This page was used vertically, both ways up. As Cecilia Powell has noted, the diagrammatic elements relate to the immense stone hillside infrastructure leading up to the temple-like Walhalla1 at Donaustauf near Regensburg. The building was then not quite complete, and the sketches are slight and hurried, the most developed being recognisable by the general form of diverging and converging steps, albeit inaccurate or fanciful in its details. For numerous contemporary studies and views in this sketchbook and elsewhere, see under folio 33 verso (D31341).2
The other way up, there is a slight but more conventional view of a hilltop tower or ruined castle, the slopes rapidly shaded to suggest its being silhouetted, perhaps against a sunset sky. It is possibly an impression of a passing effect looking west along the Danube Valley from below the Walhalla to nearby Donaustauf, although the castle and its setting there are recorded in detail with a less jagged outline elsewhere in this book (see for example folio 41 recto; D31356).
At any event, just as the light in another Donaustauf view reminded the artist of his illustrious predecessor Claude Lorrain (folio 36 verso; D31347), so this subject, wherever it was observed, called to mind ‘Tom Girtin’. Turner and the short-lived Thomas Girtin (1775–1802) had been friendly rivals and sometime collaborators as young watercolourists (see Andrew Wilton’s ‘Monro School c.1794–8’ section in the present catalogue). Girtin had been noted for his evocative light effects, most famously in the twilit 1800 White House at Chelsea (Tate N04728), which Turner sometimes mentioned or noted specifically in relation to his own later drawings (see Tate D34267; Turner Bequest CCCXLII 66v).3