In a letter dated 13 May 1662 Salvator Rosa wrote to his friend Ricciardi of his journey through the Apennines. The passage as a whole suggests a response to real landscape rather than such 'mountain scenery as people could conceive, who lived in towns in the seventeenth century', as Ruskin claims at Works, 12.369:
The country is such an extravagant mixture of the horrid and the tame, of the flat and the precipitous, that the eye cannot hope to find anything more pleasing. I can swear to you that the colours of one of these mountains are far more beautiful than anything I have seen under the Tuscan sky. Your Verrucola (which I used to think had a certain horrid quality) I will in future call a garden by comparison with the mountains I have crossed... Good God, how many times I have wanted you with me, how many times I called to you to look at some solitary hermitage hermit sighted on the way. Fate alone knows how much they tempted me! We went to Ancona and Sirolo and on the way back to Assisi over and above the journey - all places of extraordinary fascination for painting... Isaw the famous waterfall of the Velino, the river of the Rieti. It was enough to inspire the most exacting brain through it horrid beauty: the sight of a river hurtling down a half-mile mountain precipice and raising a column of foam fully as high. (Modified from Haskell, Patrons and Painters; original quoted in Salerno, Salvator Rosa: L'opera completa.)
Rosa calls the route 'pittoresco' in what appears to be the eighteenth century English sense of 'picturesque'. The letter is two years earlier than the first Italian citation for the word 'pittoresco' given in the Oxford English Dictionary from Francesco Redi in 1664.
It is, however, true, as Wittkower, says that the romantic quality of Rosa's landscape is 'superimposed on a classical structure, a recipe of 'landscape making which he shares with the classicists'. Wittkower adds:
Based on accepted formulas, such landscapes were carefully devised in the studio; they are moreover 'landscapes of thought' because more often than not the figures belong to mythology or the Bible and tie the genre, sometimes by a tender link, to the great tradition of Italian painting. ( Wittkower, Art and Architecture in Italy 1600-1750, p. 216)