This view of the fortress in the Royal Park at Portici, with Vesuvius in the background, is mounted in an album of watercolours that was bought by Joseph Mallord William Turner (1775–1851) at the posthumous sale of Dr Thomas Monro (1759–1833) (Exhibitions: Christie’s, 28 June 1833, lot 78). The sixty-four drawings were the outcome of a unique collaboration between Girtin and Turner working together at Monro’s London home at the Adelphi. Here the artists were employed across three winters, probably between 1794 and 1797, to make ‘finished drawings’ from the ‘Copies’ of the ‘outlines or unfinished drawings of Cozens’ and other artists, amateur and professional, either from Monro’s collection or lent for the purpose. As the two young artists later recalled, Girtin generally ‘drew in outlines and Turner washed in the effects’. ‘They went at 6 and staid till Ten’, which may account for the generally monochrome appearance of the works, and, as the diarist Joseph Farington (1747–1821) reported, Turner received ‘3s. 6d each night’, though ‘Girtin did not say what He had’ (Farington, Diary, 12 November 1798).¹

The view is based on a simple outline drawing by John Robert Cozens (1752–97), inscribed ‘Fortress in the Boschetto – Portici – august 26’, that is mounted in an album now at the Yale Center for British Art, New Haven (see the source image above). This was almost certainly traced by Cozens himself from an on-the-spot sketch he made in 1782 on a second visit to Naples (Bell and Girtin, 1935, no.245), when the artist travelled with his patron William Beckford (1760–1844) and stayed for four months in the region. The sketch is contained in the second of seven sketchbooks that survive from the trip (The Whitworth, Manchester (D.1975.5.16)), and it was presumably traced by Cozens because the books were retained by Beckford. Monro’s posthumous sale, in 1833, contained only twenty or so sketches by Cozens, so the patron must have borrowed the majority of the ‘outlines or unfinished drawings’ copied by Girtin and Turner. In this case, the source of the watercolour was presumably purchased at the sale of ‘Mr COZENS’ in July 1794 by Sir George Beaumont (1753–1827).² As Kim Sloan has noted, Beaumont mounted ‘215 “tracings” or drawings on oiled paper’ in an album that he presumably lent to Monro, and it was from this collection that the two young artists produced more than fifty watercolours (Sloan and Joyner, 1993, pp.89–91). Cozens’ sketch was taken from near the villa at Portici of the British envoy Sir William Hamilton (1730–1803), where Cozens and the Beckford party stayed in August 1782. The inscription, which states that the fortress was located in the ‘Boschetto’, which translates as ‘grove of trees’, has caused some confusion. The fortress was built in the upper part of the park, to the north of the royal palace at Portici by Ferdinand IV of Naples (1751–1825), who ordered that it should take the form of a reduced copy of the Fortezza di Capua in order to make the military exercises conducted there more realistic.

The album containing this drawing was sold in 1833 as the work of Turner, but the cataloguer of the Turner Bequest, Alexander Finberg, thought that Girtin alone was responsible for many of the watercolours, whilst more recently Andrew Wilton has established their joint authorship (Finberg, 1909, vol.2, p.1232; Wilton, 1984a, pp.8–23). Identifying the division of labour within Monro School drawings is considerably helped, as here, when the colour washes leave some of the pencil work untouched in order to create highlights, with the result that Girtin’s inventive and fluent hand is clearly apparent alongside Turner’s economical use of a simple palette of blues and greys.