OF REMOTE AGES. 333 
finished arch is the common gateway of fortifica- 
tions of the third style.* 
I have, as yet, been able to discover no excep- 
tion to this rule. In some cases as at Ferentino, 
in Latium,} the arch has been formed in walls of 
the polygonal order, but on a closer examination, 
it is always obvious that the arch was a subsequent 
addition, either of Roman or Htruscan architects. 
In the two earlier orders it is curious to trace the 
regular advance from the rudest gateway, con- 
structed of two upright stones, and one horizontal, 
to the pyramidal form, and then gradually bending, 
till it approached more and more nearly to the se- 
micircle.—Drawing IV. gives a series of these, 
from Mycene, Thorikos, Arpino, Segni, &e.— 
Excellent specimens of the perfect arch, as con- 
nected with Hitruscan walls, may be seen in draw- 
ing V. which represents gateways at Volterra and 
Fresole. 
Some authors, however, and among them Col. 
Leake, seem to consider the Treasury of Atreus, 
(a dome-shaped building, which I described in a 
* See Drawing V. 
+ See Drawing VI. 
¢ Travels inthe Morea. II. 380. 
