# 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: Great Circle Course via calculator & HO 208
From: Bill B
Date: 2016 Oct 4, 23:12 -0400

```On 10/4/2016 2:13 PM, David Fleming wrote:
> Appologies to Gary and all Navlist members my previous reply was too
> terse and further should have been directed to Bill B.
>
> Google Earth claims1 degree longitude at 41 N represents .76 degree arc.
>  This is correct.
>
> GE also says the arc is 45.46 nm long.  therefore 45.46nm / 60 nm/degree
> = .7576 degrees.
>

Perhaps semantics.

To the best of my knowledge there are 360 degrees in a circle, 60
minutes per degree, and 60 seconds per minute.

Short answer, 86 degrees - 85 degrees = 1 degree, period.

I suspect you are comparing apples to oranges. Certainly the distance in
miles, meters feet etc. between meridians diminishes as the position
moves from the equator to the poles, but a circle created by a parallel
is still a circle (albeit with a smaller radius) and  degree remains a
degree (as do arc minutes and arc seconds relationship to a degree).

How then should I report my position on the 41st parallel half way
between the 85th and 86th meridian? As 85d 22' 44" given your assertion
that a degree is "45.46nm / 60 nm/degree = .7576 degrees" which equals
45'27". (45' 27"/2 = 22' 44").

I would prefer to report my longitude as 85d 30', especially if in need
of rescue (perhaps lost in a sweetcorn maze?)! Less terse, but IMHO a
superior answer if you want a chopper to show up with boiling water and
butter :-)

```
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)