A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: Richard M Pisko
Date: 2003 Mar 25, 14:06 -0700
Back before the dawn of time (on Tue, 25 Mar 2003 12:06:12 -0800, to be exact), "Royer, Doug"
wrote: >5. Work the equation and the result will be the distance off the object. >Hopefully this diagram will be transmitted better than the one yesterday.In >fact if this diagram goes through it was basically the same set-up as >yesterday's diagram. > The 1911 Encyclopedia mentioned yesterday for telegraph cables wrote about a similar system double sighting system under "rangefinder". There was mention of a 50 yard cord for a base line, two people, and two sextants held horixontally. One was fixed at 45 degrees, and the other read the angle ... which I think may have had a special spiral scale on a micrometer drum so as to read directly in yards. To bad the encyclopedia on line doesn't show illustrations to match the descriptions. One apparent problem was making sure both observers merged the same target object with the split image of the other observer's sextant. However, I thought you mentioned a military compass, which is graduated in mils in the US. Could you not just take a bearing, walk away from that point so as to keep the object more or less at right angles to your (perhaps slightly curved) path, and stop when the new bearing is 10 mils different from your first? That way, the distance to the object will be 100 times the distance you traveled ... barring local magnetic anomalies. Just a thought. -- Richard ...