Today's lecture is about the history of the bicycle. The first pedal-driven bicycle was invented in Scotland in 1839 by Kirkpatrick Macmillan. However, it wasn't until the 1880s that the modern 'safety bicycle' with two equal-sized wheels became popular. This design was much safer than the earlier 'penny-farthing', which had a very large front wheel. The invention of pneumatic tires in 1888 by John Boyd Dunlop made cycling even more comfortable and practical. By the early 20th century, bicycles had become a common mode of transport for ordinary people, especially in cities.