Andes, By Michael Jacobs

Michael Jacobs has dedicated his bulky record of travelling down the Andes to his brother, who survived being stoned in Peru, and to the bus drivers. Although parts of this extraordinary feat involve trains, planes, a ferry and taxis, it's the buses and their drivers - who rattle up and down giddy-making gorges and over oxygen-starving mountain passes, often compared to a rollercoaster – that count. To trust these death-defying buses, with landslides, punctures, tales of guerrilla hold-ups, fog, blinding rain and crosses signalling crashes down ravines, is astonishing.

Jacobs even enjoyed this constant massaging on unpaved roads. Unlike his earlier account of travels in South America in search of his grandfather, there seems no deep motive, other than childhood images and fertile books. Jacobs follows his guiding authors, like the liberator-turned-dictator Simó*Bolívar and his tellingly named dog Nevado, and the explorer Humboldt (and his mute companion Bonpland, who wasn't under house arrest in Bolivia, but in Paraguay) - often along their exact tracks.

His dual journey with these authors, and others like Isherwood, makes for vivid reading. We have a layered history of first impressions as these authors and Jacobs pass, sometimes hurtle, south down the mountain chain. Jacobs's art historian's training impels him beyond the picturesque, aware that prose descriptions don't really work; yet there are only six illustrations. Where he stands out from previous travellers is in his rapport with those he meets. Not only does he have – or develop - a network of friends, but he entices out of these encounters a human warmth and depth.

Travelling is not only backpacking and reading earlier travellers, but also meeting people. Jacobs cut his teeth (food is important in this book) in Spain. He's an old-fashioned Hispanist of the ilk of Ford, Borrow and Brenan, highly literate but genuinely democratic. If there's a bar, Jacobs will be there all night; the seedier, the better. His earlier Spanish books, including an encyclopaedic guide to Andalucia, led him to settle in rural Jaén, which he has memorably written about. Many asides come from comparisons with this Spain he knows so well. Linking his Andean travels with Spain revives the maligned colonial inheritance.

Like many travellers, Jacobs is also accompanied, first by a faceless teacher from his village, and then by fellow travel writer Chris Stewart (and then others), but none becomes a foil in Bonpland's way with Humboldt. Whether peeping into eco-lodges or battlefields or Inca ruins, Jacobs is fully there, suffering, panting, pacing up and down.

As he zigzags down the Andes, we learn to trust, with relief, this "ageing" backpacker's perceptions. There's not one boast; he never feels superior, or clever at a native's expense, and is often extremely funny. He is the self-deprecating eccentric and solitary abroad. His created persona is often nostalgic, even sad (he misses his dog) but he endures. In many ways he cannot compete with his hero Humboldt – who had such dazzling learning that even Goethe was knackered after an hour with him – but he shares not being self-centred during his six-week ordeal, and his enthusiasm never flags.

Some passages are more vivid than others, like his memorable account of the Bolivarian society in Quito when, packed with well-dressed generals shouting "Viva", he's asked to speak, ashamed of his travel rags. He recalls the old Spanish love of pompous ceremonies and feels as if in a dream, without any clothes on.

Behind the anecdotes, there's a sense of the Andes being ruined, especially in Argentina, by modern life. The snow on the peaks is diminishing; eucalyptus is planted ubiquitously and dense woods deforested. He's aware of the politics, of Morales and Chávez, but above all, has a dream-like sense of the Andes fractured into self-contained local climates and terrains. When he finds Chaví*like "an empty wine cellar", we realise that the Andes are a lesson not only in our transitoriness, but also in loss. He cites a bishop in 1768, who couldn't find any Indians left to convert and ended up speaking with shadows. Right down in Puerto Williams, on an empty peak with prowling wild dogs, Jacobs is told that he has come all the way to the end of the world, but stays only a day.

Jason Wilson is author of 'The Andes: a cultural history' (Signal Books)