The driving wheels were connected with the axle by means of a pair of ratchets furnished with a double set of ratchet teeth and a reversing pall. By this one wheel could be advanced or backed while the other remained stationary, or moving in a contrary direction, an arrangement necessary for turning and backing. The steersman controlled the reversing pall by connecting rods and lever.
Motion was communicated to the driving wheels by a double set of spur wheel gear, arranged to give different powers or velocities, by having both a large and a small wheel fixed on the driving as well as the driven axis. By shifting the large wheel on the driving axis into gear with the small wheel on the driven axis speed was obtained, and by shifting their relative position till the small wheel on the driving axis came into gear with the large wheel on the driven axis, power was obtained at the expense of speed. These two axes were kept at the same distance from each other by means of connecting rods, although the relative positions might be changed by the motion of the carriage on rough roads.
In August, 1833, the Heatons placed a steam drag on the road between Worcester and Birmingham. A slight accident occurred at the start, but after repairs were made the trial was a success. Attached to the engine was a stage-coach, carrying twenty passengers, the load weighing nearly two tons. Lickey Hill was ascended, a rise of one in nine, and even one in eight in some places. Many parts of the hill were very soft, but by putting both wheels in gear they ascended to the summit, seven hundred yards in nine minutes. A company was formed in Birmingham to construct and run these carriages, subject to the condition of keeping up an average speed of ten miles an hour. A new carriage was built and tried in 1834, but after trials, the Messrs. Heaton dissolved their contract, as they were unable to do more than seven or eight miles an hour. After spending upwards of ten thousand dollars in endeavors to effect steam traveling, they retired from the field, stating that the wear and tear were excessive at ten miles an hour, and that the carriage was heavy, and wasteful in steam.
An English engineer, connected with the Deptford Chemical Works, Hill was among the first to be interested in steam-road locomotion. He was familiar with Hancock's experiments and made a carriage of his own that was tried in 1840. He journeyed to Sevenoaks and elsewhere and ran up steep hills with the carriage, fully loaded, at twelve miles an hour, and on the level at sixteen miles an hour. He adopted the compensating gear that was invented by Richard Roberts and that by some writers has been credited to him.