Nikola Tesla U.S. Patent 645,576 - System of Transmission of Electrical Energy Patent Wrapper Page 16

134 ? of such a scheme? We now know that electric vibration may be transmitted through a single conductor. Why, then, not try to avail ourselves of the earth for this purpose? We need not be frightened by the idea of distance. To the weary wanderer counting the mile-posts, the earth may appear very large; but to that happiest of all men, the astronomer, who gazes at the heavens, and by their standard judges the magnitude of our globe, it appears very small. And so I think it must seem to the electrician, for when considers the speed with which an electric disturbance is propagated through the earth, all his ideas. of distance must completely vanish. A point of great importance would be first to know what is the capacity of the earth, and what charge does it contain if electrified. Though we have no positive evidence of a charged body existing in space without other oppositely electrifled bodies being near, there is a fair probability that the earth is such a body, for by whatever process it was separated from other bodiesand this is the accepted view of its originit must have retained a charge, as occurs in all processes of mechan2 ican separation. If it be a charged body insulated in the space, its capacity should be extremely smallless than one-thousandth of a farad. But the upper strata air are conducting, and so, perhaps, is the medium in free space beyond the atmosphere, and these may contain an opposite charge. Then the capacity might be incomparably greater. In any case, it is of the greatest importance to get an idea of what quantity of electricity the earth contains. It is difficult to say whether we shall ever 2