[145] See p. 101, 102.
[146] Ruprich-Robert, pl. LXXXVII.
[147] Rivoira, I, p. 225.
[148] Rivoira, I, p. 224, Figs. 330, 331.
[149] Porter, Cons. of Lombard and Gothic Vault.
[150] Porter, Cons. of Lombard and Gothic Vaults, p. 22.
[151] Porter, Cons. of Lombard and Gothic Vaults, p. 23.
[152] See Cattaneo, p. 227.
[153] The word square is used to denote bays which are approximately as well as actually equilateral.
[154] See list in Enlart, I, p. 264 note 2 and note 3. Examples of transverse arches of earlier date exist in Syrian and Early Christian architecture, but not with a regular alternate system.