NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: mechanical chronometers
From: Alexandre Eremenko
Date: 2006 May 15, 22:52 -0500
Dear Red,
The data I cited about chronometers is taken
from Encyclopedia Britanica.
Concerning the quartz watches, I experimented
with my own watches, the better ones go about
0.1 sec per day, that is keep time better than
the best chronometers.
About the top of the line mechanical wristwatches,
I do not know as I never had one. According to some data
that I read, the best ones go by 1-2 seconds per day,
so they are comparable to average chronometers.
Average good mechanical wristwatch will go about 15 sec
per day, according to my experience.
Much depends on the conditions.
As I understand, even the best watches or chronometers
will be affected if you change their orientation in space.
That's why gimballs are used.
A watch lying flat on my desc shows time more accurately
that the same watch when I carry it in my pocket.
(This applies to mechanical watches, of course).
Also temperature matters. An old Russian navigation manual describes
a table of chronometer corrections depending on temperature.
The table is attached to the box cover.
Alex
P.S. Apparently chronometers were always expensive.
A book I am reading now mentions that there were only 44
chronometers in the whole French Navy in 1833.
Whether the rest used Lunars or just relied on dead reckoning
for longitude I don't know.
On Mon, 15 May 2006, Red wrote:
>
>
> Alex, so you are saying that marine chronometers typically vary ["go"] randomly
> inaccurate by a second each day? In addition to the usual fast/slow overall rate
> as compared to the time?
>
> I wasn't familiar with time-pieces being compared that way but it does make
> sense. Would you have any idea how that compares to better quality mechanical
> watches (i.e. Rolex perhaps) and to the quartz chronos? I would expect the
> quartzes "go" much less, and that a solar powered quartz of even the cheapest
> source would outperform these instruments in all ways, no?
>
> >>The average chronometer "goes" about a second per day,
> and the best ones about 0.2 of a second.
> "Going" of a chronometer is the technical term which describes
> non-uniformity of its rate<<
>
>
> >
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From: Alexandre Eremenko
Date: 2006 May 15, 22:52 -0500
Dear Red,
The data I cited about chronometers is taken
from Encyclopedia Britanica.
Concerning the quartz watches, I experimented
with my own watches, the better ones go about
0.1 sec per day, that is keep time better than
the best chronometers.
About the top of the line mechanical wristwatches,
I do not know as I never had one. According to some data
that I read, the best ones go by 1-2 seconds per day,
so they are comparable to average chronometers.
Average good mechanical wristwatch will go about 15 sec
per day, according to my experience.
Much depends on the conditions.
As I understand, even the best watches or chronometers
will be affected if you change their orientation in space.
That's why gimballs are used.
A watch lying flat on my desc shows time more accurately
that the same watch when I carry it in my pocket.
(This applies to mechanical watches, of course).
Also temperature matters. An old Russian navigation manual describes
a table of chronometer corrections depending on temperature.
The table is attached to the box cover.
Alex
P.S. Apparently chronometers were always expensive.
A book I am reading now mentions that there were only 44
chronometers in the whole French Navy in 1833.
Whether the rest used Lunars or just relied on dead reckoning
for longitude I don't know.
On Mon, 15 May 2006, Red wrote:
>
>
> Alex, so you are saying that marine chronometers typically vary ["go"] randomly
> inaccurate by a second each day? In addition to the usual fast/slow overall rate
> as compared to the time?
>
> I wasn't familiar with time-pieces being compared that way but it does make
> sense. Would you have any idea how that compares to better quality mechanical
> watches (i.e. Rolex perhaps) and to the quartz chronos? I would expect the
> quartzes "go" much less, and that a solar powered quartz of even the cheapest
> source would outperform these instruments in all ways, no?
>
> >>The average chronometer "goes" about a second per day,
> and the best ones about 0.2 of a second.
> "Going" of a chronometer is the technical term which describes
> non-uniformity of its rate<<
>
>
> >
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---
