In Environmental Issues and Sustainable Futures: A Critical Guide to
Recent Books, Reports and Periodicals (World Future Society, $35,
ISBN 0 930242 51 3), Marien gives us clear, crisp synopses of 450 works he
considers most important. The guide includes an annotated list of relevant
periodicals and publishers in this field. It is well organised and easy to use.
The abstracts are also richly rewarding to browse through and offer an excellent
introduction to the major themes.

What is meant by “sustainable development” in the urban context? Can it be
achieved through the existing political and institutional framework or does it
require a new political ideology? Where do poor inhabitants of unserviced slums
really fit into the equation? These are some of the questions addressed in
Sustainability, the Environment and Urbanization, edited by Cedric Pugh
(Earthscan, ÂŁ14.95, ISBN 1 85383 357 6).

A collection of essays by urban development experts, it discusses topics from
the Healthy Cities Project, a multipartner public health initiative guided by
the WHO to radical new models for providing water and sewerage to communities
usually bypassed by public services because they cannot afford them. There are
interesting ideas here, but the flat academic style and occasional verbosity
make the book hard work.

By contrast, Making Cities Work, by Richard Gilbert et al
(Earthscan, ÂŁ13.95, ISBN 1 85383 354 1) is thoroughly absorbing. Starting
from the point that most of the world’s people and most of the new environmental
challenges will be in towns and cities, it explains why local authorities are
best placed to tackle sustainable development and what they need to be
effective. The growing trend in local government towards forging global
alliances is discussed here with reference to practical examples from Senegal to
Brazil. And the book ends with recommendations for action.

Optimism encouraged by Making Cities Work is soon dispelled by
Material Concerns by Tim Jackson (Routledge, ÂŁ13.99, ISBN 0 415 13249
5), a frightening analysis of the causes of the environmental degradation.
Jackson argues that the rot set in when we began exploiting fossil fuels to
drive our industries. Whereas ecosystems dependent on renewable energy from the
Sun are self-regulating, industrial systems driven by non-renewable energy are
not. This lucid and compelling book offers radical prescriptions for minimising
adverse consequences.

Postcards from the Country by Peter Marren and Mike Birkhead (BBC
Books, ÂŁ16.99, ISBN 0 563 37157 9) is a reminder of simpler times and
simpler relationships with nature. Written to accompany a television series, it
offers old photographs and oral history to dip into and delight in.

Finally, another reference book. Anyone who compiles a specialist dictionary
is on a hiding to nothing: readers are more likely to damn it for its omissions
than praise it for its accomplishments. The Dictionary of Environment and
Sustainable Development by Alan Gilpin (Wiley, ÂŁ14.99, ISBN 0 471
96220 1) gives clear and concise definitions; the simple illustrations of
certain phenomena are generally excellent; and the boxes giving more information
on selected topics are useful. However, the apparent arbitrariness in the choice
of entries in all categories, from diseases, dams, and national parks to
environmental processes and principles, is irritating. It is a useful addition
to a collection, rather than invaluable in its own right.

The challenge, says Young, was to design a device that encouraged natural
hunting behaviour and was simple, practical and cheap.

His device consists of two pulleys that run by gravity one after the other
along a steel cable that slopes down across the enclosure. The pulleys are
weighted to regulate their speed, and the bait—a dead rabbit—is
suspended from a nylon cord that hangs down between the pulleys as they run down
the cable. The back pulley is tethered to the top of the cable, and brakes a few
metres short of the end, while the front pulley completes the run. This takes up
the slack of the loop and yanks the rabbit—if it has not yet been
caught—out of the cheetahs’ reach. This stops them from simply waiting at
the end of the line for their food, explains Young.

The bait is set exactly within swiping distance of a sprinting cheetah, but
not low enough for the animal to tangle itself in the cord. Its travelling speed
is regulated to encourage the chase without overstretching the predator.

Throughout history these Aboriginal people have been treated as objects to be
managed and described in terms that reveal more about the observer than the
observed. Miscast: Negotiating the Presence of the Bushmen edited by
Pippa Skotness (University of Cape Town Press, Tel + 27 21 244 519, R268.00,
ISBN 0 7992 1652 6) is a fascinating exploration of this phenomenon.

In 32 essays, academics from anthropologists to linguists trace the
simultaneous and contradictory depictions of the Bushmen—noble savages,
base savages, primitive beings studied by scientists, thieves hunted as vermin,
highly spiritual people, bag people living on the fringe of modern society.

However, the most powerful material in this book, published in conjunction
with a travelling exhibition, is the wealth of original documents which appear
alongside the essays as a parallel text. London posters in 1847 advertised the
live exhibition of a Bushman family. Newspapers described them as “probably the
very lowest in the scale of creation” and “in appearance little above the
monkey”. Photographs and detailed descriptions of Bushman genitalia also
demonstrate a pornographic exploitation which masqueraded as scientific inquiry.
However, positive relationships such as the one established in the 1880s between
a Bushman family and the philologists Wilhelm Bleek and Lucy Lloyd also appear
in this wide-ranging book.

A few of the essays in Miscast are badly and inaccessibly written.
But its main weakness is the extremely limited testimony from Bushmen. This
illustrates the fact that, even today, these people remain trapped by the
perceptions of others. Bushmen are not represented in parliament in either
Botswana, Namibia or South Africa.

The main culprits in corrosion are chloride ions, which come chiefly from the
salt used as a de-icer on roads or from sea spray. Water seeps through the
concrete, carrying the chloride ions with it and eventually allowing them to
attack the steel reinforcements inside the structure.

The new analysis technique was developed by a team from the Universities of
Dundee, Surrey and Kent. It is a variation of an established technique called
nuclear magnetic resonance spectroscopy (NMR). The nuclei of certain atoms have
a property called spin, and in a strong magnetic field they can be in one of two
spin states, which have slightly different energies. A burst of radio waves of
the right frequency can kick the nuclei from the lower spin state to the higher
one, and as they fall back into line they release a characteristic
electromagnetic signal. The frequency of the radio waves needed, and of the
signal emitted when the nuclei fall back into line, depends on the strength of
the magnetic field.

NMR is widely used as an imaging technique in biological studies, but it
encounters serious problems when used with inorganic materials, because the
signals given off by the nuclei tend to decay more rapidly. The rate at which
they decay depends on the physical and chemical environment of the nuclei under
observation. According to Geoff Hunter, professor of chemistry at Dundee, it is
particularly rapid in concrete, which contains paramagnetic and ferromagnetic
impurities. “The image you get using conventional NMR techniques is so poor you
can forget it,” he says.

The researchers have overcome the problems by building an instrument based on
a technique known as Stray Field Imaging. First suggested by a Russian physicist
in 1988, SFI involves placing the sample outside the central region of the
magnetic field. The gradient of the field is much steeper around the rim, and
this spreads the NMR signals over a much wider range of frequencies. As a
result, any inaccuracies arising at a particular frequency are less significant,
and this minimises distortion overall. The researchers have been able to use the
new technique to follow the movement of water through concrete, and also to
establish for the first time how well water-resistant coatings work.

“We’re working now to establish reliable, validated models of the movement of
water and chloride within concretes,” says Rod Jones, one of the engineers
involved at the University of Dundee. This will help designers select materials
most appropriate to the environmental conditions in which they operate.

The team also wants to look at the interaction between chloride ions and
binders such as power station fly ash, which are routinely added to the
concrete. To do this they use a form of NMR called Magic Angle Spinning
Spectroscopy.

The construction industry has yet to see the benefits of the new technology.
But Les Parrott of the British Cement Association believes a nondestructive
technique for studying concrete samples is a significant advance. Any tool that
improves our understanding of water movement in concrete and helps predict
durability “has got a lot of mileage”, he says.