Hi Tom,
Thanks for your ‘inside small sundial’ information, and for the mirror links.
It’s a great idea.
I’ve found an Australian convex mirror manufacturer and have requested prices.
It will be fun trying to project the beam across the room onto the far wall.
Good luck with your NASS article
An
interesting idea to project the sunbeam across the room. One
other thought that may be useful for your application: the size
of the pinhole I used was 1/8 inch, although my particular
project wasn't very sensitive to size. Smaller diameter worked;
Good question. I found that a "hemispherical" (I put it in quotes
because the mirror I use actually has an essentially ellipsoidal
cross-section about the axis of rotation) mirror was needed to
observe the entire day's travel of the sun in midsummer. There's an
