Concrete, Cement, Plaster and Stucco History
The art of using mortars in some shape or other, is as old as civilization, as there is evidence of its use in ruins that date long before historical times, not only in the older countries of Asia and Europe, but also in the ruins of Mexico, Central America and Peru; and the workmen were evidently experts at the trade, for some of the remains of their work show that the work was done by men who not only had a knowledge of their trade, but also possessed a fair knowledge of the qualities of the materials they used. Plastering is one of the earliest instances of man's power of inductive reasoning, for when men built they plastered: at first, like the birds and the beavers, with mud; but they soon found a more lasting and more comfortable method, and the earliest efforts of civilization were directed to plastering.
So far as we yet know, some of the earliest plastering which remains excels in its scientific composition to that of the present day, telling of ages of experimental attempts. The pyramids of Egypt contain plaster work executed at least four thousand years ago (some, indeed, say a much longer period), and this, where violence has not disturbed it, still exists in perfection, outliving in durability the very rock it covers, where this is not protected by its shield of plaster. Dr. Flinders Petrie, in his 'Pyramids and Temples of Gizeh,' shows us how these master plasterers worked with the painters, the sculptors, and the architects. Indeed the plasterer's very tools remain, showing that the technical processes then were the same used now, for there are in Dr. Petrie's collection hand floats which in design, shape and purpose are precisely those which are in use today. Even canvas plaster was well known then, and by it were made the masks which still preserve on the mummy cases the lineaments of their occupants.
The plaster used by the Egyptians for their finest work was derived from burnt gypsum, and was therefore exactly the same as today's "plaster of paris." Its base was of lime stucco, which, when used on partitions, was laid in reeds, laced together with cords, for lathing, is in effect "three coat work," about 3/4 of an inch thick, haired and finished.
Nor was it merely for its beauty and comfort that plaster work was used. Even then its sanitary value was recognized, and the directions given in Leviticus xiv, 42-48, which was probably written about one hundred years before this date, show that the knowledge of its antiseptic qualities was widely known, and the practice of it regarded as religious duty.
Plaster was also used very early in Greek architecture, and in this case a true lime stucco of most exquisite composition, thin, fine and white. Some has been found at Mycenae, a city of Homeric date. It existed in perfection in Greece about five hundred years before the Christian era. With this the temples were covered externally, and internally where they were not built of marble, and in some cases where they were. This fine stucco was often used as a ground on which to paint their decorative ornament, but not infrequently left quite plain in its larger masses, and some of it remains in very fair preservation even to this day. The Temple of Apollo at Bassae, built of yellow sandstone about 470 B. C, has on its columns the remains of a fine white stucco.
Pavements of thick, hard plaster, stained, of various colors, were common in the Greek temples. One of these, that of the Temple of Jupiter Panhellenius at Aegina, built about 570 B. C., is described as existing in the early part of the century, in good condition, though the temple itself was destroyed. At Agrigentum plaster still exists in a perfect state, though scarcely thicker than an egg-shell, on the sheltered parts of a temple built at least three hundred years B.C., yet the unprotected stone was weather worn and decayed.
What care the ancient Greeks bestowed on their stucco may be inferred from Pliny's statement that in the temple at Elis about 450 B. C., Panaenus, the nephew of Phidias, used for the groundwork of his picture "stucco mixed with milk and saffron, and polished with spittle rubbed on by the ball of the thumb, and," says he, "it still retains the odor of saffron." Lysippus, the first of the Greek "realists" in sculpture, was the first who took casts of the faces of living sitters about 300 B. C, so the art of plaster casting must have advanced a good deal by that time, as he made presents of copies to his friends.
Whether the Greeks used stucco for modeling is a somewhat doubtful point amongst antiquarians. Pausanius, who describes the temple at Stymphalus, an almost deserted and ruined city when he visited it about 130 A. D., describes the ceiling of the Temple of the Stymphalides, built about 400 B. C., as being "either of stucco or carved wood," he could not decide which, but his very doubt would imply that stucco or wood were equally common. This ceiling was ornamented with panels and figures of the harpies—omens of evil, half woman and half bird, with outspread wings. He also mentions a statue of Bacchus in "colored stucco." Of course these are not definite proofs of early Greek stucco modeling, but as the city of Stymphalus had decayed and become depopulated before 200 B. C, there is certainly presumptive evidence of the ancient practice of the art. Again, figures of unburnt earth are mentioned in contradistinction to those of terra cotta, and sundry other allusions to plastic work occur, which lead one to believe that quite early in Greek art this mode of using plaster began. At any rate it was early introduced into Magna Grecia—the earliest Southern Italian colony of the Greeks; and it seems that this technique was imported rather than invented by them. Thence it spread to the Etruscans of Middle Italy, by whom both plain and modeled stucco was largely used. The practical Etruscans constructed the roads and the sewers, and gave health to Rome. The Latins added to their territory until it embraced half of Europe, giving wealth to Rome, and not till the luxury and comfort thus created did the artistic element of the Greek come in, giving beauty to Rome, and the day of decorative plaster work approached its noontide glory, making Rome the attraction of the world. There is little left of the very early plaster work of Rome. Some knowledge of that plaster work comes from Vitruvius, who wrote his book on architecture about 16 B. C, and dedicated it to the emperor, "in order to explain the rules and limits of art as a standard by which to test the merits of the buildings he had erected or might erect."
Vitruvius was a man who had traveled and seen much. He was with Julius Caesar as a military engineer in his African campaign in 46 B. C. Afterwards he became a designer of military engines, or what we should call head of the Ordnance Department, as well as a civil engineer. Thus he had practical and artistic training. Here is what he says on matters connected with plaster work in Book VII, Chapter 11. On tempering lime for stucco: ''This requires that the lime should be of the best quality, and tempered a long time before it is wanted for use; so that if any of it be not burnt enough, the length of time employed in slaking it may bring the whole mass to the same consistency." He then advises it to be chopped with iron hatchets, adding that "if the iron exhibits a glutinous substance adhering to it, it indicates the richness of the lime, and the thorough slaking of it." For cradling out, and for ceiling joists, he recommends "the wood to be of cypress, olive, heart of oak, box and juniper,'' as neither is liable to "rot or shrink." For lathing he specifies ''Greek reeds bruised and tied with cords made from Spanish broom," or if these are not procurable "marsh reeds tied with cords." On these a coat of lime and sand is laid, and an additional coat of sand is laid on to it. As it sets it is then polished with chalk or marble. This for ceilings. For plaster on wall he says: "The first coat on the walls is to be laid on as roughly as possible, and while drying, the sand and coat spread thereon. When this work has dried, a second and a third coat is laid on. The sounder the sand and coat is, the more durable the work will be. The coat of marble dust then follows, and this is to be so prepared that when used it does not stick to the trowel. Whilst the stucco is drying, another thin coat is to be laid on: this is to be well worked and rubbed, then still another, finer than the last. Thus with three coats and the same number of marble dust coats the walls will be solid, and not liable to crack. The wall that is well covered with plaster and stucco, when well polished, not only shines, but reflects images falling on it. The plasterers of the Greeks not only make their stucco work hard by adhering to these directions, but when the plaster is mixed, cause it to be beaten with wooden staves by a great number of men, and use it after this preparation. Hence some persons cutting slabs of plaster from ancient walls use them for tables and mirrors."
