The Measure of All Things: the Seven-Year Odyssey That Transformed the World.
Little, Brown 477pp. 15.99 [pounds sterling] ISBN 0316859893
THE JUDGES OF THE 2002 History Today/Longman Book Prize had no difficulty in shortlisting this well-written and fascinating book. Alder--a specialist in French science and government in the Revolutionary and Napoleonic period--has taken the invention and early history of the metre as his topic. The introduction of the metric system was part of a major attempt to rethink the measurements of life that included the replacement of the Christian calendar by the Revolutionaries.
That did not last, but both the replacement of France's traditional provinces by new departments and, eventually, the metric system did. The metre was seen as symbolising the brotherhood of man and as making trade easier. Yet this was far from an easy process. The decision to replace the multiplicity of ancien regime weights and measures seemed a sensible step to ensure progress and to mark a break from the anachronisms of the past, but there was no shortage of difficulties in the brave new Revolutionary world.
In 1792, Pierre Mechain and Jean-Baptiste Delambre, two eminent astronomers, set off in opposite directions from Paris in order, by means of triangulation, to measure the distance of the meridian are between Barcelona and Dunkirk. It was intended to divide this distance by ten million to produce a definitive length for the new metre. It was planned that this would take a year. In fact, it took seven and revealed the chaos of the revolutionary years. Changes in government led to Delambre being dismissed by the Committee of Public Safety. Difficulties of travel added to the travails of suspicion and arrest the two encountered as mysterious agents of the outside world. It did not help that France and Spain went to war.
In the event, the quest was based on a flawed premise. The world is not a perfect sphere and meridians vary on what, in detail, is a buckled globe. The search for perfection, so typical of Revolutionary goals, was therefore bound to fail.
Napoleon made the metric system compulsory in 1801, although in 1812 he rescinded it. In this time, in response to the threat from France, the Ordnance Survey was mapping southern England, and tire contrast between its activities and those described by Alder say much about the differences between the two states.
Alder's ability to impregnate his story with the human element makes the quest for the metre a parable of human achievement. Whereas Delambre achieved his task, Mechain couldn't cope with the realisation of error. This is both morality tale and adventure story.
Jeremy Black is the author of War. An Illustrated History (Sutton, 2003).