WALTER HANCOCK was the most successful and persevering of all those who attempted the introduction of steam on the common road. He had, in 1827, patented a boiler of such peculiar form, that it deserves description. It consisted of a collection of flat chambers, of which the walls were of boiler-plate. These chambers were arranged side by side, and connected laterally by tubes and stays, and all were connected by short vertical tubes to a horizontal large pipe placed across the top of the boiler-casing, and serving as a steam-drum or separator. This earliest of "sheet flue-boilers" did excellent service on Hancock's steam-carriages, where experience showed that there was little or no danger of disruptive explosions. Hancock's first steam-carriage was mounted on three wheels, the leading-wheel arranged to swivel on a king-bolt, and driven by a pair of oscillating cylinders connected with its axle, which was "cranked" for the purpose. The engines turned with the steering-wheel. This carriage was by no means satisfactory, but it was used for a long time, and traveled many hundreds of miles without once failing to do the work assigned it. By this time there were a half-dozen steam-carriages under construction for Hancock, for Ogle & Summers, and for Sir Charles Dance. In 1831, Hancock placed a new carriage on a route between London and Stratford, where it ran regularly for hire. Dance, in the same season, started another on the line between Cheltenham and Gloucester, where it ran from February 21st to June 22d, traveling 3,500 miles and carrying 3,000 passengers, running the 9 miles in 55 minutes usually, and sometimes in three-quarters of an hour, and never meeting with an accident, except the breakage of an axle in running over heaps of stones which had been purposely placed on the road by enemies of the new system of transportation. Ogle & Summers's carriage attained a speed, as testified by Ogle before a committee of the House of Commons, of from 32 to 35 miles an hour, and on a rising grade, near Southampton, at 24-1/2 miles per hour. They carried 250 pounds of steam, ran 800 miles, and met with no accident. Colonel Macerone, in 1833, ran a steam-carriage of his own design from London to Windsor and back, with 11 passengers, a distance of 23-1/2 miles, in 2 hours. Sir Charles Dance, in the same year, ran his carriage 16 miles an hour, and made long excursions at the rate of 9 miles an hour. Still another experimenter, Heaton, ascended Lickey Hill, between Worcester and Birmingham, on gradients of one in eight and one in nine, in places; this was considered one of the worst pieces of road in England. The carriage towed a coach containing 20 passengers.