and greatly ,fostered h_v electrotechniccl ihnllen~yes of ' electricul communirution (teleyraph,v. telephoned, rudio, television) und electric power (Jiyhting, generutors, motors), by o74r time thr .simple, fbmiliar electric circuit concept has become ji'rrnl~~ estahlisl7ed in scientific. thinkinq. Yet insuficient note has been tuken of the f&t thut tlIe raliditJ of this remurkabl~~ ,fiuitfid coriwpt rests upon essential locx~l homo,yeneitj~ us bt,ell as upon nn implicit thermod~nnmit crssumption of' an isothermnl und bvorkless em~ironment. OlIm IIimself recoynixd the impossihilit), of muin tainiII,y constunt and uniform tcmperriture conditions ~vhm confronted ,i.ifh the ~ircessrq~ presence qf' internal IIeat production antf the ussociated en trap!' production rmd tempertrture gradients. Kirchhoff; in turn, obtained the loop arzd node luw.s,fiIr resistiw circuits 1~~. upplying the circuiution and diwrgenee theorems to LI plane conductiny sheet, but since the discowrl)~ of'niuiual induction in 1831 by Michael Furadu~s it 11'u.s kno11n thut couJrliny could occur between circuits ~~xhich could be phj~sicail~ remote and topoloyicull)~ distinct. Actire circuitq, cleuril, rommenced \l.ith tlIe initiul USC in Morse teieyruph~ of' Joseph Henry's ek~~ct,onzu~9!yrlrtii~ reiqx and c.ontinued witll the dewiopnlent of' triodes und transistors. TlIcse rcrolutiorzur)~ dwiws u.shewd in the "Second Jndustrial Rerolution 'I und ~firstered the