Chapter I: , Of the Open Sky

§ 1. The peculiar adaptation of the sky to the pleasing and teaching of man. 204 § 2. The carelessness with which its lessons are received. 205 § 3. The most essential of these lessons are the gentlest. 205 § 4. Many of our ideas of sky altogether conventional. 205 § 5. Nature, and essential qualities of the open blue. 206 § 6. Its connection with clouds. 207 § 7. Its exceeding depth. 207 § 8. These qualities are especially given by modern masters. 207 § 9. And by Claude. 208 § 10. Total absence of them in Poussin. Physical errors in his general treatment of open sky. 208 § 11. Errors of Cuyp in graduation of color. 209 § 12. The exceeding value of the skies of the early Italian and Dutch schools. Their qualities are unattainable in modern times. 210 § 13. Phenomena of visible sunbeams. Their nature and cause. 211 § 14. They are only illuminated mist, and cannot appear when the sky is free from vapor, nor when it is without clouds. 211 § 15. Erroneous tendency in the representation of such phenomena by the old masters. 212 § 16. The ray which appears in the dazzled eye should not be represented. 213 § 17. The practice of Turner. His keen perception of the more delicate phenomena of rays. 213 § 18. The total absence of any evidence of such perception in the works of the old masters. 213 § 19. Truth of the skies of modern drawings. 214 § 20. Recapitulation. The best skies of the ancients are, in quality, inimitable, but in rendering of various truth, childish. 215 Chapter II., Of Truth of Clouds:—First, of the Region of the Cirrus. § 1. Difficulty of ascertaining wherein the truth of clouds consists. 216 § 2. Variation of their character at different elevations. The three regions to which they may conveniently be considered as belonging. 216 § 3. Extent of the upper region. 217 § 4. The symmetrical arrangement of its clouds.[Page lxiii] 217 § 5. Their exceeding delicacy. 218 § 6. Their number. 218 § 7. Causes of their peculiarly delicate coloring. 219 § 8. Their variety of form. 219 § 9. Total absence of even the slightest effort at their representation, in ancient landscape. 220 § 10. The intense and constant study of them by Turner. 221 § 11. His vignette, Sunrise on the Sea. 222 § 12. His use of the cirrus in expressing mist. 223 § 13. His consistency in every minor feature. 224 § 14. The color of the upper clouds. 224 § 15. Recapitulation. 225