NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: UNK
Date: 2014 Nov 20, 13:37 -0000
Thanks Hanno,
Yes, good advice. I’ve relying too long on others to do the “dark arts” of computer generated scales etc. I really must get myself a maths education!
I suspect that a combination of the SI photograph and the 2 papers should provide enough information to produce a good replica.
Best wishes.
Francis
From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Hanno Ix
Sent: 20 November 2014 01:35
To: francisupchurch@gmail.com
Subject: [NavList] Re: Longhand Sight Reduction
Francis,
you call yourself inumerate - which is good. Let the computer do the number crunching. The only way I could help you making a Brown Nassau is this:
Enroll in one of those magnificent adult education opportunities Cornwall seems to offer, specifically in a math related class - nothing too fancy. When choosing an institution or class make sure you qualify for the MATLAB student version which is cheap AND very good. Buy it. This is the only way to get the student version.
Once you installed it play with the demos, particularly the graphics. It is not difficult, actually it is rather intuitive and even easier to use than BASIC. You will get fast results with less work.
Check printers or graphic design businesses and ask if they can print .pdf or .tif files.
If so, you are half to were you want to be. BTW: This is cheaper than buying your own quality printer. I suspect there are such places close by since they made your Bygrave and Fuller scales, no?
Now start by generating simple things such as compass cards or sun dials and have them printed as a test. Make sure, annotation is included such that it turns with the direction. Sounds much more difficult than it actually is because the rich MATLAB documentation shows you by examples how to do things .
When you are at that point I can explain to you the math and the formulas needed to generate your Brown Nassau - if you still need such help. Actually, a small collection of trig formulas is all that is required - not a "superior mathematical brain" .
At this point you will be able to create many other graphs or tables by yourself.
H
On Wed, Nov 19, 2014 at 11:46 AM, Francis Upchurch <NoReply_Upchurch@fer3.com> wrote:
Gentlemen, (Hanno and Greg)
If I as a largley inumerate medic can be so bold, I think you have both done great work here. The current Doniol works well as do the hv tables and indeed the sin/cos tables.As we say in Cornwall, England, "Proper job".
I now need your superior mathematical brains to range over other areas of new and even greater importance. My latest enthusiasm. The Brown-Nassau spherical , graphical circular slide rule.
Please look at my postings and tell me what to do.
I think I now know I can make the thing from the graphs from the 2 papers, but it will be primitive without computer generated curves which are beyond my limited brain.
Gentlemen, please think deep and come to my rescue!
Best to both.
Francis
