Friction, Backlash, and Wire Stretch: Where Analogue Error Lived
No rounding error — but plenty of drag. How friction, gear backlash, and wire stretch set the accuracy floor every brass predictor lived with.
How-It-Works
The mechanisms, explained with drawings instead of hand-waving. Harmonic constituents, gear ratios that model the moon, pulley adders that sum waves on a wire, and the error physics — friction, backlash, stretch — that set every machine’s limits. Start with the spring–neap breathing if you are new.
The Pulley Adder: How Wires Add Waves
The cleverest part of every tide machine: how floating pulleys sum a dozen crank motions onto one wire, and why friction was the eternal enemy.
Spring vs. Neap: Why the Range Breathes Every Fortnight
The fortnightly heartbeat of the tide: how the moon and sun take turns amplifying and cancelling each other, in plain English with a visual.
Tide Staff vs. Tide Gauge vs. Tide Predictor: What's the Difference?
Three instruments, three jobs: the staff you read by eye, the gauge that records, and the predictor that foretells. How observation became prediction.
Gear Ratios That Model the Moon: A Visual Primer
How toothed wheels approximate the 12.42-hour lunar period: compound trains, continued fractions, and the craft of the gear cutters explained visually.
Why 37? The Harmonic Constituents M2, S2, K1, O1 in Plain English
Meet the waves inside every prediction: the big four constituents, their shallow-water children, and why America's Machine No. 2 stopped at 37.