of large size, adapted to the higher speed and lighter uses of passenger traffic. [Illustration: FIG. 185.--TREVITHICK’S STEAM CARRIAGE, 1801.] It is not possible to trace the succeeding steps in steam carriage development by James and Anderson, by Gurney, in 1822, by Marcerone and Squire in 1833, by Russel in 1846, and many others; it is sufficient to know that bad roads and the success attending the steam locomotive on rails diverted attention from the steam road carriage, and not until the latter part of the Nineteenth Century was there any marked revival of interest in this field. Then came first the ponderous road engine, known as a traction engine, and used for heavy hauling; and this in the last decade has been followed by the modern steam motor carriage, an example of which is seen in Figs. 186 and 186A, which represent the “Locomobile” and its actuating mechanism. The fuel used is gasoline, stored in a three-gallon tank under the footboard. The boiler, which is arranged under the seat, is a vertical cylinder wrapped with piano wire for greater tensile strength, and contains 298 copper tubes. The engine, which is seen in Fig. 186A, is arranged in upright position under the seat, in front of the boiler, has two cylinders, 2½-inch diameter and 4-inch stroke, a Stephenson link-motion and an ordinary D-valve. Sprocket wheels and a chain connect the engine shaft to the rear axle. The engine runs from 300 to 400 revolutions per minute and develops from four to five horse power. It has a muffle for the steam exhaust and the whole weight is 550 pounds. It is one of the lightest and cheapest of automobiles, runs easily at ten to twelve miles an hour, and is an efficient hill-climber. Although naming the steam automobile first because of its earlier genesis, it is not to be understood as representing at present the most popular type of motor carriage, although it bids fair to become so. [Illustration: FIG. 186.--“LOCOMOBILE” STEAM CARRIAGE.] [Illustration: FIG. 186A.--THE FOUR HORSE POWER ENGINES OF “LOCOMOBILE.”] In France and the continent of Europe the type employing an explosive mixture of gasoline and air is most frequently found, and in England and the United States the electric motor with the storage battery is chiefly used.