ing five pounds and the value of the book, and the fine shall be paid to the trustees or authority to whom the book ought to have been delivered.
(7) For the purposes of this section, the expression "book" includes every part or division of a book, pam- phlet, sheet of letter-press, sheet of music, map, plan, chart or table separately published, but shall not include any second or subsequent edition of a book unless such edition contains additions or alterations either in the letterpress or in the maps, prints, or other engravings belonging thereto.
Special Provisions as to certain Works. Works of 16. — (i) In the case of a work of joint authorship, copy-
joint authors right shall subsist during the life of the author who first dies and for a term of fifty years after his death, or during the life of the author who dies last, whichever period is the longer, and references in this Act to the period after the expiration of any specified number of years from the death of the author shall be construed as references to the period after the expiration of the like number of years from the death of the author who dies first or after the death of the author who dies last, whichever period may be the shorter, and in the provisions of this Act with respect to the grant of compulsory licences a reference to the date of the death of the author who dies last shall be substituted for the refer- ence to the date of the death of the author.
(2) Where, in the case of a work of joint authorship, some one or more of the joint authors do not satisfy the conditions conferring copyright laid down by this Act, the work shall be treated for the purposes of this Act as if the other author or authors had been the sole author or authors thereof:
Provided that the term of the copyright shall be the same as it would have been if all the authors had satisfied such conditions as aforesaid.
(3) For the purposes of this Act, ' ' a work of joint author- ship" means a work produced by the collaboration of two or more authors in which the contribution of one author is