# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Message:αβγ
Message:abc
 Add Images & Files Posting Code: Name: Email:
Re: Poor St. Hilaire
From: John Karl
Date: 2007 Oct 27, 18:56 -0700

```
I sure can understand why some of you are wondering what all the St.
Hilaire fuss is about.  I'm new to the List and 'am finding out how
hard it is to carry on technical discussions in this format - as some
of you have mentioned.  A major, major, part of the problem is
definitions, and understanding what each other means - as others of
you  have said.  After starting this topic, now with 36 posts under
got my point across.  I'm embarrassed, and apologize for not being
able to communicate better.

I was speaking from the viewpoint of a modern author introducing the
St. Hilaire method and the reader trying to understand.  I'm talking
about how the method is introduced in any number of commonly used
books: books by Blewitt, Bowditch (2000 edition), Cunliffe, Dutton
(2004 edition), Howell, Letcher, Meyrier, Moody, Schlereth, Turner,
and Toghill, to name a few.  These authors all are discussing using HO
229, HO 249, or a calculator.  They are all talking about finding a
single LOP - not a fix, not an iteration of fixes.  They're not taking
about older log-trig methods or the Sumner method.

My statement was that all of these authors either don't attempt to
explain the REASON for the assumed position, or they explain it
incorrectly.  For example,

A. Some say that an assumption is necessary because the distance
between the sun's GP and the ship is too great to plot.  While that's
true (for most sights and charts), it's not the reason for the assumed
position.

B.  Some say the AP is necessary because there's insufficient
information to plot the LOP.  That's false.  We know everything
necessary to plot the LOP

C.  Others say the AP is necessary because we don't know how to plot
the exact LOP.  That's also false.  They are several ways to plot the
LOP exactly.

I mused about WHY so many authors either don't explain the reason for
the AP, or they have it incorrect - I think that the term "assumed
position" has misled these folks.  But of course, that's only my
guess.

I wonder what List members think the reason is for their
misunderstanding, particularly when they're supposed to be teaching
others!  No one has addressed this - yet.

John

--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To unsubscribe, send email to NavList-unsubscribe@fer3.com
-~----------~----~----~----~------~----~------~--~---

```
Browse Files

Drop Files

### Join NavList

 Name: (please, no nicknames or handles) Email:
 Do you want to receive all group messages by email? Yes No
You can also join by posting. Your first on-topic post automatically makes you a member.

### Posting Code

Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
 Email:

### Email Settings

 Posting Code:

### Custom Index

 Subject: Author: Start date: (yyyymm dd) End date: (yyyymm dd)