Mr. Riggs considers _seriatim_ nine objections to the ordinary methods of estimating cost of replacement which were mentioned specifically by the writer, as among the most important commonly omitted items, in an address before the New York Traffic Club, delivered during January, 1909. He concedes that the writer is correct in urging that allowances for "working capital with which to carry on the business" and for "impact and adaptation" ought to be included, and were omitted in Michigan and have been usually omitted. These are two of the nine objections specifically raised. As to five others, Mr. Riggs seems to be in considerable doubt. Concerning the objection that an allowance of 3% for interest during construction is too low, he contends that it was justified in Michigan by the "assumption," that the whole work of replacement would be accomplished in one year, and also "that on long roads partial operation would commence as various sections of the line were completed." He admits that these assumptions "clearly would not be proper" under different conditions, but appears to hold that they were warranted as to the Michigan work. Another of the writer's objections was the absence of an allowance for "wear and tear of materials during the period of construction." As to this, Mr. Riggs says: "This deterioration is a necessary incident to any construction work. It has not been customary or usual to take account of it. To add to the amount capitalized on account of this item would be manifestly improper. The only way in which this could be cared for would be in an adjustment of the depreciation reserve when raised to cover that which takes place during the construction period." Of course, the depreciation account, when there is one, is a charge to operation. Therefore, Mr. Riggs' anxiety to disagree with the writer has led him into a frame of mind in which he is prepared to find that it is "manifestly improper" to charge to capital the real cost of construction, but is quite proper to charge to operation a part of the cost of construction, even though this results in carrying into the operating account items of expense incurred long before operation began or could have begun. Mr. Riggs thinks that the writer was incorrect in objecting that "a uniform price for earthwork was used, thus ignoring the varying character of soil and length of haul," but he admits that there was "practically no classification in the Southern Peninsula of Michigan, or, in fact, on 90% of the mileage of the State," and his defense goes no further than to assert that "the price * * * was not much out of the way when considered as a fair average for the territory."