In this way, before Turner shut up his book he had made over a dozen skeleton designs, which he had only to clothe in colour and light and shade to develop into beautiful pictures. But when he got home and actually set to work to make the drawing of Rochester for the _Rivers of England_ series, he deliberately ignored every one of nature’s pregnant suggestions, and began to build up his own design in his own way. Perhaps he thought nature’s designs wanted more space than he had at his command in a plate that was to be only a few inches square; perhaps it was the sheer delight in the exercise of his creative powers that was the main motive force, for though his sketch-books teem with designs caught in this way on the wing, yet he never once, so far as I can discover, adopted one of them in his own pictures, without so modifying and recasting it as to make it into a quite new and independent construction. I am not at all sure of the exact date when the sketch of Bolton Abbey (Plate LXIV.) was made. It is the sketch upon which the water-colour engraved in the _England and Wales_ series was based. The engraving was published in 1827, so the water-colour must have been made a year or two earlier, but as the sketch occurs in a book which contains a number of the _Devonshire Rivers_ subjects, it probably belongs to about the time of Turner’s second visit to Devonshire. This visit took place in either 1812 or 1813, and the Wharfedale sketches, of which the ‘Bolton’ is one, cannot have been later than 1815. So it is probable that at least ten years elapsed between the making of the sketch and the water-colour drawing in which the sketch was elaborated.