View of equipment room in sub-basement, Main Library, Detroit Public Library during construction. Steam pipes, air ducts and fan units visible; construction worker stands in background. Printed on front: "Detroit Library Commission. Addns & alterations to Main Public Library, Stage IV. F.H. Martin Const. Co., contr. Sub basement lkg. west. No. 146. Date: 10-13-64. Win Brunner, photographer."