The Preface was written for the 1818 edition of Frankenstein by Shelley's husband, the poet Percy Bysshe Shelley. This Preface certainly represents itself as being by the author of the book (which was published anonymously.)
What influences on the story does the Preface mention? Are these the same as in the 1831 Introduction? How does the Preface describe the origins of the story of Frankenstein? Are these origins consistent with those given in the 1831 Introduction