His finished works perhaps appear to you more vague than any other master's: no man loses his outlines more constantly. You will be surprised to know that his frankness in losing depends on his certainty of finding if he chooses; and that, while all other landscape-painters study from Nature in shade or in color, Turner always sketched with the point. "Always," of course, is a wide word. In your copying series I have put a sketch by Turner in color from Nature; some few others of the kind exist, in the National Gallery and elsewhere. But, as a rule, from his boyhood to the last day of his life, he sketched only with the fine pencil point, and always the outline, more if he had time, but at least the outline, of every scene that interested him; and in general, outline so subtle and elaborate as to be inexhaustible in examination and uncopiable for delicacy. Here is a sketch of an English park scene which represents the average character of a study from Nature by Turner; and here the sketch from Nature of Dumblane Abbey for the _Liber Studiorum_, which shows you what he took from Nature, when he had time only to get what was most precious to him. 21. The first thing, therefore, you have to learn in landscape, is to outline; and therefore we must now know precisely what an outline is, how it ought to be represented; and this it will be right to define in quite general terms applicable to all subjects. We saw in the fifth Lecture[5] that every visible thing consisted of spaces of color, terminated either by sharp or gradated limits. Whenever they are sharp, the line of separation, followed by the point of your drawing instrument, is the proper outline of your subject, whether it represents the limits of flat spaces or of solid forms. [Footnote 5: "Lectures on Art, 1870," Sec. 130.] 22. For instance, here is a drawing by Holbein of a lady in a dark dress, with bars of black velvet round her arm. Her form is seen everywhere defined against the light by a perfectly sharp linear limit which Holbein can accurately draw with his pen; the patches of velvet are also distinguished from the rest of her dress by a linear limit, which he follows with his pen just as decisively. Here, therefore, is your first great law. Wherever you see one space of color distinguished from another by a sharp limit, you are to draw that limit firmly; and that is your outline. 23. Also, observe that as your representing this limit by a dark line is a conventionalism, and just as much a conventionalism when the line is subtle as when it is thick, the great masters accept and declare that conventionalism with perfect frankness, and use bold and decisive outline, if any.