Longitude man's secrets sold

THE DIARY of a Yorkshire clockmaker's struggle to solve the greatest scientific problem of his age was sold at auction for pounds 89,500 yesterday.

John Harrison's 230-year-old journal chronicles the problems he had trying to convince the Commissioners of the Board of Longitude that he had invented a clock that would keep accurate time at sea, something which is essential for calculating longitude. Lacking the ability to measure how far east or west they weremeant that sailors were unable to navigate with any accuracy once they lost sight of land.

In 1714 Parliament offered pounds 20,000 to anyone who could solve the problem. Harrison's meetings with the board have been well documented in the minutes of their meetings but the story has never been told in his own words.

He wrote the journal, covering the years 1761-66, after building his most successful timekeeper, the H4.

This was impervious to the pitch and roll of a ship and changes in temperature and humidity and could keep the precise time at sea. Sailors could then compare the time in Greenwich with the position of the midday sun, calculate how far east or west they were and plot their position. But each time Harrison tried to claim the prize, the Board of Commissioners found a reason to deny him and he became ever more frustrated. He was finally paid in instalments but was never acknowledged as the winner. The story became one of the surprise bestsellers of the decade when the American journalist Dava Sobel wrote Longitude - The True Story of a Lone Genius who Solved the Greatest Scientific Problem of his Time.

The journal was written by the inventor's friend Walter Williams, although it is in Harrison's own words, and has corrections in the hand of his son, William. It was expected to fetch up to pounds 150,000.

A spokeswoman for Sotheby's said: "It is a bit sad that it didn't go crazy but at least it sold. The problem is that no-one has any money at this time of year."