2. Patents-for importations.

19. It is enacted¹ by the act of March 3, 1839, s. 6, that no person shall be debarred from receiving a patent for any invention or discovery, as provided in the act approved on the fourth day of July, one thousand eight hundred and thirty-six, to which this is additional, by reason of the same having been patented in, a foreign country, more than six months prior to his application: Provided, That the same shall not have been introduced into public and common use, in the United States, prior to the application for such patent: And provided, also, That in all cages every such patent shall be limited to the term of fourteen years from the date or publication of such foreign letters-patent. 20. And by the act of July 4, 1836, s. 8, it is provided, that nothing in this act contained shall be, construed² to deprive an origisal and true inventor of the right to a patent for his invention, by reason of his having previously³ taken out letters-patent therefor in a foreign country, and the same having been published at any time within six mouths next preceding the filing of his specification⁴ and drawing.

4. Of the caveat⁵ and other preliminary, proceedings⁶.

21. The act of July 4, 1836, s. 12, provides that any citizen of the United States, or alien who have been resident in the United States one year next preceding, and shall have made oath of his intention to become a citizen thereof, who shall have invented any new art, machine, or improvement thereof, and shall desire further time to mature the same, may, on paying to the credit of the treasury⁷, in manner as provided in the ninth section of this act, the sum of twenty dollars, file in the patent office a caveat, setting forth⁸ the design and purpose thereof, and its principal and distinguishing characteristics, and praying protection of his right, till he shall have matured his invention - which sum of twenty dollars, in case the person filing such caveat shall afterwards take out a patent for the invention therein mentioned, shall be considered a part of the sum herein required for the same. And such caveat shall be filed in the confidential⁹ archives of the office, and preserved in secrecy¹⁰. And if application shall be made by any other person within one year from the time of filing such caveat, for a patent of any invention with which it may in any respect interfere¹¹, it shall be the duty of the commissioner¹² to deposit the description, specifications¹³, drawings, and model, in the confidential archives of the office, and to give notice, by mail, to the person filing the caveat, of such application, who shall, within three months after receiving the notice, if he would avail himself of the benfit of his caveat, file his description, specifications, drawings, and model: and if, in the opinion of the commissioner, the specifications of claim interfere with each other, like proceeding& may be had in all respects as are in this act provided in the case of interfering¹⁴ applications: Provided, however, That no opinion or decision of any board of examiners, under the provisions of this act, shall preclude¹⁵ any person interested in favor of or against the validity of any patent which has been or may hereafter be granted, from the right to contest the same in any judicial¹⁶ court in any action in which its, validity may come in question.

22. And the same act, s. 8, directs, that whenever, the applicant¹⁷ shall request it, the patent shall take date from the time of the filing of the specification and drawings, not however, exceeding six mouths prior to the actual issuing of the patent; and on like request, and the payment of the duty herein required, by any applicant, his specification and drawings shall be filed in the secret archives of the office, until he shall furnish the model and the patent be issued, not exceeding the term of one year, the applicant being entitled to notice of interfering application.