(_g_) _Design._—Among the matters which were considered in the Michigan work was that of adaptability, or the economical questions of location, design, and construction. It is possible that in some properties, such as water, gas or electric companies, the efficiency of the plant may be very greatly affected by faulty design, uneconomical arrangement, improper construction, and to such an extent that any cost of reproduction, less any ordinary depreciation, would be greatly in error without further allowance. This may also be true of railroads. Excessive curvature and gradients greatly decrease the tonnage hauled by a given power, without decreasing the cost per train-mile. It is extremely difficult to treat this as a physical element. It is impossible to reduce it to terms of dollars and cents by any usual or customary methods. It is impossible to separate it from any one of half a dozen other items that may be brought up. It opens the door to endless speculation as to what might or might not take place under somewhat different conditions. For these reasons, it was treated in the Michigan appraisal as a non-physical element of value and dismissed from all consideration in the physical appraisal. This was clearly proper, and the subject is only referred to here for the purpose of making clear that it was fully studied and a definite conclusion reached. Adaptation.—In the sense that this term is used by Mr. Williams and Mr. Morgan, the appreciation or solidification of roadbed was considered in the Michigan work, but given no place in the appraisal. This is a very proper item to consider, but it would appear to be better to include it directly with the roadbed item in the physical appraisal as appreciation or solidification. There can be no reasonable objection to adding to the contract prices for grading, ballasting, etc., a reasonable amount to cover, not so much the seasoning and settling of the new roadbed, as the actual money disbursed in work on this new roadbed during the first 3 or 4 years of operation in order to bring it up to the proper operating condition. A very considerable part of the money spent on "maintenance of track" for the first few years after a new line is built is in reality deferred construction cost.