for a Ba&longs;ement to them you mu&longs;t make a <lb/>
Plinth half the Height of the Ba&longs;ement at the <lb/>
Bottom. </s> <s>But nothing can be a greater Orna<lb/>
ment either to Squares or the Meeting of &longs;eve<lb/>
ral Streets, than Arches at the Entrance of the <lb/>
Streets; an Arch being indeed nothing el&longs;e but <lb/>
a Gate &longs;tanding continually open. </s> <s>I am of <lb/>
Opinion, that the Invention of Arches were <lb/>
owing to tho&longs;e that fir&longs;t enlarged the Bounds <lb/>
of the Empire: For it was the ancient Cu&longs;tom <lb/>
with &longs;uch, as we are informed by <emph type="italics"/>Tacitus,<emph.end type="italics"/> to <lb/>
enlarge the Pomoerium, or vacant Space left <lb/>
next the City Walls, as we find particularly <lb/>
that <emph type="italics"/>Claudius<emph.end type="italics"/> did. </s> <s>Now though they extend<lb/>
ed the Limits of the City, yet they thought it <lb/>
proper to pre&longs;erve the old Gates, for &longs;everal <lb/>
Rea&longs;ons, and particularly becau&longs;e they might <lb/>
&longs;ome Time or other happen to be a Safeguard <lb/>
again&longs;t the Irruption of an Enemy. </s> <s>Afterwards <lb/>
as the&longs;e Gates &longs;tood in the mo&longs;t con&longs;picuous <lb/>
Places, they adorned them with the Spoils <lb/>
which they had won from their Enemies, and <lb/>
the En&longs;igns of their Victories. </s> <s>To the&longs;e Be<lb/>
ginnings it was that Arches owed their Tro<lb/>
phies, In&longs;criptions, Statues and Relieves. </s> <s>A <lb/>
very proper Situation for an Arch is where a <lb/>
Street joins into a Square, and e&longs;pecially in the <lb/>
Royal Street, by which Name I under&longs;tand the <lb/>
<arrow.to.target n="marg42"/><lb/>
mo&longs;t eminent in the City. </s> <s>An Arch, like a <lb/>
Bridge, &longs;hould have no le&longs;s than three open <lb/>
Pa&longs;&longs;ages: That in the Middle for the Soldiers <lb/>
to return through in Triumph to pay their <lb/>
Devotions to their paternal Gods, and the two <lb/>
Side ones for the Matrons and Citizens to go <lb/>
out to meet and welcome them Home. </s> <s>When <lb/>
you build one of the&longs;e Triumphal Arches, let <lb/>
the Line of the Platform which runs length<lb/>
ways with the Street be the Half of the Line <lb/>
that goes cro&longs;s the Street from Right to Left, <lb/>
and the Length of this Cro&longs;s-line &longs;hould never <lb/>
be le&longs;s than fifty Cubits. </s> <s>This Kind of Struc<lb/>
tures is very like that of a Bridge, only it never <lb/>
con&longs;i&longs;ts of more than four Piers and three <lb/>
Arches. </s> <s>Of the &longs;horte&longs;t Line of the Platform <lb/>
which runs lengthways with the Street, leaves <lb/>
one eighth Part towards the Square, and as <lb/>
much behind on the other Side, for the Plat<lb/>
forms of Columns to be erected again&longs;t the <lb/>
Piers. </s> <s>The other longer Line which cro&longs;&longs;es the <lb/>
Street mu&longs;t al&longs;o be divided into eight Parts, <lb/>
two whereof mu&longs;t be given to the Aperture in <lb/>
the Middle, and one to each Pier and to each <lb/>
Side opening. </s> <s>The perpendicular Upright of <lb/>
the Piers that &longs;upport the middle Arch, to the <lb/>
Spring of that Arch, mu&longs;t be two of the afore<lb/>
&longs;aid Parts and a Third; and the Piers of the <lb/>
two Side Arches mu&longs;t bear the &longs;ame Proporti<lb/>
on to their re&longs;pective Aperture. </s> <s>The Soffit of <lb/>
the Arches mu&longs;t be per&longs;ect Vaults. </s> <s>The <lb/>
Crowns of the Piers beneath the Spring of the <lb/>
Arch, may be made in Imitation of the <emph type="italics"/>Doric<emph.end type="italics"/><lb/>
Capital, only in&longs;tead of the Ovolo and Abacus <lb/>
they may have a projecting Cornice either <emph type="italics"/>Co<lb/>
rinthian<emph.end type="italics"/> or <emph type="italics"/>Ionic,<emph.end type="italics"/> and beneath the Cornice by <lb/>
Way of Gorgerine, a plain Freze, and below <lb/>
that an A&longs;tragal and a Fillet like tho&longs;e at the <lb/>
Top of the Shaft of a Column. </s> <s>All the&longs;e Or<lb/>
naments together &longs;hould take up the ninth Part <lb/>
of the Height of the Pier. </s> <s>This ninth Part <lb/>
mu&longs;t be again &longs;ubdivided into nine &longs;maller Parts, <lb/>
five whereof mu&longs;t be given to the Cornice, <lb/>
three to the Freze, and one to the A&longs;tragal <lb/>
and Fillet. </s> <s>The Architrave or Face of the <lb/>
Arch that turns from Pier to Pier mu&longs;t never <lb/>
be broader than the tenth Part of its Aperture, <lb/>
nor narrower than the twelfth. </s> <s>The Columns <lb/>
that are placed in Front again&longs;t the Piers mu&longs;t <lb/>
be regular and in&longs;ulate; they mu&longs;t be &longs;o rai&longs;ed <lb/>
that the Top of their Shafts may be equal to <lb/>
the Top of the Arch, and their Length mu&longs;t <lb/>
be equal to the Breadth of the middle Aper<lb/>
ture. </s> <s>The&longs;e Columns mu&longs;t have their Ba&longs;es, <lb/>
Plinths and Pede&longs;tals as al&longs;o their Capitals, <lb/>
either <emph type="italics"/>Corinthian<emph.end type="italics"/> or <emph type="italics"/>Compo&longs;ite<emph.end type="italics"/> together with <lb/>
Architrave, Freze and Cornice, either <emph type="italics"/>Ionic<emph.end type="italics"/> or <lb/>
<emph type="italics"/>Corinthian,<emph.end type="italics"/> according to the Proportions al<lb/>
ready pre&longs;cribed for tho&longs;e &longs;everal Members. <lb/>
</s> <s>Above the&longs;e Columns mu&longs;t be a plain Wall, <lb/>
half as high as the whole Sub&longs;tructure from <lb/>
the lowe&longs;t Ba&longs;ement to the Top of the Cornice, <lb/>
and the Height of this additional Wall mu&longs;t <lb/>
be divided into eleven Parts, one of which mu&longs;t <lb/>
be given to a plain Cornice at the Top, with<lb/>
out either Freze or Architrave, and one and an <lb/>
Half to a Ba&longs;ement with a rever&longs;ed Cymatium <lb/>
which mu&longs;t take up one third of the Height of <lb/>
that Ba&longs;ement. </s> <s>The Statues mu&longs;t be placed <lb/>
directly over the Intablature of the Columns, <lb/>
upon little Pede&longs;tals who&longs;e Height mu&longs;t be <lb/>
equal to the Thickne&longs;s of the Top of the Sha&longs;t <lb/>
of the Columns. </s> <s>The Height of the Statues <lb/>
with their Pede&longs;tals mu&longs;t be eight of the eleven <lb/>
Parts to which we divided the upper Wall. </s> <s>At <lb/>
the Top of the whole Structure, e&longs;pecially to<lb/>
wards the Square, mu&longs;t be placed larger Sta<lb/>
tues, triumphal Cars, Animals and other Tro<lb/>
phies. </s> <s>The Ba&longs;e for the&longs;e to &longs;tand upon, mu&longs;t <lb/>
be a Plinth three Times as high as the Cor<lb/>
nice, which is immediately below it. </s> <s>The&longs;e <lb/>
larger Statues which we thus place uppermo&longs;t, <lb/>
</s></p>