On Apr 17, 2014, at 8:47 PM, Wesley Groot  wrote:

> Andy, I think the surveyor's chain was/is 66'. I read a book called "Measuring
America" which was an excellent read. It was a while ago, and I loaned it to
someone that never returned it...

>From Wikipedia:

"A chain is a unit of length. It measures 66 feet, or 22 yards, or 100 links, or
4rods. There are 10 chains in a furlong, and 80 chains in onestatute mile. An
acre is the area of 10 square chains (that is, an area of one chain by one
furlong). The chain has been used for several centuries in Britain and in some
other countries influenced by British practice."

Back in the days of slide rules, 1960 as I recall, I worked with a surveyor for
about one year. We were not working on flat ground. We both kept separate notes
on everything we did, and at the end of the day, we both did all the
calculations. My calculations had to match his exactly, or we had to re-survey
what we did that day. Lots of fun, and good trig practice. I learned to keep
good clean notes, and to be very precise.

I remember reading somewhere that in the great survey of India, way back when,
using theodolites, that it took years to complete, and at the end they were only
off by a matter of inches, in some 800 miles. I am truly impressed with that.