Good morning. Today we're going to discuss the history of the bicycle. Now, many people think the bicycle was invented in the 19th century, but in fact, early prototypes appeared in the late 18th century. The first two-wheeled vehicle, called a 'velocipede', was made in France in 1790. However, it had no pedals and riders pushed it with their feet. The first pedal-driven bicycle was developed in Scotland in 1839 by Kirkpatrick Macmillan. Interestingly, it was not widely adopted because the design was considered too unstable. It wasn't until the 1880s, with the invention of the chain drive and pneumatic tires, that bicycles became truly popular.
❓ According to the lecture, why was Macmillan's pedal-driven bicycle not widely used?