Where the dominant heritage is transferred or devolves, by act of parties or by operation of law, the transfer or devolution shall, unless a contrary intention appears, be deemed to pass the easement to the person in whose favour the transfer or devolution takes place.
                                        Illustration
     A has certain land to which a right of way is annexed. A lets the land to B for twenty years. The right of way vests in B and his legal representative so long as the lease continues.