Heavy knit sweaters, football favorites of the '20s and still beloved by cheer-leaders today are all over the sporting scene this fall. When a hand-knit one in a checkerboard pattern was pictured in SI, Sept. 6 a whole college fraternity wanted to buy others like it. Women are wearing white hand-knit sweaters with fancy patterns to dog trials, in open sports cars. The original Frank Merriwell, roll-collar coat sweater, first hand-knit by the Shakers of Pennsylvania, was called a "Shaker." A search for the old Shaker revealed one company still making it. There were also a raft of new heavy knits from six countries (next page), among them cardigans from France and Austria and an English yachting sweater called the "Pig's Whisker." Many are from Europe, in the newly popular cardigan which European skiers now wear with their brightly colored ski pants. Most of the imported sweaters are found only in metropolitan department stores and sports shops. But the demand for them has grown so much this fall that they'll soon be available in American versions in stores everywhere.