The wooden mechanism secrets of master clockmaker John Harrison

If you've read the book Longitude, you know that John Harrison was the man who created a clock capable of telling very accurate time while on a ship at sea. To accomplish this very difficult task, he develop many innovations. The video shown here uses a replica long case clock (commonly called a "Grandfather clock") to show the innovative elements of the wooden clock movement. Most of these new features have to do with reducing friction, minimizing the effects of temperature and humidity, and reducing wear. Worth noting are the use of the grasshopper escapement, Lignum Vitae bearings, a novel pinion design in which the trundles rotate, and adding gear teeth to a circular blank to ensure that each tooth is as strong as possibe.

For more on John Harrison, check out Dava Sobel's book, Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time.

Better still perhaps is the one with pictures titled, The Illustrated Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time

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