At an age when the Victoria and Albert Museum was incomprehensible, only the Natural History Museum with its dinosaurs and stuffed animals was a rival in the affection of children innocent of videos, computer games, drive-thru' burger joints and American-style superstores. True, the British Museum had mummies and "Ginger", the dead cave man, but as it was far off in Bloomsbury, its Grecian halls could not be visited on the same half-term holiday.
The Science Museum, like the V&A and Natural History Museum, was a spin- off from the Great Exhibition of 1851. Its charter, and one enthusiastically championed by Prince Albert (a prince for whom the modern world was to be embraced rather than scorned), called for its curator and trustees to exhibit great inventions in science, technology and medicine. It was to represent great moments in the past; at the same time it was to be a showcase of the new and challenging.
Over the years, it has become more a celebration of the past than of the present. The very building where its collection is housed is a dull, fusty and tightly buttoned example of chaste and late-flowering Edwardian Classicism (the Exhibition Road frontage, designed by Sir Richard Allison, dates from 1928). In other words, the architecture chosen to house the Science Museum was at best conservative, at worst retrogressive.
It does seem odd that, of all the great museums at South Kensington, the Science Museum has the drabbest buildings. Is it because the English have found science so boring (school teachers loved to make it boring; hopefully this is not true today) that the design of the Science Museum was handed over to dull architects? Maybe. Our fascination for (if not love of) wildlife produced the exuberant architecture of the Natural History Museum (Alfred Waterhouse), while the bravura skyline of the V&A (Captain Francis Fowke) demonstrated the wealth and ambition of the decorative arts brigade.
The situation seems bizarre today, when our interest in science is accelerating as rapidly as the high electrostatic potentials in Mr Van de Graaff's celebrated device. As the Science Museum has grown old, its exhibits have aged with it. Stephenson's "Rocket", the 3,300hp English-Electric "Deltic" diesel, and even the magic-eye automatic door that children once had to be prised away from, no longer seem at the cutting edge of British science and technology.
The news that the Science Museum is to build a new wing dedicated to contemporary science, technology and medicine comes, therefore, as a pleasant surprise. The Wellcome Wing, costing pounds 45.5m (pounds 15m from the Wellcome Trust, pounds 6m from other private and museum funds and the rest, presumably, from the lottery), will open in 1999. Its architects are MacCormac Jamieson Prichard, whose most recent designs include the superb Cable & Wireless College in Coventry, a fascinating Modern-meets-Classical extension to St John's College, Oxford and the new Underground station that, when open in 1998, will serve the up-and-coming Tate Gallery of Modern Art at Bankside.
The choice is an inspired one; Richard MacCormac and his team (including the engineers Ove Arup and Partners) will bring considerable intelligence to the project, creating a gallery that will not only house, but enhance the proposed exhibits and displays. Finally, the Science Museum will have a building that matches its own collective intelligence and which will reflect our own increasing fascination with modern science.
The Wellcome Wing will, however, be largely hidden from view. Although big, it will be tucked away at the west end, or back, of the museum, a site currently littered with an assortment of ramshackle huts and other temporary buildings. The whole point of the new building, however, is that it will come as a thrilling surprise to visitors (1.3 million a year) after they have made their way through the old Machine Hall and the older galleries.
What visitors will see is a potentially breathtaking interior space: they will enter the new wing and look up from its belly to its brain, catching sight of the metal skeletons of floor after floor cantilevered like a series of trays from solid walls. The wing will be dominated by an IMAX cinema screening 3-D films and other presentations.
Here, in this new wing, we will all be curious children again, rushing to see the latest inventions presented through the latest curatorial technologies. And, yes, for true museological cranks, there will be buttons to press.
"It was a historical inevitability," says John Durant, deputy director of the Science Museum and the man in charge of the new wing, "that the Science Museum would end up addressing the past rather than the present and future. As museums' collections expand, more time and energy has to be spent on conservation. Given our very limited funds, we have had to watch, not altogether hopelessly, as time has overtaken the museum.
"In fact, we've been watching for a long time; the Bell Committee of 1911 recommended that the government help the museum fund a new wing devoted to contemporary science and technology, but the money never came. Perhaps, though, the wait has been worthwhile, because we can now create an impressive gallery where all the wonderful new techniques in museum presentation can be brought together and used to full effect.
"What can you expect to see? Displays demonstrating the most significant developments in contemporary bio-medicine, bio-technology and artificial intelligence. We aim to guide visitors through the very latest in communication technology.
"All those questions we hear people ask - when will computers talk like HAL in 2001? can we transfer our thoughts into a computer without a keyboard? how far can we go with genetic engineering? - and many, many more will be explored and, as far as possible, answered."
Those for whom the modern world and all its sciences and technologies are evils can relax: the Wellcome Wing will not take away existing exhibits. Boulton & Watt pumping engines, veteran aircraft, models of "Battle of Britain" Pacifics, the big Van de Graaff generator and assorted inscrutable machines that go "ping!" will not be zapped by the forces of contemporary science.
The only sad thing about this particularly welcome wing is that we will have to wait at least another three years before we can rush in, press buttons, crank handles and, in so doing, come closer than ever before to the secret of how we ourselves are cranked into action.