Real or personal property may be granted, bequeathed, devised and conveyed to the city for the purpose of developing, maintaining, expanding, or relocating such museum of art provided for herein, upon such trusts and conditions as may be prescribed by the grantors or devisors thereof and agreed to by such art museum board. All property so devised, granted, bequeathed or conveyed, and the rents, issues, profits and income thereof, shall be subject to the management and control of said art museum board.