On 12 September 1508 Leonardo opened up a new notebook with a cover of thin grey card and inscribed it, ‘Cominciato a Milano a dì 12 di settembre 1508’. It is a notebook of 192 pages; at the end of it he writes the date October 1508, so it seems he filled the entire book over a concentrated period of six weeks or so – perhaps less. The compactness and regularity of the handwriting would confirm this. He gave it the title ‘Di mondo ed acque’ – ‘Of the World and Its Waters’ – though it is now known less sonorously as Paris MS F. He instructs himself:
Write first of water, in each of its motions; then describe all of its beds and the substances therein… and let the order be good, for otherwise the work will be confused. Describe all the forms that water assumes from its largest to its smallest wave, and their causes.59
The pages on water have small, vivid sketches – superb examples of Leonardo’s mastery in representing complex volatile structures. He treats of ‘retrosi’ (back-currents) and vortices (p. 150). He coins the phrase aqua panniculata – creased or crumpled water – to describe agitated surfaces. The fascination with the intricate forms of running water seems to be echoed in the rolling, flowing tresses of the Leda, on which Leonardo – or at any rate his assistants – were probably working at this time. The interest in water is also practical. There is a machine ‘for excavating earth so as to make the water of the padule deeper’, which can be linked to canalization projects under way at this time.60
The flying-machine is under consideration once more. A curt note reads, ‘Anatomize the bat, and keep to this, and base the machine on this.’61 He had earlier recognized the bat as the physiological model for the wings of the machine, ‘because the membranes serve as the framework of the wings’, but now – perhaps as a result of the failed trial on Monte Ceceri – he seems to be stressing the bat as a more stable model for flight in general. He later notes that bats ‘can follow their prey upside down, and sometimes in a slanting position, and so in various ways, which they could not do without causing their own destruction if their wings were of feathers with gaps in between’. 62
His passion for geometry is undimmed: we find him delving into the arcana of square- and cube-roots, and tussling with the Delos problem, so called because it is expressed in the classical story of Apollo, who delivered the islanders of Delos from plague and demanded in return that they double the size of their altar to him; as the altar was a perfect cube of marble, they were obliged to work out a cube-root in order to satisfy him.63
There are discussions of optics and light which shade into cosmological theory. A powerfully written discourse ‘In Praise of the Sun’ covers a two-page spread, citing and disputing the opinions of Epicurus and Socrates about the size of the sun, and concluding:
In the whole universe there is nowhere to be seen a body of greater magnitude and power than the sun. Its light gives light to all the celestial bodies which are distributed throughout the universe. From it descend all the vital forces [anime], for the heat that is in all living creatures comes from these vital forces, and there is no other heat and no other light in the universe.64
There is an echo here of the old Platonic-planetary magic of Ficino, but if one substitutes ‘solar system’ for ‘universe’ the passage makes perfect scientific sense. It tends towards an idea of heliocentricity, but does not actually express it. The famous note reading, ‘Il sole non si muove’ (‘The sun does not move’), found on a Windsor sheet of c. 1510, has been taken as an inspired astronomical insight pre-dating Copernicus by thirty years, but this cannot be certain. The idea of heliocentricity – though not the proof – is as old as Pythagoras, and anyway the words appear on their own, with no preamble or explanation, and are as likely to be a jotting connected with a pageant or masque, or perhaps the motto of an emblem illustrating some quality of steadfastness.65
He also pursues in MS F his fascination with geological and aetiological cycles, which is such a feature of the contemporary Codex Leicester. He considers the possibility of the earth’s emergence from the sea, and foresees, in a prophetic tone, the return of the earth to the ‘lap’ (grembo) or womb of the sea.66 In this passage we hear the first germs of his apocalyptic Deluge drawings, where the drama of natural cataclysms conveys also an idea of the collapse of categories and distinctions – an engulfing of the intellect by a Nature uncontrollable and in the end unknowable.
Among these big themes there is also that quality of momentariness which is such a pungent aspect of the notebooks. Here are some of the phrases scribbled down on the cover:
inflate the lungs of a pig
Avicenna on fluids
map of Elefan of India which Antonello Merciaio has
enquire at the stationers’ for Vitruvius
ask Maestro Mafeo why the Adige rises for seven years and falls for
seven years
go every Saturday to the hot baths and you will see naked men.67
Broadly contemporary with this notebook is another, Paris MS D, a booklet of twenty pages, neatly and consistently written, and wholly concerned with a single subject – the science of vision. Some of it elaborates previously written notes, particularly drawing on MS A of the early 1490s. It is a further sign of Leonardo’s thoughts tending towards compilation, finalization, and hence publication.68
The same desire is undoubtedly to be seen in his anatomical sheets of this period, a gathering of eighteen folios on one of which is the note ‘In the winter of this year 1510 I expect to complete all this anatomy.’ In these the graphic illustrations aligned with short blocks of explanatory text constitute what would now be called the ‘layout’ for a printed page. A note refers explicitly to a future printed edition: ‘As regards this benefit I give to posterity, I show the method of printing it in order, and I beseech you who come after me not to let avarice constrain you to make the prints in [… ]’ The last word is missing owing to paper-loss near the margin, but enough is left to suggest the word legno, wood.69 He wishes, in other words, that his anatomical writings should be illustrated not with woodcuts – cheaper, as he says, but much cruder – but with the more expensive and accurate process of copper engraving. This is confirmed by Paolo Giovio, who had first-hand knowledge of Leonardian anatomy through their shared connection with the anatomist Marcantonio della Torre. Leonardo, he says, ‘tabulated with extreme accuracy all the different parts of the body, down to the smallest veins and the composition of the bones, in order that this work on which he had spent so many years should be published from copper engravings for the benefit of art’. As Carlo Pedretti notes, this expectation may explain the slightly lifeless drawing-style in these anatomical folios: ‘The calligraphic precision of line, and a shading rendered by a minute, uniform hatching, are characteristics that Leonardo was expecting from copper engravings.’70
Another compilation of this period, no doubt also with a printed edition in mind, is the manuscript ‘book’ on painting which Melzi catalogued (after Leonardo’s death) as Libro A. It formed an important part of Melzi’s compilation of Leonardo’s writings on painting, the Codex Urbinas, which in turn provided the copy-text of the Trattato della pittura. The original manuscript is lost, but some of its contents are recoverable from Melzi’s text. It also contained some notes on hydraulics which were copied by Leonardo himself into the Codex Leicester.71 Thus in his studio in Milan the great project of inquiry proceeds, page by page, pen-nib by pen-nib, towards the distant goal of publication. ‘In this labour of mine’, he promises, men ‘will discern the marvellous works of Nature.’