Subject: Re: [BoundaryPoint] Fiat boundaries<br/>
Date: May 02, 2001 @ 00:50<br/>
Author: Brendan Whyte (&quot;Brendan Whyte&quot; &lt;brwhyte@...&gt;)<br/>
<a href="2317.htm">Prev</a>&nbsp;&nbsp;&nbsp;&nbsp;Post in Topic&nbsp;&nbsp;&nbsp;&nbsp;<a href="2325.htm">Next</a>&emsp;[<a href="topic2251.htm">All</a> Posts]<br/>
<a href="2317.htm">Prev</a>&nbsp;&nbsp;&nbsp;&nbsp;Post in Time&nbsp;&nbsp;&nbsp;&nbsp;<a href="2319.htm">Next</a><br/>
<br/><br/>
<div id="ygrps-yiv-1736510717"><blockquote><span title="ireply">&gt;From: &quot;Jesper & Nicolette Nielsen&quot; &lt;<a rel="nofollow" target="_blank" href="mailto:jesniel@...">jesniel@...</a>&gt;<br/>
&gt;Reply-To: <a rel="nofollow" target="_blank" href="mailto:BoundaryPoint@yahoogroups.com">BoundaryPoint@yahoogroups.com</a><br/>
&gt;To: &lt;<a rel="nofollow" target="_blank" href="mailto:BoundaryPoint@yahoogroups.com">BoundaryPoint@yahoogroups.com</a>&gt;<br/>
&gt;Subject: [BoundaryPoint] Fiat boundaries<br/>
&gt;Date: Tue, 1 May 2001 07:45:41 +0200<br/>
&gt;<br/>
&gt;Which international boundaries are 100% fiat, meaning 100% straight?<br/>
&gt;<br/>
&gt;On the map I see:<br/>
&gt;<br/>
&gt;Morocco-Western Sahara<br/>
&gt;Algeria-Mauretania<br/>
&gt;Western Sahara-Algeria<br/>
&gt;Nigeria-Chad<br/>
&gt;<br/>
&gt;But perhaps there are minor irregularities I cannot see on my map, so who <br/>
&gt;can confirm this?<br/>
&gt;<br/>
<br/>
 </span></blockquote>Define &#39;straight&#39;. Especially on a sphere. The only stright line on a sphere <br/>
occurs on a great circle. A line following any parallel apart fomr the <br/>
equator (the only great circle of latitude) is not straight, it bends left <br/>
or right. Therefore the US Canada boundary along the 49th is NOT a straight <br/>
line.<br/>
therefore the N-S segments of Mor-West sahara, the small WS-Alg and parts of <br/>
Niger-Chad probably are.<br/>
Second, although defined in treaties as following given parallels or <br/>
latitudes, or &#39;stright lines&#39; joining certian points on diagonals (eg <br/>
Algeria&#39;s boundaries... are they great circles, or not?), most boundaries on <br/>
the ground are straight lines joining pillars erected where the paralleles <br/>
etc are thought at the time to be.<br/>
The US-Canada boundary was so defined, a series of line segments joining <br/>
pillars. Even if the pillars ARE on the 49th, the &#39;stright lines&#39; joining <br/>
them will not be except at those pillars. So at leats once, intermediate <br/>
pillars were erected to make shorter line segments, and keep the boundary as <br/>
close as practical to the pilars.<br/>
<br/>
I am guessing that a straight line of sight fomr a pillar to another IS a <br/>
great circle segment.<br/>
<br/>
BW<br/>
<br/>
<br/>
<br/>
<br/>
<br/>
<blockquote><span title="ireply"> &gt;Jesper<br/>
&gt;<br/>
<br/>
 </span></blockquote>_________________________________________________________________________<br/>
Get Your Private, Free E-mail from MSN Hotmail at <a rel="nofollow" target="_blank" href="http://www.hotmail.com">http://www.hotmail.com</a></div>