A COLLECTION of rare books including a copy of Darwin's On the Origin of Species comes under the hammer in Dorchester next week.

The sale at Duke's of Dorchester is thought to be the largest book auction outside of London for many years and features the sale of two major collections.

The Newton library was started by Sir Henry Newton in 1920 and continued by his family until 2000. Guy Schwinge of Duke's said: "He was lucky to be buying at a time when supply of rare books was abundant, and he recorded many of his most important purchases in a book of letters to his son.

"He records buying the first edition of Euclid's Elements, the foundation of geometry printed in Venice by Erhard Ratdolt in 1482, from the London firm of Maggs in the 1920s for £60.

"While he acknowledged that Maggs had made a handsome profit of £20 on the book, his family is likely to make a handsomer one: the book is now estimated at between £20,000 and £40,000."

Other books being sold from the collection included a first edition of Isaac Newton's Principia Mathematica, 1687, estimated to sell for £30,000 to £40,000, and a copy of Darwin's On the Origin of Species, printed in 1859.

"Newton's copy of this is one of the great prizes of the collection, in remarkably good unrestored original condition: its estimate is £30,000 to £50,000," said Mr Schwinge.

Other books being sold include first editions of Robinson Crusoe and Gulliver's Travels - both estimated to sell for up to £10,000 each. "The major book of the 20th century in the collection is the Subscribers' Edition of TE Lawrence's Seven Pillars of Wisdom, a fine copy, estimated to fetch between £12,000 and £20,000," said Mr Schwinge.

Other books in the sale on March 8 include the library of the late Jean Preston of Oxford.

Among the books belonging to Miss Preston are two fine illuminated books of hours on vellum, from the late 15th century, estimated between £15,000 and £25,000 each.

A rare copy of William Morris's Kelmscott Press edition of Chaucer's Canterbury Tales, printed in 1897. "Only 48 copies were made and it is estimated to go at between £30,000 and £40,000," said Mr Schwinge. Two rare paintings once owned by Miss Preston, discovered during a valuation by Mr Schwinge last year, are expected to sell for an estimated £1 million when they are auctioned at Duke's next month.

The panels measuring 15 inches by five inches are by one of the greatest Renaissance artists, Fra Angelico. They had been missing for years. Mrs Schwinge found them in Miss Preston's spare room. They will be sold on April 19.