i. ch. v. § 12, sec ii. ch. ii. § 18; vol. iv. pt. v. ch. xvi. § 24). These remarks cannot be better illustrated than in the present picture. Abraham and Isaac--the former with a lighted torch, the latter with the wood--are ascending the hill on the right to the sacrifice; while Abraham's two servants await his return below. The whole spirit of the picture is "solemn and unbroken," in perfect harmony with the subject. But it is kept from being a really grand picture by the "hopeless want of imagination" in the forms of the clouds, the colour of the sky, and the treatment of the distant landscape. These painters, says Ruskin, looked at clouds, "with utter carelessness and bluntness of feeling; saw that there were a great many rounded passages in them; found it much easier to sweep circles than to design beauties, and sat down in their studies, contented with perpetual repetitions of the same spherical conceptions, having about the same relation to the clouds of nature, that a child's carving of a turnip has to the head of the Apollo.... Take the ropy, tough-looking wreath in the 'Sacrifice of Isaac,' and find one part of it, if you can, which is not the repetition of every other part of it, all together being as round and vapid as the brush could draw them" (_Modern Painters_, vol. i. pt. ii. sec. iii. ch. iii. § 8). Equally deficient is the colour of the sky:-- "It is here high noon, as is shown by the shadow of the figures; and what sort of colour is the sky at the top of the picture? Is it pale and gray with heat, full of sunshine, and unfathomable in depth? On the contrary, it is of a pitch of darkness which, except on Mont Blanc or Chimborazo, is as purely impossible as colour can be. He might as well have painted it coal-black: and it is laid on with a dead coat of flat paint, having no one quality or resemblance of sky about it. It cannot have altered, because the land horizon is as delicate and tender in tone as possible, and is evidently unchanged; and to complete the absurdity of the whole thing, this colour holds its own, without gradation or alteration, to within three or four degrees of the horizon, where it suddenly becomes bold and unmixed yellow. Now the horizon at noon may be yellow when the whole sky is covered with dark clouds, and only _one_ open streak of light left in the distance from which the whole light proceeds; but with a clear, open sky, and opposite the sun, at noon, such a yellow horizon as this is physically impossible.... We have in this sky (and it is a fine picture, one of the best of Gaspar's that I know) a notable example of the truth of the old masters--two impossible colours impossibly united!... Nor is this a solitary instance; it is Gaspar Poussin's favourite and characteristic effect" (_ibid._, vol. i. pt. ii. sec. iii. ch. i. § 10).