On my bookshelf I keep three items: a pink stone, an aluminum disk and the seed of a lantana palm.

One piece I keep is from Asia. In 1976, near the hamlet of Badaling, in China, I walked, jogged and wandered along the roadway at the top of the Great Wall. Suddenly the passage ended. Although the Great Wall is 3,000 miles long, at that time only a small part is in good enough repair to walk upon. Beyond the sign forbidding further going, the wall hugs the ridge of the mountains as a huge dragon's tail making its way to the sea. But the missing pieces, broken turrets, cracked slabs and ramparts made passing prohibited and dangerous.

I sat in a watchtower, looking onto the mountains fading in slate gray and rose. In my mind's eye I raced across centuries. I placed a tiny piece of the wall in my pocket. (At that time, there were no signs saying that fragments should be left untouched,)

Another item on my shelf is from the US. The silvery disk is from the Montana Rockies, near Hungry Horse Dam. In the middle of an evergreen forest, needles seared by chemical fumes, is an aluminum smelting plant. In the center of the building are pits smoking molten metal. Workers stand beside the pits sweeping bauxite into the flames. The foreman makes his rounds on a bicycle. The air is all heat and haze.