"It would seem to us preferable to substitute a phrase which indicates the fact that Congress desires an inventory valuation of railway property. By inventory valuation is meant that the property of the several railways shall be listed in detail, and that each kind or class of property so listed shall have assigned to it a valuation to be determined from the point of view of the contracting engineer, and not from the point of view of a court or board of arbitration which, from the nature of the case, cannot judge of what is 'fair value' except in the light of some specific use to be made of the valuation."[35] As has already been noted herein, and amply verified by quotations, Mr. Riggs is fully aware that replacement cost and real value can rarely, if ever, coincide, and therefore plainly agrees, as to that elementary and essential point, with the writer and disagrees with Professor Adams, who would ignore or destroy every non-physical element of value in the property of all public service corporations. Mr. Riggs' recognition of the inadequacy of mere replacement cost is shown also by the excellent and convincing example which he cites[36] of competitive railway routes between two Michigan cities which were built and are maintained and operated under such conditions that the far more costly of the two, which inferentially has correspondingly higher replacement cost, has much lower earning capacity, both as to gross and net, and is therefore actually worth much less than its less costly competitor. Mr. Riggs explicitly favors full recognition of the non-physical elements in every valuation; and, therefore, may be ranked as an opponent of any such scheme of valuation as that advocated by Professor Adams before the American Economic Association, or in the letter of the Chairman of the Interstate Commerce Commission, hereinbefore quoted. Mr. Riggs, however, believes that the determination of the cost of replacement is an essential first step toward the ascertainment of real value. He says: "The worth of the physical property is primarily that on which the value of the whole property rests." The thought which the writer would place in opposition to the foregoing is that: Physical property has no value which is not an expression of its adaptation to economic needs. This is only another way of expressing the inevitable economic law, from which there is no escape, either in theory or in practice, that has been stated and sanctioned by the Supreme Court of the United States, as follows: "But the value of property results from the use to which it is put, and varies with the profitableness of that use, present and prospective, actual and anticipated. There is no pecuniary value outside of that which results from such use."[37] Mr. Riggs' own definition of value is not inconsistent with the foregoing. He says: