Hi Bill, I am pleased to see that you have posted the alternative file formats. This is a great technique for determining wall declination. I applauded your presentation in Tucson where you outlined this carpenter's square method. It seem to be just what we needed, a simple method, using ordinary tools that almost any one could use to measure and calculate wall declination for vertical declining dials.
I finally got to test the technique myself. The good news is that it works well. It accurately determined that my wall declined south 49 degrees west. Good thing because that is what the "Walking Shadows Dial" is designed for. The bad news is that it was not as easy to use as I thought it would be. I made some errors and there are still some bugs to work out. First I had to learn how to hold the square, turn it to the minimum shadow, keep it perpendicular to the wall and measure the shadow length. Now I know that it is easier than it sounds and the technique is accurate, intuitive and forgiving. The math is not. I made several mechanical errors using a scientific calculator before I finally got the right answer. The spreadsheet should be easier to use if you have MSWorks. But I don't not have MSWorks. I was able to borrow a computer that did and test the spreadsheet. I still had a couple of problems. The program set its own date format default. This varies for different country set-ups. I had to use DD/MM/YYYY rather than the MM/DD/YYYY format that you specified. Then I got the right answers. I saved the file as an Excel file but had problems with range names and circular references when I tried this file in Excel. Changing a few cells back to your original formula corrected this problem and the Excel version also gave me the right answer. I think we are now pretty close to meeting the objective, a technique that we could describe to a novice to use with some confidence and get back data on the declination of a wall for a vertical declining sundial design. The raw data of date, time and shadow length should be used as I would not always trust some one else to calculate the results. Cheers, Roger Bailey -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: October 15, 2002 7:06 AM To: [email protected] Subject: Wall Dec Roger Bailey has adapted my MSworks (or, more aptly, MSdoesntworks) spreadsheet for finding wall declination to Excel Format. It is available at www.precisionsundials.com/software.htm, along with a word document explaining the method. -Bill G. - -
