Solomon Gessner (1730-1788), Swiss poet and landscape engraver and painter, quoted in Manwaring, Italian Landscape in Eighteenth Century England, p 71, began by drawing after nature, but decided instead to take the work of other artists as his starting point, and Rosa's reputation was such that he drew on him for his rocks:
I determined to draw after nature. But I soon found my precision in copying from this master led me astray... I found I must form myself upon the works of the best masters... For rocks I chose the bold masses of Berghem and Salvator Rosa as my models... Lorrain instructed me in the disposition and harmony of foreground, and in the representing of soft fading distances... The bold genius of Salvator Rosa astonished and delighted me... But the two Poussins and Claude Lorrain at last possessed me entire.
Rocks and mountains formed the basis of Rosa's reputation and therefore the basis for Ruskin's depreciation of Rosa.