As far as I understood the main reason for using sun compasses in the Sahara was that a magnetic compass would be rather unreliable on those moving masses of steel called tanks during WW2.
At 08:04 24-3-99 +1000, you wrote: -----Original Message/Oorspronkelijk bericht-------------- >Folks, > >Roger's comment re sun compasses is correct and also applies >partially to Antarctica. > >Up to at least the 1970s, ANARE (Australian National Antarctic >Research Expeditions) used surplus military Astro Compasses on >over-ice traverses. > >When I wintered at Davis Station 68o 35' S 78o 00'E, we used >magnetic compasses ALL the time. All I had to do was remember that >the deviation was 78o W (I think it was west!). At times, this caused >some interesting discussions about directions! > >Altho the large deviation was inconvenient, it was not really a >problem. > >Of course, GPSs have ended all that! > >John > > >Dr John Pickard >Senior Lecturer, Environmental Planning >Graduate School of the Environment >Macquarie University, NSW 2109 Australia >Phone + 61 2 9850 7981 (work) > + 61 2 9482 8647 (home) >Fax + 61 2 9850 7972 (work) > > ----------------------------------------------------------------- Thibaud Taudin-Chabot, home email: [EMAIL PROTECTED] (attachments max 500kB, in case of larger attachments contact me)
