RAMASWAMI, J.

This revision petition is filed against the order of the Tribunal setting aside the penalty levied under section 10(b) read with section 10A of the Central Sales Tax Act, 1956. The respondents are dealers registered under the Central Sales Tax Act. They are film producers and processors of cinema films. They purchased an Otis lift for Rs. 20, 630 on 30th September, 1960, by issuing C forms. On the ground that the registration certificate issued under the Central Sales Tax Act did not authorise the purchase of Otis lift by issue of C forms, the Joint Commercial Tax Officer, T. Nagar Division, initiated proceedings under section 10(b) read with section 10A of the Act. The respondents replied by their letter dated 9th May, 1967, that Otis lift purchased by them would come either within the class of articles mentioned in category (b) of the certificate of registration or under category (c) as accessories of plant and machinery necessary to execute the contracts for studio hire. In support of their contention that the lift was indispensable for the manufacturing process carried on in their premises and, therefore, it would come within the class of goods mentioned in category (b), the respondents also filed an affidavit by their technical manager. The Joint Commercial Tax Officer, T. Nagar, in the view that the certificate issued did not authorise the purchase of Otis lift by issue of C forms held that the respondents have committed an offence under section 10(b) and imposed a penalty of Rs. 2, 166.15 under section 10A of the Act. This order was confirmed by the Appellate Assistant Commissioner. But, on further appeal, the Tribunal was of the view that the Otis lift in question was intimately and essentially connected with the manufacturing process carried on in the laboratory of the assessees and that, therefore, it would be deemed to have been included in the registration certificate. Though the Tribunal noted the argument of the respondents that in any case they acted bona fide in the belief that the article in question was covered by the registration certificate, it did not give any finding on that aspect. But, on the finding that the certificate of registration covered such Otis lifts, it held that the offence has not been committed and accordingly set aside the penalty levied. The revenue has preferred this revision petition.The learned Government Pleader submitted that Otis lifts would not be covered by any of the class of goods mentioned in category (b) of the certificate of registration. He also contended that category (c) referred to in the certificate of registration is not available to the respondent, as section 8(3) of the Act has been amended with effect from 1st October, 1958, by Act 31 of 1958, which excluded the goods required for use in the execution of contracts from the category of goods which could be covered by the certificate of registration under that provision. On the other hand, the learned counsel for the respondents contended that Otis lifts will be covered in the class of goods referred to in category (b) of the certificate of registration. In any case, even if the legal position is that after the amendment of section 8 with effect from 1st October, 1958, the goods referred to in category (c) would not be included in the certificate of registration, still since the certificate itself was not called for and amended, the respondents bona fide believed that it could rely on category (c) as well.

The first question, therefore, which arises for consideration is whether the certificate of registration includes Otis lifts either in the class of goods mentioned in category (b) or category (c). Section 8(3) as it stood before the amendment included the following categories of goods for which (c) form declarations could be given. They are goods of the description (i) intended for resale, (ii) for use by the purchaser in the manufacture of goods for sale, and (iii) for use by him in the exec