Wall Declination Measurement

[John Carmichael]

Hello Carol: (c.c Sundial List)   I'm back home and this morning I'm looking at your wall declination measurements.  Unfortunately, I am not accustomed to using the nail method you used and I hesitate to comment because I don't want to make a mistake.  I have heard of this method however.  I am going to forward your letter to our Sundial List discussion group and hopefully somebody there will be able to check your measurements.   But I was able to check your solar azimuth data that you got from your astronomy program.  According to the program I use (The Dialist Companion), the solar azimuth at that latitude, longitude and time was about 20.45 degrees west of south, not 209 degrees.  Just think about it.  If the solar declination were 180 degrees west of south, the sun would be due north and that's not possible.  209 degrees would be towards the North East which is also impossible.   Hopefully, somebody from the sundial list will help us.   John ----- Original Message ----- From: carol arnold To: John Carmichael Sent: Monday, November 22, 2004 1:09 PM Subject: declination John, I was just having a go at measuring the declination of a window in my house - I am not convinced of the accuracy of my measurement of sun angle to wall,but I wondered if you could double check the calcualtions? The window was approx south facing.   22 nov 2004 at14.01 gmt I used a nail 92mm long on a vertical board and its shadow was 50mm to the right of the nail. So the sun angle to the wall is 28 deg 31min 23sec west of south. My astronomy program gave me azimuth of sun to be 209 deg 44min 31sec ie 29deg 44min 31sec west of south, for lat 51deg 25min 20sec North and long 2 deg 42 min 30 sec west. So I reckon the the wall faces 1 deg 13 min 8 sec west of south??   Regards and hope you dont mind my asking you about this, Carol Carol Arnold Stained glass artist, commissions welcome, please take a look at my stained glass website  http://www.carolarnold.co.uk Moving house? Beach bar in Thailand? New Wardrobe? Win £10k with Yahoo! Mail to make your dream a reality.