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Architecture is the harmonious planning and construction of a building; that is, the designing of rooms, window-spaces, doorways, roofs and all parts so that they fulfill collectively and separately the purpose for which they were built and yet look pleasing, both in themselves and in their setting, to the eye of the onlooker.
All the styles of architecture have developed from the materials used in their building and the technique and methods of construction available to the builders at the time. Under primitive conditions there were few means for transporting bulky materials any considerable distance, so materials readily at hand were used. The ease with which the materials were capable of being worked had a decisive influence.
In the northern softwood conifer forest areas the log hut was typical. In the predominantly hardwood oak forest areas the half-timbered frame building developed. Oak logs can be split from end to end, but take much hard labor to saw or adze to finer shape. The walls in this type of building were not structural but merely infillings of dry earth, bricks or mortar, with glass windows placed at will—a method which allowed great flexibility in planning.
In the hill or highland country where good stone was readily available, either broken down to small sizes in mountain streams and easy to manhandle or by quarrying from hillsides, the walls were built of stone. For less important buildings, rough-hewn stones were bedded in dry earth. Mortar necessary for larger structures and requiring lime had to be obtained from regions where limestone or chalk were to be found, and so was only used sparingly.
In the lowlands extensive use was made of the technique of building walls with unbaked earth. The technique varied: one method was to ram damp earth into temporary wooden shuttering; another method was to daub wetter earth onto wattle fencing which would remain in the wall as a form of reinforcement; while a third method common in hot dry climates was to use sun-dried bricks reinforced with chopped straw—a practice referred to in the Bible. It is most likely that in the history of mankind this method of construction has been used most frequently for domestic building, and is sound so long as the roof remains watertight. There are a surprising number of dry-earth buildings to be found in the lowland country districts in Britain.
The familiar baked brick was the logical development of the sun-dried brick. The clay brick is baked in kilns which change its nature into a rough type of earthenware and gives it strength to withstand damp. The size and shape has been fixed within narrow limits by traditional usage, and the standard brick is of a size which can be picked up with one hand while the bricklayer manipulates the mortar trowel with the other. It is also twice as long as it is deep, which makes it possible for some bricks to be laid across the thickness of a two-brick thick wall to bond the courses together. The brick was the earliest example of mass production of a single unit and still holds its own as a most adaptable building material. The size of the plan of rooms in any building depended on the type of material available, and the skill with which it could be fashioned, to- span the space between the walls. Timber can be laid horizontally from wall to wall, and the length of the logs limits the width of rooms, although the length of the room may be increased at will. This method usually sufficed for domestic purposes, but for larger halls of assembly, temples or churches, the necessity for greater floor space brought forth great variety of methods to increase the size of the covered area. A first step was to replace interior walls by rows of columns. These latter were eliminated when the art of designing and constructing elaborate wooden roofs, such as the hammer-beam roofs of late Gothic and Tudor architecture, was evolved.
As communities increased in wealth important public buildings, originally humble structures of wood, were often replaced by larger and more durable buildings in stone. These at first often closely followed the original structures in general planning and incorporated decorative features borrowed from the wood prototypes. In small buildings it was still possible to span the space between the columns by single large slabs of stone. Larger spans called for other methods, and in stone the arch, built up of accurately worked wedge-shaped stones of moderate size, was the answer. This brought a new force into play: the outward thrust of the arch which had to be held by a sufficient weight of masonry each side. The Roman and Renaissance arches were semicircular in form; the pointed arch characteristic of Gothic times allowed for greater flexibility in planning in that arches which spanned unequal widths could be made to rise to an equal height. The early stone roofs known as a barrel or tunnel vault were in effect a continuous arch down the full length of the building.
The efforts of Gothic builders of stone vaults were directed to the design of lighter structures through various designs of arched ribs filled in with light panels of stone. The Romans, not satisfied with the size limitation imposed by the post and lintel construction so widely used by the Greeks, and by the masonry arch, made considerable use of concrete construction with brick reinforcement. The rotunda of the Pantheon in Rome may be quoted as an outstanding example of large-scale concrete construction. It is a hemispherical dome, all in one piece like some vast inverted basin or plant pot. Concrete, being a manufactured article, does not show characteristics of a locality, and concrete structures do not have the automatically harmonious relationship with the surrounding country which the use of local materials gives to buildings of other types, but concrete allows the architect much greater freedom in planning. Roofing materials of various kinds have been traditionally used and have been a major influence in planning and the determination of style. The simple necessity of keeping out the wet has been achieved v/ith thatch of leaves, straw or reeds, by overlapping thin slates, thicker slabs of stone, or wood shingles, tiles manufactured by a similar method to bricks, or by lead or copper sheets. All forms of thatch, slating and tiling were normally hung on wooden rafters at a considerable angle to prevent the penetration of wind-driven rain. Wood shingles may be hung at a very steep angle, and thatch also requires a steep slope, but slate tiles can be hung at a lower angle, while large, heavy stone slabs used in the limestone districts need the lowest angle of all. Sheet metal is used for almost flat roofs, and asphalt often makes a waterproof covering for concrete roofs. In areas of winter snow the roofs are either very steep to shed the snow as it falls, or, on the other hand, of very low pitch to retain the snow, which insulates the home from the greater cold outside. The latter roofs have to be constructed with great strength to withstand the added load.
In the hot, dry Mediterranean lands the heat and intensity of the sun is such that people welcome shade. The typical Roman villa had few or no windows on the outside walls, but the rooms opened on to inner courts shaded by vines, where the heat of the day was tempered by the sound
of water splashing in fountains. Most frequently the Greek and Roman temples were windowless, the light reflected through the open doors from the pavement outside, and possibly through the translucent thin marble slabs used to cover the roof, being sufficient. The blank outside walls gave, in troublesome times, the additional advantage of protection from raiders. It was no doubt partly for this reason, and not only because of lack of skill in building technique, that early Saxon and Norman churches in England had thick walls and small windows more appropriate to sunnier lands. As times became more settled the desire for more window space to let in the weak northern sun led to the glories of the Perpendicular Gothic of the fifteenth century, the style in which the walls were reduced to narrow supporting piers for elaborate roofs and the windows were filled with stained glass.
New materials and new manufacturing processes developed during the nineteenth and present centuries have vastly increased the technical resources available to architects and builders. The use of steel girders to form a frame on which panels of stone, brick and glass are hung is a modern echo of the sixteenth-century wooden-framed buildings and has made possible the vast commercial structures culminating in the American skyscrapers. Concrete structures are lightened as well as strengthened by reinforcement with steel. Today, even traditional materials are being transformed by modern factory processes, so that they can be used in the construction of the vast structures demanded by twentieth-century living.