Is this a railway travel show or Carry on Choo-Choos, Mr Portillo? CHRISTOPHER STEVENS reviews last night's TV

• e-mail

Oysters are aphrodisiacs, nature’s Viagra, renowned for their potent invigorating effect. Michael Portillo certainly had his dander up, scattering innuendoes left and right after a visit to a historic Boston oyster bar.

Leaning across the counter to a burly oyster shucker, the man prising open the shellfish, on travel series Great American Railroad Journeys (BBC2), Michael twinkled: ‘Has anyone ever told you, sir, that you are a great shuck?’

Twisting apart another shell with a flick of his wrist, the beefy shucker didn’t flinch. ‘I appreciate that, sir,’ he said neutrally. Perhaps he’d heard the line too often from saucy customers — or perhaps they don’t do double entendres in Boston.

Luminous in his usual selection of neon lemon jackets and electric indigo slacks, with a peacock handkerchief erupting from his breast pocket, Michael appeared to be auditioning for the nudge-nudge, wink-wink award, first perfected in Bake Off.

On the show Great American Railroad Journeys, Christopher Stevens said: 'The pretence that this series has anything to do with trains has almost entirely been abandoned'

‘I’m intrigued by an entry in my Appleton’s,’ he declared, waving his ancient railway guide, ‘that the second largest organ in the world is to be found at Boston music hall.’ This he had to see.

When he discovered the organ, however, it was guarded by the ladies of the Handel And Haydn Choral Society, a most proper and God-fearing collective. Michael’s nerve left him, and he referred to the giant organ only as ‘an instrument’.

The pretence that this series has anything to do with trains has almost entirely been abandoned. Every day at teatime over the next four weeks, our dandy traveller will make his way from New England to the Canadian shores of the Great Lakes. This will involve rail travel, but it barely gets a mention: he might as well be going by car.

The frequent stops provide the entertainment, whether he’s inspecting a 19th-century loom mill or taking a ride on an underground tram. After a re-enactment of a rabble-rousing speech, from the start of the American Revolution, he was capering about and whirling a tricorn hat in the air. I don’t recall seeing him so excited at the Tory Party Conference.

Rushing down to the docks, to throw packages of tea over the sides of British cargo ships as they did in 1773, Michael was brought up short by one of the re-enacters. ‘Any of you revolutionaries,’ he boomed, ‘might really be a Tory spy!’

For a moment, Michael did look guilty. What did these Bostonians know of his past? Shrugging off suspicion, he picked up his bale of tea and hurled it . . . into the clear blue water.

Two hundred and forty-five years after the Boston Tea Party, the ‘special relationship’ between Britain and America was warmer than ever, especially on the deliriously daft Silent Witness (BBC1).

The ‘special relationship’ between Britain and America was warmer than ever, especially on the deliriously daft Silent Witness (BBC1) as Dr Nikki Anderson leapt into bed with a U.S. diplomat on her second date

Pathologist Dr Nikki Alexander (Emilia Fox) was taking time off from a murder investigation to flirt like mad with a charming U.S. diplomat . . . so charming that on their second date she leapt into bed with him.

Dr Nikki does have a lethal effect on boyfriends and, sure enough, no sooner had she slipped out of bed to the bathroom than her new beau had vanished, apparently kidnapped from between the sheets.

Our intrepid investigator ran to the front door and stared around in dismay, as though it was her dog that had vanished, not her lover.

Meanwhile, a tropical bug was doing the rounds. Everyone who contracted it was being murdered. Only a really nasty infection can bring you out in bulletholes.

The Americans wanted it all hushed up. ‘Unbelievable!’ groaned Dr Nikki’s boss. He can say that again.