NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Ducruy Jacques
Date: 2013 May 30, 10:01 -0700
Hello Frank,
Thank you for your answer.
I know that Douwes méthod is the prototype (or one of the prototype) of double altitude method.
But il your compare this method with the method used in France (Pézénas méthod, or Facio Duiller method for Ch Cotter), the principle is very different.
In the Douwes method, you calculate : 1) an hour angle 2) a latitude via the versine formula ... and you do the same for ex meridian method !
It seems that Douwes method was used often in UK : cf books of JH Moore, Mackay or Norie (I had 1914 edition of Norie)... before the Ivory method in 1821 !
Good evening
Jacques
Jacques
----------------------------------------------------------------
NavList message boards and member settings: www.fer3.com/NavList
Members may optionally receive posts by email.
To cancel email delivery, send a message to NoMail[at]fer3.com
----------------------------------------------------------------
