What 19th-century bicycle had a very large front wheel and a small rear wheel?

The 19th-century bicycle with a very large front wheel and a small rear wheel was the penny-farthing.

Also called a high wheeler, high bicycle, or ordinary, the penny-farthing became popular during the 1870s and 1880s. Its pedals were attached directly to the front-wheel hub, so enlarging that wheel increased the distance traveled with each pedal rotation and allowed higher speeds.

The name compares two British coins: the much larger penny and the tiny farthing. From the side, the bicycle's large front wheel and small rear wheel resembled that size relationship. The design also gave a smoother ride than earlier velocipedes with smaller wheels and solid tires.

It was fast but hazardous. Because the rider sat above the front axle, hitting an obstacle or braking sharply could throw the rider forward in a “header.” The machine was eventually displaced by the safety bicycle, whose chain drive, lower seat, and pneumatic tires offered comparable speed with easier mounting and less severe falls. A boneshaker was an earlier bicycle type, not the canonical name for this high-wheeled design.