Cozens’ on-the-spot sketch is inscribed ‘From the Road between Caserta & the Aqueduct – Novr.26’, and it also identifies the locations of ‘Caserta’, ‘Capua Vecchia’ and ‘Capue Nuova’ (Bell and Girtin, 1935, no.327). The sketch is found in the fifth of the seven sketchbooks from Cozens’ second Italian trip, which saw him travel to Naples in 1782 in the company of his patron William Beckford (1760–1844). It is unlikely that the Monro School watercolour was copied directly from the sketch by Cozens, however. It would have been uncharacteristic of Beckford to have lent the sketchbooks to Monro, and the existence of a large number of tracings of their contents by Cozens himself suggests that the patron, rather than the artist, retained the books. An album put together by Sir George Beaumont (1753–1827), now in the collection of the Yale Center for British Art, New Haven, includes more than seventy tracings from on-the-spot drawings in the first three of the sketchbooks, and these provided the basis for at least thirty Monro School works. There are only five tracings from the next three books, but there is no reason to think that others did not exist, and it was presumably from these lost copies by Cozens that as many as thirty-five more watercolours were produced by Girtin and Turner. The fact that the Monro School copies never follow either the shading or the distribution of light seen in the on-the-spot sketches, though they always replicate the basic outlines, further suggests that Girtin and Turner worked from tracings of the sketchbook views. This was certainly my initial impression in this case, but looking again at the Monro commission and comparing it with a Cozens watercolour of the same composition (figure 2) I wonder if we are not looking at something different here. Features such as the branches of a tree seen to the left that appear in both the Monro School work and the Cozens watercolour but not the on-the-spot sketch suggest that an outline drawing was not the model for Girtin and Turner's work. Above all, it is the skyscape that clinches the argument for the Monro School drawing closely follows the complex disposition of clouds seen in the Cozens watercolour and this is barely hinted at in the sketchbook drawing, even less in any lost tracing (figure 1). Given that the Monro School drawing is roughly the same size as the original sketch what I think we have here is a unique instance whereby the pencil underdrawing was copied from a lost tracing with the colouring added with reference to a Cozens watercolour, presumably the work now at the Whitworth (figure 2). 

The bulk of the works sold at Monro’s posthumous sale in 1833 were attributed to Turner alone, and, in spite of the pioneering article published by Andrew Wilton in 1984, which established the joint authorship of many of the Monro School copies, this example was still listed as by Turner when it appeared on the art market in 2015 (Wilton, 1984a, pp.8–23). This is not entirely surprising given that the watercolour has been quite heavily worked by Turner with a full palette of colours, which has effaced much of Girtin’s characteristic pencil work. Arguably, enough of Girtin’s hand is still apparent in the lighter middle ground to point to his involvement in its production, albeit at the most basic level, tracing the outlines from a Cozens drawing; it was Turner’s more onerous task to obscure the essentially mechanical practice of replication and produce something that approximates to a finished work and this is helped considerably by the addition of a complex skyscape.

A copy of this drawing is to be found in a collection of watercolours painted from Monro School collaborations known as ‘The Le Geyt Volume’ after a later owner May Le Geyt (d.1942) who was a descendent of Dr Thomas Monro (Lacy Scott & Knight, 11 March 2017, lot 1464 (p.18)). One of the drawings is inscribed ‘J. Monro’, presumably John Monro (1801-80) the fourth son of the doctor and he may have been the author of all of the sheets in the book. Some of the drawings are dated 1827 and 1837 suggesting that the copies were made both prior to the 1833 sale, whilst others, as in this case, were painted from material retained by the Monro family.