The writer is sure this discussion will not be construed as in any sense a criticism on Mr. Riggs' paper; it is rather a suggestion of an unwritten chapter in the literature of valuation. The American Society of Civil Engineers is to be congratulated in securing from one of its members so complete and satisfactory a discussion of the principles and methods for the valuation of public service corporation property. CARL C. WITT, M. AM. SOC. C. E. (by letter).—The appraisal of the railway property in Michigan was a wonderful performance in a great many ways, not the least of which was the thoroughness of the work, considering the short time available, and the writer desires to express his appreciation of this paper, as it is a valuable addition to the meager literature on this subject. More recent appraisals, made by States traversed by the same railway systems as those involved in the Michigan appraisal, have been made with a freedom from opposition by railway companies due to the educational effect of this pioneer work. Particularly is this true of the recently completed appraisal, by the Board of Railroad Commissioners of South Dakota, of the physical property of the railways in that State, of which work the writer was the Engineer in charge. No opposition was met; in fact, some of the railway companies had established regular departments for furnishing inventories and appraisals, had completed the necessary field work in South Dakota before the inventory had been requested by the State, and were able to furnish a very complete appraisal in a short time after the request for it was made. This appraisal was made in compliance with an act of the Legislature of 1907, which required the Board of Railroad Commissioners to ascertain the true cash value of all the property of every railroad company in South Dakota used in the operation and maintenance of their respective roads. No attention was paid to the purpose of the appraisal, but one of the first uses made of the information thus secured was in the litigation following the passage of an act by the Legislature of 1909, prescribing a maximum passenger fare of 2 cents per mile on all railroads operating within the State. In connection with a rate case of this kind, some questions have been raised regarding proper bases for land values, the use of an item for adaptation and solidification as an element of physical value, the value of the intangible assets, etc.