151. 'Moss will grow on the best stone.' The first thing your modern restorer would do is to scrape it off; and with it, whatever knitted surface, half moss root, protects the interior stone. Have you ever considered the infinite functions of protection to mountain form exercised by the mosses and lichens? It will perhaps be refreshing to you after our work among the Pisan marbles and legends, if we have a lecture or two on moss. Meantime I need not tell you that it would not be a satisfactory natural arrangement if moss grew on marble, and that all fine workmanship in marble implies equal exquisiteness of surface and edge.
152. You will observe also that the importance of laying the stone in the building as it lay in its bed was from the first recognised by all good northern architects, to such extent that to lay stones 'en delit,' or in a position out of their bedding, is a recognized architectural term in France, where all structural building takes its rise; and in that form of 'delit' the word gets most curiously involved with the Latin delictum and deliquium. It would occupy the time of a whole lecture if I entered into the confused relations of the words derived from lectus, liquidus, delinquo, diliquo, and deliquesco; and of the still more confused, but beautifully confused, (and enriched by confusion,) forms of idea, whether respecting morality or marble, arising out of the meanings of these words: the notions of a bed gathered or strewn for the rest, whether of rocks or men; of the various states of solidity and liquidity connected with strength, or with repose; and of the duty of staying quiet in a place, or under a law, and the mischief of leaving it, being all fastened in the minds of early builders, and of the generations of men for whom they built, by the unescapable bearing of geological laws on their life; by the ease or difficulty of splitting rocks, by the variable consistency of the fragments split, by the innumerable questions occurring practically as to bedding and cleavage in every kind of stone, from tufo to granite, and by the unseemly, or beautiful, destructive, or protective, effects of decomposition. {1} The same processes of time which cause your Oxford oolite to flake away like the leaves of a mouldering book, only warm with a glow of perpetually deepening gold the marbles of Athens and Verona; and the same laws of chemical change which reduce the granites of Dartmoor to porcelain clay, bind the sands of Coventry into stones which can be built up halfway to the sky.
{Footnote 1: This passage cannot but seem to the reader loose and fantastic. I have elaborate notes, and many an unwritten thought, on these matters, but no time or strength to develop them. The passage is not fantastic, but the rapid index of what I know to be true in all the named particulars. But compare, for mere rough illustration of what I mean, the moral ideas relating to the stone of Jacob's pillow, or the tradition of it, with those to which French Flamboyant Gothic owes its character.}
153. But now, as to the matter immediately before us, observe what a double question arises about laying stones as they lie in the quarry. First, how do they lie in the quarry? Secondly, how can we lay them so in every part of our building?
A. How do they lie in the quarry? Level, perhaps, at Stonesfield and Coventry; but at an angle of 45° at Carrara; and for aught I know, of 90° in Paros or Pentelicus. Also, the bedding is of prime importance at Coventry, but the cleavage at Coniston. {1}
{Footnote 1: There are at least four definite cleavages at Coniston, besides joints. One of these cleavages furnishes the Coniston slate of commerce; another forms the ranges of Wetherlam and Yewdale crag; a third cuts these ranges to pieces, striking from north-west to south-east; and a fourth into other pieces, from north-east to south-west.}
B. And then, even if we know what the quarry bedding is, how are we to keep it always in our building? You may lay the stones of a wall carefully level, but how will you lay those of an arch? You think these, perhaps, trivial, or merely curious questions. So far from it, the fact that while the bedding in Normandy is level, that at Carrara is steep, and that the forces which raised the beds of Carrara crystallized them also, so that the cleavage which is all-important in the stones of my garden wall is of none in the duomo of Pisa,—simply determined the possibility of the existence of Pisan sculpture at all, and regulated the whole life and genius of Nicholas the Pisan and of Christian art. And, again, the fact that you can put stones in true bedding in a wall, but cannot in an arch, determines the structural transition from classical to Gothic architecture.
154. The structural transition, observe; only a part, and that not altogether a coincident part, of the moral transition. Read carefully, if you have time, the articles 'Pierre' and 'Meneau' in M. Violet le Duc's Dictionary of Architecture, and you will know everything that is of importance in the changes dependent on the mere qualities of matter. I must, however, try to set in your view also the relative acting qualities of mind.
You will find that M. Violet le Duc traces all the forms of Gothic tracery to the geometrical and practically serviceable development of the stone 'chassis,' chasing, or frame, for the glass. For instance, he attributes the use of the cusp or 'redent' in its more complex forms, to the necessity, or convenience, of diminishing the space of glass which the tracery grasps; and he attributes the reductions of the mouldings in the tracery bar under portions of one section, to the greater facility thus obtained by the architect in directing his workmen. The plan of a window once given, and the moulding-section,—all is said, thinks M. Violet le Duc. Very convenient indeed, for modern architects who have commission on the cost. But certainly not necessary, and perhaps even inconvenient, to Niccola Pisano, who is himself his workman, and cuts his own traceries, with his apron loaded with dust.
155. Again, the redent—the 'tooth within tooth' of a French tracery—may be necessary, to bite its glass. But the cusp, cuspis, spiny or spearlike point of a thirteenth century illumination, is not in the least necessary to transfix the parchment. Yet do you suppose that the structural convenience of the redent entirely effaces from the mind of the designer the aesthetic characters which he seeks in the cusp? If you could for an instant imagine this, you would be undeceived by a glance either at the early redents of Amiens, fringing hollow vaults, or the late redents of Rouen, acting as crockets on the outer edges of pediments. 156. Again: if you think of the tracery in its bars, you call the cusp a redent; but if you think of it in the openings, you call the apertures of it foils. Do you suppose that the thirteenth century builder thought only of the strength of the bars of his enclosure, and never of the beauty of the form he enclosed? You will find in my chapter on the Aperture, in the "Stones of Venice," full development of the aesthetic laws relating to both these forms, while you may see, in Professor Willis's 'Architecture of the Middle Ages,' a beautiful analysis of the development of tracery from the juxtaposition of aperture; and in the article 'Meneau,' just quoted of M. Violet le Duc, an equally beautiful analysis of its development from the masonry of the chassis. You may at first think that Professor Willis's analysis is inconsistent with M. Violet le Duc's. But they are no more inconsistent than the accounts of the growth of a human being would be, if given by two anatomists, of whom one had examined only the skeleton and the other only the respiratory system; and who, therefore, supposed—the first, that the animal had been made only to leap, and the other only to sing. I don't mean that either of the writers I name are absolutely thus narrow in their own views, but that, so far as inconsistency appears to exist between them, it is of that partial kind only.