The Ten Books on Architecture Part 18

7. If, however, it seems needful to use still greater care, lay two-foot tiles, jointed together in a bed of mortar, over the broken stone, with little channels of one finger's breadth cut in the faces of all the joints. Connect these channels and fill them with a mixture of lime and oil; then, rub the joints hard and make them compact. Thus, the lime sticking in the channels will harden and solidify into a ma.s.s, and so prevent water or anything else from penetrating through the joints.

After this layer is finished, spread the nucleus upon it, and work it down by beating it with rods. Upon this lay the floor, at the inclination above described, either of large cubes or burnt brick in herring-bone pattern, and floors thus constructed will not soon be spoiled.

CHAPTER II

THE SLAKING OF LIME FOR STUCCO

1. Leaving the subject of floors, we must next treat of stucco work.

This will be all right if the best lime, taken in lumps, is slaked a good while before it is to be used, so that if any lump has not been burned long enough in the kiln, it will be forced to throw off its heat during the long course of slaking in the water, and will thus be thoroughly burned to the same consistency. When it is taken not thoroughly slaked but fresh, it has little crude bits concealed in it, and so, when applied, it blisters. When such bits complete their slaking after they are on the building, they break up and spoil the smooth polish of the stucco.

2. But when the proper attention has been paid to the slaking, and greater pains have thus been employed in the preparation for the work, take a hoe, and apply it to the slaked lime in the mortar bed just as you hew wood. If it sticks to the hoe in bits, the lime is not yet tempered; and when the iron is drawn out dry and clean, it will show that the lime is weak and thirsty; but when the lime is rich and properly slaked, it will stick to the tool like glue, proving that it is completely tempered. Then get the scaffolding ready, and proceed to construct the vaultings in the rooms, unless they are to be decorated with flat coffered ceilings.

CHAPTER III

VAULTINGS AND STUCCO WORK

1. When vaulting is required, the procedure should be as follows. Set up horizontal furring strips at intervals of not more than two feet apart, using preferably cypress, as fir is soon spoiled by decay and by age.

Arrange these strips so as to form a curve, and make them fast to the joists of the floor above or to the roof, if it is there, by nailing them with many iron nails to ties fixed at intervals. These ties should be made of a kind of wood that neither decay nor time nor dampness can spoil, such as box, juniper, olive, oak, cypress, or any other similar wood except common oak; for this warps, and causes cracks in work in which it is used.

2. Having arranged the furring strips, take cord made of Spanish broom, and tie Greek reeds, previously pounded flat, to them in the required contour. Immediately above the vaulting spread some mortar made of lime and sand, to check any drops that may fall from the joists or from the roof. If a supply of Greek reed is not to be had, gather slender marsh reeds, and make them up with silk cord into bundles all of the same thickness and adjusted to the proper length, provided that the bundles are not more than two feet long between any two knots. Then tie them with cord to the beams, as above described, and drive wooden pegs into them. Make all the other preparations as above described.

3. Having thus set the vaultings in their places and interwoven them, apply the rendering coat to their lower surface; then lay on the sand mortar, and afterwards polish it off with the powdered marble. After the vaultings have been polished, set the impost mouldings directly beneath them. These obviously ought to be made extremely slender and delicate, for when they are large, their weight carries them down, and they cannot support themselves. Gypsum should by no means be used in their composition, but powdered marble should be laid on uniformly, lest gypsum, by setting too quickly should keep the work from drying uniformly. We must also beware of the ancients' scheme for vaultings; for in their mouldings the soffits overhang very heavily, and are dangerous.

4. Some mouldings are flat, others in relief. In rooms where there has to be a fire or a good many lights, they should be flat, so that they can be wiped off more easily. In summer apartments and in exedrae where there is no smoke nor soot to hurt them, they should be made in relief.

It is always the case that stucco, in the pride of its dazzling white, gathers smoke not only from its own house but also from others.

5. Having finished the mouldings, apply a very rough rendering coat to the walls, and afterwards, when the rendering coat gets pretty dry, spread upon it the layers of sand mortar, exactly adjusted in length to rule and line, in height to the plummet, and at the angles to the square. The stucco will thus present a faultless appearance for paintings. When it gets pretty dry, spread on a second coat and then a third. The better the foundation of sand mortar that is laid on, the stronger and more durable in its solidity will be the stucco.

6. When not less than three coats of sand mortar, besides the rendering coat, have been laid on, then, we must make the mixture for the layers of powdered marble, the mortar being so tempered that when mixed it does not stick to the trowel, but the iron comes out freely and clean from the mortar trough. After this powdered marble has been spread on and gets dry, lay on a medium second coat. When that has been applied and well rubbed down, spread on a finer coat. The walls, being thus rendered solid by three coats of sand mortar and as many of marble, will not possibly be liable to cracks or to any other defect.

7. And further, such walls, owing to the solid foundation given by thorough working with polis.h.i.+ng instruments, and the smoothness of it, due to the hard and dazzling white marble, will bring out in brilliant splendour the colours which are laid on at the same time with the polis.h.i.+ng.

These colours, when they are carefully laid on stucco still wet, do not fade but are permanent. This is because the lime, having had its moisture burned out in the kiln, becomes porous and loses its strength, and its dryness makes it take up anything that may come in contact with it. On mixing with the seeds or elements that come from other substances, it forms a solid ma.s.s with them and, no matter what the const.i.tuent parts may then be, it must, obviously, on becoming dry, possess the qualities which are peculiar to its own nature.

8. Hence, stucco that is properly made does not get rough as time goes on, nor lose its colours when it is wiped off, unless they have been laid on with little care and after it is dry. So, when the stucco on walls is made as described above, it will have strength and brilliancy, and an excellence that will last to a great age. But when only one coat of sand mortar and one of fine marble have been spread on, its thin layer is easily cracked from want of strength, and from its lack of thickness it will not take on the brilliance, due to polis.h.i.+ng, which it ought to have.

9. Just as a silver mirror that is formed of a thin plate reflects indistinctly and with a feeble light, while one that is substantially made can take on a very high polish, and reflects a brilliant and distinct image when one looks therein, so it is with stucco. When the stuff of which it is formed is thin, it not only cracks but also soon fades; when, however, it has a solid foundation of sand mortar and of marble, thickly and compactly applied, it is not only brilliant after being subjected to repeated polis.h.i.+ngs, but also reflects from its surface a clear image of the beholder.

10. The Greek stucco-workers not only employ these methods to make their works durable, but also construct a mortar trough, mix the lime and sand in it, bring on a gang of men, and beat the stuff with wooden beetles, and do not use it until it has been thus vigorously worked. Hence, some cut slabs out of old walls and use them as panels, and the stucco of such panels and "reflectors" has projecting bevelled edges all round it.

11. But if stucco has to be made on "wattle and daub," where there must be cracks at the uprights and cross-sticks, because they must take in moisture when they are daubed with the mud, and cause cracks in the stucco when they dry and shrink, the following method will prevent this from happening. After the whole wall has been smeared with the mud, nail rows of reeds to it by means of "fly-nails," then spread on the mud a second time, and, if the first rows have been nailed with the shafts transverse, nail on a second set with the shafts vertical, and then, as above described, spread on the sand mortar, the marble, and the whole ma.s.s of stucco. Thus, the double series of reeds with their shafts crossing on the walls will prevent any chipping or cracking from taking place.

CHAPTER IV

ON STUCCO WORK IN DAMP PLACES, AND ON THE DECORATION OF DINING ROOMS

1. Having spoken of the method by which stucco work should be done in dry situations, I shall next explain how the polished finish is to be accomplished in places that are damp, in such a way that it can last without defects. First, in apartments which are level with the ground, apply a rendering coat of mortar, mixed with burnt brick instead of sand, to a height of about three feet above the floor, and then lay on the stucco so that those portions of it may not be injured by the dampness. But if a wall is in a state of dampness all over, construct a second thin wall a little way from it on the inside, at a distance suited to circ.u.mstances, and in the s.p.a.ce between these two walls run a channel, at a lower level than that of the apartment, with vents to the open air. Similarly, when the wall is brought up to the top, leave airholes there. For if the moisture has no means of getting out by vents at the bottom and at the top, it will not fail to spread all over the new wall. This done, apply a rendering coat of mortar made with burnt brick to this wall, spread on the layer of stucco, and polish it.

2. But if there is not room enough for the construction of a wall, make channels with their vents extending to the open air. Then lay two-foot tiles resting on the margin of the channel on one side, and on the other side construct a foundation of pillars for them, made of eight-inch bricks, on top of each of which the edges of two tiles may be supported, each pillar being not more than a hand's breadth distant from the wall.

Then, above, set hooked tiles fastened to the wall from bottom to top, carefully covering the inner sides of them with pitch so that they will reject moisture. Both at the bottom and at the top above the vaulting they should have airholes.

3. Then, whitewash them with lime and water so that they will not reject the rendering coat of burnt brick. For, as they are dry from the loss of water burnt out in the kiln, they can neither take nor hold the rendering coat unless lime has been applied beneath it to stick the two substances together, and make them unite. After spreading the rendering coat upon this, apply layers of burnt brick mortar instead of sand mortar, and finish up all the rest in the manner described above for stucco work.

4. The decorations of the polished surfaces of the walls ought to be treated with due regard to propriety, so as to be adapted to their situations, and not out of keeping with differences in kind. In winter dining rooms, neither paintings on grand subjects nor delicacy of decoration in the cornice work of the vaultings is a serviceable kind of design, because they are spoiled by the smoke from the fire and the constant soot from the lamps. In these rooms there should be panels above the dadoes, worked in black, and polished, with yellow ochre or vermilion blocks interposed between them. After the vaulting has been treated in the flat style, and polished, the Greek method of making floors for use in winter dining rooms may not be unworthy of one's notice, as being very inexpensive and yet serviceable.

5. An excavation is made below the level of the dining room to a depth of about two feet, and, after the ground has been rammed down, the ma.s.s of broken stones or the pounded burnt brick is spread on, at such an inclination that it can find vents in the drain. Next, having filled in with charcoal compactly trodden down, a mortar mixed of gravel, lime, and ashes is spread on to a depth of half a foot. The surface having been made true to rule and level, and smoothed off with whetstone, gives the look of a black pavement. Hence, at their dinner parties, whatever is poured out of the cups, or spirted from the mouth, no sooner falls than it dries up, and the servants who wait there do not catch cold from that kind of floor, although they may go barefoot.

CHAPTER V

THE DECADENCE OF FRESCO PAINTING

1. For the other apartments, that is, those intended to be used in Spring, Autumn, and Summer, as well as for atriums and peristyles, the ancients required realistic pictures of real things. A picture is, in fact, a representation of a thing which really exists or which can exist: for example, a man, a house, a s.h.i.+p, or anything else from whose definite and actual structure copies resembling it can be taken.

Consequently the ancients who introduced polished finis.h.i.+ngs began by representing different kinds of marble slabs in different positions, and then cornices and blocks of yellow ochre arranged in various ways.

2. Afterwards they made such progress as to represent the forms of buildings, and of columns, and projecting and overhanging pediments; in their open rooms, such as exedrae, on account of the size, they depicted the facades of scenes in the tragic, comic, or satyric style; and their walks, on account of the great length, they decorated with a variety of landscapes, copying the characteristics of definite spots. In these paintings there are harbours, promontories, seash.o.r.es, rivers, fountains, straits, fanes, groves, mountains, flocks, shepherds; in some places there are also pictures designed in the grand style, with figures of the G.o.ds or detailed mythological episodes, or the battles at Troy, or the wanderings of Ulysses, with landscape backgrounds, and other subjects reproduced on similar principles from real life.

3. But those subjects which were copied from actual realities are scorned in these days of bad taste. We now have fresco paintings of monstrosities, rather than truthful representations of definite things.

For instance, reeds are put in the place of columns, fluted appendages with curly leaves and volutes, instead of pediments, candelabra supporting representations of shrines, and on top of their pediments numerous tender stalks and volutes growing up from the roots and having human figures senselessly seated upon them; sometimes stalks having only half-length figures, some with human heads, others with the heads of animals.

4. Such things do not exist and cannot exist and never have existed.

Hence, it is the new taste that has caused bad judges of poor art to prevail over true artistic excellence. For how is it possible that a reed should really support a roof, or a candelabrum a pediment with its ornaments, or that such a slender, flexible thing as a stalk should support a figure perched upon it, or that roots and stalks should produce now flowers and now half-length figures? Yet when people see these frauds, they find no fault with them but on the contrary are delighted, and do not care whether any of them can exist or not. Their understanding is darkened by decadent critical principles, so that it is not capable of giving its approval authoritatively and on the principle of propriety to that which really can exist. The fact is that pictures which are unlike reality ought not to be approved, and even if they are technically fine, this is no reason why they should offhand be judged to be correct, if their subject is lacking in the principles of reality carried out with no violations.

5. For instance, at Tralles, Apaturius of Alabanda designed with skilful hand the scaena of the little theatre which is there called the [Greek: ekklesiasterion], representing columns in it and statues, Centaurs supporting the architraves, rotundas with round roofs on them, pediments with overhanging returns, and cornices ornamented with lions' heads, which are meant for nothing but the rainwater from the roofs,--and then on top of it all he made an episcaenium in which were painted rotundas, porticoes, half-pediments, and all the different kinds of decoration employed in a roof. The effect of high relief in this scaena was very attractive to all who beheld it, and they were ready to give their approval to the work, when Licymnius the mathematician came forward and said that (6.) the Alabandines were considered bright enough in all matters of politics, but that on account of one slight defect, the lack of the sense of propriety, they were believed to be unintelligent. "In their gymnasium the statues are all pleading causes, in their forum, throwing the discus, running, or playing ball. This disregard of propriety in the interchange of statues appropriate to different places has brought the state as a whole into disrepute. Let us then beware lest this scaena of Apaturius make Alabandines or Abderites of us. Which of you can have houses or columns or extensive pediments on top of his tiled roof? Such things are built above the floors, not above the tiled roofs. Therefore, if we give our approval to pictures of things which can have no reason for existence in actual fact, we shall be voluntarily a.s.sociating ourselves with those communities which are believed to be unintelligent on account of just such defects."

7. Apaturius did not venture to make any answer, but removed the scaena, altered it so that it conformed to reality, and gave satisfaction with it in its improved state. Would to G.o.d that Licymnius could come to life again and reform the present condition of folly and mistaken practices in fresco painting! However, it may not be out of place to explain why this false method prevails over the truth. The fact is that the artistic excellence which the ancients endeavoured to attain by working hard and taking pains, is now attempted by the use of colours and the brave show which they make, and expenditure by the employer prevents people from missing the artistic refinements that once lent authority to works.

8. For example, which of the ancients can be found to have used vermilion otherwise than sparingly, like a drug? But today whole walls are commonly covered with it everywhere. Then, too, there is malachite green, purple, and Armenian blue. When these colours are laid on, they present a brilliant appearance to the eye even although they are inartistically applied, and as they are costly, they are made exceptions in contracts, to be furnished by the employer, not by the contractor.

I have now sufficiently explained all that I could suggest for the avoidance of mistakes in stucco work. Next, I shall speak of the components as they occur to me, and first I shall treat of marble, since I spoke of lime at the beginning.