A heated fightagainst devastationForest Fires: Behavior andEcological Effectsedited by Edward A. Johnson & Kiyoko MiyanishiAcademic: 2001. 594 pp. $74.95

Daniel Nepstad

Major forest fire research programmes wereset up during the twentieth century in anattempt to reduce the considerable costs offorest fires to society and to provide a sci-entific basis for forest fire management systems. A new synthesis of forest fire sciencethat promises to distil the vast scientific literature produced by these programmes is awelcome contribution. Edward Johnson andKiyoko Miyanishi have edited this volume tofoster a more mechanistic, physically basedapproach to forest fire science, going beyondthe ‘traditional’ descriptive approaches. Thebook is intended to bridge the gap betweenelementary forest fire texts and the highlytechnical literature on the subject. To theseends, it is partially successful. The book provides a rich summary of our currentknowledge of several important aspects offorest fire science, from fuel dynamics tocoupled atmosphere–fire modelling. But itlacks a synthesis of the ecological and economic importance of forest fires and anintegrated analysis of the critical gaps in ourunderstanding of this phenomenon.

Dozens of careers and decades of researchhave been devoted to forest fire science in theUnited States, Canada, Australia and Russia.But in the emerging forest fire hotbeds ofBrazil, Indonesia and Mexico, forest fire sci-entists can be counted on the fingers of onehand. These disparate scientific communi-ties have very different reading needs. Thedecades-old forest fire school has alreadydeveloped and tested empirically basedapproaches to assessing the risks of forestfires. It has also modelled fire behaviour andfuel dynamics in many forest types, and documented the ecological effects of forestfires. Fire laboratories in these countriesexamine the physical and chemical aspects offorest fires under controlled conditions.Johnson and Miyanishi target this school,hoping to speed up its transition to physi-cally based forest fire science. And it is for thisaudience that the book will be most useful.

The incipient forest fire research commu-nities of developing nations are just begin-ning to conduct the type of descriptiveresearch that Johnson and Miyanishi hope tomove beyond. We still don’t know how muchof the Amazon or Bornean rainforests catchfire each year, for example; at least 10,000square kilometres of standing forest wereignited in each region during the severe

droughts of the 1997–98 El Niño episode.The book highlights a pioneering study offorest fires in Amazonia by Christopher Uhland Boone Kauffman as an example of theflawed, descriptive forest fire research thatmust be avoided. But Uhl and Kauffman’s isboth an important and a timely contribu-tion, documenting effects of selective loggingon the mass and moisture content of the fuellayer. The way in which the leaf canopy regu-lates the flux of radiant energy to the forestinterior is the single most important deter-minant of tropical rainforest flammability,but this is not mentioned in Forest Fires.

An effective bridging of the gap betweenelementary forest fire texts and the highlytechnical forest fire journals requiresoverview chapters describing the ecologicaland economic importance of forest fires on aglobal scale, and indicating the most im-portant gaps in the science.The absence ofsuch chapters in Forest Fires means that theforest fire neophyte encounters chapters richin equations and literature references, butpoor in didactic explanations of the basicprinciples of forest fire behaviour and itsecological effects. An issue as important asthe effect of global warming on future fire regimes is tucked away in a chapter on“Climate, weather and area burned”, illus-trated by illegible maps.

The book’s strength is as a state-of-the-artreview of research on pyrolysis, flames, lightening, fuel–moisture dynamics, smoke,combustion chemistry, and more. Everychapter carefully defines its notation, andsome of the chapters are written in engagingprose. But the editors’ odd attack on descrip-tive research sends the wrong message toprospective forest fire scientists in regionssuffering rapidly escalating problems with

such fires. The first step in establishingresearch programmes in places such as Amazonia, Borneo and Mexico is to walkthrough burning and burned forests, talk toproperty owners who ignite and fight fire,and quantify and systematize these fieldobservations. My fire science students andcolleagues in the Brazilian Amazon use ForestFires as a reference. But the inspiration fortheir studies is still the classic Introduction toWildland Fire by Stephen Pyne, PatriciaAndrews and Richard Laven (Wiley, 1996). ■

Daniel Nepstad is at the Woods Hole ResearchCenter, Woods Hole, Massachusetts 02543, USA,and the Instituto de Pesquisa Ambiental daAmazônia, CEP 66087-430, Belém, Pará, Brazil.

Every secondcountsThe Measurement of Time: Time,Frequency and the Atomic Clock by Claude Audoin & Bernard Guinot(translated by Stephen Lyle)Cambridge University Press: 2001. 346 pp.£75, $110 (hbk), £27.95, $40 (pbk)

Ken Johnston

In our daily lives, time regulates our activi-ties. Almost everyone wears a watch. Theaccuracy with which time is measuredincreased by orders of magnitude in the latter half of the twentieth century — today’swatches, based on quartz-crystal technolo-gy, are accurate to a second a month. And the advent of the atomic clock and spacesatellites has brought worldwide time synchronization to within 20 billionths of a

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Burning issue: research into forest fires has escalated over the past decades.

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second. This has made possible navigation to within 10 metres using satellites, milli-arcsecond studies of celestial radio sources,studies of the Earth’s rotation and preciseknowledge of the Earth’s gravitational field.It also affects fundamental research in areasthat measure physical constants and inatomic physics and general relativity.

Time must be based on a phenomenon innature that has a definite repeatability; thisdefines the frequency of the ‘standard’. Thisfrequency can be measured, but it takes analmost continuous comparison between‘standards’ to determine and disseminate aunique timescale by which laboratories cansynchronize their clocks to produce the unit of time, the second. Further time mustalso be considered in the framework of general relativity.

The measurement of time was based originally on astronomical phenomena suchas the rotation of the Earth and the motion ofthe planets. Since 1967, however, it has beenbased on an atomic-frequency standard —the second is defined by the use of a caesium-133 atom. Our daily lives are governed bycivil time, which is based on CoordinatedUniversal Time (UTC). This is the time at thelongitude of the Greenwich meridian, fromwhich the time zones are offset to give localcivil time, which follows the rising and set-ting of the Sun. UTC is International AtomicTime (Temps Atomique International, orTAI) offset by an integral number of secondsin order to keep it in near-synchronizationwith the rotation of the Earth. As the Earth’s

rotation is slowing down by one hour every1,000 years, ‘leap seconds’ are added to UTC(at the end of either June or December) whenthe discrepancy of the Earth’s rotation withTAI is 0.9 seconds.

The Measurement of Time gives an excel-lent, detailed introduction to all aspects oftime and frequency. Topics covered includeprinciples, measurements, models, the evo-lution of time definitions, clock time, atomicstandards, atomic time, astronomical time,ultra-precise time and frequency standards,as well as definitions and advanced timeapplications. All of these topics are well referenced, making this an excellent sourcefor scientists and students in the field of timemeasurement as well as for historians ofphysics and astronomy.

Most of the book should also be accessibleto a more general audience. Although thereare many other books on this subject for the general public, this is perhaps the most authoritative, as it provides the precise definitions used in this field. Suchknowledge could provide an interestingtopic at cocktail parties when there is a lull in the conversation. ■

Ken Johnston is at the US Naval Observatory, 3450 Massachusetts Avenue, NW, Washington DC 20392, USA.

More on timeCalendrical Calculations: TheMillennium Editionby Edward M. Reingold & Nachum DershowitzCambridge University Press, £24.95, $37.95 (pbk)

When politicscolours diseaseDying in the City of the Blues:Sickle Cell Anemia and thePolitics of Race and Healthby Keith WailooUniversity of North Carolina Press: 2001. 360 pp. $34.95 (hbk), $16.95 (pbk)

Ken Fox

The power of black bodies and their afflic-tions to “tell a moral tale” about changingracial relations in US society is bound to fas-cinate, infuriate and inspire readers of Dyingin the City of the Blues. Keith Wailoo’s tellinghistorical narrative chronicles the changingmeanings — clinical, scientific, political,symbolic — of sickle-cell disease over thecourse of the twentieth century in America.Fundamentally, this remarkable text on thesocial construction of the illness speaks ofhow ancient, bloody, brutal and enduringthe facts of racial disparity in health and carereally are in the American experience.

Wailoo’s meticulous scholarship exca-vates a deep and dizzying range of primarydocumentary resources. Arcane manuscriptcollections, nearly four dozen technical, scientific and popular journals, newspapers,fiction, blues lyrics, cartoons and sermonsare mined to reveal the politics of race andhealth in America.

What makes this book such an achieve-ment is the author’s eye and ear for luminousdetail. In one example, Wailoo uses lyricsfrom bluesman W. C. Handy’s 1909 MemphisBlues to introduce readers to Edward ‘Boss’Crump, mayor and chief architect of citypolitics in early-twentieth-century Memphis.Crump, “closest thing to a plantation masterMemphis had”, was “a Democratic Party bosswho blended southern paternalism andhumor with brutality toward those who dis-agreed with him”. On election day, Crump’shenchmen rounded up Handy’s audiences,escorted them to the polls, and doled out giftsin exchange for votes. All the while, Crump’sregime was viciously policing the boundariesof Jim Crow segregation. Wailoo thus aptly characterizes Memphis blacks as both “pawnsand political forces in the urban power struggle”. In another example, Wailoo bringsMemphis’s famous Beale Street to life. Once apotent centre of black capitalism, Beale Streetwas a major theatre in the holy war waged by“Negro doctors” against “sidewalk barkers”and sellers of “roots, herbs, grape leaves, rabbits’ feet, wine and whiskey concoctions”.

Through Wailoo’s window, the politics ofrace and health are inextricably bound to class tensions, and central to his interpretiveframework is the conception of sickle-cell disease as a ‘commodity’. The history of the ill-ness may be traced along its shifting positions

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Measured time: thephases of the Moon(right), and a pocketsundial from thesixteenth or seventeenthcentury. From TheDiscovery of Time, editedby Stuart McCready (MQPublications, £14.99).

Clock-watching through the ages

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