Descartes composing his system of the world, Ren? Descartes at work, signed: Desfontaines (del.); Moret (sculp.); chez Blin, C no. 52, Swebach-Desfontaines, Jacques Fran?ois Joseph (del.); Morret, Jean-Baptiste (sc.); Blin (chez), Antoine Fran?ois Se