Heliostat - reflecting lights to one point (i.e PS10 in Spain)
Be sure to note whether your library has daylight saving time (aka GMT offset)
Most sundials (like horizontal) tell the clock time by spacing the geometry out. Even though they are further apart, the represent an hour. An equatorial sundial has the entire disk/dial portion tilted at the latitude with gnomon at 90 degrees and even spacing. In the winter, you look under it to read the time as the equinox has passed so markings need to be on the front and back. Because it’s even spacing, you could rotate it for different timezones whereas a horizontal one has the dial markings as specific to location. Both need to face north.
Lines projected out are the Tropic of Cancer, Tropic of Capricorn, etc. so these are the lines on scaphes and astrolabes?
A complication - horological term, timekeeper that keeps something beyond the time (like date or season). Lunar complications
An escapement - horological term, the thing that turns something into a counting integer. such as water in water gear
If you are at the equator, you can see all the stars due to rotation. North or south pole, only half
Celestial sphere - depends on if intention is that you are looking from the center of the sphere or looking at the sphere. It’s different each way (inverted?)
Watches
Edward Tufte - data visualization books, small multiples helps you see a collection of objects, (their design, trends, etc.)
Least amount of torque for second hand
Metal laser cutter
UV printer - different textures, colors, etc. on different materials (rounded also?)
Soft sundials
Volvelle
Calendar synesthesia
The Chinese Typewriter byThomas Shawn Mullaney