Tide-predicting machine (nonfiction)

10-component tide-predicting machine of 1872-3, conceived by Sir William Thomson (Lord Kelvin), and designed by Thomson and collaborators, at the Science Museum, South Kensington, London.

A tide-predicting machine is a special-purpose mechanical analog computer of the late 19th and early 20th centuries, constructed and set up to predict the ebb and flow of sea tides and the irregular variations in their heights – which change in mixtures of rhythms, that never (in the aggregate) repeat themselves exactly.

Its purpose is to shorten the laborious and error-prone computations of tide-prediction. Such machines usually provide predictions valid from hour to hour and day to day for a year or more ahead.

The first tide-predicting machine, designed and built in 1872-3, and followed by two larger machines on similar principles in 1876 and 1879, was conceived by Sir William Thomson (who later became Lord Kelvin).

Thomson had introduced the method of harmonic analysis of tidal patterns in the 1860s and the first machine was designed by Thomson with the collaboration of Edward Roberts (assistant at the UK HM Nautical Almanac Office), and of Alexander Légé, who constructed it.

In the News

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  Cinnamon pirates said to have treasure map for legendary Tide-predicting machine.

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  From beyond the grave, Olivier Levasseurs yearns to sail pirate ships Tide-predicting machines.

Fiction cross-reference

• Neptune Slaughter

Nonfiction cross-reference

• Aquaman (nonfiction)

External links:

• Tide-predicting machine @ Wikipedia