[Notes on early measurements]
[provided by Judith Vinson, texaslil@flash.net, 9 Oct 2001]
 
Mark, to answer some of your question marks:

A chain/"chane" carrier was a surveyor.  Your James Murphy was obviously 
employed as such.  Land was measured with a sextant (they now use a transit--
same thing) and a chain of a specified length.  
From the journal of William Vincent b. 1779 NC:
_______________________________________________________________________

                         LAND MEASURE
Note  3 barley corn make 1 inch  12 inches makes 1 foot  3 feet make 1
yard  2 yards make 1 fathom  5 1/2 yards or 16 1/2 feet makes 1 pole or
perch  40 perches  or 220 yards makes 1 furlong -------? furlongs makes
1 mile  3 miles 1 league  20 leagues or 60 miles one degree and 360
degrees is the circumference of the earth. 
                               William Vincent His Cyphering Book 
                               Anadomine 1797
_______________________________________________________________________

  *A "pole" was also known as a "perch" and also a "rod."  They all
measured 16 1/2 feet.
  *There are 4 poles to a "chain" or 66 ft.---so a "chain" was an object 
for measuring and also a length of 66 ft.
  *There are 10 square chains to an acre.  
  *The First Continental Congress adopted the term "chain" in 1796, but
oddly enough, it was a term neither enforced or repealed since that time for surveyors.  
William Vincent was the grandson of Peter Vincent b. ca 1718.  Peter was a surveyor 
and speculator in Granville Co. NC about 1744. 

In May of 1800 surveyors were paid the equivalent of $2.00 per mile for
7 ranges (whatever a range is?)  After that, they were paid 3.00 per
mile of land surveyed.  Considering the times, it was a good wage, but
hard earned.  They trekked a wilderness to accomplish the job.  There
were Indians to pacify, landowners? already claiming title (willing to
shoot them), and often the flies were so bad that they threatened to
suffocate the horses by filling and packing their nostrils.  On
occasion, these early day surveyors had to stop to pull cattle or horses 
from bogs and quicksand. The term "su ch carrier" referred to substitute 
Chain carrier.  One might assume there were many substitutes considering 
the conditions under which they labored.

Hope this helps.

Regards, Judith Vinson in Texas