VISITORS to Ireland several centuries ago became aware of what to them was a very novel source of energy. Sir William Petty, for example, writing in 1691, remarked: "Their fuel is turf in most places, even where wood is most plentiful and to be had for nothing, the cutting and carriage of the turf being considered easier than that of wood."
Moreover, in some parts of the country, the inhabitants had no alternative, as Thomas Dinley, a few years earlier, had pointed out in his Observations on a Voyage through the Kingdom of Ireland "The wars and the rebellions, which have been so frequent here, have destroyed all their woods both for timber and for firing; this want, however, is supplied in plenty by the bogs."
Now one might wonder how a bog could provide supplies of timber. The answer lies in the great preserving power of peat.
The lack of oxygen and the natural acidity of this water-logged environment almost completely prevents the normal process of decay, so stumps, and even trunks, of oak, birch, pine and yew were, and indeed still are, to be found intact in abundance in our may bogs.
Bogs are living things. Given the right conditions they grow upwards and outwards as successive generations of undecomposed vegetation accumulate layer by layer.
During very wet periods in our climatic history the bogs have thrived, while many of our forests have succumbed to the waterlogged environment.
Their timbers were engulfed and preserved in the encroaching peatlands, to be exposed many centuries later by those in search of a valuable resource.
The methodology used, for example, in Co Galway is described in detail by yet another visitor to our shores, one called De Latocnaye, who wrote A Frenchman's Walk through Ireland in 1796: "Hardly a tree is to be seen but the country at one time must have been covered with them for they are frequently found in the mosses. The way of discovering them on the surface is simplicity itself.
"The inhabitants go over the bog in the morning while the dew is on the ground, carrying with them long spits or rods of iron. They observe the places where the dew has disappeared and there they pierce the ground, nearly always finding wood, and being able immediately to say with fair accuracy its length, size and quantity by renewing the operation in different places.
"They proceed to dig; the trees unearthed are generally pretty sound and furnish the only wood which the inhabitants can use in the building of their cabins."