ARCHITECTURE. 



with an archivolt ; sometimes interrupted 

 a( the summit with a kc\ -stone, in the 

 form of a console, or marsh, or some 

 otlu-r appropriate sculptured ornament. 

 The archivolt rises sonn-iiim. sfrom a plat- 

 hanil, or impost, placed on the top of the 

 piers; and at other times from an enta- 

 blature, supported hy columns on each 

 side of tin- arch. In some instances t In- 

 arches of arcades are supported entirely 

 by single or coupleil columns, without 

 the entablature ; as in the temple of 

 Fan mis at Home. This form is far from 

 being' agreeable to the c\ e ; it wall's sia- 

 hility, as the columns would be incapable 

 of resisting 1 tbe lateral pressure of the 

 arches, were they not placed within an- 

 other walled enclosure, or in a circular 

 colonade. In large arches the key-stones 

 should never be omitted, and should be 

 carried to the sofh't of the architrave, 

 where they will be useful in supporting 

 the middle of the entablature, \\hieh 

 otherwise would have too great a bear- 

 ing. 



When columns are detached, as in the 

 triumphal arches of Scptimius Severus 

 and Constantine, at Koine, it becomes ne- 

 to break the entablature, making 

 its projection over the Intel-columns the 

 same as if pilasters had been used instead 

 of columns ; or so much as is just suffi- 

 cient to relieve it from the nakedness of the 

 v. nil. This is nerrvviry in all interco- 

 lumns of great width, but should be prac- 

 tised as little as possible, as it d> 



i uine use of the entablature. A\ ben 

 columns are without pcdestals,thcy should 

 stand upon a plinth, in order to keep the 

 liases dry and clean, and prevent them 

 from being broken. 



Arcades should never be much more, 

 nor much less, than double their breadth. 

 The breadth of the pier should seldom 

 exceed two-thirds, nor be less than one- 

 third, of that of the arcade ; and the an- 

 g-ular pier should have an addition of a 

 third, or a half, as the nature of the de- 

 sign may require. The impost should 

 not be more than one-seventh, nor less 

 than a ninth, of the breadth of the arch ; 

 and the archivolt not more than one- 

 eighth, nor less than one-tenth, of that 

 breadth. The breadth of the bottom of 

 the key-stone should be equal to that of 

 the archivolt; and its length not less th:ui 

 one and a half of its bottom breadth, nor 

 more than double. In groined porticos, 

 the thickness of the piers depends on the 

 width of the portico, and the superincum- 

 bent building; but with respeet to the 

 beauty of the building, it should not be 



in one quarter, nor 

 third, of the breadth of 

 the anades form blank re( esses, the 



t which are pierced \\ith t!' 

 windov 



recesses should be at least M 

 keep the most 



';in their r 



In the upper stories of the theatres and 

 aniphitheatn-s < r'thr !{.>man-. the . 

 stood upon the podia, or inncr-|x . 

 of the columns ; perhaps as much for the 

 purpose of proportioning the apertures, 

 as to form a proper parapet for leaning 



0\ <!. 



C'l/'nnuit'x. A colonade is a rai 

 attached or insulated columns, supporting 

 an entablature. The inten 

 the columns, measured by the inferior 

 diameter of tli>- column, is called 

 tcrcolumniation ; and the whole area be- 

 two columns i> called an in- 

 tercolumn. \\hen the intercolunu 

 is one diameter and a half, it is 

 |i\ (Hostile, or columns thick set; when 

 two di i i tw o and a 



quarter, custyle ; when thn 

 and when four, ara:ostyle,or colun. 



\ colonade is also named according 

 to the number of columns which support 

 the entablature, or fastigium : when there 

 are four columns, it is called tetrastyle ; 

 when six, hcxastyle ; when eight, octo- 

 st\le; and when ten. The 



intercolumniations of the Doric or* 

 regulated by the number of triglxphs, 

 placing 1 one over every interim -d 

 lumn : when there is one triglyph o\< r 

 the iuU-nal, it is called monotriglyph; 

 when there are two, it is called ditri- 

 glyph ; and so on, according to the pro- 

 gressive order of the linck numerals. 

 The iutercoliimniation of thi < 

 ric is almost constant!) the monotriglyph : 

 from this practice there are onh two de- 

 viations to be met \\ ith xt Athens, the OM 

 in the Doric Portico, and the other in the 

 Prop\laca; but these internals only be- 

 long to the middle intercolumin 

 which are both ditrighph, and becuBC 

 necessar\ , on account of their being 1 op- 

 o tin principal entrances. As the 

 character of tbe Grecian Doric is more 

 massy and dignified than th:r 

 man, the mouotriglyphic succeeds best; 

 but in the Hom.m it is < 

 for the passage through the intercolunuM 

 woulil be too narriA, particularly ill SflMi 



tie ditrigl>ph is t!.. 

 . n< r;dl\ adopted. The aneostyte 



applied to rustic struct! 

 in iutcrcoloaMBations, where UK 



