In 1800, you could walk right across London, from Hyde Park to Wapping in just an hour. The capital city was just five miles from east to west, and it held around one million people.

London in the Nineteenth Century is a much-praised study by Jerry White [Jonathan Cape, 2007, pp. 640]. It is a delightful read, combining statistical data, contemporary reportage and anecdote to superb effect.

Earlier, White gave us his history of London in the 20th century and in doing so, said that it simply begged for a recounting of the earlier period. In researching one, he found that it had to grow out of the other. No era in London's history witnessed such dramatic developments as the 19th century. White draws on a wealth of eloquent contemporary sources - from Hazlitt and Mahew, Dickens to Thackeray, and the work is packed with engaging potted histories of everything: from the police force and mob violence to office blocks and the hygiene of prostitutes!

We know that this is a massive subject. History, in the retelling, needs to be "magisterial" but White has written at a heady pace and with a driving enthusiasm. One gets the feeling that, looking back from the 20th to the 19th, one sees a Victorian city that has been transformed but still wearing its 19th century clothes.

By the 20th century, London's population has swelled to 6.5 million and was then the largest city the world had ever seen, stretched to 17 mile wide and bigger than Paris, Berlin and Vienna combined.

As White says, the newer 20th century London was "crow-barred into place" - and he tells of the whole infrastructure of the city doggedly falling into place: slums were cleared, grand public buildings were raised, thoroughfare erected, roads, railways and undergrounds, schools, and of course sewers.

This is a passionate book. White revivifies every incident and resuscitates every rogue. It's an exciting example of how a story of a city should be written.

Justin Cartwright is an uneven writer - startlingly uneven, I would say. He does give us some leaden dialogue and he likes his narrator to utter hackneyed platitudes. But he has taken to hand a new novel, The Song Before it is Sung (Bloomsbury, 2007, pp 276) that also carries a richly detailed evocation of one of darkest periods of history. It is meant to be an eloquent exploration of human fallibility and guilt, but I get that sneaking feeling that it got a little too big for the author's boots.

The novel tells the story of a shy Jewish philosopher and a dashing German aristocrat. It is a fictionalised version of the Jew, Isaiah Berlin, and the German officer, Adam von Trott. If readers remember, von Trott was executed for his part in the "Generals’ Uprising" against Hitler in 1944.

In the book, the pair meet in Oxford in the 1930s and fall out when the German takes up a post in Hitler's Foreign Ministry. The story, as we have it, tells of the research by a London journalist who is obsessed by the German's terrible end and of how von Trott was tortured, then hung, and the whole execution filmed for Hitler's viewing pleasure.