A LOST ART A statement about the Buildings of Piazza dei Miracoli, Pisa, Italy Scribner's Monthly, 1874 FOUR years ago in the month of February, I entered the square in Pisa, which contains the Leaning Tower, the Cathedral, the Baptistery and the Campo Santo. From the street by which I approached, the Cathedral is viewed from the side, and an obliquity of the cornice which runs above its first story (marked 2 in Fig. III) immediately struck me as being scarcely less curious' than the inclination of the Tower.

There is a corresponding obliquity in 'the cornice" of the transept, both falling toward the point of meeting at the junction of the latter with the main building. 'The hypothesis of sinking is inconsistent with the fact that the pilasters of the wall below are built in corresponding graduated height, and that the plinth and substructure are perfectly level and intact. Puzzling over this obliquity, I turned for a walk beyond the city wall, in order to get the view from the road near the railway to Lucca - a view which may well leave the visitbr in doubt if any building in the world has greater claims to fame than the Pisa Cathedral. It was in returning from this round, and not far outside the gate a few streets east of the Cathedral, that a singular freak in the roof cornice of a small chapel induced me to enter, although its exterior was so unattractive that on one side not even a window broke the monotony of its walls. Within was found the key to the results set down in this paper. I wish first to draw attention to proof of design in the leaning ,western front of the Pisa Cathedral; second, to evidence of perspective intention in the oblique cornice; third, to proof of intention in a curve; fourth, to evidence that the whole building is constructed on principles of subtle architectural illusion. That the Cathedral facade leans towards the Baptistery is not generally known. although Mr. Ruskin has remarked it in his " Seven Lamps." He says (Lamp of Life) : " The whole west front literally overhangs. (I have not plumbed it, but the inclination may be seen by the eye by bringing it into visual contact with the upright pilasters of the Campo Santo), and a most extraordinary distortion in the masonry of the southern wall shows that the inclination had begun when the first story was built. The cornice above the first arcade touches the tops of eleven out of its fifteen arches, but it suddenly leaves the tops of the four western-most, the arches nodding ,westward and sinking into the ground, while the cornice rises (or seems to rise,) leaving, at any rate, whether by the rise of the one or the fall of the other, an interval of more than two feet between it arid the top of the ,western arch, filled by added courses of masonry." Figures II and III (pp. 434-5), present this distortion, together with still another, which proves that the inclination is not to be explained by sinking. It will be seen that the dark stripes of the wall (white ,and dark green marble} although broken abruptly downwards at the fifth arch from the western front, still enter its corner pillar at right angles; thus their change of direction will at once mark and measure its inclination, the deviation from the horizontal, which these obtuse angles indicate, being an index of the deviation of the pillar from the perpendicular. The architects began their corner pillars with a wedge-shaped base (Fig. II. G). The succession of dark stripes entering the pillar at right-angles to its rising line marks the fact that they continued it with rectangular blocks. The resulting inclination was, therefore, intended. Measurement in detail of the masonry below the first dark stripe, between the point of deflection and the facade, proves that the downward defleclion of the stripes is produced by the cutting away of the blocks a, b, c, and d. From the height of the facade, (according to Kugler, 104 ft. 2 in.) the lean may be approximately calculated without plumbing, by the divergence of the fourth pilaster from the fifth, the former being parallel with the corner pillar and the latter approximately perpendicular. The second stripe, F, is two centimeters longer between these two pilasters, than the first, E, the distance between the stripes (F & E) being seventy centimeters. This gives a lean of one in thirty-five or about three feet for the inclination of the facade. The measurements of the drawing are from the southern wall, the same downward bend of the stripes occurs on the northern side, the base at the northwestern pillar is wedged three centimeters; the variation (between five and a half and three) equalizes an upward slope of the ground at the southwestern corner; the ground is quite level on the western side. Deflection produced by the cutting of masonry of course cannot be referred to sinking. Fig. I. presents certain ad- ditional facts which preclude any resort to this theory, the cathedral being surrounded by a carefully graded raised pavement, sloping downward from the walls to the five steps by which it is ascended, and the plinth supporting the walls nowhere sinks below it nor breaks its line. Mr. Ruskin, as already quoted, has remarked that the cornice (marked 2 in Fig. III. See also Fig. II.) suddenly leaves the tops of the four westernmost arches but is evidently not aware (since he questions whether these four arches fall or the cornice rises) that the cornice rises throughout its whole length at nearly the same angle and that the remaining eleven arches rise with it. In the wooden model of the i cathedral kept in one of the galleries, its oblique direction is accurately copied. How is it that so marked an obliquity should be unnoticed by an eye engaged in noting irregularities and with attention directed toward the cornice?

Obliquity of horizontal line is a perspective effect to which the eye is accustomed from every standpoint except the single one in which it is equally distant from two extremities of a line, and is therefore easily mistaken for it. The above cut is copied from the ordinary photographic view of the Cathedral. It is evident, for instance, that from the standpoint here taken, the heavy cornices falling toward the

junction of transept and main building, appear to fall from perspective effect. The Cathedral simply appears larger than it is. There may be an additional reason why this obliquity is not generally noticed. It has been shown (figures II. and III.). that the distortion in the stripes of the Cathedral is connected with the inclination of the facade, and this distortion is doubtless a device to deceive the eye into believing the facade to be upright by causing the stripes to enter its corner pillar at a right angle. But is it not possible that the distortion has an effect beyond this ? viz. : that of making the cornice appear horizontal by leading the eye to believe that its divergence from the line of the stripes is owing to the palpable bend downwards of the latter. Should this be so, the divergence of the line of the arches from the line of the cornice would be also explained; it would be an attempt to make the eye believe that the cornice does not rise, but that the arches fall - an attempt we must call at least a partial success in the case of Mr. Ruskin, for he says, as already quoted, " the cornice rises (or seems to rise), leaving at any rate, whether by the rise of the one or the fall of the other, an interval of more than two feet between it and the top of the western arch." Doubtless this divergence and that of the stripes assist in preventing the eye from perceiving the perspective deception. The story above the cornice repeats nearly, though not quite, its divergence from the horizontal. With regard to the roof line of the main building it is not quite so easy to determine, but of the transepts it is certain that the roof lines follow the obliquity of the cornice, and that the obliquity of cornice in both transept and main building is owing to the arrangement of masonry courses. Figure IV. presents a partial ground plan of the Cathedral, showing a curve of the southern wall at its western extremity. As already noted, the cathedral is surrounded by a pavement delicately sloped and graded; this pavement is decorated with a black stripe running beside the wall. Its corresponding curve furnishes at this spot proof of design in the curve of the wa.ll; for its component blocks are cut and fitted at the necessary angles. (See figure IV., 2.) It is evident that this change in the direction of the southern wall, amounting to twenty-eight centimeters, gives an effect of greater width to the whole church to anyone standing within and near the entrance door, for the standard of the nearer part is always taken by the eye as a standard for the whole. From any point of view outside, south of this portion of the southern wall, the wall is nearer tban the eye believes it, appears larger, and gives a false standard for more distant parts. Is there not an architectural illusion produced by these irregularities aside from the apparent increase of material size, and, if so, was this fact recognized on pripciple by architects in Pisa ? That variety in corresponding parts, and deviations from strict symmetry are the soul and the life of all decorative art and all architecture, is a fact which no aesthetically trained person pretends to ignore; as little will any such one deny that herein lies the superiority of the Greek temple and the medieval church over all modern copying and supposed imitation. I have, however, evidence to show that not only was this law of "life " a recognized principle of building in Pisa to an extent undreamed of even by its most ardent advocate, - Mr. Ruskin in the " Seven Lamps,"- but that a still more subtle effect was habitually studied. Say, for instance, that an observer stands opposite the oblique cornice of the Pisa Cathedral at the point where it appears to be horizontal. With an ordinary building, the point where its horizontal lines are not subject to perspective obliquity is exactly opposite the center. As there is an actual obliquity in the line of the cornice in question, it will not appear horizontal unless the observer stands at some distance to the right of the real central point (in looking at the southern wall) and here there is a marked inequality in what, from the horizontal cornice line, the eye supposes to be two equal halves of the building. I have assumed that the spectator stands at the point where the oblique cornice appears horizontal, in order to illustrate plainly the optical contradictions between apparent fact and actual appearance - but these must exist from any point of view in which the cathedral is seen. Is there not in a building so constructed an architectural illusion springing from this mystification of the eye. Mystification of the eye is the secret of all "life " in art, is the secret of the charm which the variations of the Greek scroll-work, of the arabesque pattern, of the medieval detail, from dead symmetry have for all of us. Here the whole building is made to vibrate in an architectural illusion of the same character. On me, at least, the Pisa Cathedral, as seen from the Lucca railroad, made the effect of a ship under sail. Let us take again the inclined facade. Why should so delicate and expensive a device be employed, if it is not for the life breathed into this wonderful creation by reason of the fact that the eye, assuming the facade to be upright, is mystified in making the unconscious rectification required by its inclination. I query if there is not a continual wavering of the eye between the innumerable possible lines of rectification lying between base and summit, resulting in a suggestion of mirage. With regard to the curve described I would also put the inquiry if the continual variation in the lines of the building which the curve produces, does not in like manner mystify the eye, and thereby again contribute to the optical effect?

Thus, having first established the facts of an intentional inclination, an intentional obliquity, and an intentional curve in the Pisa Cathedral, I have raised the question if their optical effect is not something more than the pure and simple apparent increase of material size undeniably present in the

two latter irregularities. I propose to debate this point by offering some cumulative evidence as to other intentional irregularities and leaving it to the reader to determine if they can have any other purpose.

The very perceptible inclination of the Pisa Baptistery is not generally remarked by travelers. On figure V.1, may be found a series of measurements that go far to show that this inclination was intended. It must be borne in mind that the polygonal surrounding pavement rises from its edge toward the circular wall of the Baptistery, being as carefully joined at the edges of its sections as a piece of veneered furniture. On the face of things, therefore, the preservation of this

delicate upward sloping grade on all sides is good presumptive proof against sinking. But, still farther than this, the foundation layers above the surface of this pavement are cut in gradually lessening height in the direction of the greatest inclination. These foundation layers (fig. V.,4) of masonry are three in number, arranged in step fashion; above them is a string-course cut in so rich a profile that wedging (i. e., cutting the block in converging lines) would be impossible, and above this is the wall proper.

The measurements of the three foundation layers at each particular point are given as added together. Observation will reveal the fact that the Baptistery has a very perceptible inclination in the direction where these measurements would lead us to expect it.

Figure V 4 gives a view of the foundation layers, figure V 3 of the delicate provisions for drainage, the want of which is the general cause of sinking foundations, the gutter below each polygonal side of the pavement curves upward toward the center; (C, c=I2 centimeters. B, b = 15-1/2 centimeters). In fig. V. I, the marks on the circle show the position of the pillars; the position of each measurement denotes approximately the spot where it was taken. The measurements are at unequal distances, and must be tested at exactly the same positions for the following reason: The rising slope of the polygonal pavement makes the lines at the junction of the segments rise higher because they rise farther. (Compare, in drawing V., cut 3, the lines a, B and e, F). At each segment line, therefore, the first foundation layer is cut to equalize this variation. (A, a = 16-1/3 centimeters, and E, e = 18 centimeters.) The measurements were, therefore, taken invariably at the center of each segment, and were omitted where this falls at the base of a pilaster, and opposite the doors, because in these places the line of the foundation 1ayers is broken into.

May not this leaning of a round building have an optical effect? The eye not especially directed to the fact of the leaning will insensibly partially or wholly rectify it, and the result of seeing the building in a position it does not occupy may produce an effect of optical vibration similar to that I have suggested as existing in the case of the facade, the cornice and the curve. It would appear that all those who have looked at the Pisa Baptistery without perceiving its pronounced inclination must have made this unconscious rectification. (See fig, VI.) We will now return to the ground plan of the Cathedral, in order to remark the fact indicated in figure IV., that the wall of the main building, on the southern side, meets the transept wall at an acute angle. The corresponding angle in the surrounding pavement (4-1/2 centimeters in 56) is more than twice as acute as the angle of the walls (2 centimeters in 56). The neat cutting and fitting of the masonry at both points is proof of an intention. The question rises again here, was the small increase in apparent length of the building hereby gained the only motive, or was a still, more subtle optical effect designed? The divergence of the line of the pavement from the line of the building, which the difference in the angle produces, is palpably a device to conceal the strong curve at the western end of the wall by making the outer line of the pavement straight throughout its length without sacrificing approximate equality of width at the two ends. It not only furnishes a second incontestable proof of design in the curve, but also enables us to measure it: (5m.84-5.76)+ (6m. 4 - 5m. 84) = 28 cent. Another irregularity may be noted before passing to the interior. The line of the wall proper both on the northern and southern sides does not correspond with the line of the plinth on which it rests, but curves in and out along its whole length. In the diagram the wave line of the wall is indicated. without representing the line of the plinth. Measured on the northern side the distances (in centimeters) of the wall proper from its supporting plinth, vary in fifteen equal distances as follows. 3-1/2 - 4 - 4 - 4-1/2 - 3-1/2 - 3-1/2 - 5 - 4 - 5-1/2 - 6 - 6-1/2 - 5 - 6 - 3 - 4-1/2. Those who know the Pisan masonry will neither here nor elsewhere be disposed to speak of carelessness. It is an instance of the carefulness in detail of the architects of these buildings, that of all the pilasters of this wall not one has a base profiled like its neighbors, although all profiles are of Athenian grace. I have preferred to rest my case for the numerous external curves on one which admitted of direct personal examiriation of the masonry. Of two others it can be said, at least, that they are not the result of sinking, the cornice and first roof line of the northern side (reproduced in fig. III) of the southern side, curve strongly in opposite directions, ( compare lines 2 and 3). Passing to the interior, I would first call attention to a perspective deception of very obvious effect. Of the two large arches (fig. VII) spanning the nave at its junction with the transept, that nearest the choir is round, and the other pointed; the apparent width of the transept space in the direction of the choir is thereby very much increased. Of a more subtle character is the arrangement of the galleries. Th.e northern gallery rises ftom the transept toward -- the western end, as far as the seventh arch from the transept, twenty centimeters - here the line of the gallery is broken abruptly downward, and falls twenty centimeters in the remaining three arches; the western gallery rises from north to south twenty-three centimeters, and from its southern extremity the south. ern gallery rises eleven centimeters in the first three arches, where a break similar to that in the corresponding point on the northern side takes place, but not at so marked an angle; the line of the southern gallery from this point to the transept being nearly horizontal. Thus at the third arch from the western entrance the southern gallery is fourteen centimeters higher than the northern (eleven + twenty-three- twenty), and at the transept is thirty-four centimeters higher, (approximately fourteen + twenty). The hypothesis of sinking would here shipwreck not only on the perfect joints of the masonry, and well-preserved substructure and plinth of the northwestern angle, but also on the fact that the unbroken oblique cornices without correspond to the broken oblique galleries within; the cornice forbids us to assume sinking for the gallery, and vice versa. This variation in the height of the galleries is made still more perplexing for the eye, because there is a stripe of white masonry above the northern arches, but none above the southern (see VII), the latter being, therefore, not higher in proportion but disproportionately higher. As this inequality in the height of the galleries would be a perspective effect from any standpoint south of a central line drawn east and west through the nave with galleries of equal height, it follows that in any part of the nave the eye is deceived as to its real standpoint, and, therefore, mystified and deceived as to the proportion of the building. The gentle curve of the pilasters supporting the great arches of the nave from the base outward is represented in drawing VII, and in the Pisan Church of Santo Paolo Ripa d'Arno, where the same appearance repeats itself, measurement of the masonry will prove that the blocks are cut and fitted at the necessary angles. (In the cathedral the masonry is not accessible). In the alignment of the columns will be found considerable irregularity. No two bases are in the same line, and the eye loses thereby its standard for computing the length of the rows. One is inclined to believe the irregularity designed, on ex amining the stripes of the pavement and cutting of the blocks. Most wonderful of all is that the columns are inclined from the perpendicular by wedge-shaped bases, varying as much as a centimeter in the height of the opposite sides. The effect, as compared with that of erect and perfectly aligned columns, has the superiority of the forest vista over the symmetrically arranged trees of an artificial plantation. In some cases, where the base is not wedged, the column proves to have been already cut in antiquity for a leaning position. In the Pisan Church of St. Frediano the wedged bases (here half a centimeter variation) are all turned in one direction, which precludes the idea of chance, both rows of columns leaning the same way. Three churches in Pisa have facades of oblique ground plan - San Matteo, San Pietro in Vinculi, and the celebrated little gothic chapel, Maria della Spina - where - by an effect slmliar to that suggested for the leaning facade may have been contemplated. What I claim for all these deviations of alignment, obliquities, inclinations and curves is, first, that they tend to mystify and perplex the eye by depriving it of its ordinary standards of measurement, A correspondent of the N. Y. "Nation" May 21st, 1874, notes the enormous perspective effect of the interior of the Pisa Cathedral as contrasted with its actual size. and so produce an effect of indefinite (i. e., of greater) extension; and, second, that they throw the building into a species of optical vibration by making upon the eye, at whatever standpoint, the varying effects of different standpoints, at one and the same moment. The arrangement of corresponding objects in unlike dimensions or unlike positions, is an additional element of optical effect, by giving the eye so many additional varying effects of shadow and new stopping points from which to begin afresh its computation. It is a curious fact that Jacob Burckhardt, one of the very greatest of living art critics, has recognized the existence of this latter principle in the architectural deformities of the Beraini period, in the I7th century decadence (pages 369-377 " Cicerone." vol I. not translated) but has failed to see its infinitely beautiful application in the Pisan buildings of the 11th century. Ruskin, on the other hand, recognizes the idea of" life" in the varying size of th. Pisan arches, of which no two contiguous ones, either within or without, are equal, ("Seven Lamps", Lamp of Life) but without suspecting the optical deceptions with which the Cathedral swarms, proven by the masonry to be designed,and of which I consider the unequal arches simplya phase. Forster (Italian guide-book, Germ., not translated,) having noticed, as few can fail to do, the more prominent irregularities of the Cathedral, considers them, like the Tower, as evidence of a clumsy medieval objection to regularity (vol. I, p. 364), without attempting measurements or giving a word to the subject in his more lately published history of Italian Art. The fact that no two contiguous arches of the Pisa Cathedral are equal must, therefore, increase its apparent size.

A longitudinal section of the little chapel (not St. Stefano within the walls) first mentioned is given in fig. VIII; its length is twenty-three paces. The five arches on either side lessen in width toward the choir and fall in height correspondingly. The roof falls fifty-six centimeters between entrance and choir. The distances between the pillars were measured with a stick which I lost before taking its length.

In my note-book only the remainders over are given in centimeters; the numbers will give the proportion, however: 7 lengths, 6 lengths and 17 centimeters; 5 and 34 centimeters; 5 and 27 centimeters; 5 and 23 centimeters. The chapel appears three times its real size to the spectator turned, as all worshipers are, in the direction of the choir. This finger-post in the history of Pisan architecture was, of course, the work of a village builder wanting the means and the subtlety of his city neighbors. It proves conclusively that perspective illusion was employed in Pisa. Is it necessary to say that I consider the Leaning Tower as the extreme phase of the Pisan irregularities? It might be supposed that clearly visible irregularities are inconsistent with optical tllusion, but such is not the case. To show this, a simple experiment may be tried in any parlor by laying obliquely on the floor a rug of striking color, some-what smaller than the room. The room will appear larger, and its walls will appear to recede, each in the direction of the widening angle. The eye perceives that the rug is awry , but assumes a line kaifwaJI between the edge of the rug and the wall as the rectangular line. The walls will a~pear oblique in spite of all knowledge to the contrary. In the same manner, a tendency of the eye to partiall~ rectify the inclination of the Tower would contribute to its effect of ..life," and it is not entirely absurd to assume this tendency in view of the numbers who fail to notice the pronounced inclination of the Baptistery and of the facade. That Kugler and Burckhardt resort to a purely hypothetical sinking after the statement of fact. made in the "Descrizione di Pisa e suoi contorni," by Ranieri Grassi. 3 vols., 1837, can be only explained by supposing the work unknown to them. The story of a sinking foundation rests on the fact that it curves from the fourth story toward the perpendicular, whence the conclusion that sinking took place when the building had reached this height. We see, according to Mr. Ruskin, that the inclination of the facade had also begun when the first story was finished. What break-neck fellows these Pisans must have been, to go on with their buildings, already in a sinking condition before half way done, exactly as if nothing had happened! And how curious the chance which arrested further yielding forever afterward. At any rate, whatever the bearing of the measurements recorded in this paper on the question of the Tower, close observation and masonry measurements will reveal the fact that perspective illusion was not confined to Pisa, but practiced on a most extensive scale throughout Italy and the whole of Europe in the Middle Age. It was in 1837 that the horizontal curves of the Parthenon were discovered by Mr. Pennethorn, although such curves are also prescribed in Vitruvius, the only antique architect whose writings have come down to us. Since then the masonry measurements of Penrosehave established the intention of'the curves; together with the existence and intention of many other remarkable irregularities in the Parthenon and the majority of Greek temples. "An investigation of the principles of Athenian architecture, or the results of a recent survey, conducted chiefly with reference to the optical refinements exhibited in the construction of the ancient buildings at Athens, by Francis Cranmer Penrose. London, 1851." All the horizontal lines of the stylobate, architrave, frieze, cornice, &c., curve upward and outward. The columns of the colonnade lean inward, as do also the side walls, the architrave, frieze and pediment, while the cornice, acroteria and subordinate faces lean outward; the end walls are perpendicular, but the antre, or pilasters of the projecting wall-ends at the corners lean outward; " perpendicular faces are the exception, not the rule." Thus far it has been customary to follow the lead of Penrose in explaining these curves and inclination as designed to correct optical effects. I hold, on the contrary, that they were intended to produce them. Penrose is himself surprised at the results of his measurements as to intention for the outward inclination of the antae; here, as regarding the also intended inward leaning of the door - jambs, his theory is at fault, and he has no explanation for the direction of Vitruvius, which he quotes, that all faces above the columns, - architrave, frieze, and pediment, - shall lean outward. Penrose also proves a deviation of level in the substructure to be intended, for which his theory affords no solution. The variations in application of this optical illusion are exactly what we should expect them to be, according to the laws of structural art. The Greek temple is simply a shrine for the statue of the Divinity; it is not intended to be large, nor to look large, The Christian cathedral of the Middle Age is the material embodiment of its spiritual unity. It must hold the community, and must look as though it could, hence the enormous development of perspective illusion. Since public building has ceased to be the highest expression of national pride, and with its adornment, the sole expression of the art-sense of the commumty. It can no longer be expected that money will pay for, or taste demand, the subtle refinements of Greece and the Middle Age. This does not diminish our interest in them; viewed from the standpoint of either art or history they teach some lessons that are eminently practical. Viewed in connection with the similar manifestations of the Pisa Cathedral, do we not gain new insight at once into the purpose of the Greek refinements, and the origin of those in Pisa. Pisa was in most intimate commercial relations with the Greek civilization of the Byzantine Empire. In the Levant, where Italian is universally spoken, it is still the Pisan dialect (not the Venetian) which is used. For eighty years of the eleventh century, from the close of which the cathedral dates (1063), the Doge of Pisa was also Duke of Athens. That we are dealing in the cathedral with Greek architecture is certain; its builders are recorded to have been Byzantine Greeks. Is it not a link in the history of civilization that irregular spacings, curves, inclined faces, and leaning columns, characterize Greek architecture alike in B.C.440, and A.D. 1100; that the facade at Pisa obeys the prescriptions of Vitruvius, and copies in its inclination the antre of the Parthenon?

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Posted: 31 May 2002