Hi Steve et al,
It's usually just called a disc dial. I don't think the example shown is
latitude-adjustable: the suspension point is fixed. All the historical ones
I've seen are single latitude devices. Only the occulus is adjustable, for date
(declination). Earlier examples had the hour
There has been some confusion in the discussion so far. Here is my take:
The sundial pictured is called a “vertical disk dial.” It is an altitude
sundial.
The example pictured is similar to one at CHSI (inv. 7270) signed “I W” with a
punch mark of a crown and date 1672. It is for latitude
