(1) If the Wealth tax officer, Appellate Assistant Commissioner, Commissioner or Appellate Tribunal in the course of any proceedings under this Act is satisfied that any person (a) has without reasonable cause failed to furnish the return of his net wealth which he is required to furnish under sub section (a) of section 14 or by notice given under sub section (2) of section 14 or section 17 or has without reasonable cause failed to furnish it within the time allowed and in the manner required by sub section (1) of section 14 or by such notice, as the case may be; or (b) . . (c) . . 426 he or it may, by order in writing, direct that such person shall pay by way of penalty (i) in the cases referred to in clause (a), in addition to the amount of wealth tax, if any, payable by him, a sum equal to two per cent of the tax for every month during which the default continued, but not exceeding in the aggregate fifty per cent of the tax; After April 1, 1969 and as on March 18, 1971 on which date the returns were filed "18.