So far as the writer has been able to ascertain, the first known painting where a crucifix is thrown against the sky is by Antonella da Messina.[a] The Cross is fixed in the foreground and extends to the top of the picture, being cut half-way up and just below the feet of Christ by the line of the horizon. The relief is very fine. This scheme was imitated with more or less success but never quite so perfectly, till Titian produced his magnificent Cross. Here the Crucifix is cast against a sombre evening sky, with the Virgin and two imploring Saints at the foot.[b] Rubens improved upon this design with several variations. In one he hid the foot of the Cross, though the tops of buildings are seen in the middle distance[c]; and in another, which is still finer, the time of the scene is late evening, and dark vague outlines suggest a landscape. But all these examples are cast into the shade by Van Dyck's Antwerp picture, than which there is certainly no more impressive painted Crucifixion in existence. In this the foot of the Cross is not shown, nor is there any ground to be seen, and the figure stands out against a dark forbidding sky, awful, but sublimely real, as if set in boundless space for all eternity.[d] [a] National Gallery, London. [b] Ancona Gallery. [c] Antwerp Museum. [d] This work was repeated several times with variations. See Plate 22. There are many variations of the above designs, particularly among the Works of Venetian artists, but those quoted may be regarded as typical. How easy it is to hinder the illusion is seen in Sodoma's Sacrifice of Abraham,[a] where both figures are set against the sky, but trees behind them and at the side destroy the relief, though the foliage is by no means thick. In Girolami da Libri's Madonna and Child with St. Anne, a pomegranate tree interposes[b]; and a curtain falls at the back of a group by Bernadino da Conti,[c] the illusion in both cases being consequently robbed of its effect. [a] Pisa Cathedral. [b] National Gallery, London. [c] Poldo Pezzoli Museum, Milan.