The Probert Encyclopaedia of Recreation

TROTTING

Trotting (Harness-racing) is a form of horse racing in which the rider is towed along in a small, light, cart known as a sulky, having two bicycle wheels 28 inches in diameter with pneumatic tyres. Races are run in heats and a horse has generally to win three heats to be declared the winner of a race.

The ideal trotting-ground is a rectabgular-shaped track with rounded ends either half a mile or a mile in circumference. Mud tracks are most prevalent in America.
Research Trotting