S. 17 (1) of Copyright Act, 1911 (referred to in paragraph 9 of Seventh Schedule):—

In the case of a literary, dramatic or musical work, or an engraving, in which copyright subsists at the date of the death of the author or, in the case of a work of joint authorship, at or immediately before the date of the death of the author who dies last, but which has not been published, nor, in the case of a dramatic or musical work, been performed in public, nor, in the case of a lecture, been delivered in public, before that date, . . . the proviso to section three of this Act shall . . . apply as if the author had died at the date of such publication or performance or delivery in public as aforesaid.