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The Legacy of Sir Lawrence Bragg: Selections and Reflections edited
by John M. Thomas and David Phillips, Science Reviews*, pp 320, £28.50/
$60

‘In a crystal the atoms and atomic groupings are ranged in perfect geometric
regularity, and it is by observing their concerted effects on the X-rays
that we can investigate the intimate structure of solid bodies.’ Thus Lawrence
Bragg in his first Royal Institution Discourse of 1920, at the age of 30
was already a Nobel Laureate of five years’ standing.

John Thomas and David Phillips have compiled The Legacy of Sir Lawrence
Bragg to mark the centenary of Bragg’s birth in 1890. Through his own words
and the eyes of his associates, the book presents a kaleidoscopic view of
Bragg and his unique role in the creation and development of X-ray crystallography
and the successive transformations wrought by it in the fields of chemistry,
mineralogy, metallurgy and biology.

There is no full-length biography of Bragg. This book, together with
Bragg’s own The Development of X-Ray Analysis, seem likely to stand as his
two-part biography: the first personal, the second technical.

The Legacy of Sir Lawrence Bragg opens with a reproduction of the Royal
Society Biographical Memoir of Bragg. This lengthy and scholarly memoir,
written by Phillips, first appeared in 1979, some eight years after Bragg’s
death. There follows an engaging account by Max Perutz of the beginnings
of X-ray crystallography, whom Bragg had inherited as a research assistant
from J. D. Bernal on coming to Cambridge. The very title of the essay (‘How
Lawrence Bragg invented X-ray analysis’) reveals the care Perutz takes to
acknowledge Lawrence’s priority over his father, Sir William Bragg, in establishing
the principles of the subject. Perutz draws usefully on Bragg’s unpublished
autobiographical notes in the archives of the Royal Institution.

Thereafter an illustrious array of Bragg’s former colleagues and students
provide a mixed bag of short recollections, anecdotes and appraisals of
the great man and the heroic days of X-ray crystallography. The contributors
include John Kendrew, Dorothy Hodgkin, Aaron Klug, Nevill Mott, Linus Pauling,
Francis Crick, James Watson, Jack Dunitz and George Porter. The style varies
from the adulatory to the matter-of-fact, and some write more about themselves
than about Bragg, but the overall picture that emerges is pleasingly rounded.

Certain themes recur – Bragg’s skill as a lecturer-demonstrator, honed
during his directorship of the Royal Institution. His dislike of committees
and his love of family. His struggles with quantum con-cepts and his anger
at his own failure (understandable in a mathematician turned classical
physicist) to recognise the planarity of the peptide bond in fibrous proteins.
Although Alexander Todd, with characteristic bluntness, pointed this out
to Bragg, it was too late to prevent Pauling’s priority in establishing
the a-helical structures of these proteins.

Above all, there comes across Bragg’s enduring enthusiasm for X-rays
and the wonderful structures they revealed. His pleasure and pride in the
achievement of Perutz and Kendrew in unravelling the structures of haemoglobin
and myoglobin is evident in the final remarks of his 1966 Royal Institution
discourse:

‘It still seems to me miraculous that X-ray analysis, which started
with such simple structures, can now determine the positions of thousands
of atoms in a protein molecule, and do it with such precision. It has come
as a wonderful climax to 50 years of research in this field.’

But these impressions form only the first half of the book. The second
half consists of generous selections from Bragg’s publications, and very
good reading they make.

His spectacular first paper on the correct reinterpretation of Max von
Laue’s X-ray photographs of zinc blende, read to the Cambridge Philosophical
Society on 11 November 1912, is rightly reproduced in full, as are his late
pieces on the art of talking about science. Bragg’s other seminal contributions
– the recognition that most simple inorganic compounds do not contain discrete
molecules but rather geometrically-determined ion lattices, the determination
of the structure of the silicate minerals beryl and diopside and the identification
of the ubiquitous SiO4 building block, the heroic application of two-dimensional
Fourier analysis to the solution of multipa-rameter structures, the determination
of the superlattice structure of g-brass and his intuitive understanding
of order-disorder phenomena – are sketched in by extracts and abstracts
stretching over 40 years.

But for all Bragg’s early technical brilliance, the enduring impression
left of the young man who had learnt of the joint award of the Nobel Prize
for Physics to him and his father near the front at Ypres is that of the
well-loved avuncular director of the Royal Institution in his ‘repertory
theatre’ of science. Of the RI lectures for schoolchildren, which he introduced,
Bragg wrote:

‘It might be thought that it would be tedious for the lecturer to repeat
the same talk day after day, but my experience has been exactly the reverse
. . . I have often felt I am becoming a showman when I take advantage of
my experience as to what stirs interest or arouses pleasure . . . . A point
is either made with complete success or it falls completely flat, and one
soon finds out which.’

Bragg knew the necessary, though sadly not sufficient, condition for
successful research (‘The fatal enemy of research is a full engagement
book’), the difference between writing a good paper (‘It is as if the writer
were giving evidence on oath, and had to justify the accuracy of every word’)
and giving a good lecture (‘The force of the impression depends upon a ruthless
sacrifice of unnecessary detail’). Would that we all acquired such wisdom
with age.

Mary Archer is chairman of the National Energy foundation. She worked
at the Royal Institution from 1972 and 1976, and was subsequently a manager
of the RI.

*Science Reviews, 40 The Fairway, Northwood, Middlesex HA6 3DY