Tesla plan for the utilization of terrestrial heat to efficiently produce cheap power

Dr. Tesla, long given to Verne-like predictions which, also Verne-like, eventually materialize - frequently through his own ingenuity, has suggested this plan for the utilization of terrestrial heat to efficiently produce cheap power in vast abundance. As outlined in the above sketch, water is sent down a deep shaft, where it is heated by the high temperature of the inner earth and so returned in the form of steam. This steam is used to drive a turbine, after which it is passed through a condenser, and then, once again as water, returned into the shaft, so forming an unending cycle.