This is a rare 1915 US Army Ponton Manual. When you use it, handle it gently because the spine is fragile and the binding is loose. To read, just open the book carefully. Since the pages have some soiling and yellowing, avoid getting it dirty further. For maintenance, store it in a dry and cool place. Keep it away from direct sunlight to prevent further damage to the covers and pages. Don't bend the covers too much as they are already curling.