Or the slot near one end of the adelaide is just to guide the adelaide as
it slides back and forth in the internal geared mechanism.
Clearly a vertical gnomon had to be present on some part of the adelaide.
I think Steve is on the right track.
In terms of the screws or pins blocking movement of
My two cents:
I have a different guess about the round dial with the indicator. My guess
is that it is a calendar of months, and that turning the indicator to the
correct month adjusts the length of the adelaide to the correct distance
for reading time on the azimuth dial. I do not know what
Thank you, Sara and Patrick for your replies to my question.
I shall try to get to the Science Museum sometime to have a look at the
dial, if that can be arranged.
I’ve been trying to figure out how the cam that Sara mentioned might work.
I’ve never studied the working of cams and this case
Hi Steve,
The photo of the azimuth dial is hard to read. I don't know what screws you
are talking about preventing the arm from turning. The arm is backwards at the
moment since the pointed end should be on the scale of hour lines. I am not
convinced that there is a flap on the square end of
I'm afraid I can't give you any answers , but the original is in the
Science Museum, London. They don't give any clues either, but I guess you
could contact them
https://collection.sciencemuseumgroup.org.uk/objects/co143/azimuth-sun-dial-simple-azimuth-sundial
Best wishes,
Patrick Vyvyan
On Mon,
