See Wheatstone's Polarizing Sundial by Jim Mahaffey in The Compendium
8(2):1-3, Jun 2001. This is an expanded version of his article that first
appeared in Optics and Photonic News, 11(7):14-15, Jul 2000.
Fred
On Mon, Mar 30, 2015 at 12:24 AM, Roger Bailey rtbai...@telus.net wrote:
Hello
Hi
So what is required is some coating that absorbs in the radio part of the
spectrum (i.e. not absorbed by clouds), then reemits in the visible? You then
coat the dial plate and can tell what is in the radio shadow of the gnomon.
OK, that may be a little outside the box
Ian
Chester, UK
---
Hi all,
Wheatstone designed still another type of polarization dial than the one
described by Jim Mahaffey. A specimen is in the collection of the British
National Maritime Museum in Greenwich, see
http://collections.rmg.co.uk/collections/objects/265579.html.
When viewing the celestial pole, the
I am trying to make contact with the Sundial organisation without sending an
email to everyone on the circulation list for the group.
I have enjoyed receiving emails from the group over at least a decade.
I am due to retire, and I would like the Sundial group to send their emails to
another
That is an excellent question! I have seen this photo before, and never
noticed the numbers running twice in a semicircle. I, too, am perplexed.
I read about this dial in Hester Higton's book Sundials at Greenwich.
The dial operates on two successive polarizations of light - the first
being
