Original patent lithograph for Nikola Tesla's "Apparatus for the Utilization of Radiant Energy," five pages, 7.75 x 11.25, Patent No. 685,957, issued November 5, 1901. The diagram features views of the apparatus from multiple angles, and features Tesla's facsimile signature. Marked at the bottom: "The Norris Peters Co., Photo-Litho, Washington, D.C." Includes the printed United States Patent Office specification sheet, which explains, in small part: "It is well known that certain radiations—such as those of ultra-violet light, cathodic, Roentgen rays, or the like—possess the property of charging and discharging conductors of electricity, the discharge being particularly noticeable when the conductor upon which the rays impinge is negatively electrified. These radiations are generally considered to be ether vibrations of extremely small wave lengths, and in explanation of the phenomena noted it has been assumed by some authorities that they ionize or render conducting the atmosphere through which they are propagated. My own experiments and observations, however, lead me to conclusions more in accord with the theory heretofore advanced by me that sources of such radiant energy throw off with great velocity minute particles of matter which are strongly electrified, and therefore capable of charging an electrical conductor, or, even if not so, may at any rate discharge an electrified conductor either by carrying off bodily its charge or otherwise." The cover sheet is annotated in contemporary ink with dates of filing, issuance, and expiry. In fine condition, with light toning and a few small edge tears.
From the personal collection of a lifelong collector, teacher, and traveler with a passion for world history. His collecting years ranged from the 1970s to the present day, meaning that several of the premier pieces have not been on the market in decades.
