horizontal dial: sundial where the hour lines are marked on a horizontal surface, see article on the sundial.
hour lines: the time divisions on a sundial or other astronomical instrument.
hour ring: the part of a sundial marked with the time divisions, where this part is in the form of a ring or broken ring.
inclining dial: type of sundial projected as a horizontal dial for a particular latitude, but which can be inclined for use in a range of other latitudes.
Italian hours: system of hour reckoning, see article on time and date.