Padmanabhan, J.

The question that arises for consideration in this writ appeal is whether the porcelain shells which are used in the manufacture of lightning arresters by the respondents, Messrs W.S. Insulators of India Ltd., are liable to excise duty under tariff item 23-B of the First Schedule to the Central Excises and Salt Act.

2.The respondents manufacture, among others, lightning arresters with the technical collaboration of Messrs Westing House Electric International Company, U.S.A. For the purpose of manufacturing the lightning arrester the respondents also manufacture what is called a shell made of porcelain; shells are manufactured according to a particular design for use in the manufacture of lightning arresters. The appellants sought to levy excise duty on these porcelain shells on the basis that they constituted porcelainware within the meaning of tariff item 23-B of the First Schedule of the Central Excises and Salt Act. It may be stated in this context that the respondents have a licence under the Act for the manufacture of chinaware and porcelainware which are excisable under tariff item 23-B, of the First Schedule to the Act. The respondents opposed the l