Document grid convergence
commit513935e0536fa24e5cb10b443a0e915c3e201112
authorOlly Betts <olly@survex.com>
Sat, 28 May 2016 13:46:44 +0000 (29 01:46 +1200)
committerOlly Betts <olly@survex.com>
Sat, 28 May 2016 13:46:44 +0000 (29 01:46 +1200)
treea50c447c7c7647f7d465cd986f5b96ccc5a3e421
parentdcb33cbebd8c462b2757ebc1fcde20b3bf101d43
Document grid convergence

And improve discussion of magnetic declination
doc/manual.sgml