This is a tracing, on a larger sheet, from Tate D00155 (Turner Bequest XIV B), with the elements slightly separated, presumably to create a larger design, as in Tate D00685 (Turner Bequest XXVII X). Finberg1 suggested that the small view (D00155) was the final version of this subject, but it is evidently the source of the tracing. It seems to be earlier and does not incorporate the adjustments indicated in the tracing. For another tracing of about this date on similar paper see Tate D00149 (Turner Bequest XIII D).
Finberg 1909, I, p.18.
The sheet has been folded vertically 45 mm from right edge.