NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
How good were chronometers?
From: Jim Hickey
Date: 2006 Mar 9, 13:04 EST
From: Jim Hickey
Date: 2006 Mar 9, 13:04 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