It is in these painterly preconceptions of the characters and in Polypthon's account of Scottish scenery (pp. 23-4) that hints of Gilpin's later career are announced: the second edition of the _Dialogue_ even talks of his "Observations" on Stowe, a term that became a standard ingredient in the titles of his picturesque tours. The education of sight by the study of paintings and prints was clarified and expounded in the _Essay on Prints_, written at least by 1758 and published ten years later. The picturesque tours themselves were started in the 1770s and published from 1782 onwards. In them Gilpin refines and enlarges upon the methods and ideas of his Stowe _Dialogue_. The adjudication between a taste for natural beauties (what his _Three Essays_ term the "correct knowledge of objects")[15] and the inclination to adjust them according to painterly criteria (in 1792 termed "scenes of fancy") is more sophisticated and consistent. He still delights in the variety of a landscape; but the roughness that Stowe only occasionally allowed becomes one of his guiding rules in appraising scenery. Perhaps the most significant items in the _Dialogue_ for readers of Gilpin's later writings will be his psychological emphasis and his attention to verbal and visual associations. Although his picturesque tours never entirely neglected the topographical obligation to describe actual localities, it is increasingly an imaginative response to landscape that is his concern.[16] In the _Dialogue_ he explained how a good imagination will "improve" upon the sight of a grand object, just as Burke a few years later was to discuss the essential vagueness of the sublime and its appeal to the private sensibility. Polypthon's reactions at Stowe suggest something of this potential in contradistinction to Callophilus' ability to read the message of each temple or vista. What Gilpin displays in 1748 is more intricately adumbrated in the _Three Essays_ of 1792: a scene may strike "us beyond the power of thought ... and every mental operation is suspended. In this pause of intellect, this deliquirium of the soul, an enthusiastic sensation of pleasure over spreads it ...".[17] As the final pages of _Dialogue_ suggest, that experience was also available in the gardens of Stowe. But the more mature imagination in Gilpin is tempted simultaneously in two directions, which perhaps explains why one contemporary was moved to commend the published tours for being "the Ne plus ultra of the pen and pencil united."[18] At Stowe he is attentive to the expressive potential of scenery and its associations ("The Eye naturally loves Liberty" [p. 54]), which are best expounded in the written commentary. But he also delights in the shapes and forms of scenery, the abstract qualities of the Stowe landscape that please the eye rather than the mind's eye. These are best recorded in his watercolours and the illustrations which become a main feature of his later books.