A CLUMSY museum visitor tripped on a shoelace and shattered a set of priceless 300-year-old Chinese vases. The three Qing vases had survived on a windowsill at the Fitzwilliam Museum in Cambridge, England, for more than 40 years. A witness said: "He was still sitting there stunned when staff appeared. He kept pointing to his shoelace, saying: `There it is, that's the culprit'." A museum spokeswoman said: "They are in very, very small pieces but we are determined to put them back together."