Sabyasachi Mukharji, J.
1. This is an application under Article 226 of the Constitution challenging the rectification proceedings under Section 154 of the Income-tax Act, 1961. For the assessment year 1963-64, the petitioner filed its return of income along with and supported by its audited profit and loss account, balance-sheet, depreciation statement and various other statements. The petitioner is a company and carries on business of manufacture and sale of safety razor blades, steel files, bandsaws, small tools and other articles. The petitioner alleges that during the course of the said assessment proceedings for the said assessment year before the Income-tax Officer the petitioner produced and/or caused to be produced various books of accounts, papers and other documents and had given various explanations, information and evidence that was necessary and/or required by the Income-tax Officer. The petitioner contends that the petitioner disclosed all primary facts and material facts necessary for the proper assessment. Since the assessment year 1952-53 onwards including the assessment year 1963-64 the petitioner had claimed and had been allowed depreciation at the special rate of 10 per cent., inter alia, on the machinery meant for and used in the manufacture of safety razor blades from steel strips under the Indian Income-tax Act, 1922^ and the Income-tax Act, 1961. For the assessment year 1963-64 the petitioner was assessed at a total income of Rs. 42,17,021 under Section 143(3) of the Income-tax Act, 1961. In so assessing the petitioner the Income-tax Officer had allowed the petitioner depreciation on the said machinery amongst other things at a special rate of 10 per cent. For the said assessment year certain additions were made and certain amounts were disallowed. Being aggrieved by the said assessment order the petitioner preferred an appeal before the Appellate Assistant Commissioner. The Appellate Assistant Commissioner passed an order dated 20th July, 1968, directing the Income-tax Officer to revise the assessment in accordance with the directions given by the Appellate Assistant Commissioner. On the 20th October, 1970, the Income-tax Officer served upon the petitioner a notice issued under Section 154/155 of the Income-tax Act, 1961, for the assessment year 1963-64 wherein it was stated that the said assessment required rectification as there was a mistake apparent from the record. The nature of the mistake proposed to be rectified was ' mistake in computation of depreciation '. It has been stated by the petitioner in its petition that on 27th October, the petitioner appeared before the Income-tax Officer and the said officer informed the petitioner that the allowance of special depreciation on machinery for manufacture of safety razor blades at the rate of 10 per cent, was incorrect and excessive and was done inadvertently and erroneously inasmuch as the said machinery was entitled to the allowance of depreciation at the general rate of 7 per cent. The petitioner by its letter dated 27th October, 1970, recorded the said fact and stated that the notice did not disclose necessary particulars of the mistakes. The petitioner further stated that the petitioner was allowed depreciation at the special rate of 10 per cent, inasmuch as the manufacture of safety razor blades from steel strips was an ' iron and steel industry'. The petitioner stated that according to item III(ii) I(3)(b) of Appendix I of the Income-tax Rules, 1962, machinery and plant used in an ' iron and steel industry ' was entitled to special depreciation allowance at the rate of 10 per cent, and not at the general rate of 7 per cent. The petitioner contended that there was no mistake apparent from the record in the computation of depreciation relating to the relevant assessment year. The petitioner submitted in any event the question whether on the aforesaid plant and machinery depreciation at the special rate of 10 per cent, should be allowed or not depended on the interpretation to be given to the particular item, namely, 'iron and steel industry ' of Appendix I of the said rules arid, as such the question of interpretation could not be a mistake apparent from the record. In the premises the petitioner submitted that the proceedings under Section 154 of the Income-tax Act, 1961, were without jurisdiction. It has been alleged that the Income-tax Officer adjourned the case up to November 6, 1970, and was not inclined to accept the petitioner's contention. Thereupon, the petitioner has moved this court under Article 226 of the Constitution challenging the said proceedings.
2. Two points were taken in the petition, firstly, that there was no mistake apparent from the record and as such Section 154 of the Income-tax Act, 1961, had no application, and, secondly, that after the assessment order had merged in the order of the Appellate Assistant Commissioner, the Income-tax Officer had not retained the jurisdiction to take steps for rectification. At the hearing of this application no argument was advanced before me on the second aspect mentioned hereinbefore and counsel for the petitioner confined his submissions only on the first point. I, therefore, need not consider the second question at all. The short question with which I am concerned in this application, is whether, in the facts and circumstances of this case, the mistake that was proposed to be rectified was a mistake apparent from the record. Section 154 of the Income-tax Act, 1961, gives the authorities named in the section powers to rectify any mistake apparent from the record. Therefore, the exercise of the power is dependent upon there being a mistake apparent from the record. It is the case of the petitioner that the proposed mistake, namely, the question whether depreciation should be allowed at the special rate of 10 percent, or at the general rate of 7 per cent, is not a question which is obvious or apparent. Counsel for the petitioner drew my attention to certain authorities to which I would refer later in the judgment. Counsel for the respondents on the other hand contended that at this stage only a notice had been given and no order had yet been passed, and, therefore, at this stage it was premature. Secondly, it was urged on behalf of the respondents that there was no question of interpretation here. It was a question of application of certain provisions of the Income-tax Rules and it was apparent, according to counsel for the respondents, that the petitioner-company, on the facts disclosed, was not entitled to depreciation at the special rate. It was lastly urged that the notice was not a condition precedent for proceedings under Section 154 of the Income-tax Act, 1961, and as such it was not a question of jurisdiction and the court should not interfere at this stage. Reliance was placed on the Bench decision of this court in the case of Giridharilal Jhajkaria v. Commissioner of Income-tax,  18 I.T.R. 133 (Cal.).
3. The short question with which I am concerned in this application, as mentioned before, is whether the mistake proposed to be, rectified comes within the purview of Section 154 of the Income-tax Act, 1961. Appendix I of the Income-tax Rules, Part I, provides the statement at which depreciation is allowed. Item III is in the following terms ' Machinery and plant ' and the general rate allowed as mentioned is 7 per cent. In Clause (ii) of item III certain items have been ' mentioned where special rates are to be applied to the whole of the machinery and plant used in certain named concerns and under the heading ' I ' comes the ' Iron & Steel Industry ' which has three sub-clauses. The Iron & Steel Industry is divided into two heads--one is rolling mill rolls which is category (a) where the depreciation is nil and the other is category (b) which is 'other machinery and plant (blast furnace plant, steel making plant, steel rolling plant, forges, generators, boilers and sheet mills) '. These are allowed depreciation at 10 per cent. From the petition and the averments made therein and the statements made in the affidavit-in-opposition it is apparent that the mistake that is proposed to be rectified is dependent on the question whether the machinery used for production of safety razor blades can be said to be part of ' Iron & Steel Industry ' and can come within category (b) mentioned hereinbefore. This requires interpretation of the expression ' other machinery and plant '. It was contended that other machinery and plant was intended to cover all machinery used in iron & steel industry apart from the rolling mill rolls. It was urged that otherwise there was no purpose of using the expression ' other '. It was further urged that in respect of this machine-rolling mill roll only nil depreciation was allowed for special reasons mentioned in the column of remarks. On the other hand it was urged on behalf of the respondent that the particular items mentioned within the brackets in III(i)(1)(3)(b) of Appendix I mentioned hereinbefore were exhaustive of the other machinery and plant included in the heading ' Iron & Steel Industry '. This is surely a question which requires, firstly, an interpretation of the expression ' other machinery and plant ' and, secondly, the nature of the machinery and plant used by the petitioner-company and whether they come within the expression ' other machinery and plant ' or as well as under the items mentioned within the brackets. This will require investigation, in my opinion, both of facts as well as interpretation of law. It is not necessary for me to decide the question whether the petitioner's plant and machinery used for safety razor blades merit depreciation under this head or come under the general head of plant and machinery. But in view of the language used it appears to me that it cannot be said that it is an obvious and apparent mistake which is self-evident and does not require either a process of argument or investigation. If that is the position in law then, in rny opinion, proceedings under Section 154 cannot be initiated. Reliance may be placed for this proposition on the decision of the Supreme Court in the case of Maharana Mills (Private) Ltd. v. Income-fax Officer, Porbandar, : 36ITR350(SC) . The Supreme Court observed at page 358 of the report:
' The power under Section 35 of the Income-tax Act is no doubt limited to the rectification of mistakes which are apparent from the record. A mistake contemplated by the section is not one which has to be discovered as a result of an argument but it is open to the Income-tax Officer to examine the record including the evidence and if he discovers any mistake he is entitled to rectify the error provided that if the result is enhancement of assessment or reducing the refund then notice has to be given to the assessee and he should be allowed a reasonable opportunity of being heard.'
4. Therefore, it has to be a mistake which is not necessary to discover as a result of an argument. Reliance may be placed on the Bench decision of the Bombay High Court in the case of National Rayon Corporation Lid. v. G. R. Bahmani, Income-tax Officer,  56 I.T.R. 114 (Bom.) Bombay, where the High Court of Bombay held that the jurisdiction of the Income-tax Officer to make an order for rectification under Section 35 of the Indian Income-tax Act, 1-922, of which the corresponding provision is Section 154 of the Income-tax Act, 1961, depended upon the existence of mistake apparent from the record. That mistake need not be a clerical or mathematical mistake. It might be a mistake of fact as well as a mistake of law. A mistake would become a mistake apparent from the record when it was a glaring, obvious or self-evident mistake, A mistake which had to be discovered by a long drawn process of reasoning or examining arguments on points, where there might conceivably be two opinions, could not be said to be a mistake or error which was apparent from the record. In the case of Volkart Brothers v. Income-tax Officer, Companies Circle IV(4), Bombay,  65 I.T.R. 179 (Bom.) more or less the same position was reiterated by the Bombay High Court. In the case of P. M. Bharucha & Co. v. G. S. Venkatesan, Income-tax Officer, Circle I, Ward A, Bhavnagar,  74 I.T.R. 313 (Guj.) the Gujarat High Court reiterates almost the same position. It, therefore, appears to me that the mistake, if any, in this case is one which cannot be called either obvious or glaring or self-evident. It is a mistake which appears from the record, but it is not apparent. It is a mistake which has to be discovered after interpretation of a certain section and investigation of certain facts. In the premises there cannot be any jurisdiction for the Income-tax Officer to take proceedings under Section 154 in view of the facts disclosed. Counsel for the respondent contended that at this stage only a notice had been given and it was premature for the petitioner to come to this court at this stage. In view of the undisputed facts it appears however that the proceedings under Section 154 of the Income-tax Act, 1961, are without jurisdiction. I am of opinion that the petitioner is entitled to maintain this application and it cannot be said that the application is premature. It has been held that where on undisputed facts a proceeding is without jurisdiction the aggrieved party is entitled to come at the earliest stage and need not await the completion of the whole proceeding So far as the decision of this court in the case of Giridharilal Jhajkaria v. Commissioner of Income-tax, referred to hereinbefore, is concerned, I am of opinion that that was entirely in a different context. That case was dealing with the question whether service of a notice was a condition precedent for taking proceedings under Section 154. The court held that the section made it clear that it was not. But where on undisputed facts it is apparent to the court that there is no mistake apparent from the record, Section 154 cannot be invoked and the proceedings would be without jurisdiction.
5. In that view of the matter I am of the opinion that counsel for the respondents cannot draw much support from the aforesaid Division Bench judgment of this court. In the view I have taken, this application must succeed and the proceedings taken pursuant to the notice dated the 19th September, 1970, are quashed. Let a writ of certiorari issue accordingly. The respondents are restrained from taking steps pursuant to the said notice. Let a writ of mandamus issue accordingly.
6. The rule Is made absolute to the extent indicated above. There will be no order as to costs.