scale, and in common things, the phenomenon is of constant occurrence; the "dirt bands" on a glacier, for instance, are not to be counted on the glacier itself, and yet their appearance is truly stated by Professor Forbes to be "_one of great importance_, though from the two circumstances of being _best seen at a distance_, or considerable height, and in a feeble or slanting light, it had very naturally been overlooked both by myself and others, like what are called blind paths over moors, visible at a distance, but lost when we stand upon them."[29] Sec. 14. Not only, however, does this take place in a picture very notably, so that a group of touches will tell as a compact and intelligible mass, a little way off, though confused when seen near; but also a dark touch gains at a little distance in apparent _darkness_, a light touch in apparent _light_, and a colored touch in apparent color, to a degree inconceivable by an unpractised person; so that literally, a good painter is obliged, working near his picture, to do in everything only about half of what he wants, the rest being done by the distance. And if the effect, at such distance, is to be of confusion, then sometimes seen near, the work must be a confusion worse confounded, almost utterly unintelligible; hence the amazement and blank wonder of the public at some of the finest passages of Turner, which look like a mere meaningless and disorderly work of chance; but, rightly understood, are preparations for a given result, like the most subtle moves of a game of chess, of which no bystander can for a long time see the intention, but which are, in dim, underhand, wonderful way, bringing out their foreseen and inevitable result.