Hierarchical subdivision of the Roman
Data source: Dilke (1985).
Egyptian surveyors, offer fascinating insights into the historical roots and
centrality of locational and coordinate systems. The technical details of the
centuration system also highlight concepts that societies today still rely on.
The similarity between the Roman foot, at 29.57 cm, and the modern Ameri-
can foot, at 30.48 cm, or just about 0.9 cm different, points to the persis-
tence of common measurements.
Roman administrators actively surveyed conquered and politically asso-
ciated areas undergoing integration into the empire. The survey created new
rectangular subdivisions of land that could be more easily administered and
awarded to army veterans as compensation for their years of service. Evi-
dence of centuration can still be found in areas of modern Italy, France,
Tunisia, Spain, and Great Britain.
Centuration usually involved the creation of a local location system
based on two orthogonal meridians. One meridian ran north-south, the
other ran east-west. Based on this initial grid, the area was further subdi-
vided into smaller and smaller units of land. Because the meridians were
local and not tied to a projection and datum each centuration was a
The Public Land Survey
The Public Land Survey (PLS), also known as the Public Land Survey Sys-
tem (PLSS), is similar in concept to the Roman centuration. It is used in
most areas of the United States to survey land for recording ownership using