Presented by John Ruskin to the Ruskin Drawing School (University of Oxford), 1875; transferred from the Ruskin Drawing School to the Ashmolean Museum, c.1949.
Ruskin, John, Catalogue of the Educational Series (London: Smith, Elder, 1871), cat. Educational no. 17.B
Ruskin, John, Catalogue of the Educational Series (London: Spottiswoode, 1874), cat. Educational no. 28
Ruskin, John, Catalogue of Examples Arranged for Elementary Study in the University Galleries (Oxford: Clarendon Press, 1870), cat. Educational no. 21
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. Educational no. 28
It is a curve everywhere, as you will find by applying your ruler to it. Measure, and draw it with pencil and brush. You shall have the curves of all characteristic heads of pillars and their foliage in the same way; but they are terribly difficult things to do, and would not interest you at present.