Nor is the history of the assumption by public authority of its inherent right to control railroads, as narrow an interest as it at first appears. Transportation, as a service, is the commodity produced by common carriers. The manner in which the price of this commodity has been brought under governmental regulation has a direct bearing upon another problem just beginning to open up; namely that of the control by the state of the prices of other things. It is not unlikely, in my judgment, that the final solution of the so-called Trust Problem in the United States, whether for good or ill, may ultimately contain as one important feature, the determination by governmental authority of reasonable prices for such prime necessities of life as milk, ice, coal, sugar and oil, when produced under monopolistic conditions. This view is shared by my colleague Professor Taussig in his "Principles of Economics." It is also distinctly set forth by President Van Hise of the University of Wisconsin, in his recent "Concentration and Control." When the seed of such an industrial policy is planted, as I believe it possible in time, the soil will have been richly prepared for its reception by our experience in the determination of reasonable charges for the services of railroads and other public utilities. A word of explanation may also be offered to the reader who finds in these pages an almost exuberant mass of illustrative material. Possibly, even, it may be alleged that in places so thick are the circumstantial trees of evidence that one can scarcely perceive the wood of principle. But, under the circumstances, it is almost inevitable that this should be so. The method of inquiry adopted has been mainly inductive. Text books and theoretical treatises have been used only by the way. I hold them to be merely of secondary importance. The principal reliance has been upon concrete data, painstakingly gathered through many years from original sources. In this present excursion in the far more complex domain of the social sciences, an endeavor has been made to adhere strictly to the same scientific method pursued in the field of natural science in writing "The Races of Europe." A search far and wide for every possible bit of raw material had to be made at the outset. To this succeeded the classification and realignment of the concrete data thus obtained. The last step of all, was the formulation of the governing economic principles. But an almost indispensable result of this mode of work is a plenitude of reference and example. One might almost say that under such circumstances it becomes second nature to demand concrete illustration for every economic theory or principle laid down. Such a statement, however, would be fallacious. It would misrepresent the true sequence of events as above outlined. Rather should it be affirmed, that, inasmuch as the concrete examples are the sources of the reasoning, no theory can be