§ 2. "That in lieu of the duty chargeable under Section nine of the Roads Act, 1920, in respect of general licences isued under that Section, there shall, in the event of the Minister of Transport in pursuance of any powers which may be conferred upon him issuing two different sets of regulations applicable to such licences, be chargeable in respect of such licences duty at the following yearly rates:—
§ duties at rates which shall be fixed by the Treasury after consultation with the Minister of Health and the Secretary for Scotland, and which shall be such that the duties levied under the said Act shall not exceed the amount required to meet the costs incurred in respect of the remuneration (including superaanuation allowances) and 999 expenses of the inspectors, and otherwise in connection with inspection under the said Act, and different rates of duty may be fixed as respects different classes of works."