The author first discusses the conditions which have led the French Government to consider an extensive electrification scheme, of which the railways will form only a part, and he then explains the general method adopted in drawing up the scheme and utilizing in the most economical manner the sources of power available.Particulars are given of the power supply to the Orléans Railway and the rolling stock already in use and on order.Finally, the design of electric locomotives is discussed, and a comparison is made between electric and steam locomotives.