"The great masters were all at an early age great in the mechanical department of their art, before they established any name by their philosophical style and character. Michael Angelo, when a mere youth, modelled and drew in a manner which astonished his own master. Raphael, at not more than nineteen years of age, rivalled his instructor, Pietro Perugino, in his executive talent; and, owing to this, he was enabled, at the age of only twenty-five, to send forth his two great works, _the Dispute on the Sacrament_, and _the School of Athens_. Guido, Bernini, and many others of the first class, pursued the same course of study, and were in the full possession of their powers very young. Vandyke, before he was twenty years old, assisted Reubens in his greatest works; and on a certain occasion, when the pupils of Reubens were amusing themselves in the absence of their master, one of them happened to fall against 'the Mother,' in the Descent from the Cross, which Vandyke repaired in a manner so admirable, that when the painter came next to the picture, he expressed himself surprised at the excellence of his own work, and said, that he thought he had not done that arm so well. In a word, wherever we find the executive power high at an early age, whether in painting or sculpture, we have an assurance of future excellence, which nothing but indolence can prevent. And, to give that early facility correctness of execution, remember and pursue the great maxim of Apelles:-- "'_Nulla dies, sine linea._'