*888OPINION.
Teussell: The questions presented in this appeal are. whether the taxpayer is entitled to a greater rate of depreciation on mining machinery and equipment and dwelling houses erected near the mines, less salvage, than that allowed by the Commissioner; and, also, whether taxpayer is entitled to a greater deduction for depletion of mines than that allowed by the Commissioner.
Section 234 (a) (9) of the Revenue Act of 1918 provides that taxpayers engaged in the recovery and merchandising of natural resources may have deductions from gross income due to the depletion of such resources and the wear and tear of equipment used in the business, and such provision is in the following language:
In case of mines, oil and gas wells, other natural deposits, and timber, a reasonable allowance for depletion and for depreciation of improvements, according to the peculiar conditions in each case, based upon cost including cost of development not otherwise deducted.
• The’ Commissioner, with the approval of the Secretary of the Treasury, for the purpose of administering this provision of law, adopted a regulation as follows (Regulations 45, art. 165) :
The capital sum to be replaced should be charged off over the useful life of the property either in equal annual installments or in accordance with any other recognized trade practice, such as an apportionment of the capital sum over units of production.
The record of this appeal establishes that the taxpayer began business in 1916 with coal-bearing lands, either at that time or immediately thereafter acquired at a cost of $266,700 and having a coal tonnage in place originally estimated as 3,822,530 tons of merchantable coal. Some time later this estimate was revised. The engineer’s final figures of original coal content of the lands owned by the taxpayer is 3,205,958 tons; and, for the purpose of the computation of depreciation and depletion, we have accepted the latter estimate as the amount of recoverable merchantable coal originally underlying the taxpayer’s properties. Mining operations began in 1916, and the engineer’s estimate established the period of continuing mining operations as ending December 31, 1931. Depreciation, therefore, of the taxpayer’s equipment should be computed upon the cost of equipment used, in the light of its character and the period of operations beginning in 1916 and ending in 1931.
The equipment installed and used by the taxpayer appears, for the purposes of depreciation, to be all properly considered in two groups, in one of which should be the units of steam and electric shovels, the estimated life of which is limited to the production of not more than 500,000 tons of coal per unit of shovels, while in another group all the other miscellaneous equipment and buildings necessary to the taxpayer’s business, with such additions and *889replacements as the operations require, may be included and may be depreciated upon the basis of use throughout the period of mining operations.
In view of all the facts set forth in the findings, we are of the opinion: (1) That the total cost of all the miscellaneous equipment, buildings, and miners’ dwellings, less estimated salvage, if any, at the completion of mining operations, should be credited with an annual depreciation deduction found as follows: To the cost of such equipment at the beginning of each year, less salvage, if any, and depreciation actually sustained bn the basis of this formula, add the coát, less salvage, of additions not including replacements made during the year averaged, divide this amount by the quantity of coal in place at the beginning of the year, ascertained by deducting from 8,205,958 tons the total number of tons mined to the beginning of the taxable year, and multiply by the number of tons removed during the year; (2) that the total cost of steam and electric shovel units, less estimated salvage, if any, should be credited with depreciation deduction each year, found as follows: To the original cost, less estimated salvage, if any, add additions not including replacements made during the year, if any, divide by 500,000 tons and multiply by the number of tons of coal removed during each year by each shovel unit in use.
Depletion of coal content for each of the years under consideration should be found by dividing the cost of coal-bearing lands by 3,205,958, the estimated number of tons in place at the beginning of operations. This process will produce a depletion unit of 8.31888 cents per ton of recoverable coal.