History of the Peloponnesian War

In this way they ascertained the proper length of the ladders, guessing the measure from the thickness of the bricks.

Now the wall of the Peloponnesians was of the following construction. It consisted of two lines round the place, one against the Plataeans, and another in case any one should attack them on the outside from Athens; and the lines were about sixteen feet apart.

In this interval then of the sixteen feet there were quarters built, and partitioned out amongst the soldiers that were on guard; and these were continuous, so that it appeared but one thick wall, with battlements on each side.