First, it was their whalebone-and-driftwood boat frames with the sea-lion skins stretched over them and waterproofed with whale fat. Over the centuries, that invention by the Inuits of the Arctic led to modern Olympic canoeing and kayaking. Now comes their second direct contribution to the Olympic Games, albeit delayed by centuries again. This time, it's their walrus skins. When the Sydney 2000 Games introduces trampoline as the newest gymnastic discipline, it will be celebrating gravity-defying acts apparently first unveiled by Alaskan Inuits. The English were tossing people into the air on blankets around the same time, but the Inuits' use of walrus skins for the same game seems to have launched the trampoline idea. Evidence suggests the Comanche Indians of North America used a type of trampoline at least as early as the mid-1800s, and circus acrobats have used devices resembling trampolines for at least 200 years. According to circus lore, the modern springy trampoline began its evolution at the circus with an acrobat named Du Trampolin. He allegedly saw the possibility of using the trapeze safety net as a form of propulsion and landing device, and he experimented with different systems of suspension, eventually reducing the net to a practical size for separate use. By the late 1800s, top performers were turning double and triple somersaults over rows of horses or elephants. In the early 1930s in the United States, a man named George Nissen emerged from his garage with a prototype similar to today's trampoline. He used it to help with his diving and tumbling, then decided he could entertain audiences and let them participate in his demonstrations. A new field of play was born. While trampoline use passed through a serious stage - first, helping US pilots and navigators gain orientation skills in World War II, then helping US and Soviet astronauts adjust to different body positions in space - it kept growing as sport. US schools and universities staged the first competitions, but Europe was close behind. Kurt Baechler of Switzerland and Ted Blake of Great Britain pioneered the game there, and Great Britain held the first televised national championships in 1958. Six years later, London hosted the first World Championships. By the next year, the International Trampoline Federation had gained formal recognition as the governing body just outside London, and trampoline became serious business. The first European Championship was held in Paris in 1969, and, from then on, it has alternated years with the World Championships. The United States dominated the World Championships at first, but several lawsuits over trampoline soon slowed development in that country. Although most countries began trampoline about the same time, in the 1950s and '60s, the major European countries gradually began to dominate and never have let up. In recent years, Russia has become the main force. Great Britain and Germany remain the Russians' top challengers as Sydney approaches. The British often have managed to split the top spots with Russia, even winning four World Championships.