Ashmolean The Elements of Drawing, John Ruskin’s teaching collection at Oxford

The drawing shows the Romanesque apse of the Duomo at Pisa, from the south-east: an arcade of tall, round-headed arches supports two open colonnades, one of round-headed arches, the other topped by very shallow curved arches. Ruskin has focussed only on the top of the ground-floor arcade and the colonnade above it; the rest is indicated very summarily.

In Fors Clavigera (lett. 18, § 1 = XXVII.304-5), Ruskin notes that on 28 April he was 'drawing the east end of the Duomo' - during which he was distracted by a group of men spitting at the Leaning Tower, and a boy who ended up turning somersaults over the railings.

In 1873, when Ruskin referred to it in the lectures that would become Val d'Arno, the drawing seems to have been in the Rudimentary Series; however, it was first catalogued in the Oxford collections only in 1906, by Cook and Wedderburn, as no. 76 in the Reference Series (a position which had previously been occupied by the drawing that is now no. 112 in the Reference Series).

When the drawing was displayed in his Turner exhibition of 1878, Ruskin drew viewers' attention 'to the subtlety of the arch curves, intersections of the horizontal curve of the circular apse with stilted Saracenic curves widening the voussoirs as they spring' (no. 60.R = XIII.528). In his lecture on Nicola Pisano (20 October 1873), he called the drawing an example 'of "quella vecchia maniera Greca, goffa e sproporzionata [that old Greek manner, clumsy and ill-proportioned - quoting from Vasari]." My own judgement respecting them is ... that no architecture on this grand scale, so delicately skilful in execution, or so daintily disposed in proportion, exists elsewhere in the world.' The work at Pisa embodied good Greek art which the uneducated (including Vasari) were unable to distinguish from the crude. (Val d'Arno, §§ 11-13 = XXIII.16-17.)