The original electric railway laid down by Messrs. Siemens and Halske at Berlin seems likely to be the parent of many others. One of the most recent is the underground electric line laid down by the firm in the mines of Zankerodain Saxony. An account of this railway has appeared in _Glaser's Annalen_, together with drawings of the engine, which we are able to reproduce. They are derived from a paper by Herr Fischer, read on the 19th December, 1882, before the Electro-Technical Union of Germany. The line in question is 700 meters long--770 yards--and has two lines of way. It lies 270 meters--300 yards--below the surface of the ground. It is worked by an electric locomotive, hauling ten wagons at a speed of 12 kilometers, or 7½ miles per hour. The total weight drawn is eight tons. The gauge is a narrow one, so that the locomotive can be made of small dimensions. Its total length between the buffer heads is 2.43 meters; its height 1.04 meters; breadth 0.8 meter; diameter of wheels, 0.34 meter. From the rail head to the center of the buffers is a height of 0.675 meter; and the total weight is only 1550 kilogrammes, or say 3,400 lb. We give a longitudinal section through the locomotive. It will be seen that there is a seat at each end for the driver, so that he can always look forwards, whichever way the engine may be running. The arrangements for connection with the electric current are very simple. The current is generated by a dynamo machine fixed outside the mine, and run by a small rotary steam engine, shown in section and elevation, at a speed of 900 revolutions per minute. The current passes through a cable down the shaft to a T-iron fixed to the side of the heading. On this T-iron slide contact pieces which are connected with the electric engine by leading wires. The driver by turning a handle can move his engine backward or forward at will. The whole arrangement has worked extremely well, and it is stated that the locomotive, if so arranged, could easily do double its present work; in other words, could haul 15 to 16 tons of train load at a speed of seven miles an hour. The arrangements for the dynamo machine on the engine, and its connection with the wheels, are much the same as those used in Sir William Siemens' electric railway now working near the Giant's Causeway.--_The Engineer_. [Illustration: THE SIEMENS ELECTRIC RAILWAY AT ZANKERODA MINES.] * * * * * THE EARLIEST GAS-ENGINE.