Just remember, we do not have an inkling of the unit of measure used by
prehistoric people and yet we impose all manner of measurement on their
features. There could have been thousands of ways to measure "standard"
lengths.

Also, folks often assume architecture to be at clean 90, 180 etc. angles. I
excavated the base of a 1796 Spanish cannon battery totally using metric. We
converted a 1772 publication on fortification design from "varas" to meters
and found inconsistencies due to selection of field materials. There were no
smaller increments to convert. All the angles measured 30 and 32 degrees,
which make sense if you understand the fort was made from mud-mortared
cobbles holding sand and rock layers, buttressed with 32 degree slopes of
cobbles, and topped with plaster coated and mortared fire brick of at least 5
different shapes.

My point here is that metric neutralizes the inconsistencies and enables us
all to read common increments. It is not mean to impose metric on the
creators of the features we study.

Ron May
Legacy 106, Inc.