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THE AMERICAN VIGNOLA
The Five Orders
A BUILDING is a shelter from rain, sun, and wind. This implies a Roof, and Walls to support it. If the walls entirely enclose the space within, there are Doorways for access, and Windows for light. Roofs and walls, doors and windows are the essential features of buildings.
Roofs may be flat, sloping, or curved. A roof with one slope is called a Lean-to, Fig. 1. When two sloping roofs rest upon parallel walls and lean against one another, they meet in a horizontal Ridge, Fig. 2, at the top, and form a Gable at each end. Roofs that rise from the same wall in opposite directions form a Horizontal Valley, Fig. 3, at the wall. If two walls make a projecting angle, their roofs intersect in an inclined line called a Hip, Fig. 4. If the walls meet in a reentering angle, the inclined line of intersection is called a Valley. Circular walls carry conical, Fig. 5 (a) or domical roofs, Fig. 5 (b).
If there is more than one story, the flat roof of the lower story becomes the Floor of the story above. If the roof extends beyond the wall that supports it, the projection is called the Eaves, Fig. 6. If the wall also projects, to support the extension of the roof, the projection is called a Cornice, Fig. 7. The principal member of a cornice, which projects like a shelf and crowns the wall, is called a Corona, Fig. 8.
Walls are generally made wider just at the bottom, so as to get a better bearing on the ground. This projection is the Base, Fig. 9. A similar projection at the top is called a Cap, or, if it projects much, a Cornice, as has been said. A low wall is called a Parapet. A short piece of wall about as long as it is thick is called a Post, and if it supports something, a Pedestal, Fig. 10, the part between its Cap and Base is then the Die. A tall post is called a Pier, Fig. 11, if it is square, and a Column if it is round. Caps of piers and columns are called Capitals, and the part between the Cap and the Base, the Shaft. The flat upper member of a Capital is called the Abacus.
A beam that spans the space between two piers or columns, or between a pier or column and a wall, is called an Architrave, or Epistyle. Above it, between the Architrave and the Cornice, there is generally a little strip of wall called the Frieze. Architrave, Frieze, and Cornice constitute the Entablature. A series of columns is called a Colonnade, Fig. 12. The spaces between piers or columns are sometimes spanned by Arches, a series of which is called an Arcade, Fig. 13.
The space between two parallel walls is sometimes covered by a sort of continuous arch, called a Vault, instead of by a floor or roof, Fig. 14.
The under surface of a beam or architrave is called its Soffit, and the same name is used also for the Intrados, or under surface of an arch or vault. The upper surface, or back of an arch, is called the Extrados, and the triangular space of wall above is called a Spandrel.
The Wall, the Pier, and the Column, with or without a Pedestal, constitute the chief supporting members; the Frieze and Cornice, with the roof that rests upon them, constitute the chief part of the load they carry. The Architrave, the Arches, and the Spandrels form part of the load, relatively to what is below them, but are supporting members relatively to what is above them.
Besides being valuable as a shelter, a building may be in itself a noble and delightful object, and architects are builders who, by giving a building good proportions and fine details, and by employing beautiful materials, make it valuable on its own account, independently of its uses. Their chief instruments in this work are Drawings, both of the whole building and, on a larger scale, of the different features which compose it and of their details, which are often drawn full size. These drawings comprise Plans, Sections, Elevations, and Perspective Views, Fig. 15. They serve to explain the intention of the architects to their clients and to their workmen.
THE simplest decorative details and those that are most universally used in buildings are called Moldings. They are plane or cylindrical surfaces, convex, concave, or of double curvature, and they are sometimes plain and sometimes enriched by carving. They are called by various technical names: Greek, Latin, Italian, French, and English. The cross-section of a molding is called its Profile.
A small plane surface is called a Band, Face, or Fascia, Fig. 16, and if very small a Fillet, Raised or Sunk, Fig. 17, Horizontal, Vertical, or Inclined.
A convex molding is called an Ovolo, Fig. 18, Torus, Fig. 19, or Three-quarter Molding, Fig. 20, according to the amount of the curvature of its profile. A small Torus is called a Bead, Fig. 21, Astragal, or Reed, and an elliptical one, a Thumb Molding, Fig. 22. Concave moldings are, in like manner, called Cavetto, Fig. 23, Scotia, Fig. 24, or Threequarter Hollow, but the term Scotia (darkness) is often used for any hollow molding. A Cavetto tangent to a plane surface is called a Congé, Fig. 25.
A molding with double curvature is called a Cyma, or Wave Molding. If the tangents to the curve at top and bottom are horizontal, as if the profile were cut from a horizontal wavy line, it is called a Cyma Recta, Fig. 26; if vertical, as if cut from a vertical line, a Cyma Reversa, Fig. 27. The Cyma Recta is sometimes called Cyma Reversa, Fig. 26 (c), when it is turned upside down. But this leads to confusion. The Cymas vary also, Fig. 28, in the shape and relative size of their concave and convex elements. A small Cyma is called a Cymatium. A small molding placed above a Band, or any larger molding, as a decoration, is also called a Cymatium, Fig. 29, whatever its shape.
When a convex and a concave molding, instead of being tangent, come together at an angle, they constitute a Beak Molding, Fig. 30.
Some architectural features, such as Bases, Caps, and Balusters, consist entirely of moldings. Others consist mainly of plane surfaces, moldings being employed to mark the boundary between different features, as between the Architrave and Frieze, or between different members of the same feature, as between the Shaft of a column and its Capital, Fig. 31. In these cases the moldings, since they occur on the edges of the stone blocks, indicate, while they conceal, the position of the joints of the masonry. Moldings are often placed also in the internal angle where two plane surfaces meet, as is the case between the Frieze and the Corona of the Cornice, and under the Abacus of the Capital. When placed upon the external angle formed by two planes, they are, in the Gothic Styles, Fig. 32, often cut in, so as to lie below the surface of both planes, but in the Classical Styles, they project beyond the plane of one of the surfaces, like a little cornice, as is often seen in the Abacus of a Capital.
Horizontal Moldings, separating plane surfaces, are called a String-Course, Fig. 33.
TABLE OF MOLDINGS, PLATE I
Plane.—Face, Band, or Fascia; Beveled, Inclined, or Splay Face; Fillet, vertical, horizontal, or beveled, Raised or Sunk.
Convex.—Ovolo, or Quarter Round; Torus, or Half Round; Thumb Molding, or Elliptical Torus; Three-quarter Round; Bead, Astragal, or Reed; Three-quarter Bead.
Concave.—Cavetto or Quarter Hollow; Congé; Half Hollow; Scotia; Three-quarter Hollow.
Double Curvature.—Cyma Recta; Cyma Reversa; Cymatium; Beak Molding.
Besides the differences of size and shape already mentioned, and indicated in the table, moldings of the same name differ in the kind of curve they employ. They may be arcs, either of circles, ellipses, parabolas, or hyperbolas, or of any other curve
DIFFERENT systems of construction have prevailed among different races, some employing only the Beam and Column, some also the Arch and Vault. In the choice of moldings, also, some have adopted one set of forms, some another. The forms employed by the Greeks and Romans constitute what are called the Classical Styles; those used in the Middle Ages, the Byzantine, Romanesque, and Gothic Styles. Some of the Gothic moldings have special names, such as Boltel, Scroll, etc.
At the close of the Middle Ages, about four hundred years ago, the Classical styles were revived, as the Medieval styles have been during the last hundred years. Both are now in use. The styles of Egypt, India, and China are employed only occasionally and as a matter of curiosity.
IN the Classical styles, several varieties of Column and Entablature are in use. These are called the Orders. Each Order, Fig. 34, comprises a Column with Base, Shaft, and Capital, with or without a Pedestal, with its Base, Die, and Cap, and is crowned by an Entablature, consisting of Architrave, Frieze, and Cornice. The Entablature is generally about one-fourth as high as the Column, and the Pedestal one-third, more or less.
The principal member of the Cornice is the Corona, Fig. 35. Above the Corona, the Cornice is regularly terminated by a member originally designed to serve as a gutter to receive the water running down the roof. It generally consists of a large Cyma Recta, though the Ovolo and the Cavetto are often used. It is called the Cymatium, in spite of its large size, and whatever its shape.
NOTE.—The word Cymatium thus has three meanings: (1) A small Cyma. (2) A small crowning member, of whatever shape, though it is most frequently a Cyma Reversa. (3) The upper member of a Cornice, occupying the place of a gutter, whatever its shape, though it is generally a large Cyma Recta. In Classical Architecture, the Cyma Recta seldom occurs, except at the top of the Cornice and at the bottom of the Pedestal.
It would seem as if a cornice that occurs at the top of a wall and carries the edge of a roof would properly have a Cymatium, this being the place for a gutter, and that Cornices used as String Courses, half way up a wall, would naturally be without this member. But the significance of the Cymatium has frequently been overlooked, in ancient times and in modern. Many Greek temples have a Cymatium on the sloping lines of the gable, where a gutter would be useless, Fig. 120, and none along the Eaves, and in many modern buildings the cornices are crowned by large Cymatia in places where there are no roofs behind them.
The Corona is supported by a Molding or group of Moldings, called the Bed Mold. A row of brackets, termed Blocks, Fig. 36, Modillions, or Mutules, Fig. 37, according to their shape, resting on the Bed Mold and supporting the soffit of the Corona, is often added. At the top of the Architrave is a projecting molding that, when square, is called a Tnia, and the face of the Architrave is often broken up into two or three Bands or Fascias, Fig. 38, each of which often carries a small molding as a Cymatium or covering member.
The Abacus of the Capital also has a sort of bed mold beneath it, which, when convex, is called an Echinus, Fig. 39, from the sea shell, Fig. 40, which it resembles in shape. The little Frieze below it is called the Necking. But if the bed mold under the Abacus is concave, it dies into the necking like a large Congé, and the two together constitute the Bell of the Capital, Fig. 41. The Abacus is square in plan, but the Echinus, or the Bell below it, is round, like the column.
At the top of the shaft is a member called the Astragal, consisting of a Bead, Fillet, and Congé. It has a flat surface on top, as wide as the projection of the Congé, Fig. 42. At the bottom of the shaft is another Congé, called the Apophyge, below which is a broad fillet called the Cincture, Fig. 43. The Base generally has, below the base moldings, a plain member called the Plinth, which is square in plan like the Abacus.
The Shaft diminishes as it rises, Fig. 44, and the outline is not straight, but curved. This curve, which is called the Entasis, or bending, as of a bow, generally begins one-third of the way up, the lower third being cylindrical. The Entasis is not to be confounded with the Diminution, which is generally one-sixth, the upper Diameter being five-sixths of the lower.
The Pedestal also generally has a Corona and Bed Mold, but no gutter, and sometimes a Frieze, or Necking, above the Die, and a Base Molding and Plinth below it.
In the choice and use of moldings, the tastes and fashions of the Greeks and Romans were quite contrary to those of their successors in the Middle Ages. The Ancients preferred to use vertical and horizontal surfaces at right angles to each other, and seldom used an oblique line, or an acute or obtuse angle, as the Gothic architects did. They also preferred the Cyma Reversa, seldom employing the Cyma Recta, which in the Middle Ages was rather the favorite. Moreover, as has been said, the Gothic architects, in decorating a corner or edge, often cut it away to get a molding, but the Ancients raised the molding above the plane of the surface to which it was applied. In the composition and sequence of moldings also, the Classical architects generally avoid repetition, alternating large and small, plain and curved, convex and concave. The convex and concave profiles seldom describe an arc of more than 180 degrees, and except in the case of the Beak Molding and of the Bead, moldings are always separated by Fillets. When a molding is enriched, it is generally by carving ornamental forms, Fig. 45, upon it which resemble its own profile. The Greeks frequently employed elliptical and hyperbolic profiles, while the Romans generally used arcs of circles.
Among the Greeks, the forms, Fig. 46, used by the Doric race, which inhabited Greece itself and had colonies in Sicily and Italy, were much unlike those of the Ionic race, which inhabited the western coast of Asia Minor, and whose art was greatly influenced by that of Assyria and Persia. The Romans modified the Ionic and Doric styles, Fig. 47, and also devised a third, which was much more elaborate than either of them, and employed brackets, called Modillions, in the Cornice. This they called the Corinthian, Fig. 48. They used also a simpler Doric called the Tuscan, Fig. 49, and a cross between the Corinthian and Ionic called the Composite, Fig. 50. These are the Five Orders. The ancient examples vary much among themselves and differ in different places, and in modern times still further varieties are found in Italy, Spain, France, Germany, and England.
The best known and most admired forms for the Orders are those worked out by Giacomo Barozzi da Vignola, in the 16th century, from the study of ancient examples. The Orders that are shown in the large Plates almost exactly follow Vignola's rules.
VIGNOLA'S ORDERS—PLATE II
PLATE II shows the proportions of the Orders according to Vignola, in terms of the lower diameter of the columns. These vary in height from seven diameters to ten.
NOTE.—It is worth noting that, in ordinary handwriting, the T, for Tuscan, looks like a 7; D, for Doric, like an 8; I, for Ionic, like a 9; Co, for Corinthian and Composite reminds one of 10.
The Entablature is in all of them ordinarily one-fourth the height of the column, but it is sometimes made as small as one-fifth. The projection of the Cornice is the same as its height, except in the Doric Order, where it is greater. The lower band of the Architrave is made to come in line with the upper face of the shaft.
But it is only when seen in elevation that these relations obtain. When seen in perspective, as is generally the case, the cornice appears much larger, in proportion, and the frieze and architrave, being foreshortened, much smaller, and the architrave overhangs the shaft, Figs. 53 and 57.
In the Greek Orders, the Column is from five to ten diameters in height and the Entablature always about two diameters. In the Greek Orders, accordingly, the taller the Column, the lighter the Entablature, relatively; but in the Roman Orders, the taller the Column, the heavier the Entablature, actually. It follows that the weight of the Greek Entablature is proportioned to the diameter of the Column, irrespective of its height; of the Roman to the height of the Column, regardless of its diameter. The Romans put the least weight on the shortest and strongest supports. The Greek plan shows more regard to principles of construction, the Roman to principles of decorative composition.
Vignola used half of the lower diameter of the Column as his unit of measure, or Module. This he divided into twelve Parts for the Tuscan and Doric Orders, and into eighteen Minutes for the others, and he gives all the dimensions both of the larger members and of the moldings in terms of Modules and Parts, or Minutes, sometimes using even the quarter. Minute, or one one-hundred-and-forty-fourth of a Diameter. But it is equally practicable and more convenient to use the whole Diameter as a unit of measure, dividing it only into Fourths and Sixths, and occasionally using an Eighth or a Twelfth.
Excerpted from THE AMERICAN VIGNOLA by William R. Ware. Copyright © 1994 Classical America. Excerpted by permission of Dover Publications, Inc..
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