( 1 ) THE petitioner in this case, the National Tobacco Co. of India Ltd. , carries on the business of manufacturing cigarettes and tobacco at Agarpara, in 24 Parganas. As such manufacturer, it has to pay excise duty on the value of cigarettes manufactured by it. In this case, we are not concerned with anything else. The rate at which the excise duty is levied, changes from time to time, and it is unnecessary for me to go into the details thereof. It is sufficient to say that at the relevant time, which concerns the years 1955 to 1957, the duty was levied upon a slab system. For example, if the price was within a slab exceeding Rs. 10/- but not exceeding Rs. 15/-per thousand, then there was a particular rate of duty to be charged. If, however, the price was within the next slab, namely higher than Rs. 15/-but not exceeding Rs. 20/- per thousand, then the duty payable is very much more. It follows that if the price is even a few annas more than the maximum limit of the slab, the rate of duty becomes calculable at the higher rate. It is, there-fore, to the interest of the manufacturer to keep the value within the lower slab, and it is always the headache of the Excis