Next message: Nels Tomlinson: "Re: Alternate methods of sight reduction"
Zvi, I'd be very interested in seeing the scales, or the software, or
both. Mostly the scales, I guess, since I'd like to make a working
model myself. Could you email them to me, or post them somewhere?
Thanks,
Nels
On 12/7/05, Zvi Doron <> wrote:
>
> Hi Jim
>
> I must run so it will be short - sorry
>
> I have studied the Bygrave slide rule and built several working models
> including developing a piece of software to draw the scales - to my mind the
> Bygrave is the most practical way of reducing a sight for a small boat where
> accuracy of 1 mile is perfectly acceptable.
>
> Kind regards
>
> Zvi
>
> ----- Original Message -----
> From: Jim Hickey
> To:
>
> Sent: 06 December 2005 20:47
> 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 St. Augustine,
> Florida. I have been interested in celestial navigation for many years much
> to the amusement and entertainment of my wife! Even got the programming bug
> early on but have it under reasonable control at this time. It has been a
> delight to read many of the fascinating postings for some time now.
>
> 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
