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On 21 Nov 2006 at 17:39, FrankReedCT@aol.com wrote:

> George H you wrote:
>> "What, then, would be the procedure for discovering the moment of  noon
>>AT noon, in such a way that the moment of noon can be "called  out"?"
>
> I was referring to the "common practice" for setting local time on pocket
> watches carried by the ship's officers. I believe you are under the
> impression  that ordinary watches were rare c.1800. There's good evidence
> that they were  not. Most officers aboard ship seem to have carried them by
> this date. They set  them at noon to local apparent time as determined by
> "calling out" noon during  the Noon sight. This was a common practice,
> whether we like it from a modern  theoretical standpoint or not. Navigators
> later in the day "regulated the watch"  by doing a time sight. This would
> lead to an adjustment (or correction) of the  watch by a few minutes. That
> "regulated" local time from the time sight  would then be compared with the
> Greenwich time from a lunar  distance sight or the chronometer.

When keeping apparent time on a watch, it seems to me that using the
approximate time of noon through a sextant altitude observation is
perfectly satisfactory. In my own attempts to keep apparent time on a
mechanical pocket watch, I found it impossible to set accurately from a
time sight. It was much easier to simply set the approximate time (taking
care to match the position of the minute hand between tick marks to the
position of the second hand) and then use a time sight to get the error.
Between the equation of time and any East/West motion, the watch will be
off so quickly that there is really no point in taking pains to set it
accurately.

Ken Muldrew.

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