Bogoak
Bogwood is a form of timber unique to the ancient peat bogs of Ireland. The specific acidic conditions of the peat bog helped preserve giant trees that formed the great oak forests of Ireland thousands of years ago. The bogs themselves formed as rotting vegetation collected in swamps where it was broken down by micro-organisms. Timber that fell into the swamps sank slowly, and were gradually buried beneath semisolid layers of peat. The low pH levels acted as a preservative, effectively “pickling” the wood and preventing it from rotting. As the bogs have been reclaimed for agriculture or exploited for fuel, huge trees have been thrown up. These trees, miraculously preserved, have lain underneath a blanket of peat for thousands of years and are greatly prized as raw material for sculptors. Dendrochronology has shown some pieces of bogwood to be over 4000 years old.
Historically, bogwood was greatly prized for its durability, especially as it was often the only timber to which people had access to in the early 19th century. An elaborate and specialised vocabulary grew up around bog timber, and its many uses and associated crafts. It was often used as a structural material for houses. For centuries the roof timbers of tenant houses were made almost entirely of bog oak and bog pine, because the timber of the appropriate size for roof timber was not available outside of the large estates. It was often used in larger buildings such as churches.
Interestingly, bogwood was also commonly used in the malting of bog wood rope; a craft that dates back thousands of years. The wood was shredded, beaten until flexible then woven with a “twister” to produce very strong two-ply ropes about 2cm thick. These were mostly used for cording wooden beds. This rope was also used to hold down thatch roofs on houses during winter months.
Bog yew was greatly prized for furniture being similar to rosewood but more durable, superior in beauty, firmness and texture.
Bog pine(usually called fir) is much more common, and was used in building and in the making of furniture of all sorts.
Bog oak is black, and very hard. However it tends to decay after long exposure to the air, so traditionally it was used in damp situations, such as for waterworks. When bog wood is dug out it is sometimes quite soft, but when it dries it becomes as hard as iron. It was widely used for making wooden vessels and tubs. Bog oak was especially favoured for making butter vessels and pine churns while oak skimmers were used for skimming cream from milk. Its high resin content made bogwood suitable for lighting fires or as deal torches. Dramatic uses of these torches include that of salmon spearing by night. This was common in county Galway. The fish were lured and dazzled by the blazing light and then speared.
Bog wood lies buried beneath the bog, and there is a very particular method for finding it. A visit is made to the bog early in the morning, while the dew is still on the ground. A place were the dew evaporates quickly suggests buried timber. Once the place is located the nature of the timber is explored using a long metal probe. The experienced hand can not only tell if the wood is sound, but also its dimensions and orientation. Buried trees can also be detected by noting places where fallen snow or frost quickly disappears.
During heavy frost, the bog is traversed and the buried log staked out. A bog hole is opened along the site of the log. The turf cut away then lets the operator raise the timber. Getting a tree out requires a lot of labour with the logs usually rolled out of the bog.
The dating
Having completed a sculpture entitled “Thank you to the Choctaw”, (which is now part of Ireland's great hunger museum) Kieran decided to send an off-cut of this sculpture to Queen's University Belfast to be dated. The dating of trees is referred to as Dendrochronology. This is a scientific method of dating based on the analysis of patterns of tree rings also known as tree growth.
This bog oak was retrieved from a bog in East Galway and samples were deemed suitable for testing. Testing was carried out by David M. Brown of the School of Geography, Archaeology and Palaeocology at Queen's university. The methods for testing followed those described by Bailie (1982) and English Heritage (1998).
Following calculation of results, one of the samples findings indicated that the measured tree-ring series dates from 1707BC to 1389BC, making it in excess of 3722 years old. The best estimated death date for the tree was be 1357BC +/-9 year.
"Thank you to the Choctaw" as part of the permanent famine exhibition at Ireland's Great hunger museum, Hamden CT and is part of the “Coming Home: Art and the Great Hunger” exhibition currently on show at Dublin Castle.