Already before 1900 *), researchers investigated near crop fields with a compass, and were not surprised, that after some lightning discharge, that appeared several days or weeks before, compass shows something different than in normal conditions.
Tayari kabla 1900 *), watafiti kuchunguzwa karibu mashamba ya mazao na dira, na walikuwa si kushangaa, Kwamba baada ya kutokwa baadhi umeme, Hiyo alionekana siku kadhaa au wiki kabla, dira inaonyesha kitu tofauti joto kama katika hali ya kawaida.