Some More M&D Background Info

[Brian D. McCary]

Seems like every book I pick up these days mentions M&D.  Here's a section 
on the background to their survey from "The Mapmakers", by John Nobel
Wilford.  (This is a history of cartography)

"...  In actuality, the line surveyed by Mason and Dixon defined only the boundry 
between the British colonies of Pennsylvania and Maryland.
	For decades this had been a hotly disputed border and a source of enmity 
between the Penns of Pennsylvania and the Calverts of Maryland.  George Calvert, 
the first Lord Baltimore, recieved the lands of Maryland as a royal grant in 1632. 
 William Penn obtained the lands to the north by a royal grant in 1681; a 
subsequent grant gave Penn land to the south on the Delmarva 
(Delaware-Maryland-Virginia) peninsula.  But it was not made clear where one grant 
ended and the other began.  As for the northern boudary, the Maryland charter had 
read: "that Part of the Bay of Delaware on the North, which lieth under the 
Fortieth Degree of North Latitude, where New England is Terminated"  The fortieth 
parallel would have put Maryland's northern border within the present city of 
Philadelphia, which the Penns would not tolerate, and so a critical issue in the 
dispute was how far "under" the fourtieth parallel the boudary was to run.
	The dispute reached such an impasse in 1761 that the Penns and Calverts 
finally agreed to seek outside, independent help.  Local surveyors had proved 
unable to conduct the type of astronomical and mathematical operations required to 
fix and connect the north-south and the east-west boundaries of the two provinces.
	Thomas and Richard Penn, sons of William, were advised by their 
representatives "to send over from England some able Mathematicians with a proper 
set of Mathematical instruments."  These persons, moreover, should be "of Great 
Integrity and totally uinbiassed and unprejudiced on either side of the question." 
 The Penns and Frederic, the sixth Lord Baltimore, appealed to the Astronomer 
Royal at Greenwich for recommendations.  Mason and Dixon were his choices.
	Charles Mason was an astronomer who had worked closely with the Astronomer 
Royal at Greenwich on a catalog of lunar positions and on improvements in 
astronomical instruments.  Jeramiah Dixon was a mathematician and surveyor from 
Durham.  The two men had worked together as a team set by the Royal Societ to the 
Cape of Good Hope to observe the transit of Venus across the face of the Sun.  It 
was when they returned to England in 1762 that they learned of their new 
assignment."
	
The next three pages are mostly a technical description of the survey, which
I'll spare you.  But the more I hear about this pair of characters, the
more excited I get about this book.  There is some echos of GR (with the 
splitting of territory by vested powers, this time the Calverts and Penns
instead of the Allies, and I see the Six Nations, who helped in the 
survey, or the Shawnees, who were raiding locally during it, reprising
the Herero role) but there is also the whole issue of how gaining the
ability to accurately and abstractly divide space and time (through accurate
maps and chronometers) changed our relationship with the planet.  Plus, the
opportunity to look ahead to the Civil War.

Brian McCary.