Gurdev Singh, J.

1. This order will dispose of 14 petitioners under this Articles 226 and 227 of the Constitution (Civil Writ Nos. 2198 of 1966 and 159, 206, 416, 438, 439, 443, 484, 517, 518, 636, 2547 and 2720 of 1967), in which common questions of law have been raised. Dr. Shanthi Sarup Sharma and other petitioners have been engaging in and carrying on the business of manufacture and sale of bricks in various parts of the State of Punjab, as it stood before its reorganization in the year 1966. All of them hold valid licences to carry on this trade in accordance with the provisions of the Punjab Control Bricks Supplies Order, 1956, and they are running brick-kilns for manufacture of bricks in the lands, of which some of the petitioners are owners, and the other lessees.

2. In the year 1957 the Parliament enacted the Mines and Minerals (Regulation and Development) Act LXVII of 1957 (hereinafter called the Act ) for regulation of mines and development of minerals under the control of the union . ;In section 3 of the Act "minerals" are defined to include all minerals except mineral oils. Provisions regarding the prospecting licences and mining leases are contained in