,transcrib]'s ,note ,italic text display$ z3 italic ,,little ,,blue ,,book ,,no4 #acc ,edit$ by ,e4 ,haldeman-,julius ,pr9ciples ( ,electricity ,mayn>d ,%ipley ,,haldeman-,,julius ,,company ,,gir>d1 ,,kansas ,copyright1 #aibe1 ,haldeman-,julius ,company4 ,,pr9t$ ,,9 ,,! ,,unit$ ,,/ates ,,( ,,am]ica ,,pr9ciples ,,( ,,electricity ,,cont5ts ,*apt] ,page #a4 8,:at ,is ,electricity80 #e #b4 ,magnetic ,ph5om5a #ac #c4 ,pione]s 9 ,electromagnetic ,!ory #ai #d4 ,!ories ( ,electricity #cj #e4 ,mod]n ,magnetic ,!ory #da #f4 ,pro(s t ,electrons ,are ,atoms ( ,electricity #dd #g4 ,! ,discov]y ( ,wireless ,telegraphy #ee ,,pr9ciples ,,( ,,electricity ,,*apt] #a 8,,:at ,,is ,,electricity80 ,_m p]sons :o h devot$ no "t to ! /udy ( physics wond] :at ! =ce is t drives ! /reet-c> along--turn+ its :eels1 :ile at ! same "t furni%+ inc&esc5t lamps 7light7 = ! pass5g]s4 ,!y h be5 told1 ( c\rse1 t ! 8p[]0 us$ is 8electricity01 g5]at$ by dynamos 8at ! p[]-h\se01 & convey$ to ! rapidly mov+ c> by ! ov]head wire4 8,electricity3 yes1 b :at is electricity80 ,?is is a natural & p]fectly legitimate "q = a layman to ask4 ,sci5ti/s & philosoph]s are ask+ ! same "q4 ,b !y und]/& q well t x is l ask+3 8,:at is matt]80 ,v probably ! av]age inquir] does n ask ! "q1 8,:at is electricity80 9 ! same _s4 ,we c answ] "o "q no bett] ?an ! o!r1 if ! ultimate nature ( ei!r matt] or electricity is :at ! inquir] has 9 m9d4 ,= matt]1 9 ! la/ analysis1 is electricity4 ,yet ! same p]son :o might ask3 8,:at is electricity80 w\ld n ?9k ( ask+3 8,:at is matt]80 ,he ?9ks he kn[s :at matt] is--8 common s5se tells him t matt] is :at x appe>s to be4 8,matt]'s matt]1 & !re's an end ( x40 ,& j s ! physici/ insi/s ^u 8 common-s5se "r to reply3 8,electricity is electricity40 ,x is :at x appe>s to him to be4 ,& x appe>s to be a =m ( en]gy1 or a mode ( motion4 ,?ales1 ! reput$ f\nd] ( ,greek sci5ce & philosophy1 w\ld call electricity 8! s\l ( ! univ]se01 because x 8end[s all ?+s ) motion04 ,?is 8s\l01 int]p5etrat+ all matt]--if n con/itut+ x--is by nature always mov+--x is self-mov+2 motion is "p ( its v ess5ce4 ,9 ! lode/one1 said ,?ales1 8x moves iron40#a ,z has be5 said s _m times be=e1 ,?ales 0 ! fir/ to call att5tion to ! fact t amb] 7fossiliz$ res971 :5 rubb$ ) wool or fur1 possesses ! curi\s prop]ty ( attract+ small p>ticles1 su* z /raw1 pi?1 l9t1 dri$ leaves1 etc42--?\gh !re is no reason to suppose t he 0 ! discov]] ( ?is ph5om5on4 ,he call$ ! amb] elektron2 & today we call ! indivisible corpuscles1 or natural unit *>ges ( negative electricity1 electrons--! true atoms ( electricity4 ,b h>d rubb]1 or seal+-wax1 is j z 8my/]i\s0 z ! lode/one 7magnetite--natural magnetic iron74 ,rub ! seal+-wax ) fur1 & x w exhibit all ! peculi> prop]ties ( ! lode/one4 ,rub glass ) silk1 & x1 too1 becomes a lode/one 9 effect4 ,! anci5t ,greek philosoph]s c\ld n expla9 ^! ph5om5a 9 precise t]ms4 ,emp$ocles 7born betwe5 #ejj & #dhj ,b4 ,c47 acc\nt$ = ! attraction ( iron to ! magnet on ! hypo!sis t 8emanations0 or 8efflu5ces0 f ! magnet p5etrate into ! 8symmetrical pores0 ( ! iron1 draw+ ! iron itself & hold+ x fa/4 ,! concept 8electricity0 0 unkn[n to ! ,greeks4 ,b x is possible t ,emp$ocles _h 9 m9d "s su* 8efflu5ce0 or 8emanation0 z ! 8fluid0 electricity ( ,b5jam9 ,frankl9 7#agjf-agij7 & 8 successors4 ,! s\l-=ce 78mov+ p[]07 ( ,?ales--always mov+ & caus+ movem5t--& ! 8efflu5ces0 ( ,emp$ocles h become ! 8field ( =ce0 ( ,f>aday1 ,sir ,j4 ,j4 ,?omson1 & ,sir ,oliv] ,lodge4 ,! self-mov+ 8s\l0 ( nature1 manife/ 9 ! lode/one1 or act+ on ! lode/one1 or on ! p>ticles said to be 8attract$0 by ! lode/one1 is b a synonym = ! l9es ( =ce ( ! magnetic field ( mod]n physics4 ,?ales & ,emp$ocles spoke 9 ! language 7t]m9ology7 ( _! day & age4 ,! 8emanations0 ( ,emp$ocles are ! 8corpuscles0 ( ,?omson--a body becom+ positively electrifi$ by 8los+ "s ( its corpuscles01 & h5ce capable ( draw+ negatively *>g$ p>ticles to itself4 ,electricity & magnetism are relat$ b n id5tical4 ,a mov+ magnet c induce an electric curr5t 9 a wire1 & an electric curr5t c produce magnetism 9 iron4 ,! con/ruction ( telegraph & telephone in/rum5ts dep5ds on ! fact t an electric curr5t c produce magnetism & t magnetism c produce an electric curr5t4 ,we "k effects :i* we call 8electricity01 j z we "k ! ph5om5a associat$ ) liv+ protoplasm )\t kn[+ :at 8life0 is4 ,x may be t 8life0 & 8electricity01 z well z 8electricity0 & 8magnetism01 are all diff]5t aspects ( ! same ?+4 ,today we say1 9 ! words ( ,dr4 ,*>les ,p4 ,/e9metz 78,relativity & ,space01 ,pages #ah-ai73-- 8,! space surr\nd+ a magnet is a magnetic field4 ,if we electrify a piece ( seal+-wax by rubb+ x1 x surr\nds itself by a dielectric or electro/atic field1 & bodies susceptible to electro/atic =ces--su* z light pieces ( pap]--are attract$4 ,! e>? is surr\nd$ by a gravitational field1 ! l9es ( gravitational =ce issu+ radially f ! e>?4 ,if a /one falls to ! e>?1 x is due to ! /one's be+ 9 ! gravitational field ( ! e>? & be+ act$ ^u by x40 ,aga93--8,suppose we h a p]man5t b> magnet & br+ a piece ( iron ne> x4 ,x is attract$1 or mov$2 t is1 a =ce is ex]t$ on x4 ,we br+ a piece ( copp] ne> ! magnet1 & no?+ happ5s4 ,we say t ! space surr\nd+ ! magnet is a magnetic field4 ,a field1 or field ( =ce1 we def9e z #8a condition 9 space ex]t+ a =ce on a body susceptible to ?is field'4 ,?us1 a piece ( iron be+ magnetizable--t is1 susceptible to a magnetic field--w be act$ ^u2 a piece ( copp]1 n be+ magnetizable1 %[s no action4444 ,to produce a field ( =ce requires en]gy1 & ?is en]gy is /or$ 9 ! space we call ! field4 ,?us we c g fur!r & def9e ! field z #8a condition ( en]gy /orage 9 space ex]t+ a =ce on a body susceptible to ?is en]gy'40 ,?ales said t ! 8div9e mov+ p[]01 ! s\l ( nature1 "u c]ta9 conditions 8moves iron01 ?r\gh ! my/]i\s prop]ties ( ! lode/one4 ,mod]n sci5ce1 borr[+ f ,ari/otle ! t]m en]gia1 sub/itutes = 8s\l ( nature0 ! s+le ^w en]gy4 ,ari/otle decl>$ t 8n capacity1 b en]gy 444 is ! fir/ pr9ciple ant]ior to & sup]ior to any?+ else0 7,metaphysics xii1 #g3 cf4 also ,physics ii1 #i1 #f74 ,mod]n sci5ce describes 9 m precise phrases :at occurs :5 a body susceptible to ! influ5ce ( ! magnet is br\ght into proximity to a lode/one 7magnetite74 ,x gives u a picture ( 8l9es ( =ce0 7en]gy7 9 a def9$ 8field04 ,b x tells u no m ab\t :at en]gy is ?an ,?ales tells u :at 8 8mov+ p[]0 is4 ,dr4 ,/e9metz tells u t 8en]gy is ! only real exi/+ entity1 ! prim>y conception1 :i* exi/s = u because our s5ses respond to x0 7,op4 cit41 ,page #bc74 ,= ,?ales ! univ]sal 8mov+ p[]0 ( nature op]ates on or 9 all matt]2 = ! physici/ ( today ! mov+ p[] 7en]gy7 is matt]--man's p]ception ( matt] be+ ! response ( 8 s5ses to ! vibrations ( en]gy4 8,all s5se p]ceptions are exclusively en]gy effects10 & 8en]gy is ! only real exi/+ entity40 ,?ales may or may n h consid]$ ! cosmos z 8matt]0 & 8s\l0 or 8mov+ p[]04 ,9 any ev5t ! pre-,socratic ,ionian philosoph]s recogniz$ no di/9ction betwe5 matt] & s\l 9 our mod]n s5se4 ,! mov+ p[] ( nature 7s\l7 0 z mu* a mat]ial sub/ance z gross matt] itself1 only m r>efi$1 m elusive4 ,x 0 equival5t to ! 8en]gy0--electricity--( mod]n sci5ce4 ,"h we h1 !n1 ! answ] to ! "q3 8,:at is electricity80 ,x is en]gy--8! only real exi/+ entity1 ! prim>y conception1 :i* exi/s = u because our s5ses respond to x40 8,all s5se p]ceptions are exclusively en]gy effects40 ,?is is ! answ] to ! "q3 8,:at are ! ,h]tzian waves1 us$ 9 #8wireless'80 ,x is ! answ] also to ! "q3 8,:at is light80 z well z 8,:at is electricity80 ,by c>ry+ ! explanation ( ! beam ( light & ! electromagnetic wave 7l t ( ! radio communication /ation or t surr\nd+ a p[] transmission l9e7 back to ! en]gy field 7or1 less accurately1 ! field ( =ce71 we h c>ri$ x back1 z ,dr4 ,/e9metz well decl>$1 z f> z possible1 8to ! fundam5tal or prim>y conceptions ( ! human m9d1 ! p]ceptions ( ! s5ses40 ,all t we "k ( ! _w is d]iv$ f ! p]ceptions ( our s5ses1 :i* are = u ! only real facts1 all ?+s else be+ conclusions f !m2 & 8all s5se p]ceptions are exclusively en]gy effects40 ,electricity is an en]gy effect1 p]ceiv$ by our s5ses4 ,no o!r def9ition or explanation c or ne$ be giv51 s9ce en]gy is ! prim>y conception4 ,& ?is expla9s also :at matt] is1 s9ce en]gy & matt] are int]*angeable--or equival5t--t]ms4 ,:at we call electricity is "o ( ! effects ( en]gy on our s5ses4 ,9 itself1 x is en]gy1 ! /uff t matt] is made (2 at once ! 8mov+ p[]0 & ! ?+ mov$4 ,ev]y?+ has be5 said t c be said n[ z to :at electricity is3 our conc]n 9 ! rema9d] ( ?is volume w be to discov] :at electricity does & h[ x acts4 99 99 99 99 99 ,! read] ( ?is little book :o may be m or less famili> ) l>g] volumes deal+ ) electricity1 en]gy1 electrons1 electromagnetic waves or oscillations1 magnetic & dielectric fields 7usually comb9$71 light-waves1 etc41 w notice t no m5tion has be5 made ( ! classical e!r hypo!sis1 ! univ]sal pl5um 9 :i* en]gy is said to be /or$1 & 9 :i* transv]se waves ( light are said to occur1 e!r atoms or vibrations mov+ at "r angles 7p]p5dicul>ly7 to ! light-beam4 ,n[1 transv]se waves c exi/ only 9 rigid 7solid7 bodies4 ,! univ]sal e!r ( space1 ref]r$ to 9 ! text-books1 mu/--= reasons :i* ,i ne$ n discuss "h--be a solid body ( a rigidity mu* great] ?an t ( /eel1 :ile at ! same "t possess+ a v great ela/icity s t bodies 7su* z ! planets7 mov+ ?r\gh x meet ) no resi/ance1 no friction4 ,! electron !ory ( ,lor5tz1 ,l>mor1 ,?omson1 ,lodge & o!rs is bas$ ^u ! assumption t su* a pl5um1 or m$ium1 is a real sub/ance4 ,z a matt] ( fact1 x is n kn[n t any su* m$ium 7or e!r7 does exi/1 & x is n[ recogniz$ t :ile light is a wave1 a p]iodic ph5om5on1 l an alt]nat+ curr5t1 x is n necess>ily a wave motion ( some?+ or 9 some?+1 any m ?an x is necess>y to assume ! alt]nat+ curr5t or voltage wave to be a motion ( matt]4 ,electrical eng9e]s make no assumption reg>d+ ! exi/5ce ( an e!r fill+ all space & int]p5etrat+ all matt]--h no ne$ = an e!r z ! hypo!tical c>ri] ( ! electric wave4 ,& j s ! physici/ ( today has no real ne$ = ! classical assumption t ! light-wave is a wave motion ( or 9 some?+ ( great rigidity yet highly ela/ic & frictionless1 fill+ all space4 ,light is n[ kn[n to be a high-frequ5cy electromagnetic wave1 & _c logically be consid]$ z a wave motion ( a hypo!tical e!r4 8,! e!r ?us vani%es1 foll[+ ! phlogi/9 & o!r antiquat$ conceptions40#b ,z ,pr(4 ,a4 ,s4 ,edd+ton rem>ks 9 8 8,report on ! ,relativity ,!ory ( ,gravitation0 7#aibj71 8,light does n cause electromagnetic oscillations2 x is ! oscillations40 ,we "k no?+ :atev] ab\t ! s-call$ e!r ( space2 b we c =mulate v cle>ly 8,! ,pr9ciples ( ,electricity0 )\t ! aid ( t hypo!sis4#c ,,footnotes3 #a ,if a light piece ( iron is plac$ ne> a magnet1 x moves to ! magnet & cl+s to x2 b if ! magnet is ! light] ( ! two bodies1 x moves t[>d ! piece ( iron4 #b ,/e9metz1 ,dr4 ,*>les ,p41 8,f\r ,lectures on ,relativity & ,space10 ,pages #ba-bb1 ,london & ,new ,york1 #aibc4 ,see ,lecture ,,ii1 8,conclusions f ! ,relativity ,!ory10 ,pages #ab-de4 ,see also1 ,campbell1 ,dr4 ,norman ,r41 8,mod]n ,electrical ,!ory4 ,supplem5t>y ,*apt]s3 ,relativity10 ,cambridge ,univ]sity ,press1 #aibc4 ,,*apt] #b ,,magnetic ,,ph5om5a ,x 0 long ago obs]v$ t if glass is rubb$ by silk1 or a piece ( seal+-wax or h>d rubb] by fur or wool1 an effect occurs simil> to t not$ by ,?ales :5 amb] is rubb$ by simil> mat]ials--i4 e41 light bodies su* z bits ( dry pap]1 pi?1 etc41 w cl+ to ! surface ( ! sub/ance4 ,aft] com+ 9 contact ) ! attract+ sub/ance1 ! bits ( pap]1 /raw1 etc41 are !n repell$4 ,if a ball made ( pi? be susp5d$ at ! end ( a silk ?read1 & a glass rod :i* has j be5 rubb$ ) silk be br\ght close to ! ball1 ! pi?-ball imm$iately flies to ! rod1 cl++ to x = a "t4 ,!n x jumps away1 & in/ead ( hang+ v]tically1 seems to be pu%$ away f ! glass by a my/]i\s =ce4 ,a second ball1 treat$ l ! fir/1 & br\ght ne> ! fir/1 is viol5tly repell$4 ,b if "o ball is *>g$ f ! glass & "o f ! wax1 !y attract in/ead ( repell+ ea* o!r4 ,two pieces ( glass or two pieces ( wax repel ea* o!r4 ,a simil> attraction & repulsion 0 e>ly obs]v$ betwe5 ! poles ( ! magnet4 ,?is influ5ce seems to be transmitt$ by "s invisible ag5cy or m$ium across ! int]v5+ space betwe5 ! bodies1 & 9 ?is respect ! =ce does n diff] f t act+ betwe5 ! moon & ! e>?1 or ! e>? & ! sun4 ,& j s1 if a light piece ( iron is plac$ ne> a magnet1 x moves to ! magnet & cl+s to x2 b if ! magnet is ! light] ( ! two bodies1 x moves t[>d ! piece ( iron4 ,al?\gh ,?ales _h attempt$ to expla9 ! cause or nature ( magnetic attraction z long ago z ! end ( ! sev5? c5tury ,b4 ,c41 or 9 ! fir/ qu>t] ( ! six? c5tury 7ab\t #b1ejj ye>s ago71 x 0 n until ! ye> #aehb ,a4 ,d4 t ,dr4 ,william ,gilb]t 7#aedj-afjc71 ( ,col*e/]1 physician to ,que5 ,elizabe?1 made ! fir/ exp]im5tal /udy ( magnetic ph5om5a4 ,x is to ,dr4 ,gilb]t t we owe ! "n electricity z appli$ to ?is =ce1 d]iv$ f 8 vis electrica4 ,by #afjj1 ,dr4 ,gilb]t _h publi%$ 8 epo*al "w 8,de ,magnete01 :i* n only conta9$ ! fir/ rational treatm5t ( magnetic & electrical ph5om5a1 b 0 also virtually ! fir/ sci5tific "w publi%$ 9 ,engl&4 ,x is to ?is truly great treatise t mu/ be trac$ ! beg9n+s ( ! sci5ce ( electricity4#d ,?r[+ aside1 z useless1 m]e philosophical speculation z to ! nature ( magnets1 ,gilb]t expla9$ 9 8 book h[ practical exp]im5ts %\ld be c>ri$ out4 ,he insi/$ t x is to nature h]self t we mu/ apply = ! answ]s to problems 9 8natural hi/ory04 ,gilb]t's p>ticul> objective 0 n1 h[ev]1 discov]y ( ! laws ( magnetism or electricity2 :at he mo/ desir$ to le>n 0 ! composition ( ! e>?3 he wi%$ to "k ?r\gh actual rese>* j :at is its inn]mo/ con/itution4 ,8 exp]im5ts l$ him to ! conclusion t ! e>? is a magnet4 ,x may1 inde$1 be consid]$ a huge sph]oidal lode/one4 ,gilb]t told 8 read]s to take a piece ( lode/one 7natural magnetic iron7 ( conv5i5t size1 turn x on a la! to ! =m ( a ball1 !n place on ! t]ella 7z he call$ ! sph]ical lode/one7 a piece ( iron wire4 ,x w !n be obs]v$ t ! ends ( ! wire 8move r\nd its middle po9t40#e ,lode/ones1 fragm5ts ( magnetite 7,fe#c,o#d71 are said to h be5 fir/ discov]$ at ,magnesia1 9 ,asia ,m9or1--h5ce ! ^w magnetism4 ,"s ( ! e>lie/ ref]5ces to ! lode/one relate to its prop]ty ( ly+ 9 a nor?-&-s\? direction :5 an elongate /one is freely susp5d$1 "o p>ticul> end always po9t+ nor?w>d1 j z ! great magnet ! e>?1 or ! m>9]'s compass-ne$le1 has two opposite magnetic poles4 ,! location ( ! poles ( a disk-%ap$ /one is readily f\nd by turn+ x r\nd 9 ! pres5ce ( a compass-ne$le4#f ,iron & /eel are m /rongly magnetic ?an any o!r metals4 ,:ile only "o k9d ( iron ore is naturally magnetic--=m+ magnets--! prop]ty ( magnetism may always be giv5 to any k9d ( iron or /eel4 ,"o ne$ only /rike an iron b> :ile x is ly+ 9 a nor?-s\? position1 or rub ! iron ) a magnet1 & x becomes a magnet4 ,if x is desir$ to make a p]man5t magnet1 /eel mu/ be employ$4 ,a compass-ne$le is !re=e made ( magnetiz$ /eel4 ,if balanc$ ^u a pivot1 ! positive pole ( ! ne$le w po9t 7r\ghly7 t[>ds ! e>?'s nor? geographical pole4#g ,a compass-ne$le is also a 8dipp+ ne$le01 unless ! susp5d$ magnetiz$ ne$le lies ab\t half way betwe5 ! e>?'s magnetic poles4 ,! nor? magnetic pole lies bel[ ! e>?'s surface--at an unkn[n dep?--at ! extreme nor!a/]n corn] ( ! cont95t ( ,nor? ,am]ica2 & ! correspond+ s\? magnetic pole on ! edge ( ! ,ant>ctic cont95t--,k+ ,george's ,l&--ab\t #b1cjj miles s\? ( ,au/ralia4 ,^! magnetic poles d n correspond ev5 r\ghly ) ! geographic poles1 nor does ! magnetic equator by any means correspond ) ! geographic equator4 ,only a small section ( ! magnetic equator runs nor? ( ! true 7geographic7 equator--e4 g41 f ! coa/ ( ,brazil to ! coa/ ( ,kam]un 7,africa74 ,accord+ to ,pr(4 ,t4 ,j4 ,j4 ,see1 8! :ole magnetic sy/em has be5 pu%$ s\?w>d #bjj miles by bodily displacem5t ( bo? poles t[>ds ! ocean hemisph]e40 ,?is em95t physici/-a/ronom] also /at$ 79 #aibb7 t 8 rese>*es l$ him to ! discov]y t ! two magnetic poles are at unequal dep?s 9 ! e>?1 ! ,nor? ,pole be+ mu* deep] ?an ! ,s\? ,pole1 8) ! result t ! total magnetic =ces 9 ! s\!rn hemisph]e are consid]ably /rong] ?an 9 ! nor!rn hemisph]e40#h ,x 0 long ago discov]$ t if "o />ts nor?w>d f ! magnetic equator1 ! compass-ne$le soon beg9s to dip d[nw>d 7& nor?w>d74 ,at ! s\!rn bord] ( ! ,unit$ ,/ates1 ! d[nw>d incl9ation am\nts to ab\t #eg degrees4 ,at ! bord]s ( ,nor? ,dakota & ,ma9e ! dip is ab\t #gf degrees4 ,by ! "t ,hudson ,bay is rea*$ ! ne$le assumes a v]tical position4 ,?is means t x is "h susp5d$ imm$iately ov] ! nor? magnetic pole itself4 ,at ! magnetic equator 9 ,p]u1 a ne$le susp5d$ by a ?read is exactly balanc$4 ,dr4 ,see /ates t at ! ,nor? & ,s\? ,poles !re is a d[nw>d pull--by ! magnetic =ce--( j "o million? ( ! gravitational =ce1 :ile 9 ,p]u ! total magnetic =ce is precisely "o t5 million?s ( gravitation4 ,x has be5 f\nd t bo? ! ,nor? & ! ,s\? ,poles are any?+ b fix$ 9 position4 ,!y 8w&] ab\t 9 _! subt]ranean region04 ,9 ! c\rse ( c5turies1 ! compass-ne$le sw+s f we/ ( nor?1 & !n to ! ea/4 ,ev5 ! am\nt ( ! dip sl[ly *anges1 9 a p]iodic way1 & at e po9t on ! e>?4 ,= example1 9 #aegf1 ! nor? end ( ! ne$le at ,london dipp$ at an angle ( #ga degrees #ej m9utes4 ,by #agbj ! angle _h increas$ to #gd degrees #db m9utes--almo/ up & d[n4 ,s9ce !n1 ! dip at ,london has cont9ually decreas$4 ,at ! pres5t "t we are puzzl$ by ! fact t ! incl9ation ( ! dip is #ff degrees at ,london & m ?an #gj degrees at ,wa%+ton4 ,x has long be5 kn[n t v>iations 9 magnetic decl9ation ( ! delicately m\nt$ ne$les1 9 obs]vatories1 are directly correlat$ ) sol> di/urbances4 ,! late ,dr4 ,a4 ,wolf] 7sometime director ( ! ,zuri* ,obs]vatory7 0 ! fir/ to %[ u h[ closely ! curve ( ! sun-spot activity rises & falls ) ! fluctuations ( magnetic decl9ations4 ,be=e attempt+ to expla9 ! peculi>ities ( magnetic action 9 t]ms ( ! mod]n electromagnetic !ory1 x w be well to recall c]ta9 /ages ( progress 9 ! developm5t ( ?is !ory4 ,?is plan w p]mit elucidation ( ! !ory itself by 8easy /eps04 ,,footnotes3 #c ,cf4 ,:ittak]1 ,e4 ,t41 8,a ,hi/ory ( ! ,!ories ( ! ,e!r & ,electricity f ! ,age ( ,desc>tes to ! ,close ( ! ,n9ete5? ,c5tury10 ,dubl9 & ,london1 #aiaj4 ,see also1 ,com/ock & ,trol&1 8,! ,nature ( ,matt] & ,electricity10 ,new ,york1 #aiag2 ,/e9metz1 ,dr4 ,*>les ,p41 8,elem5t>y ,lectures on ,electric ,dis*>ges1 ,waves & ,impulses & ,o!r ,transi5ts10 ,new ,york1 #aiad2 & ,/>l+1 ,dr4 ,sydney ,g41 8,electricity10 ,london & ,new ,york1 #aibb4 #d ,on ! ,cont95t1 exp]im5tal "w 9 o!r fields 0 already 9 progress1 ?anks to ! g5ius ( ,desc>tes1 ,galileo & o!r f\nd]s ( mod]n sci5ce4 ,gilb]t1 l ,h>vey1 sp5t "s ye>s 9 ,italy1 com+ "u ! direct influ5ce ( ! great ,italian physici/-a/ronom]-physician ,galileo4 ,h>vey 0 9 ,padua 7#aeih-afjb7 dur+ ,galileo's pr(essoriate4 ,! introduction ( sci5tific me?ods 9 ,engl& at ?is "t may well be cr$it$ to ,italian & ,fr5* influ5ces4 #e ,gilb]t's book is usually ref]r$ to simply z 8,! ,magnet10 b ! full title is3 8,conc]n+ ! ,magnet & ,magnetic ,bodies1 & ,conc]n+ ! ,great ,magnet ! ,e>?3 ,a ,new ,natural ,hi/ory 7,physiologia7 ,demon/rat$ by ,_m ,argum5ts & ,exp]im5ts40 #f ,magnetite does n always possess pol>ity4 ,x is call$ 8lode/one0 only :5 x does4 ,x occurs n only 9 ! =m ( m or less massive /ones1 b also z loose s& & 9 e>?y =ms4 #g ,! fact t a lode/one possesses two 8poles0 0 discov]$ 9 ! ?irte5? c5tury by ,petrus ,p]egr9us1 ( ,pic>dy1 :ile he 0 exp]im5t+ ) a sph]ical lode/one & a ne$le4 #h ,f notes tak5 at a lecture by ,dr4 ,see be=e ! ,cali=nia ,academy ( ,sci5ces 9 #aibb4 ,dr4 ,see1 9 *>ge ( ! ,unit$ ,/ates ,naval ,obs]vatory at ,m>e ,isl& 7,cali=nia71 pres5t$ 9 ! lecture 8,a ,new ,!ory ( ! ,e!r10 9 :i* he outl9$ ! gr\nds ^u :i* he bas$ 8 new !ory ( a direct connection betwe5 magnetism & univ]sal gravitation4 ,x is highly int]e/+1 9 ?is connection1 to le>n t ,dr4 ,alb]t ,e9/e91 9 collaboration ) ,pr(essor ,edd+ton 7( ,cambridge7--work+ on ! pr9ciple ( ,relativity--has discov]$ a connection betwe5 ! e>?'s p[] ( attraction 7gravitation7 & electricity4 ,,*apt] #c ,,pione]s ,,9 ,,electromagnetic ,,!ory ,! ,dani% physici/1 ,hans ,*ri/ian r/$1 pr(essor ( natural philosophy at ! ,univ]sity ( ,cop5hag51 %[$ u1 m ?an a c5tury ago1 t a magnetic ne$le c be deflect$ by an electric curr5t4 ,he _h be5 l$ by !oretical consid]ations to assume t !re mu/ be a correlation betwe5 electric & magnetic =ces4 ,:ile yet a "y man1 r/$ endeavor$ by p]sev]+ exp]im5tation to prove ! correctness ( 8 !ory4 ,:ile he did n expect a p>allel action ( ! two =ces1 he 0 firmly conv9c$ t magnetism & electricity 7 insep>able tw9s4 ,he not$ t bo? heat & light radiat$ f a conductor :5 heat$ to inc&esc5ce4 ,he also assum$ t magnetic =ces are radiat$ f a conductor trav]s$ by electricity4 ,9 #ahbj1 :ile lectur+ be=e 8 class1 he became conv9c$ t ! app>atus he 0 !n us+ c\ld be made to demon/rate ! correctness ( 8 views4 ,he ask$ 8 pupils to accompany him to 8 laboratory1 :]e1 z he pr$ict$1 a slight deflection ( ! magnetic ne$le1 turn$ at "r angles to ! electric curr5t1 0 %[n :5 plac$ close to ! copp] wire4 ,"s mon?s aft]w>ds1 ) a /rong] curr5t 7made up ( tw5ty cells71 he obta9$ mu* m int5se effects4 ,inve/igat+ ^! 9 detail1 he f\nd t !y met all ! requirem5ts ( 8 !ory4 ,s1 on ,july #ba1 #ahbj1 he s5t out to ! sci5tific _w 8 n[ fam\s circul>1 8,exp]im5ta circa effectum conflictus electrici 9 acum magneticum0 7,exp]im5ts on ! effect ( ! electrical conflict 9 ! magnetic ne$le74 r/$ %[$1 fur!rmore1 h[ *anges 9 ! position ( ! magnetic ne$le occurr$ ) v>iation ( ! position ( ! conductor 7copp] wire7 9 reg>d to x4 ,he demon/rat$ also t ! magnetic effect 0 n weak5$ by insulators--t x w\ld p5etrate v>i\s mat]ials1 :e!r ^! 7 conductors ( electric curr5ts or n4 ,he %[$ t ! magnetic field creat$ by ! electric curr5t does n h any influ5ce on a ne$le ( non-magnetic mat]ial--i4 e41 brass1 glass1 etc4 ,x is1 9 fact1 *iefly 9 ! fact t x _c be insulat$ t magnetism diff]s f electricity4 ,x w freely pass ?r\gh air1 /one1 mica1 glass1 clay1 brick1 or any insulat+ mat]ial4 ,x is well wor?y ( especial m5tion t r/$ employ$ ! t]m 8conflictus0 to designate ! electric curr5t1 _m decades be=e ! orig9 ( ! electron !ory ( matt]4 ,=1 on mod]n !ories ( electricity1 x is ! movem5t to & fro ( electric p>ticles 7electrons7 ?r\gh ! conductor1 & _! impact 78conflictus07 t produces :at we call electrical ph5om5a4 r/$'s fundam5tal discov]y ( ! mutual effects betwe5 electricity & magnetism l$ to fur!r discov]ies :i* made possible ! con/ruction ( telegraph & telephone in/rum5ts1 s9ce ^! dep5d on ! fact t an electric curr5t c produce magnetism1 & t magnetism c produce an electric curr5t4 ,if we w9d ar\nd an iron b> a numb] ( turns ( insulat$ wire1 & an electric curr5t is all[$ to pass ?r\gh ! coil1 ! b> becomes a /rong electromagnet4 ,b x rema9s a magnet only z long z ! curr5t is pass+4 ,n[1 ! magnetic effects obta9$ ) ! electromagnet are id5tical ) ^? obta9$ f a p]man5t magnet--su* z ! famili> horse%oe magnet1 commonly se5 on ! fly:eel ( ! ,=d automobile1 or 9 ! ord9>y telephone g5]ator = call+ up 8,c5tral04 ,9 ! case ( a telegraph in/rum5t1 x is important t ! iron is a tempor>y magnet4 ,on ! o!r h&1 a p]man5t magnet is an ess5tial "p ( e ,bell telephone receiv]4 ,?is p]man5cy is secur$ by employ+ a b> ( /eel in/ead ( a piece ( iron--a tempor>y magnet4 ,! p[] produc$ f a dynamo--or electric g5]ator--dep5ds ^u ! fact t :5 a magnet is put into a coil ( wire1 only a mom5t>y curr5t ( electricity passes ?r\gh ! wire1 9 "o direction4 ,if ! magnet is )drawn1 a curr5t />ts 9 ! opposite direction4 ,copp] wire coil$ ab\t an iron core =ms ! 8armature0 ( ! dynamo4 ,! rotat+ coils are said to 8cut ! magnetic field40 ,on ?is pr9ciple ( electricity1 int5se electric curr5ts are produc$1 furni%+ ! 8p[]0 = ! electric motors 9 electric c>s1 elevators1 musical in/rum5ts1 etc41 & = electric lights--inc&esc5t & arc4 ,dynamos may conta9 ei!r p]man5t magnets or electromagnets4 ,!y produce ! magnetic field 9 :i* ! 8armature0 or conductor--! coils ( wire w\nd ar\nd ! iron core--rotates4 ,a ma*9e ) p]man5t magnets is usually t]m$ a magneto1 & is nev] made 9 l>ge sizes4 ,! curr5t = ! electromagnets may be d]iv$ :olly f an outside s\rce1 or "p ( ! curr5t :i* x g5]ates may be us$ = t purpose4 ,! curr5t g5]at$ 9 ! armature w9d+ is alt]nat+1 b may be rectifi$ to a direct curr5t by a commut] if desir$2 o!rwise x is convey$ to ! l9e circuit by collector or slip r+s & bru%es4 ,we owe mu* ( our k ( magnetism & electricity to ,mi*ael ,f>aday 7#agia-ahfg71 :o brilliantly cov]$ ! :ole field ( ^! sci5ces4 ,f>aday 0 di/+ui%$ alike z a *emi/ & z an exp]im5t] 9 electricity & magnetism4 r/$ _h %[n t magnetism c\ld be produc$ by a curr5t ( electricity1 b x rema9$ = ,f>aday to produce curr5t electricity by a magnetic 8field ( =ce01 ?us lay+ ! f\ndation = ^? mod]n indu/ries :i* d]iv$ motive =ce = _! ma*9]y f ! gigantic dynamos ( our 8p[] h\ses04 ,b ,i mu/ "h introduce a few facts conc]n+ ! contributions to electric !ory & practice ( ! great ,fr5* ma!matician & physici/1 ,&r ,m>ie ,ampre 7#agge-ahcf74 ,8 discov]ies 9 electrodynamics aid$ greatly 9 lay+ a broad f\ndation = ?is sci5ce4 ,v notable 0 ! influ5ce ex]cis$ by ,ampre on ! developm5t ( electrodynamics4 ,& x 0 he :o fir/ cle>ly e/abli%$ ! fact t magnetic action is a peculi> =m ( electromotive action1 & t1 9 ph5om5a ( ?is class1 8action & reaction are equal & opposite40 ,f ^! consid]ations x 0 natural = him to suppose t magnetism might be made to produce electricity1 z x _h already be5 %[n t electricity might be made to imitate all ! effects ( magnetism4 ,num]\s attempts 7 made to effect ?is pr$ict$ result1 b = "s ye>s all su* ef=ts prov$ to be fruitless4 ,mean:ile ! ,fr5* physici/ & a/ronom]1 ,franois ,arago 7#aghe-ahec71 0 also conduct+ exp]im5ts ) ! object ( produc+ electricity by magnetism4 ,"o ( 8 exp]im5ts actually involv$ ! effect s\ght1 b x 0 n cle>ly recogniz$4 ,arago obs]v$ t ! rapid revolution ( a conduct+ plate 9 ! neighborhood ( a magnet gave rise to a =ce act+ on ! magnet4 ,b x 0 n recogniz$ by ei!r ,arago or o!r physici/s ( ! day t ! =ces involv$ 7 electric curr5ts--produc$ by ! rapidly revolv+ conduct+ plate4 ,f>aday1 9 #ahca1 aft] sev]al ye>s ( preoccupation ) o!r problems1 return$ to 8 task ( discov]+ electrodynamical induction1 begun 9 #ahbe4 ,aft] a numb] ( fruitless ef=ts1 he 0 f9ally rew>d$ ) success1 b n 9 ! =m :i* _h be5 anticipat$4 ,x 0 obs]v$ t at ! precise "t ( mak+ or break+ ! contact :i* clos$ ! galvanic circuit1 a mom5t>y effect 0 induc$ 9 a neighbor+ wire1 :i*1 h[ev]1 disappe>$ in/antly4#i ,f>aday !n discov]$ t a simil> effect c\ld be induc$ m]ely by mov+ ! wire ne>] to or f>!r away f ! clos$ circuit--in/ead ( sudd5ly mak+ or break+ ! contact ( ! 8induc+ circuit04 ,lat] he f\nd t ! effects 7 increas$ by ! proximity ( s(t iron1 & t :5 ! s(t iron 0 affect$ by an ord9>y magnet in/ead ( ! voltaic wire1 ! same effect /ill recurr$4 ,! mom5t>y electric curr5t 0 produc$ ei!r by mov+ ! magnet or by mov+ ! wire ) ref]5ce to ! magnet4 ,f9ally1 x 0 f\nd t ! e>? itself might be sub/itut$ = a magnet1 n only 9 ?is exp]im5t b also 9 o!rs4 ,m]e motion ( a wire1 "u prop] conditions1 produc$ ! effect4 ,"h1 !n1 0 ! true explanation ( ,arago's exp]im5t3 by ! rapid revolution ( ! plate ! mom5t>y effect became cont9u\s4 ,)\t us+ ! magnet1 a revolv+ plate became an electrical ma*9e4 ,a revolv+ globe 0 f\nd to exhibit electromagnetic action1 ! circuit be+ complete 9 ! globe itself )\t ! addition ( any wire4 ,x 0 lat] f\nd by ,f>aday t m]e motion ( ! wire ( a galvanomet] produc$ an electrodynamic effect ^u ! ne$le4#aj ,mean:ile1 ,ampre1 8by a comb9ation ( ma!matical skill & exp]im5tal +5uity1 fir/ prov$ t two electric curr5ts act on "o ano!r1 & !n analyz$ ?is action into ! resultant ( a sy/em ( pu%-&-pull =ces betwe5 ! elem5t>y p>ts ( ^! curr5ts40#aa r/$ hav+ %[n t electric curr5ts produc$ c]ta9 effects on magnets )\t be+ 9 actual contact1 & ,ampre hav+ demon/rat$ t magnets c 9 _! turn be supplem5t$ by electric curr5ts1--a magnetic ne$le be+ deflect$ n only by a curr5t pass+ ?r\gh a wire1 b also by ano!r magnet br\ght into its neighborhood1 & two electric curr5ts act+ on "o ano!r at a di/ance--! "q n[ arose z to :e!r or n electrical attraction & repulsion c\ld be r$uc$ to an action at a di/ance proportional to ! inv]se squ>e ( ! di/ance4 ,z e>ly z #aggc1 ,h5ry ,cav5di% 7#agca-ahaj7--"o ( ! =emo/ *emi/s & exp]im5tali/s ( 8 day--answ]$ ?is "q affirmatively by exp]im5t4#ab ,c\lomb 7#agcf-ahjf7--;inv5tor ( ! torsion balance--%[$ t pond]able matt] *>g$ ) electricity foll[$ ! same =mula = attraction & repulsion z gravitat+ bodies did4 ,poisson 7#agha-ahdj7 work$ out ! difficult ma!matics ( fluids actuat$ by repell+ =ces dep5d+ on ! inv]se squ>e ( ! di/ance4 ,laplace 7#agdi-ahbg7 _h v e>ly become conv9c$ t ! actions ( pond]able sub/ances 9 :i* electric curr5ts 7 fl[+ c\ld be r$uc$ to an action at a di/ance proportional to ! inv]se squ>e ( ! elem5ts ( ! electric curr5t4 ,f>aday reg>d$ ! electric field z full ( l9es ( electric =ce1 9 a /ate ( t5sion1 & naturally repell+ ea* o!r4 ,to him1 z to a numb] ( 8 contempor>ies1 ! idea ( 8action at a di/ance0 0 repugnant2 ?\gh su* a possibility seem$ to be indicat$ by ! action ( gravitation--! relation ( ! =ces betwe5 two *>g$ bodies to ! di/ance betwe5 !m be+ v simil> to t ( ! gravitational =ces betwe5 two bodies to ! di/ance betwe5 !m4 ,b ,f>aday1 l ! great ,desc>tes long be=e him1 reject$ ! !ory ( action at a di/ance 9 favor ( 8action ?r\gh a m$ium40 ,ampre _h s\ght = "s sort ( me*anism = ! transmission ( electromagnetic curr5ts4 ,8 own discov]ies & ^? ( r/$ l$ him to =mulate ! hypo!sis t ! field 9 ! vic9ity ( a magnetic body is produc$ by a numb] ( exce$+ly small circul> curr5ts :i* fl[ undamp$ 9 or ar\nd ! molecules & t magnetization consi/s m]ely ( ! br++ ( ^! molecul> curr5ts into a p>allel direction4 ,b x 0 difficult = "s physici/s1 ev5 9 ,ampre's day1 to accept ! hypo!sis ( undim9i%$ curr5ts possess+ no resi/ance4 ,if we trans=m ! idea ( ! 8molecul> curr5ts0 ( ,ampre into ! language ( today1 sub/itut+ = ^! molecul> curr5ts electrons revolv+ 9 atoms1 x c be %[n t ! great ,fr5* sci5ti/ 0 sub/antially correct 9 8 assumptions4 ,9 #aiae ,dr4 ,alb]t ,e9/e9 & ,w4 ,j4 de ,haas a/oni%$ ! _w ( physici/s by %[+ exp]im5tally--by means ( a mo/ +5i\s app>atus--t ! 8molecul> curr5ts0 or revolv+ electrons really exi/4 ,9 #aiai1 ,pr(essor ,kram]l+h-,onnes1 at ! ,univ]sity ( ,leyd51 0 able to produce :at he call$ imitations ( amp]e curr5ts--i4 e41 8undim9i%$ curr5ts produc+ no resi/ance40 ,x 0 demon/rat$ t ! resi/ance ( pure gold & pure plat9um diff] v little if at all f nil at l[ temp]atures4 ,b wires ( ^! metals1 ( absolute purity1 are difficult to obta91 s m]cury 0 select$ = ! exp]im5ts4 ,! resi/ance ( ! metal at ! l[e/ atta9able temp]ature ( liquefi$ helium1-#bga4e ,c41 7at a pressure ( #c mm4 ( ! m]cury column71 prov$ to be immeasurably small4 ,! resi/ance d[n to a position %ortly bel[ #d4b ,k4 7,kelv9's absolute scale7 sudd5ly dropp$ f a measurable am\nt to a value practically nil4 ,x 0 f\nd t ! induc$ curr5t rema9$ 9 a /ate ( circulation1 & t ! decrease 9 ! /r5g? ( ! curr5t am\nt$ to less ?an #a p] c5t p] h\r1 f :i* x foll[$ t ! 8"t ( relaxation0 mu/ am\nt to m ?an f\r days6#ac ,at ! absolute z]o ( temp]ature1 x is suppos$ t ! orbits ( electrons 9 atoms are p]fect circles1 :atev] _! pa?s may be at measurable temp]atures4 ,?is motion ( ! electrons rema9s :5 all heat has disappe>$1 s9ce x is n ?is motion ( ! revolution ( ! electrons 9 _! orbits t is associat$ ) ! en]gy ( heat4 ,heat is a mode ( motion ( ! atoms !mselves1 n ( _! conta9$ electrons2 ?\gh increase ( heat d\btless results 9 an increase 9 ! av]age orbital velocity ( ! electrons4 ,s9ce ,ampre's day we h le>n$ at all ev5ts1 t an electric curr5t means ! fl[ ( electrons1 ei!r f atom to atom1 or pass+ betwe5 ! atoms1 along conductors4 ,9 #aibj1 ,"l ,kelv9 came to ! conclusion t at ! absolute z]o resi/ance ( metals mu/ be inf9itely great1 ! degrees ( dissociation ( ! electron be+1 he suppos$1 nil at ! z]o h\r4 ,if any free electrons rema9$1 he believ$ !y w\ld lose _! p[] ( motion1 cond5s+ l a vapor ^u ! metal atoms & freez+ fa/ to !m 7to borr[ a phrase f ,kam]l+h-,onnes74 ,! exp]im5ts ( ! celebrat$ ,holl& physici/ %[ t ! resi/ance ( metals decreases ) l[]+ ( temp]ature1 & w\ld probably become nil at ! absolute z]o ) employm5t ( a p]fectly pure plat9um wire4 ,if ?is is true1 !n w\ld a curr5t ( electricity1 once set up 9 a conductor1 cont9ue =ev]8 ,,footnotes3 #i ,philosophical ,transactions1 ,page #abg1 #ahcb2 ,fir/ ,s]ies1 ,article #aj4 #aj ,"o ( ! fir/ electrical exp]im5t]s to devise ! in/rum5t kn[n z a 8galvanomet]0 0 ,pr(essor ,s*weigg]1 ( ,halle4 ,!re are n[ eight or m v>ieties ( ?is in/rum5t 7or app>atus7 9 use4 ,x enables ! inve/igator to measure extremely m9ute electrodynamic actions1 or ! v weake/ int5sity ( an electric curr5t1 z well z to detect its pres5ce or direction1 usually by ! deflection ( a magnetic ne$le4 #aa ,maxwell1 ,cl]k1 8,on ,action at a ,di/ance10 7,sci5tific ,pap]s1 ,vol4 ,,ii1 ,page #cag74 #ab ,! sci5tific pap]s ( ,cav5di% 7 publi%$ 79 #ahgi7 "u ! title1 8,! ,electrical ,rese>*es ( ! ,hon4 ,h5ry ,cav5di%10 edit$ by ,cl]k ,maxwell4 ,cav5di% anticipat$ _m lat] inve/igations ( ,briti% & ,cont95tal writ]s1 includ+ ,ohm's law--i4 e41 ! proportionality betwe5 ! electromotive =ce & ! curr5t 9 ! same conductor2 & anticipat$ also ,f>aday's discov]y ( ! specific inductive capacity ( diff]5t sub/ances1 ev5 measur+ its num]ical value 9 sev]al sub/ances4 ,he _h also arriv$ at ! conceptions ( electrical capacity & ( 8pot5tial40 #ac ,see ,die ,naturwiss5s*aft5 7,b]l971 ,janu>y #bh1 #aiba4 ,,*apt] #d ,,!ories ,,( ,,electricity ,! sci5ce ( electricity is bas$ ^u obs]vation ( ^? ph5om5a ( attraction & repulsion :i* are compreh5d$ "u ! t]m electro/atics4 ,/atical electricity1 s nam$ f a ,greek ^w 7/atikos71 :i* means 8caus+ to /& 7or /ay710--also call$ frictional electricity--is ! electricity ( /ation>y *>ges caus$ by rubb+ toge!r unlike bodies1 su* z glass & silk 7not$ 9 ,*apt] ,,ii74 ,9 su* cases equal & opposite *>ges ( electricity are always produc$4 ,! t]m /atical electricity applies prop]ly1 h[ev]1 to ! electricity ( all /ation>y *>ges1 h[ev] produc$4 ,! electricity ^u ! surface ( glass is call$ positive electricity2 t ^u rubb]1 negative electricity4 ,:5 silk is rubb$ ^u glass x receives a negative *>ge f ! glass & conf]s a positive *>ge ^u ! silk4 ,wool or fur rubb$ on wax or rubb] receives a positive *>ge 9 ex*ange = a negative *>ge2 8equal & opposite *>ges ( electricity are always produc$40 ,a piece ( glass & a piece ( silk attract "o ano!r2 two pieces ( silk or two pieces ( glass or wax repel "o ano!r1 because a body :i* is positively *>g$ is attract$ by "o negatively *>g$ & repell$ by "o negatively *>g$1 & vice v]sa4 ,a piece ( glass rubb$ by a piece ( silk1 "u suitable conditions1 attracts any o!r body ) :i* x has n be5 9 contact4 ,! piece ( silk w d likewise4 ,9 all ^! cases1 ! attraction or repulsion becomes weak] ) increase ( di/ance betwe5 ! attract+ & repell+ bodies4 ,a ?ird body :i* has be5 9 contact ) a piece ( glass or a piece ( silk acquires to "s ext5t ! prop]ties ( ! glass or silk ) :i* ! ?ird body has be5 9 contact4 ,&1 conv]sely1 ! glass or silk ) :i* ! ?ird body has be5 9 contact attracts or repels ) less =ce ?an be=e4 ,if a h& is drawn ov] ! surface ( an object aft] x has be5 *>g$ ) electricity1 ! electricity disappe>s4 ,x has be5 conduct$ ?r\gh ! h& & ! body to ! e>?4 ,?is ph5om5on %[s t ! human body is a conductor ( electricity4 ,b mo/ metals are mu* bett] conductors4 ,moi/ air & damp wood are r poor conductors1 :ile dry air1 dry wood1 porcela91 glass1 h>d rubb] & seal+-wax are non-conductors1 or insulators4 ,! t]m dielectric is us$ 9 pref]5ce to insulation :5 ref]5ce is made to ! prop]ty ( transmitt+ induction--a process q di/9ct f ord9>y transmission ( an electric curr5t4 ,9 electro/atic induction1 a body electro/atically *>g$ induces 9 a neighbor+ conductor a l *>ge 9 ! p>ts f>!/ f ! *>g$ body1 & an unlike *>ge 9 ! ne>] p>ts2 ! repell$ l *>ge be+ remov$ by connect+ any "p ( ! conductor mom5t>ily ) ! e>?1 :ile ! b\nd unlike *>ge spreads ov] ! :ole surface ( ! conductor & rema9s !re ev5 :5 ! induc+ body is mov$ away1 or its *>ge neutraliz$1 if ! conductor is prop]ly insulat$4 ,dielectric /r5g? ref]s to ! ability ( an insulat+ mat]ial to resi/ rupture by high voltage1 measur$ by ! voltage necess>y to effect a disruptive dis*>ge ?r\gh x4 ,insulation resi/ance1 on ! o!r h&1 ref]s to ! ohmic resi/ance (f]$ by an insulat+ mat]ial to an impress$ voltage1 t5d+ to induce a breakage ( curr5t ?r\gh x4 ,! t]m dielectric is us$ z a synonym = insulator1 9 ! s5se t a *>ge on "o "p ( a non-conductor is n communicat$ to any o!r "p4 ,a *>ge giv5 to a conductor spreads to all p>ts ( ! body4 ,a dielectric possesses ! prop]ty ( transmitt+ electric =ce by 9duction b n by conduction4 ,a *>ge on "o "p ( a non-conductor or dielectric is n communicat$ to any o!r "p4 ,jeans sugge/s t s9ce ! pres5ce ( magnetic en]gy is always associat$ ) *>ges 9 motion1 :]eas electro/atic en]gy is pres5t :5 all ! *>ges are at re/ relatively to ea* o!r1 x may be prop] to id5tify electro/atic en]gy ) pot5tial en]gy1 & magnetic en]gy ) k9etic en]gy#ad--;i4 e41 en]gy due to motion ( p>ticles1 r ?an to en]gy ( position1 z ( a coil$ spr+4 ,/atical en]gy is di/+ui%$ f 8curr5t electricity0 by ! fact t x accumulates on v>i\s bodies--is /or$ up--& z soon z prop] connections are made1 x dis*>ges in/antly4 ,/atical electricity is us$ by physicians 9 electrical treatm5t ( diseases & 9 ,x-ray "w4 ,ma*9es h be5 con/ruct$ t w produce v /rong *>ges ( /atical electricity4 ,if a suffici5tly l>ge *>ge ( electricity accumulates ^u an insulat$ conductor 9 an electrical ma*9e1 x f9ally dis*>ges itself1 pass+ ?r\gh ! air to ! ne>e/ body4 ,a fla% ( lightn+ is ! result ( an ov]*>ge ( /atical electricity accumulat$ ^u cl\d p>ticles1 & may pass f cl\d to cl\d or desc5d to ! e>?4#ae ,c>eful driv]s ( gasol9e-tank wagons all[ an iron or /eel *a9 to drag on ! roadway f a metallic connection1 :i* conducts any surplus 8/atic0 to ! gr\nd4 ,failure to provide = su* an em]g5cy sometimes results 9 a t]rific explosion ) consequ5t loss ( life4 ,ab\t ! beg9n+ ( ! n9ete5? c5tury1 ! ,italian sci5ti/1 ,aless&ro ,volta 7#agde-ahbg71--;& o!r physici/s--discov]$ :at has be5 call$1 aft] ,volta1 voltaic electricity1 a curr5t g5]at$ by *emical action betwe5 metals & diff]5t liquids z arrang$ 9 a voltaic batt]y4 ,! t]m 8volt0--! electromotive =ce :i* p]=ms "w at ! rate ( "o j\le p] second 7"o watt7 9 produc+ a curr5t ( "o amp]e--0 simil>ly d]iv$4 ,x 0 le>n$ t if two diff]5t metals1 su* z copp] & z9c amalgam1 are plac$ 9 a weak acid solution 7su* z "o "p ,h#b,,s#d to f\r p>ts ,h#b,o71 & connect$ by a wire fa/5$ securely to ! metals1 a curr5t ( electricity 7ab\t two volts7 w pass ?r\gh ! wire4 ,c>bon 7a non-metal7 & a metal ^u :i* ! solution acts *emically may be us$ in/ead ( two metals4 ,!re mu/ be *emical action betwe5 ! liquid & "o metal1 or !re w be no curr5t4 ,su* a comb9ation con/itutes a cell1 & two or m cells make a batt]y4 ,! curr5t />ts ) ! z9c1 is conduct$ by ! solution to ! copp]1 & !nce by wire back to ! z9c1 complet+ a circuit4 ,! z9c con/itutes ! negative pole 7or electrode71 ! copp] or c>bon ! positive pole 7or electrode74 ,a cell frequ5tly employ$1 :]e a weak 7ab\t #a4a volts7 b con/ant electromotive =ce 78,e4 ,m4 ,f407 is requir$1 is "o devis$ by ! ,engli% physici/1 ,john ,d4 ,daniell 7#agij-ahde74 ,9 ?is cell a copp] sulphate solution conta9+ a copp] electrode is plac$ 9 contact 7by means ( a por\s wall or p>tition--usually an unglaz$ porcela9 cup7 ) a z9c sulphate solution conta9+ a z9c electrode4 ,! z9c electrode is negative to ! copp]4 ,at ea* electrode !re exi/s a pot5tial diff]5ce betwe5 solution & electrode4#af ,! two electrodes be+ connect$ ext]nally by a wire1 a curr5t ( electricity w fl[ ?r\gh ! wire f ! copp] to ! z9c1 & z9c w dissolve at ! anode 7positive pole7 & copp] deposit$ on ! ca?ode 7negative pole74 ,! curr5t 9 ?is case1 z 9 ! prec$+1 is said to be produc$ by voltaic action & ! cell is a prim>y batt]y4 ,voltaic action & electrolysis--! process ( *emical decomposition 7or dissociation ( comp\nds or molecules7--by ! action ( an electric curr5t produc$ ext]nally 7z by a dynamo7 & =c$ ?r\gh ! cell1 are ess5tially id5tical ph5om5a1 & obey ! same laws4#ag ,! famili> dry cell conta9s no liquid :i* might be spill$1 & is v useful = c]ta9 purposes1 z 9 automobiles1 & 9 op]at+ door-bells4 ,x is m]ely a voltaic cell ^: *emical cont5ts are made practically solid 7or pa/e-l7 by ! use ( "s absorb5t1 z gelat9e1 sawdu/1 etc4 ,9 cells ( ! ,leclan* type1 a mixture ( pla/] ( ,p>is1 fl\r1 & sal ammoniac takes ! place ( ! solution :i* acts *emically ^u "o ( ! conta9$ metals4 ,:5 us$ up1 a dry cell mu/ be replac$ by an entirely new cell4 ,two or m dry cells con/itute a dry batt]y4 ,we h se5 t !re are two types ( *>g$ bodies1 ( :i* *>g$ glass & *>g$ silk are famili> examples4 ,x 0 ,dufay 7#afii-agci7 :o discov]$ t !re 7 two k9ds ( electricity1 "o ( :i* he call$ vitre\s 7f glass7 & ! o!r res9\s 7f res9--amb]74 ,! t]ms 8positive0 & 8negative0 9 relation to electricity 7 fir/ appli$ by ,b5jam9 ,frankl91 9 #agef4 ,to ! electricity ( ! glass rod ,frankl9 gave ! "n 8positive0 & to t ( ! seal+-wax 7or h>d rubb]1 amb]1 etc47 ! "n 8negative40 ,^! names are n[ univ]sally 9 use--?\gh ,fr5* physici/s /ill speak ( vitre\s & res9\s electricity4 ,i h spok5 also ( a positive pole 7or electrode7 & a negative pole 7or electrode74 ,! electrodes con/itut+ ! two poles ( a curr5t are also call$ ! anode & ! ca?ode1 ! =m] be+ ! positive electrode & ! latt] ! negative electrode4#ah ,:5 x 0 le>n$ t electrical *>ges c\ld be di/+ui%$ by two oppos+ t]ms--positive & negative--x 0 natural to suppose t !re 7 two di/9ct k9ds ( electricity1 or 8fluids40 ,?is 0 ! view tak5 by ! ,fr5* *emi/ ,dufay4 ,b ! ,g]man electrician p9us 7#agbd-ahjb71 9 8 great pione] "w1 8,t5tam5 ,!oriae ,electriciatis et ,magnetismi0 7,an ,attempt at a ,!ory ( ,electricity & ,magnetism--#agei71 consid]$ ! ma!matical consequ5ces ( ! hypo!sis ( a s+le fluid1 attract+ all matt] b repell+ itself4 ,x soon became app>5t1 h[ev]1 t he mu/ assume ei!r ! exi/5ce ( two electrical fluids or ! mutual repulsion ( mat]ial p>ticles4 ,he *ose ! latt] !ory4 ,he expla9$ ! ph5om5a ( ! opposite poles z results ( ! excess & defici5cy ( a 8magnetic fluid10 :i* 0 dislodg$ & accumulat$ 9 ! ends ( ! body1 by ! repulsion ( its own p>ticles1 & by ! attraction ( iron & /eel1 z 9 ! case ( induc$ electricity4#ai p9us1 :o 0 unque/ionably "o ( ! greate/ physici/s ( ! eighte5? c5tury1 devis$ a me?od ( exam9+ ! nature ( ! electricity at any "p ( ! surface ( a body1 by :i* means he 0 enabl$ to asc]ta9 its di/ribution4 ,he f\nd t ! di/ribution 0 9 agreem5t ) ! attractions & repulsions :i* objects ex]t :5 !y are 9 ! neighborhood--8electrical atmosph]e0--( electrifi$ bodies4 ,today we say t su* bodies are electrifi$ by induction4 ,! p9ian !ory ( electricity & ( magnetism 0 modifi$ & pres5t$ 9 a new =m 79 #aghh7 by ,c\lomb1 ) two fluids in/ead ( "o4 ,8 fir/ task1 be=e r$uc+ ! !ory to calculation1 0 to det]m9e ! law ( ! =ces involv$--n be+ satisfi$1 = example1 ) ,newton's assumption t ! attractive =ce ( magnetism is inv]sely to ! cube ( ! di/ance4 ,may] 9 #agfj1 & ,lamb]t a few ye>s lat]1 _h f\nd ! law to be t ( ! inv]se squ>e4 ,c\lomb desir$ exp]im5tal confirmation ( ?is law be=e accept+ x z e/abli%$4 ,?is he secur$ by means ( 8 torsion-balance 7ab\t #aghd74bj ,x 0 9 pursuance ( ?is inve/igation t ,c\lomb br\ght to light = ! fir/ "t ! fact t ! directive magnetic =ces :i* ! e>? ex]ts ^u a ne$le is a con/ant quantity1 p>allel to ! magnetic m]idian1 & pass+ ?r\gh ! same po9t ( ! ne$le :atev] be its position4 ,b>l[1 :o _h adopt$ ! two-fluid hypo!sis1 %[$ t ! magnetic 8fluids0 7 collect$ at ! surface ( sph]es 7( iron71 ! surface be+ ! only "p 9 :i* !re c\ld be detect$ any magnetism4 ,he demon/rat$ t a %ell ( iron produces ! same effect z a solid ball ( ! same diamet]4 ,poisson's lat] analysis 7#ahbd7 %[$ t ?is 0 a consequ5t to be expect$4 ,m]z has well said t :at ,laplace did = ,newton 0 done by ,poisson 7#agha-ahdj7 8= ,c\lomb's elem5t>y law ( electric & magnetic action1 & on a /ill l>g] scale by ,gauss1 :o work$ out ! ma!matical !ory & appli$ x to ! case ( ! magnetic di/ribution on ! e>?'s surface4 ,9 ,engl&1 already be=e ,c\lomb's rese>*es 7 publi%$1 ,cav5di% _h1 likewise by a comb9ation ( exp]im5t & calculation1 e/abli%$ ! elem5t>y =mulae & prop]ties ( electrical ph5om5a40#ba ,b5jam9 ,frankl91 ! fir/ ,am]ican to ga9 int]national r5[n z a sci5ti/1 adopt$ & develop$ a 8"o-fluid !ory ( electricity40 ,on ?is supposition ! p>ts ( ! fluid repel ea* o!r1 & ! excess 9 "o surface ( ! glass--= example--repels ! fluid f ! o!r surface4 ,! fluid itself 0 reg>d$ by ,frankl9 z positive1 ! "p ( ! o!r 7negative electricity7 be+ tak5 by ord9>y matt]1 ! p>ticles ( :i* 7 suppos$ to repel ea* o!r & attract ! positive fluid1 j z ! p>ticles ( ! negative fluid did on ! two-fluid !ory4 ,on bo? ! two-fluid & ! "o-fluid !ories1 z we h se51 ! p>ticles ( ! positive fluid repell$ ea* o!r by =ces v>y+ inv]sely z ! squ>e ( ! di/ance betwe5 !m--z %[n by bo? p9us & ,c\lomb4 ,?is is true also ( ! p>ticles ( ! negative fluid4 ,! p>ticles ( ! positive fluid attract$ ^? ( ! negative fluid4 ,9 ,frankl9's "o-fluid !ory x 0 ! ord9>y p>ticles ( matt] :i* attract$ ! positive fluid & repell$ "o ano!r4 ,bo? !ories f _! v nature imply1 z ,sir ,j4 ,j4 ,?omson long ago 7#aijf7 po9t$ out1 ! idea ( action at a di/ance4 ,9 8 v int]e/+ book1 8,matt] & ,en]gy0 7#aiab71 ,pr(essor ,soddy says3 8,all electrical ph5om5a c be expla9$ z well on ! "o-fluid z on ! two-fluid idea1 b our ignorance at ! pres5t "t z to :e!r !re are two k9ds ( electricity or "o is fundam5tal4 ,until ! "q is settl$1 ! hopes t h be5 ent]ta9$ t1 ?r\gh ! /udy ( electricity1 we %all be able to arrive at a philosophical explanation ( matt]1 are likely to prove unf\nd$40 ,our mod]n view ( electrification be>s a close resemblance to ! "o-fluid !ory ( ,frankl91 :e!r we suppose !re is "o k9d ( electricity1 or two k9ds4 ,at all ev5ts1 if !re be su* a sep>ate =ce1 or su* units ( en]gy1 z 8positive0 electricity1 x has nev] be5 isolat$1 z h be5 ! negative atoms or electrons4 ,negative electrification is b a collection ( ^! negative corpuscles or unit *>ges4 ,! p>ticles ( ! 8electric fluid0 ( ,frankl9 correspond to ^! electrons4 8,in/ead ( tak+1 z ,frankl9 did1 ! electric fluid to be positive electricity1 we take x to be negative10 says ,j4 ,j4 ,?omson1 9 8 8,corpuscul> ,!ory ( ,matt]0 7#aijf74 ,& 8! transf]5ce ( electrification f "o place to ano!r is effect$ by ?is motion ( corpuscles f ! place :]e !re is a ga9 ( positive electrification to ! place :]e !re is a ga9 ( negative4 ,a positively electrifi$ body is "o t has lo/ "s ( its corpuscles40#bb ,,footnotes3 #ad ,jeans1 ,j4 ,h41 8,electricity & ,magnetism10 ,page #dhc1 #aiaa4 #ae ,b5jam9 ,frankl9 0 fir/ to %[ 79 a lett] to ,pet] ,coll9son1 writt5 ,octob] #ai1 #ageb7 t lightn+ & electricity are "o & ! same ?+4 ,he 0 also inv5tor ( ! lightn+-rod4 #af 8,pot5tial0 is analog\s to level 7or pressure7 9 hydro/atics or me*anics4 #ag ,= fur!r explanation1 see ,%ipley1 ,mayn>d1 8,! ,a4 ,b4 ,c4 ( ! ,electronic ,!ory ( ,matt]10 ,little ,blue ,book ,s]ies1 ,no4 #fjc4 #ah ,see1 9 ?is connection1 ,%ipley1 ,op4 cit4 #ai ,a v simil> hypo!sis 0 read be=e ! ,royal ,society by ,h5ry ,cav5di%1 9 #agga1 ! "w ( p9us be+ unkn[n to him at ! "t4 #bj ,by means ( ?is in/rum5t v m9ute =ces c be accurately measur$1 su* z electro/atic or magnetic attraction & repulsion1 by ! torsion 7turn+ or twi/+7 ( a wire or filam5t1 ! angle ( torsion be+ proportional to ! am\nt ( =ce ex]t$4 #ba ,m]z1 ,h5ry1 8,hi/ory ( ,european ,?\ght 9 ! ,n9ete5? ,c5tury10 ,vol4 ,i1 ,page #cfb4 #bb ,= a rec5t "w on mod]n electrical !ory1 see ,/>l+1 ,sydney ,g41 7head ( ! dep>tm5t ( physics 9 ! ,we/ ,ham ,municipal ,college1 ,london71 8,electricity10 ,london1 #aibb4 ,= ! pione] "w ( ,ampre1 see 8 8,!orie des ,ph5om5es ,electrodynamiques10 #ahbf4 ,,*apt] #e ,,mod]n ,,magnetic ,,!ory ,we h already %[n h[ ! magnetism ( a magnet is conv]t$ into electricity1 by means ( rotat+ coils cutt+ ! l9es ( magnetic =ce 9 ! 8field40 ,! en]gy us$ to drive ! ma*9]y may1 ( c\rse1 be d]iv$ ei!r f wat]-p[] or by /eam4 ,gravity gives en]gy to fall+ wat]2 *emical en]gy produc$ by ! oxidation ( coal becomes heat en]gy1 :i* 9 turn causes ! expansion ( /eam1 :i* produces en]gy ( motion 9 a pi/on2 & ?is motion1 transmitt$ to ! p>ts ( an eng9e to a dynamo1 produces electrical en]gy4 ,:5 ! electric curr5t f ! dynamo has be5 conduct$ to any desir$ po9t by cables1 ano!r motor1 act+ 9 ! opposite s5se1 causes ! electricity to *ange back aga9 into ! orig9al me*anical en]gy1 less ! loss due to imp]fections 9 ! op]ation4 ,"h we h1 !n a cle> picture ( :at is meant by ! phrase1 trans=mation ( en]gy4 ,b ano!r "q naturally arises at ?is po9t4 ,we "k t ) a f9ite quantity ( magnetism we c produce an unlimit$ quantity ( electricity4 ,yet we add no new mat]ial1 no s\rce ( supply1 to ! dynamo4 ,let ! rotat+ coils cont9ue to cut ! l9es ( magnetic =ce 9 ! magnetic field1 & ! magnetism ( ! magnet w be trans=m$ into curr5t electricity--furni%+ a lit]ally exhau/less supply f ! great /oreh\se ( nature4 ,= u ! en]gy ( ! univ]se is inf9ite 9 quantity4 ,! res]voir ( en]gy is exhau/less1 & ! dynamo is man's op5 sesame4 ,b j "h ! v int]e/+ "q arises3 ,is ! inexhau/ible supply ( electric curr5t ) ! exp5diture ( a limit$ quantity ( magnetism fully expla9$ by say+ t x is due to ! rotational movem5t ( ! coil8 ,c ! m]e rotation ( a metal 9 a magnetic field actually create an endless supply ( available en]gy8 ,n likely6 ,z ,dr4 ,gu/ave ,le ,bon well says3 8,su* a metamorphosis w\ld be z m>vel\s z trans=mation ( lead into gold by simply %ak+ x 9 a bottle4 ,ano!r int]pretation mu/ be s\ght = ! ph5om5on40 ,n[1 a curr5t ( electricity is kn[n to be a /ream ( electrons 7negative *>ges7 fl[+ along or 9 a conductor2 & an electron is an atom (--en]gy4 ,b :]e 0 ?is en]gy /or$8 8,9 ! all-p]vasive e!r10 say _m physici/s4 8,!re is no e!r10 say o!rs4 ,! electromagnetic field repres5ts en]gy /orage 9 space--n 9 a univ]sal1 incompreh5sible1 p>adoxical some?+ call$ 8e!r40 ,a field ( en]gy is intelligible4 ,x takes ! place ( ! conception ( action at a di/ance & ( ! e!r4 ,no 8e!r0 ne$ be po/ulat$ z ! c>ri] ( ! field en]gy 9 space4 ,x is its own c>ri]4 8,en]gy is ! only real exi/+ entity1 ! prim>y conception1 :i* exi/s = u because our s5ses respond to x0 7,/e9metz74 8,l9es ( =ce10 says ,dr4 ,n4 ,r4 ,campbell1 ! fam\s ,engli% physici/1 8are j l9es ( =ce1 indep5d5t = _! exi/5ce ( all surr\nd+ bodies1 & !re is no m to be said ab\t !m4444 ,our ,electrical !ory1 s f> f provid+ additional support = ! conception ( ! e!r fill+ all space1 does n require su* a conception at all40 ,dr4 ,le ,bon f9ds ! exhau/less s\rce ( electricity 9 ! int]ior ( atoms4 ,! atoms 9 "o p\nd ( e>? conta9 en\gh en]gy to run all ! factories1 mills1 railroads1 etc41 & light all ! cities & villages ( ! ,unit$ ,/ates1 = a mon?1 ,/e9metz tells u4 8,x w\ld10 he /ates fur!r 78,relativity & ,space10 ,page #de71 8supply ! fuel = ! bigge/ transatlantic l9] = #cjj trips f ,am]ica to ,europe & back4 ,& if ?is en]gy ( "o p\nd ( dirt c\ld be let loose in/antane\sly1 x w\ld be equal 9 de/ructive p[]s to ov] a million tons ( dynamite40 ,f ! above /atem5t1 we may well und]/& ,dr4 ,le ,bon's int]pretation ( ! "w ( a dynamo3 8,matt] be+ easily dissociat$ & con/itut+ an imm5se res]voir ( intra-atomic en]gy1 x is en\gh to admit t ! l9es ( =ce seiz$ ^u by ! conduct+ body 7! coils71 :i* cuts !m & causes !m to fl[ 9 ! =m ( an electric curr5t1 are con/antly replac$ at ! exp5se ( ! intra-atomic en]gy4 ,?is latt] be+ relatively almo/ inexhau/ible1 a s+le magnet c furni% an almo/ inf9ite numb] ( l9es ( =ce40 ,x c be %[n t ! k9etic en]gy ( "o kilogram 7#b4b p\nds7 weight ( matt] is ab\t #ijjj millions ( millions ( kilogram-met]s1 or #be ?\s& million kil[att-h\rs 7a kil[att-h\r #ajjj watt h\rs74 ,?is means1 9 o!r words1 t ! quantity ( en]gy 9 ! atoms ( #b4b p\nds ( ord9>y matt] is ?\s&s ( million times great] ?an ! en]gy ( an equal quantity ( coal1 releas$ by *emical combu/ion4 ,e/imat+ ! total en]gy consum$ dur+ ! ye> on e>? = heat1 light1 p[]1 etc41 z ab\t #ae millions ( millions 7 #ae1jjj1jjj1jjj1jjj7 ( kil[att-h\rs1 ,/e9metz tells u t #fjj kilograms1 or less ?an two-?irds ( a ton1 ( 8dirt10 if x c\ld be dis9tegrat$ into en]gy1 w\ld supply all ! heat1 light & en]gy dem& ( ! :ole e>? = a ye>4 ,sev]al em95t physici/s are n[ specializ+ on ! problem ( h[ to lib]ate & control intra-atomic en]gy = man's uses--or abuses4 ,be>+ 9 m9d ! pres5t intellectual1 moral & economic /atus ( our 8lead]s ( ?\ght0 & _! foll[]s1 & rememb]+ t "o p\nd ( common soil conta9s intra-atomic en]gy equal 9 de/ructive p[] to m ?an a million tons ( dynamite1 let u hope t ! secret ( releas+ & 8controll+0 intra-atomic en]gy w n be discov]$ 9 our day & age4 ,,*apt] #f ,,pro( ,,t ,,electrons ,,are ,,atoms ,,( ,,electricity ,,! ,,zeeman ,,effect ,he9ri* ,h]tz demon/rat$ 9 #ahhg t he c\ld produce 9 ! 8e!r0--or at lea/ 9 space--:at are n[ kn[n z 8wireless waves10 by all[+ a *>ge ( electricity to oscillate to & fro4 ,l>mor & ,lor5tz 71 at ! same "t1 endeavor+ to =mulate a !ory :i* w\ld acc\nt = ! production ( ! f> %ort] light-waves4 ,lor5tz suppos$ t ea* atom conta9$ "o or m inf9itesimal p>ticles1 or electric *>ges 7electrons71 ^: excessively rapid vibrations caus$ ! emission ( light-rays4 ,maxwell %[$ t !re mu/ be a close connection betwe5 light & electricity1 a !ory conv]t$ into demon/rable fact by ! "w ( ,h]tz4 ,t !re is a simil> relation betwe5 light & magnetism 0 ! firm conviction ( ,f>aday4 ,9 #ahde1 he plac$ a block ( v d5se glass betwe5 ! poles ( ! mo/ p[]ful electromagnet produceable at ! "t4 ,be=e turn+ on ! swit*1 he all[$ a beam ( light to pass ?r\gh ! glass1 produc+ 8pol>ization0--a modification ( light-rays result+ f _! reflection 79 ?is case f a cry/all9e sub/ance71 imp>t+ to ! beam a def9ite direction--! plane ( vibration or plane ( pol>ization4 ,:5 ! swit* 0 clos$1 p]mitt+ ! fl[ ( ! electric curr5t1 :i* produc$ ! magnetic field1 ! beam ( light 0 8rotat$40 ,t is1 ! beam ( light 0 8plane-pol>iz$0 by ! cry/al1 & 8rotat$0 by ! magnetic field2 i4 e41 n[ *ang$ into two 8circul>ly pol>iz$0 rays1 "o a left-h&$ motion & ! o!r a "r-h&$ motion 79 ! direction ( ! h&s ( a wat*74 ,?is c\ld be acc\nt$ = only on ! !ory t light is affect$ by magnetism1 s9ce ! beam 0 n rotat$ by ! glass alone--9 itself a v important discov]y4 ,b ! exp]im5t did n yield ,f>aday an answ] to ! "q upp]mo/ 9 8 m9d3 namely1 c a magnetic field *ange ! rate ( vibration ( a light-emitt+ p>ticle8 ,t is to say1 9 effect1 c a magnetic field cause a ray ( light to %ift its normal place 9 ! spectrum8 ,x 0 n until #ahfb1 sev5te5 ye>s aft] ! exp]im5t j describ$1 t ,f>aday attempt$ to solve ?is important !oretical problem4 ,he n[ plac$ a sodium flame 9 front ( ! slit ( ! spectroscope1 :i* normally yields two *>act]i/ic yell[ l9es 7! ,d l9es ( ! spectrum71 & obs]v$ !m ) ! be/ spectroscope at 8 comm&1 "u ! mo/ p[]ful electromagnetic field :i* he c\ld produce4 ,no *ange f ! normal c\ld be detect$4 ,o!r obs]v]s tri$ ! same exp]im5t1 b ) negative results4 ,we "k t 8 !ory 0 well f\nd$1 & t only ! lack ( a bett] spectroscope & a m p[]ful magnet prev5t$ 8 discov]y ( :at is n[ kn[n z ! ,zeeman effect--a discov]y :i* has already ?r[n a flood ( light on a numb] ( difficult physical problems4#bc ,work+ ) mu* m p[]ful app>atus1 b foll[+ ! same me?od ( proc$ure employ$ by ! immortal ,f>aday1 ,dr4 ,piet] ,zeeman1 ( ,leyd51 succe$$1 9 #ahif1 9 exp]im5tally demon/rat+ ! close relation%ip betwe5 light & magnetism4 ,dr4 ,h4 ,a4 ,lor5tz1 !n ,pr(essor ( ,physics 9 ! ,univ]sity ( ,leyd51 n[ ma!matical physici/ at ! ,norman ,bridge ,laboratory ( ,physics1 ,pasad5a1 ,cali=nia1 _h pr$ict$ ! nature ( ! *ange 9 ! spectral l9es to be expect$1 & ?is k 0 us$ by ,dr4 ,zeeman z a *eck on 8 results4 ,us+ a ,r[l& grat+1 in/ead ( a less effici5t prism spectroscope1 ,dr4 ,zeeman f\nd t :5 a relatively weak electric curr5t 0 appli$1 ! two sodium l9es 7 m]ely wid5$4 ,9 a /ill m p[]ful magnetic field1 ea* ( ! l9es 0 decompos$ into two or ?ree compon5ts1 :5 ! l9es ( =ce 7 p>allel to ! l9e ( sight4#bd ,moreov]1 ! rays ( ! compon5ts ( ea* l9e 87 n ^? ( natural light10 b 7 8pol>iz$ 9 a *>act]i/ic way10 i4 e41 7 circul>ly pol>iz$ 9 opposite directions--8! direction ( ! vibration dep5d+ 9 a simple mann] on ! direction ( ! magnetic l9es ( =ce40#be ,! same effect has m rec5tly be5 produc$ 9 ! case ( ! spectral rays ( ne>ly--if n q--all ! o!r elem5ts4 ,! process1 z describ$ by ,dr4 ,george ,ell]y ,hale1 is v simple3 8,we place our iron ore or sp>k betwe5 ! poles ( a p[]ful magnet1 & photograph its spectrum4 ,! l9es behave 9 ! mo/ div]se way1 "s splitt+ into triplets1 o!rs into quadruplets1 qu9tuplets1 sextuplets1 etc4 ,"o *romium l9e is resolv$ by ! magnet into tw5ty-"o compon5ts4444 ,! di/ance betwe5 ! compon5ts ( a l9e is directly proportional to ! /r5g? ( ! magnetic field40#bf ,! mean+ ( ?is splitt+ & pol>ization ( light-rays 9 ! magnetic field is t1 z ,lor5tz _h pr$ict$1 !re are pres5t 9 ! lum9\s vapor vibrat+ p>ticles negatively *>g$1 or 8electrons40 ,measurem5t ( ! di/ances ap>t ( ! compon5ts ( ! triple l9e reveals ! relation betwe5 ! *>ge & ! mass ( ! p>ticles4#bg ,x is int]e/+ to add t ! di/urbances 9 ! magnetic field1 z obs]v$ by ,zeeman1 7 precisely ( ! am\nt calculat$ by ,lor5tz purely on !oretical gr\nds1 & ! mass ( ! electron 0 f\nd by ?is me?od to be #a_/ahdj t ( ! hydrog5 atom4 ,by a diff]5t me?od1 ,sir ,j4 ,j4 ,?omson obta9$ a value ( #a_/ahjj ! mass ( ! hydrog5 atom2 :ile ,dr4 ,rob]t ,a4 ,millikan1 by means ( 8 fam\s 8electrical balance10 d]iv$ a value ( #a_/ahde t ( ! hydrog5 atom4#bh ,9 8 monograph ( #aiac1 ,zeeman rem>k$ t 9 discov]ies ( optics 8we may always *]i% ! hope t !y w lead ultimately to applications to a/ronomy40 ,s f> z /udy ( sol> ph5om5a & ! ,zeeman effect are conc]n$1 ?is hope has be5 fully realiz$1 & attempts are be+ made to ext5d ! applications ( ?is me?od ( inve/igation to o!r /ell> bodies4 ,( ! g5]al value ( ,zeeman's discov]y1 ,dr4 ,hale writes3 8,! complex ph5om5a ( ! ,zeeman effect 7z reveal$ 9 a comp>ative /udy1 ) p[]ful spectrographs1 & an int5se magnetic field1 ( ! l9es ( a long li/ ( elem5ts7 furni% mat]ial available = wide g5]alization1 important 9 _! be>+ on !ories ( radiation & atomic /ructure0 7,op4 cit41 ,page #cf74 ,discov]y by ,hale & 8 co-work]s at ,m\nt ,wilson ( ! ,zeeman effect 9 sun-spots l$ to ! v important conclusion t ^! di/urbances repres5t :irl+ vortices ( electrons1 produc+ a magnetic field4 8,! /r5g? ( ! magnetic field produc$1 :i* is measur$ by ! degree ( sep>ation ( ! triple l9es1 increases ) ! diamet] ( ! spot4444 ,x has long be5 kn[n t sun-spots usually occur 9 pairs1 & our /udy ( ! ,zeeman effect indicates t ! two pr9cipal spots 9 su* a gr\p are almo/ inv>iably ( opposite pol>ity0 7,hale1 ,op4 cit41 ,pages #bh-ca74 ,! sun1 l ! e>? is n[ kn[n to be a magnet1 ^: g5]al magnetic field is ab\t #hj times z int5se z t ( ! e>?4 ,at ! di/ance ( ! e>? ! sol> magnetic field is n appreciable1 8s9ce ! effect ( "o pole c\nt]acts ! equal & opposite effect ( ! o!r pole40 ,7 x n = our k conc]n+ ! ,zeeman effect1 x w\ld n yet be kn[n = a c]ta9ty t ! sun is a va/ magnetic globe1 s9ce ?is fact c\ld n be assum$ to be a s\rce ( ! sun's gravitational p[]4 8,inde$10 says ,dr4 ,hale1#bi 8its attraction _c be felt by ! mo/ delicate in/rum5ts at ! di/ance ( ! e>?1 & w\ld /ill be unkn[n 7 x n = ! influ5ce ( magnetism on light4 ,auroras1 magnetic /orms1 & su* electric curr5ts z ^? t rec5tly d]ang$ sev]al ,atlantic cables are due1 n to ! magnetism ( ! sun or its spots1 b probably to /reams ( electrons1 %ot out f highly di/urb$ areas ( ! sol> surface surr\nd+ great sun-spots1 trav]s+ #ic million miles ( ! e!r ( space1 & p5etrat+ deep into ! e>?'s atmosph]e40 ,by means ( ! fam\s #aej-;foot t[] telescope at ,m\nt ,wilson1 :i* produces at a fix$ po9t 9 a laboratory an image ( ! sun ab\t sixte5 in*es 9 diamet]1 ! magnetic ph5om5a ( sun-spots are be+ /udi$ to great advantage1 ! enl>g$ sun-spots mak+ possible sep>ate obs]vation ( _! v>i\s p>ts4 8,?is analysis is accompli%$ ) a spectroscope #hj feet 9 l5g?1 m\nt$ 9 a subt]ranean *amb] b5ea? ! t[]40 ,by ?is means ! v important discov]y 0 made by ,director ,hale t ! entire sun1 rotat+ on its axis1 is a great magnet4 8,h5ce10 says ,dr4 ,hale1 8we may reasonably inf] t e />1 & probably e planet1 is also a magnet1 z ! e>? has be5 kn[n to be s9ce ! days ( ,gilb]t's #8,de ,magnete4' ,b>nett has succe$$ 9 produc+ magnetism by rapidly :irl+ masses ( metal 9 ! laboratory0 7,hale1 8,! ,new ,heav5s10 ,pages #fi-gj74 ,m rec5tly 7,octob]1 #aibb71 ,hale1 ,ell]man & ,ni*olson1 all ( ! ,m\nt ,wilson ,obs]vatory1 h detect$ invisible sun-spots by se>*+ = evid5ces ( ! ,zeeman effect 9 promis+ regions1 su* z areas ( flocculi foll[+ a l>ge spot4 8,a special pol>iz+ app>atus p]mits v small magnetic fields to be f\nd by ! alt]nate wid5+ to r$ & violet ( ! iron triplet ,lambda #fagc10 say ,hale & ,adams 78,summ>y ( ! ,ye>'s ,"w at ,m\nt ,wilson10 ,publications ( ! ,a/ronomical ,society ( ! ,pacific1 ,octob]1 #aibb1 ,pages #bfi-gj ,vol4 ,,xxxiv1 ,no4 #bja74 8,! results confirm ! view t a spot repres5ts a vortex1 :i* becomes visible only :5 ! cool+ due to ! expansion 7( gases7 is suffici5tly great to produce a p]ceptible decrease 9 ! brightness ( ! photosph]e40 ,f :at has be5 said1 x is evid5t t ,dr4 ,zeeman's desire to see ! results ( 8 discov]y appli$ to ! /udy ( a/ronomical problems has be5 fully realiz$4 ,,! ,,/>k ,,effect ,lor5tz's pr$iction reg>d+ ! effect ( a /rong magnetic field on spectral rays1 & ! movem5ts ( electrons 9 ! field hav+ be5 confirm$ s brilliantly by ,zeeman1 x rema9$ to asc]ta9 :at effect1 if any1 w\ld be ex]t$ by electrical =ce on light-rays4 ,! answ] to ?is problem 0 giv5 by ,pr(4 ,johannes ,/>k1 at ,aix-la-,*apelle1 9 #aiac1 by 8 skillful demon/ration ( ! electrical decomposition ( ! spectral rays ( hydrog51 helium & li?ium4#cj ,/>k's task 0 a m difficult "o ?an ,zeeman's1 ow+ to ! fact t he _h to deal ) lum9esc5t gases1 :i*1 be+ conductors1 exhau/ ! electrical field almo/ be=e any obs]vations c be made1 ev5 hurri$ly4 ,?is condition gives rise to difficulties 9 connection ) ! application ( ! electric field4 ,b ^! 7 v +5i\sly met by employm5t ( highly evacuat$ tubes & ! light emitt$ by ! 8canal rays0--positively *>g$ p>ticles simil> to ! alpha rays4#ca ,:]e ! rays issue f ! p]=at$ electrode 7or 8canal071 ! conduction ( electricity is weak1 & ,/>k 0 able to apply int5se electric fields 9 a small space4 ,x 0 !n f\nd t ! diffuse rays ( ! spectrum produc$ 7 /rongly influ5c$1 :ile ! 8%>p0 rays 7 less s4 ,! att5tive read] w note t ?is result 0 9 m>k$ contra/ ) ! magnetic decomposition produc$ 9 ! ,zeeman exp]im5t1 9 :i* ! rays did n diff] "o f ano!r 9 respect to ! degree ( _! decomposition4 ,9 all ! details !re is a diff]5ce betwe5 ! electric & magnetic decompositions1 & analogy exi/+ only 9 ?is1 namely1 t 9 bo? cases pol>iz$ rays 7 obta9$4 ,9 bo? cases ! results produc$ 7 due to di/urbance ( ! motions ( electrons1 giv+ rise to broad5+1 displacem5t or o!r modifications ( spectral laws4 ,bo? 8effects0 confirm ! !oretical view ( ,maxwell1 namely1 t light is an electromagnetic ph5om5on4 ,f>aday's fam\s "q is ?us m ?an answ]$ 9 ! affirmative3 n only is ! rate ( vibration ( 8atoms0 7electrons7 *ang$ by a magnetic field1 b also "u ! action ( an electro/atic field1 produc+ decomposition ( c]ta9 spectral l9es1 :i* are usually pol>iz$1 z 9 ! ,zeeman effect4 ,z a result ( 8 int5sive inve/igations ( ! ,zeeman effect1 ,dr4 ,h5ri ,a4 ,desl&res1 ,director ( ! ,a/rophysical ,obs]vatory at ,meudon 7a s\!rn suburb ( ,p>is71 propos$ a new g5]al =mula :i* repres5ts ! s]ies relation%ip ( ! compon5t l9es & heads ( b&s bo? = emission & absorption spectra4 ,accord+ to 8 exp]im5tally-d]iv$ law1 8! orig9 ( ^! radiations may be f\nd 9 ! transv]se & longitud9al vibrations ( ! atoms40 ,! lam5t$ ,dr4 ,p4 ,s4 ,ep/e91 a gift$ pupil ( ,somm]feld1 :o--l ,mosely--fell a m>tyr to ! ,_w ,w>1 succe$$ 9 apply+ ! quantum dynamics to ! ,/>k effect1 :]eby ! motions ( ! electron 9 produc+ ! ,h-beta 79 ! blue-gre57 & ,h-gamma 79 ! violet7 l9es obs]v$1 8are acc\nt$ = ) great accuracy0 7,lor+1 8,atomic ,!ories10 ,page #fg74 ,x may be said 9 conclusion1 t ! mo/ promis+ attempts fully to expla9 ! ph5om5a ( ! ,zeeman & ,/>k effects seem to be made f ! po9t ( view ( ,planck's ,quantum ,!ory ( ,light4 ,on ! o!r h&1 x mu/ be admitt$ t !re has n be51 s f> z ,i c asc]ta91 any !ory propos$ :i* expla9s all ( ! ph5om5a involv$4 ,,footnotes3 #bc ,= a good summ>y ( ! ma9 results conc]n+ ! ,zeeman effect1 see von ,au]ba*1 ,felix1 8,mod]ne ,magnetik10 ,leipsic1 #aiba4 ,an excell5t acc\nt ( ! quantum treatm5t ( ! ,zeeman effect may be f\nd 9 ,*apt] ,,xv 7,s]ies ,spectra7 ( ,dr4 ,n4 ,r4 ,campbell's 8,mod]n ,electrical ,!ory1 ,supplem5t>y ,*apt]s10 ,cambridge ,univ]sity ,press1 #aiba4 #bd ,x seems t ?is ph5om5on _h previ\sly be5 obs]v$ by ,m4 ,fievez4 7,cf4 ,mi*elson1 ,dr4 ,alb]t ,a41 8,light ,waves & ,_! ,uses10 ,page #ajg47 8,he ?\ght t ea* sep>ate l9e 0 d\bl$ or quadrupl$40 ,locky]1 9 #ahff1 obs]v$ t "s ( ! l9es 9 a sun spot spectrum 7 wid5$4 ,pr(4 ,*>les ,"y & ,w4 ,m4 ,mit*ell obs]v$ t "s ( ! l9es 7 ev5 d\ble1 b x 0 n suspect$ t ^! ph5om5a 7 caus$ by a /rong magnetic field 9 sun-spots1 br\ght ab\t by free electrons be+ driv5 ar\nd 9 a vortex movem5t4 ,9 fact1 ,mit*ell ref]r$ to ! d\blets z 8rev]sals40 #be ,zeeman1 8,les ,lignes ,spectrales et les ,!ories ,mod]nes10 ,sci5tia1 ,janu>y #a1 #aiba1 ,page #ah 7,vol4 ,,xix1 ,no4 ,,cv--,i74 #bf ,hale1 8,t5 ,ye>s ,"w ( a ,m\nta9 ,obs]vatory10 ,pages #bi-cj1 ,wa%+ton1 ,d4 ,c4 7,c>negie ,in/itution ( ,wa%+ton71 #aiae4 ,see also1 ,babcock1 ,h>old ,d41 8,! ,zeeman ,effect = ,*romium10 ,contributions f ,m\nt ,wilson ,obs]vatory1 ,vol4 ,,ii1 ,pap] ,no4 #eb2 also 8,! ,correspond5ce betwe5 ,zeeman ,effect & ,pressure ,displacem5t = ! ,spectra ( ,iron1 ,*romium & ,titanium10 ,ar?ur ,s4 ,k+1 ,loc4 cit41 ,pap] ,no4 #df2 & 8,! ,zeeman ,effect on ! ,sun10 ,adriaan van ,maan51 ,publications ( ! ,a/ronomical society ( ! ,pacific1 ,page #bd1 ,vol4 ,,xxxiv1 ,no4 #aig 7,febru>y1 #aibb74 #bg ,zeeman1 ,loc4 cit41 ,page #ah4 ,see also ! classical monograph by ! same au?or1 8,rese>*es 9 ,magneto-,optics10 ,london1 #aiac4 #bh ,millikan1 ,physical ,review1 #b1 #adc 7#aiac72 8,! ,electron10 #aiag 7revis$ edition1 #aibd74 ,see also1 ,proce$+s ( ! ,national ,academy ( ,sci5ces1 #c1 #cad 7#aiag74 #bi 8,! ,new ,heav5s10 ,page #gj1 ,new ,york1 #aibb4 #cj ,cf4 ,/>k1 8,die ,atomion5 *emis*]e ,elem5te und ihre ,kana/rahl5spektra10 ,b]l91 #aiac4 ,see also1 8,elektris*e ,spektralanalyse *emis*5 ,atome10 ,leipsic1 #aiad4 #ca ,call$ 8canal rays0 by ! ,g]man physici/1 ,eug5 ,gold/e91 :o1 9 #ahhf1 fir/ obta9$ !m by ! use ( a p]=at$ ca?ode2 t is1 he us$ a metallic tube = a ca?ode1 ?r\gh :i* tube1 call$ by ,gold/e9 a 8canal10 ! rays issu$4 ,,*apt] #g ,,! ,,discov]y ,,( ,,wireless ,,telegraphy ,! exp]im5tal f\ndation = ! discov]y ( wireless telegraphy 0 laid by ! rese>*es ( ,f>aday4#cb ,accept+ ,f>aday's physical views z a po9t ( dep>ture1 ,james ,cl]k ,maxwell 7#ahca-ahgi71 ,pr(essor ( ,exp]im5tal ,physics 9 ! ,univ]sity ( ,cambridge1 began 7ab\t #ahfj7 ! developm5t ( 8 con/ructive speculations 9 electrical !ory :i* culm9at$ 9 ! n[ univ]sally accept$ electromagnetic !ory ( light4#cc ,f\rte5 ye>s aft] ! publication ( ,maxwell's classic treatise1 ,he9ri* ,h]tz 7#ahei-ahid7--;a brilliant pupil ( ,helmholtz 7#ahba-ahid7--succe$$ 9 produc+ electrical dis*>ges f a ,leyd5 j>1 :i* oscillations 9 turn gave rise to electromagnetic waves ( f> great] l5g? ?an any previ\sly kn[n4#cd ,h]tz demon/rat$ also t ! velocity ( propagation ( ^! waves 0 ! same z t ( light-waves--approximately #ahf1jjj miles a second1 equival5t to ab\t sev5 times ! circumf]5ce ( ! e>? 9 "o second4 ,x 0 %[n t ! only diff]5ce betwe5 ! ,h]tzian 78wireless07 waves1 = example1 & ! light-waves1 is 9 _! respective l5g?1 or1 reciprocally1 _! rates ( vibration p] second4 ,h]tz lat] demon/rat$ t ^! invisible waves produc$ by a ,leyd5 j> c\ld be reflect$1 refract$1 & pol>iz$1 z 9 ! case ) ! f> %ort] light-waves or rays4#ce ,^! results _h be5 pr$ict$ by ,maxwell4 ,9 ?is great discov]y ! f\ndation = wireless telegraphy & wireless telephony 0 laid--= ,h]tz _h f\nd :at are n[ kn[n z 8wireless0 or radio waves--de/9$1 p]haps1 to revolutionize our me?ods ( obta9+ p[] = ma*9]y1 & = transportation1 z !y h already revolutioniz$ our me?ods ( communication4 ,h]tz _h done m ?an ?is3 = 8 inve/igations made possible a f> m satisfactory rese>* into ! /ructure ( atoms4 8,if we 7 ask$ to pick out "o date t /&s out m prom95tly ?an o!rs 9 our acquisition ( k be>+ ^u ! /ructure ( matt]10 says ,dr4 ,alb]t ,c4 ,crehore1 8x might be ?is epo*-mak+ "w ( ,h]tz40#cf ,:ile x is true t ! waves t ,h]tz discov]$ & measur$ 8diff] f light-waves m]ely 9 wave-l5g? or p]iod ( vibration & quality10 on ! o!r h& ! diff]5ce 9 wave-l5g? is s great t no in/rum5t _h z yet be5 devis$ to measure or detect waves t 7 met]s long1 z comp>$ ) light-waves b a m9ute fraction ( a c5timet] 9 l5g?4 ,x 0 ,h]tz's task--foll[+ up ,maxwell's pr$iction--to devise an in/rum5t :i* w\ld detect waves n cognizable by our s5ses alone4 ,= ?is purpose he us$ a simple loop ( wire ) ! ends br\ght ne> toge!r1 ea* t]m9at+ 9 a metal ball4 ,:5 ^! balls 7 br\ght almo/ into contact1 a small electrical sp>k 0 se5 to pass betwe5 ! balls :5 ! 8oscillator0--! app>atus us$ to g5]ate ! oscillat+ curr5ts1 or electric waves1 ( high frequ5cy--0 set 9 op]ation4#cg ,h]tz n only prov$ t ! spe$ ( electric waves is ! same z t ( light1 & t !y are subject1 "u c]ta9 conditions1 to 8int]f]5ce0 z are light-waves1 b he also succe$$ 9 actually measur+ ! l5g? ( ! waves produc$ by 8 crude app>atus4 ,?is 0 accompli%$ by produc+ :at are kn[n z 8/&+ waves10 analog\s to ! s\nd-waves produc$ by an organ-pipe4 ,mov+ 8 detector sl[ly along ! wire1 ,h]tz obs]v$ t ! sp>k w\ld appe> :5 a c]ta9 int]val ( space 0 rea*$1 & z he cont9u$ to move ! detector ! sp>ks w\ld disappe> & reappe> at regul> di/ances4 ,he rightly conclud$ t ^! po9ts ( disappe>ance & reappe>ance ( ! sp>k correspond$ to ! nodes & loops ( ! 8/&+ waves10 repres5t+ ! wave-l5g? ( ! electrical undulations4 ,x has s9ce be5 e/abli%$ t ! diff]5ce 9 wave-l5g? betwe5 ! electric undulations produc$ by ,h]tz & ^? ( light-waves may be enorm\s or q mod]ate4 ,pr(essor ,mi*elson tells u t 8a telegraphic wave01 :i* is practically an electromagnetic di/urbance1 may be z long z #ajjj miles4 ,! waves produc$ by ! oscillations ( a cond5s]1 l a ,lyd5 j>1 may be z %ort z #ajj feet2 ! waves produc$ by a ,h]tz oscillator may be z %ort z "o-t5? ( an in*4 ,betwe5 ?is & ! longe/ light-wave !re is n an enorm\s gap1 = ! latt] has a l5g? ( ab\t #a_/ajjj in*4 ,?us ! diff]5ce betwe5 ! ,h]tz vibrations & ! longe/ light-wave is less ?an ! diff]5ce betwe5 ! longe/ & %orte/ light-waves1 = "s ( ! %orte/ oscillations are only a few million?s ( an in* long4 ,d\btless ev5 ?is gap w soon be bridg$ ov]4#ch ,! ,h]tz app>atus 0 greatly improv$ by ,augu/e ,righi1 9 ! ,univ]sity ( ,bologna4 ,9 ! same class 9 physics 0 ,m>coni1 :o began 8 fruitful exp]im5ts 9 #ahie1 "o ye> aft] ,sir ,oliv] ,lodge _h p]fect$ ! coh]]4 ,lodge's coh]]1 us$ by ,m>coni 9 8 e>ly "w1 consi/$ ( a glass tube conta9+ a p9* ( nickel & silv] fil+s 9 equal p>ts4 ,crude z ?is detector 01 judg$ by pres5t-day /&>ds1 x mat]ially improv$ ! conductivity ( contact metals 9 ! case ( ,h]tzian waves4 ,9 #ahii wireless communication 0 e/abli%$ across ! ,engli% ,*annel1 & 9 #aijb ,m>coni s5t ! fir/ wireless message f ,engl& to ,am]ica4 ,today1 wireless waves measur+ miles f cre/ to cre/ are be+ employ$ 9 ! transmission ( messages f po9ts sep>at$ by ?\s&s ( miles1 & ! human voice has already be5 c>ri$ across ! ,atlantic by radiophone1 b only 9 "o direction4 ,! wireless s5d+ & receiv+ /ation ( ! ,dut* gov]nm5t1 at ,kootmyck1 9 ! ,prov9ce ( ,geld]l&1 is equipp$ to employ a #ab1jjj-met] wave-l5g? 9 s5d+ & receiv+ simultane\sly messages betwe5 ,holl& & ,java1 #g1ejj miles di/ant4 ,x has ! same capacity z our ,long ,isl& 7,rocky ,po9t7 /ation1 & is !re=e "o ( ! bigge/ 9 ! _w4 ,on ,decemb] #ai1 #aibb1 a long di/ance phonograph :i* records s\nds made hundr$s ( miles away 0 demon/rat$ to ! ,society ( ,we/]n ,eng9e]s1 by ,e4 ,h4 ,colpitts1 ( ! ,we/]n ,electric ,company4 ,! transmission ( electric p[] by radio is z yet b a dream2 b x is a dream :i* may come true )9 ! next five ye>s4#ci ,signals are n[ be+ receiv$ f /ations situat$ at di/ances z great z #ab1jjj miles1 made possible1 x is believ$ by ! exi/5ce ( an electrical conduct+ lay]--electrifi$ du/ expell$ by ! sun--"s #aej miles 9 dep?1 ! b5d+ ( ! radio-waves ar\nd ! e>? be+ caus$ by diffraction4 ,"s unkn[n factor is op]at+ to give ! signals a /r5g? millions ( times great] ?an c be acc\nt$ = at pres5t by any plausible !ory1 accord+ to ,pr(4 ,j4 ,a4 ,flem+ 7,fif? ,h5ry ,truman ,wood ,lecture be=e ! ,royal ,society ( ,arts1 ,london1 #aibb74 ,x is n reasonable to assume t no o!r electromagnetic waves rema9 to be discov]$4 ,we may yet he> 8! ro> ( ! sun-spots10 ?\gh ,edison's exp]im5ts along ?is l9e 7 unsuccessful4 ,:at1 inde$1 7 ! my/]i\s 8signals0 occasionally report$ z hav+ be5 receiv$ at ,m>coni wireless /ations--regi/]$1 x 0 report$ 9 ! press1 8only :5 a m9imum ( sixty-five-mile wave-l5g?s _h be5 e/abli%$10 b waves issu+ f ! mighty sun1 #ic1jjj1jjj miles di/ant8 ,h[ev]1 ,m>coni tells u t "o ( ! 8signals0 comes z ?ree %ort raps--8,s0 9 ! ,morse code4 ,he believes t ^! 8signals0 may h be5 s5t out f ,m>s or ,v5us4 ,simil> my/]i\s 8signals0 7 report$ by wireless /ations 9 diff]5t p>ts ( ! _w dur+ ! apposition ( ,m>s 9 ,augu/1 #aibd4 8,outside ( ! radio-waves t are float+ ab\t !re may be hundr$s ( o!rs :i* we h n z yet be5 able to regi/]4444 ,!re may be _m o!r waves com+ to u f ! sun1 ( :i* we h no k today4444 ,! human e> _c he> bel[ eight vibrations p] second & n high] ?an ab\t #cj1jjj vibrations p] second4 ,c]ta9 animals c he> bel[ & above t scale4 ,by means ( our vacuum tubes c]ta9 rese>*es indicate t a trem5d\s am\nt ( noise goes on bel[ ! eight vibrations p] second1 & /ill m noise above ! #cj1jjj vibrations4 ,entirely new worlds lie 9 ^! two directions1 ( :i* no?+ is kn[n today4 ,! vacuum tube is likely to solve ^! my/]ies & take u into ! un*>t$ worlds1 f> into ! unkn[n1 )9 ! next few ye>s40#dj ,9 ,m>*1 #aibb1 ! late ,dr4 ,*>les ,p4 ,/e9metz said t he consid]$ well f\nd$ ! supposition t p]=mances ( l[-p[] radio s5d+ app>atus 9 transmitt+ messages to surpris+ di/ances gave an indication t ! radiations peculi> to wireless transmission pass ) equal ease ?r\gh ! e>? or ?r\gh ! 8e!r40 ,su* radiations w\ld be 9 accordance ) accept$ electrical laws1 z ! gr\nd1 to :i* bo? ! s5d+ ant5nae & ! receiv+ set are connect$1 w\ld act z a return circuit = ! curr5t4 ,simil>ly1 wat] might s]ve z a m$ium = radio conv]sations betwe5 %ips1 or betwe5 %ips & ! l&4 ,moreov]1 x 0 ann\nc$ dur+ ! same mon? t wireless telephony _h be5 revolutioniz$ by ! successful p]=mances ( ! duplex transmitt]s :i* ! ,g5]al ,electric ,company _h j complet$4 ,conv]sations 7 held betwe5 ,new ,york & pass5g]s abo>d ! /eam] 8,am]ica10 :i*1 at ! "t1 0 at a di/ance ( #cfj miles f %ore4 ,! ?ree-electrode audion or vacuum tube 0 p]fect$ 9 #aiab1 mak+ radio-telephony possible4 ,9 #aiba1 ,reg9ald ,a4 ,heis+1 a "y physici/ work+ = a degree ( ,ma/] ( ,sci5ce at ! ,univ]sity ( ,wiscons91 conceiv$ ! brilliant idea ( putt+ into ! vacuum tube ! am\nt ( en]gy produc$ by ! voice1 & !n gett+ x out _m times amplifi$ 9 ! =m ( high-frequ5cy p[] 9 ! ant5na4 ,?is problem he soon solv$1 s f> z ! pr9ciple ( ! modulation sy/em 0 conc]n$1 & 9 #aibb ! practical problem 0 work$ out & ! me?od all b p]fect$4 ,all ^! great utilit>ian advances h be5 made possible by ! rese>*es ( m5 int]e/$ 9 ! advancem5t ( k = its own sake4 ,z has be5 po9t$ out rec5tly by ,dr4 ,hale 78,! ,new ,heav5s10 ,pages #hg-hh71 8,f>aday1 /udy+ ! laws ( electricity1 discov]$ ! pr9ciples :i* r5d]$ ! dynamo possible4 ,maxwell1 ,h5ry & ,h]tz1 equally unconc]n$ ) mat]ial advantage1 made wireless telegraphy possible4444 ,wireless telephony & transcont95tal telephony )\t wires 7 bo? r5d]$ possible by /udies ( ! nature ( ! electric dis*>ge 9 vacuum tubes40 ,9 an int]view 9 ,decemb]1 #aibb1 ,dr4 ,nikola ,tesla gave x z 8 op9ion1 bas$ ^u exp]im5ts already c>ri$ out 9 8 own laboratory 9 ,new ,york ,city1 t p[] fla%$ ?r\gh space by radio w soon be employ$ 9 all ! _w's activities4 8,besides bridg+ enorm\s di/ances 9 flight & wireless conv]sation10 he said1 8mod]n sci5ce w span ! e>? ) p[] fla%$ ?r\gh ! air by radio4 ,airplanes & %ips & tra9s w c>ry no fuel1 b w run by transmitt$ en]gy4 ,) wireless p[] no "o--explor]s1 travel]s1 camp]s--ne$ be cut (f f civilization & its com=ts40 8,n only t1 b we %all see at great di/ances by aid ( wireless en]gy4 ,& see+ our neighbors across ! oceans w make = a unit$ social & political _w40 ,,footnotes3 #cb ,see 8 8,exp]im5tal ,rese>*es 9 ,electricity10 ,ev]yman's ,libr>y ,s]ies4 #cc ,maxwell1 ,james ,cl]k1 8,treatise on ,electricity & ,magnetism10 #ahgc4 #cd ,! !oretical inve/igation ( ! mode ( dis*>ge ( a cond5s] _h be5 giv5 by ,sir ,william ,?omson 7lat] ,"l ,kelv97 9 #ahec1 9 ! ,philosophical ,magaz9e = ,june ( t ye>4 #ce ,:5 all ! atoms & molecules ( a sub/ance vibrate 9 "o plane1 e4 g41 z ! plane ( a tra9 ( waves w\ld be if drawn on ?is page1 ! wave is said to be pol>iz$4 ,ord9>ily1 light-rays are s5t out f p>ticles vibrat+ 9 diff]5t planes2 !y may be v]tical or horizontal1 or diagonal1 or !y may move 9 a curv$ pa?--circles or ellipses4 ,ord9>y light-vibrations are mix$ up toge!r1 vibrat+ 9 all planes1 & special devices--8pol>iz]s0--are requir$ 9 ord] to sep>ate any "o p>ticul> vibration f ! re/4 #cf ,crehore1 ,dr4 ,alb]t ,c41 8,! ,my/]y ( ,matt] & ,en]gy10 ,page #bh1 ,new ,york1 #aiag4 #cg ,by means ( an induction coil c\pl$ to a circuit conta9+ capacity t]m9als1 ?us =m+ an 8oscillatory circuit40 #ch ,mi*elson1 ,dr4 ,a4 ,a41 8,light ,waves & ,_! ,uses10 ,pages #afj-fa4 ,! gap 0 clos$ dur+ ! ye> #aibd1 heat-waves be+ measur$ :i* 7 ( su* great l5g? z to m]ge into ! %orte/ ,h]tzian or 8wireless0 waves4 #ci ,see an int]e/+ article on ?is "q 9 ,sci5ce & ,inv5tion1 ,decemb]1 #aibb1 ,page #gdd 7,vol4 ,x1 ,:ole ,no4 #aaf74 #dj ,g]nback1 ,h41 ,editorial 9 ,sci5ce & ,inv5tion1 ,decemb]1 #aibb4 ,transcrib]'s ,notes pg #bd ,*ang$3 conduct+ plate 9 ! neighborhod ( a magnet to3 conduct+ plate 9 ! neighborhood ( a magnet pg #be ,*ang$3 0 affect$ by on ord9>y magnet to3 0 affect$ by an ord9>y magnet