Proof of fact judicially noticed

No evidence of any fact of which the court will take judicial notice need be given by the party alleging its existence, but the judge, on being called upon to take judicial notice thereof, may, if he is unacquainted with that fact, refer to any person or to any document or book of reference for his satisfaction in relation thereto, or may refuse to take judicial notice thereof unless and until the party calling upon him to take the notice produces the document or book of reference.