Today's lecture is about the history of the bicycle. Early bicycles in the 19th century had wooden frames and iron tires, which made riding very uncomfortable. In 1885, John Kemp Starley introduced the 'safety bicycle' with a chain drive and equal-sized wheels, which was much more stable. Later, in 1888, John Boyd Dunlop invented pneumatic tires, which greatly improved comfort and speed. By the early 20th century, bicycles became a popular and affordable means of transport for ordinary people, especially in Europe and North America.