Mike Shaw's method sounds too wonderfully simple to be true. However, I would perhaps suggest one small change if this is to apply to distant 'clients' ordering dials (which is how I seem to remember this thread starting!). I would supply paper to which was attached a square or thin strip of reflective 'melinex' or similar plastic. How many people necessarilly have a plain mirror (or is that plane mirror) to hand or even know what is meant by the term?
One point: I assume one has to look for the reflection at 90 degrees to the plain of the paper (this may be a naive point to ask, but I'd just like to be sure) Peter Tandy At 09:32 PM 7/29/02 +0100, you wrote: > John carmichael wrote << I wish we could come up with an easy >> My >suggestion is: Give these instructions to the client. paper to the >outside of a vertical window on the wall whose declination you want to >know. 2) Hang a plumb bob about 1 foot away from the window, with the bob >in a bucket of water (as a damper). 3) Hold a small plain mirror against >the paper. 4) Note the date and time when the string, the shadow of the >string, and the reflection of the string all coincide. When you get the >results, use the "Dialists Companion" programme to get the sun's azimuth, >and hence the wall's declination. 1 minute is equivalent to about 0.25 of >a degree. Assumes you know the correct latitude and longitude. Mike Shaw > >mailto:[EMAIL PROTECTED] > >http://homepage.ntlworld.com/jmikeshaw/ > >N 53º 21' 24" >W 03º 01' 47" >Wirral, UK. > > -
