Professor Jameson hazards the conjecture[56] that Irving's real importance in the development of American historiography is not at all to be discerned in the serious works which have just been mentioned, but rather in his quaintly humorous picture of New York under the Dutch, contained in the pretended narration of Diedrich Knickerbocker, and published as early as 1809. There can be no doubt that, as Professor Jameson says, this book did much to excite both interest and curiosity concerning the Dutch régime. "Very likely the great amount of work which the state government did for the historical illustration of the Dutch period, through the researches of Mr. Brodhead in foreign archives, had this unhistorical little book as one of its principal causes." Here, indeed, is only one more illustration of the fact that the work which one does in his natural vein and in his own way is certain not only to be his best, but to exercise a genuine influence in spheres which at the time were quite beyond the writer's consciousness. Something has already been said concerning Prescott in his relationship to Motley as an historian. A brief but more explicit comparison may be added here. The diligence and zeal of the investigator both men shared on even terms. The only advantage which Motley possessed was the opportunity, denied to Prescott, of prosecuting his own researches, of discovering his own materials, and of visiting and living in the very places of which he had to write, instead of working largely through the eyes and brains of other men. This was a very real advantage; for the inspiration of the search and of the scenes themselves gave a keen stimulus to the ambition of the scholar and a glow to the imagination of the writer. One attaches less importance to Motley's academic training; for while it was broader than that of Prescott, and comprised the valuable teaching which was given him in the two great universities of Berlin and Göttingen, we cannot truthfully assert that Prescott's equipment was inferior to that of his contemporary. Indeed, _Ferdinand_ and _Isabella_ and _Philip II._ can better stand the test of searching criticism than Motley's _Dutch Republic_.