In 1730 Holberg was appointed Professor of History, and for the next sixteen years, covering the whole of the reign of Christian VI., he displays the activity of an historian, an essayist, and a philosophical writer--another proof of the remarkable versatility of his genius. Within recent years this phase of Holberg's authorship has been subjected to a close and interesting examination, especially by Norwegian Holberg students, and many valuable features, adding to the correctness of Holberg's portrait as an author and as a man, have been established beyond doubt. His historical works, obsolete though they are and superseded by modern contributions, are imbued with the same spirit as _Peder Paars_ and the _Comedies_. In his _History of Denmark_ (I.-III.) his greatest and most mature work; in his _Description of Denmark and Norway_; in his _Description of Bergen_; in his _General History of the Church_; in his _History of Heroes_ and in his _History of Heroines_, to mention only the most important historical works of this part of his life, in all of them we discover the same qualities which struck us as characteristic features in his first work, deepened by his experiences and sharpened by his superior faculty of observation. In particular, we notice the light thread of irony running through the whole tissue of his reflection and composition, stamping argument and style alike by the irresistible humour of his genius. It is as if the playwright is constantly casting a glance on the manuscript over the shoulder of the historian, and as if merry Thalia always takes a fancy to tease her serene sister Kalliope. In the midst of his learned studies Holberg, in a relapse, as it were, to his former satirical humour, surprised the public by a work which very soon got international reputation. It appeared at Leipzig in 1741, in Latin, under the title of _Nicolai Klimii Iter Subterraneum_, and was promptly translated into a number of European languages, among them English. The first English translation of _Niels Klim_ dates from 1742; the next from 1828.[3] It ought to reappear in a new translation, and be included among the World's Classics, for next to _Gulliver's Travels_ there is hardly a work in any literature to which it can be adequately compared.