Many who are familiar with this simile have never been at the pains to remember, or enquire, what it illustrates. Indeed its appearance in the poem is almost startling, as if it were there for no purpose but to prophesy of the coming glories of English poetry. The visitors to the Castle of Indolence are met at the gate by the porter, who supplies them with dressing-gowns and slippers, wherein to take their ease. They then stroll off to various parts of the spacious grounds, and their disappearance is the occasion for this wonderful verse. Thomson cared no more than his readers for the application of the figure; what possessed him was his memory of the magic twilight on the west coast of Scotland. Pope and Prior were metropolitan poets; it is worth noting that Dyer belonged to Wales, and Thomson to Scotland. It is even more significant that Dyer was by profession a painter, and that Thomson's poems were influenced by memories of the fashionable school of landscape painting. The development of Romantic poetry in the eighteenth century is inseparably associated with pictorial art, and especially with the rise of landscape painting. Two great masters of the seventeenth century, Salvator Rosa and Claude Lorrain, are more important than all the rest. We have here to do not with the absolute merits of painting, nor with its technical beauties and subtleties, but with its effect on the popular imagination, which in this matter does not much differ from the poetic imagination. The landscapes of Salvator Rosa and Claude were made familiar to an enormous public by the process of engraving, and poetry followed where painting led. There are exquisite landscapes in the backgrounds of the great Italian masters; Leonardo, Titian, and others; but now the background became the picture, and the groups of figures were reduced to serve as incidents in a wider scheme. Exactly the same change, the same shift of the centre of interest, may be seen in Thomson's poetry compared with Spenser's. No doubt it would be difficult to balance the creditor and debtor account as between poetry and painting; the earlier pictorial landscapes borrowed some hints from the older romances; but in England, at least, landscapes of wild rocks, and calm lakes, and feudal castles lit up by the glow of the setting sun were familiar before the reaction in poetry set in. Romance, in its modern development, is largely a question of background. A romantic love-affair might be defined as a love-affair in other than domestic surroundings. Who can use the word "romantic" with more authority than Coleridge? In _Kubla Khan_, a poem which some would choose as the high-water mark of English romantic poetry, he gets his effect from the description of a landscape combining the extremes of beauty and terror: