Why is the Eiffel Tower like the Forth Bridge? Both are miracles of civil engineering built in 1889. Why is the Forth Bridge not like the Eiffel Tower? They've stopped repainting the Forth Bridge. Jonathan Glancey reports.
Every seven years, the Eiffel Tower is repainted from iron top to iron toe. This year is the 17th of those seven. Throughout the summer, and until early next year, visitors to Paris will be able to watch the gravity-defying antics of a school of French painters whose work, while it will never hang in the Louvre, is essential to a city that has long sold its art hard to culture-hungry tourists.

Visitors to the 116-year-old tower can gawp at painters hanging from safety lines and looking, for all the world, like itzy-bitzy spiders climbing up and down some titanic web.

Each of the 25 spidermen dabs thick coats of brown paint on to the iron members of the tower with an old-fashioned brush. Sprayguns would be wasteful of paint and anti-social too: pigeons, tourists and Parisians scurrying in the shadow of the tower would end up looking like lesser- spotted characters from some vast, artless pointilist canvas.

The spidermen do more, in fact, than paint. While hanging from Gustave Eiffel's masterpiece, they also scrape, clean, grind and polish the tower's struts and girders in a rigorous, if tedious, maintenance routine which, when the paint is finally applied, will keep the 321-metre (1,052ft) symbol of Paris in tip-top condition, until the process begins all over again in 2002.

The press office at the Eiffel Tower says, charmingly, that "the Dame de Fer continues to be cosseted like a child," which seems only right and proper. How unlike - how very unlike - the fate of our own, dear, Forth Railway Bridge, exact contemporary of the Eiffel Tower and an equally inventive and sublime work of late 19th-century engineering.

British Rail, or Railtrack, or whichever Mickey Mouse operation now owns the Forth Bridge, has decided that it does not need to be painted on a continuous basis. Until last year, it had always been considered all but essential, maintaining a great British myth and keeping the famous bridge looking perpetually new. The argument for not painting it is that the Forth Bridge is a tough bit of steel and will survive perfectly well without being cosseted. Even if this is true, Paris knows differently: a shabby Eiffel Tower would be a mark of shame on a city that prides itself on the opulence of its tourist quarters.

What is odd is that the shabbily treated Forth Railway Bridge, when built, was applauded by people of all classes - first, second and third - while the cosseted Eiffel Tower was savaged by public and experts alike when it opened, as centrepiece of the great Paris Exhibition of 1889. It was reviled more than ever the Pompidou Centre was 90 years later; more so, in fact, than any major monument that went on to become universally admired. The reviled tower was to become the mainspring of French tourist brochures.

A century on, it would take a perverse soul to damn Eiffel's design. The great engineer, who died in 1923 at the age of 90, was one of his own fiercest critics: he always regretted having to add fancy filigree frocks of superfluous decorative iron to the basic structure of the tower to keep officials happy. The spidermen repainting the tower this year would probably agree: the unnecessary decorative panels that hang from the bottom stage of the tower add many hot days to their task.

Watching this great machine-for-viewing being revamped is a true pleasure in an age when the words "maintenance" and "repair" have become as antique as the tower itself. So after dropping in to the Louvre to say bonjour to Mona Lisa, and zut, alors to blue ladies in the Musee Picasso, take the lift up Eiffel's tower and enjoy one of the best paintings Europe has to offer this summer