Bloomsbury £12.99 pp403

Now that there are only a few tufts of genuine terra incognita left scattered around the globe, travel books — even the very good ones, such as Bruce Chatwin’s In Patagonia — require what critics call a conceit and cynics call a gimmick. You know the sort of thing: hitching around Tierra del Fuego with a vacuum cleaner, visiting every city that rhymes with “orange” , following in the footsteps of St Simeon Stylites. Ian Marchant’s conceit in The Longest Crawl is alcoholic. He took it into his head to make a meandering, month-long, south-north journey through the pubs of our boozy nation, drinking and driving from the Turk’s Head in the Scilly Isles (lose a quiz point if you said Land’s End) to Baltasound on the isle of Unst in Shetland (ditto if you said John O’Groats).

Quite brilliant as the idea is in terms of freelance taxation — how gratifying to write off 18 pints and a vindaloo, times 30, as legitimate business expenses — it is not self-evidently alluring as a source of copy, especially if you are the kind of person whose thirst for chat about booze is in inverse proportion to your taste for the stuff itself. Cue dismal visions of fat blokes in holey sweaters or Camra t-shirts, droning on about specific gravities and “guesstimating” relative malt contents.

It takes only a few pages of browsing for this scepticism to lift. Marchant, though self-confessedly a fat, bald, fortyish bloke with a mighty thirst for the fine liquids protected by Camra, is no pub bore. Bar-room philosopher is closer to the mark: a man with a view, generally humane and often amusing, on just about everything under our rainy skies; a Zen Anglican with a streak of reverence for tradition and beauty, an old lefty who has no objection to giving a good thump to violent, stupid, lagered-up teenagers, an unreconstructed hippie who is as happy to chew the fat about St Augustine on the weakness of the will as on the relative merits of the Clash and the Ramones.

When the chat ranges this widely, even the grumpiest of saloon-bar solitaries can’t really moan too loudly about his frequent booze-buff pages on, say, the brewers who still employ dray horses for delivery, or why rum barrels are used in fermenting cider (gives it sweetness and strength), or the full mysteries of what makes Marston’s Pedigree unique.

Teetotallers — and, yes, a lightning history of that odd heresy is also included here — may well be frowning at what they will have correctly inferred is Marchant’s light-hearted, indeed broadly comic view of boozing. They may be slightly mollified to learn that the author, gazing down thoughtfully at his beer belly, gives due weight to all the negatives, from increased midriff-fat deposits to decreased memory, lacerating hangovers and grave social ills: “alcohol causes 1.2m violent domestic incidents, including some 350K cases of domestic abuse, a year”, and so on. Don’t fuss him with the stats, he already knows them, and has probably deployed them in a pub quiz. What’s more, his travelling companion and photographer has a day job as an alcohol counsellor.

Due concession having been made to the Dandelion and Burdock opposition, Marchant sketches in all the reasons why he still loves his pint and thinks we should love it, too. He follows his unexpected heroes Chesterton and Belloc in upholding the sanity and, dammit, Britishness of our long-term romance with intoxicating liquids; he follows Orwell in dreaming of an ideal pub that is not a mere booze-shop and short-cut to catatonia but a place where we can engage in real, democratic civil life for a couple of hours a day. Nor is he only a rhapsodist of grog; this book contains what must be the most lyrical evocation of the pork scratching ever committed to paper, and the most painstaking account of what exactly goes on inside a scratching factory.

Marchant himself makes a few self-conscious asides to those recent humorous travel books that are his obvious competition, but his work is really of a higher literary order. Its ancestors are those charming, digressive English travel books that flourished from roughly the Edwardian period until the mid-1930s, such as JC Squire’s The Honeysuckle and the Bee. Beneath Marchant’s effing and blinding, his huge spliffs and his penchant for punk is a spendidly old-fashioned English soul. If there’s a literary equivalent of Camra, he should be marked down for preservation at once.

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