In 1826 he constructed a coach about twenty feet long, which would accommodate six inside and fifteen outside passengers, besides the engineer. The driving-wheels were five feet diameter, and the leading wheels three feet nine inches diameter. Two propellers were used, which could be put in motion when the carriage was climbing hills. Gurney's patent boiler was used for supplying steam to the twelve horse-power engine. The total weight of the carriage was about a ton and a half. In front of the coach was a capacious boot, while behind, that which had the appearance of a boot, was the case for the boiler and the furnace, from which it was calculated that no inconvenience would be experienced by the outside passenger, although in cold weather a certain degree of heat might be obtained, if required. In descending a hill, there was a brake fixed on the hind wheel, to increase the friction; but, independently of this, the guide had the power of lessening the force of the steam to any extent by means of the lever at his right hand, which operated upon the throttle valve, and by which he could stop the action of the steam altogether and effect a counter vacuum in the cylinders. By this means also he regulated the rate of progress on the road. There was another lever by which he could stop the vehicle instantly, and in a moment reverse the motion of the wheels. This carriage traveled up Highgate Hill to Edgeware, and also to Stanmore, and went up both Stanmore Hill and Brockley Hill. In ascending these hills the driving-wheels did not slip, so that the legs were not needed. After these experiments the propellers were removed. Gurney obtained another patent in 1827, and under this worked a steam carriage resembling the common stage coach, with the boiler in the hind boot. This carriage was run experimentally to Barnet, Edgeware, Finchley, and other places, and in 1828 it was said that a trip was made from London to Melksham, thirteen miles from Bath, a distance of nearly two hundred miles. On the return trip the rate of speed was about twelve miles an hour. Gurney's carriage so fully established its practicability, that in 1830, Sir Charles Dance contracted for several, and ran them successfully from London to Holyhead, and from Birmingham to Bristol. In the following year he ran over the turnpike road between Gloucester and Cheltenham for four months in succession, four times a day, without an accident or delay of consequence. The distance of nine miles was regularly covered in from forty-five to fifty-five minutes. Nearly three thousand persons were carried, and nearly four thousand miles traveled.