The text presented here is not precisely as published by OUP, but modifications are minor. Illustrations are another matter. Where images used in the original book were not my copyright, I have in most cases been able to substitute links to sources on the web. See Image Acknowledgements.
Note. When this text was submitted as part of a PhD thesis in 1996, the Notes were greatly extended. As the reader may prefer to ignore them, they have been collected into separate web pages. They are a mixture of: simple page references; additional examples or quotations to justify generalisations; and some afterthoughts. As there are so many, the existence of a Note is indicated discreetly in the text below in the form [3.x]. (These are not links.) [Notes to Chapter 3.]
Introduction.
This chapter deals with the 'formal analysis' of buildings and structures: the perception in buildings of form, space, scale, 'movement', rhythm, proportion, balance, composition and other concepts developed in the world of the fine arts. The term is used to dissociate the pleasures of immediate perception from empathetic reactions such as nostalgia, awe, admiration, insecurity, or elation, which will be considered in later chapters. The following is a description of the way in which many people look at and respond to built form, based on their own account. Readers who have difficulty in accepting these experiences as real, should approach this chapter simply as a means of learning terms and concepts which will allow them to talk with architects and others about the visual qualities of a project.
For someone with a technological background, it may be annoying to see familiar words bent to unfamiliar uses. We read of 'movement', 'acceleration', and 'dynamics' in relation to immobile objects; of the 'weight' and even 'potential energy' of coloured surfaces; and of immobile columns 'boring' up through floor slabs when we know that somebody has taken particular care to avoid this type of failure. [3.1] However, such poetic metaphors are adopted for good reasons: because our language lacks a suitable term to describe an impression which the author experiences; or because a re-working of familiar words conveys that impression particularly well. If we wish to understand and communicate with those who have adopted or been schooled in such usage, we have little alternative but to accept it.
Differences in perception.
'Seeing' is largely the process of making sense of the blur of light on our retina by discovering in it patterns which can be related to mental images we have stored as a result of former experience. At all times we must choose where we wish to concentrate our vision, and how much detail we wish to take in. 'Seeing' and 'understanding' are closely related, as is illustrated by the fact that if someone proposes a new theory to us, we may reply 'I just don't see!', when what we mean is 'I do not understand' or 'I cannot fit the construction you place on that aspect of reality into my existing view of the subject'.
The drive to impose constructs on what we see is so powerful that our mind looks only for sufficient clues to suggest an expected pattern, and then fills in the rest. As a result, we often 'see' patterns that do not exist. When proof-checking a typescript we 'overlook' glaring spelling mistakes because we 'see' the familiar image of the correctly-spelt word. The reverse may also apply. We sometimes cannot 'see' what really is before us, because we do not know what patterns to expect. The novice anthropologist cannot 'see' bones and arrowheads lying on the ground which are 'obvious' to a more experienced colleague. It is obvious that a sort of 'apprenticeship in seeing' must be served in such cases, and this applies equally if we are to increase the richness and variety of our impressions of art and architecture.
An excellent way to commence at the purely visual level, largely avoiding architectural theory and philosophy, is to study books on how to sketch and photograph buildings. [3.2] There is no better way of learning to really look at the world around us than by attempting to draw it. We can develop a more keen eye for light and shade by examining the way in which artists are able to suggest the form of solids by hinting at the shadows which surround them (Fig. 3.1). They are careful to provide a centre of interest in a sketch to counter the tendency of the eye to wander. They ensure that the amount of detail and tonal contrast decreases from the centre outwards in order to simulate the loss of acuity at the periphery of vision. We can learn also from the fact that the artist's major problem is to decide how much detail to leave out, rather than how much to put in. These techniques tell us much about perception. As Guptill amongst others notes, the artist's job is to reproduce the mental impression we 'see', not the infinite detail that is really present in the object. [3.3]
Fig. 3.1. Form defined by shadow. (After Guptill 1946.)
Texts on architectural photography explain what aspects of buildings the artist considered important in composing the photograph, why a particular time of day was chosen, what adjustments were made to perspective, and how the development of the print was modified. These insights help us not only to study the way in which artists look at buildings, but also to interpret the photographs on which we depend for so much of our knowledge of world architecture.
Different habits in using our eyes are reinforced by different interests, to produce dissimilar perceptions. Engineers will more readily perceive the solidity, bulk, and immobility of walls which art critics see as 'receding' or 'advancing'. They are more likely to perceive the equilibrium of countervailing forces (the type measured in Newtons) in columns and cables, while the critic sees flowing lines and unidirectional 'movement'. Engineers have a probably justified reputation for being interested in detail. They are thus more likely to work outwards from details to overall form. Art critics and artists tend to look first at the overall composition; and the latter, drawing from life, sketch in the outlines of an object with broad strokes and then fill in only as many details as appear necessary to comprehension. [3.4]
The importance of the mental predisposition of the observer is illustrated many times in Rudolph Arnheim's The dynamics of architectural form (1977). In comparing the 'balance' of Nervi's Florence Stadium with that of the famous chair designed by Mies van der Rohe, he is obviously more interested in the visual 'weight' of the geometric shapes formed in side elevation, than in the static balance of forces. Elsewhere, he describes a haunched portal as a visual 'hybrid': as a cross between a rectangular portal and an arch. [3.5] As a result he experiences a 'tension' due to the fact that the reality falls part way between these two categories of opening. An engineer, accustomed to haunching in beams, and knowing that arched openings in walls do not function as true arches, would slot the two primary shapes into completely different mental categories, and would perhaps see the 'hybrid' shape simply as a clumsy example of baroque extravagance.
Differences in habits of perception occur also amongst artists. Representations of buildings are greatly influenced by the training and interests of those who drew them. Some are interested primarily in light and shade, while others emphasize outline. At a more fundamental level, Gombrich illustrates the remarkable difference between representations of the English lake district by native and Chinese artists. [3.6] Romantic paintings of the Australian landscape made by the first European artists to visit the continent have little to do with what we today see as the harshness of the Australian bush. [3.7]
It is perhaps for this reason that many writers on aesthetics argue that visual analysis can only be properly performed if all visual memories, as well as extraneous feelings and associations, are eliminated, leaving the observer free to concentrate on the direct impressions of the moment. It is, however, impossible to find a text in which this principle is actually put into practice.
The limitations of two-dimensional representation.
Before commencing our study of the purely visual qualities of buildings, it is appropriate to consider some of the limitations of the photographs and drawings on which we depend for our understanding of built form.
The way that our interests govern our perception is apparent in the photographs used in the literature of built form. Nervi's aircraft hangars are often displayed without their cladding in order to highlight the delicate tracery of his concrete trusses. Space frames and shells are frequently shown just prior to cladding. [3.8] Completed buildings of this type are often photographed at night or from an angle which allows a view clear through the structure, to avoid the daytime reflectivity of glass walls. [3.9] A tall structure may be photographed from its base with a very high camera angle to make it appear more dramatic and imposing. Such images remain with us and influence our perceptions when we view the building under everyday conditions. An interesting experiment is to make a photocopy of an architectural photograph, and then crop it progressively, noting how the perceived 'character' of the building changes as the scope of the view is reduced, and the sky, foreground, and adjacent buildings disappear.
Many photographs of Le Corbusier's Ronchamp Chapel (Fig. 3.2) illustrate a frequent practical problem. If the shutter is opened sufficiently to expose the detail on the east wall which is shaded by the overhang of the roof, the white tower in the background merges into the sky and is barely visible. If the shutter is closed in order to capture the tower, the east wall is lost in gloom. Some correction can be made during printing, but the camera does not have the versatility of the human eye. We depend on such fine differences in tone not only to indicate the shape of a building, but to give us the impression of volume in external form and interior space.
Fig. 3.2. Favoured view from the south-east of the chapel of Notre Dame du Haut, Ronchamp, Haute-Saône. 1955. Extreme tonal contrast poses problems for photographer and printer. (Archt: Le Corbusier.)
An important contribution to the illusion of depth is provided by perspective. The photographer is able to adjust this by choice of lens and of camera angle and by inclining the print during development. Lines which are horizontal in reality may be restored to the horizontal in the image, or left with a slight inclination. The increased angularity of the image in the latter case has a subtle effect on the mood of the photograph. These adjustments also affect the ratio of vertical to horizontal scale. Columns may thus appear farther apart in the adjusted view than in the original, giving an impression of a much more 'open' space. The extent to which this is done depends on the objectives of the photographer, architect, or owner. An even more important factor is the choice of viewpoint. This decides which features are to be emphasized and which omitted. It is usual to omit surrounding buildings so that the subject is seen out of context. [3.10]
Technologists might argue that the photographer should strive to overcome these difficulties in order to represent 'reality' as closely as possible. The renowned architectural photographer Eric de Maré thought otherwise. He admits that
"An undistinguished structure, situated in some grim desert of cultural sterility and seen mostly below the grey skies of this watery island, can be made to appear in a photograph like a masterpiece in a dream world where the sun is always blazing, the skies are the deepest Mediterranean blue, the trees eternally in leaf, the chiaroscuro pure drama - a world where the paintwork is always gleaming, the stucco never cracks and all materials possess a richness of texture to be directly experienced, possibly, only under the influence of mescalin." [3.11]
But, he asks, "why complain?"
"a recreative shot of part of a building seen under interesting conditions of light has often provided architects, through an original interpretation, with an inspirational thrill which they might not have experienced when seeing the whole building in actuality under less favourable conditions." [3.12]
Professional photographs of built form thus present a very different image from that of the sort of 'snap-shot' which the layman might take. [3.13] The question must be asked, both in the case of such 'glamour' photography and of architectural sketching and rendering, whether there is an intention to mislead. The answer is probably 'not to any criminal extent'. Presentation of buildings in their best light is no more reprehensible than putting on one's best suit for a job interview. Many designers probably believe that their building 'really' does look as they have shown it, because so much of perception occurs in the mind. In some quarters, both forms of representation are seen as art forms in themselves, the artwork being almost more important than the building, which becomes an inadequate realization of it.
Usually the economics of publishing limit representation in books to one or two photographs for each building. Difficulties in tracing ownership of copyright and obtaining artwork mean that certain views of a particular building come to dominate discussion. It is interesting to compare the impression given by the favoured view of Ronchamp shown in Fig. 3.2 with that provided by the much less common view of the north elevation (Fig. 3.3). Occasionally, sufficient photographs are provided to enable the reader to build up a reasonably comprehensive three-dimensional image of a building, and in recent decades there has been a welcome trend towards providing plans, sections, and isometric drawings. The type of cutaway drawing provided in texts such as Norwich (1979) and Flon (1988) are an additional help in gaining a complete understanding of a building. The problem of cost also ensures that we are introduced to many buildings through black-and-white photography, despite the fact that colour greatly influences response to built form.
Fig. 3.3. Ronchamp. The contrasting character of the north elevation.
On the basis of this analysis, it could be argued that a sketch must convey a more reliable impression of a building than a photograph. Unfortunately, a sketch is even more the product of the subjective processes of selection, and emphasizes just those characteristics which the artist considered important. The photograph, despite its inadequacies, provides a fuller representation of detail from which we have more hope of choosing what appears important and relevant to ourselves.
Thus all forms of two-dimensional representation are inadequate and liable to mislead. This problem was taken so seriously by E.T. Hall, the author of a book on perception entitled The hidden dimension, that he provided no illustrations whatsoever. [3.14] Unfortunately, most of us must rely on two-dimensional representation if we are to get to know the buildings of the world, and we must make the best of it. One way to reduce the danger of misinterpretation is to compare buildings which are within our reach with their published photographs. With practice we can then extrapolate better from photographs of unseen buildings to obtain a reasonably reliable impression of their complete form.
Keeping these difficulties in mind, it is now time to consider the various concepts that are employed in the 'formal' analysis of art and architecture.
Size and scale.
The size of a building, and of its elements such as entrances, windows, and interior spaces, has an important direct influence on our emotional response. It also affects our estimate of visual weight, which is important in terms of aesthetic evaluation and of emotional response to perceptions of harmony and balance.
At this stage we are concerned only with the process of estimating size by means of visual clues. This is a matter of establishing dimensions. An instinctive technique is to compare a building or one of its elements with a nearby object of known size: a process of scaling. If we are close to the element we may compare its size with our own. Otherwise we will pick up clues from the surrounding environment. The sizes of cars and people are reasonably well fixed. Trees and light-poles are perhaps a little less reliable.
Alternatively we may make comparisons with our mental image of what we consider to be the 'standard' size of regular building elements such as doors, windows, or bricks. The heights of steps and handrails are good indicators because it is difficult for architects to alter them much from human scale. In multi-storey buildings, economic constraints ensure that storey heights are reasonably consistent, at least above ground-floor level. Windows and doors should be reliable indicators, but architects may vary their scale precisely to manipulate the viewer's perception of size. We are thus very interested in cross-checking the inter-relationships between the sizes of the various elements of a building.
Once such elemental sizes and relationships have been established we are able to measure the size of an entire building by starting from the smaller elements and working upwards in magnitude. This process is least difficult when there is a succession of elements of gradually increasing size enabling us to 'step-up' easily from one range of element-sizes to the next: from steps or handrails to windows, to doors, to storey heights, and so on. The architects of the Renaissance are considered to have been adept at providing this continual progression. A glance at their buildings, with larger 'orders' of full building height superimposed on orders of more normal size, but all in the anticipated proportions, provides ample cues with which to build up an idea of the size of the building (Fig. 1.5).
More modern examples are provided by the boiler factory at Thun in Switzerland (Fig. 3.4) and the Calgary Saddledome (Fig. 3.5). In the latter, the massive size of the suspended roof is made more comprehensible by the gradual build-up through the large external staircases, whose presence and importance is emphasized by colour.
Fig. 3.4. Scale, proportion and brut concrete. The W.P. Müller boiler factory, Thun, Switzerland. 1959. (Archts: Atelier 5.) Photo: archINFORM
Fig. 3.5. Calgary Olympic Ice Stadium. ('Saddledome'). Calgary, Canada. 1983. Carefully proportioned and coloured ancillary forms match the scale and visual power of the suspended roof. (Struct. Engrs: Jan Bobrowski and Ptnrs. Archt: Graham McCourt.) Photo: PlanetWare.
In certain buildings the intervals between the sizes of the clues may be much more rapid, or may accelerate, or there may be a jump from very small clues to overall form with no intermediate stages at all. One would expect this most in large buildings with featureless walls, where no clues are provided on the building itself and the observer must make the connection from human size to total building size in one bound. However the assessment of size is almost as difficult when the only clues provided on the building are much smaller than its overall form, and where these elements are repeated apparently endlessly, as in the facade of many modern multi-storey buildings (Fig. 3.6). This is perhaps what Geoffrey Scott was talking about when he described the Natural History Museum in London as "smallness multiplied". [3.15] The same might be said of modern space frames. These have a built-in 'scale' in the sense of measured intervals, but when they cover large expanses it is little help to the observer, who must multiply the length of an individual chord member many times to arrive at the overall size. There is no gradation in scale except where the spacing of internal supports supplies a longer yardstick. [3.16]
Fig. 3.6. Menzies Building, Monash University, Clayton, Victoria. 1963, 1965. Repetitive (load-bearing) mullions provide little clue to scale. Unity in monotony is relieved by occupant-controlled blinds. Mullions and blinds provide contrasting textures. (Archts: Eggleston, Macdonald and Secomb. Struct. Engr: John Fowler of Irwin Johnston and Ptnrs.)
Architects may vary the intervals of size to control formal composition or to achieve emotional effect. Renaissance architects have a reputation for the skilful manipulation of scale in this way. A commonly-quoted example is Saint Peter's in Rome where the elements, including entrances and windows, are so well proportioned relative to each other and to the overall form, that people usually underestimate the size of the building until they are near it, at which stage they are overwhelmed by its true magnitude. The Renaissance practice of superimposing orders of different sizes is often praised as a means of keeping scale under control in buildings of monumental size. However, this does not seem to work when an adjacent building of more human size is available for comparison. [3.17]
Conventional formal criticism places little value on auditory perceptions. Obviously, these are of great importance in experiencing built form, and provide important clues concerning the size of internal spaces.
Proportion.
The concept of proportion has two slightly different components. One is related to shape. It is what most people are talking about when they ask of a column 'is it slender or squat?', or of a beam 'is it short, wide, and deep; or long, thin and shallow?' These questions concern the relationships between the major overall dimensions of the object. The other sense is related closely to scale. Proportion has thus been described as "the relation of one part to another and to the whole" and some writers use the word 'proportion' where 'scale' is used in this book. [3.18]
Over the millennia the subject has evoked intense interest amongst aestheticians and architects. There is some evidence that our brains are predisposed to accept certain proportional relationships as more pleasing than others. If people are asked to divide a length of rod into two non-equal parts, they are said to choose on average a ratio of about 1.6 to 1: the so-called 'golden mean'. Asked to draw a rectangle, they tend to draw the sides in a similar ratio. In classical times theorists thought that the ratios constituting the third, fifth, and the octave in music must reflect some fundamental principle of the universe, and that those same proportions, incorporated in buildings, would be as pleasing to the eye as they are to the ear.
In ancient architecture fairly consistent relationships were established between the diameter of a column and dimensions such as the height of its base and capital, the height of the entablature, and the spacing between columns. These proportions varied with time and location. The Roman Vitruvius described four basic systems, or 'orders': the Ionic, the Doric, the Corinthian, and the Tuscan [3.19]. Vitruvius was not dogmatic about their proportions, but during the Renaissance the treatise was 'rediscovered' and his descriptions began to acquire the status of hard rules.
Leone Battista Alberti (1404-72) developed the specifications, taking into consideration the evidence of extant buildings, and a century later Serlio started what John Summerson in The classical language of architecture (1980) calls the "process of embalming, of canonization". Throughout this period architects devoted much time to choosing proportions of rooms and apertures which they hoped would be found 'beautiful' or 'harmonious'. The theory was (and remains) that because these proportions accorded with the fundamental nature of the universe they were aesthetically pleasing to those people sufficiently sensitive to appreciate this resonance. At the same time, being based on practical experience of building, they ensured structural safety. Therefore there was seen to be a "natural rightness" about them. [3.20]
During the Gothic era the plans and facades of churches and the form of elements from arcades to pinnacles were derived from geometrical constructions, or tracés régulateurs based on isosceles and equilateral triangles, squares, and circles. [3.21]
Working in the opposite direction, many theorists have attempted to analyse buildings which are generally recognized as beautiful, in the hope of identifying the proportions which are the secret of their beauty. Although they are extremely enthusiastic about the results, it seems that if a line is drawn at 30, 45, or 60 degrees from the bottom corner of anything as complicated as the cross-section of a Gothic cathedral, it is almost certain to intersect a large number of apparently significant points, be they heads of statues, tips of pinnacles, or apexes of arches. It is doubtful that this has much to do with their beauty. [3.22] One of the best-known analyses of proportion in architecture is Rowe's Mathematics of the ideal villa (1976).
In our times Le Corbusier designed several buildings using his modulor system of exponential dimensions based on the Fibonacci series (Le Corbusier 1968). Steen Eiler Rasmussen argues convincingly that Corbusier's system is more idiosyncratic than rational [3.23] and it is generally agreed that the success of such architects lies more in their innate sense of proportion than in the systems they advocate. While it is true that beautiful and harmonious compositions may be formed from geometrical figures, the more successful are based on quite simple elements (Fig. 1.1).
A problem with traditional rules for proportioning is that they were developed for rectilinear and domed buildings and therefore have nothing to say about modern forms such as tents, shells, and suspended roofs. So far no theorist appears to have tackled these forms in a similarly prescriptive way. This is probably because their mathematics is more complex, and their geometry is largely imposed on the designer by the 'laws' of nature. (See, however, D'Arcy Thompson's analysis of complex form in nature (1917).)
Form and shape.
Rasmussen is amongst those who feel that solid 'form' cannot be discussed separately from the sort of space that is 'not-form'. [3.24] There is much to be said for this approach, but here they will be treated largely as distinct entities. The word 'form' is often applied to areas of paint on a canvas, and the intervening areas may be described as 'space'. Some writers draw a distinction between 'form' and 'shape', defining the latter as the outline or silhouette of an object.
It is worth recounting briefly some basic facts of perception in two dimensions. [3.25] Regular shapes such as circles and squares are easier to perceive than complex ones. Familiar forms are recognized more easily and quickly than unfamiliar ones. Large plain areas that are devoid of detail may prove disturbing to the eye, which will seek some aspect of interest, such as minor variations in colouring, or will travel constantly to the boundaries in search of interest (Fig. 3.7). Otherwise the greatest attention is devoted to objects within the outline which have potential meaning for the observer, such as the eyes and mouth in a portrait. Yarbus provides an example of a painting showing birch trees in a wood in which the eyes of participants in his experiment followed the dominant horizontal and vertical lines provided by the ground line and the tree trunks. [3.26]
Fig. 3.7. Eye movements during perception of portrait of Queen Nefertiti (Yarbus 1967). [Image not yet organised.]
He notes that
"… the number of details contained in an element of the picture does not determine the degree of attention attracted to this element … for in any picture, the observer can obtain essential and useful information by glancing at some details, while others tell him nothing new or useful." [3.27]
"Eye movements" he concludes "reflect the human thought processes". [3.28] It is to be expected that similar principles will apply to the perception of facades in buildings.
The appreciation of three-dimensional form requires the perception of depth. This process depends on many clues in addition to those provided by binocular vision. The more obvious are those provided by linear perspective and by difference in the intensity of light reflected from differently-oriented surfaces. These are the clues most used by contemporary western artists. They are very important in the perception of basic forms such as boxes, spheres, cylinders, cones, and domes, and more complex smooth forms such as that of an aircraft propeller blade.
Many other clues may be used in the perception of highly irregular or complex objects, including buildings and structures which consist of clusters of individual masses, or of many skeletal members. Gibson (1950) considers a number of clues which are relevant to the perception of space as well as form. [3.29] The distance of an element may be judged from the rate of change in its apparent size as the observer approaches. If the viewer makes a traverse past a complex structure, there is a difference in the rates of apparent relative movement of its elements. Those closer to the observer appear to be 'left behind' at a faster rate than those in the distance, an effect sometimes described as 'parallax' in architectural literature.
When the observer is stationary, information may be gained from the simple fact that the outlines of distant objects are interrupted by the shapes of objects which lie in front of them, and that if the observer is elevated, more distant objects appear higher in the field of view. Other clues are provided by the apparent size of objects whose 'real' size we know well, or the apparent difference in size of identical objects situated at different distances. Differences in tonal intensity of colours are also important, more distant objects having a paler hue. (These were the main clues used in paintings of the Gothic era.) The amount of textural detail that can be observed on surfaces provides further information, as does the apparent size of the 'grain' at different distances. This is particularly so if the size of the protruberences is well known, as in the case of a brick wall. More subtle clues to relative distance are related to the blur and double imagery that affects objects at distances other than that at which the eyes are focused.
Our perception of form is greatly influenced by our experience of linear perspective. In the case of simple forms such as box-like buildings, the effect of perspective may be enhanced by the provision of string courses and cornices. We often extrapolate from such clues to make assumptions about the shape of that portion of the building which is hidden from sight. [3.30] If a row of regular elements in a building is viewed from a single vantage point, the image of the elements gradually alters with distance (Fig. 3.22), providing additional information. When repeated forms do not lie on a straight line, we are able to build up an even clearer composite image of their shape (Fig. 3.8). The extra information is not always welcome. Billington notes frequently in his book The tower and the bridge (1983) how a bridge which looks slender and elegant in side elevation becomes disappointingly heavy when viewed from a position slightly off centre-line, as often occurs when making a curved approach to it.
Fig. 3.8. Repetition of differently-oriented objects permits clearer perception of form and develops complex rhythm. Sports Stadium, Riyadh, Saudi Arabia. (Architecture and conception: Fraser Roberts and Ptnrs with Geiger and Berger. Engrs: Jörg Schlaich and Partner.) [Photo: archINFORM.]
The fact that built form cannot be comprehended fully from a single vantage point is a source of difficulty for some aestheticians. Memory must come into play if the observer is to appreciate the entire architectural experience, and there are some who maintain that it is impossible to have a true aesthetic experience if one is not actually looking at the aesthetic object.
Thinking in three dimensions is not a simple process. The ability develops quite late in childhood, and remains under-developed in many adults. In the early stages of historical styles, representation even in sculpture is often two-dimensional. The heads of early Egyptian sphinxes comprised a combination of full-face and profile images. [3.31] Critics claim that each culture and era has its different way of perceiving three-dimensional form and space. [3.32] Rasmussen sees Gothic form as being always convex and the result of addition of further bulk to a basic core, as in the church piers of the time (Fig. 3.9a). He cites a sculpture of Saint George and the Dragon in which the beast is covered in, and partly composed of spiky protuberances. Significantly, he concentrates on the nature of the 'not-form' in writing that "no human being could possibly conceive of the shape of the space surrounding the dragon". In contrast, Renaissance architecture is generally seen as the creation of well-shaped cavities. The plan of Saint Peter's in Rome shows that what an engineer would call the structure of the building consists of what has been left after the 'cavities' have been, as it were, hollowed out from within a preconceived mass (Fig. 3.9b). [3.33]
|
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| Fig. 3.9 (a). Gothic form derived by addition to a basic core. Cross-section of a church pier. | Fig. 3.9 (b). Renaissance space 'hollowed out' within a pre-defined mass. Plan of St Peter's, Rome. 1546. (Michelangelo.) |
One way of comprehending complex forms is to identify in them some relationship to simpler forms. Alberti wrote that "a row of columns is indeed nothing else but a wall, open and discontinued in several places". [3.34] Arnheim (1977) discusses a similar perception of a row of columns in the Palazzo Chiericati. [3.35] Elsewhere he writes of Victorian lacework forming a boundary plane more 'dense' than that produced by a row of columns, and sees 'surfaces' of the Eiffel Tower defined by the latticework. [3.36]
Arnheim also points out that a box-like building with small windows will be seen as a container with holes punched in it, whereas one with large windows may be seen as a collection of room-size boxes, boards, and posts. [3.37] It is interesting to speculate at what ratio of window area to surface area these perceptions change. There may well be a range over which each 'Gestalt' is more or less equally attractive. If it is possible to construct in the mind a box from a building which is almost a box, it is also possible to see the building as a box from which part of the surface has been 'eroded' (Figs 3.10 and 7.6). Sometimes, of course this is because the architect actually designed the building in this way, starting with the abstract concept of box, and inserting areas of glazed surface or completely removing parts of the volume and envelope.
Fig. 3.10. Volume 'eroded' by glazed sections of envelope. Wastewater treatment facilities, Fitchburg, Mass. (Archt: Robert Pillsbury of Johnson-Hotvedt. Struct. Engrs: Camp Dresser and McKee.) [Photo: © Steve Rosenthal.]
Francis Ching, in his Architecture: form, space and order tackles the comprehension of form by defining a sort of 'language' of simple forms. [3.38] More complex forms may then be comprehended as assemblages of these elements, and the more frequent ways of assembling them may also be labelled. This is an appropriate approach in view of the fact that perception may be thought of as a process of pattern recognition. Ching sees form as built up from 'primary elements': points, lines, planes, and volumes. He then identifies as primary shapes the circle, triangle, and square, and lists the Platonic solids, the sphere, cylinder, cone, pyramid, and cube. These may then be 'transformed' by the processes of erosion or addition discussed above, to give two categories of complex volume: 'subtractive' and 'additive' volumes. Arrangements of elements are seen as either centralized, linear, radial, clustered, or grid-like.
Superimposition of the basic forms and arrangements are seen as leading to 'formal collisions' of geometry. The concept of 'collision' is a favourite in the world of criticism, and in a case such a the Sankt Paulus Kirche shown in Fig. 3.11, the body of the hall might be described as 'crashing through' the glazed semi-cylinder. Ching's list of collisions includes ground plans containing superimposed circles and squares, and superimposed grids which have been rotated relative to each other.
Fig. 3.11. Movement in architecture: one form perceived to 'crash' through another. (St Paulus Kirche, Velbert, Germany. Archt: Gottfried Böhm. Struct. Engr: Leopold Wolf.)
Space.
As Sinclair Gauldie has noted, there are times when we are very conscious of the space around us, particularly if we live in a split-level house or an attic with a low sloping ceiling. [3.39] We have a heightened awareness when we use a flight of stairs that is steep or one which changes direction. However, in these cases there is a sense of danger, or of dramatic change, which demands our attention. Under normal circumstances, it is necessary for us to make a conscious effort to appreciate the space around us.
There are several ways of conceiving of 'space'. The differences are quite subtle, but may have an important effect on our response. The first concept is reflected in Plato's description of space as "the mother and receptacle of all … things" [author's emphasis]. It exists quite independently of the existence of objects, and when they are introduced into it, it continues to permeate them. The second is characterized by Aristotle's idea that portions of space co-exist separately alongside those portions that are occupied by the objects. [3.40] A third approach is to concentrate on the idea that the space between or around objects is 'not-object'. Thus Ching envisages a relationship between form and space as a 'unity of opposites'. [3.41]
It is unfortunate that the English language makes no distinction between the sort of space which permeates everything, and the sort which is 'not-object'. Rasmussen tries to overcome this limitation by reserving the word 'space' for the Platonic concept, and using 'cavity' for 'not-object' when the latter is enveloped in material.
It is useful to examine some properties of space as a two-dimensional entity because this simplifies the discussion of a number of points, and relates directly to buildings in which the facade has special importance. Arnheim notes that painters and architects have a special perception of the nature, or 'qualities' of space (as not-object). They see the 'presence' of objects extending beyond their physical boundaries into some sort of zone of influence. Thus the space between the two objects shown in Fig. 3.12a may be considered "more actively and densely filled" than that between the shapes in Fig. 3.12b. Arnheim describes the space between two objects close together as "denser" or "more intense" than when they are far apart, in which case it is "looser and thinner". [3.42]
Fig. 3.12a. Space 'densely filled'.
Varying perceptions of space and figure. (After Arnheim 1977).
Fig. 3.12b. Space less densely filled.
Varying perceptions of space and figure. (After Arnheim 1977).
Space in a painting may be thought of as occupying the entire canvas, or as being only those parts which remain visible after the various 'figures' have been added. The latter approach leads to the concepts of 'figure' and 'ground' illustrated in Fig. 3.12(c). Even when the figures are abstract shapes, the observer has the impression that they have been added to a plain, receptive 'background'. However it is quite possible to alter the Gestalt so that what was first thought of as ground becomes figure. Artists apparently use this technique to study the balance of spaces and figures in a painting.
Fig. 3.12c. 'Figure' and 'Ground'.
Varying perceptions of space and figure. (After Arnheim 1977).
A similar choice may be made in Fig. 3.12(d) which can be seen either as a solid figure with two prongs enclosing a bullet-nosed space, or as a rectangle which has been invaded by something which is more tangible than 'space' and is pressing in from the right-hand side. The curved boundary can be seen as belonging to either figure, and psychologists label the resulting ambiguity 'contour rivalry'. The straight line is the only boundary in which this does not occur, because shapes either side of it are accorded equal value.
Fig. 3.12d. Contour rivalry: alternative Gestalts.
Varying perceptions of space and figure. (After Arnheim 1977).
Returning to the figures within a frame (Fig. 3.12c) Arnheim sees the space within the enclosed outlines as 'positive' and the rest as 'negative'. He considers the positive spaces have a tendency to expand which is resisted only by the countervailing tendency of adjacent positive spaces. There are thus visual 'forces' at work which in a balanced composition will appear to be in a state of equilibrium. A similar notion, this time of unbalanced expansion, is frequently reported in regard to built form. Domes (made of solid stone) are described as 'bulging' or 'pressing' outwards and suspended roofs (adequately supported by steel cables) as 'pressing in'.
There are a number of ways in which the nature of 'raw' space may be varied. Arnheim feels that the volume of internal space within a building envelope is of more importance to the observer than the surfaces which enclose it. However pillars and columns within this space may counteract the dominance of cavity over envelope, and "strengthen the … claim … of walls, ceiling, and floor" to an independent existence. Thus the crypt of an old church may be seen as an interplay between the voids of the vaults, and the equally strong solids of the piers. In Fig. 3.13 the visual interest of the piers is increased by their strong bases and capitals and by the alternation of ornament.
Fig. 3.13. Interplay of solid and void in the crypt of a church. [Photo: Courtauld Institute.]
Space may be considered to possess 'direction'. Its qualities are seen as fundamentally asymmetric because of our natural preference for the vertical over the horizontal direction. In plan, it may be given a directional emphasis by a number of factors. Hallways, corridors, and long rectangular spaces such as the naves of basilica-type churches have an in-built directionality. Sinclair Gauldie provides a series of floor plans of a church (Fig. 3.14(a)) showing how the sense of directionality may be emphasized in a rectangular building by having an entrance at one end, and an alcove at the other (1). The effect is increased if rows of columns or arcading are inserted parallel to the longitudinal walls (2). However the sense of directionality is lessened or made more complex when subsidiary cells such as side-chapels "invite a sideways glance" (3), or when an intermediate centre of attention is provided (4).
Fig. 3.14 (a). Hypothetical plans showing different qualities of directionality and impulse to movement in a church. (Gauldie 1969.)
Even exterior space may be given direction. In city squares it may be 'centralized' by means of a fountain or statue, or may be given a particular direction by the magnetism of a noteworthy facade or a building of special importance. The same sort of effect may be induced in an entire village or in the countryside by a dominating tower, while the construction of a bridge has been seen as affecting the perception of space between the banks of a river. [3.43]
We have seen how, for many people, form need not be precisely delimited by continuous surfaces. The same applies to the definition of space. A common instance is the 'false ceiling' defined by a grid of timber beams or metal slats, which is used to reduce the apparent height of tall rooms in old buildings, or to conceal the services in modern ones. Similarly, a row of columns, or the mullions of a glass wall may define a permeable but effective 'boundary' to an internal space. For many people, space may also be defined by the imagined extension of partial wall surfaces.
Effective delimitation may also be achieved by a change in floor level. Examples occur in 'split-level' houses, where this may be the only division between two rooms. In some modern churches two or three low steps provide a subtle division between choir and nave. Spaces may even be distinguished by variations in the nature or colour of the floor covering. These techniques obviously demand some effort of imagination on the part of the observer. Gauldie provides a number of floor-plans showing how they might be employed (Fig. 3.14b). He attributes the different perceptions in each case to the differing opportunities for freedom of movement.
Fig. 3.14 (b). Real and suggested division of space. (Gauldie 1969.)
Mies van der Rohe's renowned German State Pavilion for the Barcelona World Exhibition of 1929 (Fig. 3.15) provides an example of the gifted use of several of these effects. [3.44]
Fig. 3.15. Subtle demarcation of space by imagined extension of wall planes. Plan of the German Pavilion, International Exposition, Barcelona. 1929. (Archt: Mies van der Rohe.) [Plan archINFORM. (See also Sullivan.)]
The space within the hammer-beam roofs of small churches is effectively divided by the permeable boundaries formed in the plane of the 'trusses' (Fig. 3.16).
Fig. 3.16. Division of space in a hammer-beam roof. Trunch Church, Norfolk. (After Brandon and Brandon 1849).
Ching provides many illustrations showing how space may be not so much 'defined', as suggested in a subtle way. [3.45] An area of ground depressed slightly below grade level may define a 'space' much greater than the physically contained volume. Examples are sunken gardens and the 'conversation pits' found in some houses. An elevated plane, such as a simple wooden platform, may also lay claim to the space above it. Mies van der Rohe often provided his buildings with a deck, or platform, 'hovering' above ground level, approached by steps having a minimum of evident support (Fig. 3.17). The ancient Greeks chose sites such as the Acropolis, and the Aztecs built flat-topped pyramids for their temples, not only to impress those who observed them from below, but also because of the special nature of the space created on the summit.
Fig. 3.17. Minimalism, elegance, and rationalism in the Farnsworth House, Fox River, Plano, Illinois. 1950. Subtle definition of space by strong horizontal planes, glass, and light vertical members makes no strong distinction between 'inside' and 'outside' space. (Archt: Mies van der Rohe.) Photo: farnsworthhouse.org.
As Ching points out, vertical planes are more 'active' in our visual field than horizontal planes, and the delimitation of space is accordingly stronger. [3.46] For some people, even a single wall can define a sort of space adjacent to it. Within a certain zone, it can offer some privacy, and some shelter from sun, wind and unwanted views. Its height is an important consideration because it governs the degree of interruption caused to potential movement and vision. Two walls at right-angles define a more definite space, and two walls parallel to each other create a special kind of space similar to that in a short alleyway. Walls forming a 'U'-shaped plan provide a more clearly defined space. The ultimate sole use of vertical planes is total enclosure, as in a walled garden.
Ching refers to the Roman 'tetrastyle' as an example of the effect of columns on interior space. [3.47] A group of four columns in the internal courtyard of the house framed a rectangular space. There was a pool at ground level, and the roof above was left open. This motif was adopted by Palladio during the Renaissance, and has recently been re-applied by post-modern architects (Fig. 3.18).
Fig. 3.18. Definition of space by columns, well, and canopy. The Roman 'tetrastyle' revived in post-modern architecture. Moore House, Orinda, California. 1962. (Archt: Charles Moore.) [Image not yet organised.]
Because the 'surfaces' defined by rows of columns are mental constructs, they can be perceived as 'permeable'. Depending on the strength of the image, it is possible to speak of the degree of permeability or of its opposite, the 'degree of closure'. Space is said to 'escape' or 'leak out' when closure is not complete. Moore and Allen (1976) cite as instances the imaginative drawings of Piranesi where space "disappears into mind-boggling distances", and the mosque at Córdoba where "an orchard of columns fades into the dark distance and equivocates about the limits of the place and the position of spaces and objects within it". [3.48] A similar but less dramatic effect may be seen in the crypt illustrated in Fig. 3.13.
Permeability of vertical boundaries reduces the distinction between 'inside space' and 'outside space'. With the large glazed areas and slender skeletons possible in modern construction, this factor has particular significance (Fig. 3.17). At the other end of the spectrum, a small degree of permeability may be introduced into a box-like enclosure by varying the size of windows or introducing slits at the corners.
Visual clues about the nature of space include many more than those derived from linear perspective. Gibson's list, which was applied in the previous Section to the perception of form, was actually derived from experiments concerning the perception of space. Senses other than vision are also of great importance. One is our sense of locomotion: our ability to move, or to imagine ourselves moving within a space. The psychologist Piaget, whose research into the mental development of children is renowned, described spatial concepts as 'internalized action'. [3.49] Hall adds
"man's sense of space and distance … has very little to do with the single-viewpoint linear perspective developed by the Renaissance artists … his perception of space is dynamic because it is related to action - to what can be done in a given space - rather than what is seen by passive viewing". [3.50]
When we walk down the aisle of a church we experience the 'directionality' of its space in a very real way. There is a sense of 'exploring' space in ascending the sort of triumphal staircase found in traditional opera houses, or moving along the walkway in the complex spaces made possible by modern construction (Fig. 3.19). Architects are interested in the effect of 'parallax' on our perception of space. Motion from one space to another also heightens our experience, especially when we move from a confined space to a larger one, as in passing from the constricted foyer of a sports hall into the vast space of the auditorium.
Fig. 3.19. Twentieth-century materials permit new spatial experiences. Foyer, staircase, and walkways. Philharmonic Concert Hall, Berlin. 1963. (Archt: Hans Scharoun. Struct. Engr: Werner Koepcke.) [I have not found an image on the internet similar to the one used in my book. Impressive use of space may be seen in the foyer of the Elbe Philharmonic Hall, Hamburn. Skyscrapercity. Scroll down for an artist's impressions of interior spaces.]
Amongst non-visual clues to the permeability of space, Gauldie lists the presence of breezes, and the admission of light, flying creatures, and noises. [3.51] The introduction of fabrics for tent and inflated structures has led to a radically new quality for interior space and its separation from outside space. Changes in light conditions are much more noticeable, the shadows of clouds and passing birds may be seen on the fabric, and the noise of passing aircraft is heard more clearly.
Nevertheless, vision is for most of us the most important sense in apprehending space, if only in measure of the freedom of vision which it affords. Gauldie contrasts our experience of a totally enclosed stairwell in an old apartment block, with that of a modern external glass-enclosed staircase (Fig. 3.20). [3.52] We would perceive the space in a windowless room on the thirtieth floor of a building as geometrically different if the outer wall were replaced by a large window, despite the fact that this had in no way increased our freedom of movement!
Fig. 3.20. The glass-enclosed staircase permits a special experience of space and exposes its function to the viewer. Model Factory, Werkbund Exhibition, Cologne, Germany. 1914. (Archts: Walter Gropius and Adolf Meyer.)
Source for photograph: Casteels, M. Die Sachlichkeit in der modernen Kunst, Jonquières, Paris and Leipzig, 1930, Plate 16.
Visual weight.
The visual 'weight' of areas and volumes is of major importance in the unity, balance, and composition of facades and massed forms (Fig. 3.21). It is influenced by light, colour, and texture, and designers may use these parameters to modify the more general effects. Sinclair Gauldie demonstrates that the assessment of visual weight is a matter of applying reasoning to the impression that meets our eye
"We would not expect a tea-chest to weigh as much as a granite block of the same size; and even if some joker has filled the tea-chest with concrete, it will still look lighter than the stone block." [3.53]
Fig. 3.21. Impressions of grandeur and self-confidence are due to the tallness, the steady rhythm, and the visual weight of these regularly massed forms. Approach spans of Thomas Telford's suspension bridge over the Menai Straits, Wales. 1826.
[Photo: Anglesey history.]
Renaissance architecture provides many lessons in the perception and manipulation of visual weight. Rasmussen cites as an example the Doge's Palace in Venice (Fig. 3.22). [3.54]
Fig. 3.22. The Doge's Palace, Venice. c.1365. The apparent form of elements varies with their closeness to the observer. Consistent rhythms in the arcades: interrupted rhythms in the windows of the upper storeys. Visual weight of the upper part is seen to be reduced by the tiled pattern.
[Photo: Sullivan.]
"Contrary to all architectural rules its walls are massive above and completely pierced below. But this is not at all disturbing; there is no feeling of top-heaviness. The upper part, though actually solid and heavy, seems light, more buoyant than inert."
This perception is related to the way in which the walls of the canal facade are faced with a checkered pattern of red and white marble.
"The design is cut off arbitrarily at the edges as if the whole thing were a huge piece of material that had been cut to fit."
As a result, the upper wall has the appearance not of stone, but of a "gay, tent-like surface". When people speak of the 'weight' of a surface, rather than a solid, they might be thinking in a more abstract fashion but the same principles apply.
Texture.
Texture is the 'size and organization' of the particles constituting a surface. [3.55] At the finer end of the scale is the texture of polished granite, which the eye identifies by its sheen. The texture of concrete may vary all the way from the smoothness of steel-formed surfaces to the roughness produced by bush-hammering. A brick wall has texture at two levels. There is the rough, porous surface of the bricks themselves, and then at a larger scale, the visual impression of texture formed by the bricks standing proud of the mortar. Where designers have felt a need for an even more bold texture this has been imposed by techniques such as striation in concrete (Fig. 8.3) and by the 'rustication' of masonry (Fig. 1.6).
Another sort of texture has more to do with repetition of small design elements, than with the nature of surfaces. Common examples of this in modern architecture include facades constructed of precast concrete elements, and multi-storey blocks with accentuated mullions (Fig. 3.6). More exotic examples are the ribs of Nervi's Sport Palaces (Fig. 3.23) and the nodes of the cable net in the Munich Olympic Stadium (Fig. 3.24). Many commentators have seen texture in the repetitious members and joints of space frames. A similar effect can be observed in the lattice-type steelwork of the late nineteenth century such as the Eiffel Tower and the Garabit Viaduct (Fig. 3.25). This is sometimes described as 'macro-texture' in contrast with the 'micro-texture' of surface quality. [3.56] Obviously the details which form the 'texture' must be small in relation to the overall form of the structure and it is interesting to speculate at what ratio of magnitude the separate members of a steel frame cease to be seen as individual, random components, and become 'macro-texture'.
Fig. 3.23. Interior of the roof of Nervi's Palazzetto dello Sport. The repetitive precast elements provide a continuously varying visual texture. (See also Fig. 1.3.)
Photo: Roslyn Oxley / Harry Seidler.
Fig. 3.24. Texture is apparent in the nodes of the cable-net roof of the Olympic Stadiums, Munich, Germany. 1972. (Archts: Behnisch and Ptnrs with Frei Otto. Struct. Engrs: Leonhardt and Andrä.)
Fig. 3.25. Viaduct over the dammed River Truyère, Garabit, France. 1888. Secondary members provide texture to the major forms of arch and deck. From certain angles, the strong visual qualities of the arch contrast with the sparseness of the superstructure. (Struct. Engr: Gustave Eiffel.)
Source of photo: L'Architecture d'aujourd'hui, Nov. 1936, p.55 (Lacheroy).
Texture may have a great effect on visual weight, as well as being an important contributor to the architectural experience in its own right. Objects or planes which have smooth surfaces are commonly perceived as being less 'heavy' than those which have rough surfaces. The reason probably lies in the added visual interest and attraction of complex surfaces. Perhaps the most striking example of this effect is again the 'rusticated' wall of the Renaissance palazzo.
Light.
We have seen how light plays an important part in emphasizing the nature of form (Fig. 3.1), and how shading is an important tool of the artist in giving an appearance of solidity to a two-dimensional drawing. Le Corbusier is recognized as a master in exploiting the shadow of carefully-organized sun screens. [3.57] The nature of light varies from day to day and from season to season. In different locations it may be affected by latitude, climate, level of pollution, and proximity to sea or desert. Different cities in the same country may have very different light qualities. Built forms are often adapted to such regional variations. Where the sun is high and the sky glaring, hard-edged forms tend to predominate. Where the sun tends to be weak and low, shapes appear softer, and forceful colours are needed to give strong definition. [3.58] Gauldie notes how a Greek Revival building in Edinburgh or Manchester
"can give no more than a faint hint of the precisely etched clarity of line which characterized its prototype, while by contrast the bold, deep relief of Gothic mouldings makes them conspicuous even in the mistiest northern light." [3.59]
The play of light has a great effect on the perception of texture, as can be seen from Fig. 3.26. When the incident light is inclined to the surface it enhances texture. When it is normal, it may obliterate it altogether.
Fig. 3.26. Light and shade emphasize the striated texture and overall form of the Elephant and Rhinoceros Pavilion at London Zoo. 1965. (Archts: Casson Conder Partnership.) GuardianUnlimited.
Light is equally important in influencing the perception of interior space. The positioning and size of windows plays a large part in this. The light from clerestory windows has a special quality, and the use of 'light chambers' in the Baroque architecture of Borromini is beautifully illustrated in Portoghesi's The Rome of Borromini. [3.60] In modern buildings, artificial lights have been directed upwards into the heavy, 'dead' space within deep space frames to diminish their visual weight. The quality of the space within a room is greatly affected by changes in the angle and colour of the incident daylight. Nelson (1979) has written of the very special experience of light within a fabric structure, but this, and effects such as that of light streaming through the windows of a Gothic cathedral are perhaps best left for Chapter 4.
Colour and pattern.
The psychology of colour is a complex and highly subjective field. Our mechanical perception of it is influenced by the size of the sample, the presence of other colours in the vicinity, and the colour of the incident light. Most designers consider the 'colour wheel' a sure guide to matching colours, but some find it restrictive. Our emotional response is easily influenced by the suggestions of others. Caudill and his co-authors warn that if someone describes a colour as a 'cheery yellow' or 'cool green' we are quite likely to see it that way. [3.61] Nevertheless, there is widespread agreement that reds, oranges, and yellows are 'warm'; while blues, violets, and greens are 'cool'. Some researchers claim to have established that warm colours raise the blood pressure, respiration, and heart rate, while cool ones have the opposite effects. [3.62] It is a commonplace in the 'art world' that areas of warm colour on a canvas 'advance' while cool colours 'recede'. Interior designers use this impression to make large rooms seem smaller, and small rooms larger.
Some experiments have suggested that boxes painted in dark colours are judged heavier than identical boxes painted in light colours. Colour may thus be an important contributor to 'visual weight'. When a firm of French 'colour consultants' were engaged to reduce the bleakness of dockland areas near Marseilles, a number of wharfside cranes were painted in a range of pastel colours. The drivers protested that the cranes now seemed extremely light, and they were tempted to handle them accordingly. To restore a proper feeling of gravity to the situation, the cranes were repainted in 'heavier' colours. [3.63]
It is claimed that if each side of a solid cube is painted in a different colour, our attention is drawn to its surfaces rather than its volume as a whole, and we tend to see it as a hollow box rather than a solid cube. [3.64] Pattern, which generally involves colour, is also seen as effective in drawing attention to the surfaces of a volume, and this could be a factor in perceptions of the Doge's Palace in Venice (see p. 000).
French colour consultants have also used brightly coloured 'camouflage' to break up the shapes of buildings whose rectilinear forms were considered to be monotonous. [3.65] Rasmussen notes that when the concept of camouflaging warships was introduced in World War One, and the heavy grey battleships were 'dazzle painted' with black, white, and blue abstract figures, they appeared much lighter in weight. In an interesting comment on changing habits of perception, he notes that the camouflage of World War Two employed muddy colours and sinuous curves instead of the bright colours, straight lines, and triangles which predominated during the First War. He suggests that this change was related to the differing styles in art which were current in each period. [3.66]
Piano and Rogers have used colour to compensate for the lack of scale which has occurred due to the replacement of masonry by metal sheet cladding. Rasmussen states that it may be used to draw attention away from 'ugly' structural details. Foster Associates used a similar principle in the design of temporary offices housed in a pneumatic structure. They specified a red carpet to attract attention away from the distracting shadows of birds and clouds moving across the translucent fabric. [3.67]
Composition: balance, unity, harmony, and duality.
Anyone who has taken a photograph of a landscape or cityscape is familiar with the problem of 'composition'. We must decide what to include and what to leave out. We may wish to choose the field of view that encloses the most pleasing, and most 'well-balanced' assemblages of forms. A related problem is posed when we hang a picture on a wall. [3.68] If we do not wish to have a symmetrical arrangement, we may ask someone else to hold the picture while we stand back and say 'no, it wants to go higher' or 'it wants to go further to the left'. When we are finally satisfied, we feel that we have achieved a state of 'balance', 'equilibrium', or 'repose' in the composition.
Technologists may object to this use of language to endow inanimate objects with desires, or tendencies to motion, when these sensations are obviously in the mind of the observer, but it is accepted practice, and these are the 'forces' of which art critics write. They may be seen as analogous to magnetic repulsion and attraction (which are not necessarily vertical) and the 'visual weights' of elements may be seen as a measure of the magnitude of these effects. However, many observers make some connection between visual weight and gravity. An evaluation of 'equilibrium' and 'balance' may thus be based on a complex interaction between these impressions. From this, the observer arrives at a conclusion as to the position of the 'visual centroid', and the degree of equilibrium which exists between the visual forces. The question is obviously complex, and Arnheim (1982) devotes several chapters solely to the problem of 'locating the centre' of a work of art.
Balance in a two-dimensional composition is reasonably easy to achieve and perceive. If the facade or building is symmetrical, balance is assured. Balance in three dimensions is more complex. Gauldie prefers the term 'visual mass' in this case. [3.69] Even if the building is doubly-symmetric, it may not appear so from most points of view. Whether the composition appears unbalanced may depend on whether the observer sees only the projected two-dimensional image, or forms a mental impression of the solid bulk, including what is not directly visible.
Many writers assert that 'unity' is an essential element in a composition, and it has often been equated directly with beauty. Described simply, it is the quality possessed by a building or group of buildings in which the elements are seen to be 'bound together' for some reason. In a symmetrical composition this occurs because each element has a 'partner' in its mirror-image across the centre-line. In an asymmetrical composition it is derived in a more complex way from the visual forces of attraction and compatibility, and from the sense of balance. A grouping will appear to have unity when the visual centres of gravity of the individual elements are clustered close to the centre of gravity of the whole. Lines or forms connecting the elements obviously assist in 'tying' the grouping together.
A richer integration is achieved when these effects occur at several levels: first in terms of the broad outlines of the building, and then at gradually descending levels of detail, in a 'hierarchical' progression. Thus in certain of its aspects, unity is closely related to progression of scale and to 'order'.
Unity may also be achieved through similarities in texture, colour, and detailing of elements. Many modern buildings with monotonous detail, such as high-rise office blocks and prefabricated concrete buildings possess more of this type of unity than many people are able to tolerate (Fig. 3.6). In skeletal steel structures unity occurs when the individual members are small compared to the overall form, and thus appear 'dense'. Of course the overall form itself should also exhibit 'unity', and the Garabit Viaduct (Fig. 3.25) is disconcerting in this respect because the unity established by the strong sweep of the arch is counteracted by the sparseness of the superstructure. It is instructive to compare the strong lines of this arch with the airiness of an electricity transmission tower. A similar contrast is found between the strong though sparse articulation of Kenzo Tange's Omatsuru Square space frame and the denser, highly repetitive arrangement of members in a typical long-span space frame over a warehouse. [3.70] (The perception of 'unity' in a modern building is often the result of an intellectual appreciation of the integrated functioning of the parts in relation to each other and to the whole. This aspect will be discussed in Chapter 7.)
A third element of composition, 'harmony', is reasonably self-explanatory. The Oxford Pocket Dictionary defines it as 'agreement; concord', and this is how most commentators see it. Some, however, following the ancient Greeks and the Renaissance theorists, see it mainly as a question of proportion. In the visual terms on which we are now concentrating, 'agreement' between the elements of a composition may be achieved by a correspondence of aspects such as outline, detailed content, or colour. The appreciation of harmony has much to do with emotional response and intellectual appreciation, and will be further discussed in Chapter 4.
It is a fundamental rule of 'composition' that 'duality' should be avoided. Duality is present when the eye is attracted by two stimuli of equal importance which prevent resolution of the composition into a unified whole. A common instance of this is the highway overpass bridge which has a central pier and openings of equal size either side. Gauldie provides an example of two towers which are spaced too far apart for the eye to see them as a unit, but not far enough apart for them to be perceived as completely independent (Fig. 3.27). He 'resolves' this duality by inserting a dominant central block between the others. [3.71] Duality may be experienced also when the facades of a building have equal horizontal and vertical emphasis. It is a conventional principle that one or other effect should clearly predominate.
Fig. 3.27. Two adjacent forms having identical interest represent 'duality'. This is resolved if a central dominant form is interposed. (After Gauldie 1969.)
All of the above concepts: unity, balance, and harmony, are associated with stability and order and tend to be found where patrons and architects have wished to convey such impressions. However at many periods people have exhibited an impatience with them, whether in mannerism or modernism. In these periods, concepts of unity, balance, and harmony become less rigid and more complex, and designers consciously introduce elements which compromise their perfection.
Movement and rhythm in buildings.
Perceptions of movement and rhythm in buildings are greatly affected by our emotional and intellectual predisposition. However they have their origin in the fundamental nature of vision. Each eye covers an angle of some 145 degrees in plan, of which about 110 degrees is available for binocular vision. In the vertical plane the angle is about 110 degrees with 45 degrees above eye level and 65 degrees below. However, for sharp vision the subtended angle is only one degree. [3.72] It is therefore necessary for the eyes to scan an object, if we wish to apprehend it in any detail. Further, the brain is more sensitive to changes in light values and patterns, than to constant stimulus. Hence if we are interested in an object we have another motivation to scan it actively (Fig. 3.7).
As our centre of vision moves across a building, items such as windows and doors, and changes in texture become important 'events'. Increase or decrease in height is significant, especially if the change is sudden. Thus Scully (1974) in describing Aalto's church at Vuoksenniska (Fig. 3.28) writes of how the building,
"responds to the sound within it and wraps its planes flexibly around it … while its tower suddenly shoots up to explode above the pines …" The building "looks out at the world with crocodile eyes". [3.73]
Fig. 3.28. Alvar Aalto's Vuoksenniska Church, Imatra, Finland. 1959.
Photo: AGRAM. Select "Alvar Aalto" then "Church of the three crosses".
Movement of this kind is often seen in multi-storey buildings, particularly where the vertical direction has been emphasized, as in the CBS Building in New York (Fig. 3.29). Because of this, many people feel uneasy about the visual qualities of a building in which the upper and lower portions are not differentiated from the remainder. It is interesting to compare the C.B.S. Building with Johnson and Burgee's AT&T Building which has a clearly defined base and pediment (Fig. 3.30). [3.74] Theorists use a similar reasoning to justify the presence of bases and capitals on columns and feel uneasy when a beam or slab simply 'sits' on the top of a column. Arnheim is one of the few commentators who recognize that visual movement can be seen to occur in either direction, depending on the sense in which the observer 'reads' the building. However, he claims that objects of diminishing real size, such as the branches of a tree are always 'read' from root to tip. [3.75]
Fig. 3.29. Lacking a visually differentiated base and top, Eero Saarinen's CBS Building in New York (1959) has been seen both to 'crash' into the ground and to 'soar' aloft. (Struct. Engr: Paul Weidlinger.)
Photo: Emporis.
Fig. 3.30. Philip Johnson's AT&T Building in New York (1983) has a clearly defined base, middle, and top. These arrest eye movement. They also carry multiple associations. (Struct. Engr: Leslie E. Robertson.)
Photos: Sullivan and Philip Johnson Alan Ritchie Architects (select "Towers").
Another interesting form of perceived movement is the 'spin' attributed to circular colonnades. Summerson (1980) sees this in the colonnade beneath the dome of the Panthéon in Paris (Fig. 3.31)
"To my mind, the narrower inter-columniation of the Panthéon and the elimination of the solid piers in every fourth bay result in a loss of gravity: the Panthéon dome spins rather too airily over the rectangles of the cross-shaped structure below." [3.76]
Fig. 3.31. The dome of the Panthéon in Paris (1792) has been seen to 'spin' because of the closeness and regularity of the columns beneath it. (Archt: Jacques-Germain Soufflot. Mathematical analysis: E-M. Gauthey and J-B. Rondelet.) [Photo: The Pantheon Paris. The slide show includes photos of the dome.]
This vertiginous sensation must be caused where there is a high degree of optical stimulation combined with orderly and monotonous repetition. Jencks notes a similar effect in the less orderly 'optical buzz' of a complex space frame (c.f. Fig. 4.2). [3.77] Summerson finds that 'spin' is avoided in the colonnade around the drum of St Paul's in London because solid piers are introduced at intervals around the circumference, having the appearance of blank bays on which the eye may rest. [3.78] However, many people are not troubled by such perceptions, suggesting that they become important only when observers are particularly sensitive to visual stimuli, or actively pursue an aesthetic experience by concentrating their attention on some particular aspect.
As the eye scans across a building it is affected by the regularity or otherwise of elements such as windows, mullions, columns, and arches which may give rise to an impression of 'rhythm' (Figs 1.5, 3.8, and 3.21). Rhythms may be seen as slow and legato when they are based on a few elements which are widely spaced relative to the overall form, or rapid and staccato. Compound rhythms may be established when columns are grouped in pairs. They are also seen in renaissance or neo-classical facades in which windows are flanked by a column on each side. Rhythms may of course, be read vertically, as well as horizontally.
Too regular a rhythm may induce boredom, and an occasional discontinuity adds interest. Gauldie cites the Doge's Palace in Venice (Fig. 3.22) as an example of this. [3.79] A perfectly regular rhythm is established by the arcades at ground and first-floor level. A marked contrast is provided by the large arched windows because, at the right-hand side, the last two step down in level. The circular windows above them (plus two rectangular ones) follow a syncopated beat which becomes chaotic at the right-hand side. Regularity is once more established by the decorative points along the roof line.
Flow of space.
Commentators on architecture see a potential for 'movement' or 'flow' in space as well as in form. They have a sense that a room contains 'space' just as it might contain some sort of gas, and that this may flow in a similar manner. If the only outlet visible in a room is a small door in a far wall, space will be seen as 'confined'. However, if the far boundary is 'permeable', consisting of a row of columns or a large window rather than a blank wall, the 'gas' or 'space' will be seen to flow out through it. Sometimes it is possible to catch glimpses through doorways or permeable boundaries to an adjoining room, and suggestions of further volumes beyond, or to build up in the mind a three-dimensional image of the entire building.
Such perceptions of movement of space are obviously connected with freedom of vision and of projected movement, as has been noted above. This apparent freedom has been greatly increased since the introduction of modern materials which permit the use of narrower columns, wider spans, fewer walls, and larger windows. In Mies' Barcelona Pavilion the definition and bounding of space is highly abstract, depending greatly on the mental projections and constructs discussed in the section on space. Space is seen to 'flow' through these permeable boundaries as well as through large areas of glazing. [3.80]
The opposite of such 'dynamic' space is the sort of 'static' space contained within a circular room, where there is no predominant axis and no impulsion to movement in any direction. A similar effect, this time probably due to confinement of vision, is felt under a dome. As Caudill et al point out, most of us convert 'dynamic' space to 'static' space every evening when we draw the curtains of our living-room. [3.81]
Image Acknowledgements. Linked images, Chapter 3.
AGRAM (Rein Saariste). Link
Anglesey history (Warren Kovack). Link
archINFORM. Link
Courtauld Institute. Link
Emporis. Link.
Farnsworth House. Link
Galinsky. Link
Guardian newspaper. Link
The Pantheon Paris. Link
Philip Johnson Alan Ritchie Architects. Link
PlanetWare. Link
Skyscrapercity. Link.
Steve Rosenthal. Link
Roslyn Oxley 9 Gallery. Link
Sullivan (Prof. Mary Ann), Bluffton College. Link.
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