Each will contain displays inspired by concepts of time, including past present future and even the more subjective dream variety. All will be designed to capture the imagination of visitors to Britain's projected year long exhibition to celebrate the arrival of the year 2000.

The Government , through the Millennium Commission which distributes state lottery profits, has pledged £200 million for the enterprise, depending upon continuing adequate private sector partnership funding to meet the estimated £700 million cost of putting on a show capable of receiving 100,000 visitors daily.

The designated 120 hectare former gas works complex, where it will all take place, is appropriately crossed by the Greenwich prime meridian, the starting point for the 21st century from which the world's time zones are calculated.

Transformation of the derelict site into a venue for a display, which has Precedents in the Great Exhibition of 1851 and the Festival of Britain which gave the nation a break from post- war austerity a century later, will mark the end of a decade in which planners are working to realise the Thames's potential.

Public forums organised by the Architecture Foundation for Londoners to debate their capital's future began in January. Lively exchanges revealed some appreciation gaps between public and experts . One leading architect (Sir Richard Rogers) good naturedly submitted to hearing one of his works described as a "monstrosity" by a member of the capacity audience of some 2500 at Westminster Central Hall.

One evening was devoted to the 150 km 1ong Thames, which most, including the Environment Secretary, John Gummer, felt had been neglected both as a recreational amenity and a working waterway where it bisects London.

South Bank Development
"I want London to achieve what it never managed even in medieval times; to make the south bank of the Thames an integral and vibrant part of the capital " he said.

Unlike the Seine in Paris, the river bank is largely in private hands, although this has not prevented a path on the south bank being progressively lengthened over the past five years.

The 1990s have become the decade of the Thames, just as the focus during the 1980s was on the east London docklands business and residential area dominated by the 60-storey Canary Wharf tower, and the 1970s saw pedestrianisation extended and the creation of piazzas like that at Covent Garden where outdoor restaurants and speciality shops have replaced the vegetable market.

The catalyst for making better use of the Thames is the Cross River Partnership, an initiative launched in May 1995 involving London boroughs, employers, transport and port authorities.

The partnership is one sponsor of an exhibition at the Architecture Foundation in London of scale models and drawings of imaginative projects, including some for which Millennium funding is now being considered. Displays will continue there until July at the foundation's Bury Street headquarters where visitors can express their approval or outrage in a video box for viewing at a symposium to be held later this year.

Cable Car
Among the most adventurous on show is a cable car linking the Royal Opera House in Covent Garden with the South Bank arts complex which in turn would be part covered by a rolling glass canopy alleviating the bleak concrete brutalism of the walkways.

Another proposal is for an inhabited bridge featuring shops and cafes, linking St. Paul's Cathedral with the new Tate Gallery of Modern Art on the south of the river now being converted from the existing redundant power station with the help of £l08 million of Millennium money. Less controversial are plans for a cross-Thames tramway system linking Waterloo and King's Cross stations.

While imaginations soared at the forums with calls for more Thames-side jetties landscape gardens, and a properly funded riverboa t service , environmentalist were more concerned with sustainability.

Herbert Girardet, the environmental writer, wanted to see more cycle routes and the Iining of new buildings with photovoltaic cells to conserve energy, Nicky Gavron, chairwoman of the London Planning Advisory Committee , deplored the waste of waste. London still buried, burned or dumped at sea most of it, she said, instead of regarding it as a resource which could serve a "green" recycling industry empleying the latest technology.

Michael Cassidy, policy chairman of the Corporation of London, which is responsible for the capital's famous financial square mile, drew attention to a new study which London Transport had commissioned from a team at the London School of Economics. It concludes that some big cities, including London, despite transport and pollution drawbacks, are often the best settlements for boosting national economies.

It describes London as an "agglomeration economy" in which firms enjoy increased productivity by locating close to a pool of qualified labour and other enterprises with which they do business. Such advantages, including the opportunity for face to face contact, the report states, outweigh the extra cost of city location and it even suggests indirectly that. the arnenities provided by "agglomerations" can contribute to human happiness.

This view was adopted by Mr Gummer who chided the "moaners and groaners" for failing to appreciate the capital's scope for an exciting future.