2 86 Miscellanea Curiofa. 



? Tis true indeed , if the Surveyor go the 

 whole furround of the Lands A and B, he 

 will find their Figure and Contents exa&ly 

 agreeable to the Map here exprefTed. But 

 then the Bearings of the Lines are all 7 De- 

 grees different from the Bearings in the Map, 

 and they will run in and out upon the adja- 

 cent Neighbouring Lands, and caufe endleft 

 Differences between their PofTeObrs as is 

 manifeft from the Figure : wherein the prickt 

 Lines reprefent the Difagreement in the 

 Bearings of the Lines, protracted from the 

 Point P j and we fee A incroaching on his 

 Neighbours on the Weft ward, as he incroaches 

 on i? , and B\ Eaftward Neighbours in- 

 croaching on him, and fo forward and clear 

 round. Whereas, by a due allowance for the 

 Variation of the Needle, all this Confullon 

 and Difagreement is avoided , and every 

 thing hits right. 



Thus for inftance in the Cafe before us, 

 knowing that the Magnetick Variation has 

 caufed the prefent Magnetick Meridian to 

 fall in the Line n q P 7 Degrees from the 

 North to the Weftward ; to reduce this to 

 the Magnetick Meridian at the time of the 

 Down Survey, I muft make the Meridian of 

 my Map to fall 7 E)egrees to the Eaftward of 

 my Magnetick Meridian j as we fee the Line 

 P i9 falls 7 Degrees to the Eaftward of the 

 Line P q. 



What is here faid on fuppofition that the 

 Magnet had no Variation at the time of the 

 firft Survey taken, and that it had 7 De- 

 grees variation Weftward at the time of the 

 fecond Survey, may ealily be accommodated 



to 



