We have spoken of the book as an attack on Claude, and of the “intention” of the work, but we are not sure that we are not using too definite ideas to express the variety of impulses in Turner’s mind that tended to the commencement of the “Liber.” We have seen that the first notion of it, and its divisions, were suggested by Mr. Wells, and the plates are nothing more nor less than a selection from his sketches and pictures, arranged under these heads. His early topographical drawings and studies in England provided him with the architectural and pastoral subjects, his studies of Claude and the Poussins and Wilson, with the elegant pastoral, Vandevelde and nature with the marine, and his one or two visits to the Continent with the mountainous. The frontispiece, the first attempt to give a coherent signification to the whole, was not published till 1812, and it was not till 1816 that the advertisement to which we have called attention appeared when, after four years’ intermission, the issue of the “Liber” was recommenced; even then it is only described as “an illustration of Landscape Composition;” and it is quite probable that the desire to make money, to display his art, to rival Claude, and to educate the public, contributed to the production of the work, without any very vivid consciousness on his part as to his motives of action. It has, like all Turner’s work, the characteristics of a gradual growth rather than of the carrying out of a well-defined conception.