“ Now the rent is a duty created by the parties upon the reservation, and had there been a covenant to pay it, there had been no question but the lessee must have made it good, notwithstanding the interruption by enemies, for the law would not protect him beyond his own agreement, no more then in the case of reparations; this reservation then being a covenant in law, and whereupon an action of covenant hath been maintained (as Roll said) it is all one as if there had been an actual covenant. ”
