It is difficult to define the exact relationship of Turner’s love for his art, with his passionate and unwearying study of natural phenomena. My own impression is that his love of nature was at best to some extent subordinate to his love of art; that he loved nature partly at least as a means to artistic expression, and not altogether for itself. But however this may be, the extent of his knowledge of, and intimate familiarity with, nature’s ways counts for much in the attractions of his pictures. The evidence of his keen though intermittent study of natural phenomena is writ large in the collection of his sketch-books. The very extent of his knowledge, no doubt, led at times to a certain overcrowding of his works, but it forms the secret of his supple and ample style, and the inexhaustible fecundity of his invention. It is then to the magic of his style that Turner’s later works owe a great deal of their strange power of compelling attention and extorting a sometimes unwilling admiration. He had in a quite pre-eminent degree what Reynolds has called the genius of mechanical execution. And this power is as remarkable in his earlier works as in his later. But in his earlier works this power was used to give definite embodiment to a range of worthy and significant ideas and emotions, and the sheer beauty of their content is apt to divert our attention from the consummate skill implied in this rarest and highest artistic achievement. But in the later work the very weakness and poverty of the content has the effect of keeping our attention fixed upon the suggestiveness and visual beauty of the material elements of expression. In the poetry of the French Symbolists we see a somewhat similar effect consciously aimed at. The poverty of thought is used as a foil to throw the greatest possible emphasis on the beauty of sounds and the faint suggestions of individual words. In this way the attenuation of significance in Turner’s later works throws into startling prominence all the innate and intrinsic splendours of the painter’s palette. We shall have occasion to amplify and illustrate these observations as we trace the gradual development of Turner’s later manner, the task to which we have now to address ourselves. * * * * * I have alluded above to what I regard as the first oil painting in which the change that took place in Turner’s artistic aims about the year 1830 was clearly indicated. This was the ‘Calais Sands, low water,’ exhibited at the Royal Academy in May, 1830. But before painting this picture Turner had been experimenting in his new manner in a series of water-colour sketches. These sketches were made at Petworth, where Turner went to stay for a few weeks with Lord Egremont, probably in 1829, after his return from his second journey to Italy.