Warsztat Kochańskiego

Demonstration version 0.9 — a working model. Everything marked as reconstruction awaits refinement once archival research is done. See what we still don't know.

Turning an oscillation into a second

sourcemodern model

In 1659 Kochański proposes replacing the pendulum with a regulating spring and fixing the number of beats per hour — sixteen years before Huygens's balance spring. Both solutions board the same ship below: Jean Richer's voyage from La Rochelle to Cayenne, 1672.

A clock case on the deck of a ship rolling in a swell.
Cumulative position error of both clocks over the days of the voyage, with the latitude profile of the route. 56 km pendulum spring — 0 La Rochelle Cayenne
0
5°

Latitude
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Temperature
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Pendulum drift
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Spring drift
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Position error — pendulum
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Position error — spring
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At this sea state the escapement loses its impulse. The pendulum stops and the clock measures nothing at all.

The spring is not better — it moves the problem from gravity to temperature. Compensation had to wait for Harrison, ninety years after Kochański's proposal.

The route is simplified to a steady run south and the temperature is derived from latitude rather than a ship's log.

Text description of the instrument

A clock regulated in La Rochelle loses time on the way to Cayenne in three ways: gravity weakens, rolling widens the pendulum's swing, and the temperature rises. After 64 days the position error reaches several thousand kilometres. A spring-regulated clock is immune to the first two but ten times more sensitive to temperature. Only temperature compensation brings the error near the longitude prize threshold of half a degree, about 56 km.