In today's lecture, we'll discuss the history of the bicycle. The first two-wheeled vehicle, called the draisine, was invented in 1817 by Karl von Drais. It had no pedals, and riders pushed their feet against the ground to move. In the 1860s, pedals were added to the front wheel, creating the velocipede. However, it was uncomfortable because of its rigid frame. Later, the high-wheel bicycle became popular in the 1870s, but it was dangerous due to its large front wheel. Finally, in 1885, John Kemp Starley introduced the 'safety bicycle' with a chain drive and two equal-sized wheels, which is the basis for modern bicycles.