( 1 ) THE petitioner was holder of a quarry lease for lime stone for a period of five years commencing from 3rd November, 1961. Under Clause (3) of the lease, he was liable to pay royalty at the rate of 10 per cent of the sale value at the pit's mouth subject to a minimum of 0. 50 paise per ton for lime stone, 0. 75 paise per ton for slacked lime and Re. 1 per ton for unslacked lime. This was also the rate of royalty then prescribed for lime stone in Schedule I to the Madhya Pradesh Minor minerals Rules, 1961. There was a proviso to Clause (3) of the lease, which enabled the lessor to revise the rate of royalty every five years commencing from the date of the lease. By a notification dated 9th December, 1965 Schedule I to the Minor Minerals Rules was amended by the State Government and the rate of royalty for lime stone was fixed at Rs. 2 per tonne from 1st January, 1966. For the period after 1st January, 1966, the petitioner was assessed to royalty by the mining Officer at the rate of Rs. 2 per tonne. The petitioner protested and claimed that in his case the rate of royalty could not be revised before expiry of five years, and that he was governed by the rate of royalty