HB book, "Airplane Design", Volume 1, by Alfred Niles,  by Engineering Division U.S. Army Air Service, 1926 (pretty sure a 1st), 495 pages with some b/w illustrations.  Book is in good shape, some minor cover wear, gilt lettering, some fading on spine, binding is good, some yellowing, small owner's address sticker in front, clean pages.  A pretty unique book.