[GTALUG] Surveying

[Stewart C. Russell]

On 2016-04-20 09:06 AM, phiscock at ee.ryerson.ca wrote:
> 
> … a remarkably strong case can be made for
> the weird units of measurements used in the past - rods and chains, for
> example.

Yeah, spent a bit too much time around plans and surveys.

The basis of most land measurement is Gunter's Chain
<https://en.wikipedia.org/wiki/Gunter's_chain>, a 17th century invention
that made it easy to measure out distances and acreages. One chain is 66
feet, and there are 4 rods (or poles, or pikes) to the chain. There are
100 links to the chain, so it's vaguely base-10 too.

The original reason for the 16th and 17th century English mania for
survey was the valuation of lands seized from the Catholic church by
Henry VIII. It also helped with land valuation for Enclosure, and the
end of the Commons.

Many land surveys are done in metes and bounds, which are a series of
vector measurements from a point (usually a defined survey point; if you
ever stumble over a low square metal peg half-buried, it's likely a
survey marker) to define a land area. Annoyingly, in the US, most of
these measurements use US Survey Feet, which very slightly different to
the 12 × 25.4 mm feet that we might know.

Tiny aside: My wife's great-great-grandfather surveyed the Santa Fe
trail for the carters, who felt that the US government was underpaying
them for the distance. Somewhere in the family vaults is the chain that
Martin O. Jones and his team dragged from Independence, MO to Santa Fe,
and proved the carters right.

units(1) has many interesting asides on measurements.

cheers,
 Stewart