STEAM-CARRIAGE. The application of the steam-engine to the purpose of locomotion upon railways, has been noticed elsewhere. [RAILWAY.] In a steam-carriage for use upon a common road, provision must be made for passing over rough, soft, and constantly varying surfaces, and for surmounting accli vities of considerable steepness ; the machine must be provided with a steering apparatus, by which it may be guided with ease and cer tainty along the sinuosities of a common road or street, among other vehicles, and round sharp comets; the weight must be kept within the smallest possible limits ; and the machinery must be compacted within a small space.
There were various attempts to construct such machines in the last century ; but the first invention which claims notice is that patented in 1802 by Messrs. Trevithick and Vivian, and shortly afterwards brought into operation. Their carriage was mounted upon four wheels ; the principal weight resting upon the hind wheels, which were of large diameter, while the fore wheels, which were used for guid ing the carriage, were small, and nearer together than the others. The boiler and the steam cylinder were placed at the back of the hind axle, and the cylinder was horizontal. The carriage, shortly after the date of this patent, was exhibited in London with sufficient suc cess to prove the practicability of the invention. The inventors, however, soon gave up their experiments on common-road locomotion, and adapted their machinery to use upon a rail way.
For about twenty years after the experiments of Trevithick, no steam-carriages for common roads were constructed ; but when the im proved state of the turnpike-roads rendered steam-locomotion more practicable upon them, steam-carriage projectors arose in rapid suc cession. Mr. Griffith's steam-carriage, pa tented in 1821, had the boiler and machinery suspended from the framework by chains and helical springs. Mr. David Gordon's machine, patented in 1822, had its wheels surrounded by cogs or projecting teeth. Another machine, by the same inventor, had two long propellers or legs, intended to obviate the supposed ten dency of wheels to slip, when ascending a slope. Of others who have invented and
built steam-carriages between 1824 and the present time, the names of Goldsworthy Gur ney, Burstall and Hill, W. H. James, Walter Hancock, Summers and Ogle, Messrs. Heaton, Dr. Church, Dance and Field, Squire and Macerone, Scott Russell, Hills, and Sir James Anderson, are the most prominent, althmigh many others have appeared upon the field. Several of these inventors have produced carriages capable of maintaining an average speed of from ten to twelve miles per hour for considerable distances, and a much more rapid rate of motion for a short time ; and some have succeeded in performing extensive jour neys with their steam-carriages. The greatest amount of success yet attained was in a steam carriage constructed by Mr. Gurney, and brought forward by Mr. Charles Dance, who established a regular steam-conveyance be . tween Gloucester and Cheltenham ; but com mercial failure has hitherto attended all these attempts.
The forms of apparatus in these carriages are of course various. As to the boiler, the essential requisites are the power of generating steam very rapidly ; strength, to secure it from explosion ; lightness ; and compactness. A great number of contrivances have been tried with the hope of accomplishing the desired union of these qualities ; all of them consisting either of small tubes, or of separate I chambers. The means adopted for producing a' strong draft in the fire are of two kinds ; viz., by an air chamber, and by air-fans. Many different arrangements have been adopted for communicating the power of the pistons to the wheels of the carriage; as indeed is also the case in respect to railway locomotives. The operation of steering is usually performed by a hand-wheel in the fore-part of the carriage, giving motion, by means of a rack and pinion, or a chain and pulley, to the fore-axle. The Brake, by which the motion of the steam-carriage may be arrested when necessary, usually consists of metallic bands, capable of being pressed against either the nave or the periphery of one or both of the hind-wheels.