West Sussex's Moon anniversary

Little known is the fact that West Sussex can claim its own slice of the action - the 400th anniversary of the earliest known record of an observation of the moon through a telescope.

West Sussex Record Office is highlighting one of the most unusual collections of documents in its care in the exhibition Thomas Harriot, England's Galileo.

The exhibition marks the 400th anniversary of the observation of the moon, made on 26 July 1609, by Thomas Harriot (1560-1621) - a viewing which predates Galileo's much better-known observations by a number of months.

Alison McCann, assistant county archivist, puts the annivesary in context: "The telescope had probably been invented in Holland in 1608, and its use spread rapidly through Europe. What could be seen of the moon, and sun and stars with the aid of this revolutionary instrument overturned beliefs about the universe that had been accepted for centuries.

"Part of Thomas Harriot's papers are in the Petworth House Archives, which the Record Office administers on behalf of Lord Egremont, who owns them. Harriot's principal patron was the 9th Earl of Northumberland, who is an ancestor of Lord Egremont.

"The Earl gave Harriot a house in the grounds of his own house at Syon in Middlesex, from where Harriot observed the moon, the comets of 1607 and 1618, spots on the sun, and the planets of Jupiter, which had recently been discovered by Galileo.

"But Harriot's interests were not confined to astronomy. He is known as the father of English algebra, and some of his work on algebra was published after his death. His papers also include work on geometry, and chronology and optics, and navigation. He was an expert in navigation, and taught Sir Walter Raleigh's sea captains the subject, and took part in Sir Walter's expedition to Virginia in 1585-6."

Although he was described by a contemporary as "one of the rarest mathematicians of our age", Harriot is comparatively little known, because so little of his work was published.

His A briefe and true report of the new found land of Virginia was published in 1588, and his work on algebra in 1631, but none of the results of his other scientific explorations were published.

He himself said that he was "contented with a private life for the love of learning".

"The aim of the exhibition is to help to restore him to his rightful place in the history of science," Alison said.

"On display will be facsimiles of his first observation of the moon, as well as a number of observations made in the following years.

"There are also examples of all the different areas of his scientific interest which are contained in his papers in the Petworth House Archives. Copies of all his papers from the Petworth House Archives will be available to read."

The exhibition runs until August 28 at West Sussex Record Office, Orchard Street, Chichester.

Opening hours are from 9.30 to 4.30pm Monday to Friday, 9.30 to 12.30pm, 1.30 to 4.30pm on Saturdays. Admission is free.