The many notes about this subject only points out its importance.
In the September 2001 issue of the NASS compendium there was included an article by Gianni Ferrari on methods for finding the orientation of a plane using the sun. The digital edition included his program WallDec that uses about 8 different methods. In correspondence with Gianni he reported that he often has helped people who were using his programs. He said he sends them the times of solar transit for their location and asks them to use his "small board" method which finds the angle the sun's shadow makes with the wall at that time. They merely telephone him with the information. He says this nearly always has worked and has done so 15 to 20 times. My recent experience with trying to determine the declination of a client's wall by e-mail reflects the many cautions of others. Don't expect many to follow even good instructions! Above all, don't expect them to set or even read their own watch correctly. Send them a digital watch. I would not send them a camera. You might get a lot of fuzzy out of focus images. Here is my own tale of woe: I asked that a surveyor find which way the wall faces. He reported 84.16 degrees! I knew from the client that the wall faced somewhat South and that must mean a declination of 5.86 degrees to the east. I made a test dial and sent it to them. The reported times were off by more than 30 minutes! With much effort I finally got some readings to agree only if I accepted that the "surveyor" was off by 9 degrees! I suspect that the building contractor may have used a magnetic compass or was merely reading construction plans. The result is if I do this again I would have the client use the board method even if they claim to have a reliable surveyor - the sun is the best surveyor. I would send a board with a perpendicular attached. On the board would be a bubble level and a digital watch. Have the client draw along the shadow of the perpendicular while holding the board level against the wall. Then note the time to the second. Have them repeat this at several intervals at least hours apart and at different locations along the wall. When they return everything you have the shadows you can measure. You can also check the time on the digital watch. Claude Hartman 35.13 N 120.58 W Even with the best of -
