The resulting velocipede, or draisine, was the first vehicle to use the key principle of modern bicycle design: balance. "To modern eyes balancing on two wheels seems easy and obvious," says Lessing. "But it wasn't at the time, in a society that normally only took its feet off the ground when riding horses or sitting in a carriage."It's a good read.
Ice skaters, who balance on a blade, were the main exception to this rule. There are contemporary accounts of Dutch women skating from village to village along frozen canals, balancing a milk churn on their heads while doing their knitting.