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; riders pushed their feet against the ground. Later, in the 1860s, pedals were added to the front wheel, creating the boneshaker. However, it was uncomfortable due to its rigid frame. The high-wheel bicycle, or penny-farthing, appeared in the 1870s, offering greater speed but posing safety risks. Finally, in 1885, the safety bicycle with a chain drive and equal-sized wheels became popular, making cycling accessible to more people.