ii. 75, 78, 303, 305;

semicircular or segmental, i. 49, 244; in rims or orders, 224; of windows, their filling in, 253; suggest a higher pitch of roof than trabeated construction, 255; as to form, 354; to windows in Anglo-Saxon work, ii. 37; in form rather than construction, 52; most obvious form of, 73, 178; development of, 74, 136; decoration by mouldings, etc., 76, 120, 139, 141; orders of, 76, 78, 86, 142, 143, 146, 151; semicircular, 178, 179; semi-elliptical, 179; introduced by the Romans into their architecture, 303, 305.

Architects, English, duties of, i. 352; Royal Institute of British, 364;