Sec. 4959. The proprietor of every copyrignt book or other article shall deliver at the office of the Librarian of Congress, or deposit in the mail, addressed to the Librarian of Congress, at Washington, District of Columbia, a copy of every subsequent edition wherein any substantial changes shall be made: Provided, however, That the alterations, revisions and additions made to books by foreign authors heretofore published, of which new editions shall appear subsequently to the taking effect of this act, unless they form a part of the series in course of publication at the time this act shall take effect.

A change in the title of a subsequent edition, is not such a substantial difference as would work a forfeiture of the copyright.24

Penalty for Omission. Sec. 4960. For every failure on the part of the proprietor of any copyright to deliver or deposit in the mail either of the published copies, or description or photograph, required by sections four thousand nine hundred and fifty-six, and four thousand nine hundred and fifty-nine, the proprietor of the copyright shall be liable to a penalty of twenty-five dollars, to be recovered by the Librarian of Congress, in the name of the United States, in an action in the nature of an action of debt, in any district court of the United States within the jurisdiction of which the delinquent may reside or be found.