§ V. But before we come to particular examination of these minor forms, let us see how far we can simplify it. Look back to [Fig. LI.], above. There are distinguished in it six forms of moulding. Of these, c is nothing but a small corner; but, for convenience sake, it is better to call it an edge, and to consider its decoration together with that of the member a, which is called a fillet; while e, which I shall call a roll (because I do not choose to assume that it shall be only of the semicircular section here given), is also best considered together with its relative recess, f; and because the shape of a recess is of no great consequence, I shall class all the three recesses together, and we shall thus have only three subjects for separate consideration:—
1. The Angle.
2. The Edge and Fillet.
3. The Roll and Recess.
§ VI. There are two other general forms which may probably occur to the reader’s mind, namely, the ridge (as of a roof), which is a corner laid on its back, or sloping,—a supine corner, decorated in a very different manner from a stiff upright corner: and the point, which is a concentrated corner, and has wonderfully elaborate decorations all to its insignificant self, finials, and spikes, and I know not what more. But both these conditions are so closely connected with roofs (even the cusp finial being a kind of pendant to a small roof), that I think it better to class them and their ornament under the head of roof decoration, together with the whole tribe of crockets and bosses; so that we shall be here concerned only with the three subjects above distinguished: and, first, the corner or Angle.
§ VII. The mathematician knows there are many kinds of angles; but the one we have principally to deal with now, is that which the reader may very easily conceive as the corner of a square house, or square anything. It is of course the one of most frequent occurrence; and its treatment, once understood, may, with slight modification, be referred to other corners, sharper or blunter, or with curved sides.
§ VIII. Evidently the first and roughest idea which would occur to any one who found a corner troublesome, would be to cut it off. This is a very summary and tyrannical proceeding, somewhat barbarous, yet advisable if nothing else can be done: an amputated corner is said to be chamfered. It can, however, evidently be cut off in three ways: 1. with a concave cut, a; 2. with a straight cut, b; 3. with a convex cut, c, [Fig. LII.]
| Fig. LII. |
The first two methods, the most violent and summary, have the apparent disadvantage that we get by them,—two corners instead of one; much milder corners, however, and with a different light and shade between them; so that both methods are often very expedient. You may see the straight chamfer (b) on most lamp posts, and pillars at railway stations, it being the easiest to cut: the concave chamfer requires more care, and occurs generally in well-finished but simple architecture—very beautifully in the small arches of the Broletto of Como, [Plate V.]; and the straight chamfer in architecture of every kind, very constantly in Norman cornices and arches, as in Fig. 2, [Plate IV.], at Sens.
§ IX. The third, or convex chamfer, as it is the gentlest mode of treatment, so (as in medicine and morals) it is very generally the best. For while the two other methods produce two corners instead of one, this gentle chamfer does verily get rid of the corner altogether, and substitutes a soft curve in its place.