Abstract art tends towards architecture. The work of Naum Gabo, who studied engineering at the Technische Hochschule in Munich rather than fine art, illustrates this well. In his sculptures, immense stringed arrays demarcate space, following the complex curved geometry of their framework: a Constructivism of curves rather than straight lines.
The interlocked spiral ramps and oval plan of Lubetkin's Penguin Pool reflect a similar sensibility. Gabo himself tried his hand at architectural design, for example submitting an entry in the Palace of Soviets competition, with curved plan forms roofed by shells. Settled in England from 1936 to 1946, he was one of the editors of Circle with Leslie Martin and Ben Nicholson.
To those whose view of Gabo was shaped by the impressive Tate retrospective in 197677, this exhibition will come as something of a surprise. The Tate show, just preceding Gabo's death, displayed a succession of sculptural works of seemingly immaculate execution and natural or neutral colouring. The present show, apart from a single sculpture at its centre - a clear Perspex tower-like work from 1975, reminiscent of Le Corbusier's proposed cruciform skyscrapers of the 1920s - is devoted to drawings, paintings and monoprints, often highly coloured and roughly executed. They are not a well-known aspect of Gabo's work.
In the Realist Manifesto published in Moscow in 1920, the 30-year-old Gabo wrote: 'We renounce colour as a pictorial element? colour is accidental and it has nothing to do with the innermost essence of a thing.' But later he explained that there are two words meaning colour in Russian - tsvet, surface colour reflecting light, and faktura, the depth of colour absorbing light.
He had no quarrel with faktura. The colour in these graphic or painterly works can certainly be persuasive and distinctive, as in Turquoise - Kinetic Painting (1945) or the mauves of Enclosed Space (1968).
Another aspect of the Realist Manifesto is more directly illustrated: 'We renounce volume as a pictorial and plastic form of space? Look at our space - what is it if not one continuous depth? - We renounce mass as a sculptural element. It is known to every engineer that the static forces of a solid body and its material strength do not depend on the quantity of the mass? Thus we bring back to sculpture the line as a direction and in it we affirm depth as the one form of space.'
Enclosed Space does not suggest its converse volume, and the Sketch for a Carving in Stone (1930) conveys no sense of mass.
The reduction of mass was a common 'progressive' theme - found, for instance, in Sant'Elia's Futurist architectural manifesto, and in the writings of Le Corbusier (who nonetheless certainly retained a sense of volume). The meaning of space as 'one continuous depth' is not quite clear, but it may imply the kind of undifferentiated space-asbackground within which essentially linear motifs 'hover', as in Hovering (1940s-70s), or Opus 10 (1960s).
Such space came to have a spiritual quality for many abstract artists and can be felt to have had for Gabo.
But for those for whom a sense of mass lies at the root of sculpture, this mass-less sculpture is somewhat frustrating and hard to grasp emotionally. Perhaps the graphic media, with their essential linearity, did in fact suit Gabo's sensibility particularly well. You do not feel that the works in this exhibition are a tentative sideline.
James Dunnett is an architect in London