The greatest mystery is as a way to move these trolleys. No wheels they do not: "... Hang hooks; no whip, no guides, themselves twisted, curving '. Involuntarily there is an analogy with the crawler, if so? What mean the ancient Chinese authors, who and what would make such 'carts - the vessels' 5,000 years ago? However, with mining carts, which are known in northern China, in the southern part he operated a mysterious Chi Yu and his numerous assistants. Description of the Chi Yu is also associated in our minds with the complex multi-function robot.