The Librarian of Congress and the Register of Copyrights jointly are authorized "at suitable intervals" to determine what articles received during any period of years and remaining undisposed of, are useful for permanent preservation, and in their discretion to provide for the destruction of others, after a statement of the years of receipt of such articles and notice to permit any lawful claimant to claim and remove them has been printed in the catalogue of copyright entries from February to November, permitting their reclamation within the month of December. There is a special proviso that no manuscript of an unpublished work shall be destroyed during the term of copyright without specific notice to the copyright proprietor of record, permitting him to claim and remove it. {Sidenote: Register of Copyrights} The Register of Copyrights, originally appointed by the Librarian of Congress under the act of February 19, 1897, is made by the new code of 1909 a permanent administrative officer, appointed by and under the direction and supervision of the Librarian of Congress at a salary of $4000 per year and under bonds of $20,000. He is authorized under the law to make rules and regulations for the registration of claims to copyright, subject to the approval of the Librarian of Congress; is required to make an annual report to the Librarian of Congress to be printed in the annual report on the Library of Congress; to cover all fees into the Treasury and report as to the same to the Secretary of the Treasury and to the Librarian of Congress, and to provide and keep the necessary record books, indexes, etc. He is authorized to affix the seal of the Copyright Office provided for by law, and is happily relieved by the new code from the necessity of formal signature of certificates, etc., which under the old law wasted precious and difficult hours in small routine work, the affixing of the seal being the sufficient and sensible substitute for the personal signature. An assistant register of copyrights at a salary of $3000 was provided for in the new act, also to be appointed by the Librarian of Congress, with authority during the absence of the Register to attach the seal and perform other necessary functions. {Sidenote: Catalogues and indexes} The law directs that the Register of Copyrights "shall print at periodic intervals a catalogue of the titles of articles ... together with suitable indexes, and at stated intervals ... complete and indexed catalogues for each class of copyright entries, "which shall be admitted in any court as _prima facie_ evidence," shall be promptly distributed to collectors of customs and postmasters of all exchange offices and shall be furnished to others at a price not exceeding $5 per annum for the complete catalogue or $1 for the catalogues issued during the year for any one class.