318 ROYAL SOCIETY OF CANADA 
pendently from the local standpoint, and I shall here only summarize 
what seems important from our present point of view. 
The surveyors reached the monument at the source of the St. Croix 
in July, 1817, and replaced the marked tree of the earlier surveys 
by a more permanent monument. 
It was first necessary to determine the magnetic variation, for 
of course the north line could only be run by compass, and by making 
allowance for the magnetic variation. The greater this could be 
made to appear the more it would throw the line to the east and favor 
the American claim, and the lesser the more favorable to the British 
claim. It was determined to be 13° .51° an amount which Campbell 
in a letter to Chipman implies was favorable to the British cause.? 
A line had already been run north from this point by Col. Turner 
prior to 1807, in connection with land grants here made by Massachu- 
setts, and it was soon found that the new line was running west of the 
old, to such an extent that at the 12th mile it was 101 rods to the west 
of it, much to the distress of the American surveyors. As soon as 
this line was started, it was left to the assistant surveyors, Campbell 
and Burnham, while the chiefs, Bouchette and Johnson pushed ahead 
on an exploratory north line to try to find the highlands of the treaty.’ 
Some forty miles north of the starting point, the line passed over a 
part of the elevation known as Mars Hill, seemingly part of a con- 
siderable range of hills crossing the St. John at this point, and it 
crossed the St. John not far above Grand Falls. Late in October 
they reached the watershed between the St. John and the Restigouche, 
where the line was stopped, partly because of the lateness of the 

1 An excellent figure of this monument and its surroundings is given 
in a lithograph by Bouchette in his work, British Dominions in North 
America. The essential part of it is copied in Winsor’s America, VII., 172, 
and in Fiske’s Critical Period, 25. 
? “T really think that had Johnson been competent to undertake a regular 
course of astronomical observations with our Surveyor-General, he would 
not have compromised for less than fourteen degrees; as it is the Colonel 
has completely the advantage.’’ (Letter of Aug. 3, 1817). 
But Campbell is here mistaken, for the extremely accurate survey by 
Graham in 1841 showed that the line should have run still farther to the 
westward. 
’They took observations for height with ‘one of Sir H. Inglefield’s 
mountain barometers,’ and from these observations was made that barome- 
tric section of the north line published in the Blue-book of 1840. The eleva- 
tions proved, however, when later more accurate observations were made 
by the Survey of 1842, extremely erroneous, being enormously too high. 
This exploratory line has great importance to our subject, for it was 
adopted as the boundary by the Treaty of 1842, and is the present boundary. 
