NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Peter Fogg
Date: 2005 Dec 7, 08:20 +1100
There certainly were a lot of
old-fashioned methods, Jim. Tables were useful to allow computation of the
navigational triangle, and apparently some List members still prefer to use a
slide rule, possibly because they are familiar with it and it gives a result
appropriate for their needs.
However, a few decades ago the small,
inexpensive electronic calculator was introduced. With it and appropriate
formulas a precise result can be quickly and directly produced. Tables and
slide rules still have the advantage of not needing batteries, as well as being
less liable to the corrosive effects of on-board life.
Having said that, there is a lot of
interest on the List in the history of navigational methods and instruments,
and in the past various books, websites, etc
have come up for mention. Thus there is a wealth of information within the
archives of the List, apart from whatever responses you may get directly.
Happy hunting
From: Navigation
Mailing List [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM] On Behalf Of Jim Hickey
Sent: Wednesday, 7 December 2005
7:47 AM
To:
NAVIGATION-L@LISTSERV.WEBKAHUNA.COM
Subject: Alternate methods of
sight reduction
Alternate methods of sight reduction
First, allow me to introduce myself as a new member. My name is Jim
Hickey. My wife Judy and I currently live aboard our sailboat in
I have a volume of Bowditch that discusses a variety of sight reduction
methods. I believe all the old table methods and more have been discussed. Has
anyone had access to or knowledge of the old slide rule type method that is
referenced? I believe the instrument was called a Bygrave computer which looked
cylindrical.
As well, there is also a picture of a wonderfully elegant looking globe
like device that is set up with sliding arms that solves the navigational
triangle directly.
I have been intrigued by these items for years and of course would love
to mess with them if I had the chance as I am sure many here would.
Very curious to know how effective these approaches were and if there
are others etc. etc.
Cheers,
Jim