William Dean Howells
Familiar Spanish Travels
http://ebooks.adelaide.edu.au/h/howells/william_dean/familiar/chapter8.html

Here follows a bit of general theory of Roman-type land surveying (the fact that you often find parallelogram Roman forts shows they didn’t have it completely sorted) as well as some other crap, copy-pasted indiscriminately:

The assignment of lands among the Tuscans was conducted with religious ceremonies, and private property was secured by the sanction of the gods. The first step was to draw two main lines with scientific accuracy ; one from south to north, which, as corresponding to the axis of the world, was termed cardo; the other at right angles to it, which therefore ran due east and west, and was named decumanus. Other lines, as many as were required, were drawn parallel to these two and divided the district, which was to be parcelled out, into allotments of a quadrangular form and of an equal area ; the extremities of all the lines were marked by a row of stones inscribed with numerals. The sale or transfer of landed property by individuals, when the whole estate was not alienated, was always in parts according to the duodecimal scale. See Niebuhr’s sections on this subject.

When Sesostris made an assignment of land in Egypt, he parcelled out the district into allotments of equal extent and of a quadrangular form, (Herodot. 2. 109 ; ) and as the estates granted to the members of the military caste are said to have consisted of twelve aruree each (2. 141), it is probable that every allotment under a public assignment had its particular subdivisions on the duodecimal scale; Herodotus adds that each arura was the square of 100 Egyptian cubits, (2.168.) According to Niebuhr, the common landmeasure of Etruria was the rorsus, or square of 100 feet. Thus the Tuscan agreed with the Egyptian ; but the Roman differed from both. The jiyerum, as the very name implies, was a double measure ; and the real unit in the Roman landmeasure was the act us, or a square of which each side was 120 feet. Vol. ii. p. 626.

Muller says it would be extremely arbitrary to derive the limitatio of Etruria from Egypt, merely because the allotments of Sesostris were quadrangular; since similar customs may arise in various countries from very different principles. (Etrusker, vol. ii. p. 152.) But when we remember that in addition to their quadrangular form, the allotments were also of an equal area which was subdivided upon a duodecimal scale, and that the common landmeasure among the Tuscans and Egyptians was the square of 100 feet, whilst that of the Romans was the square of 120 feet; when we see that Tirhakah, king of Cush, can be traced to Italy, and that the Tuscan language may be illustrated from the Coptic, of course the imputation of arbitrariness at once falls to the ground. Neither, as Muller states with respect to the cardo or meridian line, needed the Tuscans to wait for the gnomon till the Greeks had previously received it from the Babylonians in the age of Pherecydes and Anaximenes: Tirhakah’s colony certainly brought with them sufficient science to construct a gnomon and determine the cardinal points.

The decempeda (percha in Spanish) was a ten-foot pole used by the agrimensores, imperial land surveyors. Similar to the standard measures - lengths of iron - to be found at the gates of medieval towns for purpose of ref by merchants and consumers in that horrible things happened to people who cheated

[Churches often don't align east-west, and for a variety of reasons. One:

Then to her Patron Saint a previous rite
Resounded with deep swell and solemn close,
Through unremitting vigils of the night,
Till from his couch the wished-for Sun uprose.

He rose, and straight--as by divine command--
They who had waited for that sign to trace
Their work's foundation, gave with careful hand
To the altar its determined place.

The sun of course rises at a great variety of different points
]