^ '«'• vr.^ { ■^H i IMAGE EVALUATION TEST TARGET (MT-3) 1.0 1.1 1.25 m Ml L4_ 11^ tr ¥ *i t ,_^^- ,.^,.* -^ 1 • <«^:**!■ dV i Canadian Instituta for Hiatori€al Microraproductiont / InatHut Canadian da mlcroraproductlona hiatoriquaa TIM iMllMM Ml a tmmi n »4 !• IMV to MMtafrapMwNv •ftfMlHMptln MfMVMWtVV •llM* of f MMRln^ flfV L'lNMliMl • miwofMM* l« IM4NMH •■•Miplakc «i'M ^fd MHt« pMrt-4tra on ^ piMum •■IfW WM aM^HlMOWl lU □ -*- D^ CoHMTitirt rwlMirte f t/ev p< mt i oompta tanu da la condition at da la nattat4 da I'aiiamplaira fllm4. at •n eonformiti avao laa conditiona du tontrat do fllmaga. ^ ' Jfit is Laa awamplalraa orlglnaux "dont la oouvartiiro %n paplar ast imprimOa aont fllm4a an oomman^ant par la pramiar plat at •n tarmtnant salt par la "darnlAra paga qui comporia uno ampralnta d'Imprasblon ou d'illuatratlon. aOlt par la aaoond plat, salon la cas. Tous laa autraa aiiamplalraa orlginauK sont fiimAa on oommangant par lo pramlAra paga qui oomporta una afjiprolnta d'impraaalon ou d'llluatration at an tarmlnant par la darnlAra paga qui oomporta una talla - ampralnta. ^ Un Has symbolas sulvants apparatira auT la darnlAra Imaga da ohaqua miorofloha. salon la C«s: la symbols — ^ signifla "A tUIVRI". la •ymbolaV signifla "FIN". ' '' Las oartaa, plandhfa, tablatUK. ato.. pauvant Itra fitm«s * das tauM da r«duotion dIffAranta. Lorsqua lo documant ast trop grand pour ttra raprodult on un soul olioh*. 11 oat film* i partir da I'angia supAriaur gauoha. da gauoha i droito. ot da haut an baa. on pranant la nombra d'lmagas n^oossaira. Laa diagrpmmaa aulvanta llluatrant la mAthoda. ■A . s , ^ •> . ♦ ■■ ■ 1 / 2 ;. 3 9 ,. 1 . ■ V"' -. .' ,-■ ' 4 .. 5 6 ■..::::...::?::::::^.j._ii • ■■ ■ '■ " ' ' '■ -. ;■''"■ - ■'■■ : ^' •■ '-•■.■'*.-■ ^ . - " • ■ ■ n f,« vl: •J f^OU THE nmqACnOKS of THI royal society of C4NA0A iBCOMO VOI.WI#Ji. ,r..*- J-, }i'V; f. ■ \ ;, . . . ilCTlOM IM J. ; , .'■■■■' '^ MAtNBMATieAU PNYtlOAL AND OHBMIOAL •CIBNCM »■■ 'I «•>- . »» ■■*■ A ■♦•:;v/ ,^#? ■ ]Elcctw ScriBciiiiig in Vacuum Tube* \' \- / :\ .. ..^ Mclennan, b Pbjrtica, Unhrtrti^ A., Ph.D« of Toraato "^ J. Ron * tout, OtTAWA'i THB COPT^LAKK CO^ TORONTO MRNAMP QUARITCH. LONDOM. INOLAMD ^ ^ ^ 1900 vL» !Mj/il /■>, ^^'r* ""P^^^ » .f HI., two (MJ m\ aaa f #" * ^ *' . By J. a VoUirirAjr, B.A., Ph.p. * ^ OvmoMUktor In I'byalea. UnlvMvlty of TorooUv (rommiinlraUit by l>raald«nt l^oudon and r*«a May W, igoa) In hia work •ntitltd " DlMh»rgt of Kl«ctrlcity through QumT piffo no, l»rofeMOT J. J. Thoiwon d«oribM an tffcot whioh h« obwrrwl In • soriet of experiment, with Faraday cylindari inawtwl in Ttoanm (ub«a for tha protection of oiploring alaotrodoa. _„ In th«M izparlmanU tubaa aimilar in form to that ahown in Mf. 1 wera tiaed. An axploring alactroda C. waa aealad into tha taba and aur- , rounded by a metal cylinder /;. Tha end of thia cylindar facing tha bulb of (ha diicharga tuba waa oloaed by a plata of aoma aelaotad matal •ach u aluminium or braM. A amall opening e wrved to equaliae tha air praaaurea inaida and ouUida tha oyUndar, and airaboniU plug oloaad tha lower end and acted aa a aupport to hold tha oyUndar> poaition. On pauing an electric discharge through thaaa tubaa no nnoanal lotion waa obaenred at high preMurcn ; but when a preaiure of about ona milllmetro of moroury waa raaohed the gas within the oylindor Iwonmo conducting, and alaotrio chnrgea given to the inoloaod eloo- trodaa warn gradually diaatpated. With praaaurea low enough to allow tho cathode raya to full upon the and of t|i« ^lindar, the protected electrode gained a nagaUTe oharga. With atlll higher azhaua- tiona tho uma effect waa obtained, but tho rate at which tho negativo charge waa gained • rapidly inoraaaed aa tha preaanre waa lowered. The effect waa obtained when tha anda Off the cylindara were oloaed by plates ranging •11 tha way ftom thin aluminium foil up to • brasa IB mma. in thiokneaa, but tha rate at whIoh tho charge waa acquired by tho elec- trode deoreaaad with tha thioknon of tho plataaelM^. in d&uaring thia aflbot Profuaaor Thom- bon brought forward the hypotheais that Sf^ti^a*" *** ■°'"* "^"•' P"^"«^ »» t»« «M suffoiindlDg ■■■::.%: ^.:'^-.--^- ■'^'-■.'/.'■■v-: ...,..: -i:-.---: -■•;-'^'' "■■..''■••■ • r .#,*. "H %fi .it^amaaaaaijiajai \^£M W IK>YAL KWnRT Of CANADA U k vdli known that UiMt rajn tnpnM •iMthaal Modaailvitj vpMi fiMt which Ui«7 trtfCTM, tod U Ui gtMimlly affTMd that Umj oooiial of fcry tnull oagiUrtlj charged partlclM of matUr. Th«ir prM«na« Withta th« ejrliadcn would tl\«r«fur« account for the obaarTwl oonduo* Uvlty, atfd for th« ncgaUvo chargw gaiood by tlM •i«etnKla at U>v pniiimai ^ Hut thtra ar« diffleulti« eoiiii«flt«d with tha rappotad prodtifltian of catho coma nagativaly chargad, and acting aa ntw cathodaa may hara pr«>> Jactad atraama of oathoda raya agaiuat tha alaotroda. Am an objaotion to thia tsplanation it may ba pointad out thai vlMB tha diaohaiga tubaa wara axo^Ud. tha cylindan wara always oo»* naetad to aarth by wirca of amall nhtanca. It tharafora aaama pro* babla that if portiona of cylinders acquired potantiala auAciantly high to produce dischargee of eathode rays, theee dischargee would aleo have bean "accompanied by electric currents of considerable intensity abnf the e%rth wiree. There appears, however, to be no indication that such currents existed, and in defsult ol further eiperimental eTidenoe tha hypothesis of sccondsry discliarges seems hardly tenable. The object of the exparimenta described in this paper was to in« vestigata this point more fully and to determine, if possible, a mora satisfsctory explanation of the effect. The inrcstigation was begun with tubes identical in construction with those uied by Professor Thomson, but as these could not ba taken apart to make changes in the cylinders the experiments wera com* pleted with tubes somewhat modiflcd in form. The experiments sro described under the foUowiag sobdiYiaiona }•-• 1. Preliminary ex|)erimants. 2. Electrical conduction along the surface of glasa. 8. Penetrating power of cathode rays. -^ , 4. Influence of bsd earth connections. 0. Influence of small openings in Faraday qrlindara iaaarlad in Tscuum tubas. f, ./ - Caimua) MUonuo KUnmiirQ tN y^kOVVU Tf ma I. FUUMIKAIT IsVMlMWm. U IMM MpwtaMto Ml dlor* ««• nad* to work um itf ptwiMlf ^ *^ ^ftdHioM u ikom mUcUd by fnammf Thommm. Th. form of t«b« uMd. m lUwd, m«,Uoii«i. «t« tkai .ho,, in fy;* ;. '^'»« *'*nd»j eyllniUr /> whirh Mrv.d m • wrMa f or Um •!«•■ r? \r* ^ ''«»«*•»*» »» -rU, by m-n. of • H„. pUi,„u,„ »,,, of Uik cjUndor «m m.od Inatiktor. mn wm ia.« to prt f.al any i.di f„o, ,b, .j^^^, „^, j^ ,^^ ^^,^j !!ft? l"**"*"^*' T*^ -^ 'w- to- to tlma through out tli« tiporimanU •how.d that thia InaukUon aufflo^l to maintalainT OhtrgB f ivtn to th« •loctrtKia «hcn Hi« tub« waa not axoltMl. Tho tab* waa kapt coanactwl to • marvory pomp throochovl tiio inrntlfilion and waa aioitod by aa tifht inch apark l.n«ih Induction coll runnin, undar a taoai|g^f aight tolta. Tha aiploriBg alactrod. waa Jolnad to a quadimnt m»omat*r and tbia lnatnim«.t tofthar with tha oonnaoUng wlra WM^nnroundad by an oarth connactad oos. ductor In ordtr to lerara off alaotrootoUo aetioa. ii. ^u**!*! ^T ~°'**"°°^ »* ^ '-"d t^ on paaaing a diaoharga through tha tuba tha alaotromatar indioalad no acUon until a pmanr. Ii.H^k"* Z\ "'"i™*" °' "•"«'7 waa raachad. At thia praaaui., with tha ooil joinad to any two of tha thraa Unninala A. B and D, poai- tlra or nagaUra ohargaa giran to tha protaotad alaotitKla gradually laakad oha^. Thia chargf. howarar, did not go on inmaaing whan tho dbcharga waa paaaing. but aftar • tima raaohad a Unitini ndoa and then ramainad aUtionary. •-.» •ma ana nlua x^f tha UmiUng oharga inciaaa^l and waa mora qoicUy cached. mm. praaanm ao low that oathoda rmya could trafana tA bnlb of * J 'JLT'*"'"'*'^ diacharga aulll<»d, whan A actad aa a otthode , i^^!^ r^*"* *^°°** "*• "^ '' **»• •••ctromatar, a Talua whJoh iadiottad a charga of at laaat flva or aiz toIU. ^ Although thia atatamant rapraanita in a ganaral way tho molta ob- tainad, it waa aieaadingly dUBeuIt to trace uniformity in tha tffecta It frequently happened that the electrode C, inatead of wodting a negal 1 r.i jT' "?u •? ' r1"" '«•' "^^ »»^ -P*rf^y the caae wh« AtaAB were tho torminala and ndther oonnaoUd to earth. III,. > * Mz^^^. \ KdYAL MlCtVrt Of CAHAbA If IkfjiMrwto v«f« gtw iMNi t IpaHUT* «f • MfiliT* aliarg* aaUflMM* »ikMi lh« tMrmtMU H Mi 4 ««f« flMUMciad by • •!!• m4 iMth Mtad •ImuiUiMoiMljr m <«tlvi4«s wUh Ji m th« wiatU AIm Ukr<}tt^M»«*t tt>« •■tMrtmanK tuiMm andl vIoImiI tMlMtuiM vara ts*- «|iMnUjr obuuMtl whiflh mmomU lu imitcaU airoof iiMlaeUfa mUini Mh «oni|wnl««l by •|wrlila( wllkUi Um •jUna«r. Willi Ukla form of tuba Iha ramUta wmtm aieaadiagty unaitlilMtary. OwlRff to gM balng ffiTan uff bj th« matel It vaa dlfll«itll to niAlnUts 1^ aamo dafvva u( akhauatlon for any Ungth of tiflM. TW obarwtor «f Iha dlMharg* aIm MMiMd to b« 4ira«tod bjr Um tl*!* ol Um alaatfo«l«iV Ul4 It VM aofiMquatttly alnoat Impoaalbla to rafMrotioM all tha cua- dlUona ntmmmj !• a^ ft fivpir W ja |Mi iga j rf wwiilt o^^ •! dlffartnt tiniaa. Biiiilii. Ik* fMsday cyllndM Ummwa^hm tmm dafael*. BohiM. tof» \m ahowa IImI wIw« a vlgorwua dlaeharfa U pwawl through ooo Mmpartroant of a racuum tuba tha gaa In an adjoining ona ia aUo thrown into ■ araaiUva ttaU. It waa Juat poaaibla than that, though Iha opmlBf C iarvad t« aqualiaa tha piaaatirM, it alau alTordad, by dlffa> •Ion, a rnaana of communicating to tha gaa inalda tha cylinder tha con* duotivity lmpr«aa«i up«>n that ouUida by tha diaoharga fiooi tha iadiM- Item coU. Again, In thU form of tuba tha aUotroda naeaaaarlly ptMad through tha glaaa -and could not tharafora ba oomptaUly aarroondad by tha aylindar. In ofdar to ovarooma any diaturbing influanoa ariaing from thaa* dafacU, and to lo<»liia mora daflnitoly Iha affaat UiYaaUgatad, a nav form of tuba iraa darkad which could raadily ba takan apart and whioh did not raqaira aran a amaU opanlng in tha Faraday oylindar. I. KLaOTBIOAL COWDOOTIOM AU)l»0 TMa BOBfAOB Of OutM. Thla form of tuba which ia ihown in Fig. II, waa ditldad into two eompartmanU whioh could ba aaparaUIy axhaualad. Tha mate! cyllii- dar D in thii oaaa fonnad p«rt of a matal aockat H into whioh tha glaaa parta of tha tuba wara faatanad. Air tight Jointa wara mada by In- •arting rubbar waahara h batwaan two barallad braaa onea, and than compraiaing tha whola by a thraadad brua plaoa which alid otar Iha gla« and could ba tciawad into tha aockat Tha uppar and of tha cylindar waa mada alr'Mghi by placing laad Vtahaft abota and balow tha plata d and than acrawtng a btaaa op *♦#-■' -^ iM'iMMj mMsnm «aunuio li VApnai ^mb hi Mia* lk«A >laA^ ^ :ji« . * \ iil' lM«fe««M. .igkl U Mi4 *r IW M4 .^tlM 4grUa4«r ••rtJl iliruMgh iIm nwiH /I. BapnIaiMila wen iiM iimi|« b^ •iU«m|- litff tH« upiwr rlMMilwr, «MI« ik« la«w«M WM liifit at •lmin«(«r atlt^^lMMl lo th* •iMtnxJ* fgi^, Uw alightaM witl.m,, of w,j .iMtHo Mtlon Tl« two MM|Ninn««ii of Um laU ««,« in united, M .howB |„ n^ II, ^ p^ ▼W*l with tk« Wm. UL ri«.ii. to|« ir Md /p. On Umb r»«ihftiMUngtli«ap|Mr ebftaUr and kasping ih« up F oloMd, oo Mtion WM ofaMnrwl ubUI • prManr* wmvwhat, low«r than • ■illliflMtra of marourjr waa raachad . At Uiia point tha aJaotromatar hagan to g»ln • MffaUra oharga, and Uia notion bacama mora lotanna •• \ht •Rbaoation prooaadad . Il WM^^rj Wrongly markad whan A npd Jf wara tha larmlnala, and wa|i"maaaar- •bla, thoogb fbabia, wban il and # Wwa tba dlaobargiag aiaotrodat, Tha alkot appwtrad to ba allghi* I7 grwter wban U wm tha oathoda nad ^ tb« anoda, than whan tb* oppodta airangamant wm mada. At tha air in tba lowar ohambar WM at atmoaphario praarara dur- '*;- ft I ■\ §0 lOVAl. MXSNrV Of CAII4DA |» onl«r to l«l Oil* llM •l*'tn»««« w« •i«|»ly «»««««^ to IM MB •* ittH-U «f to Ih. .l-fllr^^U C. Dm IkM •M*««| Uto i«fc« «fc« MM tltorglBt MltMi «■• tMalMl tusUtor for mmII t«»Ur« •«'h m Iho*. mm[ in lMUn« Ih. iMaUtUm of lh« .l.«i«^ ^' •»»«« «« «i»«'h*H« ^ P^»»f '» ">• *•'»•'* •" iMl fuflUitMll to ml off wmdiwttoii «loti| Ui« fl«M wHwi IM WW ••• Millli If ttt Murium coll, T» ©f#«iw Uib dimfl«tly p»t •# tiw ll«i tab* *i l^^lli l»*^»*^ Md f^U«*l by oiM of hnm h.W in poiaikm by tmiiag WM. WlUi tWJ |«b« )Bt»it to •«!!» th« •ipwtmwito JimI iU«rU|M * tad f w«« k-pl MM iBd both rh«mb«. .ih.u-U.1 U.f*th«r until kny d«tir«l pr«««i» ^ fmch»A Th. Up !• irt» l^ fik*d tad th* «h»ui4lo« In l»to apptr ehambvr compUtoA • . . j . ..-*• to lye viy • wid« rang* of praMurM wm •nmtn«d tnd In no tarn dl4 tiM tUctioiMtor fiM Mj Indlonlion U«t th» •l-ctrod. V •Hhm l^n*d or lo«t « charri irh«» th« tub* wm •icitwi. In til th... t.^ th« Up F »M k«i»t rliwKl wh«n th« dUch«rg« wm pMilng In th« tnbt in onl.r U» pr«»»nt tny po-ibU conduction In th. gu from on. ch«mb«f to Ih. otiitr. This wm found to b. Mp.oi.Uy n.cMMry .t »try low prM- inf. wh«i A ud // mm tm\^i»A m th. dlich.rflng .loctrodM. Oth». wiM th. w.U known ph.noro.non illu«tr«t«l by Hlttorf. .ipwinMOto o«eurr«d. th. dtacharg. prtftrHng to Uk. th« longw p«th rt.und by th« tub* M, r, «lh«r th*n th. .hort on. icroM th. bolb of th. tub. from th. oylindw P to th. dlM il. In .11 th. .ip«4ni«iU with thU form of tub. Itith.rto dwfirlbMl th. «»d of th. cylindw D coMi.t«l of • dkc of alomlnium d 04 mUU- nMtiM thick. Thk diM wm now r.pl.rwl by on. only MMH millimptrM In thlckn.M tnd both chamber. w.ro m highly .ih.uit*! M poMibl.. Th. Up F WM th«i cloMd .nd th. tub. .icit^l. Different m.thod. of conn.cUng th. coil to tH. tub. wtro tri.d but in frery cm. th. cylinder •Mill dTMtlTrif. icmndl th.#lictrod. C, and no charging wa. ob- ^^ Ch*riMgitfnlnd.p«id«itlytoth..lactrod.Ow»a»laomaiii. 1, ^ .if. ^ f"« Ul1«NtM) BUmmi » ' -.4 •*»;! s ' •7. Ui«ki»^ • (wiMii of timlUr nyt t^w^fmm Ui« »fpmiU tm^m ol Um Mi^^.on «ohI<1 |m«, bMS gtvwi hf lk» •tmif»mMm tl Mlt if|gM|ii •I L*mM r«y« wlUila th« eyUnAmt .* f f/ ,, INl Iha UiVMl prMsurM slUiiMbU villi Uii* fens of Mt liillf f^n^t«4 %h» Mthml* (lark aiMMt io aiUoU aWut wm ImUI tb« 4i«UiMw r*^ \ ■" ' T*_ t, I l^Hiia. ihTrfOPI. Bat NMk tiM 4iw 4( IM» «||h«fe „y, «„,|rt iHjii WMl. ikk fonn «! U^ »m thm of jM iirflM la looUnc th« MOM of th« •dm ftkmmd hf Ptotmmf T«.i|Mon it wm not •alUbU fot tiM prtidaetlon of Ui* l<>w«it Motel «lU«li il «onUla«(l. A Ihlnl tbtm of tuba wm tlian dovliMRl In oni«r to •munln* Iho. onrMming Milon of Fonula/ o/ltn- 4mm ■« vory bw |trMMirm 1. PBM«TIATtM« POWU Off OA-raora ILvib In thU tuK ^n. IT., tko •lofltrio MnMnliiK wm portly bnnif ht nbout by th« um of mcr- oory. TWo tub* Uwlf oonoUtiMi of two p«rUi, whioh wvra iinitotl 1^ o oorofullj ground JoUil, onU tko ogrliBdor D woo modo fVom • Moot tab* bdd in poriUon by fltllng tightly to • plug of «b«>n- iU ft. Tbid plugkiM* fltl4Kl tight- ly to coBtrmI gloM tubo, ond wao plomwi. M ahown in ^i flguro, by • •moll liola whivb |wrmittod tha proMorw inaldo «n'* \ i ^ '!■»..*' /»r' fW.IV. "7^ ■l ' ' f : — 1 ■r- •1 ^ 4 1 • a .1 . ' • 'M • , -ur * ^ ■'-'-iLi ' '.iifis^T' -..^ /r»i.W-. . 1 'i Jij?« 'sr, c '•a: ■ ■mKt r In BOYAi^ ■ocimr Of oakada l%m aiipw wd of tht eyllndw wm tctin m«i» •irUght in tli» ■MDT .lr«d, d«cn»-d and wm clo^d by . thin di.0 o! Aluminium k pUUnum wi« .tUch«l to tht cylind« m.d« d-clrio.! connwt.oa with th. mfitjury and to Imn wir. dipping Into'th. mw«ufy la thi W oriTW H conn«jt«d the whoU to ••rth. ^ Ai Ufow, th« el^strod. wm cwfully lniuUt«i by mtlttog i^l- mg wu on th« tobo tt a and a'. To pwf.nt °d«<^'»» » »"« **** rarfac o( th. glw th. part of th« tuba bulow the bulb wa. tighUy bound with tin foil connaetad to aarth. .... # The higheet tacua could be obtained with thii tuba and the um of the ground Joint gata ea.y accem to the InUrior without, oauaing an> derangement of the apparatus. When ready for u«,. the tube wa. pl«3ed in podtjon with t. low.r end extending into the earth-connected meUl box that containad the .l«,trometer. The air wm then exhau.ted through th. tuba W un^ toy dadred preeeura wm laaohed and the mercury rmiied unttl il mA» eonUbbt with the eteel cylinder. ^ .». 4«.i By thla arrangement the Faraday cylinder oonaiatad of tha atael tuba 2J,4ha mercury, and the meUl box conUining the elect«>'»;^«'"' tha whole praoUcally conttituting a lingla aarth connected metaUic **° In the llrat etperiment. with thi. tube aluminium 04 mUlimetrea WM uaed for the plate d. The air wm then .exhausted until the cathode dark .pace extended completely acro« the bulb of tha tub. and iU walla ware covered with a green phoaphoreacente. With theM conditiona A, B and D, were in turn selected a. the nagatit. terminal of the tube, but in no cmc wm there obtained any •Tid.nce of electrical acUon within the cylinder. Charge., either pci- tlTa or negatiye, given independenUy to the exploring electrode w«t» maintained without loM when tha tube WM excited. The aluminium plate d wm then rapUced by one 004 milhmetrea in thlcknM. and the tube riHJxhanited. ,„ j{„.«„« With B or Z> now acting M a cathode thete WM again no indication of electrical action within the cylinder, even with tha loweat P™-'^ obtainable. But, when 4 wm taken M th. ntigatire t*"^' "J" fomid that JMt « won M the walk of the tube in the neighbouriiood of d began to phoq»horMoe, the dectrode C dowly acquired a negaUve charge. With .till lower praMUrt. thi. charging became more rapid nnta finally with very high exhauation. a momentary diadiarge in tha tuba rofficad to charge the elwtroda beyond the rang, of the electro- ■ metor. -' -■'■-.■ !.-.'■■'.■ /•• "■^"■•" "^ •> 1 9. i ■ tn%mnnw} mCPIUlO fICftKBfllfO m VACUUM TUBn . ..i.A ^M M.%^ A 99 . , ^■. #■ v.f /•• tht ejUndar. Tu Ttrify this ooncliuion th« induotion coil wm raddtnlj vhil* tht «lwtrod« wu gaining lU ch*rg«. Thta aotlon tt ohm •topped the flfftct and th« •l«ctrom«t«r nMdJ* oam* to nst and i^ nuinflil •Utionary. On again rtrerting tha ooll tha charging imiiMdiat** 1/ recommenced. ^y^eotromagnat waa then placed in poaiUon with the bulb of th« tube NWeen iU pole pieoea. " On exoiUng thia magnet the cathode rays eoming from A were deflected and again the charging ceaaed and the electrode C maintained ita charge. When the electromagnet waa cut off the cathode raye once mora impinged upon the diio d, and the charging at once began again. < Theae experimenta then showed that the charge gained by waa doe to the cathode raye produced within the cylinder by the action of the pencil impinging on the outaide. ^ Wmm A eonaideration of the reaulta^obiaineSl with all tha tnba^ II thua aeema CTident that a oloeed Farijday cylinder, placed within • ▼aottum tube in which a diid^arge ia pftM^g. will completely aoreen off aU electrical action unleaa made of metal thip enough to permit tha paaaage of cathode raya through it 4. Inwivmsxcm b» Bad Eabtu OomrionoKt. In the experimenta deacribed in Section III, apeoial oaxa waa taken with the earth connections. Theae were made by soldering an iron wire to a water main and then inserting the end of the win in tha menury in the teaael J7. To teat the influence of bad earth connections the cylindjsr was first capped at d with a thick disc to cut off the cathode rays, and then a wet string or a column of xylol waa placed in the earth circuit between tha iron wire and the mercury. «• Under these conditions the passage of the discharge in the tube waa almost inTariably accompanied by marked induotion effects. With yery high exhaustions for example, il and B being the ter- minals and neither connected to earth, there was no inductiTe action when the connection was made by the iron wire or the wet •tring; but when the column of xylol waa inserted in circuit the electrometer showed a strong positire induction. Thia action, howeyer, waa not ac- companied by any permanent chai^ng aa the insertion of the iron wire in the meroniy was sufficient to at once bring the elactrometer nMdle to rest in ita initial position. s ^1* -• ;' ' vi-i ■■ ' ■ . 1 ■ , ■ " ?-r - ^ ■ . *. r. ,' ', ■;. V,-- !.,,•■.;' "' "j,, ' •\'- 1 1 4 ^ ■ , ' « \ . .'■ / * ^* lOYAL iOOUrrY or CAMADA ' ^ . J^^^ c^ - ^^ t" ^TtZT^ putt. oyUnL WM «.d. through th. wrt .trinf ; bat •»»« fj" P« ^ Tm anod. .nd i» <»thod. and th. w.t tnoc in^rUd m I-^ /[JJ lJ2iTl^t th«* w- . Unr. po^ti.. inductkru If B '•• P«^-^ .Tb«tlittl.wh«lAwM-rth.d. I-»«":"»-,^,t.\Trnr „uoh mor. int«.M. when th. column o .,lo "P^';» '^^V ^J*/^",^ At high.r pm.um .«ch m on. mlll.metr. «' ««^«'7 th« "^o" .«in TwiJl irith th. condiUon. of th. .xp«rim.nt. Wh«»^ -^d ^ !S« thr.l«:tn>d« .nd wither conn.ct.d to .«th • MiuU poriU^. In- i:in I otl^l wh.n th. column of xylol wm in^rUd, buU^on. Vh^ th. conn«,tion wm m.d. by mean, of "»• ^[^V^ J^ jji ovZ hand wh.n on. of th«. .l«Jtwd« w.. w.« .arthad th«. wM* r^^^S^r&i*^ thU direction wer. -*^ ^^'jf '^ '"^'V^ ^ pre^^nc oT^inductiT. acUon w- iuillci«i to •»7.^* j^J^"*™ Sh.Tin« «ood Mirth conn«!tion. in inT<»tigation. of thk dair '' V^m^ mulU it appaar. WgWy p«babl. that th. .od^ d^ ,J:. obUined in t^-i^t^^Ill^ rr^w r^^^^^ r.\^^^on; p" n-lTplLt'eonUct with th. cyUnd«. 5. iMWL^cu Of BMAix 0P.N1K0. m TH. Pabadat Otuhwm " - Whil. dwrtrio conduction along th. aurfac of th. «»» W*«jJ ' to«^tSnSLd-crib.din.«^.nI.it • ZTtii. dr«rt. inigW b. du. in a m«mo to th. F-.no. of th. «^ Fi. tv^aaTZ c... th. hoi. couM b. r..da, do«^ by .to^ To *»'«^ff^"*" ^ di«5 d waa mad. of motal thick enough to th. moroniy lowwod. ^« '*^..^!^'V°^^ ...^ through th. tnb« mt of th. oathod. taya, and a diicharge ^" P^ TnL^ADhnnt "pS«t both high and low, -«h of th. dectrod- ^ B and I) b«ng in torn •dact.d aa th. cathoda. ^ . . . ■./-' ■ - ^ a wwdt of tha t..t. no .tid«»ce waa oMainad of «»»• F-wioe ot :^«strlcal charge within th. cylinder ««rpt in ona caaa. f; V .•- .■/ '*'" ^tsSHOP^B Ci^JMAV] ILUniO llplBlflMU III VACUUM TUHBi This oeoarrad only dl vary low pnaronw whan A aotocl m telhod* D u uioda. Th« alMstrodo thon jUowly gaimd a very tllght iM|^v« oh«rg«. Iti •mdant, howtvtr, wu not at til oonp«mbl« with thMbarfM obtainid In the aiparimanta pmrioiMly diwribtd, and wovld b« folly aeooant«d for by a alight diffuaion of nagatiT* lona through tha opaning in tha abonita plug. Vr* t 6. SniMABT Of RnuiA 1. In paaaing a diaoharga throagh a Taouom tnba, aapadally at low praaiuraa, an alaotrio conduction takaa placa along tha anrfaca of tha glaaa which, unlaw gpa^ly guardad againat, ia apt to iniarfara with tha atttdy of tnia aflfaeta within tha tuba. S. In tha uaa of Faraday oylindara in Taouum tnbaa good Mffth aonnaotiona ara vary aMantial. t. Evan Tary nnall opaningi in such cylindaii axardaa a diaturbing Idlnanca. 4. CathodirnyvwSaranowad to fall upon Faraday oylindan^ do not impr^ alaotrioal oonduotiTity upon the gaa within unlaia the oyUn- dan ara mada of inatal thin enough to fMnnit tha imyi to paaa through. Tha expariipanta were conducted in the OaTandiah Laboratory and my thanka ara due to Profeeaor Thomaon who propoaed tha inraatiga- tion and oflarad many Taluabla auggeationa throughout ita prograia. 'x^ ■'■;■■■• ■■■ /' , ■"■ ■■ ■0- e % y. ^"1? / ■* ' ; 'f*ti. JIWt' / ,/ ,pt' < X wmm 'ik' i*-^"'^''J««' i.^'»^^^:Uidk'?^^'^-M^ r*»' 'P|H-l«nl|- #""! l^^ifHIIiipU ^IIP If V li'.-WM X' -»'.A ■^.v," Ji t ^.v^i' '*.d,' r y f^-"': ■tt* f!h f