135. "Notable man": Francesco Soderini (in Rome) to NM, October 26, 1504, Machiavelli and His Friends, #94, pp. 106-7.

136. "this undertaking, begun": Francesco Guicciardini, Storia d’Italia, VI, cited in Machiavelli and His Friends, p. 98 (italics added).

136. Piero Soderini, who had supported: Butters, Governors and Governed, p. 91.

136. Niccolò, now widely viewed: F. Gilbert, Machiavelli and Guicciardini, p. 173.

136. In the Dedication: First Decennale, in NM, Chief Works, ed. A. Gilbert, vol. III, p. 1444.

136. Did Niccolò volunteer: Such a suggestion would not have been inconceivable. When Niccolò was attacked five years later on the charge that his father was illegitimate, Buonaccorsi would write him that "I have been urged at this point by someone who loves you, and is a person that you consider highly to write you to stay where you are and not return here for anything." Biagio Buonaccorsi to Niccolò Machiavelli, December 28, 1509, in A & S, #181, p. 193), italics added. The "someone" who "urged" Buonaccorsi to write was probably Soderini, because later in the letter Biagio adds that he has also been "urged" to write by "private citizens." At the time of this letter, anonymous "adversaries" had again raised the charge that Niccolò was illegitimate and hence could not legally serve as Second Chancellor.

136. Niccolò’s citizen army, a plan supported by Soderini: Machiavelli and His Friends, p. 463 (n. 3 to #109).

136. In the poem, which borrows: Ridolfi, Machiavelli, pp. 82-83.

136. "Nor did you desist": First Decennale, 499-507, in NM, Chief Works, ed. Gilbert, vol. III, p. 1456.

137. In apparently the only explicit: To my knowledge, the closest thing to another reference occurs in the Art of War, which notes that "many generals have poisoned waters and turned rivers aside in order to take cities, even though in the end they might not succeed." Art of War, book 7, ed. Gilbert, vol. II, p. 713, italics added. See also Masters, Machiavelli, Leonardo, and the Science of Power, appendix III, pp. 257-58.

137. At the end of his poem: The last verse of the First Decennal is thus a fascinating transformation of Plato's famous parable of the ship and the innumerable images of the "ship of state" derived from it: "Yet we trust in the skilful steersman [sc. Piero Soderini], in the oars, in the sails, in the cordage; but the voyage would be easy and short if you would reopen the temple of Mars [i.e., the God of war]."First Decennale, 547-50, in Chief Works, ed. Gilbert, vol. III, p. 1457.

137. Although he stayed in Piombino for six or seven weeks: Bramly, Leonardo, p. 342; Pedretti, Literary Writings, vol. I, pp. 191, 193, 194, 294, 330, 351, 382; vol. II, pp. 24, 51, 55, 64-70, 80, 189, 192, 199-200, 221, 277, 319-20, 342, 352, 355, 382; Pedretti, Leonardo: A Study in Chronology and Style, p. 95; Heydenreich, "The Military Architect," in Reti, Unknown Leonardo, esp. pp. 156-57, 163-64; Zammatio, "Mechanics of Water and Stone," in Reti, Unknown Leonardo, pp. 200-201.

139. The Great Council Hall was made ready: Leonardo, Notebooks, ed. Irma Richter, p. 357.

139. "On 6 June 1505": Serge Bramly, Leonardo, pp. 347-48.

139. Leonardo was not given: For a reproduction of this page of Leonardo’s Notebooks, see Anna Maria Brizio, "The Painter," in The Unknown Leonardo, ed. Reti, p. 45. Brizio -- I believe correctly -- sees Leonardo's note as a comment on an unusual meteorological event, and not as a matter of superstition. As she points out, the day was a Friday, the day of week traditionally viewed as inauspicious for beginning a project. Ibid., pp. 45, 50.

139. Leonardo, who was one: On the introduction of oil painting in Italian painting and Leonardo’s development of the technique, see Bramly, Leonardo, pp. 101-7.

139. Discouraged, he apparently: Bramly, Leonardo, pp. 347-50.

141. But the paint continued: Bramly, Leonardo, p. 350.

141. The science and technology of controlling water: See Leonardo da Vinci, Codex Leicester: A Masterpiece of Science, ed. Claire Farago (New York: American Museum of Natural History, 1996), p. 135 (reproducing page 13 recto of the codex). This codex, with its remarkable record of Leonardo’s scientific research, has recently been published in facsimile edition and made available on CD-ROM: Leonardo da Vinci (Bellevue, Wash.: Corbis, 1996), CD-ROM #011N-D01. For the date of this manuscript, see Carlo Pedretti, "The Structure and Dating of the Codex Leicester," in Codex Leicester, ed. Farago, pp. 31-32. Leonardo’s procedure was to write a number of related "cases" on a single large sheet, folded in four pages. As a result, a single page contains distinct observations laid down over a period of time, with sketches along the margins to illustrate the text. For example, one sheet of the codex (reproduced in Farago, p. 134) contains three apparently disparate matters: on the top, "a geometric method for determining the speed of a boat" along with a description of a "seagoing clock" and ways of measuring a ship’s course; in the middle, illustration of "underwater vortices created when something blocks the current" and below, sketches showing "the course of the Arno at four different points on its route toward Florence."

141. Leonardo's extenisive Notebook: See Claire Farago, ed., Leonardo da Vinci, Codex Leicester: A Masterpiece of Science (New York: American Museum of Natural History, 1996), p. 135 (reproducing page 13 recto of the codex). Since this Codex, with its remarkable record of Leonardo's scientific research, has recently been published in facsimile edition and made available on CD-ROM, we can look at the page containing this comment (Figure 7.2) and assess its implications.

141. although started as early as 1503-4: Carlo Pedretti, "The Structure and Dating of the Codex Leicester," ibid., pp. 31-32. Leonardo's procedure was to write a number of related "cases" on a single large sheet, folded in four pages (of which the sheet in Figure 7.2 is one). As a result, a single page contains distinct observations laid down over a period of time, with sketches along the margins to illustrate the text.This sheet of the Codex contains three apparently disparate matters. On the top, "a geometric method for determining the speed of a boat" along with a description of a "seagoing clock" and ways of measuring a ship's course. In the middle, illustration of "underwater vortices created when something blocks the current." And below, sketches showing "the course of the Arno at four different points on its route toward Florence." Farago, Codex Leicester, p. 134

141. In addition to continued studies: Zammattio, "Mechanics of Water and Stone," pp. 196-207. The most extensive work on hydraulics is the Codex Leicester itself, which has been dated between 1508 and 1510: Pedretti, "Structure and Dating of the Codex Leicester," p. 31. See also the reproductions in Leonardo da Vinci: Scientist, Inventor, Artist, eds. Letze and Buchsteiner, pp. 126-27, 140-41, 150-55.

141. Leonardo further explored means of improving: On the cosmology associated with navigation, see Leonardo, Notebooks, vol. II, ed. J. P. Richter, #864, p. 139 (c. 1506-9) as well as #861, #862, #866, and #867, pp. 138-40; rev. ed., Vol. II, p. 110-111 (c. 1508: Pedretti, Literary Works, vol. II, p. 121). For Leonardo’s work with clocks, see Silvio A. Bedini and Ladislao Reti, "Horology," in The Unknown Leonardo, ed. Reti, pp. 242-63.

141. Scholars explain that this: Leonardo, Notebooks, ed. I. Richter, p. 357; rev. ed., Vol. II, p. 295; Bramly, Leonardo, pp. 346-47, 461. It is interesting that the enigmatic Leda and the Swan, perhaps also dates from this time. Did Leonardo seek to endow the swan with a symbolic meaning (human technology capable of controlling nature) that art historians have missed?. The most explicitly dated reference is to Leonardo's observation of a 'corton', bird of prey, which I saw as I was going to Fiesole, above the place of Barbiga, in 1505, on the fourteenth day of March." Because the Florentines dated the new year from March 25, on our calendars this would be March 14, 1506.

142. another failure to divert the Arno: The mystique of Leonardo's dream of manned flight has inspired Jack Dann's recent novel, The Memory Cathedral: A Secret History of Leonardo da Vinci (New York: Bantam, 1995). The conceit that Leonardo disappeared between 1482 and 1486 because he was in the service of the Caliph is amusing, but for plausibility it relies on Jean-Paul Richter's nineteenth-century assertion that "we have no information as to Leonardo's history" during these years (ibid., p. 486). More recent biographers have convincing evidence that he was in Milan during this time. The truth behind the fiction is, however, very real: Leonardo seriously sought to invent man-made flight, designed many machines to do so, and probably thought of the problem in the context of warfare and military technology.

142. After the failure: Butters, Governors and Governed, pp. 92-94.

142. Niccolò did not return: Ridolfi, Machiavelli, pp. 83-86. For the fee offered by Florence, the marquis was willing to provide only 150 men-at-arms and 500 foot soldiers, and he placed impossible restrictions on which enemies he would fight (Butters, Governors and Governed, pp. 94-95). These negotiations make it more obvious why Niccolò sought to create a civilian militia.

143. These complications were aggravated: Butters, Governors and Governed, pp. 94-95.

143. "we here find ourselves": Biagio Buonaccorsi to NM, July 25, 1505, Machiavelli and His Friends, #102, pp. 112-13.

143. "Keep what I am writing": NM to Antonio Tebalducci [Giacomini], August 27, 1505, Machiavelli and His Friends, #103, p. 113.

143. And so, again, Florence: For Machiavelli’s account of this event, see Discourses on Titus Livy, I, 53, ed. Mansfield and Tarcov, p. 108.

144. They feared that Soderini: Guicciardini, Storie Fiorentine, cited in Ridolfi, Machiavelli, p. 277.

144. Though the Signoria: It will be remembered that Niccolò had been present in Sinigaglia when Cesare seized and killed his previously rebellious condottiere on December 31, 1502 (see Machiavelli, The Prince, ch. 7; ed. Mansfield, p.29 and above, chapter 5, pp.00). Don Michele was Cesare's executioner (apparently he garrotted his victims).

144. He was not to return: Ridolfi, Machiavelli, pp. 84-91.

144. By late April: Bramly, Leonardo, pp. 353-55.

145. In 1513, after Giovanni: Butters, Governors and Governed, pp. 217-18.

145. In fact, although the exiled: Piero Soderini to NM, April 13, 1521, in Machiavelli and His Friends, #267, p. 334. Soderini’s offer was a position managing the affairs of "Lord Prospero" for two hundred ducats plus expenses, far more than the payments Niccolò was receiving to write the Florentine Histories.

146. "That night when Piero": Epigram, "Piero Soderini," in NM, Chief Works, ed. Gilbert, vol. III, p. 1463.

146. "Pluto roared: ‘Why’": See Dante, Inferno XXXI, 70.

146. "go up into Limbo": Epigram, Piero Soderini, in Machiavelli, Chief Works (ed. Gilbert), III, 1463. Gilbert suggests this was composed before the overthrow of the government in 1512, whereas Ridolfi follows those who claim it was just a "joke" (Machiavelli, pp. 203-4). Neither of these judgments reflects Niccolò's long-standing relationship with Soderini's rivals.

146. "there is no easier way": NM, Discourses on Titus Livy, I, 53, ed. Mansfield and Tarcov, p. 108.

147. Though gunpowder and cannon: For Machiavelli’s mature view of technology, political power, and warfare, see Masters, Machiavelli, Leonardo, and the Science of Power, pp. 186-95.

147. "virtue" and "one’s own arms": NM, The Prince, chap. 6, ed. Mansfield, p. 25.

147. "good arms" and "good laws": NM, The Prince, chap. 12, ed. Mansfield, p. 48. Compare "A Provision for Infantry," in Chief Works, ed. Gilbert, vol. I, p. 3.