A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: Mark Coady
Date: 2018 Jul 29, 07:04 -0700
One thing that puzzles me. I suppose many of you have heard the adage that a "shortcut can be the longest distance between two points".
My own experience was first reading about and attempting to do Lunars a fairly "hard way". Being overprecise and overconcerned with some things that simply did not matter. They were intimidating.
The Dutch East Indiamen I also understand were faced with a historical time period (1760's) where the later catalouged solutions were not yet tabulated. The Lunar then without a pocket calculator becomes a cumbersome excercise indeed.
The method proposed by Chichester in Along the Clipper Way, and horizon based Lunar measures in the end, once described, with the multiple sights over an extended period, seems pretty involved. Especially satisfying yourself with a lower potential accuracy. I also understand that this is limited in that it is applied when the moons horns are horizontal, but not vertical.
By Chichester's day, while Bowditch and other's and dropped lunar's from their later editions, it seems that lunars had been simplified to the point where they weren't such an intimidating excercise? Various corner cosine methods, etc. had been worked out and made life a bit easier.
When I did Frank's lunar class I learned that lunars were no longer a source of mathamatical pain and suffering, and that their discontinuation was not so much the result mathamatical gyrations as the result of the common availability of timepieces of high accuracy. I found the Bowditch-Thompson method or others cookbook enough not to be intimidating.
In other words, Chichester's method seems in some ways more painful than the tabulated approach to the lunar Lunar itself, even pre-calculator.
Was it that he simply made this effort without the other references at hand? Or is my own sketchy knowledge of this subject leaving gaps in understanding the historical context?
One comment on originality and claiming things to be original. As an engineer whose best skill tends to be troubleshooting, I have several times in my career, inlcuding a few months ago, needed a solution to a problem and "invented it"; even though, later on it was discovered to already exist.
I recently faced a problem for a client and developed a well thought out solution. Annoyingly, however; it would have required expensive custom fabrication of the componants I sketched. Although we had looked around, and not found what we wanted yet, my comment then was that this problem is not new, so a solution must already exist. Surely enough after a search reworking the old google string fifteen or twenty times, I found one other source for the solution on the internet, with a now manufacured version so close to my own concept sketch as to be uncanny.
Was my thinking original, well yes in that it was not aided from the other person...... Did I invent it, well yes, to a point I suppose I could say that. Independently working from my own mind without cheating and without prior knowledge of the other person's work. I will say I won't make any claim to its invention, but I get some of the satisfaction. I guess what I am saying is that I will leave any stone of criticism unthrown on this call. Sometimes the satisfaction of somewhat independent thinking might overwhelm our caution at recognizing it's not so unique a solution after all. Sometimes there's nothing new, just different paths to arrive at the exact same conclusion. Most of what we do is not original discovery, it is reapplying the same ideas over and over with theme and variation and our own unique bias.
Pre-internet, this was even more common, as we had less ready reference to the vast compost heap of world information; so we found and fixed problems more on our own. Years later we found identical solutions or other variations on the theme elsewhere.