With Seif and Adham Wanly the difference, like the devil, is in the detail, writes Nigel Ryan Walking into Horizon One and wandering around its current show of works by the Wanly brothers it is difficult to resist speculating on just how the two really got on. Seif and Adham, with only two years separating them, Seif being born in 1906, Adham in 1908: what sibling rivalries sent them spinning in ostensibly the same direction but with such different results? Adham, though younger, is the one who signs himself Wanly. He has grabbed the family name for himself while Seif, the older, appears content to sign himself Seif. And this seems to be evidence of something -- a certain insecurity, perhaps, on the side of Adham; a degree of confidence on the part of the older Seif? On such flimsy foundations are detective novels built. Such triflings provide a more or less amusing diversion while wandering round the huge number of small scale works that comprise the show and, believe me, you will need the occasional diversion. These are tiny pieces, many no more than over-sized postage stamps, and it takes steady concentration to peer at the images drowning in their mounts, or else occasionally obscured by the reflections of the spotlights bouncing off the glass. Sporadic breaks are necessary. But there aren't that many red herrings: the show, even these small scale works (particularly, perhaps, such small scale things) makes the most important point abundantly clear -- Seif is far and away the better artist. In 12 square inches and 15 lines he can do a crowded cocktail party. With two felt tip pens and a grey wash he does Venice, or at least a view towards the Piazza San Marco. In a small drawing from the early 60s he manages, with three coloured pencils, a small crowd of solitary strollers across lawns beneath trees. And that is no mean feat. A small crowd, yet they remain solitary figures, and this on a piece of paper five inches by three. The lawn is reduced to several green dots: it is pointillism through the widest- angled lens possible. The trees are a hangover from the more schematised, design led paintings of the 50s, cubed patches of green with the odd fruit hanging. But mostly it is the paper that shows. There are no more marks than is absolutely necessary. It is a virtuoso show of discipline. The Exhibition of the Wanly Brothers: the titling of the show is unnecessarily misleading, implying a belated retrospective. But it is, in the end, an exhibition of off-cuts, of marginal notes. These are pages torn from sketch-books, doodles on the back of bills, on odd scraps of paper, dry cleaning receipts and scraps of opera house programmes. There is nothing large scale, and precious few pieces in oil or pastel (of the latter two most examples are by Adham). But being convincing on this scale requires immense skill -- rather more, in the majority of cases, than with things more overblown. There are occasional miracles of draughtsmanship: a café completed in two contrasting checks, one for the tiled floor, one for the table cloths, and little else. And this one really is a postage stamp, though a postage stamp with depth. There is a beautiful sketch of an oud player sitting on an elaborate arabesque chair -- one of those pompously weighty bits of Syrian furniture -- in what looks like black felt-tip. It is drawn on an old bill -- the calculation is clearly visible, the purchases having come to 148 piastres. And you can feel the heaviness of the wooden chair. Look at the musician sitting and you know exactly where the weight is distributed, on which buttock, on which foot. This is an old-fashioned skill, and one increasingly absent. Among the more whimsical exhibits are Seif's scribbles in the margins of musical programmes. A cellist -- a mad, cartoon cellist with hair flowing wildly and bow describing ever more frantic arcs -- ascends the blank space to the left of the programme. A more focussed portrait of the same occupies the right. Indeed, there are a number of musicians, some scrupulously identified. To the right of the gallery is an incisive line portrait with Pieter Sechlin, solo (piano) inscribed beneath. There are works from the 30s to the 70s (Seif died in 1979, Adham, much earlier, in 1959). Adham's works appear at once more contrived, more laboured, than those of his older sibling. At their best, in a small sketch of a village house with figures and a donkey, they echo Seif's spontaneity, but too often he overworks the image, dulling whatever edge it might have possessed. At his best, he is a convincing caricaturist, but one feels this was not quite enough to satisfy his ambition. Hence the laboured pastels of groups, savagely cropped, and seeming to invite unflattering comparisons. What worked in Paris in the 1890s looks jaded a half century on. Typical is a watercolour portrait of an unidentified peasant. It is a trying image from 1931, all wrinkled brow and folksy hat and peasant clothes, and if it recalls anything it is one of those notorious postcards produced in series during the teens and 20s of the last century under the title Arab types. Compare it with a portrait by Seif: close by hangs an image of a woman singing. It comprises a profile in black ink, a three- quarter view of the face, mouth open, the lips red on black, and then, floating over the right shoulder, a second, disembodied mouth, the same black outlined by a slash of scarlet. Without resorting to the kind of meretricious fiddle-faddle of his younger brother, but excluding all but the most telling detail, Seif manages to convey far, far more. He possesses an eye for the significant detail that his brother lacked. Adham, who manages fluidity occasionally -- there are two Sumo-type wrestlers occupying the bottom of a page of jottings to show what might have been achieved if only he'd stopped trying so hard to achieve -- all too often works and works and works and in the end fails to bake his cake for fear of melting the icing. Seif didn't even bother with the decorative overlay. He didn't need to. The exhibition is the first, apparently, in a planned series covering early 20th century Egyptian artists -- the pioneers, as they are rather nondescriptly referred to. It could be an exciting series of events, certainly if this show is anything to go by. Certainly, it was refreshing not to be the only person in the gallery: for once, it seemed almost crowded. That, perhaps, is the pulling power of a pioneer. For full details, see Listings