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               To 
                differentiate Tesla's wireless method from contemporary understanding 
                of the technique, and from the misunderstandings arising from 
                the chronology of Tesla's research into the nature of electrical 
                communication, his method can be contrasted with modern patents 
                for electrostatic submarine communication and the inventor's earlier 
                work in this field. 
                
              Contemporary Patents 
                
              L. 
                Gilstrap's patent for an Electrostatic Communication System, #3,964,051, issued June 15, 
                1976, describes a device consisting of two concentric conducting 
                spheres (#26 & #28) separated by a dielectric layer to form 
                a monopole radiator for electrostatic waves. 
                
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               Gilstrap 
                patent 3,964,051 
                
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              Curry states: 
                 
                
              The antenna 
                system for an electromagnetic emission into space circulates energy 
                in accordance with the laws governing electrical current in motion. 
                Since the field strength produced by an antenna is proportional 
                to the alternating currents circulating in it, its optimum structural 
                relationships are directed to a reduction of the total antenna 
                resistance, thus to increase the total current for a given power 
                input to a radiator.13 
                
              He adds: 
                
              Being 
                a current-actuated device, such an [electromagnetic] antenna will not operate in any physical conducting 
                medium such aswater or earth.14 
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               The 
                patent states that "longitudinal electrostatic or capacitive 
                waves, also called scalar or polarization waves because of their 
                relationship to the Maxwell wave equations" are the means 
                of propagation but the patent does not explain how these waves 
                differ from conventional forms of electromagnetic radiation. It 
                simply states that as the spheres are subject to voltages of opposite 
                polarity the "outer sphere then appears as an ideal monopole 
                radiator to the external dielectric medium, in this case water."12 
                
              In this configuration, 
                electric field is confined to the region between the two conducting 
                spheres of the transmitter. Little energy, if any, is available 
                to stress the external dielectric medium, the water.  
                
              P. Curry's 
                patent for an Underwater Electric Field Communica-tion 
                System, #3,265,972, issued August 9, 1966 proposes a ra-diator 
                of a different configuration and presents a detailed discus-sion of communication by electrostatic induction.  
                
                
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              While 
                a radiator for electromagnetic emission produces its field strength 
                by the effect of changing currents; the radiator for electrostatic 
                emission of the type here to be described produces its field strength 
                by the effect of changing potentials.15 
                
                
              Curry 
                proposes "the electrical potentials of the signal to be transmitted 
                to two equal metal plates (#17 & #18) each of which is hermetically 
                sealed within insulating material (#20 & #21)... immersed 
                in a conducting fluid such as sea water."16 
              By 
                applying a varying potential to the plates of the radiator, charge 
                of opposite polarity accumulates on the two plates such that a 
                charge gradient exists in the region between the radiators. The 
                patent explains: 
                
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