s first set out by this Court in Gjerstadengen v. Hartzell, 9 N.D. 268, 275-276, 83 N.W. 230, 232 (1900):The rule as to the requisites of an estoppel in pais as applied to the title to realty which appeals to us as the most equitable to all parties is that announced by Field, J., in Boggs v. Mining Co., 14 Cal., on page 367.