“All persons working Shod-wheel’d Carts, Waggons, Drays, &c. of all Breadths, are desired to meet at the Sun Tavern in St. Paul’s Churchyard, on Friday next, at four o’clock in the Afternoon. Enquire for No. 1.” And more pamphlets appeared, but the roads failed to improve. Then in 1770 another Act was passed giving privileges to the roller-carts which were denied to the ordinary waggons. “All carriages,” it ordered, “moving upon rollers the breadth of fifteen inches, are allowed to be drawn with any number of horses, or other cattle.” And, as a further inducement, such carts were to be toll-free for a year. Mr. Sharpe, of Leadenhall Street, prospered, and wrote to the papers to say so. The rollers, he maintained, were light and strong, and there was considerably less friction when they were used. And he challenged the world to disprove his statement. Whereupon an anonymous writer belonging to the rival faction—possibly Joseph Jacob, a coachbuilder who had already written against the system—entered the field, and ventured to suggest that cast iron was exceedingly brittle and not very light. Mr. Sharpe speedily replied. “The principle,” he said, and his point is of interest, “upon which rolling carriages are adopted is simply this, That, by the use of them the roads may be made smooth and hard, and by that means, _become part of the mechanism_: for thus the rollers are made to answer all the purposes of light wheels.” The anonymous writer appears to have felt the point of this argument, and was forced to retort, quite unworthily, that in any case Mr. Sharpe’s rollers were not his own ideas. “No,” replied Sharpe, “they were Mr. Daniel Bourn’s idea—a very sensible man and good mechanic, and who was also the first contriver of nine-inch broad wheels, who so long as ten or eleven years ago built a waggon on rollers at Leominster where he then lived, and brought it to the Society of Arts and Sciences in the Strand, by whom upon trial it was rejected.” The anonymous writer left it at that, but the controversy raged fiercely. It became so highly technical and apparently so interminable that somebody suggested we should all use flying machines and leave the wretched roads to look after themselves. We may leave the war of the wheels here. The roller-carts were discarded soon afterwards, and M’Adam and his successors rendered for ever such wars unnecessary. But it must not be wholly neglected, and is a tiny chapter by itself in the history of locomotion. We come to the curiosities.