With the sketchbook turned to the right is a drawing of Dumbarton Rock as seen from the River Clyde to the south. Although there is limited detail in the sketch, the outline of the rock is carefully delineated, as is the Governor’s House which sits on a low plateau at its southern end. To the left of the church is the mouth of the River Leven. The spire, presumably of Dumbarton Riverside Parish Church, can be seen at this point. At the top right of the page is a sketch of Dumbarton Bridge, as seen in the sketch on folio 2 (D26621) and in Turner’s watercolour of the subject: Dumbarton Castle and River Leven circa 1833 (whereabouts unknown);1 the bridge is also shown in a sketch of 1801 (Tate D02980; Turner Bequest LVI 35 a).
David Wallace-Hadrill and Janet Carolan suggest that Turner made the sketch as he steamed along the River Clyde from Bowling, on his way to the River Leven and onto Loch Long.2