Nikola Tesla is famous for the Tesla Coil, but another of his inventions is the subject of this book and had nothing to do with electricity, other than as a possible means of generating it. This was his Disc Turbine for which a British Patent, which also covered a compressor variant, was granted in 1910. Unlike a conventional turbine, in which the rotor consists of bladed segments, in Tesla’s machine these were replaced by discs, working on the concept of flowing media being converted to rotary motion by friction working on the discs. Tesla claimed that a very small, but extremely powerful machine was possible using this principle - his aim was to produce a 25 hp machine that would fit inside a bowler hat. Here W. Cairns describes in detail the concept, and the history, of the original engines. He then proposes a number of uses for such turbines, including car and light aircraft use, all of which illustrate the extraordinary versatility of Tesla’s engine. Finally he provides the design and building instructions for a small Tesla turbine which any model engineer should be able to build. Not only does a Tesla Turbine provide a very high power to size ratio, it can be used as a compressor or pump. Tesla used steam on his test machines, and the model featured here would probably be run on compressed air, but the gas turbine principle can also be used; this really is a remarkably versatile machine. This versatility means that ninety four years after the original Patents were granted there are signs of re-awakened interest in Tesla’s machine, as many of the original problems can be overcome with modern materials. What is really exciting is that any revival can be boosted by individual experimenters- here is the place to start! High quality. 34 A4 format pages. Numerous drawings and sketches, including 6 pages of drawings specifically for a small Tesla turbine you can build. Slightly amended second edition.