Fly me to the moon...

An epic account of the antics of The Lunar Men: The Friends Who Made the Future by Jenny Uglow shows eighteenth-century inventiveness at its most fascinating

The Lunar Men: The Friends Who Made the Future
by Jenny Uglow
Faber £25, pp518

In the mid-eighteenth century, three men - Erasmus Darwin, a doctor, Matthew Boulton, a Birmingham metal-goods manufacturer, and the porcelain man Josiah Wedgwood - were at the centre of a society that met in Birmingham on the Monday nearest each full moon (so they had enough light to get home in the evening) for, as Darwin put it, 'a little philosophical laughing'.

The group included James Watt, inventor of the steam engine, Joseph Priestley, who discovered oxygen, the conjuror Richard Lovell Edgeworth and Thomas Day, a follower of Rousseau. Together, they classified plants and isolated gases, they built clocks and telescopes, they flew in hot-air balloons and invented machines that could speak, performed tricks with magnets and dreamt up recipes for disappearing ink. Many of them were self-taught, some were dissenters and radicals, all were ingenious. And in this spectacular, epic book, Jenny Uglow shows how childlike daydreams and Heath-Robinson contraptions gave way to some of the greatest inventions of mankind.

It is perhaps pointless to pick a particular subject as Uglow's best - she is as comfortable explaining how a doctor's diagnosis might be indebted to the theories of Herman Boerhaave or how closely an eighteenth-century idea about matter relates to atomic physics as she is telling you that Erasmus Darwin spoke with a stammer, that James Watt was a hypochondriac or that Josiah Wedgwood walked seven miles a day to and from school.

The individual is as important to her as the intellectual. But the figure who comes across as the hero of the tale is the extraordinary Darwin, grandfather of Charles. What is so appealing about Darwin, in Uglow's account, is that although he was a great inventor, physician and poet (he wrote, among other works, a long poem on the sex life of plants), he saved lives by understanding what you might call the alchemy of the emotions. Not unlike Joseph Bell, the doctor who inspired the character of Sherlock Holmes a century later, Darwin observed human beings in all their psychic splendour, and saw what they gave away despite themselves as well as their more ordinary symptoms. In Zoonomia, a book written towards the end of his life, he listed scarlet fever and measles, but also included entries for other afflictions: anger, ambition, credulity, love.

His sense of humour was characterised by 'a jocose and wounding irony', and he had no time for the pretentious or vain. His son remembered him saying, with reference to the wigs in fashion at the time, that common sense would only have its day when 'men left off wearing as much flour on their heads as would make a pudding'. Though generally supportive of women, when asked to see a patient who had, in a jealous rage, slashed a portrait of her husband's first wife, Darwin promptly told her that the subject of the painting was 'infinitely her superior in every respect, including beauty'. The cure (for vanity?) worked a treat: the threat of calling for Darwin again was enough to dispel further outbursts.

Uglow also tells the story of Thomas Day, who adopted an 11-year-old orphan in order to educate her according to the principles of his idol Jean-Jacques Rousseau and turn her into his wife. 'I know how to make a circle and an equilateral triangle,' his enlightened pupil soon wrote in a letter, 'I know the cause of night and day, winter and summer.' But Day was not happy with the way his 'philosophic romance' - to which none of his esteemed Lunar friends objected - turned out. He never married the girl, considering her a hopeless case. The tale is material enough for a novel, and perfect example of Uglow's territory: a strange story about human beings which is driven by philosophy, branches out into science, and whose goal is sentimental love.

Uglow writes that in order to understand the lives and work of the Lunar Men 'we have to wrench our minds round, abandoning divisions', because there was a boundless logic to their activities, and a Renaissance span to their interests. 'They felt,' she writes, 'the greatness of the cosmos' and also 'the beauty of the infinitely small'. There could be no better guide to this world view than Jenny Uglow, the learned biographer and effervescent historian, a discoverer of extraordinary facts. Like her subjects, she has a firm and subtle grasp of the big ideas (Adam Smith, Locke and Hume), the big events (the Jacobite invasion, the French Revolution), the big inventions (Newton and optics, Franklin and electricity, Priestley and oxygen); and she is equally confident with such minuscule details as the exact fabric of Matthew Boulton's second wife's wedding dress. Everything is part of the story and it seems natural that Uglow should know such things; it's only afterwards you realise that never has the eighteenth century come so much to life in the twenty-first.