Weber quoting Maxwell Zur Anseinandcrsetzun!!; zwit;chen der Weberschen Theorie del" Elektrizitat lind der emfkommenden lVIaxwelIschen Elektrodynaillik Andf(~ Koch Torres Assis, Campinas, Sao Paulo, Brasil, and Karl Heinrich \Vicdcrkehr, Hamburg Zusamrnenfassung Die Abhandlllllg spt7:t sidl mit del' Ablos\lll!-\ der iilterPIl Ekktrodynamik vou \Vilhdill \Ve­ bef und Fran;. Npumunll durch die .\laxwf'lJschr Theoric im lebten Drittel des 19. .lahr­ h\llldf'rt~ aus!'inClIHirr. AuflliingrT fiir die Darst.ellllng der Pl'oblcl11<Jtik sind <iiI" w€nigen i':ltatp, dk sidl bci VI/ilhe]m \Ve!wr findcn. Di(' Diskuf'sioll wUrci(' daIllals h,mpt~iicblich (lurch Carl Nculllanu lind Johann Karl Friedrich Z;ii1hwr gcfUhrt" Ikidc warell cngagienE' und !eidpIIschaftlidlP AnhiiTlger lind Vertei<iiger (\r-~r \\"f'bcr~dlPII Sieht uml Darstl'lluIlg der Thl'orie von d('r ElekLrb:iUit" Streit,pnnkte waf(~n (1) dk N<l,hwirkungHtlH'orie, die mit dem \laxwell~c1wn Feldkoll7Ppt identiHch illt unci 1m Gegel1H<l,tz zur FermvirkUllg-~theorie (Pro­ toLyp: ~ewtonscheH Gravitati()lI~gesetz) c,t,anli, und (2) die Annalilne der ExiSlenz piner ~ub~tant.iellen EkktrizitiiL \V("\H'r beharrte his ;;ulpt7.t auf scinPHl Konzept nnt! entwickeite ein ,\t,omnH)(\ell, d,u.; ab Vor~tufe des Jlutherford-Hohr~chE'n At()lllIllOdcJl~ angesehen wer­ den kalln. Konsen~ bestand Lei den absoluten eiektrischpn :'\,Ia.i;sYHt,emen. J_ Cl. lvI~wel1 Ii\..'; au~ d('lll Kohlransch-\VclwT-E::qJPrinwnt die LirhtgeHthwindigkeit heraU'" die flir ~eine ('lektnJInagnl'tiHthc l .. ichttheorie cine wiehtige Stiitze war. Da.s absolnte elektrornagneLi~che I\IaJ~SVHr,em (\icnLe <lh Crul1dlagp fur die InternaLionalen 'l\Iar~einheiten 1881. Abstract This a.rticle deah-; with the super~("Hsiun of \Vilhelm \Veher's and FraIl;" NeUlllann's 01- dpr tlwory of electrodynamics by :\IaxwcJr~ theory in the last Lhinl of thc 19th cenlury. St,arting-poini; and l)<-l~is for the present.ation arc th(" few quotatiolls Lhat. Gill be found ill \\-'el)('r's work~. The discu~Hi()1I was mainly p(~rforilled by C<lrl von Neumann und Jo­ hann Karl Fricdrich Zi:jllner. Both were ("ngaged supporters and a(h-ocat(;~ of \Veber's view of elpctlicit.~'. Poillts of coutrovefl<,Y were: (1) The theory of dose-range ei-rects. which is identical to :'\,Iaxwclh (:oncept of field and which ~to(ld in eontr<lst to the dic,tant )"ange theory' (protoype: !\lewton's gravitational la~v), and (2) the assumption of the exisLence uf un dpctTic.al suhHtallee. \V("hpr persi:-ted righl to the end in hiH concept, amI developed an atomic model that ca.n be reganlpd as an initial stage of the ltut.herforcl- Bohr atomic mod!'L ConscnC.us existed in the abe;olnte electrical m(~a~urp.IIlent ~y~tellls. J. Cl. '\Iaxwell inf!'rrpd the velocity of light from the Kohlrant>ch-Vi-'eb("T-experiment. \Veber'c. ahsolutc~ t'lecLro-magneLic e;ystPIll served i\.." a ba~i~ for the international units of nW<ll<ure in 1881. 53 1 Introduction Two of thc~ leading figure~ of XTXth century elenrodynamk~ were James Clerk II;Iaxwl'll (18.31 1870) and \Vilhelm Eduard \Yelwr (1804 1891), 27 ye;(trs oldc'r than \laxwC'i1 ([OJ a portrait of \Yilhelm \Y,o'iwr see pal',e 8). It ic. well kllown ,hat :\1axwell quot(;d in hi~ papers on e[e~Lromagndislll of 18~3, 1864 amI 1868 the wOiks of \Veber, sl'e [II, 121. I:~] and [-'1]. In Maxwell's "Jfreatisc on Electricity and Magnetism (1873), which illtwclm·{"cl to Continental Europe a new epoch of resC'areh into electricity, \Vilhdm \V<:'1)('r. !Hext ro i\.lidlael Faraday and VViliiam Thomson (Lord KelYin), is most fn"(juPIltly (l1lOt('ti, 15]. \Vhat if, airnofot unknown is that \V",iwr also quoted }laxwell a few times in his works. \Vilhelm \Ye!JPr had alrpady formulated a fullfiedl',ed theory of p[edr()(lynamics, which was acknowledged on the Conlinenl unlil lhe 1870's as one of the leading ones. logether with th(" studi("s of Fnm7. SeumanIl. It dealt with t.hp alr('atiy \wll-knO"wn pIWll()]ll('lla of mag-ndisHl ami diamapldi~IlI using a~ support the hypothp~es of (;It'ct.rical lllol('cular currents, Coulomb's law of plectrostaticC', Ampere's study of attraction <lJld n'\mbion of two E'1E'etrieal currents, amI Fara(by's work on induction. Thl' CE'nt.H)'! point of \\-'eiwr's theory was the basic law of electrical action, which he propou]](led in 18-'16, 16J. In \Yei){'r'~ writing~ I\-IaxwdI\ namp apppar;; only ~ix time~. \.\1(' give the~e instan("('s helow. and rdittt' them to their hiktoric<l.l nmt("xt. Thi~ is the t.opic ofthik work, n"Sllitmg from a systpm<l.tic perU~;i1 of hik pap("rk. All of th('"~(" citations an; in the fourth volume (1894) of VVeber'~ collected works, a &et of 6 volullles publi~hed during 1892 and 1891, 17[. It ~lj()uld OP ob~erved that there ;ire no index of names nor ~uhject. index in t.he~e yolumes. 2 First and Second Quotations The fir~t quotation appears in a paper of 1871: "Electrodyna.mic Illea~menwllt~ relat.ing ~lH'­ cially to ,ht; principle of the conseryation ofenprgy", [7, Vol. 4, pp. 247 299. H(~(, esp. p. 2GIJ. This pappr has already been translated into Engli~h, [B, see esp. p. nl. It is only all imli­ teet citation, as he i~ quoting Tait's work and it i~ Tait that. cites \"]<tXWl'll'~ lIanH'. In thi~ work \Yeher ~how~ the" compatihilit.y of his fund<JIllenwl law of elenricitv d('snihing th(' interaction betv.,T(~n charged particlp~ wit.h the principle of con~(;rvation of ('lIprgy. At. th(~ end of Section 6 :vIaxwell's name appears in a footuote: In Profl'ssor Taies very instructive work, 'A Sketch of TIH'IIllOd:dtalllics· (EdinbUIgh, 1868), the following passage occurs al page 76, ill referenc(' ~o the investigations of Riemann and LOr<?nL which appeared in Pogg('ndoIlr~ Annalen for 1867 [l'hil. ~lag. S. 4, vol. xxxiv, pp. 368 <Jllri 287J: "But t.h(' ill­ vestigations of T hpse authors are emirely ha~E'd on \VE'iJE'r·k ina(hllissil)l", Th("lJr, of the forceH ex("rtpd Oil each orllPr by tn!J1]ing du:trir; l}(f,didf:.~, for which t.hp conkervatiun of energ~' i~ nOT tnit', while ::'vlaxwell's result is in perfect eOIl~i­ st.(m("(' with tbat Kl"pat prillciple" This ,,~~ertion of Prof('s~or 'rait's ~e~('lllS to h(~ in contradiction with tIl(' ahow'. At pagr~ 56 of th(' ~anw work I'd1". Tai, m(;ntions t.hat Helmholt7 lI<i~ ba9'~d the doctrilH" of enprgy on Newton·", prin­ cipl", awl un the following postulate: ":\Iatter consists of ultimate partid('s which exerL upon each oLher forces whose directions are Lho~e of Ow lille~ joining each pair of part.ides, and whose \llagnitude~ depend solely on tlw distances between t.he partic1e~." The cont.radiction bnwe(m the fundamental law of ekct.ricity ;;nd this post1ltatc i~ ('yident; belt. t.Iw contr<Jrlict.ion b(~tw('e·~ll it awl the principif: of thf' co'n.lfTaatirJn of o!ngy is by no means E'vidE'nt., a disLincUoll which Professor Tai~ seems Lo have overlooked. 51 Clos(·l,. rekvant i~ tilt' f>econd quotation, which appear!; in a paper of 1878, the "eventh papl'r in thp fatuous ~l'rie;; of Elfxtr-odynamic Measll,n:mnifs, ]91, 5cr r:~p, p. 36;{ of Vol. ,j of \V('l)('r'~ vVf,r·h:. Thi;; quot(ltion deals with the ~(lllH~ t.opic and appcar;; in the first paragraph of t,hi~ papr'r, our ~ran;;latioll: l1('lmholt7. lIIailltain(~d, and \ViIliam Thom~Oll, Tait and others agn~pd with him, that the general fundamental law of electrical adion pr('~ented ill the ~'ear 18'lG in thE:' Electrodynamic J\:le(ll'nrements1, to which waH added in Pog­ geIl(!orlI's Ann,llen 1848, VoL 73, p. 229,2 the dcriY{~d potential of the dcct.ric fOIl'e, wa~ in contradiction with principle of thc con~('rvatioll of energy; ho­ w('y('r C. Neuman)] and }Iaxwell demon~tra.tf~d the opposi~(', proving thar all ,'lTOl' Wfts madl~ in the prE'SPllLation of the theorem by Helmholtz, that the prill('ipil" of the cons('rv(ltion of energy i~ valid only for [or("l~s which dE'pE'nd 801d:1f on tlj(~ distanc<' ..'l The ~t(lrt of til(> con[.rovers.y bd,ween \Vilhclm \Vpher and Hermann von HelIflholt~ (1821- 18(4) dates back LO 1847. In hi~ fatuous your-Mill study On the ronseTl}ation of force H('llllholtz m1un(.aiJl('d, when considering cr:ntr(ll forces, t.ha~ the law propounded by \Ve­ ber was at variance with ~he principle of the con5crv'l.tioll of energy. Illl, with English t.ran~lation in [12J. The rrH.<;on W(lH that in \Veber\ force, heyond t.hc 1/r2 Conlombiall tCllll_ t,jH'l"(' wpr<' t,erillS dependin~ on tllE' relative velocit.y amI acceleration lw,tween the intt'ract.ing electrical charge;; (or rather cledrical particie;,)4. \'Veber had ~pecified in 18,'18 a t("rm for the pot(~nti(ll of eledrical encrg:v, [16J, with English translation in llOl-" Herma.ml von Helmholtz continned to at-g-ue ahout thiH problem in spvera.l treatises [rom 1870-187.';i, trying Lo e~tahlish a distinction between the hitherto concurring eledrical theorie~, ("s,,<;ellti­ ally t)]O;;(~ of\Veber and :\Iaxwdl, [17, sep esp.