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would follow the description of the remainder of the operation, we have not encumbered the diagram with more letters of reference; the lines showing, on inspection, similar applications of the process for all parts of the curve. The fact is, that the whole of the shadow may be completed by taking the line DD as the transverse axis of an ellipsis, and finding the semi-conjugate axis Oa by the means above described, for Da"D is a semi-ellipsis in form, inasmuch as it is the projection of a section of a hemisphere. This example is applicable to the shadow of a cylindrical niche with a hemispherical head. The line NN shows the shadow of the portion of the head, and the remainder is obtained by the mere intersection of lines in the direction of the light from different points to the left of N, of which enough has been already given in the previous examples to make the application intelligible.

2476. Fig. 852. is the representation of a pediment wherein the section A is that of the

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mouldings of the pediment at its

apex. In the section, ab drawn from the projection a of the corona in the direction of the light, determines the point b therein, wherefrom the horizontal line intercepted by the line ab in the elevation, also drawn parallel to the direction of the light, gives the point b in the elevation. A line from b, parallel to the inclined sides of the pediment on the left, will give the shadow of the corona on the tympanum on that side, and similarly the line of shadow from b on the right side. cd determines the line of shadow on the frieze, and B is the section of the shadow of the assemblage of mouldings on the right.

2477. In fig. 853. is given the plan, elevation, and section of a square recess, covered with a cylindrical head. The lines AA, BB, CC of the elevation are determined by aa, bb, and cc of the plan; and in the section c'e' is the representation of the line cc of the plan. D, the point at which the direction of the light begins to touch the circular head, is d' in the section.

2478. Fig. 854. is the elevation of an arch, below which is its plan and the shadow cast by it on the plane upon which it stands. AA is shown by aa on the plan, the corresponding points in the rear of the arch being a' a', and a" a" the points in the shadow. In a similar way, by BB corresponding with bb' on the plan the points b"b" are obtained in the shadow.

2479. Fig. 855. is the plan and elevation of the upper part of a house,

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wherein the upper story is occupied by an attic in the centre, against which, on each flank, the sloping roof is terminated. aa on the plan in the direction of the light, produced to intersect the hip at b, gives, by a vertical to B on the elevation, the direction BB of the shadow thereon; and BB cut by AA in the direction of the light, the length BA of the line of shadow, which may, by letting fall the vertical Aa, determine the length aa on the plan. The line of shadow ac is determined by letting fall a vertical from C, where the line of shadow is intercepted by the hip of the roof; and from c the shadow will be found on trial to return as shown in the diagram.

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E

and D on the elevation are found,

Fig. 855.

as seen in previous examples, in ee, and d on the plan, and their shadows at e'e' and d'. 2480. What is called an attic base is given in plan and elevation by fig. 856. The me thod of obtaining the shadows thereof

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in plan and elevation is now to be explained. It is an example which constantly occurs in architectural subjects, and should be well studied and understood. The operations requisite for obtaining a representation of the lines of shadow of the different mouldings in this example depend upon the principles developed in the preceding subsections. The lower portion of the figure exhibits the plan, and the middle portion the elevation of the attic base in question. The uppermost portion of it presents three sections of the mouldings of the base in question cut in three different places parallel to the direction of the light. This last portion of the figure is not absolutely necessary, inasmuch as the profiles in question might have been obtained upon the elevation; but we have preferred keeping it separate to prevent a confusion of subsidiary lines. There is moreover another advantage in thus separating the parts from each other, namely, that of immediately and more distinctly seeing the lines at each selected place, in which the rays of light separate the parts actually in light from those in shadow; and where the student is likely to meet with matters of perplexity, nothing should be left untried to save his time, and, what is often more important, his patience. The mode to be adopted is as follows:

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Fig. 856.

Make on the plan any number of sections a'a'a'a', b'b'b'b' in the direction of the light, and draw on the elevation the corresponding sections aaaa, bbbb. LL being the direction of the light, draw parallel thereto tangents to the curves of the convex mouldings, and the boundaries of their shades will be obtained, as will also those of their shadows, by continuing them from such boundaries till they cut the other parts in each section, as will be more especially seen at cc. It will be recollected that in our first mention of the projected representation of the line of light and shadow we found that it was an angle of 54 44' of the diagonal of a cube. This angle is set out in xyz on the plan. We have therefore another mode of finding the boundaries of shade and shadow on the moulding, by developing the sections a'a'a'a', b'b'b'b', &e., as at A, B, and C, and drawing tangents yz to the convex mouldings for

boundaries of shade thereon, and continuing them, or otherwise, for the other parts, as shown in the diagram.

2481. In fig. 857., which represents the capital of a column, a similar method is used to that last mentioned for obtaining the shades and shadows, by means of a'a'a'a' and b'b'b'b', which are shown on the elevation by aaaa and bbbb. We apprehend this will be understood by little more than inspection of it.

It is obvious that the means here adopted for obtaining the lines of shadow are precisely similar to those used in the preceding example. In this, however, the sections of the capital parallel to the direction of the light are made on the elevation, and it will be seen that many of them are not required to obtain an accurate boundary of the lines of shadow sought; for after having obtained those points from which the longest shadow falls, and on the other side those where the line of shadow com

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mences, a curve line of an elliptical nature connects the points found. If the drawing to be made be on a large scale, it may then be worth the architect's while to increase the number of points wherefrom the shadow is to be projected, so as to produce the greatest possible accuracy in the representation.

2482. The shadows of an Ionic capital are given in fig. 858. The shadow of the volute on the column is obtained by any number of lines AA, BB, CC, &c. from its different

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parts and verticals from their corresponding ones aa, bb, cc, &c. on the plan, and similarly the shadow of the capital on the wall. In this example, as in those immediately preceding, the employment of sectional lines parallel to the direction of the light is again manifest. The use of them is most especially seen in the example of the Corinthian capital which follows. As a general rule, it may be hinted to the student of sciography, that in the difficulties that may occur, they will be most expeditiously and clearly resolved by the use of the sectional lines, whereon we have thought it proper so much to dilate.

2483. The Corinthian capital in fig. 859. will require little more than inspection to understand the construction of its sciography; and all that we think necessary to particularise are the developed projections A, B, C, D, E, F of the abacus and the leaves, whereon the termination of the shadows at angles of 54° 44', as explained in fig. 856., give their respective depths on the elevation.

There is another method of arriving at the result here exhibited, by drawing sectional lines parallel to the direction of the light through the different parts and leaves of the

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capital on its elevation, as in fig. 857., and such was the mode we were formerly in the habit of adopting. It however induces such a confusion of lines, that we have long since abandoned it, and have no hesitation in recommending the process here given as the best and most likely to avoid confusion. It is of course unnecessary, in making drawings, to project more than the shadow of one capital, as in a portico, or elsewhere, similar capitals, similarly exposed to the light, will project similar shadows, so that the projection on one serves for the projection on all of them.

2484. For instruction upon the mode in which reflected light acts upon objects in shade and shadow, we must refer the learner to the contemplation of similar objects in relief. The varieties of reflexes are almost infinite; and though general rules might be laid down, they would necessarily be so complicated, that they would rather puzzle than instruct, and under this head we recommend the study of nature, which will be found the best instructress the student can procure.

to man.

SECT. IV.

GENERAL PRINCIPLES OF COMPOSITION.

2485. The end of architecture, without whose aid no other art can exist, is not merely to please the eye, but so to provide against the changes of the seasons as to be serviceable Pleasure to the eye may, however, result from the useful, well combined with the beautiful modifications whereof it is susceptible. It is in combining thus that the genius of the architect is exhibited. The art of decorating a well-proportioned edifice is a very secondary and comparatively easy part of his work, though requiring, of course, the early cultivation of his taste and an intimate acquaintance with the parts, whereof this may be taught and that acquired; but the distribution and arrangement of the several portions on the plan, upon which every accessory is dependent, requires great knowledge and considerable experience. And in this is involved not only the general convenience and effect of the building, but what is of much consequence to the proprietor, the cost of the work. None but those practically conversant with the planning of a building would believe the saving that may be produced by proper distribution. In the case of many external breaks, for instance, much addition arises in the length of walls enclosing the edifice, without generally increasing the convenience of the interior, but always when the elevation comes to be adapted to the plan, with the certainty of breaking up the masses, and destroying the simplicity of the effect. This is mentioned merely as an instance of simplicity of plan always producing implicity of section and elevation.

2486. All ornament in architecture is non-essential, inasmuch as the pleasure received by the eye is not its end. To public and private utility, the welfare and comforts of individuals, which are the ends of the art, every other point must be sacrificed; and it is only when these have been accomplished that we are to think of decoration. An anecdote is related of a certain nobleman, who, having boasted to a friend of the beauty of the façade of his house, which within was exceedingly ill contrived, was told that he thought the peer would do well to take the house opposite, that he might be thus always able to look at it. Those who make the internal parts of an editice subservient to the project of a façade, and adjust their plan and section to the elevation, must be considered as making the end of less importance than the ornament of the building.. Those who work in this mode produce little variety in their designs, which, numerous though they be, consist of but few different combinations, whilst those that result from the natural order of making the façade subservient to the internal parts, which the plan and section impose, are susceptible of infinite variety and decoration.

2487. It is not, however, to be supposed that we are, in what has been said, sanctioning the student's neglect of careful composition and adjustment of the façades. Upon the adaptation of the different fronts of the building to sort with the internal convenience, the greatest care should be bestowed. It is from these his reputation is likely to flow, because they are the parts most susceptible of comprehension by the public. The architect will, upon every succeeding day's experience, find that the two objects are not incompatible; but if such a case, which is possible, arise, he had far better sacrifice the façade, considering first the comforts of those who are to inhabit the house, and then the gratification of those who are only to look at it.

2488. Durand has well observed that compositions conducted on the above principles must please. "Has not nature," says that author, "attached pleasure to the satisfaction of our wants, and are our most lively pleasures other than the satisfaction of our most pressing wants? These wants are better satisfied in the interior distribution of a building than in the exterior." Who leaves the Pantheon without more satisfaction than he expected from the view of the portico, fine though it be? Again, faulty as are both St. Peter's and St. Paul's, will any one who understands the subject aver that he has received more pleasure from their respective façades than from their noble interiors? The pleasurable sensations produced by both are entirely dependent on their interior distribution. But when we find that in the former of these buildings there is no mockery of a dome, the interior and exterior being as far dependent on each other as the circumstances of construction would permit, whilst the dome of the latter is worse than a mockery, the interior and exterior domes having nothing in common with each other, the last being no more than a timber leaded appurtenance to the fabric, Wren, with all his greatness, for great he was, shrinks into nothingness by the side of Michael Angelo, although the external form of the dome of London be more elegant than that of the Vatican. This is a strong but not a forced illus. tration of our opinions, the good sense whereof must be left for appreciation to our readers, who, we doubt not, on a little reflection, will concur with us.

course.

2489. In ninety-nine cases out of a hundred the student will find that a good distribution of his plan leads him, with anything like ordinary tact, to the composition of good sections and good elevations, far better, indeed, than he could arrive at by pursuing an opposite In domestic Gothic architecture, this is notorious, for in that a regular distribution of the openings would often produce the tamest and least picturesque effect. The Gothic architects placed windows internally where only they would be serviceable, letting them take their chance in the exterior. It is not to be understood, because such would be rather outré, that this method will exactly suit the principles of composition in Italian architecture; but it is well known to practical men that a required opening in a particular place, instead of being a blemish, may be converted on many occasions into a beauty. Indeed, it is incontrovertibly true that distribution and disposition are the first objects that should engage the architect's attention, even of him whose great aim is to strike the attention by ornament, which can never please unless its source can be traced to the most convenient and economical distribution of the leading parts. Theorists may be laughed at, but it does not move us, nor diminish our regret to see many architects without any other theory than that whereon, in an inverted position, their own wild fancies are grafted. If what we have stated be true, and from the nature of things we cannot imagine a controversy can arise upon our observations, the talent of the architect is to be estimated, as Durand properly observes, according to his solution of the two following problems:

First. For a given sum, as in private buildings, to erect the most convenient and suitable house for his employer.

Second. The requisites in a building being given, as in public buildings, to erect it at the smallest possible expense.

2490. An investigation of all the modes of accomplishing these desiderata can only be fully effected in a work of much larger extent than this; but we have, in the practical parts of our volume, so prepared the reader, that he will not generally be at a loss in respect of the construction of a building, whatever its nature or destination.

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