Astral Complications

You would think, by the title, that this article is about some sort of new-age relationship jargon, but it is about machines - minerals that have been worked into gears and springs that tirelessly calculate various astronomical functions - without the assistance of digital chips or electricity - that's what Astral Complications are all about. Even more amazing is the fact that the scientists/craftsmen who work with these marvels have been at it for hundreds of years.

"Complication", as used here, is a horologists' term for any function of a clock or watch that indicates something other than hours, minutes and seconds. Although the definition includes electronic and digital watches, I will not be discussing those: my topic is the mechanical soloutions for the problems of celestial mechanics.

Complications fall into two distinct categories depending on whether or not they are related to measuring time.

The complications not related to timekeeping that have been placed on wristwatches include barometers, compasses and, as you may have seen on a mechanical pilot's watch, an altimiter.

Complications related to timekeeping include the following categories:

Acoustic complications

  1. Time Signal
  2. Alarm
  3. Repeaters (hour, 15 minutes, minute, etc.)
  4. Chimes (grand sonnerie and petit sonnerie)
  5. Silencer (to dampen the sound of the movements)

Measures of short time

  1. These are the chronographic and other split-second functions, and those scales and such that serve to make tachymetric or telemetric measurements

Now we shall move on to a list of really interesting complications:

Common, or everyday complications

  1. World and universal time
  2. Multiple time zones
  3. Diving dial
  4. Tide gauge
  5. Power reserve indicator

Astronomical (astral) complications

  1. Simple calendar (full or partial)
  2. "Perpetual" calendar
  3. Week number
  4. Year
  5. Equation of time
  6. Sunrise and sunset for a given location
  7. Phase of the Moon
  8. Sidereal time
  9. Declination of the Sun
  10. Apparent movement of the planets
  11. Line of node
  12. Star chart for a given location

Precision and convenience complications

  1. Self-winding
  2. Tourbillon

As you can see, these complications can perform most astrometric functions mechanically.