2
" Let no one read my principles who is not a mathematician,” he famously declared (less famous is the fact that the principles he was referring to were his theories of how the aortic pulmonary valve worked). Ironically, he himself was a poor mathematician, often making simple mistakes. In one of his notes he counted up his growing library: “25 small books, 2 larger books, 16 still larger, 6 bound in vellum, 1 book with green chamois cover.” This reckoning (with its charmingly haphazard system of classification) adds up to fifty, but Leonardo reached a different sum: “Total: 48,” he confidently declared. "
― Ross King , Leonardo and the Last Supper
6
" According to St. Augustine, the left hand represented the temporal, the mortal, and the bodily, as opposed to the right, which stood for “God, eternity, the years of God which fail not.”25 For centuries the preference for the right hand over the left governed how people fished, ploughed fields, twisted rope, and ate their meals. The Greeks and Romans, for example, always reclined on the left side, propped on the left elbow, leaving the right hand free for the business of eating and drinking. Plutarch noted that parents taught children to eat right-handed from a young age, and “if they do put forth the left hand, at once we correct them.”26 The prejudice against the left hand persisted during the Renaissance, with parents freeing a child’s right hand from its swaddling clothes to ensure right-handedness at the dinner table as well as at the writing desk. "
― Ross King , Leonardo and the Last Supper
7
" Leonardo’s twenty-six-year-old father, Ser Piero, was (as his honorary title implied) a notary: someone who wrote wills, contracts, and other commercial and legal correspondence. The family had produced notaries for at least five generations, but with Leonardo the chain was to snap. He was, as his grandfather’s tax return stated a few years later, “non legittimo”—born out of wedlock—and as such he (along with criminals and priests) was barred from membership in the Guild of Judges and Notaries. Leonardo’s mother was a sixteen-year-old girl named Caterina, and an apparent difference in their social status meant she and Piero, a bright and ambitious young man, did not marry. Almost "
― Ross King , Leonardo and the Last Supper
14
" A stylus was a metal-tipped drawing instrument widely used by artists before the invention of the pencil (graphite was not discovered until in 1504, and the wooden-cased graphite pencil appeared only in the second half of the seventeenth century). For drawing with a stylus, artists used paper specially coated with a ground made from, among other things, powdered bone. One fifteenth-century recipe recommended incinerated table scraps, such as chicken wings, whose ground-up ashes were sprinkled thinly on the paper or parchment and then brushed off with a hare’s foot.44 With the paper thus prepared, the artist went to work on its granular surface with his stylus, which was usually made from silver and sharpened to a point, and which, as it was drawn across the surface, left particles behind; these traces quickly oxidized, producing delicate lines of silvery gray. "
― Ross King , Leonardo and the Last Supper
