Chapel, in which there is evidently some improvement; but at the time of its construction perfect knowledge on this subject had not been attained. In a catenarian chain formed of links of equal length, every side is a tangent to the curve, and the direction of each link is at right angles to it, acting in a direction perpendicular to the line it forms in the catenaria; and hence its useful application to the science of construction. It is quite clear that wherever the curve passes through the section of a building, stability is obtained; and where it does not, it is doubtful: certainly the best application of flying buttresses ig that which can be tested by this principle.. The main arches of the roof abut against the outer buttresses, and spring from a cluster of mouldings set round a circular pier; the situation of the small columns and hollows which decorate it being determined by the crossing of equilateral triangles. The ribs of each severy abut in the centre upon a circle 3 feet 6 inches in diameter, formed of two stones, and indicated by No. 1.: in the middle is a mortise-hole 9 inches square; No. 2. is in width 17 inches in the widest part; No. 3 is 2 feet 2 inches; No. 4., 3 feet 8 inches; No. 5., the same; No. 6., 3 feet 3 inches; No. 7. 4 feet 3 inches; No. 8., the same; No. 9., 3 feet 2 inches, and No. 10., which abuts against the outer wall, 4 feet. By a reference to the plan on fig. 1312., it will be understood how the several rings of voussoirs which compose the quarter of the para. bolic conoid abut and are locked one into the other: the construction of this vault is somewhat similar to that adopted by Soufflout at the Church of St. Geneviève at Paris, although his manner of applying it materially differs. X............... 9 10 Fig. 1311. Fig. 1310. KING'S COLLEGE CHAPEL: RIBS OF VAULT. The buttress in the present example has an area of 56 feet, equal to that of the piers, to which it is attached; or the two piers and buttresses together have an area of 224 feet: it is curious to find that of the 336 feet before given to the points of support, one-sixth should be applied to the piers, one-sixth to the buttresses, and the other portion to the walls between; for 55 ft. 6 in. x 6=336 feet-the area of the points of support taken on both sides; so equally are the parts even distributed. When the Normans first used flying buttresses, as at the Cathedral at Chartres, the Abbaye aux Hommes at Caen, and several other buildings, they abutted them against the ordinary outside wall; but it was soon discovered that a greater resistance was necessary to oppose the thrust, and prevent the abutments from yielding. Salisbury Cathedral was probably one of the earliest where flying buttresses were used; and the opinion of Sir Christopher Wren is worthy of quoting upon this subject, as it applies more particularly to the first constructed, and not so immediately to those erected in the fourteenth or fifteenth centuries. "Almost all the cathedrals of the Gothic form are weak and defective in the poise of the vault of the aisles; as for the vaults of the nave, they are on both sides equally supported and propped up from spreading by the bowes or flying buttresses, which rise from the outward walls of the aisles: but for the vaults of the aisles, they are indeed supported on the outside by the buttresses; but inwardly, they have no other stay but the pillars themselves, which, as they are usually proportioned, if they stood alone, without the weight above, could not resist the spreading of the aisles one minute: true, indeed, the great load above of the walls and vaulting of the nave should seem to confine the pillars 2 in their perpendicular station, that there should be no need of butment inwards, but experience hath shown the contrary, and there is scarce any Gothic cathedral, that I have seen at home or abroad, wherein I have not observed the pillars to yield and bend inwards from the weight of the vault of the aisle; but this defect is the most conspicuous upon the angular pillars of the cross, for there not only the vault wants butment, but also the angular arches that rest upon that pillar, and therefore both conspire to thrust it inwards towards the centre of the cross." At King's College chapel, flying buttresses are dispensed with, and happily the knowledge of construction had arrived at such perfection, when its astonishing vault was projected, that we have no evidence whatever of its yielding in any part. It may seem extraordinary that the Pointed style made so little progress in Italy, the Byzantine being always preferred: the architects of that country were probably unwilling to relinquish a mode of construction so economical, half only of the material employed in the lightest, and a quarter in the earliest of the Gothic style, being required for the basilica: for example, where 100 rods of stonework would be used in the latter, 200 would be necessary for the style practised at King's College, St. George's Chapel, and Bath Abbey Church, and 400 for that of the Chapter-house at Wells; this result would lead to the Conclusion, that no style is so well adapted for the wants of the present day as the Byzantine. St. George's Chapel, Windsor. If we suppose a line on the plan to pass through the centre of the buttresses and piers, and one severy of the nave to be defined, we shall have a width of 12 feet, and a length of 84 feet, the area of which is 1008 feet: after this we shall find the area of the walls and piers comprised within this severy to be 168 feet, or one-sixth of the whole; such are the proportions of mass and void found in this chapel. The clear width of the side aisles between the columns is 11 feet 9 inches; that of the nave 34 feet 10 inches, and between the outer walls 69 feet 2 inches: the height of the top of the vaulting of the nave is 54 feet 2 inches. The height up to the springing line of the great vault over the nave being equal to half the entire width, it is evident that two squares must comprise within them the entire building beneath this line; upon setting them out we find the nave and its pillars occupy one, whilst the other is given to the side aisles, external walls, and buttresses. The Rev. John Milner, in his admirable treatise on the Ecclesiastical Architecture of England, which has been the text-book for all modern writers, states that "its rise, progress, and decline, occupy little more than four centuries in the chronology of the world as its characteristic perfection consisted in the due elevation of the arch, so its decline commenced by an undue depression of it. This took place in the latter part of the 15th century, and is to be seen, amongst other instances, in parts of St. George's Chapel, Windsor, commenced by Edward IV. in 1482; in King's College Chapel, Cambridge, and in the Chapel of Henry VII. at Westminster. It is undoubtedly true that the architects of these splendid and justly admired erections, Bishop Cloose, Sir Reginald de Bray, &c. displayed more art and more professional science than their predecessors had done; but they did this at the expense of the characteristic excellence of the style itself which they built in." "In St. George's Chapel we have the work covered with tracery and carvings of the most exquisite design and execution, but which fatigue the eye, and cloy the mind by their redundancy:" but we have also a building constructed with one-half the materials that would have been employed had the style practised in the chapter-house of Wells been adopted. The admirers of the Pointed style have not sought for the true principles which mark its several changes; they have not examined into its constructive arrangements; had they done so, they would have perceived that, as the skill of the freemasons advanced, and their workmanship improved, they economised material, constructed more solidly, and produced a richer and more harmonious effect, without sacrificing any of the principles which governed their practice; the improvements they made were as great as those noticed when the Doric proportions were changed to the Ionic. In the Doric we had two-thirds mass, onethird void; in the Ionic half mass, half void; at Wells Chapter-house one-third mass, two-thirds void; in St. George's Chapel, one-sixth mass and five-sixths void. The plan of the pillars is that of a double square, or parallelogram, the diagonals of which latter figure become the sides of equilateral triangles that serve for the setting out the splays, upon which the several mouldings are cut: from east to west these piers are 3 feet 1 inch, from north to south 3 feet 6 inches, not comprising in this last dimension. the three small columns on the fall towards the nave, or the single column on that towards the side aisles, the first of which projects 6 inches, and the latter 4 inches. The mouldings around the windows and their mullions are shown at the side of the pier in their proper position. Division of the Nave of St. George's Chapel.-The mouldings set around the plan of the pier are continued up to the vaulting of the roof, without any other interruption except where they are mitred round the arches. Bath Abbey Church is 89 feet 5 in. wide from face to face of the buttresses to the nave: whose clear width is 29 feet 10 in., or one-third of the whole; and each of the side aisles is a trifle more than the half of the width of the nave, being 15 feet 8 inches: the walls and piers added together are not quite equal to a third, as they amount only to 14 feet 2 inches on each side, or together to 28 feet 4 inches, the difference being given to increase the side aisles. The section of this beautiful building presents to us all the improvements made in vaulting, and the right proportions as well as directions to be given to the flying buttresses: in the first application of those supports, as at Salisbury, they are evidently misapplied, but in the example before us we find that the constructors had arrived at a knowledge of the principles of the catenarian curve, which is traceable through the solid masses of the section: it was by slow degrees that the freemasons arrived at a knowledge of the peculiar properties of this figure; had it been known at the first commencement of the introduction of flying buttresses, we should have had a better application of them; in several instances we find them adopted where no advantage, or very little, could be derived from them. Division in Bath Abbey Church differs from all other examples of this period, by the height given to the clerestory and the omission of the triforium: the judicious and excellent arrangement of the flying buttresses permits of the greater display of glass, which in the sixteenth century had arrived at its most gorgeous state, rich in every colour, and beautiful from the drawing of the patterns, and figures with which it was covered. Bishop King commenced this building about the year 1500, on an entirely new site, near the old church: from the centre of one pier to that of the other is 20 feet 1 inch; the thickness of the outer buttresses 3 feet, and their projection 4 feet; one severy of building contains 1650 feet, and the area of the points of support is 275 feet, or one-sixth. The pillars are square, though set diagonally, their width from north to south and from east to west being 5 feet, and the opening of the arches between them 15 feet 1 inch; half their plan and base is shown at fig. 1320.: the height from the pavement to the top of the capitals, where the sculptured angel is placed, is 56 feet 3 inches, and to the top of the vaulting 73 feet 6 inches, within 7 feet as much as the clear width between the outer walls. Fig. 1517. BATH ABBEY CHURCH. Fig. 1321. shows the plan of the stone vaulting, which is perfectly geometrical in its setting out; the cloisters at Gloucester, the aisle at the east end of Peterborough cathedral, and St. George's Chapel, Windsor, have vaults of a similar kind. The thickness of the stone which comprises the vaults of fan tracery varies according to its position, but in no instance is it considerable, or more than absolutely necessary to resist crushing. The spire of Salisbury, 180 feet in height, of an octangular form, 10easures from east to west internally 33 feet 2 inches, and from north to south 6 inches more; the thickness of the spire at bottom is only 2 feet, or the area of its base is half that of the void, the void containing two parts, and the solid around it one; this spire diminishes in thickness for the first 20 feet, after which it is 9 inches in thickness throughout; at about 30 feet from the summit is a hole, by which an exit from the interior may be made, and by means of the crockets and irons on the outside the top of the spire may be attained: in 1816 the writer examined the position of the vane, and the manner in which the capping stone was placed, and descended astonished at the perfection of the masonry, and the thinness of the stone with which it was constructed. |