(concurring specially) : I concur'in the conclusion reached, but not in all that is said in the opinion. The supreme court established as a rule of evidence that to modify a written contract upon the ground of fraud or mistake a mere preponderance of the evidence is not sufficient. For the reason that the district court told the jury that a preponderance of the evidence was sufficient to entitle the plaintiff to a recovery, based upon the reformation of the written contract set up in this case, a new trial will have to be awarded, that the defendant may be given the benefit of this rule.