The height of the nave and aisles is, according to Mr. Francis Bond in his book “Gothic Architecture in England,” respectively nearly three times their span, and the vastness of the fenestration is very striking, particularly in the clerestory, through whose lower mouldings the triforium is negotiated, thus dividing each bay into two storeys, clerestory and pier arch, instead of into three, clerestory triforium and pier arch. This gives the effect after which the French architect strove: one vast blaze of light and colour through the upper windows, coming not only from the clerestory, but from the glazed triforium also; the magnificent deep blue glass typifying the splendour of the heavens. On the other hand, in a sunny clime, builders cared less for light, and preferred the effect of a blind triforium which throws the choir below into gloomy and mysterious shadow. Thus we see that upon the design of the triforium depends to a very great extent the effect of the light and shade of the interior of a great church. Once, being personally conducted by the dean over one of the cathedrals of the west of England, the writer was suddenly called upon to give the derivation of “triforium.” The word is applied to the ambulatory or passage, screened by an arcade, which runs between the pier arches and clerestory windows, and is considered to refer to the three openings, or spaces, _trinæ fores_, into which the arcading was sometimes divided. It probably has nothing to do with openings in multiples of three, nor with a Latinised form of “thoroughfare,” as suggested in Parker’s Glossary, although the main idea is that of a passage running round the inside of a church, either as at Westminster, in the form of an ambulatory chamber, or of a gallery pierced through the main walls, from whence the structure can be inspected without the trouble of using ladders or erecting scaffolding. M. Enlart in his “Manuel d’Archéologie Française,” derives the word from a French adjective “trifore,” or “trifoire,” through the Latin “transforatus,” a passage pierced through the thickness of the wall; and this idea of a passage-way is certainly suggested by an old writer, Gervase, who, in his description of the new Cathedral of Canterbury, rebuilt after the fire, alludes to the increased number of passages round the church under the word “triforia.” “Ibi triforium unum, hic duo in choro, et in alâ ecclesiæ tercium.” On the north side of the Cathedral flows the Somme, and there is perhaps no better means of realising the great height and mass of the building than by walking along the river banks, whence we see the old houses, great and small, rise tier above tier under the quiet grey outline of this “giant in repose.” [Illustration: EVENING ON THE SOMME AT AMIENS]