(concurring) .
I concur in Judge VAN OOSTER-HOUT’S opinion. Because, however, I reach his result with somewhat different emphases, I make these additional comments :
1. The standards of the statute and the Regulations. § 23 (Í) (1) of the 1939 Code creates for this taxpayer three conditions for its claimed depreciation deduction: (1) that the asset be an exhausting one; (2) that it be used in the trade or business; and (3) that the allowance be reasonable. The statute itself does not distinguish between tangible and intangible assets and it says nothing by way of disqualifying an asset for depreciation merely because it is an intangible. Neither does the statute say in so many words that an asset, to be depreciable, must have a definitely limited life. It requires only that the allowance be “reasonable.”
Treasury Regulations 111, issued under the 1939 Code, attempt to reach these details. § 29.23(l)-3 deals with intangible property; § 29.23(l)-5 concerns itself with the method of computing depreciation; and § 29.23 (m)-9 has to do with the determination of contents of mines and of oil and gas wells. These three sections taken together — and I feel that they are not separable — would establish what appear to be seven conditions for this taxpayer’s deduction for depreciation of its intangible rights-of-way: (1) that they be acquired through a capital outlay; (2) that they be used in the trade or business; (3) that they be “definitely limited in duration”, or “of value * * * for only a limited period”, i. e., exhausting; (4) that this period be capable of estimation from experience; (5) that the period also be capable of estimation with reasonable certainty; (6) that the determination be upon conditions known to exist at the end of the taxable period; and (7) that the estimate be made according to the method current in the industry and in the light of the most accurate and reliable information obtainable. The Regulations thus would supply an interpretation of the statutory requirement of resonableness. I feel that this interpretation is itself reasonable and proper enough and I have no great difficulty in concluding that these sections of the Regulations are valid.
2. The application of these standards here. The basic conflict between the Commissioner and the taxpayer lies in the area of application of these standards and, because the Commissioner does not really challenge the exhausting character of the rights-of-way (the district court found that those assets were undergoing exhaustion, at page 185 of 174 F.Supp.), it centers on the question of whether the rights-of-way have an ascertainable life. The taxpayer argues that proven reserves have a definite significance in the industry; that they are determined with reasonable accuracy; that consumption of gas in the past is known and in the future can be estimated with reasonable certainty; that proven reserves and consumption have a relationship which, with proper adjustments, results in a limited supply period; and that, therefore, the standards of the statute and the Regulations are adequately met in the light of known facts as of the end of each taxable year. The Commissioner says that this is not realistic; that proven reserves to a large extent are artificial because they are limited by economic and operational considerations; that the taxpayer has unproved acreage and prospective acreage; that its and the industry’s history shows an ability to connect facilities with new sources of supply; that if known reserves increase, as they have, • the determination of useful life of rights-of-way is exceedingly difficult; that gas not presently owned by the taxpayer will certainly pass through its lines in the future; and that, therefore, there *140is no reasonable relationship between proven reserves and the life of the rights-of-way.
The Commissioner’s argument has force. There are instances where the courts have refused a depreciation deduction for an intangible asset with an elusive life length. Nachman v. Commissioner, 5 Cir., 191 F.2d 934; KWTX Broadcasting Co. v. Commissioner, 5 Cir., 272 F.2d 406; Meredith Publishing Co. v. Commissioner, 8 Cir., 64 F.2d 890, certiorari denied 290 U.S. 646, 54 S.Ct. 64, 78 L.Ed. 560; National Weeklies v. Commissioner, 8 Cir., 137 F.2d 39; Dodge Bros. v. United States, 4 Cir., 118 F.2d 95; International Textbook Co. v. United States, Ct.Cl., 44 F.2d 254; Coca-Cola Bottling Co. v. Commissioner, 6 B.T.A. 1333; Shufflebarger v. Commissioner, 24 T.C. 980. Compare Pasadena City Lines, Inc. v. Commissioner, 23 T.C. 34. These cases, however, all involve good will, subscription lists, renewable licenses, or perpetual franchises and do not seem to me to control the facts here. On the other hand, as Judge Van Oosterhout has noted, this court has recognized a deduction for depreciation of rights-of-way under appropriate circumstances. Union Electric Co. v. Commissioner, 8 Cir., 177 F.2d 269, 275. The case before us, therefore, comes down to the question of proof.
The Commissioner’s insistence in this^ case that there be a fixed and definitely, limited period of time must equate only with the practical need of a measure. But that measure need not be one determined with precision accuracy and be good for all time. A “reasonable approximation” or even “a rough estimate”, say the Niagara Falls and Ludey cases, is enough. In this light, the elements involved here, namely, proven reserves, production, reserve life index, load factor and the others, become aceeptable for consideration in the absence of proof that they are wholly fallacious. These elements at first glance may seem to be difficult of application, but, if so, the difficulty bears upon only computational aspects and not upon basic eligibility. The amount of the deduction will change from year to year as proven reserves change and as additional costs of rights-of-way may be incurred. These changes are only computational but, when properly taken into account, they prevent the complete consumption, through deductions, of rights-of-way costs before the end of the rights-of-way life. There is thus no premature recovery of these costs.
In my judgment, therefore, the taxpayer, who has the burden of proof, has met the seven conditions above described and has sustained that burden. Its case may be thin and not overwhelming but I feel that, on the record here, it has been established and that the Commissioner has not succeeded in undermining it. Furthermore, the result seems to me to coincide with good business practice and good accounting.
3. The inconsistency in the Commissioner’s position. I feel, too, that the Commissioner’s positive emphasis and insistence here upon the necessity of a definitely limited period of time involves a basic inconsistency with his historic stand on depreciation and depletion allowances.
Under the income tax laws a corporation since March 1, 1913, has been permitted to deduct a “reasonable allowance” for depreciation or for exhaustion of property used in the trade or business.1 Similarly, since March 1, 1913, a corporation has been permitted to deduct a “reasonable allowance” for depletion, to some extent at least, of mines, oil and gas wells, and other natural de*141posits.2 The successive regulations issued under the depreciation sections of the respective Revenue Acts read substantially the same as the pertinent sections of Regulations 111 under the 1939 Code so far as they stress the concept of reasonable certainty.3 In determining the depletion allowance the Regulations permit, where adjusted cost basis of the property rather than a percentage of gross income is utilized, a computation based upon a determination of remaining units. For this there is established a standard of what is “reasonably known, or on good evidence believed, to have existed,” and revision of the estimate from time to time is contemplated. Regulations 111, § 29.23(m)-9 under the 1939 Code. See also, as to other periods, Title 26 C.F.R. § 1.611-2(c) under the 1954 Code, and corresponding sections of prior regulations.
Depletion and depreciation allowances to a large extent are similar and parallel.4 If, in the determination of a deduction for depletion, when computed upon adjusted cost basis, a distinct element of estimate is properly involved and contemplated, the presence of a like element of estimate in the determination of a deduction for depreciation is neither fatal nor disqualifying. Indeed, this has always been so, and one familiar with the application of our income tax laws over a period of years has been aware of recurring adjustments made by the taxpayer or periodically proposed, often on a wide scale, by the Commissioner in even such a common item as building depreciation.
I therefore regard an estimate in the computation of depreciation of an intangible asset, so long as it is reasonable, as much available to the taxpayer as an estimate in the computation of depletion. If and to the extent the Commissioner’s position here would establish a more rigorous standard for depreciation than it does for depletion, that position, I feel,; involves an inconsistency not warranted by the statutes or by the Commissioner’s own successive regulations.
. Revenue Act of 1913, § II G (b); Revenue Act of 1916, § 12(a) Second; Revenue Act of 1918, § 234(a) (7) ; Revenue Act of 1921, § 234(a) (7); Revenue Act of 1924, § 234(a) (7); Revenue Act of 1926, §234 (a) (7); Revenue Act of 1928, § 23 (k) ; Revenue Act of 1932, § 23 (k) ; Revenue Act of 1934, § 23 (l); Revenue Act of 1936, § 23 (l) ; Revenue Act of 1938, § 23 (l); Internal Revenue Code of 1939, § 23 (l) ; Internal Revenue Code of 1954, § 167(a).
. Revenue Act of 3913, § II G(b) ; Revenue Act of 1916, § 12(b) Second; Revenue Act of 1918, § 234(a) (9); Revenue Act of 3921, § 234(a) (9); Revenue Act of 1924, § 234(a) (8); Revenue Act of 1926, § 234(a) (8); Revenue Act of 1928, § 23(l) ; Revenue Act of 1932, § 23(l) ; Revenue Act of 3934, § 23(m) ; Internal Revenue Code of 1939, § 23 (m); Internal Revenue Code of 1954, § 011(a), 20 U.S.C.A. § 611(a).
. Regulations 45, Article 163 under the 1938 Act; Regulations 62, Article 163 under the 3921 Act; Regulations 65, Article 163 under the 1924 Act; Regulations 69, Article 163 under the 1926 Act; Regulations 74, Article 203 under the 1928 Act; Regulations 77, Article 203 under the 1932 Act; Regulations 86, Article 23(l)-8 under the 3934 Act; Regulations 94, Article 23(l)-3 under the 1936 Act; Regulations 101, Article 23(l)— 3 under the 1938 Act; Regulations 103, § 19.23(l)-3 under the 1939 Code; Title 26 C.F.R. § 1.167 (a)-3 under the 1954 Code.
. “In essence the deduction for depletion does not differ from the deduction for depreciation.” United States v. Ludey, 274 U.S. 295, 303, 47 S.Ct. 608, 611, 71 L.Ed. 1054.