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l-ands, between Neighbour and Neighbour, after the 
Inundations of the Ni/^, which, we are told, gave the 
fir ft Or glnal to Geometry and Surveying. Abfolute 
Nec€;> ry and life having introduced thtie, as DeJight 
and Diverfion introduced Aftronon^iy amongft the Chal- 
Jeans. 
And this brings me to another Objeftion which may 
be made againft the Inflance before laid down: (t may 
be faid , That certainly the Surveyor which B imployed 
was very ignorant, who would choofe to judge of the 
Line P Q^s rather by its bearing than by determining 
the Point -2^, by meafuring from ^and G. To this I 
anfv^er^ What if both the Points H and G were vanifli'd 
fince the Down Survey was takea ? What if the whole 
face of the Country were chang'd, fave only the Point P 
and the Line P Qj How fhall the Surveyor then judge 
of the Line P Q^but by its bearing > That this is no 
extravagant Suppofition, we have an Example in Egjpt 
above-mentioned, where the Nile lays all flat before it, 
and fo uniformly covers all with Mud, that there is no 
diftindion. In fuch a Cafe your Bearing muft certain* 
Jy help you out, there is no other way. 
But I anfwer fecondly, To fay that the Surveyor 
might have determind the Point Q^by admeafurement 
.from G and ^Z", or any other adjoining noted 'Pointy, as 
from F,K,I,&ic. 'tis very true ; But then 'tis againft 
our Suppofition. I am upon fhewing an Error that ari^- 
fes from judging of the Line P Q^ly Magnetkk hearingy 
and to tell me that this might be avoided by another 
way, is to fay nothing. I my feif (hew how'it may be 
avoided by allowing for the Variation,- butflill itisan 
& ror, till jt be avoided. . 
