The whole register
Twenty-five entries, five sections
Filed by mechanism. Each entry states what the escapement does, what error it introduces, and what was done about it — with the quantities worth knowing attached.
- Something Must Let the Train Forward in Equal AmountsThe central difficulty of every mechanical timepiece: energy has to reach the oscillator without disturbing it, and the oscillator has to release the train without being pushed off its own rhythm. Every escapement is one answer to that.
- The VergeThe first workable answer, and why it interferes with the oscillator so badly.
- Anchor and RecoilBetter, but it pushes the train briefly backwards at every beat. What that costs.
- The DeadbeatRemoving the recoil so the seconds hand stops dead. Why precision regulators use it.
- The LeverThe escapement in nearly every mechanical watch: detached, self-starting and tolerant of being carried around.
- The DetentThe most accurate mechanical escapement and the least practical to wear — why marine chronometers used it.
- Why a Pendulum Keeps TimePeriod depends on length and gravity and almost nothing else — which is the whole reason it works, and also the source of every problem that follows.
- Circular ErrorPeriod drifts with amplitude unless the swing is small. Why regulator clocks swing so little.
- Temperature Changes the LengthA steel rod grows in summer and the clock loses. The problem stated plainly.
- Gridiron and MercuryTwo compensations using opposed expansion. Elegant, and superseded.
- The Alloy That Solved ItA material that barely expands, and what it did to precision timekeeping.
- The Balance and Its SpringA pendulum you can carry: what replaces gravity, and why the spring's material matters more than the wheel.
- Counting the BeatsGear ratios turning oscillations into seconds, minutes and hours. The arithmetic of a going train.
- Even Power From an Uneven SpringA mainspring pushes hardest when fully wound. The fusee and the remontoire as answers.
- Keeping It Going While You Wind ItThe small mechanism that stops the clock stopping during winding.
- Why There Are Rubies In ItHard bearings at the fastest pivots. What they actually reduce.
- What a Timing Trace Is Actually Showing YouRate, beat error and amplitude read off a microphone and a screen. How each fault looks, and why amplitude is the number that reveals the health of the movement.
- In BeatEqual intervals either side of rest. What being out of beat sounds like and why it matters.
- Six PositionsA watch runs differently on its back than on its edge. Why adjustment is done in several positions.
- IsochronismThe ideal of a period that does not change with amplitude — the property the whole site is named for.
- A Crystal That CountsA quartz oscillator runs at tens of thousands of cycles per second and costs almost nothing, which ended the argument commercially even where mechanics survived culturally.
- Quartz Has a Temperature Problem TooThe parabola, and how a compensated movement corrects for it.
- Counting an AtomWhat an atomic standard actually measures and why the second is defined that way.
- Getting the Time From Somewhere ElseRadio and network synchronisation — a clock that no longer needs to keep time, only to receive it.
- Why Mechanical Survived AnywayOnce accuracy stopped being the argument, what was left as the reason to make them.