So why was the inventor, John Harrison, all but forgotten for 200 years?

Harrison's story, and three rare publications which trace his battle to have his invention accepted, were revealed at Orange City Library yesterday.

Paul Brunton, senior curator with the Mitchell Library at the State Library of NSW, brought the $300,000 publications to Orange, putting them on public display for the first time since they were purchased by the library last year.

About 120 people attended Mr Brunton's talks on the history of longitude and how Harrison invented the marine chronometer.

According to Mr Brunton, the accurate calculation of longitude at sea was one of the most pressing issues facing the Royal Navy in the 18th century, eventually forcing officials to offer a £20,000 prize to anyone who could solve the puzzle.

"Harrison was an uneducated carpenter from the wilds of Lincolnshire, but he was also a genius," Mr Brunton said.

"When a tradesman, a mechanic, solved the problem that all the scientists and clockmakers and academics couldn't solve, they didn't believe him. They believed it was a trick, constantly testing the invention and making him duplicate it.

"It took him 13 years to get the money, which the Board of Longitude eventually gave him as 'a reward and encouragement', but they never gave him the honour of officially winning the prize."

Mr Brunton said Harrison was forgotten about outside academic circles for centuries, until author Dava Sobel's best-selling book Longitude was published in 1995.

"Sobel's book created a sensation," Mr Brunton said.

"No one had believed a book on longitude would sell, but it was the story of the man and his battle that fascinated people.

"I enjoy telling Harrison's story and I also enjoy bringing the books to regional centres.

"The State Library is not just for Sydney. It's important that these things are seen in regional centres as well."