Mannheim on June 12, 1817, he covered 13 km (eight miles) in less than an hour. Constructed almost entirely of wood, the draisine weighed 22 kg (48 pounds), had brass bushings within the wheel bearings, iron shod wheels, a rear-wheel brake and 152 mm (6 inches) of trail of the front-wheel for a self-centering caster effect. This design was welcomed by mechanically minded men daring to balance, and several thousand copies were built and used, primarily in Western Europe and in North America. Its popularity rapidly faded when, partly due to increasing numbers of accidents, some city authorities began to prohibit its use. However, in 1866 Paris a Chinese visitor named Bin Chun could still observe foot-pushed velocipedes. The Draisine is regarded as the first bicycle and Karl von Drais is seen as the "father of the bicycle". The concept was picked up by a number of British cartwrights; the most notable was Denis Johnson of London announcing in late 1818 that he would sell an improved model. New names were introduced when Johnson patented his machine “pedestrian curricle” or “velocipede,” but the public preferred nicknames like “hobby-horse,” after the children's toy or, worse still, “dandyhorse,” after the foppish men who often rode them. Johnson's machine was an improvement on Drais's, being notably more elegant: his wooden frame had a serpentine shape instead of Drais's straight one, allowing the use of larger wheels without raising the rider's seat, but was still the same design. During the summer of 1819, the "hobby-horse", thanks in part to Johnson's marketing skills and better patent protection, became the craze and fashion in London society. The dandies, the Corinthians of the Regency, adopted it, and therefore the poet John Keats referred to it as "the nothing" of the day. Riders wore out their boots surprisingly rapidly, and the fashion ended within the year, after riders on pavements (sidewalks) were fined two pounds. 1820s to 1850s: An Era of 3 and 4-Wheelers The intervening decades of the 1820s–1850s witnessed many developments concerning human-powered vehicles often using technologies similar to the draisine, even if the idea of a workable two-wheel design, requiring the rider to balance, had been dismissed. These new machines had three wheels (tricycles) or four (quadracycles) and came in a very wide variety of designs, using pedals, treadles, and hand-cranks, but these designs often suffered from high weight and high rolling resistance. However, Willard