ART / Along roughly democratic lines: The Tate has dusted off some old drawings and watercolours: a mixed bag that contains plenty of jewels

IS THERE any period that we can confidently call a great age in British drawing? It's not today, everyone will agree, and few people will say that work on paper was of great importance in the classic, country-house centuries of pomp and portraiture. I think drawing was at its height between 1780 and 1830; but at the Tate, a case is being made for a quite different epoch, the years between late Victorianism and modern art.

Not that the organisers of Beardsley to Bomberg: British Drawings and Watercolours 1870-1920 have any desire to be argumentative. On one level, this is simply an anthology from the Tate's collections, worth seeing because the sheets are rarely on public display. Yet the show does make a point, in the first place by virtue of its size. All three of the lower galleries in the old British wing have been used and there are drawings by more than 60 artists, a number of whom have no especial place in the history books. This is welcome and historically justified. For if the period was short on genius there was compensation in the form of quantity. This was drawing's democratic age.

Hundreds of artists, professional or amateur, made their observations on the world. But the show is short on the drawing generated by the new media, newspapers and periodicals that used draughtsmen to enliven their pages. A pity that such material has not found a home on Millbank. Meanwhile, there's a drawing by Phil May and two by George Belcher - who does have a historical place, for in 1946 he was the first humorous artist to be elected a Royal Academician. Belcher's drawings are in the Punch mode, but none the worse for that.

I don't like the manner of Edwin Austin Abbey's illustration to Sally in Our Alley - while Belcher has the right kind of vulgarity, he has the wrong kind - but Abbey's career shows another aspect of the period, American artists making it on the British scene. He was a redneck staffer from Harper's magazine who got to paint Edward VII's coronation picture. There's democracy for you. Of Abbey's countryman, Whistler, there is no sign in this exhibition, except in the form of influence. Arthur Melville, who was one of those travelling Scottish landscapists, contributes a thoughtful, Whistlerian view of Venice.

Melville's picture looks the more impressive because it is placed next to five watercolours by John Singer Sargent. Here's an American whose attempts to be posh fell to the ground when he used a lighter medium. The Sargent touch did not translate from his bold and unctuous pigment. The whole exhibition shows watercolour was poorly equipped to deal with the modern world. No wonder the end of the 19th century produced anti-watercolour artists, of whom the most powerful was Aubrey Beardsley. He blackened the character of watercolour. Atmosphere was banished, colour negated, line asserted over touch, and all in the evident service of night. We know his art through the reproduction for which it was always destined, so a sight of the originals is exciting. It looks as though he pored over them, carefully rubbing and scraping at his gouache surface, probably by lamplight and with the devil whispering in his ear.

Beardsley's death in 1898 robbed the dawning century. It is conceivable that his sexual and theatrical themes might have matured. And he could have developed his command of design in flat areas, making art on a larger scale than illustration allowed. One can't imagine him becoming repetitious, like his contemporary, Arthur Rackham. This unforgettable draughtsman, employed in the same ways until his death in 1939, became what we nowadays call a trademark artist. But his 1904 Dance in Cupid's Alley is from the height of his imagination and virtuosity - a weird and sinuous little symphony from goblinland.

These two seem aeons away from the work of, for instance, Beatrix Potter, who is represented by all her drawings for that over-long book The Tailor of Gloucester. This is not to say that Potter was cut off from her times. Her style is a neat amalgam of influences from contemporaries such as Crane and Caldecott; and she shared the aesthetes' desire to make a page that showed a new marriage between text and picture.

Rackham's and Potter's palettes were calculated to reproduce well in book form. So were the pale tints, generally green but with splashes of copper and sky-blue, that we find in Max Beerbohm. He dominates the Illustration section because the Tate happens to possess the original artwork for his publication Rossetti and his Friends. He was one of the first people to find the great Victorians funny, but Beerbohm's gift was not confined to making fun of the literary and artistic giants of the previous generation. Like many gossips, he was good at taking notes. He must have studied the Rossetti circle with care. Otherwise he could not have done his trick of treating their achievements as foibles. The result is cheeky, but poignant too. Beerbohm brought a note of lamentation into portraiture.

One thing he lamented was the slender scope of his own talent. He was less naughty than wistful. However ludicrous the Victorians, their gifts were on a massive scale. Many drawings by turn-of-the-century artists have a thin and reedy look, as though there were not enough personality behind the pen or brush. The fading strains of Pre-Raphaelitism are exemplified by Augustus John - a personality indeed, but on paper a hesitant portraitist. We all know his sketch of Yeats, so often reproduced with the poems. The drawing, though, feels helpless. John got his subject's face, his likeness, but could not continue and signed off with wisps.

The exhibition does not make much of the modern movement, though there are useful sections devoted to Sickert, his follower Bomberg, Mark Gertler, Henri Gaudier-Brzeska and Camden Town painters such as Charles Ginner and Spencer Gore. The Sickert drawings make one wish all the more that his work on paper had been included in the present retrospective at the Royal Academy. Gertler's portrait of his mother is an affecting work, but we don't really have more than a glimpse of the contribution to British art made by the Camden Town group. No doubt that's because they were primarily painters rather than natural draughtsmen, as may be seen from the way that Harold Gilman squared up his drawings for transfer to canvas.

What is more depressing than a squared-up drawing? I prefer middle-of-the-road paintings that tend towards hedonism to good exam results, and find pleasure in William Orpen's The Model, of 1911. Orpen could paint rings round his comrade Augustus John, or those descriptive dullards from NW1. The Model has some of his qualities: it's too subtle and clever to be merely masculine; it's bluff but not boorish; and the model tells us that her silly old painter is in a happy world of his own.

'Beardsley to Bomberg' continues to 14 Feb (071-821 1313).