Recently I found myself in a company of six friends making an expedition onto the Great Heath, or quaking bog, which lies at the heart of our island. Until a few years ago this was the scene of regularly scheduled nature walks, but the fear that such tours would damage the terrain brought an end to them, and now the heath lies invisited, approached by a small path, swampy and overgrown, which winds through an unmarked wood. Our group was led by a young botanist, Patrick Chasse, who gave us eyes to see and facts to ponder.
A bog, I learned, is formed over the millenniums; this one dates its beginning to the last glacial age, 10,000 years ago. In a depression containing water, bottomed with bed-rock or impervious clay, aciduous and lacking in drainage, the creeping process starts. Sedges and pond plants along the margin anchor a slow-forming carpet of sphagnum moss; peat falls to the bottom while such heath plants as laurels, blueberries and bog rosemary encroach. As the gap continues to fill, the increasing acidity of the water preserves organic matter and the low oxygen level inhibits bacterial decomposition. The subterranean waters freeze early and the ice holds late into spring. Conditions are almost arctic; many of the botanical developments are those of a northern tundra.
The morning was fair, with a light breeze, as our little company emerged into the sunlight and silence of the bog. For a time no one spoke. While we made our way in single file across that unfamiliar and forbidding scene, I noted that the earth sank visibly beneath the footsteps of the walker in front of me and then rose springily so as to leave no trace of human passage. Vague recollections came to mind of travelers lost in such surroundings. Had I not read old Irish tales of criminals condemned to wander upon the heath until they disappeared forever? But the mild day was reassuring, and soon we were sitting on the mossy ground, adn a few lay out full length, as upon a huge and monstrous water bed.
In that inhospitable terrain the trees that did grow -- red maple, tamarack, spruce -- were stunted, rising no higher than bushes. The plants were mostly of a weird or poisonous nature. Our botanist friend pointed out the lethal sheep laurel and the carnivorous organisms that digested plankton and small insects within the curves of their fatal leaves. The horned bladderwort, the pitcher plant and the round-leaf sundew we all inspected with a slight chill. But the bog cranberry, we were assured, was as innocent as it appeared, and the baked-apple berry, a charming red fruit, looked good enough to eat. We tasted of it indeed, suffering no ill consequences.
At the center of the open expanse lay what looked like a small and amiable pond. No shrubbery or small trees surrounded it, and its borders were in fact composed of the sedges and sphagnum moss which mark the first stages of the bog's creation. In some other age -- I forget whether it will be several hundred or several thousand years away -- the moss and pond plants will begin to support trees; the ground beneath will grow solid, and the boreal forest which surrounds the bog will again take over. As it was before the last ice age so it shall be again. Nature will have completed a giant cycle, while men and women came and went and gazed as we did upon the slowly evolving scene.
For us, when we started out, the midsummer excursion had seemed to have for its objective only the enjoyment of an exotic landscape. But turning homeward -- Pat Chasse had prudently marked the point of entrance so that we could find it again -- a new mood was upoon us.We had participated in a great drama of time. We had sensed that what appeared fixed was transitory and that the hand of change was hovering over all. We were one with the eternal flux. Somehow in that moment the friendship among us quickened,as if heart reached out to heart for assurance of something that endured.