Nikola Tesla Books
CHAPTER FOUR away. I might have been better still, had it not been tedious to wait for the sounds to arrive, in definite intervals, as heralded precisely by an electrical indicating apparatus -- nearly an hour before. Tesla quickly assembled his preliminary apparatus and began to investigate electrical fluctuations in the earth itself. In the middle of June, while preparations for other work were going on, I arranged one of my receiving transformers with the view of determining in a novel manner, experimentally, the electric potential of the globe and studying its periodic and casual fluctuations... The earth was found to be literally alive with electrical vibrations, and soon I was deeply absorbed in this interesting investigation... Colorado is a country famous for the natural displays of electric force. In that dry and rarefied atmosphere the sun's rays beat the objects with fierce intensity... Lightning discharges are, accordingly, very frequent and sometimes of inconceivable violence. On one occasion approximately twelve thousand discharges occurred in two hours, and all in a radius of certainly less than fifty kilometers from my laboratory. Many of them resembled gigantic trees of fire with the trunks up or down. Later that month Tesla noticed that his instruments recorded strong electrical disturbances associated with storms which were not in the immediate neighbourhood. What could be the cause of such measurements? Tesla was deeply puzzled about the origin of the disturbances and felt himself to be on the edge of âa great revelation'. It was on the third of July - the date I shall never forget - when I obtained the first decisive experimental evidence of a truth of overwhelming importance for the advancement of humanity. A dense mass of strongly charged clouds gathered in the west and towards the evening a violent storm broke loose which, after spending much of its fury in the mountains, was driven away with great velocity over the plains. Heavy and long persisting arcs formed almost in regular time intervals. My observations were now greatly facilitated and rendered 46
