British Museum studies trees used by ancestors to bind ships and baskets
A scientist at the British Museum is using tree samples from two national collections to find out what our ancestors used to bind and waterproof baskets, ships and riggings.
More than 12kg of pine wood from Bedgebury Pinetum in Kent and up to 1kg of birch bark from Stone Lane Gardens, in Devon, were collected for the study.
The 14 species have been heated to create a black sticky tar-like substance, which was used as a glue and waterproofing agent.
Scientist, Dr Pauline Burger, who is behind the project, said the tar was used during the Iron Age.
She hopes to create a database of characteristics for each tar, which she can then compare with the tars used by our ancestors on the objects at the British Museum.
"In the past not all tree species grew everywhere, therefore, I might also get an idea where the tar was produced," she said.
Her study includes looking at the tar used on a medieval craft, the Newport Ship.
Thousands flocked to the banks of the River Usk in Newport in Wales when excavation work for a new theatre and arts centre uncovered the 500-year-old remains of the trading ship.
Archaeologists have said it is the world's best preserved example of a 15th Century vessel.
Modern-day plant hunter
Talking about her work, Dr Burger said: "I chop the bark and wood samples into small bits and heat them in a laboratory kiln, in an almost oxygen-free atmosphere, for between eight and 15 hours.
"They are heated at various temperatures between 300-350 degrees Celsius to obtain the tar."
The study is using 12 species of pine tree from Bedgebury Pinetum, which is managed by the Forestry Commission.
Curator Chris Reynolds said: "It highlights the importance of these botanic collections which are essentially a reference library of trees."
Dr Burger is using the samples from both gardens because the trees have been well studied and are easily accessible.
Paul Bartlett, garden manager at Stone Lane, said: "We are delighted to be involved in such an interesting and important project.
"If these collections weren't available, scientists would have to travel far and wide to get samples. For example, one species the British Museum has collected is native to North America, but is grown here in Devon.
"It's always good to make practical use of the national collection... it's here to be studied."
The gardens began more than 40 years ago when a modern-day plant hunter, Kenneth Ashburner, travelled across the Northern Hemisphere in search of birch and alder trees to grow in Devon.
The study is expected to finish in October, although the results will not be published until next year.