The Mayor of the District of Columbia is authorized in his discretion to rent, until their removal becomes necessary, at fair rental values, buildings acquired by the District in the municipal center, and to use such part of the rentals heretofore and hereafter collected as may be necessary for expenses of collection, repairs, and alterations to buildings by day labor or otherwise, expenses of moving and preservation and operating expenses of such buildings as may continue in private occupancy, the balance of the rentals to be covered into the Treasury to the credit of the revenues of the District of Columbia.
