Iwanami Bunko, published 1976, ¥300 This is an old book I found while cleaning out my bookshelf. It's one of the three-part series by Poincaré (the other two have already been sold). I could read it with ease when I was younger, but the old-style kanji and small print size now require a magnifying glass for my aging eyes. There is yellowing due to age, but no damage or tears.