Not sure if this is to obvious, a help or hindrance..... The "human" dials I have seen at the gnomon point have a "ladder" painted on the ground marked off in height so if you are 5' you stand here and 6' up one "rung" 4' down one "rung"
Regards, Henry PNW USA -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Steve Lelievre Sent: Tuesday, August 08, 2000 09:56 To: John Carmichael Cc: Sundial mailing list Subject: Re: analemmatic program & fotos John, The NASS site has some DeltaCad macros. As regards how big to make the dial, I suspect that people size will not be a meaningful starting point. In the extreme case, there is hardly any shadow. Your dial is S.Calif - say about 33 and a bit degrees N. At the Summer solstice, the sun at noon is 23 and a bit degrees N, so the sun gets to within 10 degrees of being overhead. Thus a person of height 1.70m will cast a noon shadow of only 1.7m x tan(10), which is 30 cm. That's a 5 foot 7 inches person giving a 1 foot shadow, in imperial units. Some men (including me!) and many women aren't that tall, so most users would have even shorter shadows. At other times of day and other times of year the problem would be less noticable, but I reckon that overall for that location the shadow often won't reach edge of a sizeable dial. So what I'm saying is that people will often have to make a imaginary line to the edge of the dial anyway to read the time, so why not just make the dial to suit the location and don't put lots of emphasis on getting the dial size to match shadow sizes. I saw instructions for an Aussie analemmic dial which told users to clasp their hands together above their heads in order to lengthen their shadows. Cheers, Steve
