The nature of the work these railway ferry-steamers have to perform, and the fact that every one has to be built to suit the special conditions of the ferriage where it is to be employed, make it inevitable that no two of them are alike, except such as may be sister vessels employed on the same station. In Russia the conditions are very difficult. The current of the River Volga is swift, the height of the water-level varies as much as 45 feet, and as the ice is frequently two feet in thickness the work of maintaining the ferry is not to be undertaken lightly. The vessel by which the service is performed was built by Messrs. Armstrong, Mitchell and Co. To enable it to be sent to its destination it was constructed in four parts, so that it would pass through the Marinsky Canal to get to the Volga. The boat is 252 feet long by 55 feet 6 inches broad, and 14 feet 6 inches deep. It has four lines of rails, converging at the bow into two, and altogether can accommodate twenty-four trucks. At the bow is a high framework for a hydraulic hoist which lifts the trucks between the deck and the rails ashore, a distance of 25 feet, the difficulty of negotiating the remaining portion of the difference in the level being overcome by there being two levels of rails on the landing-stage. The propelling machinery, of the surface-condensing type with twin screws, gives the vessel a speed of nine knots an hour. The bronze propellers are unusually strong and heavy to withstand blows from the ice in the river; the actual ice-breaking to keep the passage clear is performed by another steamer. A ferry-steamer of a different type is that which plies across Lake Baikal in Central Asia in connection with the Transasiatic Railway. As the lake is frozen over for nearly half the year and the vessel has to do duty as an icebreaker as well, the hull has been made extraordinarily strong and heavy. The stem and stern are of massive steel castings. The vessel, which is of steel throughout, is 290 feet in length by 57 feet beam, and the draught of water is rather over 18 feet. The hull bears an outer plate an inch thick and 9 feet wide, placed from end to end along the water-line as a further protection against the friction of the ice. The vessel is also subdivided extensively into water-tight compartments in addition to the usual bulkheads. Over the railway deck are large and sumptuous public and private staterooms. Three sets of triple-expansion engines have been installed with boilers working at a pressure of 160 lb.; there are twin propellers at the stern, and a third propeller at the bow.