Philosopher in his study; At the light coming from an oil lamp; a man in a dark room is studying a book on the table in front of him. Behind the book is a magnifying glass and an open box filled with paper and an hourglass on the table; scholar in his study; magnifying glass; hourglass; Johannes Pieter de Frey (mentioned on object); 1796; paper; etching; h 220 mm x w 167 mm