# 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:
From: Millard Kirk
Date: 1997 Jul 09, 12:42 PM

```Russell Sher wrote:
>
> Hi - I've just subscribed. Does anyone know the formula for calculating
> meridional parts if given the Latitude ?
> Cheers
> Russell Sher

>From "The Calculator Afloat"

M=7915.7045 x log tan (45d +L/2) - 23.2698 sin L

Example:  Our position is Lat 32d 14.7'N, Lon 66d 28.9' W, and we wish
to determine the course and distance to a point near Chesapeake Light,
in Lat 36d 58.7'N, Lon 75d 42.2'S, be Mecator sailing.

L1      32d 14.7'N
L2	36d 58.7'N
----------
l        284.0' n        l = difference of L1 and L2

M1 = 7915.7045 x log tan(45d + 32.2450d/2) -23.2689 x sin 32.2450d x sin
32.2450d
2045.7409 - 12.4149 = 2033.3

~ = asbsolute value

L1      32d 14.7'N       M1	2033.3
~                        ~
L2	36d 58.7'N       M2     2377.0
----------              -------
l        284.0' n 	         343.7

next step difference in Lon in min of arc:

Lon1    66d 28.9' W
~
Lon2    75d 42.2' W
-----------
DLO       553.3' W

Tan C = 553.3'/343.7 = 1.6098

Therefore:  course is N 58.1522d W; the course to steer will be Cn
301.8d

Distance  D = 284.0'/cos 58.1522d  = 538.2206  or 538.2 miles

Hope this will help

--

Learning the Hard Way!!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Millard Kirk KB8YQO 	Email - mkirk@marshall.edu
116 Lewis Ave	     	Homepage- http://webpages.marshall.edu/~mkirk/
Barboursville, WV      A West Virginia Blue Water Sailor
25504                  (304) 736-6544
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-=
=-=  TO UNSUBSCRIBE, send this message to majordomo@ronin.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)