A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bill Morris
Date: 2017 Jun 15, 21:36 -0700
David, the Marks IX A, IXBM have the same works, except that the averager is two speed and a 2 power telescope has been added to the BM, i.e. in each case you have a "fresh cast" IXA body with a choice of averager and addition of telescope. Yhe Mark IX has different works with only a six shot averager.