Tesla's Dirigible Boat

Several American journals have now published extracts of Tesla’s patent for the construction of a vessel which can be controlled from a distance without conducting wires. We have carefully read the accounts which have appeared, and, curiously, it is a fact that in each case the real innovation or invention is not described. In fact, the details published are obvious ones which would suggest themselves to the youngest electrician. The wireless system of telegraphy is used as a means of communication to the crewless vessel, and one receiver only is provided. This receiver works four different relays for steering and stopping and starting. These relays are comparatively simple, but not a word has yet been published as to how four differentiating signals are transmitted to the one receiver. Surely this must be disclosed in the patent; but why are the technical papers so lax in their extracting ?