In one of the many anecdotes told of Turner he is represented as saying to an artist who had complained of the disappointment he had experienced on revisiting a certain place, “Don’t you know you must paint your impressions”--or words to that effect. I don’t know how true the story is--and I may confess that I have almost got into the habit of disbelieving _all_ the stories told about Turner--but whether true or not this particular anecdote is certainly well invented. Turner knew quite well how large a part his subjective feelings and ideas played in all his work, and it made him shy of revisiting places that had once impressed him. But when he spoke of his “impressions” we must be careful not to suppose that he could have used the expression in the way it is often used now. He did not abstract his particular visual impressions from the emotional and ideational context in which they were experienced. In so far as Impressionism means this kind of abstraction, Turner was never an impressionist. And as his first ideas of places were steeped in the colouring of his own subjective life, so his ideas were ever taking on different hues as his temper and character changed. In this way he could use the same sketch again and again and always get different effects from it; the sensuous datum was merely a point of departure for each fresh improvisation, a form into which he could pour his meditations, but a flexible, plastic form which readily took the shape of its spiritual content. These considerations may help us to understand what is apt at first to strike the student of Turner’s drawings and sketches as strange and incomprehensible. Turner was always sketching from nature, and often making drawings that contain an amazing wealth of detail and definition, yet the usefulness of his sketches seemed to vary in inverse ratio to their definition and to the time spent upon them. The beautiful drawings never seemed to lead to anything, all the pictures being painted by preference from the slightest and vaguest sketches. Thus the sketch book which contains the sketch of _Norham Castle_ is filled with over ninety drawings, most of them full of detail and delightfully precise and graceful in handling. Turner made good use of most of this material, but the most prolific “breeding” subject--to use one of Richard Wilson’s expressions--was unquestionably the hurried scribble of Norham, which was so slight as not to indicate even the general shape of the ruined tower with precision, and which left the number of windows or embrasures entirely undetermined. But when we see how Turner used his sketches we can easily understand that this absence of definition must often have been a positive advantage to him when he came to paint his pictures. There was less “to put him out,” fewer obstacles in the way of his subjective utterance, the form was more fluid and tractable to his immediate purpose. The more detailed studies were of course not wasted,