Good morning, everyone. Today we're going to discuss the history of the bicycle. Now, you might think the bicycle was invented in the 19th century, but in fact, the first two-wheeled vehicle, called a 'draisine', appeared in 1817. It had no pedals; riders pushed their feet against the ground. Later, in the 1860s, pedals were added to the front wheel, creating the 'velocipede'. Interestingly, the modern chain-driven bicycle with two equal-sized wheels wasn't developed until the 1880s. So, the key point is that the bicycle evolved gradually over several decades.