NARSES, general and statesman, in the reign of Justinian, rebuilt the Pons Salarus, 191. NATIONAL DEFENCE, in its relation to bridges, vii, viii, 15, 238-9, 244, 259, 260, 261, 272, 328, 331, 334, 337, 350, 352, 355-9. NATURAL ARCHES, 6, and _footnote_, 150-6. NATURAL BRIDGES, 3, 4, 6, and _footnote_; see also Chapter II. NATURE, her social rule in her cellular commonwealths is far superior to the social rule in human societies, 19. NATURE, her School for Mimics, see Chapter II. NATURE-MADE BRIDGES, 3, 4, 6, and _footnote_; see also Chapter II. NATURE’S STRIFE, 3, 4, 37; see also “Strife and Historic Bridges,” 14-52. NAVILLY, PONT DE, by Gauthey, its imperfect decoration, 322. NERONIANUS, PONS, 197. NERO’S AQUEDUCT, 189. NESTS, BIRDS’, their influence on handicraft, 111, 112. NEUILLY-SUR-SEINE, PONT DE, by Perronet, 338. NEVILLE, COUNT, in 1440, bequeathed twenty pounds to “Ulshawe Bridge,” 10. NEW BRIDGE on Thames, near Kingston, its Early English arches, 96. NEWCASTLE BRIDGE possessed a chapel, 231. NEWCASTLE HIGH LEVEL BRIDGE, 79-80. NEWMAN, CARDINAL, on the terrible strife in human history, 38, 39. NEW MANHATTAN BRIDGE at New York, 354. NEW PORT at Lincoln, a Roman arch, 162. NEY, MARSHAL, his celebrated criticism of the aqueduct of Segovia, 184. NOBLEMEN, RIVAL, in the Middle Ages, often opposed the building of bridges, 250-1. NOMENTANO, PONTE, 298-9; also the picture facing page 296. NONE-SUCH HOUSE on Old London Bridge, 216. NORFOLK BRIDGES, 135. NORFOLK SHRINES in the Middle Ages, 236. NORMAN BRIDGES, 96, 97, 98. NOTRE-DAME, PONT, Paris, 225. OBELISKS on the Hoogesluis at Amsterdam, 323. OGIVALE ARCHES, see “Pointed Arches.” OLD LONDON BRIDGE, see “London Bridge, Old.” ORENSE, in Gallicia, her famous gabled bridge, 28, 29, and _footnote_. ORLÉANS, PONT D’, in the fifteenth century, 239; her Belle Croix, 246-7. ORNAMENT ON BRIDGES, see “Bridge Decoration” or “Decoration of Bridges.”