The present essay embraces the results of a statistical investigation of the growth of cities during the nineteenth century which was originally undertaken for a doctor's dissertation. In preparing the essay for a wider circle of readers than the specialists to whom the doctor's thesis primarily appeals, the author realized the difficulty of reconciling the aims of a scientific treatise, wherein sharply-defined technical terms and simple, abstract statements lend conciseness to style, with the requisites of a popular work; and in explaining technical terms and illustrating the propositions laid down or deductions drawn, he has had to expand the essay beyond his original intention. While its value may thereby have been somewhat impaired for the specialist, the subject itself is so important to present-day students that it will lend interest to almost any attempt to present the facts with clearness and impartiality.
The assistance rendered to the author by instructors, librarians and friends has been so generous that full acknowledgment cannot be given in this place. He is under especial obligation, however, to Dr. E. Blenck, director of the Royal Prussian Statistical Bureau in Berlin, through whose courtesy he was enabled to collect most of his statistical data in the unrivalled statistical library of the Bureau ; to Professors Johannes Conrad, of the University of Halle, Max Sering, of the University of Berlin, and John B. Clark, of Columbia University, for helpful suggestions ; and most of all to Professor Walter F. Willcox, of Cornell University, for stimulating criticism and sound advice during almost the entire period of the preparation of the essay. Acknowledgments are also due to Professors Edwin R. A. Seligman and Richmond Mayo-Smith, of Columbia University, who read the proof. All responsibility for errors, however, rests upon the writer alone. While he has exercised due care in the copying and compilation of statistics, he does not hope for absolute accuracy, and begs the indulgence of his readers in their judgment of arithmetical errors.
Albany, May 15, 1899.