NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg B
Date: 2013 Dec 27, 19:01 -0500
Please help me understand the 'instrument time line'. What is the angular resolution of a cross-staff or back-staff?
I always thought it was about +/- a degree, and if thats true why would you care about 1 arc minuet?
I always thought the first sub degree instrument was the octant.
~Greg
On 12/27/2013 06:04 PM, Alexandre Eremenko wrote:
I am reading a book about Thomas Harriot (an outstanding British mathematician) In 1595, he wrote "Instructions for assisting the navigators of Sir Walter Raleigh's voyage to Guiana.
The instructions contain the following dip table
1 3'
2 4'
3 5'
4 5'
5 6'
6 6'
7 7'
8 7'
9 8'
10 8',
where the left column is the height in PASE's; according to the authr of the paper,
1 pase=5 feet.The paper also has a reference to an early Portuguese source: Pedro Nunes, De arte ratione navigandi libri due (Coimbra, 1546).
The article I am reading is Jon V. Pepper, Harriot's earlier works on mathematical navigation: theory and practice.
Gary: have you received my request sent off-the-list?
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