The lost wheel map of Ambrogio Lorenzetti

2. How to pursue this avenue of investigation became apparent to me only after stimulating conversations with Paul Binski, who deserves much of the credit for clarifying the formal problems posed by Lorenzetti's revolving map and none of the blame for any errors in the solution I propose.

3. I am here borrowing a concept articulated by R. Starn, "The Republican Regime of the 'Room of Peace' in Siena, 1338-40," Representations, XVIII, 1987, 1-32, esp. 3, and further developed in R. Starn and L. Partridge, Arts of Power: Three Halls of State in Italy, 1300-1600, Berkeley, 1992, 9-80, 261-66, esp. 14.

4. On the controversy over the Guidoriccio, see the following (in chronological order): G. Moran, "An Investigation regarding the Equestrian Portrait of Guidoriccio da Fogliano in the Sienese Palazzo Pubblico," Paragone, XXVIII, no. 333, 1977, 81-88; M. Mallory and G. Moran, "Guido Riccio da Fogliano: A Challenge to the Famous Fresco Long Ascribed to Simone Martini and the Discovery of a New One in the Palazzo Pubblico in Siena," Studies in Iconography, VII-VIII, 1981-82, 1-13; G. Moran, "Guido Riccio da Fogliano: A Controversy Unfolds in the Palazzo Pubblico in Siena," Studies in Iconography, VII-VIII, 1981-82, 14-20; Seidel; J. Polzer, "Simone Martini's Guidoriccio da Folignano: A New Appraisal," Jahrbuch der Berliner Museen, XXV, 1983, 103-41; News from RILA, 11, Feb. 1984, 1, 3-5; Polzer, 1985; C. Frugoni and O. Redon, "Accuse Guido Riccio de Fogliano, defendez-vous!" Medievales, IX, 1985, 119-31; M. Mallory and G. Moran, "New Evidence Concerning 'Guidoriccio,'" Burlington Magazine, CXXVIII, no. 997, 1986, 250-59; Martindale, 1986; Polzer, 1987; P. Toritti, letter, Burlington Magazine, CXXXI, no. 1036, 1987, 485-86; C. B. Strehlke, "Niccolo di Giovanni di Francesco Ventura e il 'Guidoriccio,'" Prospettiva, L, 1987, 45-48; L. Bellosi, "Ancora sul 'Guidoriccio,'" Prospettiva, L, 1987, 49-55; Martindale, 1988, 209-11; P. Torriti, "La parete del 'Guidoriccio,'" in Simone Martini: Atti del convegno, Siena, 27, 28, 29 marzo 1985, ed. L. Bellosi, Florence, 1988, 87-97; and Maginnis. Additional bibliography is cited in n. 25 below.

5. Cronache Senesi, ed. A. Lisini and F. Iacometti, in Rerum Italicarum scriptores, ed. L. A. Muratori, n.s. 15, VI, Bologna, 1935, 547. On problems concerning the date of the chronicle's compilation, see Martindale, 1986, 261-62; Mallory, and Moran, 1986 (as in n. 4), 251 n. 11 with bibliography; and Maginnis, 141.

6. G. Milanesi, Documenti per la storia dell'arte senesi, 3 vols. (Siena, 1854), rpr. Soest, 1969, II, 37, citing the Libro del Camarlingo of the Biccherna, chap. 56, for Dec. 11, 1393: "Deliberaverunt, quod Bartalus magistri Fredi, Cristofanus magistri Bindocci et Meus Petri, pictores, habeant ab operario Camere Comunis Sen: quatuor flor: auri in auro pro eorum salario et labore, eo quod pinxerunt et reactaverunt Mappamundum - Item det et solvat eis quas spenderunt (sic) in azuro et aliis coloribus in dicto aconcimine dicti Mappamundi: in totum libras duodecim." The vernacular summary of this authorization is cited by U. Morandi, in Brandi et al., 423, no. 231.