With the written approval of the Governor, the Science Museum of Virginia and the Department of General Services are hereby authorized to effect a conveyance of a strip of land containing approximately 0.508 acres located on the north side of Leigh Street in the City of Richmond in exchange for a permanent nonexclusive easement for a railroad spur line or track on, over and across adjacent property to the west.  Any agreement, deed or other instrument shall be approved as to form by the Attorney General.