The motor would continue running until the earth was cooled to the temperature of outer space."This would be an inanimate engine which, to all evidence, would be cooling a portion of the medium below the temperature of the surrounding, and operating by the heat abstracted," that is, it would produce energy directly from the environment without "the consumption of any material." Tesla goes on in the article to describe how he worked on the development of such an energy device, and here it takes a bit of detective work to focus on which of his inventions he meant.In the 1880's he patented the alternating current generator, motor, and transformer.During the 1890's he intensively investigated other methods of power generation including a charged particle collector patented in 1901.
The unique point about this water pump is that instead of using some form of paddle wheels inside a box to move the water, he discovered that more water could be moved faster by using a set of flat metal disks.More precise information is available through his correspondence in the Columbia University Library's collection. Johnson, editor of Century Magazine, Tesla included a clipping from the previous day's New York Herald about a Clemente Figueras, a "woods and forest engineer" in Las Palmas, capital of the Canary Islands, who had invented a device for generating electricity without burning fuel.What became of Figueras and his fuelless generator is not known, but this announcement in the paper prompted Tesla, in his letter to Johnson, to claim he had already developed such a device and had revealed the underlying physical laws.IDENTIFYING THE INVENTION The device that, at first, seems to best fit this description is found in Tesla's patent for an "Apparatus for the Utilization of Radiant Energy," number 685,957, that was filed for on March 21, 1901 and granted on November 5, 1901.The concept behind the older technical language is a simple one.In the 1880's, Nikola Tesla invented the alternating current system we use today.