'There is a pleasure in painting which none but painters know.' In writing, you have to contend with the world; in painting, you have only to carry on a friendly strife with Nature. You sit down to your task, and are happy. From the moment that you take up the pencil, and look Nature in the face, you are at peace with your own heart. No angry passions rise to disturb the silent progress of the work, to shake the hand, or dim the brow: no irritable...