Exercise 3: sample answer

Similarities: both were fashions that spread from one country to others in a few years, and both faded because the machines were heavy and tiring and roads were poor. Differences: the 1860s machine had pedals, so the rider's feet left the ground; and the 1860s craze was larger, with riding schools, races and exports, and it left a lasting industry behind, whereas the hobby horse largely disappeared (check).