As the unframed examples had not been given an order by Ruskin, they have been given arbitrary accession numbers based upon their position in Cook and Wedderburn's list of the unframed objects (XXI.308) for the purposes of the current catalogue.
Presumably presented by John Ruskin to the Ruskin Drawing School (University of Oxford); first recorded in the Ruskin Drawing School in 1906; not recorded in the Drawing School subsequently.
Ruskin, John, ‘The Ruskin Art Collection at Oxford: Catalogues, Notes and Instructions’, Edward T. Cook and Alexander Wedderburn, eds, The Works of John Ruskin: Library Edition, 39 (London: George Allen, 1903-1912), 21, cat. Unframed