Ferdinand Bauer, greatest of botanical illustrators, a study in colour

The question of colour in natural history illustration is the focus of a small but absorbing exhibition.

Rainbow lorikeet (Trichoglossus haematodus moluccanus) by Ferdinand Bauer (1802).

Almost exactly 350 years ago, the French Academy was riven by controversy. What were meant to be courteous and scholarly monthly debates about the principles that lay behind the finest art of ancient and modern times were increasingly overtaken by squabbles about the relative merits, indeed the primacy, of line and colour in the practice of painting.

The so-called “quarrel of colour” of the 17th century went back to the rivalry, more than 100 years earlier, of Michelangelo, representing the Florentine-Roman mainstream school of painting, and Titian, the leader of the Venetian school, which stood for the most prominent alternative approach.

The proponents of line maintained that correct drawing was the basis of art, while colour was merely an additional ornament, and they held up the great works of Raphael and Michel­angelo as evidence. The proponents of colour maintained that drawing alone was sterile without the chromatic realisation that seemed so magical in the art of Titian that centuries later Rubens, Rembrandt and Reynolds were all striving to fathom his secrets.

At the Academie Royale de Peinture, the figures of Michelangelo and Titian were soon updated to the more contemporary examples of Poussin and Rubens, but the respective positions remained broadly the same, merely teased out in more explicit terms. And even though everyone ultimately agreed that both were indispensable, the rivalry of line and colour proved remarkably persistent, embodied later in the opposition of Ingres and Delacroix, and even implicitly in that of Picasso and Matisse.

But the quarrel of colour in fact goes back to an even earlier Renaissance rivalry, that of ­Michelangelo and Leonardo, which led to a debate over the relative merits of sculpture and painting. In what became known as the para­gone, proponents of sculpture held that three-dimensional form was superior to painting’s flat images, but supporters of painting claimed mere form without colour was lifeless. Cover your best friend’s face in flour, they said, and you would not recognise him. It was colour that made images seem to live and breathe.

This debate explains why Rubens was obsessed with the rosiness of cheeks and lips, the moisture of eyes, the semi-translucent lustre of hair and beards. Whereas the harshest opponents of colour at the academy tended to dismiss it as akin to a harlot’s face painting, others saw it as the essence of the illusion of life itself.

Ferdinand Bauer’s southern pygmy leatherjacket (Brachaluteres jacksonianus).

We cannot be sure of the extent to which these debates affected the thinking of artists working in more functional and illustrative genres, such as natural history painting. But it seems hard to believe that ideas that were so pervasive in the theory of fine art could not have affected the consciousness of anyone involved in the practice of painting. And the case of natural history painting is particularly striking, for while it is crucial to delineate a plant, an insect or a flower with the utmost accuracy, it is almost equally important to capture the precise chromatic effects that define its living character.

This question of colour in natural history illustration is the focus of a small but absorbing exhibition at the State Library of NSW, which serves as something of a tip of the iceberg of an ambitious online exhibition in the form of a comprehensive database, and is also accompanied by a beautiful and scholarly publication by David Mabberley, Painting by Numbers: The Life and Art of Ferdinand Bauer.

The two exhibitions and the book are specifically focused on the life and work of Bauer (1760-1826), often considered the greatest of all botanical illustrators. He came from an artistic family in what was then Austria, was orphaned at an early age and subsequently trained, together with his two brothers, by a remarkable natural scientist and cleric, Norbert Boccius.

Even before leaving the continent, Bauer had achieved fame for the remarkable accuracy, character and feeling of his botanical drawings. Later, in London, he attracted the interest of ­Joseph Banks, who arranged for him to accompany Matthew Flinders on his circumnavigation of Australia in 1802-03. There was a vast amount of work to do, in a new world teeming with plant varieties that needed to be recorded and classified, and above all this work had to be carried out in a very limited period of time.

When great numbers of new flora and fauna could be gathered in a single day, it was not easy to study them and execute comprehensive drawings before specimens perished, withered or dried out. Clearly — recalling the line and colour debate — the first priority was to draw the characteristic morphology of each specimen. Colour would often have to be added later, when there was more leisure. But at the same time, colour was essential to the vital character of each plant. It was imperative for it to be accurate, and yet the colour of specimens would soon fade and memory or verbal descriptions in notes would be grossly unreliable.

A facsimile of the Feldsberg chart from Haenke’s colour chart.

The solution, already adopted in his earlier work by Bauer and foreshadowed by other scientists since the 17th century, was to make up a chart of colour hues that could be referred to by numbers. With the aid of such a chart, drawings could be completed in watercolour much later but with relative accuracy.

The structure of these early charts was, however, empirical compared to later theoretical developments in the 19th and early 20th centuries, which eventually culminated in the Maunsell system of defining ­colourspace in the three dimensions of hue, value and chroma: hue being the difference between, say, yellow and orange on a circular ­colour wheel, value being the darkness or lightness of the colour, and chroma its intensity or saturation.

An example of the late-18th-century charts is included in the exhibition: a facsimile of the colour chart used by Thaddaeus Haenke, another botanical artist from the Austro-Hungarian Empire, who drew it up around 1785 and took it with him on an expedition to the Pacific in 1789. Quite possibly also used by Bauer at the start of his career, it is a beautiful and impressive tool for a natural history artist, comprising 140 colour patches in seven rows of 20.

The colours of natural things like flowers and insects are, however, almost infinitely varied and subtly different from each other, and even a range of 140 colours would not be enough to account for all the significant nuances. And this is where Bauer’s system is particularly astonishing, because his drawings are annotated with colours numbered up to 999, and these were supplemented by other signs and annotations, presumably recording shades, textures or transitions.

Passionflowers, London, by Ferdinand Bauer (c. 1794).

But Bauer’s chart was for a long time a mystery of science, because the document itself has not survived, and may never even have existed as a physical chart — that is to say Bauer may have held this whole system of more than 1000 colour variations in his head.

This would mean that he possessed a prodigy-like understanding of the dimensions of colourspace, analogous in a way to Michelangelo’s unprecedented and unequalled feeling for three-dimensional form, or indeed Leonardo’s understanding of movement.

But even if Bauer had actually taken the trouble to draw up a chart of 1000 or perhaps many more separate colour patches, the complexity of the system and the subtlety of the differences between hues would have made its use slow and cumbersome. The speed with which he evidently worked suggests, amazing as it may seem, that he was referring to his grid of colours from memory.

A couple of decades ago, scientists started putting clues together systematically, matching Bauer’s numbers with watercolours that he had actually completed as well as with samples of the plants or creatures whose colours he had recorded numerically — as in the annotated drawing and later painting of a parrot on pages 100 and 101 of the book.

Port Lincoln ringneck (Barnardius zonarius) by Ferdinand Bauer.

Thus the code was eventually cracked, and the exhibition contains a remarkable practical application of this achievement: Marion Westmacott, a contemporary botanical artist, was able to reconstruct the appearance of a now extinct plant, Solanum bauerianum, based on Bauer’s original drawing, by filling in the colours on the basis of his numerical code.

The exhibition also includes many drawings, watercolours and prints that evoke the botanical passion of the time and the setting of early colonial Australia. Particularly notable are a couple of beautiful original watercolours by Bauer, one from a private collection and another recently rediscovered, and both published for the first time in Painting by numbers.

Mabberley’s book is not only an outstanding work of scholarship but a pleasure to read, and gripping both in its discussion of technical matters such as colour tables and in its evocation of the world of botanical scholarship two centuries ago, when scientists were also travellers and adventurers. Thus, before Bauer joined the Flinders expedition, he had already accompanied the young Oxford professor John Sibthorp on a journey through the eastern Mediterranean that resulted in the magnificent and extremely rare publication Flora Graeca (1825-40).

As important as the book and more durable than the physical exhibition is the online version or website that has been created as a way of making Bauer’s drawings accessible to the Australian and indeed international public, for most of the originals are held in Vienna.

The website has been designed to be easily searchable in an intuitive manner, and to provide expandable high-resolution images of Bauer’s extant work — mostly held overseas — so that in effect each drawing or watercolour can be examined more closely and better appreciated than in any other way, apart from studying the original with a magnifying glass.

This approach to displaying Bauer’s work is particularly appropriate not only to the scientific nature of the subject, which requires close examination, but also to the aesthetic of his work, in which both the refinements of descriptive drawing and the chromatic subtlety of the colouring have to be appreciated as the products of many hours of unwavering attention.

The most remarkable manifestation of that attention, in a sense, is the exquisitely sensitive colouring, and it is extraordinary to think that these watercolours, so full of the sensation of vital immediacy, were often in fact completed many years later, from the resources of memory aided by a colour system that may have been essentially in the artist’s encyclopedic mind.

However, there can be little doubt that here, as in the high art tradition, it is colour that brings the image of a natural plant or creature to life. And, as unexpected as it may seem, the shiny eye of Anoplocapros inermis, the eastern smooth boxfish, is a distant cousin of those in Rubens’s portraits.

Botanical inspirations, State Library of NSW