Importance of depreciation for valuation, 630. — A well maintained property is yet normally in a state of depreciation, 632. — How to allow for this circumstance depends on the purpose for which accounts are made up, 635. — Mode of reckoning depreciation required by Interstate Commerce Commission, 637. — "Replacement account, " "Reserve for accrued Depreciation, " 639. — A possible alternative, 644. — The general procedure justified for purposes of regulation, 648. — Criticism possible as regards earlier charges made, 654. — A different principle and a different rule by other regulating bodies, 656. — Wisconsin Commission, 657. — The United States Supreme Court, 660. — Conclusion, 662.