MONET is a magic name - certainly the public's favourite. London's last Monet blockbuster (at the Royal Academy in 1990) produced record attendances of 800,000 and queues round the block. The new National Gallery show, London's Monets, until May 5, comprises a mere 25 pictures, but it is an absolute gem and merits a ''must see'' on anyone's list.

Small is often beautiful and these two rooms lined with ravishing Impressionist pictures are more than enough to take in on one visit. Moreover you won't have to queue - and it's free.

These 25 oils span Monet's entire six-decade career: from an early delicate coastal scene painted outdoors from the beach near his hometown of Le Havre, when he was in his early 20s via impressionism - right up to the large late semi-abstract Water-lilies from a few years before his death in 1926.

London is often wrongly accused of lagging behind Paris and New York in the big art exhibition league. In fact, recent years have seen a plethora of exciting, top-class shows. Moreover, the National Gallery almost single-handedly provides a surfeit of superb displays (currently Monet; young Gainsborough and Mahon Collection of Italian Baroque). All come complete with the supreme advantage of perfect presentation, clear labelling, and fascinating documentation (not too much or too little) and always written in straightforward English.

This may seem obvious, even essential, but is all too rare. Exhibition ''interpretation'' is fast becoming a boom industry, with curators wielding huge personal power. Getting the balance right while avoiding the dogmatic, the patronising or elitist gobbledygook is very difficult. The National Gallery definitely leads the field in clarity.

Organised to highlight the sensible rationalisation and exchange of nineteenth and twentieth-century pictures between the National and Tate Galleries, (taking 1900 as a dividing line) before the re-arrangements, this show gathers together all the Monets in London: from public galleries including the Courtauld plus seven in private hands including the Queen Mother's bold and uncharacteristically sombre Study Of Rocks in the Massif Central from 1889.

That London has any Monets at all is a miracle. To say the British didn't like Monet is an understatement. After having refused several gifts of Monet's paintings, as late as 1914 National Gallery trustee, Lord Redesdale even opposed the idea of a loan, saying: ''I should as soon expect to hear of a Mormon service being conducted in St Paul's Cathedral as to see an exhibition of the works of the modern French Art Rebels in the sacred precincts of Trafalgar Square.''

The British reluctance to buy his pictures is the more surprising in the case of Monet's many memorable views of the Thames and the Palace of Westminster. Monet first came to London in 1870-71 to avoid the Franco-Prussian war. The Thames Below Westminster 1871, a luminous, misty, and romantic picture of distant spires, tugboats, and rippling pearly water, was painted from the Victoria Embankment.

Monet was a frequent visitor to London's National Gallery, where he discovered the works of Turner, becoming quite a fan. The influence of Whistler's simplified foggy London views can also be seen in this picture, along with the asymmetry of Japanese art, so popular with all artists of the period.

Monet returned to London many times ''to explore the colouristic possibilities offered by the city's spectacular pollution'', says director Neil MacGregor (remember it was the era of the pea-souper) and the Thames at Westminster became his favourite subject around 1901.

On his return to Paris Monet quickly became a seminal figure in the Impressionist movement and along with Renoir, Pissarro, Sisley, and Degas took part in the controversial 1874 First Impressionist Exhibition held in a former photography studio on the Boulevard des Capucines.

A critic named the group ''impressionists'' after the title of one of Monet's paintings, Impression: Sunrise. Thus was born the most popular art movement of the past 100 years.

The National Gallery show includes typical sunlight river scenes, The Beach at Trouville (peppered with grains of sand - proof it was painted on the spot! ) a smoky Gare St Lazare, and examples of his huge series of haystacks and poplar trees seen at various times of the day.

Lavacourt Under Snow 1881, which captures the sparkle of light via pink and blue crystalline paint flurries, was one of the pictures originally turned down by the National Gallery.

By 1888 Monet was in Antibes, setting himself the challenge of capturing intense southern light heat and colour. ''It's so difficult, so tender and so delicate, while I'm so inclined to brutality,'' he wrote.

Eventually, satisfied with his efforts, he concluded: ''What I bring back from here will be sweetness itself, white, pink, blue, all of it enveloped in this fairy-tale-like air.''

By 1891 he had acquired his own personal paradise, a fairy-tale home at Giverny on the River Epte where over the next 20 years he created his beautiful water garden and lily pond which provided endless inspiration for a huge number of wonderful paintings: first the Japanese bridge dripping with wisteria, then the free-floating lilypads with their decorative calligraphy and colourfield harmonies.

Despite their easy semi- abstraction, these late pictures drove Monet to distraction and were often the result of long and laborious efforts to try to capture the endlessly shifting nuances of light and shade.

The show is accompanied by the perfect, fully illustrated slim volume - cheap at #3.99 - you can also visit the National Gallery's computer information room, The Micro Gallery, to play on the computer touch screens and pay #1 for a card to print out some basic - very basic - information.

Ok for fifth formers but I recommend you buy the book. I learned yesterday that the exhibition, open a mere week, has already attracted almost 100,000 folk towards its annual 4,000,000 visitors.

nLondon's Monets, sponsored by Merrill Lynch, runs until May 5. It is open 10am to 6pm with late night Wednesday until 8pm.