Submission of plans for new institutions; investigation of institutions.

All plans for new institutions shall, before adoption of the same, be submitted to the Board of Public Welfare for suggestion and criticism. The Mayor of the District of Columbia may at any time order an investigation by the Board, or a committee of its members, of the management of any penal, charitable, or reformatory institution in the District of Columbia; and said Board, or any authorized committee of its members, when making such investigation, shall have power to send for persons and papers and to administer oaths and affirmations; and the report of such investigation, with the testimony, shall be made to the Mayor.