Sometime ago I was at my mother's and she had there a book that someone had offered her, or someone had left there, or someone was about to through it away and she rescued. It was a book she clearly was not interested in. The book looked old, the edition was not very beautiful. The title, in Portuguese, could be translated as something like "For the sake of an inventory" and I think is the translation of the French title. The title of the English version is "The dark brain of Piranesi and other essays". It was the author, Marguerite Yourcenar (an anagram of her real surname, Crayencour), that made me pick it up immediately. And it is true that it contains an essay about a series of Piranesi engravings representing imaginary prisons ( Carceri d'Invenzione ). The subject of this works is mysterious enough and I spent a great deal of time looking at these and other works of Piranesi that can be found easily on the Internet. But as magical as these engraving...