[190] A later instance does appear and this, too, on a very large scale in the rebuilt choir vaults of Beauvais cathedral (1284), but the six-part vaults of this church are entirely due to the subdivision of four-part rectangular vaults in order to obtain greater stability. [191] Among the more important examples not mentioned are: Laon (Aisne), Cath.; Mantes (Seine-et-Oise), Cath.; Dijon (Côte-d’Or), Notre Dame, etc. [192] Other examples are: Lincoln, Cath. choir; (Fig. 35) Durham, Cath. east transept; Rochester, Cath. presbytery, (Moore, Mediaeval Church Architecture of England, pl. XVIII), etc. [193] Porter, Cons. of Lombard and Gothic Vaults, Figs. 58-60. [194] Other Italian examples are: Casamari, Ch.; San Galgano, Ch.; San Martino, Ch.; etc. [195] This bay was rebuilt (cir. 1237-1239) after the fall of the tower and is, therefore, later than the transept (cir. 1200). [196] In La Trinité there are no side aisles, but a series of chapels constitutes virtually the same arrangement. [197] Lubke, I, p. 440, Fig. 313. [198] Sturgis, II, p. 435, Fig. 382. [199] Sturgis, II, p. 439, Fig. 386. [200] See also one bay of Lincoln choir (Fig. 35) rebuilt cir. 1239, also Bourges, S. Pierre-le-Guillard, early thirteenth century, vaults rebuilt on original lines in the fifteenth century. Nesle (Somme) Ch. also has this vaulting form according to Moore, Mediaeval Church Architecture of England, p. 114, note 1. [201] See also Erfurt, Frankiskanerkirche. [202] Gurlitt, pl. 83. [203] Ex. Voulton (Seine-et-Marne), Ch. Baudot and Perrault-Dabot, I, pl. 62. [204] Bumpus, illustration opp. p. 92. [205] Ill. in Moore, p. 51. [206] See p. 96 and Fig. 44. [207] Bond, p. 643. [208] Rivoira, II, pp. 235-243. [209] Moore, Mediaeval Church Architecture of England, p. 25. [210] Lasteyrie, p. 497, note 1. [211] Bond, p. 370. [212] Bond, pp. 315 and 319. [213] Bond, p. 319. [214] The system, moreover, is complete with a transverse arch which might seem to indicate that it was later than that at Durham. [215] The other three are, the sexpartite and pseudo-sexpartite vaults and the irregular four-part method employed at Durham. [216] Moore, p. 80, Fig. 32. [217] Whether these concealed buttresses were first used in Normandy or the Ile-de-France is an open question, but in either case their origin would seem to be traceable to such prototypes as the ramping walls above the transverse aisle arches of such Lombard churches as Sant’ Ambrogio at Milan and perhaps even to Roman monuments like the basilica of Maxentius at Rome. The really important question is to learn when these concealed buttresses were first raised above the aisle roofs to constitute true flying-buttresses. This would seem to have taken place in the Ile-de-France, perhaps at Domont as Porter suggests (Porter, II, pp. 91-92), or at Noyon towards the middle of the twelfth century. [218] Ill. in Moore, p. 76.