When filed, it is required to be printed in the appeal record. Practice Book, 1908, p. 275, § 23. It may be resorted to by this court for the purpose of ascertaining the rulings of the trial court upon questions of law, or for interpreting the finding of facts. Cummings v. Hartford, 70 Conn. 115, 124, 38 A. 916; Waters v. White, 75 Conn. 88, 92, 52 A. 401. Such a stipulation as that filed does not become a part of the record unless made so by the trial court. It is merely a substitute, for use in the trial court, for the regular legal evidence of the facts stated in it. 1 Greenleaf on Ev. (13th Ed.) § 205.