In news:44d0481c$0$40698$dbd45001@news.wanadoo.nl,
dre <v> typed:

There's no reason to suspect it's inaccurate.

oh boy.
explained that.

In terms of N,S,E,W alignment they could have easily made a compass using
some loadstone tied to a wooden stick floated in a pool of water. Or simply
used the North Star. What is more difficult though is getting something
close to the centre of the Earth's Land mass.
-- 
Amanda