An alibi for pleasure: Sadly for Mr Blair the copyright he craves has already been claimed

In 1824 construction began on a pleasure dome on a site between Albany Street and Cambridge Terrace, on the fringes of Regent's Park. It was eventually to be called the Colosseum and it was conceived on a suitably grand scale. Designed by a young architect called Decimus Burton, its central feature was a rotunda with a dome 30 feet wider than St Paul's and 112 feet high at its apex.

There was no controversy about what it would contain. It had been specifically constructed to house what was then the largest panorama ever painted - a 134 foot diameter depiction of the view from the very pinnacle of St Paul's (the painter, a topographical artist called Thomas Hornor, had actually constructed a hut above the cross and ball of Wren's cathedral, mounted on precarious looking scaffolding). No less than 46,000 square feet of canvas were to be covered with a meticulous representation of every street, facade and rooftop visible from that vantage point.

By contrast with the Millennium Dome, of course, the Colosseum was a relatively modest enterprise - its expanses of daubed canvas a mere pocket- handkerchief alongside the prairie of Teflon-coated fabric which will soon be hoisted into position south of the Thames. But if the architectural dimensions (not to mention the building costs) show evidence of inflationary pressure there is still a kind of kinship between Horner's enterprise and Mr Mandelson's great adventure.

When the contents of the Millennium Dome were unveiled last week, to the accompaniment of a bracing sermon from the Prime Minister on the virtues of positive thinking and the vice of cynicism, it was striking to see how traditional they were. The carapace of the exhibits might look futuristic and the inner-workings might be technologically advanced but the essential spirit - that of improving spectacle - strikes a much more venerable note. Its showmanship is essentially Victorian and almost every exhibit strikes some kind of echo with the didactic attractions of Victorian London.

Take Wyld's Great Globe, for example, a commercial spectacle constructed where Leicester Square is now situated. This huge hollow sphere carried on its inside surface a relief map of the world (constructed from 6,000 plaster casts - the Victorians were as fond of breathtaking statistics as we are today). Spectators entered through Antartica and could view the surface of the world - including the satisfactory evidence of expanding British dominion - from a series of viewing platforms. The Great Globe was so unimpeachable a recreation that even that most extreme fundamentalist Philip Gosse took his son Edmund to see it, just as, one imagines, dutiful parents will guide their children through the carefully de-sexed colossus that will house the Dome's Body Zone.

Browse through Richard Altick's wonderful account of Victorian entertainment, The Shows of London, and you are repeatedly struck by the same blend of education and recreation that characterises the Dome exhibits, its presentation of knowledge as a grand day out with the added bonus of self-improvement. The Victorians were peerless at the creation of such diversions, in particular at exploiting the way in which information could provide an alibi for pleasure.

This was a period, too, when a place of public resort could be called the Polytechnic Institutes (their big draw being a diving bell in which intrepid visitors could undertake a total immersion experience) and when the oxyhydrogen microscope - a device which could project magnified slides - was as indispensable an attraction as a virtual reality headset. Sometimes the desire to feed the public's appetite for edifying novelty took rather peculiar turns - as with Richardson's Rock Harmonicon, an instrument modelled on the xylophone and constructed (over a period of 13 years) by a Cumberland mason, who carved each stone key until it gave the right tonal response to being whacked with a mallet. The repertory included extracts from Beethoven, Rossini and Haydn and the instrument was played by Richardson's sons, who billed themselves as "the Original Rock Band". Had they been around today they would almost certainly have been invited to a Number Ten drinks party.

And if the Dome is essentially Victorian in its attitudes - a cathedral to technological optimism and social improvement - it is surely consistent with the overall moral tone of the current government. Listen to Tony Blair in almost any speech and you can hear the exhortatory prose of Samuel Smiles, the very first guru of self-help. "It is the men that advance in the highest and best directions, who are the true beacons of human progress", wrote Smiles in an essay on Character. "They are as lights set upon a hill, illumining the moral atmosphere around them; and the light of their spirit continues to shine upon all succeeding generations".

Change a few words here and there and you would have a Blair speech about Britain's role in the world, gleaming with inspirational lighting effects. Even the rather preachy invitations to look upon the future with muscular confidence have their counterparts in Smiles' positivism: "The habit of viewing things cheerfully, and of thinking about life hopefully, may be made to grow up in us like any other habit", Smiles wrote in his best- seller Self-Help. "It was not an exaggerated estimate of Dr Johnson to say, that the habit of looking at the best side of any event is worth more than a thousand pounds a year." Hoping to persuade journalists to look at the best side of the Millennium event, Blair struck a very similar note of bootstrap philosophy.

In my view this isn't necessarily a bad thing - you have to go a long way to find a society as dedicated to the idea of steady amelioration as the Victorians, or a time in which there was such optimism about the susceptability of human problems to the energy of individual citizens. Some of it was misguided, some of it mendacious, but we've coasted on their legacy through a large part of the current century - using but not repairing their drains, allowing their rail networks to die back from a branching profusion, impoverishing their galleries and museums.

If we are to succeed in the next millennium there are far worse models we might look to. When the 1951 Festival of Britain was in full swing much was made of the historical coincidence of another Elizabethan age. Past historical glories were enlisted as a galvanizing example for future efforts. The only problem for the Labour party - as Victorian a government as we have had for years in its moral sternness and occasional fits of priggishness - is that they can't easily do the same thing. Someone else beat them for the copyright on Victorian values.