Prospero and Miranda - The Tempest, act 1 scene 2
Approaching old age, Reuben is illustrating Shakespeare's last play. Reuben had no children but the father-daughter relationship of Prospero and Miranda may have reminded Reuben of his relationship with Polly, now a young woman.
Sketch. About 1886. From a bound volume 'Sketches' in private collection.
Compare this with the oil painting of the same subject.