10. Commissioners of Wealth- tax. The Board may empower as many persons as it thinks fit to exercise under this Act the functions of a Commissioner of Wealth- tax, and on being so empowered the Commissioners of Wealth- tax shall perform their functions in respect of such areas or such persons or such classes of persons as the Board may direct and where such directions have assigned to two or more Commissioners the same area or the same persons or the same classes of persons they shall have concurrent jurisdiction 1[ and shall perform such functions in relation to the said area or persons or classes of persons as the Board may, by general or special order in writing, specify, for the distribution and allocation of the work to be performed].