National Geographic : 2019 May
The engineering for this gilded copper ball, completed during his apprenticeship with artist Andrea del Ver- rocchio in Florence, made a lasting impact on Leonardo da Vinci. Checking for light- ning damage, Sandro Schievenin emerges from the sphere atop the Cathedral of Santa Maria del Fiore. PREVIOUS PHOTO Leonardo’s “Mona Lisa” is believed to depict Lisa Gherardini, the wife of Francesco del Giocondo, a Florentine silk merchant. Every year, millions of visitors jostle for a view at the Louvre Museum in Paris. The painting, pro- tected by a thick layer of glass that must be cleaned regularly, has never been restored.