The first bicycle, probably created by the German Baron Karl de Drais de Sauerbrun in the early 1800s, was a form of hobby-horse(木馬)that was propelled(推進する)by the rider's feet pushing against the ground. The first treadle-propelled(ペダルで進む)cycle was designed by the Scottish blacksmith(かじや)Kirkpatrick Macmillan around 1839. By the end of the 19th century, bicycles had wire wheels, metal frames, and pneumatic(空気の)tires.