This, it seems, complicates actual present values with conditions which might, or might not, continue. Outside of the physical valuation of the plant, which offers the easiest problem presented, how can one fairly put a value on operating expenses and revenues, which might be affected favorably or advisedly by good or bad management, and by numerous other complex and almost incomprehensible circumstances. The tendency of all such commissions seems to be to confuse together and mix up some things which are logically separate. Thus, the value of the plant and franchise, good will, and present investment or income value, etc., are too often taken together. The value of the plant is dependent on the cost of reproduction, and also the depreciation of the structures, as engineering structures, and should be based on present prices for which the work could be replaced, minus the depreciation, which is a question of engineering judgment and experience. The other items of value are largely dependent on the situation of the plant and its prospects as an income-producing property, and this again is a matter of opinion, in which the opinions of financiers and investors are sometimes of more moment than those of engineers. The opinion of lawyers as to the value of the franchises and the cost of the legal complications possible or probable must also enter into any seriously worthy opinion as to value. The few salient lights in the picture of valuation, presented by the author, serve especially to reveal the darkness which involves the whole subject of valuation, estimating, and the use of cost data for such purposes, and to suggest that, with all the wonderful progress on the theoretical side of the profession, engineers have as yet advanced but little in this division of the practical side—cost data, valuation, and estimating. Engineers cannot compare the results of different estimators and appraisers without sorrow and even shame for their ignorance, or their incapacity to agree in the application of scientific principles and the results of practical experience to this branch of their work. At present we would seem to be a long way from a method of valuation, "such as to minimize or entirely eliminate all differences due to errors of personal judgment."