Page:Canadian patent 142352.djvu/2

 To all whom it may concern:

Be it known that I, Nikola Tesla, a citizen of the United States, residing in the Borough of Manhattan, in the City, County, and State of New York, have discoverd a new and useful Improvement in the Art of Transmitting Electrical Energy Through the Natural Mediums of which the following is a specification, reference being had to the drawings accompanyng and forming a part of the same.

It is known since a long time that electric currents may be propagated through the earth, and this knowledge has been utilized in many ways in the transmission of signals and the operation of a variety of receiving devices remote from the source of energy, mainly with the object of dispensing with a return conducting-wire. It is also known that electrical disturbances may be transmitted through portions of the earth by grounding only one of the poles of the source, and this fact I have made use of in systems which I have devised for the purpose of transmitting through the natural media intelligible signals or power and which are now familiar; but all experiments and observations hertofore made have tended to confirm the opinion held by the majority of scientific men that the earth, owing to its immense extent, although possessing conducting properties, does not behave in the manner of a conductor of limited dimensions with respect to the disturbances produced, but, on the contrary, much like a vast reservoir or ocean, which, while it may be locally disturbed by a commotion of some kind remains unresponsive and quiescent in a large part or as a whole. Still another fact now of common knowledge is that when electrical waves or oscillations are impressed upon such a conducting-path as a metallic wire reflection taken place under certin condi