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From: Jim Hickey (no email)
Date: Thu Mar 09 2006 - 13:04:48 EST
I have found the "navigation in 1897" and the "Summner" threads of
particular interest with respect to how celestial navigation developed and the
eventual acceptance of the celestial line of position as the standard.
It seems to me that perhaps the slow acceptance of the celestial line of
position might relate more to chronometer availability cost and reliability. One
book I read of late regarding chronometers initially after Harrison's time
commented that a chronometer would cost about 500 pounds sterling, a sizable
sum compared to a ship at about 1500. So, chronometers were expensive.Then you
need at least 3 if you want a reasonably simple way to check how consistent
the rates are holding, so more expense.
It would seems to me if you were not confident in the chronometer and you
found working out lunar distances a little daunting, you would find yourself
sailing down latitudes and using any other method at ones disposal.
Slocum for example opted for an old tin clock instead of his chronometer and
gives me the impression that on those occasions that he did use celestial
navigation that it was almost as if he were checking his celestial navigation
against his dead reckoning as opposed to the other way round. He was always
confident that he new where he was and how to approach those various landfalls.
He didn't need a fancy expensive chronometer to get by although he was
clearly as familiar with celestial navigation as I would assume most navigators
would be at that time. I get the impression that sailors of the day were more
tuned in to all the elements affecting dead reckoning and relied on it heavily
which may be a bigger reason for the slow acceptance of the LOP. Marvin
Creamer certainly showed that you could do some great navigation without
resorting to sextants and chronometers.
Since on the other hand we have great tables, calculators and above all,
great time sources that it makes more sense to take a far more prescriptive
approach to celestial navigation and plot that LOP. Take the sight, take the time
and plot that LOP.
So, that is a long winded approach to getting to the question. What was the
experience with chronometers like for the average seafaring navigator when
mechanical chronometers were the order of the day? How often did a ship have
more than one? How reliable? Was Summner a bit of an exception in relying on
his chronometer and subsequently the that first LOP? Maybe others looked at
this and thought, I see where he's going with that but gee, I would sure want
to make sure my chronometer was right on in that situation or take another
course of action.
Cheers,
Jim
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