Huygens Title page of Eustachius de Diuinis Septempedanus Pro sua annotatione in systema Saturnium Christiani Hugenii … Christiaan Huygens letter dated 25 Sept. 1659 Christiaan Huygens letter dated 25 Sept. 1659
Title page of Eustachius de Diuinis Septempedanus Pro sua annotatione in systema Saturnium Christiani Hugenii …