Clockmaker develops accurate tide clock

Archie McQuater's design is about twice as accurate as existing models, the Scotsman said. By accounting for the movement of the sun, his machine approximates computer tide estimates.

McQuater, 78, created the Moon and Sun Tidal Clock in answer to a challenge made in 2005 to develop a design to improve the moon time clocks. Before computers, sailors and fishermen relied on moon clocks, which have been around since the 17th century.

"A normal clock is affected by the moon only. It's not precise, as by the time the moon is 3 1/2 days old the tide is actually later than it predicts," McQuater said. "What I have made is affected by the sun as well and is much more accurate."

McQuater said he doesn't plan to market his design.

John Amson, a former St. Andrews University lecturer who issued the challenge, said McQuater's achievement was very significant.

"Archie has built the first addition to the clockwork to show the effect of the sun," Amson said.

Copyright 2007 by United Press International