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>Quinn wrote:
>
>>Someone in an introductory nav. class I recently taught wanted to know how to
>>find a piece of property he purchased somewhere in South America using
>>celestial, and I had to tell him I hadn't the foggiest.  Without a horizon
>>and a clear sky, I'm lost!  BTW, I advised him to beg, borrow, or buy a
>>portable GPS.
>
>Ah! what you need is an artificial horizon, and a refraction correction
>table for altitudes above sea-level!
>
BIG Snip

I have no problem with your remarks except for needing a horizon.  Many of
the early surveyous used a transit for their work.  Such an instrument has
both vertical and horozontal arcs and a leveling bubble.  Leveling the
transit on its' tripod and being on solid ground as opposed to being on a
rolling boat negated the need for a visiable horizon.  Leveling the
instrument set the horizon.

Surveyors as late as 1960 were taught how to go into the field and by using
their transit and a Ephemeris (their version of of the Nautical Almanac) to
locate their position described by latitude and longitude rather than
reference to the local grid system.  The outter banks of North Carolina were
surveyed using this method. They established control points (posts) and then
used triangulation from one post to the next to fill in the details.  At one
time I had copies of the original surveys done for the Coast and Geoditic
Survey section of the Government in the 1850's.  This was the second mapping
of the coastline in this area, the first being done in the late 1700's.

I have a copy of a surveying book by Michael V. Smirnoff called
"MEASUREMENTS FOR ENGINEERING and other surveys" (1961) that gives about
thirty pages of this type of navagation (land).  Anyone wishing a fax copy
of this work can have one by sending me your fax number (or snail mail
address). I will send it. (Copies will be for historical purposes only and
are not to be sold or reused in any work without permission from
Prentice-Hall Inc publishers who still have current copyrights to this
material)  I will be away until Jan 9th so be patient.  Just a note.  George
Washington set a portion of the southern border of Virginia running a
lattitude line using a transit and the methods used in the text.  The
methods had not changed much in the intervining two hundred years to that
point.  They have really changed since.

Best of the Christmas Season to all. (Micah 6:8)

George

>Cheers!
>
>J.
>
>P.S. -- unless you live in California, the Earth doesn't move much ;-), so
>you can do a multiple body fix using only the sun throughout the course of
>the day...
>
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>
  JOY... Quartering wind at 10 to 15 knots, Temperature 78 F, Sea State less
than 3' , full moon
 sky full of stars, a bone in her teeth, and a wake of phosphorescence fire
 :-))).

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