On Sat, 5 Jan 2002, John Carmichael wrote: > You could float the mirror inside a cup containing liquid mercury. You'd > make the cup slightly larger in diameter than the mirror, but not so large > that it could float too far. For my size room, I'd use a round 1 cm. mirror > and a round 1.2 cm. cup and I'd hermetically cover and seal the cup with a > thin piece of glass. The whole thing would then be securely mounted to the > outside structure of the house (maybe a steel rod?) This is the only sure > way I can think of to perfectly level a mirror.
If you're going to the trouble of sealing the mercury inside a glass shell, why not use the clean surface of the mercury as your mirror? Have the thin cover glass angled away from the house, so its reflection doesn't interfere, and place an annular black mask just above the surface, to hide the positive meniscus curve. Dave 37.29N 121.97W
