Grrr82CU , On the back side of the picture we call the Arno Valley in Leonardo da vinci's writing backwards shows proof of the "Y" being used in the name "MARY". by L;eonardo The writing says " Leonardo’s study of the landscape began early in his artistic career. The inscription on this drawing, written in Leonardo’s characteristic mirror-writing reads, [b]“(feast) of Saint Mary of the Snow/ - day of August 5th, 1473”. [/b]As such, it is Leonardo’s earliest surviving drawing, executed when he was just 21 years old.