Today's lecture is about the history of the bicycle. Although early prototypes appeared in the 19th century, the first widely popular design was the penny-farthing, introduced in the 1870s. It had a large front wheel and a small rear wheel, which made it fast but dangerous. By the 1880s, the safety bicycle, with two equal-sized wheels and a chain drive, became the standard. Interestingly, the rise of the safety bicycle coincided with a significant increase in women's mobility, as it allowed them to travel independently without wearing restrictive clothing. This shift had profound social implications, contributing to the women's suffrage movement in the early 20th century.