Today's lecture is about the history of the bicycle. The first bicycle, invented in the early 19th century, had no pedals and was pushed along by the rider's feet. It was called a 'hobby horse'. Later, in the 1860s, pedals were added to the front wheel, creating the 'velocipede'. However, this design was uncomfortable due to its rigid frame and wooden wheels. In the 1880s, the 'safety bicycle' was developed with a chain drive and two equal-sized wheels, which made riding much safer and more efficient. This design became the basis for modern bicycles, and by the early 20th century, bicycles had become a popular means of transport for ordinary people.