Doric Capital

[A]Though the proportions given are approximately accurate for general division, it will be found necessary in detailing to adopt a more intimate system of measurement. In the following diagrams the diameter is divided into 36 parts, which are expressed in figures, giving heights, etc., of the various features.

The Doric abacus consists of a rectangular slab, square on plan, which in detail consists of a fillet and reversa moulding surmounting a facia. Its extreme width is one and a half times the upper diameter. The square abacus is supported by an ovolo, which is circular on plan, and is connected with the necking by three small fillets.

No. 159. Doric Capital.

The capital is half a diameter in height, exclusive of the mouldings between the necking and the shaft, and the upper part to the underside of the ovolo occupies rather more than half.

No. 160. Ionic Capital.

The necking is a vertical extension of the upper diameter of the column, and is separated from the shaft by a boldly projecting moulding, which in height should be about equal to the three small fillets below the ovolo. The moulding consists of a torus and a fillet, and a cavetto curve is carried from the underside of the fillet and dies into the line of the shaft of the column.

Sometimes the ovolo is decorated with its characteristic egg and tongue detail, and occasionally thereversa of the abacus is also enriched. The necking is sometimes ornamented with four rosettes, which are placed centrally under the square faces of the abacus.

The Ionic capital is half a diameter high, and is readily distinguished by its bolster-like form with voluted ends. This bolster is rectangular on plan, and measures laterally rather more than one and a half diameters, while from back to front it is slightly less than a diameter.

The shaft terminates in a cavetto curve, and is surmounted by a fillet, a small torus and an ovolo moulding, which is invariably decorated with egg and tongue detail. These mouldings all conform to the circular plan of the shaft. On the ovolo rests the voluted bolster.

The abacus, which is square on plan, consists of a reversa moulding and fillet.

From the top of the abacus to the base of the ovolo the height is about a third of a diameter, and one-fourth of this height will give the height of the abacus.

The centre or eye of the volute can readily be found by dropping a perpendicular from the lower edge of the reversa to intersect the horizontal line defining the base of the ovolo. This point of intersection is the required centre.

From this as centre and one part as radius describe a circle. Within this circle draw a square, having for a diagonal the diameter of the circle. Bisect the sides of the square and draw the diameters by joining the points ofbi-section. Divide these diameters of the square into six and these points will be the centres for the segments of circles which form the volute. Vertical and horizontal lines drawn from the centres will define the extent of each segment.

No. 161. Ionic Capital, with angular volutes.

For small scale drawings the volutes are drawn free-hand, but for larger working drawings it is necessary to use some method such as that given here.

The angle formed by the meeting of the ovolo and the volute is masked by a detail of anthemion form.

The ends of the bolster between the volutes consist of concave or ogee curves, which are symmetrically arranged from a centre line; moulded ridges or conventional leaf detail decorate the centre.

The form of the Ionic capital, while suitable for afaçade, requires some modification if it is to be carried round the side of a building, owing to the great dissimilarity in the front and side views. In this case the end volute of the capital at the angle of the building is projected forward at an angle of 45 degrees, and the side is then treated in the same way as the front.

In late Renaissance buildings this difficulty was overcome by making all the volutes project at angles of 45 degrees, so that the four faces of the capital were uniform. This entails the bolster being dispensed with, and the volutes, no longer connected laterally, spring directly from the top of the ovolo moulding, and the space between the springing lines is occupied by a husk.

No. 162. Ionic Capital. Detail of Angular Volute.

As the volutes make equal angles they conform moreor less to a square plan. The plan of the abacus is composed of four concave curves with small straight intervals at the meeting angles. The general proportions for this form of capital are the same as for the bolster type.

The Corinthian capital differs widely from those of the preceding orders in proportion and detail.

Its general form may be described as a bell, which is circular on plan. It springs from the upper extremity of the shaft, from which it is separated by a necking moulding.

Under the abacus it terminates in a fillet.

The bell is one diameter high. The height of the abacus is one-sixth of a diameter in addition; on plan the abacus falls within a square, having four concave faces with short straight lines at the angles. The distance across the diagonal is two diameters. The bell is clothed with leaves of acanthus type, which are arranged in two tiers of eight leaves each. Between the upper leaves are eight stems with husks and branching scrolls, which terminate in volutes at the angles and centres.

The necking moulding consists of a small torus and fillet.

Although the arrangement of the principal features of the Corinthian capital is horizontal, yet owing to the channelling of the leaves and the firmly springing scrolls the vertical direction appears to predominate.

This verticality emphasises the function of the capital as a supporting feature, and is æsthetically satisfactory, being in harmony with the flutings of the shaft.

No. 163. Corinthian Capital.

The effect produced by the capitals of the other two orders is horizontal, and suggests the idea of binding. They are equally satisfactory as giving contrast of direction.

No. 164. Corinthian Capital.Detail giving divisions of height, and profiles.

No. 164. Corinthian Capital.

Detail giving divisions of height, and profiles.

In all the orders a square plinth is the lowest member of the base of the column. On this plinth rests a series of mouldings which follow the circular plan ofthe shaft. The shaft invariably terminates in a fillet, the diameter of which exceeds that of the column, and on to which the line of the shaft is carried by means of a curve.

No. 165. Doric Base.

The Doric base is extremely simple. It consists of the square plinth on which rests a torus mouldingsurmounted by a smaller moulding of the same section and a fillet above.

The width of the plinth is one and a third the diameter of the column, and its height a quarter diameter or half the total height of the base. The other half is made up of the large torus, the small torus and fillet. The torus moulding should be bold in projection, practically semi-circular and at the fullest part of its curvature in vertical alignment with the centres of the horizontal faces of the plinth block. The small torus and fillet are about equal in height.

No. 166. Ionic Base.

The Ionic base differs from the Doric in the introduction of a hollow or scotia moulding between the two torus mouldings. Æsthetically it may be considered more satisfactory in that the strong shadow obtained by the use of the scotiaproduces an effect of binding which adds to the impression of strength. The type is technically known as the Attic base.

The total width is one and a third diameter.

The height of half a diameter may be divided into three. One of these divisions will give the height of the plinth, one the large torus and the fillet above it, and the other the scotia and small torus with the fillets above and below. The fillets either side of the upper torus may be in the same vertical alignment.

No. 167. Corinthian Base.

The smallest diameter of the base, which will be in the hollow of the scotia, should exceed the diameter of the shaft, or an effect of weakness will be imparted.

As in the Doric base a curve of a quarter circle connects the shaft with the upper fillet.

The orthodox base of the Corinthian order is similar to that of the Ionic, with an additional scotia and small torus with its accompanying fillets.

The width of the plinth is one and a third diameter.

The height of half a diameter does not include the top fillet. The proportions may be approximated by dividing the height into four. One of these parts will be the height of the plinth, another that of the large torus and its fillet, the third—the upper edge of fillet of top scotia, and the fourth that of the upper scotia and torus with the intervening fillet. Vertically the uppermost fillet is in alignment with that of the upper scotia, and the extremity of the upper torus with the small bead mouldings dividing this from the lower scotia.

Although this is the orthodox Corinthian base, it is not used as frequently as the Ionic type, but when the order is on a large scale the more elaborate version is justified.

When the arch is used in conjunction with the column it is supported on pilasters which are attached to the columns. The columns and pilasters thus form piers.

In the Doric order the columns are placed five diameters apart from centre to centre, in the Ionic five and a quarter, and in the Corinthian five and a half.

The necking moulding of the capital is generally carried through above the arch, the outer line of which is struck so as to nearly touch the underside.

The projection of the pilasters which carry the archis half a diameter from the outer lines of the column, and is measured on the same level as the springing point of the arch.

The centre from which the arch is struck is sometimes in the same horizontal line as the springing points, but more frequently a little above the line and thereby a rather better effect is produced.

The arch-band or archivolt is the same width as the pilaster supporting it, and a series of mouldings known as the impost is placed at the top of the pilaster. The base of the pilaster consists of a plain plinth of slight projection equal in height to the base of the column.

From the spacing of the columns and the proportions here given it will be seen that the height and width of the aperture made by the arch and pilasters are arrived at automatically, but if measured, the height will be found to be about twice the width and the top of the impost about two-thirds the height of the column. These proportions may be accepted as giving satisfactory results under ordinary conditions.

As a general rule, in all the orders the impost is half a diameter high, and so is the same as the projection of the pilaster and the width of the archivolt.

This rule is not always adhered to, however, but in any case the width of the archivolt should never be more than one-eighth or less than one-tenth of the diameter of the arch, and should always be the same as the width of the pilaster.

The mouldings of the Doric Impost are as follows:

At the top there is a fillet and a bold ovolo, belowwhich there is a bead-moulding or small torus with fillet and two facias. The lower facia, which is of slight projection is one-fourth of the total height. The upper facia and fillet are half the remainder.

No. 168. Detail of Archivolts and Imposts.

The archivolt mouldings are in the Doric order, the same as those of the impost.

The total height of half a diameter may be divided into two, and the upper half sub-divided into three. Then the upper division will be the height of the top fillet and a reversa moulding; the second the height of a facia and the third an ovolo and small torus.

The lower half of the impost consists of two facias, the upper of which is broader than the lower.

The archivolt, commencing at the outer rim, consists of a fillet and bold reversa moulding which occupies rather less than a fourth of the total width, and two facias of unequal widths. The width of the inner facia is nearly one-third more than that of the reversa moulding.

The Corinthian impost differs from those of the other two orders in having a necking and necking moulding in place of the two unequal facias.

The total height should be divided into two, and the upper half divided into four. Then the top fillet and reversa moulding will be one of these divisions, the facia two, and the supporting ovolo will occupy the remaining one.

The lower half of the impost consists of a small torus and fillet beneath the ovolo, the necking, and the torus and fillet which form the necking moulding.

The archivolt, commencing at the outer rim, consists of a fillet and reversa and three unequal facias.

If the total width is divided into two, the point of bisection will be the centre of a small reversa moulding between the two outer facias. The outer reversa and the inner facia are each about one-sixth of the total width and the small reversa is about two-thirds of the inner facia.

A projecting block, or keystone, is sometimes usedat the centre of the arch. The face width of its lowest edge should not be less than the width of the archivolt. Its height is not often less than one and a half times or more than twice this width.

It may be decorated in various ways, and is frequently in the shape of a console. This form is especially suitable when the keystone comes in contact with the architrave of the entablature, in which case it is capped with a moulded abacus.

The height of the pedestal is a fourth that of the column and entablature together, though this proportion may be varied to suit different conditions. For instance, when the pedestal forms part of the structure of a balcony or balustrading the height must be modified to suit the special requirements of the position.

The pedestal is composed of plinth, die and capping.

The width of the die is the same as the plinth of the base of the column above it, that is, one and one-third diameter. The projection of the capping, which is the same for all three orders is obtained by drawing a line at an angle of 30 degrees with the vertical from the top of the die.

The width of the plinth corresponds to the projection of the capping, and is determined by dropping perpendiculars from the top fillet.

The height of the mouldings between the die and plinth is determined by a line drawn from the bottom of the die at an angle of 45 degrees to intersect the vertical face of the plinth. The angle is the same for all the orders.

In the Doric order the height of the capping is one-third diameter. The face of the die is square, and this determines the height of the plinth.

No. 169. Detail of Pedestals.

The capping mouldings consist of a fillet, facia, ovolo, fillet and cavetto. The facia is carried to the underside of the fillet in a curve, and its height is half the total height of the capping. The facia is supported by the ovolo, and a fillet and cavetto complete the capping.

The height of the course of mouldings at the top of the plinth should be divided into three, then the upper third will contain a cavetto moulding and fillet, and the remaining two-thirds an ogee and final fillet.

In the Ionic pedestal the plinth with its mouldings should occupy one-third the height and the capping one-fifth the remainder.

The mouldings are similar to those of the Doric pedestal, but a little more elaborate. In the capping a reversa is used under the top fillet and a small torus or bead is placed between the ovolo and the cavetto. In the mouldings of the plinth a similar bead is introduced above the ogee moulding.

The same general divisions as the Ionic will give the proportions of the Corinthian pedestal, the difference being that of the scale and the detail of the mouldings.

The capping may be divided into two. The top half consists of a fillet, reversa and facia, and the lower half a supporting cyma recta, a bead and a cavetto curve. The plinth mouldings are the same as those of the Ionic pedestal with the addition of a torus beneath the ogee. The height of this torus is one-fourth the total height and is about equal to that of the cavetto and bead together.

When the pedestal is employed the arch becomes proportionately larger. In the Doric order the columns are then spaced seven and a half diameters apart; in the Ionic seven and three quarters, and in the Corinthian eight diameters centre to centre.

The archivolt, the radius of which is determined by the above spacing, is supported as before by an impost and pilaster. The base of the pilaster consists of aslightly projecting block equal in height to the plinth block of the pedestal.

The height of the arch varies slightly, inasmuch as the inner curve may be about a diameter from the architrave, but in the Corinthian order should not fall below the level of the necking moulding of the capital.

As already stated, the pedestal may be used as a part of a balustrading associated with balusters, and must conform to the proportions necessitated by the conditions. The usual height for balustradings, whether to steps, balconies, or before windows, is three feet two inches, though in special cases it may be slightly more.

The baluster is a species of small column. Its usual form is bulbous or vase-shaped, and it is furnished with a capital and base. A series of balusters is technically known as a balustrade.

The balusters are raised on a plinth, which corresponds to the plinth of the pedestal, and surmounted by a rail of horizontal mouldings, which correspond to the capping of the pedestal; hence the baluster is of the same height as the die.

The height of the baluster should be divided into five, then one-fifth will be the height of the base, and the capital exclusive of the necking will be another fifth. The extreme diameter of the bulbous shaft is one-third the total height of the baluster, and the diameter of the necking and the top of the shaft is about one-sixth. The capital has a square abacus slightly less in width than the plinth of the base. Below the abacus is

No. 170. Detail of Balusters.

an ovolo and fillet, which are circular on plan. The necking is separated from the shaft by a small torus and fillet. The base has for its lowest member a square plinth, which occupies rather less than half the height and is equal in width to the extreme diameter of the bulbous shaft. Above the plinth is a scotia and a necking moulding, which are circular on plan.

The balusters should be spaced with not more than half their diameters or less than a third between their bases, except when employed on the rake of steps, when they may be slightly closer.

In a balustrading an unequal number of balusters should always be used, and not less than five in one group exclusive of the half balusters which are attached to the flanking or dividing dies. Seven and nine form very satisfactory groups, but if more than nine are necessary for the space to be filled, intermediate dies must be interposed, and these may vary from two-thirds to three-quarters the width of the principal dies.

In some cases, when a large number of balusters are to be grouped, the dies are flanked by half dies, which are less in projection than the dies themselves.

Balustrades are sometimes used above the cornice of a building, and their height should not be more than four-fifths or less than two-thirds the height of the entablature. This height would be exclusive of the plinth on which the balusters are raised. The height of the plinth is determined by the height of the building, and the projection of the cornice, as its purpose isto raise the balusters so that they may be seen from the ordinary point of view. The principal dies may be placed over columns or pilasters and should be equal in width to the upper diameters of these, though flanking half dies may be used in addition to avoid an appearance of thinness. The plinth and capping mouldings always follow the plan of the principal dies, and are carried in unbroken lines across each interval.

When the height of the balustrade does not conform to the orthodox proportions the method of determining the relative proportions is as follows:—The height is divided into seven parts; of these one part gives the height of the capping, four the baluster and two the plinth.

The mouldings in character and detail are the same as those of the pedestal, and should be in harmony with the order used.

When balustrading forms part of a stair, the height on landings should be three feet two inches. On the rake two feet ten inches from the step at a line vertical with the face of the riser. The plinth is invariably used as a string enclosing the ends of the steps and following the rake or angle in a straight line, and carried to the levels by means of curving ramps.

In interior work the bulbous shafts of balusters are often decorated with carved detail, and the mouldings also may be enriched.

Columns were originally used in the porticos and courts of temples and other buildings, and sometimes to form supports for vaulted roofs. Wherever employedtheir function was directly structural, but this was not the case at the time of the Renaissance. The requirements demanded by widely different social conditions led to their being used more as decorative than structural features.

The use of engaged columns and pilasters in a façade can be justified to some extent. Although such columns and pilasters may not be absolutely essential for support, yet they act as buttresses and add to the strength of the structure with a certain economy of material. Also they are æsthetically satisfactory in their effect of light and shade.

The disposition of columns either in a façade or a colonnade is controlled by proportions which have been found to be desirable or are necessitated by special features of the order itself. The latter is the case with the Doric order, the spacing being determined by the trigylphs and metopes. If the triglyphs are placed centrally over the columns or pilasters the spacing of these apart will be two and a half diameters centre to centre, three and three-quarters, or five diameters, with two, three or four metopes respectively between them in the frieze. With the wider spacing of five diameters it is usual to employ coupled columns to add to the appearance of strength. As the triglyphs are one and a quarter diameters apart centre to centre, the coupled columns are brought very close together, entailing a slight modification of the bases. Since the ordinary projection of the plinth of a sixth of a diameter beyond the line of the shaft is not possiblebetween the two columns, the plinth-blocks are united, and the torus moulding made slightly less in projection.

No. 171. Spacing of Columns.

The capitals being less in width are not affected, a small interval is left between the crowning reversa mouldings.

In the Ionic order the columns are spaced three and a quarter, three and three-quarters and four and a quarter diameters centre to centre. The coupled columns used with the wide spacing are one and a halfdiameters centre to centre or half a diameter apart at the lower extremity of the shafts.

The Corinthian spacing is slightly wider, three and a half diameters, four diameters, or with coupled columns four and a half diameters centre to centre. The coupled columns are placed as in the Ionic order one and a half diameters centre to centre.

It is desirable that attention should be given to the vertical alignment of the principal features. Dentils and modillions and indeed all strongly marked features should centre with the columns, and be equally spaced in the intervals.

Occasionally in façades orders are used above one another. The Colosseum is an antique Roman example of this, and it was a treatment often adopted by the architects of the early Renaissance. It is desirable that the simpler order should be the lower one. Ionic may be used over Doric, or Corinthian over Ionic.

It is obvious that the central axes of the columns or pilasters of each order used should be in vertical alignment, not only when seen from the front, but in the case of detached columns, from the side view also.

When engaged columns or pilasters are employed, the upper tier may be set back slightly from the face of the lower order which supports it; an example of this is to be found in the Theatre of Marcellus at Rome.

The proportions of the upper order are obtained by making the lower diameter of the upper tier of columns or pilasters equal to the upper diameter of those

No. 172. Order above Order.

of the supporting order, and an effect of continuous tapering is produced.

It is usual to place above the entablature of the lower order a plinth on which the bases of the upper columns rest. The height of the plinth is regulated by the point of view, as its purpose is to display the bases of the imposed order above the projecting cornice. Generally this height will be about half a diameter.

In many historical examples the upper columns are placed on pedestals, but this treatment, although useful when a balcony is desired, is not to be recommended as the extra width and projection which the use of the pedestal entails, gives an appearance of undue weight to be borne by the supporting columns. If balconies are necessary they may terminate with their own pedestals, which can be kept clear of the columns and should not exceed them in projection.

It may be as well to deal here with the treatment of pilasters, which may be defined as columns in bas-relief. Their projection may vary from one-half to about one-sixth their face width, though in antique examples it is sometimes much less than this. In the pilasters of the Pantheon at Rome it is one-tenth.

The projection is, however, partly determined by the order with which the pilaster is used, as an appearance of mutilation might easily be produced in the capitals of the Ionic and Corinthian orders. The Doric capital, being composed of moulded profiles, is not in any way affected by the amount of projection. Nor does the Ionic capital suffer when the volutes are in oneplane except when used on an angle. But if the later Renaissance type with the volutes arranged at angles of 45 degrees is employed, the projection of the pilaster must not be less than half its upper diameter, so that the volute on the return face may be complete.

The Corinthian capital would be affected in the same way, and should also be not less than half a diameter in projection in order to obtain a satisfactory result.

The pilaster is usually tapered, and when associated with columns and supporting the same entablature it is essential to preserve universal alignment in the upper extremities and the architrave, but when used by itself the pilaster is often not tapered. At the angle of buildings, where both faces are displayed, it is an invariable rule that pilasters should be straight.

The details of capitals and bases are the same as those of the columns. When fluting is employed an odd number of channels should be used, usually seven on the front face.

No. 173. Doric Order. Treatment of coupled Column and Pilaster.

Arcades, as already suggested, may be composed of a series of arches, supported on pilasters which flank the columns. The backs of the piers thus formed maybe treated with pilasters, which can be repeated on the opposite wall, with the architrave frieze and cornice above.

There are several alternative treatments for the ceilings of arcades. They may be flat and panelled by beams carried across in a line with the pilasters and with a cornice moulding carried round the sides of the beams.

No. 174. Doric Arcading.

The interior can also be vaulted by means of archivolts springing from the line of the imposts. The archivolts should be supported by pilasters at the back of the piers and on the opposite wall, and a cornice may be carried round between the vaults. Cross vaulting also may be employed, and in this case the entablature is no longer necessary.

The proportions already given determine the width of piers when an order is used, but when an order is not used some further general rules for proportions are necessary.

The height of the opening formed by arches, which may spring from piers—with or without an impost—should be about twice the width. The supporting piers should not be less than a third or more than two-thirdsthe width of the aperture. In any form of arcading, piers must be employed at the angles, and these should be wider than the intermediate ones by a half, a third, or a fourth.

No. 175. Doric Arch, with pedestal.

A secondary or subsidiary order is sometimes used in an arcading. The height of the arch should then be twice its width, and the height of the small order two-thirds the height of the column of the principal order.

This height of two-thirds the column should be sub-divided into nine parts, of which eight will give the height of the column and the remaining one that of the entablature. The entablature consists of architrave and cornice, the frieze being omitted, and a division into five will give the relative proportions. Two-fifths may be taken as the height of the architrave and three that of the cornice.

No. 176. Employment of the Subsidiary Order.

Pilasters are used with the columns of the subsidiary order with a space of half a diameter between them and the columns.

No. 177. Subsidiary Order. Division of Entablature.

The archivolt should be equal in width to the upper diameter of the column, and the width of the lower edge of the keystone should also be of the same dimension.

The subsidiary order may be the same as the principal order, but more often the Ionic is used in conjunction with the Doric, or the Corinthian with the Ionic.

As regards the treatment of the bases, the horizontal alignment must be maintained. It is obvious that if the height of the base of the large column is adopted for the subsidiary one it will be very much out of proportion. This can be obviated by carrying through the plinth of the larger column to form a step on which the base of the smaller rests, and always the top line of the smaller bases should agree with that of the larger.

When arcades are used one above the other, the lower order is usually mounted on a plinth, and the upper furnished with a pedestal. The height of the pedestal is determined by the balustrading or balcony, the height of which is governed by its use.

If the Doric is taken as the lower order the centres of the columns are six and a quarter diameters apart, which gives a frieze of five metopes with interveningtriglyphs. The plinth on which the order stands is three-quarters of a diameter high. The pilaster supporting the archivolt projects half a diameter, and the height of the arch is determined by the impost, which is two-thirds the height of the column inclusive of the plinth. The base of the pilaster may be moulded, but the top line should coincide with the top of the plinth.

Above the Doric an Ionic order might be placed, and the die and plinth of the superimposed order should be kept as narrow as possible so as to reduce the impression of weight. The pilasters carrying the arch rest on the plinth of the pedestal, and the plinth mouldings are carried round the bases. The plinth and rail of the balustrading should not project but be kept between the pilasters.

The centres of the arches of both tiers are in a line with the tops of the imposts, and the outer edges of the archivolts may nearly reach the lower lines of the architraves.

When the Ionic is used as the lower order it may be surmounted by the Corinthian. The distance between the centres of the lower columns should then be six and a half diameters. The other proportions can be obtained in the same way as the preceding.

If a subsidiary order is employed the columns of the principal order are placed further apart. In the case of the Doric the distance is seven and a half diameters, and the other orders are increased in proportion.

The joints of the material used must necessarily be considered, and when plain piers or plain wall surfacesoccur the joints may readily be accentuated and so turned to decorative account. The edges of the stones forming the separate courses may be chamfered or moulded. The joints may also be worked so as to form a square recess.

TYPES OF RUSTICATIONNo. 178. Rustication.

The surface of the stone is sometimes roughly tooled or frosted, or worked in an arbitrary pattern, which is termed “vermiculated.” This treatment probably gave rise to the word rustication.

When rusticated work is used with an order the height of each course of stone should not be less than half a diameter, and when square recessed joints are used they can be one-eighth or one-tenth the height of the course.

Occasionally only the horizontal courses are thus marked, and this has been objected to as producing a boarded appearance, though undoubtedly the horizontal effect is at times agreeably in contrast to the vertical features. A much more usual treatment in Renaissance examples was to emphasise the vertical joints also.

The length of each stone should be from one and a half to three times the height.

Rustication may be used in the formation of the arch, which frequently has at its springing line a slightly projecting course, in which the vertical joints are not emphasised.

No. 179. Rusticated Arcade.

Rustication is also used in columns, either square on plan or conforming to the plan of the column.

Its most legitimate employment is in basements and to emphasise the angles of buildings.

A basement is really a continuous pedestal on which an order rests. It necessarily varies in height according to conditions, thus if its purpose is merely to raise the ground floor it may be no more than three to six feet high, but if it is required to form a storey, it should not exceed the height of the order employed or be less than one half.

The joints of the work in basements are generallyaccentuated by some form of rustication, and the heights of the horizontal courses should not be less than half a diameter of the column of the order above.

When a high basement is used it is sometimes crowned with a cornice, or more frequently with a slightly projecting facia technically known as a plat-band. In either case, the height should be equal to that of the courses exclusive of moulded edges or chamfers. Also a plinth is placed at the base of the same height as the plat-band or a little more. When a cornice is used the plinth should be moulded and may then exceed the height of the courses.

An attic storey is sometimes used instead of a second order, and this may vary from one-third to one-tenth the height of the order beneath it.

The attic may be quite plain, but it often has breakings or projections on its face corresponding to the vertical features of the supporting order.

It usually forms a storey in a building, and then is of necessity pierced with windows.

In architectural design the character and requirements of the building must, of course, be the first consideration, but the basement may constitute the ground floor, the height occupied by the order may contain two stories and the attic may be an upper floor.

When an order is not employed the divisions and proportions already stated may still be applied, the heights and widths should govern each other as would be the case if the façade were divided into bays by columns or pilasters.

In the absence of the order a cornice is substituted for the entablature, and this, according to different authorities, may be from one-twelfth to one-sixteenth the total height from the ground, but one-fourteenth or one-fifteenth will be found a safe mean.

The pediment in its original and orthodox employment was a gable conforming to the pitch of the roof. It is framed with mouldings, and the enclosed space is technically known as the tympanum.

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