The plaintiffs are entitled to maintain this action for rent in their name as lessors. The assignment, not being under seal, did not transfer to the purchaser the legal title to the instrument, so as to enable him to maintain an action on its covenants. An assignment should be by an instrument of as high a nature as the instrument which it purports to transfer. Brewer v. Dyer, 7 Cush. 337. The purchaser of the lease by the written transfer, not under seal, became its equitable owner; but he has not such legal title as to maintain an action on it in his own name as assignee..

The claim in set-off cannot be allowed. It is not due from the plaintiffs only, but from them in connection with another person who is joint promisor with them. The claim is not, therefore, due in the same right, nor from the same persons, as that for which the action i» brought. Judgment for the plaintiffs.