2. The copyright, (q. v.) or exclusive right to print and publish a book, may be secured to the author and his assigns for the term of twenty-eight years; and, if the author be living, and a citizen of the United States, or resident therein, the same right shall be continued to him for the further term of fourteen years, by complying with the conditions of the act of Congress; one of which is, that he shall, within three months after publication, deliver, or cause to be delivered, a copy of the same to the clerk of the said district. Act of February 3, 1831. 4 Sharsw. cont. of Story's L. U. S. 2223.