[147] Leonardo, in his letter to Sforza of Milan giving the list of services that he would render to any potentate, with no shy or uncertain estimate of his worth, does not set himself down as artist above all, but as scientist. Nor were his gifts greater in artistry, whether of design or painting or sculpture or music, whether in that mighty activity of architecture that is science and art united, than was his astonishing knowledge of engineering, geology, mathematics, the science of war and the engines of war, or in human anatomy and in worldly philosophy. His writings on the theory and practice of art are profound. He could find time, amid prodigious intellectual pursuits such as might have wearied a score of great brains, to plan and design the Court pageants of the Duke of Milan. And to the invention of a flying-machine he brought his untiring genius with dogged insistence. His restless and active imagination dreamed no vague dreams ; the cunning of his hands, above all of his wonderful left hand, itched ever to bring to reality the prodigious schemings of his scientific and practical brain.

Leonardo could scarce have settled in Milan when he began to paint in oils his famous La Vierge aux Rochers- " the Virgin of the Rocks "-the work of 1482, his thirtieth year. The painting remained in Milan some twelve years, when, about 1494, it was sold to the king of France. A petition was presented to the Duke of Milan by the artists Ambrogio da Predis and Leonardo da Vinci, " the Florentine," begging him to be judge of a dispute that had broken out between the aforesaid artists on the one side, and the Brotherhood of the Conception at S. Francesco in Milan on the other, as to the moneys to be paid for " a picture in oils of the Madonna." This painting is held to be the [148] Vierge aux Rochers, to-day in the Louvre ; the which Leonardo da Vinci had painted some ten years earlier, in 1482, as we have seen. At the same time, it is difficult to see why Ambrogio da Predis should have been mixed up in the squabble, unless he too had had a hand in the painting of the Louvre picture. However that may be, the picture is said to have been sold about 1495 for the amount demanded by the painters to another buyer, supposed to have been acting for the king of France. The two artists then wrought another version of this Vierge aux Rochers, the Virgin of the Rocks, reputed to have been painted by Ambrogio da Predis under the guidance of Leonardo da Vinci for the smaller price which the Brotherhood were ready to pay, to be set up in the Chapel of the Conception. This picture was brought to England some three hundred years later by Gavin Hamilton in 1777, who sold it to the then Marquess of Lansdowne, by whom it was exchanged for another picture at Charlton Park, in Wiltshire, belonging to the Earl of Suffolk, from whom it was bought by the National Gallery for nine thousand pounds in 1880.

The differences between the Louvre version of the Vierge aux Rochers and the National Gallery Virgin of the Rocks in general arrangement are so slight as to prove that one is at least an intended replica of the other ; but in spite of the fact that the Louvre painting, if by Leonardo, is obviously earlier and less mature than the London Virgin of the Rocks, considerable doubt must hang about the greater claim to authentic certainty as regards the Louvre picture. We have seen that Ambrogio da Predis was partner in Leonardo's appeal concerning the payment for it, the which establishes da Predis's handiwork upon the Louvre picture for a certainty. It may be that both paintings were wrought by the two painters.

XX
LEONARDO DA VINCI
1452 - 1519
FLORENTINE SCHOOL
"MONA LISA" (La Joconde)
(LOUVRE)
The portrait of Lisa di Anton Maria di Noldo Gherardini, third wife of Francesco di Bartolommeo de Zenobi del Giocondo. This picture is world-renowned for the sphinx-like smile of Mona Lisa.
Painted in tempera on panel, and restored in oil. 2 ft. 6 1/2 in. x 1 ft. 9 in. (0.79x0.53).