4] runs (it will be seen) in horizontal lines up to the very edge of the arch, thus suggesting a construction common in many of the early Greek arches, where the stones are so cut away that an arched opening is formed, though the real constructive principle of the arch has no place in such specimens.
With regard to the uses whereto the Assyrians applied the arch, it would certainly seem, from the evidence which we possess, that they neither employed it as a great decorative feature, nor yet as a main principle of construction.

So far as appears, their chief use of it was for doorways and gateways.

Not only are the town gates of Khorsabad found to have been arched over, but in the representations of edifices, whether native or foreign, upon the bas-reliefs, the arch for doors is commoner than the square top.

It is most probable that the great palace gateways were thus covered in, while it is certain that some of the interior doorways in palaces had rounded tops.

Besides this use of the arch for doors and gates, the Assyrians are known to have employed it for drains, aqueducts, and narrow chambers or galleries.