NavList:

Dear David, Do you have the "Precision Astrolabe" PDF in full? I'm interested in the "automatic averaging of sights" (Chapter 12) also. Francis M Rogers must have written very interesting book indeed! Thank you in advance. Regards, Tony

I haven’t a copy, but it wouldn’t surprise me if GL had the full copy.  There’s a copy of the actual book in the British Library in London, but I’m guessing you live just about as far away from there as it’s possible to do so.  I’ll try and transmit a copy of 1500 words I wrote for Navigation News about aircraft sextants in general, but it’s about 7MB, so it might not travel.  If so I’ll send you a private email.  There are a couple of good references; Deborah Warner is particularly worth reading.  It’s worth looking at the full list of Francis M Rogers papers.  He had the most amazing span of interests. DaveP