With the sketchbook turned horizontally, Turner filled this page with a study of the castle, harbour, and arsenal of the Brittany town of Brest. The sketch may have been used by Turner when devising an unfinished oil painting in the Turner Bequest; see Tate N05514. 1 Brest features on multiple pages in this part of the volume, a list of which is included in the sketchbook introduction.
Martin Butlin and Evelyn Joll, The Paintings of J.M.W. Turner, revised ed., New Haven and London 1984, p.528 no.527, pl. 511.