ɪt wʌz swˈɪtʃt ˌɔn baɪ ˈɑːpɚɹˌeɪɾɪŋ bɹˈɪŋɪŋ tˈuː ᵻlˈɛktɹoʊdz klˈoʊsɚ baɪ ɐ mˈɛkənˌɪzəm wˌɪtʃ ˈɔːlsoʊ ɐdʒˈʌstᵻd ˈɑːɹk lˈɛŋθ.
It was switched on by operating bringing two electrodes closer by a mechanism which also adjusted arc length.