Moonrise and phase

[richardabeattie]

This is a challenge to the astro navigators. The French invaded Fishguard on the evening of 22 Feb 1797. What time was moonrise and what phase was showing? My best efforts indicate it was the the last day or two of a waning moon so not much light to aid the galloping messengers trying to raise the alarm. I've tried Mr Google and have been left a bit baffled.

 

[VicS]

Dust off some of the old Reeds on the top shelf of the book case

Last quarter Feb 18, New moon Feb 26

on 22 Feb waning crescent with 16% of the Moon's visible disk illuminated.

​

Moonset 12:16 on preceding day
Moonrise 05:28
Moon transit 09:17
Moonset 13:06
Moonrise 06:12 on following day

So no moon at all during the evening

BTW Feb 22 1797 was a Wednesday

Sorry I forget what the weather was doing

but

​

Begin civil twilight 06:46
Sunrise 07:20
Sun transit 12:34
Sunset 17:48
End civil twilight 18:22

 

[jdc]

Blimey! I knew that VicS is old, but >217 is positively biblical!

On 22nd February 1797 at Fishguard the moon set just after 13:00 GMT and it would have been getting really quite dark by 18:00 (the sun at >2° below the horizon), and pitchy black by 19:00. This agrees with VicS's post (presumably he didn't look at Reeds.

To get this data, I looked up the lat and long of Fishguard: 51° 59.9'N, 004° 58.9'W (ok, unnecessary precision), and then used this site http://aa.usno.navy.mil/data/docs/celnavtable.php and entered 22nd Feb 1797, which, to my amazement, it just seems to accept!

I'd take it with a pinch of salt however as I doubt that it's been tested or verified by its designers that far into the past.

 

[richardabeattie]

Blimey!

All I can add was that the weather was fine and despite that they lost their artillery as they landed. This forum is simply amazing. Many thanks.

 

[Ruffles]

I reckon the actual time of day would have been somewhat uncertain in Fishguard in 1797. Would they think in terms of hours after sunset?

 

[sarabande]

well at least the poor computer does not have to deal with the Calendrical Changes (Julian >>> Gregorian) which were rife in Europe and the USA a few years earlier !

The question of time is interesting. Some parts of England were still working on 'watches' (lengths of time, not wrist candy) which varied according to the length of day. So in a short day (winter) daylight would be divided into 12 watches of about 40 minutes each. Come the summer, a watch could be almost 90 Minutes.

 

[Leighb]

The "time" in Fishguard in 1797 would not have been quite the same as in London, each place basically worked on local time by the sun. It was not really until the advent of the railways that some sort of standard time was adopted over the whole of the UK.

 

[sarabande]

Fishguard is a fraction below 5 degrees W of London. So roughly 20 minutes later than London.

 

[Leighb]

Thanks, I hadn't done the maths.

Slight thread drift, but as all may know Portugal is the one other European country (Not sure about Eire?) that uses GMT and BST, which is fair enough as it is on pretty much the same longitude, however so does Madeira which is about 17 W, so around an hour West of Greenwich. You don't have to change your watch when you go there, but Sunrise/Sunset are markedly different.

 

[macd]

Slight thread drift, but as all may know Portugal is the one other European country (Not sure about Eire?) that uses GMT and BST...

Even driftier, but not forgetting the Isle of Man and various pebbles off the French coast. (Not that the Island sees much by way of sun-rises, or sun-anything else.) Republic of Ireland does indeed share time with UK.

 

[jdc]

And Faeroes