§ That there shall be charged for the financial year ending the thirty-first day of March, nineteen hundred and ten, and every subsequent financial year, on the rental value of all rights to work minerals and of all mineral wayleaves, a duty at the rate in each case of one shilling for every twenty shillings of that rental value.
§ The rental value to be taken to be—
- (a) Where the right to work the minerals is the subject of a mining lease, the amount of rent paid by the working lessee in the last working year in respect of that right; and
- (b) Where minerals are being worked by the proprietor thereof, the amount which is determined by the Commissioners of Inland Revenue to be the sum which would have been received as the rent by the proprietor in the last working year if the right to work the minerals had been let and the minerals had been worked to the same extent and in the same manner as they have been worked by the proprietor in that year; and
- (c) In the case of a mineral wayleave, the amount of rent paid by the working lessee in the last working year in respect of the wayleave.