) ! same l5g? ( sp>k gap4 ,9 addition to ?is1 we h1 p]haps1 ! production ( a m effective radiation1 z ass]t$ by ,fess5d51 :5 ! air pressure exce$s a c]ta9 critical value4 ,! next elem5t :i* we h to consid] 9 ! transmitt+ arrangem5ts is a cond5s] ( "s k9d = /or+ ! en]gy :i* is radiat$ at int]vals4 ,:]e a cond5s] o!r ?an ! a]ial is employ$ = /or+ ! electric en]gy :i* is to be radiat$ by ! a]ial1 "s =m ( x mu/ be con/ruct$ :i* w )/& high pot5tials4 ,z ! dielectric = su* a cond5s]1 only two mat]ials seem to be ( any practical use1 viz41 glass & micanite4 ,glass cond5s]s 9 ! =m ( ,leyd5 j>s h be5 ext5sively employ$1 b !y h ! disadvantage t !y are v bulky 9 proportion to _! electrical capacity4 ,! in/rum5t mak]'s qu>t ,leyd5 j> has a capacity ( ab\t "o-five hundr$? ( a micr(>ad1 b x occupies ab\t #aej cubic in*es or m4 ,pr(essor ,braun has employ$ 9 8 transmitt+ arrangem5ts cond5s]s consi/+ ( small glass tubes l te/ tubes1 l9$ on ! inside & outside ) t9foil1 :i* are m economical 9 space4 ,! au?or has f\nd t cond5s]s = ?is purpose are be/ made ( %eet glass ab\t "o-eigh? or "o-t5? ( an in* 9 ?ickness1 coat$ to )9 "o in* ( _! edge on bo? sides ) t9foil1 & arrang$ 9 a vessel conta9+ res9 or l9se$ oil1 l ! plates ( a /orage batt]y4 ,m4 d',arsonval has employ$ micanite1 b al?\gh ?is mat]ial has a consid]ably high] dielectric /r5g? ?an glass1 x is mu* m exp5sive to obta9 a giv5 capacity by means ( micanite ?an by glass1 al?\gh ! bulk ( ! cond5s] = a giv5 capacity is less4 ,to /ore up a c]ta9 am\nt ( electric en]gy 9 a cond5s]1 we require a c]ta9 def9ite volume ( dielectric1 no matt] h[ we may arrange x1 & ! volume requir$ p] unit ( en]gy is det]m9$ by ! dielectric /r5g? ( ! mat]ial4 ,?us1 = in/ance1 ord9>y %eet glass _c be safely employ$ ) a great] electric =ce ?an is repres5t$ by #bj1jjj volts = "o-t5? ( an in* 9 ?ickness1 or1 say1 a pot5tial gradi5t ( #afj1jjj volts p] c5timetre4 ,?is is equival5t to an electric =ce ( ab\t #ejj electro/atic units4 ,?is may be call$ ! safe-work+ =ce4 ,! electro/atic capacity ( a cond5s] =m$ ( two metal surfaces a foot squ>e sep>at$ by glass ?ree millimetres 9 ?ickness is betwe5 #a_/cfj & #a_/djj ( a micr(>ad4 ,if ?is cond5s] is *>g$ to #bj1jjj volts1 we h /or$ up 9 x half a j\le ( electric en]gy1 & ! volume ( ! dielectric is #bgj cubic c5timetres4 ,h5ce1 to /ore up 9 a glass cond5s] electric en]gy repres5t$ by "o j\le at a pressure ( #bj1jjj volts1 we require #ejj cubic c5timetres ( glass1 & x w be f\nd t if we d\ble ! pressure & d\ble ! ?ickness ( ! glass1 we /ill require ! same volume4#bj ,h5ce1 9 ! con/ruction ( high-t5sion cond5s]s to /ore up a giv5 am\nt ( en]gy1 ! economical problem is h[ to obta9 ! greate/ en]gy-/or+ capacity = ! lea/ money4 ,glass fulfils ?is condition bett] ?an any o!r mat]ial4 ,al?\gh "s mat]ials may h v high dielectric /r5g?1 su* z pap] saturat$ ) v>i\s oils1 or res9s1 yet !y _c be us$ = ! purpose ( mak+ cond5s]s to yield oscillatory dis*>ges1 because ! oscillations are damp$ out ( exi/5ce too soon by ! dielectric4 ,9 arrang+ cond5s]s to atta9 a giv5 capacity1 reg>d has to be tak5 ( ! fact t = a giv5 pot5tial diff]5ce !re mu/ be a c]ta9 total ?ickness ( dielectric1 & t if cond5s]s ( equal size are be+ arrang$ 9 p>allel x adds to _! capacity1 :il/ jo9+ !m 9 s]ies divides _! capacity4 ,if ,n equal cond5s]s or ,leyd5 j>s h ea* a capacity repres5t$ by ,c1 & if !y are jo9$ n 9 s]ies & m 9 p>allel1 ! jo9t capacity ( ! :ole numb] is m,c_/n1 :]e ! product mn ,n4 ,pass+ on next to ! consid]ation ( oscillation trans=m]s ( v>i\s k9ds--^! are appliances ( ! nature ( induction coils = trans=m+ ! curr5t or electromotive =ce ( electrical oscillations 9 a requir$ ratio4 ,^! coils are1 h[ev]1 de/itute ( any iron core1 & !y g5]ally consi/ ( coils ( wire w\nd on a fibre1 wood5 or ebonite frame1 & mu/ be imm]s$ 9 a vat ( oil to pres]ve ! necess>y insulation4 ,no dry insulation ( ! nature ( indi>ubb] or gutta-p]*a w )/& ! high pressures t are br\ght to be> ^u ! circuits ( an oscillation trans=m]4 ,9 con/ruct+ ^! trans=m]s we h to set aside all previ\s notions ga!r$ f ! design ( l[-frequ5cy iron-core trans=m]s4 ,! *ief difficulty we h to cont5d aga9/ 9 ! con/ruction ( an effective oscillation trans=m] is ! inductance ( ! prim>y circuit & ! magnetic leakage t takes place4 ,9 o!r words1 ! failure ( ! :ole ( ! flux g5]at$ by ! prim>y circuit to pass ?r\gh or be l9k$ ) ! second>y circuit4 ,mr4 ,m>coni has employ$ an excell5t =m ( oscillation trans=m]1 9 ! design ( :i* he 0 guid$ by a l>ge am\nt ( exp]i5ce4 ,9 ?is trans=m] ! two circuits are w\nd r\nd a squ>e wood5 frame4 ,! prim>y circuit consi/s ( a numb] ( /r&s ( ?ick insulat$ cable laid on 9 p>allel1 s t x consi/s ( only "o turn ( a /r&$ conductor4 ,! second>y circuit consi/s ( a numb] ( turns1 say1 t5 to tw5ty1 ( ?9n] insulat$ wire laid ov] ! prim>y circuit & close to x1 s t ! trans=m] has ! trans=mation ratio ( "o to t5 or "o to tw5ty4 ,9 ! arrangem5ts devis$ & pat5t$ by ,mr4 ,m>coni1 ^! two circuits1 ) _! respective capacities 9 s]ies ) !m1 are tun$ to "o ano!r1 s t ! "t-p]iod ( ea* circuit is exactly ! same1 & )\t ?is tun+ ! device becomes ineffective z a trans=m]4#ba ,!re is no advantage 9 putt+ a numb] ( turns on ! prim>y circuit1 because su* multiplication simply increases ! inductance1 &1 !re=e1 dim9i%es ! prim>y curr5t 9 ! same ratio :i* x multiplies ! turns1 & h5ce ! magnetic field due to ! prim>y circuit rema9s ! same4 ,:]e x is desir$ to put a numb] ( turns ^u a coil1 & yet at ! same "t keep ! inductance d[n1 ! writ] has adopt$ ! device ( w9d+ a silk or hemp rope well p>aff9$ betwe5 ! turns ( ! circuit1 s z to keep !m fur!r ap>t f "o ano!r1 & z ! inductance dep5ds on ! turns p] c5timetre1 ?is has ! effect ( r$uc+ ! inductance4 ,! next & mo/ important elem5t 9 any transmitt+ /ation is ! a]ial or radiator1 & x 0 ! introduction ( ?is elem5t by ,mr4 ,m>coni :i* laid ! f\ndation = ,h]tzian wave telegraphy z oppos$ to m]e exp]im5ts ) ! ,h]tzian waves4 ,we may consid] ! diff]5t v>ieties ( a]ial :i* h be5 evolv$ f ! fundam5tal idea4 ,! simple s+le ,m>coni a]ial consi/s ( a b>e or insulat$ wire1 g5]ally ab\t #ajj;ft4 or #aej;ft4 9 l5g?1 susp5d$ f a sprit atta*$ to a tall ma/4 ,z ^! ma/s h g5]ally to be erect$ 9 expos$ positions1 consid]able c>e has to be tak5 9 erect+ !m ) a l>ge m>g9 ( /r5g?4 ,to ! end ( a sprit is atta*$ an insulator ( "s k9d1 :i* may be a simple ebonite rod1 or sometimes a m elaborate arrangem5t ( oil insulators1 & to ! l[] end ( ?is insulator is atta*$ ! a]ial wire4 ,z at ! top ( ! a]ial we h to deal ) pot5tials capable sometimes ( giv+ sp>ks sev]al feet 9 l5g?1 ! insulation ( ! upp] end ( ! a]ial is an important matt]4 ,9 ! orig9al ,m>coni sy/em1 ! l[] end ( ! a]ial 0 simply atta*$ to "o sp>k ball connect$ to "o t]m9al ( ! induction coil1 & ! o!r t]m9al & sp>k ball 7 connect$ to ! e>?4 ,9 ?is arrangem5t1 ! a]ial act$ n only z radiator1 b z en]gy-/or+ capacity1 & z already expla9$1 its radiat+ p[] 0 on t acc\nt limit$4 ,! e>? connection is an important matt]4 ,= long di/ance "w1 a good e>? is ess5tial4 ,?is e>? mu/ be made by emb$d+ a metal plate 9 ! soil1 & _m p]sons are "u ! impression t ! effici5cy ( ! e>? plate dep5ds ^u its area1 b ?is is n ! fact4 ,x dep5ds mu* m ^u its %ape1 & pr9cipally ^u ! am\nt ( its edge4 ,x has be5 %[n by ,pr(essor ,a4 ,tanakadate1 ( ,japan1 t if a metal plate ( negligible resi/ance is emb$d$ 9 an inf9ite m$ium hav+ a resi/ivity r1 ! electrical conductance ( ?is plate is equal to #dpi_/r times ! electro/atic capacity ( ! same plate plac$ 9 a dielectric ( inf9ite ext5t4 ,h5ce 9 design+ an e>? plate1 we h to consid] n h[ to give x ! utmo/ am\nt ( surface1 b h[ to give x ! greate/ electro/atic capacity1 & = ?is purpose x is f> bett] to divide a giv5 am\nt ( metal into long /rips radiat+ out 9 diff]5t directions1 r ?an to employ x 9 ! =m ( "o big squ>e or circul> plate4 ,! importance ( ! good e>? w h be5 se5 f our discussion on ! mode ( =mation ( electric waves4 ,!re mu/ be a p]fectly free access = ! electrons to pass into & out ( ! a]ial4 ,h5ce1 if ! soil is dry1 or badly conductive 9 ! neighb\rhood1 we h to g d[n to a level at :i* we get a good moi/ e>?4 ,9 fact1 ! precautions :i* h to be tak5 9 mak+ a good e>? = ,h]tzian wave telegraphy are exactly ^? :i* %\ld be tak5 9 mak+ a good e>? = a lightn+ conductor4 ,:il/ on ! subject ( a]ials1 a ^w may be said on ! localisation ( wireless telegraph /ations on ! ,m>coni sy/em4 ,= reasons :i* 7 expla9$ previ\sly1 ! transmission ( signals is effect$ m easily ov] wat] ?an ov] dry l&1 & x is h9d]$ if ! soil 9 ! neighb\rhood ( ! s5d+ /ation is a poor conductor4 ,h5ce1 all active ,h]tzian wave telegraph /ations1 l all active volcanoes1 are g5]ally f\nd ne> ! sea4 ,9 ^? cases 9 :i* a multiple a]ial has to be put up consi/+ ( _m wires1 "o ma/ may be insuffici5t to support ! /ructure1 & sev]al ma/s arrang$ 9 ! =m ( a squ>e or a circle h to be employ$4 ,! illu/rat$ pap]s h reproduc$ num]\s pictures ( ! ,m>coni p[] /ations at ,poldhu 9 ,cornwall1 ,glace ,bay 9 ,nova ,scotia1 & ,cape ,cod 9 ! ,unit$ ,/ates4 ,9 ^! /ations1 aft] prelim9>y failures to obta9 ! necess>y /ructural /r5g? ) ord9>y ma/s1 tall lattice gird] wood5 t[]s h be5 built1 ab\t #bae feet 9 height1 well /ay$ aga9/ w9d pressure1 & :i* s f> h prov$ !mselves capable ( )/&+ any /orm ( w9d :i* has come aga9/ !m4 ,an important "q 9 connection ) ! s5d+ p[] ( an a]ial is t ( ! relation ( its height to ! di/ance cov]$4 ,"s "t ago ,mr4 ,m>coni enunciat$ a law1 z ! result ( 8 exp]im5ts1 connect+ ^! two quantities1 :i* may be call$ ,m>coni's ,law4 ,he /at$ t ! height ( ! a]ial to cov] a giv5 di/ance1 o!r ?+s rema9+ ! same1 v>ies z ! squ>e root ( ! di/ance4 ,let ,d be ! di/ance & let ,l be ! l5g? ( ! a]ial1 !n if bo? ! transmitt+ & receiv+ a]ial are ! same height1 we may say t ,d v>ies z ,l#b4 ,?is relation may be !oretically d$uc$ z foll[s3--,any giv5 receiv+ app>atus = ,h]tzian wave telegraphy requires a c]ta9 m9imum en]gy to be imp>t$ to x to make x yield a signal4 ,if ! resi/ance & ! capacity ( ! receiv] is tak5 z con/ant1 ?is m9imum work+ en]gy is proportional to ! squ>e ( ! electromotive =ce set up 9 ! receiv+ a]ial by ! impact on x ( ! electric waves4 ,?is electromotive =ce v>ies z ! l5g? ( ! receiv+ a]ial & z ! magnetic =ce due to ! wave cutt+ across x1 & ! magnetic =ce v>ies z ! curr5t 9 ! transmitt+ a]ial1 & !re=e1 = any giv5 voltage v>ies z ! capacity1 & !re=e z ! l5g? ( ! transmitt+ a]ial4 ,if1 !re=e1 ! transmitt+ & receiv+ a]ial h ! same l5g?1 ! m9imum en]gy v>ies z ! squ>e ( ! electromotive =ce 9 ! receiv+ a]ial1 & !re=e z ! f\r? p[] ( ! l5g? ( ei!r a]ial1 s9ce ! electromotive =ce v>ies z ! product ( ! l5g?s ( ! a]ials4 ,h5ce1 :5 ! di/ance betwe5 ! a]ials is con/ant1 ! m9imum work+ en]gy v>ies z ! f\r? p[] ( ! height ( ei!r a]ial1 b :5 ! l5g?s ( ! a]ials are con/ant1 ! en]gy caught up by ! receiv+ a]ial mu/ v>y inv]sely z ! squ>e ( ! di/ance ,d betwe5 ! a]ials4 ,h5ce1 if we call e ?is m9imum work+ en]gy1 e mu/ v>y z #a_/;,d#b :5 ,l is con/ant1 or z ,l#d :5 ,d is con/ant1 & s9ce e is a con/ant quantity = any giv5 arrangem5ts ( receiv] & transmitt]1 x foll[s t :5 ! height ( a]ial & di/ance v>y1 ! ratio ,l#d_/;,d#b is con/ant1 or1 9 o!r words1 ,d#b v>ies z ,l#d or ,d v>ies z ,l#b--;i4e41 di/ance v>ies z ! squ>e ( ! height ( ! a]ial1 :i* is ,m>coni's ,law4 ,! curve1 !re=e1 connect+ height ( a]ial ) s5d+ di/ance = giv5 arrangem5ts is a portion ( a p>abola4 ,o!rwise1 ! law may be /at$ 9 ! =m ,l asq,d1 :]e a is a num]ical coeffici5t4 ,if ,l & ,d are bo? measur$ 9 metres1 !n1 = rec5t ,m>coni app>atus z us$ on %ips1 a #j4ae r\ghly4 7,see a report on exp]im5ts made = ! ,italian ,navy1 #aijj-aija1 by ,capta9 ,qu9t9o ,bonomo--,telegrafia s5za fili1 ,rome1 #aijb47 ,?is law1 h[ev]1 mu/ n be us$ )\t discretion4 ,aft] ,mr4 ,m>coni _h transmitt$ signals across ! ,briti% ,*annel1 "s p1 =gett+ t a little k is a dang]\s ?+1 pr$ict$ t a]ials a ?\s& feet 9 height w\ld be requir$ to signal across ! ,atlantic1 b ,mr4 ,m>coni has made su* improvem5ts ( late ye>s 9 ! receiv+ arrangem5ts t he has be5 able to receive signals ov] ?ree ?\s& miles 9 #aijc ) a]ials only ?irty-?ree p] c5t4 long] ?an ^? :i*1 9 #ahii1 he employ$ to cov] tw5ty miles across ! ,engli% ,*annel4 ,illu/ration3 ,,fig4 #ae4--;,,alt]nat+-,,curr5t ,,d\ble-,,trans=mation ,,p[] ,,plant ,,= ,,g5]at+ ,,electric ,,waves 7,flem+74 a1 alt]nator2 ,h#a;,h#b1 *ok+ coil2 ,k1 signall+ key2 ,t1 /ep-up trans=m]2 ,s#a,s#b sp>k-gap2 ,c#a;,c#b cond5s]s2 ,t#a,t#b1 oscillation trans=m]s2 ,a1 a]ial2 ,e1 e>?plate4 ,we turn1 9 ! next place1 to ! consid]ation ( ^? devices = putt+ m p[] into ! a]ial ?an c be a*iev$ :5 ! a]ial itself is simply employ$ z ! res]voir ( en]gy4 ,pr(essor ,braun1 ( ,/rassburg1 9 #ahii1 describ$ a me?od = do+ ?is by induc+ oscillations 9 ! a]ial by means ( an oscillation trans=m]1 ^! oscillations be+ set up by ! dis*>ges f a ,leyd5 j> or batt]y ( ,leyd5 j>s1 :i* =m$ ! res]voir ( en]gy4 ,! induction coil is employ$ to produce a rapidly int]mitt5t s]ies ( electrical oscillations 9 ! prim>y coil ( an oscillation trans=m] by ! dis*>ge ?r\gh x ( a ,leyd5 j>4 ,mr4 ,m>coni imm5sely improv$ ?is arrangem5t1 z describ$ by him 9 a lecture giv5 be=e ! ,society ( ,arts on ,may #ag1 #aija1 by syntonis+ ! two circuits & mak+ ! circuit1 consi/+ ( ! capacity ( ! a]ial & ! inductance ( ! second>y circuit ( ! oscillation trans=m]1 h ! same "t-p]iod z ! circuit consi/+ ( ! ,leyd5 j>s1 or en]gy-/or+ cond5s]1 & ! prim>y circuit ( ! oscillation trans=m]1 & by s do+ imm5sely add$ to ! p[] & range ( ! app>atus4 ,/>t+ f ^! inv5tions ( ,braun & ,m>coni1 ! au?or devis$ a d\ble transmission sy/em 9 :i* ! oscillations are twice trans=m$ be=e be+ g5]at$ 9 ! a]ial1 ea* "t ) a multiplication ( electromotive =ce & a multiplication ( ! numb] ( gr\ps ( oscillations p] second4 ,?is arrangem5t c be/ be und]/ood f ! diagram 7see ,fig4 #ae74 ,9 ?is case a trans=m]1 ,t1 or trans=m]s receive alt]nat+ l[-frequ5cy curr5t f an alt]nator1 a1 be+ regulat$ by pass+ ?r\gh two v>iable *ok+ coils1 ,h#a & ,h#b1 s z to control x4 ,?is alt]nat+ curr5t is trans=m$ up f a pot5tial ( two ?\s& to tw5ty1 =ty or a hundr$ ?\s&1 & is employ$ to *>ge a l>ge cond5s]1 ,c#a1 :i* dis*>ges across a prim>y sp>k-gap1 ,s#a1 ?r\gh ! prim>y coil ( an oscillation trans=m]1 ,t#a4 ,! second>y circuit ( ! oscillation trans=m] is connect$ to a second pair ( sp>k balls1 ,s#b1 :i* 9 turn are connect$ by a second>y cond5s]1 ,c#b1 & ! prim>y circuit ( a ?ird trans=m]1 ,t#b & ! second>y circuit ( ?is la/ trans=m] are ins]t$ betwe5 a ,m>coni a]ial1 ,a1 & ! e>? ,e4 ,:5 all ^! circuits are tun$ to resonance by ,mr4 ,m>coni's me?ods1 we h an enorm\sly p[]ful arrangem5t = creat+ electric waves1 or r tra9s ( electric waves1 s5t out f ! a]ial1 & ! oscillations are controll$ & ! signals made by %ort-circuit+ "o ( ! *ok+ coils4 ,ano!r transmitt+ arrangem5t1 :i* involves a slightly diff]5t pr9ciple1 & employs no oscillation trans=m]1 is "o due also to ,pr(essor ,braun4 ,9 ?is case1 a cond5s] & inductance are connect$ 9 s]ies to ! sp>k balls ( an induction coil1 & oscillations are set up 9 ?is circuit4 ,accord+ly1 !re are rapid fluctuations ( pot5tial at "o t]m9al ( ! cond5s]4 ,if to ?is we connect a long a]ial1 ! l5g? ( :i* has be5 adju/$ to be "o qu>t] ( ! l5g? ( wave correspond+ to ! frequ5cy1 9 o!r words1 to make x a qu>t]-wave resonator1 !n p[]ful oscillations w be accumulat$ 9 ?is rod4 ,! relation betwe5 ! height 7,h7 ( ! a]ial & ! frequ5cy is giv5 by ! equation #c x #ajaj #dn,h1 :]e n is ! frequ5cy ( ! oscillations & ,h ! height ( ! a]ial 9 c5timetres4 ,! frequ5cy ( ! oscillations is det]m9$ by ! capacity 7,c7 & inductance 7,l7 ( ! cond5s] circuit1 & c be calculat$ f ! =mula n 7#e1jjj1jjj7 _/ 7sq,c 79 mfds47 x ,l 79 cms4774 ,t is1 ! frequ5cy is obta9$ by divid+ into ! numb] #e1jjj1jjj1 ! squ>e root ( ! product ( ! capacity 9 micr(>ads1 & inductance 9 c5timetres1 ( ! cond5s] circuit4 ,x w be f\nd1 on apply+ ^! rules1 t x is impossible to unite toge!r any a]ial ( a l5g? obta9able 9 practice ) a cond5s] circuit ( m ?an a v mod]ate capacity4 ,x has be5 %[n t = an a]ial two hundr$ feet 9 height ! correspond+ resonat+ frequ5cy is ab\t "o & a qu>t] million4#bb ,z we are limit$ 9 ! am\nt to :i* we c r$uce ! inductance ( a dis*>ge circuit1 probably to some?+ l a ?\s& c5timetres1 a simple calculation %[s t ! l>ge/ capacity we c employ is ab\t a sixtie? ( a micr(>ad4 ,?is capacity1 ev5 if *>g$ at #fj1jjj volts1 w\ld only conta9 ?irty j\les ( en]gy1 or ab\t #bb4e foot-p\nds1 :i* is a small /orage comp>$ to t :i* c be a*iev$ :5 we are employ+ ! above-describ$ me?ods1 :i* involve ! use ( an oscillation trans=m]4 ,9 su* a case1 h[ev]1 x is an advantage to employ a sp>k-gap 9 compress$ air1 because we c !n raise ! voltage to a mu* high] value ?an 9 air ( ord9>y pressure )\t l5g!n+ ! sp>k s mu* z to r5d] x non-oscillatory4 ,:5 employ+ me?ods involv+ ! use ( an oscillation trans=m]1 x is possible to use multiple a]ials hav+ l>ge capacity1 & h5ce to /ore up a v l>ge am\nt ( en]gy 9 ! a]ial1 :i* is lib]at$ at ea* dis*>ge4 ,! mo/ effective arrangem5t is "o 9 :i* ! radiator draws (f gradually a l>ge supply ( en]gy f a non-radiat+ circuit1 & s s5ds out a true tra9 ( waves1 & n m]e impulses1 into ! e!r1 & z we %all see lat] on1 x is only :5 ! radiation takes place 9 ! =m ( true wave tra9s t any?+ l syntony c be obta9$4 ,!re are a numb] ( v>iants ( ! above me?ods ( arrang+ ! radiator & associat$ en]gy-/or+ 9 circuit4 ,descriptions ( ^! arrangem5ts w be f\nd 9 pat5ts by ,mr4 ,m>coni1 ,pr(essor ,slaby & ,c\nt von ,arco1 ,sir ,oliv] ,lodge1 ,dr4 ,muirhead1 ,pr(essor ,pop(f1 ,pr(essor ,fess5d5 & o!rs4 ,9 all cases1 h[ev]1 !y are v>iations ( ! ?ree simple =ms ( radiator already describ$4 ,return+ to ! analogy ) ! air or /eam sir5 sugge/$ at ! comm5cem5t ( ?is article1 ! read] w see 9 ! light ( ! explanations already giv51 t all p>ts ( ! air-wave produc+ app>atus h _! analogues 9 ! electrical radiator z us$ 9 ,h]tzian wave telegraphy4 ,! object 9 ! "o case is to produce rapid oscillations ( air p>ticles 9 a tube1 :i* result 9 ! production ( an air wave 9 ext]nal space2 9 ! o!r case1 ! arrangem5t s]ves to produce oscillations ( electrons or electrical p>ticles 9 a wire1 ! movem5ts ( :i* create a di/urbance 9 ! e!r call$ an electrical wave4 ,comp>+ toge!r1 item by item1 x w be se51 !re=e1 t ! induction coil or trans=m] us$ 9 connection ) electric-wave app>atus is analog\s to ! air pump 9 ! sir5 plant4 ,9 ! electrical app>atus1 ?is electron pump is employ$ to put an electrical *>ge into a cond5s]2 9 ! air wave app>atus1 ! air pump is employ$ to *>ge an air vessel ) high pressure air4 ,f ! electrical cond5s] ! *>ge is releas$ 9 ! =m ( a s]ies ( electrical oscillations1 & 9 ! air wave produc+ appliance1 ! compress$ air is releas$ 9 ! =m ( a s]ies ( int]mitt5t puffs or bla/s4 ,9 ! electrical wave produc+ app>atus1 ^! electrical oscillations 9 ! cond5s] circuit are f9ally made to produce o!r oscillations 9 an air wire or op5 circuit1 j z ! puffs ( air f9ally exp5d !mselves 9 produc+ a]ial oscillations 9 ! sir5 tube4 ,f9ally1 9 ! "o case we h a s]ies ( air waves & 9 ! o!r case1 a s]ies ( electrical waves4 ,^! tra9s ( electric waves or air waves1 z ! case may be1 are int]mitt$ into long & %ort gr\ps1 9 accordance ) ! signals ( ! ,morse alphabet1 &1 !re=e1 ! ,h]tzian wave transmitt]1 9 :atev] =m x may be employ$1 :5 op]at$ by means ( a ,m>coni a]ial1 is 9 fact an electrical sir5 app>atus1 ! function ( :i* is to create p]iodic di/urbances 9 ! univ]sal e!r ( ! same "* z ^? :i* ! sir5 produces 9 atmosph]ic air4 99 99 99 99 99 ,we h to consid] 9 ! next place ! arrangem5ts ( ! receiv+ /ation & ! v>i\s =ms ( receiv]s t h be5 devis$ = effect+ telegraphy by ,h]tzian waves4 ,j z ! transmitt+ /ation consi/s ess5tially ( two p>ts1 viz41 a "p = creat+ electrical oscillations & a "p = ?r[+ out or radiat+ electric waves1 s ! receiv+-/ation appliances may be divid$ into two portions2 ! function ( "o be+ to cat* up a portion ( ! en]gy ( ! pass+ wave1 & t ( ! o!r to make a record or intelligible signal 9 "s mann] 9 ! =m ( an audible or visible sign4 ,accord+ly1 !re mu/ be at ! receiv+ /ation an arrangem5t call$ a receiv+ a]ial1 :i* 9 g5]al takes ! =m ( a long v]tical wire or wires1 simil> 9 =m to ! transmitt+ a]ial1 ,!re is1 h[ev]1 a di/9ct diff]5ce 9 ! function ( ! transmitt+ a]ial & ! receiv+ a]ial4 ,! function ( ! fir/ is effective radiation1 & = ?is purpose ! a]ial mu/ h associat$ ) x a /ore ( en]gy to be releas$ z wave en]gy2 b ! function ( ! receiv+ a]ial is to be ! seat ( an electromotive =ce :i* is creat$ by ! electric =ce & ! magnetic =ce ( ! incid5t electric wave4 ,9 trac+ out ! mode ( op]ation ( ! transmitt+ a]ial1 x 0 po9t$ out t ! electric waves emitt$ consi/$ ( alt]nations ( electric =ce 9 a direction :i* is p]p5dicul> to ! surface ( ! e>?1 & magnetic =ce p>allel to ! surface ( ! e>?4 ,^! two quantities1 ! electric =ce & ! magnetic =ce1 are call$ ! wave vectors1 & !y bo? lie 9 a plane p]p5dicul> to ! direction 9 :i* ! wave is travell+ & at "r angles to "o ano!r1 ! electric =ce be+ p]p5dicul> to ! surface ( ! e>?4 ,9 optical language1 ! wave s5t out by ! a]ial w\ld be call$ a plane pol>is$ wave1 ! plane ( pol>isation be+ p>allel to ! magnetic =ce4 ,h5ce1 if at any po9t 9 ! pa? ( ! wave we erect a v]tical conductor1 z ! wave passes ov] x1 x is cut transv]sely by ! magnetic =ce ( ! wave & longitud9ally by ! electric =ce4 ,bo? ( ^! op]ations result 9 ! creation ( an alt]nat+ electromotive =ce 9 ! receiv+ a]ial wire4 ,z 9 all o!r cases ( oscillatory motion1 ! pr9ciple ( resonance may "h be br\ght into play to increase imm5sely ! amplitude ( ! curr5t oscillations !reby set up 9 ! receiv+ a]ial4 ,z already expla9$1 any v]tical insulat$ wire plac$ ) its l[] end ne> ! e>? has capacity ) respect to ! e>?1 & x has also inductance1 ! value ( ^! factors dep5d+ on its %ape & height4 ,accord+ly1 x has a natural electrical "t-p]iod ( its own1 & if ! p]iodic electromotive impulses :i* are set up 9 x by ! passage ( ! waves ov] x agree 9 p]iod ) its own natural "t-p]iod1 !n ! amplitude ( ! curr5t vibrations 9 x may become enorm\sly great] ?an :5 !re is a disagreem5t betwe5 ^! two p]iods4 ,be=e conclud+ ^! articles we %all return to ?is subject ( electric resonance & syntony1 & discuss x ) ref]5ce to :at is call$ ! tun+ ( ,h]tzian wave /ations4 ,mean:ile1 x may be said t = ! sake ( obta9+1 at any rate 9 an approximate degree1 ?is co9cid5ce ( "t-p]iod1 x is g5]ally usual to make ! receiv+ a]ial z f> z possible id5tical ) ! transmitt+ a]ial4 ,if ! receiv+ a]ial is n insulat$1 b is connect$ to ! e>? at its l[] end ?r\gh ! prim>y coil ( an oscillation trans=m]1 we c /ill set up 9 x electrical oscillations by ! impact on x ( an electric wave ( prop] p]iod2 & if ! oscillation trans=m] is prop]ly con/ruct$ we c draw f its second>y circuit electric oscillations 9 a simil> p]iod4 ,"o problem 9 connection ) ! design ( a receiv+ a]ial is t ( increas+ its effective l5g? & capacity s z to increase correspond+ly ! electromotive =ce or curr5t oscillations 9 x4 ,x is cle> t if we put a numb] ( receiv+ wires 9 p>allel s t ea* "o ( !m is op]at$ ^u by ! wave sep>ately1 al?\gh we c increase 9 ?is way ! magnitude ( ! alt]nat+ curr5t :i* c be drawn (f f ! a]ial1 we _c increase ! electromotive =ce 9 x except by increas+ ! actual height ( ! wires4 ,un=tunately1 !re is a limit to ! height ( ! receiv+ a]ial4 ,x has to be susp5d$1 l ! transmitt+ a]ial1 f a ma/ or t[]1 & ! eng9e]+ problem ( con/ruct+ su* a p]man5t support+ /ructure high] ?an1 say1 two hundr$ feet is a difficult "o4 ,s9ce any "o /ation has to s5d z well z receive1 x is usual to make "o & ! same a]ial wire or wires d d\ble duty4 ,x is swit*$ ov] f ! transmitt+ to ! receiv+ app>atus1 z requir$4 ,?is1 h[ev]1 is a concession to conv5i5ce & co/4 ,9 "s respects x w\ld be bett] to h two sep>ate a]ials at ea* /ation1 ! "o ( ! be/ =m = s5d+1 & ! o!r ( ! be/ =m = receiv+4 ,9 ,mr4 ,m>coni's e>ly arrangem5ts1 ! s-call$ coh]] or s5sitive wave-detect+ appliance1 to be describ$ m 9 detail pres5tly1 0 ins]t$ betwe5 ! base ( ! insulat$ receiv+ a]ial & ! e>?1 b x 0 subsequ5tly f\nd by him to be a great improvem5t to act ^u ! receiv+ device1 n directly by ! electromotive =ce set up 9 ! a]ial1 b by ! induc$ electromotive =ce ( a special =m ( /ep-up oscillation trans=m] he calls a jigg]1 ! prim>y circuit ( :i* 0 ins]t$ 9 betwe5 ! receiv+ a]ial & ! e>? plate1 & ! second>y circuit 0 connect$ to ! s5sitive organ ( ! telegraphic receiv+ arrangem5ts4#bc ,a sugge/ion to employ trans=m$ oscillations 9 affect+ a coh]]1 _h also be5 describ$ 9 a pat5t specification by ,sir ,oliv] ,lodge1 9 #ahig1 b ! ess5ce ( success 9 ! use ( ?is device is n m]ely ! employm5t ( a trans=m]1 b ( a trans=m] con/ruct$ specially to trans=m electrical oscillations4 ,turn+1 !n1 to ! consid]ation ( ! relation exi/+ betwe5 ! transmitt+ & receiv+ a]ials1 we note t 9 _! simple/ =m ^! consi/ ( two simil> tall rods ( metal plac$ upright1 ) _! feet 9 good connection ) ! e>? at two places4 ,we may ?9k ( !m z two id5tical lightn+ conductors1 well e>!d at ! bottom1 & support$ by non-conduct+ ma/s or t[]s4 ,^! rods mu/ be 9 good connection ) ! e>?1 & !re=e ) x =m1 z x 71 "o conductor4 ,if1 z usual1 ^! a]ials are sep>at$ by ! sea1 ! int]m$iate portion ( ?is circuit is an electrolyte4 ,! op]ations :i* take place :5 a signal is s5t are z foll[s3-- ,at ! transmitt+ /ation1 we set up 9 ! transmitt+ a]ial electric oscillations1 ( :i* ! frequ5cy may be ( ! ord] ( a million1 i4e41 ! oscillations z long z !y la/ are at ! rate ( a million a second4 ,ea* sp>k dis*>ge at ! transmitt] results1 h[ev]1 only 9 ! production ( a tra9 ( a doz5 or two oscillations1 & ^! tra9s succe$ ea* o!r at a rate dep5d+ ^u ! transmitt+ arrangem5ts us$4 ,ea* oscillation 9 ! transmitt+ a]ial is accompani$ by ! deta*m5t f x ( semi-loops ( electric /ra91 z already expla9$4 ,! alt]ations ( electric /ra9 direct$ p]p5dicul>ly to ! e>?1 & ( ! associat$ magnetic =ce p>allel to ! e>?1 con/itute an electric wave 9 ! e!r1 j z ! alt]nations ( pressure & motion ( air molecules con/itute an air wave4 ,associat$ ) ^! physical actions above gr\nd1 !re is a propagation ?r\gh ! e>? ( electric action1 :i* may consi/ 9 a motion or atomic ex*ange ( electrons4 ,ea* *ange or movem5t ( a semi-loop ( electric /ra9 above gr\nd has its equival5t bel[ gr\nd 9 int]-atomic ex*anges or movem5ts ( ! electrons1 on :i* ! ends ( ^! semi-loops ( electric /ra9 t]m9ate4 ,! e>? mu/ play1 !re=e1 a v important "p 9 s-call$ wireless telegraphy1 & we might also say ! e>? does z mu* z ! e!r 9 its production4 ,! function ( ! receiv+ a]ial is to br+ ab\t a union betwe5 ^! two op]ations above & bel[ gr\nd4 ,:5 ! electric waves fall ^u x1 !y give rise to electromotive =ce 9 ! receiv+ a]ial1 &1 !re=e1 produce oscillations 9 x :i*1 9 fact1 are electric curr5ts fl[+ into & out ( ! receiv+ a]ial4 ,we may say t ! transmitt+ a]ial1 ! receiv+ a]ial & ! e>? =m "o gigantic ,h]tz oscillator4 ,9 "o "p ( ?is sy/em1 electric oscillations ( a c]ta9 p]iod are set up by ! dis*>ge ( a cond5s] & are propagat$ to ! o!r "p4 ,9 ! e>?1 !re is a propagation ( electric oscillations2 9 ! space above & betwe5 ! a]ials1 !re is a propagation ( electric waves4 ,! receiv+ a]ial feels1 !re=e1 :at is happ5+ at ! di/ant a]ial & c be made to record x4#bd ,we h next to consid] ! "q ( ! wave-detect+ devices :i* enable u to appreciate & record ! impact ( a wave or wave tra9 aga9/ ! a]ial4 ,at ! v outset x w be necess>y to co9 a new ^w to apply g5]ally to ^! appliances4 ,mo/ read]s are probably famili> ) ! t]m coh]]1 :i* 0 appli$ by ,sir ,oliv] ,lodge1 9 ! fir/ in/ance1 to an electric wave-detect+ device ( "o p>ticul> k9d--viz41 t 9 :i* a metal po9t 0 lightly press$ aga9/ ano!r metal surface & caus$ to /ick to x :5 an electric wave fell ^u x4 ,z our k increas$1 x 0 f\nd t !re 7 _m cases 9 :i* ! effect ( ! electric radiation 0 to cause a sev]ance & n a coh]5ce1 & h5ce su* clumsy phrases z anticoh]] & self-decoh]+ coh]] h come into use4 ,moreov]1 we h n[ _m k9ds ( electric wave detectors bas$ on q diff]5t physical pr9ciples4 ,at ! risk ( incurr+ reprobation = add+ to sci5tific nom5clature1 ! au?or v5tures to ?9k t ! "t has arriv$ :5 a simple & inclusive t]m w be f\nd useful to describe all ! devices1 :atev] _! nature1 :i* are employ$ = detect+ ! pres5ce ( an electric wave4 ,= ?is purpose ! t]m kumascope1 f ! ,greek ,greek3 kuma 7a wave71 is sugge/$4 ,! sci5tific /udy ( waves has already be5 call$ kumatology1 & 9 view ( our famili>ity ) su* t]ms z microscope1 electroscope & hygroscope1 !re does n seem to be any objection to enl>g+ our vocabul>y by call+ a wave-detect+ appliance a kumascope4 ,we are !n able to look at ! subject broadly & to classify kumascopes ( diff]5t k9ds4 ,we may1 9 ! fir/ place1 arrange !m accord+ to ! pr9ciple on :i* !y act4 ,?us1 we may h electric1 magnetic1 !rmal1 *emical & physiological op]ations involv$2 & f9ally1 we may divide !m into ^? :i* are self-re/or+1 9 ! s5se t aft] ! passage or action ( a wave ^u !m !y return to _! orig9al s5sitive condition2 & ^? :i* are non-re/or+1 9 t !y mu/ be subject$ to "s treatm5t to br+ !m back aga9 to a condition 9 :i* !y are fit to respond aga9 to ! action ( a wave4 ,we h no space to ref] to ! :ole ( ! /eps ( discov]y :i* l$ up to ! inv5tion ( all ! v>i\s =ms ( ! mod]n electric kumascope or wave detector4 ,suffice x to say t ! rese>*es ( ,h]tz 9 #ahhg ?rew a flood ( light ^u _m previ\sly obscure ph5om5a1 & enabl$ u to see t an electric sp>k1 & especially an oscillatory sp>k1 creates a di/urbance 9 ! e!r1 :i* has a resemblance 9 ,nature to ! exp&+ ripples produc$ by a /one hurl$ into wat]4 ,sci5tific inve/igation !n return$ ) fre% int]e/ to previ\sly incompreh5sible effects1 & a new mean+ 0 read into _m old obs]vations4 ,aga9 & aga9 x _h be5 notic$ t loose metallic contacts1 loose aggregations ( metallic fil+s or fragm5ts1 _h a my/]i\s way ( alt]+ _! conductivity "u ! action ( electric sp>ks1 lightn+ dis*>ges & high electromotive =ces4 ,z f> back z #aheb1 ,mr4 ,v>ley _h notic$ t masses ( p[d]$ metals _h a v small conductivity1 :i* increas$ 9 a rem>kable way dur+ ?und]/orms2#be & 9 #ahff1 ,c4 & ,s4 ,a4 ,v>ley pat5t$ a device = protect+ telegraphic in/rum5ts f lightn+1 :i* consi/$ ( a small box ( p[d]$ c>bon 9 :i* 7 buri$ two ne>ly t\*+ metal po9ts1 & !y /at$ t p[d]$ conduct+ matt] (f]s a great resi/ance to a curr5t ( mod]ate t5sion1 b (f]s b little resi/ance to curr5ts ( high t5sion4#bf ,we !n pass ov] a long int]val & f9d t ! next publi%$ acc\nt ( simil> obs]vations 0 due to ,pr(essor ,t4 ,calzec*i-,one/i1 :o describ$ 9 an ,italian j\rnal1 ,il ,nuovo ,cim5to 7see ,vol4 ,,xvi41 p4 #eh1 & ,vol4 ,,xvii41 p4 #ch71 9 #ahhd & #ahhe 8 obs]vations on ! decrease 9 resi/ance ( metal p[d]s :5 ! sp>k f an induction coil 0 s5t ?r\gh !m4#bg ,^! obs]vations did n attract mu* att5tion until ,pr(essor ,e4 ,branly1 ( ,p>is1 9 #ahij & #ahia1 repeat$ !m on an ext5d$ scale & ) great v>iations1 mak+ ! important obs]vation t an electric sp>k at a di/ance _h a simil> effect 9 increas+ ! conductivity ( metallic p[d]s4#bh ,branly1 h[ev]1 notic$ t 9 "s cases ( conductors 9 p[d]1 su* z ! p]oxide ( lead or antimony1 ! effect ( ! sp>k 0 to cause a decrease ( conductivity4 ,to ,pr(essor ,e4 ,branly unque/ionably belongs ! hon\r ( giv+ to sci5ce a new weapon 9 ! %ape ( a tube conta9+ metallic fil+s or p[d] r loosely pack$ betwe5 metal plugs1 & ( %[+ t :5 ! pressure on ! p[d] 0 adju/$ su* a tube may be a conductor ( v high resi/ance1 b t ! electrical conductivity is enorm\sly increas$ if an electric sp>k is made 9 its neighb\rhood4 ,he also prov$ t ! same effect occurr$ 9 ! case ( two slightly oxidis$ /eel or copp] wires laid across "o ano!r ) light pressure1 & t ?is loose or imp]fect contact 0 extraord9>ily s5sitive to an electric sp>k1 dropp+ 9 resi/ance f ?\s&s ( ohms to a few ohms :5 a sp>k 0 made _m y>ds away4 ,x is curi\s to notice h[ long "s important rese>*es take to become g5]ally kn[n4 ,branly's "w did n attract mu* att5tion 9 ,engl& until #ahib1 :5 ,dr4 ,dawson ,turn] describ$ 8 own repetition ( ,branly's exp]im5ts ) ! metallic fil+s tube at a meet+ ( ! ,briti% ,association 9 ,ed9burgh4 ,9 ! discussion :i* foll[$1 ,pr(essor ,george ,=bes made an important rem>k4 ,he ask$ :e!r x 0 possible t ! decrease 9 resi/ance c\ld be br\ght ab\t by ,h]tz waves4#bi ,?is "q %[s t ev5 9 #ahib ! idea t ! effect ( ! sp>k on ! ,branly tube 0 really due to ,h]tzian waves 0 only j beg9n+ to arise4 ,! foll[+ ye>1 h[ev]1 ,mr4 ,w4 ,b4 ,cr(t repeat$ ,branly's exp]im5t ) copp] fil+s be=e ! ,physical ,society ( ,london1 & entitl$ 8 %ort ,pap] ,electric ,radiation on ,copp] ,fil+s4#cj ,he exhibit$ a tube conta9+ copp] fil+s loosely held betwe5 two copp] plugs & jo9$ 9 s]ies ) a galvanomet] & cell4 ,! effect ( an electric sp>k at a di/ance1 9 caus+ increase ( conductivity1 0 %[n1 & ! return ( ! tube to its non-conduct+ /ate :5 tapp$ 0 also notic$4 ,9 ! discussion :i* foll[$ ! read+ ( ?is ,pap]1 ,pr(essor ,m9*9 describ$ ! effects ( electric radiation on 8 impulsion cells4 ,he foll[$ up ?is by read+ a ,pap] to ! ,physical ,society on ,novemb] #bd1 #ahic1 on ! action ( ,h]tzian radiation on films conta9+ metallic p[d]s1 & express$ ! op9ion t ! *ange 9 resi/ance ( ! ,branly tube 0 due to electric radiation4#ca ,?us1 at ! end ( #ahic1 a few physici/s cle>ly recognis$ t a new means _h be5 giv5 to u = detect+ ^? invisible e!r waves1 ! *ief prop]ties ( :i* ,h]tz _h unravell$ ) surpass+ skill six ye>s be=e1 by means ( a detector consi/+ ( a r+ ( wire hav+ a small sp>k-gap 9 x4 ,9 ,june1 #ahid1 ,sir ,oliv] ,lodge deliv]$ a disc\rse at ! ,royal ,in/itution1 entitl$ ,! ,"w ( ,h]tz1 & at ?is lecture use 0 made ( ! ,branly tube z a ,h]tz wave detector4 ,! *ief object ( ! lecture 0 to describe ! prop]ties ( ,h]tzian waves & _! reflection1 absorption & transmission1 & _m brilliant quasi-optical exp]im5ts 7 exhibit$4 ,al?\gh a ,branly tube1 or imp]fect metallic contact1 !n nam$ by him a coh]]1 0 employ$ by ,sir ,oliv] ,lodge to detect an electric wave g5]at$ 9 ano!r room1 !re 0 no m5tion 9 ?is lecture ( any use ( ! in/rum5t = telegraphic purposes4#cb ,z we are "h conc]n$ only ) ! applications 9 telegraphy1 we %all n sp5d any m "t discuss+ ! purely sci5tific "w done ) laboratory =ms ( ?is wave detector4 ,)\t attempt+ to t\* ! v delicate "q z to ! precise po9t at :i* laboratory rese>* pass$ into te*nical application1 we %all briefly describe ! =ms ( kumascope :i* h be5 devis$ ) special ref]5ce to ,h]tzian wave telegraphic "w4 ,a v exact classification is at pres5t impossible1 b we may say t telegraphic kumascopes may be r\ghly divid$ into six classes4 ,! fir/ class includes all ^? t dep5d = _! action on ! coh]] pr9ciple or ! r$uction ( ! resi/ance ( a metallic microphone by ! action ( electromotive =ce4 ,z !y dep5d ^u an imp]fect contact1 !y may be call$ contact kumascopes4 ,?is class is fur!rmore subdivid$ into ! self-re/or+ & ! non-self-re/or+ v>ieties4 ,! second class comprises ! magnetic kumascopes :i* dep5d ^u ! action ( an electrical oscillation z a magnetis+ or demagnetis+ ag5cy4 ,! ?ird class comprises ! electrolytic respond]s1 9 :i* ! action ( electric oscillations ei!r promotes or de/roys ! results ( electrolysis4 ,! f\r? class consi/s ( ! electro!rmal detectors1 9 :i* ! p[] ( an electrical oscillation z a high frequ5cy electric curr5t to heat a conductor is utilis$4 ,! fif? class comprises ! electromagnetic or electro-dynamic in/rum5ts1 :i* are virtually v s5sitive alt]nat+-curr5t ammet]s1 adapt$ = imm5sely high frequ5cy4 ,! six? class mu/ be made to conta9 all ^? :i* _c be well fitt$ at pres5t into any ( ! o!rs1 su* z ! s5sitive respond] ( ,s*aef]1 ! action ( :i* is n v cle>ly made out4 ,we may proce$ briefly to describe ! con/ruction ( ! pr9cipal =ms ( kumascope com+ "u ! above head+s4 ,9 ! fir/ place1 let u consid] ^? :i* are commonly call$ ! coh]]s or1 z ! writ] pref]s to call !m1 ! contact kumascopes4 ,! simple/ ( ^! is ! cross$ ne$le or s+le contact1 :i* orig9at$ ) ,pr(essor ,e4 ,branly4#cc ,! pressure ( ! po9t ( a /eel ne$le aga9/ an alum9ium plate 0 subsequ5tly f\nd by ,sir ,oliv] ,lodge to be a v s5sitive arrangem5t :5 s adju/$ t a s+le cell s5ds little or no curr5t ?r\gh ! contact4#cd ,:5 an electric wave passes ov] x1 good conduct+ contact ensues4 ,! po9t is1 9 fact1 weld$ to ! plate1 & c only be deta*$ by giv+ ! plate or ne$le a light %ock or vibration4 ,a v>iation ( ! above =m is a pair ( cross$ ne$les1 "o re/+ on ! o!r4 ,pr(essor ,branly f\nd1 9 #ahia1 t if a pair ( slightly-oxidis$ copp] wires re/ across "o ano!r ! contact-resi/ance may fall f #h1jjj to #g ohms by ! impact ( an electric wave4 ,he has rec5tly devis$ a tripod arrangem5t1 9 :i* a light metal /ool ) ?ree slightly-oxidis$ legs /&s on a poli%$ plate ( /eel4 ,! contact po9ts mu/ be oxidis$1 b n too heavily1 & ! /ool makes a bad electrical contact until a wave falls ^u x4#ce ,! decoh]5ce is effect$ by giv+ ! /ool a tilt by means ( an electromagnet4 ,^! s+le or multiple-po9t kumascopes lab\r "u ! disadvantage t only a v small curr5t c be pass$ ?r\gh ! v>iable contact :5 us$ z a relay arrangem5t1 )\t weld+ !m toge!r s mu* t a consid]able me*anical %ock is requir$ to break ! contact & reset ! trap4 ,! logical developm5t ( ! s+le contact is1 !re=e1 ! inf9ite numb] ( contacts exi/+ 9 ! tube ( metallic fil+s1 :i* has be5 ! =m ( kumascope mo/ us$ = _m ye>s4 ,9 its typical =m x consi/s ( a tube ( insulat+ mat]ial ) metallic plugs at ea* end1 & betwe5 !m a mass ( metallic p[d]1 fil+s1 bor+s1 granules or small sph]es1 lightly t\*+ "o ano!r4 ,imp]fect contact mu/ be arrang$ by light pressure1 & 9 ! majority ( cases ! resi/ance is v l>ge until an electric wave falls ^u ! tube1 :5 x drops sudd5ly to a small value & rema9s !re until ! tube is giv5 a slight %ake or ! granules di/urb$ 9 any way1 :5 ! resi/ance sudd5ly rises aga94 ,?is type ( respond] is a non-re/or+ kumascope1 & requires ! cont9ual op]ation ( "s ext]nal ag5cy to keep x 9 a condition 9 :i* x is receptive or s5sitive to electric waves4 ,mu* discussion & consid]able rese>* h tak5 place 9 connection ) ! action & improvem5t ( ^! metallic p[d] kumascopes4 ,z reg>ds mat]ials1 ! magnetic metals1 nickel1 iron & cobalt1 9 ! ord] nam$1 appe> to give ! be/ results4 ,! noble metals1 gold1 silv] & plat9um1 are too s5sitive1 & ! v oxidisable metals too ins5sitive1 = telegraphic "w1 b an admixture may be advantage\sly made4 ,omitt+ ! int]m$iate developm5ts ( inv5tion1 x may be said t ,mr4 ,m>coni 0 ! fir/ to recognise t to secure great s5sibility 9 an electric wave detector ( ?is type ! foll[+ conditions mu/ be fulfill$3 ,an exce$+ly small mass ( metallic fil+s mu/ be plac$ 9 a v n>r[ gap betwe5 two plugs1 ! :ole be+ conta9$ 9 a vessel :i* is :olly or p>tly exhau/$ ( its air4 ,mr4 ,m>coni devot$ himself ) great success to ! developm5t ( ?is in/rum5t1 & 9 a v %ort "t succe$$ 9 trans=m+ x f an unc]ta9 laboratory appliance1 capable ( yield+ results only 9 v skill$ h&s1 into an in/rum5t c]ta9 & simple 9 its op]ations z an ord9>y telegraphic relay4 ,he did ?is1 p>tly by r$uc+ its size1 & p>tly by a mo/ judici\s selection ( mat]ials = its con/ruction4 ,z made at pres5t1 ! ,m>coni metallic fil+s tube consi/s ( a small glass tube1 ! int]ior diamet] ( :i* is n mu* m ?an "o-eigh? ( an in*1 :i* has 9 x two silv] plugs :i* are bevell$ (f obliquely4 ,^! are plac$ opposite to ea* o!r1 s z to =m a w$ge-%ap$ gap1 ab\t a millimetre 9 wid? at ! bottom & two1 or at mo/ ?ree1 millimetres 9 wid? at ! top 7see ,fig4 #af74 ,! silv] plugs exactly fill ! ap]ture ( ! tube1 & are connect$ to plat9um wires seal$ ?r\gh ! glass4 ,! tube has a lat]al glass tube fus$ into x1 by :i* ! exhau/ion is made1 :i* is aft]w>ds seal$ (f1 & ?is tube projects on ! side ( ! wid] portion ( ! gap betwe5 ! silv] plugs4 ,! s5sitive mat]ial consi/s ( a mixture ( metallic fil+s1 five p] c5t4 silv] & n9ety-five p] c5t4 nickel1 be+ c>efully mix$ & sift$ to a c]ta9 /&>d f95ess4 ,9 ! manufacture ( ^! tubes1 great c>e is tak5 to make !m z f> z possible absolutely id5tical4 ,ea* tube :5 f9i%$ is exhau/$1 b n to a v high vacuum4 ,! tube s f9i%$ is atta*$ to a bone hold]1 by :i* x c be held 9 a horizontal position4 ,! object ( bevell+ (f ! plugs 9 ! ,m>coni tube is to enable ! s5sitiv5ess ( ! tube to be v>i$ by turn+ x r\nd1 s t ! small quantity ( fil+s lie 9 betwe5 a wid] or n>r[] "p ( ! gap4#cf ,illu/ration3 ,,fig4 #af4--,,m>coni ,,s5sitive ,,tube ,,or ,,metallic ,,fil+s ,,kumascope4 ,,pp1 silv] plugs2 ,,tt1 plat9um wires2 ,f1 nickel & silv] fil+s4 ,o!r ways ( adju/+ ! quantity ( ! fil+s to ! wid? ( ! gap h be5 devis$4 ,sometimes "o ( ! plugs is made movable4 ,9 o!r cases1 su* z ! tubes devis$ by ,m4 ,blondel & ,sir ,oliv] ,lodge1 !re is a pocket 9 ! glass receptacle to hold squ>e fil+s1 f :i* m or less c be %ak5 into ! gap4 ,an int]e/+ "q1 :i* we h n "t to discuss 9 full1 is ! cause ( ! initial coh]5ce ( ! metallic fil+s 9 a ,branly tube4 ,x does n seem to be a simple weld+ action due to heat1 & x c]ta9ly takes place ) a diff]5ce ( pot5tial1 :i* is v f> inde$ bel[ t :i* we "k is requir$ to produce a sp>k4 ,on ! o!r h&1 x seems to be prov$ t 9 a ,banly tube1 :5 act$ ^u by electric waves1 *a9s ( metallic p>ticles are produc$4 ,! effect is n peculi> to electric waves4 ,x c be accompli%$ by ! application ( any high electromotive =ce4 ,?us ,branly f\nd t coh]5ce may be produc$ by ! application ( an electromotive =ce ( tw5ty or ?irty volts1 op]at+ ?r\gh a v high wat] resi/ance1 & ?us preclud+ ! passage ( any b an excessively small curr5t4 ,aga91 ! coh]5ce seems to take place 9 "s cases :5 metallic p>ticles are imm]s$ 9 a liquid1 or ev5 9 a solid1 insulator4 ,processor ,branly has1 !re=e1 pref]r$ to speak ( masses ( metallic granules z radio-conductors1 & ,pr(essor ,bose has divid$ sub/ances into positive & negative1 accord+ z ! op]ation ( electromotive =ce is to increase ! coh]5ce ( ! p>ticles or to decrease x4 ,x has be5 ass]t$ t = e p>ticul> ,branly tube1 !re is a critical electromotive =ce1 9 ! neighb\rhood ( two or ?ree volts :i* causes ! tube to break d[n & pass in/antly f a non-conductive to a conductive condition1 & t ?is critical electromotive =ce may become a measure ( ! utility ( ! tube = telegraphic purposes4 ,?us1 ,c4 ,k9sley 7,physical ,review1 ,vol4 ,,xii41 p4 #agg1 #aija7 has made measurem5ts ( ?is suppos$ critical pot5tial = diff]5t coh]]s1 & subsequ5tly te/$ ! same z receiv]s at a wireless telegraph /ation ( ! ,u4,s4,a4 ,signal ,corps4 ,! av]age ( tw5ty-f\r exp]im5ts gave 9 "o case #b4b volts z ! break+ d[n pot5tial ( "o ( ^! coh]]s or ,branly tubes1 #c4h volts = a second & #e4e volts = ! ?ird4 ,^! same in/rum5ts1 te/$ z telegraphic kumascopes1 %[$ t ! fir/ ( ! ?ree 0 mo/ s5sitive4 ,on ! o!r h&1 ,w4 ,h4 ,eccles 7,electrician1 ,vol4 ,,xlvii41 pp4 #fhb & #gae1 #aija7 has made exp]im5ts ) ,m>coni nickel-silv] s5sitive tubes1 us+ a liquid pot5tiomet] made ) copp] sulphate1 to apply ! pot5tial s t inf9itesimal sp>k contacts might be avoid$ & ! *anges 9 pot5tial made )\t any abruptness4 ,he /ates t if ! coh]] tube is cont9u\sly tapp$1 say at ! rate ( fifty vibrations p] second1 :il/ at ! same "t an increas+ pot5tial is appli$ to its t]m9als & ! curr5t pass+ ?r\gh x measur$ on a galvanomet]1 !re is no abrupt *ange 9 curr5t at any po9t4 ,he f\nd t :5 ! curr5t & voltage 7 plott$ aga9/ ea* o!r1 a regul> curve 0 obta9$1 :i* aft] a "t becomes l9e>4 ,a decid$ *ange occurs 9 ! conductivity ( ! mass ( metallic fil+s :5 treat$ 9 ?is mann] at voltages l[] ?an ! critical voltage obta9$ by previ\s me?ods4 ,he asc]ta9$ t !re 0 a complete correspond5ce betwe5 ! s5sitiv5ess ( ! tubes us$ z telegraphic in/rum5ts & ! =m ( ! *>act]i/ic curve ( curr5t & voltage drawn by ! above-describ$ me?od4 ,9 ! same mann]1 ,k4 ,e4 ,gu! & ,a4 ,tr[bridge 7,physical ,review1 ,vol4 ,,ii41 p4 #bb1 #aijj7 inve/igat$ ! action ( a simple ball coh]] =m$ ( half a doz5 /eel1 lead or phosphor-bronze balls 9 slight contact4 ,!y measur$ ! curr5t i pass+ ?r\gh ! s]ies "u ! action ( a diff]5ce ( pot5tial v betwe5 ! ends1 & f\nd a relation :i* c\ld be express$ 9 ! =m v ,v7#a - eki71 :]e ,v & k are con/ants4 ,! curr5t ?r\gh ?is ball coh]] is1 !re=e1 a log>i?mic function ( ! pot5tial diff]5ce betwe5 its ends1 ( ! =m i log7v - ,v7 & exhibits no discont9uity4 ,! inf]5ce 0 drawn t ! resi/ance is due to films ( wat] adh]+ to ! metallic p>ticles ?r\gh :i* electrolytic action occurs4 ,a good metallic fil+s tube = use z a receiv] 9 ,h]tzian wave telegraphy %\ld exhibit a con/ancy ( action & %\ld coh]e & decoh]e1 to use ! common t]ms1 %>ply1 at ! smalle/ possible tap4 ,x %\ld n h a curr5t pass$ ?r\gh x by ! ext]nal cell ( m ?an a fraction ( a milliamp]e1 or else x becomes w\nd$ & uns5sitive4 ,! inve/igations :i* h already tak5 place seem to %[ pretty cle>ly t ! ag5cy caus+ ! masses ( fil+s to pass f a non-conductive to a conductive condition is electromotive =ce1 & t1 !re=e1 x is ! electromotive =ce set up 9 ! a]ial by ! incid5t waves :i* is ! effective ag5t 9 caus+ ! *ange 9 ! metallic fil+s tube1 :5 ?is is us$ z a telegraphic kumascope4 ,?is trans=mation ( ! tube f a non-conductor to a conductor is made to act z a circuit-clos]1 complet+ ! circuit1 by means ( :i* a s+le cell ( a local batt]y is made to s5d curr5t ?r\gh an ord9>y telegraph relay1 & s by ! aid ( a second batt]y op]ate a telegraphic pr9t] or record] ( any k9d4 ,h5ce x is cle> t aft] "o impact1 ! metallic fil+s tube has to be br\ght back to its non-conductive condition1 & ?is may be a*iev$ 9 sev]al ways4 7#a7 ,by ! adm9i/ration ( c>efully-regulat$ taps or %ocks or by rotat+ ! tube on its axis2 7#b7 by ! aid ( an alt]nat+ curr5t2 7#c7 9 ^? cases :]e fil+s ( magnetic metals are employ$1 by magnetism4 ,! decoh]5ce by taps 0 discov]$ by ,branly1#cg & ,pop(f1 foll[+ ! example ( ,sir ,oliv] ,lodge1 employ$ an electric bell arrangem5t = ?is purpose4#ch ,mr4 ,m>coni1 9 8 orig9al receiv+ in/rum5ts1 plac$ an electromagnet "u ! coh]] tube ) a vibrat+ armature l an electric bell4#ci ,?is armature c>ries a small hamm] or tapp]1 :i*1 :5 set 9 action1 hits ! tube on ! "u side1 & v>i\s adju/+ screws are arrang$ = regulat+ exactly ! =ce & amplitude ( ! bl[s4 ,?is tapp] is actuat$ by ! same curr5t z ! ,morse pr9t]1 or o!r telegraphic record]1 s t :5 ! signal is receiv$ & ! metallic fil+s tube passes into ! conductive condition & closes ! relay circuit1 ?is latt] 9 turn closes ! circuit ( ! ,morse pr9t] or o!r record]1 & at ! same "t1 a curr5t passes ?r\gh ! electromagnet ( ! tapp] & ! tube is tapp$ back4 ,?is sequ5ce ( op]ations requires a c]ta9 "t :i* limits ! spe$ ( receiv+4 ,! tapp] has to be s arrang$ t x is possible to receive & to record n only ! dot b a da% on ! ,morse sy/em4 ,! da% is really a s]ies ( closely adjac5t dots1 :i* run toge!r 9 virtue ( ! in]tia & inductance ( ! diff]5t p>ts ( ! :ole receiv+ app>atus4 ,! adju/m5t has s to be made t1 :il/ ! da% is be+ record$ & a cont9u\s tapp+ is kept up1 yet1 nev]!less ! cont9u$ electromotive =ce 9 ! a]ial1 due to ! cont9ually arriv+ tra9s ( waves1 is able to act aga9/ ! tapp+ & to keep ! fil+s 9 ! tube 9 ! conductive condition4 ,h5ce1 ! successful op]ation ( ! arrangem5t requires att5tion to a numb] ( adju/m5ts1 b ^! are n m difficult1 or ev5 z difficult1 z ^? involv$ 9 ! use ( _m telegraphic receiv]s employ$ 9 ord9>y telegraphy ) wires4 ,mr4 ,m>coni also introduc$ devices = prev5t+ ! sp>ks at ! contacts ( ! electromagnetic hamm] f directly affect+ ! tube1 & also to prev5t ! electric oscillations :i* are set up 9 ! a]ial f be+ p>tly %unt$ ?r\gh o!r circuits ?an t ( ! s5sitive tube4 ,we pass on to notice ! rema9+ devices = re/or+ ! metallic fil+s tube to a condition ( s5sitiv5ess or receptiv5ess4 ,a me?od = do+ ?is by alt]nat+ curr5ts is due to ,mr4 ,s4 ,g4 ,br[n4#dj ,! pole pieces ( ! coh]] tube are made ( iron1 & !y are envelop$ 9 magnetis+ coils trav]s$ by an alt]nat+ electric curr5t4 ,betwe5 ^! pole pieces is plac$ a small quantity ( nickel or iron fil+s1 & "u ! action ( ! electromotive =ce1 due to an electric wave act+ on !m1 may be made to coh]e 9 ! usual fa%ion2 b ! mom5t t ! wave ceases1 ! alt]nat+ magnetism ( ! electrodes causes ! fil+s to drop ap>t or decoh]e4 ,9 place ( ! alt]nat+ curr5t1 ,mr4 ,br[n f9ds t a revolv+ p]man5t magnet c be us$ to produce ! alt]nat+ magnetisation ( ! pole pieces ( ! s5sitive tube or coh]]4 ,! ?ird me?od ( caus+ ! decoh]5ce ( ! fil+s is t due to ,t4 ,tommas9a4 ,he f\nd t :5 a ,branly tube is made ) fil+s ( a magnetic metal1 su* z iron1 nickel & cobalt1 ! decoh]5ce ( ! fil+s c be produc$ by means ( an electromagnet plac$ 9 a suitable position "u ! tube4#da ,! explanation ( ?is fact seems to be t1 :5 an electric wave falls ^u ! tube or :5 any o!r s\rce ( electromotive =ce acts ^u x1 *a9s ( metallic p>ticles are =m$1 /ret*+ f "o electrode to ! o!r4 ,tommas9a cont5ds t he has prov$ ! exi/5ce ( ^! *a9s ( p>ticles by exp]im5ts made ) iron fil+s2 & ,r4 ,malagoli1#db 9 ref]r+ to ,tommas9a's ass]tion1 /ates t x c be witness$ 9 ! case ( brass fil+s plac$ betwe5 two plates ( metal & imm]s$ 9 vasel9e oil1 :5 a diff]5ce ( pot5tial is made betwe5 ! plates4 ,t4 ,sundorph#dc says he has confirm$ ,tommas9a's discov]y ( ! =mation ( ^! *a9s ( metallic p>ticles 9 ! coh]]4 ,! fil+s d n all cl+ toge!r1 b c]ta9 *a9s are =m$ :i* af=d a conduct+ pa? = ! curr5t subsequ5tly pass$ ?r\gh ! coh]] f an ext]nal s\rce4 ,accord+ly1 ,tommas9a's me?od ( caus+ decoh]5ce 9 ! case ( fil+s ( magnetic metals is to pull !m ap>t by an ext]nal magnetic field2 & he /at$ t decoh]5ce c be effect$ m easily & regul>ly 9 ?is way ?an by tapp+4 ,:il/ on ?is po9t1 x may be m5tion$ t ,c4 ,tissot#dd says t he has f\nd t ! s5sitiv5ess ( a coh]] =m$ ( nickel & iron fil+s c be increas$ by plac+ x 9 ! magnetic field1 ! l9es ( :i* are p>allel to ! axis ( ! tube4 ,accord+ to ,,mm4 ,a4 ,blondel & ,g4 ,dobkevit*1 ?is is m]ely ! result ( an increas$ coh]5ce ( ! p>ticles4 99 99 99 99 99 ,q rec5tly1 ,sir ,oliv] ,lodge & ,dr4 ,muirhead h employ$ z a self-re/or+ coh]] or kumascope a /eel disc revolv$ by clockwork1 ! edge ( :i* j t\*es a globule ( m]cury cov]$ ) a ?9 film ( p>aff9 oil4 ,! contact is made betwe5 ! m]cury & ! /eel by ! electric wave g5]at+ an electromotive =ce 9 ! a]ial1 suffici5t to break ?r\gh ! ?9 film ( oil4 ,:5 ! wave /ops1 ! circuit is aga9 int]rupt$ automatically4 ,?is device is us$ )\t a relay to actuate directly a syphon record] z us$ 9 subm>9e telegraphy4 ,! work+ batt]y employ$ ) x mu/ only h an electromotive =ce ( ab\t a t5? ( a volt4 ,x may be us$ also ) a telephone 9 circuit & c1 !re=e1 be employ$ ei!r = telegraphic or telephonic reception4#de ,illu/ration3 ,,fig4 #ag4--;,,italian ,,navy ,,self-,,re/or+ ,,kumascope4 ,c1 c>bon plug2 ,i1 iron plug2 ,m1 m]cury globule2 ,a1 a]ial2 ,b1 batt]y2 ,t1 telephone2 ,s1 adju/+ screw4 ,"o ( ! mo/ s5sitive ( ^! self-re/or+ kumascopes is ! c>bon-/eel-m]cury coh]]1 ! inv5tion ( :i* has be5 attribut$ to ,ca/elli1 a signalman 9 ! ,italian ,navy1#df b also /at$ on good au?ority to h be5 ! inv5tion ( (fic]s 9 ! ,royal ,italian ,navy1 & has1 !re=e1 be5 call$ ! ,italian ,navy coh]]4#dg ,?is in/rum5t has be5 arrang$ 9 sev]al =ms1 b 9 ! simple/ ( ^! x consi/s ( a glass tube1 hav+ 9 x a plug ( iron & a plug ( arc-lamp c>bon1 or two plugs ( iron ) a plug ( c>bon betwe5 !m4 ,! plugs ( iron1 or ( iron & c>bon1 are sep>at$ by an exce$+ly small globule ( m]cury1 ! size ( :i* %\ld be betwe5 "o & a-half & ?ree millimetres4 ,! plugs clos+ ! tube mu/ be capable ( movem5t1 "o ( !m by means ( a screw1 z %[n 9 ! diagram 7,fig4 #ag71 tak5 f a pat5t specification communicat$ to ,mr4 ,m>coni by ! ,m>*ese ,luigi ,sol>i1 ( ! ,royal ,italian ,navy4 ,"o ( ! plugs ( ?is tube is connect$ to ! a]ial & ! o!r to ! e>?1 & !y are also connect$ ?r\gh ano!r circuit compos$ ( a s+le dry cell & a telephone4 ,! arrangem5t !n =ms an extremely s5sitive detector ( electric waves or ( small electromotive =ces1 or1 if a wave falls on ! a]ial1 ! electromotive =ce at once improves ! contact betwe5 ! m]cury & ! plugs1 & !re=e causes a sudd5 increase 9 ! curr5t ?r\gh ! telephone1 giv+ rise to a s\nd2 b :5 ! wave ceases1 or ! electromotive =ce is )drawn1 ! resi/ance falls back aga9 to its orig9 value1 & ! arrangem5t is1 !re=e1 self-act+1 requir+ no tapp+ or o!r device = re/or+ x to receptivity4 ,a v +5i\s =m ( comb9$ telephone & coh]] has be5 devis$ by ,t4 ,tommas9a4#dh ,9 ?is in/rum5t ! diaphragm ( an ord9>y ,bell telephone c>ries ^u x a v small c>bon or metallic coh]]4 ,?is coh]] is connect$ 9 betwe5 ! a]ial & ! e>?1 & is also 9 circuit ) a batt]y & ! electromagnet ( a telegraphic relay4 ,:5 ?is relay op]ates x closes ! circuit ( ano!r batt]y :i* is plac$ 9 s]ies ) ! telephone coil4 ,! mom5t ! curr5t passes ?r\gh ! telephone coil x attracts1 & !re=e vibrates1 ! diaphragm & %akes up ! metallic fil+s4 ,if an obs]v]1 !re=e1 places ! telephone to 8 e>1 he he>s a s\nd correspond+ to e tra9 ( waves incid5t ^u ! a]ial4 ,) ?is arrangem5t1 "o c obta9 two diff]5t k9ds ( results1 accord+ to ! nature ( ! coh]+ p[d] plac$ 9 ! cavity 9 ! diaphragm4 ,fir/1 if ! p[d] consi/s ( a non-magnetic metal1 gold1 silv]1 plat9um or ! l1 ! receiv] w be v s5sitive2 & at ! same "t ! curr5t pass+ ?r\gh x :5 x is coh]$ w be suffici5t to "w a s5sive record+ app>atus 9 s]ies ) ! telephone coil4 ,secondly1 if ! metallic p[d] plac$ 9 ! cavity is a magnetic metal1 ! receiv] w be some:at less s5sitive1 b w "w ) m precision1 because ( ! magnetic action ( ! magnet ( ! telephone ^u ! coh]+ p[d]4 ,if no record+ app>atus is us$1 ! obs]v] mu/ write d[n ! signals z he>d 9 ! telephone1 s9ce correspond+ to a %ort sp>k at ! transmitt+ /ation1 a s+le tick or %ort s\nd is he>d at ! telephone1 & correspond+ to a s]ies ( rapidly successive sp>ks1 a m prolong$ s\nd is he>d 9 ! telephone4 ,^! two s\nds1 z already expla9$1 con/itute ! dot & ! da% ( ! ,morse signals4 ,we may1 9 ! next place1 ref] to t =m ( kumascope 9 :i* ! action ( ! wave or ( electromotive =ce is n to decrease ! resi/ance ( a contact1 b to increase t ( an imp]fect contact4 ,z already m5tion$1 ,pr(essor ,branly discov]$ long ago t p]oxide ( lead acts 9 an opposite mann] to metallic fil+s1 9 t :5 plac$ 9 a ,branly tube x increases its resi/ance "u ! action ( an electric sp>k1 in/ead ( decreas+ x4 ,aga91 ,pr(essor ,bose has f\nd t fragm5ts ( metallic potassium 9 k]os5e oil behave 9 a simil> mann]1 & t c]ta9 v>ieties ( silv]1 antimony & ( ars5ic1 & a few o!r metals1 h a simil> prop]ty4 ,branly tubes1 !re=e1 made ) ^! mat]ials1 or any arrangem5ts :i* act 9 a simil> mann]1 h be5 call$ anti-coh]]s4 ,! mo/ int]e/+ arragem5t :i* has be5 call$ by ?is "n is t ( ,s*aef]4#di ,s*aef]'s kumascope is made 9 ! foll[+ mann]3 ,a v ?9 film ( silv] is deposit$ ^u glass1 & a /rip ( ?is silv] is scrat*$ across ) a diamond1 mak+ a f9e transv]se cut or gap4 ,if ! resi/ance ( ?is divid$ /rip ( silv] is measur$1 x w be f\nd n to be inf9ite1 b may h a resi/ance z l[ z =ty or fifty ohms if ! /rip is ?irty millimetres wide4 ,on exam9+ ! cut 9 ! /rip ) a microscope1 x w be f\nd t ! edges are ragg$ & t !re are little p>ticles ( silv] ly+ ab\t 9 ! gap4 ,if1 !n1 an electromotive =ce ( ?ree volts or m is put on ! two sep>at$ p>ts ( ! /rip1 ^! little p>ticles ( silv] fly to & fro l ! pi? balls 9 a famili> electrical exp]im5t1 & !y convey electricity across f side to side4 ,h5ce a curr5t passes hav+ a magnitude ( a few milliamp]es4 ,if1 h[ev]1 ! /rip is employ$ z a kumascope & connect$ at "o end to ! e>? & at ! o!r end to an a]ial1 :5 electric waves fall ^u ! a]ial1 ! electrical oscillations !reby excit$ seem to h ! prop]ty ( /opp+ ?is dance ( silv] p>ticles & ! resi/ance ( ! gap is increas$ sev]al times1 b falls aga9 :5 ! wave ceases4 ,if1 !re=e1 a telephone & batt]y are connect$ betwe5 two portions ( ! /rip1 ! v>iation ( ?is batt]y curr5t w affect ! telephone 9 accordance ) ! waves :i* fall ^u ! a]ial1 & ! arrangem5t becomes !re=e a wave-detect+ device4 ,x is said to h be5 us$ 9 wireless telegraph exp]im5ts 9 ,g]many up to a di/ance ( n9ety-five kilometres4 ,we mu/ next direct att5tion to ^? wave-detect+ devices :i* dep5d ^u magnetisation ( iron1 & "h we are able to record rec5t & mo/ int]e/+ developm5ts4 ,m ?an sev5ty ye>s ago ,joseph ,h5ry1 9 ! ,unit$ ,/ates1 notic$ ! effect ( an electric sp>k at a di/ance ^u magnetis$ ne$les4#ej ,( rec5t times1 ! subject came back into notice ?r\gh ! rese>*es ( ,pr(essor ,e4 ,ru!r=d1#ea :o c>ri$ out at ,cambridge1 ,engl&1 9 #ahif1 a valuable s]ies ( exp]im5ts on ?is subject4 ,he f\nd t if a magnetis$ /eel ne$le or a v small bundle ( extremely ?9 iron wires is magnetis$ & plac$ 9 ! int]ior ( a small coil1 ! ends ( :i* are connect$ to two long collect+ wires1 !n an electric wave />t$ f a ,h]tz oscillator at a di/ance causes an imm$iate demagnetisation ( ! iron4 ,?is demagnetisation he detect$ by means ( ! movem5t ( ! ne$le ( a magnetomet] plac$ ne> "o end ( ! iron wire4 ,al?\gh ,ru!r=d's wave detector has be5 mu* us$ 9 sci5tific rese>*1 x 0 n1 9 ! =m 9 :i* he us$ x1 a telegraphic in/rum5t1 & c\ld n record alphabetic signals4 ,n long ago ,mr4 ,m>coni inv5t$1 h[ev]1 a telegraphic in/rum5t bas$ ^u 8 discov]y t ! magnetic hy/]esis ( iron c be annull$ by electric oscillations4 ,9 "o =m1 ,mr4 ,m>coni's magnetic receiv] is con/ruct$ z foll[s#eb 7see ,fig4 #ah73 ,an endless b& ( ?9 iron wire compos$ ( sev]al iron wires ab\t ,no4 #cf gauge1 arrang$ 9 p>allel1 is made to move sl[ly r\nd on two pulleys1 l ! driv+ belt ( a ma*9e4 ,9 "o "p ( its pa? ! wire passes ?r\gh a glass tube1 on :i* are f\nd two coils ( wire1 "o a r %ort1 ?ick coil1 & ! o!r a v f9e1 long "o4 ,! f9e1 long coil is connect$ ) a telephone1 & ! %ort] coil is connect$ at "o end to ! e>? & ! o!r to ! a]ial4 ,two p]man5t horse-%oe magnets are plac$ z %[n n ,fig4 #ah1 ) _! simil> poles toge!r1 &1 z ! iron b& passes ?r\gh _! field1 a c]ta9 l5g? ( x is magnetis$1 & ow+ to ! hy/]esis ( ! mat]ial1 x reta9s ?is magnetism = a %ort "t aft] x has pass$ out ( ! c5tre ( ! field4 ,if !n an electric oscillation1 com+ d[n f ! a]ial1 is pass$ ?r\gh ! %ort] coil1 x *anges ! position ( ! magnetis$ portion ( ! iron &1 s to speak1 br+s ! magnetis$ portion ( iron back into ! position x w\ld h occupi$ if ! iron _h _h no hy/]esis4 ,?is action1 by v>y+ ! magnetic flux ?r\gh ! second>y coil1 creates 9 x an electromotive =ce :i* causes a s\nd to be he>d 9 ! telephone connect$ to x4 ,if at a di/ant place a s+le wave or tra9 ( waves is />t$ & receiv$ by ! a]ial1 ?is w express itself by mak+ an audible tick 9 ! telephone1 & if sev]al gr\ps ( closely adjac5t wave tra9s are s5t1 ^! w indicate !mselves by produc+ a rapid s]ies ( ticks 9 ! telephone1 he>d z a %ort cont9u\s noise & tak5 z equival5t to ! ,morse da%4 ,illu/ration3 ,,fig4 #ah4--,,m>coni ,,magnetic ,,receiv]4 ,w#a,w#b1 :eels2 ,i1 iron wire b&2 ,p1 prim>y coil2 ,s1 second>y coil2 ,t1 telephone2 ,a1 a]ial2 ,e1 e>?plate4 ,x 0 by means ( ?is rem>kably +5i\s in/rum5t t ,mr4 ,m>coni 0 able1 9 ! summ] ( #aijb1 to detect ! waves s5t out f ,poldhu on ! coa/ ( ,cornwall1 & receive messages z f> z ,cron/adt 9 ! ,baltic1 9 "o direction1 & z f> z ,spezzia 9 ! ,m$it]ranean 9 ano!r direction1 & also to receive messages across ! ,atlantic f ! p[] /ations situat$ 9 ,glace ,bay1 ,nova ,scotia1 & f "o at ,cape ,cod 9 ,massa*usetts1 ,u4,s4,a41 9 ,decemb]1 #aijb4 ,!re c be no "q t ?is magnetic detector ( ,mr4 ,m>coni's1 us$ 9 connection ) a good telephone & an acute human e>1 is ! mo/ s5sitive device yet inv5t$ = ! detection ( electric waves & _! utilisation 9 telegraphy )\t cont9u\s wires4 ,x is m>vell\sly simple1 +5i\s & yet effective1 z a ,h]tzian wave telegraphic receiv]4 ,:il/ on ! subject ( magnetic wave detectors1 ! au?or may describe exp]im5ts t he has be5 rec5tly mak+ to con/ruct a ,h]tzian wave detector on ! ,ru!r=d pr9ciple1 :i* %all be /rictly quantitative4 ,all ! receiv]s ( ! coh]] type & electrolytic type give no indications t are at all proportional to ! en]gy ( ! incid5t wave4 ,_! indications are m or less accid5tal & dep5d ^u ! mann] 9 :i* ! receiv] 0 la/ left4 ,!re is a great ne$ = a quantitative wave detector1 ! indications ( :i* %all give u a measure ( ! en]gy ( ! arriv+ wave4 ,x is only by ! possession ( su* an in/rum5t t we c hope to /udy prop]ly ! s5d+ p[]s ( v>i\s transmitt]s or ! effici5cy ( diff]5t =ms ( a]ial or devices by :i* ! wave is produc$4 ,?is magnetic receiv] is con/ruct$ z foll[s3 ,a coil ( f9e wire is con/ruct$ 9 sections l ! second>y coil ( an induction coil1 & 9 ! in/rum5t already made1 ?is coil conta9s ?irty or =ty ?\s& turns ( wire4 ,9 ! int]ior ( ?is coil are plac$ a numb] ( little bundles ( f9e iron wire w\nd r\nd ) two coils1 a f9e wire coil :i* is a magnetis+ coil1 & a ?ick] wire coil :i* is a demagnetis+ coil4 ,^! sets ( coils are jo9$ up1 respectively1 9 s]ies or 9 p>allel4 ,!n1 associat$ ) ?is =m ( induction coil is a commutator ( a peculi> k9d1 :i* p]=ms ! foll[+ functions :5 a batt]y is connect$ to x & :5 x is made to revolve by a motor or by clockwork4 ,fir/1 dur+ "p ( ! revolution1 ! commutator closes ! batt]y circuit & magnetises ! iron cores1 & :il/ ?is is tak+ place ! second>y circuit ( ! induction coil is %ort-circuit$ & ! galvanomet] is disconnect$ f x4 ,secondly1 ! magnetis+ curr5t is /opp$1 & soon aft] t ! second>y coil is un%ort-circuit$ & connect$ to ! galvanomet]1 & rema9s 9 ?is condition dur+ ! rema9d] ( ! revolution4 ,?is cycle ( op]ations is repeat$ at e revolution4 ,if !n an electrical oscillation is s5t into ! demagnetis+ coils1 & if x cont9ues long] ?an "o revolution ( ! commutator1 x w demagnetise ! iron core dur+ t p]iod ( "t 9 :i* ! batt]y is disconnect$ & ! galvanomet] connect$4 ,! demagnetisation ( ! iron :i* ensues produces an electromotive =ce 9 ! second>y coil & causes a deflection ( ! galvanomet]1 & ?is deflection w cont9ue & rema9 /eady if ! oscillation p]si/s4 ,moreov]1 s9ce ?is deflection is due to ! passage ?r\gh ! galvanomet] ( a rapid s]ies ( dis*>ges1 x is l>ge :5 ! oscillations cont9ue = a long "t & are p[]ful1 & small :5 !y cont9ue = a %ort "t or are weak4 ,we c1 !re=e1 ) ?is arrangem5t1 receive on ! galvanomet]1 j z on ! mirror galvanomet] us$ 9 subm>9e cable "w1 a dot or da%1 &1 moreov]1 ! magnitude ( ^! deflections is a measure ( ! en]gy ( ! wave4 ,x is probable t :5 ?is arrangem5t is p]fect$ x w become exce$+ly useful = mak+ all k9ds ( te/s & measurem5ts 9 connection ) ,h]tzian telegraphy1 ev5 if x is n s5sitive en\gh to use z a long di/ance receiv]4 ,( late ye>s a v>iety ( wave-detect+ devices h be5 br\ght =w>d :i* dep5d ^u electrolysis4 ,"o ( ! be/ kn[n ( ^! is t by ,de ,=e/ & ,smy!4#ec ,9 ?is arrangem5t1 a tube conta9s two small electrodes l plugs1 :i* may be made ( t91 silv] or nickel1 or o!r metal4 ,! ends ( ^! plugs are flat & sep>at$ f ea* o!r by ab\t "o two-hundr$? ( an in*4 ,sometimes ! end ( "o ( ^! plugs is made cup %ap$ & ! cup or recess is fill$ ) a mass ( p]oxide ( lead & glyc]9e4 ,9 ! int]val betwe5 ! electrodes is plac$ an electrolyzable mixture1 :i* consi/s ( glyc]9e or vasel9e mix$ ) wat] or alcohol1 & a small quantity ( li?>ge & metallic fil+s4 ,^! metallic fil+s act z second>y electrodes4 ,:5 a small electromotive =ce is appli$ betwe5 ! t]m9als ( ! electrodes ( ?is tube ?r\gh a v high resi/ance ( tw5ty or ?irty ?\s& ohms1 an exce$+ly small curr5t passes ?r\gh ?is mixture1 & x causes an electrolytic action :i* results 9 ! production ( *a9s ( metallic p>ticles connect+ ! two electrodes toge!r4 ,if1 9 addition to ?is1 "o t]m9al or electrode ( ! arrangem5t is connect$ to an a]ial wire & ! o!r t]m9al to ! e>?1 !n on ! arrival ( an electric wave creat+ oscillations 9 ! wire1 ^! oscillations pass d[n into ! electrolytic cell1 :]e !y break up ! *a9s ( metallic p>ticles & ?us int]rupt ! curr5t pass+ ?r\gh ! telephone q sudd5ly1 :i* is he>d z a slight tick by an e> appli$ to x4 ,z soon z ! wave ceases1 ! *a9 ( metallic p>ticles is re-e/abli%$1 s t ! appliance is always 9 a condition to be affect$ by a wave4 ,x is said t ?is break+ up & re=mation ( ! *a9s ( metallic p>ticles is s rapid t a %ort sp>k made at ! transmitt+ /ation is he>d z a tick 9 ! telephone1 b a rapid succession ( oscillatory sp>ks is he>d z a %ort cont9u\s s\nd2 h5ce ! two signals necess>y = alphabetical conv]sation c be transmitt$4 ,ano!r receiv] :i* has "s resemblance to ! above1 al?\gh diff]5t 9 pr9ciple1 is t ( ,neugs*w5d]4#ed ,9 ?is arrangem5t1 :i* to a c]ta9 ext5t resembles ! ,s*aef] detector1 a glass plate has ^u x a deposit ( silv] 9 ! =m ( a /rip1 :i* is cut across at "o place1 ?us int]rupt+ x4 ,if ! cut is brea!d ^u or plac$ 9 a moi/ atmosph]e1 a little dew is deposit$ ^u ! glass1 :i* bridges ov] ! cut 9 ! metal & creates an electric cont9uity4 ,h5ce a small curr5t c be pass$ across ! gap & ?r\gh a telephone by "o or two cells ( a batt]y4 ,if1 h[ev]1 an electric oscillation passes across ! gap on its way f an a]ial to ! e>?1 !n ! cont9uity ( ! liquid film is de/roy$1 & ! curr5t is int]rupt$ & a s\nd creat$ 9 ! telephone4 ,! op9ion has be5 express$ by ,sir ,oliv] ,lodge t 9 ?is case ! int]ruption ( ! circuit :i* occurs is really due to ! coalesc5ce ( m9ute wat] p>ticles into l>g] drops1 z :5 vap\r is cond5s$ into ra91 & h5ce ! cont9uity ( ! mat]ial is int]rupt$4 ,we mu/ !n make a brief ref]5ce to o!r kumascopes :i* dep5d ^u ! heat+ p[] ( an electrical oscillation1 :i* x possesses 9 common ) e o!r =m ( electric curr5t4 ,pr(essor ,r4 ,a4 ,fess5d5#ee has con/ruct$ a v +5i\s !rmal receiv] 9 ! foll[+ mann]3 ,an extremely f9e plat9um wire1 ab\t #j4jjc ( an in* 9 diamet]1 is emb$d$ 9 ! middle ( a silv] wire ab\t "o t5? ( an in* 9 diamet]1 l ! wick ( a c&le4 ,?is comp\nd wire is !n drawn d[n until ! diamet] ( ! silv] wire is only #j4jjb ( an in*1 & h5ce ! plat9um wire 9 its int]ior1 be+ r$uc$ 9 ! same ratio1 w h be5 drawn to a diamet] ( #j4jjjjf ( an in*4 ,a %ort piece ( ?is drawn wire is !n b5t into a loop & ! ends fix$ to wires4 ,! tip ( ! loop is !n imm]s$ 9 nitric acid & dissolv$ 9 ! silv]1 leav+ an exquisitely f9e plat9um wire a few hundr$?s ( an in* 9 l5g? & hav+ a resi/ance ( ab\t ?irty ohms4 ,?is little loop is seal$ into a glass bulb l a v small inc&esc5t lamp1 or x may be enclos$ 9 a small silv] bulb & ! air may be exhau/$4 ,if an electrical oscillation is s5t ?r\gh ?is exce$+ly f9e plat9um wire x heats x & rapidly increases its resi/ance4 ,! electrical oscillations produc$ 9 an a]ial are s5t ?r\gh a numb] ( ^! loops arrang$ 9 p>allel1 & ! loops are %ort-circuit$ by a telephone1 jo9$ 9 s]ies ) a s\rce ( v small electromotive =ce produc$ by %unt+ a s+le cell or oppos+ to "o ano!r two cells ( ne>ly equal electromotive =ce4 ,any v>iation ( resi/ance ( ! little plat9um loops due to ! heat produc$ by ! oscillations1 by sudd5ly alt]+ ! curr5t fl[+ ?r\gh ! telephone1 w cause a s\nd to be he>d 9 x4 ,! electrical oscillations :5 pass+ ?r\gh ! loops are !re=e detect$ by ! heat :i* !y g5]ate 9 ^! exquisitely f9e plat9um wires4 ,f9ally1 "o ^w mu/ be said on ! subject ( electrodynamic receiv]s1 due to ! same inv5tor4 ,an exce$+ly small silv] r+ is susp5d$ by a qu>tz fibre & has a mirror atta*$ to x 9 ! mann] ( a galvanomet]4 ,?is r+ is susp5d$ betwe5 two coils jo9$ 9 s]ies1 :i* are plac$ ei!r 9 ! circuit ( ! a]ial or 9 ! second>y circuit ( ! small air core trans=m] ins]t$ betwe5 ! a]ial & ! e>?4 ,:5 electrical oscillations travel d[n ! a]ial !y induce o!r electrical oscillations 9 ! silv] r+1 & if ! r+ is s plac$ t its normal position is ) its plane incl9$ at an angle ( =ty-five degrees to ! plane ( ! fix$ coils1 !n ! r+ w be slightly deflect$ e "t an oscillation occurs 9 ! a]ial4 ,omitt+ fur!r m5tion ( ! details ( ! kumascopes 9 use & ! receiv+ a]ial1 we mu/ next proce$ to consid] ! receiv+ arrangem5ts tak5 z a :ole4 ,9 ! orig9al ,m>coni sy/em1 ! s5sitive tube or coh]] 0 ins]t$ betwe5 ! bottom ( ! receiv+ a]ial & ! e>?4#ef ,accord+ly1 :5 ! incid5t electric wave /rikes ! receiv+ a]ial & creates 9 x an oscillatory electromotive =ce1 ?is la/ w1 if ( suffici5t amplitude1 cause ! p>ticles ( ! coh]] to coh]e & become conductive4 ,?is sudd5 *ange f a ne>ly p]fect non-conductivity to a conductive condition is made to act z a swit* or relay1 clos+ or complet+ ! circuit ( a s+le cell1 & s s5d+ a curr5t ?r\gh an ord9>y telegraphic relay1 clos+ or complet+ ! circuit ( a s+le cell1 :i* may 9 turn actuate ano!r record+ telegraphic in/rum5t1 su* z a ,morse pr9t]4 ,to prev5t ! oscillations f pass+ into ! relay circuit1 small *ok+ or inductance coils are ins]t$ betwe5 ! ends ( ! s5sitive tube & ! relay & cell & s]ve to conf9e ! oscillations to ! tube4 ,x has already be5 po9t$ out t 9 ! transmitt+ a]ial ! amplitude at ! pot5tial vibrations increases f ! bottom to ! top1 & :5 vibrat+ 9 its fundam5tal mann] !re is a pot5tial node at ! e>? connection & a pot5tial loop or ant9ode at ! top4 ,! same is true ( ! receiv+ a]ial4 ,h5ce1 if ! kumascope employ$ is a ,branly metallic fil+s tube & is ins]t$ ne> ! base ( ! a]ial1 ! diff]5ce ( pot5tial betwe5 its two ends w be small4 ,x has also be5 m5tion$ t a receiv] ( ?is type acts 9 virtue ( electromotive =ce or pot5tial diff]5ce1 & h5ce ! prop] place to ins]t ! coh]] is n at ! base ( ! a]ial1 b betwe5 ! top ( ! a]ial & ! e>?4 ,?is1 h[ev]1 c\ld n be done by runn+ up ano!r wire f ! e>?1 z t w\ld am\nt to putt+ ! coh]] betwe5 ! tops ( two id5tical a]ials1 & betwe5 its ends !re w\ld be no diff]5ce ( pot5tial4 ,pr(essor ,slaby1 9 conjunction ) ,c\nt von ,arco1 has giv5 an +5i\s solution ( ?is problem4 ,if we take two equal l5g?s ( wire1 b5t at "r angles1 & connect ! po9t ( int]section ) ! e>?1 plac+ "o ( ^! wires v]tically & ! o!r horizontally1 we !n h an arrangem5t :i* responds to ! impact ( electric waves1 & has electrical oscillations set up 9 x 9 su* fa%ion t ! common po9t ( ! two wires has a v small amplitude ( pot5tial1 b ! two extremities h equal & l>ge v>iations4 ,if1 !n1 we ins]t a coh]] tube betwe5 ! e>? & ! out] extremity ( ! horizontal wire1 x is influ5c$ 9 ! same mann] z x w\ld be by ! pot5tial v>iations at ! top ( ! v]tical wire4 ,9 o!r words1 x is act$ ^u by a l>ge diff]5ce ( pot5tial in/ead ( a small "o4 ,x is n f\nd necess>y to /ret* ! horizontal wire out /raight2 x may be coil$ into a spiral ) op5 turns1 & ! slight decrease 9 capacity & increase 9 inductance result+ f ?is c be comp5sat$ by cutt+ (f a %ort piece ( x4 ,illu/ration3 ,,fig4 #ai4--,,slaby ,,receiv]4 ,a1 a]ial2 ,e1 e>? plate2 ,f1 coh]]2 ,m1 multipli]2 ,c1 cond5s]2 ,r1 relay2 ,b1 batt]y2 ,e1 e>? plate4 ,9 ?is way we h an arrangem5t 7see ,fig4 #ai7 9 :i* ! out] extremity ( ?is op5 spiral exp]i5ces v>iations or pot5tial :i* exactly correspond ) ^? at ! summit ( ! v]tical a]ial4 ,! receiv+ arrangem5ts are !n complet$ z 9 ,fig4 #ai1 "o end ( ! coh]] be+ atta*$ to ! out] end ( ! spiral & ! o!r end ?r\gh a cond5s] to ! e>?1 a relay & a voltaic cell be+ arrang$ z %[n 9 ! diagram4 ,! mode ( op]ation ( ?is receiv] is z foll[s3 ,:5 ! wave /rikes ! a]ial x sets up 9 x electrical oscillations ) a pot5tial ant9ode at ! summit1 & at ! same "t a pot5tial ant9ode is creat$ at ! out] end ( ! spiral atta*$ ne> ! base ( ! a]ial1 ?is spiral be+ call$ by ,pr(essor ,slaby a multiplicator4 ,z long z ! coh]] tube rema9s non-conductive1 ! local cell _c s5d a curr5t ?r\gh ! relay1 b1 z soon z ! resi/ance is brok5 d[n by ! impact ( a wave1 ! local cell s5ds a curr5t ?r\gh ! coh]] tube :i*1 pass+ d[n to ! e>? ?r\gh ! base ( ! a]ial & up ?r\gh ! e>? connection to ! cond5s]1 completes its circuit ?r\gh ! relay4 ,_m v>iations ( ?is arrangem5t h be5 made by ,slaby & ,von ,arco & by ! ,allgeme9e ,elektricitaets ,gesells*aft ( ,b]l94 ,9 #ahih1 ,mr4 ,m>coni made a great advance 9 ! con/ruction ( 8 receiv+ app>atus by ! ins]tion ( 8 jigg] or oscillation trans=m] 9 ! a]ial receiv+ circuit4#eg ,9 ?is arrangem5t1 ! prim>y coil ( an air core trans=m] w\nd 9 a p>ticul> way is ins]t$ betwe5 ! receiv+ a]ial & ! e>?1 & ! second>y circuit is cut 9 ! middle & connect$ to ! two surfaces ( a cond5s]1 ^! surfaces be+ also connect$ ?r\gh ! circuit ( an ord9>y telegraphic relay & a s+le cell 7see ,fig4 #bj74 ,! ends ( ! second>y circuit ( ?is oscillation trans=m] are also connect$ to ! t]m9als ( ! coh]] tube1 & ^! aga9 are %ort-circuit$ by a small cond5s]4 ,illu/ration3 ,,fig4 #bj4--,,m>coni ,,receiv]4 ,a1 a]ial2 ,j1 jigg]2 ,,cc1 cond5s]s2 ,f1 fil+s tube2 ,t1 tapp]2 ,r1 relay2 ,b1 batt]y2 ,m1 ,morse pr9t]4 ,! op]ation ( ?is receiv] is z foll[s3 ,! oscillations set up 9 ! a]ial pass ?r\gh ! prim>y circuit ( ! jigg]1 & ^! induce o!r oscillations 9 ! second>y circuit2 ! electromotive =ce or diff]5ce ( pot5tial betwe5 ! prim>y t]m9als be+ trans=m$ up 9 any desir$ ratio4 ,x is ?is exalt$ electromotive =ce :i* is made to act on ! coh]] tube1 &1 inasmu* z ! jigg] op]ates 9 virtue ( a curr5t pass+ ?r\gh its prim>y circuit & ?is curr5t is at a maximum at ! l[] end ( ! a]ial1 ! arrangem5t is exce$+ly effective1 because x1 s to speak1 conv]ts curr5t into voltage4 ,at ! l[] end ( ! a]ial1 al?\gh ! amplitude ( ! pot5tial oscillations is a m9imum1 ! amplitude ( ! curr5t oscillations is a maximum1 & ! jigg] trans=ms ^! l>ge curr5t oscillations into l>ge pot5tial oscillations1 provid$ x is con/ruct$ 9 ! "r mann]4 ,we c also trans=m up or increase ! amplitude ( ! small pot5tial v>iations ne> ! bottom ( ! a]ial by employ+ ! pr9ciple ( resonance4 ,_m devices ( ?is k9d1 due to ,pr(essor ,slaby & o!rs1 h be5 sugge/$ & tri$ b ! details are r too te*nical to be fully describ$ "h4 ,x w be notic$ t ! receiv+ a]ial may be arrang$ 9 "o ( two ways--x may be ei!r e>!d at ! l[] end or x may be insulat$4 ,x has be5 claim$ t !re is a great advantage 9 e>?+ ! receiv+ a]ial directly 9 t x elim9ates atmosph]ic di/urbances4 ,we %all allude to ?is po9t m p>ticul>ly lat] on4 ,mean:ile x may be m5tion$ t ! receiv+ arrangem5ts1 z a :ole1 con/itute a s5sitive arrangem5t1 z %[n by ,pop(f1 ,tommas9a & by all ! l>ge exp]i5ce ( ,mr4 ,m>coni himself = detect+ *anges 9 ! electrical condition ( ! atmosph]e1 :i* are d\btless ( ! nature ( electrical oscillations4 ,on ! o!r h&1 ! receiv+ arrangem5ts may be p]fectly insulat$ & "s exp]im5tali/s h ass]t$ t by ?is me?od ! greate/ fre$om is secur$ f atmosph]ic di/urbances4 ,among/ ! non-e>!d arrangem5ts ! sy/em inv5t$ by ,pr(essor ,f4 ,braun1 ( ,/rassburg1 & work$ by ,messrs4 ,siem5s1 ( ,b]l91 may be m5tion$4#eh ,illu/ration3 ,,fig4 #ba4--;,,braun',s ,,non-,,e>!d ,,receiv]4 ,i1 induction coil2 ,,cc1 cond5s]s2 ,s1 sp>k gap2 ,j1 transmitt+ jigg]2 ,k1 receiv+ jigg]2 ,f1 fil+s tube2 ,r1 relay2 ,b1 batt]y4 ,pr(essor ,braun's arrangem5ts are indicat$ 9 ! diagram 9 ,fig4 #ba4 ,9 ?is case an induction coil is us$ to create a dis*>ge betwe5 two sp>k balls1 & to ^! two balls are connect$ ! two out] coat+s ( two cond5s]s1 ! inn] coat+s ( :i* are connect$ toge!r ?r\gh ! prim>y coil ( an air core trans=m]4 ,! second>y coil ( ?is trans=m] is connect$ to two ext5sion wires =m+ a ,h]tz resonator1 & ! l5g? ( ^! wires is s adju/$ ) ref]5ce to ! "t p]iod ( ! prim>y circuit t !y resonate to x1 ! :ole l5g? f end to end ( ! second>y circuit be+ half a wave-l5g?4 ,! receiv]1 z %[n 9 ! diagram1 consi/s ( a pair ( qu>t] wave-l5g? receiv+ wires connect$ ?r\gh two cond5s]s1 :i* are %ort-circuit$ by ! prim>y coil ( an oscillation trans=m]4 ,! second>y circuit ( ?is la/ oscillation trans=m] has two ext5sion wires to x1 turn$ 9 ! same mann]1 to respond to ! prim>y oscillator2 & 9 ! circuit ( "o ( ^! ext5sion wires is plac$ a coh]] tube1 %ort-circuit$ by a relay & a local batt]y4 ,x w ?us be se5 t !re is an entire abolition ( gr\nd connection1 :i*1 ,pr(essor ,braun claims1 practically avoids all atmosph]ic di/urbances4#ei ,! details ( ! receiv+ arrangem5t are z foll[s3--,! coh]] tube consi/s ( an ebonite tube conta9+ h>d /eel p>ticles ( a uni=m size1 plac$ 9 ! adju/able space betwe5 two poli%$ /eel electrodes4 ,x is f\nd t ) ?is /eel coh]]1 a small am\nt ( magnetism 9 ! p>ticles increases its s5sitiv5ess1 & to obta9 ?is1 a r+ magnet is employ$ 9 connection ) a coh]] tube4 ,receiv+ app>atus arrang$ on ?is sy/em is said to h be5 us$ = telegraph+ betwe5 ,heligol& & ,cuxhav51 a di/ance ( ?irty-six miles4 ,all ! imm5se exp]i5ce1 h[ev]1 ga9$ by ,mr4 ,m>coni & ^? :o h work$ ) 8 sy/em1 is 9 fav\r ( us+ ! e>? connection4 ,!re is no d\bt t ,h]tzian wave telegraphy c be conduct$ ov] %ort di/ances by means ( totally insulat$ a]ials1 b = long di/ances ! e>? connection is ess5tial1 = ! reasons t h be5 expla9$ previ\sly4 ,!re are _m ( ! details ( ! receiv+ arrangem5ts :i* rema9 to be consid]$4 ,if ! communication is receiv$ by a telegraphic in/rum5t l ! ,morse pr9t]1 :i* requires a curr5t ( any?+ l t5 milliamp]es to "w x1 !n an important elem5t 9 ! receiv+ arrangem5t is ! relay4 ,! relay t is g5]ally us$ is a modifi$ =m ( ! ,siem5s pol>is$ relay1 :i* is s adju/$ z to make a s+le contact4 ,= m>9e "w on bo>d %ip1 x is ess5tial t ?is relay %all be balanc$ s t v>iations 9 position %all n affect x4 ,sometimes ! relay is hung 9 gimbals l a compass1 & at o!r times susp5d$ f a support by ela/ic b&s1 s z to avoid jolt+4 ,9 any case1 ! relay mu/ be s adju/$ t no *ange ( position w cause x to close ! circuit ( ! telegraphic pr9t] or record]4 ,its s5sibility ought to be su* t x is actuat$ by a t5? ( a milliamp]e1 &1 if possible1 ev5 by less4 ,! alt]ation ( s5sibility 9 ! ord9>y contact =m ( relay is ! pressure t is necess>y to br+ ! plat9um po9ts ( ! circuit clos] toge!r1 s z to pass ! m9imum curr5t :i* w "w ! telegraph pr9t]4 ,! important matt]1 h[ev]1 9 connection ) ! use ( ! relay 9 ,h]tzian wave telegraphy1 is t x %\ld be capable ( adju/m5t )\t extraord9>y skill4 ,x is no use to put into ! h&s ( an op]ator a relay :i* requires abnormal dext]ity to make x "w at all4 99 99 99 99 99 ,x rema9s1 !n1 to consid] "s ( ! que/ions connect$ ) practical ,h]tzian wave telegraphy & ! problem ( ! limitation ( communication4 ,^! matt]s at ! pres5t mom5t v mu* occupy ! public att5tion1 & _m conflict+ op9ions are express$ conc]n+ !m4 ,x may be obs]v$ at ! outset t ! difficulty ( deal+ ) ! subject z freely z _m desire is t ,h]tzian wave telegraphy is no long] m]ely a subject ( sci5tific inve/igation1 b has develop$ into a bus9ess & involves1 !re=e1 o!r int]e/s ?an ! simple advancem5t ( sci5tific k4 ,we c1 h[ev]1 discuss 9 a g5]al mann] "s ( ! sci5tific problems :i* pres5t !mselves = solution4 ,! fir/ ( ^! is ! indep5d5ce ( communication betwe5 /ations4 ,x is desirable1 at ! outset1 to cle> up a little misund]/&+4 ,!re is a great diff]5ce betwe5 prev5t+ ! reception ( communication :5 x is n desir$ by ! recipi5t1 & prev5t+ x :5 x is ! object ( ! latt] to ov]he> if he c4 ,x is1 !re=e1 necess>y to di/+ui% betwe5 isolation & ov]he>+4 ,we may say t a /ation is isolat$ :5 x is n affect$ by ,h]tzian waves o!r ?an ^? x desires to receive2 b t a /ation ov]he>s :5 x c1 if x *ooses1 pick up communications n int5d$ = x1 or _c help receiv+ !m aga9/ its w4 ,?is di/9ction is a p]fectly fair "o4 ,any telegraph or telephone wire c be tapp$1 if x is desir$1 b unless !re is "s fault on ! l9e1 no /ation w receive a message aga9/ its desires4 ,moreov]1 x may be not$ t !re are p5alties atta*$ to tapp+ a telegraph wire1 & at pres5t !re are none connect$ ) ! misappropriation ( an e!r wave4 ,we %all1 !re=e1 consid] 9 ! fir/ place ! me?ods s f> propos$ = prev5t+ any giv5 receiv] f be+ affect$ by ,h]tzian waves s5t out f o!r /ations1 except t ( ^? f :i* x is desir$ to receive !m4 ,! fir/ me?od is t :i* has be5 call$ ! me?od ( electrical syntony1 & consi/s 9 adju/+ ! electrical capacity & inductance ( ! v>i\s op5 & clos$ circuits ( ! receiv+ & transmitt+ /ations to be put 9 communication s t !y h ! same electrical "t-p]iod4#fj ,9 ! ,cantor ,lectures be=e ! ,society ( ,arts 9 #aijj1 on electrical oscillations & electric waves1 ! au?or has discuss$ at l5g? ! conditions "u :i* p[]ful electrical oscillations c be set up 9 a circuit4 ,x 0 !re %[n t e electric circuit hav+ capacity & inductance has a p>ticul> or natural "t-p]iod ( electrical oscillation dep5d+ on ! product ( ^! qualities1 & t1 to accumulate p[]ful electrical oscillations 9 x1 ! electromotive impulses on x mu/ be deliv]$ at ?is rate4 ,illu/rations 7 drawn f me*anics1 su* z ! examples furni%$ by vibrat+ p5dulums & spr+s1 & f ac\/ics1 z illu/rat$ by ! ph5om5a ( resonance1 to %[ t small or feeble bl[s or impulses deliv]$ at ! prop] "t int]vals h a cumulative effect 9 sett+ up vibrations 9 a body capable ( oscillation4 ,x is a famili> fact t if we "t our bl[s1 we c a*ieve t :i* no s+le bl[1 h[ev] p[]ful1 c accompli% 9 ?r[+ into vibration a body su* z a p5dulum1 :i* is capable ( oscillation "u ! action ( a re/or+ =ce4 ,precisely ! same is true ( an electric circuit4 ,we h already se5 t ! receiv+ a]ial has an alt]nat+ electromotive =ce set up 9 x by ! impact ( ! successive electric waves s5t out f ! transmitt]4 ,x mu/1 h[ev]1 be rememb]$ t ! transmitt] s5ds out a s]ies ( tra9s ( waves1 n by any means a cont9u\s tra91 b "o cut up into gr\ps ( probably t5 to fifty waves1 ea* sep>at$ by int]vals ( sil5ce1 long1 comp>$ ) ! duration ( a s+le tra9 ( waves4 ,illu/ration3 ,,fig4 #bb4--,,seibt',s ,,app>atus ,,= ,,exhibit+ ,,electric ,,resonance4 ,i1 induction coil2 ,s1 sp>k gap2 ,,cc1 cond5s]s2 ,l1 v>iable inductance2 ,e1 e>? plate2 ,,ww1 wire spirals2 ,,vv1 vacuum tubes4 ,if1 h[ev]1 by a suitable adju/m5t ( capacity & inductance1 we make ! natural "t-p]iod ( oscillation ( ! receiv+ a]ial circuits agree ) ^? ( ! transmitt+ a]ial1 )9 c]ta9 limits ! =m] w only be receptive = waves ( ! frequ5cy s5t out by ! transmitt]4 ,x is q easy to illu/rate ?is pr9ciple by num]\s exp]im5ts4 ,x c be done by means ( an app>atus devis$ by ,dr4 ,georg ,seibt = %[+ 9 an int]e/+ mann] ! syntonisation or tun+ ( two electric circuits4 ,?is consi/s ( two bobb9s1 ea* consi/+ ( "o lay] ( insulat$ wire w\nd on a wood5 rod 7see ,fig4 #bb74 ,ea* ( ^! bobb9s has a c]ta9 electrical capacity ) respect to ! e>?1 :5 consid]$ z an insulat$ conductor1 & x has also a c]ta9 inductance4 ,if1 !re=e1 electromotive impulses are appli$ to "o end ( ! bobb9 at regul> int]vals1 electrical oscillations w be set up 9 x1 &1 z already expla9$1 if ^! are tim$ at a c]ta9 rate1 ! bobb9 w act l a clos$ organ-pipe to air impulses & oscillations ( pot5tial w be accumulat$ at ! opposite end1 :i* h mu* great] amplitude ?an ! impress$ oscillations at ! end at :i* !y are appli$4 ,we c make ! exi/5ce ( ! amplitude oscillations ( pot5tial evid5t by atta*+ to "o end ( ! bobb9 a vacuum tube1 :i* w be illum9at$ !reby1 or by t]m9at+ x by a po9t$ piece ( wire1 s t an electrical bru% c be =m$ at ! po9t1 if ! pot5tial v>iations h suffici5t amplitude4 ,we arrange also ano!r clos$ oscillation circuit1 consi/+ ( two ,leyd5 j>s & a v>iable inductance coil & a pair ( sp>k balls :i* are connect$ to an induction coil4 ,9 ?is mann] we c set up oscillations 9 ! dis*>ge circuit ( ^! ,leyd5 j>s1 & we c v>y ! "t p]iod by alt]+ ! inductance & ! capacity4 ,if we d5ote ! capacity ( ! j>s 9 ! micr(>ads by ! lett] ,c & ! inductance 9 c5timetres ( ! dis*>ge circuit ( ! j>s by ! lett] ,l1 x c !n be %[n t ! numb] ( oscillations p] second d5ot$ by n is giv5 by ! expression--#fa n 7#e1jjj1jjj1jjj7 _/ 7sq,,cl74 ,if n[ we adju/ ! ,leyd5 j> circuit to a p>ticul> rate ( oscillation1 we h betwe5 ! t]m9als ( ! j> or cond5s] an alt]nat+ diff]5ce ( pot5tial or electromotive =ce4 ,if we connect "o side ( ! j>s to ! e>? & ! o!r side to ! foot ( "o ( ! spirals or bobb9s above describ$1 we %all f9d p]haps t ! vacuum tube at ! o!r end is n r5d]$ lum9\s4 ,:51 h[ev]1 we adju/ ! inductance 9 ! dis*>ge circuit ( ! j> to a c]ta9 value to make ! frequ5cy ( ! cond5s] oscillations agree ) ! natural "t p]iod ( ! bobb9 t]m9at$ by ! vacuum tube1 ?is latt] at once lights up brilliantly4 ,aga91 if we connect bo? ^! bobb9s at ! same "t to ! dis*>ge circuit ( ! ,leyd5 j>1 we %all f9d t we c make an adju/m5t ( ! inductance ( t circuit1 su* t ei!r ( ! bobb9s at pleasure c be made to respond & be set 9 electrical vibration1 z %[n by ! illum9ation ( ! vacuum tube at its upp] end or by an electrical bru% be+ =m$ at ! t]m9al4 ,9 mak+ ?is adju/m5t ( inductance1 we are tun+1 z x is call$1 ! ,leyd5 j> dis*>ge circuit to ! resonat+ bobb94 ,a v small v>iation ( ! inductance ( ! j> circuit causes ! vacuum tube to *ange 9 lum9osity4 ,if1 h[ev]1 ! natural "t p]iods ( ^! bobb9s d n lie v f> ap>t1 !n a fa9t lum9osity w make its appe>ance 9 bo? ! vacuum tubes4 ,suppos+1 !re=e1 t we connect to ! oscillat+ circuit ( ! j> a numb] ( bobb9s hav+ diff]5t "t p]iods ( oscillation1 l organ-pipes1 & supply !m all ) "o common alt]nat+ electromotive =ce4 ,^! bobb9s1 ^: natural "t p]iod is v diff]5t to t ( ! osciilat+ circuit or impress$ electromotive =ce1 w n respond1 b ^? bobb9s ( :i* ! natural "t p]iod lies ne> to1 ev5 if n q exactly ! same z1 t ( ! impress$ electromotive =ce w give evid5ce ( be+ set 9 oscillation4 ,a v viol5t electromotive =ce w cause !m all to respond to "s slight ext5t1 no matt] :e!r ! p]iod ( t impluse is tun$ to _! common p]iod precisely or n4 ,at ?is po9t que/ions arise ( great practical importance4 ,a matt] :i* has be5 9 dispute 9 connection ) practical ,h]tzian wave telegraphy is h[ f> ?is electrical tun+ is a suffici5t solution ( ! practical problem ( isolation4 ,x is n d5i$ t exp]im5ts su* z ^? made ) ,seibt's app>atus c be %[n on a small scale2 &1 on a /ill l>g] scale1 ,mr4 ,m>coni gave to ! au?or 9 ,septemb]1 #aijj1 a demon/ration 9 practical telegraphic "w ( s5d+ two indep5d5t ,h]tzian wave messages & receiv+ !m on two indep5d5t receiv]s atta*$ to ! same a]ial4 ,s9ce t date mu* exp]i5ce has be5 ga9$ & l>ge p[] /ations erect$1 & a /atem5t has be5 frequ5tly made t syntony is no protection aga9/ int]f]5ce :5 "o ( ! /ations is s5d+ out v p[]ful waves4 ,! cont5tion has be5 rais$ t l>ge p[] /ations produc+ electric waves w !re=e play havoc ) ,h]tzian wave telegraphy on a small] scale1 su* z ! %ip to %ore & int]m>9e communication4 ,"u ^! circum/ances1 x appe>$ to ! au?or important to subject ! matt] to a special te/1 & ,mr4 ,m>coni1 !re=e1 (f]$ to give a demon/ration1 ) ?is object1 9 support ( ! op9ion t he has express$ positively t waves f 8 p[] /ations d n int]f]e ) ! work+ ( 8 %ip in/allations4 ,?is matt] is vital to ! :ole "q ( practical ,h]tzian wave telegraphy1 = ! %ip to %ore communication is ( /up5d\s importance2 & if ,mr4 ,m>coni _h done no?+ else except to r5d] ?is possible & effective1 he w\ld h e>n$1 z he has done1 ! gratitude ( humanity = all "t4 ,accord+ly1 ! au?or embrac$ ! opportunity ( mak+ "s c>eful te/s to settle ! "q :e!r ! p[]ful waves s5t out f a /ation su* z ,poldhu did or did n affect ! ex*ange ( messages betwe5 %ip & %ore /ations 9 proximity1 equipp$ ) ,m>coni app>atus ( a suitable type4 ,^! exp]im5ts 7 c>ri$ out on ! eighte5? ( ,m>* la/1 at ,poldhu1 9 ,cornwall1 & a programme 0 arrang$ by ! au?or ( ! foll[+ k9d4 ,close to ! ,poldhu /ation is an isolat$ ma/1 :i* 0 equipp$ by ,mr4 ,m>coni ) a ,h]tzian wave app>atus1 simil> to t he places on %ips4 ,six miles f ,poldhu is ! ,liz>d receiv+ /ation1 ) :i* %ips proce$+ up or d[n ! ,engli% ,*annel communicate4 ,x 0 arrang$ t a s]ies ( secret messages1 "s ( !m 9 ciph]1 %\ld be deliv]$ simultane\sly at c]ta9 kn[n times1 bo? to ! p[] /ation at ,poldhu & to ! small adjac5t %ip /ation2 & x 0 arrang$ t ^! messages %\ld be s5t (f simultane\sly1 ! op]ators be+ kept 9 ignorance up to ! mom5t ( s5d+ z to ! nature ( ! messages4 ,at ! ,liz>d1 ,mr4 ,m>coni connect$ two ( 8 receiv+ in/rum5ts to ! a]ial1 "o ( !m tun$ to ! waves proce$+ f ! p[] /ation at ,poldhu1 & ! o!r to ^? proce$+ f ! small %ip /ation4 ,at ! appo9t$ "t1 ^! two sets ( messages 7 receiv$ simultane\sly 9 ! pres5ce ( ! au?or1 ea* message be+ pr9t$ d[n indep5d5tly on its own receiv]2 & ,mr4 ,m>coni read (f & int]pret$ all ^! messages p]fectly correctly1 n hav+ kn[n be=e :at 0 ! message t 0 ab\t to be s5t4 ,9 addition to ?is1 precautions 7 tak5 to prove t ! p[] /ation at ,poldhu 0 really emitt+ waves suffici5tly p[]ful to cross ! ,atlantic & n be+ made to s+ small = ! occasion4 ,to assi/ 9 prov+ ?is1 ! messages s5t out f ! p[] /ation 7 also receiv$ at a /ation at ,poole1 two hundr$ miles away1 & ! assi/ant !re 0 in/ruct$ to telegraph back ^! messages by wire z soon z he receiv$ !m4 ,^! messages came back p]fectly correctly1 ?us demon/rat+ t ! p[] /ation 0 s5d+ out p[] waves4 ,! :ole programme 0 c>ri$ out ) ! greate/ c>e to avoid any mi/akes on ! "p ( ! assi/ants1 & provid$ an absolute demon/ration ( ! tru? ( ,mr4 ,m>coni's ass]tion t ! waves f "o ( 8 p[] /ations1 su* z ,poldhu1 d n 9 ! lea/ degree int]f]e ) ! transmission & reception ( messages betwe5 %ip & %ore1 effect$ by means ( c]ta9 =ms ( ,m>coni app>atus = produc+ & detect+ waves ( a diff]5t wave l5g?4#fb ,?is complete indep5d5ce ( transmission1 h[ev]1 is entirely due to ! employm5t ( a receiv+ circuit ( a c]ta9 type 9 ,mr4 ,m>coni's receiv]s4 ,x does n at all foll[ t a receiv+ circuit ( any k9d1 ev5 a ,m>coni receiv] n especially arrang$1 set up 9 proximity to a p[] /ation w\ld n be affect$4 ,?is1 h[ev]1 is n an important matt]4 ,f> m important is x to %[1 z has be5 %[n1 t practically p]fect isolation c be a*iev$ if x is desir$4 ,x mu/ be not$1 h[ev]1 t1 al?\gh ! fact t electric circuits h a natural "t-p]iod ( oscillation ( _! own is a sci5tific pr9ciple :i* c>ries u a consid]able way t[>ds a solution ( :at is call$ syntonic ,h]tzian wave telegraphy1 x is n 9 itself alone 9 e respect an entire solution ( ! practical problem4 ,! degree to :i* x is a solution dep5ds to a consid]able ext5t ^u ! nature ( ! detect+ device1 or kumascope1 :i* we are employ+4 ,! coh]]1 or ,branly fil+s tube1 has ! peculi>ity t its passage f a non-conductive to a conductive condition foll[s imm$iately :5 ! diff]5ce ( pot5tial betwe5 its ends is made suffici5tly great4 ,9 o!r words1 if ! tube is act$ ^u by a suffici5t electromotive =ce1 x is n necess>y t electromotive =ce %\ld be repeat$ at int]vals to make ?is p>ticul> =m ( kumascope responsive4 ,aga91 if we consid] ! nature ( ! oscillations :i* are s5t out f any transmitt+ a]ial1 we f9d t ea* gr\p ( oscillations correspond+ to a s+le sp>k consi/s ( waves gradually decreas+ 9 amplitude4 ,9 o!r words1 ! fir/ wave ( ! gr\p is ! /ronge/1 & ! decay 9 amplitude is (t5 v rapid4 ,suppos+1 !n1 we con/ruct a simple receiv] consi/+ ( an a]ial hav+ ins]t$ 9 its circuit a s5sitive ,branly fil+s tube4 ,su* a receiv] is almo/ entirely non-syntonic2 t is to say1 x is affect$ by any wave pass+ ov] x :i* is suffici5tly p[]ful4 ,we may look ^u x t if ! fir/ wave ( ! s]ies is suffici5tly p[]ful to affect ! kumascope1 ! conductive *ange takes place :e!r or n ! fir/ wave is foll[$ by o!rs4 ,accord+ly1 x is p]fectly c]ta9 t if a transmitt] is s5d+ out tra9s ( waves ( any p]iod1 a simple comb9ation ( coh]] & a]ial w be influ5c$1 if x is plac$ ne> en\gh to ! transmitt]4 ,on ! o!r h&1 x is possible to comb9e a kumascope ( a c]ta9 type ) a receiv+ a]ial & o!r circuits 9 su* a mann] t :5 ! waves t rea* x are feeble x %all n respond at all unless ^? waves h v ne>ly a "t p]iod ( a c]ta9 value4 ,at ?is /age1 x may be p]haps well to expla9 a little 9 detail :at is meant by an easily responsive circuit1 &1 on ! o!r h&1 by an irresponsive circuit1 or1 z we may call x1 a /iff circuit4 ,suppos+ t we consid] an a]ial consi/+ ( a simple /raight wire hav+ small capacity & small inductance1 su* a circuit admits ( be+ s5t into electrical oscillation1 n only by waves ( its own natural "t-p]iod1 b by ! sudd5 application ( any viol5t electromotive impulse4 ,if1 on ! o!r h&1 we be/[ ^u ! circuit 9 any way consid]able inductance1 we !n obta9 :at may be call$ a /iff or irresponsive circuit1 :i* is "o 9 :i* electrical oscillations c be accumulat$ only by ! prolong$ action ( impulses tun$ to a p>ticul> p]iod4 ,a me*anical analogue ( ?is diff]5ce may be f\nd 9 consid]+ ! diff]5t behavi\r ( ela/ic bodies to me*anical bl[s4 ,take1 = in/ance1 a piece ( ela/ic /eel & fix ! bottom end 9 a vice4 ,! /eel /rip may be ?r[n into vibration by deflect+ ! upp] end4 ,x has1 h[ev]1 a v small mass1 & !re=e any viol5t bl[ or bl[s1 ev5 al?\gh n repeat$1 w set x 9 oscillation4 ,if1 h[ev]1 we add mass to x by fix+ at ! o!r end a heavy weight1 su* z a ball ( lead1 & at ! same "t make ! spr+ /iff]1 we h an arrangem5t :i* is capable ( be+ s5t into consid]able oscillation only by ! action ( a s]ies ( impulses or bl[s :i* are tim$ at a p>ticul> rate4 ,return+ !n to ! electrical problem1 we see t 9 ord] to pres]ve a kumascope or wave detector f be+ op]at$ on by any vagrant wave or waves hav+ a p]iod v diff]5t to an assign$ p]iod1 x mu/ be associat$ ) an electrical circuit ( ! k9d above call$ a /iff circuit4 ,we w n[ consid] ! mann] 9 :i* ! problem has be5 practically attack$ by ,mr4 ,m>coni1 ,dr4 ,slaby1 ,sir ,oliv] ,lodge & o!rs1 :o h inv5t$ =ms ( receiv] & transmitt]1 :i* are syntonic or sympa!tic to "o ano!r4 ,"s ( ! me?ods :i* ,mr4 ,m>coni has devis$ = ! a*ievem5t ( syntonic wireless telegraphy 7 fully describ$ by him 9 a ,pap] read be=e ! ,society ( ,arts on ,may1 #ag1 #aija4fc ,illu/ration3 ,,fig4 #bc4--,,m>coni ,,transmitt] ,,& ,,receiv]4 ,i1 induction coil2 ,a1 a]ial2 ,e1 e>? plate2 ,,hh1 *ok+ coils2 ,s1 sp>k gap2 ,j1 transmitt+ jigg]2 ,k1 receiv+ jigg]2 ,r1 relay2 ,c1 cond5s]2 ,f1 fil+s tube2 ,b1 batt]y4 ,_m practical details are omitt$4 ,on ref]r+ to 8 ,pap]1 x w be se5 t 9 "o =m 8 transmitt] consi/s ( an a]ial1 ne> ! base ( :i* is ins]t$ ! second>y circuit ( an oscillation trans=m] or transmitt+ jigg]4 ,"o end ( ?is second>y circuit is atta*$ to ! a]ial & ! o!r end is connect$ to ! e>? ?r\gh a v>iable inductance coil4 ,! prim>y circuit ( ?is oscillation trans=m] is connect$ 9 s]ies ) a cond5s]1 consi/+ ( a batt]y ( ,leyd5 j>s1 & ! two toge!r are connect$ across to ! sp>k balls :i* close ! second>y circuit ( an induction coil1 hav+ ! usual make & break key 9 ! prim>y circuit4 ,mr4 ,m>coni s adju/s ! induction ( ! a]ial & ! capacity ( ! cond5s]1 or batt]y ( ,leyd5 j>s1 t ! two circuits1 consi/+ respectively ( ?is batt]y ( ,leyd5 j>s & ! prim>y circuit ( ! trans=m]1 & on ! o!r h& ( ! capacity ( ! a]ial & ! inductance 9 s]ies ) x1 & t ( ! second>y circuit ( ! trans=m] h ! same "t p]iod4 ,9 o!r words1 ^! two inductive circuits are tun$ toge!r4 ,at ! receiv+ end1 ! a]ial is connect$ 9 s]ies ) a v>iable inductance & ) ! prim>y circuit ( ano!r oscillation trans=m]1 ! second t]m9al ( :i* is connect$ to ! e>?4 ,! second>y circuit ( ?is la/ oscillation trans=m] is cut 9 ! middle & is connect$ to ! t]m9als ( a small cond5s]4 ,! out] t]m9als ( ?is second>y circuit are connect$ to ! metallic fil+s tube or o!r s5sitive receiv] & to a small cond5s] 9 p>allel ) x 7see ,fig4 #bc74 ,! t]m9als ( ! cond5s] :i* is ins]t$ 9 ! middle ( ! second>y circuit ( ! oscillation trans=m] are connect$ ?r\gh two small inductance coils ) a relay & a s+le cell4 ,?is relay 9 turn actuates a ,morse pr9t] by means ( a local batt]y4 ,! two circuits ( ! oscillation trans=m] are tun$ or syntonis$ to "o ano!r1 & also to ! simil> circuit ( ! transmitt+ arrangem5t4 ,:5 ?is is ! case1 ! transmitt] affects ! co-resonant receiv+ arrangem5t1 b w n affect any o!r simil> arrangem5t1 unless x is )9 a c]ta9 m9imum range ( di/ance4 ,ow+ to ! inductance ( ! oscillation trans=m] =m+ "p ( ! receiv+ arrangem5ts1 ! receiv+ circuit is1 z be=e /at$1 v /iff or irresponsive2 ! s5sitive tube is !re=e n act$ ^u 9 virtue m]ely ( ! impact ( ! s+le wave aga9/ ! a]ial1 b x ne$s repeat$ or accumulat$ effects ( a great _m waves1 com+ 9 prop] "t1 to break d[n ! coh]] & cause ! record+ me*anism to act4 ,an inspection ( ! diagram w %[ t z soon z ! second>y electromotive =ce 9 ! small oscillation trans=m] or jigg] ( ! receiv+ in/rum5t is ( suffici5t amplitude to break d[n ! resi/ance ( ! coh]]1 ! local cell 9 circuit ) ! relay c s5d a curr5t ?r\gh x & cause ! relay to act & 9 turn make ! associat$ telegraphic in/rum5t record or s\nd4 ,mr4 ,m>coni describ$ 9 ! above-m5tion$ ,pap] "s o!r arrangem5ts = a*iev+ ! same result1 b ^? m5tion$ all dep5d = _! op]ation ^u ! con/ruction ( a receiv+ circuit on :i* ! "t-p]iod ( electrical oscillations is id5tical ) t ( a transmitt+ arrangem5t4 ,by ?is means he %[$ exp]im5ts dur+ ! read+ ( 8 ,pap]1 illu/rat+ ! fact t two pairs ( transmitt+ & receiv+ arrangem5ts c\ld be s syntonis$ t ea* receiv] respond$ only to its p>ticul> transmitt] & n to ! o!r4 ,) arrangem5ts ( sub/antially ! same nature1 he made exp]im5ts 9 ! autumn ( #aijj betwe5 ,niton1 9 ! ,isle ( ,wight1 & ,b\rnem\?1 a di/ance ( ab\t ?irty miles1 9 :i* indep5d5t messages 7 s5t & receiv$ on ! same a]ial4 ,dr4 ,slaby & ,c\nt von ,arco1 work+ 9 ,g]many1 h foll[$ v mu* on ! same l9es z ,mr4 ,m>coni1 ?\gh ) appliances ( a some:at diff]5t nature4 ,z con/ruct$ by ! ,g5]al ,electric ,company1 ( ,b]l91 ! ,slaby-,arco syntonic sy/em ( ,h]tzian telegraphy is arrang$ 9 "o =m z foll[s3--,! transmitt] consi/s ( a v]tical rod l a lightn+ conductor1 say1 #ajj or #aej feet 9 height4 ,at a po9t six or n9e feet above ! gr\nd1 a connection is made to a sp>k ball 7see ,fig4 #bd71 & ! correspond+ ball is connect$ ?r\gh a v>iable inductance ) "o t]m9al ( a cond5s]1 ! o!r t]m9al ( :i* is connect$ to ! e>?4 ,! two sp>k balls are connect$ to an induction coil1 or alt]nat+ curr5t trans=m]1 & by v>iation ( ! inductance & capacity ! frequ5cy is s arrang$ t ! wave-l5g? correspond+ to x is equal to f\r times ! l5g? ( t portion ( ! a]ial :i* is above ! sp>k ball connection4 ,! me?od by :i* ?is tun+ is a*iev$ is to ins]t 9 ! portion ( ! a]ial bel[ ! sp>k balls1 betwe5 x & ! e>?1 a hot wire ammet] ( "s =m4 ,x has already be5 %[n t 9 ! case ( su* an e>!d a]ial1 :5 electrical oscillations are set up 9 x1 !re is a pot5tial node at ! e>? & a pot5tial anti-node or loop at ! summit1 if x is vibrat+ 9 its fundam5tal mann]2 also1 !re is a node ( curr5t at ! summit ( ! a]ial & an anti-node at ! base4 ,?is am\nts to say+ t ! amplitude ( ! pot5tial vibrations is greate/ at ! top end ( ! a]ial1 & ! amplitude ( ! curr5t vibrations is greate/ at ! bottom or e>!d end4 ,accord+ly1 ! inductance & capacity ( ! lat]al bran* ( ! transmitt] is alt]$ until ! hot wire ammet] 9 ! base ( ! a]ial %[s ! l>ge/ possible curr5t4 ,illu/ration3 ,,fig4 #bd4--,,slaby-,,arco ,,syntonic ,,transmitt] ,,& ,,receiv]4 ,i1 induction coil2 ,m1 multipli]2 ,b1 batt]y2 ,a1 a]ial2 ,f1 fil+s tube2 ,r1 relay2 ,e1 e>? plate2 ,c1 cond5s]4 ,! correspond+ receiv] is con/ruct$ 9 a v simil> mann]4 ,a lightn+ conductor or long v]tical rod ( ! same height z ! transmitt+ a]ial is set up at ! receiv+ /ation1 & at a po9t six or n9e feet f ! gr\nd a circuit is tak5 (f1 consi/+ ( a wire loosely coil$ 9 a spiral1 ! l5g? ( :i* is ne>ly equal to1 al?\gh a little %ort] ?an1 ! height ( ! v]tical wire above ! po9t ( connection4 ,! out] end ( ?is loose spiral is connect$ to "o t]m9al ( ! coh]] tube1 & ! o!r t]m9al ( ! coh]] is connect$ to ! e>? ?r\gh a cond5s] ( r l>ge capacity4 ,! t]m9als ( ?is la/ cond5s] are %ort-circuit$ by a relay & a s+le cell4 ,:5 ! adju/m5ts are prop]ly made1 x is claim$ t ! receiv] responds only to waves com+ f its own syntonis$ or tun$ transmitt]4 ,9 ?is case ! l5g? ( ! receiv+ a]ial above ! po9t ( junction ) ! coh]] circuit is "o qu>t] ! l5g? ( ! wave4 ,a v>iation ( ! above arangem5ts consi/s 9 mak+ ?is lat]al circuit equal 9 l5g? to "o-half ( a wave1 & connect+ ! coh]] to its c5tre ?r\gh a cond5s] to ! e>?4 ,! out] end ( ?is lat]al circuit is also connect$ to ! e>? 7see ,fig4 #bd74fd ,dr4 ,slaby claims t ?is arrangem5t is n affect$ by atmosph]ic electricity1 & t ! complete & direct e>?+ ( ! a]ial & also 9 ! second arrangem5t1 ( ! receiv] ( ! out] end ( ! lat]al conductor1 conduces to pres]ve ! receiv] immune f any electrical di/urbances except ^? hav+ a p]iod to :i* x is tun$4 ,illu/ration3 ,,fig4 #be4--,,lodge-,,muirhead ,,syntonic ,,receiv]4 ,i1 induction coil2 ,s1 sp>k gap2 ,a1 a]ial2 ,,cc1 cond5s]s2 ,e1 e>? plate2 ,r1 relay2 ,l1 v>iable inductance2 ,f1 fil+s tube2 ,b1 batt]y4 ,a me?od has also be5 arrang$ by him = receiv+ on ! same a]ial two messages f diff]5t transmitt+ /ations simultane\sly4 ,9 ?is case1 two lat]al wires ( diff]5t l5g?s are connect$ to ! receiv+ a]ial1 & to ! out] end ( ea* ( ^! is connect$ a coh]] tube1 ! o!r end ( :i* is e>!d ?r\gh a cond5s]4 ,"o ( ^! lat]al wires is made equal1 or ne>ly equal1 9 l5g? to ! a]ial1 & ! o!r is made long] to fulfil ! foll[+ condition4#fe ,if we call ,h ! height ( ! receiv+ a]ial above po9t ( junction ( ! lat]al wires1 !n ! l5g? ( "o lat]al wire is made equal to ,h1 & ! height ( ! a]ial is adju/$ to be equal to "o-qu>t] ( ! wave l5g? ( "o incid5t wave4 ,! o!r lat]al wire may !n be made ( a l5g? equal to "o-?ird ( ,h1 & x w !n respond to ! fir/ odd h>monic ( t wave1 ( :i* ! fundam5tal is 9 syntony ) ! v]tical wire4 ,by suitably *oos+ ! relation betwe5 ! wave-l5g?s ( ! two transmitt+ /ations1 x is possible to receive 9 ?is mann] two diff]5t messages at ! same "t on ! same a]ial4 ,subsequ5tly to ! date ( ! above-m5tion$ demon/ration ( multiplex wireless telegraphy by ,mr4 ,m>coni an exhibition ( a simil> nature 0 giv5 by ,pr(essor ,slaby 9 a lecture giv5 9 ,b]l9 on ,decemb] #bb1 #aijj4ff ,bo? ! above-describ$ syntonic sy/ems ( ,mr4 ,m>coni & ,dr4 ,slaby are e>!d sy/ems1 b arrangem5ts = syntonic telegraphy h be5 devis$ by ,sir ,oliv] ,lodge & ,pr(essor ,braun :i* are non-e>!d4 ,sir ,oliv] ,lodge & ,dr4 ,muirhead h devis$ also syntonic sy/ems4 ,accord+ to _! la/ me?ods1 ! sy/onic transmitt+ & receiv+ arrangem5ts are z %[n 9 ,fig4 #be4fg ,on exam9+ ! diagrams x w be se5 t ! second>y t]m9als ( ! induction coil are1 z usual1 connect$ to a pair ( sp>k balls1 & t ^! sp>k balls are connect$ by a cond5s] & by a v>iable inductance4 ,"o t]m9al ( ! cond5s] is e>!d ?r\gh ano!r cond5s] ( l>ge capacity1 & ! rema9+ t]m9al ( ! fir/ cond5s] is connect$ to an a]ial4 ,x %\ld1 !re=e1 be borne 9 m9d 9 deal+ ) electrical oscillations t a cond5s] ( suffici5t capacity is practically a conductor1 & an inductance coil ( suffici5t inductance is practically a non-conductor4 ,h5ce ! ins]tion ( a l>ge capacity 9 ! pa? ( ! a]ial wire is no advantage :atev] & makes no ess5tial diff]5ce 9 ! arrangem5t4 ,9 ord] to obta9 any p[]ful radiation1 ! l5g? ( ! a]ial1 or sky wire1 z !y call x1 mu/ be s adju/$ t its l5g? is "o-qu>t] ! wave-l5g? correspond+ to ! oscillation circuit1 consi/+ ( ! cond5s] & v>iable inductance4 ,! receiv+ arrangem5t consi/s ( a simil> sky wire or a]ial e>!d ?r\gh a cond5s] ( l>ge capacity & hav+ 9 ! portion above ?is la/ cond5s] ano!r cond5s] ( simil> capacity4 ,at ! e>!d side ( ?is la/ cond5s] a connection is made to a resonant circuit1 consi/+ ( a v>iable inductance1 & ano!r cond5s] & a s5sitive metallic fil+s tube ( ! ,branly type2 also a portion ( ?is resonant circuit is %unt$ by ano!r consi/+ ( a batt]y & telegraphic relay1 z %[n 9 ! diagram4 ,! circuit1 includ+ ! coh]]1 is tun$ to its own a]ial & also to t ( ! transmitt+ circuit1 & "u ^! circum/ances tra9s ( waves ?r[n (f at ! transmitt+ a]ial w sympa!tically affect ! receiv+ a]ial4 ,!re is no?+ 9 ! arrangem5t :i* specially calls = notice4 ,x is simply a v>iation ( o!r kn[n =ms ( syntonic transmitt] & receiv]1 & possesses all ! advantages & disadvantages atta*+ to su* electrical syntonic me?ods4 ,pr(essor ,braun's syntonic sy/em1 ! receiv] & transmitt] ( :i* h be5 describ$1 is also 9 "o =m a non-e>!d sy/em4 ,innum]able o!r pat5tees h tak5 out pat5ts = devices :i* are modifications 9 small degree ( ! above arrangem5ts4 ,x may be well to note at ?is po9t ! disadvantages t are possess$ by any =m ( coh]] z a telegraphic kumascope 9 connection ) propos$ arrangem5ts = ! isolation ( ,h]tzian wave /ations4 ,all ! detectors ( ! coh]] type really dep5d = _! actuation ^u electromotive =ce2 t is to say1 ^u ! application to ! t]m9als ( ! detector ( a c]ta9 electromotive =ce4 ,al?\gh !re may be no %>p & def9$ critical electromotive =ce1 yet1 nev]!less1 z a matt] ( fact1 if ! electromotive =ce appli$ exce$s a c]ta9 value1 !n ! detector passes sudd5ly f "o /ate ( conductivity to ano!r4 ,x may be ( great conductivity1 z 9 ! case ( ! ,branly coh]]1 or ( less] conductivity1 z 9 ! case ( ! s-call$ anti-coh]]s1 ( :i* ! ,s*aef] kumascope may be tak5 z a type4 ,accord+ly1 :5 ^! in/rum5ts are subject$ to a tra9 ( waves1 ea* individual gr\p ( :i* is damp$1 _! op]ation is l>gely gov]n$ by ! fact t if ! fir/ wave or oscillation set up 9 ! receiv+ circuit is p[]ful en\gh to break d[n ! coh]]1 !n ! receiv+ me*anism acts1 no matt] :e!r ! fir/ impulse is foll[$ by o!rs or n4 ,9 comp>ison ) s-call$ coh]]s1 ^? dep5d+ ^u ! *anges 9 ! magnetisation ( iron by electrical oscillations c]ta9ly h an advantage1 because ?is is a process :i* requires ! application ( alt]nat+ electric curr5ts decreas+ 9 /r5g? = a c]ta9 "t2 & x is f\nd1 !re=e1 t ! magnetic receiv]s d n require to be associat$ ) su* a /iff or irresponsive resonant circuit to conf9e _! indications to oscillations or waves ( "o def9ite p]iod1 & t !y l5d !mselves mu* m p]fectly to ! "w ( tun+ or syntonis+ /ations ?an d ^? kumascopes dep5d+ ^u ! contact or coh]] pr9ciple4 ,we may !n glance at ! alt]native solutions ( ! problem (f]$ by o!r inve/igators4 ,m4 ,blondel has propos$ to effect ! syntonisation ( two /ations1 n by syntonis+ ! receiv] = ! exce$+ly high-frequ5cy oscillations ( ! individual electric waves1 b to syntonise x = ! mu* l[] frequ5cy1 correspond+ to t ( ! int]vals betwe5 ! gr\ps ( waves4 ,?us1 = in/ance1 if an ord9>y simple transmitt+ a]ial is set up1 ! production ( sp>ks betwe5 ! sp>k balls results 9 ! emission ( %ort tra9s ( waves1 ea* ( :i* may consi/ ( half a doz5 or m individual waves1 ! "t ( production ( ! :ole gr\p be+ v small comp>$ ) ! int]val betwe5 ! gr\ps4 ,m4 ,blondel proposes1 h[ev]1 to syntonise ! receiv]1 n = ! high-frequ5cy p]iod ( ! waves !mselves1 :i* may be reckon$ 9 millions p] second1 b = ! l[-frequ5cy p]iod betwe5 ! gr\ps ( waves1 :i* is reckon$ 9 hundr$s p] second4 ,?us1 = in/ance1 if sp>ks are made at ! rate ( fifty or a hundr$ p] second1 !y c be made to actuate ! telephone receiv] & s produce 9 ! telephone a s\nd correspond+ to a frequ5cy ( #ej or #ajj2 9 o!r words1 to make a l[ musical note or hum4 ,?is cont9u\s s\nd c be cut up1 by means ( a key plac$ 9 ! prim>y circuit ( ! transmitt+ arrangem5t1 into long or %ort p]iods1 & h5ce ! lett]s ( ! alphabet signal4 ,m4 ,blondel's arrangem5ts comprise a ,m]cadi]'s monotone telephone & ei!r a coh]] or a p>ticul> =m ( vacuum tube z a kumascope4 ,on ,augu/ #af1 #ahih1 ,m4 ,blondel deposit$ ) ! ,academy ( ,sci5ces 9 ,p>is a seal$ envelope conta9+ a description ( 8 improvem5ts 9 syntonic wireless telegraphy1 :i* 0 op5$ on ,may #ai1 #aijj4fh ,! arrangem5t ( ! receiv+ app>atus 0 z foll[s3--,a s+le-batt]y cell keeps a cond5s] *>g$ until ! kumascope is r5d]$ conductive by ! oscillations com+ d[n ! a]ial2 & "u ^! circum/ances ! cond5s] dis*>ges ?r\gh ! telephone & causes a tick to be he>d 9 x4 ,if ! tra9s ( waves are at ! rate ( #ej or #ajj p] second1 ^! small s\nds run toge!r into a musical note1 & ?is cont9u\s hum c be cut up into long & %ort spaces1 9 accordance ) ! ,morse alphabet signals4 ,! telephone mu/ n be an ord9>y telephone1 capable ( be+ influ5c$ by any frequ5cy1 b be "o :i* responds only to a p>ticul> note1 & "u ^! conditions ! receiv+ arrangem5t is receptive only :5 ! tra9s ( waves arrive at c]ta9 regul> pr$et]m9$ int]vals1 correspond+ ) ! tone to :i* ! telephone is s5sitive4 99 99 99 99 99 ,a numb] ( m or less imp]fect arrangem5ts1 hav+ ! isolation ( communications = _! object1 h be5 devis$ or pat5t$1 :i* are dep5d5t ^u ! use ( sev]al a]ials1 ea* suppos$ to be responsive only to a p>ticul> frequ5cy2 & attempts h be5 made to solve ! problem ( isolation by ,,mm4 ,tommasi1 ,tesla1 ,jegon1 ,tissot1 ,ducretet & o!rs4 ,we may !n pass on to notice ! attempts t h be5 made to secure isolation by a plan :i* is n dep5d5t on electrical syntony4 ,"o ( ^!1 :i* has ! appe>ance ( develop+ into a practical solution ( ! problem1 is t due to ,&]s ,bull4#fi ,9 ! fir/ arrangem5ts propos$ by ?is inv5tor1 a receiv] is con/ruct$ :i* is n capable ( be+ act$ ^u m]ely by a s+le wave or tra9 ( waves or ev5 a regul>ly-spac$ tra9 ( electric waves1 b only by a gr\p ( wave tra9s :i* are sep>at$ f "o ano!r by c]ta9 unequal1 pr$et]m9$ int]vals ( "t4 ,?us1 = in/ance1 to take a simple in/ance1 ! transmitt+ arrangem5ts are s devis$ z to s5d out gr\ps ( electric waves1 ^! wave tra9s foll[+ "o ano!r at "t int]vals :i* may be repres5t$ by ! numb]s #a1 #c & #e2 t is to say1 ! int]val :i* elapses betwe5 ! second & ?ird is ?ree times t betwe5 ! fir/ two1 & ! int]val betwe5 ! f\r? & fif? is five times t betwe5 ! fir/ two4 ,?is is a*iev$ by mak+ five electric oscillatory sp>ks ) a transmitt] ( ! ord9>y k9d1 ! int]vals betwe5 :i* are settl$ by ! int]vals betwe5 holes pun*$ ^u /rips ( pap]1 l t us$ 9 a ,:eat/one automatic telegraphic in/rum5t4 ,x w easily be und]/ood t by a device ( ?is k9d1 gr\ps ( sp>ks c be made1 say1 five sp>ks rapidly succe$+ ea* o!r1 b n at equal int]vals ( "t4 ,"o su* gr\p con/itutes ! ,morse dot1 & two or ?ree su* gr\ps succe$+ "o ano!r v quickly con/itute ! ,morse da%4 ,^! waves1 on arriv+ at ! receiv+ /ation1 are caus$ to actuate a pun*+ arrangem5t by ! int]m$iation ( a coh]] or o!r kumascope1 & to pun* ^u a uni=mly mov+ /rip ( pap] holes1 :i* are at int]vals ( "t correspond+ to ! int]vals betwe5 ! sp>ks at ! transmitt+ /ation4 ,?is /rip ( pap] !n passes ?r\gh ano!r telegraphic in/rum5t1 :i* is s con/ruct$ t x pr9ts ^u ano!r /rip a dot or a da%1 accord+ to ! disposition ( ! holes on ! fir/ /rip4 ,accord+ly1 tak5 z a :ole1 ! receiv+ arrangem5t is n capable ( be+ influ5c$ s z to pr9t a telegraphic sign except by ! op]ation ( a s]ies ( wave tra9s succe$+ "o ano!r at c]ta9 assign$ int]vals ( "t4 ,an improvem5t has be5 lately describ$ by ! same inv5tor1#gj 9 :i* ! app>atus us$1 al?\gh m complicat$1 p]=ms ! same functions4 ,at ea* /ation two in/rum5ts h to be employ$2 at ! transmitt+ /ation "o to effect ! conv]sion ( ,morse signals into ! prop]ly arrang$ s]ies ( wave tra9s1 & at ! receiv+ /ation an in/rum5t to effect ! re-conv]sion ( ! s]ies ( wave tra9s into ! ,morse signals4 ,^! are call$ respectively ! disp5s] & ! collector4 ,! details ( ! arrangem5ts are some:at complicat$1 & c only be describ$ by ! aid ( num]\s detail$ draw+s1 b ! inv5tor /ates t he has be5 able to c>ry on ,h]tzian wave telegraphy by means ( ^! arrangem5ts = %ort di/ances4 ,moreov]1 ! me?od l5ds itself to an arrangem5t ( multiplex telegraphy1 by s5d+ out f diff]5t transmitt]s signals :i* are bas$ ^u diff]5t arrangem5ts ( "t int]vals betwe5 ! electric wave tra9s4 ,al?\gh ?is me?od may succe$ 9 prev5t+ a receiv+ arrangem5t f be+ influ5c$ by vagrant waves or waves n int5d$ = x1 yet an objection :i* arises is t !re is no?+ to prev5t any "o f int]cept+ ^! wave tra9s1 & ) a little skill int]pret+ _! mean+4 ,?us1 if ! record 7 receiv$ 9 ! ord9>y way on a simple receiv]1 correspond+ to a ,morse dot w\ld be pr9t$ five dots at unequal int]vals1 & correspond+ to a ,morse da% w\ld be pr9t$ two su* sets ( five dots4 ,a little skill w\ld !n enable an op]ator to int]pret ^! arbitr>y signals4 ,on ! o!r h&1 ! inv5tor ass]ts t he c ov]come ?is difficulty by mak+ int]vals ( "t betwe5 ! impulses 9 ! s]ies s long t ! latt] become long] ?an ! int]vals betwe5 ea* ( ! s]ies ( waves :i* are despat*$ 9 cont9u\s succession :5 ! key is press$ = a da%4 ,9 ?is case1 :5 telegraph+1 ! s]ies ( dots w\ld ov]lap & int]m+le ) ea* o!r 9 a way :i* w\ld make ! record un9telligible if receiv$ 9 ! usual mann]1 b w\ld be p]fectly legible if receiv$ & int]pret$ by a receiv] adapt$ = ! purpose4 ,ano!r way ( oblit]at+ ! record1 z f> z outsid]s are conc]n$1 is to int]polate betwe5 ! gr\ps ( signals an irregul> s]ies ( dots--i4e41 ( wave tra9s--:i* w\ld affect an ord9>y coh]]1 & s make an un9telligible record on an ord9>y receiv]1 b ^! dots are n receiv$ or pick$ up by ! appropriate select+ in/rum5t us$ 9 ! ,&]s ,bull sy/em4 ,! matt] mo/ int]e/+ to ! public at ! pres5t "t is ! long-di/ance telegraphy by ,h]tzian waves to ! accompli%m5t ( :i* ,mr4 ,m>coni has devot$ himself ) s mu* en]gy ( late ye>s4 ,ev]yone1 except p]haps ^? ^: int]e/s may be ?reat5$ by 8 a*ievem5ts1 mu/ accord _! he>ty admiration ( ! indomitable p]sev]ance & c\rage :i* he has %[n 9 ov]com+ ! imm5se difficulties :i* h pres5t$ !mselves4 ,five ye>s ago he 0 engag$ 9 s5d+ signals f ,alum ,bay1 9 ! ,isle ( ,wight1 to ,b\rnem\?1 a di/ance ( twelve or f\rte5 miles2 & to-day he has conqu]$ twice t numb] ( hundr$ miles & succe$$ 9 s5d+1 n m]ely signals1 b long messages ( all descriptions ov] ?ree ?\s& miles across ! ,atlantic4 ,critics !re are 9 abundance1 :o decl>e t ! process c nev] become a comm]cial "o1 t x w de/roy %ort-di/ance ,h]tzian telegraphy1 or t ! multiplication ( long-di/ance /ations w end 9 ! annihilation ( all ,h]tzian wave telegraphy4 ,no "o1 h[ev]1 c contemplate ! hi/ory ( any developm5t ( appli$ sci5ce )\t s]i\sly tak+ to he>t ! lesson t ! ob/acles :i* arise & :i* prove s]i\s 9 any eng9e]+ und]tak+ are nev] ^? :i* occur to arm*air critics4 ,sometimes ! seem+ly impossible proves ! mo/ easy to accompli%1 :il/ difficulties ( a =midable nature (t5 spr+ up :]e lea/ expect$4 ,! long-di/ance transmission is a matt] ( peculi> int]e/ to ! au?or ( ^! articles1 because he 0 at an e>ly /age 9 connection ) x invit$ to r5d] ,mr4 ,m>coni assi/ance 9 ! matt]4#ga ,! p>ticul> "w entru/$ to him 0 t ( plann+ ! electrical eng9e]+ arrangem5ts ( ! fir/ p[] /ation erect$ = ! production ( electric waves = long-di/ance ,h]tzian wave telegraphy at ,poldhu1 9 ,cornwall4 ,:5 ,mr4 ,m>coni return$ f ! ,unit$ ,/ates 9 ! e>ly "p ( #aijj1 he _h arriv$ at ! conclusion t ! "t _h come = a s]i\s attempt to accompli% wireless telegraphy across ! ,atlantic4 ,up to t date ! project _h be5 an inv5tor's dream1 mu* discuss$1 long pr$ict$1 b nev] be=e practically tak5 9 h&4 ,! only appliances1 moreov]1 :i* _h be5 us$ = creat+ ,h]tzian waves 7 induction coils or small trans=m]s1 & ! greate/ di/ance cov]$1 ev5 by ,mr4 ,m>coni himself1 _h be5 some?+ l #aej miles ov] sea4 ,accord+ly1 to grapple ) ! difficulty ( creat+ an electric wave capable ( mak+ itself felt at a di/ance ( #c1jjj miles1 ev5 ) ! delicate receiv+ appliances inv5t$ by ,mr4 ,m>coni1 seem$ to require ! means ( produc+ at lea/ f\r hundr$ times ! wave-en]gy t _h be5 previ\sly employ$4 ,! au?or 01 !re=e1 reque/$ to prep>e plans & specifications = an electric g5]at+ plant = ?is purpose1 :i* w\ld enable electrical oscillations to be set up 9 an a]ial on a scale nev] be=e accompli%$4 ,?is "w involv$1 n m]ely ! ord9>y exp]i5ce ( an electrical eng9e]1 b also ! c>eful consid]ation ( _m new problems & ! con/ruction ( devices n be=e us$4 ,e /ep _h to be made secure by laboratory exp]im5ts be=e ! responsibility c\ld be incurr$ ( advis+ on ! nature ( ! ma*9]y & appliances to be ord]$4 ,_m mon?s 9 ! ye> #aija 7 ?us occupi$ by ! au?or 9 mak+ small-scale exp]im5ts 9 ,london & 9 sup]9t5d5ce ( l>ge-scale exp]im5ts at ! site ( ! fir/ p[] /ation at ,poldhu1 ne> ,mullion1 9 ,cornwall1 be=e ! plant 0 erect$ & any attempt 0 made by ,mr4 ,m>coni to comm5ce actual telegraphic exp]im5ts4 ,z ?is "w 0 ( a highly confid5tial nature1 x is obvi\sly impossible to ent] into ! details ( ! arrangem5ts1 ei!r z made by ! writ] 9 ! fir/ in/ance1 or z !y h be5 subsequ5tly modifi$ by ,mr4 ,m>coni4 ,! design ( ! a]ial & ( ! oscillation trans=m]s & _m ( ! details 9 ! work+ appliances are entirely due to ,mr4 ,m>coni1 b z a f9al result1 a p[] plant 0 erect$ = ! production ( ,h]tzian waves on a scale nev] be=e attempt$4 ,! utilisation ( #ej ,h4,p4 or #ajj ,h4,p4 = electric wave production has involv$ deal+ ) _m difficult problems 9 electrical eng9e]+1 n s mu* 9 novelty ( g5]al arrangem5t z 9 details4 ,x w easily be und]/ood t ,leyd5 j>s1 sp>k balls & oscillators1 :i* are q suitable = use ) an induction coil1 w\ld be de/roy$ imm$iately if employ$ ) a l>ge alt]nat+-curr5t plant & imm5sely p[]ful trans=m]s4 ,illu/ration3 ,,fig4 #bf4--,,wood5 ,,t[]s ,,support+ ,,! ,,m>coni ,,a]ial ,,at ,,poldhu ,,p[] ,,/ation1 ,,cornwall1 ,,engl&4 ,9 ! initial exp]im5ts ) ?is ma*9]y & 9 its fir/ work+ !re 0 v consid]able risk1 ow+ to its novel & dang]\s nature2 b ?r\gh\t ! :ole ( ! "w f ! v beg9n+1 no accid5t ( any k9d has tak5 place1 s great h be5 ! precautions tak54 ,! only ?+ 9 ! nature ( a mi%ap 0 ! collapse ( a r+ ( tall ma/s1 erect$ 9 ! fir/ place to su/a9 ! a]ial wires1 b :i* n[ h be5 replac$ by f\r sub/antial timb] t[]s1 #bae feet 9 height1 plac$ at ! corn]s ( a squ>e1 #bjj feet 9 l5g?4 ,^! f\r t[]s su/a9 a conical arrangem5t ( insulat$ wires 7see ,fig4 #bf7 :i* c be us$ 9 sections & :i* con/itute ! transmitt+ radiator or receiv]1 z ! case may be4 ,ea* ( ^! wires is #bjj feet 9 l5g? & =m$ ( b>e /r&$ wire4 ,at ! outset1 !re 0 mu* unc]ta9ty z to ! effect ( ! curvature ( ! e>? on ! propagation ( a ,h]tzian wave ov] a di/ance ( _m hundr$s ( miles4 ,9 ! case ( ! ,atlantic transmission betwe5 ! /ation at ,poldhu 9 ,cornwall & t at ,cape ,cod 9 ,massa*usetts1 ,u4,s4,a41 we h two /ations sep>at$ by ab\t #de degrees ( longitude on a great circle1 or "o-eigh? "p ( ! circumf]5ce ( ! _w4 ,9 ?is case1 ! v]s9e ( ! arc or height ( ! sea at ! half-way po9t above ! /raight l9e or *ord jo9+ ! two places is #cjj miles4 ,! "q has rec5tly attract$ ! att5tion ( sev]al em95t ma!matical physici/s4 ,! ext5t to :i* a free wave propagat$ 9 a m$ium b5ds r\nd any object or is diffract$ dep5ds on ! relation betwe5 ! l5g? ( ! wave & ! size ( ! object4 ,?us1 = in/ance1 an object ! size ( an orange held j 9 front ( ! m\? does n p]ceptibly int]f]e ) ! propagation ( ! waves produc$ by ! speak+ or s++ voice1 because ^! are f two to six feet 9 l5g?3 b if arrangem5ts are made by means ( a ,galton :i/le to produce air waves half an in* 9 l5g?1 !n an ob/acle ! size ( an orange causes a v di/9ct ac\/ic %ad[4 ,! same ?+ is true ( waves 9 ! e!r4 ,! am\nt ( b5d+ ( light waves r\nd mat]ial objects is exce$+ly small1 because ! av]age l5g? ( light waves is ab\t "o-fifty-?\s&? "p ( an in*4 ,9 ! case ( ,h]tzian wave telegraphy1 we are1 h[ev]1 deal+ ) e!r waves _m hundr$s ( feet 9 l5g?1 & ! waves s5t out f ,poldhu h a wave-l5g? ( a ?\s& feet or m1 say1 "o-fif? to "o-qu>t] ( a mile4 ,! di/ance1 !re=e1 betwe5 ,poldhu & ,cape ,cod is only at mo/ ab\t twelve ?\s& wave-l5g?s1 & /&s 9 ! same relation to ! l5g? ( ! ,h]tzian wave us$ z does a body ! diamet] ( a pea to ! wave-l5g? ( yell[ light4 ,!re is unque/ionably a l>ge am\nt ( diffraction or b5d+ ( ! electric wave r\nd ! e>?1 &1 proportionately speak+1 x is l>g] ?an 9 ! case ( light waves incid5t on objects ( ! same relative size4 ,q rec5tly ,mr4 ,h4 ,m4 ,macdonald 7see ,proc4 ,roy4 ,soc41 ,london1 ,vol4 ,,lxxi41 p4 #bea7 has submitt$ ! problem to calculation1 & has %[n t ! p[] requir$ to s5d giv5 electric waves #c1jjj miles along a m]idian ( ! e>? is great] ?an w\ld be requir$ to s5d !m ov] ! same di/ance if ! sea surface 7 flat 9 ! ratio ( #aj to #c4 ,h5ce ! rotundity ( ! e>? does introduce a v important r$uction factor1 al?\gh x does n inhibit ! transmission4 ,mr4 ,macdonald's ma!matical argum5t has1 h[ev]1 be5 criticis$ by ,"l ,rayleigh & by ,m4 ,h4 ,po9c>e 7see ,proc4 ,roy4 ,soc41 ,vol4 ,,lxxii41 p4 #dj1 #aijc74 ,! accompli%m5t ( v long di/ances by ,h]tzian wave telegraphy is1 h[ev]1 n m]ely a "q ( p[]1 x is also a "q ( wave-l5g?4 ,hav+ reg>d1 h[ev]1 to ! possibility t ! propagation :i* takes place 9 ,h]tzian wave telegraphy is n t simply ( a free wave 9 space1 b ! transmission ( a semi-loop ( electric /ra9 ) its feet te!r$ to ! e>?1 x is q possible t if x 7 wor? :ile to make ! attempt1 an e!r di/urbance c\ld be made 9 ,engl& suffici5tly p[]ful to be felt 9 ,new ,zeal&4 ,leav+1 h[ev]1 ^! hypo!tical que/ions & matt]s ( pure conjecture1 we may consid] "s ( ! facts :i* h result$ f ,mr4 ,m>coni's long-di/ance exp]im5ts4 ,"o ( ! mo/ int]e/+ ( ^! is ! effect ( daylight ^u ! wave propagation4 ,9 "o ( 8 voyages across ! ,atlantic1 :5 receiv+ signals f ,poldhu on bo>d ! ,s4,s4 ,philadelphia1 he notic$ t ! signals 7 receiv$ by night :5 !y c\ld n be detect$ by day4#gb ,9 ^! exp]im5ts ,mr4 ,m>coni in/ruct$ 8 assi/ants at ,poldhu to s5d signals at a c]ta9 rate f #ab to #a a4m41 f #f to #g a4m41 f #ab to #a p4m41 & f #f to #g p4m41 ,gre5wi* mean "t1 e day = a week4 ,he has /at$ t on bo>d ! ,philadelphia he did n notice any app>5t diff]5ce betwe5 ! signals receiv$ 9 ! day & ^? receiv$ at night until aft] ! vessel _h rea*$ a di/ance ( #ejj /atute miles f ,poldhu4 ,at di/ances ( ov] #gjj miles1 ! signals transmitt$ dur+ ! day fail$ entirely1 :ile ^? s5t at night rema9$ q /rong up to #a1eea miles1 & 7 cle>ly deciph]able up to a di/ance ( #b1jii miles f ,poldhu4 ,mr4 ,m>coni also not$ t at di/ances ( ov] #gjj miles1 ! signals at #f a4m41 9 ! week betwe5 ,febru>y #bc & ,m>* #a1 7 q cle> & di/9ct1 :]eas by #g a4m4 !y _h become weak almo/ to total disappe>ance4 ,?is fact l$ him at fir/ to conclude t ! cause ( ! weak5+ 0 due to ! action ( ! daylight ^u ! transmitt+ a]ial1 & t z ! sun rose ov] ,poldhu1 s ! wave en]gy radiat$1 dim9i%$1 & he sugge/$ z an explanation ! kn[n fact ( ! dissipat+ action ( light ^u a negative *>ge4 ,al?\gh ! facts seem to support ?is view1 ano!r explanation may be sugge/$4 ,x has be5 %[n by ,pr(essor ,j4 ,j4 ,?omson t gase\s ions or electrons c absorb ! en]gy ( an electric wave1 if pres5t 9 a space ?r\gh :i* waves are be+ transmitt$4#gc ,if x be a fact1 z sugge/$ by ,pr(essor ,j4 ,j4 ,?omson1 t ! sun is project+ into space /reams ( electrons1 & if ^! are cont9ually fall+ 9 a %[] ^u ! e>?1 9 accordance ) ! fasc9at+ hypo!sis ( ,pr(essor ,arrh5ius1 !n t portion ( ! e>?'s atmosph]e :i* is fac+ ! sun w h pres5t 9 x m electrons or gase\s ions ?an t portion :i* is turn$ t[>ds ! d>k space1 & x w !re=e be less transp>5t to long ,h]tzian waves4#gd ,9 o!r words1 cle> sunlit air1 ?\gh extremely transp>5t to light waves1 acts z if x 7 a slightly turbid m$ium = long ,h]tzian waves4 ,! divid+ l9e betwe5 t portion ( ! e>?'s atmosph]e :i* is impregnat$ ) gase\s ions or electrons is n %>ply delimit$ f ! "p n s illum9at$1 & !re may be1 !re=e1 a consid]able p5etration ( ^! ions into ! regions :i* ,i may call ! twilight areas4 ,accord+ly1 z ! e>? rotates1 a di/rict 9 :i* ,h]tzian waves are be+ propagat$ is br\ght1 t[>ds ! "t ( sunrise1 into a position 9 :i* ! atmosph]e beg9s to be ionis$1 al?\gh f> f z freely z is ! case dur+ ! h\rs ( bright sun%9e4 ,mr4 ,m>coni /ates t he has f\nd a simil> effect betwe5 inl& /ations1 signals hav+ be5 receiv$ by him dur+ ! night betwe5 ,poldhu & ,poole ) an a]ial ! height ( :i* 0 n suffici5t to receive !m by day4 ,x has be5 f\nd1 h[ev]1 t ! effect simply am\nts to ?is1 t r m p[] is requir$ by day ?an by night to s5d signals by ,h]tzian waves ov] long di/ances4 ,"s int]e/+ obs]vations h also be5 made by ,capta9 ,h4 ,b4 ,jackson1 ,r4,n41#ge on ! influ5ce ( v>i\s /ates ( ! atmosph]e ^u ,h]tzian wave telegraphy4 ,^! exp]im5ts 7 all made betwe5 %ips ( ! ,briti% ,royal ,navy1 furni%$ ) ,h]tzian wave telegraphy app>atus on ! ,m>coni sy/em4 ,"s ( 8 obs]vations conc]n$ ! effect ( ! int]positon ( l& betwe5 two %ips4 ,he f\nd t ! int]position ( l& conta9+ iron ores r$uc$ ! signall+ di/ances1 comp>$ ) ! maximum di/ance at op5 sea1 to ab\t #cj p] c5t4 ( ! latt]2 :il/ h>d lime/one r$uc$ x to ne>ly #fj p] c5t4 & s(t s&/one or %ale to #gj p] c5t4 ,^! results %[ t !re is a consid]able absorption effect :5 waves ( c]ta9 wave-l5g? pass ?r\gh or ov] h>d rocks conta9+ iron ores4 ,x w\ld be int]e/+ to "k1 h[ev]1 :e!r ?is r$uction 0 9 any degree proportional to ! dryness or moi/ure ( ! soil4 ,e>? conductivity is f> m dep5d5t ^u ! pres5ce or abs5ce ( moi/ure ?an ^u ! p>ticul> nature ( ! mat]ial :i* composes x o!r ?an wat]4 ,! obs]vations ( ,capta9 ,jackson1 h[ev]1 only confirm ! already well-kn[n fact t ,h]tzian waves1 z employ$ 9 ! ,m>coni sy/em ( wireless telegraphy1 )9 a c]ta9 range ( wave-l5g?1 are consid]ably weak5$ by _! passage ?r\gh l&1 ov] l& or r\nd l&4 ,9 "s cases he notic$ t q %>p electric %ad[s 7 produc$ by rocky promontories project+ into ! l9e ( transmission4 ,8 att5tion 0 also direct$ 7loc4 cit47 to ! m important matt] ( ! effect ( atmosph]ic electrical conditions ^u ! transmission4 ,! effect ( all lightn+ dis*>ges1 :e!r visible or invisible1 is to make a record on ! telegraphic receiv]4 ,on ! approa* ( an atmosph]ic electrical di/urbance t[>ds ! receiv+ /ation on a %ip1 ! fir/ visible indications g5]ally are ! record+ ( dots at int]vals f a few m9utes to a few seconds on ! telegraphic tape4 ,capta9 ,jackson /ates t ! mo/ frequ5t record is t ( ?ree dots1 ! fir/ be+ sep>at$ f ! o!r two by a slight int]val l ! lett]s ,e ,i on ! ,morse code1 & ?is is ! sign mo/ frequ5tly record$ by di/ant lightn+4 ,b 9 addition to ?is1 da%es are record$ & irregul> signs1 :i*1 h[ev]1 sometimes spell out words 9 ! ,morse code4 ,he not$ t ^! di/urbances are m frequ5t 9 summ] & autumn ?an 9 w9t] & spr+1 & 9 ! neighb\rhood ( high m\nta9s m ?an 9 ! op5 sea4 ,9 settl$ wea!r1 if pres5t1 !y rea* _! maximum betwe5 #h p4m4 & #aj p4m41 & frequ5tly la/ dur+ ! :ole ( ! night1 ) a m9imum ( di/urbance betwe5 #i a4m4 & #a p4m4 ,ano!r important matt] not$ by ,capta9 ,jackson is ! %ort] di/ance at :i* signals c usually be receiv$ :5 any electrical di/urbances are pres5t 9 ! atmosph]e1 comp>$ ) ! di/ance at :i* !y c be receiv$ :5 none are pres5t4 ,?is r$uction 9 signall+ di/ance may v>y f #bj to #gj p] c5t1 ( t obta9able 9 f9e wea!r4 ,x does n 9 any way decrease ) ! numb] ( lightn+ fla%es1 b r ! rev]se1 ! loss 9 signall+ di/ance g5]ally prec$+ ! fir/ indications on ! in/rum5t ( ! approa*+ electrical di/urbance4 ,x is cle> t ^! obs]vations fit 9 v well ) ! !ory outl9$ above1 viz41 t ! atmosph]e :5 impregnat$ ) free electrons or negatively-*>g$ gase\s ions is m opaque to ,h]tzian waves ?an :5 !y are abs5t4 ,capta9 ,jackson gives an in/ance ( %ips ^: normal signall+ di/ance 0 #fe miles1 fail+ to communicate at #bb miles :5 9 ! neighb\rhood ( a region ( electrical di/urbance4 ,^! effects 9 ! case ( wireless telegraphy h _! p>allel 9 ! di/urbances caus$ to telegraphy ) wires by e>? curr5ts & magnetic /orms4 ,ano!r effect :i* he /ates r$uces ! usual maximum signal+ di/ance is ! pres5ce ( mat]ial p>ticles held 9 susp5sion by ! wat] sph]ules 9 moi/ atmosph]e4 ,! effect has be5 notic$ 9 ! ,m$it]ranean ,sea :5 ! sirocco w9d is bl[+4 ,?is is a moi/ w9d convey+ du/ & salt p>ticles f ! ,african coa/4 ,a consid]able r$uction 9 signall+ di/ance is produc$ by its adv5t4 ,ano!r int]e/+ obs]vation due to ,capta9 ,jackson is ! exi/5ce ( c]ta9 zones ( weak signals4 ,?us1 = in/ance1 two %ips at a c]ta9 di/ance may be communicat+ well2 if _! di/ance increases1 ! signall+ falls (f1 b is improv$ aga9 at a /ill great] di/ance4 ,he advances an +5i\s !ory to %[ t ?is fact may be due to ! int]f]5ce betwe5 two sets ( waves s5t out by ! transmitt] hav+ diff]5t wave-l5g?s4 ,f9ally1 9 ! ,pap] ref]r$ to1 he emphasises ! well-kn[n fact t long-di/ance signall+ c only be accompli%$ by ! aid ( an a]ial wire & a good e>?4 ,summ+ up 8 results1 he concludes3 7#a7 ,t int]v5+ l& ( any k9d r$uces ! practical signall+ di/ance betwe5 two %ips or /ations1 comp>$ ) t :i* w\ld be obta9able ov] ! op5 sea1 & t ?is loss 9 di/ance v>ies ) ! height1 ?ickness1 cont\r1 & nature ( ! l&2 7#b7 mat]ial p>ticles1 su* z du/ & salt1 held 9 susp5sion 9 a moi/ atmosph]e also r$uce ! signall+ di/ance1 probably by dissipat+ & absorb+ ! waves2 7#c7 t electrical di/urbances 9 ! atmosph]e also act mo/ adv]sely 9 addition to affect+ ! receiv+ in/rum5t & mak+ false signals or /rays1 z !y are call$2 7#d7 t ) c]ta9 =ms ( transmitt+ arrangem5t1 int]f]5ce effects may take place :i* h ! result ( creat+ c]ta9 areas ( sil5ce v simil> to ^? :i* are obs]v$ 9 connection ) s\nd signals f a sir54 ,x is cle>1 !re=e1 f all ! above obs]vations1 t ,h]tzian-wave telegraphy tak+ place ?r\gh ! t]re/rial atmosph]e is n by any means equival5t to ! propagation ( a wave 9 free or empty space2 & t j z ! atmosph]e v>ies 9 its opacity to rays ( light1 sometimes be+ cle> & sometimes cl\d$1 s x v>ies f "t to "t 9 transp>5cy to ,h]tzian waves1 ! cause ( ?is v>iation 9 transp>5cy probably be+ ! pres5ce 9 ! atmosph]e ( negatively-*>g$ corpuscles or electrons4 ,if !re are pres5t 9 ! atmosph]e at c]ta9 times cl\ds ( electrons or electronic fogs1 ^! may h ! effect ( produc+ a c]ta9 opacity1 or r dim9ution 9 transp>5cy to ,h]tzian waves1 j z wat] p>ticles d 9 ! case ( sunlight4 ,we may1 !re=e1 9 conclusion1 review a few ( ! out/&+ problems await+ solution 9 connection ) ,h]tzian wave wireless telegraphy4 ,9 spite ( ! fact t ?is new telegraphy has n be5 accord$ a v he>ty welcome by ! repres5tatives ( (ficial or e/abli%$ telegraphy 9 ,great ,brita91 x has rea*$ a po9t1 unque/ionably ow+ to ,mr4 ,m>coni's en]gy & inv5tive p[]1 at :i* x is b\nd to cont9ue its progress4 ,b t progress w n be assi/$ by %utt+ our eyes to facts4 ,_m problems ( great importance rema9 to be solv$4 ,we h n yet rea*$ a complete solution ( all ! difficulties connect$ ) isolation ( /ations4 ,9 ! next place1 ! "q ( localis+ ! s\rce ( ! signals & waves is mo/ important4 ,our kumascopes & receiv+ appliances at pres5t are l ! rudim5t>y eyes ( ! l[] organisms1 :i* are probably s5sitive to m]e diff]5ces 9 light & d>kness1 b :i* are n able to see or visualise1 9 ! s5se ( locat+ ! direction & di/ance ( a radiat+ or lum9\s body4 ,j z we h1 z little *ildr51 to le>n to see1 s a simil> process has to be accompli%$ 9 connection ) ,h]tzian telegraphy1 & ! accompli%m5t ( ?is does n seem by any means impossible or ev5 di/ant4 ,we are deal+ ) hemisph]ical waves ( electric & magnetic =ce1 :i* are s5t out f a c]ta9 radiat+ c5tre1 & 9 ord] to localise t c5tre we h to det]m9e ! position ( ! plane ( ! wave & also ! curvature ( ! surface at ! receiv+ po9t4 ,some?+1 !re=e1 equival5t to a range f9d] 9 connection ) light is necess>y to enable u to locate ! di/ance & ! direction ( ! radiant po9t4 ,la/ly1 !re are important improvem5ts possible 9 connection ) ! g5]ation ( ! waves !mselves4 ,at ! pres5t mom5t1 our mode ( g5]at+ ,h]tzian waves involves a dissipation ( en]gy 9 ! =m ( ! light & heat ( ! sp>k4 ,j z 9 ! case ( ord9>y artificial illum9ants1 su* z lamps ( v>i\s k9ds1 we h to manufacture a l>ge am\nt ( e!r radiation ( long wave l5g?1 :i* is ( no use to u = visual purposes--9 fact1 creat+ n9ety-five p] c5t1 ( d>k & useless waves = e five p] c5t4 ( lum9\s or useful waves--s 9 connection ) pres5t me?ods ( g5]at+ ,h]tzian waves1 we are b\nd to manufacture by ! dis*>ge sp>k a l>ge am\nt ( light & heat rays :i* are n want$1 9 ord] to create ! ,h]tzian waves we desire4 ,x is impossible yet to /ate precisely :at is ! effici5cy1 9 ! ord9>y s5se ( ! ^w1 ( a ,h]tzian wave radiator2 h[ mu* ( ! en]gy imp>t$ to ! a]ial falls back ^u x & contributes to ! production ( ! sp>k1 & h[ mu* is dis*>g$ into ! e!r 9 ! =m ( a wave4 ,no?+ is m rem>kable1 h[ev]1 ?an ! small am\nt ( en]gy :i*1 if prop]ly utilis$ 9 electric wave mak+1 w suffice to influ5ce a s5sitive receiv] at a di/ance ( ev5 "o or two hundr$ miles4 ,suppose1 = in/ance1 t we *>ge a cond5s] consi/+ ( a batt]y ( ,leyd5 j>s1 hav+ a capacity ( "o sev5ty-fif? ( a micr(>ad1 to a pot5tial ( #ae1jjj volts2 ! en]gy /or$ up 9 ?is cond5s] is !n equal to #a4e j\les1 or a little m ?an "o foot-p\nd4 ,if ?is en]gy is dis*>g$ 9 ! =m ( a sp>k five millimetres 9 l5g? ?r\gh ! prim>y coil ( an oscillation trans=m]1 associat$ ) an a]ial #aej feet 9 height1 ! circuits be+ prop]ly tun$ by ,mr4 ,m>coni's me?od1 !n su* an a]ial w affect1 z he has %[n1 "o ( ,mr4 ,m>coni's receiv]s1 includ+ a nickel silv] fil+s coh]] tube1 at a di/ance ( ov] two hundr$ miles ov] sea4 ,consid] :at ?is means4 ,! en]gy /or$ up 9 ! ,leyd5 j>s _c all be radiat$ z wave en]gy by ! a]ial1 probably only half ( x is ?us radiat$4 ,h5ce ! imp>tation to ! e!r at any "o locality ( ab\t half a foot-p\nd ( en]gy 9 ! =m ( a long ,h]tzian wave is suffici5t to affect s5sitive receiv]s situat$ at any po9t on ! circumf]5ce ( a circle ( #bjj miles radius describ$ on ! op5 sea4 ,h]tzian wave telegraphy is sometimes describ$ z be+ extravagant 9 p[]1 b1 z a matt] ( fact1 ! mo/ rem>kable ?+ ab\t x is ! small am\nt ( p[] really involv$ 9 conduct+ x4 ,on ! o!r h&1 ,h]tzian wave manufacture is n altoge!r a matt] ( p[]4 ,x is mu* m dep5d5t ^u ! mann] 9 :i* ! e!r is /ruck4 ,j z half an ounce ( dynamite 9 explod+ may make m noise ?an a ton ( gunp[d]1 because x hits ! air m sudd5ly1 s ! =mation ( an effective wave 9 ! e!r is bett] a*iev$ by ! "r application ( a small en]gy ?an by ! wrong mode ( application ( a mu* l>g] am\nt4 ,if we translate ?is fact into ! language ( electronic !ory1 x am\nts simply to ?is4 ,x is ! electron alone :i* has a grip ( ! e!r4 ,to create an e!r wave1 we h to />t or /op cr[ds ( electrons v sudd5ly4 ,if 9 motion1 _! motion implies en]gy1 b x is n only _! en]gy :i* is conc]n$ 9 ! wave mak+1 b ! accel]ation1 positive or negative--i4e41 ! quickness ) :i* !y are />t$ or /opp$4 ,x is possible we may discov] 9 "t a way ( manufactur+ long e!r waves )\t ! use ( an electric sp>k1 b at pres5t we "k only "o way ( do+ ?is--viz41 by ! dis*>ge ( a cond5s]1 & 9 ! dis*>ge ( l>ge cond5s]s ( v high pot5tials x is difficult to secure t extreme sudd5ness ( />t+ ! dis*>ge :i* we c d 9 ! case ( small] capacities & voltages4 ,h[ /range x is t ! dis*>ge ( a ,leyd5 j> /udi$ s pr(\ndly by ,frankl91 ,h5ry1 ,f>aday1 ,maxwell1 ,kelv9 & ,lodge %\ld h become an electrical eng9e]+ appliance ( great importance6 ,:il/ !re are _m matt]s connect$ ) ! comm]cial aspect ( ,h]tzian wave telegraphy ) :i* we are n "h conc]n$1 !re is "o on :i* a ^w may prop]ly be said4 ,! ability to communicate ov] long di/ances by ,h]tzian waves is n[ demon/rat$ beyond "q1 & ev5 if all difficulties are n ov]come at once1 x has a field ( v practical utility1 & may ev5 become ( national importance4 ,"u ^! circum/ances1 we may consid] :e!r x is absolutely necess>y to place ! signall+ /ations s ne> ! coa/4 ,! great] facility ( transmission ov] sea has already be5 discuss$ & expla9$1 b 9 "t ( w>1 ! ma/s & t[]s :i* are ess5tial at pres5t 9 connection ) transmitt+ /ations c\ld be wreck$ by %ot or %ell f an enemy's battle%ip at a di/ance ( five or six miles out at sea1 & w\ld c]ta9ly be done )9 t]ritorial wat]s4 ,%\ld n ?is "q receive att5tion 9 *oos+ ! location ( important signall+ /ations8 ,= if !y c1 )\t prejudice to _! use1 be plac$ inl& by a di/ance suffici5t to conceal !m f sight1 _! value z a national asset 9 "t ( w> might be greatly increas$4 ,x has be5 (t5 cont5d$ t :il/ cables c\ld be cut 9 "t ( w> no "o c cut ! e!r2 b wireless telegraph /ations 9 expos$ situations on high promontories1 :]e !y are visible = t5 to fifte5 miles out at sea & undef5d$ by any =ts1 c\ld easily be de/roy$4 ,! great t[]s :i* are ess5tial to c>ry l>ge a]ials are a conspicu\s object = t5 miles out at sea2 & a s+le well-plac$ %ell f a six-in* gun w\ld wreck ! place & put ! /ation completely out ( use = _m mon?s4 ,h5ce if oceanic telegraphy is ev] to be conduct$ 9 a mann] 9 :i* ! communication w be inviolable or1 at any rate1 n be capable ( int]ruption by acts ( w>1 ! c>eful selection ( ! sites = /ations is a matt] ( importance4 ,a small /ation consi/+ ( a s+le #aej-;foot ma/ & a wood5 hut c easily be remov$ or replac$1 b an exp5sive p[] /ation1 ! m]e a]ial ( :i* may co/ sev]al ?\s& p\nds1 is n to be put up 9 a %ort "t4#gf ,mean:ile1 :atev] may be ! future a*ievem5ts ( ?is new sup]m>9e wireless telegraphy conduct$ ov] long di/ances1 !re c be no "q z to its enorm\s utility & pres5t value = int]communication betwe5 %ips on ! ocean & %ips & ! %ore4 ,at ! pres5t "t1 !re are "s =ty or m ( ! transatlantic ocean l9]s & _m o!r %ips equipp$ ) ?is ,h]tzian wave wireless telegraph app>atus on ! ,m>coni sy/em4 ,provid$ ) ?is late/ weapon ( appli$ sci5ce1 !y are able to *at ) "o ano!r1 ?\gh a hundr$ miles ap>t on ! ocean1 ) ! ease ( gue/s r\nd a d9n] table1 to ex*ange news or make dem&s = assi/ance4 ,%ips t pass 9 ! night1 & speak ea* o!r 9 pass+-- ,only a signal %[n1 & a di/ant voice 9 ! d>kness2 ,s1 on ! ocean ( life1 we pass & speak "o ano!r1 ,only a look & a voice1 !n d>kness aga91 & a sil5ce4 ,abundant exp]i5ce has be5 ga!r$ to %[ ! inexpressible value ( ?is means ( communication 9 case ( accid5t1 & x c h>dly be d\bt$ t be=e long ! possession ( ?is app>atus on bo>d e pass5g] vessel w be dem&$ by ! public1 ev5 if n made compulsory4 ,al?\gh ! privacy ( an ocean voyage may h be5 some:at dim9i%$ by ?is utilisation ( e!r waves1 !re is a va/ comp5sation 9 ! security t is !reby ga9$ to human life & prop]ty by ?is late/ application ( ! great en]gies ( nature = ! use & b5efit ( mank9d4 ,,geo4 ,,tuek]1 ,,pr9t]1 ,,salisbury ,,c\rt1 ,,fleet ,,/reet1 ,,london4 #a ,?is s]ies ( articles is bas$ on ! ,cantor ,lectures deliv]$ be=e ! ,society ( ,arts1 ,london1 9 ,m>*1 #aijc4 ,! lectures 7 att5d$ by _m ( ! lead+ ,briti% sci5tific m5 & electrical eng9e]s1 & attract$ wide att5tion z ! mo/ complete & au?oritative /atem5t hi!rto made ( wireless telegraphy4 ,9 writ+ ! articles = ! ,popul> ,sci5ce ,mon?ly1 ! au?or has omitt$ advanc$ te*nicalities 9 ord] t ! sub/ance may be suitable = ! g5]al read]4--,,editor4 #b ,= a m detail$ acc\nt ( ?is hypo!sis1 ! read] is ref]r$ to an article by ! pres5t writ]1 entitl$ ,! ,electronic ,!ory ( ,electricity1 publi%$ 9 ! ,popul> ,sci5ce ,mon?ly = ,may1 #aijb4 #c ,see ,j4 ,j4 ,?omson1 ,rec5t ,rese>*es 9 ,electricity & ,magnetism1 *ap4 ,i41 p4 #af4 #d ,see ,o4 ,heaviside1 ,electromagnetic ,!ory1 ,vol4 ,i41 p4 #ed4 #e ,wi$emann's ,annal51 #cf1 p4 #a1 #ahhi2 or 9 8 republi%$ ,pap]s1 ,electric ,waves1 p4 #acg1 ,engli% translation by ,d4 ,e4 ,jones4 #f ,! fraction #g_/bb "h d5otes a /r&$ wire =m$ ( sev5 /r&s1 ea* s+le wire hav+ a diamet] express$ by ! numb] #bb on ! ,briti% /&>d wire gauge4 #g ,g4 ,m>coni1 ,syntonic ,wireless ,telegraphy1 ,j\rnal ( ! ,society ( ,arts1 ,vol4 ,,xlix41 p4 #eja1 #aija4 #h ,in/ruction = ! manufacture ( l>ge induction coils may be obta9$ f a ,treatise on ! ,con/ruction ( ,l>ge ,induction ,coils1 by ,a4 ,t4 ,h>e4 7,me?u5 ,co41 ,london47 ,also see ,vol4 ,,ii4 ( ,! ,alt]nate-,curr5t ,trans=m]1 by ,j4 ,a4 ,flem+1 *ap4 ,i4 7,! ,electrician ,pr9t+ & ,publi%+ ,co41 #a1 #b & #c1 ,salisbury-c\rt1 ,fleet-/reet1 ,london1 ,e4,c47 #i ,see ,! ,alt]nate-,curr5t ,trans=m]1 by ,j4 ,a4 ,flem+4 ,vol4 ,i41 p4 #ahd4 #aj ,du ,moncel /ates t ,mac,gauley ( ,dubl9 indep5d5tly inv5t$ ! =m ( hamm] break z n[ us$4 ,see ,! ,alt]nate-,curr5t ,trans=m]1 ,vol4 ,,ii4 *ap4 ,i4 ,j4 ,a4 ,flem+4 #aa ,see ,pr(essor ,j4 ,tr[bridge1 ,on ! ,induction ,coil ,phil4 ,mag41 ,april1 #aijb ,vol4 ,,iii41 ,s]ies #f1 p4 #cic4 #ab ,see ,dr4 ,wehnelt's article 9 ! ,elektrote*nis*e ,zeits*rift1 ,janu>y1 #ahii4 #ac ,see ,! ,electrician1 ,vol4 ,,xlii41 #ahii1 pp4 #gba1 #gbh1 #gca1 #gcb & #hda2 communications f ,mr4 ,campbell ,sw9ton1 ,pr(essor ,s4 ,p4 ,?ompson1 ,dr4 ,m>*ant1 ! au?or & o!rs2 also p4 #hfd1 same volume1 = a lead] on ! subject2 also p4 #hgj1 lett]s by ,m4 ,blondel & ,pr(essor ,e4 ,?omson4 ,see also ,! ,electrician1 ,vol4 ,,xliii41 p4 #e1 #ahii1 extracts f a ,pap] by ,p4 ,b>ry2 ,comptes ,r5dus1 ,april1 #ahii4 ,see also ! ,electrical ,review1 ,vol4 ,,xliv41 p4 #bce1 #ahii1 ,febru>y #ag4 #ad ,see ,! ,electrician1 ,vol4 ,,xlii41 #ahii4 #ae ,= a discussion ( ! function ( ! cond5s] 9 an ord9>y induction coil1 see ,! ,alt]nate-,curr5t ,trans=m]1 by ,j4 ,a4 ,flem+4 ,vol4 ,,ii41 p4 #ea4 #af ,see ,"l ,rayleigh1 ,phil4 ,mag41 ,decemb]1 #aija4 #ag ,x has sometimes be5 /at$ t ! sp>k balls mu/ be solid metal & no holl[1 b ?is is a fallacy1 & has be5 disprov$ by ,mr4 ,c4 ,a4 ,*ant4 ,see ,an ,exp]im5tal ,inve/igation into ! ,sk9 ,effect 9 ,electrical ,oscillators1 ,phil4 ,mag41 ,vol4 ,,iii41 ,sec4 #f1 p4 #dbe1 #aijb4 #ah ,see ,proc4 ,roy4 ,soc41 ,london1 ,febru>y #bc & ,april #ab1 #ahfj2 or repr9t ( ,pap]s on electro/atics & magnetism1 p4 #bdg4 #ai ,see ,phil4 ,mag41 ,augu/1 #aijb1 ,vol4 ,,iv41 p4 #bbd1 #f? ,s]ies4 ,mr4 ,j]vis-,smi? has also describ$ an exp]im5t to %[ h[ mu* ! use ( compress$ air r\nd a sp>k gap is ( advantage 9 work+ an ord9>y ,tesla coil4 ,9 8 ,briti% specification1 ,no4 #ab1jci ( #ahif1 ,mr4 ,m>coni _h long previ\sly m5tion$ ! use ( compress$ air r\nd ! sp>k gap4 #bj ,?is en]gy /orage is at ! rate ( #dd foot-p\nds p] cubic foot ( glass4 ,?is figure %[s :at a relatively small am\nt ( en]gy is capable ( be+ /or$ up 9 ! =m ( electric /ra9 9 glass4 ,9 ! case ( an air cond5s]1 x is only /or$ at ! rate ( #a foot-p\nd p] cubic foot4 #ba ,see ,briti% specification ,no4 #g1ggg ( #aijj4--;,g4 ,m>coni4 ,improvem5ts 9 ,app>atus = ,wireless ,telegraphy4 #bb ,t ?is numb] really does repres5t ! ord] ( ?is oscillation frequ5cy 9 an a]ial has be5 %[n by ,c4 ,tissot1 ,comptes ,r5dus1 #acb1 p4 #gfc1 ,m>* #be1 #aija1 by photographs tak5 ( ! oscillatory sp>k ( a ,h]tzian wave telegraphic transmitt]4 7,see ,sci5ce ,ab/racts1 ,vol4 ,,iv41 ,abs4 #a1eah47 ,he f\nd frequ5cies f #j4e million to #a4f million4 #bc ,! t]m jigg] is "o ( ^? slang t]ms :i* contrive to effect a p]man5t atta*m5t to v>i\s arts & crafts4 ,simil>ly1 ! ^w boo/] is n[ us$ = a /ep-up or voltage-rais+ trans=m] or dynamo1 ins]t$ 9 s]ies ) an electric supply ma94 ,! ^w boo/ is a slang t]m signify+ to raise or lift up4 ,to give a real good boo/ is an expression = l5d+ a help+ h&4 ,! t]m jigg]1 9 ! same mann]1 is an adaptation ( a seaman's t]m = hoi/+ tackle or lift4 #bd ,! e>? itself probably only conducts electrolytically4 ,all su* mat]ials z s&1 clay1 *alk1 etc41 & mo/ surface soils are fairly good insulators :5 v dry1 b conduct 9 virtue ( moi/ure pres5t 9 !m4 #be ,! ,electrician1 ,vol4 ,,xl41 p4 #hf 7lead]74 #bf ,briti% ,pat5t ,specification1 ,c4 & ,s4 ,a4 ,v>ley1 ,no4 #afe1 #ahff4 #bg ,see also ,j\rnal de ,physique1 ,vol4 ,v41 p4 #egc1 #ahhf4 #bh ,see ,comptes ,r5dus1 ,vol4 ,,cxi41 p4 #ghe2 ,vol4 ,,cxii41 p4 #aab1 #ahia2 or ,la ,lumi]e ,electrique1 ,vol4 ,,xl41 pp4 #cja1 #ejf1 #ahia2 or ,! ,electrician1 ,vol4 ,,xxvii41 #ahia1 pp4 #bba1 #ddh4 #bi ,see ,! ,electrician1 ,vol4 ,,xxix41 #ahib1 pp4 #cig & #dcb4 #cj ,mr4 ,w4 ,b4 ,cr(t1 ,proc4 ,phys4 ,soc41 ,vol4 ,,xii41 p4 #dba4 ,report ( meet+ on ,octob] #bg1 #ahic4 #ca ,see ,pr(essor ,m9*91 ,proc4 ,phys4 ,soc41 ,novemb] #bd1 #ahic2 or ,! ,electrician1 ,vol4 ,,xxxii41 #ahic1 p4 #abc4 ,see also ,pr(essor ,m9*91 ,phil ,mag41 ,janu>y1 #ahid1 ,vol4 ,,xxxvii41 p4 #ij1 ,on ! ,action ( ,electromagnetic ,radiation on ,films conta9+ ,metallic ,p[d]s4 #cb ,?is lecture 0 aft]w>ds publi%$ z a book1 ! fir/ edition be>+ ! same title z ! lecture--viz41 ,! ,"w ( ,h]tz & ,"s ( ,8 ,successors4 ,9 ! second edition1 publi%$ 9 #ahih1 an app5dix 0 add$ 7p4 #ei7 conta9+ ,! ,hi/ory ( ! ,coh]] ,pr9ciple1 & ! orig9al title ( ! "w _h prefix$ to x ,signall+ ,)\t ,wires4 #cc ,see ,! ,electrician1 ,vol4 ,,xxvii41 p4 #bbb1 #ahia4 ,e4 ,branly1 ,v>iations ( ,conductivity "u ,electrical ,influ5ce4 #cd ,see ,! ,electrician1 ,vol4 ,,xl41 p4 #ij4 ,sir ,oliv] ,lodge1 ,! ,hi/ory ( ! ,coh]] ,pr9ciple4 #ce ,see ,pr(essor ,e4 ,branly1 ,a ,s5sitive ,coh]]1 ,comptes ,r5dus1 ,vol4 ,,cxxxiv41 p4 #a1ahg1 #aijb2 or ,sci5ce ,ab/racts1 ,vol4 ,v41 p4 #heb1 #aijb4 #cf ,?is device ( mak+ ! int]-electrode gap 9 a tubul> fil+s coh]] w$ge-%ap$ has be5 pat5t$ aga9 & aga9 by v>i\s inv5tors4 ,see ,g]man pat5t ,no4 #aaf1aac1 ,class #ba;a1 #aijj4 ,x has also be5 claim$ by ,m4 ,tissot4 #cg ,see ,! ,electrician1 ,vol4 ,,xxvii41 #ahia1 p4 #ddh4 #ch ,j\rnal ( ! ,russian ,physical & ,*emical ,society1 ,vol4 ,,xxviii41 ,division ( ,physics1 ,"p ,i41 ,janu>y1 #ahif4 #ci ,see ,briti% ,pat5t ,specification ,no4 #ab1jci1 ,june #b1 #ahif4 #dj ,briti% ,pat5t ,specification ,no4 #ai1gaj ( #ahii4 #da ,comptes ,r5dus41 ,vol4 ,,cxxviii41 p4 #a1bbe1 #ahhi2 ,sci5ce ,ab/racts1 ,vol4 ,,ii41 p4 #eba4 #db ,il ,nuovo ,cim5to1 ,vol4 ,x41 p4 #bgi1 #ahii4 #dc ,wi$ ,ann41 ,vol4 ,,lxviii41 p4 #eid1 #ahii2 ,sci5ce ,ab/racts1 ,vol4 ,,ii41 p4 #geg4 #dd ,comptes ,r5dus1 ,vol4 ,,cxxx41 p4 #ijb1 #aijj2 ,sci5ce ,ab/racts1 ,vol4 ,,iii41 p4 #fae4 #de ,see ,proc4 ,roy4 ,soc41 ,london1 ,vol4 ,,lxxi41 p4 #djb4 #df ,see ,report by ,capt4 ,qu9t9o ,bonomo1 ,telegrafia ,s5za ,fili1 ,rome1 #aijb2 ,l',elettrici/a1 ,s]4 ,,ii41 ,vol4 ,i41 pp4 #aah1 #agc4 #dg ,see ,royal ,in/itution1 ,friday ev5+ disc\rse1 by ,mr4 ,m>coni1 ,june #ac1 #aijb2 also ,! ,electrician1 ,vol4 ,,xlix41 p4 #dij2 also a lett] to ,! ,times ( ,july #c1 #aijb1 by ! ,m>*ese ,luigi ,sol>i4 #dh ,see ,u4,s4,a4 ,pat5t ,specification ,no4 #gjj1afa1 ,may #bd1 #aijj4 #di ,see ,e4 ,m>x1 ,phys4 ,zeits*rift1 ,vol4 ,,ii41 p4 #bdi2 ,sci5ce ,ab/racts1 ,vol4 ,,iv41 p4 #dga4 ,see also ,g]man ,pat5t ,specification ,no4 #aba1ffc1 ,class #ba;a4 #ej ,see ,! ,sci5tific ,writ+s ( ,pr(essor ,joseph ,h5ry4 #ea ,phil4 ,trans4 ,roy4 ,soc41 ,london1 #ahig1 ,vol4 ,,clxxxix4,a1 p4 #a4 #eb ,see ,proc4 ,roy4 ,soc41 ,london1 ,june #ab1 #aijb4 ,note on a ,magnetic ,detector = ,electric ,waves :i* c be employ$ z a ,receiv] = ,space ,telegraphy1 by ,g4 ,m>coni4 #ec ,see ,u4,s4,a4 ,pat5t ,specification ,no4 #gaf1jjj1 ,application ( ,july #e1 #aija4 #ed ,see ! ,electrical ,review1 ,vol4 ,,xliv41 #ahii1 ,may #bf2 ,wi$ ,ann41 ,vol4 ,,lxviii41 p4 #ib2 or ,g]man ,pat5t ,specification ,no4 #ajg1hdc4 #ee ,u4,s4,a4 ,pat5t ,specification ,no4 #gjf1gdb1 #aijb4 #ef ,see ,briti% ,pat5t ,specification1 ,g4 ,m>coni1 ,no4 #ab1jci1 ,june #b1 #ahif4 #eg ,see ,g4 ,m>coni1 ,briti% ,pat5t ,specification ,no4 #ab1cbf1 ( ,june #a1 #ahih4 #eh ,see ! ,electrical ,review1 ,septemb] #bf1 #aijb1 ,vol4 ,,li41 p4 #edc4 #ei ,!re is a good deal ( contradiction betwe5 v>i\s inv5tors on ?is po9t1 "s say+ t e>!d a]ials obviate atmosph]ic electrical di/urbances1 & o!rs t insulat$ a]ials are 9 ?is respect sup]ior4 ,! tru? appe>s to be t1 nei!r =m is absolutely free f risk ( di/urbance by ?is cause4 #fj ,! capacity ( an electrical circuit corresponds to ! ela/ic pliability1 or :at is commonly call$ ! ela/icity1 ( a mat]ial sub/ance1 & ! inductance to mass or in]tia4 ,h5ce capacity & inductance are qualities ( an electric circuit :i* are analog\s to ! ela/icity & in]tia ( su* a body z a heavy spr+4 #fa ,see ,cantor ,lectures1 on ,electrical ,oscillations & ,electric ,waves1 deliv]$ be=e ! ,society ( ,arts1 ,london1 ,novemb] #bf1 ,decemb] #d1 #aj1 #ag1 #aijj4 ,lecture ,i41 p4 #ab1 ( repr9t4 #fb ,a full] acc\nt ( ^! exp]im5ts 0 giv5 by ! au?or 9 a lett] to ! ,london ,times publi%$ on ,april #ad1 #aijc4 #fc ,see ,j\rnal ( ! ,society ( ,arts1 ,vol4 ,,xlix41 p4 #eje4 ,syntonic ,wireless ,telegraphy1 by ,g4 ,m>coni4 #fd ,see ,g]man ,pat5t ,specifications1 ,class #ba;a1 ,no4 #g1deb ( #aijj1 & also ,no4 #h1jhg ( #aija4 #fe ,see ,g]man ,pat5t ,specification1 ,class #ba;a1 ,no4 #g1dih ( #aijj1 appli$ = ,novemb] #i1 #aijj4 ,! above-m5tion$ pat5t is subsequ5t 9 date to ,mr4 ,m>coni's exp]im5ts on ! same subject4 #ff ,see ,! ,electrician1 ,janu>y #ah1 #aijj1 ,vol4 ,,xlvi41 p4 #dge4 ,also repr9t ( a ,pap] ( ,pr(essor ,a4 ,slaby1 ,abge/immte und mehrfa*e ,funk5telegraphie4 #fg ,see ,briti% ,specification ,no4 #aa1cdh ( #aija4 #fh ,see ,comptes ,r5dus1 ,may #ba1 #aijj2 ,rapports du ,congres ,int]national d',electricite1 ,p>is1 #aijj1 p4 #cda4 #fi ,see ,! ,electrician1 ,vol4 ,,xlvi41 p4 #egc1 ,febru>y #h1 #aija4 #gj ,see ,! ,electrician1 ,vol4 ,l41 p4 #dah1 ,janu>y #b1 #aijc4 #ga ,see ,mr4 ,m>coni's ,friday ev5+ disc\rse at ! ,royal ,in/itution1 ,june #ac1 #aijb2 also ,! ,electrician1 ,vol4 ,,xlix41 p4 #cij4 #gb ,see ,proc4 ,roy4 ,soc41 ,june #ab1 #aijb4 ,a ,note on ! ,effect ( ,daylight ^u ! ,propagation ( ,electromagnetic ,impulses ov] ,long ,di/ances1 by ,g4 ,m>coni4 #gc ,see ,phil4 ,mag41 ,vol4 ,,iv41 p4 #bec1 ,s]ies #f1 ,augu/1 #aijb4 ,j4 ,j4 ,?omson1 ,on ,"s ,consequ5ces ( ! ,emission ( ,negatively-electrifi$ ,corpuscles by ,hot ,bodies4 #gd ,! op9ion t ionisation ( ! air by sunlight is a cause ( ob/ruction to ,h]tzian waves propagat$ ov] long di/ances has also be5 express$ by ,mr4 ,j4 ,e4 ,taylor4 ,see ,proc4 ,roy4 ,soc41 ,vol4 ,,lxxi41 p4 #bbe1 #aijc4 ,*>act]i/ics ( ,e>? ,curr5t ,di/urbances & _! ,orig94 #ge ,see ,proc4 ,roy4 ,soc41 ,may #ae1 #aijb4 ,on ,"s ,ph5om5a affect+ ! ,transmission ( ,electric ,waves ov] ! ,surface ( ! ,sea & ,e>?1 by ,capta9 ,h4 ,b4 ,jackson1 ,r4,n41 ,f4,r4,s4 #gf ,mr4 ,m>coni has in=m$ ! writ] t ^! /rategic que/ions h receiv$ att5tion 9 select+ ! sites = l>ge ,m>coni p[] /ations 9 ,italy4 99 99 99 99 99 ,detail$ ,transcrib]'s ,notes ,! text has be5 made to mat* ! orig9al text z mu* z possible reta9+ all app>5t pr9t]'s errors & inconsi/5cies4 ,! foll[+1 detail ! app>5t pr9t]'s errors etc4 id5tifi$ 9 ! orig9al text4 ,v>iation 9 spell+1 ,/rasburg & ,/rassburg = ,/rasb\rg4 ,!re are a numb] ( inconsi/5cies 9 hyph5ation pres5t 9 ! orig9al text4 ,^? conc]n$ ) ! v>iation betwe5 "o ^w or a hyph5at$ ^w are detail$ bel[4 ,^? conc]n$ ) ! v>iation betwe5 multiple words & hyph5at$ words are too num]\s to detail individually4 ,inconsi/5t hyph5ation ( ^w1 'anti-node' & 'ant9ode' bo? pres5t 9 orig9al text4 ,inconsi/5t hyph5ation ( ^w1 'electro-dynamic' & 'electrodynamic' bo? pres5t 9 orig9al text4 ,inconsi/5t hyph5ation ( ^w1 'horse-%oe' & 'horse%oe' bo? pres5t 9 orig9al text4 ,inconsi/5t hyph5ation ( ^w1 'ov]-bl[+' & 'ov]bl[+' bo? pres5t 9 orig9al text4 ,page #e1 possible pr9t]'s error1 a = at1 'consi/+ :5 a re/'4 ,page #f1 pr9t]'s error1 comma r ?an full /op at end ( s5t5ce1 'e!r con/itut+ electric radiation1'4 ,page #aj1 pr9t]'s error1 millmetre = millimetre1 '?ree ?\s& volts p] millmetre1'4 ,page #ac1 possible pr9t]'s error1 set = sets1 '!re are ?ree set ( ph5om5a'4 ,page #ac1 pr9t]'s error1 duplicate ^w1 'deta*$ & & travel away4'4 ,page #ac1 brackets add$ to 9-l9e equation to aid cl>ity1 ',f 7#c_/h7;,,cv#b_/ajf4'4 ,page #ac1 bo? equations orig9ally multi-l9e fraction1 r5d]$ into "o l9e = cl>ity4 ,page #ae1 bo? equations orig9ally multi-l9e fraction1 r5d]$ into "o l9e = cl>ity4 ,page #bb1 pr9t]'s error1 correpond+ = correspond+1 'correpond+ to ?is frequ5cy'4 ,page #bb1 pr9t]'s error1 consi/ = consi/s1 'due to ,braun1 consi/ ( atta*+'4 ,page #bd1 pr9t]'s error1 "o-hundre? = "o-hundr$?1 'capacity ( "o-hundre? ( a micr(>ad1'4 ,page #bh1 pr9t]'s error1 miss+ full /op at end ( s5t5ce add$1 '9 ! case ( ! hamm] break4'4 ,page #cc1 pr9t]'s error1 supppse = suppose1 ',let u supppse'4 ,page #dd1 equation orig9ally multi-l9e fraction1 r5d]$ into "o l9e = cl>ity4 ,page #df1 pr9t]'s error1 comma r ?an full /op at end ( s5t5ce1 'to ! transmitt+ a]ial1'4 ,page #dh1 possible pr9t]'s error1 alt]ations = alt]nations1 'alt]ations ( electric /ra9'4 ,page #ed1 pr9t]'s error1 ,banly = ,branly1 'prov$ t 9 a ,banly tube1'4 ,page #ef1 v>iation 9 spell+1 uns5sitive = ins5sitive1 'w\nd$ & uns5sitive4'4 ,page #ei1 possible pr9t]'s error1 s5sive = s5sitive 'to "w a s5sive record+ app>atus'4 ,page #ei1 possible pr9t]'s error1 arragem5t = arrangem5t1 'mo/ int]e/+ arragem5t'4 ,page #fa1 pr9t]'s error1 miss+ lett] i1 'z %[n n ,fig4 #ah1'4 ,page #gj1 equation orig9ally multi-l9e fraction1 r5d]$ into "o l9e = cl>ity4 ,page #ga1 pr9t]'s error1 osciilat+ = oscillat+1 'to t ( ! osciilat+ circuit'4 ,page #ga1 pr9t]'s error1 impluse = impulse1 '! p]iod ( t impluse'4 ,page #gd1 possible pr9t]'s error1 extra comma 9 date1 'on ,may1 #ag1 #aija4'4 ,page #gf1 pr9t]'s error1 arangem5ts = arrangem5ts1 'v>iation ( ! above arangem5ts'4 ,page #gg1 pr9t]'s error1 sy/onic = syntonic1 '! sy/onic transmitt+'4 ,page #hf1 pr9t]'s error1 int]positon = int]position1 'effect ( ! int]positon ( l&'4 ,page #hg1 pr9t]'s error1 signal+ = signall+1 '! usual maximum signal+'4 ,footnote #ag1 pr9t]'s error1 miss+ lett] t1 'mu/ be solid metal & no holl[1'4 ,footnote #ca1 pr9t]'s error1 miss+ full /op aft] abbreviation1 ',phil ,mag4'4 ,footnote #da1 pr9t]'s error1 extra full /op aft] ref]5ce1 ',comptes ,r5dus4'4