"[F]our hundred years hence the power question in England may be solved somewhat as follows: The country will be covered with rows of metallic windmills working electric motors [generators] which in their turn supply current at a very high voltage to great electric mains. At suitable distances, there will be great power stations where during windy weather the surplus power will be used for the electrolytic decomposition of water into oxygen and hydrogen. ...In times of calm, the gasses will be recombined in explosion motors working dynamos which produce electrical energy once more, or more probably in oxidation cells."