It will perhaps interest some readers to know how much fuel a locomotive burns. This, of course, depends upon the quality of fuel, work done, speed, and character of the road. With freight trains consisting of as many cars as a heavy locomotive can draw without difficulty, the consumption of coal will not exceed from 1 to 1½ pounds of coal per car per mile if the engine is carefully managed. It takes from 15 to 20 pounds of coal per mile to move an engine and tender alone, the consumption being dependent upon the size of the engine, speed, grades, and number of stops. If this amount of coal is allowed for the engine and tender, and the balance that is consumed is divided among the cars, it will reduce the quantity for hauling the cars alone to even less amounts than those given above. In ordinary average practice the consumption is from 3 to 5 pounds per freight-car per mile, without making any allowance for the engine and tender. With passenger trains, the cars of which are heavier and the speed higher, the coal consumption is from 10 to 15 pounds per car per mile. A freight locomotive with a train of 40 cars will burn 40 to 200 pounds of coal per mile, the amount depending on the care with which it is managed, quality of the coal, grades, speed, weather, and other circumstances. AMERICAN CARS. Peter Parley's illustration (p. 101) of the Baltimore & Ohio Railroad represents one of the earliest passenger-cars used in this country. The accuracy of the illustration may, however, be questioned. Probably the artist depended upon his imagination and memory somewhat when he drew it. The engraving below (Fig. 40) is from a drawing made by the resident engineer of the Mohawk & Hudson Railroad, and from which six coaches were made by James Goold for the Mohawk & Hudson Railroad in 1831. It is an authentic representation of the cars as made at that time. Other old prints of railroad cars represent them as substantially stage-coach bodies mounted on four car-wheels, as shown by Figure 41. The next step in the development of cars was that of joining together several coach-bodies. This form was continued after the double-truck system was adopted, as shown by Figure 42, which represents an early Baltimore & Ohio Railroad car, having three sections, united. It was soon displaced by the rectangular body, as shown in Figure 43, which is a reproduction from an old print. [Illustration: Fig. 40.--Mohawk & Hudson Car, 1831. (From the original drawing by the resident engineer.) Fig. 41.--Early Car. (From an old print.)] [Illustration: Fig. 42.--Early Car on the Baltimore & Ohio Railroad.]