The Central Government's power to enhance royalty on a mineral under Section 9(3) of the Mines and Minerals (Regulation and Development) Act, 1957, is limited by proviso (b), which restricts such enhancement to once during any period of four years. The enhancement of royalty in respect of one grade of a mineral would be considered an enhancement of royalty in respect of that mineral, and further enhancement of royalty even in respect of the other grade would be governed by the proviso.

V. P. TYAGI, J.

( 1 ) ALL the three petitioner companies in these three separate writ petitions are quarrying lime-stone from the areas leased out to them and therefore all of them have challenged the validity of the notification dated 29th January, 1970, issued by the Union of India whereby item No. 8 in the Second Schedule of the Mines and minerals (Regulation and Development) Act, 1957 (hereinafter called the Act) has been amended. Since common questions of law are raised in all these petitions, I propose to dispose them of by one judgment.

( 2 ) PETITIONER companies have been holding areas in their respective fields of operation under the mining lease granted to them for quarrying limestone. The contention of the petitioners is that the limestone quarried by each one of them is of inferior grade with less than 45% calcium oxide. Section 9 of the Act lays down that the holder of a mining lease shall pay royalty on the mineral in accordance with the rates for the time being specified in the Second Schedule in respect of that mineral. Sub-section (3) of this section empowers the Central Government to amend the Second Schedule by issuing a notification so as to enhance or reduce the rate at which royalty shall be payable in respect of any mineral with effect from such date as may be specified in the notification, but a rider has been put by the statute on this power of the Central Government by adding a proviso thereto which lays down that the Central Government shall not (a) fix the rate of royalty in respect of any mineral so as to exceed twenty per cent of the sale price of the mineral at the pits head, or (b) enhance the rate of royalty in respect of any mineral more than once during any period of four years.

( 3 ) WHEN the said Act came into force from 1st of June, 1958, the rate of royalty specified for limestone in the Second Schedule was as follows: 5% of the sale price at the pits mouth subject to a minimum of 37 paise per tonne.

( 4 ) IN the year 1962 this item in the Second Schedule was amended by the Central government by issuing a notification on 31st of October, 1962, whereby the rate of royalty for limestone was fixed thus: re. 0. 75 per tonne, but subject to a rebate of Re. 0. 38 per tonne to be given on limestone beneficiated by froth floatation method.

( 5 ) THE system of granting rebate on the royalty of limestone as was provided in 1962 was, however, abolished in the year 1968 and the Central Government by issuing another notification dated 29th June, 1968, amended item No. 8 of the second Schedule as follows:

"8. Limestone - (a) Superior grade one rupee twenty with 45 % or more five paise per cao. tonne. " (b) Inferior grade with less than 45% cao. Seventy-five paise per tonne. "

( 6 ) BY issuing the impugned notification dated 29th January, 1970, the Central government abolished the two grades of limestone as specified in the Second schedule and laid down that henceforward item No. 8 in the Second Schedule shall be read as follows: "8. Limestone--One rupee and twenty-five paise per tonne. "

( 7 ) THE grievance of the petitioner companies is that by issuing the impugned notification the two grades of limestone have been abolished by the Central government and the result of it is that the rate of royalty on the inferior grade of limestone having content of less than 45% Cao is enhanced from Re. 0. 75 per tonne to Rs. 1. 25 per tonne. According to the petitioners, this power of enhancing the rate of royalty could not be used by the Central Government before the expiry of four years from 29th June, 1968, when the last notification was issued by the central Government in the exercise of its power under proviso (b) to Sub-section (3) of Section 9 of the Act. In these circumstances, this last notification is challenged on the ground that the Central Government had no authority to enhance the rate of royalty on limestone of inferior grade before the expiry of four years from the date of the last notif