NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
The Old vs. The New
From: Frank Reed CT
Date: 2004 Jan 18, 19:19 EST
From: Frank Reed CT
Date: 2004 Jan 18, 19:19 EST
Chances are good that nearly everyone on this list learned celestial navigation in a form that used to be called the "New Navigation". It's essentially the St.Hilaire method. Today it might make more sense to call it 20th century navigation, but the older "new" name is quaint so let's keep it. The "New Navigation" replaced the "Old Navigation" which was the set of tradtional celestial navigation techniques used for most of the 19th century.
Features of the New Navigation:
1) All altitude sights are treated as equivalent. There are no separate sights for latitude and longitude.
2) For every sight, a distance away and azimuth are calculated from an assumed position (possibly the DR position).
3) Position is determined by intercept plotted on a chart as a "Line of Position". Crossing two or more LOPs determines the vessel's position on the chart.
4) Star sights are common and encouraged.
5) Simple tabular methods are common. Navigators using tables in practice rarely encounter the mathematical terminology underlying their calculations.
Features of the Old Navigation:
1) Longitude and latitude treated separately both conceptually and practically.
2) Latitude determined primarily by Noon Sun, often by Double Altitudes, and very rarely determined by sights of other objects. Star sights are rare.
3) Longitude determined by comparing the local time derived from a time sight, usually based on an altitude of the Sun in the early morning or late afternoon, and the Greenwich Time kept on a chronometer (or two).
4) Occasional exotic sights like lunars (which were fairly common in the early part of the 19th century and then faded rapidly).
5) Calculations generally involve few tabular simplifications, and a navigator has to learn to pronounce (if not understand!) phrases like "log cosecant" and "proportional logarithm".
5) Almost no plotting except for the final position itself.
So here's a couple of questions that I thought might spark some discussion: When did the New take over decisively from the Old? This will vary by country, by economic segment, etc. What was the *last* "school of navigators" who consistently used the "Old Navigation"? Mixter suggested that time sights and LAN sights were still the standard method of navigation in the US Merchant Marine as late as 1942 though it certainly wasn't the method he advocated.
Are there any other methods and techniques that would distinguish the old methods from the new? Were there any major regional variations in the Old Navigation? For example, did Ottoman navigators use the same basic set of techniques as their counterparts in America, Western Europe, and elsewhere?
Frank E. Reed
[X] Mystic, Connecticut
[ ] Chicago, Illinois
Features of the New Navigation:
1) All altitude sights are treated as equivalent. There are no separate sights for latitude and longitude.
2) For every sight, a distance away and azimuth are calculated from an assumed position (possibly the DR position).
3) Position is determined by intercept plotted on a chart as a "Line of Position". Crossing two or more LOPs determines the vessel's position on the chart.
4) Star sights are common and encouraged.
5) Simple tabular methods are common. Navigators using tables in practice rarely encounter the mathematical terminology underlying their calculations.
Features of the Old Navigation:
1) Longitude and latitude treated separately both conceptually and practically.
2) Latitude determined primarily by Noon Sun, often by Double Altitudes, and very rarely determined by sights of other objects. Star sights are rare.
3) Longitude determined by comparing the local time derived from a time sight, usually based on an altitude of the Sun in the early morning or late afternoon, and the Greenwich Time kept on a chronometer (or two).
4) Occasional exotic sights like lunars (which were fairly common in the early part of the 19th century and then faded rapidly).
5) Calculations generally involve few tabular simplifications, and a navigator has to learn to pronounce (if not understand!) phrases like "log cosecant" and "proportional logarithm".
5) Almost no plotting except for the final position itself.
So here's a couple of questions that I thought might spark some discussion: When did the New take over decisively from the Old? This will vary by country, by economic segment, etc. What was the *last* "school of navigators" who consistently used the "Old Navigation"? Mixter suggested that time sights and LAN sights were still the standard method of navigation in the US Merchant Marine as late as 1942 though it certainly wasn't the method he advocated.
Are there any other methods and techniques that would distinguish the old methods from the new? Were there any major regional variations in the Old Navigation? For example, did Ottoman navigators use the same basic set of techniques as their counterparts in America, Western Europe, and elsewhere?
Frank E. Reed
[X] Mystic, Connecticut
[ ] Chicago, Illinois
