^^^ Both the boys are right , this does work! But its never going to be as strong as before it snapped. If there's any doubt just get a new one.
or
Of its an extra long leggie and you've got enough lenth on each half, tie em together using two "bowlines"- ya know, the ol rabbit comes out of the hole, round the tree and back into the hole. This knot will get tighter the more load that is put on it. but only if ya get reeeeeely desperate
