Island at the Top of the World question

Has anyone besides me who has read this book also read King Solomons Mines by H. Rider Haggard, If you have or if you do now read it, would you agree that the book we are discussing is a blatant imitation? I won't call it plagarism because King Solomon's Mines might have been out of copyright. But shouldn't a novelist produce something novel,i.e. new.