ii. 143;

at the mosque of Touloun, Cairo, 144; in Norman work, 146; their arrangement and development, 147-149; in vaulting, 156; suggested by diagonal ribs, 177.

Colouring, lessons in, i. 339.

Columba, St., ii. 16, 19.

Columns, i. 46, 49, 274; at Noyon, 102; differences between classic and Gothic, 148; clustered, 225;