STEAM CARRIAGE.. The idea of driving car riages by means of mechanical power is of con siderable antiquity, and in the older works on me chanics, we meet with drawings of carriages impelled by the action of wind upon sails, and of others driven by the action of the feet of men in the carriage. Maillard's chaise driven by winches, Brodie's self driving chaise, and Maillard's chaise with an artificial horse, may be enumerated among carriages driven by mechanical power.
Dr. Robison seems to have first suggested the idea of driving carriages by steam, and it appears that Mr. Symington of Falkirk, so early as 1787, was oc cupied with a plan of applying the steam engine to carriages. These proposals, however, were never carried into effect, so that the real merit of intro ducing the steam carriage belongs to Messrs. Trevi thick and Vivian, who invented their high pressure engine with the express view of using it in propelling carriages on railways. Although their patent was taken out in 1802, yet it was not till 1805 that it was actually applied in the experiment of moving car riages on a railway at Merthyr Tydvil, when trials were made at different times, but it was not till 1811 that the first steam carriage was actually used for practical purposes. This was done by Mr. Blink ensop (proprietor of the Middleton coal works, which supply the town of Leeds with coal), who introduced steam for the purpose of conveying coal wagons along his rail-roads. In the steam carriage which Mr. Blinkensop used, the boiler was supported by four wheels without teeth ; but it was driven by a crank connected with the piston, which needed other two wheels in the centre of the carriage having teeth in their circumference. These teeth engaged in teeth on the rail-road, and in this manner the carriage was moved along followed by a train of thirty coal wagons.
In the year 1816 Messrs. Losh and Stephenson of Newcastle took out a patent for improvements in steam carriages and railways, which we have repre sented in Plate DXI. Figs. 1, 2, 3 and 4. Fig. 1. is
a section of the steam carriage, Fig. 2. is a view of it dragging after it the carriage EF, containing coals at E and water at F, and the first wagon G of the train. The steam-engine shown at AB has two cylinders, whose pistons T, B, drive the crank rods AC, BD, which give a rotatory motion to the two wheels C, D, to whose axles they are fixed. The two opposite wheels, which are not seen in the figure, are driven by similar rods. The circumferences of the wheels take 'hold of the rail rod RR merely by friction. The middle pair of wheels receive their motion from the other two pair by means of a chain passing over two rag wheels tn, n, placed in the centre of each axle as seen at c, Fig. 5. This chain drives a third rag wheel c, and thus drives the middle pair of wheels. In the steam-carriage used by Mr. Blinkensop, the engine was supported directly by the axles, but Messrs. Losh and Stephenson connect the boiler with the axle by means of six floating pistons b, b, &c, movable with in cylinders a, a, a, a, into which the steam and the water is allowed to enter. These cylinders are best seen in Fig. 1. where b, b, are the floating pistons con nected with wrought iron rods below; the ends of which rest upon the hearing brasses of the axles of the wheels C, D. These pistons press equally on all the axles, and thus make each wheel bear with equal force on the rail-rod R, R, and act upon them with equal friction, even though the rails should not be all in the same plane. This effect is produced in conse quence of the bearing brasses having a certain degree of play in a groove or slide in a vertical direction; and as they carry the axles and wheels along with them, they force the wheels to accommodate themselves to the irregularities of the road. A steady motion is thus obtained, and shocks are better prevented than if the engine rested on the finest steel springs. The construction of the rail-road and the wheels is shown in Figs. 3 and 4.