Leif N. Johnson appeals from a decree of the Superior Court of Los Angeles County appointing him and respondent eoadministrators of the estate of Thorvald Johnson, also known as Thorvald Johannesen, deceased.

Thorvald Johnson died intestate August 8, 1948. August 10, 1948, respondent Lillian L. Comstock as daughter of decedent petitioned for letters of administration. Shortly thereafter, Leif N. Johnson as son of decedent filed his petition for letters of administration and written objections to the appointment of Lillian L. Comstock upon the ground that she did not qualify as administratrix under section 422 of the Probate Code, inasmuch as she is not a daughter of the deceased but a niece by marriage. The matters were consolidated and upon trial the following facts were established:

Thorvald Johnson, the deceased, was born in Norway; his Norwegian name was Thorvald Johannesen; he came to the United States as a young man and married Anna Johanna Borreson January 22, 1888. In 1895 or 1896, the Johnsons returned to Norway, where they remained some eight years; they were accompanied by Lauritz Borreson, a brother of Mrs. Johnson. Lillian L. Comstock was born December 15, 1896, in Norway to Lauritz Borreson and Alexandra Andersen. In March, 1898, Lauritz Borreson died. By written instrument dated August 22,1898, an agreement was entered into between Alexandra Andersen and the Johnsons, claimed by Lillian L. Comstock to constitute a legal adoption under the laws of Norway or a contract to adopt. Two translations of said instrument were offered in evidence after testimony by expert witnesses appearing for Lillian L. Comstock and Leif N. Johnson.

The translation of the document as testified to by the expert witness produced by respondent Lillian L. Comstock was as follows:

The expert witness offered by appellant Leif N. Johnson testified to the following translation:

It was stipulated at the trial that respondent Mrs. Comstock lived with Mr. and Mrs. Johnson from August, 1898, until the date of her marriage on June 26, 1920, except for a period when she was away at school, which was less than one year. During that time she was supported by the Johnsons and treated as a member of the family. After her marriage the family relationship continued, consisting of visits back and forth and respondent caring for the Johnsons during times of illness.

Leif N. Johnson was born July 1, 1903, to the Johnsons and in 1904 the Johnsons left Norway with the two children and returned to the United States, settling in California.

Mrs. Johnson, the wife of deceased, died in November, 1935, and the mutual will executed by her and the deceased, and admitted to probate in her estate, referred to Lillian L. Corn-stock as their daughter.

During the trial, William B. Stern, foreign law librarian of the Los Angeles County Law Library, was called as an expert witness on behalf of Lillian L. Comstock. He testified that he was a graduate of the University of Wuersburg, Germany, where he received his Doctor of Laws and Referenda!’ degrees covering German law and civil law; that in his capacity as foreign law librarian he was asked questions concerning foreign law, including the law of Norway and had testified as an expert as to foreign law in the Superior Courts of the Counties of Los Angeles, Alameda, and Ventura; in a District Court of Texas, in the Federal District Court for the Southern District of California, and in the Municipal Court of Los Angeles, and that articles written or testimony given by him had been cited by the courts; that he had testified on the law of 20 foreign countries; that he was familiar in general with the law of Norway as it existed on' August 22, 1898, and in his capacity as foreign law librarian he had been asked a number of questions on the law of Norway and that he was familiar with the law of Norway in regard to adoption of minors as the law existed on August 22, 1898. He further testified that he had never lived in Norway; that he did not speak the Norwegian language; that he spoke German and at one time could speak Italian, French, and Latin; that he could read Latin, Classical Greek, French, Italian, Spanish, Portuguese, and Dutch, and with the aid of a dictionary, Danish, Norwegian, and Swedish; that he had studied basic low-high German, the basic language of all modern Nordic Languages. He named various sources of reference in English and foreign languages he had consulted pertaining to Norwegian law. He also testified that, he could not read the original document in question, since “it is almost impossible for me to read the handwriting here.” His testimony as to the law of Norway on August 22, 1898, and its application to respondent’s translation of the instrument in question was as follows:

Trial of this matter commenced March 25, 1949, and continued March 28th, March 29th, March 30th, and May 10th. On March 30th counsel for Leif N. Johnson requested a stipulation on “taking a deposition from someone over in . . . Norway.

At the commencement of proceedings on May 10th, after the continuance from March 30th, the following took place:

Following further discussion, the court stated:

Motion for a new trial by contestant Leif N. Johnson was denied on the ground that the affidavit in support thereof was not filed within the statutory time.

Appellant urges error on the part of the trial court in its findings as to the effect of the instrument in question. Both parties agree that the status of an adopted child is determined by the laws of the state or foreign country in which the adoption was effected; that such laws must be alleged and proved as facts; and that in the instant ease proof of unwritten law was involved. Appellant then contends that respondent failed to prove the unwritten law of Norway under section 1902 of the Code of Civil Procedure, inasmuch as Mr. Stern lacked qualifications to testify as an expert on the unwritten law of Norway, never having resided in Norway and observed the customs of the country.

The qualification of a witness to testify as an expert is a matter within the sound discretion of the trial court, and where there is no showing of a clear abuse of that discretion the ruling of that court will not be disturbed on appeal (10 Cal.Jur. 963; 5 Cal.Jur. 10-Yr.Supp. 1944 Rev. 693 and cases there cited), nor will the ruling be disturbed if there is any substantial evidence to support it (Humiston v. Hook, 86 Cal.App.2d 101 [ 194 P.2d 122 ]). In view of the qualifications of Mr. Stern as hereinabove set forth, this court cannot say as a matter of law that a clear abuse of discretion occurred in the trial court. And while residence within the jurisdiction of Norway and firsthand observation of the customs of the country might go to the. weight of Mr. Stern’s testimony, it does not go to its admissibility and the position of appellant that the lack thereof disqualified Mr. Stern as an expert witness is untenable.

As already pointed out and as agreed by both parties, unwritten laws of a foreign country are questions of fact. And under familiar rules, findings of fact by the trial court based upon substantial evidence may not be disturbed on appeal (McKinney’s New Cal. Digest, “Appeal and Error,” § 1273 and cases there cited).

In view of the above holdings as to the qualifications of the expert witness and the rule concerning substantiality of the evidence, the further contentions of appellant based on the premise that the law of Norway pertaining to adoption was not established need not be considered.

The final contention of appellant is also untenable, namely, that it was a prejudicial abuse of discretion on the part of the trial court to refuse to grant him an extension of time to take depositions of qualified persons in Norway to show that the instrument in question was not a valid adoption. Appellant had notice of the existence of the written agreement more than six months prior to the date trial was commenced. Furthermore, in view of what transpired at the trial as hereinabove set forth relative to the motion for continuance, it cannot be said that there was an abuse of discretion on the part of the trial court in refusing to grant the motion.

The decree is affirmed.

Doran, J., and Drapeau, J., concurred.