19. (1) The Commissioner may of his own motion call for the record of any proceeding under this Act which has been taken by any Excess Profits Tax Officer or Appellate Assistant Commissioner subordinate to him, and on receipt of the record may make such enquiry, or cause such enquiry to be made, and, subject to the provisions of this Act, may pass such orders thereon (including an order enhancing an assessment) as he thinks fit: Provided that he shall not pass any order prejudicial to a person to whose business this Act applies without hearing him, or giving him a reasonable opportunity of being heard. (2) On the coming into operation of Part II of the Indian Income-tax (Amendment) Act, 1939, sub-section (1) shall cease to have effect, but thereafter any Excess Profits Tax Officer or any person in respect of whose business an order under section 14 has been passed who objects to an order passed by an Appellate Assistant Commissioner under section 16 or section 17 may, within the prescribed time and in the prescribed manner, appeal against such order to the Appellate Tribunal constituted under the Income tax Act, 1922 . (3) The Appellate Tribunal shall determine the appeal after giving both parties to the appeal an opportunity of being heard. If the Appellate Tribunal is not satisfied that the assessment, decision or order which is the subject of appeal ought to be interfered with, it shall reject the appeal and the assessment, decision or order shall stand good. If it is satisfied that the assessment, decision or order ought to be interfered with, it shall, subject to the provisions of this Act, pass such orders as it thinks fit, and such orders may include an order enhancing the assessment or penalty: Provided that an order enhancing an assessment or penalty shall not be made unless the person affected thereby has been given an opportunity of showing cause against the enhancement.