Is it chutzpah? The willing suspension of disbelief? Or sheer stupidity? One wonders--and so does McPhee (Rising from the Plains, Table of Contents, etc.) as he describes, most graphically, three cases of humanity living at the brink of natural disasters. The first long piece describes man's never-satisfied efforts to tame the Mississippi. The mental picture that develops is of a channel forced into deeper and deeper cuts and levees built ever higher as dams are raised and flood plains tamed in an effort to prevent periodic flooding and natural spills into distributaries. But now look at one structure (that's what the Army Corps of Engineers calls a navigation lock complex) that controls the flow where the Mississippi and Atchafalaya rivers come together. Its purpose: nothing less than to maintain the volume and course of the Mississippi just as it was in 1950 and thus preserve the river's connection to Baton Rouge and New Orleans. Next comes a tale of Iceland and the sheer heroism of a small band to tame molten lava by, of all things, hosing it down with water. Even their fellow townspeople laughed at such folly--until they saw that it worked. At stake was the preservation of a great natural harbor at the town of Heimaey--Iceland's richest fishing center. Incredibly, the hosing saved the harbor--but not the town, now buried deep in lava. McPhee contrasts the Nordic approach with that of Hawaiians who accept Mt. Pele's whims fatalistically, their propitiatory gestures limited to offerings of flowers and gin. The last of these cautionary tales is set in California in the canyons and surrounds of the San Gabriel Mountains. Here, the incredible views, natural beauty, and freedom from smog and city are sufficient to close many a mind to the predictable disasters that follow subtle combinations of wind, fire, and heavy rain. Neither man-made pits nor dams can then stay the muck and mud that race down the mountains to bury million-dollar homes (while their tearful owners are interviewed on TV). As always, McPhce is apt at metaphor and simile, more so here where he is less the cerebral lecturer in geology and more the reporter and eyewitness, capturing the words of people and the music of nature. First-rate.