At the centre of the horizon to the south is the tower of Calstock Church, above the Cornish bank of the River Tamar, with Morwell Rocks on the Devon side to the left. Turner’s exact viewpoint south of Gunnislake’s Newbridge is now hard to establish due to changes in the distribution of buildings in the valley and extensive wooded areas. The foreground of the sketch appears difficult to read, but may include aspects of the short Tamar Manure Navigation Canal which had recently bypassed Weir Head on the Tamar. The composition is inverted relative to the sketchbook’s foliation. There are clearer views of the canal from the south on folios 52 verso and 53 verso (D10277, D10279; CXXXVII 49a, 50a). Calstock Church is also shown on its ridge on folios 49 verso, 50 verso and 51 recto (D10271, D10273, D10274; CXXXVII 46a, 47a and 48) which informed Turner’s painting Crossing the Brook, exhibited in 1815 (Tate N00497).1
The sketchbook contains numerous views in and around the Tamar and Tavy valleys between folios 46 verso (D10265; CXXXVII 43a) and 58 verso (D10289; CXXXVII 55a), probably made in the summer of 1813 in conjunction with those in the smaller Devon Rivers, No.1 sketchbook (Tate; Turner Bequest CXXXII). The latter is covered in the section of the present catalogue specifically devoted to Turner’s 1813 visit to Devon, where further information on Turner’s work in the locality will be found.
Martin Butlin and Evelyn Joll, The Paintings of J.M.W. Turner, revised ed., New Haven and London 1984, pp.93–4 no.130, pl.123 (colour).