Following the recent death of Alberto Sartoris, Professor James Ackerman's topic for the third annual Soane lecture, 'The Reinvention of Architectural Drawing 1250-1550', was poignantly appropriate. Just as Sartoris struggled to evolve modes of representation to communicate the new forms of Modernism, and as (with a certain sceptical reservation) we might think of present- day computer-imaging and Decon, so laboured the architects of the late Middle Ages and Renaissance.
Ackerman demonstrated the fruits of a long and diligent career. He contrasted Bernardo's drawings with one by Villard de Honnecourt, whose sketchbook of Rheims Cathedral dates from the thirteenth century. Its orthogonal projection, split between half-elevation and half-section, developed in the Gothic workshops of northern Europe, explained Ackerman, and 'was probably copied from an architect's drawing', although it is the earliest surviving example of this 'basic convention of architectural representation'. Villard's drawing may have had 'a lot of uncertainties', but within a very short time Peter Parler's drawings showed 'perfect measurements' in orthogonal projection, which is, of course, the advantage of orthogonal representation over perspective. By the next century, drawings of Strasbourg Cathedral showed how 'the mode of drawing and the linear style of Gothic go together perfectly'.
Three hundred years after Villard, Palladio used exactly the same technique of showing a building half in elevation with the other half cut to the interior. In between, however, orthogonal projection was rejected in fourteenth- century Italy. Drawings for the cathedrals in Orvieto and Siena are 'richly coloured and historicated' and pictorial, often adopting the shape of contemporary alterpiece frames. In the north, contended Ackerman, architects were trained in masons' lodges and architectural priorities dominated; in Italy painting dominated and most Italian architects started as painters or sculptors. Italians in the early Renaissance could cite Vitruvius's promotion of 'scenographia' while conveniently ignoring his inclusion of plan and elevation. As perspective developed ever greater sophistication it became more and more persuasive. Eventually, even in the north, it overwhelmed the Gothic tradition.
Alberti had cried in the wilderness that perspective's distortion of dimensions made it unsuited to be the only means of representing architecture. But not until Raphael wrote to Pope Leo X in the second decade of the sixteenth century, pointing out that by showing plan, external and internal walls you could 'consider minutely all parts of the building', was his warning heeded. Even Raphael backed down in a later version of that letter, and the limitations of perspective, especially to show fashionable, centrally planned and polygonal or circular buildings, became ever more apparent. Here were new architectural forms which a contemporary development in the pictorial field was unable to render satisfactorily, especially in describing dimensions and construction.
Fortunately Guiliano Sangallo showed more resolve than Raphael. His sketchbook built up sectional images from a plan to show the orthogonally correct position of columns and niches without foreshortening; rendering the plan, interior and exterior of a drum-like building in one picture still proved elusive. Not until the 1520s did Peruzzi, in a rendering of the Pantheon, combine the section and elevation as Villard had done, but for a building whose aesthetic ambitions were formal and spatial rather than linear, with dimensions derived from a plan.
The world Ackerman depicted seemed to have uncanny echoes of today. Architects striving for new forms picking up and forging new techniques of representation from all sorts of sources: those backward northerners or the photocopier. That certainly justified his closing contention, that our critical perspective of Renaissance architecture, so long dominated by proportional studies, might be enriched by considering the clash between painterly and orthogonal representation.