And it is hereby enacted That if the said Henry Ashley his Heires or Assignes shall pull downe or remove any Bridge or Bridges he or they at his or their proper Costs and Charges shall erect others as sufficient and substantiall and as fitt and usefull as the former and that such Parts of the old Bridges as shall be altered by the said Henry Ashley his Heires or Assignes shall be made and left as strong and substantiall as they were before the alteration thereof