Good morning, class. Today we're going to discuss the history of the bicycle. Now, many people think the bicycle was invented in the 19th century, and that's partly true. However, the very first two-wheeled vehicle, called a 'draisine' or 'running machine', appeared in 1817, invented 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 'velocipede'. But it wasn't until the 1880s that the modern 'safety bicycle' with a chain drive and two equal-sized wheels became popular. So, the key innovation that made cycling safe and widespread was the chain drive system.