On Metallic Minerals. 4l5 



NOTE IS. 



if the townships and allotments of land in these Provinces 

 have been laid down by compass, they cannot possiblv be 

 correct, for with all the care an experienced survevor 

 could bestow, he would not have been able to make the 

 proper allowance for the degree o( local magnetic attraction, 

 the comparative intensity of which, at different places is so 

 various and uncertain. We shall be told that the surveyor, 

 in running an allotment or township, first commenced his 

 operations from some plain or bank of a river, far removed 

 from hills or mountains, (the more frequent depository of 

 magnetic iron,) and out of the rciicli of local magnetic 

 influence ; and that having there laid down a magnetic 

 meridian he no longer used the compass, but produced his 

 lines hy covering vertical pickets. 



This method is perhaps the best that can be adopted m 

 the absence of all instruments except the compass, but after 

 all it is very liable to error, for, not to mention the impos- 

 sibUity of always finding a spot free from mountain or liill, 

 if a i)lain or bank of a river so situated, be found, who can 

 be sure that local magnetic attraction docs not extend to it ; 

 wlio can be sure that it is not itself the seat of that attrac 

 tion — may not the very sand at your feet or the boulders 

 on which you are seated be magnetic. 



Where primary rocks occur in this country, the presense 

 of magnetic iron may be suspected. Some of the secondary 

 trap division arc also magnetic. But local attraction is 

 sometimes so little indicated by external appearances that 

 the most experienced may be deceived. Mr. \N'att3 of 

 Cafjc Diamond, and Mr. Saxe of the Surveyor Ci'eneral'a 

 Department of L(jwer Canada, both agree in stating that 

 the ncigliboiirhood of L'Acadie is remarkable for tlic local 



I <. 



