THE story of Portland stone is not one that can be covered in a week, so this week we take up the tale of the island's most famous export again and how it was used for some of this country's finest arts and administrative buildings.

The tale of Portland stone has been covered in its entirety by author Gill Hackman in her comprehensive new book 'Stone to Build London'.

In the first half of the nineteenth century there was a building boom in London and prices for Portland stone had risen by as much as 25 per cent because of a newly introduced tax and high freight costs during the war with France.

Portland stone had strong competition from Bath, which was exporting the very popular Bath stone, which was slightly cheaper but easily became damaged by weathering and pollution.

The striking looking National Gallery, a familiar building on Trafalgar Square, was built between 1833 and 1838.

The stone used for it is said to have come from Weston's quarries on Portland.

A shipload of stone was delivered from Portland each month.

Our local stone crops up again in the Royal Exchange, which is today occupied by shops and a restaurant.

It was built between 1841 and 1844 and replaced the original building which was destroyed by fire in February 1838.

Portland stone was used for the west facade of the building, including the portico and pediments, for parts of the other facades and for most of the interior walls and staircases.

Stone for the Royal Exchange came from Waycroft quarries on the north wast edge of Top Hill.

And on to one of the jewels in the crown of our capital - The British Museum, an extremely large advert for Portland stone.

The building was faced with Portland stone ashlar which was fixed to Yorkshire stone.

Its masonry was best Portland stone.

Stone for the British Museum came from a number of Portland quarries.

Back on Portland the way of life was very traditional, most quarrymen were still farmers or smallholders.

Hackman writes: "The system of farming in open fields divided into strips made it difficult to develop quarries on private land or to improve the efficiency of agriculture."

Average wages were very low and quarrymen were only paid for stone actually delivered.

In 1826 the Merchants' Railway opened. It was designed to carry stone from the top of the island down to piers near the castle.

Hackman writes: "It was not connected to any national network.

"It started on the top of the hill on the north of the island and ran eastwards around the contour of the hill before descending steeply to sea level at the stone piers to the east of the castle."

Stone would come from the quarries on horse drawn carts and be loaded by crane onto the railway wagons.

The railway helped to open the door to large-scale quarrying on top of the island.

The number of piers used for exporting stone from Portland by sea increased during the first half of the nineteenth century to eight in total on the island.

Back in London the Foreign, Home and Colonial Offices were built between 1863 and 1873.

They form a large office block built of Portland stone. Questions about the stone used were even raised in Parliament when designer Sir Gilbert Scott was asked to ensure that the stone used came from the quarry with the most durable stone.

It was decided that the very best stone came from the north west of the island.

Coming shortly afterwards was the Royal Courts of Justice on the Strand.

It used 620,000 tons of Portland stone and is said to have kept the stone firms working day and night for most of the 1870s.

The stone got the royal seal of approval when it was used to create a professional route from Buckingham Palace to Trafalgar Square.

To celebrate the life of Queen Victoria the east front of Buckingham Palace was erfaced in stone over 13 weeks.

The route ended with another Portland stone building Admiralty Arch.

*Next week we're looking at how two world wars and national and international events shaped the development of the London and Portland stone industry.

'Stone to Build London’ is available from Folly Books for £24.99 with free postage and packaging. See follybooks.co.uk