HEAVEN'S BREATH; A Natural History Of the Wind. By Lyall Watson. Morrow. 384 pp. $19.95.
THIS is the kind of book that answers dozens of questions first arising in childhood and lingering unresolved until there was Lyall Watson. Here are some of mine. What is gossamer? What does the expression three-dog night mean? Why is mountain-climbing so taxing?
Armed with doctorates in anthropology and ethnology and credentials with the BBC, Watson provides these and many more answers. Gossamer is spider webbing, lifted and carried by the wind -- an identification that wasn't made until 1741, thus ending a mystery which puzzled poets for centuries. A three-dog night is one in which a Yukon trapper would need to snuggle up against three dogs in order to keep warm.
The mountain question requires a little more development. Sure, mountain air is thin, but that's not an adequate response: why can't one just breathe more deeply and make up the oxygen deficit? The answer according to Watson is that "the maximum amount of oxygen that any body can consume declines by 10 per cent with every kilometer climbed. So everyone, no matter how well they may be acclimatized, tires more quickly at altitude."
Admittedly some of these facts are a bit tangential to the book's ostensible subject. Closer to the mast is Watson's discussion of the Coriolis Effect, the deflection by inertia of a moving body linked to a rotating one. "All movement in the northern hemisphere," he writes, "is deflected to the right, while in the southern hemisphere deflection is to the left." The effect makes a difference to sailors, including the jellyfish known as the Portuguese man-of- war.
In the northern hemisphere sargasso weeds bend to the right in obedience to the effect; in the southern hemisphere they bend to the left. Thus, up north "anything that has a tendency to sail to the left, rather than directly downwind, is less likely to become trapped" in the weeds.
"And, as luck and provident evolution will have it, recent studies of (the man-of-war) show that the majority of colonies in the northern hemisphere bulge to the right of their floats, which means that they sail at an angle to the left, between the windrows of weed. In the southern hemisphere, the opposite situation exists and the majority of colonies are right-sailors."
If you have weather-forecasting aspirations, Heaven's Breath will not disappoint you. Early on, Watson delineates a simple system for tracking weather changes. The book is even more valuable, however, as a demonstration of the earth's organic unity. Watson makes a persuasive case for the proposition that the withdrawal of nurturing winds from Mesopotamia 8,000 years ago spawned civilization itself. "People were thrown together into large groups requiring greater organization, priests and bureaucrats emerged to guide and govern, refugee herdsmen found themselves compelled to work for others for a living -- and it was this factor, the existence of dependent and indentured labor, that made cities and civilization possible."
ONE OF Watson's set pieces is an account of a bridge destroyed by harmonic tremors. There have been several such incidents; the one he chooses happened on Puget Sound in 1940, when the Tacoma Narrows Bridge began to vibrate in a wind "just strong enough to blow foam off the top of waves and make the local fishermen think twice about going out. But this was sufficient to get under the roadway of the central section of the bridge and start it oscillating up and down. Before long it began to 'gallop.' Standing waves were set up, with as many as four crests at a time humping their way across the Narrows, sending frightened drivers fleeing on foot from their abandoned, but by no means stationary, cars."
Two hours later the bridge started to twist, "turning the roadway through forty-five degrees like a corkscrew, spilling cars down into the Sound. The structure had developed a 'Karman Vortex,' which is the engineering equivalent of hysteria . . . Three hours after the wind and movement began, the bridge collapsed into the waters far below."
Another long section reports on the Russian rocket flights that have gone far to solve the riddle of how flu bacteria spread so rapidly and leapfroggingly. The answer seems to be that some microbes can sail into the stratosphere and descend -- still noxious -- hundreds of miles away. As Watson puts it, we appear to be dealing with species "adapted to the edges of space as a normal habitat."
Late in the book, as if to excuse its elusive organization, Watson remarks that "wind is almost anything you want it to be. There are few things as steady or as changeable, as fierce or as gentle, as unstable or as undeviating, as light or as bold, as wroth, as balmy, or as protean as wind." Protean would also be a kind way of characterizing Heaven's Breath: Watson's pot-pourri of wind poetry, wind jokes and wind facts is so diverting that one hardly minds losing the thread now and then. After all, where else could you learn the sources for two weird wind- names. A cold, violent southeasterly in Morocco is the mezzerifoullousen -- "that which plucks the fowls." A strong gust in Cheshire is called a whittle, after Captain Whittle, whose coffin was buffeted to the ground as his pallbearers approached the church.