IT is known that in the last years of his life, on the banks of the Loire, Leonardo da Vinci worked out for his royal master – no doubt at Francis I's request – a vast project for the amelioration of the Sologne. According to this scheme, Romorantin was to play an important role, because quite close to this place, the canal, which was to bring the waters of the Beuvron, would empty into the Sauldre; at the same time another canal which was to bring the waters of the Cher above Villefranche, would also empty into the Sauldre. In this way the Sauldre would be navigable from Romorantin as far as its mouth in the Cher. Some sketches by Leonardo accompanied by detailed explanations inform us of the complicated elaboration of this project.

IN a comparison between the Virgin of the Rocks (Fig. 13) in the National Gallery, and La Vierge aux Rochers (Fig. 2) in the Louvre, two major differences are apparent, one of style, the other of iconography. The factor of style, because of its inter-relation with questions of dating and attribution, has tended to obscure the exact nature of the modification in the iconography; this modification (though 'transformation' would be a more adequate description) is concerned with the form of the attendant angel.

LEONARDO DA VINCI'S sketch of Neptune at Windsor (Fig. 18) has been generally regarded for some time as representing, in all probability, a preliminary study for the drawing which, according to Vasari, was presented by Leonardo to his friend Antonio Segni. Various allusions to a possible classical prototype have been made from time to time together with some recognition that Leonardo's design became very influential. But an essential link in the process of reconstructing the lost original and of tracing the extent of its influence seems hitherto to have been overlooked. It is a drawing in the Accademia Carrara, Bergamo (Fig. 19) which bears an attribution to Michelangelo but which is, in fact, clearly a mutilated copy of Leonardo's finished drawing. The desirability of publishing the Bergamo drawing may also be considered to justify some review of the subject as a whole.

AMONG the drawings attributed to Francesco Melzi in the Ashmolean Museum at Oxford there is a small drawing in red chalk and pen, 6.2 x 4.7 cm., representing the bust of a young woman, head turn three-quarters to right (Fig. 24). The small piece of paper on which the head is sketched has obviously been cut from a larger sheet. This was, unfortunately, a very common practice at the end of the sixteenth century, when collectors like Pompeo Leoni reassembled the manuscripts and papers of Leonardo, negligently scattered by Francesco Melzi's heirs. Hundreds of sheets or pages of notebooks were cut at that time, the sketches kept and the written notes thrown away. Many such scraps of paper in every collection (particularly at Windsor, Milan and Venice) bear witness to the misguided but dutiful habits of those amateur collectors, who preserved and destroyed at the same time.

'ONE can only grow through obligations.' This remark of Saint-Exupery's sums up the argument for Renato Guttuso's large painting of Garibaldi and his Thousand fighting their way to Palermo (Fig. 30). First seen in this year's Biennale at Venice, this picture was outstanding among many more suave works, because it so obviously implied an ambitious and compelling sense of obligation. The unprejudiced visitor was forced to admit that it had been painted to serve something beyond the artist's own reputation, and that his aesthetic sensibility was a talent properly used - not the raison d'etre of the work itself. The same could of course be said of any good recruiting poster, but it is also true that no tradition or single masterpiece has ever been produced without such a sense of service. It is significant, for example, that Picasso has never surpassed Guernica, or Henry Moore produced such profound drawings as those he did in the tube shelters during the war. In periods less revolutionary than our own, the artist has simply been able to serve a general, diffused way-of-life, but today, if his attitude (intuitive or conscious) is vital enough to admit the necessary interaction between art and life, it is almost inevitable that he will see his cause as an urgent one. Even as sheltered a painter as Bonnard has had to express his faith in sensuous domesticity in a way which, for all its marvellous subtleties, is strident compared to that of Chardin or Velazquez.