The mortgagor sold part of the mortgaged premises to Morgan and Peters, who assumed the mortgage and agreed to pay the debt. They in turn resold to Jones and Dalton who also assumed the mortgage and agreed to pay the debt. The remainder of the mortgaged premises was sold by the mortgagor to Bursell under a warranty deed free from all incumbrances. The mortgagee at the request of the mortgagor and of Jones and Dalton but without the knowledge of Morgan and Peters extended the time of payment five years. The mortgage remaining unpaid at the end of that time, the mortgagee foreclosed and caused the mortgaged premises to be sold. Bursell to protect himself redeemed his portion and brought an action in equity against Morgan and Peters based upon their contract with the mortgagor to assume the mortgage and to pay the debt. Morgan and Peters contended that the extension of time without their consent released them, but the court held that extension of time to a surety could not injure a principal and consequently did not release him from liability. Bursell v. Morgan (Minn. 1930) 233 N.W. 12.