Hi Steve: you wrote: > Isn't the problem down there in Tucson that the water would evaporate before > any algae has a chance to grow?
If the container is sealed with glass, the water couldn't evaporate, and the algae would grow. But you'd also get great amounts of condensation on the glass which would ruin the sun's reflection. Also, water freezes. I'd stay away from water.... >As Gino pointed out, if one creates a dial by calculation, there may be a > problem transferring it to a room by measuring off, because walls and > ceilings aren't plumb true or may be bowed. Even projecting the dial using a > transparent acetate slide using a laser pointer won't work if the slide is > not true vertical or not at precisely the declination used in calculation. > He's right as far as I can see, so simply plotting the actual position of a > reflection at known times may be the best way after all. > > With the latter approach, it doesn't matter if the mirror is not level. Is > that not so? That's what I think. Without a doubt, the latter approach is the best way. > John John L. Carmichael Jr. Sundial Sculptures 925 E. Foothills Dr. Tucson Arizona 85718 USA Tel: 520-696-1709 Email: [EMAIL PROTECTED] Website: <http://www.sundialsculptures.com> ----- Original Message ----- From: "Steve Lelievre" <[EMAIL PROTECTED]> To: "John Carmichael" <[EMAIL PROTECTED]> Cc: <[email protected]> Sent: Monday, January 07, 2002 8:13 AM Subject: Re: Ceiling Sundials: Mirror Placement > John, > > > > Steve > >
