Seven Wonders of the Industrial World

BBC2, 9.00pm

French Leave C4, 8.30pm

Seven Wonders of the Industrial World ended last night as it began: as an exemplary exercise in historical documentary-making that ought to be required viewing for anyone

contemplating yet another series revealing how the Romans sank Atlantis while building Stonehenge as a giant barbecue pit.

The final instalment was everything except pretty. It solved the problem of merging drama with documentary (clue: give the actors a script that isn't carved out of plywood); it looked amazing, with lustrous special effects that did not compete with the narrative; and it told a tale that was more than a mere curiosity. The only pity, of no great moment, lay in the fact that the entire effort was dedicated to ordure.

Let's not be squeamish, however. Crap is important stuff. As the engineers of one council drainage department used to observe: ''It may be shit to you, but it's bread and butter to us.'' In London, in the 1840s, human waste was a matter of life and, rather more frequently, death. As the commentary observed, the most densely-populated city on earth was drowning in its own sewage.

Mercifully, smell-o-vision is not yet with us, but the beautifully-realised visuals of the piece conveyed quite enough of a sense, thanks very much, of how disgusting the great metropolis was. A population explosion and newfangled water closets had overwhelmed the old underground streams and culverts. Typhoid, dysentery, and cholera were rife. Worse, no-one even understood how cholera was transmitted, far less how to deal with it.

Some thought ye olde London miasma (fog) was to blame; advanced thinkers like Edwin Chadwick of the Poor Law Commission believed

that ''all smell is disease''. Chadwick then had the brilliant idea of flushing all of the sewers, and all their accumulated waste, into the Thames. The result was the worst outbreak of disease since the Great Plague. Step forward the great, unsung engineer Joseph Bazalgette, the Sewer King.

Uniquely in TV, this seventh wonder was shit of the highest order. A simple enough question - why do our cities no longer kill hordes of their citizens? - and a brilliantly engrossing answer. You could quibble over the presentation of history as a series of singular and heroic endeavours, but this series broke genuinely new ground. I couldn't have enough of it.

I have had enough, in contrast, of John Burton Race, his whining kids, their pastiche ''French experience'' and the contrivances of reality film-makers. If French Leave is anything to go by, it is no longer enough for a Michelin-starred chef to want to explore the greatest cuisine in the world and make some films on the subject. These days, even on C4, you have to drag in his mother-and-law, too.

Ostensibly, episode three was about the art of making decent bread. In fact, more time was wasted on a farcical

manufactured ''row'' over

mum-in-law Patsy's attempts to stuff the brats' faces with sliced Hovis and chocolate. Merde, in any language.