While parol evidence is inadmissible to alter or vary the terms of a written contract, still it is admissible for the purpose of explaining the true meaning of any portion of a written contract which is of itself unintelligible or ambiguous. The court in this case did not err in permitting evidence explanatory of what was meant by the stipulation in the present contract, under which the plaintiff agreed to furnish, in addition to the articles which were the subjeet-matter of purchase, “all advertising matter that goes with an order of this size.” The superior court did not err in overruling the certiorari.

Judgment affirmed.