With the sketchbook turned to the left are two sketches of Bass Rock and one of Tantallon Castle, made as Turner passed between them on his return journey by sea to London from Edinburgh (see folio 78 verso; D17645). Both were subjects that he had been commissioned to illustrate for the topographical publication the Provincial Antiquities and Picturesque Scenery of Scotland. Although the engraving after his watercolour Tantallon Castle, 1821 (Manchester City Art Galleries)1 had been published just a month earlier in the sixth number of the publication, he was yet to paint the Bass Rock. While there are dozens of drawings of the island in the 1818 Scottish sketchbooks (see Tour of Scotland 1818 Tour Introduction) the two sketches on this page, and another on folio 78 verso are perhaps closest to the final design which was a composite of many sketches.
In both sketches on the present page, Bass Rock is seen from the south with the remains of the ruined fort halfway up the rock and a signal light at the very top. The sketch at the bottom of the page includes a vessel sailing past. This is presumably the second of two boats shown in the drawing on folio 78 verso.
From where he sketched the Bass, Turner only needed to turn around to draw Tantallon Castle, drawn in the middle of the page from due north.
Sketches of Bass Rock and Tantallon continue on folio 79 verso (D17647), as Turner’s boat moved west.
Andrew Wilton, J.M.W. Turner: His Life and Work, Fribourg 1979, p.426 no.1067.