George Heimann, on the 30th of December, 1913, filed an application in Austria for a patent for a semiautomatic or automatic graded service telephone exchange system and telephone substation with graded service facilities. On the 7th of January, 1914, Heimann filed an application in Great Britain to secure a patent for the same invention, and on that application a patent was issued, known as No. 450 of 1914.
On May 7, 1917, William Walter Owen filed an application in the United States Patent Office, praying for a patent to new and useful improvements in “measured service telephone systems.” Owen’s application was granted, and letters patent were issued to him by the Patent Office on October 26,1920.
On the 16th of August, 1921, Elsie Hecht, formerly Heimann, administratrix of the estate of George Heimann, deceased, of Berlin, Germany, filed an application in the Patent Office of the United States in behalf of the estate for letters patent for a semiautomatic or automatic graded service telephone system, claim 29 of which, as amended, corresponded to claim 26 of the patent issued to Owen. Because those claims were substantially the same, and substantially claimed the same invention, an interference was declared on the 3d of August, 1922.
On the ground that Owen’s filing date and consequent constructive reduction to practice was subsequent to December 30, 1913, the date of George Heimann’s Austrian application and the date of his constructive reduction to practice, a motion was made on October 18, 1922, by the applicant, Elsie Hecht, formerly Heimann, to shift the burden of proof to Owen, the senior party. As it appeared from Owen’s preliminary statement that he conceived the subject-matter of the count in interference on or about January 31,1917, and that the invention was constructively reduced to practice on the 7th of May, 1917, the date of filng his application, the motion was granted. Owen declined to assume.the burden of proof imposed upon him by that ruling, and, having failed to make any showing why a judgment on the record should not be entered against him, priority of invention of the subject-matter in issue was awarded by the Examiner of Interferences to the administratrix of the estate of George Heimann, deceased. The Board of Examiners in Chief affirmed the *174decision of the Examiner of Interferences, and the Board’s decision was affirmed by the Commissioner. Erom the Commissioner’s decision this appeal was taken.
• The appellant in support of his appeal contends (1) that the German citizenship of Heimann was not proven; (2) that no evidence was submitted to the tribunals of the Patent Office, proving or tending to prove, that the German empire or the German republic granted to American citizens rights and privileges substantially the same as those accorded by the Nolan Act; (3) that the Nolan Act did not intend to make, and by its terms did not make, the date of the filing of Heimann’s Austrian application effective as Heimann’s date of invention in the United States; and (4) that to construe the Nolan Act so as to make the date of Heimann’s Austrian application effective in the United States as Heimann’s date of invention, would render the act unconstitutional.
The motion to shift the burden of proof alleged that George . Heimann and Elsie Heeht, administratrix of his estate, were German citizens. Elsie Hecht’s application for a patent and the oath attached thereto filed in the United States Patent Office alleged that she was at the time of filing the application a citizen of the German republic. Her application also averred that George Heimann was at the time of his death a citizen of Germany, and as evidence of his citizenship referred to United States patent No. 1,341,801, the application for which filed by George Heimann on August 28, 1913, recited that he was a subject of the German emperor, residing at Charlottenburg, Berlin, Germany.
The issuance to Owen of a patent by the Patent Office vested in him no property right, of which he could not be deprived by the interference proceedings provided for by section 4904 of the Revised Statutes (Comp. St. § 9449), or by the suit in equity contemplated by section 4915 of the Revised Statutes (Comp. St. § 9460). The right to a patent is purely statutory and Congress has full power to prescribe to whom and upon what terms and conditions a patent shall issue. Every patentee takes his patent with full knowledge that his claim' to priority of invention may be attacked in the manner provided by law and that if 'it be successfully assailed, his patent is rendered worthless without leaving any ground for complaint that his constitutional rights have been invaded. Seror et al. v. Dick, 55 App. D. C. 151, 152, 3 F.(2d) 92; Kling v. Haring, App. D. C.—, 11 F.(2d) 202 (Patent Appeal No. 1739, decided Feb. 1, 1926); Stewart v. Kahn, 11 Wall. 493, 506, 20 L. Ed. 176.
The German patent laws were certified by the German Foreign Office to the United States Patent Office, and the Commissioner of Patents by formal order announced that they accorded to American citizens privileges substantially reciprocal to the privileges granted by the Nolan Act (Comp. St. Ann. Supp. 1923, §§ 9431a-9431h), and that consequently the privileges of the Nolan Act should be extended to German citizens. Commissioner’s Order 2703, 291 O. G. 677. The German patent laws certified by the German office were part of the records of the United States Patent Office, and as they were recognized by an official order, which made it obligatory on patent officials to extend the privileges of the Nolan Act to German citizens, the tribunals of the Patent Office had the right to take judicial notice of such laws, in the same way as judicial, notice is taken of other records of the office. In re Appeals of Drawbaugh, 9 App. D. C. 219, 242, 256, 257, 258; Cain v. Park, 14 App. D. C. 42, 45, 46; Seror v. Dick, supra, 55 App. D. C. at page 152, 3 F.(2d) 92; Scalione v. Bosch et al., App. D. C. —, 12 F.(2d) 171, patent appeal 1824, decided concurrently herewith.
The evidence as to the German citizenship of the applicant and of the inventor, Heimann, may not have been the best evidence, but it was certainly sufficient to establish German citizenship, in the absence of any objection to its competency, and in view of the fact that the opposition to the motion was based on other grounds. See Seror et al. v. Dick, supra, 55 App. D. C. at page 152, 3 F.(2d) 92. We are of the opinion that the German citizenship of the appellee and of George Heimann must, under the circumstances, be taken as established prima facie.
The decision appealed from is affirmed.