Fetish for facts

The Measure of All Things: the seven-year odyssey that transformed the world

Ken Alder <em>Little,

These days, making a buck in the book business seems to be less about how you tell it than how you sell it. Ever since the huge success of Dava Sobel's Longitude (subtitled "the true story of a lone genius who solved the greatest scientific problem of his time") in the mid-1990s, the publishers of narrative micro-history have played an absurd, inflationary game of hype. We have been offered, for example, Nathaniel's Nutmeg ("how one man's courage changed the course of history"), The Map That Changed the World and, most startling of all, Mauve ("how one man invented a colour that changed the world").

It need hardly be said that such breezy repetition of claims of world-changing significance rather diminishes the impact. In fact, the escalation of rhetoric contributes to some pretty bad writing, at least in the case of Ken Alder's account of the creation of the metric system in 18th-century France. This American historian writes like a man who feels the burden of his subtitle.

In 1792, two illustrious French astro-nomers, Jean-Baptiste-Joseph Delambre and Pierre-Francois-Andre Mechain, were asked to establish a new system of measurement by the leaders of the revolution. Alder contends that "our methods of measurement define who we are". He has a point - under the ancien regime, weights and measures varied across France, hampering trade. But the revolution had proclaimed universal rights, so the metre was to be a universal measure derived from nature - one-ten-millionth of the distance from the pole to the equator.

Alder doesn't develop his thesis so much as frequently reiterate it, as he describes how Delambre and Mechain spent seven years separately measuring the meridian from Dunkirk to Barcelona. The mission fell in and out of favour as all hell broke loose around them - bread riots, political witch-hunts, wars. However, drawing on the personality-driven methods of television history programmes, Alder concentrates on dramatising the emotional trajectory of their relationship. He also indulges in some folksy psychology along the way.

So Delambre, lacking eyelashes, was "an observer rather than a man observed". Mechain, whose "religion" was "accuracy", had a "mouth that drooped towards self-doubt". As such, it should come as little surprise that the expedition's pursuit of precision was marred by Mechain himself - who slides willingly into death after guiltily covering up a critical discrepancy in his data.

While the narrative micro-history genre relies on dazzling the reader with previously unnoticed historical oddities, this potentially fascinating story is deadened by long-winded exposition. Alder's knowledge of the sources is undeniable, but he suffers from a fetish for facts. He struggles to distinguish between the curious and telling (for example, Delambre was denounced during the Terror for lacking an "abhorrence of kings") and the curious yet inconsequential (after Delambre had supervised Descartes's reburial in 1819, Sweden sent France a skull, wrongly claiming it was the philosopher's).

Alder and his publishers seem to think that we like our history strong on sugary narrative, to sweeten the bitter pill of analysis. At the margins, Alder discusses the new kind of economically liberated citizen the leaders of the revolution hoped to unlock through the metric system. But much of the book focuses on Mechain's feelings about his error and Delambre's shifting view of his colleague. It is only when Alder finally explores the origins and consequences of Mechain's error that he begins to justify his subtitle.

Delambre and Mechain were savants - Enlightenment thinkers, investigators of a world they believed would be revealed to be perfectly constructed. Alder argues that Mechain's error was a turning point because it forced the savants to accept imperfection. Delambre realised that Mechain's measurements were inevitably flawed because the natural world is flawed. And so, writes Alder, science began the modern struggle with quantifying uncertainty.

The author has a peculiar nostalgia for the days when it was easier to argue that science was an unambiguous driver of progress. He describes Delambre, perched high on the roof of the Pantheon, measuring points on the edge of Paris. Below him the city is in turmoil, a backdrop to a luminous image of steadfast reason. Blinded by images, Alder's method is not up to explaining why the revolution both enabled the mission and threatened it. "Topsy-turvy times will flip and flip again," he writes. Elsewhere, he admiringly quotes Delambre himself: "The historian owes the dead nothing but the truth." Noble stuff. But, ultimately, it is how you tell the truth that is at issue here.

Tristan Quinn is culture producer of BBC 2's Newsnight