The Roman Historian Livy wrote "Their slings were apparently more accurate than the standard one strap slings that others used. "They consisted of three thongs, stiffened by beings sewn together. This prevented the bullet from flying off at random when the thong was let go; when fixed in the sling it could be so whirled round as to fly out as though from the string of a bow." Does any one have any idea how this would work. I've tried a few ideas but nothing seemed workable.