Subsection (2) of section seven of the Income Tax Act, 1945 (which provides that the allowances under section fifteen of the Finance Act, 1937, in respect of mills, factories and other similar premises shall cease in all cases after the year 1950-51) shall have effect and be deemed always to have had effect as if for the words " the next four years of assessment", in both places where those words occur, there were substituted the words " the next nine years of assessment ".