[35] D and d may be expressed as the respective periodic amount-multipliers necessary to create sinking funds of one dollar each under the conditions as to time and rate for V and V₁. VD and V₁d become, therefore, the periodic amounts of true depreciation, i.e., decrement in value.

[36] In “Depreciation and Wasting Assets.”

[37] From “Valuation, Depreciation and the Rate-Base,” by C. E. Grunsky.

[38] That is, cost less salvage.

[39] That is, the number of times renewal of the asset will be required during the longest life-period of any of the assets.

[40] Dollar-years, column (f), is the product of the total invested values as shown in column (e), and the life of each group as shown by column (b). Thus, $400,000 invested for 5 years is the equivalent of $2,000,000 invested for 1 year.

[41] (d) = (c) ÷ (b).

[42] See Consolidated Gas Co. v. City of New York, 157 Fed. Rep. 855, and 20 I. C. C. Rep. 344.

[43] Valuation Committee of the American Society of Civil Engineers.

[44] In “Accounting Practice and Procedure.”